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[tor-commits] [tor/master] Merge branch 'ticket25573-034' into ticket25573-master
commit 93ff8b411a2ac8eb6c3b58d90e2476d3e0a372ec
Merge: 810152b20 ce894e20b
Author: Mike Perry <mikeperry-git@xxxxxxxxxxxxxx>
Date: Wed Aug 29 17:10:06 2018 +0000
Merge branch 'ticket25573-034' into ticket25573-master
changes/ticket25573 | 5 +
src/core/or/circuitbuild.c | 3 +-
src/core/or/circuitbuild.h | 3 +-
src/core/or/circuitlist.c | 9 +
src/core/or/connection_edge.c | 226 ++++++++++++++
src/core/or/connection_edge.h | 11 +
src/core/or/half_edge_st.h | 34 ++
src/core/or/origin_circuit_st.h | 4 +
src/core/or/relay.c | 75 ++++-
src/feature/client/circpathbias.c | 63 ++++
src/feature/client/circpathbias.h | 1 +
src/lib/container/smartlist.c | 2 +-
src/lib/container/smartlist.h | 2 +-
src/test/test_relaycell.c | 640 +++++++++++++++++++++++++++++++++++---
14 files changed, 1033 insertions(+), 45 deletions(-)
diff --cc src/core/or/circuitbuild.c
index 5c3d20944,000000000..205160ed5
mode 100644,000000..100644
--- a/src/core/or/circuitbuild.c
+++ b/src/core/or/circuitbuild.c
@@@ -1,3010 -1,0 +1,3009 @@@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file circuitbuild.c
+ *
+ * \brief Implements the details of building circuits (by chosing paths,
+ * constructing/sending create/extend cells, and so on).
+ *
+ * On the client side, this module handles launching circuits. Circuit
+ * launches are srtarted from circuit_establish_circuit(), called from
+ * circuit_launch_by_extend_info()). To choose the path the circuit will
+ * take, onion_extend_cpath() calls into a maze of node selection functions.
+ *
+ * Once the circuit is ready to be launched, the first hop is treated as a
+ * special case with circuit_handle_first_hop(), since it might need to open a
+ * channel. As the channel opens, and later as CREATED and RELAY_EXTENDED
+ * cells arrive, the client will invoke circuit_send_next_onion_skin() to send
+ * CREATE or RELAY_EXTEND cells.
+ *
+ * On the server side, this module also handles the logic of responding to
+ * RELAY_EXTEND requests, using circuit_extend().
+ **/
+
+#define CIRCUITBUILD_PRIVATE
+
+#include "core/or/or.h"
+#include "feature/client/bridges.h"
+#include "core/or/channel.h"
+#include "feature/client/circpathbias.h"
+#define CIRCUITBUILD_PRIVATE
+#include "core/or/circuitbuild.h"
+#include "core/or/circuitlist.h"
+#include "core/or/circuitstats.h"
+#include "core/or/circuituse.h"
+#include "core/or/command.h"
+#include "app/config/config.h"
+#include "app/config/confparse.h"
+#include "core/mainloop/connection.h"
+#include "core/or/connection_edge.h"
+#include "core/or/connection_or.h"
+#include "feature/control/control.h"
+#include "lib/crypt_ops/crypto_rand.h"
+#include "feature/dircache/directory.h"
+#include "feature/client/entrynodes.h"
+#include "core/crypto/hs_ntor.h"
+#include "core/mainloop/main.h"
+#include "feature/nodelist/microdesc.h"
+#include "feature/nodelist/networkstatus.h"
+#include "feature/nodelist/nodelist.h"
+#include "core/crypto/onion.h"
+#include "core/crypto/onion_tap.h"
+#include "core/crypto/onion_fast.h"
+#include "core/or/policies.h"
+#include "core/or/relay.h"
+#include "core/crypto/relay_crypto.h"
+#include "feature/rend/rendcommon.h"
+#include "feature/stats/rephist.h"
+#include "feature/relay/router.h"
+#include "feature/nodelist/routerlist.h"
+#include "feature/nodelist/routerparse.h"
+#include "feature/nodelist/routerset.h"
+#include "feature/client/transports.h"
+
+#include "core/or/cell_st.h"
+#include "core/or/cpath_build_state_st.h"
+#include "core/or/entry_connection_st.h"
+#include "core/or/extend_info_st.h"
+#include "feature/nodelist/node_st.h"
+#include "core/or/or_circuit_st.h"
+#include "core/or/origin_circuit_st.h"
+#include "feature/nodelist/microdesc_st.h"
+#include "feature/nodelist/routerinfo_st.h"
+#include "feature/nodelist/routerstatus_st.h"
+
+static channel_t * channel_connect_for_circuit(const tor_addr_t *addr,
+ uint16_t port,
+ const char *id_digest,
+ const ed25519_public_key_t *ed_id);
+static int circuit_deliver_create_cell(circuit_t *circ,
+ const create_cell_t *create_cell,
+ int relayed);
+static crypt_path_t *onion_next_hop_in_cpath(crypt_path_t *cpath);
+STATIC int onion_append_hop(crypt_path_t **head_ptr, extend_info_t *choice);
+static int circuit_send_first_onion_skin(origin_circuit_t *circ);
+static int circuit_build_no_more_hops(origin_circuit_t *circ);
+static int circuit_send_intermediate_onion_skin(origin_circuit_t *circ,
+ crypt_path_t *hop);
+static const node_t *choose_good_middle_server(uint8_t purpose,
+ cpath_build_state_t *state,
+ crypt_path_t *head,
+ int cur_len);
+
+/** This function tries to get a channel to the specified endpoint,
+ * and then calls command_setup_channel() to give it the right
+ * callbacks.
+ */
+static channel_t *
+channel_connect_for_circuit(const tor_addr_t *addr, uint16_t port,
+ const char *id_digest,
+ const ed25519_public_key_t *ed_id)
+{
+ channel_t *chan;
+
+ chan = channel_connect(addr, port, id_digest, ed_id);
+ if (chan) command_setup_channel(chan);
+
+ return chan;
+}
+
+/** Search for a value for circ_id that we can use on <b>chan</b> for an
+ * outbound circuit, until we get a circ_id that is not in use by any other
+ * circuit on that conn.
+ *
+ * Return it, or 0 if can't get a unique circ_id.
+ */
+STATIC circid_t
+get_unique_circ_id_by_chan(channel_t *chan)
+{
+/* This number is chosen somewhat arbitrarily; see comment below for more
+ * info. When the space is 80% full, it gives a one-in-a-million failure
+ * chance; when the space is 90% full, it gives a one-in-850 chance; and when
+ * the space is 95% full, it gives a one-in-26 failure chance. That seems
+ * okay, though you could make a case IMO for anything between N=32 and
+ * N=256. */
+#define MAX_CIRCID_ATTEMPTS 64
+ int in_use;
+ unsigned n_with_circ = 0, n_pending_destroy = 0, n_weird_pending_destroy = 0;
+ circid_t test_circ_id;
+ circid_t attempts=0;
+ circid_t high_bit, max_range, mask;
+ int64_t pending_destroy_time_total = 0;
+ int64_t pending_destroy_time_max = 0;
+
+ tor_assert(chan);
+
+ if (chan->circ_id_type == CIRC_ID_TYPE_NEITHER) {
+ log_warn(LD_BUG,
+ "Trying to pick a circuit ID for a connection from "
+ "a client with no identity.");
+ return 0;
+ }
+ max_range = (chan->wide_circ_ids) ? (1u<<31) : (1u<<15);
+ mask = max_range - 1;
+ high_bit = (chan->circ_id_type == CIRC_ID_TYPE_HIGHER) ? max_range : 0;
+ do {
+ if (++attempts > MAX_CIRCID_ATTEMPTS) {
+ /* Make sure we don't loop forever because all circuit IDs are used.
+ *
+ * Once, we would try until we had tried every possible circuit ID. But
+ * that's quite expensive. Instead, we try MAX_CIRCID_ATTEMPTS random
+ * circuit IDs, and then give up.
+ *
+ * This potentially causes us to give up early if our circuit ID space
+ * is nearly full. If we have N circuit IDs in use, then we will reject
+ * a new circuit with probability (N / max_range) ^ MAX_CIRCID_ATTEMPTS.
+ * This means that in practice, a few percent of our circuit ID capacity
+ * will go unused.
+ *
+ * The alternative here, though, is to do a linear search over the
+ * whole circuit ID space every time we extend a circuit, which is
+ * not so great either.
+ */
+ int64_t queued_destroys;
+ char *m = rate_limit_log(&chan->last_warned_circ_ids_exhausted,
+ approx_time());
+ if (m == NULL)
+ return 0; /* This message has been rate-limited away. */
+ if (n_pending_destroy)
+ pending_destroy_time_total /= n_pending_destroy;
+ log_warn(LD_CIRC,"No unused circIDs found on channel %s wide "
+ "circID support, with %u inbound and %u outbound circuits. "
+ "Found %u circuit IDs in use by circuits, and %u with "
+ "pending destroy cells. (%u of those were marked bogusly.) "
+ "The ones with pending destroy cells "
+ "have been marked unusable for an average of %ld seconds "
+ "and a maximum of %ld seconds. This channel is %ld seconds "
+ "old. Failing a circuit.%s",
+ chan->wide_circ_ids ? "with" : "without",
+ chan->num_p_circuits, chan->num_n_circuits,
+ n_with_circ, n_pending_destroy, n_weird_pending_destroy,
+ (long)pending_destroy_time_total,
+ (long)pending_destroy_time_max,
+ (long)(approx_time() - chan->timestamp_created),
+ m);
+ tor_free(m);
+
+ if (!chan->cmux) {
+ /* This warning should be impossible. */
+ log_warn(LD_BUG, " This channel somehow has no cmux on it!");
+ return 0;
+ }
+
+ /* analysis so far on 12184 suggests that we're running out of circuit
+ IDs because it looks like we have too many pending destroy
+ cells. Let's see how many we really have pending.
+ */
+ queued_destroys = circuitmux_count_queued_destroy_cells(chan,
+ chan->cmux);
+
+ log_warn(LD_CIRC, " Circuitmux on this channel has %u circuits, "
+ "of which %u are active. It says it has %"PRId64
+ " destroy cells queued.",
+ circuitmux_num_circuits(chan->cmux),
+ circuitmux_num_active_circuits(chan->cmux),
+ (queued_destroys));
+
+ /* Change this into "if (1)" in order to get more information about
+ * possible failure modes here. You'll need to know how to use gdb with
+ * Tor: this will make Tor exit with an assertion failure if the cmux is
+ * corrupt. */
+ if (0)
+ circuitmux_assert_okay(chan->cmux);
+
+ channel_dump_statistics(chan, LOG_WARN);
+
+ return 0;
+ }
+
+ do {
+ crypto_rand((char*) &test_circ_id, sizeof(test_circ_id));
+ test_circ_id &= mask;
+ } while (test_circ_id == 0);
+
+ test_circ_id |= high_bit;
+
+ in_use = circuit_id_in_use_on_channel(test_circ_id, chan);
+ if (in_use == 1)
+ ++n_with_circ;
+ else if (in_use == 2) {
+ time_t since_when;
+ ++n_pending_destroy;
+ since_when =
+ circuit_id_when_marked_unusable_on_channel(test_circ_id, chan);
+ if (since_when) {
+ time_t waiting = approx_time() - since_when;
+ pending_destroy_time_total += waiting;
+ if (waiting > pending_destroy_time_max)
+ pending_destroy_time_max = waiting;
+ } else {
+ ++n_weird_pending_destroy;
+ }
+ }
+ } while (in_use);
+ return test_circ_id;
+}
+
+/** If <b>verbose</b> is false, allocate and return a comma-separated list of
+ * the currently built elements of <b>circ</b>. If <b>verbose</b> is true, also
+ * list information about link status in a more verbose format using spaces.
+ * If <b>verbose_names</b> is false, give nicknames for Named routers and hex
+ * digests for others; if <b>verbose_names</b> is true, use $DIGEST=Name style
+ * names.
+ */
+static char *
+circuit_list_path_impl(origin_circuit_t *circ, int verbose, int verbose_names)
+{
+ crypt_path_t *hop;
+ smartlist_t *elements;
+ const char *states[] = {"closed", "waiting for keys", "open"};
+ char *s;
+
+ elements = smartlist_new();
+
+ if (verbose) {
+ const char *nickname = build_state_get_exit_nickname(circ->build_state);
+ smartlist_add_asprintf(elements, "%s%s circ (length %d%s%s):",
+ circ->build_state->is_internal ? "internal" : "exit",
+ circ->build_state->need_uptime ? " (high-uptime)" : "",
+ circ->build_state->desired_path_len,
+ circ->base_.state == CIRCUIT_STATE_OPEN ? "" : ", last hop ",
+ circ->base_.state == CIRCUIT_STATE_OPEN ? "" :
+ (nickname?nickname:"*unnamed*"));
+ }
+
+ hop = circ->cpath;
+ do {
+ char *elt;
+ const char *id;
+ const node_t *node;
+ if (!hop)
+ break;
+ if (!verbose && hop->state != CPATH_STATE_OPEN)
+ break;
+ if (!hop->extend_info)
+ break;
+ id = hop->extend_info->identity_digest;
+ if (verbose_names) {
+ elt = tor_malloc(MAX_VERBOSE_NICKNAME_LEN+1);
+ if ((node = node_get_by_id(id))) {
+ node_get_verbose_nickname(node, elt);
+ } else if (is_legal_nickname(hop->extend_info->nickname)) {
+ elt[0] = '$';
+ base16_encode(elt+1, HEX_DIGEST_LEN+1, id, DIGEST_LEN);
+ elt[HEX_DIGEST_LEN+1]= '~';
+ strlcpy(elt+HEX_DIGEST_LEN+2,
+ hop->extend_info->nickname, MAX_NICKNAME_LEN+1);
+ } else {
+ elt[0] = '$';
+ base16_encode(elt+1, HEX_DIGEST_LEN+1, id, DIGEST_LEN);
+ }
+ } else { /* ! verbose_names */
+ elt = tor_malloc(HEX_DIGEST_LEN+2);
+ elt[0] = '$';
+ base16_encode(elt+1, HEX_DIGEST_LEN+1, id, DIGEST_LEN);
+ }
+ tor_assert(elt);
+ if (verbose) {
+ tor_assert(hop->state <= 2);
+ smartlist_add_asprintf(elements,"%s(%s)",elt,states[hop->state]);
+ tor_free(elt);
+ } else {
+ smartlist_add(elements, elt);
+ }
+ hop = hop->next;
+ } while (hop != circ->cpath);
+
+ s = smartlist_join_strings(elements, verbose?" ":",", 0, NULL);
+ SMARTLIST_FOREACH(elements, char*, cp, tor_free(cp));
+ smartlist_free(elements);
+ return s;
+}
+
+/** If <b>verbose</b> is false, allocate and return a comma-separated
+ * list of the currently built elements of <b>circ</b>. If
+ * <b>verbose</b> is true, also list information about link status in
+ * a more verbose format using spaces.
+ */
+char *
+circuit_list_path(origin_circuit_t *circ, int verbose)
+{
+ return circuit_list_path_impl(circ, verbose, 0);
+}
+
+/** Allocate and return a comma-separated list of the currently built elements
+ * of <b>circ</b>, giving each as a verbose nickname.
+ */
+char *
+circuit_list_path_for_controller(origin_circuit_t *circ)
+{
+ return circuit_list_path_impl(circ, 0, 1);
+}
+
+/** Log, at severity <b>severity</b>, the nicknames of each router in
+ * <b>circ</b>'s cpath. Also log the length of the cpath, and the intended
+ * exit point.
+ */
+void
+circuit_log_path(int severity, unsigned int domain, origin_circuit_t *circ)
+{
+ char *s = circuit_list_path(circ,1);
+ tor_log(severity,domain,"%s",s);
+ tor_free(s);
+}
+
+/** Return 1 iff every node in circ's cpath definitely supports ntor. */
+static int
+circuit_cpath_supports_ntor(const origin_circuit_t *circ)
+{
+ crypt_path_t *head, *cpath;
+
+ cpath = head = circ->cpath;
+ do {
+ /* if the extend_info is missing, we can't tell if it supports ntor */
+ if (!cpath->extend_info) {
+ return 0;
+ }
+
+ /* if the key is blank, it definitely doesn't support ntor */
+ if (!extend_info_supports_ntor(cpath->extend_info)) {
+ return 0;
+ }
+ cpath = cpath->next;
+ } while (cpath != head);
+
+ return 1;
+}
+
+/** Pick all the entries in our cpath. Stop and return 0 when we're
+ * happy, or return -1 if an error occurs. */
+static int
+onion_populate_cpath(origin_circuit_t *circ)
+{
+ int r = 0;
+
+ /* onion_extend_cpath assumes these are non-NULL */
+ tor_assert(circ);
+ tor_assert(circ->build_state);
+
+ while (r == 0) {
+ r = onion_extend_cpath(circ);
+ if (r < 0) {
+ log_info(LD_CIRC,"Generating cpath hop failed.");
+ return -1;
+ }
+ }
+
+ /* The path is complete */
+ tor_assert(r == 1);
+
+ /* Does every node in this path support ntor? */
+ int path_supports_ntor = circuit_cpath_supports_ntor(circ);
+
+ /* We would like every path to support ntor, but we have to allow for some
+ * edge cases. */
+ tor_assert(circuit_get_cpath_len(circ));
+ if (circuit_can_use_tap(circ)) {
+ /* Circuits from clients to intro points, and hidden services to rend
+ * points do not support ntor, because the hidden service protocol does
+ * not include ntor onion keys. This is also true for Single Onion
+ * Services. */
+ return 0;
+ }
+
+ if (circuit_get_cpath_len(circ) == 1) {
+ /* Allow for bootstrapping: when we're fetching directly from a fallback,
+ * authority, or bridge, we have no way of knowing its ntor onion key
+ * before we connect to it. So instead, we try connecting, and end up using
+ * CREATE_FAST. */
+ tor_assert(circ->cpath);
+ tor_assert(circ->cpath->extend_info);
+ const node_t *node = node_get_by_id(
+ circ->cpath->extend_info->identity_digest);
+ /* If we don't know the node and its descriptor, we must be bootstrapping.
+ */
+ if (!node || !node_has_preferred_descriptor(node, 1)) {
+ return 0;
+ }
+ }
+
+ if (BUG(!path_supports_ntor)) {
+ /* If we're building a multi-hop path, and it's not one of the HS or
+ * bootstrapping exceptions, and it doesn't support ntor, something has
+ * gone wrong. */
+ return -1;
+ }
+
+ return 0;
+}
+
+/** Create and return a new origin circuit. Initialize its purpose and
+ * build-state based on our arguments. The <b>flags</b> argument is a
+ * bitfield of CIRCLAUNCH_* flags. */
+origin_circuit_t *
+origin_circuit_init(uint8_t purpose, int flags)
+{
+ /* sets circ->p_circ_id and circ->p_chan */
+ origin_circuit_t *circ = origin_circuit_new();
+ circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_CHAN_WAIT);
+ circ->build_state = tor_malloc_zero(sizeof(cpath_build_state_t));
+ circ->build_state->onehop_tunnel =
+ ((flags & CIRCLAUNCH_ONEHOP_TUNNEL) ? 1 : 0);
+ circ->build_state->need_uptime =
+ ((flags & CIRCLAUNCH_NEED_UPTIME) ? 1 : 0);
+ circ->build_state->need_capacity =
+ ((flags & CIRCLAUNCH_NEED_CAPACITY) ? 1 : 0);
+ circ->build_state->is_internal =
+ ((flags & CIRCLAUNCH_IS_INTERNAL) ? 1 : 0);
+ circ->base_.purpose = purpose;
+ return circ;
+}
+
+/** Build a new circuit for <b>purpose</b>. If <b>exit</b>
+ * is defined, then use that as your exit router, else choose a suitable
+ * exit node.
+ *
+ * Also launch a connection to the first OR in the chosen path, if
+ * it's not open already.
+ */
+origin_circuit_t *
+circuit_establish_circuit(uint8_t purpose, extend_info_t *exit_ei, int flags)
+{
+ origin_circuit_t *circ;
+ int err_reason = 0;
+ int is_hs_v3_rp_circuit = 0;
+
+ if (flags & CIRCLAUNCH_IS_V3_RP) {
+ is_hs_v3_rp_circuit = 1;
+ }
+
+ circ = origin_circuit_init(purpose, flags);
+
+ if (onion_pick_cpath_exit(circ, exit_ei, is_hs_v3_rp_circuit) < 0 ||
+ onion_populate_cpath(circ) < 0) {
+ circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_NOPATH);
+ return NULL;
+ }
+
+ control_event_circuit_status(circ, CIRC_EVENT_LAUNCHED, 0);
+
+ if ((err_reason = circuit_handle_first_hop(circ)) < 0) {
+ circuit_mark_for_close(TO_CIRCUIT(circ), -err_reason);
+ return NULL;
+ }
+ return circ;
+}
+
+/** Return the guard state associated with <b>circ</b>, which may be NULL. */
+circuit_guard_state_t *
+origin_circuit_get_guard_state(origin_circuit_t *circ)
+{
+ return circ->guard_state;
+}
+
+/** Start establishing the first hop of our circuit. Figure out what
+ * OR we should connect to, and if necessary start the connection to
+ * it. If we're already connected, then send the 'create' cell.
+ * Return 0 for ok, -reason if circ should be marked-for-close. */
+int
+circuit_handle_first_hop(origin_circuit_t *circ)
+{
+ crypt_path_t *firsthop;
+ channel_t *n_chan;
+ int err_reason = 0;
+ const char *msg = NULL;
+ int should_launch = 0;
+ const or_options_t *options = get_options();
+
+ firsthop = onion_next_hop_in_cpath(circ->cpath);
+ tor_assert(firsthop);
+ tor_assert(firsthop->extend_info);
+
+ /* Some bridges are on private addresses. Others pass a dummy private
+ * address to the pluggable transport, which ignores it.
+ * Deny the connection if:
+ * - the address is internal, and
+ * - we're not connecting to a configured bridge, and
+ * - we're not configured to allow extends to private addresses. */
+ if (tor_addr_is_internal(&firsthop->extend_info->addr, 0) &&
+ !extend_info_is_a_configured_bridge(firsthop->extend_info) &&
+ !options->ExtendAllowPrivateAddresses) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Client asked me to connect directly to a private address");
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
+
+ /* now see if we're already connected to the first OR in 'route' */
+ log_debug(LD_CIRC,"Looking for firsthop '%s'",
+ fmt_addrport(&firsthop->extend_info->addr,
+ firsthop->extend_info->port));
+
+ n_chan = channel_get_for_extend(firsthop->extend_info->identity_digest,
+ &firsthop->extend_info->ed_identity,
+ &firsthop->extend_info->addr,
+ &msg,
+ &should_launch);
+
+ if (!n_chan) {
+ /* not currently connected in a useful way. */
+ log_info(LD_CIRC, "Next router is %s: %s",
+ safe_str_client(extend_info_describe(firsthop->extend_info)),
+ msg?msg:"???");
+ circ->base_.n_hop = extend_info_dup(firsthop->extend_info);
+
+ if (should_launch) {
+ if (circ->build_state->onehop_tunnel)
+ control_event_bootstrap(BOOTSTRAP_STATUS_CONN_DIR, 0);
+ n_chan = channel_connect_for_circuit(
+ &firsthop->extend_info->addr,
+ firsthop->extend_info->port,
+ firsthop->extend_info->identity_digest,
+ &firsthop->extend_info->ed_identity);
+ if (!n_chan) { /* connect failed, forget the whole thing */
+ log_info(LD_CIRC,"connect to firsthop failed. Closing.");
+ return -END_CIRC_REASON_CONNECTFAILED;
+ }
+ }
+
+ log_debug(LD_CIRC,"connecting in progress (or finished). Good.");
+ /* return success. The onion/circuit/etc will be taken care of
+ * automatically (may already have been) whenever n_chan reaches
+ * OR_CONN_STATE_OPEN.
+ */
+ return 0;
+ } else { /* it's already open. use it. */
+ tor_assert(!circ->base_.n_hop);
+ circ->base_.n_chan = n_chan;
+ log_debug(LD_CIRC,"Conn open. Delivering first onion skin.");
+ if ((err_reason = circuit_send_next_onion_skin(circ)) < 0) {
+ log_info(LD_CIRC,"circuit_send_next_onion_skin failed.");
+ circ->base_.n_chan = NULL;
+ return err_reason;
+ }
+ }
+ return 0;
+}
+
+/** Find any circuits that are waiting on <b>or_conn</b> to become
+ * open and get them to send their create cells forward.
+ *
+ * Status is 1 if connect succeeded, or 0 if connect failed.
+ *
+ * Close_origin_circuits is 1 if we should close all the origin circuits
+ * through this channel, or 0 otherwise. (This happens when we want to retry
+ * an older guard.)
+ */
+void
+circuit_n_chan_done(channel_t *chan, int status, int close_origin_circuits)
+{
+ smartlist_t *pending_circs;
+ int err_reason = 0;
+
+ tor_assert(chan);
+
+ log_debug(LD_CIRC,"chan to %s, status=%d",
+ channel_get_canonical_remote_descr(chan), status);
+
+ pending_circs = smartlist_new();
+ circuit_get_all_pending_on_channel(pending_circs, chan);
+
+ SMARTLIST_FOREACH_BEGIN(pending_circs, circuit_t *, circ)
+ {
+ /* These checks are redundant wrt get_all_pending_on_or_conn, but I'm
+ * leaving them in in case it's possible for the status of a circuit to
+ * change as we're going down the list. */
+ if (circ->marked_for_close || circ->n_chan || !circ->n_hop ||
+ circ->state != CIRCUIT_STATE_CHAN_WAIT)
+ continue;
+
+ if (tor_digest_is_zero(circ->n_hop->identity_digest)) {
+ /* Look at addr/port. This is an unkeyed connection. */
+ if (!channel_matches_extend_info(chan, circ->n_hop))
+ continue;
+ } else {
+ /* We expected a key. See if it's the right one. */
+ if (tor_memneq(chan->identity_digest,
+ circ->n_hop->identity_digest, DIGEST_LEN))
+ continue;
+ }
+ if (!status) { /* chan failed; close circ */
+ log_info(LD_CIRC,"Channel failed; closing circ.");
+ circuit_mark_for_close(circ, END_CIRC_REASON_CHANNEL_CLOSED);
+ continue;
+ }
+ if (close_origin_circuits && CIRCUIT_IS_ORIGIN(circ)) {
+ log_info(LD_CIRC,"Channel deprecated for origin circs; closing circ.");
+ circuit_mark_for_close(circ, END_CIRC_REASON_CHANNEL_CLOSED);
+ continue;
+ }
+ log_debug(LD_CIRC, "Found circ, sending create cell.");
+ /* circuit_deliver_create_cell will set n_circ_id and add us to
+ * chan_circuid_circuit_map, so we don't need to call
+ * set_circid_chan here. */
+ circ->n_chan = chan;
+ extend_info_free(circ->n_hop);
+ circ->n_hop = NULL;
+
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ if ((err_reason =
+ circuit_send_next_onion_skin(TO_ORIGIN_CIRCUIT(circ))) < 0) {
+ log_info(LD_CIRC,
+ "send_next_onion_skin failed; circuit marked for closing.");
+ circuit_mark_for_close(circ, -err_reason);
+ continue;
+ /* XXX could this be bad, eg if next_onion_skin failed because conn
+ * died? */
+ }
+ } else {
+ /* pull the create cell out of circ->n_chan_create_cell, and send it */
+ tor_assert(circ->n_chan_create_cell);
+ if (circuit_deliver_create_cell(circ, circ->n_chan_create_cell, 1)<0) {
+ circuit_mark_for_close(circ, END_CIRC_REASON_RESOURCELIMIT);
+ continue;
+ }
+ tor_free(circ->n_chan_create_cell);
+ circuit_set_state(circ, CIRCUIT_STATE_OPEN);
+ }
+ }
+ SMARTLIST_FOREACH_END(circ);
+
+ smartlist_free(pending_circs);
+}
+
+/** Find a new circid that isn't currently in use on the circ->n_chan
+ * for the outgoing
+ * circuit <b>circ</b>, and deliver the cell <b>create_cell</b> to this
+ * circuit. If <b>relayed</b> is true, this is a create cell somebody
+ * gave us via an EXTEND cell, so we shouldn't worry if we don't understand
+ * it. Return -1 if we failed to find a suitable circid, else return 0.
+ */
+static int
+circuit_deliver_create_cell(circuit_t *circ, const create_cell_t *create_cell,
+ int relayed)
+{
+ cell_t cell;
+ circid_t id;
+ int r;
+
+ tor_assert(circ);
+ tor_assert(circ->n_chan);
+ tor_assert(create_cell);
+ tor_assert(create_cell->cell_type == CELL_CREATE ||
+ create_cell->cell_type == CELL_CREATE_FAST ||
+ create_cell->cell_type == CELL_CREATE2);
+
+ id = get_unique_circ_id_by_chan(circ->n_chan);
+ if (!id) {
+ static ratelim_t circid_warning_limit = RATELIM_INIT(9600);
+ log_fn_ratelim(&circid_warning_limit, LOG_WARN, LD_CIRC,
+ "failed to get unique circID.");
+ goto error;
+ }
+
+ memset(&cell, 0, sizeof(cell_t));
+ r = relayed ? create_cell_format_relayed(&cell, create_cell)
+ : create_cell_format(&cell, create_cell);
+ if (r < 0) {
+ log_warn(LD_CIRC,"Couldn't format create cell");
+ goto error;
+ }
+ log_debug(LD_CIRC,"Chosen circID %u.", (unsigned)id);
+ circuit_set_n_circid_chan(circ, id, circ->n_chan);
+ cell.circ_id = circ->n_circ_id;
+
+ append_cell_to_circuit_queue(circ, circ->n_chan, &cell,
+ CELL_DIRECTION_OUT, 0);
+
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ /* Update began timestamp for circuits starting their first hop */
+ if (TO_ORIGIN_CIRCUIT(circ)->cpath->state == CPATH_STATE_CLOSED) {
+ if (!CHANNEL_IS_OPEN(circ->n_chan)) {
+ log_warn(LD_CIRC,
+ "Got first hop for a circuit without an opened channel. "
+ "State: %s.", channel_state_to_string(circ->n_chan->state));
+ tor_fragile_assert();
+ }
+
+ tor_gettimeofday(&circ->timestamp_began);
+ }
+
+ /* mark it so it gets better rate limiting treatment. */
+ channel_timestamp_client(circ->n_chan);
+ }
+
+ return 0;
+ error:
+ circ->n_chan = NULL;
+ return -1;
+}
+
+/** We've decided to start our reachability testing. If all
+ * is set, log this to the user. Return 1 if we did, or 0 if
+ * we chose not to log anything. */
+int
+inform_testing_reachability(void)
+{
+ char dirbuf[128];
+ char *address;
+ const routerinfo_t *me = router_get_my_routerinfo();
+ if (!me)
+ return 0;
+ address = tor_dup_ip(me->addr);
+ control_event_server_status(LOG_NOTICE,
+ "CHECKING_REACHABILITY ORADDRESS=%s:%d",
+ address, me->or_port);
+ if (me->dir_port) {
+ tor_snprintf(dirbuf, sizeof(dirbuf), " and DirPort %s:%d",
+ address, me->dir_port);
+ control_event_server_status(LOG_NOTICE,
+ "CHECKING_REACHABILITY DIRADDRESS=%s:%d",
+ address, me->dir_port);
+ }
+ log_notice(LD_OR, "Now checking whether ORPort %s:%d%s %s reachable... "
+ "(this may take up to %d minutes -- look for log "
+ "messages indicating success)",
+ address, me->or_port,
+ me->dir_port ? dirbuf : "",
+ me->dir_port ? "are" : "is",
+ TIMEOUT_UNTIL_UNREACHABILITY_COMPLAINT/60);
+
+ tor_free(address);
+ return 1;
+}
+
+/** Return true iff we should send a create_fast cell to start building a given
+ * circuit */
+static inline int
+should_use_create_fast_for_circuit(origin_circuit_t *circ)
+{
+ const or_options_t *options = get_options();
+ tor_assert(circ->cpath);
+ tor_assert(circ->cpath->extend_info);
+
+ if (!circuit_has_usable_onion_key(circ)) {
+ /* We don't have ntor, and we don't have or can't use TAP,
+ * so our hand is forced: only a create_fast will work. */
+ return 1;
+ }
+ if (public_server_mode(options)) {
+ /* We're a server, and we have a usable onion key. We can choose.
+ * Prefer to blend our circuit into the other circuits we are
+ * creating on behalf of others. */
+ return 0;
+ }
+ return networkstatus_get_param(NULL, "usecreatefast", 0, 0, 1);
+}
+
+/**
+ * Return true if <b>circ</b> is the type of circuit we want to count
+ * timeouts from.
+ *
+ * In particular, we want to consider any circuit that plans to build
+ * at least 3 hops (but maybe more), but has 3 or fewer hops built
+ * so far.
+ *
+ * We still want to consider circuits before 3 hops, because we need
+ * to decide if we should convert them to a measurement circuit in
+ * circuit_build_times_handle_completed_hop(), rather than letting
+ * slow circuits get killed right away.
+ */
+int
+circuit_timeout_want_to_count_circ(const origin_circuit_t *circ)
+{
+ return !circ->has_opened
+ && circ->build_state->desired_path_len >= DEFAULT_ROUTE_LEN
+ && circuit_get_cpath_opened_len(circ) <= DEFAULT_ROUTE_LEN;
+}
+
+/** Decide whether to use a TAP or ntor handshake for connecting to <b>ei</b>
+ * directly, and set *<b>cell_type_out</b> and *<b>handshake_type_out</b>
+ * accordingly.
+ * Note that TAP handshakes in CREATE cells are only used for direct
+ * connections:
+ * - from Single Onions to rend points not in the service's consensus.
+ * This is checked in onion_populate_cpath. */
+static void
+circuit_pick_create_handshake(uint8_t *cell_type_out,
+ uint16_t *handshake_type_out,
+ const extend_info_t *ei)
+{
+ /* torspec says: In general, clients SHOULD use CREATE whenever they are
+ * using the TAP handshake, and CREATE2 otherwise. */
+ if (extend_info_supports_ntor(ei)) {
+ *cell_type_out = CELL_CREATE2;
+ *handshake_type_out = ONION_HANDSHAKE_TYPE_NTOR;
+ } else {
+ /* XXXX030 Remove support for deciding to use TAP and EXTEND. */
+ *cell_type_out = CELL_CREATE;
+ *handshake_type_out = ONION_HANDSHAKE_TYPE_TAP;
+ }
+}
+
+/** Decide whether to use a TAP or ntor handshake for extending to <b>ei</b>
+ * and set *<b>handshake_type_out</b> accordingly. Decide whether we should
+ * use an EXTEND2 or an EXTEND cell to do so, and set *<b>cell_type_out</b>
+ * and *<b>create_cell_type_out</b> accordingly.
+ * Note that TAP handshakes in EXTEND cells are only used:
+ * - from clients to intro points, and
+ * - from hidden services to rend points.
+ * This is checked in onion_populate_cpath.
+ */
+static void
+circuit_pick_extend_handshake(uint8_t *cell_type_out,
+ uint8_t *create_cell_type_out,
+ uint16_t *handshake_type_out,
+ const extend_info_t *ei)
+{
+ uint8_t t;
+ circuit_pick_create_handshake(&t, handshake_type_out, ei);
+
+ /* torspec says: Clients SHOULD use the EXTEND format whenever sending a TAP
+ * handshake... In other cases, clients SHOULD use EXTEND2. */
+ if (*handshake_type_out != ONION_HANDSHAKE_TYPE_TAP) {
+ *cell_type_out = RELAY_COMMAND_EXTEND2;
+ *create_cell_type_out = CELL_CREATE2;
+ } else {
+ /* XXXX030 Remove support for deciding to use TAP and EXTEND. */
+ *cell_type_out = RELAY_COMMAND_EXTEND;
+ *create_cell_type_out = CELL_CREATE;
+ }
+}
+
+/**
+ * Return true iff <b>purpose</b> is a purpose for a circuit which is
+ * allowed to have no guard configured, even if the circuit is multihop
+ * and guards are enabled.
+ */
+static int
+circuit_purpose_may_omit_guard(int purpose)
+{
+ switch (purpose) {
+ case CIRCUIT_PURPOSE_TESTING:
+ case CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT:
+ /* Testing circuits may omit guards because they're measuring
+ * liveness or performance, and don't want guards to interfere. */
+ return 1;
+ default:
+ /* All other multihop circuits should use guards if guards are
+ * enabled. */
+ return 0;
+ }
+}
+
+/** This is the backbone function for building circuits.
+ *
+ * If circ's first hop is closed, then we need to build a create
+ * cell and send it forward.
+ *
+ * Otherwise, if circ's cpath still has any non-open hops, we need to
+ * build a relay extend cell and send it forward to the next non-open hop.
+ *
+ * If all hops on the cpath are open, we're done building the circuit
+ * and we should do housekeeping for the newly opened circuit.
+ *
+ * Return -reason if we want to tear down circ, else return 0.
+ */
+int
+circuit_send_next_onion_skin(origin_circuit_t *circ)
+{
+ tor_assert(circ);
+
+ if (circ->cpath->state == CPATH_STATE_CLOSED) {
+ /* Case one: we're on the first hop. */
+ return circuit_send_first_onion_skin(circ);
+ }
+
+ tor_assert(circ->cpath->state == CPATH_STATE_OPEN);
+ tor_assert(circ->base_.state == CIRCUIT_STATE_BUILDING);
+
+ crypt_path_t *hop = onion_next_hop_in_cpath(circ->cpath);
+ circuit_build_times_handle_completed_hop(circ);
+
+ if (hop) {
+ /* Case two: we're on a hop after the first. */
+ return circuit_send_intermediate_onion_skin(circ, hop);
+ }
+
+ /* Case three: the circuit is finished. Do housekeeping tasks on it. */
+ return circuit_build_no_more_hops(circ);
+}
+
+/**
+ * Called from circuit_send_next_onion_skin() when we find ourselves connected
+ * to the first hop in <b>circ</b>: Send a CREATE or CREATE2 or CREATE_FAST
+ * cell to that hop. Return 0 on success; -reason on failure (if the circuit
+ * should be torn down).
+ */
+static int
+circuit_send_first_onion_skin(origin_circuit_t *circ)
+{
+ int fast;
+ int len;
+ const node_t *node;
+ create_cell_t cc;
+ memset(&cc, 0, sizeof(cc));
+
+ log_debug(LD_CIRC,"First skin; sending create cell.");
+
+ if (circ->build_state->onehop_tunnel) {
+ control_event_bootstrap(BOOTSTRAP_STATUS_ONEHOP_CREATE, 0);
+ } else {
+ control_event_bootstrap(BOOTSTRAP_STATUS_CIRCUIT_CREATE, 0);
+
+ /* If this is not a one-hop tunnel, the channel is being used
+ * for traffic that wants anonymity and protection from traffic
+ * analysis (such as netflow record retention). That means we want
+ * to pad it.
+ */
+ if (circ->base_.n_chan->channel_usage < CHANNEL_USED_FOR_FULL_CIRCS)
+ circ->base_.n_chan->channel_usage = CHANNEL_USED_FOR_FULL_CIRCS;
+ }
+
+ node = node_get_by_id(circ->base_.n_chan->identity_digest);
+ fast = should_use_create_fast_for_circuit(circ);
+ if (!fast) {
+ /* We know the right onion key: we should send a create cell. */
+ circuit_pick_create_handshake(&cc.cell_type, &cc.handshake_type,
+ circ->cpath->extend_info);
+ } else {
+ /* We don't know an onion key, so we need to fall back to CREATE_FAST. */
+ cc.cell_type = CELL_CREATE_FAST;
+ cc.handshake_type = ONION_HANDSHAKE_TYPE_FAST;
+ }
+
+ len = onion_skin_create(cc.handshake_type,
+ circ->cpath->extend_info,
+ &circ->cpath->handshake_state,
+ cc.onionskin);
+ if (len < 0) {
+ log_warn(LD_CIRC,"onion_skin_create (first hop) failed.");
+ return - END_CIRC_REASON_INTERNAL;
+ }
+ cc.handshake_len = len;
+
+ if (circuit_deliver_create_cell(TO_CIRCUIT(circ), &cc, 0) < 0)
+ return - END_CIRC_REASON_RESOURCELIMIT;
+
+ circ->cpath->state = CPATH_STATE_AWAITING_KEYS;
+ circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_BUILDING);
+ log_info(LD_CIRC,"First hop: finished sending %s cell to '%s'",
+ fast ? "CREATE_FAST" : "CREATE",
+ node ? node_describe(node) : "<unnamed>");
+ return 0;
+}
+
+/**
+ * Called from circuit_send_next_onion_skin() when we find that we have no
+ * more hops: mark the circuit as finished, and perform the necessary
+ * bookkeeping. Return 0 on success; -reason on failure (if the circuit
+ * should be torn down).
+ */
+static int
+circuit_build_no_more_hops(origin_circuit_t *circ)
+{
+ guard_usable_t r;
+ if (! circ->guard_state) {
+ if (circuit_get_cpath_len(circ) != 1 &&
+ ! circuit_purpose_may_omit_guard(circ->base_.purpose) &&
+ get_options()->UseEntryGuards) {
+ log_warn(LD_BUG, "%d-hop circuit %p with purpose %d has no "
+ "guard state",
+ circuit_get_cpath_len(circ), circ, circ->base_.purpose);
+ }
+ r = GUARD_USABLE_NOW;
+ } else {
+ r = entry_guard_succeeded(&circ->guard_state);
+ }
+ const int is_usable_for_streams = (r == GUARD_USABLE_NOW);
+ if (r == GUARD_USABLE_NOW) {
+ circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_OPEN);
+ } else if (r == GUARD_MAYBE_USABLE_LATER) {
+ // Wait till either a better guard succeeds, or till
+ // all better guards fail.
+ circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_GUARD_WAIT);
+ } else {
+ tor_assert_nonfatal(r == GUARD_USABLE_NEVER);
+ return - END_CIRC_REASON_INTERNAL;
+ }
+
+ /* XXXX #21422 -- the rest of this branch needs careful thought!
+ * Some of the things here need to happen when a circuit becomes
+ * mechanically open; some need to happen when it is actually usable.
+ * I think I got them right, but more checking would be wise. -NM
+ */
+
+ log_info(LD_CIRC,"circuit built!");
+ circuit_reset_failure_count(0);
+
+ if (circ->build_state->onehop_tunnel || circ->has_opened) {
+ control_event_bootstrap(BOOTSTRAP_STATUS_REQUESTING_STATUS, 0);
+ }
+
+ pathbias_count_build_success(circ);
+ if (is_usable_for_streams)
+ circuit_has_opened(circ); /* do other actions as necessary */
+
+ if (!have_completed_a_circuit() && !circ->build_state->onehop_tunnel) {
+ const or_options_t *options = get_options();
+ note_that_we_completed_a_circuit();
+ /* FFFF Log a count of known routers here */
+ log_notice(LD_GENERAL,
+ "Tor has successfully opened a circuit. "
+ "Looks like client functionality is working.");
+ if (control_event_bootstrap(BOOTSTRAP_STATUS_DONE, 0) == 0) {
+ log_notice(LD_GENERAL,
+ "Tor has successfully opened a circuit. "
+ "Looks like client functionality is working.");
+ }
+ control_event_client_status(LOG_NOTICE, "CIRCUIT_ESTABLISHED");
+ clear_broken_connection_map(1);
+ if (server_mode(options) && !check_whether_orport_reachable(options)) {
+ inform_testing_reachability();
+ router_do_reachability_checks(1, 1);
+ }
+ }
+
+ /* We're done with measurement circuits here. Just close them */
+ if (circ->base_.purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) {
+ circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_FINISHED);
+ }
+ return 0;
+}
+
+/**
+ * Called from circuit_send_next_onion_skin() when we find that we have a hop
+ * other than the first that we need to extend to: use <b>hop</b>'s
+ * information to extend the circuit another step. Return 0 on success;
+ * -reason on failure (if the circuit should be torn down).
+ */
+static int
+circuit_send_intermediate_onion_skin(origin_circuit_t *circ,
+ crypt_path_t *hop)
+{
+ int len;
+ extend_cell_t ec;
+ memset(&ec, 0, sizeof(ec));
+
+ log_debug(LD_CIRC,"starting to send subsequent skin.");
+
+ if (tor_addr_family(&hop->extend_info->addr) != AF_INET) {
+ log_warn(LD_BUG, "Trying to extend to a non-IPv4 address.");
+ return - END_CIRC_REASON_INTERNAL;
+ }
+
+ circuit_pick_extend_handshake(&ec.cell_type,
+ &ec.create_cell.cell_type,
+ &ec.create_cell.handshake_type,
+ hop->extend_info);
+
+ tor_addr_copy(&ec.orport_ipv4.addr, &hop->extend_info->addr);
+ ec.orport_ipv4.port = hop->extend_info->port;
+ tor_addr_make_unspec(&ec.orport_ipv6.addr);
+ memcpy(ec.node_id, hop->extend_info->identity_digest, DIGEST_LEN);
+ /* Set the ED25519 identity too -- it will only get included
+ * in the extend2 cell if we're configured to use it, though. */
+ ed25519_pubkey_copy(&ec.ed_pubkey, &hop->extend_info->ed_identity);
+
+ len = onion_skin_create(ec.create_cell.handshake_type,
+ hop->extend_info,
+ &hop->handshake_state,
+ ec.create_cell.onionskin);
+ if (len < 0) {
+ log_warn(LD_CIRC,"onion_skin_create failed.");
+ return - END_CIRC_REASON_INTERNAL;
+ }
+ ec.create_cell.handshake_len = len;
+
+ log_info(LD_CIRC,"Sending extend relay cell.");
+ {
+ uint8_t command = 0;
+ uint16_t payload_len=0;
+ uint8_t payload[RELAY_PAYLOAD_SIZE];
+ if (extend_cell_format(&command, &payload_len, payload, &ec)<0) {
+ log_warn(LD_CIRC,"Couldn't format extend cell");
+ return -END_CIRC_REASON_INTERNAL;
+ }
+
+ /* send it to hop->prev, because that relay will transfer
+ * it to a create cell and then send to hop */
+ if (relay_send_command_from_edge(0, TO_CIRCUIT(circ),
+ command,
+ (char*)payload, payload_len,
+ hop->prev) < 0)
+ return 0; /* circuit is closed */
+ }
+ hop->state = CPATH_STATE_AWAITING_KEYS;
+ return 0;
+}
+
+/** Our clock just jumped by <b>seconds_elapsed</b>. If <b>was_idle</b> is
+ * true, then the monotonic time matches; otherwise it doesn't. Assume
+ * something has also gone wrong with our network: notify the user, and
+ * abandon all not-yet-used circuits. */
+void
+circuit_note_clock_jumped(int64_t seconds_elapsed, bool was_idle)
+{
+ int severity = server_mode(get_options()) ? LOG_WARN : LOG_NOTICE;
+ if (was_idle) {
+ tor_log(severity, LD_GENERAL, "Tor has been idle for %"PRId64
+ " seconds; assuming established circuits no longer work.",
+ (seconds_elapsed));
+ } else {
+ tor_log(severity, LD_GENERAL,
+ "Your system clock just jumped %"PRId64" seconds %s; "
+ "assuming established circuits no longer work.",
+ (
+ seconds_elapsed >=0 ? seconds_elapsed : -seconds_elapsed),
+ seconds_elapsed >=0 ? "forward" : "backward");
+ }
+ control_event_general_status(LOG_WARN, "CLOCK_JUMPED TIME=%"PRId64
+ " IDLE=%d",
+ (seconds_elapsed), was_idle?1:0);
+ /* so we log when it works again */
+ note_that_we_maybe_cant_complete_circuits();
+ control_event_client_status(severity, "CIRCUIT_NOT_ESTABLISHED REASON=%s",
+ "CLOCK_JUMPED");
+ circuit_mark_all_unused_circs();
+ circuit_mark_all_dirty_circs_as_unusable();
+ if (seconds_elapsed < 0) {
+ /* Restart all the timers in case we jumped a long way into the past. */
+ reset_all_main_loop_timers();
+ }
+}
+
+/** Take the 'extend' <b>cell</b>, pull out addr/port plus the onion
+ * skin and identity digest for the next hop. If we're already connected,
+ * pass the onion skin to the next hop using a create cell; otherwise
+ * launch a new OR connection, and <b>circ</b> will notice when the
+ * connection succeeds or fails.
+ *
+ * Return -1 if we want to warn and tear down the circuit, else return 0.
+ */
+int
+circuit_extend(cell_t *cell, circuit_t *circ)
+{
+ channel_t *n_chan;
+ relay_header_t rh;
+ extend_cell_t ec;
+ const char *msg = NULL;
+ int should_launch = 0;
+
+ if (circ->n_chan) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "n_chan already set. Bug/attack. Closing.");
+ return -1;
+ }
+ if (circ->n_hop) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "conn to next hop already launched. Bug/attack. Closing.");
+ return -1;
+ }
+
+ if (!server_mode(get_options())) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Got an extend cell, but running as a client. Closing.");
+ return -1;
+ }
+
+ relay_header_unpack(&rh, cell->payload);
+
+ if (extend_cell_parse(&ec, rh.command,
+ cell->payload+RELAY_HEADER_SIZE,
+ rh.length) < 0) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Can't parse extend cell. Closing circuit.");
+ return -1;
+ }
+
+ if (!ec.orport_ipv4.port || tor_addr_is_null(&ec.orport_ipv4.addr)) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Client asked me to extend to zero destination port or addr.");
+ return -1;
+ }
+
+ if (tor_addr_is_internal(&ec.orport_ipv4.addr, 0) &&
+ !get_options()->ExtendAllowPrivateAddresses) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Client asked me to extend to a private address");
+ return -1;
+ }
+
+ /* Check if they asked us for 0000..0000. We support using
+ * an empty fingerprint for the first hop (e.g. for a bridge relay),
+ * but we don't want to let clients send us extend cells for empty
+ * fingerprints -- a) because it opens the user up to a mitm attack,
+ * and b) because it lets an attacker force the relay to hold open a
+ * new TLS connection for each extend request. */
+ if (tor_digest_is_zero((const char*)ec.node_id)) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Client asked me to extend without specifying an id_digest.");
+ return -1;
+ }
+
+ /* Fill in ed_pubkey if it was not provided and we can infer it from
+ * our networkstatus */
+ if (ed25519_public_key_is_zero(&ec.ed_pubkey)) {
+ const node_t *node = node_get_by_id((const char*)ec.node_id);
+ const ed25519_public_key_t *node_ed_id = NULL;
+ if (node &&
+ node_supports_ed25519_link_authentication(node, 1) &&
+ (node_ed_id = node_get_ed25519_id(node))) {
+ ed25519_pubkey_copy(&ec.ed_pubkey, node_ed_id);
+ }
+ }
+
+ /* Next, check if we're being asked to connect to the hop that the
+ * extend cell came from. There isn't any reason for that, and it can
+ * assist circular-path attacks. */
+ if (tor_memeq(ec.node_id,
+ TO_OR_CIRCUIT(circ)->p_chan->identity_digest,
+ DIGEST_LEN)) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Client asked me to extend back to the previous hop.");
+ return -1;
+ }
+
+ /* Check the previous hop Ed25519 ID too */
+ if (! ed25519_public_key_is_zero(&ec.ed_pubkey) &&
+ ed25519_pubkey_eq(&ec.ed_pubkey,
+ &TO_OR_CIRCUIT(circ)->p_chan->ed25519_identity)) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Client asked me to extend back to the previous hop "
+ "(by Ed25519 ID).");
+ return -1;
+ }
+
+ n_chan = channel_get_for_extend((const char*)ec.node_id,
+ &ec.ed_pubkey,
+ &ec.orport_ipv4.addr,
+ &msg,
+ &should_launch);
+
+ if (!n_chan) {
+ log_debug(LD_CIRC|LD_OR,"Next router (%s): %s",
+ fmt_addrport(&ec.orport_ipv4.addr,ec.orport_ipv4.port),
+ msg?msg:"????");
+
+ circ->n_hop = extend_info_new(NULL /*nickname*/,
+ (const char*)ec.node_id,
+ &ec.ed_pubkey,
+ NULL, /*onion_key*/
+ NULL, /*curve25519_key*/
+ &ec.orport_ipv4.addr,
+ ec.orport_ipv4.port);
+
+ circ->n_chan_create_cell = tor_memdup(&ec.create_cell,
+ sizeof(ec.create_cell));
+
+ circuit_set_state(circ, CIRCUIT_STATE_CHAN_WAIT);
+
+ if (should_launch) {
+ /* we should try to open a connection */
+ n_chan = channel_connect_for_circuit(&ec.orport_ipv4.addr,
+ ec.orport_ipv4.port,
+ (const char*)ec.node_id,
+ &ec.ed_pubkey);
+ if (!n_chan) {
+ log_info(LD_CIRC,"Launching n_chan failed. Closing circuit.");
+ circuit_mark_for_close(circ, END_CIRC_REASON_CONNECTFAILED);
+ return 0;
+ }
+ log_debug(LD_CIRC,"connecting in progress (or finished). Good.");
+ }
+ /* return success. The onion/circuit/etc will be taken care of
+ * automatically (may already have been) whenever n_chan reaches
+ * OR_CONN_STATE_OPEN.
+ */
+ return 0;
+ }
+
+ tor_assert(!circ->n_hop); /* Connection is already established. */
+ circ->n_chan = n_chan;
+ log_debug(LD_CIRC,
+ "n_chan is %s",
+ channel_get_canonical_remote_descr(n_chan));
+
+ if (circuit_deliver_create_cell(circ, &ec.create_cell, 1) < 0)
+ return -1;
+
+ return 0;
+}
+
+/** Initialize cpath-\>{f|b}_{crypto|digest} from the key material in key_data.
+ *
+ * If <b>is_hs_v3</b> is set, this cpath will be used for next gen hidden
+ * service circuits and <b>key_data</b> must be at least
+ * HS_NTOR_KEY_EXPANSION_KDF_OUT_LEN bytes in length.
+ *
+ * If <b>is_hs_v3</b> is not set, key_data must contain CPATH_KEY_MATERIAL_LEN
+ * bytes, which are used as follows:
+ * - 20 to initialize f_digest
+ * - 20 to initialize b_digest
+ * - 16 to key f_crypto
+ * - 16 to key b_crypto
+ *
+ * (If 'reverse' is true, then f_XX and b_XX are swapped.)
+ *
+ * Return 0 if init was successful, else -1 if it failed.
+ */
+int
+circuit_init_cpath_crypto(crypt_path_t *cpath,
+ const char *key_data, size_t key_data_len,
+ int reverse, int is_hs_v3)
+{
+
+ tor_assert(cpath);
+ return relay_crypto_init(&cpath->crypto, key_data, key_data_len, reverse,
+ is_hs_v3);
+}
+
+/** A "created" cell <b>reply</b> came back to us on circuit <b>circ</b>.
+ * (The body of <b>reply</b> varies depending on what sort of handshake
+ * this is.)
+ *
+ * Calculate the appropriate keys and digests, make sure KH is
+ * correct, and initialize this hop of the cpath.
+ *
+ * Return - reason if we want to mark circ for close, else return 0.
+ */
+int
+circuit_finish_handshake(origin_circuit_t *circ,
+ const created_cell_t *reply)
+{
+ char keys[CPATH_KEY_MATERIAL_LEN];
+ crypt_path_t *hop;
+ int rv;
+
+ if ((rv = pathbias_count_build_attempt(circ)) < 0) {
+ log_warn(LD_CIRC, "pathbias_count_build_attempt failed: %d", rv);
+ return rv;
+ }
+
+ if (circ->cpath->state == CPATH_STATE_AWAITING_KEYS) {
+ hop = circ->cpath;
+ } else {
+ hop = onion_next_hop_in_cpath(circ->cpath);
+ if (!hop) { /* got an extended when we're all done? */
+ log_warn(LD_PROTOCOL,"got extended when circ already built? Closing.");
+ return - END_CIRC_REASON_TORPROTOCOL;
+ }
+ }
+ tor_assert(hop->state == CPATH_STATE_AWAITING_KEYS);
+
+ {
+ const char *msg = NULL;
+ if (onion_skin_client_handshake(hop->handshake_state.tag,
+ &hop->handshake_state,
+ reply->reply, reply->handshake_len,
+ (uint8_t*)keys, sizeof(keys),
+ (uint8_t*)hop->rend_circ_nonce,
+ &msg) < 0) {
+ if (msg)
+ log_warn(LD_CIRC,"onion_skin_client_handshake failed: %s", msg);
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
+ }
+
+ onion_handshake_state_release(&hop->handshake_state);
+
+ if (circuit_init_cpath_crypto(hop, keys, sizeof(keys), 0, 0)<0) {
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
+
+ hop->state = CPATH_STATE_OPEN;
+ log_info(LD_CIRC,"Finished building circuit hop:");
+ circuit_log_path(LOG_INFO,LD_CIRC,circ);
+ control_event_circuit_status(circ, CIRC_EVENT_EXTENDED, 0);
+
+ return 0;
+}
+
+/** We received a relay truncated cell on circ.
+ *
+ * Since we don't send truncates currently, getting a truncated
+ * means that a connection broke or an extend failed. For now,
+ * just give up: force circ to close, and return 0.
+ */
+int
- circuit_truncated(origin_circuit_t *circ, crypt_path_t *layer, int reason)
++circuit_truncated(origin_circuit_t *circ, int reason)
+{
+// crypt_path_t *victim;
+// connection_t *stream;
+
+ tor_assert(circ);
- tor_assert(layer);
+
+ /* XXX Since we don't send truncates currently, getting a truncated
+ * means that a connection broke or an extend failed. For now,
+ * just give up.
+ */
+ circuit_mark_for_close(TO_CIRCUIT(circ),
+ END_CIRC_REASON_FLAG_REMOTE|reason);
+ return 0;
+
+#if 0
+ while (layer->next != circ->cpath) {
+ /* we need to clear out layer->next */
+ victim = layer->next;
+ log_debug(LD_CIRC, "Killing a layer of the cpath.");
+
+ for (stream = circ->p_streams; stream; stream=stream->next_stream) {
+ if (stream->cpath_layer == victim) {
+ log_info(LD_APP, "Marking stream %d for close because of truncate.",
+ stream->stream_id);
+ /* no need to send 'end' relay cells,
+ * because the other side's already dead
+ */
+ connection_mark_unattached_ap(stream, END_STREAM_REASON_DESTROY);
+ }
+ }
+
+ layer->next = victim->next;
+ circuit_free_cpath_node(victim);
+ }
+
+ log_info(LD_CIRC, "finished");
+ return 0;
+#endif /* 0 */
+}
+
+/** Given a response payload and keys, initialize, then send a created
+ * cell back.
+ */
+int
+onionskin_answer(or_circuit_t *circ,
+ const created_cell_t *created_cell,
+ const char *keys, size_t keys_len,
+ const uint8_t *rend_circ_nonce)
+{
+ cell_t cell;
+
+ tor_assert(keys_len == CPATH_KEY_MATERIAL_LEN);
+
+ if (created_cell_format(&cell, created_cell) < 0) {
+ log_warn(LD_BUG,"couldn't format created cell (type=%d, len=%d)",
+ (int)created_cell->cell_type, (int)created_cell->handshake_len);
+ return -1;
+ }
+ cell.circ_id = circ->p_circ_id;
+
+ circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_OPEN);
+
+ log_debug(LD_CIRC,"init digest forward 0x%.8x, backward 0x%.8x.",
+ (unsigned int)get_uint32(keys),
+ (unsigned int)get_uint32(keys+20));
+ if (relay_crypto_init(&circ->crypto, keys, keys_len, 0, 0)<0) {
+ log_warn(LD_BUG,"Circuit initialization failed");
+ return -1;
+ }
+
+ memcpy(circ->rend_circ_nonce, rend_circ_nonce, DIGEST_LEN);
+
+ int used_create_fast = (created_cell->cell_type == CELL_CREATED_FAST);
+
+ append_cell_to_circuit_queue(TO_CIRCUIT(circ),
+ circ->p_chan, &cell, CELL_DIRECTION_IN, 0);
+ log_debug(LD_CIRC,"Finished sending '%s' cell.",
+ used_create_fast ? "created_fast" : "created");
+
+ /* Ignore the local bit when ExtendAllowPrivateAddresses is set:
+ * it violates the assumption that private addresses are local.
+ * Also, many test networks run on local addresses, and
+ * TestingTorNetwork sets ExtendAllowPrivateAddresses. */
+ if ((!channel_is_local(circ->p_chan)
+ || get_options()->ExtendAllowPrivateAddresses)
+ && !channel_is_outgoing(circ->p_chan)) {
+ /* record that we could process create cells from a non-local conn
+ * that we didn't initiate; presumably this means that create cells
+ * can reach us too. */
+ router_orport_found_reachable();
+ }
+
+ return 0;
+}
+
+/** Helper for new_route_len(). Choose a circuit length for purpose
+ * <b>purpose</b>: DEFAULT_ROUTE_LEN (+ 1 if someone else chose the
+ * exit). If someone else chose the exit, they could be colluding
+ * with the exit, so add a randomly selected node to preserve
+ * anonymity.
+ *
+ * Here, "exit node" sometimes means an OR acting as an internal
+ * endpoint, rather than as a relay to an external endpoint. This
+ * means there need to be at least DEFAULT_ROUTE_LEN routers between
+ * us and the internal endpoint to preserve the same anonymity
+ * properties that we would get when connecting to an external
+ * endpoint. These internal endpoints can include:
+ *
+ * - Connections to a directory of hidden services
+ * (CIRCUIT_PURPOSE_C_GENERAL)
+ *
+ * - A client connecting to an introduction point, which the hidden
+ * service picked (CIRCUIT_PURPOSE_C_INTRODUCING, via
+ * circuit_get_open_circ_or_launch() which rewrites it from
+ * CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT)
+ *
+ * - A hidden service connecting to a rendezvous point, which the
+ * client picked (CIRCUIT_PURPOSE_S_CONNECT_REND, via
+ * rend_service_receive_introduction() and
+ * rend_service_relaunch_rendezvous)
+ *
+ * There are currently two situations where we picked the exit node
+ * ourselves, making DEFAULT_ROUTE_LEN a safe circuit length:
+ *
+ * - We are a hidden service connecting to an introduction point
+ * (CIRCUIT_PURPOSE_S_ESTABLISH_INTRO, via
+ * rend_service_launch_establish_intro())
+ *
+ * - We are a router testing its own reachabiity
+ * (CIRCUIT_PURPOSE_TESTING, via router_do_reachability_checks())
+ *
+ * onion_pick_cpath_exit() bypasses us (by not calling
+ * new_route_len()) in the one-hop tunnel case, so we don't need to
+ * handle that.
+ */
+int
+route_len_for_purpose(uint8_t purpose, extend_info_t *exit_ei)
+{
+ int routelen = DEFAULT_ROUTE_LEN;
+ int known_purpose = 0;
+
+ if (circuit_should_use_vanguards(purpose)) {
+ /* Clients want an extra hop for rends to avoid linkability.
+ * Services want it for intro points to avoid publishing their
+ * layer3 guards. They want it for hsdir posts to use
+ * their full layer3 guard set for those connections.
+ * Ex: C - G - L2 - L3 - R
+ * S - G - L2 - L3 - HSDIR
+ * S - G - L2 - L3 - I
+ */
+ if (purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND ||
+ purpose == CIRCUIT_PURPOSE_S_HSDIR_POST ||
+ purpose == CIRCUIT_PURPOSE_HS_VANGUARDS ||
+ purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO)
+ return routelen+1;
+
+ /* If we only have Layer2 vanguards, then we do not need
+ * the extra hop for linkabilty reasons (see below).
+ * This means all hops can be of the form:
+ * S/C - G - L2 - M - R/HSDir/I
+ */
+ if (get_options()->HSLayer2Nodes && !get_options()->HSLayer3Nodes)
+ return routelen+1;
+
+ /* For connections to hsdirs, clients want two extra hops
+ * when using layer3 guards, to avoid linkability.
+ * Same goes for intro points. Note that the route len
+ * includes the intro point or hsdir, hence the +2.
+ * Ex: C - G - L2 - L3 - M - I
+ * C - G - L2 - L3 - M - HSDIR
+ * S - G - L2 - L3 - M - R
+ */
+ if (purpose == CIRCUIT_PURPOSE_S_CONNECT_REND ||
+ purpose == CIRCUIT_PURPOSE_C_HSDIR_GET ||
+ purpose == CIRCUIT_PURPOSE_C_INTRODUCING)
+ return routelen+2;
+ }
+
+ if (!exit_ei)
+ return routelen;
+
+ switch (purpose) {
+ /* These two purposes connect to a router that we chose, so
+ * DEFAULT_ROUTE_LEN is safe. */
+ case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
+ /* hidden service connecting to introduction point */
+ case CIRCUIT_PURPOSE_TESTING:
+ /* router reachability testing */
+ known_purpose = 1;
+ break;
+
+ /* These three purposes connect to a router that someone else
+ * might have chosen, so add an extra hop to protect anonymity. */
+ case CIRCUIT_PURPOSE_C_GENERAL:
+ case CIRCUIT_PURPOSE_C_HSDIR_GET:
+ case CIRCUIT_PURPOSE_S_HSDIR_POST:
+ /* connecting to hidden service directory */
+ case CIRCUIT_PURPOSE_C_INTRODUCING:
+ /* client connecting to introduction point */
+ case CIRCUIT_PURPOSE_S_CONNECT_REND:
+ /* hidden service connecting to rendezvous point */
+ known_purpose = 1;
+ routelen++;
+ break;
+
+ default:
+ /* Got a purpose not listed above along with a chosen exit.
+ * Increase the circuit length by one anyway for safety. */
+ routelen++;
+ break;
+ }
+
+ if (BUG(exit_ei && !known_purpose)) {
+ log_warn(LD_BUG, "Unhandled purpose %d with a chosen exit; "
+ "assuming routelen %d.", purpose, routelen);
+ }
+ return routelen;
+}
+
+/** Choose a length for a circuit of purpose <b>purpose</b> and check
+ * if enough routers are available.
+ *
+ * If the routerlist <b>nodes</b> doesn't have enough routers
+ * to handle the desired path length, return -1.
+ */
+STATIC int
+new_route_len(uint8_t purpose, extend_info_t *exit_ei, smartlist_t *nodes)
+{
+ int num_acceptable_routers;
+ int routelen;
+
+ tor_assert(nodes);
+
+ routelen = route_len_for_purpose(purpose, exit_ei);
+
+ num_acceptable_routers = count_acceptable_nodes(nodes);
+
+ log_debug(LD_CIRC,"Chosen route length %d (%d/%d routers suitable).",
+ routelen, num_acceptable_routers, smartlist_len(nodes));
+
+ if (num_acceptable_routers < routelen) {
+ log_info(LD_CIRC,
+ "Not enough acceptable routers (%d/%d). Discarding this circuit.",
+ num_acceptable_routers, routelen);
+ return -1;
+ }
+
+ return routelen;
+}
+
+/** Return a newly allocated list of uint16_t * for each predicted port not
+ * handled by a current circuit. */
+static smartlist_t *
+circuit_get_unhandled_ports(time_t now)
+{
+ smartlist_t *dest = rep_hist_get_predicted_ports(now);
+ circuit_remove_handled_ports(dest);
+ return dest;
+}
+
+/** Return 1 if we already have circuits present or on the way for
+ * all anticipated ports. Return 0 if we should make more.
+ *
+ * If we're returning 0, set need_uptime and need_capacity to
+ * indicate any requirements that the unhandled ports have.
+ */
+MOCK_IMPL(int,
+circuit_all_predicted_ports_handled, (time_t now, int *need_uptime,
+ int *need_capacity))
+{
+ int i, enough;
+ uint16_t *port;
+ smartlist_t *sl = circuit_get_unhandled_ports(now);
+ smartlist_t *LongLivedServices = get_options()->LongLivedPorts;
+ tor_assert(need_uptime);
+ tor_assert(need_capacity);
+ // Always predict need_capacity
+ *need_capacity = 1;
+ enough = (smartlist_len(sl) == 0);
+ for (i = 0; i < smartlist_len(sl); ++i) {
+ port = smartlist_get(sl, i);
+ if (smartlist_contains_int_as_string(LongLivedServices, *port))
+ *need_uptime = 1;
+ tor_free(port);
+ }
+ smartlist_free(sl);
+ return enough;
+}
+
+/** Return 1 if <b>node</b> can handle one or more of the ports in
+ * <b>needed_ports</b>, else return 0.
+ */
+static int
+node_handles_some_port(const node_t *node, smartlist_t *needed_ports)
+{ /* XXXX MOVE */
+ int i;
+ uint16_t port;
+
+ for (i = 0; i < smartlist_len(needed_ports); ++i) {
+ addr_policy_result_t r;
+ /* alignment issues aren't a worry for this dereference, since
+ needed_ports is explicitly a smartlist of uint16_t's */
+ port = *(uint16_t *)smartlist_get(needed_ports, i);
+ tor_assert(port);
+ if (node)
+ r = compare_tor_addr_to_node_policy(NULL, port, node);
+ else
+ continue;
+ if (r != ADDR_POLICY_REJECTED && r != ADDR_POLICY_PROBABLY_REJECTED)
+ return 1;
+ }
+ return 0;
+}
+
+/** Return true iff <b>conn</b> needs another general circuit to be
+ * built. */
+static int
+ap_stream_wants_exit_attention(connection_t *conn)
+{
+ entry_connection_t *entry;
+ if (conn->type != CONN_TYPE_AP)
+ return 0;
+ entry = TO_ENTRY_CONN(conn);
+
+ if (conn->state == AP_CONN_STATE_CIRCUIT_WAIT &&
+ !conn->marked_for_close &&
+ !(entry->want_onehop) && /* ignore one-hop streams */
+ !(entry->use_begindir) && /* ignore targeted dir fetches */
+ !(entry->chosen_exit_name) && /* ignore defined streams */
+ !connection_edge_is_rendezvous_stream(TO_EDGE_CONN(conn)) &&
+ !circuit_stream_is_being_handled(TO_ENTRY_CONN(conn), 0,
+ MIN_CIRCUITS_HANDLING_STREAM))
+ return 1;
+ return 0;
+}
+
+/** Return a pointer to a suitable router to be the exit node for the
+ * general-purpose circuit we're about to build.
+ *
+ * Look through the connection array, and choose a router that maximizes
+ * the number of pending streams that can exit from this router.
+ *
+ * Return NULL if we can't find any suitable routers.
+ */
+static const node_t *
+choose_good_exit_server_general(router_crn_flags_t flags)
+{
+ int *n_supported;
+ int n_pending_connections = 0;
+ smartlist_t *connections;
+ int best_support = -1;
+ int n_best_support=0;
+ const or_options_t *options = get_options();
+ const smartlist_t *the_nodes;
+ const node_t *selected_node=NULL;
+ const int need_uptime = (flags & CRN_NEED_UPTIME) != 0;
+ const int need_capacity = (flags & CRN_NEED_CAPACITY) != 0;
+ const int direct_conn = (flags & CRN_DIRECT_CONN) != 0;
+
+ connections = get_connection_array();
+
+ /* Count how many connections are waiting for a circuit to be built.
+ * We use this for log messages now, but in the future we may depend on it.
+ */
+ SMARTLIST_FOREACH(connections, connection_t *, conn,
+ {
+ if (ap_stream_wants_exit_attention(conn))
+ ++n_pending_connections;
+ });
+// log_fn(LOG_DEBUG, "Choosing exit node; %d connections are pending",
+// n_pending_connections);
+ /* Now we count, for each of the routers in the directory, how many
+ * of the pending connections could possibly exit from that
+ * router (n_supported[i]). (We can't be sure about cases where we
+ * don't know the IP address of the pending connection.)
+ *
+ * -1 means "Don't use this router at all."
+ */
+ the_nodes = nodelist_get_list();
+ n_supported = tor_calloc(smartlist_len(the_nodes), sizeof(int));
+ SMARTLIST_FOREACH_BEGIN(the_nodes, const node_t *, node) {
+ const int i = node_sl_idx;
+ if (router_digest_is_me(node->identity)) {
+ n_supported[i] = -1;
+// log_fn(LOG_DEBUG,"Skipping node %s -- it's me.", router->nickname);
+ /* XXX there's probably a reverse predecessor attack here, but
+ * it's slow. should we take this out? -RD
+ */
+ continue;
+ }
+ if (!node_has_preferred_descriptor(node, direct_conn)) {
+ n_supported[i] = -1;
+ continue;
+ }
+ if (!node->is_running || node->is_bad_exit) {
+ n_supported[i] = -1;
+ continue; /* skip routers that are known to be down or bad exits */
+ }
+ if (node_get_purpose(node) != ROUTER_PURPOSE_GENERAL) {
+ /* never pick a non-general node as a random exit. */
+ n_supported[i] = -1;
+ continue;
+ }
+ if (routerset_contains_node(options->ExcludeExitNodesUnion_, node)) {
+ n_supported[i] = -1;
+ continue; /* user asked us not to use it, no matter what */
+ }
+ if (options->ExitNodes &&
+ !routerset_contains_node(options->ExitNodes, node)) {
+ n_supported[i] = -1;
+ continue; /* not one of our chosen exit nodes */
+ }
+
+ if (node_is_unreliable(node, need_uptime, need_capacity, 0)) {
+ n_supported[i] = -1;
+ continue; /* skip routers that are not suitable. Don't worry if
+ * this makes us reject all the possible routers: if so,
+ * we'll retry later in this function with need_update and
+ * need_capacity set to 0. */
+ }
+ if (!(node->is_valid)) {
+ /* if it's invalid and we don't want it */
+ n_supported[i] = -1;
+// log_fn(LOG_DEBUG,"Skipping node %s (index %d) -- invalid router.",
+// router->nickname, i);
+ continue; /* skip invalid routers */
+ }
+ /* We do not allow relays that allow single hop exits by default. Option
+ * was deprecated in 0.2.9.2-alpha and removed in 0.3.1.0-alpha. */
+ if (node_allows_single_hop_exits(node)) {
+ n_supported[i] = -1;
+ continue;
+ }
+ if (node_exit_policy_rejects_all(node)) {
+ n_supported[i] = -1;
+// log_fn(LOG_DEBUG,"Skipping node %s (index %d) -- it rejects all.",
+// router->nickname, i);
+ continue; /* skip routers that reject all */
+ }
+ n_supported[i] = 0;
+ /* iterate over connections */
+ SMARTLIST_FOREACH_BEGIN(connections, connection_t *, conn) {
+ if (!ap_stream_wants_exit_attention(conn))
+ continue; /* Skip everything but APs in CIRCUIT_WAIT */
+ if (connection_ap_can_use_exit(TO_ENTRY_CONN(conn), node)) {
+ ++n_supported[i];
+// log_fn(LOG_DEBUG,"%s is supported. n_supported[%d] now %d.",
+// router->nickname, i, n_supported[i]);
+ } else {
+// log_fn(LOG_DEBUG,"%s (index %d) would reject this stream.",
+// router->nickname, i);
+ }
+ } SMARTLIST_FOREACH_END(conn);
+ if (n_pending_connections > 0 && n_supported[i] == 0) {
+ /* Leave best_support at -1 if that's where it is, so we can
+ * distinguish it later. */
+ continue;
+ }
+ if (n_supported[i] > best_support) {
+ /* If this router is better than previous ones, remember its index
+ * and goodness, and start counting how many routers are this good. */
+ best_support = n_supported[i]; n_best_support=1;
+// log_fn(LOG_DEBUG,"%s is new best supported option so far.",
+// router->nickname);
+ } else if (n_supported[i] == best_support) {
+ /* If this router is _as good_ as the best one, just increment the
+ * count of equally good routers.*/
+ ++n_best_support;
+ }
+ } SMARTLIST_FOREACH_END(node);
+ log_info(LD_CIRC,
+ "Found %d servers that might support %d/%d pending connections.",
+ n_best_support, best_support >= 0 ? best_support : 0,
+ n_pending_connections);
+
+ /* If any routers definitely support any pending connections, choose one
+ * at random. */
+ if (best_support > 0) {
+ smartlist_t *supporting = smartlist_new();
+
+ SMARTLIST_FOREACH(the_nodes, const node_t *, node, {
+ if (n_supported[node_sl_idx] == best_support)
+ smartlist_add(supporting, (void*)node);
+ });
+
+ selected_node = node_sl_choose_by_bandwidth(supporting, WEIGHT_FOR_EXIT);
+ smartlist_free(supporting);
+ } else {
+ /* Either there are no pending connections, or no routers even seem to
+ * possibly support any of them. Choose a router at random that satisfies
+ * at least one predicted exit port. */
+
+ int attempt;
+ smartlist_t *needed_ports, *supporting;
+
+ if (best_support == -1) {
+ if (need_uptime || need_capacity) {
+ log_info(LD_CIRC,
+ "We couldn't find any live%s%s routers; falling back "
+ "to list of all routers.",
+ need_capacity?", fast":"",
+ need_uptime?", stable":"");
+ tor_free(n_supported);
+ flags &= ~(CRN_NEED_UPTIME|CRN_NEED_CAPACITY);
+ return choose_good_exit_server_general(flags);
+ }
+ log_notice(LD_CIRC, "All routers are down or won't exit%s -- "
+ "choosing a doomed exit at random.",
+ options->ExcludeExitNodesUnion_ ? " or are Excluded" : "");
+ }
+ supporting = smartlist_new();
+ needed_ports = circuit_get_unhandled_ports(time(NULL));
+ for (attempt = 0; attempt < 2; attempt++) {
+ /* try once to pick only from routers that satisfy a needed port,
+ * then if there are none, pick from any that support exiting. */
+ SMARTLIST_FOREACH_BEGIN(the_nodes, const node_t *, node) {
+ if (n_supported[node_sl_idx] != -1 &&
+ (attempt || node_handles_some_port(node, needed_ports))) {
+// log_fn(LOG_DEBUG,"Try %d: '%s' is a possibility.",
+// try, router->nickname);
+ smartlist_add(supporting, (void*)node);
+ }
+ } SMARTLIST_FOREACH_END(node);
+
+ selected_node = node_sl_choose_by_bandwidth(supporting, WEIGHT_FOR_EXIT);
+ if (selected_node)
+ break;
+ smartlist_clear(supporting);
+ /* If we reach this point, we can't actually support any unhandled
+ * predicted ports, so clear all the remaining ones. */
+ if (smartlist_len(needed_ports))
+ rep_hist_remove_predicted_ports(needed_ports);
+ }
+ SMARTLIST_FOREACH(needed_ports, uint16_t *, cp, tor_free(cp));
+ smartlist_free(needed_ports);
+ smartlist_free(supporting);
+ }
+
+ tor_free(n_supported);
+ if (selected_node) {
+ log_info(LD_CIRC, "Chose exit server '%s'", node_describe(selected_node));
+ return selected_node;
+ }
+ if (options->ExitNodes) {
+ log_warn(LD_CIRC,
+ "No exits in ExitNodes%s seem to be running: "
+ "can't choose an exit.",
+ options->ExcludeExitNodesUnion_ ?
+ ", except possibly those excluded by your configuration, " : "");
+ }
+ return NULL;
+}
+
+/* Pick a Rendezvous Point for our HS circuits according to <b>flags</b>. */
+static const node_t *
+pick_rendezvous_node(router_crn_flags_t flags)
+{
+ const or_options_t *options = get_options();
+ return router_choose_random_node(NULL, options->ExcludeNodes, flags);
+}
+
+/*
+ * Helper function to pick a configured restricted middle node
+ * (either HSLayer2Nodes or HSLayer3Nodes).
+ *
+ * Make sure that the node we chose is alive, and not excluded,
+ * and return it.
+ *
+ * The exclude_set is a routerset of nodes that the selected node
+ * must not match, and the exclude_list is a simple list of nodes
+ * that the selected node must not be in. Either or both may be
+ * NULL.
+ *
+ * Return NULL if no usable nodes could be found. */
+static const node_t *
+pick_restricted_middle_node(router_crn_flags_t flags,
+ const routerset_t *pick_from,
+ const routerset_t *exclude_set,
+ const smartlist_t *exclude_list,
+ int position_hint)
+{
+ const node_t *middle_node = NULL;
+
+ smartlist_t *whitelisted_live_middles = smartlist_new();
+ smartlist_t *all_live_nodes = smartlist_new();
+
+ tor_assert(pick_from);
+
+ /* Add all running nodes to all_live_nodes */
+ router_add_running_nodes_to_smartlist(all_live_nodes,
+ (flags & CRN_NEED_UPTIME) != 0,
+ (flags & CRN_NEED_CAPACITY) != 0,
+ (flags & CRN_NEED_GUARD) != 0,
+ (flags & CRN_NEED_DESC) != 0,
+ (flags & CRN_PREF_ADDR) != 0,
+ (flags & CRN_DIRECT_CONN) != 0);
+
+ /* Filter all_live_nodes to only add live *and* whitelisted middles
+ * to the list whitelisted_live_middles. */
+ SMARTLIST_FOREACH_BEGIN(all_live_nodes, node_t *, live_node) {
+ if (routerset_contains_node(pick_from, live_node)) {
+ smartlist_add(whitelisted_live_middles, live_node);
+ }
+ } SMARTLIST_FOREACH_END(live_node);
+
+ /* Honor ExcludeNodes */
+ if (exclude_set) {
+ routerset_subtract_nodes(whitelisted_live_middles, exclude_set);
+ }
+
+ if (exclude_list) {
+ smartlist_subtract(whitelisted_live_middles, exclude_list);
+ }
+
+ /**
+ * Max number of restricted nodes before we alert the user and try
+ * to load balance for them.
+ *
+ * The most aggressive vanguard design had 16 nodes at layer3.
+ * Let's give a small ceiling above that. */
+#define MAX_SANE_RESTRICTED_NODES 20
+ /* If the user (or associated tor controller) selected only a few nodes,
+ * assume they took load balancing into account and don't do it for them.
+ *
+ * If there are a lot of nodes in here, assume they did not load balance
+ * and do it for them, but also warn them that they may be Doing It Wrong.
