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[tor-commits] [tor/release-0.4.0] Merge remote-tracking branch 'tor-github/pr/791' into maint-0.4.0
commit 94523bffdc3c06a9645d8e1d81fd9e3b6b3a0551
Merge: feb7253df a3bc950e4
Author: Nick Mathewson <nickm@xxxxxxxxxxxxxx>
Date: Fri Mar 15 08:52:50 2019 -0400
Merge remote-tracking branch 'tor-github/pr/791' into maint-0.4.0
changes/bug29665 | 7 +++++++
src/core/or/circuituse.c | 4 ++++
2 files changed, 11 insertions(+)
diff --cc src/core/or/circuituse.c
index 2fdf6f7e8,000000000..fd782c0cd
mode 100644,000000..100644
--- a/src/core/or/circuituse.c
+++ b/src/core/or/circuituse.c
@@@ -1,3146 -1,0 +1,3150 @@@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file circuituse.c
+ * \brief Launch the right sort of circuits and attach the right streams to
+ * them.
+ *
+ * As distinct from circuitlist.c, which manages lookups to find circuits, and
+ * circuitbuild.c, which handles the logistics of circuit construction, this
+ * module keeps track of which streams can be attached to which circuits (in
+ * circuit_get_best()), and attaches streams to circuits (with
+ * circuit_try_attaching_streams(), connection_ap_handshake_attach_circuit(),
+ * and connection_ap_handshake_attach_chosen_circuit() ).
+ *
+ * This module also makes sure that we are building circuits for all of the
+ * predicted ports, using circuit_remove_handled_ports(),
+ * circuit_stream_is_being_handled(), and circuit_build_needed_cirs(). It
+ * handles launching circuits for specific targets using
+ * circuit_launch_by_extend_info().
+ *
+ * This is also where we handle expiring circuits that have been around for
+ * too long without actually completing, along with the circuit_build_timeout
+ * logic in circuitstats.c.
+ **/
+
+#include "core/or/or.h"
+#include "app/config/config.h"
+#include "core/mainloop/connection.h"
+#include "core/or/channel.h"
+#include "core/or/circuitbuild.h"
+#include "core/or/circuitlist.h"
+#include "core/or/circuitstats.h"
+#include "core/or/circuituse.h"
+#include "core/or/circuitpadding.h"
+#include "core/or/connection_edge.h"
+#include "core/or/policies.h"
+#include "feature/client/addressmap.h"
+#include "feature/client/bridges.h"
+#include "feature/client/circpathbias.h"
+#include "feature/client/entrynodes.h"
+#include "feature/control/control.h"
+#include "feature/dircommon/directory.h"
+#include "feature/hs/hs_circuit.h"
+#include "feature/hs/hs_client.h"
+#include "feature/hs/hs_common.h"
+#include "feature/hs/hs_ident.h"
+#include "feature/hs/hs_stats.h"
+#include "feature/nodelist/describe.h"
+#include "feature/nodelist/networkstatus.h"
+#include "feature/nodelist/nodelist.h"
+#include "feature/nodelist/routerlist.h"
+#include "feature/relay/routermode.h"
+#include "feature/relay/selftest.h"
+#include "feature/rend/rendclient.h"
+#include "feature/rend/rendcommon.h"
+#include "feature/rend/rendservice.h"
+#include "feature/stats/predict_ports.h"
+#include "lib/math/fp.h"
+#include "lib/time/tvdiff.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 "core/or/or_circuit_st.h"
+#include "core/or/origin_circuit_st.h"
+#include "core/or/socks_request_st.h"
+
+static void circuit_expire_old_circuits_clientside(void);
+static void circuit_increment_failure_count(void);
+
+/** Check whether the hidden service destination of the stream at
+ * <b>edge_conn</b> is the same as the destination of the circuit at
+ * <b>origin_circ</b>. */
+static int
+circuit_matches_with_rend_stream(const edge_connection_t *edge_conn,
+ const origin_circuit_t *origin_circ)
+{
+ /* Check if this is a v2 rendezvous circ/stream */
+ if ((edge_conn->rend_data && !origin_circ->rend_data) ||
+ (!edge_conn->rend_data && origin_circ->rend_data) ||
+ (edge_conn->rend_data && origin_circ->rend_data &&
+ rend_cmp_service_ids(rend_data_get_address(edge_conn->rend_data),
+ rend_data_get_address(origin_circ->rend_data)))) {
+ /* this circ is not for this conn */
+ return 0;
+ }
+
+ /* Check if this is a v3 rendezvous circ/stream */
+ if ((edge_conn->hs_ident && !origin_circ->hs_ident) ||
+ (!edge_conn->hs_ident && origin_circ->hs_ident) ||
+ (edge_conn->hs_ident && origin_circ->hs_ident &&
+ !ed25519_pubkey_eq(&edge_conn->hs_ident->identity_pk,
+ &origin_circ->hs_ident->identity_pk))) {
+ /* this circ is not for this conn */
+ return 0;
+ }
+
+ return 1;
+}
+
+/** Return 1 if <b>circ</b> could be returned by circuit_get_best().
+ * Else return 0.
+ */
+static int
+circuit_is_acceptable(const origin_circuit_t *origin_circ,
+ const entry_connection_t *conn,
+ int must_be_open, uint8_t purpose,
+ int need_uptime, int need_internal,
+ time_t now)
+{
+ const circuit_t *circ = TO_CIRCUIT(origin_circ);
+ const node_t *exitnode;
+ cpath_build_state_t *build_state;
+ tor_assert(circ);
+ tor_assert(conn);
+ tor_assert(conn->socks_request);
+
+ if (must_be_open && (circ->state != CIRCUIT_STATE_OPEN || !circ->n_chan))
+ return 0; /* ignore non-open circs */
+ if (circ->marked_for_close)
+ return 0;
+
+ /* if this circ isn't our purpose, skip. */
+ if (purpose == CIRCUIT_PURPOSE_C_REND_JOINED && !must_be_open) {
+ if (circ->purpose != CIRCUIT_PURPOSE_C_ESTABLISH_REND &&
+ circ->purpose != CIRCUIT_PURPOSE_C_REND_READY &&
+ circ->purpose != CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED &&
+ circ->purpose != CIRCUIT_PURPOSE_C_REND_JOINED)
+ return 0;
+ } else if (purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT &&
+ !must_be_open) {
+ if (circ->purpose != CIRCUIT_PURPOSE_C_INTRODUCING &&
+ circ->purpose != CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT)
+ return 0;
+ } else {
+ if (purpose != circ->purpose)
+ return 0;
+ }
+
+ /* If this is a timed-out hidden service circuit, skip it. */
+ if (origin_circ->hs_circ_has_timed_out) {
+ return 0;
+ }
+
+ if (purpose == CIRCUIT_PURPOSE_C_GENERAL ||
+ purpose == CIRCUIT_PURPOSE_C_HSDIR_GET ||
+ purpose == CIRCUIT_PURPOSE_S_HSDIR_POST ||
+ purpose == CIRCUIT_PURPOSE_HS_VANGUARDS ||
+ purpose == CIRCUIT_PURPOSE_C_REND_JOINED) {
+ if (circ->timestamp_dirty &&
+ circ->timestamp_dirty+get_options()->MaxCircuitDirtiness <= now)
+ return 0;
+ }
+
+ if (origin_circ->unusable_for_new_conns)
+ return 0;
+
+ /* decide if this circ is suitable for this conn */
+
+ /* for rend circs, circ->cpath->prev is not the last router in the
+ * circuit, it's the magical extra service hop. so just check the nickname
+ * of the one we meant to finish at.
+ */
+ build_state = origin_circ->build_state;
+ exitnode = build_state_get_exit_node(build_state);
+
+ if (need_uptime && !build_state->need_uptime)
+ return 0;
+ if (need_internal != build_state->is_internal)
+ return 0;
+
+ if (purpose == CIRCUIT_PURPOSE_C_GENERAL ||
+ purpose == CIRCUIT_PURPOSE_S_HSDIR_POST ||
+ purpose == CIRCUIT_PURPOSE_C_HSDIR_GET) {
+ tor_addr_t addr;
+ const int family = tor_addr_parse(&addr, conn->socks_request->address);
+ if (!exitnode && !build_state->onehop_tunnel) {
+ log_debug(LD_CIRC,"Not considering circuit with unknown router.");
+ return 0; /* this circuit is screwed and doesn't know it yet,
+ * or is a rendezvous circuit. */
+ }
+ if (build_state->onehop_tunnel) {
+ if (!conn->want_onehop) {
+ log_debug(LD_CIRC,"Skipping one-hop circuit.");
+ return 0;
+ }
+ tor_assert(conn->chosen_exit_name);
+ if (build_state->chosen_exit) {
+ char digest[DIGEST_LEN];
+ if (hexdigest_to_digest(conn->chosen_exit_name, digest) < 0)
+ return 0; /* broken digest, we don't want it */
+ if (tor_memneq(digest, build_state->chosen_exit->identity_digest,
+ DIGEST_LEN))
+ return 0; /* this is a circuit to somewhere else */
+ if (tor_digest_is_zero(digest)) {
+ /* we don't know the digest; have to compare addr:port */
+ if (family < 0 ||
+ !tor_addr_eq(&build_state->chosen_exit->addr, &addr) ||
+ build_state->chosen_exit->port != conn->socks_request->port)
+ return 0;
+ }
+ }
+ } else {
+ if (conn->want_onehop) {
+ /* don't use three-hop circuits -- that could hurt our anonymity. */
+ return 0;
+ }
+ }
+ if (origin_circ->prepend_policy && family != -1) {
+ int r = compare_tor_addr_to_addr_policy(&addr,
+ conn->socks_request->port,
+ origin_circ->prepend_policy);
+ if (r == ADDR_POLICY_REJECTED)
+ return 0;
+ }
+ if (exitnode && !connection_ap_can_use_exit(conn, exitnode)) {
+ /* can't exit from this router */
+ return 0;
+ }
+ } else { /* not general: this might be a rend circuit */
+ const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
+ if (!circuit_matches_with_rend_stream(edge_conn, origin_circ)) {
+ return 0;
+ }
+ }
+
+ if (!connection_edge_compatible_with_circuit(conn, origin_circ)) {
+ /* conn needs to be isolated from other conns that have already used
+ * origin_circ */
+ return 0;
+ }
+
+ return 1;
+}
+
+/** Return 1 if circuit <b>a</b> is better than circuit <b>b</b> for
+ * <b>conn</b>, and return 0 otherwise. Used by circuit_get_best.
+ */
+static int
+circuit_is_better(const origin_circuit_t *oa, const origin_circuit_t *ob,
+ const entry_connection_t *conn)
+{
+ const circuit_t *a = TO_CIRCUIT(oa);
+ const circuit_t *b = TO_CIRCUIT(ob);
+ const uint8_t purpose = ENTRY_TO_CONN(conn)->purpose;
+ int a_bits, b_bits;
+
+ /* If one of the circuits was allowed to live due to relaxing its timeout,
+ * it is definitely worse (it's probably a much slower path). */
+ if (oa->relaxed_timeout && !ob->relaxed_timeout)
+ return 0; /* ob is better. It's not relaxed. */
+ if (!oa->relaxed_timeout && ob->relaxed_timeout)
+ return 1; /* oa is better. It's not relaxed. */
+
+ switch (purpose) {
+ case CIRCUIT_PURPOSE_S_HSDIR_POST:
+ case CIRCUIT_PURPOSE_C_HSDIR_GET:
+ case CIRCUIT_PURPOSE_C_GENERAL:
+ /* if it's used but less dirty it's best;
+ * else if it's more recently created it's best
+ */
+ if (b->timestamp_dirty) {
+ if (a->timestamp_dirty &&
+ a->timestamp_dirty > b->timestamp_dirty)
+ return 1;
+ } else {
+ if (a->timestamp_dirty ||
+ timercmp(&a->timestamp_began, &b->timestamp_began, OP_GT))
+ return 1;
+ if (ob->build_state->is_internal)
+ /* XXXX++ what the heck is this internal thing doing here. I
+ * think we can get rid of it. circuit_is_acceptable() already
+ * makes sure that is_internal is exactly what we need it to
+ * be. -RD */
+ return 1;
+ }
+ break;
+ case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
+ /* the closer it is to ack_wait the better it is */
+ if (a->purpose > b->purpose)
+ return 1;
+ break;
+ case CIRCUIT_PURPOSE_C_REND_JOINED:
+ /* the closer it is to rend_joined the better it is */
+ if (a->purpose > b->purpose)
+ return 1;
+ break;
+ }
+
+ /* XXXX Maybe this check should get a higher priority to avoid
+ * using up circuits too rapidly. */
+
+ a_bits = connection_edge_update_circuit_isolation(conn,
+ (origin_circuit_t*)oa, 1);
+ b_bits = connection_edge_update_circuit_isolation(conn,
+ (origin_circuit_t*)ob, 1);
+ /* if x_bits < 0, then we have not used x for anything; better not to dirty
+ * a connection if we can help it. */
+ if (a_bits < 0) {
+ return 0;
+ } else if (b_bits < 0) {
+ return 1;
+ }
+ a_bits &= ~ oa->isolation_flags_mixed;
+ a_bits &= ~ ob->isolation_flags_mixed;
+ if (n_bits_set_u8(a_bits) < n_bits_set_u8(b_bits)) {
+ /* The fewer new restrictions we need to make on a circuit for stream
+ * isolation, the better. */
+ return 1;
+ }
+
+ return 0;
+}
+
+/** Find the best circ that conn can use, preferably one which is
+ * dirty. Circ must not be too old.
+ *
+ * Conn must be defined.
+ *
+ * If must_be_open, ignore circs not in CIRCUIT_STATE_OPEN.
+ *
+ * circ_purpose specifies what sort of circuit we must have.
+ * It can be C_GENERAL, C_INTRODUCE_ACK_WAIT, or C_REND_JOINED.
+ *
+ * If it's REND_JOINED and must_be_open==0, then return the closest
+ * rendezvous-purposed circuit that you can find.
+ *
+ * If it's INTRODUCE_ACK_WAIT and must_be_open==0, then return the
+ * closest introduce-purposed circuit that you can find.
+ */
+static origin_circuit_t *
+circuit_get_best(const entry_connection_t *conn,
+ int must_be_open, uint8_t purpose,
+ int need_uptime, int need_internal)
+{
+ origin_circuit_t *best=NULL;
+ struct timeval now;
+ int intro_going_on_but_too_old = 0;
+
+ tor_assert(conn);
+
+ tor_assert(purpose == CIRCUIT_PURPOSE_C_GENERAL ||
+ purpose == CIRCUIT_PURPOSE_HS_VANGUARDS ||
+ purpose == CIRCUIT_PURPOSE_C_HSDIR_GET ||
+ purpose == CIRCUIT_PURPOSE_S_HSDIR_POST ||
+ purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT ||
+ purpose == CIRCUIT_PURPOSE_C_REND_JOINED);
+
+ tor_gettimeofday(&now);
+
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ origin_circuit_t *origin_circ;
+ if (!CIRCUIT_IS_ORIGIN(circ))
+ continue;
+ origin_circ = TO_ORIGIN_CIRCUIT(circ);
+
+ /* Log an info message if we're going to launch a new intro circ in
+ * parallel */
+ if (purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT &&
+ !must_be_open && origin_circ->hs_circ_has_timed_out &&
+ !circ->marked_for_close) {
+ intro_going_on_but_too_old = 1;
+ continue;
+ }
+
+ if (!circuit_is_acceptable(origin_circ,conn,must_be_open,purpose,
+ need_uptime,need_internal, (time_t)now.tv_sec))
+ continue;
+
+ /* now this is an acceptable circ to hand back. but that doesn't
+ * mean it's the *best* circ to hand back. try to decide.
