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[tor-commits] [tor/release-0.4.0] Merge branch 'maint-0.3.4' into maint-0.3.5



commit 231036a110c1062e39b214b4b88fdc2a1eb46dc8
Merge: 742b5b32d cbce8dedd
Author: teor <teor@xxxxxxxxxxxxxx>
Date:   Fri Apr 19 12:00:41 2019 +1000

    Merge branch 'maint-0.3.4' into maint-0.3.5

 changes/bug29017           |  4 ++++
 changes/bug29665           |  7 +++++++
 doc/tor.1.txt              |  2 +-
 src/core/or/circuituse.c   |  4 ++++
 src/feature/relay/router.c | 11 +++++------
 5 files changed, 21 insertions(+), 7 deletions(-)

diff --cc src/core/or/circuituse.c
index e306307c4,000000000..02bfa15fb
mode 100644,000000..100644
--- a/src/core/or/circuituse.c
+++ b/src/core/or/circuituse.c
@@@ -1,3132 -1,0 +1,3136 @@@
 +/* 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/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);
 +      }
 +      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)
 +{
 +  control_event_circuit_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);
 +  /* 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);
 +  }
 +}
 +
 +/** 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);
 +}
diff --cc src/feature/relay/router.c
index b376046c8,000000000..dad2c6a50
mode 100644,000000..100644
--- a/src/feature/relay/router.c
+++ b/src/feature/relay/router.c
@@@ -1,3129 -1,0 +1,3128 @@@
 +/* 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 */
 +
 +#define ROUTER_PRIVATE
 +
 +#include "core/or/or.h"
 +#include "app/config/config.h"
 +#include "app/config/statefile.h"
 +#include "app/main/main.h"
 +#include "core/mainloop/connection.h"
 +#include "core/mainloop/mainloop.h"
 +#include "core/mainloop/netstatus.h"
 +#include "core/or/policies.h"
 +#include "core/or/protover.h"
 +#include "feature/client/transports.h"
 +#include "feature/control/control.h"
 +#include "feature/dirauth/process_descs.h"
 +#include "feature/dircache/dirserv.h"
 +#include "feature/dirclient/dirclient.h"
 +#include "feature/dircommon/directory.h"
 +#include "feature/dirparse/authcert_parse.h"
 +#include "feature/dirparse/routerparse.h"
 +#include "feature/dirparse/signing.h"
 +#include "feature/hibernate/hibernate.h"
 +#include "feature/keymgt/loadkey.h"
 +#include "feature/nodelist/authcert.h"
 +#include "feature/nodelist/dirlist.h"
 +#include "feature/nodelist/networkstatus.h"
 +#include "feature/nodelist/nickname.h"
 +#include "feature/nodelist/nodelist.h"
 +#include "feature/nodelist/routerlist.h"
 +#include "feature/nodelist/torcert.h"
 +#include "feature/relay/dns.h"
 +#include "feature/relay/router.h"
 +#include "feature/relay/routerkeys.h"
 +#include "feature/relay/routermode.h"
 +#include "feature/relay/selftest.h"
 +#include "lib/geoip/geoip.h"
 +#include "feature/stats/geoip_stats.h"
 +#include "feature/stats/rephist.h"
 +#include "lib/crypt_ops/crypto_ed25519.h"
 +#include "lib/crypt_ops/crypto_format.h"
 +#include "lib/crypt_ops/crypto_init.h"
 +#include "lib/crypt_ops/crypto_rand.h"
 +#include "lib/crypt_ops/crypto_util.h"
 +#include "lib/encoding/confline.h"
 +#include "lib/osinfo/uname.h"
 +#include "lib/tls/tortls.h"
 +
 +#include "feature/dirauth/authmode.h"
 +
 +#include "app/config/or_state_st.h"
 +#include "core/or/port_cfg_st.h"
 +#include "feature/dirclient/dir_server_st.h"
 +#include "feature/dircommon/dir_connection_st.h"
 +#include "feature/nodelist/authority_cert_st.h"
 +#include "feature/nodelist/extrainfo_st.h"
 +#include "feature/nodelist/node_st.h"
 +#include "feature/nodelist/routerinfo_st.h"
 +#include "feature/nodelist/routerstatus_st.h"
 +
 +/**
 + * \file router.c
 + * \brief Miscellaneous relay functionality, including RSA key maintenance,
 + * generating and uploading server descriptors, picking an address to
 + * advertise, and so on.