+ */
+ if (smartlist_len(whitelisted_live_middles) <=
+ MAX_SANE_RESTRICTED_NODES) {
+ middle_node = smartlist_choose(whitelisted_live_middles);
+ } else {
+ static ratelim_t pinned_notice_limit = RATELIM_INIT(24*3600);
+ log_fn_ratelim(&pinned_notice_limit, LOG_NOTICE, LD_CIRC,
+ "Your _HSLayer%dNodes setting has resulted "
+ "in %d total nodes. This is a lot of nodes. "
+ "You may want to consider using a Tor controller "
+ "to select and update a smaller set of nodes instead.",
+ position_hint, smartlist_len(whitelisted_live_middles));
+
+ /* NO_WEIGHTING here just means don't take node flags into account
+ * (ie: use consensus measurement only). This is done so that
+ * we don't further surprise the user by not using Exits that they
+ * specified at all */
+ middle_node = node_sl_choose_by_bandwidth(whitelisted_live_middles,
+ NO_WEIGHTING);
+ }
+
+ smartlist_free(whitelisted_live_middles);
+ smartlist_free(all_live_nodes);
+
+ return middle_node;
+}
+
+/** Return a pointer to a suitable router to be the exit node for the
+ * circuit of purpose <b>purpose</b> that we're about to build (or NULL
+ * if no router is suitable).
+ *
+ * For general-purpose circuits, pass it off to
+ * choose_good_exit_server_general()
+ *
+ * For client-side rendezvous circuits, choose a random node, weighted
+ * toward the preferences in 'options'.
+ */
+static const node_t *
+choose_good_exit_server(origin_circuit_t *circ,
+ router_crn_flags_t flags, int is_internal)
+{
+ const or_options_t *options = get_options();
+ flags |= CRN_NEED_DESC;
+
+ switch (TO_CIRCUIT(circ)->purpose) {
+ case CIRCUIT_PURPOSE_C_HSDIR_GET:
+ case CIRCUIT_PURPOSE_S_HSDIR_POST:
+ case CIRCUIT_PURPOSE_HS_VANGUARDS:
+ /* For these three, we want to pick the exit like a middle hop,
+ * since it should be random. */
+ tor_assert_nonfatal(is_internal);
+ /* Falls through */
+ case CIRCUIT_PURPOSE_C_GENERAL:
+ if (is_internal) /* pick it like a middle hop */
+ return router_choose_random_node(NULL, options->ExcludeNodes, flags);
+ else
+ return choose_good_exit_server_general(flags);
+ case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
+ {
+ /* Pick a new RP */
+ const node_t *rendezvous_node = pick_rendezvous_node(flags);
+ log_info(LD_REND, "Picked new RP: %s",
+ safe_str_client(node_describe(rendezvous_node)));
+ return rendezvous_node;
+ }
+ }
+ log_warn(LD_BUG,"Unhandled purpose %d", TO_CIRCUIT(circ)->purpose);
+ tor_fragile_assert();
+ return NULL;
+}
+
+/** Log a warning if the user specified an exit for the circuit that
+ * has been excluded from use by ExcludeNodes or ExcludeExitNodes. */
+static void
+warn_if_last_router_excluded(origin_circuit_t *circ,
+ const extend_info_t *exit_ei)
+{
+ const or_options_t *options = get_options();
+ routerset_t *rs = options->ExcludeNodes;
+ const char *description;
+ uint8_t purpose = circ->base_.purpose;
+
+ if (circ->build_state->onehop_tunnel)
+ return;
+
+ switch (purpose)
+ {
+ default:
+ case CIRCUIT_PURPOSE_OR:
+ case CIRCUIT_PURPOSE_INTRO_POINT:
+ case CIRCUIT_PURPOSE_REND_POINT_WAITING:
+ case CIRCUIT_PURPOSE_REND_ESTABLISHED:
+ log_warn(LD_BUG, "Called on non-origin circuit (purpose %d, %s)",
+ (int)purpose,
+ circuit_purpose_to_string(purpose));
+ return;
+ case CIRCUIT_PURPOSE_S_HSDIR_POST:
+ case CIRCUIT_PURPOSE_C_HSDIR_GET:
+ case CIRCUIT_PURPOSE_C_GENERAL:
+ if (circ->build_state->is_internal)
+ return;
+ description = "requested exit node";
+ rs = options->ExcludeExitNodesUnion_;
+ break;
+ case CIRCUIT_PURPOSE_C_INTRODUCING:
+ case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
+ case CIRCUIT_PURPOSE_C_INTRODUCE_ACKED:
+ case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
+ case CIRCUIT_PURPOSE_S_CONNECT_REND:
+ case CIRCUIT_PURPOSE_S_REND_JOINED:
+ case CIRCUIT_PURPOSE_TESTING:
+ return;
+ case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
+ case CIRCUIT_PURPOSE_C_REND_READY:
+ case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED:
+ case CIRCUIT_PURPOSE_C_REND_JOINED:
+ description = "chosen rendezvous point";
+ break;
+ case CIRCUIT_PURPOSE_CONTROLLER:
+ rs = options->ExcludeExitNodesUnion_;
+ description = "controller-selected circuit target";
+ break;
+ }
+
+ if (routerset_contains_extendinfo(rs, exit_ei)) {
+ /* We should never get here if StrictNodes is set to 1. */
+ if (options->StrictNodes) {
+ log_warn(LD_BUG, "Using %s '%s' which is listed in ExcludeNodes%s, "
+ "even though StrictNodes is set. Please report. "
+ "(Circuit purpose: %s)",
+ description, extend_info_describe(exit_ei),
+ rs==options->ExcludeNodes?"":" or ExcludeExitNodes",
+ circuit_purpose_to_string(purpose));
+ } else {
+ log_warn(LD_CIRC, "Using %s '%s' which is listed in "
+ "ExcludeNodes%s, because no better options were available. To "
+ "prevent this (and possibly break your Tor functionality), "
+ "set the StrictNodes configuration option. "
+ "(Circuit purpose: %s)",
+ description, extend_info_describe(exit_ei),
+ rs==options->ExcludeNodes?"":" or ExcludeExitNodes",
+ circuit_purpose_to_string(purpose));
+ }
+ circuit_log_path(LOG_WARN, LD_CIRC, circ);
+ }
+
+ return;
+}
+
+/** Decide a suitable length for circ's cpath, and pick an exit
+ * router (or use <b>exit</b> if provided). Store these in the
+ * cpath.
+ *
+ * If <b>is_hs_v3_rp_circuit</b> is set, then this exit should be suitable to
+ * be used as an HS v3 rendezvous point.
+ *
+ * Return 0 if ok, -1 if circuit should be closed. */
+STATIC int
+onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit_ei,
+ int is_hs_v3_rp_circuit)
+{
+ cpath_build_state_t *state = circ->build_state;
+
+ if (state->onehop_tunnel) {
+ log_debug(LD_CIRC, "Launching a one-hop circuit for dir tunnel%s.",
+ (rend_allow_non_anonymous_connection(get_options()) ?
+ ", or intro or rendezvous connection" : ""));
+ state->desired_path_len = 1;
+ } else {
+ int r = new_route_len(circ->base_.purpose, exit_ei, nodelist_get_list());
+ if (r < 1) /* must be at least 1 */
+ return -1;
+ state->desired_path_len = r;
+ }
+
+ if (exit_ei) { /* the circuit-builder pre-requested one */
+ warn_if_last_router_excluded(circ, exit_ei);
+ log_info(LD_CIRC,"Using requested exit node '%s'",
+ extend_info_describe(exit_ei));
+ exit_ei = extend_info_dup(exit_ei);
+ } else { /* we have to decide one */
+ router_crn_flags_t flags = CRN_NEED_DESC;
+ if (state->need_uptime)
+ flags |= CRN_NEED_UPTIME;
+ if (state->need_capacity)
+ flags |= CRN_NEED_CAPACITY;
+ if (is_hs_v3_rp_circuit)
+ flags |= CRN_RENDEZVOUS_V3;
+ if (state->onehop_tunnel)
+ flags |= CRN_DIRECT_CONN;
+ const node_t *node =
+ choose_good_exit_server(circ, flags, state->is_internal);
+ if (!node) {
+ log_warn(LD_CIRC,"Failed to choose an exit server");
+ return -1;
+ }
+ exit_ei = extend_info_from_node(node, state->onehop_tunnel);
+ if (BUG(exit_ei == NULL))
+ return -1;
+ }
+ state->chosen_exit = exit_ei;
+ return 0;
+}
+
+/** Give <b>circ</b> a new exit destination to <b>exit</b>, and add a
+ * hop to the cpath reflecting this. Don't send the next extend cell --
+ * the caller will do this if it wants to.
+ */
+int
+circuit_append_new_exit(origin_circuit_t *circ, extend_info_t *exit_ei)
+{
+ cpath_build_state_t *state;
+ tor_assert(exit_ei);
+ tor_assert(circ);
+
+ state = circ->build_state;
+ tor_assert(state);
+ extend_info_free(state->chosen_exit);
+ state->chosen_exit = extend_info_dup(exit_ei);
+
+ ++circ->build_state->desired_path_len;
+ onion_append_hop(&circ->cpath, exit_ei);
+ return 0;
+}
+
+/** Take an open <b>circ</b>, and add a new hop at the end, based on
+ * <b>info</b>. Set its state back to CIRCUIT_STATE_BUILDING, and then
+ * send the next extend cell to begin connecting to that hop.
+ */
+int
+circuit_extend_to_new_exit(origin_circuit_t *circ, extend_info_t *exit_ei)
+{
+ int err_reason = 0;
+ warn_if_last_router_excluded(circ, exit_ei);
+
+ tor_gettimeofday(&circ->base_.timestamp_began);
+
+ circuit_append_new_exit(circ, exit_ei);
+ circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_BUILDING);
+ if ((err_reason = circuit_send_next_onion_skin(circ))<0) {
+ log_warn(LD_CIRC, "Couldn't extend circuit to new point %s.",
+ extend_info_describe(exit_ei));
+ circuit_mark_for_close(TO_CIRCUIT(circ), -err_reason);
+ return -1;
+ }
+
+ // XXX: Should cannibalized circuits be dirty or not? Not easy to say..
+
+ return 0;
+}
+
+/** Return the number of routers in <b>routers</b> that are currently up
+ * and available for building circuits through.
+ *
+ * (Note that this function may overcount or undercount, if we have
+ * descriptors that are not the type we would prefer to use for some
+ * particular router. See bug #25885.)
+ */
+MOCK_IMPL(STATIC int,
+count_acceptable_nodes, (smartlist_t *nodes))
+{
+ int num=0;
+
+ SMARTLIST_FOREACH_BEGIN(nodes, const node_t *, node) {
+ // log_debug(LD_CIRC,
+// "Contemplating whether router %d (%s) is a new option.",
+// i, r->nickname);
+ if (! node->is_running)
+// log_debug(LD_CIRC,"Nope, the directory says %d is not running.",i);
+ continue;
+ if (! node->is_valid)
+// log_debug(LD_CIRC,"Nope, the directory says %d is not valid.",i);
+ continue;
+ if (! node_has_any_descriptor(node))
+ continue;
+ /* The node has a descriptor, so we can just check the ntor key directly */
+ if (!node_has_curve25519_onion_key(node))
+ continue;
+ ++num;
+ } SMARTLIST_FOREACH_END(node);
+
+// log_debug(LD_CIRC,"I like %d. num_acceptable_routers now %d.",i, num);
+
+ return num;
+}
+
+/** Add <b>new_hop</b> to the end of the doubly-linked-list <b>head_ptr</b>.
+ * This function is used to extend cpath by another hop.
+ */
+void
+onion_append_to_cpath(crypt_path_t **head_ptr, crypt_path_t *new_hop)
+{
+ if (*head_ptr) {
+ new_hop->next = (*head_ptr);
+ new_hop->prev = (*head_ptr)->prev;
+ (*head_ptr)->prev->next = new_hop;
+ (*head_ptr)->prev = new_hop;
+ } else {
+ *head_ptr = new_hop;
+ new_hop->prev = new_hop->next = new_hop;
+ }
+}
+
+#ifdef TOR_UNIT_TESTS
+
+/** Unittest helper function: Count number of hops in cpath linked list. */
+unsigned int
+cpath_get_n_hops(crypt_path_t **head_ptr)
+{
+ unsigned int n_hops = 0;
+ crypt_path_t *tmp;
+
+ if (!*head_ptr) {
+ return 0;
+ }
+
+ tmp = *head_ptr;
+ do {
+ n_hops++;
+ tmp = tmp->next;
+ } while (tmp != *head_ptr);
+
+ return n_hops;
+}
+
+#endif /* defined(TOR_UNIT_TESTS) */
+
+/**
+ * Build the exclude list for vanguard circuits.
+ *
+ * For vanguard circuits we exclude all the already chosen nodes (including the
+ * exit) from being middle hops to prevent the creation of A - B - A subpaths.
+ * We also allow the 4th hop to be the same as the guard node so as to not leak
+ * guard information to RP/IP/HSDirs.
+ *
+ * For vanguard circuits, we don't apply any subnet or family restrictions.
+ * This is to avoid impossible-to-build circuit paths, or just situations where
+ * our earlier guards prevent us from using most of our later ones.
+ *
+ * The alternative is building the circuit in reverse. Reverse calls to
+ * onion_extend_cpath() (ie: select outer hops first) would then have the
+ * property that you don't gain information about inner hops by observing
+ * outer ones. See https://trac.torproject.org/projects/tor/ticket/24487
+ * for this.
+ *
+ * (Note further that we still exclude the exit to prevent A - B - A
+ * at the end of the path. */
+static smartlist_t *
+build_vanguard_middle_exclude_list(uint8_t purpose,
+ cpath_build_state_t *state,
+ crypt_path_t *head,
+ int cur_len)
+{
+ smartlist_t *excluded;
+ const node_t *r;
+ crypt_path_t *cpath;
+ int i;
+
+ (void) purpose;
+
+ excluded = smartlist_new();
+
+ /* Add the exit to the exclude list (note that the exit/last hop is always
+ * chosen first in circuit_establish_circuit()). */
+ if ((r = build_state_get_exit_node(state))) {
+ smartlist_add(excluded, (node_t*)r);
+ }
+
+ /* If we are picking the 4th hop, allow that node to be the guard too.
+ * This prevents us from avoiding the Guard for those hops, which
+ * gives the adversary information about our guard if they control
+ * the RP, IP, or HSDIR. We don't do this check based on purpose
+ * because we also want to allow HS_VANGUARDS pre-build circuits
+ * to use the guard for that last hop.
+ */
+ if (cur_len == DEFAULT_ROUTE_LEN+1) {
+ /* Skip the first hop for the exclude list below */
+ head = head->next;
+ cur_len--;
+ }
+
+ for (i = 0, cpath = head; cpath && i < cur_len; ++i, cpath=cpath->next) {
+ if ((r = node_get_by_id(cpath->extend_info->identity_digest))) {
+ smartlist_add(excluded, (node_t*)r);
+ }
+ }
+
+ return excluded;
+}
+
+/**
+ * Build a list of nodes to exclude from the choice of this middle
+ * hop, based on already chosen nodes.
+ */
+static smartlist_t *
+build_middle_exclude_list(uint8_t purpose,
+ cpath_build_state_t *state,
+ crypt_path_t *head,
+ int cur_len)
+{
+ smartlist_t *excluded;
+ const node_t *r;
+ crypt_path_t *cpath;
+ int i;
+
+ /** Vanguard circuits have their own path selection rules */
+ if (circuit_should_use_vanguards(purpose)) {
+ return build_vanguard_middle_exclude_list(purpose, state, head, cur_len);
+ }
+
+ excluded = smartlist_new();
+
+ /* For non-vanguard circuits, add the exit and its family to the exclude list
+ * (note that the exit/last hop is always chosen first in
+ * circuit_establish_circuit()). */
+ if ((r = build_state_get_exit_node(state))) {
+ nodelist_add_node_and_family(excluded, r);
+ }
+
+ /* also exclude all other already chosen nodes and their family */
+ for (i = 0, cpath = head; cpath && i < cur_len; ++i, cpath=cpath->next) {
+ if ((r = node_get_by_id(cpath->extend_info->identity_digest))) {
+ nodelist_add_node_and_family(excluded, r);
+ }
+ }
+
+ return excluded;
+}
+
+/** Return true if we MUST use vanguards for picking this middle node. */
+static int
+middle_node_must_be_vanguard(const or_options_t *options,
+ uint8_t purpose, int cur_len)
+{
+ /* If this is not a hidden service circuit, don't use vanguards */
+ if (!circuit_purpose_is_hidden_service(purpose)) {
+ return 0;
+ }
+
+ /* If we have sticky L2 nodes, and this is an L2 pick, use vanguards */
+ if (options->HSLayer2Nodes && cur_len == 1) {
+ return 1;
+ }
+
+ /* If we have sticky L3 nodes, and this is an L3 pick, use vanguards */
+ if (options->HSLayer3Nodes && cur_len == 2) {
+ return 1;
+ }
+
+ return 0;
+}
+
+/** Pick a sticky vanguard middle node or return NULL if not found.
+ * See doc of pick_restricted_middle_node() for argument details. */
+static const node_t *
+pick_vanguard_middle_node(const or_options_t *options,
+ router_crn_flags_t flags, int cur_len,
+ const smartlist_t *excluded)
+{
+ const routerset_t *vanguard_routerset = NULL;
+ const node_t *node = NULL;
+
+ /* Pick the right routerset based on the current hop */
+ if (cur_len == 1) {
+ vanguard_routerset = options->HSLayer2Nodes;
+ } else if (cur_len == 2) {
+ vanguard_routerset = options->HSLayer3Nodes;
+ } else {
+ /* guaranteed by middle_node_should_be_vanguard() */
+ tor_assert_nonfatal_unreached();
+ return NULL;
+ }
+
+ node = pick_restricted_middle_node(flags, vanguard_routerset,
+ options->ExcludeNodes, excluded,
+ cur_len+1);
+
+ if (!node) {
+ static ratelim_t pinned_warning_limit = RATELIM_INIT(300);
+ log_fn_ratelim(&pinned_warning_limit, LOG_WARN, LD_CIRC,
+ "Could not find a node that matches the configured "
+ "_HSLayer%dNodes set", cur_len+1);
+ }
+
+ return node;
+}
+
+/** A helper function used by onion_extend_cpath(). Use <b>purpose</b>
+ * and <b>state</b> and the cpath <b>head</b> (currently populated only
+ * to length <b>cur_len</b> to decide a suitable middle hop for a
+ * circuit. In particular, make sure we don't pick the exit node or its
+ * family, and make sure we don't duplicate any previous nodes or their
+ * families. */
+static const node_t *
+choose_good_middle_server(uint8_t purpose,
+ cpath_build_state_t *state,
+ crypt_path_t *head,
+ int cur_len)
+{
+ const node_t *choice;
+ smartlist_t *excluded;
+ const or_options_t *options = get_options();
+ router_crn_flags_t flags = CRN_NEED_DESC;
+ tor_assert(CIRCUIT_PURPOSE_MIN_ <= purpose &&
+ purpose <= CIRCUIT_PURPOSE_MAX_);
+
+ log_debug(LD_CIRC, "Contemplating intermediate hop #%d: random choice.",
+ cur_len+1);
+
+ excluded = build_middle_exclude_list(purpose, state, head, cur_len);
+
+ if (state->need_uptime)
+ flags |= CRN_NEED_UPTIME;
+ if (state->need_capacity)
+ flags |= CRN_NEED_CAPACITY;
+
+ /** If a hidden service circuit wants a specific middle node, pin it. */
+ if (middle_node_must_be_vanguard(options, purpose, cur_len)) {
+ log_debug(LD_GENERAL, "Picking a sticky node (cur_len = %d)", cur_len);
+ choice = pick_vanguard_middle_node(options, flags, cur_len, excluded);
+ smartlist_free(excluded);
+ return choice;
+ }
+
+ choice = router_choose_random_node(excluded, options->ExcludeNodes, flags);
+ smartlist_free(excluded);
+ return choice;
+}
+
+/** Pick a good entry server for the circuit to be built according to
+ * <b>state</b>. Don't reuse a chosen exit (if any), don't use this
+ * router (if we're an OR), and respect firewall settings; if we're
+ * configured to use entry guards, return one.
+ *
+ * Set *<b>guard_state_out</b> to information about the guard that
+ * we're selecting, which we'll use later to remember whether the
+ * guard worked or not.
+ */
+const node_t *
+choose_good_entry_server(uint8_t purpose, cpath_build_state_t *state,
+ circuit_guard_state_t **guard_state_out)
+{
+ const node_t *choice;
+ smartlist_t *excluded;
+ const or_options_t *options = get_options();
+ /* If possible, choose an entry server with a preferred address,
+ * otherwise, choose one with an allowed address */
+ router_crn_flags_t flags = (CRN_NEED_GUARD|CRN_NEED_DESC|CRN_PREF_ADDR|
+ CRN_DIRECT_CONN);
+ const node_t *node;
+
+ /* Once we used this function to select a node to be a guard. We had
+ * 'state == NULL' be the signal for that. But we don't do that any more.
+ */
+ tor_assert_nonfatal(state);
+
+ if (state && options->UseEntryGuards &&
+ (purpose != CIRCUIT_PURPOSE_TESTING || options->BridgeRelay)) {
+ /* This request is for an entry server to use for a regular circuit,
+ * and we use entry guard nodes. Just return one of the guard nodes. */
+ tor_assert(guard_state_out);
+ return guards_choose_guard(state, purpose, guard_state_out);
+ }
+
+ excluded = smartlist_new();
+
+ if (state && (node = build_state_get_exit_node(state))) {
+ /* Exclude the exit node from the state, if we have one. Also exclude its
+ * family. */
+ nodelist_add_node_and_family(excluded, node);
+ }
+
+ if (state) {
+ if (state->need_uptime)
+ flags |= CRN_NEED_UPTIME;
+ if (state->need_capacity)
+ flags |= CRN_NEED_CAPACITY;
+ }
+
+ choice = router_choose_random_node(excluded, options->ExcludeNodes, flags);
+ smartlist_free(excluded);
+ return choice;
+}
+
+/** Return the first non-open hop in cpath, or return NULL if all
+ * hops are open. */
+static crypt_path_t *
+onion_next_hop_in_cpath(crypt_path_t *cpath)
+{
+ crypt_path_t *hop = cpath;
+ do {
+ if (hop->state != CPATH_STATE_OPEN)
+ return hop;
+ hop = hop->next;
+ } while (hop != cpath);
+ return NULL;
+}
+
+/** Choose a suitable next hop in the cpath <b>head_ptr</b>,
+ * based on <b>state</b>. Append the hop info to head_ptr.
+ *
+ * Return 1 if the path is complete, 0 if we successfully added a hop,
+ * and -1 on error.
+ */
+STATIC int
+onion_extend_cpath(origin_circuit_t *circ)
+{
+ uint8_t purpose = circ->base_.purpose;
+ cpath_build_state_t *state = circ->build_state;
+ int cur_len = circuit_get_cpath_len(circ);
+ extend_info_t *info = NULL;
+
+ if (cur_len >= state->desired_path_len) {
+ log_debug(LD_CIRC, "Path is complete: %d steps long",
+ state->desired_path_len);
+ return 1;
+ }
+
+ log_debug(LD_CIRC, "Path is %d long; we want %d", cur_len,
+ state->desired_path_len);
+
+ if (cur_len == state->desired_path_len - 1) { /* Picking last node */
+ info = extend_info_dup(state->chosen_exit);
+ } else if (cur_len == 0) { /* picking first node */
+ const node_t *r = choose_good_entry_server(purpose, state,
+ &circ->guard_state);
+ if (r) {
+ /* If we're a client, use the preferred address rather than the
+ primary address, for potentially connecting to an IPv6 OR
+ port. Servers always want the primary (IPv4) address. */
+ int client = (server_mode(get_options()) == 0);
+ info = extend_info_from_node(r, client);
+ /* Clients can fail to find an allowed address */
+ tor_assert_nonfatal(info || client);
+ }
+ } else {
+ const node_t *r =
+ choose_good_middle_server(purpose, state, circ->cpath, cur_len);
+ if (r) {
+ info = extend_info_from_node(r, 0);
+ tor_assert_nonfatal(info);
+ }
+ }
+
+ if (!info) {
+ log_warn(LD_CIRC,"Failed to find node for hop #%d of our path. Discarding "
+ "this circuit.", cur_len+1);
+ return -1;
+ }
+
+ log_debug(LD_CIRC,"Chose router %s for hop #%d (exit is %s)",
+ extend_info_describe(info),
+ cur_len+1, build_state_get_exit_nickname(state));
+
+ onion_append_hop(&circ->cpath, info);
+ extend_info_free(info);
+ return 0;
+}
+
+/** Create a new hop, annotate it with information about its
+ * corresponding router <b>choice</b>, and append it to the
+ * end of the cpath <b>head_ptr</b>. */
+STATIC int
+onion_append_hop(crypt_path_t **head_ptr, extend_info_t *choice)
+{
+ crypt_path_t *hop = tor_malloc_zero(sizeof(crypt_path_t));
+
+ /* link hop into the cpath, at the end. */
+ onion_append_to_cpath(head_ptr, hop);
+
+ hop->magic = CRYPT_PATH_MAGIC;
+ hop->state = CPATH_STATE_CLOSED;
+
+ hop->extend_info = extend_info_dup(choice);
+
+ hop->package_window = circuit_initial_package_window();
+ hop->deliver_window = CIRCWINDOW_START;
+
+ return 0;
+}
+
+/** Allocate a new extend_info object based on the various arguments. */
+extend_info_t *
+extend_info_new(const char *nickname,
+ const char *rsa_id_digest,
+ const ed25519_public_key_t *ed_id,
+ crypto_pk_t *onion_key,
+ const curve25519_public_key_t *ntor_key,
+ const tor_addr_t *addr, uint16_t port)
+{
+ extend_info_t *info = tor_malloc_zero(sizeof(extend_info_t));
+ memcpy(info->identity_digest, rsa_id_digest, DIGEST_LEN);
+ if (ed_id && !ed25519_public_key_is_zero(ed_id))
+ memcpy(&info->ed_identity, ed_id, sizeof(ed25519_public_key_t));
+ if (nickname)
+ strlcpy(info->nickname, nickname, sizeof(info->nickname));
+ if (onion_key)
+ info->onion_key = crypto_pk_dup_key(onion_key);
+ if (ntor_key)
+ memcpy(&info->curve25519_onion_key, ntor_key,
+ sizeof(curve25519_public_key_t));
+ tor_addr_copy(&info->addr, addr);
+ info->port = port;
+ return info;
+}
+
+/** Allocate and return a new extend_info that can be used to build a
+ * circuit to or through the node <b>node</b>. Use the primary address
+ * of the node (i.e. its IPv4 address) unless
+ * <b>for_direct_connect</b> is true, in which case the preferred
+ * address is used instead. May return NULL if there is not enough
+ * info about <b>node</b> to extend to it--for example, if the preferred
+ * routerinfo_t or microdesc_t is missing, or if for_direct_connect is
+ * true and none of the node's addresses is allowed by tor's firewall
+ * and IP version config.
+ **/
+extend_info_t *
+extend_info_from_node(const node_t *node, int for_direct_connect)
+{
+ tor_addr_port_t ap;
+ int valid_addr = 0;
+
+ if (!node_has_preferred_descriptor(node, for_direct_connect)) {
+ return NULL;
+ }
+
+ /* Choose a preferred address first, but fall back to an allowed address. */
+ if (for_direct_connect)
+ fascist_firewall_choose_address_node(node, FIREWALL_OR_CONNECTION, 0, &ap);
+ else {
+ node_get_prim_orport(node, &ap);
+ }
+ valid_addr = tor_addr_port_is_valid_ap(&ap, 0);
+
+ if (valid_addr)
+ log_debug(LD_CIRC, "using %s for %s",
+ fmt_addrport(&ap.addr, ap.port),
+ node->ri ? node->ri->nickname : node->rs->nickname);
+ else
+ log_warn(LD_CIRC, "Could not choose valid address for %s",
+ node->ri ? node->ri->nickname : node->rs->nickname);
+
+ /* Every node we connect or extend to must support ntor */
+ if (!node_has_curve25519_onion_key(node)) {
+ log_fn(LOG_PROTOCOL_WARN, LD_CIRC,
+ "Attempted to create extend_info for a node that does not support "
+ "ntor: %s", node_describe(node));
+ return NULL;
+ }
+
+ const ed25519_public_key_t *ed_pubkey = NULL;
+
+ /* Don't send the ed25519 pubkey unless the target node actually supports
+ * authenticating with it. */
+ if (node_supports_ed25519_link_authentication(node, 0)) {
+ log_info(LD_CIRC, "Including Ed25519 ID for %s", node_describe(node));
+ ed_pubkey = node_get_ed25519_id(node);
+ } else if (node_get_ed25519_id(node)) {
+ log_info(LD_CIRC, "Not including the ed25519 ID for %s, since it won't "
+ "be able to authenticate it.",
+ node_describe(node));
+ }
+
+ /* Retrieve the curve25519 pubkey. */
+ const curve25519_public_key_t *curve_pubkey =
+ node_get_curve25519_onion_key(node);
+
+ if (valid_addr && node->ri)
+ return extend_info_new(node->ri->nickname,
+ node->identity,
+ ed_pubkey,
+ node->ri->onion_pkey,
+ curve_pubkey,
+ &ap.addr,
+ ap.port);
+ else if (valid_addr && node->rs && node->md)
+ return extend_info_new(node->rs->nickname,
+ node->identity,
+ ed_pubkey,
+ node->md->onion_pkey,
+ curve_pubkey,
+ &ap.addr,
+ ap.port);
+ else
+ return NULL;
+}
+
+/** Release storage held by an extend_info_t struct. */
+void
+extend_info_free_(extend_info_t *info)
+{
+ if (!info)
+ return;
+ crypto_pk_free(info->onion_key);
+ tor_free(info);
+}
+
+/** Allocate and return a new extend_info_t with the same contents as
+ * <b>info</b>. */
+extend_info_t *
+extend_info_dup(extend_info_t *info)
+{
+ extend_info_t *newinfo;
+ tor_assert(info);
+ newinfo = tor_malloc(sizeof(extend_info_t));
+ memcpy(newinfo, info, sizeof(extend_info_t));
+ if (info->onion_key)
+ newinfo->onion_key = crypto_pk_dup_key(info->onion_key);
+ else
+ newinfo->onion_key = NULL;
+ return newinfo;
+}
+
+/** Return the node_t for the chosen exit router in <b>state</b>.
+ * If there is no chosen exit, or if we don't know the node_t for
+ * the chosen exit, return NULL.
+ */
+const node_t *
+build_state_get_exit_node(cpath_build_state_t *state)
+{
+ if (!state || !state->chosen_exit)
+ return NULL;
+ return node_get_by_id(state->chosen_exit->identity_digest);
+}
+
+/** Return the RSA ID digest for the chosen exit router in <b>state</b>.
+ * If there is no chosen exit, return NULL.
+ */
+const uint8_t *
+build_state_get_exit_rsa_id(cpath_build_state_t *state)
+{
+ if (!state || !state->chosen_exit)
+ return NULL;
+ return (const uint8_t *) state->chosen_exit->identity_digest;
+}
+
+/** Return the nickname for the chosen exit router in <b>state</b>. If
+ * there is no chosen exit, or if we don't know the routerinfo_t for the
+ * chosen exit, return NULL.
+ */
+const char *
+build_state_get_exit_nickname(cpath_build_state_t *state)
+{
+ if (!state || !state->chosen_exit)
+ return NULL;
+ return state->chosen_exit->nickname;
+}
+
+/** Return true iff the given address can be used to extend to. */
+int
+extend_info_addr_is_allowed(const tor_addr_t *addr)
+{
+ tor_assert(addr);
+
+ /* Check if we have a private address and if we can extend to it. */
+ if ((tor_addr_is_internal(addr, 0) || tor_addr_is_multicast(addr)) &&
+ !get_options()->ExtendAllowPrivateAddresses) {
+ goto disallow;
+ }
+ /* Allowed! */
+ return 1;
+ disallow:
+ return 0;
+}
+
+/* Does ei have a valid TAP key? */
+int
+extend_info_supports_tap(const extend_info_t* ei)
+{
+ tor_assert(ei);
+ /* Valid TAP keys are not NULL */
+ return ei->onion_key != NULL;
+}
+
+/* Does ei have a valid ntor key? */
+int
+extend_info_supports_ntor(const extend_info_t* ei)
+{
+ tor_assert(ei);
+ /* Valid ntor keys have at least one non-zero byte */
+ return !tor_mem_is_zero(
+ (const char*)ei->curve25519_onion_key.public_key,
+ CURVE25519_PUBKEY_LEN);
+}
+
+/* Is circuit purpose allowed to use the deprecated TAP encryption protocol?
+ * The hidden service protocol still uses TAP for some connections, because
+ * ntor onion keys aren't included in HS descriptors or INTRODUCE cells. */
+static int
+circuit_purpose_can_use_tap_impl(uint8_t purpose)
+{
+ return (purpose == CIRCUIT_PURPOSE_S_CONNECT_REND ||
+ purpose == CIRCUIT_PURPOSE_C_INTRODUCING);
+}
+
+/* Is circ allowed to use the deprecated TAP encryption protocol?
+ * The hidden service protocol still uses TAP for some connections, because
+ * ntor onion keys aren't included in HS descriptors or INTRODUCE cells. */
+int
+circuit_can_use_tap(const origin_circuit_t *circ)
+{
+ tor_assert(circ);
+ tor_assert(circ->cpath);
+ tor_assert(circ->cpath->extend_info);
+ return (circuit_purpose_can_use_tap_impl(circ->base_.purpose) &&
+ extend_info_supports_tap(circ->cpath->extend_info));
+}
+
+/* Does circ have an onion key which it's allowed to use? */
+int
+circuit_has_usable_onion_key(const origin_circuit_t *circ)
+{
+ tor_assert(circ);
+ tor_assert(circ->cpath);
+ tor_assert(circ->cpath->extend_info);
+ return (extend_info_supports_ntor(circ->cpath->extend_info) ||
+ circuit_can_use_tap(circ));
+}
+
+/* Does ei have an onion key which it would prefer to use?
+ * Currently, we prefer ntor keys*/
+int
+extend_info_has_preferred_onion_key(const extend_info_t* ei)
+{
+ tor_assert(ei);
+ return extend_info_supports_ntor(ei);
+}
+
+/** Find the circuits that are waiting to find out whether their guards are
+ * usable, and if any are ready to become usable, mark them open and try
+ * attaching streams as appropriate. */
+void
+circuit_upgrade_circuits_from_guard_wait(void)
+{
+ smartlist_t *to_upgrade =
+ circuit_find_circuits_to_upgrade_from_guard_wait();
+
+ if (to_upgrade == NULL)
+ return;
+
+ log_info(LD_GUARD, "Upgrading %d circuits from 'waiting for better guard' "
+ "to 'open'.", smartlist_len(to_upgrade));
+
+ SMARTLIST_FOREACH_BEGIN(to_upgrade, origin_circuit_t *, circ) {
+ circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_OPEN);
+ circuit_has_opened(circ);
+ } SMARTLIST_FOREACH_END(circ);
+
+ smartlist_free(to_upgrade);
+}
+
diff --cc src/core/or/circuitbuild.h
index 0c6f2f6ce,000000000..cee71b297
mode 100644,000000..100644
--- a/src/core/or/circuitbuild.h
+++ b/src/core/or/circuitbuild.h
@@@ -1,103 -1,0 +1,102 @@@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file circuitbuild.h
+ * \brief Header file for circuitbuild.c.
+ **/
+
+#ifndef TOR_CIRCUITBUILD_H
+#define TOR_CIRCUITBUILD_H
+
+struct ed25519_public_key_t;
+struct curve25519_public_key_t;
+
+int route_len_for_purpose(uint8_t purpose, extend_info_t *exit_ei);
+char *circuit_list_path(origin_circuit_t *circ, int verbose);
+char *circuit_list_path_for_controller(origin_circuit_t *circ);
+void circuit_log_path(int severity, unsigned int domain,
+ origin_circuit_t *circ);
+origin_circuit_t *origin_circuit_init(uint8_t purpose, int flags);
+origin_circuit_t *circuit_establish_circuit(uint8_t purpose,
+ extend_info_t *exit,
+ int flags);
+struct circuit_guard_state_t *origin_circuit_get_guard_state(
+ origin_circuit_t *circ);
+int circuit_handle_first_hop(origin_circuit_t *circ);
+void circuit_n_chan_done(channel_t *chan, int status,
+ int close_origin_circuits);
+int inform_testing_reachability(void);
+int circuit_timeout_want_to_count_circ(const origin_circuit_t *circ);
+int circuit_send_next_onion_skin(origin_circuit_t *circ);
+void circuit_note_clock_jumped(int64_t seconds_elapsed, bool was_idle);
+int circuit_extend(cell_t *cell, circuit_t *circ);
+int circuit_init_cpath_crypto(crypt_path_t *cpath,
+ const char *key_data, size_t key_data_len,
+ int reverse, int is_hs_v3);
+struct created_cell_t;
+int circuit_finish_handshake(origin_circuit_t *circ,
+ const struct created_cell_t *created_cell);
- int circuit_truncated(origin_circuit_t *circ, crypt_path_t *layer,
- int reason);
++int circuit_truncated(origin_circuit_t *circ, int reason);
+int onionskin_answer(or_circuit_t *circ,
+ const struct created_cell_t *created_cell,
+ const char *keys, size_t keys_len,
+ const uint8_t *rend_circ_nonce);
+MOCK_DECL(int, circuit_all_predicted_ports_handled, (time_t now,
+ int *need_uptime,
+ int *need_capacity));
+
+int circuit_append_new_exit(origin_circuit_t *circ, extend_info_t *info);
+int circuit_extend_to_new_exit(origin_circuit_t *circ, extend_info_t *info);
+void onion_append_to_cpath(crypt_path_t **head_ptr, crypt_path_t *new_hop);
+extend_info_t *extend_info_new(const char *nickname,
+ const char *rsa_id_digest,
+ const struct ed25519_public_key_t *ed_id,
+ crypto_pk_t *onion_key,
+ const struct curve25519_public_key_t *ntor_key,
+ const tor_addr_t *addr, uint16_t port);
+extend_info_t *extend_info_from_node(const node_t *r, int for_direct_connect);
+extend_info_t *extend_info_dup(extend_info_t *info);
+void extend_info_free_(extend_info_t *info);
+#define extend_info_free(info) \
+ FREE_AND_NULL(extend_info_t, extend_info_free_, (info))
+int extend_info_addr_is_allowed(const tor_addr_t *addr);
+int extend_info_supports_tap(const extend_info_t* ei);
+int extend_info_supports_ntor(const extend_info_t* ei);
+int circuit_can_use_tap(const origin_circuit_t *circ);
+int circuit_has_usable_onion_key(const origin_circuit_t *circ);
+int extend_info_has_preferred_onion_key(const extend_info_t* ei);
+const uint8_t *build_state_get_exit_rsa_id(cpath_build_state_t *state);
+const node_t *build_state_get_exit_node(cpath_build_state_t *state);
+const char *build_state_get_exit_nickname(cpath_build_state_t *state);
+
+struct circuit_guard_state_t;
+
+const node_t *choose_good_entry_server(uint8_t purpose,
+ cpath_build_state_t *state,
+ struct circuit_guard_state_t **guard_state_out);
+void circuit_upgrade_circuits_from_guard_wait(void);
+
+#ifdef CIRCUITBUILD_PRIVATE
+STATIC circid_t get_unique_circ_id_by_chan(channel_t *chan);
+STATIC int new_route_len(uint8_t purpose, extend_info_t *exit_ei,
+ smartlist_t *nodes);
+MOCK_DECL(STATIC int, count_acceptable_nodes, (smartlist_t *nodes));
+
+STATIC int onion_extend_cpath(origin_circuit_t *circ);
+
+STATIC int
+onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit_ei,
+ int is_hs_v3_rp_circuit);
+
+#if defined(TOR_UNIT_TESTS)
+unsigned int cpath_get_n_hops(crypt_path_t **head_ptr);
+
+#endif /* defined(TOR_UNIT_TESTS) */
+
+#endif /* defined(CIRCUITBUILD_PRIVATE) */
+
+#endif /* !defined(TOR_CIRCUITBUILD_H) */
diff --cc src/core/or/circuitlist.c
index f39e05ecd,000000000..78ecadab7
mode 100644,000000..100644
--- a/src/core/or/circuitlist.c
+++ b/src/core/or/circuitlist.c
@@@ -1,2742 -1,0 +1,2751 @@@
+/* Copyright 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file circuitlist.c
+ *
+ * \brief Manage global structures that list and index circuits, and
+ * look up circuits within them.
+ *
+ * One of the most frequent operations in Tor occurs every time that
+ * a relay cell arrives on a channel. When that happens, we need to
+ * find which circuit it is associated with, based on the channel and the
+ * circuit ID in the relay cell.
+ *
+ * To handle that, we maintain a global list of circuits, and a hashtable
+ * mapping [channel,circID] pairs to circuits. Circuits are added to and
+ * removed from this mapping using circuit_set_p_circid_chan() and
+ * circuit_set_n_circid_chan(). To look up a circuit from this map, most
+ * callers should use circuit_get_by_circid_channel(), though
+ * circuit_get_by_circid_channel_even_if_marked() is appropriate under some
+ * circumstances.
+ *
+ * We also need to allow for the possibility that we have blocked use of a
+ * circuit ID (because we are waiting to send a DESTROY cell), but the
+ * circuit is not there any more. For that case, we allow placeholder
+ * entries in the table, using channel_mark_circid_unusable().
+ *
+ * To efficiently handle a channel that has just opened, we also maintain a
+ * list of the circuits waiting for channels, so we can attach them as
+ * needed without iterating through the whole list of circuits, using
+ * circuit_get_all_pending_on_channel().
+ *
+ * In this module, we also handle the list of circuits that have been
+ * marked for close elsewhere, and close them as needed. (We use this
+ * "mark now, close later" pattern here and elsewhere to avoid
+ * unpredictable recursion if we closed every circuit immediately upon
+ * realizing it needed to close.) See circuit_mark_for_close() for the
+ * mark function, and circuit_close_all_marked() for the close function.
+ *
+ * For hidden services, we need to be able to look up introduction point
+ * circuits and rendezvous circuits by cookie, key, etc. These are
+ * currently handled with linear searches in
+ * circuit_get_ready_rend_circuit_by_rend_data(),
+ * circuit_get_next_by_pk_and_purpose(), and with hash lookups in
+ * circuit_get_rendezvous() and circuit_get_intro_point().
+ *
+ * This module is also the entry point for our out-of-memory handler
+ * logic, which was originally circuit-focused.
+ **/
+#define CIRCUITLIST_PRIVATE
+#include "lib/cc/torint.h" /* TOR_PRIuSZ */
+
+#include "core/or/or.h"
+#include "core/or/channel.h"
+#include "feature/client/circpathbias.h"
+#include "core/or/circuitbuild.h"
+#include "core/or/circuitlist.h"
+#include "core/or/circuituse.h"
+#include "core/or/circuitstats.h"
+#include "core/mainloop/connection.h"
+#include "app/config/config.h"
+#include "core/or/connection_edge.h"
+#include "core/or/connection_or.h"
+#include "feature/control/control.h"
+#include "lib/crypt_ops/crypto_rand.h"
+#include "lib/crypt_ops/crypto_util.h"
+#include "lib/crypt_ops/crypto_dh.h"
+#include "feature/dircache/directory.h"
+#include "feature/client/entrynodes.h"
+#include "core/mainloop/main.h"
+#include "feature/hs/hs_circuit.h"
+#include "feature/hs/hs_circuitmap.h"
+#include "feature/hs/hs_ident.h"
+#include "feature/nodelist/networkstatus.h"
+#include "feature/nodelist/nodelist.h"
+#include "core/crypto/onion.h"
+#include "core/crypto/onion_fast.h"
+#include "core/or/policies.h"
+#include "core/or/relay.h"
+#include "core/crypto/relay_crypto.h"
+#include "feature/rend/rendclient.h"
+#include "feature/rend/rendcommon.h"
+#include "feature/stats/rephist.h"
+#include "feature/nodelist/routerlist.h"
+#include "feature/nodelist/routerset.h"
+#include "core/or/channelpadding.h"
+#include "lib/compress/compress.h"
+#include "lib/compress/compress_lzma.h"
+#include "lib/compress/compress_zlib.h"
+#include "lib/compress/compress_zstd.h"
+#include "lib/container/buffers.h"
+
+#include "ht.h"
+
+#include "core/or/cpath_build_state_st.h"
+#include "core/or/crypt_path_reference_st.h"
+#include "feature/dircommon/dir_connection_st.h"
+#include "core/or/edge_connection_st.h"
++#include "core/or/half_edge_st.h"
+#include "core/or/extend_info_st.h"
+#include "core/or/or_circuit_st.h"
+#include "core/or/origin_circuit_st.h"
+
+/********* START VARIABLES **********/
+
+/** A global list of all circuits at this hop. */
+static smartlist_t *global_circuitlist = NULL;
+
+/** A global list of all origin circuits. Every element of this is also
+ * an element of global_circuitlist. */
+static smartlist_t *global_origin_circuit_list = NULL;
+
+/** A list of all the circuits in CIRCUIT_STATE_CHAN_WAIT. */
+static smartlist_t *circuits_pending_chans = NULL;
+
+/** List of all the (origin) circuits whose state is
+ * CIRCUIT_STATE_GUARD_WAIT. */
+static smartlist_t *circuits_pending_other_guards = NULL;
+
+/** A list of all the circuits that have been marked with
+ * circuit_mark_for_close and which are waiting for circuit_about_to_free. */
+static smartlist_t *circuits_pending_close = NULL;
+
+static void circuit_free_cpath_node(crypt_path_t *victim);
+static void cpath_ref_decref(crypt_path_reference_t *cpath_ref);
+static void circuit_about_to_free_atexit(circuit_t *circ);
+static void circuit_about_to_free(circuit_t *circ);
+
+/**
+ * A cached value of the current state of the origin circuit list. Has the
+ * value 1 if we saw any opened circuits recently (since the last call to
+ * circuit_any_opened_circuits(), which gets called around once a second by
+ * circuit_expire_building). 0 otherwise.
+ */
+static int any_opened_circs_cached_val = 0;
+
+/********* END VARIABLES ************/
+
+or_circuit_t *
+TO_OR_CIRCUIT(circuit_t *x)
+{
+ tor_assert(x->magic == OR_CIRCUIT_MAGIC);
+ return DOWNCAST(or_circuit_t, x);
+}
+const or_circuit_t *
+CONST_TO_OR_CIRCUIT(const circuit_t *x)
+{
+ tor_assert(x->magic == OR_CIRCUIT_MAGIC);
+ return DOWNCAST(or_circuit_t, x);
+}
+origin_circuit_t *
+TO_ORIGIN_CIRCUIT(circuit_t *x)
+{
+ tor_assert(x->magic == ORIGIN_CIRCUIT_MAGIC);
+ return DOWNCAST(origin_circuit_t, x);
+}
+const origin_circuit_t *
+CONST_TO_ORIGIN_CIRCUIT(const circuit_t *x)
+{
+ tor_assert(x->magic == ORIGIN_CIRCUIT_MAGIC);
+ return DOWNCAST(origin_circuit_t, x);
+}
+
+/** A map from channel and circuit ID to circuit. (Lookup performance is
+ * very important here, since we need to do it every time a cell arrives.) */
+typedef struct chan_circid_circuit_map_t {
+ HT_ENTRY(chan_circid_circuit_map_t) node;
+ channel_t *chan;
+ circid_t circ_id;
+ circuit_t *circuit;
+ /* For debugging 12184: when was this placeholder item added? */
+ time_t made_placeholder_at;
+} chan_circid_circuit_map_t;
+
+/** Helper for hash tables: compare the channel and circuit ID for a and
+ * b, and return less than, equal to, or greater than zero appropriately.
+ */
+static inline int
+chan_circid_entries_eq_(chan_circid_circuit_map_t *a,
+ chan_circid_circuit_map_t *b)
+{
+ return a->chan == b->chan && a->circ_id == b->circ_id;
+}
+
+/** Helper: return a hash based on circuit ID and the pointer value of
+ * chan in <b>a</b>. */
+static inline unsigned int
+chan_circid_entry_hash_(chan_circid_circuit_map_t *a)
+{
+ /* Try to squeze the siphash input into 8 bytes to save any extra siphash
+ * rounds. This hash function is in the critical path. */
+ uintptr_t chan = (uintptr_t) (void*) a->chan;
+ uint32_t array[2];
+ array[0] = a->circ_id;
+ /* The low bits of the channel pointer are uninteresting, since the channel
+ * is a pretty big structure. */
+ array[1] = (uint32_t) (chan >> 6);
+ return (unsigned) siphash24g(array, sizeof(array));
+}
+
+/** Map from [chan,circid] to circuit. */
+static HT_HEAD(chan_circid_map, chan_circid_circuit_map_t)
+ chan_circid_map = HT_INITIALIZER();
+HT_PROTOTYPE(chan_circid_map, chan_circid_circuit_map_t, node,
+ chan_circid_entry_hash_, chan_circid_entries_eq_)
+HT_GENERATE2(chan_circid_map, chan_circid_circuit_map_t, node,
+ chan_circid_entry_hash_, chan_circid_entries_eq_, 0.6,
+ tor_reallocarray_, tor_free_)
+
+/** The most recently returned entry from circuit_get_by_circid_chan;
+ * used to improve performance when many cells arrive in a row from the
+ * same circuit.
+ */
+static chan_circid_circuit_map_t *_last_circid_chan_ent = NULL;
+
+/** Implementation helper for circuit_set_{p,n}_circid_channel: A circuit ID
+ * and/or channel for circ has just changed from <b>old_chan, old_id</b>
+ * to <b>chan, id</b>. Adjust the chan,circid map as appropriate, removing
+ * the old entry (if any) and adding a new one. */
+static void
+circuit_set_circid_chan_helper(circuit_t *circ, int direction,
+ circid_t id,
+ channel_t *chan)
+{
+ chan_circid_circuit_map_t search;
+ chan_circid_circuit_map_t *found;
+ channel_t *old_chan, **chan_ptr;
+ circid_t old_id, *circid_ptr;
+ int make_active, attached = 0;
+
+ if (direction == CELL_DIRECTION_OUT) {
+ chan_ptr = &circ->n_chan;
+ circid_ptr = &circ->n_circ_id;
+ make_active = circ->n_chan_cells.n > 0;
+ } else {
+ or_circuit_t *c = TO_OR_CIRCUIT(circ);
+ chan_ptr = &c->p_chan;
+ circid_ptr = &c->p_circ_id;
+ make_active = c->p_chan_cells.n > 0;
+ }
+ old_chan = *chan_ptr;
+ old_id = *circid_ptr;
+
+ if (id == old_id && chan == old_chan)
+ return;
+
+ if (_last_circid_chan_ent &&
+ ((old_id == _last_circid_chan_ent->circ_id &&
+ old_chan == _last_circid_chan_ent->chan) ||
+ (id == _last_circid_chan_ent->circ_id &&
+ chan == _last_circid_chan_ent->chan))) {
+ _last_circid_chan_ent = NULL;
+ }
+
+ if (old_chan) {
+ /*
+ * If we're changing channels or ID and had an old channel and a non
+ * zero old ID and weren't marked for close (i.e., we should have been
+ * attached), detach the circuit. ID changes require this because
+ * circuitmux hashes on (channel_id, circuit_id).
+ */
+ if (old_id != 0 && (old_chan != chan || old_id != id) &&
+ !(circ->marked_for_close)) {
+ tor_assert(old_chan->cmux);
+ circuitmux_detach_circuit(old_chan->cmux, circ);
+ }
+
+ /* we may need to remove it from the conn-circid map */
+ search.circ_id = old_id;
+ search.chan = old_chan;
+ found = HT_REMOVE(chan_circid_map, &chan_circid_map, &search);
+ if (found) {
+ tor_free(found);
+ if (direction == CELL_DIRECTION_OUT) {
+ /* One fewer circuits use old_chan as n_chan */
+ --(old_chan->num_n_circuits);
+ } else {
+ /* One fewer circuits use old_chan as p_chan */
+ --(old_chan->num_p_circuits);
+ }
+ }
+ }
+
+ /* Change the values only after we have possibly made the circuit inactive
+ * on the previous chan. */
+ *chan_ptr = chan;
+ *circid_ptr = id;
+
+ if (chan == NULL)
+ return;
+
+ /* now add the new one to the conn-circid map */
+ search.circ_id = id;
+ search.chan = chan;
+ found = HT_FIND(chan_circid_map, &chan_circid_map, &search);
+ if (found) {
+ found->circuit = circ;
+ found->made_placeholder_at = 0;
+ } else {
+ found = tor_malloc_zero(sizeof(chan_circid_circuit_map_t));
+ found->circ_id = id;
+ found->chan = chan;
+ found->circuit = circ;
+ HT_INSERT(chan_circid_map, &chan_circid_map, found);
+ }
+
+ /*
+ * Attach to the circuitmux if we're changing channels or IDs and
+ * have a new channel and ID to use and the circuit is not marked for
+ * close.
+ */
+ if (chan && id != 0 && (old_chan != chan || old_id != id) &&
+ !(circ->marked_for_close)) {
+ tor_assert(chan->cmux);
+ circuitmux_attach_circuit(chan->cmux, circ, direction);
+ attached = 1;
+ }
+
+ /*
+ * This is a no-op if we have no cells, but if we do it marks us active to
+ * the circuitmux
+ */
+ if (make_active && attached)
+ update_circuit_on_cmux(circ, direction);
+
+ /* Adjust circuit counts on new channel */
+ if (direction == CELL_DIRECTION_OUT) {
+ ++chan->num_n_circuits;
+ } else {
+ ++chan->num_p_circuits;
+ }
+}
+
+/** Mark that circuit id <b>id</b> shouldn't be used on channel <b>chan</b>,
+ * even if there is no circuit on the channel. We use this to keep the
+ * circuit id from getting re-used while we have queued but not yet sent
+ * a destroy cell. */
+void
+channel_mark_circid_unusable(channel_t *chan, circid_t id)
+{
+ chan_circid_circuit_map_t search;
+ chan_circid_circuit_map_t *ent;
+
+ /* See if there's an entry there. That wouldn't be good. */
+ memset(&search, 0, sizeof(search));
+ search.chan = chan;
+ search.circ_id = id;
+ ent = HT_FIND(chan_circid_map, &chan_circid_map, &search);
+
+ if (ent && ent->circuit) {
+ /* we have a problem. */
+ log_warn(LD_BUG, "Tried to mark %u unusable on %p, but there was already "
+ "a circuit there.", (unsigned)id, chan);
+ } else if (ent) {
+ /* It's already marked. */
+ if (!ent->made_placeholder_at)
+ ent->made_placeholder_at = approx_time();
+ } else {
+ ent = tor_malloc_zero(sizeof(chan_circid_circuit_map_t));
+ ent->chan = chan;
+ ent->circ_id = id;
+ /* leave circuit at NULL. */
+ ent->made_placeholder_at = approx_time();
+ HT_INSERT(chan_circid_map, &chan_circid_map, ent);
+ }
+}
+
+/** Mark that a circuit id <b>id</b> can be used again on <b>chan</b>.
+ * We use this to re-enable the circuit ID after we've sent a destroy cell.
+ */
+void
+channel_mark_circid_usable(channel_t *chan, circid_t id)
+{
+ chan_circid_circuit_map_t search;
+ chan_circid_circuit_map_t *ent;
+
+ /* See if there's an entry there. That wouldn't be good. */
+ memset(&search, 0, sizeof(search));
+ search.chan = chan;
+ search.circ_id = id;
+ ent = HT_REMOVE(chan_circid_map, &chan_circid_map, &search);
+ if (ent && ent->circuit) {
+ log_warn(LD_BUG, "Tried to mark %u usable on %p, but there was already "
+ "a circuit there.", (unsigned)id, chan);
+ return;
+ }
+ if (_last_circid_chan_ent == ent)
+ _last_circid_chan_ent = NULL;
+ tor_free(ent);
+}
+
+/** Called to indicate that a DESTROY is pending on <b>chan</b> with
+ * circuit ID <b>id</b>, but hasn't been sent yet. */
+void
+channel_note_destroy_pending(channel_t *chan, circid_t id)
+{
+ circuit_t *circ = circuit_get_by_circid_channel_even_if_marked(id,chan);
+ if (circ) {
+ if (circ->n_chan == chan && circ->n_circ_id == id) {
+ circ->n_delete_pending = 1;
+ } else {
+ or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
+ if (orcirc->p_chan == chan && orcirc->p_circ_id == id) {
+ circ->p_delete_pending = 1;
+ }
+ }
+ return;
+ }
+ channel_mark_circid_unusable(chan, id);
+}
+
+/** Called to indicate that a DESTROY is no longer pending on <b>chan</b> with
+ * circuit ID <b>id</b> -- typically, because it has been sent. */
+MOCK_IMPL(void,
+channel_note_destroy_not_pending,(channel_t *chan, circid_t id))
+{
+ circuit_t *circ = circuit_get_by_circid_channel_even_if_marked(id,chan);
+ if (circ) {
+ if (circ->n_chan == chan && circ->n_circ_id == id) {
+ circ->n_delete_pending = 0;
+ } else {
+ or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
+ if (orcirc->p_chan == chan && orcirc->p_circ_id == id) {
+ circ->p_delete_pending = 0;
+ }
+ }
+ /* XXXX this shouldn't happen; log a bug here. */
+ return;
+ }
+ channel_mark_circid_usable(chan, id);
+}
+
+/** Set the p_conn field of a circuit <b>circ</b>, along
+ * with the corresponding circuit ID, and add the circuit as appropriate
+ * to the (chan,id)-\>circuit map. */
+void
+circuit_set_p_circid_chan(or_circuit_t *or_circ, circid_t id,
+ channel_t *chan)
+{
+ circuit_t *circ = TO_CIRCUIT(or_circ);
+ channel_t *old_chan = or_circ->p_chan;
+ circid_t old_id = or_circ->p_circ_id;
+
+ circuit_set_circid_chan_helper(circ, CELL_DIRECTION_IN, id, chan);
+
+ if (chan) {
+ chan->timestamp_last_had_circuits = approx_time();
+ }
+
+ if (circ->p_delete_pending && old_chan) {
+ channel_mark_circid_unusable(old_chan, old_id);
+ circ->p_delete_pending = 0;
+ }
+}
+
+/** Set the n_conn field of a circuit <b>circ</b>, along
+ * with the corresponding circuit ID, and add the circuit as appropriate
+ * to the (chan,id)-\>circuit map. */
+void
+circuit_set_n_circid_chan(circuit_t *circ, circid_t id,
+ channel_t *chan)
+{
+ channel_t *old_chan = circ->n_chan;
+ circid_t old_id = circ->n_circ_id;
+
+ circuit_set_circid_chan_helper(circ, CELL_DIRECTION_OUT, id, chan);
+
+ if (chan) {
+ chan->timestamp_last_had_circuits = approx_time();
+ }
+
+ if (circ->n_delete_pending && old_chan) {
+ channel_mark_circid_unusable(old_chan, old_id);
+ circ->n_delete_pending = 0;
+ }
+}
+
+/** Change the state of <b>circ</b> to <b>state</b>, adding it to or removing
+ * it from lists as appropriate. */
+void
+circuit_set_state(circuit_t *circ, uint8_t state)
+{
+ tor_assert(circ);
+ if (state == circ->state)
+ return;
+ if (PREDICT_UNLIKELY(!circuits_pending_chans))
+ circuits_pending_chans = smartlist_new();
+ if (PREDICT_UNLIKELY(!circuits_pending_other_guards))
+ circuits_pending_other_guards = smartlist_new();
+ if (circ->state == CIRCUIT_STATE_CHAN_WAIT) {
+ /* remove from waiting-circuit list. */
+ smartlist_remove(circuits_pending_chans, circ);
+ }
+ if (state == CIRCUIT_STATE_CHAN_WAIT) {
+ /* add to waiting-circuit list. */
+ smartlist_add(circuits_pending_chans, circ);
+ }
+ if (circ->state == CIRCUIT_STATE_GUARD_WAIT) {
+ smartlist_remove(circuits_pending_other_guards, circ);
+ }
+ if (state == CIRCUIT_STATE_GUARD_WAIT) {
+ smartlist_add(circuits_pending_other_guards, circ);
+ }
+ if (state == CIRCUIT_STATE_GUARD_WAIT || state == CIRCUIT_STATE_OPEN)
+ tor_assert(!circ->n_chan_create_cell);
+ circ->state = state;
+}
+
+/** Append to <b>out</b> all circuits in state CHAN_WAIT waiting for
+ * the given connection. */
+void
+circuit_get_all_pending_on_channel(smartlist_t *out, channel_t *chan)
+{
+ tor_assert(out);
+ tor_assert(chan);
+
+ if (!circuits_pending_chans)
+ return;
+
+ SMARTLIST_FOREACH_BEGIN(circuits_pending_chans, circuit_t *, circ) {
+ if (circ->marked_for_close)
+ continue;
+ if (!circ->n_hop)
+ continue;
+ tor_assert(circ->state == CIRCUIT_STATE_CHAN_WAIT);
+ if (tor_digest_is_zero(circ->n_hop->identity_digest)) {
+ /* Look at addr/port. This is an unkeyed connection. */
+ if (!channel_matches_extend_info(chan, circ->n_hop))
+ continue;
+ } else {
+ /* We expected a key. See if it's the right one. */
+ if (tor_memneq(chan->identity_digest,
+ circ->n_hop->identity_digest, DIGEST_LEN))
+ continue;
+ }
+ smartlist_add(out, circ);
+ } SMARTLIST_FOREACH_END(circ);
+}
+
+/** Return the number of circuits in state CHAN_WAIT, waiting for the given
+ * channel. */
+int
+circuit_count_pending_on_channel(channel_t *chan)
+{
+ int cnt;
+ smartlist_t *sl = smartlist_new();
+
+ tor_assert(chan);
+
+ circuit_get_all_pending_on_channel(sl, chan);
+ cnt = smartlist_len(sl);
+ smartlist_free(sl);
+ log_debug(LD_CIRC,"or_conn to %s, %d pending circs",
+ channel_get_canonical_remote_descr(chan),
+ cnt);
+ return cnt;
+}
+
+/** Remove <b>origin_circ</b> from the global list of origin circuits.
+ * Called when we are freeing a circuit.
+ */
+static void
+circuit_remove_from_origin_circuit_list(origin_circuit_t *origin_circ)
+{
+ int origin_idx = origin_circ->global_origin_circuit_list_idx;
+ if (origin_idx < 0)
+ return;
+ origin_circuit_t *c2;
+ tor_assert(origin_idx <= smartlist_len(global_origin_circuit_list));
+ c2 = smartlist_get(global_origin_circuit_list, origin_idx);
+ tor_assert(origin_circ == c2);
+ smartlist_del(global_origin_circuit_list, origin_idx);
+ if (origin_idx < smartlist_len(global_origin_circuit_list)) {
+ origin_circuit_t *replacement =
+ smartlist_get(global_origin_circuit_list, origin_idx);
+ replacement->global_origin_circuit_list_idx = origin_idx;
+ }
+ origin_circ->global_origin_circuit_list_idx = -1;
+}
+
+/** Add <b>origin_circ</b> to the global list of origin circuits. Called
+ * when creating the circuit. */
+static void
+circuit_add_to_origin_circuit_list(origin_circuit_t *origin_circ)
+{
+ tor_assert(origin_circ->global_origin_circuit_list_idx == -1);
+ smartlist_t *lst = circuit_get_global_origin_circuit_list();
+ smartlist_add(lst, origin_circ);
+ origin_circ->global_origin_circuit_list_idx = smartlist_len(lst) - 1;
+}
+
+/** Detach from the global circuit list, and deallocate, all
+ * circuits that have been marked for close.
+ */
+void
+circuit_close_all_marked(void)
+{
+ if (circuits_pending_close == NULL)
+ return;
+
+ smartlist_t *lst = circuit_get_global_list();
+ SMARTLIST_FOREACH_BEGIN(circuits_pending_close, circuit_t *, circ) {
+ tor_assert(circ->marked_for_close);
+
+ /* Remove it from the circuit list. */
+ int idx = circ->global_circuitlist_idx;
+ smartlist_del(lst, idx);
+ if (idx < smartlist_len(lst)) {
+ circuit_t *replacement = smartlist_get(lst, idx);
+ replacement->global_circuitlist_idx = idx;
+ }
+ circ->global_circuitlist_idx = -1;
+
+ /* Remove it from the origin circuit list, if appropriate. */
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ circuit_remove_from_origin_circuit_list(TO_ORIGIN_CIRCUIT(circ));
+ }
+
+ circuit_about_to_free(circ);
+ circuit_free(circ);
+ } SMARTLIST_FOREACH_END(circ);
+
+ smartlist_clear(circuits_pending_close);
+}
+
+/** Return a pointer to the global list of circuits. */
+MOCK_IMPL(smartlist_t *,
+circuit_get_global_list,(void))
+{
+ if (NULL == global_circuitlist)
+ global_circuitlist = smartlist_new();
+ return global_circuitlist;
+}
+
+/** Return a pointer to the global list of origin circuits. */
+smartlist_t *
+circuit_get_global_origin_circuit_list(void)
+{
+ if (NULL == global_origin_circuit_list)
+ global_origin_circuit_list = smartlist_new();
+ return global_origin_circuit_list;
+}
+
+/**
+ * Return true if we have any opened general-purpose 3 hop
+ * origin circuits.
+ *
+ * The result from this function is cached for use by
+ * circuit_any_opened_circuits_cached().
+ */
+int
+circuit_any_opened_circuits(void)
+{
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_origin_circuit_list(),
+ const origin_circuit_t *, next_circ) {
+ if (!TO_CIRCUIT(next_circ)->marked_for_close &&
+ next_circ->has_opened &&
+ TO_CIRCUIT(next_circ)->state == CIRCUIT_STATE_OPEN &&
+ TO_CIRCUIT(next_circ)->purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT &&
+ next_circ->build_state &&
+ next_circ->build_state->desired_path_len == DEFAULT_ROUTE_LEN) {
+ circuit_cache_opened_circuit_state(1);
+ return 1;
+ }
+ } SMARTLIST_FOREACH_END(next_circ);
+
+ circuit_cache_opened_circuit_state(0);
+ return 0;
+}
+
+/**
+ * Cache the "any circuits opened" state, as specified in param
+ * circuits_are_opened. This is a helper function to update
+ * the circuit opened status whenever we happen to look at the
+ * circuit list.
+ */
+void
+circuit_cache_opened_circuit_state(int circuits_are_opened)
+{
+ any_opened_circs_cached_val = circuits_are_opened;
+}
+
+/**
+ * Return true if there were any opened circuits since the last call to
+ * circuit_any_opened_circuits(), or since circuit_expire_building() last
+ * ran (it runs roughly once per second).
+ */
+int
+circuit_any_opened_circuits_cached(void)
+{
+ return any_opened_circs_cached_val;
+}
+
+/** Function to make circ-\>state human-readable */
+const char *
+circuit_state_to_string(int state)
+{
+ static char buf[64];
+ switch (state) {
+ case CIRCUIT_STATE_BUILDING: return "doing handshakes";
+ case CIRCUIT_STATE_ONIONSKIN_PENDING: return "processing the onion";
+ case CIRCUIT_STATE_CHAN_WAIT: return "connecting to server";
+ case CIRCUIT_STATE_GUARD_WAIT: return "waiting to see how other "
+ "guards perform";
+ case CIRCUIT_STATE_OPEN: return "open";
+ default:
+ log_warn(LD_BUG, "Unknown circuit state %d", state);
+ tor_snprintf(buf, sizeof(buf), "unknown state [%d]", state);
+ return buf;
+ }
+}
+
+/** Map a circuit purpose to a string suitable to be displayed to a
+ * controller. */
+const char *
+circuit_purpose_to_controller_string(uint8_t purpose)
+{
+ static char buf[32];
+ switch (purpose) {
+ case CIRCUIT_PURPOSE_OR:
+ case CIRCUIT_PURPOSE_INTRO_POINT:
+ case CIRCUIT_PURPOSE_REND_POINT_WAITING:
+ case CIRCUIT_PURPOSE_REND_ESTABLISHED:
+ return "SERVER"; /* A controller should never see these, actually. */
+
+ case CIRCUIT_PURPOSE_C_GENERAL:
+ return "GENERAL";
+
+ case CIRCUIT_PURPOSE_C_HSDIR_GET:
+ return "HS_CLIENT_HSDIR";
+
+ case CIRCUIT_PURPOSE_C_INTRODUCING:
+ case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
+ case CIRCUIT_PURPOSE_C_INTRODUCE_ACKED:
+ return "HS_CLIENT_INTRO";
+
+ case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
+ case CIRCUIT_PURPOSE_C_REND_READY:
+ case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED:
+ case CIRCUIT_PURPOSE_C_REND_JOINED:
+ return "HS_CLIENT_REND";
+
+ case CIRCUIT_PURPOSE_S_HSDIR_POST:
+ return "HS_SERVICE_HSDIR";
+
+ case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
+ case CIRCUIT_PURPOSE_S_INTRO:
+ return "HS_SERVICE_INTRO";
+
+ case CIRCUIT_PURPOSE_S_CONNECT_REND:
+ case CIRCUIT_PURPOSE_S_REND_JOINED:
+ return "HS_SERVICE_REND";
+
+ case CIRCUIT_PURPOSE_TESTING:
+ return "TESTING";
+ case CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT:
+ return "MEASURE_TIMEOUT";
+ case CIRCUIT_PURPOSE_CONTROLLER:
+ return "CONTROLLER";
+ case CIRCUIT_PURPOSE_PATH_BIAS_TESTING:
+ return "PATH_BIAS_TESTING";
+ case CIRCUIT_PURPOSE_HS_VANGUARDS:
+ return "HS_VANGUARDS";
+
+ default:
+ tor_snprintf(buf, sizeof(buf), "UNKNOWN_%d", (int)purpose);
+ return buf;
+ }
+}
+
+/** Return a string specifying the state of the hidden-service circuit
+ * purpose <b>purpose</b>, or NULL if <b>purpose</b> is not a
+ * hidden-service-related circuit purpose. */
+const char *
+circuit_purpose_to_controller_hs_state_string(uint8_t purpose)
+{
+ switch (purpose)
+ {
+ default:
+ log_fn(LOG_WARN, LD_BUG,
+ "Unrecognized circuit purpose: %d",
+ (int)purpose);
+ tor_fragile_assert();
+ /* fall through */
+
+ case CIRCUIT_PURPOSE_OR:
+ case CIRCUIT_PURPOSE_C_GENERAL:
+ case CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT:
+ case CIRCUIT_PURPOSE_TESTING:
+ case CIRCUIT_PURPOSE_CONTROLLER:
+ case CIRCUIT_PURPOSE_PATH_BIAS_TESTING:
+ case CIRCUIT_PURPOSE_HS_VANGUARDS:
+ return NULL;
+
+ case CIRCUIT_PURPOSE_INTRO_POINT:
+ return "OR_HSSI_ESTABLISHED";
+ case CIRCUIT_PURPOSE_REND_POINT_WAITING:
+ return "OR_HSCR_ESTABLISHED";
+ case CIRCUIT_PURPOSE_REND_ESTABLISHED:
+ return "OR_HS_R_JOINED";
+
+ case CIRCUIT_PURPOSE_C_HSDIR_GET:
+ case CIRCUIT_PURPOSE_C_INTRODUCING:
+ return "HSCI_CONNECTING";
+ case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
+ return "HSCI_INTRO_SENT";
+ case CIRCUIT_PURPOSE_C_INTRODUCE_ACKED:
+ return "HSCI_DONE";
+
+ case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
+ return "HSCR_CONNECTING";
+ case CIRCUIT_PURPOSE_C_REND_READY:
+ return "HSCR_ESTABLISHED_IDLE";
+ case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED:
+ return "HSCR_ESTABLISHED_WAITING";
+ case CIRCUIT_PURPOSE_C_REND_JOINED:
+ return "HSCR_JOINED";
+
+ case CIRCUIT_PURPOSE_S_HSDIR_POST:
+ case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
+ return "HSSI_CONNECTING";
+ case CIRCUIT_PURPOSE_S_INTRO:
+ return "HSSI_ESTABLISHED";
+
+ case CIRCUIT_PURPOSE_S_CONNECT_REND:
+ return "HSSR_CONNECTING";
+ case CIRCUIT_PURPOSE_S_REND_JOINED:
+ return "HSSR_JOINED";
+ }
+}
+
+/** Return a human-readable string for the circuit purpose <b>purpose</b>. */
+const char *
+circuit_purpose_to_string(uint8_t purpose)
+{
+ static char buf[32];
+
+ switch (purpose)
+ {
+ case CIRCUIT_PURPOSE_OR:
+ return "Circuit at relay";
+ case CIRCUIT_PURPOSE_INTRO_POINT:
+ return "Acting as intro point";
+ case CIRCUIT_PURPOSE_REND_POINT_WAITING:
+ return "Acting as rendezvous (pending)";
+ case CIRCUIT_PURPOSE_REND_ESTABLISHED:
+ return "Acting as rendezvous (established)";
+ case CIRCUIT_PURPOSE_C_GENERAL:
+ return "General-purpose client";
+ case CIRCUIT_PURPOSE_C_INTRODUCING:
+ return "Hidden service client: Connecting to intro point";
+ case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
+ return "Hidden service client: Waiting for ack from intro point";
+ case CIRCUIT_PURPOSE_C_INTRODUCE_ACKED:
+ return "Hidden service client: Received ack from intro point";
+ case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
+ return "Hidden service client: Establishing rendezvous point";
+ case CIRCUIT_PURPOSE_C_REND_READY:
+ return "Hidden service client: Pending rendezvous point";
+ case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED:
+ return "Hidden service client: Pending rendezvous point (ack received)";
+ case CIRCUIT_PURPOSE_C_REND_JOINED:
+ return "Hidden service client: Active rendezvous point";
+ case CIRCUIT_PURPOSE_C_HSDIR_GET:
+ return "Hidden service client: Fetching HS descriptor";
+
+ case CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT:
+ return "Measuring circuit timeout";
+
+ case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
+ return "Hidden service: Establishing introduction point";
+ case CIRCUIT_PURPOSE_S_INTRO:
+ return "Hidden service: Introduction point";
+ case CIRCUIT_PURPOSE_S_CONNECT_REND:
+ return "Hidden service: Connecting to rendezvous point";
+ case CIRCUIT_PURPOSE_S_REND_JOINED:
+ return "Hidden service: Active rendezvous point";
+ case CIRCUIT_PURPOSE_S_HSDIR_POST:
+ return "Hidden service: Uploading HS descriptor";
+
+ case CIRCUIT_PURPOSE_TESTING:
+ return "Testing circuit";
+
+ case CIRCUIT_PURPOSE_CONTROLLER:
+ return "Circuit made by controller";
+
+ case CIRCUIT_PURPOSE_PATH_BIAS_TESTING:
+ return "Path-bias testing circuit";
+
+ case CIRCUIT_PURPOSE_HS_VANGUARDS:
+ return "Hidden service: Pre-built vanguard circuit";
+
+ default:
+ tor_snprintf(buf, sizeof(buf), "UNKNOWN_%d", (int)purpose);
+ return buf;
+ }
+}
+
+/** Pick a reasonable package_window to start out for our circuits.
+ * Originally this was hard-coded at 1000, but now the consensus votes
+ * on the answer. See proposal 168. */
+int32_t
+circuit_initial_package_window(void)
+{
+ int32_t num = networkstatus_get_param(NULL, "circwindow", CIRCWINDOW_START,
+ CIRCWINDOW_START_MIN,
+ CIRCWINDOW_START_MAX);
+ /* If the consensus tells us a negative number, we'd assert. */
+ if (num < 0)
+ num = CIRCWINDOW_START;
+ return num;
+}
+
+/** Initialize the common elements in a circuit_t, and add it to the global
+ * list. */
+static void
+init_circuit_base(circuit_t *circ)
+{
+ tor_gettimeofday(&circ->timestamp_created);
+
+ // Gets reset when we send CREATE_FAST.
+ // circuit_expire_building() expects these to be equal
+ // until the orconn is built.
+ circ->timestamp_began = circ->timestamp_created;
+
+ circ->package_window = circuit_initial_package_window();
+ circ->deliver_window = CIRCWINDOW_START;
+ cell_queue_init(&circ->n_chan_cells);
+
+ smartlist_add(circuit_get_global_list(), circ);
+ circ->global_circuitlist_idx = smartlist_len(circuit_get_global_list()) - 1;
+}
+
+/** If we haven't yet decided on a good timeout value for circuit
+ * building, we close idle circuits aggressively so we can get more
+ * data points. These are the default, min, and max consensus values */
+#define DFLT_IDLE_TIMEOUT_WHILE_LEARNING (3*60)
+#define MIN_IDLE_TIMEOUT_WHILE_LEARNING (10)
+#define MAX_IDLE_TIMEOUT_WHILE_LEARNING (1000*60)
+
+/** Allocate space for a new circuit, initializing with <b>p_circ_id</b>
+ * and <b>p_conn</b>. Add it to the global circuit list.
+ */
+origin_circuit_t *
+origin_circuit_new(void)
+{
+ origin_circuit_t *circ;
+ /* never zero, since a global ID of 0 is treated specially by the
+ * controller */
+ static uint32_t n_circuits_allocated = 1;
+
+ circ = tor_malloc_zero(sizeof(origin_circuit_t));
+ circ->base_.magic = ORIGIN_CIRCUIT_MAGIC;
+
+ circ->next_stream_id = crypto_rand_int(1<<16);
+ circ->global_identifier = n_circuits_allocated++;
+ circ->remaining_relay_early_cells = MAX_RELAY_EARLY_CELLS_PER_CIRCUIT;
+ circ->remaining_relay_early_cells -= crypto_rand_int(2);
+
+ init_circuit_base(TO_CIRCUIT(circ));
+
+ /* Add to origin-list. */
+ circ->global_origin_circuit_list_idx = -1;
+ circuit_add_to_origin_circuit_list(circ);
+
+ circuit_build_times_update_last_circ(get_circuit_build_times_mutable());
+
+ if (! circuit_build_times_disabled(get_options()) &&
+ circuit_build_times_needs_circuits(get_circuit_build_times())) {
+ /* Circuits should be shorter lived if we need more of them
+ * for learning a good build timeout */
+ circ->circuit_idle_timeout =
+ networkstatus_get_param(NULL, "cbtlearntimeout",
+ DFLT_IDLE_TIMEOUT_WHILE_LEARNING,
+ MIN_IDLE_TIMEOUT_WHILE_LEARNING,
+ MAX_IDLE_TIMEOUT_WHILE_LEARNING);
+ } else {
+ // This should always be larger than the current port prediction time
+ // remaining, or else we'll end up with the case where a circuit times out
+ // and another one is built, effectively doubling the timeout window.
+ //
+ // We also randomize it by up to 5% more (ie 5% of 0 to 3600 seconds,
+ // depending on how much circuit prediction time is remaining) so that
+ // we don't close a bunch of unused circuits all at the same time.
+ int prediction_time_remaining =
+ predicted_ports_prediction_time_remaining(time(NULL));
+ circ->circuit_idle_timeout = prediction_time_remaining+1+
+ crypto_rand_int(1+prediction_time_remaining/20);
+
+ if (circ->circuit_idle_timeout <= 0) {
+ log_warn(LD_BUG,
+ "Circuit chose a negative idle timeout of %d based on "
+ "%d seconds of predictive building remaining.",
+ circ->circuit_idle_timeout,
+ prediction_time_remaining);
+ circ->circuit_idle_timeout =
+ networkstatus_get_param(NULL, "cbtlearntimeout",
+ DFLT_IDLE_TIMEOUT_WHILE_LEARNING,
+ MIN_IDLE_TIMEOUT_WHILE_LEARNING,
+ MAX_IDLE_TIMEOUT_WHILE_LEARNING);
+ }
+
+ log_info(LD_CIRC,
+ "Circuit %"PRIu32" chose an idle timeout of %d based on "
+ "%d seconds of predictive building remaining.",
+ (circ->global_identifier),
+ circ->circuit_idle_timeout,
+ prediction_time_remaining);
+ }
+
+ return circ;
+}
+
+/** Allocate a new or_circuit_t, connected to <b>p_chan</b> as
+ * <b>p_circ_id</b>. If <b>p_chan</b> is NULL, the circuit is unattached. */
+or_circuit_t *
+or_circuit_new(circid_t p_circ_id, channel_t *p_chan)
+{
+ /* CircIDs */
+ or_circuit_t *circ;
+
+ circ = tor_malloc_zero(sizeof(or_circuit_t));
+ circ->base_.magic = OR_CIRCUIT_MAGIC;
+
+ if (p_chan)
+ circuit_set_p_circid_chan(circ, p_circ_id, p_chan);
+
+ circ->remaining_relay_early_cells = MAX_RELAY_EARLY_CELLS_PER_CIRCUIT;
+ cell_queue_init(&circ->p_chan_cells);
+
+ init_circuit_base(TO_CIRCUIT(circ));
+
+ return circ;
+}
+
+/** Free all storage held in circ->testing_cell_stats */
+void
+circuit_clear_testing_cell_stats(circuit_t *circ)
+{
+ if (!circ || !circ->testing_cell_stats)
+ return;
+ SMARTLIST_FOREACH(circ->testing_cell_stats, testing_cell_stats_entry_t *,
+ ent, tor_free(ent));
+ smartlist_free(circ->testing_cell_stats);
+ circ->testing_cell_stats = NULL;
+}
+
+/** Deallocate space associated with circ.