+ */
+ if (!best || circuit_is_better(origin_circ,best,conn))
+ best = origin_circ;
+ }
+ SMARTLIST_FOREACH_END(circ);
+
+ if (!best && intro_going_on_but_too_old)
+ log_info(LD_REND|LD_CIRC, "There is an intro circuit being created "
+ "right now, but it has already taken quite a while. Starting "
+ "one in parallel.");
+
+ return best;
+}
+
+/** Return the number of not-yet-open general-purpose origin circuits. */
+static int
+count_pending_general_client_circuits(void)
+{
+ int count = 0;
+
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ if (circ->marked_for_close ||
+ circ->state == CIRCUIT_STATE_OPEN ||
+ !CIRCUIT_PURPOSE_COUNTS_TOWARDS_MAXPENDING(circ->purpose) ||
+ !CIRCUIT_IS_ORIGIN(circ))
+ continue;
+
+ ++count;
+ }
+ SMARTLIST_FOREACH_END(circ);
+
+ return count;
+}
+
+#if 0
+/** Check whether, according to the policies in <b>options</b>, the
+ * circuit <b>circ</b> makes sense. */
+/* XXXX currently only checks Exclude{Exit}Nodes; it should check more.
+ * Also, it doesn't have the right definition of an exit circuit. Also,
+ * it's never called. */
+int
+circuit_conforms_to_options(const origin_circuit_t *circ,
+ const or_options_t *options)
+{
+ const crypt_path_t *cpath, *cpath_next = NULL;
+
+ /* first check if it includes any excluded nodes */
+ for (cpath = circ->cpath; cpath_next != circ->cpath; cpath = cpath_next) {
+ cpath_next = cpath->next;
+ if (routerset_contains_extendinfo(options->ExcludeNodes,
+ cpath->extend_info))
+ return 0;
+ }
+
+ /* then consider the final hop */
+ if (routerset_contains_extendinfo(options->ExcludeExitNodes,
+ circ->cpath->prev->extend_info))
+ return 0;
+
+ return 1;
+}
+#endif /* 0 */
+
+/**
+ * Close all circuits that start at us, aren't open, and were born
+ * at least CircuitBuildTimeout seconds ago.
+ *
+ * TODO: This function is now partially redundant to
+ * circuit_build_times_handle_completed_hop(), but that function only
+ * covers circuits up to and including 3 hops that are still actually
+ * completing hops. However, circuit_expire_building() also handles longer
+ * circuits, as well as circuits that are completely stalled.
+ * In the future (after prop247/other path selection revamping), we probably
+ * want to eliminate this rats nest in favor of a simpler approach.
+ */
+void
+circuit_expire_building(void)
+{
+ /* circ_times.timeout_ms and circ_times.close_ms are from
+ * circuit_build_times_get_initial_timeout() if we haven't computed
+ * custom timeouts yet */
+ struct timeval general_cutoff, begindir_cutoff, fourhop_cutoff,
+ close_cutoff, extremely_old_cutoff, hs_extremely_old_cutoff,
+ cannibalized_cutoff, c_intro_cutoff, s_intro_cutoff, stream_cutoff;
+ const or_options_t *options = get_options();
+ struct timeval now;
+ cpath_build_state_t *build_state;
+ int any_opened_circs = 0;
+
+ tor_gettimeofday(&now);
+
+ /* Check to see if we have any opened circuits. If we don't,
+ * we want to be more lenient with timeouts, in case the
+ * user has relocated and/or changed network connections.
+ * See bug #3443. */
+ any_opened_circs = circuit_any_opened_circuits();
+
+#define SET_CUTOFF(target, msec) do { \
+ long ms = tor_lround(msec); \
+ struct timeval diff; \
+ diff.tv_sec = ms / 1000; \
+ diff.tv_usec = (int)((ms % 1000) * 1000); \
+ timersub(&now, &diff, &target); \
+ } while (0)
+
+ /**
+ * Because circuit build timeout is calculated only based on 3 hop
+ * general purpose circuit construction, we need to scale the timeout
+ * to make it properly apply to longer circuits, and circuits of
+ * certain usage types. The following diagram illustrates how we
+ * derive the scaling below. In short, we calculate the number
+ * of times our telescoping-based circuit construction causes cells
+ * to traverse each link for the circuit purpose types in question,
+ * and then assume each link is equivalent.
+ *
+ * OP --a--> A --b--> B --c--> C
+ * OP --a--> A --b--> B --c--> C --d--> D
+ *
+ * Let h = a = b = c = d
+ *
+ * Three hops (general_cutoff)
+ * RTTs = 3a + 2b + c
+ * RTTs = 6h
+ * Cannibalized:
+ * RTTs = a+b+c+d
+ * RTTs = 4h
+ * Four hops:
+ * RTTs = 4a + 3b + 2c + d
+ * RTTs = 10h
+ * Client INTRODUCE1+ACK: // XXX: correct?
+ * RTTs = 5a + 4b + 3c + 2d
+ * RTTs = 14h
+ * Server intro:
+ * RTTs = 4a + 3b + 2c
+ * RTTs = 9h
+ */
+ SET_CUTOFF(general_cutoff, get_circuit_build_timeout_ms());
+ SET_CUTOFF(begindir_cutoff, get_circuit_build_timeout_ms());
+
+ // TODO: We should probably use route_len_for_purpose() here instead,
+ // except that does not count the extra round trip for things like server
+ // intros and rends.
+
+ /* > 3hop circs seem to have a 1.0 second delay on their cannibalized
+ * 4th hop. */
+ SET_CUTOFF(fourhop_cutoff, get_circuit_build_timeout_ms() * (10/6.0) + 1000);
+
+ /* CIRCUIT_PURPOSE_C_ESTABLISH_REND behaves more like a RELAY cell.
+ * Use the stream cutoff (more or less). */
+ SET_CUTOFF(stream_cutoff, MAX(options->CircuitStreamTimeout,15)*1000 + 1000);
+
+ /* Be lenient with cannibalized circs. They already survived the official
+ * CBT, and they're usually not performance-critical. */
+ SET_CUTOFF(cannibalized_cutoff,
+ MAX(get_circuit_build_close_time_ms()*(4/6.0),
+ options->CircuitStreamTimeout * 1000) + 1000);
+
+ /* Intro circs have an extra round trip (and are also 4 hops long) */
+ SET_CUTOFF(c_intro_cutoff, get_circuit_build_timeout_ms() * (14/6.0) + 1000);
+
+ /* Server intro circs have an extra round trip */
+ SET_CUTOFF(s_intro_cutoff, get_circuit_build_timeout_ms() * (9/6.0) + 1000);
+
+ SET_CUTOFF(close_cutoff, get_circuit_build_close_time_ms());
+ SET_CUTOFF(extremely_old_cutoff, get_circuit_build_close_time_ms()*2 + 1000);
+
+ SET_CUTOFF(hs_extremely_old_cutoff,
+ MAX(get_circuit_build_close_time_ms()*2 + 1000,
+ options->SocksTimeout * 1000));
+
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *,victim) {
+ struct timeval cutoff;
+ bool fixed_time = circuit_build_times_disabled(get_options());
+
+ if (!CIRCUIT_IS_ORIGIN(victim) || /* didn't originate here */
+ victim->marked_for_close) /* don't mess with marked circs */
+ continue;
+
+ /* If we haven't yet started the first hop, it means we don't have
+ * any orconns available, and thus have not started counting time yet
+ * for this circuit. See circuit_deliver_create_cell() and uses of
+ * timestamp_began.
+ *
+ * Continue to wait in this case. The ORConn should timeout
+ * independently and kill us then.
+ */
+ if (TO_ORIGIN_CIRCUIT(victim)->cpath->state == CPATH_STATE_CLOSED) {
+ continue;
+ }
+
+ build_state = TO_ORIGIN_CIRCUIT(victim)->build_state;
+ if (build_state && build_state->onehop_tunnel)
+ cutoff = begindir_cutoff;
+ else if (victim->purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT)
+ cutoff = close_cutoff;
+ else if (victim->purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT)
+ cutoff = c_intro_cutoff;
+ else if (victim->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO)
+ cutoff = s_intro_cutoff;
+ else if (victim->purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND)
+ cutoff = stream_cutoff;
+ else if (victim->purpose == CIRCUIT_PURPOSE_PATH_BIAS_TESTING)
+ cutoff = close_cutoff;
+ else if (TO_ORIGIN_CIRCUIT(victim)->has_opened &&
+ victim->state != CIRCUIT_STATE_OPEN)
+ cutoff = cannibalized_cutoff;
+ else if (build_state && build_state->desired_path_len >= 4)
+ cutoff = fourhop_cutoff;
+ else
+ cutoff = general_cutoff;
+
+ if (TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out)
+ cutoff = hs_extremely_old_cutoff;
+
+ if (timercmp(&victim->timestamp_began, &cutoff, OP_GT))
+ continue; /* it's still young, leave it alone */
+
+ /* We need to double-check the opened state here because
+ * we don't want to consider opened 1-hop dircon circuits for
+ * deciding when to relax the timeout, but we *do* want to relax
+ * those circuits too if nothing else is opened *and* they still
+ * aren't either. */
+ if (!any_opened_circs && victim->state != CIRCUIT_STATE_OPEN) {
+ /* It's still young enough that we wouldn't close it, right? */
+ if (timercmp(&victim->timestamp_began, &close_cutoff, OP_GT)) {
+ if (!TO_ORIGIN_CIRCUIT(victim)->relaxed_timeout) {
+ int first_hop_succeeded = TO_ORIGIN_CIRCUIT(victim)->cpath->state
+ == CPATH_STATE_OPEN;
+ if (!fixed_time) {
+ log_info(LD_CIRC,
+ "No circuits are opened. Relaxing timeout for circuit %d "
+ "(a %s %d-hop circuit in state %s with channel state %s).",
+ TO_ORIGIN_CIRCUIT(victim)->global_identifier,
+ circuit_purpose_to_string(victim->purpose),
+ TO_ORIGIN_CIRCUIT(victim)->build_state ?
+ TO_ORIGIN_CIRCUIT(victim)->build_state->desired_path_len :
+ -1,
+ circuit_state_to_string(victim->state),
+ victim->n_chan ?
+ channel_state_to_string(victim->n_chan->state) : "none");
+ }
+
+ /* We count the timeout here for CBT, because technically this
+ * was a timeout, and the timeout value needs to reset if we
+ * see enough of them. Note this means we also need to avoid
+ * double-counting below, too. */
+ circuit_build_times_count_timeout(get_circuit_build_times_mutable(),
+ first_hop_succeeded);
+ TO_ORIGIN_CIRCUIT(victim)->relaxed_timeout = 1;
+ }
+ continue;
+ } else {
+ static ratelim_t relax_timeout_limit = RATELIM_INIT(3600);
+ const double build_close_ms = get_circuit_build_close_time_ms();
+ if (!fixed_time) {
+ log_fn_ratelim(&relax_timeout_limit, LOG_NOTICE, LD_CIRC,
+ "No circuits are opened. Relaxed timeout for circuit %d "
+ "(a %s %d-hop circuit in state %s with channel state %s) to "
+ "%ldms. However, it appears the circuit has timed out "
+ "anyway.",
+ TO_ORIGIN_CIRCUIT(victim)->global_identifier,
+ circuit_purpose_to_string(victim->purpose),
+ TO_ORIGIN_CIRCUIT(victim)->build_state ?
+ TO_ORIGIN_CIRCUIT(victim)->build_state->desired_path_len :
+ -1,
+ circuit_state_to_string(victim->state),
+ victim->n_chan ?
+ channel_state_to_string(victim->n_chan->state) : "none",
+ (long)build_close_ms);
+ }
+ }
+ }
+
+#if 0
+ /* some debug logs, to help track bugs */
+ if (victim->purpose >= CIRCUIT_PURPOSE_C_INTRODUCING &&
+ victim->purpose <= CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED) {
+ if (!victim->timestamp_dirty)
+ log_fn(LOG_DEBUG,"Considering %sopen purpose %d to %s (circid %d)."
+ "(clean).",
+ victim->state == CIRCUIT_STATE_OPEN ? "" : "non",
+ victim->purpose, victim->build_state->chosen_exit_name,
+ victim->n_circ_id);
+ else
+ log_fn(LOG_DEBUG,"Considering %sopen purpose %d to %s (circid %d). "
+ "%d secs since dirty.",
+ victim->state == CIRCUIT_STATE_OPEN ? "" : "non",
+ victim->purpose, victim->build_state->chosen_exit_name,
+ victim->n_circ_id,
+ (int)(now - victim->timestamp_dirty));
+ }
+#endif /* 0 */
+
+ /* if circ is !open, or if it's open but purpose is a non-finished
+ * intro or rend, then mark it for close */
+ if (victim->state == CIRCUIT_STATE_OPEN) {
+ switch (victim->purpose) {
+ default: /* most open circuits can be left alone. */
+ continue; /* yes, continue inside a switch refers to the nearest
+ * enclosing loop. C is smart. */
+ case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
+ break; /* too old, need to die */
+ case CIRCUIT_PURPOSE_C_REND_READY:
+ /* it's a rend_ready circ -- has it already picked a query? */
+ /* c_rend_ready circs measure age since timestamp_dirty,
+ * because that's set when they switch purposes
+ */
+ if (TO_ORIGIN_CIRCUIT(victim)->rend_data ||
+ TO_ORIGIN_CIRCUIT(victim)->hs_ident ||
+ victim->timestamp_dirty > cutoff.tv_sec)
+ continue;
+ break;
+ case CIRCUIT_PURPOSE_PATH_BIAS_TESTING:
+ /* Open path bias testing circuits are given a long
+ * time to complete the test, but not forever */
+ TO_ORIGIN_CIRCUIT(victim)->path_state = PATH_STATE_USE_FAILED;
+ break;
+ case CIRCUIT_PURPOSE_C_INTRODUCING:
+ /* That purpose means that the intro point circuit has been opened
+ * successfully but the INTRODUCE1 cell hasn't been sent yet because
+ * the client is waiting for the rendezvous point circuit to open.
+ * Keep this circuit open while waiting for the rendezvous circuit.
+ * We let the circuit idle timeout take care of cleaning this
+ * circuit if it never used. */
+ continue;
+ case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
+ case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED:
+ case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
+ /* rend and intro circs become dirty each time they
+ * make an introduction attempt. so timestamp_dirty
+ * will reflect the time since the last attempt.
+ */
+ if (victim->timestamp_dirty > cutoff.tv_sec)
+ continue;
+ break;
+ }
+ } else { /* circuit not open, consider recording failure as timeout */
+ int first_hop_succeeded = TO_ORIGIN_CIRCUIT(victim)->cpath &&
+ TO_ORIGIN_CIRCUIT(victim)->cpath->state == CPATH_STATE_OPEN;
+
+ if (TO_ORIGIN_CIRCUIT(victim)->p_streams != NULL) {
+ log_warn(LD_BUG, "Circuit %d (purpose %d, %s) has timed out, "
+ "yet has attached streams!",
+ TO_ORIGIN_CIRCUIT(victim)->global_identifier,
+ victim->purpose,
+ circuit_purpose_to_string(victim->purpose));
+ tor_fragile_assert();
+ continue;
+ }
+
+ if (circuit_timeout_want_to_count_circ(TO_ORIGIN_CIRCUIT(victim)) &&
+ circuit_build_times_enough_to_compute(get_circuit_build_times())) {
+
+ log_info(LD_CIRC,
+ "Deciding to count the timeout for circuit %"PRIu32"\n",
+ TO_ORIGIN_CIRCUIT(victim)->global_identifier);
+
+ /* Circuits are allowed to last longer for measurement.
+ * Switch their purpose and wait. */
+ if (victim->purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) {
+ circuit_build_times_mark_circ_as_measurement_only(TO_ORIGIN_CIRCUIT(
+ victim));
+ continue;
+ }
+
+ /*
+ * If the circuit build time is much greater than we would have cut
+ * it off at, we probably had a suspend event along this codepath,
+ * and we should discard the value.
+ */
+ if (timercmp(&victim->timestamp_began, &extremely_old_cutoff, OP_LT)) {
+ log_notice(LD_CIRC,
+ "Extremely large value for circuit build timeout: %lds. "
+ "Assuming clock jump. Purpose %d (%s)",
+ (long)(now.tv_sec - victim->timestamp_began.tv_sec),
+ victim->purpose,
+ circuit_purpose_to_string(victim->purpose));
+ } else if (circuit_build_times_count_close(
+ get_circuit_build_times_mutable(),
+ first_hop_succeeded,
+ (time_t)victim->timestamp_created.tv_sec)) {
+ circuit_build_times_set_timeout(get_circuit_build_times_mutable());
+ }
+ }
+ }
+
+ /* If this is a hidden service client circuit which is far enough along in
+ * connecting to its destination, and we haven't already flagged it as
+ * 'timed out', flag it so we'll launch another intro or rend circ, but
+ * don't mark it for close yet.