 + *
 + * This module handles the job of deciding whether we are a Tor relay, and if
 + * so what kind. (Mostly through functions like server_mode() that inspect an
 + * or_options_t, but in some cases based on our own capabilities, such as when
 + * we are deciding whether to be a directory cache in
 + * router_has_bandwidth_to_be_dirserver().)
 + *
 + * Also in this module are the functions to generate our own routerinfo_t and
 + * extrainfo_t, and to encode those to signed strings for upload to the
 + * directory authorities.
 + *
 + * This module also handles key maintenance for RSA and Curve25519-ntor keys,
 + * and for our TLS context. (These functions should eventually move to
 + * routerkeys.c along with the code that handles Ed25519 keys now.)
 + **/
 +
 +/************************************************************/
 +
 +/*****
 + * Key management: ORs only.
 + *****/
 +
 +/** Private keys for this OR.  There is also an SSL key managed by tortls.c.
 + */
 +static tor_mutex_t *key_lock=NULL;
 +static time_t onionkey_set_at=0; /**< When was onionkey last changed? */
 +/** Current private onionskin decryption key: used to decode CREATE cells. */
 +static crypto_pk_t *onionkey=NULL;
 +/** Previous private onionskin decryption key: used to decode CREATE cells
 + * generated by clients that have an older version of our descriptor. */
 +static crypto_pk_t *lastonionkey=NULL;
 +/** Current private ntor secret key: used to perform the ntor handshake. */
 +static curve25519_keypair_t curve25519_onion_key;
 +/** Previous private ntor secret key: used to perform the ntor handshake
 + * with clients that have an older version of our descriptor. */
 +static curve25519_keypair_t last_curve25519_onion_key;
 +/** Private server "identity key": used to sign directory info and TLS
 + * certificates. Never changes. */
 +static crypto_pk_t *server_identitykey=NULL;
 +/** Digest of server_identitykey. */
 +static char server_identitykey_digest[DIGEST_LEN];
 +/** Private client "identity key": used to sign bridges' and clients'
 + * outbound TLS certificates. Regenerated on startup and on IP address
 + * change. */
 +static crypto_pk_t *client_identitykey=NULL;
 +/** Signing key used for v3 directory material; only set for authorities. */
 +static crypto_pk_t *authority_signing_key = NULL;
 +/** Key certificate to authenticate v3 directory material; only set for
 + * authorities. */
 +static authority_cert_t *authority_key_certificate = NULL;
 +
 +/** For emergency V3 authority key migration: An extra signing key that we use
 + * with our old (obsolete) identity key for a while. */
 +static crypto_pk_t *legacy_signing_key = NULL;
 +/** For emergency V3 authority key migration: An extra certificate to
 + * authenticate legacy_signing_key with our obsolete identity key.*/
 +static authority_cert_t *legacy_key_certificate = NULL;
 +
 +/* (Note that v3 authorities also have a separate "authority identity key",
 + * but this key is never actually loaded by the Tor process.  Instead, it's
 + * used by tor-gencert to sign new signing keys and make new key
 + * certificates. */
 +
 +/** Return a readonly string with human readable description
 + * of <b>err</b>.
 + */
 +const char *
 +routerinfo_err_to_string(int err)
 +{
 +  switch (err) {
 +    case TOR_ROUTERINFO_ERROR_NO_EXT_ADDR:
 +      return "No known exit address yet";
 +    case TOR_ROUTERINFO_ERROR_CANNOT_PARSE:
 +      return "Cannot parse descriptor";
 +    case TOR_ROUTERINFO_ERROR_NOT_A_SERVER:
 +      return "Not running in server mode";
 +    case TOR_ROUTERINFO_ERROR_DIGEST_FAILED:
 +      return "Key digest failed";
 +    case TOR_ROUTERINFO_ERROR_CANNOT_GENERATE:
 +      return "Cannot generate descriptor";
 +    case TOR_ROUTERINFO_ERROR_DESC_REBUILDING:
 +      return "Descriptor still rebuilding - not ready yet";
 +  }
 +
 +  log_warn(LD_BUG, "unknown routerinfo error %d - shouldn't happen", err);
 +  tor_assert_unreached();
 +
 +  return "Unknown error";
 +}
 +
 +/** Return true if we expect given error to be transient.