+ */
+STATIC void
+circuit_free_(circuit_t *circ)
+{
+ circid_t n_circ_id = 0;
+ void *mem;
+ size_t memlen;
+ int should_free = 1;
+ if (!circ)
+ return;
+
+ /* We keep a copy of this so we can log its value before it gets unset. */
+ n_circ_id = circ->n_circ_id;
+
+ circuit_clear_testing_cell_stats(circ);
+
+ /* Cleanup circuit from anything HS v3 related. We also do this when the
+ * circuit is closed. This is to avoid any code path that free registered
+ * circuits without closing them before. This needs to be done before the
+ * hs identifier is freed. */
+ hs_circ_cleanup(circ);
+
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
+ mem = ocirc;
+ memlen = sizeof(origin_circuit_t);
+ tor_assert(circ->magic == ORIGIN_CIRCUIT_MAGIC);
+
+ circuit_remove_from_origin_circuit_list(ocirc);
+
++ if (ocirc->half_streams) {
++ SMARTLIST_FOREACH_BEGIN(ocirc->half_streams, half_edge_t*,
++ half_conn) {
++ tor_free(half_conn);
++ } SMARTLIST_FOREACH_END(half_conn);
++ smartlist_free(ocirc->half_streams);
++ }
++
+ if (ocirc->build_state) {
+ extend_info_free(ocirc->build_state->chosen_exit);
+ circuit_free_cpath_node(ocirc->build_state->pending_final_cpath);
+ cpath_ref_decref(ocirc->build_state->service_pending_final_cpath_ref);
+ }
+ tor_free(ocirc->build_state);
+
+ /* Cancel before freeing, if we haven't already succeeded or failed. */
+ if (ocirc->guard_state) {
+ entry_guard_cancel(ô->guard_state);
+ }
+ circuit_guard_state_free(ocirc->guard_state);
+
+ circuit_clear_cpath(ocirc);
+
+ crypto_pk_free(ocirc->intro_key);
+ rend_data_free(ocirc->rend_data);
+
+ /* Finally, free the identifier of the circuit and nullify it so multiple
+ * cleanup will work. */
+ hs_ident_circuit_free(ocirc->hs_ident);
+ ocirc->hs_ident = NULL;
+
+ tor_free(ocirc->dest_address);
+ if (ocirc->socks_username) {
+ memwipe(ocirc->socks_username, 0x12, ocirc->socks_username_len);
+ tor_free(ocirc->socks_username);
+ }
+ if (ocirc->socks_password) {
+ memwipe(ocirc->socks_password, 0x06, ocirc->socks_password_len);
+ tor_free(ocirc->socks_password);
+ }
+ addr_policy_list_free(ocirc->prepend_policy);
+ } else {
+ or_circuit_t *ocirc = TO_OR_CIRCUIT(circ);
+ /* Remember cell statistics for this circuit before deallocating. */
+ if (get_options()->CellStatistics)
+ rep_hist_buffer_stats_add_circ(circ, time(NULL));
+ mem = ocirc;
+ memlen = sizeof(or_circuit_t);
+ tor_assert(circ->magic == OR_CIRCUIT_MAGIC);
+
+ should_free = (ocirc->workqueue_entry == NULL);
+
+ relay_crypto_clear(ô->crypto);
+
+ if (ocirc->rend_splice) {
+ or_circuit_t *other = ocirc->rend_splice;
+ tor_assert(other->base_.magic == OR_CIRCUIT_MAGIC);
+ other->rend_splice = NULL;
+ }
+
+ /* remove from map. */
+ circuit_set_p_circid_chan(ocirc, 0, NULL);
+
+ /* Clear cell queue _after_ removing it from the map. Otherwise our
+ * "active" checks will be violated. */
+ cell_queue_clear(ô->p_chan_cells);
+ }
+
+ extend_info_free(circ->n_hop);
+ tor_free(circ->n_chan_create_cell);
+
+ if (circ->global_circuitlist_idx != -1) {
+ int idx = circ->global_circuitlist_idx;
+ circuit_t *c2 = smartlist_get(global_circuitlist, idx);
+ tor_assert(c2 == circ);
+ smartlist_del(global_circuitlist, idx);
+ if (idx < smartlist_len(global_circuitlist)) {
+ c2 = smartlist_get(global_circuitlist, idx);
+ c2->global_circuitlist_idx = idx;
+ }
+ }
+
+ /* Remove from map. */
+ circuit_set_n_circid_chan(circ, 0, NULL);
+
+ /* Clear cell queue _after_ removing it from the map. Otherwise our
+ * "active" checks will be violated. */
+ cell_queue_clear(&circ->n_chan_cells);
+
+ log_info(LD_CIRC, "Circuit %u (id: %" PRIu32 ") has been freed.",
+ n_circ_id,
+ CIRCUIT_IS_ORIGIN(circ) ?
+ TO_ORIGIN_CIRCUIT(circ)->global_identifier : 0);
+
+ if (should_free) {
+ memwipe(mem, 0xAA, memlen); /* poison memory */
+ tor_free(mem);
+ } else {
+ /* If we made it here, this is an or_circuit_t that still has a pending
+ * cpuworker request which we weren't able to cancel. Instead, set up
+ * the magic value so that when the reply comes back, we'll know to discard
+ * the reply and free this structure.
+ */
+ memwipe(mem, 0xAA, memlen);
+ circ->magic = DEAD_CIRCUIT_MAGIC;
+ }
+}
+
+/** Deallocate the linked list circ-><b>cpath</b>, and remove the cpath from
+ * <b>circ</b>. */
+void
+circuit_clear_cpath(origin_circuit_t *circ)
+{
+ crypt_path_t *victim, *head, *cpath;
+
+ head = cpath = circ->cpath;
+
+ if (!cpath)
+ return;
+
+ /* it's a circular list, so we have to notice when we've
+ * gone through it once. */
+ while (cpath->next && cpath->next != head) {
+ victim = cpath;
+ cpath = victim->next;
+ circuit_free_cpath_node(victim);
+ }
+
+ circuit_free_cpath_node(cpath);
+
+ circ->cpath = NULL;
+}
+
+/** Release all storage held by circuits. */
+void
+circuit_free_all(void)
+{
+ smartlist_t *lst = circuit_get_global_list();
+
+ SMARTLIST_FOREACH_BEGIN(lst, circuit_t *, tmp) {
+ if (! CIRCUIT_IS_ORIGIN(tmp)) {
+ or_circuit_t *or_circ = TO_OR_CIRCUIT(tmp);
+ while (or_circ->resolving_streams) {
+ edge_connection_t *next_conn;
+ next_conn = or_circ->resolving_streams->next_stream;
+ connection_free_(TO_CONN(or_circ->resolving_streams));
+ or_circ->resolving_streams = next_conn;
+ }
+ }
+ tmp->global_circuitlist_idx = -1;
+ circuit_about_to_free_atexit(tmp);
+ circuit_free(tmp);
+ SMARTLIST_DEL_CURRENT(lst, tmp);
+ } SMARTLIST_FOREACH_END(tmp);
+
+ smartlist_free(lst);
+ global_circuitlist = NULL;
+
+ smartlist_free(global_origin_circuit_list);
+ global_origin_circuit_list = NULL;
+
+ smartlist_free(circuits_pending_chans);
+ circuits_pending_chans = NULL;
+
+ smartlist_free(circuits_pending_close);
+ circuits_pending_close = NULL;
+
+ smartlist_free(circuits_pending_other_guards);
+ circuits_pending_other_guards = NULL;
+
+ {
+ chan_circid_circuit_map_t **elt, **next, *c;
+ for (elt = HT_START(chan_circid_map, &chan_circid_map);
+ elt;
+ elt = next) {
+ c = *elt;
+ next = HT_NEXT_RMV(chan_circid_map, &chan_circid_map, elt);
+
+ tor_assert(c->circuit == NULL);
+ tor_free(c);
+ }
+ }
+ HT_CLEAR(chan_circid_map, &chan_circid_map);
+}
+
+/** Deallocate space associated with the cpath node <b>victim</b>. */
+static void
+circuit_free_cpath_node(crypt_path_t *victim)
+{
+ if (!victim)
+ return;
+
+ relay_crypto_clear(&victim->crypto);
+ onion_handshake_state_release(&victim->handshake_state);
+ crypto_dh_free(victim->rend_dh_handshake_state);
+ extend_info_free(victim->extend_info);
+
+ memwipe(victim, 0xBB, sizeof(crypt_path_t)); /* poison memory */
+ tor_free(victim);
+}
+
+/** Release a crypt_path_reference_t*, which may be NULL. */
+static void
+cpath_ref_decref(crypt_path_reference_t *cpath_ref)
+{
+ if (cpath_ref != NULL) {
+ if (--(cpath_ref->refcount) == 0) {
+ circuit_free_cpath_node(cpath_ref->cpath);
+ tor_free(cpath_ref);
+ }
+ }
+}
+
+/** A helper function for circuit_dump_by_conn() below. Log a bunch
+ * of information about circuit <b>circ</b>.
+ */
+static void
+circuit_dump_conn_details(int severity,
+ circuit_t *circ,
+ int conn_array_index,
+ const char *type,
+ circid_t this_circid,
+ circid_t other_circid)
+{
+ tor_log(severity, LD_CIRC, "Conn %d has %s circuit: circID %u "
+ "(other side %u), state %d (%s), born %ld:",
+ conn_array_index, type, (unsigned)this_circid, (unsigned)other_circid,
+ circ->state, circuit_state_to_string(circ->state),
+ (long)circ->timestamp_began.tv_sec);
+ if (CIRCUIT_IS_ORIGIN(circ)) { /* circ starts at this node */
+ circuit_log_path(severity, LD_CIRC, TO_ORIGIN_CIRCUIT(circ));
+ }
+}
+
+/** Log, at severity <b>severity</b>, information about each circuit
+ * that is connected to <b>conn</b>.
+ */
+void
+circuit_dump_by_conn(connection_t *conn, int severity)
+{
+ edge_connection_t *tmpconn;
+
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ circid_t n_circ_id = circ->n_circ_id, p_circ_id = 0;
+
+ if (circ->marked_for_close) {
+ continue;
+ }
+
+ if (!CIRCUIT_IS_ORIGIN(circ)) {
+ p_circ_id = TO_OR_CIRCUIT(circ)->p_circ_id;
+ }
+
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ for (tmpconn=TO_ORIGIN_CIRCUIT(circ)->p_streams; tmpconn;
+ tmpconn=tmpconn->next_stream) {
+ if (TO_CONN(tmpconn) == conn) {
+ circuit_dump_conn_details(severity, circ, conn->conn_array_index,
+ "App-ward", p_circ_id, n_circ_id);
+ }
+ }
+ }
+
+ if (! CIRCUIT_IS_ORIGIN(circ)) {
+ for (tmpconn=TO_OR_CIRCUIT(circ)->n_streams; tmpconn;
+ tmpconn=tmpconn->next_stream) {
+ if (TO_CONN(tmpconn) == conn) {
+ circuit_dump_conn_details(severity, circ, conn->conn_array_index,
+ "Exit-ward", n_circ_id, p_circ_id);
+ }
+ }
+ }
+ }
+ SMARTLIST_FOREACH_END(circ);
+}
+
+/** Return the circuit whose global ID is <b>id</b>, or NULL if no
+ * such circuit exists. */
+origin_circuit_t *
+circuit_get_by_global_id(uint32_t id)
+{
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ if (CIRCUIT_IS_ORIGIN(circ) &&
+ TO_ORIGIN_CIRCUIT(circ)->global_identifier == id) {
+ if (circ->marked_for_close)
+ return NULL;
+ else
+ return TO_ORIGIN_CIRCUIT(circ);
+ }
+ }
+ SMARTLIST_FOREACH_END(circ);
+ return NULL;
+}
+
+/** Return a circ such that:
+ * - circ-\>n_circ_id or circ-\>p_circ_id is equal to <b>circ_id</b>, and
+ * - circ is attached to <b>chan</b>, either as p_chan or n_chan.
+ * Return NULL if no such circuit exists.
+ *
+ * If <b>found_entry_out</b> is provided, set it to true if we have a
+ * placeholder entry for circid/chan, and leave it unset otherwise.
+ */
+static inline circuit_t *
+circuit_get_by_circid_channel_impl(circid_t circ_id, channel_t *chan,
+ int *found_entry_out)
+{
+ chan_circid_circuit_map_t search;
+ chan_circid_circuit_map_t *found;
+
+ if (_last_circid_chan_ent &&
+ circ_id == _last_circid_chan_ent->circ_id &&
+ chan == _last_circid_chan_ent->chan) {
+ found = _last_circid_chan_ent;
+ } else {
+ search.circ_id = circ_id;
+ search.chan = chan;
+ found = HT_FIND(chan_circid_map, &chan_circid_map, &search);
+ _last_circid_chan_ent = found;
+ }
+ if (found && found->circuit) {
+ log_debug(LD_CIRC,
+ "circuit_get_by_circid_channel_impl() returning circuit %p for"
+ " circ_id %u, channel ID %"PRIu64 " (%p)",
+ found->circuit, (unsigned)circ_id,
+ (chan->global_identifier), chan);
+ if (found_entry_out)
+ *found_entry_out = 1;
+ return found->circuit;
+ }
+
+ log_debug(LD_CIRC,
+ "circuit_get_by_circid_channel_impl() found %s for"
+ " circ_id %u, channel ID %"PRIu64 " (%p)",
+ found ? "placeholder" : "nothing",
+ (unsigned)circ_id,
+ (chan->global_identifier), chan);
+
+ if (found_entry_out)
+ *found_entry_out = found ? 1 : 0;
+
+ return NULL;
+ /* The rest of this checks for bugs. Disabled by default. */
+ /* We comment it out because coverity complains otherwise.
+ {
+ circuit_t *circ;
+ TOR_LIST_FOREACH(circ, &global_circuitlist, head) {
+ if (! CIRCUIT_IS_ORIGIN(circ)) {
+ or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
+ if (or_circ->p_chan == chan && or_circ->p_circ_id == circ_id) {
+ log_warn(LD_BUG,
+ "circuit matches p_chan, but not in hash table (Bug!)");
+ return circ;
+ }
+ }
+ if (circ->n_chan == chan && circ->n_circ_id == circ_id) {
+ log_warn(LD_BUG,
+ "circuit matches n_chan, but not in hash table (Bug!)");
+ return circ;
+ }
+ }
+ return NULL;
+ } */
+}
+
+/** Return a circ such that:
+ * - circ-\>n_circ_id or circ-\>p_circ_id is equal to <b>circ_id</b>, and
+ * - circ is attached to <b>chan</b>, either as p_chan or n_chan.
+ * - circ is not marked for close.
+ * Return NULL if no such circuit exists.
+ */
+circuit_t *
+circuit_get_by_circid_channel(circid_t circ_id, channel_t *chan)
+{
+ circuit_t *circ = circuit_get_by_circid_channel_impl(circ_id, chan, NULL);
+ if (!circ || circ->marked_for_close)
+ return NULL;
+ else
+ return circ;
+}
+
+/** Return a circ such that:
+ * - circ-\>n_circ_id or circ-\>p_circ_id is equal to <b>circ_id</b>, and
+ * - circ is attached to <b>chan</b>, either as p_chan or n_chan.
+ * Return NULL if no such circuit exists.
+ */
+circuit_t *
+circuit_get_by_circid_channel_even_if_marked(circid_t circ_id,
+ channel_t *chan)
+{
+ return circuit_get_by_circid_channel_impl(circ_id, chan, NULL);
+}
+
+/** Return true iff the circuit ID <b>circ_id</b> is currently used by a
+ * circuit, marked or not, on <b>chan</b>, or if the circ ID is reserved until
+ * a queued destroy cell can be sent.
+ *
+ * (Return 1 if the circuit is present, marked or not; Return 2
+ * if the circuit ID is pending a destroy.)
+ **/
+int
+circuit_id_in_use_on_channel(circid_t circ_id, channel_t *chan)
+{
+ int found = 0;
+ if (circuit_get_by_circid_channel_impl(circ_id, chan, &found) != NULL)
+ return 1;
+ if (found)
+ return 2;
+ return 0;
+}
+
+/** Helper for debugging 12184. Returns the time since which 'circ_id' has
+ * been marked unusable on 'chan'. */
+time_t
+circuit_id_when_marked_unusable_on_channel(circid_t circ_id, channel_t *chan)
+{
+ chan_circid_circuit_map_t search;
+ chan_circid_circuit_map_t *found;
+
+ memset(&search, 0, sizeof(search));
+ search.circ_id = circ_id;
+ search.chan = chan;
+
+ found = HT_FIND(chan_circid_map, &chan_circid_map, &search);
+
+ if (! found || found->circuit)
+ return 0;
+
+ return found->made_placeholder_at;
+}
+
+/** Return the circuit that a given edge connection is using. */
+circuit_t *
+circuit_get_by_edge_conn(edge_connection_t *conn)
+{
+ circuit_t *circ;
+
+ circ = conn->on_circuit;
+ tor_assert(!circ ||
+ (CIRCUIT_IS_ORIGIN(circ) ? circ->magic == ORIGIN_CIRCUIT_MAGIC
+ : circ->magic == OR_CIRCUIT_MAGIC));
+
+ return circ;
+}
+
+/** For each circuit that has <b>chan</b> as n_chan or p_chan, unlink the
+ * circuit from the chan,circid map, and mark it for close if it hasn't
+ * been marked already.
+ */
+void
+circuit_unlink_all_from_channel(channel_t *chan, int reason)
+{
+ smartlist_t *detached = smartlist_new();
+
+/* #define DEBUG_CIRCUIT_UNLINK_ALL */
+
+ channel_unlink_all_circuits(chan, detached);
+
+#ifdef DEBUG_CIRCUIT_UNLINK_ALL
+ {
+ smartlist_t *detached_2 = smartlist_new();
+ int mismatch = 0, badlen = 0;
+
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ if (circ->n_chan == chan ||
+ (!CIRCUIT_IS_ORIGIN(circ) &&
+ TO_OR_CIRCUIT(circ)->p_chan == chan)) {
+ smartlist_add(detached_2, circ);
+ }
+ }
+ SMARTLIST_FOREACH_END(circ);
+
+ if (smartlist_len(detached) != smartlist_len(detached_2)) {
+ log_warn(LD_BUG, "List of detached circuits had the wrong length! "
+ "(got %d, should have gotten %d)",
+ (int)smartlist_len(detached),
+ (int)smartlist_len(detached_2));
+ badlen = 1;
+ }
+ smartlist_sort_pointers(detached);
+ smartlist_sort_pointers(detached_2);
+
+ SMARTLIST_FOREACH(detached, circuit_t *, c,
+ if (c != smartlist_get(detached_2, c_sl_idx))
+ mismatch = 1;
+ );
+
+ if (mismatch)
+ log_warn(LD_BUG, "Mismatch in list of detached circuits.");
+
+ if (badlen || mismatch) {
+ smartlist_free(detached);
+ detached = detached_2;
+ } else {
+ log_notice(LD_CIRC, "List of %d circuits was as expected.",
+ (int)smartlist_len(detached));
+ smartlist_free(detached_2);
+ }
+ }
+#endif /* defined(DEBUG_CIRCUIT_UNLINK_ALL) */
+
+ SMARTLIST_FOREACH_BEGIN(detached, circuit_t *, circ) {
+ int mark = 0;
+ if (circ->n_chan == chan) {
+
+ circuit_set_n_circid_chan(circ, 0, NULL);
+ mark = 1;
+
+ /* If we didn't request this closure, pass the remote
+ * bit to mark_for_close. */
+ if (chan->reason_for_closing != CHANNEL_CLOSE_REQUESTED)
+ reason |= END_CIRC_REASON_FLAG_REMOTE;
+ }
+ if (! CIRCUIT_IS_ORIGIN(circ)) {
+ or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
+ if (or_circ->p_chan == chan) {
+ circuit_set_p_circid_chan(or_circ, 0, NULL);
+ mark = 1;
+ }
+ }
+ if (!mark) {
+ log_warn(LD_BUG, "Circuit on detached list which I had no reason "
+ "to mark");
+ continue;
+ }
+ if (!circ->marked_for_close)
+ circuit_mark_for_close(circ, reason);
+ } SMARTLIST_FOREACH_END(circ);
+
+ smartlist_free(detached);
+}
+
+/** Return a circ such that
+ * - circ-\>rend_data-\>onion_address is equal to
+ * <b>rend_data</b>-\>onion_address,
+ * - circ-\>rend_data-\>rend_cookie is equal to
+ * <b>rend_data</b>-\>rend_cookie, and
+ * - circ-\>purpose is equal to CIRCUIT_PURPOSE_C_REND_READY.
+ *
+ * Return NULL if no such circuit exists.
+ */
+origin_circuit_t *
+circuit_get_ready_rend_circ_by_rend_data(const rend_data_t *rend_data)
+{
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ if (!circ->marked_for_close &&
+ circ->purpose == CIRCUIT_PURPOSE_C_REND_READY) {
+ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
+ if (ocirc->rend_data == NULL) {
+ continue;
+ }
+ if (!rend_cmp_service_ids(rend_data_get_address(rend_data),
+ rend_data_get_address(ocirc->rend_data)) &&
+ tor_memeq(ocirc->rend_data->rend_cookie,
+ rend_data->rend_cookie,
+ REND_COOKIE_LEN))
+ return ocirc;
+ }
+ }
+ SMARTLIST_FOREACH_END(circ);
+ return NULL;
+}
+
+/** Return the first service introduction circuit originating from the global
+ * circuit list after <b>start</b> or at the start of the list if <b>start</b>
+ * is NULL. Return NULL if no circuit is found.
+ *
+ * A service introduction point circuit has a purpose of either
+ * CIRCUIT_PURPOSE_S_ESTABLISH_INTRO or CIRCUIT_PURPOSE_S_INTRO. This does not
+ * return a circuit marked for close and its state must be open. */
+origin_circuit_t *
+circuit_get_next_service_intro_circ(origin_circuit_t *start)
+{
+ int idx = 0;
+ smartlist_t *lst = circuit_get_global_list();
+
+ if (start) {
+ idx = TO_CIRCUIT(start)->global_circuitlist_idx + 1;
+ }
+
+ for ( ; idx < smartlist_len(lst); ++idx) {
+ circuit_t *circ = smartlist_get(lst, idx);
+
+ /* Ignore a marked for close circuit or purpose not matching a service
+ * intro point or if the state is not open. */
+ if (circ->marked_for_close || circ->state != CIRCUIT_STATE_OPEN ||
+ (circ->purpose != CIRCUIT_PURPOSE_S_ESTABLISH_INTRO &&
+ circ->purpose != CIRCUIT_PURPOSE_S_INTRO)) {
+ continue;
+ }
+ /* The purposes we are looking for are only for origin circuits so the
+ * following is valid. */
+ return TO_ORIGIN_CIRCUIT(circ);
+ }
+ /* Not found. */
+ return NULL;
+}
+
+/** Return the first service rendezvous circuit originating from the global
+ * circuit list after <b>start</b> or at the start of the list if <b>start</b>
+ * is NULL. Return NULL if no circuit is found.
+ *
+ * A service rendezvous point circuit has a purpose of either
+ * CIRCUIT_PURPOSE_S_CONNECT_REND or CIRCUIT_PURPOSE_S_REND_JOINED. This does
+ * not return a circuit marked for close and its state must be open. */
+origin_circuit_t *
+circuit_get_next_service_rp_circ(origin_circuit_t *start)
+{
+ int idx = 0;
+ smartlist_t *lst = circuit_get_global_list();
+
+ if (start) {
+ idx = TO_CIRCUIT(start)->global_circuitlist_idx + 1;
+ }
+
+ for ( ; idx < smartlist_len(lst); ++idx) {
+ circuit_t *circ = smartlist_get(lst, idx);
+
+ /* Ignore a marked for close circuit or purpose not matching a service
+ * intro point or if the state is not open. */
+ if (circ->marked_for_close || circ->state != CIRCUIT_STATE_OPEN ||
+ (circ->purpose != CIRCUIT_PURPOSE_S_CONNECT_REND &&
+ circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED)) {
+ continue;
+ }
+ /* The purposes we are looking for are only for origin circuits so the
+ * following is valid. */
+ return TO_ORIGIN_CIRCUIT(circ);
+ }
+ /* Not found. */
+ return NULL;
+}
+
+/** Return the first circuit originating here in global_circuitlist after
+ * <b>start</b> whose purpose is <b>purpose</b>, and where <b>digest</b> (if
+ * set) matches the private key digest of the rend data associated with the
+ * circuit. Return NULL if no circuit is found. If <b>start</b> is NULL,
+ * begin at the start of the list.
+ */
+origin_circuit_t *
+circuit_get_next_by_pk_and_purpose(origin_circuit_t *start,
+ const uint8_t *digest, uint8_t purpose)
+{
+ int idx;
+ smartlist_t *lst = circuit_get_global_list();
+ tor_assert(CIRCUIT_PURPOSE_IS_ORIGIN(purpose));
+ if (start == NULL)
+ idx = 0;
+ else
+ idx = TO_CIRCUIT(start)->global_circuitlist_idx + 1;
+
+ for ( ; idx < smartlist_len(lst); ++idx) {
+ circuit_t *circ = smartlist_get(lst, idx);
+ origin_circuit_t *ocirc;
+
+ if (circ->marked_for_close)
+ continue;
+ if (circ->purpose != purpose)
+ continue;
+ /* At this point we should be able to get a valid origin circuit because
+ * the origin purpose we are looking for matches this circuit. */
+ if (BUG(!CIRCUIT_PURPOSE_IS_ORIGIN(circ->purpose))) {
+ break;
+ }
+ ocirc = TO_ORIGIN_CIRCUIT(circ);
+ if (!digest)
+ return ocirc;
+ if (rend_circuit_pk_digest_eq(ocirc, digest)) {
+ return ocirc;
+ }
+ }
+ return NULL;
+}
+
+/** We might cannibalize this circuit: Return true if its last hop can be used
+ * as a v3 rendezvous point. */
+static int
+circuit_can_be_cannibalized_for_v3_rp(const origin_circuit_t *circ)
+{
+ if (!circ->build_state) {
+ return 0;
+ }
+
+ extend_info_t *chosen_exit = circ->build_state->chosen_exit;
+ if (BUG(!chosen_exit)) {
+ return 0;
+ }
+
+ const node_t *rp_node = node_get_by_id(chosen_exit->identity_digest);
+ if (rp_node) {
+ if (node_supports_v3_rendezvous_point(rp_node)) {
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+/** We are trying to create a circuit of purpose <b>purpose</b> and we are
+ * looking for cannibalizable circuits. Return the circuit purpose we would be
+ * willing to cannibalize. */
+static uint8_t
+get_circuit_purpose_needed_to_cannibalize(uint8_t purpose)
+{
+ if (circuit_should_use_vanguards(purpose)) {
+ /* If we are using vanguards, then we should only cannibalize vanguard
+ * circuits so that we get the same path construction logic. */
+ return CIRCUIT_PURPOSE_HS_VANGUARDS;
+ } else {
+ /* If no vanguards are used just get a general circuit! */
+ return CIRCUIT_PURPOSE_C_GENERAL;
+ }
+}
+
+/** Return a circuit that is open, is CIRCUIT_PURPOSE_C_GENERAL,
+ * has a timestamp_dirty value of 0, has flags matching the CIRCLAUNCH_*
+ * flags in <b>flags</b>, and if info is defined, does not already use info
+ * as any of its hops; or NULL if no circuit fits this description.
+ *
+ * The <b>purpose</b> argument refers to the purpose of the circuit we want to
+ * create, not the purpose of the circuit we want to cannibalize.
+ *
+ * If !CIRCLAUNCH_NEED_UPTIME, prefer returning non-uptime circuits.
+ *
+ * To "cannibalize" a circuit means to extend it an extra hop, and use it
+ * for some other purpose than we had originally intended. We do this when
+ * we want to perform some low-bandwidth task at a specific relay, and we
+ * would like the circuit to complete as soon as possible. (If we were going
+ * to use a lot of bandwidth, we wouldn't want a circuit with an extra hop.
+ * If we didn't care about circuit completion latency, we would just build
+ * a new circuit.)
+ */
+origin_circuit_t *
+circuit_find_to_cannibalize(uint8_t purpose_to_produce, extend_info_t *info,
+ int flags)
+{
+ origin_circuit_t *best=NULL;
+ int need_uptime = (flags & CIRCLAUNCH_NEED_UPTIME) != 0;
+ int need_capacity = (flags & CIRCLAUNCH_NEED_CAPACITY) != 0;
+ int internal = (flags & CIRCLAUNCH_IS_INTERNAL) != 0;
+ const or_options_t *options = get_options();
+ /* We want the circuit we are trying to cannibalize to have this purpose */
+ int purpose_to_search_for;
+
+ /* Make sure we're not trying to create a onehop circ by
+ * cannibalization. */
+ tor_assert(!(flags & CIRCLAUNCH_ONEHOP_TUNNEL));
+
+ purpose_to_search_for = get_circuit_purpose_needed_to_cannibalize(
+ purpose_to_produce);
+
+ tor_assert_nonfatal(purpose_to_search_for == CIRCUIT_PURPOSE_C_GENERAL ||
+ purpose_to_search_for == CIRCUIT_PURPOSE_HS_VANGUARDS);
+
+ log_debug(LD_CIRC,
+ "Hunting for a circ to cannibalize: purpose %d, uptime %d, "
+ "capacity %d, internal %d",
+ purpose_to_produce, need_uptime, need_capacity, internal);
+
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ_) {
+ if (CIRCUIT_IS_ORIGIN(circ_) &&
+ circ_->state == CIRCUIT_STATE_OPEN &&
+ !circ_->marked_for_close &&
+ circ_->purpose == purpose_to_search_for &&
+ !circ_->timestamp_dirty) {
+ origin_circuit_t *circ = TO_ORIGIN_CIRCUIT(circ_);
+
+ /* Only cannibalize from reasonable length circuits. If we
+ * want C_GENERAL, then only choose 3 hop circs. If we want
+ * HS_VANGUARDS, only choose 4 hop circs.
+ */
+ if (circ->build_state->desired_path_len !=
+ route_len_for_purpose(purpose_to_search_for, NULL)) {
+ goto next;
+ }
+
+ /* Ignore any circuits for which we can't use the Guard. It is possible
+ * that the Guard was removed from the samepled set after the circuit
+ * was created so avoid using it. */
+ if (!entry_guard_could_succeed(circ->guard_state)) {
+ goto next;
+ }
+
+ if ((!need_uptime || circ->build_state->need_uptime) &&
+ (!need_capacity || circ->build_state->need_capacity) &&
+ (internal == circ->build_state->is_internal) &&
+ !circ->unusable_for_new_conns &&
+ circ->remaining_relay_early_cells &&
+ !circ->build_state->onehop_tunnel &&
+ !circ->isolation_values_set) {
+ if (info) {
+ /* need to make sure we don't duplicate hops */
+ crypt_path_t *hop = circ->cpath;
+ const node_t *ri1 = node_get_by_id(info->identity_digest);
+ do {
+ const node_t *ri2;
+ if (tor_memeq(hop->extend_info->identity_digest,
+ info->identity_digest, DIGEST_LEN))
+ goto next;
+ if (ri1 &&
+ (ri2 = node_get_by_id(hop->extend_info->identity_digest))
+ && nodes_in_same_family(ri1, ri2))
+ goto next;
+ hop=hop->next;
+ } while (hop!=circ->cpath);
+ }
+ if (options->ExcludeNodes) {
+ /* Make sure no existing nodes in the circuit are excluded for
+ * general use. (This may be possible if StrictNodes is 0, and we
+ * thought we needed to use an otherwise excluded node for, say, a
+ * directory operation.) */
+ crypt_path_t *hop = circ->cpath;
+ do {
+ if (routerset_contains_extendinfo(options->ExcludeNodes,
+ hop->extend_info))
+ goto next;
+ hop = hop->next;
+ } while (hop != circ->cpath);
+ }
+
+ if ((flags & CIRCLAUNCH_IS_V3_RP) &&
+ !circuit_can_be_cannibalized_for_v3_rp(circ)) {
+ log_debug(LD_GENERAL, "Skipping uncannibalizable circuit for v3 "
+ "rendezvous point.");
+ goto next;
+ }
+
+ if (!best || (best->build_state->need_uptime && !need_uptime))
+ best = circ;
+ next: ;
+ }
+ }
+ }
+ SMARTLIST_FOREACH_END(circ_);
+ return best;
+}
+
+/**
+ * Check whether any of the origin circuits that are waiting to see if
+ * their guard is good enough to use can be upgraded to "ready". If so,
+ * return a new smartlist containing them. Otherwise return NULL.
+ */
+smartlist_t *
+circuit_find_circuits_to_upgrade_from_guard_wait(void)
+{
+ /* Only if some circuit is actually waiting on an upgrade should we
+ * run the algorithm. */
+ if (! circuits_pending_other_guards ||
+ smartlist_len(circuits_pending_other_guards)==0)
+ return NULL;
+ /* Only if we have some origin circuits should we run the algorithm. */
+ if (!global_origin_circuit_list)
+ return NULL;
+
+ /* Okay; we can pass our circuit list to entrynodes.c.*/
+ smartlist_t *result = smartlist_new();
+ int circuits_upgraded = entry_guards_upgrade_waiting_circuits(
+ get_guard_selection_info(),
+ global_origin_circuit_list,
+ result);
+ if (circuits_upgraded && smartlist_len(result)) {
+ return result;
+ } else {
+ smartlist_free(result);
+ return NULL;
+ }
+}
+
+/** Return the number of hops in circuit's path. If circ has no entries,
+ * or is NULL, returns 0. */
+int
+circuit_get_cpath_len(origin_circuit_t *circ)
+{
+ int n = 0;
+ if (circ && circ->cpath) {
+ crypt_path_t *cpath, *cpath_next = NULL;
+ for (cpath = circ->cpath; cpath_next != circ->cpath; cpath = cpath_next) {
+ cpath_next = cpath->next;
+ ++n;
+ }
+ }
+ return n;
+}
+
+/** Return the number of opened hops in circuit's path.
+ * If circ has no entries, or is NULL, returns 0. */
+int
+circuit_get_cpath_opened_len(const origin_circuit_t *circ)
+{
+ int n = 0;
+ if (circ && circ->cpath) {
+ crypt_path_t *cpath, *cpath_next = NULL;
+ for (cpath = circ->cpath;
+ cpath->state == CPATH_STATE_OPEN
+ && cpath_next != circ->cpath;
+ cpath = cpath_next) {
+ cpath_next = cpath->next;
+ ++n;
+ }
+ }
+ return n;
+}
+
+/** Return the <b>hopnum</b>th hop in <b>circ</b>->cpath, or NULL if there
+ * aren't that many hops in the list. <b>hopnum</b> starts at 1.
+ * Returns NULL if <b>hopnum</b> is 0 or negative. */
+crypt_path_t *
+circuit_get_cpath_hop(origin_circuit_t *circ, int hopnum)
+{
+ if (circ && circ->cpath && hopnum > 0) {
+ crypt_path_t *cpath, *cpath_next = NULL;
+ for (cpath = circ->cpath; cpath_next != circ->cpath; cpath = cpath_next) {
+ cpath_next = cpath->next;
+ if (--hopnum <= 0)
+ return cpath;
+ }
+ }
+ return NULL;
+}
+
+/** Go through the circuitlist; mark-for-close each circuit that starts
+ * at us but has not yet been used. */
+void
+circuit_mark_all_unused_circs(void)
+{
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ if (CIRCUIT_IS_ORIGIN(circ) &&
+ !circ->marked_for_close &&
+ !circ->timestamp_dirty)
+ circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
+ }
+ SMARTLIST_FOREACH_END(circ);
+}
+
+/** Go through the circuitlist; for each circuit that starts at us
+ * and is dirty, frob its timestamp_dirty so we won't use it for any
+ * new streams.
+ *
+ * This is useful for letting the user change pseudonyms, so new
+ * streams will not be linkable to old streams.
+ */
+void
+circuit_mark_all_dirty_circs_as_unusable(void)
+{
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ if (CIRCUIT_IS_ORIGIN(circ) &&
+ !circ->marked_for_close &&
+ circ->timestamp_dirty) {
+ mark_circuit_unusable_for_new_conns(TO_ORIGIN_CIRCUIT(circ));
+ }
+ }
+ SMARTLIST_FOREACH_END(circ);
+}
+
+/** Mark <b>circ</b> to be closed next time we call
+ * circuit_close_all_marked(). Do any cleanup needed:
+ * - If state is onionskin_pending, remove circ from the onion_pending
+ * list.
+ * - If circ isn't open yet: call circuit_build_failed() if we're
+ * the origin.
+ * - If purpose is C_INTRODUCE_ACK_WAIT, report the intro point
+ * failure we just had to the hidden service client module.
+ * - If purpose is C_INTRODUCING and <b>reason</b> isn't TIMEOUT,
+ * report to the hidden service client module that the intro point
+ * we just tried may be unreachable.
+ * - Send appropriate destroys and edge_destroys for conns and
+ * streams attached to circ.
+ * - If circ->rend_splice is set (we are the midpoint of a joined
+ * rendezvous stream), then mark the other circuit to close as well.
+ */
+MOCK_IMPL(void,
+circuit_mark_for_close_, (circuit_t *circ, int reason, int line,
+ const char *file))
+{
+ int orig_reason = reason; /* Passed to the controller */
+ assert_circuit_ok(circ);
+ tor_assert(line);
+ tor_assert(file);
+
+ if (circ->marked_for_close) {
+ log_warn(LD_BUG,
+ "Duplicate call to circuit_mark_for_close at %s:%d"
+ " (first at %s:%d)", file, line,
+ circ->marked_for_close_file, circ->marked_for_close);
+ return;
+ }
+ if (reason == END_CIRC_AT_ORIGIN) {
+ if (!CIRCUIT_IS_ORIGIN(circ)) {
+ log_warn(LD_BUG, "Specified 'at-origin' non-reason for ending circuit, "
+ "but circuit was not at origin. (called %s:%d, purpose=%d)",
+ file, line, circ->purpose);
+ }
+ reason = END_CIRC_REASON_NONE;
+ }
+
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ if (pathbias_check_close(TO_ORIGIN_CIRCUIT(circ), reason) == -1) {
+ /* Don't close it yet, we need to test it first */
+ return;
+ }
+
+ /* We don't send reasons when closing circuits at the origin. */
+ reason = END_CIRC_REASON_NONE;
+ }
+
+ if (reason & END_CIRC_REASON_FLAG_REMOTE)
+ reason &= ~END_CIRC_REASON_FLAG_REMOTE;
+
+ if (reason < END_CIRC_REASON_MIN_ || reason > END_CIRC_REASON_MAX_) {
+ if (!(orig_reason & END_CIRC_REASON_FLAG_REMOTE))
+ log_warn(LD_BUG, "Reason %d out of range at %s:%d", reason, file, line);
+ reason = END_CIRC_REASON_NONE;
+ }
+
+ circ->marked_for_close = line;
+ circ->marked_for_close_file = file;
+ circ->marked_for_close_reason = reason;
+ circ->marked_for_close_orig_reason = orig_reason;
+
+ if (!CIRCUIT_IS_ORIGIN(circ)) {
+ or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
+ if (or_circ->rend_splice) {
+ if (!or_circ->rend_splice->base_.marked_for_close) {
+ /* do this after marking this circuit, to avoid infinite recursion. */
+ circuit_mark_for_close(TO_CIRCUIT(or_circ->rend_splice), reason);
+ }
+ or_circ->rend_splice = NULL;
+ }
+ }
+
+ /* Notify the HS subsystem that this circuit is closing. */
+ hs_circ_cleanup(circ);
+
+ if (circuits_pending_close == NULL)
+ circuits_pending_close = smartlist_new();
+
+ smartlist_add(circuits_pending_close, circ);
+ mainloop_schedule_postloop_cleanup();
+
+ log_info(LD_GENERAL, "Circuit %u (id: %" PRIu32 ") marked for close at "
+ "%s:%d (orig reason: %d, new reason: %d)",
+ circ->n_circ_id,
+ CIRCUIT_IS_ORIGIN(circ) ?
+ TO_ORIGIN_CIRCUIT(circ)->global_identifier : 0,
+ file, line, orig_reason, reason);
+}
+
+/** Called immediately before freeing a marked circuit <b>circ</b> from
+ * circuit_free_all() while shutting down Tor; this is a safe-at-shutdown
+ * version of circuit_about_to_free(). It's important that it at least
+ * do circuitmux_detach_circuit() when appropriate.
+ */
+static void
+circuit_about_to_free_atexit(circuit_t *circ)
+{
+
+ if (circ->n_chan) {
+ circuit_clear_cell_queue(circ, circ->n_chan);
+ circuitmux_detach_circuit(circ->n_chan->cmux, circ);
+ circuit_set_n_circid_chan(circ, 0, NULL);
+ }
+
+ if (! CIRCUIT_IS_ORIGIN(circ)) {
+ or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
+
+ if (or_circ->p_chan) {
+ circuit_clear_cell_queue(circ, or_circ->p_chan);
+ circuitmux_detach_circuit(or_circ->p_chan->cmux, circ);
+ circuit_set_p_circid_chan(or_circ, 0, NULL);
+ }
+ }
+}
+
+/** Called immediately before freeing a marked circuit <b>circ</b>.
+ * Disconnects the circuit from other data structures, launches events
+ * as appropriate, and performs other housekeeping.
+ */
+static void
+circuit_about_to_free(circuit_t *circ)
+{
+
+ int reason = circ->marked_for_close_reason;
+ int orig_reason = circ->marked_for_close_orig_reason;
+
+ if (circ->state == CIRCUIT_STATE_ONIONSKIN_PENDING) {
+ onion_pending_remove(TO_OR_CIRCUIT(circ));
+ }
+ /* If the circuit ever became OPEN, we sent it to the reputation history
+ * module then. If it isn't OPEN, we send it there now to remember which
+ * links worked and which didn't.
+ */
+ if (circ->state != CIRCUIT_STATE_OPEN &&
+ circ->state != CIRCUIT_STATE_GUARD_WAIT) {
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
+ circuit_build_failed(ocirc); /* take actions if necessary */
+ }
+ }
+ if (circ->state == CIRCUIT_STATE_CHAN_WAIT) {
+ if (circuits_pending_chans)
+ smartlist_remove(circuits_pending_chans, circ);
+ }
+ if (circuits_pending_other_guards) {
+ smartlist_remove(circuits_pending_other_guards, circ);
+ }
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ control_event_circuit_status(TO_ORIGIN_CIRCUIT(circ),
+ (circ->state == CIRCUIT_STATE_OPEN ||
+ circ->state == CIRCUIT_STATE_GUARD_WAIT) ?
+ CIRC_EVENT_CLOSED:CIRC_EVENT_FAILED,
+ orig_reason);
+ }
+
+ if (circ->purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) {
+ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
+ int timed_out = (reason == END_CIRC_REASON_TIMEOUT);
+ tor_assert(circ->state == CIRCUIT_STATE_OPEN);
+ tor_assert(ocirc->build_state->chosen_exit);
+ if (orig_reason != END_CIRC_REASON_IP_NOW_REDUNDANT &&
+ ocirc->rend_data) {
+ /* treat this like getting a nack from it */
+ log_info(LD_REND, "Failed intro circ %s to %s (awaiting ack). %s",
+ safe_str_client(rend_data_get_address(ocirc->rend_data)),
+ safe_str_client(build_state_get_exit_nickname(ocirc->build_state)),
+ timed_out ? "Recording timeout." : "Removing from descriptor.");
+ rend_client_report_intro_point_failure(ocirc->build_state->chosen_exit,
+ ocirc->rend_data,
+ timed_out ?
+ INTRO_POINT_FAILURE_TIMEOUT :
+ INTRO_POINT_FAILURE_GENERIC);
+ }
+ } else if (circ->purpose == CIRCUIT_PURPOSE_C_INTRODUCING &&
+ reason != END_CIRC_REASON_TIMEOUT) {
+ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
+ if (ocirc->build_state->chosen_exit && ocirc->rend_data) {
+ if (orig_reason != END_CIRC_REASON_IP_NOW_REDUNDANT &&
+ ocirc->rend_data) {
+ log_info(LD_REND, "Failed intro circ %s to %s "
+ "(building circuit to intro point). "
+ "Marking intro point as possibly unreachable.",
+ safe_str_client(rend_data_get_address(ocirc->rend_data)),
+ safe_str_client(build_state_get_exit_nickname(
+ ocirc->build_state)));
+ rend_client_report_intro_point_failure(ocirc->build_state->chosen_exit,
+ ocirc->rend_data,
+ INTRO_POINT_FAILURE_UNREACHABLE);
+ }
+ }
+ }
+
+ if (circ->n_chan) {
+ circuit_clear_cell_queue(circ, circ->n_chan);
+ /* Only send destroy if the channel isn't closing anyway */
+ if (!CHANNEL_CONDEMNED(circ->n_chan)) {
+ channel_send_destroy(circ->n_circ_id, circ->n_chan, reason);
+ }
+ circuitmux_detach_circuit(circ->n_chan->cmux, circ);
+ circuit_set_n_circid_chan(circ, 0, NULL);
+ }
+
+ if (! CIRCUIT_IS_ORIGIN(circ)) {
+ or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
+ edge_connection_t *conn;
+ for (conn=or_circ->n_streams; conn; conn=conn->next_stream)
+ connection_edge_destroy(or_circ->p_circ_id, conn);
+ or_circ->n_streams = NULL;
+
+ while (or_circ->resolving_streams) {
+ conn = or_circ->resolving_streams;
+ or_circ->resolving_streams = conn->next_stream;
+ if (!conn->base_.marked_for_close) {
+ /* The client will see a DESTROY, and infer that the connections
+ * are closing because the circuit is getting torn down. No need
+ * to send an end cell. */
+ conn->edge_has_sent_end = 1;
+ conn->end_reason = END_STREAM_REASON_DESTROY;
+ conn->end_reason |= END_STREAM_REASON_FLAG_ALREADY_SENT_CLOSED;
+ connection_mark_for_close(TO_CONN(conn));
+ }
+ conn->on_circuit = NULL;
+ }
+
+ if (or_circ->p_chan) {
+ circuit_clear_cell_queue(circ, or_circ->p_chan);
+ /* Only send destroy if the channel isn't closing anyway */
+ if (!CHANNEL_CONDEMNED(or_circ->p_chan)) {
+ channel_send_destroy(or_circ->p_circ_id, or_circ->p_chan, reason);
+ }
+ circuitmux_detach_circuit(or_circ->p_chan->cmux, circ);
+ circuit_set_p_circid_chan(or_circ, 0, NULL);
+ }
+ } else {
+ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
+ edge_connection_t *conn;
+ for (conn=ocirc->p_streams; conn; conn=conn->next_stream)
+ connection_edge_destroy(circ->n_circ_id, conn);
+ ocirc->p_streams = NULL;
+ }
+}
+
+/** Given a marked circuit <b>circ</b>, aggressively free its cell queues to
+ * recover memory. */
+static void
+marked_circuit_free_cells(circuit_t *circ)
+{
+ if (!circ->marked_for_close) {
+ log_warn(LD_BUG, "Called on non-marked circuit");
+ return;
+ }
+ cell_queue_clear(&circ->n_chan_cells);
+ if (circ->n_mux)
+ circuitmux_clear_num_cells(circ->n_mux, circ);
+ if (! CIRCUIT_IS_ORIGIN(circ)) {
+ or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
+ cell_queue_clear(&orcirc->p_chan_cells);
+ if (orcirc->p_mux)
+ circuitmux_clear_num_cells(orcirc->p_mux, circ);
+ }
+}
+
+static size_t
+single_conn_free_bytes(connection_t *conn)
+{
+ size_t result = 0;
+ if (conn->inbuf) {
+ result += buf_allocation(conn->inbuf);
+ buf_clear(conn->inbuf);
+ }
+ if (conn->outbuf) {
+ result += buf_allocation(conn->outbuf);
+ buf_clear(conn->outbuf);
+ conn->outbuf_flushlen = 0;
+ }
+ if (conn->type == CONN_TYPE_DIR) {
+ dir_connection_t *dir_conn = TO_DIR_CONN(conn);
+ if (dir_conn->compress_state) {
+ result += tor_compress_state_size(dir_conn->compress_state);
+ tor_compress_free(dir_conn->compress_state);
+ dir_conn->compress_state = NULL;
+ }
+ }
+ return result;
+}
+
+/** Aggressively free buffer contents on all the buffers of all streams in the
+ * list starting at <b>stream</b>. Return the number of bytes recovered. */
+static size_t
+marked_circuit_streams_free_bytes(edge_connection_t *stream)
+{
+ size_t result = 0;
+ for ( ; stream; stream = stream->next_stream) {
+ connection_t *conn = TO_CONN(stream);
+ result += single_conn_free_bytes(conn);
+ if (conn->linked_conn) {
+ result += single_conn_free_bytes(conn->linked_conn);
+ }
+ }
+ return result;
+}
+
+/** Aggressively free buffer contents on all the buffers of all streams on
+ * circuit <b>c</b>. Return the number of bytes recovered. */
+static size_t
+marked_circuit_free_stream_bytes(circuit_t *c)
+{
+ if (CIRCUIT_IS_ORIGIN(c)) {
+ return marked_circuit_streams_free_bytes(TO_ORIGIN_CIRCUIT(c)->p_streams);
+ } else {
+ return marked_circuit_streams_free_bytes(TO_OR_CIRCUIT(c)->n_streams);
+ }
+}
+
+/** Return the number of cells used by the circuit <b>c</b>'s cell queues. */
+STATIC size_t
+n_cells_in_circ_queues(const circuit_t *c)
+{
+ size_t n = c->n_chan_cells.n;
+ if (! CIRCUIT_IS_ORIGIN(c)) {
+ circuit_t *cc = (circuit_t *) c;
+ n += TO_OR_CIRCUIT(cc)->p_chan_cells.n;
+ }
+ return n;
+}
+
+/**
+ * Return the age of the oldest cell queued on <b>c</b>, in timestamp units.
+ * Return 0 if there are no cells queued on c. Requires that <b>now</b> be
+ * the current coarse timestamp.
+ *
+ * This function will return incorrect results if the oldest cell queued on
+ * the circuit is older than about 2**32 msec (about 49 days) old.
+ */
+STATIC uint32_t
+circuit_max_queued_cell_age(const circuit_t *c, uint32_t now)
+{
+ uint32_t age = 0;
+ packed_cell_t *cell;
+
+ if (NULL != (cell = TOR_SIMPLEQ_FIRST(&c->n_chan_cells.head)))
+ age = now - cell->inserted_timestamp;
+
+ if (! CIRCUIT_IS_ORIGIN(c)) {
+ const or_circuit_t *orcirc = CONST_TO_OR_CIRCUIT(c);
+ if (NULL != (cell = TOR_SIMPLEQ_FIRST(&orcirc->p_chan_cells.head))) {
+ uint32_t age2 = now - cell->inserted_timestamp;
+ if (age2 > age)
+ return age2;
+ }
+ }
+ return age;
+}
+
+/** Return the age of the oldest buffer chunk on <b>conn</b>, where age is
+ * taken in timestamp units before the time <b>now</b>. If the connection has
+ * no data, treat it as having age zero.
+ **/
+static uint32_t
+conn_get_buffer_age(const connection_t *conn, uint32_t now_ts)
+{
+ uint32_t age = 0, age2;
+ if (conn->outbuf) {
+ age2 = buf_get_oldest_chunk_timestamp(conn->outbuf, now_ts);
+ if (age2 > age)
+ age = age2;
+ }
+ if (conn->inbuf) {
+ age2 = buf_get_oldest_chunk_timestamp(conn->inbuf, now_ts);
+ if (age2 > age)
+ age = age2;
+ }
+ return age;
+}
+
+/** Return the age in timestamp units of the oldest buffer chunk on any stream
+ * in the linked list <b>stream</b>, where age is taken in timestamp units
+ * before the timestamp <b>now</b>. */
+static uint32_t
+circuit_get_streams_max_data_age(const edge_connection_t *stream, uint32_t now)
+{
+ uint32_t age = 0, age2;
+ for (; stream; stream = stream->next_stream) {
+ const connection_t *conn = TO_CONN(stream);
+ age2 = conn_get_buffer_age(conn, now);
+ if (age2 > age)
+ age = age2;
+ if (conn->linked_conn) {
+ age2 = conn_get_buffer_age(conn->linked_conn, now);
+ if (age2 > age)
+ age = age2;
+ }
+ }
+ return age;
+}
+
+/** Return the age in timestamp units of the oldest buffer chunk on any stream
+ * attached to the circuit <b>c</b>, where age is taken before the timestamp
+ * <b>now</b>. */
+STATIC uint32_t
+circuit_max_queued_data_age(const circuit_t *c, uint32_t now)
+{
+ if (CIRCUIT_IS_ORIGIN(c)) {
+ return circuit_get_streams_max_data_age(
+ CONST_TO_ORIGIN_CIRCUIT(c)->p_streams, now);
+ } else {
+ return circuit_get_streams_max_data_age(
+ CONST_TO_OR_CIRCUIT(c)->n_streams, now);
+ }
+}
+
+/** Return the age of the oldest cell or stream buffer chunk on the circuit
+ * <b>c</b>, where age is taken in timestamp units before the timestamp
+ * <b>now</b> */
+STATIC uint32_t
+circuit_max_queued_item_age(const circuit_t *c, uint32_t now)
+{
+ uint32_t cell_age = circuit_max_queued_cell_age(c, now);
+ uint32_t data_age = circuit_max_queued_data_age(c, now);
+ if (cell_age > data_age)
+ return cell_age;
+ else
+ return data_age;
+}
+
+/** Helper to sort a list of circuit_t by age of oldest item, in descending
+ * order. */
+static int
+circuits_compare_by_oldest_queued_item_(const void **a_, const void **b_)
+{
+ const circuit_t *a = *a_;
+ const circuit_t *b = *b_;
+ uint32_t age_a = a->age_tmp;
+ uint32_t age_b = b->age_tmp;
+
+ if (age_a < age_b)
+ return 1;
+ else if (age_a == age_b)
+ return 0;
+ else
+ return -1;
+}
+
+static uint32_t now_ts_for_buf_cmp;
+
+/** Helper to sort a list of circuit_t by age of oldest item, in descending
+ * order. */
+static int
+conns_compare_by_buffer_age_(const void **a_, const void **b_)
+{
+ const connection_t *a = *a_;
+ const connection_t *b = *b_;
+ time_t age_a = conn_get_buffer_age(a, now_ts_for_buf_cmp);
+ time_t age_b = conn_get_buffer_age(b, now_ts_for_buf_cmp);
+
+ if (age_a < age_b)
+ return 1;
+ else if (age_a == age_b)
+ return 0;
+ else
+ return -1;
+}
+
+#define FRACTION_OF_DATA_TO_RETAIN_ON_OOM 0.90
+
+/** We're out of memory for cells, having allocated <b>current_allocation</b>
+ * bytes' worth. Kill the 'worst' circuits until we're under
+ * FRACTION_OF_DATA_TO_RETAIN_ON_OOM of our maximum usage. */
+void
+circuits_handle_oom(size_t current_allocation)
+{
+ smartlist_t *circlist;
+ smartlist_t *connection_array = get_connection_array();
+ int conn_idx;
+ size_t mem_to_recover;
+ size_t mem_recovered=0;
+ int n_circuits_killed=0;
+ int n_dirconns_killed=0;
+ uint32_t now_ts;
+ log_notice(LD_GENERAL, "We're low on memory (cell queues total alloc:"
+ " %"TOR_PRIuSZ" buffer total alloc: %" TOR_PRIuSZ ","
+ " tor compress total alloc: %" TOR_PRIuSZ
+ " (zlib: %" TOR_PRIuSZ ", zstd: %" TOR_PRIuSZ ","
+ " lzma: %" TOR_PRIuSZ "),"
+ " rendezvous cache total alloc: %" TOR_PRIuSZ "). Killing"
+ " circuits withover-long queues. (This behavior is controlled by"
+ " MaxMemInQueues.)",
+ cell_queues_get_total_allocation(),
+ buf_get_total_allocation(),
+ tor_compress_get_total_allocation(),
+ tor_zlib_get_total_allocation(),
+ tor_zstd_get_total_allocation(),
+ tor_lzma_get_total_allocation(),
+ rend_cache_get_total_allocation());
+
+ {
+ size_t mem_target = (size_t)(get_options()->MaxMemInQueues *
+ FRACTION_OF_DATA_TO_RETAIN_ON_OOM);
+ if (current_allocation <= mem_target)
+ return;
+ mem_to_recover = current_allocation - mem_target;
+ }
+
+ now_ts = monotime_coarse_get_stamp();
+
+ circlist = circuit_get_global_list();
+ SMARTLIST_FOREACH_BEGIN(circlist, circuit_t *, circ) {
+ circ->age_tmp = circuit_max_queued_item_age(circ, now_ts);
+ } SMARTLIST_FOREACH_END(circ);
+
+ /* This is O(n log n); there are faster algorithms we could use instead.
+ * Let's hope this doesn't happen enough to be in the critical path. */
+ smartlist_sort(circlist, circuits_compare_by_oldest_queued_item_);
+
+ /* Fix up the indices before we run into trouble */
+ SMARTLIST_FOREACH_BEGIN(circlist, circuit_t *, circ) {
+ circ->global_circuitlist_idx = circ_sl_idx;
+ } SMARTLIST_FOREACH_END(circ);
+
+ /* Now sort the connection array ... */
+ now_ts_for_buf_cmp = now_ts;
+ smartlist_sort(connection_array, conns_compare_by_buffer_age_);
+ now_ts_for_buf_cmp = 0;
+
+ /* Fix up the connection array to its new order. */
+ SMARTLIST_FOREACH_BEGIN(connection_array, connection_t *, conn) {
+ conn->conn_array_index = conn_sl_idx;
+ } SMARTLIST_FOREACH_END(conn);
+
+ /* Okay, now the worst circuits and connections are at the front of their
+ * respective lists. Let's mark them, and reclaim their storage
+ * aggressively. */
+ conn_idx = 0;
+ SMARTLIST_FOREACH_BEGIN(circlist, circuit_t *, circ) {
+ size_t n;
+ size_t freed;
+
+ /* Free storage in any non-linked directory connections that have buffered
+ * data older than this circuit. */
+ while (conn_idx < smartlist_len(connection_array)) {
+ connection_t *conn = smartlist_get(connection_array, conn_idx);
+ uint32_t conn_age = conn_get_buffer_age(conn, now_ts);
+ if (conn_age < circ->age_tmp) {
+ break;
+ }
+ if (conn->type == CONN_TYPE_DIR && conn->linked_conn == NULL) {
+ if (!conn->marked_for_close)
+ connection_mark_for_close(conn);
+ mem_recovered += single_conn_free_bytes(conn);
+
+ ++n_dirconns_killed;
+
+ if (mem_recovered >= mem_to_recover)
+ goto done_recovering_mem;
+ }
+ ++conn_idx;
+ }
+
+ /* Now, kill the circuit. */
+ n = n_cells_in_circ_queues(circ);
+ if (! circ->marked_for_close) {
+ circuit_mark_for_close(circ, END_CIRC_REASON_RESOURCELIMIT);
+ }
+ marked_circuit_free_cells(circ);
+ freed = marked_circuit_free_stream_bytes(circ);
+
+ ++n_circuits_killed;
+
+ mem_recovered += n * packed_cell_mem_cost();
+ mem_recovered += freed;
+
+ if (mem_recovered >= mem_to_recover)
+ goto done_recovering_mem;
+ } SMARTLIST_FOREACH_END(circ);
+
+ done_recovering_mem:
+
+ log_notice(LD_GENERAL, "Removed %"TOR_PRIuSZ" bytes by killing %d circuits; "
+ "%d circuits remain alive. Also killed %d non-linked directory "
+ "connections.",
+ mem_recovered,
+ n_circuits_killed,
+ smartlist_len(circlist) - n_circuits_killed,
+ n_dirconns_killed);
+}
+
+/** Verify that cpath layer <b>cp</b> has all of its invariants
+ * correct. Trigger an assert if anything is invalid.
+ */
+void
+assert_cpath_layer_ok(const crypt_path_t *cp)
+{
+// tor_assert(cp->addr); /* these are zero for rendezvous extra-hops */
+// tor_assert(cp->port);
+ tor_assert(cp);
+ tor_assert(cp->magic == CRYPT_PATH_MAGIC);
+ switch (cp->state)
+ {
+ case CPATH_STATE_OPEN:
+ relay_crypto_assert_ok(&cp->crypto);
+ /* fall through */
+ case CPATH_STATE_CLOSED:
+ /*XXXX Assert that there's no handshake_state either. */
+ tor_assert(!cp->rend_dh_handshake_state);
+ break;
+ case CPATH_STATE_AWAITING_KEYS:
+ /* tor_assert(cp->dh_handshake_state); */
+ break;
+ default:
+ log_fn(LOG_ERR, LD_BUG, "Unexpected state %d", cp->state);
+ tor_assert(0);
+ }
+ tor_assert(cp->package_window >= 0);
+ tor_assert(cp->deliver_window >= 0);
+}
+
+/** Verify that cpath <b>cp</b> has all of its invariants
+ * correct. Trigger an assert if anything is invalid.
+ */
+static void
+assert_cpath_ok(const crypt_path_t *cp)
+{
+ const crypt_path_t *start = cp;
+
+ do {
+ assert_cpath_layer_ok(cp);
+ /* layers must be in sequence of: "open* awaiting? closed*" */
+ if (cp != start) {
+ if (cp->state == CPATH_STATE_AWAITING_KEYS) {
+ tor_assert(cp->prev->state == CPATH_STATE_OPEN);
+ } else if (cp->state == CPATH_STATE_OPEN) {
+ tor_assert(cp->prev->state == CPATH_STATE_OPEN);
+ }
+ }
+ cp = cp->next;
+ tor_assert(cp);
+ } while (cp != start);
+}
+
+/** Verify that circuit <b>c</b> has all of its invariants
+ * correct. Trigger an assert if anything is invalid.
+ */
+MOCK_IMPL(void,
+assert_circuit_ok,(const circuit_t *c))
+{
+ edge_connection_t *conn;
+ const or_circuit_t *or_circ = NULL;
+ const origin_circuit_t *origin_circ = NULL;
+
+ tor_assert(c);
+ tor_assert(c->magic == ORIGIN_CIRCUIT_MAGIC || c->magic == OR_CIRCUIT_MAGIC);
+ tor_assert(c->purpose >= CIRCUIT_PURPOSE_MIN_ &&
+ c->purpose <= CIRCUIT_PURPOSE_MAX_);
+
+ if (CIRCUIT_IS_ORIGIN(c))
+ origin_circ = CONST_TO_ORIGIN_CIRCUIT(c);
+ else
+ or_circ = CONST_TO_OR_CIRCUIT(c);
+
+ if (c->n_chan) {
+ tor_assert(!c->n_hop);
+
+ if (c->n_circ_id) {
+ /* We use the _impl variant here to make sure we don't fail on marked
+ * circuits, which would not be returned by the regular function. */
+ circuit_t *c2 = circuit_get_by_circid_channel_impl(c->n_circ_id,
+ c->n_chan, NULL);
+ tor_assert(c == c2);
+ }
+ }
+ if (or_circ && or_circ->p_chan) {
+ if (or_circ->p_circ_id) {
+ /* ibid */
+ circuit_t *c2 =
+ circuit_get_by_circid_channel_impl(or_circ->p_circ_id,
+ or_circ->p_chan, NULL);
+ tor_assert(c == c2);
+ }
+ }
+ if (or_circ)
+ for (conn = or_circ->n_streams; conn; conn = conn->next_stream)
+ tor_assert(conn->base_.type == CONN_TYPE_EXIT);
+
+ tor_assert(c->deliver_window >= 0);
+ tor_assert(c->package_window >= 0);
+ if (c->state == CIRCUIT_STATE_OPEN ||
+ c->state == CIRCUIT_STATE_GUARD_WAIT) {
+ tor_assert(!c->n_chan_create_cell);
+ if (or_circ) {
+ relay_crypto_assert_ok(&or_circ->crypto);
+ }
+ }
+ if (c->state == CIRCUIT_STATE_CHAN_WAIT && !c->marked_for_close) {
+ tor_assert(circuits_pending_chans &&
+ smartlist_contains(circuits_pending_chans, c));
+ } else {
+ tor_assert(!circuits_pending_chans ||
+ !smartlist_contains(circuits_pending_chans, c));
+ }
+ if (origin_circ && origin_circ->cpath) {
+ assert_cpath_ok(origin_circ->cpath);
+ }
+ if (c->purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED) {
+ tor_assert(or_circ);
+ if (!c->marked_for_close) {
+ tor_assert(or_circ->rend_splice);
+ tor_assert(or_circ->rend_splice->rend_splice == or_circ);
+ }
+ tor_assert(or_circ->rend_splice != or_circ);
+ } else {
+ tor_assert(!or_circ || !or_circ->rend_splice);
+ }
+}
diff --cc src/core/or/connection_edge.c
index ab3c14d2c,000000000..2cc54f774
mode 100644,000000..100644
--- a/src/core/or/connection_edge.c
+++ b/src/core/or/connection_edge.c
@@@ -1,4219 -1,0 +1,4445 @@@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file connection_edge.c
+ * \brief Handle edge streams.
+ *
+ * An edge_connection_t is a subtype of a connection_t, and represents two
+ * critical concepts in Tor: a stream, and an edge connection. From the Tor
+ * protocol's point of view, a stream is a bi-directional channel that is
+ * multiplexed on a single circuit. Each stream on a circuit is identified
+ * with a separate 16-bit stream ID, local to the (circuit,exit) pair.
+ * Streams are created in response to client requests.
+ *
+ * An edge connection is one thing that can implement a stream: it is either a
+ * TCP application socket that has arrived via (e.g.) a SOCKS request, or an
+ * exit connection.
+ *
+ * Not every instance of edge_connection_t truly represents an edge connction,
+ * however. (Sorry!) We also create edge_connection_t objects for streams that
+ * we will not be handling with TCP. The types of these streams are:
+ * <ul>
+ * <li>DNS lookup streams, created on the client side in response to
+ * a UDP DNS request received on a DNSPort, or a RESOLVE command
+ * on a controller.
+ * <li>DNS lookup streams, created on the exit side in response to
+ * a RELAY_RESOLVE cell from a client.
+ * <li>Tunneled directory streams, created on the directory cache side
+ * in response to a RELAY_BEGIN_DIR cell. These streams attach directly
+ * to a dir_connection_t object without ever using TCP.
+ * </ul>
+ *
+ * This module handles general-purpose functionality having to do with
+ * edge_connection_t. On the client side, it accepts various types of
+ * application requests on SocksPorts, TransPorts, and NATDPorts, and
+ * creates streams appropriately.
+ *
+ * This module is also responsible for implementing stream isolation:
+ * ensuring that streams that should not be linkable to one another are
+ * kept to different circuits.
+ *
+ * On the exit side, this module handles the various stream-creating
+ * type of RELAY cells by launching appropriate outgoing connections,
+ * DNS requests, or directory connection objects.
+ *
+ * And for all edge connections, this module is responsible for handling
+ * incoming and outdoing data as it arrives or leaves in the relay.c
+ * module. (Outgoing data will be packaged in
+ * connection_edge_process_inbuf() as it calls
+ * connection_edge_package_raw_inbuf(); incoming data from RELAY_DATA
+ * cells is applied in connection_edge_process_relay_cell().)
+ **/
+#define CONNECTION_EDGE_PRIVATE
+
+#include "core/or/or.h"
+
+#include "lib/err/backtrace.h"
+
+#include "feature/client/addressmap.h"
+#include "lib/container/buffers.h"
+#include "core/or/channel.h"
+#include "feature/client/circpathbias.h"
+#include "core/or/circuitlist.h"
+#include "core/or/circuituse.h"
+#include "app/config/config.h"
+#include "core/mainloop/connection.h"
+#include "core/or/connection_edge.h"
+#include "core/or/connection_or.h"
+#include "feature/control/control.h"
+#include "lib/crypt_ops/crypto_util.h"
+#include "feature/relay/dns.h"
+#include "feature/client/dnsserv.h"
+#include "feature/dircache/directory.h"
+#include "feature/dircache/dirserv.h"
+#include "feature/hibernate/hibernate.h"
+#include "feature/hs/hs_common.h"
+#include "feature/hs/hs_cache.h"
+#include "feature/hs/hs_client.h"
+#include "feature/hs/hs_circuit.h"
+#include "core/mainloop/main.h"
+#include "feature/nodelist/networkstatus.h"
+#include "feature/nodelist/nodelist.h"
+#include "core/or/policies.h"
+#include "core/proto/proto_http.h"
+#include "core/proto/proto_socks.h"
+#include "core/or/reasons.h"
+#include "core/or/relay.h"
+#include "feature/rend/rendclient.h"
+#include "feature/rend/rendcommon.h"
+#include "feature/rend/rendservice.h"
+#include "feature/stats/rephist.h"
+#include "feature/relay/router.h"
+#include "feature/nodelist/routerlist.h"
+#include "feature/nodelist/routerset.h"
+#include "core/or/circuitbuild.h"
+
+#include "core/or/cell_st.h"
+#include "core/or/cpath_build_state_st.h"
+#include "feature/dircommon/dir_connection_st.h"
+#include "core/or/entry_connection_st.h"
+#include "core/or/extend_info_st.h"
+#include "feature/nodelist/node_st.h"
+#include "core/or/or_circuit_st.h"
+#include "core/or/origin_circuit_st.h"
++#include "core/or/half_edge_st.h"
+#include "core/or/socks_request_st.h"
+#include "lib/evloop/compat_libevent.h"
+
+#ifdef HAVE_LINUX_TYPES_H
+#include <linux/types.h>
+#endif
+#ifdef HAVE_LINUX_NETFILTER_IPV4_H
+#include <linux/netfilter_ipv4.h>
+#define TRANS_NETFILTER
+#define TRANS_NETFILTER_IPV4
+#endif
+
+#ifdef HAVE_LINUX_IF_H
+#include <linux/if.h>
+#endif
+
+#ifdef HAVE_LINUX_NETFILTER_IPV6_IP6_TABLES_H
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#if defined(IP6T_SO_ORIGINAL_DST)
+#define TRANS_NETFILTER
+#define TRANS_NETFILTER_IPV6
+#endif
+#endif /* defined(HAVE_LINUX_NETFILTER_IPV6_IP6_TABLES_H) */
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+
+#if defined(HAVE_NET_IF_H) && defined(HAVE_NET_PFVAR_H)
+#include <net/if.h>
+#include <net/pfvar.h>
+#define TRANS_PF
+#endif
+
+#ifdef IP_TRANSPARENT
+#define TRANS_TPROXY
+#endif
+
+#define SOCKS4_GRANTED 90
+#define SOCKS4_REJECT 91
+
+static int connection_ap_handshake_process_socks(entry_connection_t *conn);
+static int connection_ap_process_natd(entry_connection_t *conn);
+static int connection_exit_connect_dir(edge_connection_t *exitconn);
+static int consider_plaintext_ports(entry_connection_t *conn, uint16_t port);
+static int connection_ap_supports_optimistic_data(const entry_connection_t *);
++STATIC void connection_half_edge_add(const edge_connection_t *conn,
++ origin_circuit_t *circ);
++STATIC half_edge_t *connection_half_edge_find_stream_id(
++ const smartlist_t *half_conns,
++ streamid_t stream_id);
+
+/** Convert a connection_t* to an edge_connection_t*; assert if the cast is
+ * invalid. */
+edge_connection_t *
+TO_EDGE_CONN(connection_t *c)
+{
+ tor_assert(c->magic == EDGE_CONNECTION_MAGIC ||
+ c->magic == ENTRY_CONNECTION_MAGIC);
+ return DOWNCAST(edge_connection_t, c);
+}
+
+entry_connection_t *
+TO_ENTRY_CONN(connection_t *c)
+{
+ tor_assert(c->magic == ENTRY_CONNECTION_MAGIC);
+ return (entry_connection_t*) SUBTYPE_P(c, entry_connection_t, edge_.base_);
+}
+
+entry_connection_t *
+EDGE_TO_ENTRY_CONN(edge_connection_t *c)
+{
+ tor_assert(c->base_.magic == ENTRY_CONNECTION_MAGIC);
+ return (entry_connection_t*) SUBTYPE_P(c, entry_connection_t, edge_);
+}
+
+/** An AP stream has failed/finished. If it hasn't already sent back
+ * a socks reply, send one now (based on endreason). Also set
+ * has_sent_end to 1, and mark the conn.
+ */
+MOCK_IMPL(void,
+connection_mark_unattached_ap_,(entry_connection_t *conn, int endreason,
+ int line, const char *file))
+{
+ connection_t *base_conn = ENTRY_TO_CONN(conn);
+ edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
+ tor_assert(base_conn->type == CONN_TYPE_AP);
+ ENTRY_TO_EDGE_CONN(conn)->edge_has_sent_end = 1; /* no circ yet */
+
+ /* If this is a rendezvous stream and it is failing without ever
+ * being attached to a circuit, assume that an attempt to connect to
+ * the destination hidden service has just ended.
+ *
+ * XXXX This condition doesn't limit to only streams failing
+ * without ever being attached. That sloppiness should be harmless,
+ * but we should fix it someday anyway. */
+ if ((edge_conn->on_circuit != NULL || edge_conn->edge_has_sent_end) &&
+ connection_edge_is_rendezvous_stream(edge_conn)) {
+ if (edge_conn->rend_data) {
+ rend_client_note_connection_attempt_ended(edge_conn->rend_data);
+ }
+ }
+
+ if (base_conn->marked_for_close) {
+ /* This call will warn as appropriate. */
+ connection_mark_for_close_(base_conn, line, file);
+ return;
+ }
+
+ if (!conn->socks_request->has_finished) {
+ if (endreason & END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED)
+ log_warn(LD_BUG,
+ "stream (marked at %s:%d) sending two socks replies?",
+ file, line);
+
+ if (SOCKS_COMMAND_IS_CONNECT(conn->socks_request->command))
+ connection_ap_handshake_socks_reply(conn, NULL, 0, endreason);
+ else if (SOCKS_COMMAND_IS_RESOLVE(conn->socks_request->command))
+ connection_ap_handshake_socks_resolved(conn,
+ RESOLVED_TYPE_ERROR_TRANSIENT,
+ 0, NULL, -1, -1);
+ else /* unknown or no handshake at all. send no response. */
+ conn->socks_request->has_finished = 1;
+ }
+
+ connection_mark_and_flush_(base_conn, line, file);
+
+ ENTRY_TO_EDGE_CONN(conn)->end_reason = endreason;
+}
+
+/** There was an EOF. Send an end and mark the connection for close.
+ */
+int
+connection_edge_reached_eof(edge_connection_t *conn)
+{
+ if (connection_get_inbuf_len(TO_CONN(conn)) &&
+ connection_state_is_open(TO_CONN(conn))) {
+ /* it still has stuff to process. don't let it die yet. */
+ return 0;
+ }
+ log_info(LD_EDGE,"conn (fd "TOR_SOCKET_T_FORMAT") reached eof. Closing.",
+ conn->base_.s);
+ if (!conn->base_.marked_for_close) {
+ /* only mark it if not already marked. it's possible to
+ * get the 'end' right around when the client hangs up on us. */
+ connection_edge_end(conn, END_STREAM_REASON_DONE);
+ if (conn->base_.type == CONN_TYPE_AP) {
+ /* eof, so don't send a socks reply back */
+ if (EDGE_TO_ENTRY_CONN(conn)->socks_request)
+ EDGE_TO_ENTRY_CONN(conn)->socks_request->has_finished = 1;
+ }
+ connection_mark_for_close(TO_CONN(conn));
+ }
+ return 0;
+}
+
+/** Handle new bytes on conn->inbuf based on state:
+ * - If it's waiting for socks info, try to read another step of the
+ * socks handshake out of conn->inbuf.
+ * - If it's waiting for the original destination, fetch it.
+ * - If it's open, then package more relay cells from the stream.
+ * - Else, leave the bytes on inbuf alone for now.
+ *
+ * Mark and return -1 if there was an unexpected error with the conn,
+ * else return 0.
+ */
+int
+connection_edge_process_inbuf(edge_connection_t *conn, int package_partial)
+{
+ tor_assert(conn);
+
+ switch (conn->base_.state) {
+ case AP_CONN_STATE_SOCKS_WAIT:
+ if (connection_ap_handshake_process_socks(EDGE_TO_ENTRY_CONN(conn)) <0) {
+ /* already marked */
+ return -1;
+ }
+ return 0;
+ case AP_CONN_STATE_NATD_WAIT:
+ if (connection_ap_process_natd(EDGE_TO_ENTRY_CONN(conn)) < 0) {
+ /* already marked */
+ return -1;
+ }
+ return 0;
+ case AP_CONN_STATE_HTTP_CONNECT_WAIT:
+ if (connection_ap_process_http_connect(EDGE_TO_ENTRY_CONN(conn)) < 0) {
+ return -1;
+ }
+ return 0;
+ case AP_CONN_STATE_OPEN:
+ case EXIT_CONN_STATE_OPEN:
+ if (connection_edge_package_raw_inbuf(conn, package_partial, NULL) < 0) {
+ /* (We already sent an end cell if possible) */
+ connection_mark_for_close(TO_CONN(conn));
+ return -1;
+ }
+ return 0;
+ case AP_CONN_STATE_CONNECT_WAIT:
+ if (connection_ap_supports_optimistic_data(EDGE_TO_ENTRY_CONN(conn))) {
+ log_info(LD_EDGE,
+ "data from edge while in '%s' state. Sending it anyway. "
+ "package_partial=%d, buflen=%ld",
+ conn_state_to_string(conn->base_.type, conn->base_.state),
+ package_partial,
+ (long)connection_get_inbuf_len(TO_CONN(conn)));
+ if (connection_edge_package_raw_inbuf(conn, package_partial, NULL)<0) {
+ /* (We already sent an end cell if possible) */
+ connection_mark_for_close(TO_CONN(conn));
+ return -1;
+ }
+ return 0;
+ }
+ /* Fall through if the connection is on a circuit without optimistic
+ * data support. */
+ /* Falls through. */
+ case EXIT_CONN_STATE_CONNECTING:
+ case AP_CONN_STATE_RENDDESC_WAIT:
+ case AP_CONN_STATE_CIRCUIT_WAIT:
+ case AP_CONN_STATE_RESOLVE_WAIT:
+ case AP_CONN_STATE_CONTROLLER_WAIT:
+ log_info(LD_EDGE,
+ "data from edge while in '%s' state. Leaving it on buffer.",
+ conn_state_to_string(conn->base_.type, conn->base_.state));
+ return 0;
+ }
+ log_warn(LD_BUG,"Got unexpected state %d. Closing.",conn->base_.state);
+ tor_fragile_assert();
+ connection_edge_end(conn, END_STREAM_REASON_INTERNAL);
+ connection_mark_for_close(TO_CONN(conn));
+ return -1;
+}
+
+/** This edge needs to be closed, because its circuit has closed.
+ * Mark it for close and return 0.
+ */
+int
+connection_edge_destroy(circid_t circ_id, edge_connection_t *conn)
+{
+ if (!conn->base_.marked_for_close) {
+ log_info(LD_EDGE, "CircID %u: At an edge. Marking connection for close.",
+ (unsigned) circ_id);
+ if (conn->base_.type == CONN_TYPE_AP) {
+ entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn);
+ connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_DESTROY);
+ control_event_stream_bandwidth(conn);
+ control_event_stream_status(entry_conn, STREAM_EVENT_CLOSED,
+ END_STREAM_REASON_DESTROY);
+ conn->end_reason |= END_STREAM_REASON_FLAG_ALREADY_SENT_CLOSED;
+ } else {
+ /* closing the circuit, nothing to send an END to */
+ conn->edge_has_sent_end = 1;
+ conn->end_reason = END_STREAM_REASON_DESTROY;
+ conn->end_reason |= END_STREAM_REASON_FLAG_ALREADY_SENT_CLOSED;
+ connection_mark_and_flush(TO_CONN(conn));
+ }
+ }
+ conn->cpath_layer = NULL;
+ conn->on_circuit = NULL;
+ return 0;
+}
+
+/** Send a raw end cell to the stream with ID <b>stream_id</b> out over the
+ * <b>circ</b> towards the hop identified with <b>cpath_layer</b>. If this
+ * is not a client connection, set the relay end cell's reason for closing
+ * as <b>reason</b> */
+static int
+relay_send_end_cell_from_edge(streamid_t stream_id, circuit_t *circ,
+ uint8_t reason, crypt_path_t *cpath_layer)
+{
+ char payload[1];
+
+ if (CIRCUIT_PURPOSE_IS_CLIENT(circ->purpose)) {
+ /* Never send the server an informative reason code; it doesn't need to
+ * know why the client stream is failing. */
+ reason = END_STREAM_REASON_MISC;
+ }
+
+ payload[0] = (char) reason;
+
+ /* Note: we have to use relay_send_command_from_edge here, not
+ * connection_edge_end or connection_edge_send_command, since those require
+ * that we have a stream connected to a circuit, and we don't connect to a
+ * circuit until we have a pending/successful resolve. */
+ return relay_send_command_from_edge(stream_id, circ, RELAY_COMMAND_END,
+ payload, 1, cpath_layer);
+}
+
+/* If the connection <b>conn</b> is attempting to connect to an external
+ * destination that is an hidden service and the reason is a connection
+ * refused or timeout, log it so the operator can take appropriate actions.
+ * The log statement is a rate limited warning. */
+static void
+warn_if_hs_unreachable(const edge_connection_t *conn, uint8_t reason)
+{
+ tor_assert(conn);
+
+ if (conn->base_.type == CONN_TYPE_EXIT &&
+ connection_edge_is_rendezvous_stream(conn) &&
+ (reason == END_STREAM_REASON_CONNECTREFUSED ||
+ reason == END_STREAM_REASON_TIMEOUT)) {
+#define WARN_FAILED_HS_CONNECTION 300
+ static ratelim_t warn_limit = RATELIM_INIT(WARN_FAILED_HS_CONNECTION);
+ char *m;
+ if ((m = rate_limit_log(&warn_limit, approx_time()))) {
+ log_warn(LD_EDGE, "Onion service connection to %s failed (%s)",
+ (conn->base_.socket_family == AF_UNIX) ?
+ safe_str(conn->base_.address) :
+ safe_str(fmt_addrport(&conn->base_.addr, conn->base_.port)),
+ stream_end_reason_to_string(reason));
+ tor_free(m);
+ }
+ }
+}
+
+/** Send a relay end cell from stream <b>conn</b> down conn's circuit, and
+ * remember that we've done so. If this is not a client connection, set the
+ * relay end cell's reason for closing as <b>reason</b>.
+ *
+ * Return -1 if this function has already been called on this conn,
+ * else return 0.