+ *
+ * (Circs flagged as 'timed out' are given a much longer timeout
+ * period above, so we won't close them in the next call to
+ * circuit_expire_building.) */
+ if (!(TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out)) {
+ switch (victim->purpose) {
+ case CIRCUIT_PURPOSE_C_REND_READY:
+ /* We only want to spare a rend circ if it has been specified in
+ * an INTRODUCE1 cell sent to a hidden service. A circ's
+ * pending_final_cpath field is non-NULL iff it is a rend circ
+ * and we have tried to send an INTRODUCE1 cell specifying it.
+ * Thus, if the pending_final_cpath field *is* NULL, then we
+ * want to not spare it. */
+ if (TO_ORIGIN_CIRCUIT(victim)->build_state &&
+ TO_ORIGIN_CIRCUIT(victim)->build_state->pending_final_cpath ==
+ NULL)
+ break;
+ /* fallthrough! */
+ case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
+ case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED:
+ /* If we have reached this line, we want to spare the circ for now. */
+ log_info(LD_CIRC,"Marking circ %u (state %d:%s, purpose %d) "
+ "as timed-out HS circ",
+ (unsigned)victim->n_circ_id,
+ victim->state, circuit_state_to_string(victim->state),
+ victim->purpose);
+ TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out = 1;
+ continue;
+ default:
+ break;
+ }
+ }
+
+ /* If this is a service-side rendezvous circuit which is far
+ * enough along in connecting to its destination, consider sparing
+ * it. */
+ if (!(TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out) &&
+ victim->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND) {
+ log_info(LD_CIRC,"Marking circ %u (state %d:%s, purpose %d) "
+ "as timed-out HS circ; relaunching rendezvous attempt.",
+ (unsigned)victim->n_circ_id,
+ victim->state, circuit_state_to_string(victim->state),
+ victim->purpose);
+ TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out = 1;
+ hs_circ_retry_service_rendezvous_point(TO_ORIGIN_CIRCUIT(victim));
+ continue;
+ }
+
+ if (victim->n_chan)
+ log_info(LD_CIRC,
+ "Abandoning circ %u %s:%u (state %d,%d:%s, purpose %d, "
+ "len %d)", TO_ORIGIN_CIRCUIT(victim)->global_identifier,
+ channel_get_canonical_remote_descr(victim->n_chan),
+ (unsigned)victim->n_circ_id,
+ TO_ORIGIN_CIRCUIT(victim)->has_opened,
+ victim->state, circuit_state_to_string(victim->state),
+ victim->purpose,
+ TO_ORIGIN_CIRCUIT(victim)->build_state ?
+ TO_ORIGIN_CIRCUIT(victim)->build_state->desired_path_len :
+ -1);
+ else
+ log_info(LD_CIRC,
+ "Abandoning circ %u %u (state %d,%d:%s, purpose %d, len %d)",
+ TO_ORIGIN_CIRCUIT(victim)->global_identifier,
+ (unsigned)victim->n_circ_id,
+ TO_ORIGIN_CIRCUIT(victim)->has_opened,
+ victim->state,
+ circuit_state_to_string(victim->state), victim->purpose,
+ TO_ORIGIN_CIRCUIT(victim)->build_state ?
+ TO_ORIGIN_CIRCUIT(victim)->build_state->desired_path_len :
+ -1);
+
+ circuit_log_path(LOG_INFO,LD_CIRC,TO_ORIGIN_CIRCUIT(victim));
+ if (victim->purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT)
+ circuit_mark_for_close(victim, END_CIRC_REASON_MEASUREMENT_EXPIRED);
+ else
+ circuit_mark_for_close(victim, END_CIRC_REASON_TIMEOUT);
+
+ pathbias_count_timeout(TO_ORIGIN_CIRCUIT(victim));
+ } SMARTLIST_FOREACH_END(victim);
+}
+
+/**
+ * Mark for close all circuits that start here, that were built through a
+ * guard we weren't sure if we wanted to use, and that have been waiting
+ * around for way too long.
+ */
+void
+circuit_expire_waiting_for_better_guard(void)
+{
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_origin_circuit_list(),
+ origin_circuit_t *, circ) {
+ if (TO_CIRCUIT(circ)->marked_for_close)
+ continue;
+ if (circ->guard_state == NULL)
+ continue;
+ if (entry_guard_state_should_expire(circ->guard_state))
+ circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_NONE);
+ } SMARTLIST_FOREACH_END(circ);
+}
+
+/** For debugging #8387: track when we last called
+ * circuit_expire_old_circuits_clientside. */
+static time_t last_expired_clientside_circuits = 0;
+
+/**
+ * As a diagnostic for bug 8387, log information about how many one-hop
+ * circuits we have around that have been there for at least <b>age</b>
+ * seconds. Log a few of them. Ignores Single Onion Service intro, it is
+ * expected to be long-term one-hop circuits.
+ */
+void
+circuit_log_ancient_one_hop_circuits(int age)
+{
+#define MAX_ANCIENT_ONEHOP_CIRCUITS_TO_LOG 10
+ time_t now = time(NULL);
+ time_t cutoff = now - age;
+ int n_found = 0;
+ smartlist_t *log_these = smartlist_new();
+ const or_options_t *options = get_options();
+
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ const origin_circuit_t *ocirc;
+ if (! CIRCUIT_IS_ORIGIN(circ))
+ continue;
+ if (circ->timestamp_created.tv_sec >= cutoff)
+ continue;
+ /* Single Onion Services deliberately make long term one-hop intro
+ * and rendezvous connections. Don't log the established ones. */
+ if (rend_service_allow_non_anonymous_connection(options) &&
+ (circ->purpose == CIRCUIT_PURPOSE_S_INTRO ||
+ circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED))
+ continue;
+ ocirc = CONST_TO_ORIGIN_CIRCUIT(circ);
+
+ if (ocirc->build_state && ocirc->build_state->onehop_tunnel) {
+ ++n_found;
+
+ if (smartlist_len(log_these) < MAX_ANCIENT_ONEHOP_CIRCUITS_TO_LOG)
+ smartlist_add(log_these, (origin_circuit_t*) ocirc);
+ }
+ }
+ SMARTLIST_FOREACH_END(circ);
+
+ if (n_found == 0)
+ goto done;
+
+ log_notice(LD_HEARTBEAT,
+ "Diagnostic for issue 8387: Found %d one-hop circuits more "
+ "than %d seconds old! Logging %d...",
+ n_found, age, smartlist_len(log_these));
+
+ SMARTLIST_FOREACH_BEGIN(log_these, const origin_circuit_t *, ocirc) {
+ char created[ISO_TIME_LEN+1];
+ int stream_num;
+ const edge_connection_t *conn;
+ char *dirty = NULL;
+ const circuit_t *circ = TO_CIRCUIT(ocirc);
+
+ format_local_iso_time(created,
+ (time_t)circ->timestamp_created.tv_sec);
+
+ if (circ->timestamp_dirty) {
+ char dirty_since[ISO_TIME_LEN+1];
+ format_local_iso_time(dirty_since, circ->timestamp_dirty);
+
+ tor_asprintf(&dirty, "Dirty since %s (%ld seconds vs %ld-second cutoff)",
+ dirty_since, (long)(now - circ->timestamp_dirty),
+ (long) options->MaxCircuitDirtiness);
+ } else {
+ dirty = tor_strdup("Not marked dirty");
+ }
+
+ log_notice(LD_HEARTBEAT, " #%d created at %s. %s, %s. %s for close. "
+ "Package window: %d. "
+ "%s for new conns. %s.",
+ ocirc_sl_idx,
+ created,
+ circuit_state_to_string(circ->state),
+ circuit_purpose_to_string(circ->purpose),
+ circ->marked_for_close ? "Marked" : "Not marked",
+ circ->package_window,
+ ocirc->unusable_for_new_conns ? "Not usable" : "usable",
+ dirty);
+ tor_free(dirty);
+
+ stream_num = 0;
+ for (conn = ocirc->p_streams; conn; conn = conn->next_stream) {
+ const connection_t *c = TO_CONN(conn);
+ char stream_created[ISO_TIME_LEN+1];
+ if (++stream_num >= 5)
+ break;
+
+ format_local_iso_time(stream_created, c->timestamp_created);
+
+ log_notice(LD_HEARTBEAT, " Stream#%d created at %s. "
+ "%s conn in state %s. "
+ "It is %slinked and %sreading from a linked connection %p. "
+ "Package window %d. "
+ "%s for close (%s:%d). Hold-open is %sset. "
+ "Has %ssent RELAY_END. %s on circuit.",
+ stream_num,
+ stream_created,
+ conn_type_to_string(c->type),
+ conn_state_to_string(c->type, c->state),
+ c->linked ? "" : "not ",
+ c->reading_from_linked_conn ? "": "not",
+ c->linked_conn,
+ conn->package_window,
+ c->marked_for_close ? "Marked" : "Not marked",
+ c->marked_for_close_file ? c->marked_for_close_file : "--",
+ c->marked_for_close,
+ c->hold_open_until_flushed ? "" : "not ",
+ conn->edge_has_sent_end ? "" : "not ",
+ conn->edge_blocked_on_circ ? "Blocked" : "Not blocked");
+ if (! c->linked_conn)
+ continue;
+
+ c = c->linked_conn;
+
+ log_notice(LD_HEARTBEAT, " Linked to %s connection in state %s "
+ "(Purpose %d). %s for close (%s:%d). Hold-open is %sset. ",
+ conn_type_to_string(c->type),
+ conn_state_to_string(c->type, c->state),
+ c->purpose,
+ c->marked_for_close ? "Marked" : "Not marked",
+ c->marked_for_close_file ? c->marked_for_close_file : "--",
+ c->marked_for_close,
+ c->hold_open_until_flushed ? "" : "not ");
+ }
+ } SMARTLIST_FOREACH_END(ocirc);
+
+ log_notice(LD_HEARTBEAT, "It has been %ld seconds since I last called "
+ "circuit_expire_old_circuits_clientside().",
+ (long)(now - last_expired_clientside_circuits));
+
+ done:
+ smartlist_free(log_these);
+}
+
+/** Remove any elements in <b>needed_ports</b> that are handled by an
+ * open or in-progress circuit.
+ */
+void
+circuit_remove_handled_ports(smartlist_t *needed_ports)
+{
+ int i;
+ uint16_t *port;
+
+ for (i = 0; i < smartlist_len(needed_ports); ++i) {
+ port = smartlist_get(needed_ports, i);
+ tor_assert(*port);
+ if (circuit_stream_is_being_handled(NULL, *port,
+ MIN_CIRCUITS_HANDLING_STREAM)) {
+ log_debug(LD_CIRC,"Port %d is already being handled; removing.", *port);
+ smartlist_del(needed_ports, i--);
+ tor_free(port);
+ } else {
+ log_debug(LD_CIRC,"Port %d is not handled.", *port);
+ }
+ }
+}
+
+/** Return 1 if at least <b>min</b> general-purpose non-internal circuits
+ * will have an acceptable exit node for exit stream <b>conn</b> if it
+ * is defined, else for "*:port".
+ * Else return 0.
+ */
+int
+circuit_stream_is_being_handled(entry_connection_t *conn,
+ uint16_t port, int min)
+{
+ const node_t *exitnode;
+ int num=0;
+ time_t now = time(NULL);
+ int need_uptime = smartlist_contains_int_as_string(
+ get_options()->LongLivedPorts,
+ conn ? conn->socks_request->port : port);
+
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ if (CIRCUIT_IS_ORIGIN(circ) &&
+ !circ->marked_for_close &&
+ circ->purpose == CIRCUIT_PURPOSE_C_GENERAL &&
+ (!circ->timestamp_dirty ||
+ circ->timestamp_dirty + get_options()->MaxCircuitDirtiness > now)) {
+ origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(circ);
+ cpath_build_state_t *build_state = origin_circ->build_state;
+ if (build_state->is_internal || build_state->onehop_tunnel)
+ continue;
+ if (origin_circ->unusable_for_new_conns)
+ continue;
+ if (origin_circ->isolation_values_set &&
+ (conn == NULL ||
+ !connection_edge_compatible_with_circuit(conn, origin_circ)))
+ continue;
+
+ exitnode = build_state_get_exit_node(build_state);
+ if (exitnode && (!need_uptime || build_state->need_uptime)) {
+ int ok;
+ if (conn) {
+ ok = connection_ap_can_use_exit(conn, exitnode);
+ } else {
+ addr_policy_result_t r;
+ r = compare_tor_addr_to_node_policy(NULL, port, exitnode);
+ ok = r != ADDR_POLICY_REJECTED && r != ADDR_POLICY_PROBABLY_REJECTED;
+ }
+ if (ok) {
+ if (++num >= min)
+ return 1;
+ }
+ }
+ }
+ }
+ SMARTLIST_FOREACH_END(circ);
+ return 0;
+}
+
+/** Don't keep more than this many unused open circuits around. */
+#define MAX_UNUSED_OPEN_CIRCUITS 14
+
+/* Return true if a circuit is available for use, meaning that it is open,
+ * clean, usable for new multi-hop connections, and a general purpose origin
+ * circuit.
+ * Accept any kind of circuit, return false if the above conditions are not
+ * met. */
+STATIC int
+circuit_is_available_for_use(const circuit_t *circ)
+{
+ const origin_circuit_t *origin_circ;
+ cpath_build_state_t *build_state;
+
+ if (!CIRCUIT_IS_ORIGIN(circ))
+ return 0; /* We first filter out only origin circuits before doing the
+ following checks. */
+ if (circ->marked_for_close)
+ return 0; /* Don't mess with marked circs */
+ if (circ->timestamp_dirty)
+ return 0; /* Only count clean circs */
+ if (circ->purpose != CIRCUIT_PURPOSE_C_GENERAL &&
+ circ->purpose != CIRCUIT_PURPOSE_HS_VANGUARDS)
+ return 0; /* We only pay attention to general purpose circuits.
+ General purpose circuits are always origin circuits. */
+
+ origin_circ = CONST_TO_ORIGIN_CIRCUIT(circ);
+ if (origin_circ->unusable_for_new_conns)
+ return 0;
+
+ build_state = origin_circ->build_state;
+ if (build_state->onehop_tunnel)
+ return 0;
+
+ return 1;
+}
+
+/* Return true if we need any more exit circuits.
+ * needs_uptime and needs_capacity are set only if we need more exit circuits.
+ * Check if we know of a port that's been requested recently and no circuit
+ * is currently available that can handle it. */
+STATIC int
+needs_exit_circuits(time_t now, int *needs_uptime, int *needs_capacity)
+{
+ return (!circuit_all_predicted_ports_handled(now, needs_uptime,
+ needs_capacity) &&
+ router_have_consensus_path() == CONSENSUS_PATH_EXIT);
+}
+
+/* Hidden services need at least this many internal circuits */
+#define SUFFICIENT_UPTIME_INTERNAL_HS_SERVERS 3
+
+/* Return true if we need any more hidden service server circuits.
+ * HS servers only need an internal circuit. */
+STATIC int
+needs_hs_server_circuits(time_t now, int num_uptime_internal)
+{
+ if (!rend_num_services() && !hs_service_get_num_services()) {
+ /* No services, we don't need anything. */
+ goto no_need;
+ }
+
+ if (num_uptime_internal >= SUFFICIENT_UPTIME_INTERNAL_HS_SERVERS) {
+ /* We have sufficient amount of internal circuit. */
+ goto no_need;
+ }
+
+ if (router_have_consensus_path() == CONSENSUS_PATH_UNKNOWN) {
+ /* Consensus hasn't been checked or might be invalid so requesting
+ * internal circuits is not wise. */
+ goto no_need;
+ }
+
+ /* At this point, we need a certain amount of circuits and we will most
+ * likely use them for rendezvous so we note down the use of internal
+ * circuit for our prediction for circuit needing uptime and capacity. */
+ rep_hist_note_used_internal(now, 1, 1);
+
+ return 1;
+ no_need:
+ return 0;
+}
+
+/* We need at least this many internal circuits for hidden service clients */
+#define SUFFICIENT_INTERNAL_HS_CLIENTS 3
+
+/* We need at least this much uptime for internal circuits for hidden service
+ * clients */
+#define SUFFICIENT_UPTIME_INTERNAL_HS_CLIENTS 2
+
+/* Return true if we need any more hidden service client circuits.