 + * Return false otherwise.
 + */
 +int
 +routerinfo_err_is_transient(int err)
 +{
 +  /**
 +   * For simplicity, we consider all errors other than
 +   * "not a server" transient - see discussion on
 +   * https://trac.torproject.org/projects/tor/ticket/27034
 +   */
 +  return err != TOR_ROUTERINFO_ERROR_NOT_A_SERVER;
 +}
 +
 +/** Replace the current onion key with <b>k</b>.  Does not affect
 + * lastonionkey; to update lastonionkey correctly, call rotate_onion_key().
 + */
 +static void
 +set_onion_key(crypto_pk_t *k)
 +{
 +  if (onionkey && crypto_pk_eq_keys(onionkey, k)) {
 +    /* k is already our onion key; free it and return */
 +    crypto_pk_free(k);
 +    return;
 +  }
 +  tor_mutex_acquire(key_lock);
 +  crypto_pk_free(onionkey);
 +  onionkey = k;
 +  tor_mutex_release(key_lock);
 +  mark_my_descriptor_dirty("set onion key");
 +}
 +
 +/** Return the current onion key.  Requires that the onion key has been
 + * loaded or generated. */
 +crypto_pk_t *
 +get_onion_key(void)
 +{
 +  tor_assert(onionkey);
 +  return onionkey;
 +}
 +
 +/** Store a full copy of the current onion key into *<b>key</b>, and a full
 + * copy of the most recent onion key into *<b>last</b>.  Store NULL into
 + * a pointer if the corresponding key does not exist.
 + */
 +void
 +dup_onion_keys(crypto_pk_t **key, crypto_pk_t **last)
 +{
 +  tor_assert(key);
 +  tor_assert(last);
 +  tor_mutex_acquire(key_lock);
 +  if (onionkey)
 +    *key = crypto_pk_copy_full(onionkey);
 +  else
 +    *key = NULL;
 +  if (lastonionkey)
 +    *last = crypto_pk_copy_full(lastonionkey);
 +  else
 +    *last = NULL;
 +  tor_mutex_release(key_lock);
 +}
 +
 +/** Expire our old set of onion keys. This is done by setting
 + * last_curve25519_onion_key and lastonionkey to all zero's and NULL
 + * respectively.
 + *
 + * This function does not perform any grace period checks for the old onion
 + * keys.
 + */
 +void
 +expire_old_onion_keys(void)
 +{
 +  char *fname = NULL;
 +
 +  tor_mutex_acquire(key_lock);
 +
 +  /* Free lastonionkey and set it to NULL. */
 +  if (lastonionkey) {
 +    crypto_pk_free(lastonionkey);
 +    lastonionkey = NULL;
 +  }
 +
 +  /* We zero out the keypair. See the tor_mem_is_zero() check made in
 +   * construct_ntor_key_map() below. */
 +  memset(&last_curve25519_onion_key, 0, sizeof(last_curve25519_onion_key));
 +
 +  tor_mutex_release(key_lock);
 +
 +  fname = get_keydir_fname("secret_onion_key.old");
 +  if (file_status(fname) == FN_FILE) {
 +    if (tor_unlink(fname) != 0) {
 +      log_warn(LD_FS, "Couldn't unlink old onion key file %s: %s",
 +               fname, strerror(errno));
 +    }
 +  }
 +  tor_free(fname);
 +
 +  fname = get_keydir_fname("secret_onion_key_ntor.old");
 +  if (file_status(fname) == FN_FILE) {
 +    if (tor_unlink(fname) != 0) {
 +      log_warn(LD_FS, "Couldn't unlink old ntor onion key file %s: %s",
 +               fname, strerror(errno));
 +    }
 +  }
 +  tor_free(fname);
 +}
 +
 +/** Return the current secret onion key for the ntor handshake. Must only
 + * be called from the main thread. */
 +static const curve25519_keypair_t *
 +get_current_curve25519_keypair(void)
 +{
 +  return &curve25519_onion_key;
 +}
 +/** Return a map from KEYID (the key itself) to keypairs for use in the ntor
 + * handshake. Must only be called from the main thread. */
 +di_digest256_map_t *
 +construct_ntor_key_map(void)
 +{
 +  di_digest256_map_t *m = NULL;
 +
 +  if (!tor_mem_is_zero((const char*)