+ */
+int
+connection_edge_end(edge_connection_t *conn, uint8_t reason)
+{
+ char payload[RELAY_PAYLOAD_SIZE];
+ size_t payload_len=1;
+ circuit_t *circ;
+ uint8_t control_reason = reason;
+
+ if (conn->edge_has_sent_end) {
+ log_warn(LD_BUG,"(Harmless.) Calling connection_edge_end (reason %d) "
+ "on an already ended stream?", reason);
+ tor_fragile_assert();
+ return -1;
+ }
+
+ if (conn->base_.marked_for_close) {
+ log_warn(LD_BUG,
+ "called on conn that's already marked for close at %s:%d.",
+ conn->base_.marked_for_close_file, conn->base_.marked_for_close);
+ return 0;
+ }
+
+ circ = circuit_get_by_edge_conn(conn);
+ if (circ && CIRCUIT_PURPOSE_IS_CLIENT(circ->purpose)) {
+ /* If this is a client circuit, don't send the server an informative
+ * reason code; it doesn't need to know why the client stream is
+ * failing. */
+ reason = END_STREAM_REASON_MISC;
+ }
+
+ payload[0] = (char)reason;
+ if (reason == END_STREAM_REASON_EXITPOLICY &&
+ !connection_edge_is_rendezvous_stream(conn)) {
+ int addrlen;
+ if (tor_addr_family(&conn->base_.addr) == AF_INET) {
+ set_uint32(payload+1, tor_addr_to_ipv4n(&conn->base_.addr));
+ addrlen = 4;
+ } else {
+ memcpy(payload+1, tor_addr_to_in6_addr8(&conn->base_.addr), 16);
+ addrlen = 16;
+ }
+ set_uint32(payload+1+addrlen, htonl(dns_clip_ttl(conn->address_ttl)));
+ payload_len += 4+addrlen;
+ }
+
+ if (circ && !circ->marked_for_close) {
+ log_debug(LD_EDGE,"Sending end on conn (fd "TOR_SOCKET_T_FORMAT").",
+ conn->base_.s);
++
++ if (CIRCUIT_IS_ORIGIN(circ)) {
++ origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(circ);
++ connection_half_edge_add(conn, origin_circ);
++ }
++
+ connection_edge_send_command(conn, RELAY_COMMAND_END,
+ payload, payload_len);
+ /* We'll log warn if the connection was an hidden service and couldn't be
+ * made because the service wasn't available. */
+ warn_if_hs_unreachable(conn, control_reason);
+ } else {
+ log_debug(LD_EDGE,"No circ to send end on conn "
+ "(fd "TOR_SOCKET_T_FORMAT").",
+ conn->base_.s);
+ }
+
+ conn->edge_has_sent_end = 1;
+ conn->end_reason = control_reason;
+ return 0;
+}
+
++/**
++ * Helper function for bsearch.
++ *
++ * As per smartlist_bsearch, return < 0 if key preceeds member,
++ * > 0 if member preceeds key, and 0 if they are equal.
++ *
++ * This is equivalent to subtraction of the values of key - member
++ * (why does no one ever say that explicitly?).
++ */
++static int
++connection_half_edge_compare_bsearch(const void *key, const void **member)
++{
++ const half_edge_t *e2;
++ tor_assert(key);
++ tor_assert(member && *(half_edge_t**)member);
++ e2 = *(const half_edge_t **)member;
++
++ return *(const streamid_t*)key - e2->stream_id;
++}
++
++/**
++ * Add a half-closed connection to the list, to watch for activity.
++ *
++ * These connections are removed from the list upon receiving an end
++ * cell.
++ */
++STATIC void
++connection_half_edge_add(const edge_connection_t *conn,
++ origin_circuit_t *circ)
++{
++ half_edge_t *half_conn = NULL;
++ int insert_at = 0;
++ int ignored;
++
++ /* Double-check for re-insertion. This should not happen,
++ * but this check is cheap compared to the sort anyway */
++ if (connection_half_edge_find_stream_id(circ->half_streams,
++ conn->stream_id)) {
++ log_warn(LD_BUG, "Duplicate stream close for stream %d on circuit %d",
++ conn->stream_id, circ->global_identifier);
++ return;
++ }
++
++ half_conn = tor_malloc_zero(sizeof(half_edge_t));
++
++ if (!circ->half_streams) {
++ circ->half_streams = smartlist_new();
++ }
++
++ half_conn->stream_id = conn->stream_id;
++
++ // How many sendme's should I expect?
++ half_conn->sendmes_pending =
++ (STREAMWINDOW_START-conn->package_window)/STREAMWINDOW_INCREMENT;
++
++ // Is there a connected cell pending?
++ half_conn->connected_pending = conn->base_.state ==
++ AP_CONN_STATE_CONNECT_WAIT;
++
++ /* Data should only arrive if we're not waiting on a resolved cell.
++ * It can arrive after waiting on connected, because of optimistic
++ * data. */
++ if (conn->base_.state != AP_CONN_STATE_RESOLVE_WAIT) {
++ // How many more data cells can arrive on this id?
++ half_conn->data_pending = conn->deliver_window;
++ }
++
++ insert_at = smartlist_bsearch_idx(circ->half_streams, &half_conn->stream_id,
++ connection_half_edge_compare_bsearch,
++ &ignored);
++ smartlist_insert(circ->half_streams, insert_at, half_conn);
++}
++
++/**
++ * Find a stream_id_t in the list in O(lg(n)).
++ *
++ * Returns NULL if the list is empty or element is not found.
++ * Returns a pointer to the element if found.
++ */
++STATIC half_edge_t *
++connection_half_edge_find_stream_id(const smartlist_t *half_conns,
++ streamid_t stream_id)
++{
++ if (!half_conns)
++ return NULL;
++
++ return smartlist_bsearch(half_conns, &stream_id,
++ connection_half_edge_compare_bsearch);
++}
++
++/**
++ * Check if this stream_id is in a half-closed state. If so,
++ * check if it still has data cells pending, and decrement that
++ * window if so.
++ *
++ * Return 1 if the data window was not empty.
++ * Return 0 otherwise.
++ */
++int
++connection_half_edge_is_valid_data(const smartlist_t *half_conns,
++ streamid_t stream_id)
++{
++ half_edge_t *half = connection_half_edge_find_stream_id(half_conns,
++ stream_id);
++
++ if (!half)
++ return 0;
++
++ if (half->data_pending > 0) {
++ half->data_pending--;
++ return 1;
++ }
++
++ return 0;
++}
++
++/**
++ * Check if this stream_id is in a half-closed state. If so,
++ * check if it still has a connected cell pending, and decrement
++ * that window if so.
++ *
++ * Return 1 if the connected window was not empty.
++ * Return 0 otherwise.
++ */
++int
++connection_half_edge_is_valid_connected(const smartlist_t *half_conns,
++ streamid_t stream_id)
++{
++ half_edge_t *half = connection_half_edge_find_stream_id(half_conns,
++ stream_id);
++
++ if (!half)
++ return 0;
++
++ if (half->connected_pending) {
++ half->connected_pending = 0;
++ return 1;
++ }
++
++ return 0;
++}
++
++/**
++ * Check if this stream_id is in a half-closed state. If so,
++ * check if it still has sendme cells pending, and decrement that
++ * window if so.
++ *
++ * Return 1 if the sendme window was not empty.
++ * Return 0 otherwise.
++ */
++int
++connection_half_edge_is_valid_sendme(const smartlist_t *half_conns,
++ streamid_t stream_id)
++{
++ half_edge_t *half = connection_half_edge_find_stream_id(half_conns,
++ stream_id);
++
++ if (!half)
++ return 0;
++
++ if (half->sendmes_pending > 0) {
++ half->sendmes_pending--;
++ return 1;
++ }
++
++ return 0;
++}
++
++/**
++ * Check if this stream_id is in a half-closed state. If so, remove
++ * it from the list. No other data should come after the END cell.
++ *
++ * Return 1 if stream_id was in half-closed state.
++ * Return 0 otherwise.
++ */
++int
++connection_half_edge_is_valid_end(smartlist_t *half_conns,
++ streamid_t stream_id)
++{
++ half_edge_t *half;
++ int found, remove_idx;
++
++ if (!half_conns)
++ return 0;
++
++ remove_idx = smartlist_bsearch_idx(half_conns, &stream_id,
++ connection_half_edge_compare_bsearch,
++ &found);
++ if (!found)
++ return 0;
++
++ half = smartlist_get(half_conns, remove_idx);
++ smartlist_del_keeporder(half_conns, remove_idx);
++ tor_free(half);
++ return 1;
++}
++
++/**
++ * Streams that were used to send a RESOLVE cell are closed
++ * when they get the RESOLVED, without an end. So treat
++ * a RESOLVED just like an end, and remove from the list.
++ */
++int
++connection_half_edge_is_valid_resolved(smartlist_t *half_conns,
++ streamid_t stream_id)
++{
++ return connection_half_edge_is_valid_end(half_conns, stream_id);
++}
++
+/** An error has just occurred on an operation on an edge connection
+ * <b>conn</b>. Extract the errno; convert it to an end reason, and send an
+ * appropriate relay end cell to the other end of the connection's circuit.
+ **/
+int
+connection_edge_end_errno(edge_connection_t *conn)
+{
+ uint8_t reason;
+ tor_assert(conn);
+ reason = errno_to_stream_end_reason(tor_socket_errno(conn->base_.s));
+ return connection_edge_end(conn, reason);
+}
+
+/** We just wrote some data to <b>conn</b>; act appropriately.
+ *
+ * (That is, if it's open, consider sending a stream-level sendme cell if we
+ * have just flushed enough.)
+ */
+int
+connection_edge_flushed_some(edge_connection_t *conn)
+{
+ switch (conn->base_.state) {
+ case AP_CONN_STATE_OPEN:
+ case EXIT_CONN_STATE_OPEN:
+ connection_edge_consider_sending_sendme(conn);
+ break;
+ }
+ return 0;
+}
+
+/** Connection <b>conn</b> has finished writing and has no bytes left on
+ * its outbuf.
+ *
+ * If it's in state 'open', stop writing, consider responding with a
+ * sendme, and return.
+ * Otherwise, stop writing and return.
+ *
+ * If <b>conn</b> is broken, mark it for close and return -1, else
+ * return 0.
+ */
+int
+connection_edge_finished_flushing(edge_connection_t *conn)
+{
+ tor_assert(conn);
+
+ switch (conn->base_.state) {
+ case AP_CONN_STATE_OPEN:
+ case EXIT_CONN_STATE_OPEN:
+ connection_edge_consider_sending_sendme(conn);
+ return 0;
+ case AP_CONN_STATE_SOCKS_WAIT:
+ case AP_CONN_STATE_NATD_WAIT:
+ case AP_CONN_STATE_RENDDESC_WAIT:
+ case AP_CONN_STATE_CIRCUIT_WAIT:
+ case AP_CONN_STATE_CONNECT_WAIT:
+ case AP_CONN_STATE_CONTROLLER_WAIT:
+ case AP_CONN_STATE_RESOLVE_WAIT:
+ case AP_CONN_STATE_HTTP_CONNECT_WAIT:
+ return 0;
+ default:
+ log_warn(LD_BUG, "Called in unexpected state %d.",conn->base_.state);
+ tor_fragile_assert();
+ return -1;
+ }
+ return 0;
+}
+
+/** Longest size for the relay payload of a RELAY_CONNECTED cell that we're
+ * able to generate. */
+/* 4 zero bytes; 1 type byte; 16 byte IPv6 address; 4 byte TTL. */
+#define MAX_CONNECTED_CELL_PAYLOAD_LEN 25
+
+/** Set the buffer at <b>payload_out</b> -- which must have at least
+ * MAX_CONNECTED_CELL_PAYLOAD_LEN bytes available -- to the body of a
+ * RELAY_CONNECTED cell indicating that we have connected to <b>addr</b>, and
+ * that the name resolution that led us to <b>addr</b> will be valid for
+ * <b>ttl</b> seconds. Return -1 on error, or the number of bytes used on
+ * success. */
+STATIC int
+connected_cell_format_payload(uint8_t *payload_out,
+ const tor_addr_t *addr,
+ uint32_t ttl)
+{
+ const sa_family_t family = tor_addr_family(addr);
+ int connected_payload_len;
+
+ /* should be needless */
+ memset(payload_out, 0, MAX_CONNECTED_CELL_PAYLOAD_LEN);
+
+ if (family == AF_INET) {
+ set_uint32(payload_out, tor_addr_to_ipv4n(addr));
+ connected_payload_len = 4;
+ } else if (family == AF_INET6) {
+ set_uint32(payload_out, 0);
+ set_uint8(payload_out + 4, 6);
+ memcpy(payload_out + 5, tor_addr_to_in6_addr8(addr), 16);
+ connected_payload_len = 21;
+ } else {
+ return -1;
+ }
+
+ set_uint32(payload_out + connected_payload_len, htonl(dns_clip_ttl(ttl)));
+ connected_payload_len += 4;
+
+ tor_assert(connected_payload_len <= MAX_CONNECTED_CELL_PAYLOAD_LEN);
+
+ return connected_payload_len;
+}
+
+/** Connected handler for exit connections: start writing pending
+ * data, deliver 'CONNECTED' relay cells as appropriate, and check
+ * any pending data that may have been received. */
+int
+connection_edge_finished_connecting(edge_connection_t *edge_conn)
+{
+ connection_t *conn;
+
+ tor_assert(edge_conn);
+ tor_assert(edge_conn->base_.type == CONN_TYPE_EXIT);
+ conn = TO_CONN(edge_conn);
+ tor_assert(conn->state == EXIT_CONN_STATE_CONNECTING);
+
+ log_info(LD_EXIT,"Exit connection to %s:%u (%s) established.",
+ escaped_safe_str(conn->address), conn->port,
+ safe_str(fmt_and_decorate_addr(&conn->addr)));
+
+ rep_hist_note_exit_stream_opened(conn->port);
+
+ conn->state = EXIT_CONN_STATE_OPEN;
+ connection_watch_events(conn, READ_EVENT); /* stop writing, keep reading */
+ if (connection_get_outbuf_len(conn)) /* in case there are any queued relay
+ * cells */
+ connection_start_writing(conn);
+ /* deliver a 'connected' relay cell back through the circuit. */
+ if (connection_edge_is_rendezvous_stream(edge_conn)) {
+ if (connection_edge_send_command(edge_conn,
+ RELAY_COMMAND_CONNECTED, NULL, 0) < 0)
+ return 0; /* circuit is closed, don't continue */
+ } else {
+ uint8_t connected_payload[MAX_CONNECTED_CELL_PAYLOAD_LEN];
+ int connected_payload_len =
+ connected_cell_format_payload(connected_payload, &conn->addr,
+ edge_conn->address_ttl);
+ if (connected_payload_len < 0)
+ return -1;
+
+ if (connection_edge_send_command(edge_conn,
+ RELAY_COMMAND_CONNECTED,
+ (char*)connected_payload, connected_payload_len) < 0)
+ return 0; /* circuit is closed, don't continue */
+ }
+ tor_assert(edge_conn->package_window > 0);
+ /* in case the server has written anything */
+ return connection_edge_process_inbuf(edge_conn, 1);
+}
+
+/** A list of all the entry_connection_t * objects that are not marked
+ * for close, and are in AP_CONN_STATE_CIRCUIT_WAIT.
+ *
+ * (Right now, we check in several places to make sure that this list is
+ * correct. When it's incorrect, we'll fix it, and log a BUG message.)
+ */
+static smartlist_t *pending_entry_connections = NULL;
+
+static int untried_pending_connections = 0;
+
+/**
+ * Mainloop event to tell us to scan for pending connections that can
+ * be attached.
+ */
+static mainloop_event_t *attach_pending_entry_connections_ev = NULL;
+
+/** Common code to connection_(ap|exit)_about_to_close. */
+static void
+connection_edge_about_to_close(edge_connection_t *edge_conn)
+{
+ if (!edge_conn->edge_has_sent_end) {
+ connection_t *conn = TO_CONN(edge_conn);
+ log_warn(LD_BUG, "(Harmless.) Edge connection (marked at %s:%d) "
+ "hasn't sent end yet?",
+ conn->marked_for_close_file, conn->marked_for_close);
+ tor_fragile_assert();
+ }
+}
+
+/** Called when we're about to finally unlink and free an AP (client)
+ * connection: perform necessary accounting and cleanup */
+void
+connection_ap_about_to_close(entry_connection_t *entry_conn)
+{
+ circuit_t *circ;
+ edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(entry_conn);
+ connection_t *conn = ENTRY_TO_CONN(entry_conn);
+
+ connection_edge_about_to_close(edge_conn);
+
+ if (entry_conn->socks_request->has_finished == 0) {
+ /* since conn gets removed right after this function finishes,
+ * there's no point trying to send back a reply at this point. */
+ log_warn(LD_BUG,"Closing stream (marked at %s:%d) without sending"
+ " back a socks reply.",
+ conn->marked_for_close_file, conn->marked_for_close);
+ }
+ if (!edge_conn->end_reason) {
+ log_warn(LD_BUG,"Closing stream (marked at %s:%d) without having"
+ " set end_reason.",
+ conn->marked_for_close_file, conn->marked_for_close);
+ }
+ if (entry_conn->dns_server_request) {
+ log_warn(LD_BUG,"Closing stream (marked at %s:%d) without having"
+ " replied to DNS request.",
+ conn->marked_for_close_file, conn->marked_for_close);
+ dnsserv_reject_request(entry_conn);
+ }
+
+ if (TO_CONN(edge_conn)->state == AP_CONN_STATE_CIRCUIT_WAIT) {
+ smartlist_remove(pending_entry_connections, entry_conn);
+ }
+
+#if 1
+ /* Check to make sure that this isn't in pending_entry_connections if it
+ * didn't actually belong there. */
+ if (TO_CONN(edge_conn)->type == CONN_TYPE_AP) {
+ connection_ap_warn_and_unmark_if_pending_circ(entry_conn,
+ "about_to_close");
+ }
+#endif /* 1 */
+
+ control_event_stream_bandwidth(edge_conn);
+ control_event_stream_status(entry_conn, STREAM_EVENT_CLOSED,
+ edge_conn->end_reason);
+ circ = circuit_get_by_edge_conn(edge_conn);
+ if (circ)
+ circuit_detach_stream(circ, edge_conn);
+}
+
+/** Called when we're about to finally unlink and free an exit
+ * connection: perform necessary accounting and cleanup */
+void
+connection_exit_about_to_close(edge_connection_t *edge_conn)
+{
+ circuit_t *circ;
+ connection_t *conn = TO_CONN(edge_conn);
+
+ connection_edge_about_to_close(edge_conn);
+
+ circ = circuit_get_by_edge_conn(edge_conn);
+ if (circ)
+ circuit_detach_stream(circ, edge_conn);
+ if (conn->state == EXIT_CONN_STATE_RESOLVING) {
+ connection_dns_remove(edge_conn);
+ }
+}
+
+/** Define a schedule for how long to wait between retrying
+ * application connections. Rather than waiting a fixed amount of
+ * time between each retry, we wait 10 seconds each for the first
+ * two tries, and 15 seconds for each retry after
+ * that. Hopefully this will improve the expected user experience. */
+static int
+compute_retry_timeout(entry_connection_t *conn)
+{
+ int timeout = get_options()->CircuitStreamTimeout;
+ if (timeout) /* if our config options override the default, use them */
+ return timeout;
+ if (conn->num_socks_retries < 2) /* try 0 and try 1 */
+ return 10;
+ return 15;
+}
+
+/** Find all general-purpose AP streams waiting for a response that sent their
+ * begin/resolve cell too long ago. Detach from their current circuit, and
+ * mark their current circuit as unsuitable for new streams. Then call
+ * connection_ap_handshake_attach_circuit() to attach to a new circuit (if
+ * available) or launch a new one.
+ *
+ * For rendezvous streams, simply give up after SocksTimeout seconds (with no
+ * retry attempt).
+ */
+void
+connection_ap_expire_beginning(void)
+{
+ edge_connection_t *conn;
+ entry_connection_t *entry_conn;
+ circuit_t *circ;
+ time_t now = time(NULL);
+ const or_options_t *options = get_options();
+ int severity;
+ int cutoff;
+ int seconds_idle, seconds_since_born;
+ smartlist_t *conns = get_connection_array();
+
+ SMARTLIST_FOREACH_BEGIN(conns, connection_t *, base_conn) {
+ if (base_conn->type != CONN_TYPE_AP || base_conn->marked_for_close)
+ continue;
+ entry_conn = TO_ENTRY_CONN(base_conn);
+ conn = ENTRY_TO_EDGE_CONN(entry_conn);
+ /* if it's an internal linked connection, don't yell its status. */
+ severity = (tor_addr_is_null(&base_conn->addr) && !base_conn->port)
+ ? LOG_INFO : LOG_NOTICE;
+ seconds_idle = (int)( now - base_conn->timestamp_last_read_allowed );
+ seconds_since_born = (int)( now - base_conn->timestamp_created );
+
+ if (base_conn->state == AP_CONN_STATE_OPEN)
+ continue;
+
+ /* We already consider SocksTimeout in
+ * connection_ap_handshake_attach_circuit(), but we need to consider
+ * it here too because controllers that put streams in controller_wait
+ * state never ask Tor to attach the circuit. */
+ if (AP_CONN_STATE_IS_UNATTACHED(base_conn->state)) {
+ if (seconds_since_born >= options->SocksTimeout) {
+ log_fn(severity, LD_APP,
+ "Tried for %d seconds to get a connection to %s:%d. "
+ "Giving up. (%s)",
+ seconds_since_born,
+ safe_str_client(entry_conn->socks_request->address),
+ entry_conn->socks_request->port,
+ conn_state_to_string(CONN_TYPE_AP, base_conn->state));
+ connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TIMEOUT);
+ }
+ continue;
+ }
+
+ /* We're in state connect_wait or resolve_wait now -- waiting for a
+ * reply to our relay cell. See if we want to retry/give up. */
+
+ cutoff = compute_retry_timeout(entry_conn);
+ if (seconds_idle < cutoff)
+ continue;
+ circ = circuit_get_by_edge_conn(conn);
+ if (!circ) { /* it's vanished? */
+ log_info(LD_APP,"Conn is waiting (address %s), but lost its circ.",
+ safe_str_client(entry_conn->socks_request->address));
+ connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TIMEOUT);
+ continue;
+ }
+ if (circ->purpose == CIRCUIT_PURPOSE_C_REND_JOINED) {
+ if (seconds_idle >= options->SocksTimeout) {
+ log_fn(severity, LD_REND,
+ "Rend stream is %d seconds late. Giving up on address"
+ " '%s.onion'.",
+ seconds_idle,
+ safe_str_client(entry_conn->socks_request->address));
+ /* Roll back path bias use state so that we probe the circuit
+ * if nothing else succeeds on it */
+ pathbias_mark_use_rollback(TO_ORIGIN_CIRCUIT(circ));
+
+ connection_edge_end(conn, END_STREAM_REASON_TIMEOUT);
+ connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TIMEOUT);
+ }
+ continue;
+ }
+
+ if (circ->purpose != CIRCUIT_PURPOSE_C_GENERAL &&
+ circ->purpose != CIRCUIT_PURPOSE_C_HSDIR_GET &&
+ circ->purpose != CIRCUIT_PURPOSE_S_HSDIR_POST &&
+ circ->purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT &&
+ circ->purpose != CIRCUIT_PURPOSE_PATH_BIAS_TESTING) {
+ log_warn(LD_BUG, "circuit->purpose == CIRCUIT_PURPOSE_C_GENERAL failed. "
+ "The purpose on the circuit was %s; it was in state %s, "
+ "path_state %s.",
+ circuit_purpose_to_string(circ->purpose),
+ circuit_state_to_string(circ->state),
+ CIRCUIT_IS_ORIGIN(circ) ?
+ pathbias_state_to_string(TO_ORIGIN_CIRCUIT(circ)->path_state) :
+ "none");
+ }
+ log_fn(cutoff < 15 ? LOG_INFO : severity, LD_APP,
+ "We tried for %d seconds to connect to '%s' using exit %s."
+ " Retrying on a new circuit.",
+ seconds_idle,
+ safe_str_client(entry_conn->socks_request->address),
+ conn->cpath_layer ?
+ extend_info_describe(conn->cpath_layer->extend_info):
+ "*unnamed*");
+ /* send an end down the circuit */
+ connection_edge_end(conn, END_STREAM_REASON_TIMEOUT);
+ /* un-mark it as ending, since we're going to reuse it */
+ conn->edge_has_sent_end = 0;
+ conn->end_reason = 0;
+ /* make us not try this circuit again, but allow
+ * current streams on it to survive if they can */
+ mark_circuit_unusable_for_new_conns(TO_ORIGIN_CIRCUIT(circ));
+
+ /* give our stream another 'cutoff' seconds to try */
+ conn->base_.timestamp_last_read_allowed += cutoff;
+ if (entry_conn->num_socks_retries < 250) /* avoid overflow */
+ entry_conn->num_socks_retries++;
+ /* move it back into 'pending' state, and try to attach. */
+ if (connection_ap_detach_retriable(entry_conn, TO_ORIGIN_CIRCUIT(circ),
+ END_STREAM_REASON_TIMEOUT)<0) {
+ if (!base_conn->marked_for_close)
+ connection_mark_unattached_ap(entry_conn,
+ END_STREAM_REASON_CANT_ATTACH);
+ }
+ } SMARTLIST_FOREACH_END(base_conn);
+}
+
+/**
+ * As connection_ap_attach_pending, but first scans the entire connection
+ * array to see if any elements are missing.
+ */
+void
+connection_ap_rescan_and_attach_pending(void)
+{
+ entry_connection_t *entry_conn;
+ smartlist_t *conns = get_connection_array();
+
+ if (PREDICT_UNLIKELY(NULL == pending_entry_connections))
+ pending_entry_connections = smartlist_new();
+
+ SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
+ if (conn->marked_for_close ||
+ conn->type != CONN_TYPE_AP ||
+ conn->state != AP_CONN_STATE_CIRCUIT_WAIT)
+ continue;
+
+ entry_conn = TO_ENTRY_CONN(conn);
+ tor_assert(entry_conn);
+ if (! smartlist_contains(pending_entry_connections, entry_conn)) {
+ log_warn(LD_BUG, "Found a connection %p that was supposed to be "
+ "in pending_entry_connections, but wasn't. No worries; "
+ "adding it.",
+ pending_entry_connections);
+ untried_pending_connections = 1;
+ connection_ap_mark_as_pending_circuit(entry_conn);
+ }
+
+ } SMARTLIST_FOREACH_END(conn);
+
+ connection_ap_attach_pending(1);
+}
+
+#ifdef DEBUGGING_17659
+#define UNMARK() do { \
+ entry_conn->marked_pending_circ_line = 0; \
+ entry_conn->marked_pending_circ_file = 0; \
+ } while (0)
+#else /* !(defined(DEBUGGING_17659)) */
+#define UNMARK() do { } while (0)
+#endif /* defined(DEBUGGING_17659) */
+
+/** Tell any AP streams that are listed as waiting for a new circuit to try
+ * again. If there is an available circuit for a stream, attach it. Otherwise,
+ * launch a new circuit.
+ *
+ * If <b>retry</b> is false, only check the list if it contains at least one
+ * streams that we have not yet tried to attach to a circuit.
+ */
+void
+connection_ap_attach_pending(int retry)
+{
+ if (PREDICT_UNLIKELY(!pending_entry_connections)) {
+ return;
+ }
+
+ if (untried_pending_connections == 0 && !retry)
+ return;
+
+ /* Don't allow any modifications to list while we are iterating over
+ * it. We'll put streams back on this list if we can't attach them
+ * immediately. */
+ smartlist_t *pending = pending_entry_connections;
+ pending_entry_connections = smartlist_new();
+
+ SMARTLIST_FOREACH_BEGIN(pending,
+ entry_connection_t *, entry_conn) {
+ connection_t *conn = ENTRY_TO_CONN(entry_conn);
+ tor_assert(conn && entry_conn);
+ if (conn->marked_for_close) {
+ UNMARK();
+ continue;
+ }
+ if (conn->magic != ENTRY_CONNECTION_MAGIC) {
+ log_warn(LD_BUG, "%p has impossible magic value %u.",
+ entry_conn, (unsigned)conn->magic);
+ UNMARK();
+ continue;
+ }
+ if (conn->state != AP_CONN_STATE_CIRCUIT_WAIT) {
+ log_warn(LD_BUG, "%p is no longer in circuit_wait. Its current state "
+ "is %s. Why is it on pending_entry_connections?",
+ entry_conn,
+ conn_state_to_string(conn->type, conn->state));
+ UNMARK();
+ continue;
+ }
+
+ /* Okay, we're through the sanity checks. Try to handle this stream. */
+ if (connection_ap_handshake_attach_circuit(entry_conn) < 0) {
+ if (!conn->marked_for_close)
+ connection_mark_unattached_ap(entry_conn,
+ END_STREAM_REASON_CANT_ATTACH);
+ }
+
+ if (! conn->marked_for_close &&
+ conn->type == CONN_TYPE_AP &&
+ conn->state == AP_CONN_STATE_CIRCUIT_WAIT) {
+ /* Is it still waiting for a circuit? If so, we didn't attach it,
+ * so it's still pending. Put it back on the list.
+ */
+ if (!smartlist_contains(pending_entry_connections, entry_conn)) {
+ smartlist_add(pending_entry_connections, entry_conn);
+ continue;
+ }
+ }
+
+ /* If we got here, then we either closed the connection, or
+ * we attached it. */
+ UNMARK();
+ } SMARTLIST_FOREACH_END(entry_conn);
+
+ smartlist_free(pending);
+ untried_pending_connections = 0;
+}
+
+static void
+attach_pending_entry_connections_cb(mainloop_event_t *ev, void *arg)
+{
+ (void)ev;
+ (void)arg;
+ connection_ap_attach_pending(0);
+}
+
+/** Mark <b>entry_conn</b> as needing to get attached to a circuit.
+ *
+ * And <b>entry_conn</b> must be in AP_CONN_STATE_CIRCUIT_WAIT,
+ * should not already be pending a circuit. The circuit will get
+ * launched or the connection will get attached the next time we
+ * call connection_ap_attach_pending().
+ */
+void
+connection_ap_mark_as_pending_circuit_(entry_connection_t *entry_conn,
+ const char *fname, int lineno)
+{
+ connection_t *conn = ENTRY_TO_CONN(entry_conn);
+ tor_assert(conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
+ tor_assert(conn->magic == ENTRY_CONNECTION_MAGIC);
+ if (conn->marked_for_close)
+ return;
+
+ if (PREDICT_UNLIKELY(NULL == pending_entry_connections)) {
+ pending_entry_connections = smartlist_new();
+ }
+ if (PREDICT_UNLIKELY(NULL == attach_pending_entry_connections_ev)) {
+ attach_pending_entry_connections_ev = mainloop_event_postloop_new(
+ attach_pending_entry_connections_cb, NULL);
+ }
+ if (PREDICT_UNLIKELY(smartlist_contains(pending_entry_connections,
+ entry_conn))) {
+ log_warn(LD_BUG, "What?? pending_entry_connections already contains %p! "
+ "(Called from %s:%d.)",
+ entry_conn, fname, lineno);
+#ifdef DEBUGGING_17659
+ const char *f2 = entry_conn->marked_pending_circ_file;
+ log_warn(LD_BUG, "(Previously called from %s:%d.)\n",
+ f2 ? f2 : "<NULL>",
+ entry_conn->marked_pending_circ_line);
+#endif /* defined(DEBUGGING_17659) */
+ log_backtrace(LOG_WARN, LD_BUG, "To debug, this may help");
+ return;
+ }
+
+#ifdef DEBUGGING_17659
+ entry_conn->marked_pending_circ_line = (uint16_t) lineno;
+ entry_conn->marked_pending_circ_file = fname;
+#endif
+
+ untried_pending_connections = 1;
+ smartlist_add(pending_entry_connections, entry_conn);
+
+ mainloop_event_activate(attach_pending_entry_connections_ev);
+}
+
+/** Mark <b>entry_conn</b> as no longer waiting for a circuit. */
+void
+connection_ap_mark_as_non_pending_circuit(entry_connection_t *entry_conn)
+{
+ if (PREDICT_UNLIKELY(NULL == pending_entry_connections))
+ return;
+ UNMARK();
+ smartlist_remove(pending_entry_connections, entry_conn);
+}
+
+/* DOCDOC */
+void
+connection_ap_warn_and_unmark_if_pending_circ(entry_connection_t *entry_conn,
+ const char *where)
+{
+ if (pending_entry_connections &&
+ smartlist_contains(pending_entry_connections, entry_conn)) {
+ log_warn(LD_BUG, "What was %p doing in pending_entry_connections in %s?",
+ entry_conn, where);
+ connection_ap_mark_as_non_pending_circuit(entry_conn);
+ }
+}
+
+/** Tell any AP streams that are waiting for a one-hop tunnel to
+ * <b>failed_digest</b> that they are going to fail. */
+/* XXXX We should get rid of this function, and instead attach
+ * one-hop streams to circ->p_streams so they get marked in
+ * circuit_mark_for_close like normal p_streams. */
+void
+connection_ap_fail_onehop(const char *failed_digest,
+ cpath_build_state_t *build_state)
+{
+ entry_connection_t *entry_conn;
+ char digest[DIGEST_LEN];
+ smartlist_t *conns = get_connection_array();
+ SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
+ if (conn->marked_for_close ||
+ conn->type != CONN_TYPE_AP ||
+ conn->state != AP_CONN_STATE_CIRCUIT_WAIT)
+ continue;
+ entry_conn = TO_ENTRY_CONN(conn);
+ if (!entry_conn->want_onehop)
+ continue;
+ if (hexdigest_to_digest(entry_conn->chosen_exit_name, digest) < 0 ||
+ tor_memneq(digest, failed_digest, DIGEST_LEN))
+ continue;
+ if (tor_digest_is_zero(digest)) {
+ /* we don't know the digest; have to compare addr:port */
+ tor_addr_t addr;
+ if (!build_state || !build_state->chosen_exit ||
+ !entry_conn->socks_request) {
+ continue;
+ }
+ if (tor_addr_parse(&addr, entry_conn->socks_request->address)<0 ||
+ !tor_addr_eq(&build_state->chosen_exit->addr, &addr) ||
+ build_state->chosen_exit->port != entry_conn->socks_request->port)
+ continue;
+ }
+ log_info(LD_APP, "Closing one-hop stream to '%s/%s' because the OR conn "
+ "just failed.", entry_conn->chosen_exit_name,
+ entry_conn->socks_request->address);
+ connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TIMEOUT);
+ } SMARTLIST_FOREACH_END(conn);
+}
+
+/** A circuit failed to finish on its last hop <b>info</b>. If there
+ * are any streams waiting with this exit node in mind, but they
+ * don't absolutely require it, make them give up on it.
+ */
+void
+circuit_discard_optional_exit_enclaves(extend_info_t *info)
+{
+ entry_connection_t *entry_conn;
+ const node_t *r1, *r2;
+
+ smartlist_t *conns = get_connection_array();
+ SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
+ if (conn->marked_for_close ||
+ conn->type != CONN_TYPE_AP ||
+ conn->state != AP_CONN_STATE_CIRCUIT_WAIT)
+ continue;
+ entry_conn = TO_ENTRY_CONN(conn);
+ if (!entry_conn->chosen_exit_optional &&
+ !entry_conn->chosen_exit_retries)
+ continue;
+ r1 = node_get_by_nickname(entry_conn->chosen_exit_name,
+ NNF_NO_WARN_UNNAMED);
+ r2 = node_get_by_id(info->identity_digest);
+ if (!r1 || !r2 || r1 != r2)
+ continue;
+ tor_assert(entry_conn->socks_request);
+ if (entry_conn->chosen_exit_optional) {
+ log_info(LD_APP, "Giving up on enclave exit '%s' for destination %s.",
+ safe_str_client(entry_conn->chosen_exit_name),
+ escaped_safe_str_client(entry_conn->socks_request->address));
+ entry_conn->chosen_exit_optional = 0;
+ tor_free(entry_conn->chosen_exit_name); /* clears it */
+ /* if this port is dangerous, warn or reject it now that we don't
+ * think it'll be using an enclave. */
+ consider_plaintext_ports(entry_conn, entry_conn->socks_request->port);
+ }
+ if (entry_conn->chosen_exit_retries) {
+ if (--entry_conn->chosen_exit_retries == 0) { /* give up! */
+ clear_trackexithost_mappings(entry_conn->chosen_exit_name);
+ tor_free(entry_conn->chosen_exit_name); /* clears it */
+ /* if this port is dangerous, warn or reject it now that we don't
+ * think it'll be using an enclave. */
+ consider_plaintext_ports(entry_conn, entry_conn->socks_request->port);
+ }
+ }
+ } SMARTLIST_FOREACH_END(conn);
+}
+
+/** The AP connection <b>conn</b> has just failed while attaching or
+ * sending a BEGIN or resolving on <b>circ</b>, but another circuit
+ * might work. Detach the circuit, and either reattach it, launch a
+ * new circuit, tell the controller, or give up as appropriate.
+ *
+ * Returns -1 on err, 1 on success, 0 on not-yet-sure.
+ */
+int
+connection_ap_detach_retriable(entry_connection_t *conn,
+ origin_circuit_t *circ,
+ int reason)
+{
+ control_event_stream_status(conn, STREAM_EVENT_FAILED_RETRIABLE, reason);
+ ENTRY_TO_CONN(conn)->timestamp_last_read_allowed = time(NULL);
+
+ /* Roll back path bias use state so that we probe the circuit
+ * if nothing else succeeds on it */
+ pathbias_mark_use_rollback(circ);
+
+ if (conn->pending_optimistic_data) {
+ buf_set_to_copy(&conn->sending_optimistic_data,
+ conn->pending_optimistic_data);
+ }
+
+ if (!get_options()->LeaveStreamsUnattached || conn->use_begindir) {
+ /* If we're attaching streams ourself, or if this connection is
+ * a tunneled directory connection, then just attach it. */
+ ENTRY_TO_CONN(conn)->state = AP_CONN_STATE_CIRCUIT_WAIT;
+ circuit_detach_stream(TO_CIRCUIT(circ),ENTRY_TO_EDGE_CONN(conn));
+ connection_ap_mark_as_pending_circuit(conn);
+ } else {
+ CONNECTION_AP_EXPECT_NONPENDING(conn);
+ ENTRY_TO_CONN(conn)->state = AP_CONN_STATE_CONTROLLER_WAIT;
+ circuit_detach_stream(TO_CIRCUIT(circ),ENTRY_TO_EDGE_CONN(conn));
+ }
+ return 0;
+}
+
+/** Check if <b>conn</b> is using a dangerous port. Then warn and/or
+ * reject depending on our config options. */
+static int
+consider_plaintext_ports(entry_connection_t *conn, uint16_t port)
+{
+ const or_options_t *options = get_options();
+ int reject = smartlist_contains_int_as_string(
+ options->RejectPlaintextPorts, port);
+
+ if (smartlist_contains_int_as_string(options->WarnPlaintextPorts, port)) {
+ log_warn(LD_APP, "Application request to port %d: this port is "
+ "commonly used for unencrypted protocols. Please make sure "
+ "you don't send anything you would mind the rest of the "
+ "Internet reading!%s", port, reject ? " Closing." : "");
+ control_event_client_status(LOG_WARN, "DANGEROUS_PORT PORT=%d RESULT=%s",
+ port, reject ? "REJECT" : "WARN");
+ }
+
+ if (reject) {
+ log_info(LD_APP, "Port %d listed in RejectPlaintextPorts. Closing.", port);
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
+ return -1;
+ }
+
+ return 0;
+}
+
+/** How many times do we try connecting with an exit configured via
+ * TrackHostExits before concluding that it won't work any more and trying a
+ * different one? */
+#define TRACKHOSTEXITS_RETRIES 5
+
+/** Call connection_ap_handshake_rewrite_and_attach() unless a controller
+ * asked us to leave streams unattached. Return 0 in that case.
+ *
+ * See connection_ap_handshake_rewrite_and_attach()'s
+ * documentation for arguments and return value.
+ */
+MOCK_IMPL(int,
+connection_ap_rewrite_and_attach_if_allowed,(entry_connection_t *conn,
+ origin_circuit_t *circ,
+ crypt_path_t *cpath))
+{
+ const or_options_t *options = get_options();
+
+ if (options->LeaveStreamsUnattached) {
+ CONNECTION_AP_EXPECT_NONPENDING(conn);
+ ENTRY_TO_CONN(conn)->state = AP_CONN_STATE_CONTROLLER_WAIT;
+ return 0;
+ }
+ return connection_ap_handshake_rewrite_and_attach(conn, circ, cpath);
+}
+
+/* Try to perform any map-based rewriting of the target address in
+ * <b>conn</b>, filling in the fields of <b>out</b> as we go, and modifying
+ * conn->socks_request.address as appropriate.
+ */
+STATIC void
+connection_ap_handshake_rewrite(entry_connection_t *conn,
+ rewrite_result_t *out)
+{
+ socks_request_t *socks = conn->socks_request;
+ const or_options_t *options = get_options();
+ tor_addr_t addr_tmp;
+
+ /* Initialize all the fields of 'out' to reasonable defaults */
+ out->automap = 0;
+ out->exit_source = ADDRMAPSRC_NONE;
+ out->map_expires = TIME_MAX;
+ out->end_reason = 0;
+ out->should_close = 0;
+ out->orig_address[0] = 0;
+
+ /* We convert all incoming addresses to lowercase. */
+ tor_strlower(socks->address);
+ /* Remember the original address. */
+ strlcpy(out->orig_address, socks->address, sizeof(out->orig_address));
+ log_debug(LD_APP,"Client asked for %s:%d",
+ safe_str_client(socks->address),
+ socks->port);
+
+ /* Check for whether this is a .exit address. By default, those are
+ * disallowed when they're coming straight from the client, but you're
+ * allowed to have them in MapAddress commands and so forth. */
+ if (!strcmpend(socks->address, ".exit")) {
+ log_warn(LD_APP, "The \".exit\" notation is disabled in Tor due to "
+ "security risks.");
+ control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
+ escaped(socks->address));
+ out->end_reason = END_STREAM_REASON_TORPROTOCOL;
+ out->should_close = 1;
+ return;
+ }
+
+ /* Remember the original address so we can tell the user about what
+ * they actually said, not just what it turned into. */
+ /* XXX yes, this is the same as out->orig_address above. One is
+ * in the output, and one is in the connection. */
+ if (! conn->original_dest_address) {
+ /* Is the 'if' necessary here? XXXX */
+ conn->original_dest_address = tor_strdup(conn->socks_request->address);
+ }
+
+ /* First, apply MapAddress and MAPADDRESS mappings. We need to do
+ * these only for non-reverse lookups, since they don't exist for those.
+ * We also need to do this before we consider automapping, since we might
+ * e.g. resolve irc.oftc.net into irconionaddress.onion, at which point
+ * we'd need to automap it. */
+ if (socks->command != SOCKS_COMMAND_RESOLVE_PTR) {
+ const unsigned rewrite_flags = AMR_FLAG_USE_MAPADDRESS;
+ if (addressmap_rewrite(socks->address, sizeof(socks->address),
+ rewrite_flags, &out->map_expires, &out->exit_source)) {
+ control_event_stream_status(conn, STREAM_EVENT_REMAP,
+ REMAP_STREAM_SOURCE_CACHE);
+ }
+ }
+
+ /* Now see if we need to create or return an existing Hostname->IP
+ * automapping. Automapping happens when we're asked to resolve a
+ * hostname, and AutomapHostsOnResolve is set, and the hostname has a
+ * suffix listed in AutomapHostsSuffixes. It's a handy feature
+ * that lets you have Tor assign e.g. IPv6 addresses for .onion
+ * names, and return them safely from DNSPort.
+ */
+ if (socks->command == SOCKS_COMMAND_RESOLVE &&
+ tor_addr_parse(&addr_tmp, socks->address)<0 &&
+ options->AutomapHostsOnResolve) {
+ /* Check the suffix... */
+ out->automap = addressmap_address_should_automap(socks->address, options);
+ if (out->automap) {
+ /* If we get here, then we should apply an automapping for this. */
+ const char *new_addr;
+ /* We return an IPv4 address by default, or an IPv6 address if we
+ * are allowed to do so. */
+ int addr_type = RESOLVED_TYPE_IPV4;
+ if (conn->socks_request->socks_version != 4) {
+ if (!conn->entry_cfg.ipv4_traffic ||
+ (conn->entry_cfg.ipv6_traffic && conn->entry_cfg.prefer_ipv6) ||
+ conn->entry_cfg.prefer_ipv6_virtaddr)
+ addr_type = RESOLVED_TYPE_IPV6;
+ }
+ /* Okay, register the target address as automapped, and find the new
+ * address we're supposed to give as a resolve answer. (Return a cached
+ * value if we've looked up this address before.
+ */
+ new_addr = addressmap_register_virtual_address(
+ addr_type, tor_strdup(socks->address));
+ if (! new_addr) {
+ log_warn(LD_APP, "Unable to automap address %s",
+ escaped_safe_str(socks->address));
+ out->end_reason = END_STREAM_REASON_INTERNAL;
+ out->should_close = 1;
+ return;
+ }
+ log_info(LD_APP, "Automapping %s to %s",
+ escaped_safe_str_client(socks->address),
+ safe_str_client(new_addr));
+ strlcpy(socks->address, new_addr, sizeof(socks->address));
+ }
+ }
+
+ /* Now handle reverse lookups, if they're in the cache. This doesn't
+ * happen too often, since client-side DNS caching is off by default,
+ * and very deprecated. */
+ if (socks->command == SOCKS_COMMAND_RESOLVE_PTR) {
+ unsigned rewrite_flags = 0;
+ if (conn->entry_cfg.use_cached_ipv4_answers)
+ rewrite_flags |= AMR_FLAG_USE_IPV4_DNS;
+ if (conn->entry_cfg.use_cached_ipv6_answers)
+ rewrite_flags |= AMR_FLAG_USE_IPV6_DNS;
+
+ if (addressmap_rewrite_reverse(socks->address, sizeof(socks->address),
+ rewrite_flags, &out->map_expires)) {
+ char *result = tor_strdup(socks->address);
+ /* remember _what_ is supposed to have been resolved. */
+ tor_snprintf(socks->address, sizeof(socks->address), "REVERSE[%s]",
+ out->orig_address);
+ connection_ap_handshake_socks_resolved(conn, RESOLVED_TYPE_HOSTNAME,
+ strlen(result), (uint8_t*)result,
+ -1,
+ out->map_expires);
+ tor_free(result);
+ out->end_reason = END_STREAM_REASON_DONE |
+ END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED;
+ out->should_close = 1;
+ return;
+ }
+
+ /* Hang on, did we find an answer saying that this is a reverse lookup for
+ * an internal address? If so, we should reject it if we're configured to
+ * do so. */
+ if (options->ClientDNSRejectInternalAddresses) {
+ /* Don't let clients try to do a reverse lookup on 10.0.0.1. */
+ tor_addr_t addr;
+ int ok;
+ ok = tor_addr_parse_PTR_name(
+ &addr, socks->address, AF_UNSPEC, 1);
+ if (ok == 1 && tor_addr_is_internal(&addr, 0)) {
+ connection_ap_handshake_socks_resolved(conn, RESOLVED_TYPE_ERROR,
+ 0, NULL, -1, TIME_MAX);
+ out->end_reason = END_STREAM_REASON_SOCKSPROTOCOL |
+ END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED;
+ out->should_close = 1;
+ return;
+ }
+ }
+ }
+
+ /* If we didn't automap it before, then this is still the address that
+ * came straight from the user, mapped according to any
+ * MapAddress/MAPADDRESS commands. Now apply other mappings,
+ * including previously registered Automap entries (IP back to
+ * hostname), TrackHostExits entries, and client-side DNS cache
+ * entries (if they're turned on).
+ */
+ if (socks->command != SOCKS_COMMAND_RESOLVE_PTR &&
+ !out->automap) {
+ unsigned rewrite_flags = AMR_FLAG_USE_AUTOMAP | AMR_FLAG_USE_TRACKEXIT;
+ addressmap_entry_source_t exit_source2;
+ if (conn->entry_cfg.use_cached_ipv4_answers)
+ rewrite_flags |= AMR_FLAG_USE_IPV4_DNS;
+ if (conn->entry_cfg.use_cached_ipv6_answers)
+ rewrite_flags |= AMR_FLAG_USE_IPV6_DNS;
+ if (addressmap_rewrite(socks->address, sizeof(socks->address),
+ rewrite_flags, &out->map_expires, &exit_source2)) {
+ control_event_stream_status(conn, STREAM_EVENT_REMAP,
+ REMAP_STREAM_SOURCE_CACHE);
+ }
+ if (out->exit_source == ADDRMAPSRC_NONE) {
+ /* If it wasn't a .exit before, maybe it turned into a .exit. Remember
+ * the original source of a .exit. */
+ out->exit_source = exit_source2;
+ }
+ }
+
+ /* Check to see whether we're about to use an address in the virtual
+ * range without actually having gotten it from an Automap. */
+ if (!out->automap && address_is_in_virtual_range(socks->address)) {
+ /* This address was probably handed out by
+ * client_dns_get_unmapped_address, but the mapping was discarded for some
+ * reason. Or the user typed in a virtual address range manually. We
+ * *don't* want to send the address through Tor; that's likely to fail,
+ * and may leak information.
+ */
+ log_warn(LD_APP,"Missing mapping for virtual address '%s'. Refusing.",
+ safe_str_client(socks->address));
+ out->end_reason = END_STREAM_REASON_INTERNAL;
+ out->should_close = 1;
+ return;
+ }
+}
+
+/** We just received a SOCKS request in <b>conn</b> to an onion address of type
+ * <b>addresstype</b>. Start connecting to the onion service. */
+static int
+connection_ap_handle_onion(entry_connection_t *conn,
+ socks_request_t *socks,
+ origin_circuit_t *circ,
+ hostname_type_t addresstype)
+{
+ time_t now = approx_time();
+ connection_t *base_conn = ENTRY_TO_CONN(conn);
+
+ /* If .onion address requests are disabled, refuse the request */
+ if (!conn->entry_cfg.onion_traffic) {
+ log_warn(LD_APP, "Onion address %s requested from a port with .onion "
+ "disabled", safe_str_client(socks->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
+ return -1;
+ }
+
+ /* Check whether it's RESOLVE or RESOLVE_PTR. We don't handle those
+ * for hidden service addresses. */
+ if (SOCKS_COMMAND_IS_RESOLVE(socks->command)) {
+ /* if it's a resolve request, fail it right now, rather than
+ * building all the circuits and then realizing it won't work. */
+ log_warn(LD_APP,
+ "Resolve requests to hidden services not allowed. Failing.");
+ connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,
+ 0,NULL,-1,TIME_MAX);
+ connection_mark_unattached_ap(conn,
+ END_STREAM_REASON_SOCKSPROTOCOL |
+ END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
+ return -1;
+ }
+
+ /* If we were passed a circuit, then we need to fail. .onion addresses
+ * only work when we launch our own circuits for now. */
+ if (circ) {
+ log_warn(LD_CONTROL, "Attachstream to a circuit is not "
+ "supported for .onion addresses currently. Failing.");
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+ return -1;
+ }
+
+ /* Interface: Regardless of HS version after the block below we should have
+ set onion_address, rend_cache_lookup_result, and descriptor_is_usable. */
+ const char *onion_address = NULL;
+ int rend_cache_lookup_result = -ENOENT;
+ int descriptor_is_usable = 0;
+
+ if (addresstype == ONION_V2_HOSTNAME) { /* it's a v2 hidden service */
+ rend_cache_entry_t *entry = NULL;
+ /* Look up if we have client authorization configured for this hidden
+ * service. If we do, associate it with the rend_data. */
+ rend_service_authorization_t *client_auth =
+ rend_client_lookup_service_authorization(socks->address);
+
+ const uint8_t *cookie = NULL;
+ rend_auth_type_t auth_type = REND_NO_AUTH;
+ if (client_auth) {
+ log_info(LD_REND, "Using previously configured client authorization "
+ "for hidden service request.");
+ auth_type = client_auth->auth_type;
+ cookie = client_auth->descriptor_cookie;
+ }
+
+ /* Fill in the rend_data field so we can start doing a connection to
+ * a hidden service. */
+ rend_data_t *rend_data = ENTRY_TO_EDGE_CONN(conn)->rend_data =
+ rend_data_client_create(socks->address, NULL, (char *) cookie,
+ auth_type);
+ if (rend_data == NULL) {
+ return -1;
+ }
+ onion_address = rend_data_get_address(rend_data);
+ log_info(LD_REND,"Got a hidden service request for ID '%s'",
+ safe_str_client(onion_address));
+
+ rend_cache_lookup_result = rend_cache_lookup_entry(onion_address,-1,
+ &entry);
+ if (!rend_cache_lookup_result && entry) {
+ descriptor_is_usable = rend_client_any_intro_points_usable(entry);
+ }
+ } else { /* it's a v3 hidden service */
+ tor_assert(addresstype == ONION_V3_HOSTNAME);
+ const hs_descriptor_t *cached_desc = NULL;
+ int retval;
+ /* Create HS conn identifier with HS pubkey */
+ hs_ident_edge_conn_t *hs_conn_ident =
+ tor_malloc_zero(sizeof(hs_ident_edge_conn_t));
+
+ retval = hs_parse_address(socks->address, &hs_conn_ident->identity_pk,
+ NULL, NULL);
+ if (retval < 0) {
+ log_warn(LD_GENERAL, "failed to parse hs address");
+ tor_free(hs_conn_ident);
+ return -1;
+ }
+ ENTRY_TO_EDGE_CONN(conn)->hs_ident = hs_conn_ident;
+
+ onion_address = socks->address;
+
+ /* Check the v3 desc cache */
+ cached_desc = hs_cache_lookup_as_client(&hs_conn_ident->identity_pk);
+ if (cached_desc) {
+ rend_cache_lookup_result = 0;
+ descriptor_is_usable =
+ hs_client_any_intro_points_usable(&hs_conn_ident->identity_pk,
+ cached_desc);
+ log_info(LD_GENERAL, "Found %s descriptor in cache for %s. %s.",
+ (descriptor_is_usable) ? "usable" : "unusable",
+ safe_str_client(onion_address),
+ (descriptor_is_usable) ? "Not fetching." : "Refecting.");
+ } else {
+ rend_cache_lookup_result = -ENOENT;
+ }
+ }
+
+ /* Lookup the given onion address. If invalid, stop right now.
+ * Otherwise, we might have it in the cache or not. */
+ unsigned int refetch_desc = 0;
+ if (rend_cache_lookup_result < 0) {
+ switch (-rend_cache_lookup_result) {
+ case EINVAL:
+ /* We should already have rejected this address! */
+ log_warn(LD_BUG,"Invalid service name '%s'",
+ safe_str_client(onion_address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+ return -1;
+ case ENOENT:
+ /* We didn't have this; we should look it up. */
+ log_info(LD_REND, "No descriptor found in our cache for %s. Fetching.",
+ safe_str_client(onion_address));
+ refetch_desc = 1;
+ break;
+ default:
+ log_warn(LD_BUG, "Unknown cache lookup error %d",
+ rend_cache_lookup_result);
+ return -1;
+ }
+ }
+
+ /* Help predict that we'll want to do hidden service circuits in the
+ * future. We're not sure if it will need a stable circuit yet, but
+ * we know we'll need *something*. */
+ rep_hist_note_used_internal(now, 0, 1);
+
+ /* Now we have a descriptor but is it usable or not? If not, refetch.
+ * Also, a fetch could have been requested if the onion address was not
+ * found in the cache previously. */
+ if (refetch_desc || !descriptor_is_usable) {
+ edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
+ connection_ap_mark_as_non_pending_circuit(conn);
+ base_conn->state = AP_CONN_STATE_RENDDESC_WAIT;
+ if (addresstype == ONION_V2_HOSTNAME) {
+ tor_assert(edge_conn->rend_data);
+ rend_client_refetch_v2_renddesc(edge_conn->rend_data);
+ /* Whatever the result of the refetch, we don't go further. */
+ return 0;
+ } else {
+ tor_assert(addresstype == ONION_V3_HOSTNAME);
+ tor_assert(edge_conn->hs_ident);
+ /* Attempt to fetch the hsv3 descriptor. Check the retval to see how it
+ * went and act accordingly. */
+ int ret = hs_client_refetch_hsdesc(&edge_conn->hs_ident->identity_pk);
+ switch (ret) {
+ case HS_CLIENT_FETCH_MISSING_INFO:
+ /* Keeping the connection in descriptor wait state is fine because
+ * once we get enough dirinfo or a new live consensus, the HS client
+ * subsystem is notified and every connection in that state will
+ * trigger a fetch for the service key. */
+ case HS_CLIENT_FETCH_LAUNCHED:
+ case HS_CLIENT_FETCH_PENDING:
+ case HS_CLIENT_FETCH_HAVE_DESC:
+ return 0;
+ case HS_CLIENT_FETCH_ERROR:
+ case HS_CLIENT_FETCH_NO_HSDIRS:
+ case HS_CLIENT_FETCH_NOT_ALLOWED:
+ /* Can't proceed further and better close the SOCKS request. */
+ return -1;
+ }
+ }
+ }
+
+ /* We have the descriptor! So launch a connection to the HS. */
+ log_info(LD_REND, "Descriptor is here. Great.");
+
+ base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
+ /* We'll try to attach it at the next event loop, or whenever
+ * we call connection_ap_attach_pending() */
+ connection_ap_mark_as_pending_circuit(conn);
+ return 0;
+}
+
+/** Connection <b>conn</b> just finished its socks handshake, or the
+ * controller asked us to take care of it. If <b>circ</b> is defined,
+ * then that's where we'll want to attach it. Otherwise we have to
+ * figure it out ourselves.
+ *
+ * First, parse whether it's a .exit address, remap it, and so on. Then
+ * if it's for a general circuit, try to attach it to a circuit (or launch
+ * one as needed), else if it's for a rendezvous circuit, fetch a
+ * rendezvous descriptor first (or attach/launch a circuit if the
+ * rendezvous descriptor is already here and fresh enough).
+ *
+ * The stream will exit from the hop
+ * indicated by <b>cpath</b>, or from the last hop in circ's cpath if
+ * <b>cpath</b> is NULL.
+ */
+int
+connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
+ origin_circuit_t *circ,
+ crypt_path_t *cpath)
+{
+ socks_request_t *socks = conn->socks_request;
+ const or_options_t *options = get_options();
+ connection_t *base_conn = ENTRY_TO_CONN(conn);
+ time_t now = time(NULL);
+ rewrite_result_t rr;
+
+ /* First we'll do the rewrite part. Let's see if we get a reasonable
+ * answer.
+ */
+ memset(&rr, 0, sizeof(rr));
+ connection_ap_handshake_rewrite(conn,&rr);
+
+ if (rr.should_close) {
+ /* connection_ap_handshake_rewrite told us to close the connection:
+ * either because it sent back an answer, or because it sent back an
+ * error */
+ connection_mark_unattached_ap(conn, rr.end_reason);
+ if (END_STREAM_REASON_DONE == (rr.end_reason & END_STREAM_REASON_MASK))
+ return 0;
+ else
+ return -1;
+ }
+
+ const time_t map_expires = rr.map_expires;
+ const int automap = rr.automap;
+ const addressmap_entry_source_t exit_source = rr.exit_source;
+
+ /* Now, we parse the address to see if it's an .onion or .exit or
+ * other special address.
+ */
+ const hostname_type_t addresstype = parse_extended_hostname(socks->address);
+
+ /* Now see whether the hostname is bogus. This could happen because of an
+ * onion hostname whose format we don't recognize. */
+ if (addresstype == BAD_HOSTNAME) {
+ control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
+ escaped(socks->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+ return -1;
+ }
+
+ /* If this is a .exit hostname, strip off the .name.exit part, and
+ * see whether we're willing to connect there, and and otherwise handle the
+ * .exit address.
+ *
+ * We'll set chosen_exit_name and/or close the connection as appropriate.
+ */
+ if (addresstype == EXIT_HOSTNAME) {
+ /* If StrictNodes is not set, then .exit overrides ExcludeNodes but
+ * not ExcludeExitNodes. */
+ routerset_t *excludeset = options->StrictNodes ?
+ options->ExcludeExitNodesUnion_ : options->ExcludeExitNodes;
+ const node_t *node = NULL;
+
+ /* If this .exit was added by an AUTOMAP, then it came straight from
+ * a user. That's not safe. */
+ if (exit_source == ADDRMAPSRC_AUTOMAP) {
+ /* Whoops; this one is stale. It must have gotten added earlier?
+ * (Probably this is not possible, since AllowDotExit no longer
+ * exists.) */
+ log_warn(LD_APP,"Stale automapped address for '%s.exit'. Refusing.",
+ safe_str_client(socks->address));
+ control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
+ escaped(socks->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+ tor_assert_nonfatal_unreached();
+ return -1;
+ }
+
+ /* Double-check to make sure there are no .exits coming from
+ * impossible/weird sources. */
+ if (exit_source == ADDRMAPSRC_DNS || exit_source == ADDRMAPSRC_NONE) {
+ /* It shouldn't be possible to get a .exit address from any of these
+ * sources. */
+ log_warn(LD_BUG,"Address '%s.exit', with impossible source for the "
+ ".exit part. Refusing.",
+ safe_str_client(socks->address));
+ control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
+ escaped(socks->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+ return -1;
+ }
+
+ tor_assert(!automap);
+
+ /* Now, find the character before the .(name) part.
+ * (The ".exit" part got stripped off by "parse_extended_hostname").
+ *
+ * We're going to put the exit name into conn->chosen_exit_name, and
+ * look up a node correspondingly. */
+ char *s = strrchr(socks->address,'.');
+ if (s) {
+ /* The address was of the form "(stuff).(name).exit */
+ if (s[1] != '\0') {
+ /* Looks like a real .exit one. */
+ conn->chosen_exit_name = tor_strdup(s+1);
+ node = node_get_by_nickname(conn->chosen_exit_name, 0);
+
+ if (exit_source == ADDRMAPSRC_TRACKEXIT) {
+ /* We 5 tries before it expires the addressmap */
+ conn->chosen_exit_retries = TRACKHOSTEXITS_RETRIES;
+ }
+ *s = 0;
+ } else {
+ /* Oops, the address was (stuff)..exit. That's not okay. */
+ log_warn(LD_APP,"Malformed exit address '%s.exit'. Refusing.",
+ safe_str_client(socks->address));
+ control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
+ escaped(socks->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+ return -1;
+ }
+ } else {
+ /* It looks like they just asked for "foo.exit". That's a special
+ * form that means (foo's address).foo.exit. */
+
+ conn->chosen_exit_name = tor_strdup(socks->address);
+ node = node_get_by_nickname(conn->chosen_exit_name, 0);
+ if (node) {
+ *socks->address = 0;
+ node_get_address_string(node, socks->address, sizeof(socks->address));
+ }
+ }
+
+ /* Now make sure that the chosen exit exists... */
+ if (!node) {
+ log_warn(LD_APP,
+ "Unrecognized relay in exit address '%s.exit'. Refusing.",
+ safe_str_client(socks->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+ return -1;
+ }
+ /* ...and make sure that it isn't excluded. */
+ if (routerset_contains_node(excludeset, node)) {
+ log_warn(LD_APP,
+ "Excluded relay in exit address '%s.exit'. Refusing.",
+ safe_str_client(socks->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+ return -1;
+ }
+ /* XXXX-1090 Should we also allow foo.bar.exit if ExitNodes is set and
+ Bar is not listed in it? I say yes, but our revised manpage branch
+ implies no. */
+ }
+
+ /* Now, we handle everything that isn't a .onion address. */
+ if (addresstype != ONION_V2_HOSTNAME && addresstype != ONION_V3_HOSTNAME) {
+ /* Not a hidden-service request. It's either a hostname or an IP,
+ * possibly with a .exit that we stripped off. We're going to check
+ * if we're allowed to connect/resolve there, and then launch the
+ * appropriate request. */
+
+ /* Check for funny characters in the address. */
+ if (address_is_invalid_destination(socks->address, 1)) {
+ control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
+ escaped(socks->address));
+ log_warn(LD_APP,
+ "Destination '%s' seems to be an invalid hostname. Failing.",
+ safe_str_client(socks->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+ return -1;
+ }
+
+ /* socks->address is a non-onion hostname or IP address.
+ * If we can't do any non-onion requests, refuse the connection.
+ * If we have a hostname but can't do DNS, refuse the connection.
+ * If we have an IP address, but we can't use that address family,
+ * refuse the connection.
+ *
+ * If we can do DNS requests, and we can use at least one address family,
+ * then we have to resolve the address first. Then we'll know if it
+ * resolves to a usable address family. */
+
+ /* First, check if all non-onion traffic is disabled */
+ if (!conn->entry_cfg.dns_request && !conn->entry_cfg.ipv4_traffic
+ && !conn->entry_cfg.ipv6_traffic) {
+ log_warn(LD_APP, "Refusing to connect to non-hidden-service hostname "
+ "or IP address %s because Port has OnionTrafficOnly set (or "
+ "NoDNSRequest, NoIPv4Traffic, and NoIPv6Traffic).",
+ safe_str_client(socks->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
+ return -1;
+ }
+
+ /* Then check if we have a hostname or IP address, and whether DNS or
+ * the IP address family are permitted. Reject if not. */
+ tor_addr_t dummy_addr;
+ int socks_family = tor_addr_parse(&dummy_addr, socks->address);
+ /* family will be -1 for a non-onion hostname that's not an IP */
+ if (socks_family == -1) {
+ if (!conn->entry_cfg.dns_request) {
+ log_warn(LD_APP, "Refusing to connect to hostname %s "
+ "because Port has NoDNSRequest set.",
+ safe_str_client(socks->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
+ return -1;
+ }
+ } else if (socks_family == AF_INET) {
+ if (!conn->entry_cfg.ipv4_traffic) {
+ log_warn(LD_APP, "Refusing to connect to IPv4 address %s because "
+ "Port has NoIPv4Traffic set.",
+ safe_str_client(socks->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
+ return -1;
+ }
+ } else if (socks_family == AF_INET6) {
+ if (!conn->entry_cfg.ipv6_traffic) {
+ log_warn(LD_APP, "Refusing to connect to IPv6 address %s because "
+ "Port has NoIPv6Traffic set.",
+ safe_str_client(socks->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
+ return -1;
+ }
+ } else {
+ tor_assert_nonfatal_unreached_once();
+ }
+
+ /* See if this is a hostname lookup that we can answer immediately.
+ * (For example, an attempt to look up the IP address for an IP address.)
+ */
+ if (socks->command == SOCKS_COMMAND_RESOLVE) {
+ tor_addr_t answer;
+ /* Reply to resolves immediately if we can. */
+ if (tor_addr_parse(&answer, socks->address) >= 0) {/* is it an IP? */
+ /* remember _what_ is supposed to have been resolved. */
+ strlcpy(socks->address, rr.orig_address, sizeof(socks->address));
+ connection_ap_handshake_socks_resolved_addr(conn, &answer, -1,
+ map_expires);
+ connection_mark_unattached_ap(conn,
+ END_STREAM_REASON_DONE |
+ END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
+ return 0;
+ }
+ tor_assert(!automap);
+ rep_hist_note_used_resolve(now); /* help predict this next time */
+ } else if (socks->command == SOCKS_COMMAND_CONNECT) {
+ /* Now see if this is a connect request that we can reject immediately */
+
+ tor_assert(!automap);
+ /* Don't allow connections to port 0. */
+ if (socks->port == 0) {
+ log_notice(LD_APP,"Application asked to connect to port 0. Refusing.");
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+ return -1;
+ }
+ /* You can't make connections to internal addresses, by default.
+ * Exceptions are begindir requests (where the address is meaningless),
+ * or cases where you've hand-configured a particular exit, thereby
+ * making the local address meaningful. */
+ if (options->ClientRejectInternalAddresses &&
+ !conn->use_begindir && !conn->chosen_exit_name && !circ) {
+ /* If we reach this point then we don't want to allow internal
+ * addresses. Check if we got one. */
+ tor_addr_t addr;
+ if (tor_addr_hostname_is_local(socks->address) ||
+ (tor_addr_parse(&addr, socks->address) >= 0 &&
+ tor_addr_is_internal(&addr, 0))) {
+ /* If this is an explicit private address with no chosen exit node,
+ * then we really don't want to try to connect to it. That's
+ * probably an error. */
+ if (conn->is_transparent_ap) {
+#define WARN_INTRVL_LOOP 300
+ static ratelim_t loop_warn_limit = RATELIM_INIT(WARN_INTRVL_LOOP);
+ char *m;
+ if ((m = rate_limit_log(&loop_warn_limit, approx_time()))) {
+ log_warn(LD_NET,
+ "Rejecting request for anonymous connection to private "
+ "address %s on a TransPort or NATDPort. Possible loop "
+ "in your NAT rules?%s", safe_str_client(socks->address),
+ m);
+ tor_free(m);
+ }
+ } else {
+#define WARN_INTRVL_PRIV 300
+ static ratelim_t priv_warn_limit = RATELIM_INIT(WARN_INTRVL_PRIV);
+ char *m;
+ if ((m = rate_limit_log(&priv_warn_limit, approx_time()))) {
+ log_warn(LD_NET,
+ "Rejecting SOCKS request for anonymous connection to "
+ "private address %s.%s",
+ safe_str_client(socks->address),m);
+ tor_free(m);
+ }
+ }
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_PRIVATE_ADDR);
+ return -1;
+ }
+ } /* end "if we should check for internal addresses" */
+
+ /* Okay. We're still doing a CONNECT, and it wasn't a private
+ * address. Here we do special handling for literal IP addresses,
+ * to see if we should reject this preemptively, and to set up
+ * fields in conn->entry_cfg to tell the exit what AF we want. */
+ {
+ tor_addr_t addr;
+ /* XXX Duplicate call to tor_addr_parse. */
+ if (tor_addr_parse(&addr, socks->address) >= 0) {
+ /* If we reach this point, it's an IPv4 or an IPv6 address. */
+ sa_family_t family = tor_addr_family(&addr);
+
+ if ((family == AF_INET && ! conn->entry_cfg.ipv4_traffic) ||
+ (family == AF_INET6 && ! conn->entry_cfg.ipv6_traffic)) {
+ /* You can't do an IPv4 address on a v6-only socks listener,
+ * or vice versa. */
+ log_warn(LD_NET, "Rejecting SOCKS request for an IP address "
+ "family that this listener does not support.");
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
+ return -1;
+ } else if (family == AF_INET6 && socks->socks_version == 4) {
+ /* You can't make a socks4 request to an IPv6 address. Socks4
+ * doesn't support that. */
+ log_warn(LD_NET, "Rejecting SOCKS4 request for an IPv6 address.");
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
+ return -1;
+ } else if (socks->socks_version == 4 &&
+ !conn->entry_cfg.ipv4_traffic) {
+ /* You can't do any kind of Socks4 request when IPv4 is forbidden.
+ *
+ * XXX raise this check outside the enclosing block? */
+ log_warn(LD_NET, "Rejecting SOCKS4 request on a listener with "
+ "no IPv4 traffic supported.");
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
+ return -1;
+ } else if (family == AF_INET6) {
+ /* Tell the exit: we won't accept any ipv4 connection to an IPv6
+ * address. */
+ conn->entry_cfg.ipv4_traffic = 0;
+ } else if (family == AF_INET) {
+ /* Tell the exit: we won't accept any ipv6 connection to an IPv4
+ * address. */
+ conn->entry_cfg.ipv6_traffic = 0;
+ }
+ }
+ }
+
+ /* we never allow IPv6 answers on socks4. (TODO: Is this smart?) */
+ if (socks->socks_version == 4)
+ conn->entry_cfg.ipv6_traffic = 0;
+
+ /* Still handling CONNECT. Now, check for exit enclaves. (Which we
+ * don't do on BEGIN_DIR, or when there is a chosen exit.)
+ *
+ * TODO: Should we remove this? Exit enclaves are nutty and don't
+ * work very well
+ */
+ if (!conn->use_begindir && !conn->chosen_exit_name && !circ) {
+ /* see if we can find a suitable enclave exit */
+ const node_t *r =
+ router_find_exact_exit_enclave(socks->address, socks->port);
+ if (r) {
+ log_info(LD_APP,
+ "Redirecting address %s to exit at enclave router %s",
+ safe_str_client(socks->address), node_describe(r));
+ /* use the hex digest, not nickname, in case there are two
+ routers with this nickname */
+ conn->chosen_exit_name =
+ tor_strdup(hex_str(r->identity, DIGEST_LEN));
+ conn->chosen_exit_optional = 1;
+ }
+ }
+
+ /* Still handling CONNECT: warn or reject if it's using a dangerous
+ * port. */
+ if (!conn->use_begindir && !conn->chosen_exit_name && !circ)
+ if (consider_plaintext_ports(conn, socks->port) < 0)
+ return -1;
+
+ /* Remember the port so that we will predict that more requests
+ there will happen in the future. */
+ if (!conn->use_begindir) {
+ /* help predict this next time */
+ rep_hist_note_used_port(now, socks->port);
+ }
+ } else if (socks->command == SOCKS_COMMAND_RESOLVE_PTR) {
+ rep_hist_note_used_resolve(now); /* help predict this next time */
+ /* no extra processing needed */
+ } else {
+ /* We should only be doing CONNECT, RESOLVE, or RESOLVE_PTR! */
+ tor_fragile_assert();
+ }
+
+ /* Okay. At this point we've set chosen_exit_name if needed, rewritten the
+ * address, and decided not to reject it for any number of reasons. Now
+ * mark the connection as waiting for a circuit, and try to attach it!
+ */
+ base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
+
+ /* If we were given a circuit to attach to, try to attach. Otherwise,
+ * try to find a good one and attach to that. */
+ int rv;
+ if (circ) {
+ rv = connection_ap_handshake_attach_chosen_circuit(conn, circ, cpath);
+ } else {
+ /* We'll try to attach it at the next event loop, or whenever
+ * we call connection_ap_attach_pending() */
+ connection_ap_mark_as_pending_circuit(conn);
+ rv = 0;
+ }
+
+ /* If the above function returned 0 then we're waiting for a circuit.
+ * if it returned 1, we're attached. Both are okay. But if it returned
+ * -1, there was an error, so make sure the connection is marked, and
+ * return -1. */
+ if (rv < 0) {
+ if (!base_conn->marked_for_close)
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
+ return -1;
+ }
+
+ return 0;
+ } else {
+ /* If we get here, it's a request for a .onion address! */
+ tor_assert(addresstype == ONION_V2_HOSTNAME ||
+ addresstype == ONION_V3_HOSTNAME);
+ tor_assert(!automap);
+ return connection_ap_handle_onion(conn, socks, circ, addresstype);
+ }
+
+ return 0; /* unreached but keeps the compiler happy */
+}
+
+#ifdef TRANS_PF
+static int pf_socket = -1;
+int
+get_pf_socket(void)
+{
+ int pf;
+ /* This should be opened before dropping privileges. */
+ if (pf_socket >= 0)
+ return pf_socket;
+
+#if defined(OpenBSD)
+ /* only works on OpenBSD */
+ pf = tor_open_cloexec("/dev/pf", O_RDONLY, 0);
+#else
+ /* works on NetBSD and FreeBSD */
+ pf = tor_open_cloexec("/dev/pf", O_RDWR, 0);
+#endif /* defined(OpenBSD) */
+
+ if (pf < 0) {
+ log_warn(LD_NET, "open(\"/dev/pf\") failed: %s", strerror(errno));
+ return -1;
+ }
+
+ pf_socket = pf;
+ return pf_socket;
+}
+#endif /* defined(TRANS_PF) */
+
+#if defined(TRANS_NETFILTER) || defined(TRANS_PF) || \
+ defined(TRANS_TPROXY)
+/** Try fill in the address of <b>req</b> from the socket configured
+ * with <b>conn</b>. */
+static int
+destination_from_socket(entry_connection_t *conn, socks_request_t *req)
+{
+ struct sockaddr_storage orig_dst;
+ socklen_t orig_dst_len = sizeof(orig_dst);
+ tor_addr_t addr;
+
+#ifdef TRANS_TPROXY
+ if (get_options()->TransProxyType_parsed == TPT_TPROXY) {
+ if (getsockname(ENTRY_TO_CONN(conn)->s, (struct sockaddr*)&orig_dst,
+ &orig_dst_len) < 0) {
+ int e = tor_socket_errno(ENTRY_TO_CONN(conn)->s);
+ log_warn(LD_NET, "getsockname() failed: %s", tor_socket_strerror(e));
+ return -1;
+ }
+ goto done;
+ }
+#endif /* defined(TRANS_TPROXY) */
+
+#ifdef TRANS_NETFILTER
+ int rv = -1;
+ switch (ENTRY_TO_CONN(conn)->socket_family) {
+#ifdef TRANS_NETFILTER_IPV4
+ case AF_INET:
+ rv = getsockopt(ENTRY_TO_CONN(conn)->s, SOL_IP, SO_ORIGINAL_DST,
+ (struct sockaddr*)&orig_dst, &orig_dst_len);
+ break;
+#endif /* defined(TRANS_NETFILTER_IPV4) */
+#ifdef TRANS_NETFILTER_IPV6
+ case AF_INET6:
+ rv = getsockopt(ENTRY_TO_CONN(conn)->s, SOL_IPV6, IP6T_SO_ORIGINAL_DST,
+ (struct sockaddr*)&orig_dst, &orig_dst_len);
+ break;
+#endif /* defined(TRANS_NETFILTER_IPV6) */
+ default:
+ log_warn(LD_BUG,
+ "Received transparent data from an unsuported socket family %d",
+ ENTRY_TO_CONN(conn)->socket_family);
+ return -1;
+ }
+ if (rv < 0) {
+ int e = tor_socket_errno(ENTRY_TO_CONN(conn)->s);
+ log_warn(LD_NET, "getsockopt() failed: %s", tor_socket_strerror(e));
+ return -1;
+ }
+ goto done;
+#elif defined(TRANS_PF)
+ if (getsockname(ENTRY_TO_CONN(conn)->s, (struct sockaddr*)&orig_dst,
+ &orig_dst_len) < 0) {
+ int e = tor_socket_errno(ENTRY_TO_CONN(conn)->s);
+ log_warn(LD_NET, "getsockname() failed: %s", tor_socket_strerror(e));
+ return -1;
+ }
+ goto done;
+#else
+ (void)conn;
+ (void)req;
+ log_warn(LD_BUG, "Unable to determine destination from socket.");
+ return -1;
+#endif /* defined(TRANS_NETFILTER) || ... */
+
+ done:
+ tor_addr_from_sockaddr(&addr, (struct sockaddr*)&orig_dst, &req->port);
+ tor_addr_to_str(req->address, &addr, sizeof(req->address), 1);
+
+ return 0;
+}
+#endif /* defined(TRANS_NETFILTER) || defined(TRANS_PF) || ... */
+
+#ifdef TRANS_PF
+static int
+destination_from_pf(entry_connection_t *conn, socks_request_t *req)
+{
+ struct sockaddr_storage proxy_addr;
+ socklen_t proxy_addr_len = sizeof(proxy_addr);
+ struct sockaddr *proxy_sa = (struct sockaddr*) &proxy_addr;
+ struct pfioc_natlook pnl;
+ tor_addr_t addr;
+ int pf = -1;
+
+ if (getsockname(ENTRY_TO_CONN(conn)->s, (struct sockaddr*)&proxy_addr,
+ &proxy_addr_len) < 0) {
+ int e = tor_socket_errno(ENTRY_TO_CONN(conn)->s);
+ log_warn(LD_NET, "getsockname() to determine transocks destination "
+ "failed: %s", tor_socket_strerror(e));
+ return -1;
+ }
+
+#ifdef __FreeBSD__
+ if (get_options()->TransProxyType_parsed == TPT_IPFW) {
+ /* ipfw(8) is used and in this case getsockname returned the original
+ destination */
+ if (tor_addr_from_sockaddr(&addr, proxy_sa, &req->port) < 0) {
+ tor_fragile_assert();
+ return -1;
+ }
+
+ tor_addr_to_str(req->address, &addr, sizeof(req->address), 0);
+
+ return 0;
+ }
+#endif /* defined(__FreeBSD__) */
+
+ memset(&pnl, 0, sizeof(pnl));
+ pnl.proto = IPPROTO_TCP;
+ pnl.direction = PF_OUT;
+ if (proxy_sa->sa_family == AF_INET) {
+ struct sockaddr_in *sin = (struct sockaddr_in *)proxy_sa;
+ pnl.af = AF_INET;
+ pnl.saddr.v4.s_addr = tor_addr_to_ipv4n(&ENTRY_TO_CONN(conn)->addr);
+ pnl.sport = htons(ENTRY_TO_CONN(conn)->port);
+ pnl.daddr.v4.s_addr = sin->sin_addr.s_addr;
+ pnl.dport = sin->sin_port;
+ } else if (proxy_sa->sa_family == AF_INET6) {
+ struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)proxy_sa;
+ pnl.af = AF_INET6;
+ memcpy(&pnl.saddr.v6, tor_addr_to_in6(&ENTRY_TO_CONN(conn)->addr),
+ sizeof(struct in6_addr));
+ pnl.sport = htons(ENTRY_TO_CONN(conn)->port);
+ memcpy(&pnl.daddr.v6, &sin6->sin6_addr, sizeof(struct in6_addr));
+ pnl.dport = sin6->sin6_port;
+ } else {
+ log_warn(LD_NET, "getsockname() gave an unexpected address family (%d)",
+ (int)proxy_sa->sa_family);
+ return -1;
+ }
+
+ pf = get_pf_socket();
+ if (pf<0)
+ return -1;
+
+ if (ioctl(pf, DIOCNATLOOK, &pnl) < 0) {
+ log_warn(LD_NET, "ioctl(DIOCNATLOOK) failed: %s", strerror(errno));
+ return -1;
+ }
+
+ if (pnl.af == AF_INET) {
+ tor_addr_from_ipv4n(&addr, pnl.rdaddr.v4.s_addr);
+ } else if (pnl.af == AF_INET6) {
+ tor_addr_from_in6(&addr, &pnl.rdaddr.v6);
+ } else {
+ tor_fragile_assert();
+ return -1;
+ }
+
+ tor_addr_to_str(req->address, &addr, sizeof(req->address), 1);
+ req->port = ntohs(pnl.rdport);
+
+ return 0;
+}
+#endif /* defined(TRANS_PF) */
+
+/** Fetch the original destination address and port from a
+ * system-specific interface and put them into a
+ * socks_request_t as if they came from a socks request.