+ * HS clients only need an internal circuit. */
+STATIC int
+needs_hs_client_circuits(time_t now, int *needs_uptime, int *needs_capacity,
+ int num_internal, int num_uptime_internal)
+{
+ int used_internal_recently = rep_hist_get_predicted_internal(now,
+ needs_uptime,
+ needs_capacity);
+ int requires_uptime = num_uptime_internal <
+ SUFFICIENT_UPTIME_INTERNAL_HS_CLIENTS &&
+ needs_uptime;
+
+ return (used_internal_recently &&
+ (requires_uptime || num_internal < SUFFICIENT_INTERNAL_HS_CLIENTS) &&
+ router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN);
+}
+
+/* This is how many circuits can be opened concurrently during the cbt learning
+ * phase. This number cannot exceed the tor-wide MAX_UNUSED_OPEN_CIRCUITS. */
+#define DFLT_CBT_UNUSED_OPEN_CIRCS (10)
+#define MIN_CBT_UNUSED_OPEN_CIRCS 0
+#define MAX_CBT_UNUSED_OPEN_CIRCS MAX_UNUSED_OPEN_CIRCUITS
+
+/* Return true if we need more circuits for a good build timeout.
+ * XXXX make the assumption that build timeout streams should be
+ * created whenever we can build internal circuits. */
+STATIC int
+needs_circuits_for_build(int num)
+{
+ if (router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN) {
+ if (num < networkstatus_get_param(NULL, "cbtmaxopencircs",
+ DFLT_CBT_UNUSED_OPEN_CIRCS,
+ MIN_CBT_UNUSED_OPEN_CIRCS,
+ MAX_CBT_UNUSED_OPEN_CIRCS) &&
+ !circuit_build_times_disabled(get_options()) &&
+ circuit_build_times_needs_circuits_now(get_circuit_build_times())) {
+ return 1;
+ }
+ }
+ return 0;
+}
+
+/**
+ * Launch the appropriate type of predicted circuit for hidden
+ * services, depending on our options.
+ */
+static void
+circuit_launch_predicted_hs_circ(int flags)
+{
+ /* K.I.S.S. implementation of bug #23101: If we are using
+ * vanguards or pinned middles, pre-build a specific purpose
+ * for HS circs. */
+ if (circuit_should_use_vanguards(CIRCUIT_PURPOSE_HS_VANGUARDS)) {
+ circuit_launch(CIRCUIT_PURPOSE_HS_VANGUARDS, flags);
+ } else {
+ /* If no vanguards, then no HS-specific prebuilt circuits are needed.
+ * Normal GENERAL circs are fine */
+ circuit_launch(CIRCUIT_PURPOSE_C_GENERAL, flags);
+ }
+}
+
+/** Determine how many circuits we have open that are clean,
+ * Make sure it's enough for all the upcoming behaviors we predict we'll have.
+ * But put an upper bound on the total number of circuits.
+ */
+static void
+circuit_predict_and_launch_new(void)
+{
+ int num=0, num_internal=0, num_uptime_internal=0;
+ int hidserv_needs_uptime=0, hidserv_needs_capacity=1;
+ int port_needs_uptime=0, port_needs_capacity=1;
+ time_t now = time(NULL);
+ int flags = 0;
+
+ /* Count how many of each type of circuit we currently have. */
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ if (!circuit_is_available_for_use(circ))
+ continue;
+
+ num++;
+
+ cpath_build_state_t *build_state = TO_ORIGIN_CIRCUIT(circ)->build_state;
+ if (build_state->is_internal)
+ num_internal++;
+ if (build_state->need_uptime && build_state->is_internal)
+ num_uptime_internal++;
+ }
+ SMARTLIST_FOREACH_END(circ);
+
+ /* If that's enough, then stop now. */
+ if (num >= MAX_UNUSED_OPEN_CIRCUITS)
+ return;
+
+ if (needs_exit_circuits(now, &port_needs_uptime, &port_needs_capacity)) {
+ if (port_needs_uptime)
+ flags |= CIRCLAUNCH_NEED_UPTIME;
+ if (port_needs_capacity)
+ flags |= CIRCLAUNCH_NEED_CAPACITY;
+
+ log_info(LD_CIRC,
+ "Have %d clean circs (%d internal), need another exit circ.",
+ num, num_internal);
+ circuit_launch(CIRCUIT_PURPOSE_C_GENERAL, flags);
+ return;
+ }
+
+ if (needs_hs_server_circuits(now, num_uptime_internal)) {
+ flags = (CIRCLAUNCH_NEED_CAPACITY | CIRCLAUNCH_NEED_UPTIME |
+ CIRCLAUNCH_IS_INTERNAL);
+
+ log_info(LD_CIRC,
+ "Have %d clean circs (%d internal), need another internal "
+ "circ for my hidden service.",
+ num, num_internal);
+ circuit_launch_predicted_hs_circ(flags);
+ return;
+ }
+
+ if (needs_hs_client_circuits(now, &hidserv_needs_uptime,
+ &hidserv_needs_capacity,
+ num_internal, num_uptime_internal))
+ {
+ if (hidserv_needs_uptime)
+ flags |= CIRCLAUNCH_NEED_UPTIME;
+ if (hidserv_needs_capacity)
+ flags |= CIRCLAUNCH_NEED_CAPACITY;
+ flags |= CIRCLAUNCH_IS_INTERNAL;
+
+ log_info(LD_CIRC,
+ "Have %d clean circs (%d uptime-internal, %d internal), need"
+ " another hidden service circ.",
+ num, num_uptime_internal, num_internal);
+
+ circuit_launch_predicted_hs_circ(flags);
+ return;
+ }
+
+ if (needs_circuits_for_build(num)) {
+ flags = CIRCLAUNCH_NEED_CAPACITY;
+ /* if there are no exits in the consensus, make timeout
+ * circuits internal */
+ if (router_have_consensus_path() == CONSENSUS_PATH_INTERNAL)
+ flags |= CIRCLAUNCH_IS_INTERNAL;
+
+ log_info(LD_CIRC,
+ "Have %d clean circs need another buildtime test circ.", num);
+ circuit_launch(CIRCUIT_PURPOSE_C_GENERAL, flags);
+ return;
+ }
+}
+
+/** Build a new test circuit every 5 minutes */
+#define TESTING_CIRCUIT_INTERVAL 300
+
+/** This function is called once a second, if router_have_minimum_dir_info()
+ * is true. Its job is to make sure all services we offer have enough circuits
+ * available. Some services just want enough circuits for current tasks,
+ * whereas others want a minimum set of idle circuits hanging around.
+ */
+void
+circuit_build_needed_circs(time_t now)
+{
+ const or_options_t *options = get_options();
+
+ /* launch a new circ for any pending streams that need one
+ * XXXX make the assumption that (some) AP streams (i.e. HS clients)
+ * don't require an exit circuit, review in #13814.
+ * This allows HSs to function in a consensus without exits. */
+ if (router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN)
+ connection_ap_rescan_and_attach_pending();
+
+ circuit_expire_old_circs_as_needed(now);
+
+ if (!options->DisablePredictedCircuits)
+ circuit_predict_and_launch_new();
+}
+
+/**
+ * Called once a second either directly or from
+ * circuit_build_needed_circs(). As appropriate (once per NewCircuitPeriod)
+ * resets failure counts and expires old circuits.
+ */
+void
+circuit_expire_old_circs_as_needed(time_t now)
+{
+ static time_t time_to_expire_and_reset = 0;
+
+ if (time_to_expire_and_reset < now) {
+ circuit_reset_failure_count(1);
+ time_to_expire_and_reset = now + get_options()->NewCircuitPeriod;
+ if (proxy_mode(get_options()))
+ addressmap_clean(now);
+ circuit_expire_old_circuits_clientside();
+
+#if 0 /* disable for now, until predict-and-launch-new can cull leftovers */
+
+ /* If we ever re-enable, this has to move into
+ * circuit_build_needed_circs */
+
+ circ = circuit_get_youngest_clean_open(CIRCUIT_PURPOSE_C_GENERAL);
+ if (get_options()->RunTesting &&
+ circ &&
+ circ->timestamp_began.tv_sec + TESTING_CIRCUIT_INTERVAL < now) {
+ log_fn(LOG_INFO,"Creating a new testing circuit.");
+ circuit_launch(CIRCUIT_PURPOSE_C_GENERAL, 0);
+ }
+#endif /* 0 */
+ }
+}
+
+/** If the stream <b>conn</b> is a member of any of the linked
+ * lists of <b>circ</b>, then remove it from the list.
+ */
+void
+circuit_detach_stream(circuit_t *circ, edge_connection_t *conn)
+{
+ edge_connection_t *prevconn;
+
+ tor_assert(circ);
+ tor_assert(conn);
+
+ if (conn->base_.type == CONN_TYPE_AP) {
+ entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn);
+ entry_conn->may_use_optimistic_data = 0;
+ }
+ conn->cpath_layer = NULL; /* don't keep a stale pointer */
+ conn->on_circuit = NULL;
+
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(circ);
+ int removed = 0;
+ if (conn == origin_circ->p_streams) {
+ origin_circ->p_streams = conn->next_stream;
+ removed = 1;
+ } else {
+ for (prevconn = origin_circ->p_streams;
+ prevconn && prevconn->next_stream && prevconn->next_stream != conn;
+ prevconn = prevconn->next_stream)
+ ;
+ if (prevconn && prevconn->next_stream) {
+ prevconn->next_stream = conn->next_stream;
+ removed = 1;
+ }
+ }
+ if (removed) {
+ log_debug(LD_APP, "Removing stream %d from circ %u",
+ conn->stream_id, (unsigned)circ->n_circ_id);
+
+ /* If the stream was removed, and it was a rend stream, decrement the
+ * number of streams on the circuit associated with the rend service.
+ */
+ if (circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED) {
+ hs_dec_rdv_stream_counter(origin_circ);
+ }
+
+ /* If there are no more streams on this circ, tell circpad */
+ if (!origin_circ->p_streams)
+ circpad_machine_event_circ_has_no_streams(origin_circ);
+
+ return;
+ }
+ } else {
+ or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
+ if (conn == or_circ->n_streams) {
+ or_circ->n_streams = conn->next_stream;
+ return;
+ }
+ if (conn == or_circ->resolving_streams) {
+ or_circ->resolving_streams = conn->next_stream;
+ return;
+ }
+
+ for (prevconn = or_circ->n_streams;
+ prevconn && prevconn->next_stream && prevconn->next_stream != conn;
+ prevconn = prevconn->next_stream)
+ ;
+ if (prevconn && prevconn->next_stream) {
+ prevconn->next_stream = conn->next_stream;
+ return;
+ }
+
+ for (prevconn = or_circ->resolving_streams;
+ prevconn && prevconn->next_stream && prevconn->next_stream != conn;
+ prevconn = prevconn->next_stream)
+ ;
+ if (prevconn && prevconn->next_stream) {
+ prevconn->next_stream = conn->next_stream;
+ return;
+ }
+ }
+
+ log_warn(LD_BUG,"Edge connection not in circuit's list.");
+ /* Don't give an error here; it's harmless. */
+ tor_fragile_assert();
+}
+
+/** Find each circuit that has been unused for too long, or dirty
+ * for too long and has no streams on it: mark it for close.
+ */
+static void
+circuit_expire_old_circuits_clientside(void)
+{
+ struct timeval cutoff, now;
+
+ tor_gettimeofday(&now);
+ last_expired_clientside_circuits = now.tv_sec;
+
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ if (circ->marked_for_close || !CIRCUIT_IS_ORIGIN(circ))
+ continue;
+
+ cutoff = now;
+ cutoff.tv_sec -= TO_ORIGIN_CIRCUIT(circ)->circuit_idle_timeout;
+
+ /* If the circuit has been dirty for too long, and there are no streams
+ * on it, mark it for close.
+ */
+ if (circ->timestamp_dirty &&
+ circ->timestamp_dirty + get_options()->MaxCircuitDirtiness <
+ now.tv_sec &&
+ !TO_ORIGIN_CIRCUIT(circ)->p_streams /* nothing attached */ ) {
+ log_debug(LD_CIRC, "Closing n_circ_id %u (dirty %ld sec ago, "
+ "purpose %d)",
+ (unsigned)circ->n_circ_id,
+ (long)(now.tv_sec - circ->timestamp_dirty),
+ circ->purpose);
+ /* Don't do this magic for testing circuits. Their death is governed
+ * by circuit_expire_building */
+ if (circ->purpose != CIRCUIT_PURPOSE_PATH_BIAS_TESTING)
+ circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
+ } else if (!circ->timestamp_dirty && circ->state == CIRCUIT_STATE_OPEN) {
+ if (timercmp(&circ->timestamp_began, &cutoff, OP_LT)) {
+ 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_HS_VANGUARDS ||
+ circ->purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT ||
+ circ->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO ||
+ circ->purpose == CIRCUIT_PURPOSE_TESTING ||
+ (circ->purpose >= CIRCUIT_PURPOSE_C_INTRODUCING &&
+ circ->purpose <= CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED) ||
+ circ->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND) {
+ log_info(LD_CIRC,
+ "Closing circuit %"PRIu32
+ " that has been unused for %ld msec.",
+ TO_ORIGIN_CIRCUIT(circ)->global_identifier,
+ tv_mdiff(&circ->timestamp_began, &now));
+ circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
+ } else if (!TO_ORIGIN_CIRCUIT(circ)->is_ancient) {
+ /* Server-side rend joined circuits can end up really old, because
+ * they are reused by clients for longer than normal. The client
+ * controls their lifespan. (They never become dirty, because
+ * connection_exit_begin_conn() never marks anything as dirty.)
+ * Similarly, server-side intro circuits last a long time. */
+ if (circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED &&
+ circ->purpose != CIRCUIT_PURPOSE_S_INTRO) {
+ log_notice(LD_CIRC,
+ "Ancient non-dirty circuit %d is still around after "
+ "%ld milliseconds. Purpose: %d (%s)",
+ TO_ORIGIN_CIRCUIT(circ)->global_identifier,
+ tv_mdiff(&circ->timestamp_began, &now),
+ circ->purpose,
+ circuit_purpose_to_string(circ->purpose));
+ TO_ORIGIN_CIRCUIT(circ)->is_ancient = 1;
+ }
+ }
+ }
+ }
+ } SMARTLIST_FOREACH_END(circ);
+}
+
+/** How long do we wait before killing circuits with the properties
+ * described below?
+ *
+ * Probably we could choose a number here as low as 5 to 10 seconds,
+ * since these circs are used for begindir, and a) generally you either
+ * ask another begindir question right after or you don't for a long time,
+ * b) clients at least through 0.2.1.x choose from the whole set of
+ * directory mirrors at each choice, and c) re-establishing a one-hop
+ * circuit via create-fast is a light operation assuming the TLS conn is
+ * still there.
+ *
+ * I expect "b" to go away one day when we move to using directory
+ * guards, but I think "a" and "c" are good enough reasons that a low
+ * number is safe even then.
+ */
+#define IDLE_ONE_HOP_CIRC_TIMEOUT 60
+
+/** Find each non-origin circuit that has been unused for too long,
+ * has no streams on it, came from a client, and ends here: mark it
+ * for close.
+ */
+void
+circuit_expire_old_circuits_serverside(time_t now)
+{
+ or_circuit_t *or_circ;
+ time_t cutoff = now - IDLE_ONE_HOP_CIRC_TIMEOUT;
+
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ if (circ->marked_for_close || CIRCUIT_IS_ORIGIN(circ))
+ continue;
+ or_circ = TO_OR_CIRCUIT(circ);
+ /* If the circuit has been idle for too long, and there are no streams
+ * on it, and it ends here, and it used a create_fast, mark it for close.