 +                       curve25519_onion_key.pubkey.public_key,
 +                       CURVE25519_PUBKEY_LEN)) {
 +    dimap_add_entry(&m,
 +                    curve25519_onion_key.pubkey.public_key,
 +                    tor_memdup(&curve25519_onion_key,
 +                               sizeof(curve25519_keypair_t)));
 +  }
 +  if (!tor_mem_is_zero((const char*)
 +                          last_curve25519_onion_key.pubkey.public_key,
 +                       CURVE25519_PUBKEY_LEN)) {
 +    dimap_add_entry(&m,
 +                    last_curve25519_onion_key.pubkey.public_key,
 +                    tor_memdup(&last_curve25519_onion_key,
 +                               sizeof(curve25519_keypair_t)));
 +  }
 +
 +  return m;
 +}
 +/** Helper used to deallocate a di_digest256_map_t returned by
 + * construct_ntor_key_map. */
 +static void
 +ntor_key_map_free_helper(void *arg)
 +{
 +  curve25519_keypair_t *k = arg;
 +  memwipe(k, 0, sizeof(*k));
 +  tor_free(k);
 +}
 +/** Release all storage from a keymap returned by construct_ntor_key_map. */
 +void
 +ntor_key_map_free_(di_digest256_map_t *map)
 +{
 +  if (!map)
 +    return;
 +  dimap_free(map, ntor_key_map_free_helper);
 +}
 +
 +/** Return the time when the onion key was last set.  This is either the time
 + * when the process launched, or the time of the most recent key rotation since
 + * the process launched.
 + */
 +time_t
 +get_onion_key_set_at(void)
 +{
 +  return onionkey_set_at;
 +}
 +
 +/** Set the current server identity key to <b>k</b>.
 + */
 +void
 +set_server_identity_key(crypto_pk_t *k)
 +{
 +  crypto_pk_free(server_identitykey);
 +  server_identitykey = k;
 +  if (crypto_pk_get_digest(server_identitykey,
 +                           server_identitykey_digest) < 0) {
 +    log_err(LD_BUG, "Couldn't compute our own identity key digest.");
 +    tor_assert(0);
 +  }
 +}
 +
 +/** Make sure that we have set up our identity keys to match or not match as
 + * appropriate, and die with an assertion if we have not. */
 +static void
 +assert_identity_keys_ok(void)
 +{
 +  if (1)
 +    return;
 +  tor_assert(client_identitykey);
 +  if (public_server_mode(get_options())) {
 +    /* assert that we have set the client and server keys to be equal */
 +    tor_assert(server_identitykey);
 +    tor_assert(crypto_pk_eq_keys(client_identitykey, server_identitykey));
 +  } else {
 +    /* assert that we have set the client and server keys to be unequal */
 +    if (server_identitykey)
 +      tor_assert(!crypto_pk_eq_keys(client_identitykey, server_identitykey));
 +  }
 +}
 +
 +/** Returns the current server identity key; requires that the key has
 + * been set, and that we are running as a Tor server.
 + */
 +crypto_pk_t *
 +get_server_identity_key(void)
 +{
 +  tor_assert(server_identitykey);
 +  tor_assert(server_mode(get_options()));
 +  assert_identity_keys_ok();
 +  return server_identitykey;
 +}
 +
 +/** Return true iff we are a server and the server identity key
 + * has been set. */
 +int
 +server_identity_key_is_set(void)
 +{
 +  return server_mode(get_options()) && server_identitykey != NULL;
 +}
 +
 +/** Set the current client identity key to <b>k</b>.
 + */
 +void
 +set_client_identity_key(crypto_pk_t *k)
 +{
 +  crypto_pk_free(client_identitykey);
 +  client_identitykey = k;
 +}
 +
 +/** Returns the current client identity key for use on outgoing TLS
 + * connections; requires that the key has been set.