+ *
+ * Return -1 if an error prevents fetching the destination,
+ * else return 0.
+ */
+static int
+connection_ap_get_original_destination(entry_connection_t *conn,
+ socks_request_t *req)
+{
+#ifdef TRANS_NETFILTER
+ return destination_from_socket(conn, req);
+#elif defined(TRANS_PF)
+ const or_options_t *options = get_options();
+
+ if (options->TransProxyType_parsed == TPT_PF_DIVERT)
+ return destination_from_socket(conn, req);
+
+ if (options->TransProxyType_parsed == TPT_DEFAULT ||
+ options->TransProxyType_parsed == TPT_IPFW)
+ return destination_from_pf(conn, req);
+
+ (void)conn;
+ (void)req;
+ log_warn(LD_BUG, "Proxy destination determination mechanism %s unknown.",
+ options->TransProxyType);
+ return -1;
+#else
+ (void)conn;
+ (void)req;
+ log_warn(LD_BUG, "Called connection_ap_get_original_destination, but no "
+ "transparent proxy method was configured.");
+ return -1;
+#endif /* defined(TRANS_NETFILTER) || ... */
+}
+
+/** connection_edge_process_inbuf() found a conn in state
+ * socks_wait. See if conn->inbuf has the right bytes to proceed with
+ * the socks handshake.
+ *
+ * If the handshake is complete, send it to
+ * connection_ap_handshake_rewrite_and_attach().
+ *
+ * Return -1 if an unexpected error with conn occurs (and mark it for close),
+ * else return 0.
+ */
+static int
+connection_ap_handshake_process_socks(entry_connection_t *conn)
+{
+ socks_request_t *socks;
+ int sockshere;
+ const or_options_t *options = get_options();
+ int had_reply = 0;
+ connection_t *base_conn = ENTRY_TO_CONN(conn);
+
+ tor_assert(conn);
+ tor_assert(base_conn->type == CONN_TYPE_AP);
+ tor_assert(base_conn->state == AP_CONN_STATE_SOCKS_WAIT);
+ tor_assert(conn->socks_request);
+ socks = conn->socks_request;
+
+ log_debug(LD_APP,"entered.");
+
+ sockshere = fetch_from_buf_socks(base_conn->inbuf, socks,
+ options->TestSocks, options->SafeSocks);
+
+ if (socks->replylen) {
+ had_reply = 1;
+ connection_buf_add((const char*)socks->reply, socks->replylen,
+ base_conn);
+ socks->replylen = 0;
+ if (sockshere == -1) {
+ /* An invalid request just got a reply, no additional
+ * one is necessary. */
+ socks->has_finished = 1;
+ }
+ }
+
+ if (sockshere == 0) {
+ log_debug(LD_APP,"socks handshake not all here yet.");
+ return 0;
+ } else if (sockshere == -1) {
+ if (!had_reply) {
+ log_warn(LD_APP,"Fetching socks handshake failed. Closing.");
+ connection_ap_handshake_socks_reply(conn, NULL, 0,
+ END_STREAM_REASON_SOCKSPROTOCOL);
+ }
+ connection_mark_unattached_ap(conn,
+ END_STREAM_REASON_SOCKSPROTOCOL |
+ END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
+ return -1;
+ } /* else socks handshake is done, continue processing */
+
+ if (SOCKS_COMMAND_IS_CONNECT(socks->command))
+ control_event_stream_status(conn, STREAM_EVENT_NEW, 0);
+ else
+ control_event_stream_status(conn, STREAM_EVENT_NEW_RESOLVE, 0);
+
+ return connection_ap_rewrite_and_attach_if_allowed(conn, NULL, NULL);
+}
+
+/** connection_init_accepted_conn() found a new trans AP conn.
+ * Get the original destination and send it to
+ * connection_ap_handshake_rewrite_and_attach().
+ *
+ * Return -1 if an unexpected error with conn (and it should be marked
+ * for close), else return 0.
+ */
+int
+connection_ap_process_transparent(entry_connection_t *conn)
+{
+ socks_request_t *socks;
+
+ tor_assert(conn);
+ tor_assert(conn->socks_request);
+ socks = conn->socks_request;
+
+ /* pretend that a socks handshake completed so we don't try to
+ * send a socks reply down a transparent conn */
+ socks->command = SOCKS_COMMAND_CONNECT;
+ socks->has_finished = 1;
+
+ log_debug(LD_APP,"entered.");
+
+ if (connection_ap_get_original_destination(conn, socks) < 0) {
+ log_warn(LD_APP,"Fetching original destination failed. Closing.");
+ connection_mark_unattached_ap(conn,
+ END_STREAM_REASON_CANT_FETCH_ORIG_DEST);
+ return -1;
+ }
+ /* we have the original destination */
+
+ control_event_stream_status(conn, STREAM_EVENT_NEW, 0);
+
+ return connection_ap_rewrite_and_attach_if_allowed(conn, NULL, NULL);
+}
+
+/** connection_edge_process_inbuf() found a conn in state natd_wait. See if
+ * conn-\>inbuf has the right bytes to proceed. See FreeBSD's libalias(3) and
+ * ProxyEncodeTcpStream() in src/lib/libalias/alias_proxy.c for the encoding
+ * form of the original destination.
+ *
+ * If the original destination is complete, send it to
+ * connection_ap_handshake_rewrite_and_attach().
+ *
+ * Return -1 if an unexpected error with conn (and it should be marked
+ * for close), else return 0.
+ */
+static int
+connection_ap_process_natd(entry_connection_t *conn)
+{
+ char tmp_buf[36], *tbuf, *daddr;
+ size_t tlen = 30;
+ int err, port_ok;
+ socks_request_t *socks;
+
+ tor_assert(conn);
+ tor_assert(ENTRY_TO_CONN(conn)->state == AP_CONN_STATE_NATD_WAIT);
+ tor_assert(conn->socks_request);
+ socks = conn->socks_request;
+
+ log_debug(LD_APP,"entered.");
+
+ /* look for LF-terminated "[DEST ip_addr port]"
+ * where ip_addr is a dotted-quad and port is in string form */
+ err = connection_buf_get_line(ENTRY_TO_CONN(conn), tmp_buf, &tlen);
+ if (err == 0)
+ return 0;
+ if (err < 0) {
+ log_warn(LD_APP,"NATD handshake failed (DEST too long). Closing");
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_INVALID_NATD_DEST);
+ return -1;
+ }
+
+ if (strcmpstart(tmp_buf, "[DEST ")) {
+ log_warn(LD_APP,"NATD handshake was ill-formed; closing. The client "
+ "said: %s",
+ escaped(tmp_buf));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_INVALID_NATD_DEST);
+ return -1;
+ }
+
+ daddr = tbuf = &tmp_buf[0] + 6; /* after end of "[DEST " */
+ if (!(tbuf = strchr(tbuf, ' '))) {
+ log_warn(LD_APP,"NATD handshake was ill-formed; closing. The client "
+ "said: %s",
+ escaped(tmp_buf));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_INVALID_NATD_DEST);
+ return -1;
+ }
+ *tbuf++ = '\0';
+
+ /* pretend that a socks handshake completed so we don't try to
+ * send a socks reply down a natd conn */
+ strlcpy(socks->address, daddr, sizeof(socks->address));
+ socks->port = (uint16_t)
+ tor_parse_long(tbuf, 10, 1, 65535, &port_ok, &daddr);
+ if (!port_ok) {
+ log_warn(LD_APP,"NATD handshake failed; port %s is ill-formed or out "
+ "of range.", escaped(tbuf));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_INVALID_NATD_DEST);
+ return -1;
+ }
+
+ socks->command = SOCKS_COMMAND_CONNECT;
+ socks->has_finished = 1;
+
+ control_event_stream_status(conn, STREAM_EVENT_NEW, 0);
+
+ ENTRY_TO_CONN(conn)->state = AP_CONN_STATE_CIRCUIT_WAIT;
+
+ return connection_ap_rewrite_and_attach_if_allowed(conn, NULL, NULL);
+}
+
+/** Called on an HTTP CONNECT entry connection when some bytes have arrived,
+ * but we have not yet received a full HTTP CONNECT request. Try to parse an
+ * HTTP CONNECT request from the connection's inbuf. On success, set up the
+ * connection's socks_request field and try to attach the connection. On
+ * failure, send an HTTP reply, and mark the connection.
+ */
+STATIC int
+connection_ap_process_http_connect(entry_connection_t *conn)
+{
+ if (BUG(ENTRY_TO_CONN(conn)->state != AP_CONN_STATE_HTTP_CONNECT_WAIT))
+ return -1;
+
+ char *headers = NULL, *body = NULL;
+ char *command = NULL, *addrport = NULL;
+ char *addr = NULL;
+ size_t bodylen = 0;
+
+ const char *errmsg = NULL;
+ int rv = 0;
+
+ const int http_status =
+ fetch_from_buf_http(ENTRY_TO_CONN(conn)->inbuf, &headers, 8192,
+ &body, &bodylen, 1024, 0);
+ if (http_status < 0) {
+ /* Bad http status */
+ errmsg = "HTTP/1.0 400 Bad Request\r\n\r\n";
+ goto err;
+ } else if (http_status == 0) {
+ /* no HTTP request yet. */
+ goto done;
+ }
+
+ const int cmd_status = parse_http_command(headers, &command, &addrport);
+ if (cmd_status < 0) {
+ errmsg = "HTTP/1.0 400 Bad Request\r\n\r\n";
+ goto err;
+ }
+ tor_assert(command);
+ tor_assert(addrport);
+ if (strcasecmp(command, "connect")) {
+ errmsg = "HTTP/1.0 405 Method Not Allowed\r\n\r\n";
+ goto err;
+ }
+
+ tor_assert(conn->socks_request);
+ socks_request_t *socks = conn->socks_request;
+ uint16_t port;
+ if (tor_addr_port_split(LOG_WARN, addrport, &addr, &port) < 0) {
+ errmsg = "HTTP/1.0 400 Bad Request\r\n\r\n";
+ goto err;
+ }
+ if (strlen(addr) >= MAX_SOCKS_ADDR_LEN) {
+ errmsg = "HTTP/1.0 414 Request-URI Too Long\r\n\r\n";
+ goto err;
+ }
+
+ /* Abuse the 'username' and 'password' fields here. They are already an
+ * abuse. */
+ {
+ char *authorization = http_get_header(headers, "Proxy-Authorization: ");
+ if (authorization) {
+ socks->username = authorization; // steal reference
+ socks->usernamelen = strlen(authorization);
+ }
+ char *isolation = http_get_header(headers, "X-Tor-Stream-Isolation: ");
+ if (isolation) {
+ socks->password = isolation; // steal reference
+ socks->passwordlen = strlen(isolation);
+ }
+ }
+
+ socks->command = SOCKS_COMMAND_CONNECT;
+ socks->listener_type = CONN_TYPE_AP_HTTP_CONNECT_LISTENER;
+ strlcpy(socks->address, addr, sizeof(socks->address));
+ socks->port = port;
+
+ control_event_stream_status(conn, STREAM_EVENT_NEW, 0);
+
+ rv = connection_ap_rewrite_and_attach_if_allowed(conn, NULL, NULL);
+
+ // XXXX send a "100 Continue" message?
+
+ goto done;
+
+ err:
+ if (BUG(errmsg == NULL))
+ errmsg = "HTTP/1.0 400 Bad Request\r\n\r\n";
+ log_warn(LD_EDGE, "Saying %s", escaped(errmsg));
+ connection_buf_add(errmsg, strlen(errmsg), ENTRY_TO_CONN(conn));
+ connection_mark_unattached_ap(conn,
+ END_STREAM_REASON_HTTPPROTOCOL|
+ END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
+
+ done:
+ tor_free(headers);
+ tor_free(body);
+ tor_free(command);
+ tor_free(addrport);
+ tor_free(addr);
+ return rv;
+}
+
+/** Iterate over the two bytes of stream_id until we get one that is not
+ * already in use; return it. Return 0 if can't get a unique stream_id.
+ */
+streamid_t
+get_unique_stream_id_by_circ(origin_circuit_t *circ)
+{
+ edge_connection_t *tmpconn;
+ streamid_t test_stream_id;
+ uint32_t attempts=0;
+
+ again:
+ test_stream_id = circ->next_stream_id++;
+ if (++attempts > 1<<16) {
+ /* Make sure we don't loop forever if all stream_id's are used. */
+ log_warn(LD_APP,"No unused stream IDs. Failing.");
+ return 0;
+ }
+ if (test_stream_id == 0)
+ goto again;
+ for (tmpconn = circ->p_streams; tmpconn; tmpconn=tmpconn->next_stream)
+ if (tmpconn->stream_id == test_stream_id)
+ goto again;
++
++ if (connection_half_edge_find_stream_id(circ->half_streams,
++ test_stream_id))
++ goto again;
++
+ return test_stream_id;
+}
+
+/** Return true iff <b>conn</b> is linked to a circuit and configured to use
+ * an exit that supports optimistic data. */
+static int
+connection_ap_supports_optimistic_data(const entry_connection_t *conn)
+{
+ const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
+ /* We can only send optimistic data if we're connected to an open
+ general circuit. */
+ if (edge_conn->on_circuit == NULL ||
+ edge_conn->on_circuit->state != CIRCUIT_STATE_OPEN ||
+ (edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_C_GENERAL &&
+ edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_C_HSDIR_GET &&
+ edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_S_HSDIR_POST &&
+ edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_C_REND_JOINED))
+ return 0;
+
+ return conn->may_use_optimistic_data;
+}
+
+/** Return a bitmask of BEGIN_FLAG_* flags that we should transmit in the
+ * RELAY_BEGIN cell for <b>ap_conn</b>. */
+static uint32_t
+connection_ap_get_begincell_flags(entry_connection_t *ap_conn)
+{
+ edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(ap_conn);
+ const node_t *exitnode = NULL;
+ const crypt_path_t *cpath_layer = edge_conn->cpath_layer;
+ uint32_t flags = 0;
+
+ /* No flags for begindir */
+ if (ap_conn->use_begindir)
+ return 0;
+
+ /* No flags for hidden services. */
+ if (edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_C_GENERAL)
+ return 0;
+
+ /* If only IPv4 is supported, no flags */
+ if (ap_conn->entry_cfg.ipv4_traffic && !ap_conn->entry_cfg.ipv6_traffic)
+ return 0;
+
+ if (! cpath_layer ||
+ ! cpath_layer->extend_info)
+ return 0;
+
+ if (!ap_conn->entry_cfg.ipv4_traffic)
+ flags |= BEGIN_FLAG_IPV4_NOT_OK;
+
+ exitnode = node_get_by_id(cpath_layer->extend_info->identity_digest);
+
+ if (ap_conn->entry_cfg.ipv6_traffic && exitnode) {
+ tor_addr_t a;
+ tor_addr_make_null(&a, AF_INET6);
+ if (compare_tor_addr_to_node_policy(&a, ap_conn->socks_request->port,
+ exitnode)
+ != ADDR_POLICY_REJECTED) {
+ /* Only say "IPv6 OK" if the exit node supports IPv6. Otherwise there's
+ * no point. */
+ flags |= BEGIN_FLAG_IPV6_OK;
+ }
+ }
+
+ if (flags == BEGIN_FLAG_IPV6_OK) {
+ /* When IPv4 and IPv6 are both allowed, consider whether to say we
+ * prefer IPv6. Otherwise there's no point in declaring a preference */
+ if (ap_conn->entry_cfg.prefer_ipv6)
+ flags |= BEGIN_FLAG_IPV6_PREFERRED;
+ }
+
+ if (flags == BEGIN_FLAG_IPV4_NOT_OK) {
+ log_warn(LD_EDGE, "I'm about to ask a node for a connection that I "
+ "am telling it to fulfil with neither IPv4 nor IPv6. That's "
+ "not going to work. Did you perhaps ask for an IPv6 address "
+ "on an IPv4Only port, or vice versa?");
+ }
+
+ return flags;
+}
+
+/** Write a relay begin cell, using destaddr and destport from ap_conn's
+ * socks_request field, and send it down circ.
+ *
+ * If ap_conn is broken, mark it for close and return -1. Else return 0.
+ */
+MOCK_IMPL(int,
+connection_ap_handshake_send_begin,(entry_connection_t *ap_conn))
+{
+ char payload[CELL_PAYLOAD_SIZE];
+ int payload_len;
+ int begin_type;
+ const or_options_t *options = get_options();
+ origin_circuit_t *circ;
+ edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(ap_conn);
+ connection_t *base_conn = TO_CONN(edge_conn);
+ tor_assert(edge_conn->on_circuit);
+ circ = TO_ORIGIN_CIRCUIT(edge_conn->on_circuit);
+
+ tor_assert(base_conn->type == CONN_TYPE_AP);
+ tor_assert(base_conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
+ tor_assert(ap_conn->socks_request);
+ tor_assert(SOCKS_COMMAND_IS_CONNECT(ap_conn->socks_request->command));
+
+ edge_conn->stream_id = get_unique_stream_id_by_circ(circ);
+ if (edge_conn->stream_id==0) {
+ /* XXXX+ Instead of closing this stream, we should make it get
+ * retried on another circuit. */
+ connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
+
+ /* Mark this circuit "unusable for new streams". */
+ mark_circuit_unusable_for_new_conns(circ);
+ return -1;
+ }
+
+ /* Set up begin cell flags. */
+ edge_conn->begincell_flags = connection_ap_get_begincell_flags(ap_conn);
+
+ tor_snprintf(payload,RELAY_PAYLOAD_SIZE, "%s:%d",
+ (circ->base_.purpose == CIRCUIT_PURPOSE_C_GENERAL) ?
+ ap_conn->socks_request->address : "",
+ ap_conn->socks_request->port);
+ payload_len = (int)strlen(payload)+1;
+ if (payload_len <= RELAY_PAYLOAD_SIZE - 4 && edge_conn->begincell_flags) {
+ set_uint32(payload + payload_len, htonl(edge_conn->begincell_flags));
+ payload_len += 4;
+ }
+
+ log_info(LD_APP,
+ "Sending relay cell %d on circ %u to begin stream %d.",
+ (int)ap_conn->use_begindir,
+ (unsigned)circ->base_.n_circ_id,
+ edge_conn->stream_id);
+
+ begin_type = ap_conn->use_begindir ?
+ RELAY_COMMAND_BEGIN_DIR : RELAY_COMMAND_BEGIN;
+
+ /* Check that circuits are anonymised, based on their type. */
+ if (begin_type == RELAY_COMMAND_BEGIN) {
+ /* This connection is a standard OR connection.
+ * Make sure its path length is anonymous, or that we're in a
+ * non-anonymous mode. */
+ assert_circ_anonymity_ok(circ, options);
+ } else if (begin_type == RELAY_COMMAND_BEGIN_DIR) {
+ /* This connection is a begindir directory connection.
+ * Look at the linked directory connection to access the directory purpose.
+ * If a BEGINDIR connection is ever not linked, that's a bug. */
+ if (BUG(!base_conn->linked)) {
+ return -1;
+ }
+ connection_t *linked_dir_conn_base = base_conn->linked_conn;
+ /* If the linked connection has been unlinked by other code, we can't send
+ * a begin cell on it. */
+ if (!linked_dir_conn_base) {
+ return -1;
+ }
+ /* Sensitive directory connections must have an anonymous path length.
+ * Otherwise, directory connections are typically one-hop.
+ * This matches the earlier check for directory connection path anonymity
+ * in directory_initiate_request(). */
+ if (purpose_needs_anonymity(linked_dir_conn_base->purpose,
+ TO_DIR_CONN(linked_dir_conn_base)->router_purpose,
+ TO_DIR_CONN(linked_dir_conn_base)->requested_resource)) {
+ assert_circ_anonymity_ok(circ, options);
+ }
+ } else {
+ /* This code was written for the two connection types BEGIN and BEGIN_DIR
+ */
+ tor_assert_unreached();
+ }
+
+ if (connection_edge_send_command(edge_conn, begin_type,
+ begin_type == RELAY_COMMAND_BEGIN ? payload : NULL,
+ begin_type == RELAY_COMMAND_BEGIN ? payload_len : 0) < 0)
+ return -1; /* circuit is closed, don't continue */
+
+ edge_conn->package_window = STREAMWINDOW_START;
+ edge_conn->deliver_window = STREAMWINDOW_START;
+ base_conn->state = AP_CONN_STATE_CONNECT_WAIT;
+ log_info(LD_APP,"Address/port sent, ap socket "TOR_SOCKET_T_FORMAT
+ ", n_circ_id %u",
+ base_conn->s, (unsigned)circ->base_.n_circ_id);
+ control_event_stream_status(ap_conn, STREAM_EVENT_SENT_CONNECT, 0);
+
+ /* If there's queued-up data, send it now */
+ if ((connection_get_inbuf_len(base_conn) ||
+ ap_conn->sending_optimistic_data) &&
+ connection_ap_supports_optimistic_data(ap_conn)) {
+ log_info(LD_APP, "Sending up to %ld + %ld bytes of queued-up data",
+ (long)connection_get_inbuf_len(base_conn),
+ ap_conn->sending_optimistic_data ?
+ (long)buf_datalen(ap_conn->sending_optimistic_data) : 0);
+ if (connection_edge_package_raw_inbuf(edge_conn, 1, NULL) < 0) {
+ connection_mark_for_close(base_conn);
+ }
+ }
+
+ return 0;
+}
+
+/** Write a relay resolve cell, using destaddr and destport from ap_conn's
+ * socks_request field, and send it down circ.
+ *
+ * If ap_conn is broken, mark it for close and return -1. Else return 0.
+ */
+int
+connection_ap_handshake_send_resolve(entry_connection_t *ap_conn)
+{
+ int payload_len, command;
+ const char *string_addr;
+ char inaddr_buf[REVERSE_LOOKUP_NAME_BUF_LEN];
+ origin_circuit_t *circ;
+ edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(ap_conn);
+ connection_t *base_conn = TO_CONN(edge_conn);
+ tor_assert(edge_conn->on_circuit);
+ circ = TO_ORIGIN_CIRCUIT(edge_conn->on_circuit);
+
+ tor_assert(base_conn->type == CONN_TYPE_AP);
+ tor_assert(base_conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
+ tor_assert(ap_conn->socks_request);
+ tor_assert(circ->base_.purpose == CIRCUIT_PURPOSE_C_GENERAL);
+
+ command = ap_conn->socks_request->command;
+ tor_assert(SOCKS_COMMAND_IS_RESOLVE(command));
+
+ edge_conn->stream_id = get_unique_stream_id_by_circ(circ);
+ if (edge_conn->stream_id==0) {
+ /* XXXX+ Instead of closing this stream, we should make it get
+ * retried on another circuit. */
+ connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
+
+ /* Mark this circuit "unusable for new streams". */
+ mark_circuit_unusable_for_new_conns(circ);
+ return -1;
+ }
+
+ if (command == SOCKS_COMMAND_RESOLVE) {
+ string_addr = ap_conn->socks_request->address;
+ payload_len = (int)strlen(string_addr)+1;
+ } else {
+ /* command == SOCKS_COMMAND_RESOLVE_PTR */
+ const char *a = ap_conn->socks_request->address;
+ tor_addr_t addr;
+ int r;
+
+ /* We're doing a reverse lookup. The input could be an IP address, or
+ * could be an .in-addr.arpa or .ip6.arpa address */
+ r = tor_addr_parse_PTR_name(&addr, a, AF_UNSPEC, 1);
+ if (r <= 0) {
+ log_warn(LD_APP, "Rejecting ill-formed reverse lookup of %s",
+ safe_str_client(a));
+ connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
+ return -1;
+ }
+
+ r = tor_addr_to_PTR_name(inaddr_buf, sizeof(inaddr_buf), &addr);
+ if (r < 0) {
+ log_warn(LD_BUG, "Couldn't generate reverse lookup hostname of %s",
+ safe_str_client(a));
+ connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
+ return -1;
+ }
+
+ string_addr = inaddr_buf;
+ payload_len = (int)strlen(inaddr_buf)+1;
+ tor_assert(payload_len <= (int)sizeof(inaddr_buf));
+ }
+
+ log_debug(LD_APP,
+ "Sending relay cell to begin stream %d.", edge_conn->stream_id);
+
+ if (connection_edge_send_command(edge_conn,
+ RELAY_COMMAND_RESOLVE,
+ string_addr, payload_len) < 0)
+ return -1; /* circuit is closed, don't continue */
+
+ if (!base_conn->address) {
+ /* This might be unnecessary. XXXX */
+ base_conn->address = tor_addr_to_str_dup(&base_conn->addr);
+ }
+ base_conn->state = AP_CONN_STATE_RESOLVE_WAIT;
+ log_info(LD_APP,"Address sent for resolve, ap socket "TOR_SOCKET_T_FORMAT
+ ", n_circ_id %u",
+ base_conn->s, (unsigned)circ->base_.n_circ_id);
+ control_event_stream_status(ap_conn, STREAM_EVENT_SENT_RESOLVE, 0);
+ return 0;
+}
+
+/** Make an AP connection_t linked to the connection_t <b>partner</b>. make a
+ * new linked connection pair, and attach one side to the conn, connection_add
+ * it, initialize it to circuit_wait, and call
+ * connection_ap_handshake_attach_circuit(conn) on it.
+ *
+ * Return the newly created end of the linked connection pair, or -1 if error.
+ */
+entry_connection_t *
+connection_ap_make_link(connection_t *partner,
+ char *address, uint16_t port,
+ const char *digest,
+ int session_group, int isolation_flags,
+ int use_begindir, int want_onehop)
+{
+ entry_connection_t *conn;
+ connection_t *base_conn;
+
+ log_info(LD_APP,"Making internal %s tunnel to %s:%d ...",
+ want_onehop ? "direct" : "anonymized",
+ safe_str_client(address), port);
+
+ conn = entry_connection_new(CONN_TYPE_AP, tor_addr_family(&partner->addr));
+ base_conn = ENTRY_TO_CONN(conn);
+ base_conn->linked = 1; /* so that we can add it safely below. */
+
+ /* populate conn->socks_request */
+
+ /* leave version at zero, so the socks_reply is empty */
+ conn->socks_request->socks_version = 0;
+ conn->socks_request->has_finished = 0; /* waiting for 'connected' */
+ strlcpy(conn->socks_request->address, address,
+ sizeof(conn->socks_request->address));
+ conn->socks_request->port = port;
+ conn->socks_request->command = SOCKS_COMMAND_CONNECT;
+ conn->want_onehop = want_onehop;
+ conn->use_begindir = use_begindir;
+ if (use_begindir) {
+ conn->chosen_exit_name = tor_malloc(HEX_DIGEST_LEN+2);
+ conn->chosen_exit_name[0] = '$';
+ tor_assert(digest);
+ base16_encode(conn->chosen_exit_name+1,HEX_DIGEST_LEN+1,
+ digest, DIGEST_LEN);
+ }
+
+ /* Populate isolation fields. */
+ conn->socks_request->listener_type = CONN_TYPE_DIR_LISTENER;
+ conn->original_dest_address = tor_strdup(address);
+ conn->entry_cfg.session_group = session_group;
+ conn->entry_cfg.isolation_flags = isolation_flags;
+
+ base_conn->address = tor_strdup("(Tor_internal)");
+ tor_addr_make_unspec(&base_conn->addr);
+ base_conn->port = 0;
+
+ connection_link_connections(partner, base_conn);
+
+ if (connection_add(base_conn) < 0) { /* no space, forget it */
+ connection_free(base_conn);
+ return NULL;
+ }
+
+ base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
+
+ control_event_stream_status(conn, STREAM_EVENT_NEW, 0);
+
+ /* attaching to a dirty circuit is fine */
+ connection_ap_mark_as_pending_circuit(conn);
+ log_info(LD_APP,"... application connection created and linked.");
+ return conn;
+}
+
+/** Notify any interested controller connections about a new hostname resolve
+ * or resolve error. Takes the same arguments as does
+ * connection_ap_handshake_socks_resolved(). */
+static void
+tell_controller_about_resolved_result(entry_connection_t *conn,
+ int answer_type,
+ size_t answer_len,
+ const char *answer,
+ int ttl,
+ time_t expires)
+{
+ expires = time(NULL) + ttl;
+ if (answer_type == RESOLVED_TYPE_IPV4 && answer_len >= 4) {
+ char *cp = tor_dup_ip(ntohl(get_uint32(answer)));
+ control_event_address_mapped(conn->socks_request->address,
+ cp, expires, NULL, 0);
+ tor_free(cp);
+ } else if (answer_type == RESOLVED_TYPE_HOSTNAME && answer_len < 256) {
+ char *cp = tor_strndup(answer, answer_len);
+ control_event_address_mapped(conn->socks_request->address,
+ cp, expires, NULL, 0);
+ tor_free(cp);
+ } else {
+ control_event_address_mapped(conn->socks_request->address,
+ "<error>", time(NULL)+ttl,
+ "error=yes", 0);
+ }
+}
+
+/**
+ * As connection_ap_handshake_socks_resolved, but take a tor_addr_t to send
+ * as the answer.
+ */
+void
+connection_ap_handshake_socks_resolved_addr(entry_connection_t *conn,
+ const tor_addr_t *answer,
+ int ttl,
+ time_t expires)
+{
+ if (tor_addr_family(answer) == AF_INET) {
+ uint32_t a = tor_addr_to_ipv4n(answer); /* network order */
+ connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_IPV4,4,
+ (uint8_t*)&a,
+ ttl, expires);
+ } else if (tor_addr_family(answer) == AF_INET6) {
+ const uint8_t *a = tor_addr_to_in6_addr8(answer);
+ connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_IPV6,16,
+ a,
+ ttl, expires);
+ } else {
+ log_warn(LD_BUG, "Got called with address of unexpected family %d",
+ tor_addr_family(answer));
+ connection_ap_handshake_socks_resolved(conn,
+ RESOLVED_TYPE_ERROR,0,NULL,-1,-1);
+ }
+}
+
+/** Send an answer to an AP connection that has requested a DNS lookup via
+ * SOCKS. The type should be one of RESOLVED_TYPE_(IPV4|IPV6|HOSTNAME) or -1
+ * for unreachable; the answer should be in the format specified in the socks
+ * extensions document. <b>ttl</b> is the ttl for the answer, or -1 on
+ * certain errors or for values that didn't come via DNS. <b>expires</b> is
+ * a time when the answer expires, or -1 or TIME_MAX if there's a good TTL.
+ **/
+/* XXXX the use of the ttl and expires fields is nutty. Let's make this
+ * interface and those that use it less ugly. */
+MOCK_IMPL(void,
+connection_ap_handshake_socks_resolved,(entry_connection_t *conn,
+ int answer_type,
+ size_t answer_len,
+ const uint8_t *answer,
+ int ttl,
+ time_t expires))
+{
+ char buf[384];
+ size_t replylen;
+
+ if (ttl >= 0) {
+ if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) {
+ tor_addr_t a;
+ tor_addr_from_ipv4n(&a, get_uint32(answer));
+ if (! tor_addr_is_null(&a)) {
+ client_dns_set_addressmap(conn,
+ conn->socks_request->address, &a,
+ conn->chosen_exit_name, ttl);
+ }
+ } else if (answer_type == RESOLVED_TYPE_IPV6 && answer_len == 16) {
+ tor_addr_t a;
+ tor_addr_from_ipv6_bytes(&a, (char*)answer);
+ if (! tor_addr_is_null(&a)) {
+ client_dns_set_addressmap(conn,
+ conn->socks_request->address, &a,
+ conn->chosen_exit_name, ttl);
+ }
+ } else if (answer_type == RESOLVED_TYPE_HOSTNAME && answer_len < 256) {
+ char *cp = tor_strndup((char*)answer, answer_len);
+ client_dns_set_reverse_addressmap(conn,
+ conn->socks_request->address,
+ cp,
+ conn->chosen_exit_name, ttl);
+ tor_free(cp);
+ }
+ }
+
+ if (ENTRY_TO_EDGE_CONN(conn)->is_dns_request) {
+ if (conn->dns_server_request) {
+ /* We had a request on our DNS port: answer it. */
+ dnsserv_resolved(conn, answer_type, answer_len, (char*)answer, ttl);
+ conn->socks_request->has_finished = 1;
+ return;
+ } else {
+ /* This must be a request from the controller. Since answers to those
+ * requests are not cached, they do not generate an ADDRMAP event on
+ * their own. */
+ tell_controller_about_resolved_result(conn, answer_type, answer_len,
+ (char*)answer, ttl, expires);
+ conn->socks_request->has_finished = 1;
+ return;
+ }
+ /* We shouldn't need to free conn here; it gets marked by the caller. */
+ }
+
+ if (conn->socks_request->socks_version == 4) {
+ buf[0] = 0x00; /* version */
+ if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) {
+ buf[1] = SOCKS4_GRANTED;
+ set_uint16(buf+2, 0);
+ memcpy(buf+4, answer, 4); /* address */
+ replylen = SOCKS4_NETWORK_LEN;
+ } else { /* "error" */
+ buf[1] = SOCKS4_REJECT;
+ memset(buf+2, 0, 6);
+ replylen = SOCKS4_NETWORK_LEN;
+ }
+ } else if (conn->socks_request->socks_version == 5) {
+ /* SOCKS5 */
+ buf[0] = 0x05; /* version */
+ if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) {
+ buf[1] = SOCKS5_SUCCEEDED;
+ buf[2] = 0; /* reserved */
+ buf[3] = 0x01; /* IPv4 address type */
+ memcpy(buf+4, answer, 4); /* address */
+ set_uint16(buf+8, 0); /* port == 0. */
+ replylen = 10;
+ } else if (answer_type == RESOLVED_TYPE_IPV6 && answer_len == 16) {
+ buf[1] = SOCKS5_SUCCEEDED;
+ buf[2] = 0; /* reserved */
+ buf[3] = 0x04; /* IPv6 address type */
+ memcpy(buf+4, answer, 16); /* address */
+ set_uint16(buf+20, 0); /* port == 0. */
+ replylen = 22;
+ } else if (answer_type == RESOLVED_TYPE_HOSTNAME && answer_len < 256) {
+ buf[1] = SOCKS5_SUCCEEDED;
+ buf[2] = 0; /* reserved */
+ buf[3] = 0x03; /* Domainname address type */
+ buf[4] = (char)answer_len;
+ memcpy(buf+5, answer, answer_len); /* address */
+ set_uint16(buf+5+answer_len, 0); /* port == 0. */
+ replylen = 5+answer_len+2;
+ } else {
+ buf[1] = SOCKS5_HOST_UNREACHABLE;
+ memset(buf+2, 0, 8);
+ replylen = 10;
+ }
+ } else {
+ /* no socks version info; don't send anything back */
+ return;
+ }
+ connection_ap_handshake_socks_reply(conn, buf, replylen,
+ (answer_type == RESOLVED_TYPE_IPV4 ||
+ answer_type == RESOLVED_TYPE_IPV6 ||
+ answer_type == RESOLVED_TYPE_HOSTNAME) ?
+ 0 : END_STREAM_REASON_RESOLVEFAILED);
+}
+
+/** Send a socks reply to stream <b>conn</b>, using the appropriate
+ * socks version, etc, and mark <b>conn</b> as completed with SOCKS
+ * handshaking.
+ *
+ * If <b>reply</b> is defined, then write <b>replylen</b> bytes of it to conn
+ * and return, else reply based on <b>endreason</b> (one of
+ * END_STREAM_REASON_*). If <b>reply</b> is undefined, <b>endreason</b> can't
+ * be 0 or REASON_DONE. Send endreason to the controller, if appropriate.
+ */
+void
+connection_ap_handshake_socks_reply(entry_connection_t *conn, char *reply,
+ size_t replylen, int endreason)
+{
+ char buf[256];
+ socks5_reply_status_t status =
+ stream_end_reason_to_socks5_response(endreason);
+
+ tor_assert(conn->socks_request); /* make sure it's an AP stream */
+
+ if (!SOCKS_COMMAND_IS_RESOLVE(conn->socks_request->command)) {
+ control_event_stream_status(conn, status==SOCKS5_SUCCEEDED ?
+ STREAM_EVENT_SUCCEEDED : STREAM_EVENT_FAILED,
+ endreason);
+ }
+
+ /* Flag this stream's circuit as having completed a stream successfully
+ * (for path bias) */
+ if (status == SOCKS5_SUCCEEDED ||
+ endreason == END_STREAM_REASON_RESOLVEFAILED ||
+ endreason == END_STREAM_REASON_CONNECTREFUSED ||
+ endreason == END_STREAM_REASON_CONNRESET ||
+ endreason == END_STREAM_REASON_NOROUTE ||
+ endreason == END_STREAM_REASON_RESOURCELIMIT) {
+ if (!conn->edge_.on_circuit ||
+ !CIRCUIT_IS_ORIGIN(conn->edge_.on_circuit)) {
+ if (endreason != END_STREAM_REASON_RESOLVEFAILED) {
+ log_info(LD_BUG,
+ "No origin circuit for successful SOCKS stream %"PRIu64
+ ". Reason: %d",
+ (ENTRY_TO_CONN(conn)->global_identifier),
+ endreason);
+ }
+ /*
+ * Else DNS remaps and failed hidden service lookups can send us
+ * here with END_STREAM_REASON_RESOLVEFAILED; ignore it
+ *
+ * Perhaps we could make the test more precise; we can tell hidden
+ * services by conn->edge_.renddata != NULL; anything analogous for
+ * the DNS remap case?
+ */
+ } else {
+ // XXX: Hrmm. It looks like optimistic data can't go through this
+ // codepath, but someone should probably test it and make sure.
+ // We don't want to mark optimistically opened streams as successful.
+ pathbias_mark_use_success(TO_ORIGIN_CIRCUIT(conn->edge_.on_circuit));
+ }
+ }
+
+ if (conn->socks_request->has_finished) {
+ log_warn(LD_BUG, "(Harmless.) duplicate calls to "
+ "connection_ap_handshake_socks_reply.");
+ return;
+ }
+ if (replylen) { /* we already have a reply in mind */
+ connection_buf_add(reply, replylen, ENTRY_TO_CONN(conn));
+ conn->socks_request->has_finished = 1;
+ return;
+ }
+ if (conn->socks_request->listener_type ==
+ CONN_TYPE_AP_HTTP_CONNECT_LISTENER) {
+ const char *response = end_reason_to_http_connect_response_line(endreason);
+ if (!response) {
+ response = "HTTP/1.0 400 Bad Request\r\n\r\n";
+ }
+ connection_buf_add(response, strlen(response), ENTRY_TO_CONN(conn));
+ } else if (conn->socks_request->socks_version == 4) {
+ memset(buf,0,SOCKS4_NETWORK_LEN);
+ buf[1] = (status==SOCKS5_SUCCEEDED ? SOCKS4_GRANTED : SOCKS4_REJECT);
+ /* leave version, destport, destip zero */
+ connection_buf_add(buf, SOCKS4_NETWORK_LEN, ENTRY_TO_CONN(conn));
+ } else if (conn->socks_request->socks_version == 5) {
+ size_t buf_len;
+ memset(buf,0,sizeof(buf));
+ if (tor_addr_family(&conn->edge_.base_.addr) == AF_INET) {
+ buf[0] = 5; /* version 5 */
+ buf[1] = (char)status;
+ buf[2] = 0;
+ buf[3] = 1; /* ipv4 addr */
+ /* 4 bytes for the header, 2 bytes for the port, 4 for the address. */
+ buf_len = 10;
+ } else { /* AF_INET6. */
+ buf[0] = 5; /* version 5 */
+ buf[1] = (char)status;
+ buf[2] = 0;
+ buf[3] = 4; /* ipv6 addr */
+ /* 4 bytes for the header, 2 bytes for the port, 16 for the address. */
+ buf_len = 22;
+ }
+ connection_buf_add(buf,buf_len,ENTRY_TO_CONN(conn));
+ }
+ /* If socks_version isn't 4 or 5, don't send anything.
+ * This can happen in the case of AP bridges. */
+ conn->socks_request->has_finished = 1;
+ return;
+}
+
+/** Read a RELAY_BEGIN or RELAY_BEGIN_DIR cell from <b>cell</b>, decode it, and
+ * place the result in <b>bcell</b>. On success return 0; on failure return
+ * <0 and set *<b>end_reason_out</b> to the end reason we should send back to
+ * the client.
+ *
+ * Return -1 in the case where we want to send a RELAY_END cell, and < -1 when
+ * we don't.
+ **/
+STATIC int
+begin_cell_parse(const cell_t *cell, begin_cell_t *bcell,
+ uint8_t *end_reason_out)
+{
+ relay_header_t rh;
+ const uint8_t *body, *nul;
+
+ memset(bcell, 0, sizeof(*bcell));
+ *end_reason_out = END_STREAM_REASON_MISC;
+
+ relay_header_unpack(&rh, cell->payload);
+ if (rh.length > RELAY_PAYLOAD_SIZE) {
+ return -2; /*XXXX why not TORPROTOCOL? */
+ }
+
+ bcell->stream_id = rh.stream_id;
+
+ if (rh.command == RELAY_COMMAND_BEGIN_DIR) {
+ bcell->is_begindir = 1;
+ return 0;
+ } else if (rh.command != RELAY_COMMAND_BEGIN) {
+ log_warn(LD_BUG, "Got an unexpected command %d", (int)rh.command);
+ *end_reason_out = END_STREAM_REASON_INTERNAL;
+ return -1;
+ }
+
+ body = cell->payload + RELAY_HEADER_SIZE;
+ nul = memchr(body, 0, rh.length);
+ if (! nul) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Relay begin cell has no \\0. Closing.");
+ *end_reason_out = END_STREAM_REASON_TORPROTOCOL;
+ return -1;
+ }
+
+ if (tor_addr_port_split(LOG_PROTOCOL_WARN,
+ (char*)(body),
+ &bcell->address,&bcell->port)<0) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Unable to parse addr:port in relay begin cell. Closing.");
+ *end_reason_out = END_STREAM_REASON_TORPROTOCOL;
+ return -1;
+ }
+ if (bcell->port == 0) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Missing port in relay begin cell. Closing.");
+ tor_free(bcell->address);
+ *end_reason_out = END_STREAM_REASON_TORPROTOCOL;
+ return -1;
+ }
+ if (body + rh.length >= nul + 4)
+ bcell->flags = ntohl(get_uint32(nul+1));
+
+ return 0;
+}
+
+/** For the given <b>circ</b> and the edge connection <b>conn</b>, setup the
+ * connection, attach it to the circ and connect it. Return 0 on success
+ * or END_CIRC_AT_ORIGIN if we can't find the requested hidden service port
+ * where the caller should close the circuit. */
+static int
+handle_hs_exit_conn(circuit_t *circ, edge_connection_t *conn)
+{
+ int ret;
+ origin_circuit_t *origin_circ;
+
+ assert_circuit_ok(circ);
+ tor_assert(circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED);
+ tor_assert(conn);
+
+ log_debug(LD_REND, "Connecting the hidden service rendezvous circuit "
+ "to the service destination.");
+
+ origin_circ = TO_ORIGIN_CIRCUIT(circ);
+ conn->base_.address = tor_strdup("(rendezvous)");
+ conn->base_.state = EXIT_CONN_STATE_CONNECTING;
+
+ /* The circuit either has an hs identifier for v3+ or a rend_data for legacy
+ * service. */
+ if (origin_circ->rend_data) {
+ conn->rend_data = rend_data_dup(origin_circ->rend_data);
+ tor_assert(connection_edge_is_rendezvous_stream(conn));
+ ret = rend_service_set_connection_addr_port(conn, origin_circ);
+ } else if (origin_circ->hs_ident) {
+ /* Setup the identifier to be the one for the circuit service. */
+ conn->hs_ident =
+ hs_ident_edge_conn_new(&origin_circ->hs_ident->identity_pk);
+ tor_assert(connection_edge_is_rendezvous_stream(conn));
+ ret = hs_service_set_conn_addr_port(origin_circ, conn);
+ } else {
+ /* We should never get here if the circuit's purpose is rendezvous. */
+ tor_assert_nonfatal_unreached();
+ return -1;
+ }
+ if (ret < 0) {
+ log_info(LD_REND, "Didn't find rendezvous service (addr%s, port %d)",
+ fmt_addr(&TO_CONN(conn)->addr), TO_CONN(conn)->port);
+ /* Send back reason DONE because we want to make hidden service port
+ * scanning harder thus instead of returning that the exit policy
+ * didn't match, which makes it obvious that the port is closed,
+ * return DONE and kill the circuit. That way, a user (malicious or
+ * not) needs one circuit per bad port unless it matches the policy of
+ * the hidden service. */
+ relay_send_end_cell_from_edge(conn->stream_id, circ,
+ END_STREAM_REASON_DONE,
+ origin_circ->cpath->prev);
+ connection_free_(TO_CONN(conn));
+
+ /* Drop the circuit here since it might be someone deliberately
+ * scanning the hidden service ports. Note that this mitigates port
+ * scanning by adding more work on the attacker side to successfully
+ * scan but does not fully solve it. */
+ if (ret < -1) {
+ return END_CIRC_AT_ORIGIN;
+ } else {
+ return 0;
+ }
+ }
+
+ /* Link the circuit and the connection crypt path. */
+ conn->cpath_layer = origin_circ->cpath->prev;
+
+ /* Add it into the linked list of p_streams on this circuit */
+ conn->next_stream = origin_circ->p_streams;
+ origin_circ->p_streams = conn;
+ conn->on_circuit = circ;
+ assert_circuit_ok(circ);
+
+ hs_inc_rdv_stream_counter(origin_circ);
+
+ /* Connect tor to the hidden service destination. */
+ connection_exit_connect(conn);
+
+ /* For path bias: This circuit was used successfully */
+ pathbias_mark_use_success(origin_circ);
+ return 0;
+}
+
+/** A relay 'begin' or 'begin_dir' cell has arrived, and either we are
+ * an exit hop for the circuit, or we are the origin and it is a
+ * rendezvous begin.
+ *
+ * Launch a new exit connection and initialize things appropriately.
+ *
+ * If it's a rendezvous stream, call connection_exit_connect() on
+ * it.
+ *
+ * For general streams, call dns_resolve() on it first, and only call
+ * connection_exit_connect() if the dns answer is already known.
+ *
+ * Note that we don't call connection_add() on the new stream! We wait
+ * for connection_exit_connect() to do that.
+ *
+ * Return -(some circuit end reason) if we want to tear down <b>circ</b>.
+ * Else return 0.
+ */
+int
+connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
+{
+ edge_connection_t *n_stream;
+ relay_header_t rh;
+ char *address = NULL;
+ uint16_t port = 0;
+ or_circuit_t *or_circ = NULL;
+ origin_circuit_t *origin_circ = NULL;
+ crypt_path_t *layer_hint = NULL;
+ const or_options_t *options = get_options();
+ begin_cell_t bcell;
+ int rv;
+ uint8_t end_reason=0;
+
+ assert_circuit_ok(circ);
+ if (!CIRCUIT_IS_ORIGIN(circ)) {
+ or_circ = TO_OR_CIRCUIT(circ);
+ } else {
+ tor_assert(circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED);
+ origin_circ = TO_ORIGIN_CIRCUIT(circ);
+ layer_hint = origin_circ->cpath->prev;
+ }
+
+ relay_header_unpack(&rh, cell->payload);
+ if (rh.length > RELAY_PAYLOAD_SIZE)
+ return -END_CIRC_REASON_TORPROTOCOL;
+
+ if (!server_mode(options) &&
+ circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Relay begin cell at non-server. Closing.");
+ relay_send_end_cell_from_edge(rh.stream_id, circ,
+ END_STREAM_REASON_EXITPOLICY, NULL);
+ return 0;
+ }
+
+ rv = begin_cell_parse(cell, &bcell, &end_reason);
+ if (rv < -1) {
+ return -END_CIRC_REASON_TORPROTOCOL;
+ } else if (rv == -1) {
+ tor_free(bcell.address);
+ relay_send_end_cell_from_edge(rh.stream_id, circ, end_reason, layer_hint);
+ return 0;
+ }
+
+ if (! bcell.is_begindir) {
+ /* Steal reference */
+ address = bcell.address;
+ port = bcell.port;
+
+ if (or_circ && or_circ->p_chan) {
+ const int client_chan = channel_is_client(or_circ->p_chan);
+ if ((client_chan ||
+ (!connection_or_digest_is_known_relay(
+ or_circ->p_chan->identity_digest) &&
+ should_refuse_unknown_exits(options)))) {
+ /* Don't let clients use us as a single-hop proxy. It attracts
+ * attackers and users who'd be better off with, well, single-hop
+ * proxies. */
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Attempt by %s to open a stream %s. Closing.",
+ safe_str(channel_get_canonical_remote_descr(or_circ->p_chan)),
+ client_chan ? "on first hop of circuit" :
+ "from unknown relay");
+ relay_send_end_cell_from_edge(rh.stream_id, circ,
+ client_chan ?
+ END_STREAM_REASON_TORPROTOCOL :
+ END_STREAM_REASON_MISC,
+ NULL);
+ tor_free(address);
+ return 0;
+ }
+ }
+ } else if (rh.command == RELAY_COMMAND_BEGIN_DIR) {
+ if (!directory_permits_begindir_requests(options) ||
+ circ->purpose != CIRCUIT_PURPOSE_OR) {
+ relay_send_end_cell_from_edge(rh.stream_id, circ,
+ END_STREAM_REASON_NOTDIRECTORY, layer_hint);
+ return 0;
+ }
+ /* Make sure to get the 'real' address of the previous hop: the
+ * caller might want to know whether the remote IP address has changed,
+ * and we might already have corrected base_.addr[ess] for the relay's
+ * canonical IP address. */
+ if (or_circ && or_circ->p_chan)
+ address = tor_strdup(channel_get_actual_remote_address(or_circ->p_chan));
+ else
+ address = tor_strdup("127.0.0.1");
+ port = 1; /* XXXX This value is never actually used anywhere, and there
+ * isn't "really" a connection here. But we
+ * need to set it to something nonzero. */
+ } else {
+ log_warn(LD_BUG, "Got an unexpected command %d", (int)rh.command);
+ relay_send_end_cell_from_edge(rh.stream_id, circ,
+ END_STREAM_REASON_INTERNAL, layer_hint);
+ return 0;
+ }
+
+ if (! options->IPv6Exit) {
+ /* I don't care if you prefer IPv6; I can't give you any. */
+ bcell.flags &= ~BEGIN_FLAG_IPV6_PREFERRED;
+ /* If you don't want IPv4, I can't help. */
+ if (bcell.flags & BEGIN_FLAG_IPV4_NOT_OK) {
+ tor_free(address);
+ relay_send_end_cell_from_edge(rh.stream_id, circ,
+ END_STREAM_REASON_EXITPOLICY, layer_hint);
+ return 0;
+ }
+ }
+
+ log_debug(LD_EXIT,"Creating new exit connection.");
+ /* The 'AF_INET' here is temporary; we might need to change it later in
+ * connection_exit_connect(). */
+ n_stream = edge_connection_new(CONN_TYPE_EXIT, AF_INET);
+
+ /* Remember the tunneled request ID in the new edge connection, so that
+ * we can measure download times. */
+ n_stream->dirreq_id = circ->dirreq_id;
+
+ n_stream->base_.purpose = EXIT_PURPOSE_CONNECT;
+ n_stream->begincell_flags = bcell.flags;
+ n_stream->stream_id = rh.stream_id;
+ n_stream->base_.port = port;
+ /* leave n_stream->s at -1, because it's not yet valid */
+ n_stream->package_window = STREAMWINDOW_START;
+ n_stream->deliver_window = STREAMWINDOW_START;
+
+ if (circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED) {
+ int ret;
+ tor_free(address);
+ /* We handle this circuit and stream in this function for all supported
+ * hidden service version. */
+ ret = handle_hs_exit_conn(circ, n_stream);
+
+ if (ret == 0) {
+ /* This was a valid cell. Count it as delivered + overhead. */
+ circuit_read_valid_data(origin_circ, rh.length);
+ }
+ return ret;
+ }
+ tor_strlower(address);
+ n_stream->base_.address = address;
+ n_stream->base_.state = EXIT_CONN_STATE_RESOLVEFAILED;
+ /* default to failed, change in dns_resolve if it turns out not to fail */
+
+ /* If we're hibernating or shutting down, we refuse to open new streams. */
+ if (we_are_hibernating()) {
+ relay_send_end_cell_from_edge(rh.stream_id, circ,
+ END_STREAM_REASON_HIBERNATING, NULL);
+ connection_free_(TO_CONN(n_stream));
+ return 0;
+ }
+
+ n_stream->on_circuit = circ;
+
+ if (rh.command == RELAY_COMMAND_BEGIN_DIR) {
+ tor_addr_t tmp_addr;
+ tor_assert(or_circ);
+ if (or_circ->p_chan &&
+ channel_get_addr_if_possible(or_circ->p_chan, &tmp_addr)) {
+ tor_addr_copy(&n_stream->base_.addr, &tmp_addr);
+ }
+ return connection_exit_connect_dir(n_stream);
+ }
+
+ log_debug(LD_EXIT,"about to start the dns_resolve().");
+
+ /* send it off to the gethostbyname farm */
+ switch (dns_resolve(n_stream)) {
+ case 1: /* resolve worked; now n_stream is attached to circ. */
+ assert_circuit_ok(circ);
+ log_debug(LD_EXIT,"about to call connection_exit_connect().");
+ connection_exit_connect(n_stream);
+ return 0;
+ case -1: /* resolve failed */
+ relay_send_end_cell_from_edge(rh.stream_id, circ,
+ END_STREAM_REASON_RESOLVEFAILED, NULL);
+ /* n_stream got freed. don't touch it. */
+ break;
+ case 0: /* resolve added to pending list */
+ assert_circuit_ok(circ);
+ break;
+ }
+ return 0;
+}
+
+/**
+ * Called when we receive a RELAY_COMMAND_RESOLVE cell 'cell' along the
+ * circuit <b>circ</b>;
+ * begin resolving the hostname, and (eventually) reply with a RESOLVED cell.
+ */
+int
+connection_exit_begin_resolve(cell_t *cell, or_circuit_t *circ)
+{
+ edge_connection_t *dummy_conn;
+ relay_header_t rh;
+
+ assert_circuit_ok(TO_CIRCUIT(circ));
+ relay_header_unpack(&rh, cell->payload);
+ if (rh.length > RELAY_PAYLOAD_SIZE)
+ return -1;
+
+ /* This 'dummy_conn' only exists to remember the stream ID
+ * associated with the resolve request; and to make the
+ * implementation of dns.c more uniform. (We really only need to
+ * remember the circuit, the stream ID, and the hostname to be
+ * resolved; but if we didn't store them in a connection like this,
+ * the housekeeping in dns.c would get way more complicated.)
+ */
+ dummy_conn = edge_connection_new(CONN_TYPE_EXIT, AF_INET);
+ dummy_conn->stream_id = rh.stream_id;
+ dummy_conn->base_.address = tor_strndup(
+ (char*)cell->payload+RELAY_HEADER_SIZE,
+ rh.length);
+ dummy_conn->base_.port = 0;
+ dummy_conn->base_.state = EXIT_CONN_STATE_RESOLVEFAILED;
+ dummy_conn->base_.purpose = EXIT_PURPOSE_RESOLVE;
+
+ dummy_conn->on_circuit = TO_CIRCUIT(circ);
+
+ /* send it off to the gethostbyname farm */
+ switch (dns_resolve(dummy_conn)) {
+ case -1: /* Impossible to resolve; a resolved cell was sent. */
+ /* Connection freed; don't touch it. */
+ return 0;
+ case 1: /* The result was cached; a resolved cell was sent. */
+ if (!dummy_conn->base_.marked_for_close)
+ connection_free_(TO_CONN(dummy_conn));
+ return 0;
+ case 0: /* resolve added to pending list */
+ assert_circuit_ok(TO_CIRCUIT(circ));
+ break;
+ }
+ return 0;
+}
+
+/** Helper: Return true and set *<b>why_rejected</b> to an optional clarifying
+ * message message iff we do not allow connections to <b>addr</b>:<b>port</b>.
+ */
+static int
+my_exit_policy_rejects(const tor_addr_t *addr,
+ uint16_t port,
+ const char **why_rejected)
+{
+ if (router_compare_to_my_exit_policy(addr, port)) {
+ *why_rejected = "";
+ return 1;
+ } else if (tor_addr_family(addr) == AF_INET6 && !get_options()->IPv6Exit) {
+ *why_rejected = " (IPv6 address without IPv6Exit configured)";
+ return 1;
+ }
+ return 0;
+}
+
+/** Connect to conn's specified addr and port. If it worked, conn
+ * has now been added to the connection_array.
+ *
+ * Send back a connected cell. Include the resolved IP of the destination
+ * address, but <em>only</em> if it's a general exit stream. (Rendezvous
+ * streams must not reveal what IP they connected to.)
+ */
+void
+connection_exit_connect(edge_connection_t *edge_conn)
+{
+ const tor_addr_t *addr;
+ uint16_t port;
+ connection_t *conn = TO_CONN(edge_conn);
+ int socket_error = 0, result;
+ const char *why_failed_exit_policy = NULL;
+
+ /* Apply exit policy to non-rendezvous connections. */
+ if (! connection_edge_is_rendezvous_stream(edge_conn) &&
+ my_exit_policy_rejects(&edge_conn->base_.addr,
+ edge_conn->base_.port,
+ &why_failed_exit_policy)) {
+ if (BUG(!why_failed_exit_policy))
+ why_failed_exit_policy = "";
+ log_info(LD_EXIT,"%s:%d failed exit policy%s. Closing.",
+ escaped_safe_str_client(conn->address), conn->port,
+ why_failed_exit_policy);
+ connection_edge_end(edge_conn, END_STREAM_REASON_EXITPOLICY);
+ circuit_detach_stream(circuit_get_by_edge_conn(edge_conn), edge_conn);
+ connection_free(conn);
+ return;
+ }
+
+#ifdef HAVE_SYS_UN_H
+ if (conn->socket_family != AF_UNIX) {
+#else
+ {
+#endif /* defined(HAVE_SYS_UN_H) */
+ addr = &conn->addr;
+ port = conn->port;
+
+ if (tor_addr_family(addr) == AF_INET6)
+ conn->socket_family = AF_INET6;
+
+ log_debug(LD_EXIT, "about to try connecting");
+ result = connection_connect(conn, conn->address,
+ addr, port, &socket_error);
+#ifdef HAVE_SYS_UN_H
+ } else {
+ /*
+ * In the AF_UNIX case, we expect to have already had conn->port = 1,
+ * tor_addr_make_unspec(conn->addr) (cf. the way we mark in the incoming
+ * case in connection_handle_listener_read()), and conn->address should
+ * have the socket path to connect to.
+ */
+ tor_assert(conn->address && strlen(conn->address) > 0);
+
+ log_debug(LD_EXIT, "about to try connecting");
+ result = connection_connect_unix(conn, conn->address, &socket_error);
+#endif /* defined(HAVE_SYS_UN_H) */
+ }
+
+ switch (result) {
+ case -1: {
+ int reason = errno_to_stream_end_reason(socket_error);
+ connection_edge_end(edge_conn, reason);
+ circuit_detach_stream(circuit_get_by_edge_conn(edge_conn), edge_conn);
+ connection_free(conn);
+ return;
+ }
+ case 0:
+ conn->state = EXIT_CONN_STATE_CONNECTING;
+
+ connection_watch_events(conn, READ_EVENT | WRITE_EVENT);
+ /* writable indicates finish;
+ * readable/error indicates broken link in windows-land. */
+ return;
+ /* case 1: fall through */
+ }
+
+ conn->state = EXIT_CONN_STATE_OPEN;
+ if (connection_get_outbuf_len(conn)) {
+ /* in case there are any queued data cells, from e.g. optimistic data */
+ connection_watch_events(conn, READ_EVENT|WRITE_EVENT);
+ } else {
+ connection_watch_events(conn, READ_EVENT);
+ }
+
+ /* also, deliver a 'connected' cell back through the circuit. */
+ if (connection_edge_is_rendezvous_stream(edge_conn)) {
+ /* don't send an address back! */
+ connection_edge_send_command(edge_conn,
+ RELAY_COMMAND_CONNECTED,
+ NULL, 0);
+ } else { /* normal stream */
+ uint8_t connected_payload[MAX_CONNECTED_CELL_PAYLOAD_LEN];
+ int connected_payload_len =
+ connected_cell_format_payload(connected_payload, &conn->addr,
+ edge_conn->address_ttl);
+ if (connected_payload_len < 0) {
+ connection_edge_end(edge_conn, END_STREAM_REASON_INTERNAL);
+ circuit_detach_stream(circuit_get_by_edge_conn(edge_conn), edge_conn);
+ connection_free(conn);
+ return;
+ }
+
+ connection_edge_send_command(edge_conn,
+ RELAY_COMMAND_CONNECTED,
+ (char*)connected_payload,
+ connected_payload_len);
+ }
+}
+
+/** Given an exit conn that should attach to us as a directory server, open a
+ * bridge connection with a linked connection pair, create a new directory
+ * conn, and join them together. Return 0 on success (or if there was an
+ * error we could send back an end cell for). Return -(some circuit end
+ * reason) if the circuit needs to be torn down. Either connects
+ * <b>exitconn</b>, frees it, or marks it, as appropriate.
+ */
+static int
+connection_exit_connect_dir(edge_connection_t *exitconn)
+{
+ dir_connection_t *dirconn = NULL;
+ or_circuit_t *circ = TO_OR_CIRCUIT(exitconn->on_circuit);
+
+ log_info(LD_EXIT, "Opening local connection for anonymized directory exit");
+
+ exitconn->base_.state = EXIT_CONN_STATE_OPEN;
+
+ dirconn = dir_connection_new(tor_addr_family(&exitconn->base_.addr));
+
+ tor_addr_copy(&dirconn->base_.addr, &exitconn->base_.addr);
+ dirconn->base_.port = 0;
+ dirconn->base_.address = tor_strdup(exitconn->base_.address);
+ dirconn->base_.type = CONN_TYPE_DIR;
+ dirconn->base_.purpose = DIR_PURPOSE_SERVER;
+ dirconn->base_.state = DIR_CONN_STATE_SERVER_COMMAND_WAIT;
+
+ /* Note that the new dir conn belongs to the same tunneled request as
+ * the edge conn, so that we can measure download times. */
+ dirconn->dirreq_id = exitconn->dirreq_id;
+
+ connection_link_connections(TO_CONN(dirconn), TO_CONN(exitconn));
+
+ if (connection_add(TO_CONN(exitconn))<0) {
+ connection_edge_end(exitconn, END_STREAM_REASON_RESOURCELIMIT);
+ connection_free_(TO_CONN(exitconn));
+ connection_free_(TO_CONN(dirconn));
+ return 0;
+ }
+
+ /* link exitconn to circ, now that we know we can use it. */
+ exitconn->next_stream = circ->n_streams;
+ circ->n_streams = exitconn;
+
+ if (connection_add(TO_CONN(dirconn))<0) {
+ connection_edge_end(exitconn, END_STREAM_REASON_RESOURCELIMIT);
+ connection_close_immediate(TO_CONN(exitconn));
+ connection_mark_for_close(TO_CONN(exitconn));
+ connection_free_(TO_CONN(dirconn));
+ return 0;
+ }
+
+ connection_start_reading(TO_CONN(dirconn));
+ connection_start_reading(TO_CONN(exitconn));
+
+ if (connection_edge_send_command(exitconn,
+ RELAY_COMMAND_CONNECTED, NULL, 0) < 0) {
+ connection_mark_for_close(TO_CONN(exitconn));
+ connection_mark_for_close(TO_CONN(dirconn));
+ return 0;
+ }
+
+ return 0;
+}
+
+/** Return 1 if <b>conn</b> is a rendezvous stream, or 0 if
+ * it is a general stream.
+ */
+int
+connection_edge_is_rendezvous_stream(const edge_connection_t *conn)
+{
+ tor_assert(conn);
+ /* It should not be possible to set both of these structs */
+ tor_assert_nonfatal(!(conn->rend_data && conn->hs_ident));
+
+ if (conn->rend_data || conn->hs_ident) {
+ return 1;
+ }
+ return 0;
+}
+
+/** Return 1 if router <b>exit_node</b> is likely to allow stream <b>conn</b>
+ * to exit from it, or 0 if it probably will not allow it.
+ * (We might be uncertain if conn's destination address has not yet been
+ * resolved.)
+ */
+int
+connection_ap_can_use_exit(const entry_connection_t *conn,
+ const node_t *exit_node)
+{
+ const or_options_t *options = get_options();
+
+ tor_assert(conn);
+ tor_assert(conn->socks_request);
+ tor_assert(exit_node);
+
+ /* If a particular exit node has been requested for the new connection,
+ * make sure the exit node of the existing circuit matches exactly.
+ */
+ if (conn->chosen_exit_name) {
+ const node_t *chosen_exit =
+ node_get_by_nickname(conn->chosen_exit_name, 0);
+ if (!chosen_exit || tor_memneq(chosen_exit->identity,
+ exit_node->identity, DIGEST_LEN)) {
+ /* doesn't match */
+// log_debug(LD_APP,"Requested node '%s', considering node '%s'. No.",
+// conn->chosen_exit_name, exit->nickname);
+ return 0;
+ }
+ }
+
+ if (conn->use_begindir) {
+ /* Internal directory fetches do not count as exiting. */
+ return 1;
+ }
+
+ if (conn->socks_request->command == SOCKS_COMMAND_CONNECT) {
+ tor_addr_t addr, *addrp = NULL;
+ addr_policy_result_t r;
+ if (0 == tor_addr_parse(&addr, conn->socks_request->address)) {
+ addrp = &addr;
+ } else if (!conn->entry_cfg.ipv4_traffic && conn->entry_cfg.ipv6_traffic) {
+ tor_addr_make_null(&addr, AF_INET6);
+ addrp = &addr;
+ } else if (conn->entry_cfg.ipv4_traffic && !conn->entry_cfg.ipv6_traffic) {
+ tor_addr_make_null(&addr, AF_INET);
+ addrp = &addr;
+ }
+ r = compare_tor_addr_to_node_policy(addrp, conn->socks_request->port,
+ exit_node);
+ if (r == ADDR_POLICY_REJECTED)
+ return 0; /* We know the address, and the exit policy rejects it. */
+ if (r == ADDR_POLICY_PROBABLY_REJECTED && !conn->chosen_exit_name)
+ return 0; /* We don't know the addr, but the exit policy rejects most
+ * addresses with this port. Since the user didn't ask for
+ * this node, err on the side of caution. */
+ } else if (SOCKS_COMMAND_IS_RESOLVE(conn->socks_request->command)) {
+ /* Don't send DNS requests to non-exit servers by default. */
+ if (!conn->chosen_exit_name && node_exit_policy_rejects_all(exit_node))
+ return 0;
+ }
+ if (routerset_contains_node(options->ExcludeExitNodesUnion_, exit_node)) {
+ /* Not a suitable exit. Refuse it. */
+ return 0;
+ }
+
+ return 1;
+}
+
+/** If address is of the form "y.onion" with a well-formed handle y:
+ * Put a NUL after y, lower-case it, and return ONION_V2_HOSTNAME or
+ * ONION_V3_HOSTNAME depending on the HS version.
+ *
+ * If address is of the form "x.y.onion" with a well-formed handle x:
+ * Drop "x.", put a NUL after y, lower-case it, and return
+ * ONION_V2_HOSTNAME or ONION_V3_HOSTNAME depending on the HS version.
+ *
+ * If address is of the form "y.onion" with a badly-formed handle y:
+ * Return BAD_HOSTNAME and log a message.
+ *
+ * If address is of the form "y.exit":
+ * Put a NUL after y and return EXIT_HOSTNAME.
+ *
+ * Otherwise:
+ * Return NORMAL_HOSTNAME and change nothing.
+ */
+hostname_type_t
+parse_extended_hostname(char *address)
+{
+ char *s;
+ char *q;
+ char query[HS_SERVICE_ADDR_LEN_BASE32+1];
+
+ s = strrchr(address,'.');
+ if (!s)
+ return NORMAL_HOSTNAME; /* no dot, thus normal */
+ if (!strcmp(s+1,"exit")) {
+ *s = 0; /* NUL-terminate it */
+ return EXIT_HOSTNAME; /* .exit */
+ }
+ if (strcmp(s+1,"onion"))
+ return NORMAL_HOSTNAME; /* neither .exit nor .onion, thus normal */
+
+ /* so it is .onion */
+ *s = 0; /* NUL-terminate it */
+ /* locate a 'sub-domain' component, in order to remove it */
+ q = strrchr(address, '.');
+ if (q == address) {
+ goto failed; /* reject sub-domain, as DNS does */
+ }
+ q = (NULL == q) ? address : q + 1;
+ if (strlcpy(query, q, HS_SERVICE_ADDR_LEN_BASE32+1) >=
+ HS_SERVICE_ADDR_LEN_BASE32+1)
+ goto failed;
+ if (q != address) {
+ memmove(address, q, strlen(q) + 1 /* also get \0 */);
+ }
+ if (rend_valid_v2_service_id(query)) {
+ return ONION_V2_HOSTNAME; /* success */
+ }
+ if (hs_address_is_valid(query)) {
+ return ONION_V3_HOSTNAME;
+ }
+ failed:
+ /* otherwise, return to previous state and return 0 */
+ *s = '.';
+ log_warn(LD_APP, "Invalid onion hostname %s; rejecting",
+ safe_str_client(address));
+ return BAD_HOSTNAME;
+}
+
+/** Return true iff the (possibly NULL) <b>alen</b>-byte chunk of memory at
+ * <b>a</b> is equal to the (possibly NULL) <b>blen</b>-byte chunk of memory
+ * at <b>b</b>. */
+static int
+memeq_opt(const char *a, size_t alen, const char *b, size_t blen)
+{
+ if (a == NULL) {
+ return (b == NULL);
+ } else if (b == NULL) {
+ return 0;
+ } else if (alen != blen) {
+ return 0;
+ } else {
+ return tor_memeq(a, b, alen);
+ }
+}
+
+/**
+ * Return true iff none of the isolation flags and fields in <b>conn</b>
+ * should prevent it from being attached to <b>circ</b>.
+ */
+int
+connection_edge_compatible_with_circuit(const entry_connection_t *conn,
+ const origin_circuit_t *circ)
+{
+ const uint8_t iso = conn->entry_cfg.isolation_flags;
+ const socks_request_t *sr = conn->socks_request;
+
+ /* If circ has never been used for an isolated connection, we can
+ * totally use it for this one. */
+ if (!circ->isolation_values_set)
+ return 1;
+
+ /* If circ has been used for connections having more than one value
+ * for some field f, it will have the corresponding bit set in
+ * isolation_flags_mixed. If isolation_flags_mixed has any bits
+ * in common with iso, then conn must be isolated from at least
+ * one stream that has been attached to circ. */
+ if ((iso & circ->isolation_flags_mixed) != 0) {
+ /* For at least one field where conn is isolated, the circuit
+ * already has mixed streams. */
+ return 0;
+ }
+
+ if (! conn->original_dest_address) {
+ log_warn(LD_BUG, "Reached connection_edge_compatible_with_circuit without "
+ "having set conn->original_dest_address");
+ ((entry_connection_t*)conn)->original_dest_address =
+ tor_strdup(conn->socks_request->address);
+ }
+
+ if ((iso & ISO_STREAM) &&
+ (circ->associated_isolated_stream_global_id !=
+ ENTRY_TO_CONN(conn)->global_identifier))
+ return 0;
+
+ if ((iso & ISO_DESTPORT) && conn->socks_request->port != circ->dest_port)
+ return 0;
+ if ((iso & ISO_DESTADDR) &&
+ strcasecmp(conn->original_dest_address, circ->dest_address))
+ return 0;
+ if ((iso & ISO_SOCKSAUTH) &&
+ (! memeq_opt(sr->username, sr->usernamelen,
+ circ->socks_username, circ->socks_username_len) ||
+ ! memeq_opt(sr->password, sr->passwordlen,
+ circ->socks_password, circ->socks_password_len)))
+ return 0;
+ if ((iso & ISO_CLIENTPROTO) &&
+ (conn->socks_request->listener_type != circ->client_proto_type ||
+ conn->socks_request->socks_version != circ->client_proto_socksver))
+ return 0;
+ if ((iso & ISO_CLIENTADDR) &&
+ !tor_addr_eq(&ENTRY_TO_CONN(conn)->addr, &circ->client_addr))
+ return 0;
+ if ((iso & ISO_SESSIONGRP) &&
+ conn->entry_cfg.session_group != circ->session_group)
+ return 0;
+ if ((iso & ISO_NYM_EPOCH) && conn->nym_epoch != circ->nym_epoch)
+ return 0;
+
+ return 1;
+}
+
+/**
+ * If <b>dry_run</b> is false, update <b>circ</b>'s isolation flags and fields
+ * to reflect having had <b>conn</b> attached to it, and return 0. Otherwise,
+ * if <b>dry_run</b> is true, then make no changes to <b>circ</b>, and return
+ * a bitfield of isolation flags that we would have to set in
+ * isolation_flags_mixed to add <b>conn</b> to <b>circ</b>, or -1 if
+ * <b>circ</b> has had no streams attached to it.
+ */
+int
+connection_edge_update_circuit_isolation(const entry_connection_t *conn,
+ origin_circuit_t *circ,
+ int dry_run)
+{
+ const socks_request_t *sr = conn->socks_request;
+ if (! conn->original_dest_address) {
+ log_warn(LD_BUG, "Reached connection_update_circuit_isolation without "
+ "having set conn->original_dest_address");
+ ((entry_connection_t*)conn)->original_dest_address =
+ tor_strdup(conn->socks_request->address);
+ }
+
+ if (!circ->isolation_values_set) {
+ if (dry_run)
+ return -1;
+ circ->associated_isolated_stream_global_id =
+ ENTRY_TO_CONN(conn)->global_identifier;
+ circ->dest_port = conn->socks_request->port;
+ circ->dest_address = tor_strdup(conn->original_dest_address);
+ circ->client_proto_type = conn->socks_request->listener_type;
+ circ->client_proto_socksver = conn->socks_request->socks_version;
+ tor_addr_copy(&circ->client_addr, &ENTRY_TO_CONN(conn)->addr);
+ circ->session_group = conn->entry_cfg.session_group;
+ circ->nym_epoch = conn->nym_epoch;
+ circ->socks_username = sr->username ?
+ tor_memdup(sr->username, sr->usernamelen) : NULL;
+ circ->socks_password = sr->password ?
+ tor_memdup(sr->password, sr->passwordlen) : NULL;
+ circ->socks_username_len = sr->usernamelen;
+ circ->socks_password_len = sr->passwordlen;
+
+ circ->isolation_values_set = 1;
+ return 0;
+ } else {
+ uint8_t mixed = 0;
+ if (conn->socks_request->port != circ->dest_port)
+ mixed |= ISO_DESTPORT;
+ if (strcasecmp(conn->original_dest_address, circ->dest_address))
+ mixed |= ISO_DESTADDR;
+ if (!memeq_opt(sr->username, sr->usernamelen,
+ circ->socks_username, circ->socks_username_len) ||
+ !memeq_opt(sr->password, sr->passwordlen,
+ circ->socks_password, circ->socks_password_len))
+ mixed |= ISO_SOCKSAUTH;
+ if ((conn->socks_request->listener_type != circ->client_proto_type ||
+ conn->socks_request->socks_version != circ->client_proto_socksver))
+ mixed |= ISO_CLIENTPROTO;
+ if (!tor_addr_eq(&ENTRY_TO_CONN(conn)->addr, &circ->client_addr))
+ mixed |= ISO_CLIENTADDR;
+ if (conn->entry_cfg.session_group != circ->session_group)
+ mixed |= ISO_SESSIONGRP;
+ if (conn->nym_epoch != circ->nym_epoch)
+ mixed |= ISO_NYM_EPOCH;
+
+ if (dry_run)
+ return mixed;
+
+ if ((mixed & conn->entry_cfg.isolation_flags) != 0) {
+ log_warn(LD_BUG, "Updating a circuit with seemingly incompatible "
+ "isolation flags.");
+ }
+ circ->isolation_flags_mixed |= mixed;
+ return 0;
+ }
+}
+
+/**
+ * Clear the isolation settings on <b>circ</b>.
+ *
+ * This only works on an open circuit that has never had a stream attached to
+ * it, and whose isolation settings are hypothetical. (We set hypothetical
+ * isolation settings on circuits as we're launching them, so that we
+ * know whether they can handle more streams or whether we need to launch
+ * even more circuits. Once the circuit is open, if it turns out that
+ * we no longer have any streams to attach to it, we clear the isolation flags
+ * and data so that other streams can have a chance.)
+ */
+void
+circuit_clear_isolation(origin_circuit_t *circ)
+{
+ if (circ->isolation_any_streams_attached) {
+ log_warn(LD_BUG, "Tried to clear the isolation status of a dirty circuit");
+ return;
+ }
+ if (TO_CIRCUIT(circ)->state != CIRCUIT_STATE_OPEN) {
+ log_warn(LD_BUG, "Tried to clear the isolation status of a non-open "
+ "circuit");
+ return;
+ }
+
+ circ->isolation_values_set = 0;
+ circ->isolation_flags_mixed = 0;
+ circ->associated_isolated_stream_global_id = 0;
+ circ->client_proto_type = 0;
+ circ->client_proto_socksver = 0;
+ circ->dest_port = 0;
+ tor_addr_make_unspec(&circ->client_addr);
+ tor_free(circ->dest_address);
+ circ->session_group = -1;
+ circ->nym_epoch = 0;
+ if (circ->socks_username) {
+ memwipe(circ->socks_username, 0x11, circ->socks_username_len);
+ tor_free(circ->socks_username);
+ }
+ if (circ->socks_password) {
+ memwipe(circ->socks_password, 0x05, circ->socks_password_len);
+ tor_free(circ->socks_password);
+ }
+ circ->socks_username_len = circ->socks_password_len = 0;
+}
+
+/** Free all storage held in module-scoped variables for connection_edge.c */
+void
+connection_edge_free_all(void)
+{
+ untried_pending_connections = 0;
+ smartlist_free(pending_entry_connections);
+ pending_entry_connections = NULL;
+ mainloop_event_free(attach_pending_entry_connections_ev);
+}
diff --cc src/core/or/connection_edge.h
index 24968b277,000000000..1348dd49f
mode 100644,000000..100644
--- a/src/core/or/connection_edge.h
+++ b/src/core/or/connection_edge.h
@@@ -1,248 -1,0 +1,259 @@@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file connection_edge.h
+ * \brief Header file for connection_edge.c.