++ *
++ * Also if there is a rend_splice on it, it's a single onion service
++ * circuit and we should not close it.
+ */
+ if (or_circ->p_chan && channel_is_client(or_circ->p_chan) &&
+ !circ->n_chan &&
+ !or_circ->n_streams && !or_circ->resolving_streams &&
++ !or_circ->rend_splice &&
+ channel_when_last_xmit(or_circ->p_chan) <= cutoff) {
+ log_info(LD_CIRC, "Closing circ_id %u (empty %d secs ago)",
+ (unsigned)or_circ->p_circ_id,
+ (int)(now - channel_when_last_xmit(or_circ->p_chan)));
+ circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
+ }
+ }
+ SMARTLIST_FOREACH_END(circ);
+}
+
+/** Number of testing circuits we want open before testing our bandwidth. */
+#define NUM_PARALLEL_TESTING_CIRCS 4
+
+/** True iff we've ever had enough testing circuits open to test our
+ * bandwidth. */
+static int have_performed_bandwidth_test = 0;
+
+/** Reset have_performed_bandwidth_test, so we'll start building
+ * testing circuits again so we can exercise our bandwidth. */
+void
+reset_bandwidth_test(void)
+{
+ have_performed_bandwidth_test = 0;
+}
+
+/** Return 1 if we've already exercised our bandwidth, or if we
+ * have fewer than NUM_PARALLEL_TESTING_CIRCS testing circuits
+ * established or on the way. Else return 0.
+ */
+int
+circuit_enough_testing_circs(void)
+{
+ int num = 0;
+
+ if (have_performed_bandwidth_test)
+ return 1;
+
+ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
+ if (!circ->marked_for_close && CIRCUIT_IS_ORIGIN(circ) &&
+ circ->purpose == CIRCUIT_PURPOSE_TESTING &&
+ circ->state == CIRCUIT_STATE_OPEN)
+ num++;
+ }
+ SMARTLIST_FOREACH_END(circ);
+ return num >= NUM_PARALLEL_TESTING_CIRCS;
+}
+
+/** A testing circuit has completed. Take whatever stats we want.
+ * Noticing reachability is taken care of in onionskin_answer(),
+ * so there's no need to record anything here. But if we still want
+ * to do the bandwidth test, and we now have enough testing circuits
+ * open, do it.
+ */
+static void
+circuit_testing_opened(origin_circuit_t *circ)
+{
+ if (have_performed_bandwidth_test ||
+ !check_whether_orport_reachable(get_options())) {
+ /* either we've already done everything we want with testing circuits,
+ * or this testing circuit became open due to a fluke, e.g. we picked
+ * a last hop where we already had the connection open due to an
+ * outgoing local circuit. */
+ circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_AT_ORIGIN);
+ } else if (circuit_enough_testing_circs()) {
+ router_perform_bandwidth_test(NUM_PARALLEL_TESTING_CIRCS, time(NULL));
+ have_performed_bandwidth_test = 1;
+ } else
+ router_do_reachability_checks(1, 0);
+}
+
+/** A testing circuit has failed to build. Take whatever stats we want. */
+static void
+circuit_testing_failed(origin_circuit_t *circ, int at_last_hop)
+{
+ const or_options_t *options = get_options();
+ if (server_mode(options) && check_whether_orport_reachable(options))
+ return;
+
+ log_info(LD_GENERAL,
+ "Our testing circuit (to see if your ORPort is reachable) "
+ "has failed. I'll try again later.");
+
+ /* These aren't used yet. */
+ (void)circ;
+ (void)at_last_hop;
+}
+
+/** The circuit <b>circ</b> has just become open. Take the next
+ * step: for rendezvous circuits, we pass circ to the appropriate
+ * function in rendclient or rendservice. For general circuits, we
+ * call connection_ap_attach_pending, which looks for pending streams
+ * that could use circ.
+ */
+void
+circuit_has_opened(origin_circuit_t *circ)
+{
+ circuit_event_status(circ, CIRC_EVENT_BUILT, 0);
+
+ /* Remember that this circuit has finished building. Now if we start
+ * it building again later (e.g. by extending it), we will know not
+ * to consider its build time. */
+ circ->has_opened = 1;
+
+ switch (TO_CIRCUIT(circ)->purpose) {
+ case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
+ hs_client_circuit_has_opened(circ);
+ /* Start building an intro circ if we don't have one yet. */
+ connection_ap_attach_pending(1);
+ /* This isn't a call to circuit_try_attaching_streams because a
+ * circuit in _C_ESTABLISH_REND state isn't connected to its
+ * hidden service yet, thus we can't attach streams to it yet,
+ * thus circuit_try_attaching_streams would always clear the
+ * circuit's isolation state. circuit_try_attaching_streams is
+ * called later, when the rend circ enters _C_REND_JOINED
+ * state. */
+ break;
+ case CIRCUIT_PURPOSE_C_INTRODUCING:
+ hs_client_circuit_has_opened(circ);
+ break;
+ case CIRCUIT_PURPOSE_C_GENERAL:
+ case CIRCUIT_PURPOSE_C_HSDIR_GET:
+ case CIRCUIT_PURPOSE_S_HSDIR_POST:
+ /* Tell any AP connections that have been waiting for a new
+ * circuit that one is ready. */
+ circuit_try_attaching_streams(circ);
+ break;
+ case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
+ /* at the service, waiting for introductions */
+ hs_service_circuit_has_opened(circ);
+ break;
+ case CIRCUIT_PURPOSE_S_CONNECT_REND:
+ /* at the service, connecting to rend point */
+ hs_service_circuit_has_opened(circ);
+ break;
+ case CIRCUIT_PURPOSE_TESTING:
+ circuit_testing_opened(circ);
+ break;
+ /* default:
+ * This won't happen in normal operation, but might happen if the
+ * controller did it. Just let it slide. */
+ }
+}
+
+/** If the stream-isolation state of <b>circ</b> can be cleared, clear
+ * it. Return non-zero iff <b>circ</b>'s isolation state was cleared. */
+static int
+circuit_try_clearing_isolation_state(origin_circuit_t *circ)
+{
+ if (/* The circuit may have become non-open if it was cannibalized.*/
+ circ->base_.state == CIRCUIT_STATE_OPEN &&
+ /* If !isolation_values_set, there is nothing to clear. */
+ circ->isolation_values_set &&
+ /* It's not legal to clear a circuit's isolation info if it's ever had
+ * streams attached */
+ !circ->isolation_any_streams_attached) {
+ /* If we have any isolation information set on this circuit, and
+ * we didn't manage to attach any streams to it, then we can
+ * and should clear it and try again. */
+ circuit_clear_isolation(circ);
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+/** Called when a circuit becomes ready for streams to be attached to
+ * it. */
+void
+circuit_try_attaching_streams(origin_circuit_t *circ)
+{
+ /* Attach streams to this circuit if we can. */
+ connection_ap_attach_pending(1);
+
+ /* The call to circuit_try_clearing_isolation_state here will do
+ * nothing and return 0 if we didn't attach any streams to circ
+ * above. */
+ if (circuit_try_clearing_isolation_state(circ)) {
+ /* Maybe *now* we can attach some streams to this circuit. */
+ connection_ap_attach_pending(1);
+ }
+}
+
+/** Called whenever a circuit could not be successfully built.
+ */
+void
+circuit_build_failed(origin_circuit_t *circ)
+{
+ channel_t *n_chan = NULL;
+ /* we should examine circ and see if it failed because of
+ * the last hop or an earlier hop. then use this info below.
+ */
+ int failed_at_last_hop = 0;
+
+ /* First, check to see if this was a path failure, rather than build
+ * failure.
+ *
+ * Note that we deliberately use circuit_get_cpath_len() (and not
+ * circuit_get_cpath_opened_len()) because we only want to ensure
+ * that a full path is *chosen*. This is different than a full path
+ * being *built*. We only want to count *build* failures below.
+ *
+ * Path selection failures can happen spuriously for a number
+ * of reasons (such as aggressive/invalid user-specified path
+ * restrictions in the torrc, insufficient microdescriptors, and
+ * non-user reasons like exitpolicy issues), and so should not be
+ * counted as failures below.
+ */
+ if (circuit_get_cpath_len(circ) < circ->build_state->desired_path_len) {
+ static ratelim_t pathfail_limit = RATELIM_INIT(3600);
+ log_fn_ratelim(&pathfail_limit, LOG_NOTICE, LD_CIRC,
+ "Our circuit %u (id: %" PRIu32 ") died due to an invalid "
+ "selected path, purpose %s. This may be a torrc "
+ "configuration issue, or a bug.",
+ TO_CIRCUIT(circ)->n_circ_id, circ->global_identifier,
+ circuit_purpose_to_string(TO_CIRCUIT(circ)->purpose));
+
+ /* If the path failed on an RP, retry it. */
+ if (TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND)
+ hs_circ_retry_service_rendezvous_point(circ);
+
+ /* In all other cases, just bail. The rest is just failure accounting
+ * that we don't want to do */
+ return;
+ }
+
+ /* If the last hop isn't open, and the second-to-last is, we failed
+ * at the last hop. */
+ if (circ->cpath &&
+ circ->cpath->prev->state != CPATH_STATE_OPEN &&
+ circ->cpath->prev->prev->state == CPATH_STATE_OPEN) {
+ failed_at_last_hop = 1;
+ }
+
+ /* Check if we failed at first hop */
+ if (circ->cpath &&
+ circ->cpath->state != CPATH_STATE_OPEN &&
+ ! circ->base_.received_destroy) {
+ /* We failed at the first hop for some reason other than a DESTROY cell.
+ * If there's an OR connection to blame, blame it. Also, avoid this relay
+ * for a while, and fail any one-hop directory fetches destined for it. */
+ const char *n_chan_ident = circ->cpath->extend_info->identity_digest;
+ tor_assert(n_chan_ident);
+ int already_marked = 0;
+ if (circ->base_.n_chan) {
+ n_chan = circ->base_.n_chan;
+
+ if (n_chan->is_bad_for_new_circs) {
+ /* We only want to blame this router when a fresh healthy
+ * connection fails. So don't mark this router as newly failed,
+ * since maybe this was just an old circuit attempt that's
+ * finally timing out now. Also, there's no need to blow away
+ * circuits/streams/etc, since the failure of an unhealthy conn
+ * doesn't tell us much about whether a healthy conn would
+ * succeed. */
+ already_marked = 1;
+ }
+ log_info(LD_OR,
+ "Our circuit %u (id: %" PRIu32 ") failed to get a response "
+ "from the first hop (%s). I'm going to try to rotate to a "
+ "better connection.",
+ TO_CIRCUIT(circ)->n_circ_id, circ->global_identifier,
+ channel_get_canonical_remote_descr(n_chan));
+ n_chan->is_bad_for_new_circs = 1;
+ } else {
+ log_info(LD_OR,
+ "Our circuit %u (id: %" PRIu32 ") died before the first hop "
+ "with no connection",
+ TO_CIRCUIT(circ)->n_circ_id, circ->global_identifier);
+ }
+ if (!already_marked) {
+ /*
+ * If we have guard state (new guard API) and our path selection
+ * code actually chose a full path, then blame the failure of this
+ * circuit on the guard.
+ */
+ if (circ->guard_state)
+ entry_guard_failed(&circ->guard_state);
+ /* if there are any one-hop streams waiting on this circuit, fail
+ * them now so they can retry elsewhere. */
+ connection_ap_fail_onehop(n_chan_ident, circ->build_state);
+ }
+ }
+
+ switch (circ->base_.purpose) {
+ case CIRCUIT_PURPOSE_C_HSDIR_GET:
+ case CIRCUIT_PURPOSE_S_HSDIR_POST:
+ case CIRCUIT_PURPOSE_C_GENERAL:
+ /* If we never built the circuit, note it as a failure. */
+ circuit_increment_failure_count();
+ if (failed_at_last_hop) {
+ /* Make sure any streams that demand our last hop as their exit
+ * know that it's unlikely to happen. */
+ circuit_discard_optional_exit_enclaves(circ->cpath->prev->extend_info);
+ }
+ break;
+ case CIRCUIT_PURPOSE_TESTING:
+ circuit_testing_failed(circ, failed_at_last_hop);
+ break;
+ case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
+ /* at the service, waiting for introductions */
+ if (circ->base_.state != CIRCUIT_STATE_OPEN) {
+ circuit_increment_failure_count();
+ }
+ /* no need to care here, because the service will rebuild intro
+ * points periodically. */
+ break;
+ case CIRCUIT_PURPOSE_C_INTRODUCING:
+ /* at the client, connecting to intro point */
+ /* Don't increment failure count, since the service may have picked
+ * the introduction point maliciously */
+ /* The client will pick a new intro point when this one dies, if
+ * the stream in question still cares. No need to act here. */
+ break;
+ case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
+ /* at the client, waiting for the service */
+ circuit_increment_failure_count();
+ /* the client will pick a new rend point when this one dies, if
+ * the stream in question still cares. No need to act here. */
+ break;
+ case CIRCUIT_PURPOSE_S_CONNECT_REND:
+ /* at the service, connecting to rend point */
+ /* Don't increment failure count, since the client may have picked
+ * the rendezvous point maliciously */
+ log_info(LD_REND,
+ "Couldn't connect to the client's chosen rend point %s "
+ "(%s hop failed).",
+ escaped(build_state_get_exit_nickname(circ->build_state)),
+ failed_at_last_hop?"last":"non-last");
+ hs_circ_retry_service_rendezvous_point(circ);
+ break;
+ /* default:
+ * This won't happen in normal operation, but might happen if the
+ * controller did it. Just let it slide. */
+ }
+}
+
+/** Number of consecutive failures so far; should only be touched by
+ * circuit_launch_new and circuit_*_failure_count.
+ */
+static int n_circuit_failures = 0;
+/** Before the last time we called circuit_reset_failure_count(), were
+ * there a lot of failures? */
+static int did_circs_fail_last_period = 0;
+
+/** Don't retry launching a new circuit if we try this many times with no
+ * success. */
+#define MAX_CIRCUIT_FAILURES 5
+
+/** Launch a new circuit; see circuit_launch_by_extend_info() for
+ * details on arguments. */
+origin_circuit_t *
+circuit_launch(uint8_t purpose, int flags)
+{
+ return circuit_launch_by_extend_info(purpose, NULL, flags);
+}
+
+/* Do we have enough descriptors to build paths?
+ * If need_exit is true, return 1 if we can build exit paths.
+ * (We need at least one Exit in the consensus to build exit paths.)
+ * If need_exit is false, return 1 if we can build internal paths.
+ */
+static int
+have_enough_path_info(int need_exit)
+{
+ if (need_exit)
+ return router_have_consensus_path() == CONSENSUS_PATH_EXIT;
+ else
+ return router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN;
+}
+
+/**
+ * Tell us if a circuit is a hidden service circuit.
+ */
+int
+circuit_purpose_is_hidden_service(uint8_t purpose)
+{
+ if (purpose == CIRCUIT_PURPOSE_HS_VANGUARDS) {
+ return 1;
+ }
+
+ /* Client-side purpose */
+ if (purpose >= CIRCUIT_PURPOSE_C_HS_MIN_ &&
+ purpose <= CIRCUIT_PURPOSE_C_HS_MAX_) {
+ return 1;
+ }
+
+ /* Service-side purpose */
+ if (purpose >= CIRCUIT_PURPOSE_S_HS_MIN_ &&
+ purpose <= CIRCUIT_PURPOSE_S_HS_MAX_) {
+ return 1;
+ }
+
+ return 0;
+}
+
+/**
+ * Return true if this circuit purpose should use vanguards
+ * or pinned Layer2 or Layer3 guards.
+ *
+ * This function takes both the circuit purpose and the
+ * torrc options for pinned middles/vanguards into account
+ * (ie: the circuit must be a hidden service circuit and
+ * vanguards/pinned middles must be enabled for it to return
+ * true).