 + */
 +crypto_pk_t *
 +get_tlsclient_identity_key(void)
 +{
 +  tor_assert(client_identitykey);
 +  assert_identity_keys_ok();
 +  return client_identitykey;
 +}
 +
 +/** Return true iff the client identity key has been set. */
 +int
 +client_identity_key_is_set(void)
 +{
 +  return client_identitykey != NULL;
 +}
 +
 +/** Return the key certificate for this v3 (voting) authority, or NULL
 + * if we have no such certificate. */
 +MOCK_IMPL(authority_cert_t *,
 +get_my_v3_authority_cert, (void))
 +{
 +  return authority_key_certificate;
 +}
 +
 +/** Return the v3 signing key for this v3 (voting) authority, or NULL
 + * if we have no such key. */
 +crypto_pk_t *
 +get_my_v3_authority_signing_key(void)
 +{
 +  return authority_signing_key;
 +}
 +
 +/** If we're an authority, and we're using a legacy authority identity key for
 + * emergency migration purposes, return the certificate associated with that
 + * key. */
 +authority_cert_t *
 +get_my_v3_legacy_cert(void)
 +{
 +  return legacy_key_certificate;
 +}
 +
 +/** If we're an authority, and we're using a legacy authority identity key for
 + * emergency migration purposes, return that key. */
 +crypto_pk_t *
 +get_my_v3_legacy_signing_key(void)
 +{
 +  return legacy_signing_key;
 +}
 +
 +/** Replace the previous onion key with the current onion key, and generate
 + * a new previous onion key.  Immediately after calling this function,
 + * the OR should:
 + *   - schedule all previous cpuworkers to shut down _after_ processing
 + *     pending work.  (This will cause fresh cpuworkers to be generated.)
 + *   - generate and upload a fresh routerinfo.
 + */
 +void
 +rotate_onion_key(void)
 +{
 +  char *fname, *fname_prev;
 +  crypto_pk_t *prkey = NULL;
 +  or_state_t *state = get_or_state();
 +  curve25519_keypair_t new_curve25519_keypair;
 +  time_t now;
 +  fname = get_keydir_fname("secret_onion_key");
 +  fname_prev = get_keydir_fname("secret_onion_key.old");
 +  /* There isn't much point replacing an old key with an empty file */
 +  if (file_status(fname) == FN_FILE) {
 +    if (replace_file(fname, fname_prev))
 +      goto error;
 +  }
 +  if (!(prkey = crypto_pk_new())) {
 +    log_err(LD_GENERAL,"Error constructing rotated onion key");
 +    goto error;
 +  }
 +  if (crypto_pk_generate_key(prkey)) {
 +    log_err(LD_BUG,"Error generating onion key");
 +    goto error;
 +  }
 +  if (crypto_pk_write_private_key_to_filename(prkey, fname)) {
 +    log_err(LD_FS,"Couldn't write generated onion key to \"%s\".", fname);
 +    goto error;
 +  }
 +  tor_free(fname);
 +  tor_free(fname_prev);
 +  fname = get_keydir_fname("secret_onion_key_ntor");
 +  fname_prev = get_keydir_fname("secret_onion_key_ntor.old");
 +  if (curve25519_keypair_generate(&new_curve25519_keypair, 1) < 0)
 +    goto error;
 +  /* There isn't much point replacing an old key with an empty file */
 +  if (file_status(fname) == FN_FILE) {
 +    if (replace_file(fname, fname_prev))
 +      goto error;
 +  }
 +  if (curve25519_keypair_write_to_file(&new_curve25519_keypair, fname,
 +                                       "onion") < 0) {
 +    log_err(LD_FS,"Couldn't write curve25519 onion key to \"%s\".",fname);
 +    goto error;
 +  }
 +  log_info(LD_GENERAL, "Rotating onion key");
 +  tor_mutex_acquire(key_lock);
 +  crypto_pk_free(lastonionkey);
 +  lastonionkey = onionkey;
 +  onionkey = prkey;
 +  memcpy(&last_curve25519_onion_key, &curve25519_onion_key,
 +         sizeof(curve25519_keypair_t));
 +  memcpy(&curve25519_onion_key, &new_curve25519_keypair,
 +         sizeof(curve25519_keypair_t));
 +  now = time(NULL);
 +  state->LastRotatedOnionKey = onionkey_set_at = now;
 +  tor_mutex_release(key_lock);
 +  mark_my_descriptor_dirty("rotated onion key");
 +  or_state_mark_dirty(state, get_options()->AvoidDiskWrites ? now+3600 : 0);
 +  goto done;
 + error:
 +  log_warn(LD_GENERAL, "Couldn't rotate onion key.");
 +  if (prkey)
 +    crypto_pk_free(prkey);
 + done:
 +  memwipe(&new_curve25519_keypair, 0, sizeof(new_curve25519_keypair));
 +  tor_free(fname);
 +  tor_free(fname_prev);
 +}
 +
 +/** Log greeting message that points to new relay lifecycle document the
 + * first time this function has been called.