+ **/
+
+#ifndef TOR_CONNECTION_EDGE_H
+#define TOR_CONNECTION_EDGE_H
+
+#include "lib/testsupport/testsupport.h"
+
+edge_connection_t *TO_EDGE_CONN(connection_t *);
+entry_connection_t *TO_ENTRY_CONN(connection_t *);
+entry_connection_t *EDGE_TO_ENTRY_CONN(edge_connection_t *);
+
+#define EXIT_CONN_STATE_MIN_ 1
+/** State for an exit connection: waiting for response from DNS farm. */
+#define EXIT_CONN_STATE_RESOLVING 1
+/** State for an exit connection: waiting for connect() to finish. */
+#define EXIT_CONN_STATE_CONNECTING 2
+/** State for an exit connection: open and ready to transmit data. */
+#define EXIT_CONN_STATE_OPEN 3
+/** State for an exit connection: waiting to be removed. */
+#define EXIT_CONN_STATE_RESOLVEFAILED 4
+#define EXIT_CONN_STATE_MAX_ 4
+
+/* The AP state values must be disjoint from the EXIT state values. */
+#define AP_CONN_STATE_MIN_ 5
+/** State for a SOCKS connection: waiting for SOCKS request. */
+#define AP_CONN_STATE_SOCKS_WAIT 5
+/** State for a SOCKS connection: got a y.onion URL; waiting to receive
+ * rendezvous descriptor. */
+#define AP_CONN_STATE_RENDDESC_WAIT 6
+/** The controller will attach this connection to a circuit; it isn't our
+ * job to do so. */
+#define AP_CONN_STATE_CONTROLLER_WAIT 7
+/** State for a SOCKS connection: waiting for a completed circuit. */
+#define AP_CONN_STATE_CIRCUIT_WAIT 8
+/** State for a SOCKS connection: sent BEGIN, waiting for CONNECTED. */
+#define AP_CONN_STATE_CONNECT_WAIT 9
+/** State for a SOCKS connection: sent RESOLVE, waiting for RESOLVED. */
+#define AP_CONN_STATE_RESOLVE_WAIT 10
+/** State for a SOCKS connection: ready to send and receive. */
+#define AP_CONN_STATE_OPEN 11
+/** State for a transparent natd connection: waiting for original
+ * destination. */
+#define AP_CONN_STATE_NATD_WAIT 12
+/** State for an HTTP tunnel: waiting for an HTTP CONNECT command. */
+#define AP_CONN_STATE_HTTP_CONNECT_WAIT 13
+#define AP_CONN_STATE_MAX_ 13
+
+#define EXIT_PURPOSE_MIN_ 1
+/** This exit stream wants to do an ordinary connect. */
+#define EXIT_PURPOSE_CONNECT 1
+/** This exit stream wants to do a resolve (either normal or reverse). */
+#define EXIT_PURPOSE_RESOLVE 2
+#define EXIT_PURPOSE_MAX_ 2
+
+/** True iff the AP_CONN_STATE_* value <b>s</b> means that the corresponding
+ * edge connection is not attached to any circuit. */
+#define AP_CONN_STATE_IS_UNATTACHED(s) \
+ ((s) <= AP_CONN_STATE_CIRCUIT_WAIT || (s) == AP_CONN_STATE_NATD_WAIT)
+
+#define connection_mark_unattached_ap(conn, endreason) \
+ connection_mark_unattached_ap_((conn), (endreason), __LINE__, SHORT_FILE__)
+
+MOCK_DECL(void,connection_mark_unattached_ap_,
+ (entry_connection_t *conn, int endreason,
+ int line, const char *file));
+int connection_edge_reached_eof(edge_connection_t *conn);
+int connection_edge_process_inbuf(edge_connection_t *conn,
+ int package_partial);
+int connection_edge_destroy(circid_t circ_id, edge_connection_t *conn);
+int connection_edge_end(edge_connection_t *conn, uint8_t reason);
+int connection_edge_end_errno(edge_connection_t *conn);
+int connection_edge_flushed_some(edge_connection_t *conn);
+int connection_edge_finished_flushing(edge_connection_t *conn);
+int connection_edge_finished_connecting(edge_connection_t *conn);
+
+void connection_ap_about_to_close(entry_connection_t *edge_conn);
+void connection_exit_about_to_close(edge_connection_t *edge_conn);
+
+MOCK_DECL(int,
+ connection_ap_handshake_send_begin,(entry_connection_t *ap_conn));
+int connection_ap_handshake_send_resolve(entry_connection_t *ap_conn);
+
+entry_connection_t *connection_ap_make_link(connection_t *partner,
+ char *address, uint16_t port,
+ const char *digest,
+ int session_group,
+ int isolation_flags,
+ int use_begindir, int want_onehop);
+void connection_ap_handshake_socks_reply(entry_connection_t *conn, char *reply,
+ size_t replylen,
+ int endreason);
+MOCK_DECL(void,connection_ap_handshake_socks_resolved,
+ (entry_connection_t *conn,
+ int answer_type,
+ size_t answer_len,
+ const uint8_t *answer,
+ int ttl,
+ time_t expires));
+void connection_ap_handshake_socks_resolved_addr(entry_connection_t *conn,
+ const tor_addr_t *answer,
+ int ttl,
+ time_t expires);
+
+int connection_exit_begin_conn(cell_t *cell, circuit_t *circ);
+int connection_exit_begin_resolve(cell_t *cell, or_circuit_t *circ);
+void connection_exit_connect(edge_connection_t *conn);
+int connection_edge_is_rendezvous_stream(const edge_connection_t *conn);
+int connection_ap_can_use_exit(const entry_connection_t *conn,
+ const node_t *exit);
+void connection_ap_expire_beginning(void);
+void connection_ap_rescan_and_attach_pending(void);
+void connection_ap_attach_pending(int retry);
+void connection_ap_mark_as_pending_circuit_(entry_connection_t *entry_conn,
+ const char *file, int line);
+#define connection_ap_mark_as_pending_circuit(c) \
+ connection_ap_mark_as_pending_circuit_((c), __FILE__, __LINE__)
+void connection_ap_mark_as_non_pending_circuit(entry_connection_t *entry_conn);
+#define CONNECTION_AP_EXPECT_NONPENDING(c) do { \
+ if (ENTRY_TO_CONN(c)->state == AP_CONN_STATE_CIRCUIT_WAIT) { \
+ log_warn(LD_BUG, "At %s:%d: %p was unexpectedly in circuit_wait.", \
+ __FILE__, __LINE__, (c)); \
+ connection_ap_mark_as_non_pending_circuit(c); \
+ } \
+ } while (0)
+void connection_ap_fail_onehop(const char *failed_digest,
+ cpath_build_state_t *build_state);
+void circuit_discard_optional_exit_enclaves(extend_info_t *info);
+int connection_ap_detach_retriable(entry_connection_t *conn,
+ origin_circuit_t *circ,
+ int reason);
+int connection_ap_process_transparent(entry_connection_t *conn);
+
+int address_is_invalid_destination(const char *address, int client);
+
+MOCK_DECL(int, connection_ap_rewrite_and_attach_if_allowed,
+ (entry_connection_t *conn,
+ origin_circuit_t *circ,
+ crypt_path_t *cpath));
+int connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
+ origin_circuit_t *circ,
+ crypt_path_t *cpath);
+
+/** Possible return values for parse_extended_hostname. */
+typedef enum hostname_type_t {
+ NORMAL_HOSTNAME, ONION_V2_HOSTNAME, ONION_V3_HOSTNAME,
+ EXIT_HOSTNAME, BAD_HOSTNAME
+} hostname_type_t;
+hostname_type_t parse_extended_hostname(char *address);
+
+#if defined(HAVE_NET_IF_H) && defined(HAVE_NET_PFVAR_H)
+int get_pf_socket(void);
+#endif
+
+int connection_edge_compatible_with_circuit(const entry_connection_t *conn,
+ const origin_circuit_t *circ);
+int connection_edge_update_circuit_isolation(const entry_connection_t *conn,
+ origin_circuit_t *circ,
+ int dry_run);
+void circuit_clear_isolation(origin_circuit_t *circ);
+streamid_t get_unique_stream_id_by_circ(origin_circuit_t *circ);
+
+void connection_edge_free_all(void);
+
+void connection_ap_warn_and_unmark_if_pending_circ(
+ entry_connection_t *entry_conn,
+ const char *where);
+
++int connection_half_edge_is_valid_data(const smartlist_t *half_conns,
++ streamid_t stream_id);
++int connection_half_edge_is_valid_sendme(const smartlist_t *half_conns,
++ streamid_t stream_id);
++int connection_half_edge_is_valid_connected(const smartlist_t *half_conns,
++ streamid_t stream_id);
++int connection_half_edge_is_valid_end(smartlist_t *half_conns,
++ streamid_t stream_id);
++int connection_half_edge_is_valid_resolved(smartlist_t *half_conns,
++ streamid_t stream_id);
++
+/** @name Begin-cell flags
+ *
+ * These flags are used in RELAY_BEGIN cells to change the default behavior
+ * of the cell.
+ *
+ * @{
+ **/
+/** When this flag is set, the client is willing to get connected to IPv6
+ * addresses */
+#define BEGIN_FLAG_IPV6_OK (1u<<0)
+/** When this flag is set, the client DOES NOT support connecting to IPv4
+ * addresses. (The sense of this flag is inverted from IPV6_OK, so that the
+ * old default behavior of Tor is equivalent to having all flags set to 0.)
+ **/
+#define BEGIN_FLAG_IPV4_NOT_OK (1u<<1)
+/** When this flag is set, if we find both an IPv4 and an IPv6 address,
+ * we use the IPv6 address. Otherwise we use the IPv4 address. */
+#define BEGIN_FLAG_IPV6_PREFERRED (1u<<2)
+/**@}*/
+
+#ifdef CONNECTION_EDGE_PRIVATE
+
+/** A parsed BEGIN or BEGIN_DIR cell */
+typedef struct begin_cell_t {
+ /** The address the client has asked us to connect to, or NULL if this is
+ * a BEGIN_DIR cell*/
+ char *address;
+ /** The flags specified in the BEGIN cell's body. One or more of
+ * BEGIN_FLAG_*. */
+ uint32_t flags;
+ /** The client's requested port. */
+ uint16_t port;
+ /** The client's requested Stream ID */
+ uint16_t stream_id;
+ /** True iff this is a BEGIN_DIR cell. */
+ unsigned is_begindir : 1;
+} begin_cell_t;
+
+STATIC int begin_cell_parse(const cell_t *cell, begin_cell_t *bcell,
+ uint8_t *end_reason_out);
+STATIC int connected_cell_format_payload(uint8_t *payload_out,
+ const tor_addr_t *addr,
+ uint32_t ttl);
+
+typedef struct {
+ /** Original address, after we lowercased it but before we started
+ * mapping it.
+ */
+ char orig_address[MAX_SOCKS_ADDR_LEN];
+ /** True iff the address has been automatically remapped to a local
+ * address in VirtualAddrNetwork. (Only set true when we do a resolve
+ * and get a virtual address; not when we connect to the address.) */
+ int automap;
+ /** If this connection has a .exit address, who put it there? */
+ addressmap_entry_source_t exit_source;
+ /** If we've rewritten the address, when does this map expire? */
+ time_t map_expires;
+ /** If we should close the connection, this is the end_reason to pass
+ * to connection_mark_unattached_ap */
+ int end_reason;
+ /** True iff we should close the connection, either because of error or
+ * because of successful early RESOLVED reply. */
+ int should_close;
+} rewrite_result_t;
+
+STATIC void connection_ap_handshake_rewrite(entry_connection_t *conn,
+ rewrite_result_t *out);
+
+STATIC int connection_ap_process_http_connect(entry_connection_t *conn);
+#endif /* defined(CONNECTION_EDGE_PRIVATE) */
+
+#endif /* !defined(TOR_CONNECTION_EDGE_H) */
diff --cc src/core/or/half_edge_st.h
index 000000000,000000000..5ed24dabe
new file mode 100644
--- /dev/null
+++ b/src/core/or/half_edge_st.h
@@@ -1,0 -1,0 +1,34 @@@
++/* Copyright (c) 2001 Matej Pfajfar.
++ * Copyright (c) 2001-2004, Roger Dingledine.
++ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
++ * Copyright (c) 2007-2018, The Tor Project, Inc. */
++/* See LICENSE for licensing information */
++
++#ifndef HALF_EDGE_ST_H
++#define HALF_EDGE_ST_H
++
++#include "core/or/or.h"
++
++/**
++ * Struct to track a connection that we closed that the other end
++ * still thinks is open. Exists in origin_circuit_t.half_streams until
++ * we get an end cell or a resolved cell for this stream id.
++ */
++typedef struct half_edge_t {
++ /** stream_id for the half-closed connection */
++ streamid_t stream_id;
++
++ /** How many sendme's can the other end still send, based on how
++ * much data we had sent at the time of close */
++ int sendmes_pending;
++
++ /** How much more data can the other end still send, based on
++ * our deliver window */
++ int data_pending;
++
++ /** Is there a connected cell pending? */
++ int connected_pending : 1;
++} half_edge_t;
++
++#endif
++
diff --cc src/core/or/origin_circuit_st.h
index e7b864e82,000000000..26cdf590f
mode 100644,000000..100644
--- a/src/core/or/origin_circuit_st.h
+++ b/src/core/or/origin_circuit_st.h
@@@ -1,290 -1,0 +1,294 @@@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#ifndef ORIGIN_CIRCUIT_ST_H
+#define ORIGIN_CIRCUIT_ST_H
+
+#include "core/or/or.h"
+
+#include "core/or/circuit_st.h"
+
+struct onion_queue_t;
+
+/**
+ * Describes the circuit building process in simplified terms based
+ * on the path bias accounting state for a circuit.
+ *
+ * NOTE: These state values are enumerated in the order for which we
+ * expect circuits to transition through them. If you add states,
+ * you need to preserve this overall ordering. The various pathbias
+ * state transition and accounting functions (pathbias_mark_* and
+ * pathbias_count_*) contain ordinal comparisons to enforce proper
+ * state transitions for corrections.
+ *
+ * This state machine and the associated logic was created to prevent
+ * miscounting due to unknown cases of circuit reuse. See also tickets
+ * #6475 and #7802.
+ */
+enum path_state_t {
+ /** This circuit is "new". It has not yet completed a first hop
+ * or been counted by the path bias code. */
+ PATH_STATE_NEW_CIRC = 0,
+ /** This circuit has completed one/two hops, and has been counted by
+ * the path bias logic. */
+ PATH_STATE_BUILD_ATTEMPTED = 1,
+ /** This circuit has been completely built */
+ PATH_STATE_BUILD_SUCCEEDED = 2,
+ /** Did we try to attach any SOCKS streams or hidserv introductions to
+ * this circuit?
+ *
+ * Note: If we ever implement end-to-end stream timing through test
+ * stream probes (#5707), we must *not* set this for those probes
+ * (or any other automatic streams) because the adversary could
+ * just tag at a later point.
+ */
+ PATH_STATE_USE_ATTEMPTED = 3,
+ /** Did any SOCKS streams or hidserv introductions actually succeed on
+ * this circuit?
+ *
+ * If any streams detatch/fail from this circuit, the code transitions
+ * the circuit back to PATH_STATE_USE_ATTEMPTED to ensure we probe. See
+ * pathbias_mark_use_rollback() for that.
+ */
+ PATH_STATE_USE_SUCCEEDED = 4,
+
+ /**
+ * This is a special state to indicate that we got a corrupted
+ * relay cell on a circuit and we don't intend to probe it.
+ */
+ PATH_STATE_USE_FAILED = 5,
+
+ /**
+ * This is a special state to indicate that we already counted
+ * the circuit. Used to guard against potential state machine
+ * violations.
+ */
+ PATH_STATE_ALREADY_COUNTED = 6,
+};
+
+/** An origin_circuit_t holds data necessary to build and use a circuit.
+ */
+struct origin_circuit_t {
+ circuit_t base_;
+
+ /** Linked list of AP streams (or EXIT streams if hidden service)
+ * associated with this circuit. */
+ edge_connection_t *p_streams;
+
++ /** Smartlist of half-closed streams (half_edge_t*) that still
++ * have pending activity */
++ smartlist_t *half_streams;
++
+ /** Bytes read on this circuit since last call to
+ * control_event_circ_bandwidth_used(). Only used if we're configured
+ * to emit CIRC_BW events. */
+ uint32_t n_read_circ_bw;
+
+ /** Bytes written to on this circuit since last call to
+ * control_event_circ_bandwidth_used(). Only used if we're configured
+ * to emit CIRC_BW events. */
+ uint32_t n_written_circ_bw;
+
+ /** Total known-valid relay cell bytes since last call to
+ * control_event_circ_bandwidth_used(). Only used if we're configured
+ * to emit CIRC_BW events. */
+ uint32_t n_delivered_read_circ_bw;
+
+ /** Total written relay cell bytes since last call to
+ * control_event_circ_bandwidth_used(). Only used if we're configured
+ * to emit CIRC_BW events. */
+ uint32_t n_delivered_written_circ_bw;
+
+ /** Total overhead data in all known-valid relay data cells since last
+ * call to control_event_circ_bandwidth_used(). Only used if we're
+ * configured to emit CIRC_BW events. */
+ uint32_t n_overhead_read_circ_bw;
+
+ /** Total written overhead data in all relay data cells since last call to
+ * control_event_circ_bandwidth_used(). Only used if we're configured
+ * to emit CIRC_BW events. */
+ uint32_t n_overhead_written_circ_bw;
+
+ /** Build state for this circuit. It includes the intended path
+ * length, the chosen exit router, rendezvous information, etc.
+ */
+ cpath_build_state_t *build_state;
+ /** The doubly-linked list of crypt_path_t entries, one per hop,
+ * for this circuit. This includes ciphers for each hop,
+ * integrity-checking digests for each hop, and package/delivery
+ * windows for each hop.
+ */
+ crypt_path_t *cpath;
+
+ /** Holds all rendezvous data on either client or service side. */
+ rend_data_t *rend_data;
+
+ /** Holds hidden service identifier on either client or service side. This
+ * is for both introduction and rendezvous circuit. */
+ struct hs_ident_circuit_t *hs_ident;
+
+ /** Holds the data that the entry guard system uses to track the
+ * status of the guard this circuit is using, and thereby to determine
+ * whether this circuit can be used. */
+ struct circuit_guard_state_t *guard_state;
+
+ /** Index into global_origin_circuit_list for this circuit. -1 if not
+ * present. */
+ int global_origin_circuit_list_idx;
+
+ /** How many more relay_early cells can we send on this circuit, according
+ * to the specification? */
+ unsigned int remaining_relay_early_cells : 4;
+
+ /** Set if this circuit is insanely old and we already informed the user */
+ unsigned int is_ancient : 1;
+
+ /** Set if this circuit has already been opened. Used to detect
+ * cannibalized circuits. */
+ unsigned int has_opened : 1;
+
+ /**
+ * Path bias state machine. Used to ensure integrity of our
+ * circuit building and usage accounting. See path_state_t
+ * for more details.
+ */
+ path_state_bitfield_t path_state : 3;
+
+ /* If this flag is set, we should not consider attaching any more
+ * connections to this circuit. */
+ unsigned int unusable_for_new_conns : 1;
+
+ /**
+ * Tristate variable to guard against pathbias miscounting
+ * due to circuit purpose transitions changing the decision
+ * of pathbias_should_count(). This variable is informational
+ * only. The current results of pathbias_should_count() are
+ * the official decision for pathbias accounting.
+ */
+ uint8_t pathbias_shouldcount;
+#define PATHBIAS_SHOULDCOUNT_UNDECIDED 0
+#define PATHBIAS_SHOULDCOUNT_IGNORED 1
+#define PATHBIAS_SHOULDCOUNT_COUNTED 2
+
+ /** For path probing. Store the temporary probe stream ID
+ * for response comparison */
+ streamid_t pathbias_probe_id;
+
+ /** For path probing. Store the temporary probe address nonce
+ * (in host byte order) for response comparison. */
+ uint32_t pathbias_probe_nonce;
+
+ /** Set iff this is a hidden-service circuit which has timed out
+ * according to our current circuit-build timeout, but which has
+ * been kept around because it might still succeed in connecting to
+ * its destination, and which is not a fully-connected rendezvous
+ * circuit.
+ *
+ * (We clear this flag for client-side rendezvous circuits when they
+ * are 'joined' to the other side's rendezvous circuit, so that
+ * connection_ap_handshake_attach_circuit can put client streams on
+ * the circuit. We also clear this flag for service-side rendezvous
+ * circuits when they are 'joined' to a client's rend circ, but only
+ * for symmetry with the client case. Client-side introduction
+ * circuits are closed when we get a joined rend circ, and
+ * service-side introduction circuits never have this flag set.) */
+ unsigned int hs_circ_has_timed_out : 1;
+
+ /** Set iff this circuit has been given a relaxed timeout because
+ * no circuits have opened. Used to prevent spamming logs. */
+ unsigned int relaxed_timeout : 1;
+
+ /** Set iff this is a service-side rendezvous circuit for which a
+ * new connection attempt has been launched. We consider launching
+ * a new service-side rend circ to a client when the previous one
+ * fails; now that we don't necessarily close a service-side rend
+ * circ when we launch a new one to the same client, this flag keeps
+ * us from launching two retries for the same failed rend circ. */
+ unsigned int hs_service_side_rend_circ_has_been_relaunched : 1;
+
+ /** What commands were sent over this circuit that decremented the
+ * RELAY_EARLY counter? This is for debugging task 878. */
+ uint8_t relay_early_commands[MAX_RELAY_EARLY_CELLS_PER_CIRCUIT];
+
+ /** How many RELAY_EARLY cells have been sent over this circuit? This is
+ * for debugging task 878, too. */
+ int relay_early_cells_sent;
+
+ /** The next stream_id that will be tried when we're attempting to
+ * construct a new AP stream originating at this circuit. */
+ streamid_t next_stream_id;
+
+ /* The intro key replaces the hidden service's public key if purpose is
+ * S_ESTABLISH_INTRO or S_INTRO, provided that no unversioned rendezvous
+ * descriptor is used. */
+ crypto_pk_t *intro_key;
+
+ /** Quasi-global identifier for this circuit; used for control.c */
+ /* XXXX NM This can get re-used after 2**32 circuits. */
+ uint32_t global_identifier;
+
+ /** True if we have associated one stream to this circuit, thereby setting
+ * the isolation parameters for this circuit. Note that this doesn't
+ * necessarily mean that we've <em>attached</em> any streams to the circuit:
+ * we may only have marked up this circuit during the launch process.
+ */
+ unsigned int isolation_values_set : 1;
+ /** True iff any stream has <em>ever</em> been attached to this circuit.
+ *
+ * In a better world we could use timestamp_dirty for this, but
+ * timestamp_dirty is far too overloaded at the moment.
+ */
+ unsigned int isolation_any_streams_attached : 1;
+
+ /** A bitfield of ISO_* flags for every isolation field such that this
+ * circuit has had streams with more than one value for that field
+ * attached to it. */
+ uint8_t isolation_flags_mixed;
+
+ /** @name Isolation parameters
+ *
+ * If any streams have been associated with this circ (isolation_values_set
+ * == 1), and all streams associated with the circuit have had the same
+ * value for some field ((isolation_flags_mixed & ISO_FOO) == 0), then these
+ * elements hold the value for that field.
+ *
+ * Note again that "associated" is not the same as "attached": we
+ * preliminarily associate streams with a circuit while the circuit is being
+ * launched, so that we can tell whether we need to launch more circuits.
+ *
+ * @{
+ */
+ uint8_t client_proto_type;
+ uint8_t client_proto_socksver;
+ uint16_t dest_port;
+ tor_addr_t client_addr;
+ char *dest_address;
+ int session_group;
+ unsigned nym_epoch;
+ size_t socks_username_len;
+ uint8_t socks_password_len;
+ /* Note that the next two values are NOT NUL-terminated; see
+ socks_username_len and socks_password_len for their lengths. */
+ char *socks_username;
+ char *socks_password;
+ /** Global identifier for the first stream attached here; used by
+ * ISO_STREAM. */
+ uint64_t associated_isolated_stream_global_id;
+ /**@}*/
+ /** A list of addr_policy_t for this circuit in particular. Used by
+ * adjust_exit_policy_from_exitpolicy_failure.
+ */
+ smartlist_t *prepend_policy;
+
+ /** How long do we wait before closing this circuit if it remains
+ * completely idle after it was built, in seconds? This value
+ * is randomized on a per-circuit basis from CircuitsAvailableTimoeut
+ * to 2*CircuitsAvailableTimoeut. */
+ int circuit_idle_timeout;
+
+};
+
+#endif
diff --cc src/core/or/relay.c
index 6e1adfaff,000000000..8b58725ad
mode 100644,000000..100644
--- a/src/core/or/relay.c
+++ b/src/core/or/relay.c
@@@ -1,3097 -1,0 +1,3168 @@@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file relay.c
+ * \brief Handle relay cell encryption/decryption, plus packaging and
+ * receiving from circuits, plus queuing on circuits.
+ *
+ * This is a core modules that makes Tor work. It's responsible for
+ * dealing with RELAY cells (the ones that travel more than one hop along a
+ * circuit), by:
+ * <ul>
+ * <li>constructing relays cells,
+ * <li>encrypting relay cells,
+ * <li>decrypting relay cells,
+ * <li>demultiplexing relay cells as they arrive on a connection,
+ * <li>queueing relay cells for retransmission,
+ * <li>or handling relay cells that are for us to receive (as an exit or a
+ * client).
+ * </ul>
+ *
+ * RELAY cells are generated throughout the code at the client or relay side,
+ * using relay_send_command_from_edge() or one of the functions like
+ * connection_edge_send_command() that calls it. Of particular interest is
+ * connection_edge_package_raw_inbuf(), which takes information that has
+ * arrived on an edge connection socket, and packages it as a RELAY_DATA cell
+ * -- this is how information is actually sent across the Tor network. The
+ * cryptography for these functions is handled deep in
+ * circuit_package_relay_cell(), which either adds a single layer of
+ * encryption (if we're an exit), or multiple layers (if we're the origin of
+ * the circuit). After construction and encryption, the RELAY cells are
+ * passed to append_cell_to_circuit_queue(), which queues them for
+ * transmission and tells the circuitmux (see circuitmux.c) that the circuit
+ * is waiting to send something.
+ *
+ * Incoming RELAY cells arrive at circuit_receive_relay_cell(), called from
+ * command.c. There they are decrypted and, if they are for us, are passed to
+ * connection_edge_process_relay_cell(). If they're not for us, they're
+ * re-queued for retransmission again with append_cell_to_circuit_queue().
+ *
+ * The connection_edge_process_relay_cell() function handles all the different
+ * types of relay cells, launching requests or transmitting data as needed.
+ **/
+
+#define RELAY_PRIVATE
+#include "core/or/or.h"
+#include "feature/client/addressmap.h"
+#include "lib/err/backtrace.h"
+#include "lib/container/buffers.h"
+#include "core/or/channel.h"
+#include "feature/client/circpathbias.h"
+#include "core/or/circuitbuild.h"
+#include "core/or/circuitlist.h"
+#include "core/or/circuituse.h"
+#include "lib/compress/compress.h"
+#include "app/config/config.h"
+#include "core/mainloop/connection.h"
+#include "core/or/connection_edge.h"
+#include "core/or/connection_or.h"
+#include "feature/control/control.h"
+#include "lib/crypt_ops/crypto_rand.h"
+#include "lib/crypt_ops/crypto_util.h"
+#include "feature/dircache/directory.h"
+#include "feature/relay/dns.h"
+#include "feature/stats/geoip.h"
+#include "feature/hs/hs_cache.h"
+#include "core/mainloop/main.h"
+#include "feature/nodelist/networkstatus.h"
+#include "feature/nodelist/nodelist.h"
+#include "core/crypto/onion.h"
+#include "core/or/policies.h"
+#include "core/or/reasons.h"
+#include "core/or/relay.h"
+#include "core/crypto/relay_crypto.h"
+#include "feature/rend/rendcache.h"
+#include "feature/rend/rendcommon.h"
+#include "feature/relay/router.h"
+#include "feature/nodelist/routerlist.h"
+#include "feature/nodelist/routerparse.h"
+#include "core/or/scheduler.h"
+#include "feature/stats/rephist.h"
+
+#include "core/or/cell_st.h"
+#include "core/or/cell_queue_st.h"
+#include "core/or/cpath_build_state_st.h"
+#include "feature/dircommon/dir_connection_st.h"
+#include "core/or/destroy_cell_queue_st.h"
+#include "core/or/entry_connection_st.h"
+#include "core/or/extend_info_st.h"
+#include "core/or/or_circuit_st.h"
+#include "core/or/origin_circuit_st.h"
+#include "feature/nodelist/routerinfo_st.h"
+#include "core/or/socks_request_st.h"
+
+#include "lib/intmath/weakrng.h"
+
+static edge_connection_t *relay_lookup_conn(circuit_t *circ, cell_t *cell,
+ cell_direction_t cell_direction,
+ crypt_path_t *layer_hint);
+
+static void circuit_consider_sending_sendme(circuit_t *circ,
+ crypt_path_t *layer_hint);
+static void circuit_resume_edge_reading(circuit_t *circ,
+ crypt_path_t *layer_hint);
+static int circuit_resume_edge_reading_helper(edge_connection_t *conn,
+ circuit_t *circ,
+ crypt_path_t *layer_hint);
+static int circuit_consider_stop_edge_reading(circuit_t *circ,
+ crypt_path_t *layer_hint);
+static int circuit_queue_streams_are_blocked(circuit_t *circ);
+static void adjust_exit_policy_from_exitpolicy_failure(origin_circuit_t *circ,
+ entry_connection_t *conn,
+ node_t *node,
+ const tor_addr_t *addr);
+
+/** Stop reading on edge connections when we have this many cells
+ * waiting on the appropriate queue. */
+#define CELL_QUEUE_HIGHWATER_SIZE 256
+/** Start reading from edge connections again when we get down to this many
+ * cells. */
+#define CELL_QUEUE_LOWWATER_SIZE 64
+
+/** Stats: how many relay cells have originated at this hop, or have
+ * been relayed onward (not recognized at this hop)?
+ */
+uint64_t stats_n_relay_cells_relayed = 0;
+/** Stats: how many relay cells have been delivered to streams at this
+ * hop?
+ */
+uint64_t stats_n_relay_cells_delivered = 0;
+/** Stats: how many circuits have we closed due to the cell queue limit being
+ * reached (see append_cell_to_circuit_queue()) */
+uint64_t stats_n_circ_max_cell_reached = 0;
+
+/** Used to tell which stream to read from first on a circuit. */
+static tor_weak_rng_t stream_choice_rng = TOR_WEAK_RNG_INIT;
+
+/**
+ * Update channel usage state based on the type of relay cell and
+ * circuit properties.
+ *
+ * This is needed to determine if a client channel is being
+ * used for application traffic, and if a relay channel is being
+ * used for multihop circuits and application traffic. The decision
+ * to pad in channelpadding.c depends upon this info (as well as
+ * consensus parameters) to decide what channels to pad.
+ */
+static void
+circuit_update_channel_usage(circuit_t *circ, cell_t *cell)
+{
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ /*
+ * The client state was first set much earlier in
+ * circuit_send_next_onion_skin(), so we can start padding as early as
+ * possible.
+ *
+ * However, if padding turns out to be expensive, we may want to not do
+ * it until actual application traffic starts flowing (which is controlled
+ * via consensus param nf_pad_before_usage).
+ *
+ * So: If we're an origin circuit and we've created a full length circuit,
+ * then any CELL_RELAY cell means application data. Increase the usage
+ * state of the channel to indicate this.
+ *
+ * We want to wait for CELL_RELAY specifically here, so we know that
+ * the channel was definitely being used for data and not for extends.
+ * By default, we pad as soon as a channel has been used for *any*
+ * circuits, so this state is irrelevant to the padding decision in
+ * the default case. However, if padding turns out to be expensive,
+ * we would like the ability to avoid padding until we're absolutely
+ * sure that a channel is used for enough application data to be worth
+ * padding.
+ *
+ * (So it does not matter that CELL_RELAY_EARLY can actually contain
+ * application data. This is only a load reducing option and that edge
+ * case does not matter if we're desperately trying to reduce overhead
+ * anyway. See also consensus parameter nf_pad_before_usage).
+ */
+ if (BUG(!circ->n_chan))
+ return;
+
+ if (circ->n_chan->channel_usage == CHANNEL_USED_FOR_FULL_CIRCS &&
+ cell->command == CELL_RELAY) {
+ circ->n_chan->channel_usage = CHANNEL_USED_FOR_USER_TRAFFIC;
+ }
+ } else {
+ /* If we're a relay circuit, the question is more complicated. Basically:
+ * we only want to pad connections that carry multihop (anonymous)
+ * circuits.
+ *
+ * We assume we're more than one hop if either the previous hop
+ * is not a client, or if the previous hop is a client and there's
+ * a next hop. Then, circuit traffic starts at RELAY_EARLY, and
+ * user application traffic starts when we see RELAY cells.
+ */
+ or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
+
+ if (BUG(!or_circ->p_chan))
+ return;
+
+ if (!channel_is_client(or_circ->p_chan) ||
+ (channel_is_client(or_circ->p_chan) && circ->n_chan)) {
+ if (cell->command == CELL_RELAY_EARLY) {
+ if (or_circ->p_chan->channel_usage < CHANNEL_USED_FOR_FULL_CIRCS) {
+ or_circ->p_chan->channel_usage = CHANNEL_USED_FOR_FULL_CIRCS;
+ }
+ } else if (cell->command == CELL_RELAY) {
+ or_circ->p_chan->channel_usage = CHANNEL_USED_FOR_USER_TRAFFIC;
+ }
+ }
+ }
+}
+
+/** Receive a relay cell:
+ * - Crypt it (encrypt if headed toward the origin or if we <b>are</b> the
+ * origin; decrypt if we're headed toward the exit).
+ * - Check if recognized (if exitward).
+ * - If recognized and the digest checks out, then find if there's a stream
+ * that the cell is intended for, and deliver it to the right
+ * connection_edge.
+ * - If not recognized, then we need to relay it: append it to the appropriate
+ * cell_queue on <b>circ</b>.
+ *
+ * Return -<b>reason</b> on failure.
+ */
+int
+circuit_receive_relay_cell(cell_t *cell, circuit_t *circ,
+ cell_direction_t cell_direction)
+{
+ channel_t *chan = NULL;
+ crypt_path_t *layer_hint=NULL;
+ char recognized=0;
+ int reason;
+
+ tor_assert(cell);
+ tor_assert(circ);
+ tor_assert(cell_direction == CELL_DIRECTION_OUT ||
+ cell_direction == CELL_DIRECTION_IN);
+ if (circ->marked_for_close)
+ return 0;
+
+ if (relay_decrypt_cell(circ, cell, cell_direction, &layer_hint, &recognized)
+ < 0) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "relay crypt failed. Dropping connection.");
+ return -END_CIRC_REASON_INTERNAL;
+ }
+
+ circuit_update_channel_usage(circ, cell);
+
+ if (recognized) {
+ edge_connection_t *conn = NULL;
+
+ if (circ->purpose == CIRCUIT_PURPOSE_PATH_BIAS_TESTING) {
- pathbias_check_probe_response(circ, cell);
++ if (pathbias_check_probe_response(circ, cell) == -1) {
++ pathbias_count_valid_cells(circ, cell);
++ }
+
+ /* We need to drop this cell no matter what to avoid code that expects
+ * a certain purpose (such as the hidserv code). */
+ return 0;
+ }
+
+ conn = relay_lookup_conn(circ, cell, cell_direction, layer_hint);
+ if (cell_direction == CELL_DIRECTION_OUT) {
+ ++stats_n_relay_cells_delivered;
+ log_debug(LD_OR,"Sending away from origin.");
+ if ((reason=connection_edge_process_relay_cell(cell, circ, conn, NULL))
+ < 0) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "connection_edge_process_relay_cell (away from origin) "
+ "failed.");
+ return reason;
+ }
+ }
+ if (cell_direction == CELL_DIRECTION_IN) {
+ ++stats_n_relay_cells_delivered;
+ log_debug(LD_OR,"Sending to origin.");
+ if ((reason = connection_edge_process_relay_cell(cell, circ, conn,
+ layer_hint)) < 0) {
+ /* If a client is trying to connect to unknown hidden service port,
+ * END_CIRC_AT_ORIGIN is sent back so we can then close the circuit.
+ * Do not log warn as this is an expected behavior for a service. */
+ if (reason != END_CIRC_AT_ORIGIN) {
+ log_warn(LD_OR,
+ "connection_edge_process_relay_cell (at origin) failed.");
+ }
+ return reason;
+ }
+ }
+ return 0;
+ }
+
+ /* not recognized. pass it on. */
+ if (cell_direction == CELL_DIRECTION_OUT) {
+ cell->circ_id = circ->n_circ_id; /* switch it */
+ chan = circ->n_chan;
+ } else if (! CIRCUIT_IS_ORIGIN(circ)) {
+ cell->circ_id = TO_OR_CIRCUIT(circ)->p_circ_id; /* switch it */
+ chan = TO_OR_CIRCUIT(circ)->p_chan;
+ } else {
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Dropping unrecognized inbound cell on origin circuit.");
+ /* If we see unrecognized cells on path bias testing circs,
+ * it's bad mojo. Those circuits need to die.
+ * XXX: Shouldn't they always die? */
+ if (circ->purpose == CIRCUIT_PURPOSE_PATH_BIAS_TESTING) {
+ TO_ORIGIN_CIRCUIT(circ)->path_state = PATH_STATE_USE_FAILED;
+ return -END_CIRC_REASON_TORPROTOCOL;
+ } else {
+ return 0;
+ }
+ }
+
+ if (!chan) {
+ // XXXX Can this splice stuff be done more cleanly?
+ if (! CIRCUIT_IS_ORIGIN(circ) &&
+ TO_OR_CIRCUIT(circ)->rend_splice &&
+ cell_direction == CELL_DIRECTION_OUT) {
+ or_circuit_t *splice_ = TO_OR_CIRCUIT(circ)->rend_splice;
+ tor_assert(circ->purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED);
+ tor_assert(splice_->base_.purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED);
+ cell->circ_id = splice_->p_circ_id;
+ cell->command = CELL_RELAY; /* can't be relay_early anyway */
+ if ((reason = circuit_receive_relay_cell(cell, TO_CIRCUIT(splice_),
+ CELL_DIRECTION_IN)) < 0) {
+ log_warn(LD_REND, "Error relaying cell across rendezvous; closing "
+ "circuits");
+ /* XXXX Do this here, or just return -1? */
+ circuit_mark_for_close(circ, -reason);
+ return reason;
+ }
+ return 0;
+ }
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Didn't recognize cell, but circ stops here! Closing circ.");
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
+
+ log_debug(LD_OR,"Passing on unrecognized cell.");
+
+ ++stats_n_relay_cells_relayed; /* XXXX no longer quite accurate {cells}
+ * we might kill the circ before we relay
+ * the cells. */
+
+ append_cell_to_circuit_queue(circ, chan, cell, cell_direction, 0);
+ return 0;
+}
+
+/** Package a relay cell from an edge:
+ * - Encrypt it to the right layer
+ * - Append it to the appropriate cell_queue on <b>circ</b>.
+ */
+static int
+circuit_package_relay_cell(cell_t *cell, circuit_t *circ,
+ cell_direction_t cell_direction,
+ crypt_path_t *layer_hint, streamid_t on_stream,
+ const char *filename, int lineno)
+{
+ channel_t *chan; /* where to send the cell */
+
+ if (circ->marked_for_close) {
+ /* Circuit is marked; send nothing. */
+ return 0;
+ }
+
+ if (cell_direction == CELL_DIRECTION_OUT) {
+ chan = circ->n_chan;
+ if (!chan) {
+ log_warn(LD_BUG,"outgoing relay cell sent from %s:%d has n_chan==NULL."
+ " Dropping. Circuit is in state %s (%d), and is "
+ "%smarked for close. (%s:%d, %d)", filename, lineno,
+ circuit_state_to_string(circ->state), circ->state,
+ circ->marked_for_close ? "" : "not ",
+ circ->marked_for_close_file?circ->marked_for_close_file:"",
+ circ->marked_for_close, circ->marked_for_close_reason);
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ circuit_log_path(LOG_WARN, LD_BUG, TO_ORIGIN_CIRCUIT(circ));
+ }
+ log_backtrace(LOG_WARN,LD_BUG,"");
+ return 0; /* just drop it */
+ }
+ if (!CIRCUIT_IS_ORIGIN(circ)) {
+ log_warn(LD_BUG,"outgoing relay cell sent from %s:%d on non-origin "
+ "circ. Dropping.", filename, lineno);
+ log_backtrace(LOG_WARN,LD_BUG,"");
+ return 0; /* just drop it */
+ }
+
+ relay_encrypt_cell_outbound(cell, TO_ORIGIN_CIRCUIT(circ), layer_hint);
+
+ /* Update circ written totals for control port */
+ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
+ ocirc->n_written_circ_bw = tor_add_u32_nowrap(ocirc->n_written_circ_bw,
+ CELL_PAYLOAD_SIZE);
+
+ } else { /* incoming cell */
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ /* We should never package an _incoming_ cell from the circuit
+ * origin; that means we messed up somewhere. */
+ log_warn(LD_BUG,"incoming relay cell at origin circuit. Dropping.");
+ assert_circuit_ok(circ);
+ return 0; /* just drop it */
+ }
+ or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
+ relay_encrypt_cell_inbound(cell, or_circ);
+ chan = or_circ->p_chan;
+ }
+ ++stats_n_relay_cells_relayed;
+
+ append_cell_to_circuit_queue(circ, chan, cell, cell_direction, on_stream);
+ return 0;
+}
+
+/** If cell's stream_id matches the stream_id of any conn that's
+ * attached to circ, return that conn, else return NULL.
+ */
+static edge_connection_t *
+relay_lookup_conn(circuit_t *circ, cell_t *cell,
+ cell_direction_t cell_direction, crypt_path_t *layer_hint)
+{
+ edge_connection_t *tmpconn;
+ relay_header_t rh;
+
+ relay_header_unpack(&rh, cell->payload);
+
+ if (!rh.stream_id)
+ return NULL;
+
+ /* IN or OUT cells could have come from either direction, now
+ * that we allow rendezvous *to* an OP.
+ */
+
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ for (tmpconn = TO_ORIGIN_CIRCUIT(circ)->p_streams; tmpconn;
+ tmpconn=tmpconn->next_stream) {
+ if (rh.stream_id == tmpconn->stream_id &&
+ !tmpconn->base_.marked_for_close &&
+ tmpconn->cpath_layer == layer_hint) {
+ log_debug(LD_APP,"found conn for stream %d.", rh.stream_id);
+ return tmpconn;
+ }
+ }
+ } else {
+ for (tmpconn = TO_OR_CIRCUIT(circ)->n_streams; tmpconn;
+ tmpconn=tmpconn->next_stream) {
+ if (rh.stream_id == tmpconn->stream_id &&
+ !tmpconn->base_.marked_for_close) {
+ log_debug(LD_EXIT,"found conn for stream %d.", rh.stream_id);
+ if (cell_direction == CELL_DIRECTION_OUT ||
+ connection_edge_is_rendezvous_stream(tmpconn))
+ return tmpconn;
+ }
+ }
+ for (tmpconn = TO_OR_CIRCUIT(circ)->resolving_streams; tmpconn;
+ tmpconn=tmpconn->next_stream) {
+ if (rh.stream_id == tmpconn->stream_id &&
+ !tmpconn->base_.marked_for_close) {
+ log_debug(LD_EXIT,"found conn for stream %d.", rh.stream_id);
+ return tmpconn;
+ }
+ }
+ }
+ return NULL; /* probably a begin relay cell */
+}
+
+/** Pack the relay_header_t host-order structure <b>src</b> into
+ * network-order in the buffer <b>dest</b>. See tor-spec.txt for details
+ * about the wire format.
+ */
+void
+relay_header_pack(uint8_t *dest, const relay_header_t *src)
+{
+ set_uint8(dest, src->command);
+ set_uint16(dest+1, htons(src->recognized));
+ set_uint16(dest+3, htons(src->stream_id));
+ memcpy(dest+5, src->integrity, 4);
+ set_uint16(dest+9, htons(src->length));
+}
+
+/** Unpack the network-order buffer <b>src</b> into a host-order
+ * relay_header_t structure <b>dest</b>.
+ */
+void
+relay_header_unpack(relay_header_t *dest, const uint8_t *src)
+{
+ dest->command = get_uint8(src);
+ dest->recognized = ntohs(get_uint16(src+1));
+ dest->stream_id = ntohs(get_uint16(src+3));
+ memcpy(dest->integrity, src+5, 4);
+ dest->length = ntohs(get_uint16(src+9));
+}
+
+/** Convert the relay <b>command</b> into a human-readable string. */
+static const char *
+relay_command_to_string(uint8_t command)
+{
+ static char buf[64];
+ switch (command) {
+ case RELAY_COMMAND_BEGIN: return "BEGIN";
+ case RELAY_COMMAND_DATA: return "DATA";
+ case RELAY_COMMAND_END: return "END";
+ case RELAY_COMMAND_CONNECTED: return "CONNECTED";
+ case RELAY_COMMAND_SENDME: return "SENDME";
+ case RELAY_COMMAND_EXTEND: return "EXTEND";
+ case RELAY_COMMAND_EXTENDED: return "EXTENDED";
+ case RELAY_COMMAND_TRUNCATE: return "TRUNCATE";
+ case RELAY_COMMAND_TRUNCATED: return "TRUNCATED";
+ case RELAY_COMMAND_DROP: return "DROP";
+ case RELAY_COMMAND_RESOLVE: return "RESOLVE";
+ case RELAY_COMMAND_RESOLVED: return "RESOLVED";
+ case RELAY_COMMAND_BEGIN_DIR: return "BEGIN_DIR";
+ case RELAY_COMMAND_ESTABLISH_INTRO: return "ESTABLISH_INTRO";
+ case RELAY_COMMAND_ESTABLISH_RENDEZVOUS: return "ESTABLISH_RENDEZVOUS";
+ case RELAY_COMMAND_INTRODUCE1: return "INTRODUCE1";
+ case RELAY_COMMAND_INTRODUCE2: return "INTRODUCE2";
+ case RELAY_COMMAND_RENDEZVOUS1: return "RENDEZVOUS1";
+ case RELAY_COMMAND_RENDEZVOUS2: return "RENDEZVOUS2";
+ case RELAY_COMMAND_INTRO_ESTABLISHED: return "INTRO_ESTABLISHED";
+ case RELAY_COMMAND_RENDEZVOUS_ESTABLISHED:
+ return "RENDEZVOUS_ESTABLISHED";
+ case RELAY_COMMAND_INTRODUCE_ACK: return "INTRODUCE_ACK";
+ case RELAY_COMMAND_EXTEND2: return "EXTEND2";
+ case RELAY_COMMAND_EXTENDED2: return "EXTENDED2";
+ default:
+ tor_snprintf(buf, sizeof(buf), "Unrecognized relay command %u",
+ (unsigned)command);
+ return buf;
+ }
+}
+
+/** Make a relay cell out of <b>relay_command</b> and <b>payload</b>, and send
+ * it onto the open circuit <b>circ</b>. <b>stream_id</b> is the ID on
+ * <b>circ</b> for the stream that's sending the relay cell, or 0 if it's a
+ * control cell. <b>cpath_layer</b> is NULL for OR->OP cells, or the
+ * destination hop for OP->OR cells.
+ *
+ * If you can't send the cell, mark the circuit for close and return -1. Else
+ * return 0.
+ */
+MOCK_IMPL(int,
+relay_send_command_from_edge_,(streamid_t stream_id, circuit_t *circ,
+ uint8_t relay_command, const char *payload,
+ size_t payload_len, crypt_path_t *cpath_layer,
+ const char *filename, int lineno))
+{
+ cell_t cell;
+ relay_header_t rh;
+ cell_direction_t cell_direction;
+ /* XXXX NM Split this function into a separate versions per circuit type? */
+
+ tor_assert(circ);
+ tor_assert(payload_len <= RELAY_PAYLOAD_SIZE);
+
+ memset(&cell, 0, sizeof(cell_t));
+ cell.command = CELL_RELAY;
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ tor_assert(cpath_layer);
+ cell.circ_id = circ->n_circ_id;
+ cell_direction = CELL_DIRECTION_OUT;
+ } else {
+ tor_assert(! cpath_layer);
+ cell.circ_id = TO_OR_CIRCUIT(circ)->p_circ_id;
+ cell_direction = CELL_DIRECTION_IN;
+ }
+
+ memset(&rh, 0, sizeof(rh));
+ rh.command = relay_command;
+ rh.stream_id = stream_id;
+ rh.length = payload_len;
+ relay_header_pack(cell.payload, &rh);
+ if (payload_len)
+ memcpy(cell.payload+RELAY_HEADER_SIZE, payload, payload_len);
+
+ log_debug(LD_OR,"delivering %d cell %s.", relay_command,
+ cell_direction == CELL_DIRECTION_OUT ? "forward" : "backward");
+
+ if (relay_command == RELAY_COMMAND_DROP)
+ rep_hist_padding_count_write(PADDING_TYPE_DROP);
+
+ /* If we are sending an END cell and this circuit is used for a tunneled
+ * directory request, advance its state. */
+ if (relay_command == RELAY_COMMAND_END && circ->dirreq_id)
+ geoip_change_dirreq_state(circ->dirreq_id, DIRREQ_TUNNELED,
+ DIRREQ_END_CELL_SENT);
+
+ if (cell_direction == CELL_DIRECTION_OUT && circ->n_chan) {
+ /* if we're using relaybandwidthrate, this conn wants priority */
+ channel_timestamp_client(circ->n_chan);
+ }
+
+ if (cell_direction == CELL_DIRECTION_OUT) {
+ origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(circ);
+ if (origin_circ->remaining_relay_early_cells > 0 &&
+ (relay_command == RELAY_COMMAND_EXTEND ||
+ relay_command == RELAY_COMMAND_EXTEND2 ||
+ cpath_layer != origin_circ->cpath)) {
+ /* If we've got any relay_early cells left and (we're sending
+ * an extend cell or we're not talking to the first hop), use
+ * one of them. Don't worry about the conn protocol version:
+ * append_cell_to_circuit_queue will fix it up. */
+ cell.command = CELL_RELAY_EARLY;
+ --origin_circ->remaining_relay_early_cells;
+ log_debug(LD_OR, "Sending a RELAY_EARLY cell; %d remaining.",
+ (int)origin_circ->remaining_relay_early_cells);
+ /* Memorize the command that is sent as RELAY_EARLY cell; helps debug
+ * task 878. */
+ origin_circ->relay_early_commands[
+ origin_circ->relay_early_cells_sent++] = relay_command;
+ } else if (relay_command == RELAY_COMMAND_EXTEND ||
+ relay_command == RELAY_COMMAND_EXTEND2) {
+ /* If no RELAY_EARLY cells can be sent over this circuit, log which
+ * commands have been sent as RELAY_EARLY cells before; helps debug
+ * task 878. */
+ smartlist_t *commands_list = smartlist_new();
+ int i = 0;
+ char *commands = NULL;
+ for (; i < origin_circ->relay_early_cells_sent; i++)
+ smartlist_add(commands_list, (char *)
+ relay_command_to_string(origin_circ->relay_early_commands[i]));
+ commands = smartlist_join_strings(commands_list, ",", 0, NULL);
+ log_warn(LD_BUG, "Uh-oh. We're sending a RELAY_COMMAND_EXTEND cell, "
+ "but we have run out of RELAY_EARLY cells on that circuit. "
+ "Commands sent before: %s", commands);
+ tor_free(commands);
+ smartlist_free(commands_list);
+ }
+
+ /* Let's assume we're well-behaved: Anything that we decide to send is
+ * valid, delivered data. */
+ circuit_sent_valid_data(origin_circ, rh.length);
+ }
+
+ if (circuit_package_relay_cell(&cell, circ, cell_direction, cpath_layer,
+ stream_id, filename, lineno) < 0) {
+ log_warn(LD_BUG,"circuit_package_relay_cell failed. Closing.");
+ circuit_mark_for_close(circ, END_CIRC_REASON_INTERNAL);
+ return -1;
+ }
+ return 0;
+}
+
+/** Make a relay cell out of <b>relay_command</b> and <b>payload</b>, and
+ * send it onto the open circuit <b>circ</b>. <b>fromconn</b> is the stream
+ * that's sending the relay cell, or NULL if it's a control cell.
+ * <b>cpath_layer</b> is NULL for OR->OP cells, or the destination hop
+ * for OP->OR cells.
+ *
+ * If you can't send the cell, mark the circuit for close and
+ * return -1. Else return 0.
+ */
+int
+connection_edge_send_command(edge_connection_t *fromconn,
+ uint8_t relay_command, const char *payload,
+ size_t payload_len)
+{
+ /* XXXX NM Split this function into a separate versions per circuit type? */
+ circuit_t *circ;
+ crypt_path_t *cpath_layer = fromconn->cpath_layer;
+ tor_assert(fromconn);
+ circ = fromconn->on_circuit;
+
+ if (fromconn->base_.marked_for_close) {
+ log_warn(LD_BUG,
+ "called on conn that's already marked for close at %s:%d.",
+ fromconn->base_.marked_for_close_file,
+ fromconn->base_.marked_for_close);
+ return 0;
+ }
+
+ if (!circ) {
+ if (fromconn->base_.type == CONN_TYPE_AP) {
+ log_info(LD_APP,"no circ. Closing conn.");
+ connection_mark_unattached_ap(EDGE_TO_ENTRY_CONN(fromconn),
+ END_STREAM_REASON_INTERNAL);
+ } else {
+ log_info(LD_EXIT,"no circ. Closing conn.");
+ fromconn->edge_has_sent_end = 1; /* no circ to send to */
+ fromconn->end_reason = END_STREAM_REASON_INTERNAL;
+ connection_mark_for_close(TO_CONN(fromconn));
+ }
+ return -1;
+ }
+
+ if (circ->marked_for_close) {
+ /* The circuit has been marked, but not freed yet. When it's freed, it
+ * will mark this connection for close. */
+ return -1;
+ }
+
+#ifdef MEASUREMENTS_21206
+ /* Keep track of the number of RELAY_DATA cells sent for directory
+ * connections. */
+ connection_t *linked_conn = TO_CONN(fromconn)->linked_conn;
+
+ if (linked_conn && linked_conn->type == CONN_TYPE_DIR) {
+ ++(TO_DIR_CONN(linked_conn)->data_cells_sent);
+ }
+#endif /* defined(MEASUREMENTS_21206) */
+
+ return relay_send_command_from_edge(fromconn->stream_id, circ,
+ relay_command, payload,
+ payload_len, cpath_layer);
+}
+
+/** How many times will I retry a stream that fails due to DNS
+ * resolve failure or misc error?
+ */
+#define MAX_RESOLVE_FAILURES 3
+
+/** Return 1 if reason is something that you should retry if you
+ * get the end cell before you've connected; else return 0. */
+static int
+edge_reason_is_retriable(int reason)
+{
+ return reason == END_STREAM_REASON_HIBERNATING ||
+ reason == END_STREAM_REASON_RESOURCELIMIT ||
+ reason == END_STREAM_REASON_EXITPOLICY ||
+ reason == END_STREAM_REASON_RESOLVEFAILED ||
+ reason == END_STREAM_REASON_MISC ||
+ reason == END_STREAM_REASON_NOROUTE;
+}
+
+/** Called when we receive an END cell on a stream that isn't open yet,
+ * from the client side.
+ * Arguments are as for connection_edge_process_relay_cell().
+ */
+static int
+connection_ap_process_end_not_open(
+ relay_header_t *rh, cell_t *cell, origin_circuit_t *circ,
+ entry_connection_t *conn, crypt_path_t *layer_hint)
+{
+ node_t *exitrouter;
+ int reason = *(cell->payload+RELAY_HEADER_SIZE);
+ int control_reason;
+ edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
+ (void) layer_hint; /* unused */
+
+ if (rh->length > 0) {
+ if (reason == END_STREAM_REASON_TORPROTOCOL ||
+ reason == END_STREAM_REASON_DESTROY) {
+ /* Both of these reasons could mean a failed tag
+ * hit the exit and it complained. Do not probe.
+ * Fail the circuit. */
+ circ->path_state = PATH_STATE_USE_FAILED;
+ return -END_CIRC_REASON_TORPROTOCOL;
+ } else if (reason == END_STREAM_REASON_INTERNAL) {
+ /* We can't infer success or failure, since older Tors report
+ * ENETUNREACH as END_STREAM_REASON_INTERNAL. */
+ } else {
+ /* Path bias: If we get a valid reason code from the exit,
+ * it wasn't due to tagging.
+ *
+ * We rely on recognized+digest being strong enough to make
+ * tags unlikely to allow us to get tagged, yet 'recognized'
+ * reason codes here. */
+ pathbias_mark_use_success(circ);
+ }
+ }
+
+ /* This end cell is now valid. */
+ circuit_read_valid_data(circ, rh->length);
+
+ if (rh->length == 0) {
+ reason = END_STREAM_REASON_MISC;
+ }
+
+ control_reason = reason | END_STREAM_REASON_FLAG_REMOTE;
+
+ if (edge_reason_is_retriable(reason) &&
+ /* avoid retry if rend */
+ !connection_edge_is_rendezvous_stream(edge_conn)) {
+ const char *chosen_exit_digest =
+ circ->build_state->chosen_exit->identity_digest;
+ log_info(LD_APP,"Address '%s' refused due to '%s'. Considering retrying.",
+ safe_str(conn->socks_request->address),
+ stream_end_reason_to_string(reason));
+ exitrouter = node_get_mutable_by_id(chosen_exit_digest);
+ switch (reason) {
+ case END_STREAM_REASON_EXITPOLICY: {
+ tor_addr_t addr;
+ tor_addr_make_unspec(&addr);
+ if (rh->length >= 5) {
+ int ttl = -1;
+ tor_addr_make_unspec(&addr);
+ if (rh->length == 5 || rh->length == 9) {
+ tor_addr_from_ipv4n(&addr,
+ get_uint32(cell->payload+RELAY_HEADER_SIZE+1));
+ if (rh->length == 9)
+ ttl = (int)ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE+5));
+ } else if (rh->length == 17 || rh->length == 21) {
+ tor_addr_from_ipv6_bytes(&addr,
+ (char*)(cell->payload+RELAY_HEADER_SIZE+1));
+ if (rh->length == 21)
+ ttl = (int)ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE+17));
+ }
+ if (tor_addr_is_null(&addr)) {
+ log_info(LD_APP,"Address '%s' resolved to 0.0.0.0. Closing,",
+ safe_str(conn->socks_request->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+ return 0;
+ }
+
+ if ((tor_addr_family(&addr) == AF_INET &&
+ !conn->entry_cfg.ipv4_traffic) ||
+ (tor_addr_family(&addr) == AF_INET6 &&
+ !conn->entry_cfg.ipv6_traffic)) {
+ log_fn(LOG_PROTOCOL_WARN, LD_APP,
+ "Got an EXITPOLICY failure on a connection with a "
+ "mismatched family. Closing.");
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+ return 0;
+ }
+ if (get_options()->ClientDNSRejectInternalAddresses &&
+ tor_addr_is_internal(&addr, 0)) {
+ log_info(LD_APP,"Address '%s' resolved to internal. Closing,",
+ safe_str(conn->socks_request->address));
+ connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+ return 0;
+ }
+
+ client_dns_set_addressmap(conn,
+ conn->socks_request->address, &addr,
+ conn->chosen_exit_name, ttl);
+
+ {
+ char new_addr[TOR_ADDR_BUF_LEN];
+ tor_addr_to_str(new_addr, &addr, sizeof(new_addr), 1);
+ if (strcmp(conn->socks_request->address, new_addr)) {
+ strlcpy(conn->socks_request->address, new_addr,
+ sizeof(conn->socks_request->address));
+ control_event_stream_status(conn, STREAM_EVENT_REMAP, 0);
+ }
+ }
+ }
+ /* check if the exit *ought* to have allowed it */
+
+ adjust_exit_policy_from_exitpolicy_failure(circ,
+ conn,
+ exitrouter,
+ &addr);
+
+ if (conn->chosen_exit_optional ||
+ conn->chosen_exit_retries) {
+ /* stop wanting a specific exit */
+ conn->chosen_exit_optional = 0;
+ /* A non-zero chosen_exit_retries can happen if we set a
+ * TrackHostExits for this address under a port that the exit
+ * relay allows, but then try the same address with a different
+ * port that it doesn't allow to exit. We shouldn't unregister
+ * the mapping, since it is probably still wanted on the
+ * original port. But now we give away to the exit relay that
+ * we probably have a TrackHostExits on it. So be it. */
+ conn->chosen_exit_retries = 0;
+ tor_free(conn->chosen_exit_name); /* clears it */
+ }
+ if (connection_ap_detach_retriable(conn, circ, control_reason) >= 0)
+ return 0;
+ /* else, conn will get closed below */
+ break;
+ }
+ case END_STREAM_REASON_CONNECTREFUSED:
+ if (!conn->chosen_exit_optional)
+ break; /* break means it'll close, below */
+ /* Else fall through: expire this circuit, clear the
+ * chosen_exit_name field, and try again. */
+ /* Falls through. */
+ case END_STREAM_REASON_RESOLVEFAILED:
+ case END_STREAM_REASON_TIMEOUT:
+ case END_STREAM_REASON_MISC:
+ case END_STREAM_REASON_NOROUTE:
+ if (client_dns_incr_failures(conn->socks_request->address)
+ < MAX_RESOLVE_FAILURES) {
+ /* We haven't retried too many times; reattach the connection. */
+ circuit_log_path(LOG_INFO,LD_APP,circ);
+ /* Mark this circuit "unusable for new streams". */
+ mark_circuit_unusable_for_new_conns(circ);
+
+ if (conn->chosen_exit_optional) {
+ /* stop wanting a specific exit */
+ conn->chosen_exit_optional = 0;
+ tor_free(conn->chosen_exit_name); /* clears it */
+ }
+ if (connection_ap_detach_retriable(conn, circ, control_reason) >= 0)
+ return 0;
+ /* else, conn will get closed below */
+ } else {
+ log_notice(LD_APP,
+ "Have tried resolving or connecting to address '%s' "
+ "at %d different places. Giving up.",
+ safe_str(conn->socks_request->address),
+ MAX_RESOLVE_FAILURES);
+ /* clear the failures, so it will have a full try next time */
+ client_dns_clear_failures(conn->socks_request->address);
+ }
+ break;
+ case END_STREAM_REASON_HIBERNATING:
+ case END_STREAM_REASON_RESOURCELIMIT:
+ if (exitrouter) {
+ policies_set_node_exitpolicy_to_reject_all(exitrouter);
+ }
+ if (conn->chosen_exit_optional) {
+ /* stop wanting a specific exit */
+ conn->chosen_exit_optional = 0;
+ tor_free(conn->chosen_exit_name); /* clears it */
+ }
+ if (connection_ap_detach_retriable(conn, circ, control_reason) >= 0)
+ return 0;
+ /* else, will close below */
+ break;
+ } /* end switch */
+ log_info(LD_APP,"Giving up on retrying; conn can't be handled.");
+ }
+
+ log_info(LD_APP,
+ "Edge got end (%s) before we're connected. Marking for close.",
+ stream_end_reason_to_string(rh->length > 0 ? reason : -1));
+ circuit_log_path(LOG_INFO,LD_APP,circ);
+ /* need to test because of detach_retriable */
+ if (!ENTRY_TO_CONN(conn)->marked_for_close)
+ connection_mark_unattached_ap(conn, control_reason);
+ return 0;
+}
+
+/** Called when we have gotten an END_REASON_EXITPOLICY failure on <b>circ</b>
+ * for <b>conn</b>, while attempting to connect via <b>node</b>. If the node
+ * told us which address it rejected, then <b>addr</b> is that address;
+ * otherwise it is AF_UNSPEC.
+ *
+ * If we are sure the node should have allowed this address, mark the node as
+ * having a reject *:* exit policy. Otherwise, mark the circuit as unusable
+ * for this particular address.
+ **/
+static void
+adjust_exit_policy_from_exitpolicy_failure(origin_circuit_t *circ,
+ entry_connection_t *conn,
+ node_t *node,
+ const tor_addr_t *addr)
+{
+ int make_reject_all = 0;
+ const sa_family_t family = tor_addr_family(addr);
+
+ if (node) {
+ tor_addr_t tmp;
+ int asked_for_family = tor_addr_parse(&tmp, conn->socks_request->address);
+ if (family == AF_UNSPEC) {
+ make_reject_all = 1;
+ } else if (node_exit_policy_is_exact(node, family) &&
+ asked_for_family != -1 && !conn->chosen_exit_name) {
+ make_reject_all = 1;
+ }
+
+ if (make_reject_all) {
+ log_info(LD_APP,
+ "Exitrouter %s seems to be more restrictive than its exit "
+ "policy. Not using this router as exit for now.",
+ node_describe(node));
+ policies_set_node_exitpolicy_to_reject_all(node);
+ }
+ }
+
+ if (family != AF_UNSPEC)
+ addr_policy_append_reject_addr(&circ->prepend_policy, addr);
+}
+
+/** Helper: change the socks_request->address field on conn to the
+ * dotted-quad representation of <b>new_addr</b>,
+ * and send an appropriate REMAP event. */
+static void
+remap_event_helper(entry_connection_t *conn, const tor_addr_t *new_addr)
+{
+ tor_addr_to_str(conn->socks_request->address, new_addr,
+ sizeof(conn->socks_request->address),
+ 1);
+ control_event_stream_status(conn, STREAM_EVENT_REMAP,
+ REMAP_STREAM_SOURCE_EXIT);
+}
+
+/** Extract the contents of a connected cell in <b>cell</b>, whose relay
+ * header has already been parsed into <b>rh</b>. On success, set
+ * <b>addr_out</b> to the address we're connected to, and <b>ttl_out</b> to
+ * the ttl of that address, in seconds, and return 0. On failure, return
+ * -1.
+ *
+ * Note that the resulting address can be UNSPEC if the connected cell had no
+ * address (as for a stream to an union service or a tunneled directory
+ * connection), and that the ttl can be absent (in which case <b>ttl_out</b>
+ * is set to -1). */
+STATIC int
+connected_cell_parse(const relay_header_t *rh, const cell_t *cell,
+ tor_addr_t *addr_out, int *ttl_out)
+{
+ uint32_t bytes;
+ const uint8_t *payload = cell->payload + RELAY_HEADER_SIZE;
+
+ tor_addr_make_unspec(addr_out);
+ *ttl_out = -1;
+ if (rh->length == 0)
+ return 0;
+ if (rh->length < 4)
+ return -1;
+ bytes = ntohl(get_uint32(payload));
+
+ /* If bytes is 0, this is maybe a v6 address. Otherwise it's a v4 address */
+ if (bytes != 0) {
+ /* v4 address */
+ tor_addr_from_ipv4h(addr_out, bytes);
+ if (rh->length >= 8) {
+ bytes = ntohl(get_uint32(payload + 4));
+ if (bytes <= INT32_MAX)
+ *ttl_out = bytes;
+ }
+ } else {
+ if (rh->length < 25) /* 4 bytes of 0s, 1 addr, 16 ipv4, 4 ttl. */
+ return -1;
+ if (get_uint8(payload + 4) != 6)
+ return -1;
+ tor_addr_from_ipv6_bytes(addr_out, (char*)(payload + 5));
+ bytes = ntohl(get_uint32(payload + 21));
+ if (bytes <= INT32_MAX)
+ *ttl_out = (int) bytes;
+ }
+ return 0;
+}
+
+/** Drop all storage held by <b>addr</b>. */
+STATIC void
+address_ttl_free_(address_ttl_t *addr)
+{
+ if (!addr)
+ return;
+ tor_free(addr->hostname);
+ tor_free(addr);
+}
+
+/** Parse a resolved cell in <b>cell</b>, with parsed header in <b>rh</b>.
+ * Return -1 on parse error. On success, add one or more newly allocated
+ * address_ttl_t to <b>addresses_out</b>; set *<b>errcode_out</b> to
+ * one of 0, RESOLVED_TYPE_ERROR, or RESOLVED_TYPE_ERROR_TRANSIENT, and
+ * return 0. */
+STATIC int
+resolved_cell_parse(const cell_t *cell, const relay_header_t *rh,
+ smartlist_t *addresses_out, int *errcode_out)
+{
+ const uint8_t *cp;
+ uint8_t answer_type;
+ size_t answer_len;
+ address_ttl_t *addr;
+ size_t remaining;
+ int errcode = 0;
+ smartlist_t *addrs;
+
+ tor_assert(cell);
+ tor_assert(rh);
+ tor_assert(addresses_out);
+ tor_assert(errcode_out);
+
+ *errcode_out = 0;
+
+ if (rh->length > RELAY_PAYLOAD_SIZE)
+ return -1;
+
+ addrs = smartlist_new();
+
+ cp = cell->payload + RELAY_HEADER_SIZE;
+
+ remaining = rh->length;
+ while (remaining) {
+ const uint8_t *cp_orig = cp;
+ if (remaining < 2)
+ goto err;
+ answer_type = *cp++;
+ answer_len = *cp++;
+ if (remaining < 2 + answer_len + 4) {
+ goto err;
+ }
+ if (answer_type == RESOLVED_TYPE_IPV4) {
+ if (answer_len != 4) {
+ goto err;
+ }
+ addr = tor_malloc_zero(sizeof(*addr));
+ tor_addr_from_ipv4n(&addr->addr, get_uint32(cp));
+ cp += 4;
+ addr->ttl = ntohl(get_uint32(cp));
+ cp += 4;
+ smartlist_add(addrs, addr);
+ } else if (answer_type == RESOLVED_TYPE_IPV6) {
+ if (answer_len != 16)
+ goto err;
+ addr = tor_malloc_zero(sizeof(*addr));
+ tor_addr_from_ipv6_bytes(&addr->addr, (const char*) cp);
+ cp += 16;
+ addr->ttl = ntohl(get_uint32(cp));
+ cp += 4;
+ smartlist_add(addrs, addr);
+ } else if (answer_type == RESOLVED_TYPE_HOSTNAME) {
+ if (answer_len == 0) {
+ goto err;
+ }
+ addr = tor_malloc_zero(sizeof(*addr));
+ addr->hostname = tor_memdup_nulterm(cp, answer_len);
+ cp += answer_len;
+ addr->ttl = ntohl(get_uint32(cp));
+ cp += 4;
+ smartlist_add(addrs, addr);
+ } else if (answer_type == RESOLVED_TYPE_ERROR_TRANSIENT ||
+ answer_type == RESOLVED_TYPE_ERROR) {
+ errcode = answer_type;
+ /* Ignore the error contents */
+ cp += answer_len + 4;
+ } else {
+ cp += answer_len + 4;
+ }
+ tor_assert(((ssize_t)remaining) >= (cp - cp_orig));
+ remaining -= (cp - cp_orig);
+ }
+
+ if (errcode && smartlist_len(addrs) == 0) {
+ /* Report an error only if there were no results. */
+ *errcode_out = errcode;
+ }
+
+ smartlist_add_all(addresses_out, addrs);
+ smartlist_free(addrs);
+
+ return 0;
+
+ err:
+ /* On parse error, don't report any results */
+ SMARTLIST_FOREACH(addrs, address_ttl_t *, a, address_ttl_free(a));
+ smartlist_free(addrs);
+ return -1;
+}
+
+/** Helper for connection_edge_process_resolved_cell: given an error code,
+ * an entry_connection, and a list of address_ttl_t *, report the best answer
+ * to the entry_connection. */
+static void
+connection_ap_handshake_socks_got_resolved_cell(entry_connection_t *conn,
+ int error_code,
+ smartlist_t *results)
+{
+ address_ttl_t *addr_ipv4 = NULL;
+ address_ttl_t *addr_ipv6 = NULL;
+ address_ttl_t *addr_hostname = NULL;
+ address_ttl_t *addr_best = NULL;
+
+ /* If it's an error code, that's easy. */
+ if (error_code) {
+ tor_assert(error_code == RESOLVED_TYPE_ERROR ||
+ error_code == RESOLVED_TYPE_ERROR_TRANSIENT);
+ connection_ap_handshake_socks_resolved(conn,
+ error_code,0,NULL,-1,-1);
+ return;
+ }
+
+ /* Get the first answer of each type. */
+ SMARTLIST_FOREACH_BEGIN(results, address_ttl_t *, addr) {
+ if (addr->hostname) {
+ if (!addr_hostname) {
+ addr_hostname = addr;
+ }
+ } else if (tor_addr_family(&addr->addr) == AF_INET) {
+ if (!addr_ipv4 && conn->entry_cfg.ipv4_traffic) {
+ addr_ipv4 = addr;
+ }
+ } else if (tor_addr_family(&addr->addr) == AF_INET6) {
+ if (!addr_ipv6 && conn->entry_cfg.ipv6_traffic) {
+ addr_ipv6 = addr;
+ }
+ }
+ } SMARTLIST_FOREACH_END(addr);
+
+ /* Now figure out which type we wanted to deliver. */
+ if (conn->socks_request->command == SOCKS_COMMAND_RESOLVE_PTR) {
+ if (addr_hostname) {
+ connection_ap_handshake_socks_resolved(conn,
+ RESOLVED_TYPE_HOSTNAME,
+ strlen(addr_hostname->hostname),
+ (uint8_t*)addr_hostname->hostname,
+ addr_hostname->ttl,-1);
+ } else {
+ connection_ap_handshake_socks_resolved(conn,
+ RESOLVED_TYPE_ERROR,0,NULL,-1,-1);
+ }
+ return;
+ }
+
+ if (conn->entry_cfg.prefer_ipv6) {
+ addr_best = addr_ipv6 ? addr_ipv6 : addr_ipv4;
+ } else {
+ addr_best = addr_ipv4 ? addr_ipv4 : addr_ipv6;
+ }
+
+ /* Now convert it to the ugly old interface */
+ if (! addr_best) {
+ connection_ap_handshake_socks_resolved(conn,
+ RESOLVED_TYPE_ERROR,0,NULL,-1,-1);
+ return;
+ }
+
+ connection_ap_handshake_socks_resolved_addr(conn,
+ &addr_best->addr,
+ addr_best->ttl,
+ -1);
+
+ remap_event_helper(conn, &addr_best->addr);
+}
+
+/** Handle a RELAY_COMMAND_RESOLVED cell that we received on a non-open AP
+ * stream. */
+STATIC int
+connection_edge_process_resolved_cell(edge_connection_t *conn,
+ const cell_t *cell,
+ const relay_header_t *rh)
+{
+ entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn);
+ smartlist_t *resolved_addresses = NULL;
+ int errcode = 0;
+
+ if (conn->base_.state != AP_CONN_STATE_RESOLVE_WAIT) {
+ log_fn(LOG_PROTOCOL_WARN, LD_APP, "Got a 'resolved' cell while "
+ "not in state resolve_wait. Dropping.");
+ return 0;
+ }
+ tor_assert(SOCKS_COMMAND_IS_RESOLVE(entry_conn->socks_request->command));
+
+ resolved_addresses = smartlist_new();
+ if (resolved_cell_parse(cell, rh, resolved_addresses, &errcode)) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Dropping malformed 'resolved' cell");
+ connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TORPROTOCOL);
+ goto done;
+ }
+
+ if (get_options()->ClientDNSRejectInternalAddresses) {
+ int orig_len = smartlist_len(resolved_addresses);
+ SMARTLIST_FOREACH_BEGIN(resolved_addresses, address_ttl_t *, addr) {
+ if (addr->hostname == NULL && tor_addr_is_internal(&addr->addr, 0)) {
+ log_info(LD_APP, "Got a resolved cell with answer %s; dropping that "
+ "answer.",
+ safe_str_client(fmt_addr(&addr->addr)));
+ address_ttl_free(addr);
+ SMARTLIST_DEL_CURRENT(resolved_addresses, addr);
+ }
+ } SMARTLIST_FOREACH_END(addr);
+ if (orig_len && smartlist_len(resolved_addresses) == 0) {
+ log_info(LD_APP, "Got a resolved cell with only private addresses; "
+ "dropping it.");
+ connection_ap_handshake_socks_resolved(entry_conn,
+ RESOLVED_TYPE_ERROR_TRANSIENT,
+ 0, NULL, 0, TIME_MAX);
+ connection_mark_unattached_ap(entry_conn,
+ END_STREAM_REASON_TORPROTOCOL);
+ goto done;
+ }
+ }
+
+ /* This is valid data at this point. Count it */
+ if (conn->on_circuit && CIRCUIT_IS_ORIGIN(conn->on_circuit)) {
+ circuit_read_valid_data(TO_ORIGIN_CIRCUIT(conn->on_circuit),
+ rh->length);
+ }
+
+ connection_ap_handshake_socks_got_resolved_cell(entry_conn,
+ errcode,
+ resolved_addresses);
+
+ connection_mark_unattached_ap(entry_conn,
+ END_STREAM_REASON_DONE |
+ END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
+
+ done:
+ SMARTLIST_FOREACH(resolved_addresses, address_ttl_t *, addr,
+ address_ttl_free(addr));
+ smartlist_free(resolved_addresses);
+ return 0;
+}
+
+/** An incoming relay cell has arrived from circuit <b>circ</b> to
+ * stream <b>conn</b>.
+ *
+ * The arguments here are the same as in
+ * connection_edge_process_relay_cell() below; this function is called
+ * from there when <b>conn</b> is defined and not in an open state.
+ */
+static int
+connection_edge_process_relay_cell_not_open(
+ relay_header_t *rh, cell_t *cell, circuit_t *circ,
+ edge_connection_t *conn, crypt_path_t *layer_hint)
+{
+ if (rh->command == RELAY_COMMAND_END) {
+ if (CIRCUIT_IS_ORIGIN(circ) && conn->base_.type == CONN_TYPE_AP) {
+ return connection_ap_process_end_not_open(rh, cell,
+ TO_ORIGIN_CIRCUIT(circ),
+ EDGE_TO_ENTRY_CONN(conn),
+ layer_hint);
+ } else {
+ /* we just got an 'end', don't need to send one */
+ conn->edge_has_sent_end = 1;
+ conn->end_reason = *(cell->payload+RELAY_HEADER_SIZE) |
+ END_STREAM_REASON_FLAG_REMOTE;
+ connection_mark_for_close(TO_CONN(conn));
+ return 0;
+ }
+ }
+
+ if (conn->base_.type == CONN_TYPE_AP &&
+ rh->command == RELAY_COMMAND_CONNECTED) {
+ tor_addr_t addr;
+ int ttl;
+ entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn);
+ tor_assert(CIRCUIT_IS_ORIGIN(circ));
+ if (conn->base_.state != AP_CONN_STATE_CONNECT_WAIT) {
+ log_fn(LOG_PROTOCOL_WARN, LD_APP,
+ "Got 'connected' while not in state connect_wait. Dropping.");
+ return 0;
+ }
+ CONNECTION_AP_EXPECT_NONPENDING(entry_conn);
+ conn->base_.state = AP_CONN_STATE_OPEN;
+ log_info(LD_APP,"'connected' received for circid %u streamid %d "
+ "after %d seconds.",
+ (unsigned)circ->n_circ_id,
+ rh->stream_id,
+ (int)(time(NULL) - conn->base_.timestamp_last_read_allowed));
+ if (connected_cell_parse(rh, cell, &addr, &ttl) < 0) {
+ log_fn(LOG_PROTOCOL_WARN, LD_APP,
+ "Got a badly formatted connected cell. Closing.");
+ connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
+ connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TORPROTOCOL);
+ return 0;
+ }
+ if (tor_addr_family(&addr) != AF_UNSPEC) {
+ /* The family is not UNSPEC: so we were given an address in the
+ * connected cell. (This is normal, except for BEGINDIR and onion
+ * service streams.) */
+ const sa_family_t family = tor_addr_family(&addr);
+ if (tor_addr_is_null(&addr) ||
+ (get_options()->ClientDNSRejectInternalAddresses &&
+ tor_addr_is_internal(&addr, 0))) {
+ log_info(LD_APP, "...but it claims the IP address was %s. Closing.",
+ fmt_addr(&addr));
+ connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
+ connection_mark_unattached_ap(entry_conn,
+ END_STREAM_REASON_TORPROTOCOL);
+ return 0;
+ }
+
+ if ((family == AF_INET && ! entry_conn->entry_cfg.ipv4_traffic) ||
+ (family == AF_INET6 && ! entry_conn->entry_cfg.ipv6_traffic)) {
+ log_fn(LOG_PROTOCOL_WARN, LD_APP,
+ "Got a connected cell to %s with unsupported address family."
+ " Closing.", fmt_addr(&addr));
+ connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
+ connection_mark_unattached_ap(entry_conn,
+ END_STREAM_REASON_TORPROTOCOL);
+ return 0;
+ }
+
+ client_dns_set_addressmap(entry_conn,
+ entry_conn->socks_request->address, &addr,
+ entry_conn->chosen_exit_name, ttl);
+
+ remap_event_helper(entry_conn, &addr);
+ }
+ circuit_log_path(LOG_INFO,LD_APP,TO_ORIGIN_CIRCUIT(circ));
+ /* don't send a socks reply to transparent conns */
+ tor_assert(entry_conn->socks_request != NULL);
+ if (!entry_conn->socks_request->has_finished) {
+ connection_ap_handshake_socks_reply(entry_conn, NULL, 0, 0);
+ }
+
+ /* Was it a linked dir conn? If so, a dir request just started to
+ * fetch something; this could be a bootstrap status milestone. */
+ log_debug(LD_APP, "considering");
+ if (TO_CONN(conn)->linked_conn &&
+ TO_CONN(conn)->linked_conn->type == CONN_TYPE_DIR) {
+ connection_t *dirconn = TO_CONN(conn)->linked_conn;
+ log_debug(LD_APP, "it is! %d", dirconn->purpose);
+ switch (dirconn->purpose) {
+ case DIR_PURPOSE_FETCH_CERTIFICATE:
+ if (consensus_is_waiting_for_certs())
+ control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_KEYS, 0);
+ break;
+ case DIR_PURPOSE_FETCH_CONSENSUS:
+ control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_STATUS, 0);
+ break;
+ case DIR_PURPOSE_FETCH_SERVERDESC:
+ case DIR_PURPOSE_FETCH_MICRODESC:
+ if (TO_DIR_CONN(dirconn)->router_purpose == ROUTER_PURPOSE_GENERAL)
+ control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_DESCRIPTORS,
+ count_loading_descriptors_progress());
+ break;
+ }
+ }
+ /* This is definitely a success, so forget about any pending data we
+ * had sent. */
+ if (entry_conn->pending_optimistic_data) {
+ buf_free(entry_conn->pending_optimistic_data);
+ entry_conn->pending_optimistic_data = NULL;
+ }
+
+ /* This is valid data at this point. Count it */
+ circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh->length);
+
+ /* handle anything that might have queued */
+ if (connection_edge_package_raw_inbuf(conn, 1, NULL) < 0) {
+ /* (We already sent an end cell if possible) */
+ connection_mark_for_close(TO_CONN(conn));
+ return 0;
+ }
+ return 0;
+ }
+ if (conn->base_.type == CONN_TYPE_AP &&
+ rh->command == RELAY_COMMAND_RESOLVED) {
+ return connection_edge_process_resolved_cell(conn, cell, rh);
+ }
+
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Got an unexpected relay command %d, in state %d (%s). Dropping.",
+ rh->command, conn->base_.state,
+ conn_state_to_string(conn->base_.type, conn->base_.state));
+ return 0; /* for forward compatibility, don't kill the circuit */
+// connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
+// connection_mark_for_close(conn);
+// return -1;
+}
+
+/** An incoming relay cell has arrived on circuit <b>circ</b>. If
+ * <b>conn</b> is NULL this is a control cell, else <b>cell</b> is
+ * destined for <b>conn</b>.
+ *
+ * If <b>layer_hint</b> is defined, then we're the origin of the
+ * circuit, and it specifies the hop that packaged <b>cell</b>.
+ *
+ * Return -reason if you want to warn and tear down the circuit, else 0.
+ */
+STATIC int
+connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
+ edge_connection_t *conn,
+ crypt_path_t *layer_hint)
+{
+ static int num_seen=0;
+ relay_header_t rh;
+ unsigned domain = layer_hint?LD_APP:LD_EXIT;
+ int reason;
+ int optimistic_data = 0; /* Set to 1 if we receive data on a stream
+ * that's in the EXIT_CONN_STATE_RESOLVING
+ * or EXIT_CONN_STATE_CONNECTING states. */
+
+ tor_assert(cell);
+ tor_assert(circ);
+
+ relay_header_unpack(&rh, cell->payload);
+// log_fn(LOG_DEBUG,"command %d stream %d", rh.command, rh.stream_id);
+ num_seen++;
+ log_debug(domain, "Now seen %d relay cells here (command %d, stream %d).",
+ num_seen, rh.command, rh.stream_id);
+
+ if (rh.length > RELAY_PAYLOAD_SIZE) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Relay cell length field too long. Closing circuit.");
+ return - END_CIRC_REASON_TORPROTOCOL;
+ }
+
+ if (rh.stream_id == 0) {
+ switch (rh.command) {
+ case RELAY_COMMAND_BEGIN:
+ case RELAY_COMMAND_CONNECTED:
+ case RELAY_COMMAND_END:
+ case RELAY_COMMAND_RESOLVE:
+ case RELAY_COMMAND_RESOLVED:
+ case RELAY_COMMAND_BEGIN_DIR:
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Relay command %d with zero "
+ "stream_id. Dropping.", (int)rh.command);
+ return 0;
+ default:
+ ;
+ }
+ }
+
+ /* either conn is NULL, in which case we've got a control cell, or else
+ * conn points to the recognized stream. */
+
+ if (conn && !connection_state_is_open(TO_CONN(conn))) {
+ if (conn->base_.type == CONN_TYPE_EXIT &&
+ (conn->base_.state == EXIT_CONN_STATE_CONNECTING ||
+ conn->base_.state == EXIT_CONN_STATE_RESOLVING) &&
+ rh.command == RELAY_COMMAND_DATA) {
+ /* Allow DATA cells to be delivered to an exit node in state
+ * EXIT_CONN_STATE_CONNECTING or EXIT_CONN_STATE_RESOLVING.