+ */
+int
+circuit_should_use_vanguards(uint8_t purpose)
+{
+ const or_options_t *options = get_options();
+
+ /* Only hidden service circuits use vanguards */
+ if (!circuit_purpose_is_hidden_service(purpose))
+ return 0;
+
+ /* Pinned middles are effectively vanguards */
+ if (options->HSLayer2Nodes || options->HSLayer3Nodes)
+ return 1;
+
+ return 0;
+}
+
+/**
+ * Return true for the set of conditions for which it is OK to use
+ * a cannibalized circuit.
+ *
+ * Don't cannibalize for onehops, or certain purposes.
+ */
+static int
+circuit_should_cannibalize_to_build(uint8_t purpose_to_build,
+ int has_extend_info,
+ int onehop_tunnel)
+{
+
+ /* Do not try to cannibalize if this is a one hop circuit. */
+ if (onehop_tunnel) {
+ return 0;
+ }
+
+ /* Don't try to cannibalize for general purpose circuits that do not
+ * specify a custom exit. */
+ if (purpose_to_build == CIRCUIT_PURPOSE_C_GENERAL && !has_extend_info) {
+ return 0;
+ }
+
+ /* Don't cannibalize for testing circuits. We want to see if they
+ * complete normally. Also don't cannibalize for vanguard-purpose
+ * circuits, since those are specially pre-built for later
+ * cannibalization by the actual specific circuit types that need
+ * vanguards.
+ */
+ if (purpose_to_build == CIRCUIT_PURPOSE_TESTING ||
+ purpose_to_build == CIRCUIT_PURPOSE_HS_VANGUARDS) {
+ return 0;
+ }
+
+ /* For vanguards, the server-side intro circ is not cannibalized
+ * because we pre-build 4 hop HS circuits, and it only needs a 3 hop
+ * circuit. It is also long-lived, so it is more important that
+ * it have lower latency than get built fast.
+ */
+ if (circuit_should_use_vanguards(purpose_to_build) &&
+ purpose_to_build == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO) {
+ return 0;
+ }
+
+ return 1;
+}
+
+/** Launch a new circuit with purpose <b>purpose</b> and exit node
+ * <b>extend_info</b> (or NULL to select a random exit node). If flags
+ * contains CIRCLAUNCH_NEED_UPTIME, choose among routers with high uptime. If
+ * CIRCLAUNCH_NEED_CAPACITY is set, choose among routers with high bandwidth.
+ * If CIRCLAUNCH_IS_INTERNAL is true, the last hop need not be an exit node.
+ * If CIRCLAUNCH_ONEHOP_TUNNEL is set, the circuit will have only one hop.
+ * Return the newly allocated circuit on success, or NULL on failure. */
+origin_circuit_t *
+circuit_launch_by_extend_info(uint8_t purpose,
+ extend_info_t *extend_info,
+ int flags)
+{
+ origin_circuit_t *circ;
+ int onehop_tunnel = (flags & CIRCLAUNCH_ONEHOP_TUNNEL) != 0;
+ int have_path = have_enough_path_info(! (flags & CIRCLAUNCH_IS_INTERNAL) );
+
+ /* Keep some stats about our attempts to launch HS rendezvous circuits */
+ if (purpose == CIRCUIT_PURPOSE_S_CONNECT_REND) {
+ hs_stats_note_service_rendezvous_launch();
+ }
+
+ if (!onehop_tunnel && (!router_have_minimum_dir_info() || !have_path)) {
+ log_debug(LD_CIRC,"Haven't %s yet; canceling "
+ "circuit launch.",
+ !router_have_minimum_dir_info() ?
+ "fetched enough directory info" :
+ "received a consensus with exits");
+ return NULL;
+ }
+
+ /* If we can/should cannibalize another circuit to build this one,
+ * then do so. */
+ if (circuit_should_cannibalize_to_build(purpose,
+ extend_info != NULL,
+ onehop_tunnel)) {
+ /* see if there are appropriate circs available to cannibalize. */
+ /* XXX if we're planning to add a hop, perhaps we want to look for
+ * internal circs rather than exit circs? -RD */
+ circ = circuit_find_to_cannibalize(purpose, extend_info, flags);
+ if (circ) {
+ uint8_t old_purpose = circ->base_.purpose;
+ struct timeval old_timestamp_began = circ->base_.timestamp_began;
+
+ log_info(LD_CIRC, "Cannibalizing circ %u (id: %" PRIu32 ") for "
+ "purpose %d (%s)",
+ TO_CIRCUIT(circ)->n_circ_id, circ->global_identifier, purpose,
+ circuit_purpose_to_string(purpose));
+
+ if ((purpose == CIRCUIT_PURPOSE_S_CONNECT_REND ||
+ purpose == CIRCUIT_PURPOSE_C_INTRODUCING) &&
+ circ->path_state == PATH_STATE_BUILD_SUCCEEDED) {
+ /* Path bias: Cannibalized rends pre-emptively count as a
+ * successfully built but unused closed circuit. We don't
+ * wait until the extend (or the close) because the rend
+ * point could be malicious.
+ *
+ * Same deal goes for client side introductions. Clients
+ * can be manipulated to connect repeatedly to them
+ * (especially web clients).
+ *
+ * If we decide to probe the initial portion of these circs,
+ * (up to the adversary's final hop), we need to remove this,
+ * or somehow mark the circuit with a special path state.
+ */
+
+ /* This must be called before the purpose change */
+ pathbias_check_close(circ, END_CIRC_REASON_FINISHED);
+ }
+
+ circuit_change_purpose(TO_CIRCUIT(circ), purpose);
+ /* Reset the start date of this circ, else expire_building
+ * will see it and think it's been trying to build since it
+ * began.
+ *
+ * Technically, the code should reset this when the
+ * create cell is finally sent, but we're close enough
+ * here. */
+ tor_gettimeofday(&circ->base_.timestamp_began);
+
+ control_event_circuit_cannibalized(circ, old_purpose,
+ &old_timestamp_began);
+
+ switch (purpose) {
+ case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
+ /* it's ready right now */
+ break;
+ case CIRCUIT_PURPOSE_C_INTRODUCING:
+ case CIRCUIT_PURPOSE_S_CONNECT_REND:
+ case CIRCUIT_PURPOSE_C_GENERAL:
+ case CIRCUIT_PURPOSE_S_HSDIR_POST:
+ case CIRCUIT_PURPOSE_C_HSDIR_GET:
+ case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
+ /* need to add a new hop */
+ tor_assert(extend_info);
+ if (circuit_extend_to_new_exit(circ, extend_info) < 0)
+ return NULL;
+ break;
+ default:
+ log_warn(LD_BUG,
+ "unexpected purpose %d when cannibalizing a circ.",
+ purpose);
+ tor_fragile_assert();
+ return NULL;
+ }
+ return circ;
+ }
+ }
+
+ if (did_circs_fail_last_period &&
+ n_circuit_failures > MAX_CIRCUIT_FAILURES) {
+ /* too many failed circs in a row. don't try. */
+// log_fn(LOG_INFO,"%d failures so far, not trying.",n_circuit_failures);
+ return NULL;
+ }
+
+ /* try a circ. if it fails, circuit_mark_for_close will increment
+ * n_circuit_failures */
+ return circuit_establish_circuit(purpose, extend_info, flags);
+}
+
+/** Record another failure at opening a general circuit. When we have
+ * too many, we'll stop trying for the remainder of this minute.
+ */
+static void
+circuit_increment_failure_count(void)
+{
+ ++n_circuit_failures;
+ log_debug(LD_CIRC,"n_circuit_failures now %d.",n_circuit_failures);
+}
+
+/** Reset the failure count for opening general circuits. This means
+ * we will try MAX_CIRCUIT_FAILURES times more (if necessary) before
+ * stopping again.
+ */
+void
+circuit_reset_failure_count(int timeout)
+{
+ if (timeout && n_circuit_failures > MAX_CIRCUIT_FAILURES)
+ did_circs_fail_last_period = 1;
+ else
+ did_circs_fail_last_period = 0;
+ n_circuit_failures = 0;
+}
+
+/** Find an open circ that we're happy to use for <b>conn</b> and return 1. If
+ * there isn't one, and there isn't one on the way, launch one and return
+ * 0. If it will never work, return -1.
+ *
+ * Write the found or in-progress or launched circ into *circp.
+ */
+static int
+circuit_get_open_circ_or_launch(entry_connection_t *conn,
+ uint8_t desired_circuit_purpose,
+ origin_circuit_t **circp)
+{
+ origin_circuit_t *circ;
+ int check_exit_policy;
+ int need_uptime, need_internal;
+ int want_onehop;
+ const or_options_t *options = get_options();
+
+ tor_assert(conn);
+ tor_assert(circp);
+ if (ENTRY_TO_CONN(conn)->state != AP_CONN_STATE_CIRCUIT_WAIT) {
+ connection_t *c = ENTRY_TO_CONN(conn);
+ log_err(LD_BUG, "Connection state mismatch: wanted "
+ "AP_CONN_STATE_CIRCUIT_WAIT, but got %d (%s)",
+ c->state, conn_state_to_string(c->type, c->state));
+ }
+ tor_assert(ENTRY_TO_CONN(conn)->state == AP_CONN_STATE_CIRCUIT_WAIT);
+
+ /* Will the exit policy of the exit node apply to this stream? */
+ check_exit_policy =
+ conn->socks_request->command == SOCKS_COMMAND_CONNECT &&
+ !conn->use_begindir &&
+ !connection_edge_is_rendezvous_stream(ENTRY_TO_EDGE_CONN(conn));
+
+ /* Does this connection want a one-hop circuit? */
+ want_onehop = conn->want_onehop;
+
+ /* Do we need a high-uptime circuit? */
+ need_uptime = !conn->want_onehop && !conn->use_begindir &&
+ smartlist_contains_int_as_string(options->LongLivedPorts,
+ conn->socks_request->port);
+
+ /* Do we need an "internal" circuit? */
+ if (desired_circuit_purpose != CIRCUIT_PURPOSE_C_GENERAL)
+ need_internal = 1;
+ else if (conn->use_begindir || conn->want_onehop)
+ need_internal = 1;
+ else
+ need_internal = 0;
+
+ /* We now know what kind of circuit we need. See if there is an
+ * open circuit that we can use for this stream */
+ circ = circuit_get_best(conn, 1 /* Insist on open circuits */,
+ desired_circuit_purpose,
+ need_uptime, need_internal);
+
+ if (circ) {
+ /* We got a circuit that will work for this stream! We can return it. */
+ *circp = circ;
+ return 1; /* we're happy */
+ }
+
+ /* Okay, there's no circuit open that will work for this stream. Let's
+ * see if there's an in-progress circuit or if we have to launch one */
+
+ /* Do we know enough directory info to build circuits at all? */
+ int have_path = have_enough_path_info(!need_internal);
+
+ if (!want_onehop && (!router_have_minimum_dir_info() || !have_path)) {
+ /* If we don't have enough directory information, we can't build
+ * multihop circuits.
+ */
+ if (!connection_get_by_type(CONN_TYPE_DIR)) {
+ int severity = LOG_NOTICE;
+ /* Retry some stuff that might help the connection work. */
+ /* If we are configured with EntryNodes or UseBridges */
+ if (entry_list_is_constrained(options)) {
+ /* Retry all our guards / bridges.
+ * guards_retry_optimistic() always returns true here. */
+ int rv = guards_retry_optimistic(options);
+ tor_assert_nonfatal_once(rv);
+ log_fn(severity, LD_APP|LD_DIR,
+ "Application request when we haven't %s. "
+ "Optimistically trying known %s again.",
+ !router_have_minimum_dir_info() ?
+ "used client functionality lately" :
+ "received a consensus with exits",
+ options->UseBridges ? "bridges" : "entrynodes");
+ } else {
+ /* Getting directory documents doesn't help much if we have a limited
+ * number of guards */
+ tor_assert_nonfatal(!options->UseBridges);
+ tor_assert_nonfatal(!options->EntryNodes);
+ /* Retry our directory fetches, so we have a fresh set of guard info */
+ log_fn(severity, LD_APP|LD_DIR,
+ "Application request when we haven't %s. "
+ "Optimistically trying directory fetches again.",
+ !router_have_minimum_dir_info() ?
+ "used client functionality lately" :
+ "received a consensus with exits");
+ routerlist_retry_directory_downloads(time(NULL));
+ }
+ }
+ /* Since we didn't have enough directory info, we can't attach now. The
+ * stream will be dealt with when router_have_minimum_dir_info becomes 1,
+ * or when all directory attempts fail and directory_all_unreachable()
+ * kills it.
+ */
+ return 0;
+ }
+
+ /* Check whether the exit policy of the chosen exit, or the exit policies
+ * of _all_ nodes, would forbid this node. */
+ if (check_exit_policy) {
+ if (!conn->chosen_exit_name) {
+ struct in_addr in;
+ tor_addr_t addr, *addrp=NULL;
+ if (tor_inet_aton(conn->socks_request->address, &in)) {
+ tor_addr_from_in(&addr, &in);
+ addrp = &addr;
+ }
+ if (router_exit_policy_all_nodes_reject(addrp,
+ conn->socks_request->port,
+ need_uptime)) {
+ log_notice(LD_APP,
+ "No Tor server allows exit to %s:%d. Rejecting.",
+ safe_str_client(conn->socks_request->address),
+ conn->socks_request->port);
+ return -1;
+ }
+ } else {
+ /* XXXX Duplicates checks in connection_ap_handshake_attach_circuit:
+ * refactor into a single function. */
+ const node_t *node = node_get_by_nickname(conn->chosen_exit_name, 0);
+ int opt = conn->chosen_exit_optional;
+ if (node && !connection_ap_can_use_exit(conn, node)) {
+ log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP,
+ "Requested exit point '%s' is excluded or "
+ "would refuse request. %s.",
+ conn->chosen_exit_name, opt ? "Trying others" : "Closing");
+ if (opt) {
+ conn->chosen_exit_optional = 0;
+ tor_free(conn->chosen_exit_name);
+ /* Try again. */
+ return circuit_get_open_circ_or_launch(conn,
+ desired_circuit_purpose,
+ circp);
+ }
+ return -1;
+ }
+ }
+ }
+
+ /* Now, check whether there already a circuit on the way that could handle
+ * this stream. This check matches the one above, but this time we
+ * do not require that the circuit will work. */
+ circ = circuit_get_best(conn, 0 /* don't insist on open circuits */,
+ desired_circuit_purpose,
+ need_uptime, need_internal);
+ if (circ)
+ log_debug(LD_CIRC, "one on the way!");
+
+ if (!circ) {
+ /* No open or in-progress circuit could handle this stream! We
+ * will have to launch one!
+ */
+
+ /* The chosen exit node, if there is one. */
+ extend_info_t *extend_info=NULL;
+ const int n_pending = count_pending_general_client_circuits();
+
+ /* Do we have too many pending circuits? */
+ if (n_pending >= options->MaxClientCircuitsPending) {
+ static ratelim_t delay_limit = RATELIM_INIT(10*60);
+ char *m;
+ if ((m = rate_limit_log(&delay_limit, approx_time()))) {
+ log_notice(LD_APP, "We'd like to launch a circuit to handle a "
+ "connection, but we already have %d general-purpose client "
+ "circuits pending. Waiting until some finish.%s",
+ n_pending, m);
+ tor_free(m);
+ }
+ return 0;
+ }
+
+ /* If this is a hidden service trying to start an introduction point,
+ * handle that case. */
+ if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) {
+ const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
+ /* need to pick an intro point */
+ extend_info = hs_client_get_random_intro_from_edge(edge_conn);
+ if (!extend_info) {
+ log_info(LD_REND, "No intro points: re-fetching service descriptor.");
+ if (edge_conn->rend_data) {
+ rend_client_refetch_v2_renddesc(edge_conn->rend_data);
+ } else {
+ hs_client_refetch_hsdesc(&edge_conn->hs_ident->identity_pk);
+ }
+ connection_ap_mark_as_waiting_for_renddesc(conn);
+ return 0;
+ }
+ log_info(LD_REND,"Chose %s as intro point for '%s'.",
+ extend_info_describe(extend_info),
+ (edge_conn->rend_data) ?