 + */
 +static void
 +log_new_relay_greeting(void)
 +{
 +  static int already_logged = 0;
 +
 +  if (already_logged)
 +    return;
 +
 +  tor_log(LOG_NOTICE, LD_GENERAL, "You are running a new relay. "
 +         "Thanks for helping the Tor network! If you wish to know "
 +         "what will happen in the upcoming weeks regarding its usage, "
 +         "have a look at https://blog.torproject.org/blog/lifecycle-of";
 +         "-a-new-relay");
 +
 +  already_logged = 1;
 +}
 +
 +/** Load a curve25519 keypair from the file <b>fname</b>, writing it into
 + * <b>keys_out</b>.  If the file isn't found, or is empty, and <b>generate</b>
 + * is true, create a new keypair and write it into the file.  If there are
 + * errors, log them at level <b>severity</b>. Generate files using <b>tag</b>
 + * in their ASCII wrapper. */
 +static int
 +init_curve25519_keypair_from_file(curve25519_keypair_t *keys_out,
 +                                  const char *fname,
 +                                  int generate,
 +                                  int severity,
 +                                  const char *tag)
 +{
 +  switch (file_status(fname)) {
 +    case FN_DIR:
 +    case FN_ERROR:
 +      tor_log(severity, LD_FS,"Can't read key from \"%s\"", fname);
 +      goto error;
 +    /* treat empty key files as if the file doesn't exist, and, if generate
 +     * is set, replace the empty file in curve25519_keypair_write_to_file() */
 +    case FN_NOENT:
 +    case FN_EMPTY:
 +      if (generate) {
 +        if (!have_lockfile()) {
 +          if (try_locking(get_options(), 0)<0) {
 +            /* Make sure that --list-fingerprint only creates new keys
 +             * if there is no possibility for a deadlock. */
 +            tor_log(severity, LD_FS, "Another Tor process has locked \"%s\". "
 +                    "Not writing any new keys.", fname);
 +            /*XXXX The 'other process' might make a key in a second or two;
 +             * maybe we should wait for it. */
 +            goto error;
 +          }
 +        }
 +        log_info(LD_GENERAL, "No key found in \"%s\"; generating fresh key.",
 +                 fname);
 +        if (curve25519_keypair_generate(keys_out, 1) < 0)
 +          goto error;
 +        if (curve25519_keypair_write_to_file(keys_out, fname, tag)<0) {
 +          tor_log(severity, LD_FS,
 +              "Couldn't write generated key to \"%s\".", fname);
 +          memwipe(keys_out, 0, sizeof(*keys_out));
 +          goto error;
 +        }
 +      } else {
 +        log_info(LD_GENERAL, "No key found in \"%s\"", fname);
 +      }
 +      return 0;
 +    case FN_FILE:
 +      {
 +        char *tag_in=NULL;
 +        if (curve25519_keypair_read_from_file(keys_out, &tag_in, fname) < 0) {
 +          tor_log(severity, LD_GENERAL,"Error loading private key.");
 +          tor_free(tag_in);
 +          goto error;
 +        }
 +        if (!tag_in || strcmp(tag_in, tag)) {
 +          tor_log(severity, LD_GENERAL,"Unexpected tag %s on private key.",
 +              escaped(tag_in));
 +          tor_free(tag_in);
 +          goto error;
 +        }
 +        tor_free(tag_in);
 +        return 0;
 +      }
 +    default:
 +      tor_assert(0);
 +  }
 +
 + error:
 +  return -1;
 +}
 +
 +/** Try to load the vote-signing private key and certificate for being a v3
 + * directory authority, and make sure they match.  If <b>legacy</b>, load a
 + * legacy key/cert set for emergency key migration; otherwise load the regular
 + * key/cert set.  On success, store them into *<b>key_out</b> and
 + * *<b>cert_out</b> respectively, and return 0.  On failure, return -1. */
 +static int
 +load_authority_keyset(int legacy, crypto_pk_t **key_out,
 +                      authority_cert_t **cert_out)