+ * This speeds up HTTP, for example. */
+ optimistic_data = 1;
+ } else if (rh.stream_id == 0 && rh.command == RELAY_COMMAND_DATA) {
+ log_warn(LD_BUG, "Somehow I had a connection that matched a "
+ "data cell with stream ID 0.");
+ } else {
+ return connection_edge_process_relay_cell_not_open(
+ &rh, cell, circ, conn, layer_hint);
+ }
+ }
+
+ switch (rh.command) {
+ case RELAY_COMMAND_DROP:
+ rep_hist_padding_count_read(PADDING_TYPE_DROP);
+// log_info(domain,"Got a relay-level padding cell. Dropping.");
+ return 0;
+ case RELAY_COMMAND_BEGIN:
+ case RELAY_COMMAND_BEGIN_DIR:
+ if (layer_hint &&
+ circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED) {
+ log_fn(LOG_PROTOCOL_WARN, LD_APP,
+ "Relay begin request unsupported at AP. Dropping.");
+ return 0;
+ }
+ if (circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED &&
+ layer_hint != TO_ORIGIN_CIRCUIT(circ)->cpath->prev) {
+ log_fn(LOG_PROTOCOL_WARN, LD_APP,
+ "Relay begin request to Hidden Service "
+ "from intermediary node. Dropping.");
+ return 0;
+ }
+ if (conn) {
+ log_fn(LOG_PROTOCOL_WARN, domain,
+ "Begin cell for known stream. Dropping.");
+ return 0;
+ }
+ if (rh.command == RELAY_COMMAND_BEGIN_DIR &&
+ circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED) {
+ /* Assign this circuit and its app-ward OR connection a unique ID,
+ * so that we can measure download times. The local edge and dir
+ * connection will be assigned the same ID when they are created
+ * and linked. */
+ static uint64_t next_id = 0;
+ circ->dirreq_id = ++next_id;
+ TO_OR_CIRCUIT(circ)->p_chan->dirreq_id = circ->dirreq_id;
+ }
+ return connection_exit_begin_conn(cell, circ);
+ case RELAY_COMMAND_DATA:
+ ++stats_n_data_cells_received;
+ if (( layer_hint && --layer_hint->deliver_window < 0) ||
+ (!layer_hint && --circ->deliver_window < 0)) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "(relay data) circ deliver_window below 0. Killing.");
+ if (conn) {
+ /* XXXX Do we actually need to do this? Will killing the circuit
+ * not send an END and mark the stream for close as appropriate? */
+ connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
+ connection_mark_for_close(TO_CONN(conn));
+ }
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
+ log_debug(domain,"circ deliver_window now %d.", layer_hint ?
+ layer_hint->deliver_window : circ->deliver_window);
+
+ circuit_consider_sending_sendme(circ, layer_hint);
+
+ if (rh.stream_id == 0) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Relay data cell with zero "
+ "stream_id. Dropping.");
+ return 0;
+ } else if (!conn) {
++ if (CIRCUIT_IS_ORIGIN(circ)) {
++ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
++ if (connection_half_edge_is_valid_data(ocirc->half_streams,
++ rh.stream_id)) {
++ circuit_read_valid_data(ocirc, rh.length);
++ log_info(domain,
++ "data cell on circ %u valid on half-closed "
++ "stream id %d", ocirc->global_identifier, rh.stream_id);
++ }
++ }
++
+ log_info(domain,"data cell dropped, unknown stream (streamid %d).",
+ rh.stream_id);
+ return 0;
+ }
+
+ if (--conn->deliver_window < 0) { /* is it below 0 after decrement? */
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "(relay data) conn deliver_window below 0. Killing.");
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
+ /* Total all valid application bytes delivered */
+ if (CIRCUIT_IS_ORIGIN(circ) && rh.length > 0) {
+ circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh.length);
+ }
+
+ stats_n_data_bytes_received += rh.length;
+ connection_buf_add((char*)(cell->payload + RELAY_HEADER_SIZE),
+ rh.length, TO_CONN(conn));
+
+#ifdef MEASUREMENTS_21206
+ /* Count number of RELAY_DATA cells received on a linked directory
+ * connection. */
+ connection_t *linked_conn = TO_CONN(conn)->linked_conn;
+
+ if (linked_conn && linked_conn->type == CONN_TYPE_DIR) {
+ ++(TO_DIR_CONN(linked_conn)->data_cells_received);
+ }
+#endif /* defined(MEASUREMENTS_21206) */
+
+ if (!optimistic_data) {
+ /* Only send a SENDME if we're not getting optimistic data; otherwise
+ * a SENDME could arrive before the CONNECTED.
+ */
+ connection_edge_consider_sending_sendme(conn);
+ }
+
+ return 0;
+ case RELAY_COMMAND_END:
+ reason = rh.length > 0 ?
+ get_uint8(cell->payload+RELAY_HEADER_SIZE) : END_STREAM_REASON_MISC;
+ if (!conn) {
++ if (CIRCUIT_IS_ORIGIN(circ)) {
++ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
++ if (connection_half_edge_is_valid_end(ocirc->half_streams,
++ rh.stream_id)) {
++
++ circuit_read_valid_data(ocirc, rh.length);
++ log_info(domain,
++ "end cell (%s) on circ %u valid on half-closed "
++ "stream id %d",
++ stream_end_reason_to_string(reason),
++ ocirc->global_identifier, rh.stream_id);
++ return 0;
++ }
++ }
+ log_info(domain,"end cell (%s) dropped, unknown stream.",
+ stream_end_reason_to_string(reason));
+ return 0;
+ }
+/* XXX add to this log_fn the exit node's nickname? */
+ log_info(domain,TOR_SOCKET_T_FORMAT": end cell (%s) for stream %d. "
+ "Removing stream.",
+ conn->base_.s,
+ stream_end_reason_to_string(reason),
+ conn->stream_id);
+ if (conn->base_.type == CONN_TYPE_AP) {
+ entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn);
+ if (entry_conn->socks_request &&
+ !entry_conn->socks_request->has_finished)
+ log_warn(LD_BUG,
+ "open stream hasn't sent socks answer yet? Closing.");
+ }
+ /* We just *got* an end; no reason to send one. */
+ conn->edge_has_sent_end = 1;
+ if (!conn->end_reason)
+ conn->end_reason = reason | END_STREAM_REASON_FLAG_REMOTE;
+ if (!conn->base_.marked_for_close) {
+ /* only mark it if not already marked. it's possible to
+ * get the 'end' right around when the client hangs up on us. */
+ connection_mark_and_flush(TO_CONN(conn));
+
+ /* Total all valid application bytes delivered */
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh.length);
+ }
+ }
+ return 0;
+ case RELAY_COMMAND_EXTEND:
+ case RELAY_COMMAND_EXTEND2: {
+ static uint64_t total_n_extend=0, total_nonearly=0;
+ total_n_extend++;
+ if (rh.stream_id) {
+ log_fn(LOG_PROTOCOL_WARN, domain,
+ "'extend' cell received for non-zero stream. Dropping.");
+ return 0;
+ }
+ if (cell->command != CELL_RELAY_EARLY &&
+ !networkstatus_get_param(NULL,"AllowNonearlyExtend",0,0,1)) {
+#define EARLY_WARNING_INTERVAL 3600
+ static ratelim_t early_warning_limit =
+ RATELIM_INIT(EARLY_WARNING_INTERVAL);
+ char *m;
+ if (cell->command == CELL_RELAY) {
+ ++total_nonearly;
+ if ((m = rate_limit_log(&early_warning_limit, approx_time()))) {
+ double percentage = ((double)total_nonearly)/total_n_extend;
+ percentage *= 100;
+ log_fn(LOG_PROTOCOL_WARN, domain, "EXTEND cell received, "
+ "but not via RELAY_EARLY. Dropping.%s", m);
+ log_fn(LOG_PROTOCOL_WARN, domain, " (We have dropped %.02f%% of "
+ "all EXTEND cells for this reason)", percentage);
+ tor_free(m);
+ }
+ } else {
+ log_fn(LOG_WARN, domain,
+ "EXTEND cell received, in a cell with type %d! Dropping.",
+ cell->command);
+ }
+ return 0;
+ }
+ return circuit_extend(cell, circ);
+ }
+ case RELAY_COMMAND_EXTENDED:
+ case RELAY_COMMAND_EXTENDED2:
+ if (!layer_hint) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "'extended' unsupported at non-origin. Dropping.");
+ return 0;
+ }
+ log_debug(domain,"Got an extended cell! Yay.");
+ {
+ extended_cell_t extended_cell;
+ if (extended_cell_parse(&extended_cell, rh.command,
+ (const uint8_t*)cell->payload+RELAY_HEADER_SIZE,
+ rh.length)<0) {
+ log_warn(LD_PROTOCOL,
+ "Can't parse EXTENDED cell; killing circuit.");
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
+ if ((reason = circuit_finish_handshake(TO_ORIGIN_CIRCUIT(circ),
+ &extended_cell.created_cell)) < 0) {
+ circuit_mark_for_close(circ, -reason);
+ return 0; /* We don't want to cause a warning, so we mark the circuit
+ * here. */
+ }
+ }
+ if ((reason=circuit_send_next_onion_skin(TO_ORIGIN_CIRCUIT(circ)))<0) {
+ log_info(domain,"circuit_send_next_onion_skin() failed.");
+ return reason;
+ }
+ /* Total all valid bytes delivered. */
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh.length);
+ }
+ return 0;
+ case RELAY_COMMAND_TRUNCATE:
+ if (layer_hint) {
+ log_fn(LOG_PROTOCOL_WARN, LD_APP,
+ "'truncate' unsupported at origin. Dropping.");
+ return 0;
+ }
+ if (circ->n_hop) {
+ if (circ->n_chan)
+ log_warn(LD_BUG, "n_chan and n_hop set on the same circuit!");
+ extend_info_free(circ->n_hop);
+ circ->n_hop = NULL;
+ tor_free(circ->n_chan_create_cell);
+ circuit_set_state(circ, CIRCUIT_STATE_OPEN);
+ }
+ if (circ->n_chan) {
+ uint8_t trunc_reason = get_uint8(cell->payload + RELAY_HEADER_SIZE);
+ circuit_clear_cell_queue(circ, circ->n_chan);
+ channel_send_destroy(circ->n_circ_id, circ->n_chan,
+ trunc_reason);
+ circuit_set_n_circid_chan(circ, 0, NULL);
+ }
+ log_debug(LD_EXIT, "Processed 'truncate', replying.");
+ {
+ char payload[1];
+ payload[0] = (char)END_CIRC_REASON_REQUESTED;
+ relay_send_command_from_edge(0, circ, RELAY_COMMAND_TRUNCATED,
+ payload, sizeof(payload), NULL);
+ }
+ return 0;
+ case RELAY_COMMAND_TRUNCATED:
+ if (!layer_hint) {
+ log_fn(LOG_PROTOCOL_WARN, LD_EXIT,
+ "'truncated' unsupported at non-origin. Dropping.");
+ return 0;
+ }
- circuit_truncated(TO_ORIGIN_CIRCUIT(circ), layer_hint,
++
++ /* Count the truncated as valid, for completeness. The
++ * circuit is being torn down anyway, though. */
++ if (CIRCUIT_IS_ORIGIN(circ)) {
++ circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ),
++ rh.length);
++ }
++ circuit_truncated(TO_ORIGIN_CIRCUIT(circ),
+ get_uint8(cell->payload + RELAY_HEADER_SIZE));
+ return 0;
+ case RELAY_COMMAND_CONNECTED:
+ if (conn) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "'connected' unsupported while open. Closing circ.");
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
++
++ if (CIRCUIT_IS_ORIGIN(circ)) {
++ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
++ if (connection_half_edge_is_valid_connected(ocirc->half_streams,
++ rh.stream_id)) {
++ circuit_read_valid_data(ocirc, rh.length);
++ log_info(domain,
++ "connected cell on circ %u valid on half-closed "
++ "stream id %d", ocirc->global_identifier, rh.stream_id);
++ return 0;
++ }
++ }
++
+ log_info(domain,
+ "'connected' received on circid %u for streamid %d, "
+ "no conn attached anymore. Ignoring.",
+ (unsigned)circ->n_circ_id, rh.stream_id);
+ return 0;
+ case RELAY_COMMAND_SENDME:
+ if (!rh.stream_id) {
+ if (layer_hint) {
+ if (layer_hint->package_window + CIRCWINDOW_INCREMENT >
+ CIRCWINDOW_START_MAX) {
+ static struct ratelim_t exit_warn_ratelim = RATELIM_INIT(600);
+ log_fn_ratelim(&exit_warn_ratelim, LOG_WARN, LD_PROTOCOL,
+ "Unexpected sendme cell from exit relay. "
+ "Closing circ.");
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
+ layer_hint->package_window += CIRCWINDOW_INCREMENT;
+ log_debug(LD_APP,"circ-level sendme at origin, packagewindow %d.",
+ layer_hint->package_window);
+ circuit_resume_edge_reading(circ, layer_hint);
+
+ /* We count circuit-level sendme's as valid delivered data because
+ * they are rate limited.
+ */
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ),
+ rh.length);
+ }
+
+ } else {
+ if (circ->package_window + CIRCWINDOW_INCREMENT >
+ CIRCWINDOW_START_MAX) {
+ static struct ratelim_t client_warn_ratelim = RATELIM_INIT(600);
+ log_fn_ratelim(&client_warn_ratelim,LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Unexpected sendme cell from client. "
+ "Closing circ (window %d).",
+ circ->package_window);
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
+ circ->package_window += CIRCWINDOW_INCREMENT;
+ log_debug(LD_APP,
+ "circ-level sendme at non-origin, packagewindow %d.",
+ circ->package_window);
+ circuit_resume_edge_reading(circ, layer_hint);
+ }
+ return 0;
+ }
+ if (!conn) {
++ if (CIRCUIT_IS_ORIGIN(circ)) {
++ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
++ if (connection_half_edge_is_valid_sendme(ocirc->half_streams,
++ rh.stream_id)) {
++ circuit_read_valid_data(ocirc, rh.length);
++ log_info(domain,
++ "sendme cell on circ %u valid on half-closed "
++ "stream id %d", ocirc->global_identifier, rh.stream_id);
++ }
++ }
++
+ log_info(domain,"sendme cell dropped, unknown stream (streamid %d).",
+ rh.stream_id);
+ return 0;
+ }
+
+ /* Don't allow the other endpoint to request more than our maximum
+ * (i.e. initial) stream SENDME window worth of data. Well-behaved
+ * stock clients will not request more than this max (as per the check
+ * in the while loop of connection_edge_consider_sending_sendme()).
+ */
+ if (conn->package_window + STREAMWINDOW_INCREMENT >
+ STREAMWINDOW_START_MAX) {
+ static struct ratelim_t stream_warn_ratelim = RATELIM_INIT(600);
+ log_fn_ratelim(&stream_warn_ratelim, LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Unexpected stream sendme cell. Closing circ (window %d).",
+ conn->package_window);
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
+
+ /* At this point, the stream sendme is valid */
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ),
+ rh.length);
+ }
+
+ conn->package_window += STREAMWINDOW_INCREMENT;
+ log_debug(domain,"stream-level sendme, packagewindow now %d.",
+ conn->package_window);
+ if (circuit_queue_streams_are_blocked(circ)) {
+ /* Still waiting for queue to flush; don't touch conn */
+ return 0;
+ }
+ connection_start_reading(TO_CONN(conn));
+ /* handle whatever might still be on the inbuf */
+ if (connection_edge_package_raw_inbuf(conn, 1, NULL) < 0) {
+ /* (We already sent an end cell if possible) */
+ connection_mark_for_close(TO_CONN(conn));
+ return 0;
+ }
+ return 0;
+ case RELAY_COMMAND_RESOLVE:
+ if (layer_hint) {
+ log_fn(LOG_PROTOCOL_WARN, LD_APP,
+ "resolve request unsupported at AP; dropping.");
+ return 0;
+ } else if (conn) {
+ log_fn(LOG_PROTOCOL_WARN, domain,
+ "resolve request for known stream; dropping.");
+ return 0;
+ } else if (circ->purpose != CIRCUIT_PURPOSE_OR) {
+ log_fn(LOG_PROTOCOL_WARN, domain,
+ "resolve request on circ with purpose %d; dropping",
+ circ->purpose);
+ return 0;
+ }
+ connection_exit_begin_resolve(cell, TO_OR_CIRCUIT(circ));
+ return 0;
+ case RELAY_COMMAND_RESOLVED:
+ if (conn) {
+ log_fn(LOG_PROTOCOL_WARN, domain,
+ "'resolved' unsupported while open. Closing circ.");
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
++
++ if (CIRCUIT_IS_ORIGIN(circ)) {
++ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
++ if (connection_half_edge_is_valid_resolved(ocirc->half_streams,
++ rh.stream_id)) {
++ circuit_read_valid_data(ocirc, rh.length);
++ log_info(domain,
++ "resolved cell on circ %u valid on half-closed "
++ "stream id %d", ocirc->global_identifier, rh.stream_id);
++ return 0;
++ }
++ }
++
+ log_info(domain,
+ "'resolved' received, no conn attached anymore. Ignoring.");
+ return 0;
+ case RELAY_COMMAND_ESTABLISH_INTRO:
+ case RELAY_COMMAND_ESTABLISH_RENDEZVOUS:
+ case RELAY_COMMAND_INTRODUCE1:
+ case RELAY_COMMAND_INTRODUCE2:
+ case RELAY_COMMAND_INTRODUCE_ACK:
+ case RELAY_COMMAND_RENDEZVOUS1:
+ case RELAY_COMMAND_RENDEZVOUS2:
+ case RELAY_COMMAND_INTRO_ESTABLISHED:
+ case RELAY_COMMAND_RENDEZVOUS_ESTABLISHED:
+ rend_process_relay_cell(circ, layer_hint,
+ rh.command, rh.length,
+ cell->payload+RELAY_HEADER_SIZE);
+ return 0;
+ }
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Received unknown relay command %d. Perhaps the other side is using "
+ "a newer version of Tor? Dropping.",
+ rh.command);
+ return 0; /* for forward compatibility, don't kill the circuit */
+}
+
+/** How many relay_data cells have we built, ever? */
+uint64_t stats_n_data_cells_packaged = 0;
+/** How many bytes of data have we put in relay_data cells have we built,
+ * ever? This would be RELAY_PAYLOAD_SIZE*stats_n_data_cells_packaged if
+ * every relay cell we ever sent were completely full of data. */
+uint64_t stats_n_data_bytes_packaged = 0;
+/** How many relay_data cells have we received, ever? */
+uint64_t stats_n_data_cells_received = 0;
+/** How many bytes of data have we received relay_data cells, ever? This would
+ * be RELAY_PAYLOAD_SIZE*stats_n_data_cells_packaged if every relay cell we
+ * ever received were completely full of data. */
+uint64_t stats_n_data_bytes_received = 0;
+
+/** If <b>conn</b> has an entire relay payload of bytes on its inbuf (or
+ * <b>package_partial</b> is true), and the appropriate package windows aren't
+ * empty, grab a cell and send it down the circuit.
+ *
+ * If *<b>max_cells</b> is given, package no more than max_cells. Decrement
+ * *<b>max_cells</b> by the number of cells packaged.
+ *
+ * Return -1 (and send a RELAY_COMMAND_END cell if necessary) if conn should
+ * be marked for close, else return 0.
+ */
+int
+connection_edge_package_raw_inbuf(edge_connection_t *conn, int package_partial,
+ int *max_cells)
+{
+ size_t bytes_to_process, length;
+ char payload[CELL_PAYLOAD_SIZE];
+ circuit_t *circ;
+ const unsigned domain = conn->base_.type == CONN_TYPE_AP ? LD_APP : LD_EXIT;
+ int sending_from_optimistic = 0;
+ entry_connection_t *entry_conn =
+ conn->base_.type == CONN_TYPE_AP ? EDGE_TO_ENTRY_CONN(conn) : NULL;
+ const int sending_optimistically =
+ entry_conn &&
+ conn->base_.type == CONN_TYPE_AP &&
+ conn->base_.state != AP_CONN_STATE_OPEN;
+ crypt_path_t *cpath_layer = conn->cpath_layer;
+
+ tor_assert(conn);
+
+ if (conn->base_.marked_for_close) {
+ log_warn(LD_BUG,
+ "called on conn that's already marked for close at %s:%d.",
+ conn->base_.marked_for_close_file, conn->base_.marked_for_close);
+ return 0;
+ }
+
+ if (max_cells && *max_cells <= 0)
+ return 0;
+
+ repeat_connection_edge_package_raw_inbuf:
+
+ circ = circuit_get_by_edge_conn(conn);
+ if (!circ) {
+ log_info(domain,"conn has no circuit! Closing.");
+ conn->end_reason = END_STREAM_REASON_CANT_ATTACH;
+ return -1;
+ }
+
+ if (circuit_consider_stop_edge_reading(circ, cpath_layer))
+ return 0;
+
+ if (conn->package_window <= 0) {
+ log_info(domain,"called with package_window %d. Skipping.",
+ conn->package_window);
+ connection_stop_reading(TO_CONN(conn));
+ return 0;
+ }
+
+ sending_from_optimistic = entry_conn &&
+ entry_conn->sending_optimistic_data != NULL;
+
+ if (PREDICT_UNLIKELY(sending_from_optimistic)) {
+ bytes_to_process = buf_datalen(entry_conn->sending_optimistic_data);
+ if (PREDICT_UNLIKELY(!bytes_to_process)) {
+ log_warn(LD_BUG, "sending_optimistic_data was non-NULL but empty");
+ bytes_to_process = connection_get_inbuf_len(TO_CONN(conn));
+ sending_from_optimistic = 0;
+ }
+ } else {
+ bytes_to_process = connection_get_inbuf_len(TO_CONN(conn));
+ }
+
+ if (!bytes_to_process)
+ return 0;
+
+ if (!package_partial && bytes_to_process < RELAY_PAYLOAD_SIZE)
+ return 0;
+
+ if (bytes_to_process > RELAY_PAYLOAD_SIZE) {
+ length = RELAY_PAYLOAD_SIZE;
+ } else {
+ length = bytes_to_process;
+ }
+ stats_n_data_bytes_packaged += length;
+ stats_n_data_cells_packaged += 1;
+
+ if (PREDICT_UNLIKELY(sending_from_optimistic)) {
+ /* XXXX We could be more efficient here by sometimes packing
+ * previously-sent optimistic data in the same cell with data
+ * from the inbuf. */
+ buf_get_bytes(entry_conn->sending_optimistic_data, payload, length);
+ if (!buf_datalen(entry_conn->sending_optimistic_data)) {
+ buf_free(entry_conn->sending_optimistic_data);
+ entry_conn->sending_optimistic_data = NULL;
+ }
+ } else {
+ connection_buf_get_bytes(payload, length, TO_CONN(conn));
+ }
+
+ log_debug(domain,TOR_SOCKET_T_FORMAT": Packaging %d bytes (%d waiting).",
+ conn->base_.s,
+ (int)length, (int)connection_get_inbuf_len(TO_CONN(conn)));
+
+ if (sending_optimistically && !sending_from_optimistic) {
+ /* This is new optimistic data; remember it in case we need to detach and
+ retry */
+ if (!entry_conn->pending_optimistic_data)
+ entry_conn->pending_optimistic_data = buf_new();
+ buf_add(entry_conn->pending_optimistic_data, payload, length);
+ }
+
+ if (connection_edge_send_command(conn, RELAY_COMMAND_DATA,
+ payload, length) < 0 ) {
+ /* circuit got marked for close, don't continue, don't need to mark conn */
+ return 0;
+ }
+
+ if (!cpath_layer) { /* non-rendezvous exit */
+ tor_assert(circ->package_window > 0);
+ circ->package_window--;
+ } else { /* we're an AP, or an exit on a rendezvous circ */
+ tor_assert(cpath_layer->package_window > 0);
+ cpath_layer->package_window--;
+ }
+
+ if (--conn->package_window <= 0) { /* is it 0 after decrement? */
+ connection_stop_reading(TO_CONN(conn));
+ log_debug(domain,"conn->package_window reached 0.");
+ circuit_consider_stop_edge_reading(circ, cpath_layer);
+ return 0; /* don't process the inbuf any more */
+ }
+ log_debug(domain,"conn->package_window is now %d",conn->package_window);
+
+ if (max_cells) {
+ *max_cells -= 1;
+ if (*max_cells <= 0)
+ return 0;
+ }
+
+ /* handle more if there's more, or return 0 if there isn't */
+ goto repeat_connection_edge_package_raw_inbuf;
+}
+
+/** Called when we've just received a relay data cell, when
+ * we've just finished flushing all bytes to stream <b>conn</b>,
+ * or when we've flushed *some* bytes to the stream <b>conn</b>.
+ *
+ * If conn->outbuf is not too full, and our deliver window is
+ * low, send back a suitable number of stream-level sendme cells.
+ */
+void
+connection_edge_consider_sending_sendme(edge_connection_t *conn)
+{
+ circuit_t *circ;
+
+ if (connection_outbuf_too_full(TO_CONN(conn)))
+ return;
+
+ circ = circuit_get_by_edge_conn(conn);
+ if (!circ) {
+ /* this can legitimately happen if the destroy has already
+ * arrived and torn down the circuit */
+ log_info(LD_APP,"No circuit associated with conn. Skipping.");
+ return;
+ }
+
+ while (conn->deliver_window <= STREAMWINDOW_START - STREAMWINDOW_INCREMENT) {
+ log_debug(conn->base_.type == CONN_TYPE_AP ?LD_APP:LD_EXIT,
+ "Outbuf %d, Queuing stream sendme.",
+ (int)conn->base_.outbuf_flushlen);
+ conn->deliver_window += STREAMWINDOW_INCREMENT;
+ if (connection_edge_send_command(conn, RELAY_COMMAND_SENDME,
+ NULL, 0) < 0) {
+ log_warn(LD_APP,"connection_edge_send_command failed. Skipping.");
+ return; /* the circuit's closed, don't continue */
+ }
+ }
+}
+
+/** The circuit <b>circ</b> has received a circuit-level sendme
+ * (on hop <b>layer_hint</b>, if we're the OP). Go through all the
+ * attached streams and let them resume reading and packaging, if
+ * their stream windows allow it.
+ */
+static void
+circuit_resume_edge_reading(circuit_t *circ, crypt_path_t *layer_hint)
+{
+ if (circuit_queue_streams_are_blocked(circ)) {
+ log_debug(layer_hint?LD_APP:LD_EXIT,"Too big queue, no resuming");
+ return;
+ }
+ log_debug(layer_hint?LD_APP:LD_EXIT,"resuming");
+
+ if (CIRCUIT_IS_ORIGIN(circ))
+ circuit_resume_edge_reading_helper(TO_ORIGIN_CIRCUIT(circ)->p_streams,
+ circ, layer_hint);
+ else
+ circuit_resume_edge_reading_helper(TO_OR_CIRCUIT(circ)->n_streams,
+ circ, layer_hint);
+}
+
+void
+stream_choice_seed_weak_rng(void)
+{
+ crypto_seed_weak_rng(&stream_choice_rng);
+}
+
+/** A helper function for circuit_resume_edge_reading() above.
+ * The arguments are the same, except that <b>conn</b> is the head
+ * of a linked list of edge streams that should each be considered.
+ */
+static int
+circuit_resume_edge_reading_helper(edge_connection_t *first_conn,
+ circuit_t *circ,
+ crypt_path_t *layer_hint)
+{
+ edge_connection_t *conn;
+ int n_packaging_streams, n_streams_left;
+ int packaged_this_round;
+ int cells_on_queue;
+ int cells_per_conn;
+ edge_connection_t *chosen_stream = NULL;
+ int max_to_package;
+
+ if (first_conn == NULL) {
+ /* Don't bother to try to do the rest of this if there are no connections
+ * to resume. */
+ return 0;
+ }
+
+ /* How many cells do we have space for? It will be the minimum of
+ * the number needed to exhaust the package window, and the minimum
+ * needed to fill the cell queue. */
+ max_to_package = circ->package_window;
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ cells_on_queue = circ->n_chan_cells.n;
+ } else {
+ or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
+ cells_on_queue = or_circ->p_chan_cells.n;
+ }
+ if (CELL_QUEUE_HIGHWATER_SIZE - cells_on_queue < max_to_package)
+ max_to_package = CELL_QUEUE_HIGHWATER_SIZE - cells_on_queue;
+
+ /* Once we used to start listening on the streams in the order they
+ * appeared in the linked list. That leads to starvation on the
+ * streams that appeared later on the list, since the first streams
+ * would always get to read first. Instead, we just pick a random
+ * stream on the list, and enable reading for streams starting at that
+ * point (and wrapping around as if the list were circular). It would
+ * probably be better to actually remember which streams we've
+ * serviced in the past, but this is simple and effective. */
+
+ /* Select a stream uniformly at random from the linked list. We
+ * don't need cryptographic randomness here. */
+ {
+ int num_streams = 0;
+ for (conn = first_conn; conn; conn = conn->next_stream) {
+ num_streams++;
+ if (tor_weak_random_one_in_n(&stream_choice_rng, num_streams)) {
+ chosen_stream = conn;
+ }
+ /* Invariant: chosen_stream has been chosen uniformly at random from
+ * among the first num_streams streams on first_conn.
+ *
+ * (Note that we iterate over every stream on the circuit, so that after
+ * we've considered the first stream, we've chosen it with P=1; and
+ * after we consider the second stream, we've switched to it with P=1/2
+ * and stayed with the first stream with P=1/2; and after we've
+ * considered the third stream, we've switched to it with P=1/3 and
+ * remained with one of the first two streams with P=(2/3), giving each
+ * one P=(1/2)(2/3) )=(1/3).) */
+ }
+ }
+
+ /* Count how many non-marked streams there are that have anything on
+ * their inbuf, and enable reading on all of the connections. */
+ n_packaging_streams = 0;
+ /* Activate reading starting from the chosen stream */
+ for (conn=chosen_stream; conn; conn = conn->next_stream) {
+ /* Start reading for the streams starting from here */
+ if (conn->base_.marked_for_close || conn->package_window <= 0)
+ continue;
+ if (!layer_hint || conn->cpath_layer == layer_hint) {
+ connection_start_reading(TO_CONN(conn));
+
+ if (connection_get_inbuf_len(TO_CONN(conn)) > 0)
+ ++n_packaging_streams;
+ }
+ }
+ /* Go back and do the ones we skipped, circular-style */
+ for (conn = first_conn; conn != chosen_stream; conn = conn->next_stream) {
+ if (conn->base_.marked_for_close || conn->package_window <= 0)
+ continue;
+ if (!layer_hint || conn->cpath_layer == layer_hint) {
+ connection_start_reading(TO_CONN(conn));
+
+ if (connection_get_inbuf_len(TO_CONN(conn)) > 0)
+ ++n_packaging_streams;
+ }
+ }
+
+ if (n_packaging_streams == 0) /* avoid divide-by-zero */
+ return 0;
+
+ again:
+
+ cells_per_conn = CEIL_DIV(max_to_package, n_packaging_streams);
+
+ packaged_this_round = 0;
+ n_streams_left = 0;
+
+ /* Iterate over all connections. Package up to cells_per_conn cells on
+ * each. Update packaged_this_round with the total number of cells
+ * packaged, and n_streams_left with the number that still have data to
+ * package.
+ */
+ for (conn=first_conn; conn; conn=conn->next_stream) {
+ if (conn->base_.marked_for_close || conn->package_window <= 0)
+ continue;
+ if (!layer_hint || conn->cpath_layer == layer_hint) {
+ int n = cells_per_conn, r;
+ /* handle whatever might still be on the inbuf */
+ r = connection_edge_package_raw_inbuf(conn, 1, &n);
+
+ /* Note how many we packaged */
+ packaged_this_round += (cells_per_conn-n);
+
+ if (r<0) {
+ /* Problem while packaging. (We already sent an end cell if
+ * possible) */
+ connection_mark_for_close(TO_CONN(conn));
+ continue;
+ }
+
+ /* If there's still data to read, we'll be coming back to this stream. */
+ if (connection_get_inbuf_len(TO_CONN(conn)))
+ ++n_streams_left;
+
+ /* If the circuit won't accept any more data, return without looking
+ * at any more of the streams. Any connections that should be stopped
+ * have already been stopped by connection_edge_package_raw_inbuf. */
+ if (circuit_consider_stop_edge_reading(circ, layer_hint))
+ return -1;
+ /* XXXX should we also stop immediately if we fill up the cell queue?
+ * Probably. */
+ }
+ }
+
+ /* If we made progress, and we are willing to package more, and there are
+ * any streams left that want to package stuff... try again!
+ */
+ if (packaged_this_round && packaged_this_round < max_to_package &&
+ n_streams_left) {
+ max_to_package -= packaged_this_round;
+ n_packaging_streams = n_streams_left;
+ goto again;
+ }
+
+ return 0;
+}
+
+/** Check if the package window for <b>circ</b> is empty (at
+ * hop <b>layer_hint</b> if it's defined).
+ *
+ * If yes, tell edge streams to stop reading and return 1.
+ * Else return 0.
+ */
+static int
+circuit_consider_stop_edge_reading(circuit_t *circ, crypt_path_t *layer_hint)
+{
+ edge_connection_t *conn = NULL;
+ unsigned domain = layer_hint ? LD_APP : LD_EXIT;
+
+ if (!layer_hint) {
+ or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
+ log_debug(domain,"considering circ->package_window %d",
+ circ->package_window);
+ if (circ->package_window <= 0) {
+ log_debug(domain,"yes, not-at-origin. stopped.");
+ for (conn = or_circ->n_streams; conn; conn=conn->next_stream)
+ connection_stop_reading(TO_CONN(conn));
+ return 1;
+ }
+ return 0;
+ }
+ /* else, layer hint is defined, use it */
+ log_debug(domain,"considering layer_hint->package_window %d",
+ layer_hint->package_window);
+ if (layer_hint->package_window <= 0) {
+ log_debug(domain,"yes, at-origin. stopped.");
+ for (conn = TO_ORIGIN_CIRCUIT(circ)->p_streams; conn;
+ conn=conn->next_stream) {
+ if (conn->cpath_layer == layer_hint)
+ connection_stop_reading(TO_CONN(conn));
+ }
+ return 1;
+ }
+ return 0;
+}
+
+/** Check if the deliver_window for circuit <b>circ</b> (at hop
+ * <b>layer_hint</b> if it's defined) is low enough that we should
+ * send a circuit-level sendme back down the circuit. If so, send
+ * enough sendmes that the window would be overfull if we sent any
+ * more.
+ */
+static void
+circuit_consider_sending_sendme(circuit_t *circ, crypt_path_t *layer_hint)
+{
+// log_fn(LOG_INFO,"Considering: layer_hint is %s",
+// layer_hint ? "defined" : "null");
+ while ((layer_hint ? layer_hint->deliver_window : circ->deliver_window) <=
+ CIRCWINDOW_START - CIRCWINDOW_INCREMENT) {
+ log_debug(LD_CIRC,"Queuing circuit sendme.");
+ if (layer_hint)
+ layer_hint->deliver_window += CIRCWINDOW_INCREMENT;
+ else
+ circ->deliver_window += CIRCWINDOW_INCREMENT;
+ if (relay_send_command_from_edge(0, circ, RELAY_COMMAND_SENDME,
+ NULL, 0, layer_hint) < 0) {
+ log_warn(LD_CIRC,
+ "relay_send_command_from_edge failed. Circuit's closed.");
+ return; /* the circuit's closed, don't continue */
+ }
+ }
+}
+
+/** The total number of cells we have allocated. */
+static size_t total_cells_allocated = 0;
+
+/** Release storage held by <b>cell</b>. */
+static inline void
+packed_cell_free_unchecked(packed_cell_t *cell)
+{
+ --total_cells_allocated;
+ tor_free(cell);
+}
+
+/** Allocate and return a new packed_cell_t. */
+STATIC packed_cell_t *
+packed_cell_new(void)
+{
+ ++total_cells_allocated;
+ return tor_malloc_zero(sizeof(packed_cell_t));
+}
+
+/** Return a packed cell used outside by channel_t lower layer */
+void
+packed_cell_free_(packed_cell_t *cell)
+{
+ if (!cell)
+ return;
+ packed_cell_free_unchecked(cell);
+}
+
+/** Log current statistics for cell pool allocation at log level
+ * <b>severity</b>. */
+void
+dump_cell_pool_usage(int severity)
+{
+ int n_circs = 0;
+ int n_cells = 0;
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, c) {
+ n_cells += c->n_chan_cells.n;
+ if (!CIRCUIT_IS_ORIGIN(c))
+ n_cells += TO_OR_CIRCUIT(c)->p_chan_cells.n;
+ ++n_circs;
+ }
+ SMARTLIST_FOREACH_END(c);
+ tor_log(severity, LD_MM,
+ "%d cells allocated on %d circuits. %d cells leaked.",
+ n_cells, n_circs, (int)total_cells_allocated - n_cells);
+}
+
+/** Allocate a new copy of packed <b>cell</b>. */
+static inline packed_cell_t *
+packed_cell_copy(const cell_t *cell, int wide_circ_ids)
+{
+ packed_cell_t *c = packed_cell_new();
+ cell_pack(c, cell, wide_circ_ids);
+ return c;
+}
+
+/** Append <b>cell</b> to the end of <b>queue</b>. */
+void
+cell_queue_append(cell_queue_t *queue, packed_cell_t *cell)
+{
+ TOR_SIMPLEQ_INSERT_TAIL(&queue->head, cell, next);
+ ++queue->n;
+}
+
+/** Append a newly allocated copy of <b>cell</b> to the end of the
+ * <b>exitward</b> (or app-ward) <b>queue</b> of <b>circ</b>. If
+ * <b>use_stats</b> is true, record statistics about the cell.
+ */
+void
+cell_queue_append_packed_copy(circuit_t *circ, cell_queue_t *queue,
+ int exitward, const cell_t *cell,
+ int wide_circ_ids, int use_stats)
+{
+ packed_cell_t *copy = packed_cell_copy(cell, wide_circ_ids);
+ (void)circ;
+ (void)exitward;
+ (void)use_stats;
+
+ copy->inserted_timestamp = monotime_coarse_get_stamp();
+
+ cell_queue_append(queue, copy);
+}
+
+/** Initialize <b>queue</b> as an empty cell queue. */
+void
+cell_queue_init(cell_queue_t *queue)
+{
+ memset(queue, 0, sizeof(cell_queue_t));
+ TOR_SIMPLEQ_INIT(&queue->head);
+}
+
+/** Remove and free every cell in <b>queue</b>. */
+void
+cell_queue_clear(cell_queue_t *queue)
+{
+ packed_cell_t *cell;
+ while ((cell = TOR_SIMPLEQ_FIRST(&queue->head))) {
+ TOR_SIMPLEQ_REMOVE_HEAD(&queue->head, next);
+ packed_cell_free_unchecked(cell);
+ }
+ TOR_SIMPLEQ_INIT(&queue->head);
+ queue->n = 0;
+}
+
+/** Extract and return the cell at the head of <b>queue</b>; return NULL if
+ * <b>queue</b> is empty. */
+STATIC packed_cell_t *
+cell_queue_pop(cell_queue_t *queue)
+{
+ packed_cell_t *cell = TOR_SIMPLEQ_FIRST(&queue->head);
+ if (!cell)
+ return NULL;
+ TOR_SIMPLEQ_REMOVE_HEAD(&queue->head, next);
+ --queue->n;
+ return cell;
+}
+
+/** Initialize <b>queue</b> as an empty cell queue. */
+void
+destroy_cell_queue_init(destroy_cell_queue_t *queue)
+{
+ memset(queue, 0, sizeof(destroy_cell_queue_t));
+ TOR_SIMPLEQ_INIT(&queue->head);
+}
+
+/** Remove and free every cell in <b>queue</b>. */
+void
+destroy_cell_queue_clear(destroy_cell_queue_t *queue)
+{
+ destroy_cell_t *cell;
+ while ((cell = TOR_SIMPLEQ_FIRST(&queue->head))) {
+ TOR_SIMPLEQ_REMOVE_HEAD(&queue->head, next);
+ tor_free(cell);
+ }
+ TOR_SIMPLEQ_INIT(&queue->head);
+ queue->n = 0;
+}
+
+/** Extract and return the cell at the head of <b>queue</b>; return NULL if
+ * <b>queue</b> is empty. */
+STATIC destroy_cell_t *
+destroy_cell_queue_pop(destroy_cell_queue_t *queue)
+{
+ destroy_cell_t *cell = TOR_SIMPLEQ_FIRST(&queue->head);
+ if (!cell)
+ return NULL;
+ TOR_SIMPLEQ_REMOVE_HEAD(&queue->head, next);
+ --queue->n;
+ return cell;
+}
+
+/** Append a destroy cell for <b>circid</b> to <b>queue</b>. */
+void
+destroy_cell_queue_append(destroy_cell_queue_t *queue,
+ circid_t circid,
+ uint8_t reason)
+{
+ destroy_cell_t *cell = tor_malloc_zero(sizeof(destroy_cell_t));
+ cell->circid = circid;
+ cell->reason = reason;
+ /* Not yet used, but will be required for OOM handling. */
+ cell->inserted_timestamp = monotime_coarse_get_stamp();
+
+ TOR_SIMPLEQ_INSERT_TAIL(&queue->head, cell, next);
+ ++queue->n;
+}
+
+/** Convert a destroy_cell_t to a newly allocated cell_t. Frees its input. */
+static packed_cell_t *
+destroy_cell_to_packed_cell(destroy_cell_t *inp, int wide_circ_ids)
+{
+ packed_cell_t *packed = packed_cell_new();
+ cell_t cell;
+ memset(&cell, 0, sizeof(cell));
+ cell.circ_id = inp->circid;
+ cell.command = CELL_DESTROY;
+ cell.payload[0] = inp->reason;
+ cell_pack(packed, &cell, wide_circ_ids);
+
+ tor_free(inp);
+ return packed;
+}
+
+/** Return the total number of bytes used for each packed_cell in a queue.
+ * Approximate. */
+size_t
+packed_cell_mem_cost(void)
+{
+ return sizeof(packed_cell_t);
+}
+
+/* DOCDOC */
+size_t
+cell_queues_get_total_allocation(void)
+{
+ return total_cells_allocated * packed_cell_mem_cost();
+}
+
+/** How long after we've been low on memory should we try to conserve it? */
+#define MEMORY_PRESSURE_INTERVAL (30*60)
+
+/** The time at which we were last low on memory. */
+static time_t last_time_under_memory_pressure = 0;
+
+/** Check whether we've got too much space used for cells. If so,
+ * call the OOM handler and return 1. Otherwise, return 0. */
+STATIC int
+cell_queues_check_size(void)
+{
+ time_t now = time(NULL);
+ size_t alloc = cell_queues_get_total_allocation();
+ alloc += buf_get_total_allocation();
+ alloc += tor_compress_get_total_allocation();
+ const size_t rend_cache_total = rend_cache_get_total_allocation();
+ alloc += rend_cache_total;
+ const size_t geoip_client_cache_total =
+ geoip_client_cache_total_allocation();
+ alloc += geoip_client_cache_total;
+ const size_t dns_cache_total = dns_cache_total_allocation();
+ alloc += dns_cache_total;
+ if (alloc >= get_options()->MaxMemInQueues_low_threshold) {
+ last_time_under_memory_pressure = approx_time();
+ if (alloc >= get_options()->MaxMemInQueues) {
+ /* If we're spending over 20% of the memory limit on hidden service
+ * descriptors, free them until we're down to 10%. Do the same for geoip
+ * client cache. */
+ if (rend_cache_total > get_options()->MaxMemInQueues / 5) {
+ const size_t bytes_to_remove =
+ rend_cache_total - (size_t)(get_options()->MaxMemInQueues / 10);
+ alloc -= hs_cache_handle_oom(now, bytes_to_remove);
+ }
+ if (geoip_client_cache_total > get_options()->MaxMemInQueues / 5) {
+ const size_t bytes_to_remove =
+ geoip_client_cache_total -
+ (size_t)(get_options()->MaxMemInQueues / 10);
+ alloc -= geoip_client_cache_handle_oom(now, bytes_to_remove);
+ }
+ if (dns_cache_total > get_options()->MaxMemInQueues / 5) {
+ const size_t bytes_to_remove =
+ dns_cache_total - (size_t)(get_options()->MaxMemInQueues / 10);
+ alloc -= dns_cache_handle_oom(now, bytes_to_remove);
+ }
+ circuits_handle_oom(alloc);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+/** Return true if we've been under memory pressure in the last
+ * MEMORY_PRESSURE_INTERVAL seconds. */
+int
+have_been_under_memory_pressure(void)
+{
+ return last_time_under_memory_pressure + MEMORY_PRESSURE_INTERVAL
+ < approx_time();
+}
+
+/**
+ * Update the number of cells available on the circuit's n_chan or p_chan's
+ * circuit mux.
+ */
+void
+update_circuit_on_cmux_(circuit_t *circ, cell_direction_t direction,
+ const char *file, int lineno)
+{
+ channel_t *chan = NULL;
+ or_circuit_t *or_circ = NULL;
+ circuitmux_t *cmux = NULL;
+
+ tor_assert(circ);
+
+ /* Okay, get the channel */
+ if (direction == CELL_DIRECTION_OUT) {
+ chan = circ->n_chan;
+ } else {
+ or_circ = TO_OR_CIRCUIT(circ);
+ chan = or_circ->p_chan;
+ }
+
+ tor_assert(chan);
+ tor_assert(chan->cmux);
+
+ /* Now get the cmux */
+ cmux = chan->cmux;
+
+ /* Cmux sanity check */
+ if (! circuitmux_is_circuit_attached(cmux, circ)) {
+ log_warn(LD_BUG, "called on non-attached circuit from %s:%d",
+ file, lineno);
+ return;
+ }
+ tor_assert(circuitmux_attached_circuit_direction(cmux, circ) == direction);
+
+ /* Update the number of cells we have for the circuit mux */
+ if (direction == CELL_DIRECTION_OUT) {
+ circuitmux_set_num_cells(cmux, circ, circ->n_chan_cells.n);
+ } else {
+ circuitmux_set_num_cells(cmux, circ, or_circ->p_chan_cells.n);
+ }
+}
+
+/** Remove all circuits from the cmux on <b>chan</b>.
+ *
+ * If <b>circuits_out</b> is non-NULL, add all detached circuits to
+ * <b>circuits_out</b>.
+ **/
+void
+channel_unlink_all_circuits(channel_t *chan, smartlist_t *circuits_out)
+{
+ tor_assert(chan);
+ tor_assert(chan->cmux);
+
+ circuitmux_detach_all_circuits(chan->cmux, circuits_out);
+ chan->num_n_circuits = 0;
+ chan->num_p_circuits = 0;
+}
+
+/** Block (if <b>block</b> is true) or unblock (if <b>block</b> is false)
+ * every edge connection that is using <b>circ</b> to write to <b>chan</b>,
+ * and start or stop reading as appropriate.
+ *
+ * If <b>stream_id</b> is nonzero, block only the edge connection whose
+ * stream_id matches it.
+ *
+ * Returns the number of streams whose status we changed.
+ */
+static int
+set_streams_blocked_on_circ(circuit_t *circ, channel_t *chan,
+ int block, streamid_t stream_id)
+{
+ edge_connection_t *edge = NULL;
+ int n = 0;
+ if (circ->n_chan == chan) {
+ circ->streams_blocked_on_n_chan = block;
+ if (CIRCUIT_IS_ORIGIN(circ))
+ edge = TO_ORIGIN_CIRCUIT(circ)->p_streams;
+ } else {
+ circ->streams_blocked_on_p_chan = block;
+ tor_assert(!CIRCUIT_IS_ORIGIN(circ));
+ edge = TO_OR_CIRCUIT(circ)->n_streams;
+ }
+
+ for (; edge; edge = edge->next_stream) {
+ connection_t *conn = TO_CONN(edge);
+ if (stream_id && edge->stream_id != stream_id)
+ continue;
+
+ if (edge->edge_blocked_on_circ != block) {
+ ++n;
+ edge->edge_blocked_on_circ = block;
+ }
+
+ if (!conn->read_event) {
+ /* This connection is a placeholder for something; probably a DNS
+ * request. It can't actually stop or start reading.*/
+ continue;
+ }
+
+ if (block) {
+ if (connection_is_reading(conn))
+ connection_stop_reading(conn);
+ } else {
+ /* Is this right? */
+ if (!connection_is_reading(conn))
+ connection_start_reading(conn);
+ }
+ }
+
+ return n;
+}
+
+/** Extract the command from a packed cell. */
+static uint8_t
+packed_cell_get_command(const packed_cell_t *cell, int wide_circ_ids)
+{
+ if (wide_circ_ids) {
+ return get_uint8(cell->body+4);
+ } else {
+ return get_uint8(cell->body+2);
+ }
+}
+
+/** Extract the circuit ID from a packed cell. */
+circid_t
+packed_cell_get_circid(const packed_cell_t *cell, int wide_circ_ids)
+{
+ if (wide_circ_ids) {
+ return ntohl(get_uint32(cell->body));
+ } else {
+ return ntohs(get_uint16(cell->body));
+ }
+}
+
+/** Pull as many cells as possible (but no more than <b>max</b>) from the
+ * queue of the first active circuit on <b>chan</b>, and write them to
+ * <b>chan</b>->outbuf. Return the number of cells written. Advance
+ * the active circuit pointer to the next active circuit in the ring. */
+MOCK_IMPL(int,
+channel_flush_from_first_active_circuit, (channel_t *chan, int max))
+{
+ circuitmux_t *cmux = NULL;
+ int n_flushed = 0;
+ cell_queue_t *queue;
+ destroy_cell_queue_t *destroy_queue=NULL;
+ circuit_t *circ;
+ or_circuit_t *or_circ;
+ int streams_blocked;
+ packed_cell_t *cell;
+
+ /* Get the cmux */
+ tor_assert(chan);
+ tor_assert(chan->cmux);
+ cmux = chan->cmux;
+
+ /* Main loop: pick a circuit, send a cell, update the cmux */
+ while (n_flushed < max) {
+ circ = circuitmux_get_first_active_circuit(cmux, &destroy_queue);
+ if (destroy_queue) {
+ destroy_cell_t *dcell;
+ /* this code is duplicated from some of the logic below. Ugly! XXXX */
+ /* If we are given a destroy_queue here, then it is required to be
+ * nonempty... */
+ tor_assert(destroy_queue->n > 0);
+ dcell = destroy_cell_queue_pop(destroy_queue);
+ /* ...and pop() will always yield a cell from a nonempty queue. */
+ tor_assert(dcell);
+ /* frees dcell */
+ cell = destroy_cell_to_packed_cell(dcell, chan->wide_circ_ids);
+ /* Send the DESTROY cell. It is very unlikely that this fails but just
+ * in case, get rid of the channel. */
+ if (channel_write_packed_cell(chan, cell) < 0) {
+ /* The cell has been freed. */
+ channel_mark_for_close(chan);
+ continue;
+ }
+ /* Update the cmux destroy counter */
+ circuitmux_notify_xmit_destroy(cmux);
+ cell = NULL;
+ ++n_flushed;
+ continue;
+ }
+ /* If it returns NULL, no cells left to send */
+ if (!circ) break;
+
+ if (circ->n_chan == chan) {
+ queue = &circ->n_chan_cells;
+ streams_blocked = circ->streams_blocked_on_n_chan;
+ } else {
+ or_circ = TO_OR_CIRCUIT(circ);
+ tor_assert(or_circ->p_chan == chan);
+ queue = &TO_OR_CIRCUIT(circ)->p_chan_cells;
+ streams_blocked = circ->streams_blocked_on_p_chan;
+ }
+
+ /* Circuitmux told us this was active, so it should have cells */
+ if (/*BUG(*/ queue->n == 0 /*)*/) {
+ log_warn(LD_BUG, "Found a supposedly active circuit with no cells "
+ "to send. Trying to recover.");
+ circuitmux_set_num_cells(cmux, circ, 0);
+ if (! circ->marked_for_close)
+ circuit_mark_for_close(circ, END_CIRC_REASON_INTERNAL);
+ continue;
+ }
+
+ tor_assert(queue->n > 0);
+
+ /*
+ * Get just one cell here; once we've sent it, that can change the circuit
+ * selection, so we have to loop around for another even if this circuit
+ * has more than one.
+ */
+ cell = cell_queue_pop(queue);
+
+ /* Calculate the exact time that this cell has spent in the queue. */
+ if (get_options()->CellStatistics ||
+ get_options()->TestingEnableCellStatsEvent) {
+ uint32_t timestamp_now = monotime_coarse_get_stamp();
+ uint32_t msec_waiting =
+ (uint32_t) monotime_coarse_stamp_units_to_approx_msec(
+ timestamp_now - cell->inserted_timestamp);
+
+ if (get_options()->CellStatistics && !CIRCUIT_IS_ORIGIN(circ)) {
+ or_circ = TO_OR_CIRCUIT(circ);
+ or_circ->total_cell_waiting_time += msec_waiting;
+ or_circ->processed_cells++;
+ }
+
+ if (get_options()->TestingEnableCellStatsEvent) {
+ uint8_t command = packed_cell_get_command(cell, chan->wide_circ_ids);
+
+ testing_cell_stats_entry_t *ent =
+ tor_malloc_zero(sizeof(testing_cell_stats_entry_t));
+ ent->command = command;
+ ent->waiting_time = msec_waiting / 10;
+ ent->removed = 1;
+ if (circ->n_chan == chan)
+ ent->exitward = 1;
+ if (!circ->testing_cell_stats)
+ circ->testing_cell_stats = smartlist_new();
+ smartlist_add(circ->testing_cell_stats, ent);
+ }
+ }
+
+ /* If we just flushed our queue and this circuit is used for a
+ * tunneled directory request, possibly advance its state. */
+ if (queue->n == 0 && chan->dirreq_id)
+ geoip_change_dirreq_state(chan->dirreq_id,
+ DIRREQ_TUNNELED,
+ DIRREQ_CIRC_QUEUE_FLUSHED);
+
+ /* Now send the cell. It is very unlikely that this fails but just in
+ * case, get rid of the channel. */
+ if (channel_write_packed_cell(chan, cell) < 0) {
+ /* The cell has been freed at this point. */
+ channel_mark_for_close(chan);
+ continue;
+ }
+ cell = NULL;
+
+ /*
+ * Don't packed_cell_free_unchecked(cell) here because the channel will
+ * do so when it gets out of the channel queue (probably already did, in
+ * which case that was an immediate double-free bug).
+ */
+
+ /* Update the counter */
+ ++n_flushed;
+
+ /*
+ * Now update the cmux; tell it we've just sent a cell, and how many
+ * we have left.
+ */
+ circuitmux_notify_xmit_cells(cmux, circ, 1);
+ circuitmux_set_num_cells(cmux, circ, queue->n);
+ if (queue->n == 0)
+ log_debug(LD_GENERAL, "Made a circuit inactive.");
+
+ /* Is the cell queue low enough to unblock all the streams that are waiting
+ * to write to this circuit? */
+ if (streams_blocked && queue->n <= CELL_QUEUE_LOWWATER_SIZE)
+ set_streams_blocked_on_circ(circ, chan, 0, 0); /* unblock streams */
+
+ /* If n_flushed < max still, loop around and pick another circuit */
+ }
+
+ /* Okay, we're done sending now */
+ return n_flushed;
+}
+
+/* Minimum value is the maximum circuit window size.
+ *
+ * SENDME cells makes it that we can control how many cells can be inflight on
+ * a circuit from end to end. This logic makes it that on any circuit cell
+ * queue, we have a maximum of cells possible.
+ *
+ * Because the Tor protocol allows for a client to exit at any hop in a
+ * circuit and a circuit can be of a maximum of 8 hops, so in theory the
+ * normal worst case will be the circuit window start value times the maximum
+ * number of hops (8). Having more cells then that means something is wrong.
+ *
+ * However, because padding cells aren't counted in the package window, we set
+ * the maximum size to a reasonably large size for which we expect that we'll
+ * never reach in theory. And if we ever do because of future changes, we'll
+ * be able to control it with a consensus parameter.
+ *
+ * XXX: Unfortunately, END cells aren't accounted for in the circuit window
+ * which means that for instance if a client opens 8001 streams, the 8001
+ * following END cells will queue up in the circuit which will get closed if
+ * the max limit is 8000. Which is sad because it is allowed by the Tor
+ * protocol. But, we need an upper bound on circuit queue in order to avoid
+ * DoS memory pressure so the default size is a middle ground between not
+ * having any limit and having a very restricted one. This is why we can also
+ * control it through a consensus parameter. */
+#define RELAY_CIRC_CELL_QUEUE_SIZE_MIN CIRCWINDOW_START_MAX
+/* We can't have a consensus parameter above this value. */
+#define RELAY_CIRC_CELL_QUEUE_SIZE_MAX INT32_MAX
+/* Default value is set to a large value so we can handle padding cells
+ * properly which aren't accounted for in the SENDME window. Default is 50000
+ * allowed cells in the queue resulting in ~25MB. */
+#define RELAY_CIRC_CELL_QUEUE_SIZE_DEFAULT \
+ (50 * RELAY_CIRC_CELL_QUEUE_SIZE_MIN)
+
+/* The maximum number of cell a circuit queue can contain. This is updated at
+ * every new consensus and controlled by a parameter. */
+static int32_t max_circuit_cell_queue_size =
+ RELAY_CIRC_CELL_QUEUE_SIZE_DEFAULT;
+
+/* Called when the consensus has changed. At this stage, the global consensus
+ * object has NOT been updated. It is called from
+ * notify_before_networkstatus_changes(). */
+void
+relay_consensus_has_changed(const networkstatus_t *ns)
+{
+ tor_assert(ns);
+
+ /* Update the circuit max cell queue size from the consensus. */
+ max_circuit_cell_queue_size =
+ networkstatus_get_param(ns, "circ_max_cell_queue_size",
+ RELAY_CIRC_CELL_QUEUE_SIZE_DEFAULT,
+ RELAY_CIRC_CELL_QUEUE_SIZE_MIN,
+ RELAY_CIRC_CELL_QUEUE_SIZE_MAX);
+}
+
+/** Add <b>cell</b> to the queue of <b>circ</b> writing to <b>chan</b>
+ * transmitting in <b>direction</b>.
+ *
+ * The given <b>cell</b> is copied onto the circuit queue so the caller must
+ * cleanup the memory.
+ *
+ * This function is part of the fast path. */
+void
+append_cell_to_circuit_queue(circuit_t *circ, channel_t *chan,
+ cell_t *cell, cell_direction_t direction,
+ streamid_t fromstream)
+{
+ or_circuit_t *orcirc = NULL;
+ cell_queue_t *queue;
+ int streams_blocked;
+ int exitward;
+ if (circ->marked_for_close)
+ return;
+
+ exitward = (direction == CELL_DIRECTION_OUT);
+ if (exitward) {
+ queue = &circ->n_chan_cells;
+ streams_blocked = circ->streams_blocked_on_n_chan;
+ } else {
+ orcirc = TO_OR_CIRCUIT(circ);
+ queue = &orcirc->p_chan_cells;
+ streams_blocked = circ->streams_blocked_on_p_chan;
+ }
+
+ if (PREDICT_UNLIKELY(queue->n >= max_circuit_cell_queue_size)) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "%s circuit has %d cells in its queue, maximum allowed is %d. "
+ "Closing circuit for safety reasons.",
+ (exitward) ? "Outbound" : "Inbound", queue->n,
+ max_circuit_cell_queue_size);
+ circuit_mark_for_close(circ, END_CIRC_REASON_RESOURCELIMIT);
+ stats_n_circ_max_cell_reached++;
+ return;
+ }
+
+ /* Very important that we copy to the circuit queue because all calls to
+ * this function use the stack for the cell memory. */
+ cell_queue_append_packed_copy(circ, queue, exitward, cell,
+ chan->wide_circ_ids, 1);
+
+ /* Check and run the OOM if needed. */
+ if (PREDICT_UNLIKELY(cell_queues_check_size())) {
+ /* We ran the OOM handler which might have closed this circuit. */
+ if (circ->marked_for_close)
+ return;
+ }
+
+ /* If we have too many cells on the circuit, we should stop reading from
+ * the edge streams for a while. */
+ if (!streams_blocked && queue->n >= CELL_QUEUE_HIGHWATER_SIZE)
+ set_streams_blocked_on_circ(circ, chan, 1, 0); /* block streams */
+
+ if (streams_blocked && fromstream) {
+ /* This edge connection is apparently not blocked; block it. */
+ set_streams_blocked_on_circ(circ, chan, 1, fromstream);
+ }
+
+ update_circuit_on_cmux(circ, direction);
+ if (queue->n == 1) {
+ /* This was the first cell added to the queue. We just made this
+ * circuit active. */
+ log_debug(LD_GENERAL, "Made a circuit active.");
+ }
+
+ /* New way: mark this as having waiting cells for the scheduler */
+ scheduler_channel_has_waiting_cells(chan);
+}
+
+/** Append an encoded value of <b>addr</b> to <b>payload_out</b>, which must
+ * have at least 18 bytes of free space. The encoding is, as specified in
+ * tor-spec.txt:
+ * RESOLVED_TYPE_IPV4 or RESOLVED_TYPE_IPV6 [1 byte]
+ * LENGTH [1 byte]
+ * ADDRESS [length bytes]
+ * Return the number of bytes added, or -1 on error */
+int
+append_address_to_payload(uint8_t *payload_out, const tor_addr_t *addr)
+{
+ uint32_t a;
+ switch (tor_addr_family(addr)) {
+ case AF_INET:
+ payload_out[0] = RESOLVED_TYPE_IPV4;
+ payload_out[1] = 4;
+ a = tor_addr_to_ipv4n(addr);
+ memcpy(payload_out+2, &a, 4);
+ return 6;
+ case AF_INET6:
+ payload_out[0] = RESOLVED_TYPE_IPV6;
+ payload_out[1] = 16;
+ memcpy(payload_out+2, tor_addr_to_in6_addr8(addr), 16);
+ return 18;
+ case AF_UNSPEC:
+ default:
+ return -1;
+ }
+}
+
+/** Given <b>payload_len</b> bytes at <b>payload</b>, starting with an address
+ * encoded as by append_address_to_payload(), try to decode the address into
+ * *<b>addr_out</b>. Return the next byte in the payload after the address on
+ * success, or NULL on failure. */
+const uint8_t *
+decode_address_from_payload(tor_addr_t *addr_out, const uint8_t *payload,
+ int payload_len)
+{
+ if (payload_len < 2)
+ return NULL;
+ if (payload_len < 2+payload[1])
+ return NULL;
+
+ switch (payload[0]) {
+ case RESOLVED_TYPE_IPV4:
+ if (payload[1] != 4)
+ return NULL;
+ tor_addr_from_ipv4n(addr_out, get_uint32(payload+2));
+ break;
+ case RESOLVED_TYPE_IPV6:
+ if (payload[1] != 16)
+ return NULL;
+ tor_addr_from_ipv6_bytes(addr_out, (char*)(payload+2));
+ break;
+ default:
+ tor_addr_make_unspec(addr_out);
+ break;
+ }
+ return payload + 2 + payload[1];
+}
+
+/** Remove all the cells queued on <b>circ</b> for <b>chan</b>. */
+void
+circuit_clear_cell_queue(circuit_t *circ, channel_t *chan)
+{
+ cell_queue_t *queue;
+ cell_direction_t direction;
+
+ if (circ->n_chan == chan) {
+ queue = &circ->n_chan_cells;
+ direction = CELL_DIRECTION_OUT;
+ } else {
+ or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
+ tor_assert(orcirc->p_chan == chan);
+ queue = &orcirc->p_chan_cells;
+ direction = CELL_DIRECTION_IN;
+ }
+
+ /* Clear the queue */
+ cell_queue_clear(queue);
+
+ /* Update the cell counter in the cmux */
+ if (chan->cmux && circuitmux_is_circuit_attached(chan->cmux, circ))
+ update_circuit_on_cmux(circ, direction);
+}
+
+/** Return 1 if we shouldn't restart reading on this circuit, even if
+ * we get a SENDME. Else return 0.
+*/
+static int
+circuit_queue_streams_are_blocked(circuit_t *circ)
+{
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ return circ->streams_blocked_on_n_chan;
+ } else {
+ return circ->streams_blocked_on_p_chan;
+ }
+}
diff --cc src/feature/client/circpathbias.c
index 1ee29c639,000000000..9f2ed9347
mode 100644,000000..100644
--- a/src/feature/client/circpathbias.c
+++ b/src/feature/client/circpathbias.c
@@@ -1,1578 -1,0 +1,1641 @@@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file circpathbias.c
+ *
+ * \brief Code to track success/failure rates of circuits built through
+ * different tor nodes, in an attempt to detect attacks where
+ * an attacker deliberately causes circuits to fail until the client
+ * choses a path they like.
+ *
+ * This code is currently configured in a warning-only mode, though false
+ * positives appear to be rare in practice. There is also support for
+ * disabling really bad guards, but it's quite experimental and may have bad
+ * anonymity effects.
+ *
+ * The information here is associated with the entry_guard_t object for
+ * each guard, and stored persistently in the state file.
+ */
+
+#include "core/or/or.h"
+#include "core/or/channel.h"
+#include "feature/client/circpathbias.h"
+#include "core/or/circuitbuild.h"
+#include "core/or/circuitlist.h"
+#include "core/or/circuituse.h"
+#include "core/or/circuitstats.h"
+#include "core/or/connection_edge.h"
+#include "app/config/config.h"
+#include "lib/crypt_ops/crypto_rand.h"
+#include "feature/client/entrynodes.h"
+#include "feature/nodelist/networkstatus.h"
+#include "core/or/relay.h"
+#include "lib/math/fp.h"
+#include "lib/math/laplace.h"
+
+#include "core/or/cell_st.h"
+#include "core/or/cpath_build_state_st.h"
+#include "core/or/crypt_path_st.h"
+#include "core/or/extend_info_st.h"
+#include "core/or/origin_circuit_st.h"
+
+static void pathbias_count_successful_close(origin_circuit_t *circ);
+static void pathbias_count_collapse(origin_circuit_t *circ);
+static void pathbias_count_use_failed(origin_circuit_t *circ);
+static void pathbias_measure_use_rate(entry_guard_t *guard);
+static void pathbias_measure_close_rate(entry_guard_t *guard);
+static void pathbias_scale_use_rates(entry_guard_t *guard);
+static void pathbias_scale_close_rates(entry_guard_t *guard);
+static int entry_guard_inc_circ_attempt_count(entry_guard_t *guard);
+
+/** Increment the number of times we successfully extended a circuit to
+ * <b>guard</b>, first checking if the failure rate is high enough that
+ * we should eliminate the guard. Return -1 if the guard looks no good;
+ * return 0 if the guard looks fine.
+ */
+static int
+entry_guard_inc_circ_attempt_count(entry_guard_t *guard)
+{
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ entry_guards_changed();
+
+ pathbias_measure_close_rate(guard);
+
+ if (pb->path_bias_disabled)
+ return -1;
+
+ pathbias_scale_close_rates(guard);
+ pb->circ_attempts++;
+
+ log_info(LD_CIRC, "Got success count %f/%f for guard %s",
+ pb->circ_successes, pb->circ_attempts,
+ entry_guard_describe(guard));
+ return 0;
+}
+
+/** The minimum number of circuit attempts before we start
+ * thinking about warning about path bias and dropping guards */
+static int
+pathbias_get_min_circs(const or_options_t *options)
+{
+#define DFLT_PATH_BIAS_MIN_CIRC 150
+ if (options->PathBiasCircThreshold >= 5)
+ return options->PathBiasCircThreshold;
+ else
+ return networkstatus_get_param(NULL, "pb_mincircs",
+ DFLT_PATH_BIAS_MIN_CIRC,
+ 5, INT32_MAX);
+}
+
+/** The circuit success rate below which we issue a notice */
+static double
+pathbias_get_notice_rate(const or_options_t *options)
+{
+#define DFLT_PATH_BIAS_NOTICE_PCT 70
+ if (options->PathBiasNoticeRate >= 0.0)
+ return options->PathBiasNoticeRate;
+ else
+ return networkstatus_get_param(NULL, "pb_noticepct",
+ DFLT_PATH_BIAS_NOTICE_PCT, 0, 100)/100.0;
+}
+
+/** The circuit success rate below which we issue a warn */
+static double
+pathbias_get_warn_rate(const or_options_t *options)
+{
+#define DFLT_PATH_BIAS_WARN_PCT 50
+ if (options->PathBiasWarnRate >= 0.0)
+ return options->PathBiasWarnRate;
+ else
+ return networkstatus_get_param(NULL, "pb_warnpct",
+ DFLT_PATH_BIAS_WARN_PCT, 0, 100)/100.0;
+}
+
+/* XXXX I'd like to have this be static again, but entrynodes.c needs it. */
+/**
+ * The extreme rate is the rate at which we would drop the guard,
+ * if pb_dropguard is also set. Otherwise we just warn.
+ */
+double
+pathbias_get_extreme_rate(const or_options_t *options)
+{
+#define DFLT_PATH_BIAS_EXTREME_PCT 30
+ if (options->PathBiasExtremeRate >= 0.0)
+ return options->PathBiasExtremeRate;
+ else
+ return networkstatus_get_param(NULL, "pb_extremepct",
+ DFLT_PATH_BIAS_EXTREME_PCT, 0, 100)/100.0;
+}
+
+/* XXXX I'd like to have this be static again, but entrynodes.c needs it. */
+/**
+ * If 1, we actually disable use of guards that fall below
+ * the extreme_pct.
+ */
+int
+pathbias_get_dropguards(const or_options_t *options)
+{
+#define DFLT_PATH_BIAS_DROP_GUARDS 0
+ if (options->PathBiasDropGuards >= 0)
+ return options->PathBiasDropGuards;
+ else
+ return networkstatus_get_param(NULL, "pb_dropguards",
+ DFLT_PATH_BIAS_DROP_GUARDS, 0, 1);
+}
+
+/**
+ * This is the number of circuits at which we scale our
+ * counts by mult_factor/scale_factor. Note, this count is
+ * not exact, as we only perform the scaling in the event
+ * of no integer truncation.
+ */
+static int
+pathbias_get_scale_threshold(const or_options_t *options)
+{
+#define DFLT_PATH_BIAS_SCALE_THRESHOLD 300
+ if (options->PathBiasScaleThreshold >= 10)
+ return options->PathBiasScaleThreshold;
+ else
+ return networkstatus_get_param(NULL, "pb_scalecircs",
+ DFLT_PATH_BIAS_SCALE_THRESHOLD, 10,
+ INT32_MAX);
+}
+
+/**
+ * Compute the path bias scaling ratio from the consensus
+ * parameters pb_multfactor/pb_scalefactor.
+ *
+ * Returns a value in (0, 1.0] which we multiply our pathbias
+ * counts with to scale them down.
+ */
+static double
+pathbias_get_scale_ratio(const or_options_t *options)
+{
+ /*
+ * The scale factor is the denominator for our scaling
+ * of circuit counts for our path bias window.
+ *
+ * Note that our use of doubles for the path bias state
+ * file means that powers of 2 work best here.
+ */
+ int denominator = networkstatus_get_param(NULL, "pb_scalefactor",
+ 2, 2, INT32_MAX);
+ (void) options;
+ /**
+ * The mult factor is the numerator for our scaling
+ * of circuit counts for our path bias window. It
+ * allows us to scale by fractions.
+ */
+ return networkstatus_get_param(NULL, "pb_multfactor",
+ 1, 1, denominator)/((double)denominator);
+}
+
+/** The minimum number of circuit usage attempts before we start
+ * thinking about warning about path use bias and dropping guards */
+static int
+pathbias_get_min_use(const or_options_t *options)
+{
+#define DFLT_PATH_BIAS_MIN_USE 20
+ if (options->PathBiasUseThreshold >= 3)
+ return options->PathBiasUseThreshold;
+ else
+ return networkstatus_get_param(NULL, "pb_minuse",
+ DFLT_PATH_BIAS_MIN_USE,
+ 3, INT32_MAX);
+}
+
+/** The circuit use success rate below which we issue a notice */
+static double
+pathbias_get_notice_use_rate(const or_options_t *options)
+{
+#define DFLT_PATH_BIAS_NOTICE_USE_PCT 80
+ if (options->PathBiasNoticeUseRate >= 0.0)
+ return options->PathBiasNoticeUseRate;
+ else
+ return networkstatus_get_param(NULL, "pb_noticeusepct",
+ DFLT_PATH_BIAS_NOTICE_USE_PCT,
+ 0, 100)/100.0;
+}
+
+/**
+ * The extreme use rate is the rate at which we would drop the guard,
+ * if pb_dropguard is also set. Otherwise we just warn.
+ */
+double
+pathbias_get_extreme_use_rate(const or_options_t *options)
+{
+#define DFLT_PATH_BIAS_EXTREME_USE_PCT 60
+ if (options->PathBiasExtremeUseRate >= 0.0)
+ return options->PathBiasExtremeUseRate;
+ else
+ return networkstatus_get_param(NULL, "pb_extremeusepct",
+ DFLT_PATH_BIAS_EXTREME_USE_PCT,
+ 0, 100)/100.0;
+}
+
+/**
+ * This is the number of circuits at which we scale our
+ * use counts by mult_factor/scale_factor. Note, this count is
+ * not exact, as we only perform the scaling in the event
+ * of no integer truncation.
+ */
+static int
+pathbias_get_scale_use_threshold(const or_options_t *options)
+{
+#define DFLT_PATH_BIAS_SCALE_USE_THRESHOLD 100
+ if (options->PathBiasScaleUseThreshold >= 10)
+ return options->PathBiasScaleUseThreshold;
+ else
+ return networkstatus_get_param(NULL, "pb_scaleuse",
+ DFLT_PATH_BIAS_SCALE_USE_THRESHOLD,
+ 10, INT32_MAX);
+}
+
+/**
+ * Convert a Guard's path state to string.
+ */
+const char *
+pathbias_state_to_string(path_state_t state)
+{
+ switch (state) {
+ case PATH_STATE_NEW_CIRC:
+ return "new";
+ case PATH_STATE_BUILD_ATTEMPTED:
+ return "build attempted";
+ case PATH_STATE_BUILD_SUCCEEDED:
+ return "build succeeded";
+ case PATH_STATE_USE_ATTEMPTED:
+ return "use attempted";
+ case PATH_STATE_USE_SUCCEEDED:
+ return "use succeeded";
+ case PATH_STATE_USE_FAILED:
+ return "use failed";
+ case PATH_STATE_ALREADY_COUNTED:
+ return "already counted";
+ }
+
+ return "unknown";
+}
+
+/**
+ * This function decides if a circuit has progressed far enough to count
+ * as a circuit "attempt". As long as end-to-end tagging is possible,
+ * we assume the adversary will use it over hop-to-hop failure. Therefore,
+ * we only need to account bias for the last hop. This should make us
+ * much more resilient to ambient circuit failure, and also make that
+ * failure easier to measure (we only need to measure Exit failure rates).
+ */
+static int
+pathbias_is_new_circ_attempt(origin_circuit_t *circ)
+{
+#define N2N_TAGGING_IS_POSSIBLE
+#ifdef N2N_TAGGING_IS_POSSIBLE
+ /* cpath is a circular list. We want circs with more than one hop,
+ * and the second hop must be waiting for keys still (it's just
+ * about to get them). */
+ return circ->cpath &&
+ circ->cpath->next != circ->cpath &&
+ circ->cpath->next->state == CPATH_STATE_AWAITING_KEYS;
+#else /* !(defined(N2N_TAGGING_IS_POSSIBLE)) */
+ /* If tagging attacks are no longer possible, we probably want to
+ * count bias from the first hop. However, one could argue that
+ * timing-based tagging is still more useful than per-hop failure.
+ * In which case, we'd never want to use this.
+ */
+ return circ->cpath &&
+ circ->cpath->state == CPATH_STATE_AWAITING_KEYS;
+#endif /* defined(N2N_TAGGING_IS_POSSIBLE) */
+}
+
+/**
+ * Decide if the path bias code should count a circuit.
+ *
+ * @returns 1 if we should count it, 0 otherwise.
+ */
+static int
+pathbias_should_count(origin_circuit_t *circ)
+{
+#define PATHBIAS_COUNT_INTERVAL (600)
+ static ratelim_t count_limit =
+ RATELIM_INIT(PATHBIAS_COUNT_INTERVAL);
+ char *rate_msg = NULL;
+
+ /* We can't do path bias accounting without entry guards.
+ * Testing and controller circuits also have no guards.
+ *
+ * We also don't count server-side rends, because their
+ * endpoint could be chosen maliciously.
+ * Similarly, we can't count client-side intro attempts,
+ * because clients can be manipulated into connecting to
+ * malicious intro points. */
+ if (get_options()->UseEntryGuards == 0 ||
+ circ->base_.purpose == CIRCUIT_PURPOSE_TESTING ||
+ circ->base_.purpose == CIRCUIT_PURPOSE_CONTROLLER ||
+ circ->base_.purpose == CIRCUIT_PURPOSE_S_CONNECT_REND ||
+ circ->base_.purpose == CIRCUIT_PURPOSE_S_REND_JOINED ||
+ (circ->base_.purpose >= CIRCUIT_PURPOSE_C_INTRODUCING &&
+ circ->base_.purpose <= CIRCUIT_PURPOSE_C_INTRODUCE_ACKED)) {
+
+ /* Check to see if the shouldcount result has changed due to a
+ * unexpected purpose change that would affect our results.
+ *
+ * The reason we check the path state too here is because for the
+ * cannibalized versions of these purposes, we count them as successful
+ * before their purpose change.
+ */
+ if (circ->pathbias_shouldcount == PATHBIAS_SHOULDCOUNT_COUNTED
+ && circ->path_state != PATH_STATE_ALREADY_COUNTED) {
+ log_info(LD_BUG,
+ "Circuit %d is now being ignored despite being counted "
+ "in the past. Purpose is %s, path state is %s",
+ circ->global_identifier,
+ circuit_purpose_to_string(circ->base_.purpose),
+ pathbias_state_to_string(circ->path_state));
+ }
+ circ->pathbias_shouldcount = PATHBIAS_SHOULDCOUNT_IGNORED;
+ return 0;
+ }
+
+ /* Completely ignore one hop circuits */
+ if (circ->build_state->onehop_tunnel ||
+ circ->build_state->desired_path_len == 1) {
+ /* Check for inconsistency */
+ if (circ->build_state->desired_path_len != 1 ||
+ !circ->build_state->onehop_tunnel) {
+ if ((rate_msg = rate_limit_log(&count_limit, approx_time()))) {
+ log_info(LD_BUG,
+ "One-hop circuit has length %d. Path state is %s. "
+ "Circuit is a %s currently %s.%s",
+ circ->build_state->desired_path_len,
+ pathbias_state_to_string(circ->path_state),
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state),
+ rate_msg);
+ tor_free(rate_msg);
+ }
+ tor_fragile_assert();
+ }
+
+ /* Check to see if the shouldcount result has changed due to a
+ * unexpected change that would affect our results */
+ if (circ->pathbias_shouldcount == PATHBIAS_SHOULDCOUNT_COUNTED) {
+ log_info(LD_BUG,
+ "One-hop circuit %d is now being ignored despite being counted "
+ "in the past. Purpose is %s, path state is %s",
+ circ->global_identifier,
+ circuit_purpose_to_string(circ->base_.purpose),
+ pathbias_state_to_string(circ->path_state));
+ }
+ circ->pathbias_shouldcount = PATHBIAS_SHOULDCOUNT_IGNORED;
+ return 0;
+ }
+
+ /* Check to see if the shouldcount result has changed due to a
+ * unexpected purpose change that would affect our results */
+ if (circ->pathbias_shouldcount == PATHBIAS_SHOULDCOUNT_IGNORED) {
+ log_info(LD_BUG,
+ "Circuit %d is now being counted despite being ignored "
+ "in the past. Purpose is %s, path state is %s",
+ circ->global_identifier,
+ circuit_purpose_to_string(circ->base_.purpose),
+ pathbias_state_to_string(circ->path_state));
+ }
+ circ->pathbias_shouldcount = PATHBIAS_SHOULDCOUNT_COUNTED;
+
+ return 1;
+}
+
+/**
+ * Check our circuit state to see if this is a successful circuit attempt.
+ * If so, record it in the current guard's path bias circ_attempt count.
+ *
+ * Also check for several potential error cases for bug #6475.
+ */
+int
+pathbias_count_build_attempt(origin_circuit_t *circ)
+{
+#define CIRC_ATTEMPT_NOTICE_INTERVAL (600)
+ static ratelim_t circ_attempt_notice_limit =
+ RATELIM_INIT(CIRC_ATTEMPT_NOTICE_INTERVAL);
+ char *rate_msg = NULL;
+
+ if (!pathbias_should_count(circ)) {
+ return 0;
+ }
+
+ if (pathbias_is_new_circ_attempt(circ)) {
+ /* Help track down the real cause of bug #6475: */
+ if (circ->has_opened && circ->path_state != PATH_STATE_BUILD_ATTEMPTED) {
+ if ((rate_msg = rate_limit_log(&circ_attempt_notice_limit,
+ approx_time()))) {
+ log_info(LD_BUG,
+ "Opened circuit is in strange path state %s. "
+ "Circuit is a %s currently %s.%s",
+ pathbias_state_to_string(circ->path_state),
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state),
+ rate_msg);
+ tor_free(rate_msg);
+ }
+ }
+
+ /* Don't re-count cannibalized circs.. */
+ if (!circ->has_opened) {
+ entry_guard_t *guard = NULL;
+
+ if (circ->cpath && circ->cpath->extend_info) {
+ guard = entry_guard_get_by_id_digest(
+ circ->cpath->extend_info->identity_digest);
+ } else if (circ->base_.n_chan) {
+ guard =
+ entry_guard_get_by_id_digest(circ->base_.n_chan->identity_digest);
+ }
+
+ if (guard) {
+ if (circ->path_state == PATH_STATE_NEW_CIRC) {
+ circ->path_state = PATH_STATE_BUILD_ATTEMPTED;
+
+ if (entry_guard_inc_circ_attempt_count(guard) < 0) {
+ /* Bogus guard; we already warned. */
+ return -END_CIRC_REASON_TORPROTOCOL;
+ }
+ } else {
+ if ((rate_msg = rate_limit_log(&circ_attempt_notice_limit,
+ approx_time()))) {
+ log_info(LD_BUG,
+ "Unopened circuit has strange path state %s. "
+ "Circuit is a %s currently %s.%s",
+ pathbias_state_to_string(circ->path_state),
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state),
+ rate_msg);
+ tor_free(rate_msg);
+ }
+ }
+ } else {
+ if ((rate_msg = rate_limit_log(&circ_attempt_notice_limit,
+ approx_time()))) {
+ log_info(LD_CIRC,
+ "Unopened circuit has no known guard. "
+ "Circuit is a %s currently %s.%s",
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state),
+ rate_msg);
+ tor_free(rate_msg);
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * Check our circuit state to see if this is a successful circuit
+ * completion. If so, record it in the current guard's path bias
+ * success count.