+ safe_str_client(rend_data_get_address(edge_conn->rend_data)) :
+ "service");
+ }
+
+ /* If we have specified a particular exit node for our
+ * connection, then be sure to open a circuit to that exit node.
+ */
+ if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_GENERAL ||
+ desired_circuit_purpose == CIRCUIT_PURPOSE_S_HSDIR_POST ||
+ desired_circuit_purpose == CIRCUIT_PURPOSE_C_HSDIR_GET) {
+ if (conn->chosen_exit_name) {
+ const node_t *r;
+ int opt = conn->chosen_exit_optional;
+ r = node_get_by_nickname(conn->chosen_exit_name, 0);
+ if (r && node_has_preferred_descriptor(r, conn->want_onehop ? 1 : 0)) {
+ /* We might want to connect to an IPv6 bridge for loading
+ descriptors so we use the preferred address rather than
+ the primary. */
+ extend_info = extend_info_from_node(r, conn->want_onehop ? 1 : 0);
+ if (!extend_info) {
+ log_warn(LD_CIRC,"Could not make a one-hop connection to %s. "
+ "Discarding this circuit.", conn->chosen_exit_name);
+ return -1;
+ }
+ } else { /* ! (r && node_has_preferred_descriptor(...)) */
+ log_debug(LD_DIR, "considering %d, %s",
+ want_onehop, conn->chosen_exit_name);
+ if (want_onehop && conn->chosen_exit_name[0] == '$') {
+ /* We're asking for a one-hop circuit to a router that
+ * we don't have a routerinfo about. Make up an extend_info. */
+ /* XXX prop220: we need to make chosen_exit_name able to
+ * encode both key formats. This is not absolutely critical
+ * since this is just for one-hop circuits, but we should
+ * still get it done */
+ char digest[DIGEST_LEN];
+ char *hexdigest = conn->chosen_exit_name+1;
+ tor_addr_t addr;
+ if (strlen(hexdigest) < HEX_DIGEST_LEN ||
+ base16_decode(digest,DIGEST_LEN,
+ hexdigest,HEX_DIGEST_LEN) != DIGEST_LEN) {
+ log_info(LD_DIR, "Broken exit digest on tunnel conn. Closing.");
+ return -1;
+ }
+ if (tor_addr_parse(&addr, conn->socks_request->address) < 0) {
+ log_info(LD_DIR, "Broken address %s on tunnel conn. Closing.",
+ escaped_safe_str_client(conn->socks_request->address));
+ return -1;
+ }
+ /* XXXX prop220 add a workaround for ed25519 ID below*/
+ extend_info = extend_info_new(conn->chosen_exit_name+1,
+ digest,
+ NULL, /* Ed25519 ID */
+ NULL, NULL, /* onion keys */
+ &addr, conn->socks_request->port);
+ } else { /* ! (want_onehop && conn->chosen_exit_name[0] == '$') */
+ /* We will need an onion key for the router, and we
+ * don't have one. Refuse or relax requirements. */
+ log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP,
+ "Requested exit point '%s' is not known. %s.",
+ conn->chosen_exit_name, opt ? "Trying others" : "Closing");
+ if (opt) {
+ conn->chosen_exit_optional = 0;
+ tor_free(conn->chosen_exit_name);
+ /* Try again with no requested exit */
+ return circuit_get_open_circ_or_launch(conn,
+ desired_circuit_purpose,
+ circp);
+ }
+ return -1;
+ }
+ }
+ }
+ } /* Done checking for general circutis with chosen exits. */
+
+ /* What purpose do we need to launch this circuit with? */
+ uint8_t new_circ_purpose;
+ if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_REND_JOINED)
+ new_circ_purpose = CIRCUIT_PURPOSE_C_ESTABLISH_REND;
+ else if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT)
+ new_circ_purpose = CIRCUIT_PURPOSE_C_INTRODUCING;
+ else
+ new_circ_purpose = desired_circuit_purpose;
+
+ /* Determine what kind of a circuit to launch, and actually launch it. */
+ {
+ int flags = CIRCLAUNCH_NEED_CAPACITY;
+ if (want_onehop) flags |= CIRCLAUNCH_ONEHOP_TUNNEL;
+ if (need_uptime) flags |= CIRCLAUNCH_NEED_UPTIME;
+ if (need_internal) flags |= CIRCLAUNCH_IS_INTERNAL;
+
+ /* If we are about to pick a v3 RP right now, make sure we pick a
+ * rendezvous point that supports the v3 protocol! */
+ if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_REND_JOINED &&
+ new_circ_purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND &&
+ ENTRY_TO_EDGE_CONN(conn)->hs_ident) {
+ flags |= CIRCLAUNCH_IS_V3_RP;
+ log_info(LD_GENERAL, "Getting rendezvous circuit to v3 service!");
+ }
+
+ circ = circuit_launch_by_extend_info(new_circ_purpose, extend_info,
+ flags);
+ }
+
+ extend_info_free(extend_info);
+
+ /* Now trigger things that need to happen when we launch circuits */
+
+ if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_GENERAL ||
+ desired_circuit_purpose == CIRCUIT_PURPOSE_C_HSDIR_GET ||
+ desired_circuit_purpose == CIRCUIT_PURPOSE_S_HSDIR_POST) {
+ /* We just caused a circuit to get built because of this stream.
+ * If this stream has caused a _lot_ of circuits to be built, that's
+ * a bad sign: we should tell the user. */
+ if (conn->num_circuits_launched < NUM_CIRCUITS_LAUNCHED_THRESHOLD &&
+ ++conn->num_circuits_launched == NUM_CIRCUITS_LAUNCHED_THRESHOLD)
+ log_info(LD_CIRC, "The application request to %s:%d has launched "
+ "%d circuits without finding one it likes.",
+ escaped_safe_str_client(conn->socks_request->address),
+ conn->socks_request->port,
+ conn->num_circuits_launched);
+ } else {
+ /* help predict this next time */
+ rep_hist_note_used_internal(time(NULL), need_uptime, 1);
+ if (circ) {
+ const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
+ if (edge_conn->rend_data) {
+ /* write the service_id into circ */
+ circ->rend_data = rend_data_dup(edge_conn->rend_data);
+ } else if (edge_conn->hs_ident) {
+ circ->hs_ident =
+ hs_ident_circuit_new(&edge_conn->hs_ident->identity_pk,
+ HS_IDENT_CIRCUIT_INTRO);
+ }
+ if (circ->base_.purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND &&
+ circ->base_.state == CIRCUIT_STATE_OPEN)
+ circuit_has_opened(circ);
+ }
+ }
+ } /* endif (!circ) */
+
+ /* We either found a good circuit, or launched a new circuit, or failed to
+ * do so. Report success, and delay. */
+
+ if (circ) {
+ /* Mark the circuit with the isolation fields for this connection.
+ * When the circuit arrives, we'll clear these flags: this is
+ * just some internal bookkeeping to make sure that we have
+ * launched enough circuits.
+ */
+ connection_edge_update_circuit_isolation(conn, circ, 0);
+ } else {
+ log_info(LD_APP,
+ "No safe circuit (purpose %d) ready for edge "
+ "connection; delaying.",
+ desired_circuit_purpose);
+ }
+ *circp = circ;
+ return 0;
+}
+
+/** Return true iff <b>crypt_path</b> is one of the crypt_paths for
+ * <b>circ</b>. */
+static int
+cpath_is_on_circuit(origin_circuit_t *circ, crypt_path_t *crypt_path)
+{
+ crypt_path_t *cpath, *cpath_next = NULL;
+ for (cpath = circ->cpath; cpath_next != circ->cpath; cpath = cpath_next) {
+ cpath_next = cpath->next;
+ if (crypt_path == cpath)
+ return 1;
+ }
+ return 0;
+}
+
+/** Return true iff client-side optimistic data is supported. */
+static int
+optimistic_data_enabled(void)
+{
+ const or_options_t *options = get_options();
+ if (options->OptimisticData < 0) {
+ /* Note: this default was 0 before #18815 was merged. We can't take the
+ * parameter out of the consensus until versions before that are all
+ * obsolete. */
+ const int32_t enabled =
+ networkstatus_get_param(NULL, "UseOptimisticData", /*default*/ 1, 0, 1);
+ return (int)enabled;
+ }
+ return options->OptimisticData;
+}
+
+/** Attach the AP stream <b>apconn</b> to circ's linked list of
+ * p_streams. Also set apconn's cpath_layer to <b>cpath</b>, or to the last
+ * hop in circ's cpath if <b>cpath</b> is NULL.
+ */
+static void
+link_apconn_to_circ(entry_connection_t *apconn, origin_circuit_t *circ,
+ crypt_path_t *cpath)
+{
+ const node_t *exitnode = NULL;
+
+ /* add it into the linked list of streams on this circuit */
+ log_debug(LD_APP|LD_CIRC, "attaching new conn to circ. n_circ_id %u.",
+ (unsigned)circ->base_.n_circ_id);
+
+ /* If this is the first stream on this circuit, tell circpad
+ * that streams are attached */
+ if (!circ->p_streams)
+ circpad_machine_event_circ_has_streams(circ);
+
+ /* reset it, so we can measure circ timeouts */
+ ENTRY_TO_CONN(apconn)->timestamp_last_read_allowed = time(NULL);
+ ENTRY_TO_EDGE_CONN(apconn)->next_stream = circ->p_streams;
+ ENTRY_TO_EDGE_CONN(apconn)->on_circuit = TO_CIRCUIT(circ);
+ /* assert_connection_ok(conn, time(NULL)); */
+ circ->p_streams = ENTRY_TO_EDGE_CONN(apconn);
+
+ if (connection_edge_is_rendezvous_stream(ENTRY_TO_EDGE_CONN(apconn))) {
+ /* We are attaching a stream to a rendezvous circuit. That means
+ * that an attempt to connect to a hidden service just
+ * succeeded. Tell rendclient.c. */
+ hs_client_note_connection_attempt_succeeded(ENTRY_TO_EDGE_CONN(apconn));
+ }
+
+ if (cpath) { /* we were given one; use it */
+ tor_assert(cpath_is_on_circuit(circ, cpath));
+ } else {
+ /* use the last hop in the circuit */
+ tor_assert(circ->cpath);
+ tor_assert(circ->cpath->prev);
+ tor_assert(circ->cpath->prev->state == CPATH_STATE_OPEN);
+ cpath = circ->cpath->prev;
+ }
+ ENTRY_TO_EDGE_CONN(apconn)->cpath_layer = cpath;
+
+ circ->isolation_any_streams_attached = 1;
+ connection_edge_update_circuit_isolation(apconn, circ, 0);
+
+ /* Compute the exitnode if possible, for logging below */
+ if (cpath->extend_info)
+ exitnode = node_get_by_id(cpath->extend_info->identity_digest);
+
+ /* See if we can use optimistic data on this circuit */
+ if (optimistic_data_enabled() &&
+ (circ->base_.purpose == CIRCUIT_PURPOSE_C_GENERAL ||
+ circ->base_.purpose == CIRCUIT_PURPOSE_C_HSDIR_GET ||
+ circ->base_.purpose == CIRCUIT_PURPOSE_S_HSDIR_POST ||
+ circ->base_.purpose == CIRCUIT_PURPOSE_C_REND_JOINED))
+ apconn->may_use_optimistic_data = 1;
+ else
+ apconn->may_use_optimistic_data = 0;
+ log_info(LD_APP, "Looks like completed circuit to %s %s allow "
+ "optimistic data for connection to %s",
+ circ->base_.purpose == CIRCUIT_PURPOSE_C_GENERAL ?
+ /* node_describe() does the right thing if exitnode is NULL */
+ safe_str_client(node_describe(exitnode)) :
+ "hidden service",
+ apconn->may_use_optimistic_data ? "does" : "doesn't",
+ safe_str_client(apconn->socks_request->address));
+}
+
+/** Return true iff <b>address</b> is matched by one of the entries in
+ * TrackHostExits. */
+int
+hostname_in_track_host_exits(const or_options_t *options, const char *address)
+{
+ if (!options->TrackHostExits)
+ return 0;
+ SMARTLIST_FOREACH_BEGIN(options->TrackHostExits, const char *, cp) {
+ if (cp[0] == '.') { /* match end */
+ if (cp[1] == '\0' ||
+ !strcasecmpend(address, cp) ||
+ !strcasecmp(address, &cp[1]))
+ return 1;
+ } else if (strcasecmp(cp, address) == 0) {
+ return 1;
+ }
+ } SMARTLIST_FOREACH_END(cp);
+ return 0;
+}
+
+/** If an exit wasn't explicitly specified for <b>conn</b>, consider saving
+ * the exit that we *did* choose for use by future connections to
+ * <b>conn</b>'s destination.
+ */
+static void
+consider_recording_trackhost(const entry_connection_t *conn,
+ const origin_circuit_t *circ)
+{
+ const or_options_t *options = get_options();
+ char *new_address = NULL;
+ char fp[HEX_DIGEST_LEN+1];
+
+ /* Search the addressmap for this conn's destination. */
+ /* If they're not in the address map.. */
+ if (!options->TrackHostExits ||
+ addressmap_have_mapping(conn->socks_request->address,
+ options->TrackHostExitsExpire))
+ return; /* nothing to track, or already mapped */
+
+ if (!hostname_in_track_host_exits(options, conn->socks_request->address) ||
+ !circ->build_state->chosen_exit)
+ return;
+
+ /* write down the fingerprint of the chosen exit, not the nickname,
+ * because the chosen exit might not be named. */
+ base16_encode(fp, sizeof(fp),
+ circ->build_state->chosen_exit->identity_digest, DIGEST_LEN);
+
+ /* Add this exit/hostname pair to the addressmap. */
+ tor_asprintf(&new_address, "%s.%s.exit",
+ conn->socks_request->address, fp);
+
+ addressmap_register(conn->socks_request->address, new_address,
+ time(NULL) + options->TrackHostExitsExpire,
+ ADDRMAPSRC_TRACKEXIT, 0, 0);
+}
+
+/** Attempt to attach the connection <b>conn</b> to <b>circ</b>, and send a
+ * begin or resolve cell as appropriate. Return values are as for
+ * connection_ap_handshake_attach_circuit. 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_attach_chosen_circuit(entry_connection_t *conn,
+ origin_circuit_t *circ,
+ crypt_path_t *cpath)
+{
+ connection_t *base_conn = ENTRY_TO_CONN(conn);
+ tor_assert(conn);
+ tor_assert(base_conn->state == AP_CONN_STATE_CIRCUIT_WAIT ||
+ base_conn->state == AP_CONN_STATE_CONTROLLER_WAIT);
+ tor_assert(conn->socks_request);
+ tor_assert(circ);
+ tor_assert(circ->base_.state == CIRCUIT_STATE_OPEN);
+
+ base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
+
+ if (!circ->base_.timestamp_dirty ||
+ ((conn->entry_cfg.isolation_flags & ISO_SOCKSAUTH) &&
+ (conn->entry_cfg.socks_iso_keep_alive) &&
+ (conn->socks_request->usernamelen ||
+ conn->socks_request->passwordlen))) {
+ /* When stream isolation is in use and controlled by an application
+ * we are willing to keep using the stream. */
+ circ->base_.timestamp_dirty = approx_time();
+ }
+
+ pathbias_count_use_attempt(circ);
+
+ /* Now, actually link the connection. */
+ link_apconn_to_circ(conn, circ, cpath);
+
+ tor_assert(conn->socks_request);
+ if (conn->socks_request->command == SOCKS_COMMAND_CONNECT) {
+ if (!conn->use_begindir)
+ consider_recording_trackhost(conn, circ);
+ if (connection_ap_handshake_send_begin(conn) < 0)
+ return -1;
+ } else {
+ if (connection_ap_handshake_send_resolve(conn) < 0)
+ return -1;
+ }
+
+ return 1;
+}
+
+/**
+ * Return an appropriate circuit purpose for non-rend streams.
+ * We don't handle rends here because a rend stream triggers two
+ * circuit builds with different purposes, so it is handled elsewhere.
+ *
+ * This function just figures out what type of hsdir activity this is,
+ * and tells us. Everything else is general.