 +{
 +  int r = -1;
 +  char *fname = NULL, *cert = NULL;
 +  const char *eos = NULL;
 +  crypto_pk_t *signing_key = NULL;
 +  authority_cert_t *parsed = NULL;
 +
 +  fname = get_keydir_fname(
 +                 legacy ? "legacy_signing_key" : "authority_signing_key");
 +  signing_key = init_key_from_file(fname, 0, LOG_ERR, NULL);
 +  if (!signing_key) {
 +    log_warn(LD_DIR, "No version 3 directory key found in %s", fname);
 +    goto done;
 +  }
 +  tor_free(fname);
 +  fname = get_keydir_fname(
 +               legacy ? "legacy_certificate" : "authority_certificate");
 +  cert = read_file_to_str(fname, 0, NULL);
 +  if (!cert) {
 +    log_warn(LD_DIR, "Signing key found, but no certificate found in %s",
 +               fname);
 +    goto done;
 +  }
 +  parsed = authority_cert_parse_from_string(cert, &eos);
 +  if (!parsed) {
 +    log_warn(LD_DIR, "Unable to parse certificate in %s", fname);
 +    goto done;
 +  }
 +  if (!crypto_pk_eq_keys(signing_key, parsed->signing_key)) {
 +    log_warn(LD_DIR, "Stored signing key does not match signing key in "
 +             "certificate");
 +    goto done;
 +  }
 +
 +  crypto_pk_free(*key_out);
 +  authority_cert_free(*cert_out);
 +
 +  *key_out = signing_key;
 +  *cert_out = parsed;
 +  r = 0;
 +  signing_key = NULL;
 +  parsed = NULL;
 +
 + done:
 +  tor_free(fname);
 +  tor_free(cert);
 +  crypto_pk_free(signing_key);
 +  authority_cert_free(parsed);
 +  return r;
 +}
 +
 +/** Load the v3 (voting) authority signing key and certificate, if they are
 + * present.  Return -1 if anything is missing, mismatched, or unloadable;
 + * return 0 on success. */
 +static int
 +init_v3_authority_keys(void)
 +{
 +  if (load_authority_keyset(0, &authority_signing_key,
 +                            &authority_key_certificate)<0)
 +    return -1;
 +
 +  if (get_options()->V3AuthUseLegacyKey &&
 +      load_authority_keyset(1, &legacy_signing_key,
 +                            &legacy_key_certificate)<0)
 +    return -1;
 +
 +  return 0;
 +}
 +
 +/** If we're a v3 authority, check whether we have a certificate that's
 + * likely to expire soon.  Warn if we do, but not too often. */
 +void
 +v3_authority_check_key_expiry(void)
 +{
 +  time_t now, expires;
 +  static time_t last_warned = 0;
 +  int badness, time_left, warn_interval;
 +  if (!authdir_mode_v3(get_options()) || !authority_key_certificate)
 +    return;
 +
 +  now = time(NULL);
 +  expires = authority_key_certificate->expires;
 +  time_left = (int)( expires - now );
 +  if (time_left <= 0) {
 +    badness = LOG_ERR;
 +    warn_interval = 60*60;
 +  } else if (time_left <= 24*60*60) {
 +    badness = LOG_WARN;
 +    warn_interval = 60*60;
 +  } else if (time_left <= 24*60*60*7) {
 +    badness = LOG_WARN;
 +    warn_interval = 24*60*60;
 +  } else if (time_left <= 24*60*60*30) {
 +    badness = LOG_WARN;
 +    warn_interval = 24*60*60*5;
 +  } else {
 +    return;
 +  }
 +
 +  if (last_warned + warn_interval > now)
 +    return;
 +
 +  if (time_left <= 0) {
 +    tor_log(badness, LD_DIR, "Your v3 authority certificate has expired."
 +            " Generate a new one NOW.");
 +  } else if (time_left <= 24*60*60) {
 +    tor_log(badness, LD_DIR, "Your v3 authority certificate expires in %d "
 +            "hours; Generate a new one NOW.", time_left/(60*60));
 +  } else {
 +    tor_log(badness, LD_DIR, "Your v3 authority certificate expires in %d "
 +            "days; Generate a new one soon.", time_left/(24*60*60));
 +  }
 +  last_warned = now;
 +}
 +
 +/** Get the lifetime of an onion key in days. This value is defined by the
 + * network consesus parameter "onion-key-rotation-days". Always returns a value
 + * between <b>MIN_ONION_KEY_LIFETIME_DAYS</b> and
 + * <b>MAX_ONION_KEY_LIFETIME_DAYS</b>.