+ *
+ * Also check for several potential error cases for bug #6475.
+ */
+void
+pathbias_count_build_success(origin_circuit_t *circ)
+{
+#define SUCCESS_NOTICE_INTERVAL (600)
+ static ratelim_t success_notice_limit =
+ RATELIM_INIT(SUCCESS_NOTICE_INTERVAL);
+ char *rate_msg = NULL;
+ entry_guard_t *guard = NULL;
+
+ if (!pathbias_should_count(circ)) {
+ return;
+ }
+
+ /* Don't count cannibalized/reused circs for path bias
+ * "build" success, since they get counted under "use" success. */
+ if (!circ->has_opened) {
+ if (circ->cpath && circ->cpath->extend_info) {
+ guard = entry_guard_get_by_id_digest(
+ circ->cpath->extend_info->identity_digest);
+ }
+
+ if (guard) {
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ if (circ->path_state == PATH_STATE_BUILD_ATTEMPTED) {
+ circ->path_state = PATH_STATE_BUILD_SUCCEEDED;
+ pb->circ_successes++;
+ entry_guards_changed();
+
+ log_info(LD_CIRC, "Got success count %f/%f for guard %s",
+ pb->circ_successes, pb->circ_attempts,
+ entry_guard_describe(guard));
+ } else {
+ if ((rate_msg = rate_limit_log(&success_notice_limit,
+ approx_time()))) {
+ log_info(LD_BUG,
+ "Succeeded circuit is in strange path state %s. "
+ "Circuit is a %s currently %s.%s",
+ pathbias_state_to_string(circ->path_state),
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state),
+ rate_msg);
+ tor_free(rate_msg);
+ }
+ }
+
+ if (pb->circ_attempts < pb->circ_successes) {
+ log_notice(LD_BUG, "Unexpectedly high successes counts (%f/%f) "
+ "for guard %s",
+ pb->circ_successes, pb->circ_attempts,
+ entry_guard_describe(guard));
+ }
+ /* In rare cases, CIRCUIT_PURPOSE_TESTING can get converted to
+ * CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT and have no guards here.
+ * No need to log that case. */
+ } else if (circ->base_.purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) {
+ if ((rate_msg = rate_limit_log(&success_notice_limit,
+ approx_time()))) {
+ log_info(LD_CIRC,
+ "Completed circuit has no known guard. "
+ "Circuit is a %s currently %s.%s",
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state),
+ rate_msg);
+ tor_free(rate_msg);
+ }
+ }
+ } else {
+ if (circ->path_state < PATH_STATE_BUILD_SUCCEEDED) {
+ if ((rate_msg = rate_limit_log(&success_notice_limit,
+ approx_time()))) {
+ log_info(LD_BUG,
+ "Opened circuit is in strange path state %s. "
+ "Circuit is a %s currently %s.%s",
+ pathbias_state_to_string(circ->path_state),
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state),
+ rate_msg);
+ tor_free(rate_msg);
+ }
+ }
+ }
+}
+
+/**
+ * Record an attempt to use a circuit. Changes the circuit's
+ * path state and update its guard's usage counter.
+ *
+ * Used for path bias usage accounting.
+ */
+void
+pathbias_count_use_attempt(origin_circuit_t *circ)
+{
+ if (!pathbias_should_count(circ)) {
+ return;
+ }
+
+ if (circ->path_state < PATH_STATE_BUILD_SUCCEEDED) {
+ log_notice(LD_BUG,
+ "Used circuit is in strange path state %s. "
+ "Circuit is a %s currently %s.",
+ pathbias_state_to_string(circ->path_state),
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state));
+ } else if (circ->path_state < PATH_STATE_USE_ATTEMPTED) {
+ entry_guard_t *guard = entry_guard_get_by_id_digest(
+ circ->cpath->extend_info->identity_digest);
+ if (guard) {
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ pathbias_measure_use_rate(guard);
+ pathbias_scale_use_rates(guard);
+ pb->use_attempts++;
+ entry_guards_changed();
+
+ log_debug(LD_CIRC,
+ "Marked circuit %d (%f/%f) as used for guard %s.",
+ circ->global_identifier,
+ pb->use_successes, pb->use_attempts,
+ entry_guard_describe(guard));
+ }
+
+ circ->path_state = PATH_STATE_USE_ATTEMPTED;
+ } else {
+ /* Harmless but educational log message */
+ log_info(LD_CIRC,
+ "Used circuit %d is already in path state %s. "
+ "Circuit is a %s currently %s.",
+ circ->global_identifier,
+ pathbias_state_to_string(circ->path_state),
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state));
+ }
+
+ return;
+}
+
+/**
+ * Check the circuit's path state is appropriate and mark it as
+ * successfully used. Used for path bias usage accounting.
+ *
+ * We don't actually increment the guard's counters until
+ * pathbias_check_close(), because the circuit can still transition
+ * back to PATH_STATE_USE_ATTEMPTED if a stream fails later (this
+ * is done so we can probe the circuit for liveness at close).
+ */
+void
+pathbias_mark_use_success(origin_circuit_t *circ)
+{
+ if (!pathbias_should_count(circ)) {
+ return;
+ }
+
+ if (circ->path_state < PATH_STATE_USE_ATTEMPTED) {
+ log_notice(LD_BUG,
+ "Used circuit %d is in strange path state %s. "
+ "Circuit is a %s currently %s.",
+ circ->global_identifier,
+ pathbias_state_to_string(circ->path_state),
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state));
+
+ pathbias_count_use_attempt(circ);
+ }
+
+ /* We don't do any accounting at the guard until actual circuit close */
+ circ->path_state = PATH_STATE_USE_SUCCEEDED;
+
+ return;
+}
+
+/**
+ * If a stream ever detatches from a circuit in a retriable way,
+ * we need to mark this circuit as still needing either another
+ * successful stream, or in need of a probe.
+ *
+ * An adversary could let the first stream request succeed (ie the
+ * resolve), but then tag and timeout the remainder (via cell
+ * dropping), forcing them on new circuits.
+ *
+ * Rolling back the state will cause us to probe such circuits, which
+ * should lead to probe failures in the event of such tagging due to
+ * either unrecognized cells coming in while we wait for the probe,
+ * or the cipher state getting out of sync in the case of dropped cells.
+ */
+void
+pathbias_mark_use_rollback(origin_circuit_t *circ)
+{
+ if (circ->path_state == PATH_STATE_USE_SUCCEEDED) {
+ log_info(LD_CIRC,
+ "Rolling back pathbias use state to 'attempted' for detached "
+ "circuit %d", circ->global_identifier);
+ circ->path_state = PATH_STATE_USE_ATTEMPTED;
+ }
+}
+
+/**
+ * Actually count a circuit success towards a guard's usage counters
+ * if the path state is appropriate.
+ */
+static void
+pathbias_count_use_success(origin_circuit_t *circ)
+{
+ entry_guard_t *guard;
+
+ if (!pathbias_should_count(circ)) {
+ return;
+ }
+
+ if (circ->path_state != PATH_STATE_USE_SUCCEEDED) {
+ log_notice(LD_BUG,
+ "Successfully used circuit %d is in strange path state %s. "
+ "Circuit is a %s currently %s.",
+ circ->global_identifier,
+ pathbias_state_to_string(circ->path_state),
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state));
+ } else {
+ guard = entry_guard_get_by_id_digest(
+ circ->cpath->extend_info->identity_digest);
+ if (guard) {
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ pb->use_successes++;
+ entry_guards_changed();
+
+ if (pb->use_attempts < pb->use_successes) {
+ log_notice(LD_BUG, "Unexpectedly high use successes counts (%f/%f) "
+ "for guard %s",
+ pb->use_successes, pb->use_attempts,
+ entry_guard_describe(guard));
+ }
+
+ log_debug(LD_CIRC,
+ "Marked circuit %d (%f/%f) as used successfully for guard %s",
+ circ->global_identifier, pb->use_successes,
+ pb->use_attempts,
+ entry_guard_describe(guard));
+ }
+ }
+
+ return;
+}
+
+/**
+ * Send a probe down a circuit that the client attempted to use,
+ * but for which the stream timed out/failed. The probe is a
+ * RELAY_BEGIN cell with a 0.a.b.c destination address, which
+ * the exit will reject and reply back, echoing that address.
+ *
+ * The reason for such probes is because it is possible to bias
+ * a user's paths simply by causing timeouts, and these timeouts
+ * are not possible to differentiate from unresponsive servers.
+ *
+ * The probe is sent at the end of the circuit lifetime for two
+ * reasons: to prevent cryptographic taggers from being able to
+ * drop cells to cause timeouts, and to prevent easy recognition
+ * of probes before any real client traffic happens.
+ *
+ * Returns -1 if we couldn't probe, 0 otherwise.
+ */
+static int
+pathbias_send_usable_probe(circuit_t *circ)
+{
+ /* Based on connection_ap_handshake_send_begin() */
+ char payload[CELL_PAYLOAD_SIZE];
+ int payload_len;
+ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
+ crypt_path_t *cpath_layer = NULL;
+ char *probe_nonce = NULL;
+
+ tor_assert(ocirc);
+
+ cpath_layer = ocirc->cpath->prev;
+
+ if (cpath_layer->state != CPATH_STATE_OPEN) {
+ /* This can happen for cannibalized circuits. Their
+ * last hop isn't yet open */
+ log_info(LD_CIRC,
+ "Got pathbias probe request for unopened circuit %d. "
+ "Opened %d, len %d", ocirc->global_identifier,
+ ocirc->has_opened, ocirc->build_state->desired_path_len);
+ return -1;
+ }
+
+ /* We already went down this road. */
+ if (circ->purpose == CIRCUIT_PURPOSE_PATH_BIAS_TESTING &&
+ ocirc->pathbias_probe_id) {
+ log_info(LD_CIRC,
+ "Got pathbias probe request for circuit %d with "
+ "outstanding probe", ocirc->global_identifier);
+ return -1;
+ }
+
+ /* Can't probe if the channel isn't open */
+ if (circ->n_chan == NULL ||
+ (!CHANNEL_IS_OPEN(circ->n_chan)
+ && !CHANNEL_IS_MAINT(circ->n_chan))) {
+ log_info(LD_CIRC,
+ "Skipping pathbias probe for circuit %d: Channel is not open.",
+ ocirc->global_identifier);
+ return -1;
+ }
+
+ circuit_change_purpose(circ, CIRCUIT_PURPOSE_PATH_BIAS_TESTING);
+
+ /* Update timestamp for when circuit_expire_building() should kill us */
+ tor_gettimeofday(&circ->timestamp_began);
+
+ /* Generate a random address for the nonce */
+ crypto_rand((char*)ô->pathbias_probe_nonce,
+ sizeof(ocirc->pathbias_probe_nonce));
+ ocirc->pathbias_probe_nonce &= 0x00ffffff;
+ probe_nonce = tor_dup_ip(ocirc->pathbias_probe_nonce);
+
+ tor_snprintf(payload,RELAY_PAYLOAD_SIZE, "%s:25", probe_nonce);
+ payload_len = (int)strlen(payload)+1;
+
+ // XXX: need this? Can we assume ipv4 will always be supported?
+ // If not, how do we tell?
+ //if (payload_len <= RELAY_PAYLOAD_SIZE - 4 && edge_conn->begincell_flags) {
+ // set_uint32(payload + payload_len, htonl(edge_conn->begincell_flags));
+ // payload_len += 4;
+ //}
+
+ /* Generate+Store stream id, make sure it's non-zero */
+ ocirc->pathbias_probe_id = get_unique_stream_id_by_circ(ocirc);
+
+ if (ocirc->pathbias_probe_id==0) {
+ log_warn(LD_CIRC,
+ "Ran out of stream IDs on circuit %u during "
+ "pathbias probe attempt.", ocirc->global_identifier);
+ tor_free(probe_nonce);
+ return -1;
+ }
+
+ log_info(LD_CIRC,
+ "Sending pathbias testing cell to %s:25 on stream %d for circ %d.",
+ probe_nonce, ocirc->pathbias_probe_id, ocirc->global_identifier);
+ tor_free(probe_nonce);
+
+ /* Send a test relay cell */
+ if (relay_send_command_from_edge(ocirc->pathbias_probe_id, circ,
+ RELAY_COMMAND_BEGIN, payload,
+ payload_len, cpath_layer) < 0) {
+ log_notice(LD_CIRC,
+ "Failed to send pathbias probe cell on circuit %d.",
+ ocirc->global_identifier);
+ return -1;
+ }
+
+ /* Mark it freshly dirty so it doesn't get expired in the meantime */
+ circ->timestamp_dirty = time(NULL);
+
+ return 0;
+}
+
+/**
+ * Check the response to a pathbias probe, to ensure the
+ * cell is recognized and the nonce and other probe
+ * characteristics are as expected.
+ *
+ * If the response is valid, return 0. Otherwise return < 0.
+ */
+int
+pathbias_check_probe_response(circuit_t *circ, const cell_t *cell)
+{
+ /* Based on connection_edge_process_relay_cell() */
+ relay_header_t rh;
+ int reason;
+ uint32_t ipv4_host;
+ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
+
+ tor_assert(cell);
+ tor_assert(ocirc);
+ tor_assert(circ->purpose == CIRCUIT_PURPOSE_PATH_BIAS_TESTING);
+
+ relay_header_unpack(&rh, cell->payload);
+
+ reason = rh.length > 0 ?
+ get_uint8(cell->payload+RELAY_HEADER_SIZE) : END_STREAM_REASON_MISC;
+
+ if (rh.command == RELAY_COMMAND_END &&
+ reason == END_STREAM_REASON_EXITPOLICY &&
+ ocirc->pathbias_probe_id == rh.stream_id) {
+
+ /* Check length+extract host: It is in network order after the reason code.
+ * See connection_edge_end(). */
+ if (rh.length < 9) { /* reason+ipv4+dns_ttl */
+ log_notice(LD_PROTOCOL,
+ "Short path bias probe response length field (%d).", rh.length);
+ return - END_CIRC_REASON_TORPROTOCOL;
+ }
+
+ ipv4_host = ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE+1));
+
+ /* Check nonce */
+ if (ipv4_host == ocirc->pathbias_probe_nonce) {
+ pathbias_mark_use_success(ocirc);
++ circuit_read_valid_data(ocirc, rh.length);
+ circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
+ log_info(LD_CIRC,
+ "Got valid path bias probe back for circ %d, stream %d.",
+ ocirc->global_identifier, ocirc->pathbias_probe_id);
+ return 0;
+ } else {
+ log_notice(LD_CIRC,
+ "Got strange probe value 0x%x vs 0x%x back for circ %d, "
+ "stream %d.", ipv4_host, ocirc->pathbias_probe_nonce,
+ ocirc->global_identifier, ocirc->pathbias_probe_id);
+ return -1;
+ }
+ }
+ log_info(LD_CIRC,
+ "Got another cell back back on pathbias probe circuit %d: "
+ "Command: %d, Reason: %d, Stream-id: %d",
+ ocirc->global_identifier, rh.command, reason, rh.stream_id);
+ return -1;
+}
+
+/**
++ * Check if a cell is counts as valid data for a circuit,
++ * and if so, count it as valid.
++ */
++void
++pathbias_count_valid_cells(circuit_t *circ, const cell_t *cell)
++{
++ origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
++ relay_header_t rh;
++
++ relay_header_unpack(&rh, cell->payload);
++
++ /* Check to see if this is a cell from a previous connection,
++ * or is a request to close the circuit. */
++ switch (rh.command) {
++ case RELAY_COMMAND_TRUNCATED:
++ /* Truncated cells can arrive on path bias circs. When they do,
++ * just process them. This closes the circ, but it was junk anyway.
++ * No reason to wait for the probe. */
++ circuit_read_valid_data(ocirc, rh.length);
++ circuit_truncated(TO_ORIGIN_CIRCUIT(circ),
++ get_uint8(cell->payload + RELAY_HEADER_SIZE));
++
++ break;
++
++ case RELAY_COMMAND_END:
++ if (connection_half_edge_is_valid_end(ocirc->half_streams,
++ rh.stream_id)) {
++ circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh.length);
++ }
++ break;
++
++ case RELAY_COMMAND_DATA:
++ if (connection_half_edge_is_valid_data(ocirc->half_streams,
++ rh.stream_id)) {
++ circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh.length);
++ }
++ break;
++
++ case RELAY_COMMAND_SENDME:
++ if (connection_half_edge_is_valid_sendme(ocirc->half_streams,
++ rh.stream_id)) {
++ circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh.length);
++ }
++ break;
++
++ case RELAY_COMMAND_CONNECTED:
++ if (connection_half_edge_is_valid_connected(ocirc->half_streams,
++ rh.stream_id)) {
++ circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh.length);
++ }
++ break;
++
++ case RELAY_COMMAND_RESOLVED:
++ if (connection_half_edge_is_valid_resolved(ocirc->half_streams,
++ rh.stream_id)) {
++ circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh.length);
++ }
++ break;
++ }
++}
++
++/**
+ * Check if a circuit was used and/or closed successfully.
+ *
+ * If we attempted to use the circuit to carry a stream but failed
+ * for whatever reason, or if the circuit mysteriously died before
+ * we could attach any streams, record these two cases.
+ *
+ * If we *have* successfully used the circuit, or it appears to
+ * have been closed by us locally, count it as a success.
+ *
+ * Returns 0 if we're done making decisions with the circ,
+ * or -1 if we want to probe it first.
+ */
+int
+pathbias_check_close(origin_circuit_t *ocirc, int reason)
+{
+ circuit_t *circ = ô->base_;
+
+ if (!pathbias_should_count(ocirc)) {
+ return 0;
+ }
+
+ switch (ocirc->path_state) {
+ /* If the circuit was closed after building, but before use, we need
+ * to ensure we were the ones who tried to close it (and not a remote
+ * actor). */
+ case PATH_STATE_BUILD_SUCCEEDED:
+ if (reason & END_CIRC_REASON_FLAG_REMOTE) {
+ /* Remote circ close reasons on an unused circuit all could be bias */
+ log_info(LD_CIRC,
+ "Circuit %d remote-closed without successful use for reason %d. "
+ "Circuit purpose %d currently %d,%s. Len %d.",
+ ocirc->global_identifier,
+ reason, circ->purpose, ocirc->has_opened,
+ circuit_state_to_string(circ->state),
+ ocirc->build_state->desired_path_len);
+ pathbias_count_collapse(ocirc);
+ } else if ((reason & ~END_CIRC_REASON_FLAG_REMOTE)
+ == END_CIRC_REASON_CHANNEL_CLOSED &&
+ circ->n_chan &&
+ circ->n_chan->reason_for_closing
+ != CHANNEL_CLOSE_REQUESTED) {
+ /* If we didn't close the channel ourselves, it could be bias */
+ /* XXX: Only count bias if the network is live?
+ * What about clock jumps/suspends? */
+ log_info(LD_CIRC,
+ "Circuit %d's channel closed without successful use for reason "
+ "%d, channel reason %d. Circuit purpose %d currently %d,%s. Len "
+ "%d.", ocirc->global_identifier,
+ reason, circ->n_chan->reason_for_closing,
+ circ->purpose, ocirc->has_opened,
+ circuit_state_to_string(circ->state),
+ ocirc->build_state->desired_path_len);
+ pathbias_count_collapse(ocirc);
+ } else {
+ pathbias_count_successful_close(ocirc);
+ }
+ break;
+
+ /* If we tried to use a circuit but failed, we should probe it to ensure
+ * it has not been tampered with. */
+ case PATH_STATE_USE_ATTEMPTED:
+ /* XXX: Only probe and/or count failure if the network is live?
+ * What about clock jumps/suspends? */
+ if (pathbias_send_usable_probe(circ) == 0)
+ return -1;
+ else
+ pathbias_count_use_failed(ocirc);
+
+ /* Any circuit where there were attempted streams but no successful
+ * streams could be bias */
+ log_info(LD_CIRC,
+ "Circuit %d closed without successful use for reason %d. "
+ "Circuit purpose %d currently %d,%s. Len %d.",
+ ocirc->global_identifier,
+ reason, circ->purpose, ocirc->has_opened,
+ circuit_state_to_string(circ->state),
+ ocirc->build_state->desired_path_len);
+ break;
+
+ case PATH_STATE_USE_SUCCEEDED:
+ pathbias_count_successful_close(ocirc);
+ pathbias_count_use_success(ocirc);
+ break;
+
+ case PATH_STATE_USE_FAILED:
+ pathbias_count_use_failed(ocirc);
+ break;
+
+ case PATH_STATE_NEW_CIRC:
+ case PATH_STATE_BUILD_ATTEMPTED:
+ case PATH_STATE_ALREADY_COUNTED:
+ default:
+ // Other states are uninteresting. No stats to count.
+ break;
+ }
+
+ ocirc->path_state = PATH_STATE_ALREADY_COUNTED;
+
+ return 0;
+}
+
+/**
+ * Count a successfully closed circuit.
+ */
+static void
+pathbias_count_successful_close(origin_circuit_t *circ)
+{
+ entry_guard_t *guard = NULL;
+ if (!pathbias_should_count(circ)) {
+ return;
+ }
+
+ if (circ->cpath && circ->cpath->extend_info) {
+ guard = entry_guard_get_by_id_digest(
+ circ->cpath->extend_info->identity_digest);
+ }
+
+ if (guard) {
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ /* In the long run: circuit_success ~= successful_circuit_close +
+ * circ_failure + stream_failure */
+ pb->successful_circuits_closed++;
+ entry_guards_changed();
+ } else if (circ->base_.purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) {
+ /* In rare cases, CIRCUIT_PURPOSE_TESTING can get converted to
+ * CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT and have no guards here.
+ * No need to log that case. */
+ log_info(LD_CIRC,
+ "Successfully closed circuit has no known guard. "
+ "Circuit is a %s currently %s",
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state));
+ }
+}
+
+/**
+ * Count a circuit that fails after it is built, but before it can
+ * carry any traffic.
+ *
+ * This is needed because there are ways to destroy a
+ * circuit after it has successfully completed. Right now, this is
+ * used for purely informational/debugging purposes.
+ */
+static void
+pathbias_count_collapse(origin_circuit_t *circ)
+{
+ entry_guard_t *guard = NULL;
+
+ if (!pathbias_should_count(circ)) {
+ return;
+ }
+
+ if (circ->cpath && circ->cpath->extend_info) {
+ guard = entry_guard_get_by_id_digest(
+ circ->cpath->extend_info->identity_digest);
+ }
+
+ if (guard) {
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ pb->collapsed_circuits++;
+ entry_guards_changed();
+ } else if (circ->base_.purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) {
+ /* In rare cases, CIRCUIT_PURPOSE_TESTING can get converted to
+ * CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT and have no guards here.
+ * No need to log that case. */
+ log_info(LD_CIRC,
+ "Destroyed circuit has no known guard. "
+ "Circuit is a %s currently %s",
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state));
+ }
+}
+
+/**
+ * Count a known failed circuit (because we could not probe it).
+ *
+ * This counter is informational.
+ */
+static void
+pathbias_count_use_failed(origin_circuit_t *circ)
+{
+ entry_guard_t *guard = NULL;
+ if (!pathbias_should_count(circ)) {
+ return;
+ }
+
+ if (circ->cpath && circ->cpath->extend_info) {
+ guard = entry_guard_get_by_id_digest(
+ circ->cpath->extend_info->identity_digest);
+ }
+
+ if (guard) {
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ pb->unusable_circuits++;
+ entry_guards_changed();
+ } else if (circ->base_.purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) {
+ /* In rare cases, CIRCUIT_PURPOSE_TESTING can get converted to
+ * CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT and have no guards here.
+ * No need to log that case. */
+ /* XXX note cut-and-paste code in this function compared to nearby
+ * functions. Would be nice to refactor. -RD */
+ log_info(LD_CIRC,
+ "Stream-failing circuit has no known guard. "
+ "Circuit is a %s currently %s",
+ circuit_purpose_to_string(circ->base_.purpose),
+ circuit_state_to_string(circ->base_.state));
+ }
+}
+
+/**
+ * Count timeouts for path bias log messages.
+ *
+ * These counts are purely informational.
+ */
+void
+pathbias_count_timeout(origin_circuit_t *circ)
+{
+ entry_guard_t *guard = NULL;
+
+ if (!pathbias_should_count(circ)) {
+ return;
+ }
+
+ /* For hidden service circs, they can actually be used
+ * successfully and then time out later (because
+ * the other side declines to use them). */
+ if (circ->path_state == PATH_STATE_USE_SUCCEEDED) {
+ return;
+ }
+
+ if (circ->cpath && circ->cpath->extend_info) {
+ guard = entry_guard_get_by_id_digest(
+ circ->cpath->extend_info->identity_digest);
+ }
+
+ if (guard) {
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ pb->timeouts++;
+ entry_guards_changed();
+ }
+}
+
+/**
+ * Helper function to count all of the currently opened circuits
+ * for a guard that are in a given path state range. The state
+ * range is inclusive on both ends.
+ */
+static int
+pathbias_count_circs_in_states(entry_guard_t *guard,
+ path_state_t from,
+ path_state_t to)
+{
+ int open_circuits = 0;
+
+ /* Count currently open circuits. Give them the benefit of the doubt. */
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ origin_circuit_t *ocirc = NULL;
+ if (!CIRCUIT_IS_ORIGIN(circ) || /* didn't originate here */
+ circ->marked_for_close) /* already counted */
+ continue;
+
+ ocirc = TO_ORIGIN_CIRCUIT(circ);
+
+ if (!ocirc->cpath || !ocirc->cpath->extend_info)
+ continue;
+
+ if (ocirc->path_state >= from &&
+ ocirc->path_state <= to &&
+ pathbias_should_count(ocirc) &&
+ fast_memeq(entry_guard_get_rsa_id_digest(guard),
+ ocirc->cpath->extend_info->identity_digest,
+ DIGEST_LEN)) {
+ log_debug(LD_CIRC, "Found opened circuit %d in path_state %s",
+ ocirc->global_identifier,
+ pathbias_state_to_string(ocirc->path_state));
+ open_circuits++;
+ }
+ }
+ SMARTLIST_FOREACH_END(circ);
+
+ return open_circuits;
+}
+
+/**
+ * Return the number of circuits counted as successfully closed for
+ * this guard.
+ *
+ * Also add in the currently open circuits to give them the benefit
+ * of the doubt.
+ */
+double
+pathbias_get_close_success_count(entry_guard_t *guard)
+{
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ return pb->successful_circuits_closed +
+ pathbias_count_circs_in_states(guard,
+ PATH_STATE_BUILD_SUCCEEDED,
+ PATH_STATE_USE_SUCCEEDED);
+}
+
+/**
+ * Return the number of circuits counted as successfully used
+ * this guard.
+ *
+ * Also add in the currently open circuits that we are attempting
+ * to use to give them the benefit of the doubt.
+ */
+double
+pathbias_get_use_success_count(entry_guard_t *guard)
+{
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ return pb->use_successes +
+ pathbias_count_circs_in_states(guard,
+ PATH_STATE_USE_ATTEMPTED,
+ PATH_STATE_USE_SUCCEEDED);
+}
+
+/**
+ * Check the path bias use rate against our consensus parameter limits.
+ *
+ * Emits a log message if the use success rates are too low.
+ *
+ * If pathbias_get_dropguards() is set, we also disable the use of
+ * very failure prone guards.
+ */
+static void
+pathbias_measure_use_rate(entry_guard_t *guard)
+{
+ const or_options_t *options = get_options();
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ if (pb->use_attempts > pathbias_get_min_use(options)) {
+ /* Note: We rely on the < comparison here to allow us to set a 0
+ * rate and disable the feature entirely. If refactoring, don't
+ * change to <= */
+ if (pathbias_get_use_success_count(guard)/pb->use_attempts
+ < pathbias_get_extreme_use_rate(options)) {
+ /* Dropping is currently disabled by default. */
+ if (pathbias_get_dropguards(options)) {
+ if (!pb->path_bias_disabled) {
+ log_warn(LD_CIRC,
+ "Your Guard %s is failing to carry an extremely large "
+ "amount of stream on its circuits. "
+ "To avoid potential route manipulation attacks, Tor has "
+ "disabled use of this guard. "
+ "Use counts are %ld/%ld. Success counts are %ld/%ld. "
+ "%ld circuits completed, %ld were unusable, %ld collapsed, "
+ "and %ld timed out. "
+ "For reference, your timeout cutoff is %ld seconds.",
+ entry_guard_describe(guard),
+ tor_lround(pathbias_get_use_success_count(guard)),
+ tor_lround(pb->use_attempts),
+ tor_lround(pathbias_get_close_success_count(guard)),
+ tor_lround(pb->circ_attempts),
+ tor_lround(pb->circ_successes),
+ tor_lround(pb->unusable_circuits),
+ tor_lround(pb->collapsed_circuits),
+ tor_lround(pb->timeouts),
+ tor_lround(get_circuit_build_close_time_ms()/1000));
+ pb->path_bias_disabled = 1;
+ return;
+ }
+ } else if (!pb->path_bias_use_extreme) {
+ pb->path_bias_use_extreme = 1;
+ log_warn(LD_CIRC,
+ "Your Guard %s is failing to carry an extremely large "
+ "amount of streams on its circuits. "
+ "This could indicate a route manipulation attack, network "
+ "overload, bad local network connectivity, or a bug. "
+ "Use counts are %ld/%ld. Success counts are %ld/%ld. "
+ "%ld circuits completed, %ld were unusable, %ld collapsed, "
+ "and %ld timed out. "
+ "For reference, your timeout cutoff is %ld seconds.",
+ entry_guard_describe(guard),
+ tor_lround(pathbias_get_use_success_count(guard)),
+ tor_lround(pb->use_attempts),
+ tor_lround(pathbias_get_close_success_count(guard)),
+ tor_lround(pb->circ_attempts),
+ tor_lround(pb->circ_successes),
+ tor_lround(pb->unusable_circuits),
+ tor_lround(pb->collapsed_circuits),
+ tor_lround(pb->timeouts),
+ tor_lround(get_circuit_build_close_time_ms()/1000));
+ }
+ } else if (pathbias_get_use_success_count(guard)/pb->use_attempts
+ < pathbias_get_notice_use_rate(options)) {
+ if (!pb->path_bias_use_noticed) {
+ pb->path_bias_use_noticed = 1;
+ log_notice(LD_CIRC,
+ "Your Guard %s is failing to carry more streams on its "
+ "circuits than usual. "
+ "Most likely this means the Tor network is overloaded "
+ "or your network connection is poor. "
+ "Use counts are %ld/%ld. Success counts are %ld/%ld. "
+ "%ld circuits completed, %ld were unusable, %ld collapsed, "
+ "and %ld timed out. "
+ "For reference, your timeout cutoff is %ld seconds.",
+ entry_guard_describe(guard),
+ tor_lround(pathbias_get_use_success_count(guard)),
+ tor_lround(pb->use_attempts),
+ tor_lround(pathbias_get_close_success_count(guard)),
+ tor_lround(pb->circ_attempts),
+ tor_lround(pb->circ_successes),
+ tor_lround(pb->unusable_circuits),
+ tor_lround(pb->collapsed_circuits),
+ tor_lround(pb->timeouts),
+ tor_lround(get_circuit_build_close_time_ms()/1000));
+ }
+ }
+ }
+}
+
+/**
+ * Check the path bias circuit close status rates against our consensus
+ * parameter limits.
+ *
+ * Emits a log message if the use success rates are too low.
+ *
+ * If pathbias_get_dropguards() is set, we also disable the use of
+ * very failure prone guards.
+ *
+ * XXX: This function shares similar log messages and checks to
+ * pathbias_measure_use_rate(). It may be possible to combine them
+ * eventually, especially if we can ever remove the need for 3
+ * levels of closure warns (if the overall circuit failure rate
+ * goes down with ntor). One way to do so would be to multiply
+ * the build rate with the use rate to get an idea of the total
+ * fraction of the total network paths the user is able to use.
+ * See ticket #8159.
+ */
+static void
+pathbias_measure_close_rate(entry_guard_t *guard)
+{
+ const or_options_t *options = get_options();
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ if (pb->circ_attempts > pathbias_get_min_circs(options)) {
+ /* Note: We rely on the < comparison here to allow us to set a 0
+ * rate and disable the feature entirely. If refactoring, don't
+ * change to <= */
+ if (pathbias_get_close_success_count(guard)/pb->circ_attempts
+ < pathbias_get_extreme_rate(options)) {
+ /* Dropping is currently disabled by default. */
+ if (pathbias_get_dropguards(options)) {
+ if (!pb->path_bias_disabled) {
+ log_warn(LD_CIRC,
+ "Your Guard %s is failing an extremely large "
+ "amount of circuits. "
+ "To avoid potential route manipulation attacks, Tor has "
+ "disabled use of this guard. "
+ "Success counts are %ld/%ld. Use counts are %ld/%ld. "
+ "%ld circuits completed, %ld were unusable, %ld collapsed, "
+ "and %ld timed out. "
+ "For reference, your timeout cutoff is %ld seconds.",
+ entry_guard_describe(guard),
+ tor_lround(pathbias_get_close_success_count(guard)),
+ tor_lround(pb->circ_attempts),
+ tor_lround(pathbias_get_use_success_count(guard)),
+ tor_lround(pb->use_attempts),
+ tor_lround(pb->circ_successes),
+ tor_lround(pb->unusable_circuits),
+ tor_lround(pb->collapsed_circuits),
+ tor_lround(pb->timeouts),
+ tor_lround(get_circuit_build_close_time_ms()/1000));
+ pb->path_bias_disabled = 1;
+ return;
+ }
+ } else if (!pb->path_bias_extreme) {
+ pb->path_bias_extreme = 1;
+ log_warn(LD_CIRC,
+ "Your Guard %s is failing an extremely large "
+ "amount of circuits. "
+ "This could indicate a route manipulation attack, "
+ "extreme network overload, or a bug. "
+ "Success counts are %ld/%ld. Use counts are %ld/%ld. "
+ "%ld circuits completed, %ld were unusable, %ld collapsed, "
+ "and %ld timed out. "
+ "For reference, your timeout cutoff is %ld seconds.",
+ entry_guard_describe(guard),
+ tor_lround(pathbias_get_close_success_count(guard)),
+ tor_lround(pb->circ_attempts),
+ tor_lround(pathbias_get_use_success_count(guard)),
+ tor_lround(pb->use_attempts),
+ tor_lround(pb->circ_successes),
+ tor_lround(pb->unusable_circuits),
+ tor_lround(pb->collapsed_circuits),
+ tor_lround(pb->timeouts),
+ tor_lround(get_circuit_build_close_time_ms()/1000));
+ }
+ } else if (pathbias_get_close_success_count(guard)/pb->circ_attempts
+ < pathbias_get_warn_rate(options)) {
+ if (!pb->path_bias_warned) {
+ pb->path_bias_warned = 1;
+ log_warn(LD_CIRC,
+ "Your Guard %s is failing a very large "
+ "amount of circuits. "
+ "Most likely this means the Tor network is "
+ "overloaded, but it could also mean an attack against "
+ "you or potentially the guard itself. "
+ "Success counts are %ld/%ld. Use counts are %ld/%ld. "
+ "%ld circuits completed, %ld were unusable, %ld collapsed, "
+ "and %ld timed out. "
+ "For reference, your timeout cutoff is %ld seconds.",
+ entry_guard_describe(guard),
+ tor_lround(pathbias_get_close_success_count(guard)),
+ tor_lround(pb->circ_attempts),
+ tor_lround(pathbias_get_use_success_count(guard)),
+ tor_lround(pb->use_attempts),
+ tor_lround(pb->circ_successes),
+ tor_lround(pb->unusable_circuits),
+ tor_lround(pb->collapsed_circuits),
+ tor_lround(pb->timeouts),
+ tor_lround(get_circuit_build_close_time_ms()/1000));
+ }
+ } else if (pathbias_get_close_success_count(guard)/pb->circ_attempts
+ < pathbias_get_notice_rate(options)) {
+ if (!pb->path_bias_noticed) {
+ pb->path_bias_noticed = 1;
+ log_notice(LD_CIRC,
+ "Your Guard %s is failing more circuits than "
+ "usual. "
+ "Most likely this means the Tor network is overloaded. "
+ "Success counts are %ld/%ld. Use counts are %ld/%ld. "
+ "%ld circuits completed, %ld were unusable, %ld collapsed, "
+ "and %ld timed out. "
+ "For reference, your timeout cutoff is %ld seconds.",
+ entry_guard_describe(guard),
+ tor_lround(pathbias_get_close_success_count(guard)),
+ tor_lround(pb->circ_attempts),
+ tor_lround(pathbias_get_use_success_count(guard)),
+ tor_lround(pb->use_attempts),
+ tor_lround(pb->circ_successes),
+ tor_lround(pb->unusable_circuits),
+ tor_lround(pb->collapsed_circuits),
+ tor_lround(pb->timeouts),
+ tor_lround(get_circuit_build_close_time_ms()/1000));
+ }
+ }
+ }
+}
+
+/**
+ * This function scales the path bias use rates if we have
+ * more data than the scaling threshold. This allows us to
+ * be more sensitive to recent measurements.
+ *
+ * XXX: The attempt count transfer stuff here might be done
+ * better by keeping separate pending counters that get
+ * transferred at circuit close. See ticket #8160.
+ */
+static void
+pathbias_scale_close_rates(entry_guard_t *guard)
+{
+ const or_options_t *options = get_options();
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ /* If we get a ton of circuits, just scale everything down */
+ if (pb->circ_attempts > pathbias_get_scale_threshold(options)) {
+ double scale_ratio = pathbias_get_scale_ratio(options);
+ int opened_attempts = pathbias_count_circs_in_states(guard,
+ PATH_STATE_BUILD_ATTEMPTED, PATH_STATE_BUILD_ATTEMPTED);
+ int opened_built = pathbias_count_circs_in_states(guard,
+ PATH_STATE_BUILD_SUCCEEDED,
+ PATH_STATE_USE_FAILED);
+ /* Verify that the counts are sane before and after scaling */
+ int counts_are_sane = (pb->circ_attempts >= pb->circ_successes);
+
+ pb->circ_attempts -= (opened_attempts+opened_built);
+ pb->circ_successes -= opened_built;
+
+ pb->circ_attempts *= scale_ratio;
+ pb->circ_successes *= scale_ratio;
+ pb->timeouts *= scale_ratio;
+ pb->successful_circuits_closed *= scale_ratio;
+ pb->collapsed_circuits *= scale_ratio;
+ pb->unusable_circuits *= scale_ratio;
+
+ pb->circ_attempts += (opened_attempts+opened_built);
+ pb->circ_successes += opened_built;
+
+ entry_guards_changed();
+
+ log_info(LD_CIRC,
+ "Scaled pathbias counts to (%f,%f)/%f (%d/%d open) for guard "
+ "%s",
+ pb->circ_successes, pb->successful_circuits_closed,
+ pb->circ_attempts, opened_built, opened_attempts,
+ entry_guard_describe(guard));
+
+ /* Have the counts just become invalid by this scaling attempt? */
+ if (counts_are_sane && pb->circ_attempts < pb->circ_successes) {
+ log_notice(LD_BUG,
+ "Scaling has mangled pathbias counts to %f/%f (%d/%d open) "
+ "for guard %s",
+ pb->circ_successes, pb->circ_attempts, opened_built,
+ opened_attempts,
+ entry_guard_describe(guard));
+ }
+ }
+}
+
+/**
+ * This function scales the path bias circuit close rates if we have
+ * more data than the scaling threshold. This allows us to be more
+ * sensitive to recent measurements.
+ *
+ * XXX: The attempt count transfer stuff here might be done
+ * better by keeping separate pending counters that get
+ * transferred at circuit close. See ticket #8160.
+ */
+void
+pathbias_scale_use_rates(entry_guard_t *guard)
+{
+ const or_options_t *options = get_options();
+ guard_pathbias_t *pb = entry_guard_get_pathbias_state(guard);
+
+ /* If we get a ton of circuits, just scale everything down */
+ if (pb->use_attempts > pathbias_get_scale_use_threshold(options)) {
+ double scale_ratio = pathbias_get_scale_ratio(options);
+ int opened_attempts = pathbias_count_circs_in_states(guard,
+ PATH_STATE_USE_ATTEMPTED, PATH_STATE_USE_SUCCEEDED);
+ /* Verify that the counts are sane before and after scaling */
+ int counts_are_sane = (pb->use_attempts >= pb->use_successes);
+
+ pb->use_attempts -= opened_attempts;
+
+ pb->use_attempts *= scale_ratio;
+ pb->use_successes *= scale_ratio;
+
+ pb->use_attempts += opened_attempts;
+
+ log_info(LD_CIRC,
+ "Scaled pathbias use counts to %f/%f (%d open) for guard %s",
+ pb->use_successes, pb->use_attempts, opened_attempts,
+ entry_guard_describe(guard));
+
+ /* Have the counts just become invalid by this scaling attempt? */
+ if (counts_are_sane && pb->use_attempts < pb->use_successes) {
+ log_notice(LD_BUG,
+ "Scaling has mangled pathbias usage counts to %f/%f "
+ "(%d open) for guard %s",
+ pb->circ_successes, pb->circ_attempts,
+ opened_attempts, entry_guard_describe(guard));
+ }
+
+ entry_guards_changed();
+ }
+}
diff --cc src/feature/client/circpathbias.h
index c99d1277b,000000000..9ce4a6b23
mode 100644,000000..100644
--- a/src/feature/client/circpathbias.h
+++ b/src/feature/client/circpathbias.h
@@@ -1,28 -1,0 +1,29 @@@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file circuitbuild.h
+ * \brief Header file for circuitbuild.c.
+ **/
+
+#ifndef TOR_CIRCPATHBIAS_H
+#define TOR_CIRCPATHBIAS_H
+
+double pathbias_get_extreme_rate(const or_options_t *options);
+double pathbias_get_extreme_use_rate(const or_options_t *options);
+int pathbias_get_dropguards(const or_options_t *options);
+void pathbias_count_timeout(origin_circuit_t *circ);
+void pathbias_count_build_success(origin_circuit_t *circ);
+int pathbias_count_build_attempt(origin_circuit_t *circ);
+int pathbias_check_close(origin_circuit_t *circ, int reason);
+int pathbias_check_probe_response(circuit_t *circ, const cell_t *cell);
++void pathbias_count_valid_cells(circuit_t *circ, const cell_t *cell);
+void pathbias_count_use_attempt(origin_circuit_t *circ);
+void pathbias_mark_use_success(origin_circuit_t *circ);
+void pathbias_mark_use_rollback(origin_circuit_t *circ);
+const char *pathbias_state_to_string(enum path_state_t state);
+
+#endif /* !defined(TOR_CIRCPATHBIAS_H) */
diff --cc src/lib/container/smartlist.c
index 4b29d834d,000000000..64cabfcc6
mode 100644,000000..100644
--- a/src/lib/container/smartlist.c
+++ b/src/lib/container/smartlist.c
@@@ -1,866 -1,0 +1,866 @@@
+/* Copyright (c) 2003-2004, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file smartlist.c
+ *
+ * \brief Higher-level functions for the "smartlist" resizeable array
+ * abstraction.
+ *
+ * The functions declared here use higher-level functionality than those in
+ * smartlist_core.c, and handle things like smartlists of different types,
+ * sorting, searching, heap-structured smartlists, and other convenience
+ * functions.
+ **/
+
+#include "lib/container/smartlist.h"
+#include "lib/err/torerr.h"
+#include "lib/malloc/malloc.h"
+#include "lib/defs/digest_sizes.h"
+#include "lib/ctime/di_ops.h"
+#include "lib/string/compat_ctype.h"
+#include "lib/string/compat_string.h"
+#include "lib/string/util_string.h"
+#include "lib/string/printf.h"
+
+#include "lib/log/util_bug.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+/** Append the string produced by tor_asprintf(<b>pattern</b>, <b>...</b>)
+ * to <b>sl</b>. */
+void
+smartlist_add_asprintf(struct smartlist_t *sl, const char *pattern, ...)
+{
+ va_list ap;
+ va_start(ap, pattern);
+ smartlist_add_vasprintf(sl, pattern, ap);
+ va_end(ap);
+}
+
+/** va_list-based backend of smartlist_add_asprintf. */
+void
+smartlist_add_vasprintf(struct smartlist_t *sl, const char *pattern,
+ va_list args)
+{
+ char *str = NULL;
+
+ tor_vasprintf(&str, pattern, args);
+ tor_assert(str != NULL);
+
+ smartlist_add(sl, str);
+}
+
+/** Reverse the order of the items in <b>sl</b>. */
+void
+smartlist_reverse(smartlist_t *sl)
+{
+ int i, j;
+ void *tmp;
+ tor_assert(sl);
+ for (i = 0, j = sl->num_used-1; i < j; ++i, --j) {
+ tmp = sl->list[i];
+ sl->list[i] = sl->list[j];
+ sl->list[j] = tmp;
+ }
+}
+
+/** If there are any strings in sl equal to element, remove and free them.
+ * Does not preserve order. */
+void
+smartlist_string_remove(smartlist_t *sl, const char *element)
+{
+ int i;
+ tor_assert(sl);
+ tor_assert(element);
+ for (i = 0; i < sl->num_used; ++i) {
+ if (!strcmp(element, sl->list[i])) {
+ tor_free(sl->list[i]);
+ sl->list[i] = sl->list[--sl->num_used]; /* swap with the end */
+ i--; /* so we process the new i'th element */
+ sl->list[sl->num_used] = NULL;
+ }
+ }
+}
+
+/** Return true iff <b>sl</b> has some element E such that
+ * !strcmp(E,<b>element</b>)
+ */
+int
+smartlist_contains_string(const smartlist_t *sl, const char *element)
+{
+ int i;
+ if (!sl) return 0;
+ for (i=0; i < sl->num_used; i++)
+ if (strcmp((const char*)sl->list[i],element)==0)
+ return 1;
+ return 0;
+}
+
+/** If <b>element</b> is equal to an element of <b>sl</b>, return that
+ * element's index. Otherwise, return -1. */
+int
+smartlist_string_pos(const smartlist_t *sl, const char *element)
+{
+ int i;
+ if (!sl) return -1;
+ for (i=0; i < sl->num_used; i++)
+ if (strcmp((const char*)sl->list[i],element)==0)
+ return i;
+ return -1;
+}
+
+/** If <b>element</b> is the same pointer as an element of <b>sl</b>, return
+ * that element's index. Otherwise, return -1. */
+int
+smartlist_pos(const smartlist_t *sl, const void *element)
+{
+ int i;
+ if (!sl) return -1;
+ for (i=0; i < sl->num_used; i++)
+ if (element == sl->list[i])
+ return i;
+ return -1;
+}
+
+/** Return true iff <b>sl</b> has some element E such that
+ * !strcasecmp(E,<b>element</b>)
+ */
+int
+smartlist_contains_string_case(const smartlist_t *sl, const char *element)
+{
+ int i;
+ if (!sl) return 0;
+ for (i=0; i < sl->num_used; i++)
+ if (strcasecmp((const char*)sl->list[i],element)==0)
+ return 1;
+ return 0;
+}
+
+/** Return true iff <b>sl</b> has some element E such that E is equal
+ * to the decimal encoding of <b>num</b>.
+ */
+int
+smartlist_contains_int_as_string(const smartlist_t *sl, int num)
+{
+ char buf[32]; /* long enough for 64-bit int, and then some. */
+ tor_snprintf(buf,sizeof(buf),"%d", num);
+ return smartlist_contains_string(sl, buf);
+}
+
+/** Return true iff the two lists contain the same strings in the same
+ * order, or if they are both NULL. */
+int
+smartlist_strings_eq(const smartlist_t *sl1, const smartlist_t *sl2)
+{
+ if (sl1 == NULL)
+ return sl2 == NULL;
+ if (sl2 == NULL)
+ return 0;
+ if (smartlist_len(sl1) != smartlist_len(sl2))
+ return 0;
+ SMARTLIST_FOREACH(sl1, const char *, cp1, {
+ const char *cp2 = smartlist_get(sl2, cp1_sl_idx);
+ if (strcmp(cp1, cp2))
+ return 0;
+ });
+ return 1;
+}
+
+/** Return true iff the two lists contain the same int pointer values in
+ * the same order, or if they are both NULL. */
+int
+smartlist_ints_eq(const smartlist_t *sl1, const smartlist_t *sl2)
+{
+ if (sl1 == NULL)
+ return sl2 == NULL;
+ if (sl2 == NULL)
+ return 0;
+ if (smartlist_len(sl1) != smartlist_len(sl2))
+ return 0;
+ SMARTLIST_FOREACH(sl1, int *, cp1, {
+ int *cp2 = smartlist_get(sl2, cp1_sl_idx);
+ if (*cp1 != *cp2)
+ return 0;
+ });
+ return 1;
+}
+
+/**
+ * Return true if there is shallow equality between smartlists -
+ * i.e. all indices correspond to exactly same object (pointer
+ * values are matching). Otherwise, return false.
+ */
+int
+smartlist_ptrs_eq(const smartlist_t *s1, const smartlist_t *s2)
+{
+ if (s1 == s2)
+ return 1;
+
+ // Note: pointers cannot both be NULL at this point, because
+ // above check.
+ if (s1 == NULL || s2 == NULL)
+ return 0;
+
+ if (smartlist_len(s1) != smartlist_len(s2))
+ return 0;
+
+ for (int i = 0; i < smartlist_len(s1); i++) {
+ if (smartlist_get(s1, i) != smartlist_get(s2, i))
+ return 0;
+ }
+
+ return 1;
+}
+
+/** Return true iff <b>sl</b> has some element E such that
+ * tor_memeq(E,<b>element</b>,DIGEST_LEN)
+ */
+int
+smartlist_contains_digest(const smartlist_t *sl, const char *element)
+{
+ int i;
+ if (!sl) return 0;
+ for (i=0; i < sl->num_used; i++)
+ if (tor_memeq((const char*)sl->list[i],element,DIGEST_LEN))
+ return 1;
+ return 0;
+}
+
+/** Return true iff some element E of sl2 has smartlist_contains(sl1,E).
+ */
+int
+smartlist_overlap(const smartlist_t *sl1, const smartlist_t *sl2)
+{
+ int i;
+ for (i=0; i < sl2->num_used; i++)
+ if (smartlist_contains(sl1, sl2->list[i]))
+ return 1;
+ return 0;
+}
+
+/** Remove every element E of sl1 such that !smartlist_contains(sl2,E).
+ * Does not preserve the order of sl1.
+ */
+void
+smartlist_intersect(smartlist_t *sl1, const smartlist_t *sl2)
+{
+ int i;
+ for (i=0; i < sl1->num_used; i++)
+ if (!smartlist_contains(sl2, sl1->list[i])) {
+ sl1->list[i] = sl1->list[--sl1->num_used]; /* swap with the end */
+ i--; /* so we process the new i'th element */
+ sl1->list[sl1->num_used] = NULL;
+ }
+}
+
+/** Remove every element E of sl1 such that smartlist_contains(sl2,E).
+ * Does not preserve the order of sl1.
+ */
+void
+smartlist_subtract(smartlist_t *sl1, const smartlist_t *sl2)
+{
+ int i;
+ for (i=0; i < sl2->num_used; i++)
+ smartlist_remove(sl1, sl2->list[i]);
+}
+
+/** Allocate and return a new string containing the concatenation of
+ * the elements of <b>sl</b>, in order, separated by <b>join</b>. If
+ * <b>terminate</b> is true, also terminate the string with <b>join</b>.
+ * If <b>len_out</b> is not NULL, set <b>len_out</b> to the length of
+ * the returned string. Requires that every element of <b>sl</b> is
+ * NUL-terminated string.
+ */
+char *
+smartlist_join_strings(smartlist_t *sl, const char *join,
+ int terminate, size_t *len_out)
+{
+ return smartlist_join_strings2(sl,join,strlen(join),terminate,len_out);
+}
+
+/** As smartlist_join_strings, but instead of separating/terminated with a
+ * NUL-terminated string <b>join</b>, uses the <b>join_len</b>-byte sequence
+ * at <b>join</b>. (Useful for generating a sequence of NUL-terminated
+ * strings.)
+ */
+char *
+smartlist_join_strings2(smartlist_t *sl, const char *join,
+ size_t join_len, int terminate, size_t *len_out)
+{
+ int i;
+ size_t n = 0;
+ char *r = NULL, *dst, *src;
+
+ tor_assert(sl);
+ tor_assert(join);
+
+ if (terminate)
+ n = join_len;
+
+ for (i = 0; i < sl->num_used; ++i) {
+ n += strlen(sl->list[i]);
+ if (i+1 < sl->num_used) /* avoid double-counting the last one */
+ n += join_len;
+ }
+ dst = r = tor_malloc(n+1);
+ for (i = 0; i < sl->num_used; ) {
+ for (src = sl->list[i]; *src; )
+ *dst++ = *src++;
+ if (++i < sl->num_used) {
+ memcpy(dst, join, join_len);
+ dst += join_len;
+ }
+ }
+ if (terminate) {
+ memcpy(dst, join, join_len);
+ dst += join_len;
+ }
+ *dst = '\0';
+
+ if (len_out)
+ *len_out = dst-r;
+ return r;
+}
+
+/** Sort the members of <b>sl</b> into an order defined by
+ * the ordering function <b>compare</b>, which returns less then 0 if a
+ * precedes b, greater than 0 if b precedes a, and 0 if a 'equals' b.
+ */
+void
+smartlist_sort(smartlist_t *sl, int (*compare)(const void **a, const void **b))
+{
+ if (!sl->num_used)
+ return;
+ qsort(sl->list, sl->num_used, sizeof(void*),
+ (int (*)(const void *,const void*))compare);
+}
+
+/** Given a smartlist <b>sl</b> sorted with the function <b>compare</b>,
+ * return the most frequent member in the list. Break ties in favor of
+ * later elements. If the list is empty, return NULL. If count_out is
+ * non-null, set it to the count of the most frequent member.
+ */
+void *
+smartlist_get_most_frequent_(const smartlist_t *sl,
+ int (*compare)(const void **a, const void **b),
+ int *count_out)
+{
+ const void *most_frequent = NULL;
+ int most_frequent_count = 0;
+
+ const void *cur = NULL;
+ int i, count=0;
+
+ if (!sl->num_used) {
+ if (count_out)
+ *count_out = 0;
+ return NULL;
+ }
+ for (i = 0; i < sl->num_used; ++i) {
+ const void *item = sl->list[i];
+ if (cur && 0 == compare(&cur, &item)) {
+ ++count;
+ } else {
+ if (cur && count >= most_frequent_count) {
+ most_frequent = cur;
+ most_frequent_count = count;
+ }
+ cur = item;
+ count = 1;
+ }
+ }
+ if (cur && count >= most_frequent_count) {
+ most_frequent = cur;
+ most_frequent_count = count;
+ }
+ if (count_out)
+ *count_out = most_frequent_count;
+ return (void*)most_frequent;
+}
+
+/** Given a sorted smartlist <b>sl</b> and the comparison function used to
+ * sort it, remove all duplicate members. If free_fn is provided, calls
+ * free_fn on each duplicate. Otherwise, just removes them. Preserves order.
+ */
+void
+smartlist_uniq(smartlist_t *sl,
+ int (*compare)(const void **a, const void **b),
+ void (*free_fn)(void *a))
+{
+ int i;
+ for (i=1; i < sl->num_used; ++i) {
+ if (compare((const void **)&(sl->list[i-1]),
+ (const void **)&(sl->list[i])) == 0) {
+ if (free_fn)
+ free_fn(sl->list[i]);
+ smartlist_del_keeporder(sl, i--);
+ }
+ }
+}
+
+/** Assuming the members of <b>sl</b> are in order, return a pointer to the
+ * member that matches <b>key</b>. Ordering and matching are defined by a
+ * <b>compare</b> function that returns 0 on a match; less than 0 if key is
+ * less than member, and greater than 0 if key is greater then member.
+ */
+void *
- smartlist_bsearch(smartlist_t *sl, const void *key,
++smartlist_bsearch(const smartlist_t *sl, const void *key,
+ int (*compare)(const void *key, const void **member))
+{
+ int found, idx;
+ idx = smartlist_bsearch_idx(sl, key, compare, &found);
+ return found ? smartlist_get(sl, idx) : NULL;
+}
+
+/** Assuming the members of <b>sl</b> are in order, return the index of the
+ * member that matches <b>key</b>. If no member matches, return the index of
+ * the first member greater than <b>key</b>, or smartlist_len(sl) if no member
+ * is greater than <b>key</b>. Set <b>found_out</b> to true on a match, to
+ * false otherwise. Ordering and matching are defined by a <b>compare</b>
+ * function that returns 0 on a match; less than 0 if key is less than member,
+ * and greater than 0 if key is greater then member.
+ */
+int
+smartlist_bsearch_idx(const smartlist_t *sl, const void *key,
+ int (*compare)(const void *key, const void **member),
+ int *found_out)
+{
+ int hi, lo, cmp, mid, len, diff;
+
+ tor_assert(sl);
+ tor_assert(compare);
+ tor_assert(found_out);
+
+ len = smartlist_len(sl);
+
+ /* Check for the trivial case of a zero-length list */
+ if (len == 0) {
+ *found_out = 0;
+ /* We already know smartlist_len(sl) is 0 in this case */
+ return 0;
+ }
+
+ /* Okay, we have a real search to do */
+ tor_assert(len > 0);
+ lo = 0;
+ hi = len - 1;
+
+ /*
+ * These invariants are always true:
+ *
+ * For all i such that 0 <= i < lo, sl[i] < key
+ * For all i such that hi < i <= len, sl[i] > key
+ */
+
+ while (lo <= hi) {
+ diff = hi - lo;
+ /*
+ * We want mid = (lo + hi) / 2, but that could lead to overflow, so
+ * instead diff = hi - lo (non-negative because of loop condition), and
+ * then hi = lo + diff, mid = (lo + lo + diff) / 2 = lo + (diff / 2).
+ */
+ mid = lo + (diff / 2);
+ cmp = compare(key, (const void**) &(sl->list[mid]));
+ if (cmp == 0) {
+ /* sl[mid] == key; we found it */
+ *found_out = 1;
+ return mid;
+ } else if (cmp > 0) {
+ /*
+ * key > sl[mid] and an index i such that sl[i] == key must
+ * have i > mid if it exists.
+ */
+
+ /*
+ * Since lo <= mid <= hi, hi can only decrease on each iteration (by
+ * being set to mid - 1) and hi is initially len - 1, mid < len should
+ * always hold, and this is not symmetric with the left end of list
+ * mid > 0 test below. A key greater than the right end of the list
+ * should eventually lead to lo == hi == mid == len - 1, and then
+ * we set lo to len below and fall out to the same exit we hit for
+ * a key in the middle of the list but not matching. Thus, we just
+ * assert for consistency here rather than handle a mid == len case.
+ */
+ tor_assert(mid < len);
+ /* Move lo to the element immediately after sl[mid] */
+ lo = mid + 1;
+ } else {
+ /* This should always be true in this case */
+ tor_assert(cmp < 0);
+
+ /*
+ * key < sl[mid] and an index i such that sl[i] == key must
+ * have i < mid if it exists.
+ */
+
+ if (mid > 0) {
+ /* Normal case, move hi to the element immediately before sl[mid] */
+ hi = mid - 1;
+ } else {
+ /* These should always be true in this case */
+ tor_assert(mid == lo);
+ tor_assert(mid == 0);
+ /*
+ * We were at the beginning of the list and concluded that every
+ * element e compares e > key.
+ */
+ *found_out = 0;
+ return 0;
+ }
+ }
+ }
+
+ /*
+ * lo > hi; we have no element matching key but we have elements falling
+ * on both sides of it. The lo index points to the first element > key.
+ */
+ tor_assert(lo == hi + 1); /* All other cases should have been handled */
+ tor_assert(lo >= 0);
+ tor_assert(lo <= len);
+ tor_assert(hi >= 0);
+ tor_assert(hi <= len);
+
+ if (lo < len) {
+ cmp = compare(key, (const void **) &(sl->list[lo]));
+ tor_assert(cmp < 0);
+ } else {
+ cmp = compare(key, (const void **) &(sl->list[len-1]));
+ tor_assert(cmp > 0);
+ }
+
+ *found_out = 0;
+ return lo;
+}
+
+/** Helper: compare two const char **s. */
+static int
+compare_string_ptrs_(const void **_a, const void **_b)
+{
+ return strcmp((const char*)*_a, (const char*)*_b);
+}
+
+/** Sort a smartlist <b>sl</b> containing strings into lexically ascending
+ * order. */
+void
+smartlist_sort_strings(smartlist_t *sl)
+{
+ smartlist_sort(sl, compare_string_ptrs_);
+}
+
+/** Return the most frequent string in the sorted list <b>sl</b> */
+const char *
+smartlist_get_most_frequent_string(smartlist_t *sl)
+{
+ return smartlist_get_most_frequent(sl, compare_string_ptrs_);
+}
+
+/** Return the most frequent string in the sorted list <b>sl</b>.
+ * If <b>count_out</b> is provided, set <b>count_out</b> to the
+ * number of times that string appears.
+ */
+const char *
+smartlist_get_most_frequent_string_(smartlist_t *sl, int *count_out)
+{
+ return smartlist_get_most_frequent_(sl, compare_string_ptrs_, count_out);
+}
+
+/** Remove duplicate strings from a sorted list, and free them with tor_free().
+ */
+void
+smartlist_uniq_strings(smartlist_t *sl)
+{
+ smartlist_uniq(sl, compare_string_ptrs_, tor_free_);
+}
+
+/** Helper: compare two pointers. */
+static int
+compare_ptrs_(const void **_a, const void **_b)
+{
+ const void *a = *_a, *b = *_b;
+ if (a<b)
+ return -1;
+ else if (a==b)
+ return 0;
+ else
+ return 1;
+}
+
+/** Sort <b>sl</b> in ascending order of the pointers it contains. */
+void
+smartlist_sort_pointers(smartlist_t *sl)
+{
+ smartlist_sort(sl, compare_ptrs_);
+}
+
+/* Heap-based priority queue implementation for O(lg N) insert and remove.
+ * Recall that the heap property is that, for every index I, h[I] <
+ * H[LEFT_CHILD[I]] and h[I] < H[RIGHT_CHILD[I]].
+ *
+ * For us to remove items other than the topmost item, each item must store
+ * its own index within the heap. When calling the pqueue functions, tell
+ * them about the offset of the field that stores the index within the item.
+ *
+ * Example:
+ *
+ * typedef struct timer_t {
+ * struct timeval tv;
+ * int heap_index;
+ * } timer_t;
+ *
+ * static int compare(const void *p1, const void *p2) {
+ * const timer_t *t1 = p1, *t2 = p2;
+ * if (t1->tv.tv_sec < t2->tv.tv_sec) {
+ * return -1;
+ * } else if (t1->tv.tv_sec > t2->tv.tv_sec) {
+ * return 1;
+ * } else {
+ * return t1->tv.tv_usec - t2->tv_usec;
+ * }
+ * }
+ *
+ * void timer_heap_insert(smartlist_t *heap, timer_t *timer) {
+ * smartlist_pqueue_add(heap, compare, offsetof(timer_t, heap_index),
+ * timer);
+ * }
+ *
+ * void timer_heap_pop(smartlist_t *heap) {
+ * return smartlist_pqueue_pop(heap, compare,
+ * offsetof(timer_t, heap_index));
+ * }
+ */
+
+/** @{ */
+/** Functions to manipulate heap indices to find a node's parent and children.
+ *
+ * For a 1-indexed array, we would use LEFT_CHILD[x] = 2*x and RIGHT_CHILD[x]
+ * = 2*x + 1. But this is C, so we have to adjust a little. */
+
+/* MAX_PARENT_IDX is the largest IDX in the smartlist which might have
+ * children whose indices fit inside an int.
+ * LEFT_CHILD(MAX_PARENT_IDX) == INT_MAX-2;
+ * RIGHT_CHILD(MAX_PARENT_IDX) == INT_MAX-1;
+ * LEFT_CHILD(MAX_PARENT_IDX + 1) == INT_MAX // impossible, see max list size.
+ */
+#define MAX_PARENT_IDX ((INT_MAX - 2) / 2)
+/* If this is true, then i is small enough to potentially have children
+ * in the smartlist, and it is save to use LEFT_CHILD/RIGHT_CHILD on it. */
+#define IDX_MAY_HAVE_CHILDREN(i) ((i) <= MAX_PARENT_IDX)
+#define LEFT_CHILD(i) ( 2*(i) + 1 )
+#define RIGHT_CHILD(i) ( 2*(i) + 2 )
+#define PARENT(i) ( ((i)-1) / 2 )
+/** }@ */
+
+/** @{ */
+/** Helper macros for heaps: Given a local variable <b>idx_field_offset</b>
+ * set to the offset of an integer index within the heap element structure,
+ * IDX_OF_ITEM(p) gives you the index of p, and IDXP(p) gives you a pointer to
+ * where p's index is stored. Given additionally a local smartlist <b>sl</b>,
+ * UPDATE_IDX(i) sets the index of the element at <b>i</b> to the correct
+ * value (that is, to <b>i</b>).
+ */
+#define IDXP(p) ((int*)STRUCT_VAR_P(p, idx_field_offset))
+
+#define UPDATE_IDX(i) do { \
+ void *updated = sl->list[i]; \
+ *IDXP(updated) = i; \
+ } while (0)
+
+#define IDX_OF_ITEM(p) (*IDXP(p))
+/** @} */
+
+/** Helper. <b>sl</b> may have at most one violation of the heap property:
+ * the item at <b>idx</b> may be greater than one or both of its children.
+ * Restore the heap property. */
+static inline void
+smartlist_heapify(smartlist_t *sl,
+ int (*compare)(const void *a, const void *b),
+ int idx_field_offset,
+ int idx)
+{
+ while (1) {
+ if (! IDX_MAY_HAVE_CHILDREN(idx)) {
+ /* idx is so large that it cannot have any children, since doing so
+ * would mean the smartlist was over-capacity. Therefore it cannot
+ * violate the heap property by being greater than a child (since it
+ * doesn't have any). */
+ return;
+ }
+
+ int left_idx = LEFT_CHILD(idx);
+ int best_idx;
+
+ if (left_idx >= sl->num_used)
+ return;
+ if (compare(sl->list[idx],sl->list[left_idx]) < 0)
+ best_idx = idx;
+ else
+ best_idx = left_idx;
+ if (left_idx+1 < sl->num_used &&
+ compare(sl->list[left_idx+1],sl->list[best_idx]) < 0)
+ best_idx = left_idx + 1;
+
+ if (best_idx == idx) {
+ return;
+ } else {
+ void *tmp = sl->list[idx];
+ sl->list[idx] = sl->list[best_idx];
+ sl->list[best_idx] = tmp;
+ UPDATE_IDX(idx);
+ UPDATE_IDX(best_idx);
+
+ idx = best_idx;
+ }
+ }
+}
+
+/** Insert <b>item</b> into the heap stored in <b>sl</b>, where order is
+ * determined by <b>compare</b> and the offset of the item in the heap is
+ * stored in an int-typed field at position <b>idx_field_offset</b> within
+ * item.
+ */
+void
+smartlist_pqueue_add(smartlist_t *sl,
+ int (*compare)(const void *a, const void *b),
+ int idx_field_offset,
+ void *item)
+{
+ int idx;
+ smartlist_add(sl,item);
+ UPDATE_IDX(sl->num_used-1);
+
+ for (idx = sl->num_used - 1; idx; ) {
+ int parent = PARENT(idx);
+ if (compare(sl->list[idx], sl->list[parent]) < 0) {
+ void *tmp = sl->list[parent];
+ sl->list[parent] = sl->list[idx];
+ sl->list[idx] = tmp;
+ UPDATE_IDX(parent);
+ UPDATE_IDX(idx);
+ idx = parent;
+ } else {
+ return;
+ }
+ }
+}
+
+/** Remove and return the top-priority item from the heap stored in <b>sl</b>,
+ * where order is determined by <b>compare</b> and the item's position is
+ * stored at position <b>idx_field_offset</b> within the item. <b>sl</b> must
+ * not be empty. */
+void *
+smartlist_pqueue_pop(smartlist_t *sl,
+ int (*compare)(const void *a, const void *b),
+ int idx_field_offset)
+{
+ void *top;
+ tor_assert(sl->num_used);
+
+ top = sl->list[0];
+ *IDXP(top)=-1;
+ if (--sl->num_used) {
+ sl->list[0] = sl->list[sl->num_used];
+ sl->list[sl->num_used] = NULL;
+ UPDATE_IDX(0);
+ smartlist_heapify(sl, compare, idx_field_offset, 0);
+ }
+ sl->list[sl->num_used] = NULL;
+ return top;
+}
+
+/** Remove the item <b>item</b> from the heap stored in <b>sl</b>,
+ * where order is determined by <b>compare</b> and the item's position is
+ * stored at position <b>idx_field_offset</b> within the item. <b>sl</b> must
+ * not be empty. */
+void
+smartlist_pqueue_remove(smartlist_t *sl,
+ int (*compare)(const void *a, const void *b),
+ int idx_field_offset,
+ void *item)
+{
+ int idx = IDX_OF_ITEM(item);
+ tor_assert(idx >= 0);
+ tor_assert(sl->list[idx] == item);
+ --sl->num_used;
+ *IDXP(item) = -1;
+ if (idx == sl->num_used) {
+ sl->list[sl->num_used] = NULL;
+ return;
+ } else {
+ sl->list[idx] = sl->list[sl->num_used];
+ sl->list[sl->num_used] = NULL;
+ UPDATE_IDX(idx);
+ smartlist_heapify(sl, compare, idx_field_offset, idx);
+ }
+}
+
+/** Assert that the heap property is correctly maintained by the heap stored
+ * in <b>sl</b>, where order is determined by <b>compare</b>. */
+void
+smartlist_pqueue_assert_ok(smartlist_t *sl,
+ int (*compare)(const void *a, const void *b),
+ int idx_field_offset)
+{
+ int i;
+ for (i = sl->num_used - 1; i >= 0; --i) {
+ if (i>0)
+ tor_assert(compare(sl->list[PARENT(i)], sl->list[i]) <= 0);
+ tor_assert(IDX_OF_ITEM(sl->list[i]) == i);
+ }
+}
+
+/** Helper: compare two DIGEST_LEN digests. */
+static int
+compare_digests_(const void **_a, const void **_b)
+{
+ return tor_memcmp((const char*)*_a, (const char*)*_b, DIGEST_LEN);
+}
+
+/** Sort the list of DIGEST_LEN-byte digests into ascending order. */
+void
+smartlist_sort_digests(smartlist_t *sl)
+{
+ smartlist_sort(sl, compare_digests_);
+}
+
+/** Remove duplicate digests from a sorted list, and free them with tor_free().
+ */
+void
+smartlist_uniq_digests(smartlist_t *sl)
+{
+ smartlist_uniq(sl, compare_digests_, tor_free_);
+}
+
+/** Helper: compare two DIGEST256_LEN digests. */
+static int
+compare_digests256_(const void **_a, const void **_b)
+{
+ return tor_memcmp((const char*)*_a, (const char*)*_b, DIGEST256_LEN);
+}
+
+/** Sort the list of DIGEST256_LEN-byte digests into ascending order. */
+void
+smartlist_sort_digests256(smartlist_t *sl)
+{
+ smartlist_sort(sl, compare_digests256_);
+}
+
+/** Return the most frequent member of the sorted list of DIGEST256_LEN
+ * digests in <b>sl</b> */
+const uint8_t *
+smartlist_get_most_frequent_digest256(smartlist_t *sl)
+{
+ return smartlist_get_most_frequent(sl, compare_digests256_);
+}
+
+/** Remove duplicate 256-bit digests from a sorted list, and free them with
+ * tor_free().
+ */
+void
+smartlist_uniq_digests256(smartlist_t *sl)
+{
+ smartlist_uniq(sl, compare_digests256_, tor_free_);
+}
diff --cc src/lib/container/smartlist.h
index 9705396ac,000000000..0f5af3a92
mode 100644,000000..100644
--- a/src/lib/container/smartlist.h
+++ b/src/lib/container/smartlist.h
@@@ -1,168 -1,0 +1,168 @@@
+/* Copyright (c) 2003-2004, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#ifndef TOR_SMARTLIST_H
+#define TOR_SMARTLIST_H
+
+/**
+ * \file smartlist.h
+ *
+ * \brief Header for smartlist.c
+ **/
+
+#include <stdarg.h>
+
+#include "lib/smartlist_core/smartlist_core.h"
+#include "lib/smartlist_core/smartlist_foreach.h"
+#include "lib/smartlist_core/smartlist_split.h"
+
+void smartlist_add_asprintf(struct smartlist_t *sl, const char *pattern, ...)
+ CHECK_PRINTF(2, 3);
+void smartlist_add_vasprintf(struct smartlist_t *sl, const char *pattern,
+ va_list args)
+ CHECK_PRINTF(2, 0);
+void smartlist_reverse(smartlist_t *sl);
+void smartlist_string_remove(smartlist_t *sl, const char *element);
+int smartlist_contains_string(const smartlist_t *sl, const char *element);
+int smartlist_pos(const smartlist_t *sl, const void *element);
+int smartlist_string_pos(const smartlist_t *, const char *elt);
+int smartlist_contains_string_case(const smartlist_t *sl, const char *element);
+int smartlist_contains_int_as_string(const smartlist_t *sl, int num);
+int smartlist_strings_eq(const smartlist_t *sl1, const smartlist_t *sl2);
+int smartlist_contains_digest(const smartlist_t *sl, const char *element);
+int smartlist_ints_eq(const smartlist_t *sl1, const smartlist_t *sl2);
+int smartlist_overlap(const smartlist_t *sl1, const smartlist_t *sl2);
+void smartlist_intersect(smartlist_t *sl1, const smartlist_t *sl2);
+void smartlist_subtract(smartlist_t *sl1, const smartlist_t *sl2);
+
+int smartlist_ptrs_eq(const smartlist_t *s1,
+ const smartlist_t *s2);
+
+void smartlist_sort(smartlist_t *sl,
+ int (*compare)(const void **a, const void **b));
+void *smartlist_get_most_frequent_(const smartlist_t *sl,
+ int (*compare)(const void **a, const void **b),
+ int *count_out);
+#define smartlist_get_most_frequent(sl, compare) \
+ smartlist_get_most_frequent_((sl), (compare), NULL)
+void smartlist_uniq(smartlist_t *sl,
+ int (*compare)(const void **a, const void **b),
+ void (*free_fn)(void *elt));
+
+void smartlist_sort_strings(smartlist_t *sl);
+void smartlist_sort_digests(smartlist_t *sl);
+void smartlist_sort_digests256(smartlist_t *sl);
+void smartlist_sort_pointers(smartlist_t *sl);
+
+const char *smartlist_get_most_frequent_string(smartlist_t *sl);
+const char *smartlist_get_most_frequent_string_(smartlist_t *sl,
+ int *count_out);
+const uint8_t *smartlist_get_most_frequent_digest256(smartlist_t *sl);
+
+void smartlist_uniq_strings(smartlist_t *sl);
+void smartlist_uniq_digests(smartlist_t *sl);
+void smartlist_uniq_digests256(smartlist_t *sl);
- void *smartlist_bsearch(smartlist_t *sl, const void *key,
++void *smartlist_bsearch(const smartlist_t *sl, const void *key,
+ int (*compare)(const void *key, const void **member));
+int smartlist_bsearch_idx(const smartlist_t *sl, const void *key,
+ int (*compare)(const void *key, const void **member),
+ int *found_out);
+
+void smartlist_pqueue_add(smartlist_t *sl,
+ int (*compare)(const void *a, const void *b),
+ int idx_field_offset,
+ void *item);
+void *smartlist_pqueue_pop(smartlist_t *sl,
+ int (*compare)(const void *a, const void *b),
+ int idx_field_offset);
+void smartlist_pqueue_remove(smartlist_t *sl,
+ int (*compare)(const void *a, const void *b),
+ int idx_field_offset,
+ void *item);
+void smartlist_pqueue_assert_ok(smartlist_t *sl,
+ int (*compare)(const void *a, const void *b),
+ int idx_field_offset);
+
+char *smartlist_join_strings(smartlist_t *sl, const char *join, int terminate,
+ size_t *len_out) ATTR_MALLOC;
+char *smartlist_join_strings2(smartlist_t *sl, const char *join,
+ size_t join_len, int terminate, size_t *len_out)
+ ATTR_MALLOC;
+
+/* Helper: Given two lists of items, possibly of different types, such that
+ * both lists are sorted on some common field (as determined by a comparison
+ * expression <b>cmpexpr</b>), and such that one list (<b>sl1</b>) has no
+ * duplicates on the common field, loop through the lists in lockstep, and
+ * execute <b>unmatched_var2</b> on items in var2 that do not appear in
+ * var1.
+ *
+ * WARNING: It isn't safe to add remove elements from either list while the
+ * loop is in progress.
+ *
+ * Example use:
+ * SMARTLIST_FOREACH_JOIN(routerstatus_list, routerstatus_t *, rs,
+ * routerinfo_list, routerinfo_t *, ri,
+ * tor_memcmp(rs->identity_digest, ri->identity_digest, 20),
+ * log_info(LD_GENERAL,"No match for %s", ri->nickname)) {
+ * log_info(LD_GENERAL, "%s matches routerstatus %p", ri->nickname, rs);
+ * } SMARTLIST_FOREACH_JOIN_END(rs, ri);
+ **/
+/* The example above unpacks (approximately) to:
+ * int rs_sl_idx = 0, rs_sl_len = smartlist_len(routerstatus_list);
+ * int ri_sl_idx, ri_sl_len = smartlist_len(routerinfo_list);
+ * int rs_ri_cmp;
+ * routerstatus_t *rs;
+ * routerinfo_t *ri;
+ * for (; ri_sl_idx < ri_sl_len; ++ri_sl_idx) {
+ * ri = smartlist_get(routerinfo_list, ri_sl_idx);
+ * while (rs_sl_idx < rs_sl_len) {
+ * rs = smartlist_get(routerstatus_list, rs_sl_idx);
+ * rs_ri_cmp = tor_memcmp(rs->identity_digest, ri->identity_digest, 20);
+ * if (rs_ri_cmp > 0) {
+ * break;
+ * } else if (rs_ri_cmp == 0) {
+ * goto matched_ri;
+ * } else {
+ * ++rs_sl_idx;
+ * }
+ * }
+ * log_info(LD_GENERAL,"No match for %s", ri->nickname);
+ * continue;
+ * matched_ri: {
+ * log_info(LD_GENERAL,"%s matches with routerstatus %p",ri->nickname,rs);
+ * }
+ * }
+ */
+#define SMARTLIST_FOREACH_JOIN(sl1, type1, var1, sl2, type2, var2, \
+ cmpexpr, unmatched_var2) \
+ STMT_BEGIN \
+ int var1 ## _sl_idx = 0, var1 ## _sl_len=(sl1)->num_used; \
+ int var2 ## _sl_idx = 0, var2 ## _sl_len=(sl2)->num_used; \
+ int var1 ## _ ## var2 ## _cmp; \
+ type1 var1; \
+ type2 var2; \
+ for (; var2##_sl_idx < var2##_sl_len; ++var2##_sl_idx) { \
+ var2 = (sl2)->list[var2##_sl_idx]; \
+ while (var1##_sl_idx < var1##_sl_len) { \
+ var1 = (sl1)->list[var1##_sl_idx]; \
+ var1##_##var2##_cmp = (cmpexpr); \
+ if (var1##_##var2##_cmp > 0) { \
+ break; \
+ } else if (var1##_##var2##_cmp == 0) { \
+ goto matched_##var2; \
+ } else { \
+ ++var1##_sl_idx; \
+ } \
+ } \
+ /* Ran out of v1, or no match for var2. */ \
+ unmatched_var2; \
+ continue; \
+ matched_##var2: ; \
+
+#define SMARTLIST_FOREACH_JOIN_END(var1, var2) \
+ } \
+ STMT_END
+
+#endif /* !defined(TOR_CONTAINER_H) */
diff --cc src/test/test_relaycell.c
index eb30cab0e,3f84ee830..63820c996
--- a/src/test/test_relaycell.c
+++ b/src/test/test_relaycell.c
@@@ -5,22 -5,18 +5,25 @@@
#define RELAY_PRIVATE
#define CIRCUITLIST_PRIVATE
-#include "or.h"
-#include "main.h"
-#include "config.h"
-#include "connection.h"
-#include "crypto.h"
-#include "crypto_rand.h"
-#include "circuitbuild.h"
-#include "circuitlist.h"
-#include "connection_edge.h"
-#include "log_test_helpers.h"
-#include "relay.h"
-#include "test.h"
+#include "core/or/or.h"
+#include "core/mainloop/main.h"
+#include "app/config/config.h"
+#include "core/mainloop/connection.h"
+#include "lib/crypt_ops/crypto.h"
++#include "lib/crypt_ops/crypto_rand.h"
+#include "core/or/circuitbuild.h"
+#include "core/or/circuitlist.h"
+#include "core/or/connection_edge.h"
+#include "core/or/relay.h"
+#include "test/test.h"
++#include "test/log_test_helpers.h"
+
+#include "core/or/cell_st.h"
+#include "core/or/crypt_path_st.h"
+#include "core/or/entry_connection_st.h"
+#include "core/or/origin_circuit_st.h"
+#include "core/or/socks_request_st.h"
++#include "core/or/half_edge_st.h"
static int srm_ncalls;
static entry_connection_t *srm_conn;
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