+ */
+static int
+connection_ap_get_nonrend_circ_purpose(const entry_connection_t *conn)
+{
+ const connection_t *base_conn = ENTRY_TO_CONN(conn);
+ tor_assert_nonfatal(!connection_edge_is_rendezvous_stream(
+ ENTRY_TO_EDGE_CONN(conn)));
+
+ if (base_conn->linked_conn &&
+ base_conn->linked_conn->type == CONN_TYPE_DIR) {
+ /* Set a custom purpose for hsdir activity */
+ if (base_conn->linked_conn->purpose == DIR_PURPOSE_UPLOAD_RENDDESC_V2 ||
+ base_conn->linked_conn->purpose == DIR_PURPOSE_UPLOAD_HSDESC) {
+ return CIRCUIT_PURPOSE_S_HSDIR_POST;
+ } else if (base_conn->linked_conn->purpose
+ == DIR_PURPOSE_FETCH_RENDDESC_V2 ||
+ base_conn->linked_conn->purpose
+ == DIR_PURPOSE_FETCH_HSDESC) {
+ return CIRCUIT_PURPOSE_C_HSDIR_GET;
+ }
+ }
+
+ /* All other purposes are general for now */
+ return CIRCUIT_PURPOSE_C_GENERAL;
+}
+
+/** Try to find a safe live circuit for stream <b>conn</b>. If we find one,
+ * attach the stream, send appropriate cells, and return 1. Otherwise,
+ * try to launch new circuit(s) for the stream. If we can launch
+ * circuits, return 0. Otherwise, if we simply can't proceed with
+ * this stream, return -1. (conn needs to die, and is maybe already marked).
+ */
+/* XXXX this function should mark for close whenever it returns -1;
+ * its callers shouldn't have to worry about that. */
+int
+connection_ap_handshake_attach_circuit(entry_connection_t *conn)
+{
+ connection_t *base_conn = ENTRY_TO_CONN(conn);
+ int retval;
+ int conn_age;
+ int want_onehop;
+
+ tor_assert(conn);
+ tor_assert(base_conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
+ tor_assert(conn->socks_request);
+ want_onehop = conn->want_onehop;
+
+ conn_age = (int)(time(NULL) - base_conn->timestamp_created);
+
+ /* Is this connection so old that we should give up on it? */
+ if (conn_age >= get_options()->SocksTimeout) {
+ int severity = (tor_addr_is_null(&base_conn->addr) && !base_conn->port) ?
+ LOG_INFO : LOG_NOTICE;
+ log_fn(severity, LD_APP,
+ "Tried for %d seconds to get a connection to %s:%d. Giving up.",
+ conn_age, safe_str_client(conn->socks_request->address),
+ conn->socks_request->port);
+ return -1;
+ }
+
+ /* We handle "general" (non-onion) connections much more straightforwardly.
+ */
+ if (!connection_edge_is_rendezvous_stream(ENTRY_TO_EDGE_CONN(conn))) {
+ /* we're a general conn */
+ origin_circuit_t *circ=NULL;
+
+ /* Are we linked to a dir conn that aims to fetch a consensus?
+ * We check here because the conn might no longer be needed. */
+ if (base_conn->linked_conn &&
+ base_conn->linked_conn->type == CONN_TYPE_DIR &&
+ base_conn->linked_conn->purpose == DIR_PURPOSE_FETCH_CONSENSUS) {
+
+ /* Yes we are. Is there a consensus fetch farther along than us? */
+ if (networkstatus_consensus_is_already_downloading(
+ TO_DIR_CONN(base_conn->linked_conn)->requested_resource)) {
+ /* We're doing the "multiple consensus fetch attempts" game from
+ * proposal 210, and we're late to the party. Just close this conn.
+ * The circuit and TLS conn that we made will time out after a while
+ * if nothing else wants to use them. */
+ log_info(LD_DIR, "Closing extra consensus fetch (to %s) since one "
+ "is already downloading.", base_conn->linked_conn->address);
+ return -1;
+ }
+ }
+
+ /* If we have a chosen exit, we need to use a circuit that's
+ * open to that exit. See what exit we meant, and whether we can use it.
+ */
+ if (conn->chosen_exit_name) {
+ const node_t *node = node_get_by_nickname(conn->chosen_exit_name, 0);
+ int opt = conn->chosen_exit_optional;
+ if (!node && !want_onehop) {
+ /* We ran into this warning when trying to extend a circuit to a
+ * hidden service directory for which we didn't have a router
+ * descriptor. See flyspray task 767 for more details. We should
+ * keep this in mind when deciding to use BEGIN_DIR cells for other
+ * directory requests as well. -KL*/
+ log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP,
+ "Requested exit point '%s' is not known. %s.",
+ conn->chosen_exit_name, opt ? "Trying others" : "Closing");
+ if (opt) {
+ /* If we are allowed to ignore the .exit request, do so */
+ conn->chosen_exit_optional = 0;
+ tor_free(conn->chosen_exit_name);
+ return 0;
+ }
+ return -1;
+ }
+ if (node && !connection_ap_can_use_exit(conn, node)) {
+ log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP,
+ "Requested exit point '%s' is excluded or "
+ "would refuse request. %s.",
+ conn->chosen_exit_name, opt ? "Trying others" : "Closing");
+ if (opt) {
+ /* If we are allowed to ignore the .exit request, do so */
+ conn->chosen_exit_optional = 0;
+ tor_free(conn->chosen_exit_name);
+ return 0;
+ }
+ return -1;
+ }
+ }
+
+ /* Find the circuit that we should use, if there is one. Otherwise
+ * launch it
+ */
+ retval = circuit_get_open_circ_or_launch(conn,
+ connection_ap_get_nonrend_circ_purpose(conn),
+ &circ);
+
+ if (retval < 1) {
+ /* We were either told "-1" (complete failure) or 0 (circuit in
+ * progress); we can't attach this stream yet. */
+ return retval;
+ }
+
+ log_debug(LD_APP|LD_CIRC,
+ "Attaching apconn to circ %u (stream %d sec old).",
+ (unsigned)circ->base_.n_circ_id, conn_age);
+ /* print the circ's path, so clients can figure out which circs are
+ * sucking. */
+ circuit_log_path(LOG_INFO,LD_APP|LD_CIRC,circ);
+
+ /* We have found a suitable circuit for our conn. Hurray. Do
+ * the attachment. */
+ return connection_ap_handshake_attach_chosen_circuit(conn, circ, NULL);
+
+ } else { /* we're a rendezvous conn */
+ origin_circuit_t *rendcirc=NULL, *introcirc=NULL;
+
+ tor_assert(!ENTRY_TO_EDGE_CONN(conn)->cpath_layer);
+
+ /* start by finding a rendezvous circuit for us */
+
+ retval = circuit_get_open_circ_or_launch(
+ conn, CIRCUIT_PURPOSE_C_REND_JOINED, &rendcirc);
+ if (retval < 0) return -1; /* failed */
+
+ if (retval > 0) {
+ tor_assert(rendcirc);
+ /* one is already established, attach */
+ log_info(LD_REND,
+ "rend joined circ %u (id: %" PRIu32 ") already here. "
+ "Attaching. (stream %d sec old)",
+ (unsigned) TO_CIRCUIT(rendcirc)->n_circ_id,
+ rendcirc->global_identifier, conn_age);
+ /* Mark rendezvous circuits as 'newly dirty' every time you use
+ * them, since the process of rebuilding a rendezvous circ is so
+ * expensive. There is a tradeoff between linkability and
+ * feasibility, at this point.
+ */
+ rendcirc->base_.timestamp_dirty = time(NULL);
+
+ /* We've also attempted to use them. If they fail, we need to
+ * probe them for path bias */
+ pathbias_count_use_attempt(rendcirc);
+
+ link_apconn_to_circ(conn, rendcirc, NULL);
+ if (connection_ap_handshake_send_begin(conn) < 0)
+ return 0; /* already marked, let them fade away */
+ return 1;
+ }
+
+ /* At this point we need to re-check the state, since it's possible that
+ * our call to circuit_get_open_circ_or_launch() changed the connection's
+ * state from "CIRCUIT_WAIT" to "RENDDESC_WAIT" because we decided to
+ * re-fetch the descriptor.
+ */
+ if (ENTRY_TO_CONN(conn)->state != AP_CONN_STATE_CIRCUIT_WAIT) {
+ log_info(LD_REND, "This connection is no longer ready to attach; its "
+ "state changed."
+ "(We probably have to re-fetch its descriptor.)");
+ return 0;
+ }
+
+ if (rendcirc && (rendcirc->base_.purpose ==
+ CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED)) {
+ log_info(LD_REND,
+ "pending-join circ %u (id: %" PRIu32 ") already here, with "
+ "intro ack. Stalling. (stream %d sec old)",
+ (unsigned) TO_CIRCUIT(rendcirc)->n_circ_id,
+ rendcirc->global_identifier, conn_age);
+ return 0;
+ }
+
+ /* it's on its way. find an intro circ. */
+ retval = circuit_get_open_circ_or_launch(
+ conn, CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT, &introcirc);
+ if (retval < 0) return -1; /* failed */
+
+ if (retval > 0) {
+ /* one has already sent the intro. keep waiting. */
+ tor_assert(introcirc);
+ log_info(LD_REND, "Intro circ %u (id: %" PRIu32 ") present and "
+ "awaiting ACK. Rend circuit %u (id: %" PRIu32 "). "
+ "Stalling. (stream %d sec old)",
+ (unsigned) TO_CIRCUIT(introcirc)->n_circ_id,
+ introcirc->global_identifier,
+ rendcirc ? (unsigned) TO_CIRCUIT(rendcirc)->n_circ_id : 0,
+ rendcirc ? rendcirc->global_identifier : 0,
+ conn_age);
+ return 0;
+ }
+
+ /* now rendcirc and introcirc are each either undefined or not finished */
+
+ if (rendcirc && introcirc &&
+ rendcirc->base_.purpose == CIRCUIT_PURPOSE_C_REND_READY) {
+ log_info(LD_REND,
+ "ready rend circ %u (id: %" PRIu32 ") already here. No"
+ "intro-ack yet on intro %u (id: %" PRIu32 "). "
+ "(stream %d sec old)",
+ (unsigned) TO_CIRCUIT(rendcirc)->n_circ_id,
+ rendcirc->global_identifier,
+ (unsigned) TO_CIRCUIT(introcirc)->n_circ_id,
+ introcirc->global_identifier, conn_age);
+
+ tor_assert(introcirc->base_.purpose == CIRCUIT_PURPOSE_C_INTRODUCING);
+ if (introcirc->base_.state == CIRCUIT_STATE_OPEN) {
+ int ret;
+ log_info(LD_REND, "Found open intro circ %u (id: %" PRIu32 "). "
+ "Rend circuit %u (id: %" PRIu32 "); Sending "
+ "introduction. (stream %d sec old)",
+ (unsigned) TO_CIRCUIT(introcirc)->n_circ_id,
+ introcirc->global_identifier,
+ (unsigned) TO_CIRCUIT(rendcirc)->n_circ_id,
+ rendcirc->global_identifier, conn_age);
+ ret = hs_client_send_introduce1(introcirc, rendcirc);
+ switch (ret) {
+ case 0: /* success */
+ rendcirc->base_.timestamp_dirty = time(NULL);
+ introcirc->base_.timestamp_dirty = time(NULL);
+
+ pathbias_count_use_attempt(introcirc);
+ pathbias_count_use_attempt(rendcirc);
+
+ assert_circuit_ok(TO_CIRCUIT(rendcirc));
+ assert_circuit_ok(TO_CIRCUIT(introcirc));
+ return 0;
+ case -1: /* transient error */
+ return 0;
+ case -2: /* permanent error */
+ return -1;
+ default: /* oops */
+ tor_fragile_assert();
+ return -1;
+ }
+ }
+ }
+
+ log_info(LD_REND, "Intro %u (id: %" PRIu32 ") and rend circuit %u "
+ "(id: %" PRIu32 ") circuits are not both ready. "
+ "Stalling conn. (%d sec old)",
+ introcirc ? (unsigned) TO_CIRCUIT(introcirc)->n_circ_id : 0,
+ introcirc ? introcirc->global_identifier : 0,
+ rendcirc ? (unsigned) TO_CIRCUIT(rendcirc)->n_circ_id : 0,
+ rendcirc ? rendcirc->global_identifier : 0, conn_age);
+ return 0;
+ }
+}
+
+/** Change <b>circ</b>'s purpose to <b>new_purpose</b>. */
+void
+circuit_change_purpose(circuit_t *circ, uint8_t new_purpose)
+{
+ uint8_t old_purpose;
+ /* Don't allow an OR circ to become an origin circ or vice versa. */
+ tor_assert(!!(CIRCUIT_IS_ORIGIN(circ)) ==
+ !!(CIRCUIT_PURPOSE_IS_ORIGIN(new_purpose)));
+
+ if (circ->purpose == new_purpose) return;
+
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ char old_purpose_desc[80] = "";
+
+ strncpy(old_purpose_desc, circuit_purpose_to_string(circ->purpose), 80-1);
+ old_purpose_desc[80-1] = '\0';
+
+ log_debug(LD_CIRC,
+ "changing purpose of origin circ %d "
+ "from \"%s\" (%d) to \"%s\" (%d)",
+ TO_ORIGIN_CIRCUIT(circ)->global_identifier,
+ old_purpose_desc,
+ circ->purpose,
+ circuit_purpose_to_string(new_purpose),
+ new_purpose);
+ }
+
+ old_purpose = circ->purpose;
+ circ->purpose = new_purpose;
+
+ if (CIRCUIT_IS_ORIGIN(circ)) {
+ control_event_circuit_purpose_changed(TO_ORIGIN_CIRCUIT(circ),
+ old_purpose);
+
+ circpad_machine_event_circ_purpose_changed(TO_ORIGIN_CIRCUIT(circ));
+ }
+}
+
+/** Mark <b>circ</b> so that no more connections can be attached to it. */
+void
+mark_circuit_unusable_for_new_conns(origin_circuit_t *circ)
+{
+ const or_options_t *options = get_options();
+ tor_assert(circ);
+
+ /* XXXX This is a kludge; we're only keeping it around in case there's
+ * something that doesn't check unusable_for_new_conns, and to avoid
+ * deeper refactoring of our expiration logic. */
+ if (! circ->base_.timestamp_dirty)
+ circ->base_.timestamp_dirty = approx_time();
+ if (options->MaxCircuitDirtiness >= circ->base_.timestamp_dirty)
+ circ->base_.timestamp_dirty = 1; /* prevent underflow */
+ else
+ circ->base_.timestamp_dirty -= options->MaxCircuitDirtiness;
+
+ circ->unusable_for_new_conns = 1;
+}
+
+/**
+ * Add relay_body_len and RELAY_PAYLOAD_SIZE-relay_body_len to
+ * the valid delivered written fields and the overhead field,
+ * respectively.
+ */
+void
+circuit_sent_valid_data(origin_circuit_t *circ, uint16_t relay_body_len)
+{
+ if (!circ) return;
+
+ tor_assert_nonfatal(relay_body_len <= RELAY_PAYLOAD_SIZE);
+
+ circ->n_delivered_written_circ_bw =
+ tor_add_u32_nowrap(circ->n_delivered_written_circ_bw, relay_body_len);
+ circ->n_overhead_written_circ_bw =
+ tor_add_u32_nowrap(circ->n_overhead_written_circ_bw,
+ RELAY_PAYLOAD_SIZE-relay_body_len);
+}
+
+/**
+ * Add relay_body_len and RELAY_PAYLOAD_SIZE-relay_body_len to
+ * the valid delivered read field and the overhead field,
+ * respectively.
+ */
+void
+circuit_read_valid_data(origin_circuit_t *circ, uint16_t relay_body_len)
+{
+ if (!circ) return;
+
+ tor_assert_nonfatal(relay_body_len <= RELAY_PAYLOAD_SIZE);
+
+ circ->n_delivered_read_circ_bw =
+ tor_add_u32_nowrap(circ->n_delivered_read_circ_bw, relay_body_len);
+ circ->n_overhead_read_circ_bw =
+ tor_add_u32_nowrap(circ->n_overhead_read_circ_bw,
+ RELAY_PAYLOAD_SIZE-relay_body_len);
+}
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