 + */
 +static int
 +get_onion_key_rotation_days_(void)
 +{
 +  return networkstatus_get_param(NULL,
 +                                 "onion-key-rotation-days",
 +                                 DEFAULT_ONION_KEY_LIFETIME_DAYS,
 +                                 MIN_ONION_KEY_LIFETIME_DAYS,
 +                                 MAX_ONION_KEY_LIFETIME_DAYS);
 +}
 +
 +/** Get the current lifetime of an onion key in seconds. This value is defined
 + * by the network consesus parameter "onion-key-rotation-days", but the value
 + * is converted to seconds.
 + */
 +int
 +get_onion_key_lifetime(void)
 +{
 +  return get_onion_key_rotation_days_()*24*60*60;
 +}
 +
 +/** Get the grace period of an onion key in seconds. This value is defined by
 + * the network consesus parameter "onion-key-grace-period-days", but the value
 + * is converted to seconds.
 + */
 +int
 +get_onion_key_grace_period(void)
 +{
 +  int grace_period;
 +  grace_period = networkstatus_get_param(NULL,
 +                                         "onion-key-grace-period-days",
 +                                         DEFAULT_ONION_KEY_GRACE_PERIOD_DAYS,
 +                                         MIN_ONION_KEY_GRACE_PERIOD_DAYS,
 +                                         get_onion_key_rotation_days_());
 +  return grace_period*24*60*60;
 +}
 +
 +/** Set up Tor's TLS contexts, based on our configuration and keys. Return 0
 + * on success, and -1 on failure. */
 +int
 +router_initialize_tls_context(void)
 +{
 +  unsigned int flags = 0;
 +  const or_options_t *options = get_options();
 +  int lifetime = options->SSLKeyLifetime;
 +  if (public_server_mode(options))
 +    flags |= TOR_TLS_CTX_IS_PUBLIC_SERVER;
 +  if (!lifetime) { /* we should guess a good ssl cert lifetime */
 +
 +    /* choose between 5 and 365 days, and round to the day */
 +    unsigned int five_days = 5*24*3600;
 +    unsigned int one_year = 365*24*3600;
 +    lifetime = crypto_rand_int_range(five_days, one_year);
 +    lifetime -= lifetime % (24*3600);
 +
 +    if (crypto_rand_int(2)) {
 +      /* Half the time we expire at midnight, and half the time we expire
 +       * one second before midnight. (Some CAs wobble their expiry times a
 +       * bit in practice, perhaps to reduce collision attacks; see ticket
 +       * 8443 for details about observed certs in the wild.) */
 +      lifetime--;
 +    }
 +  }
 +
 +  /* It's ok to pass lifetime in as an unsigned int, since
 +   * config_parse_interval() checked it. */
 +  return tor_tls_context_init(flags,
 +                              get_tlsclient_identity_key(),
 +                              server_mode(options) ?
 +                              get_server_identity_key() : NULL,
 +                              (unsigned int)lifetime);
 +}
 +
 +/** Compute fingerprint (or hashed fingerprint if hashed is 1) and write
 + * it to 'fingerprint' (or 'hashed-fingerprint'). Return 0 on success, or
 + * -1 if Tor should die,
 + */
 +STATIC int
 +router_write_fingerprint(int hashed)
 +{
 +  char *keydir = NULL, *cp = NULL;
 +  const char *fname = hashed ? "hashed-fingerprint" :
 +                               "fingerprint";
 +  char fingerprint[FINGERPRINT_LEN+1];
 +  const or_options_t *options = get_options();
 +  char *fingerprint_line = NULL;
 +  int result = -1;
 +
 +  keydir = get_datadir_fname(fname);
 +  log_info(LD_GENERAL,"Dumping %sfingerprint to \"%s\"...",
 +           hashed ? "hashed " : "", keydir);
 +  if (!hashed) {
 +    if (crypto_pk_get_fingerprint(get_server_identity_key(),
 +                                  fingerprint, 0) < 0) {
 +      log_err(LD_GENERAL,"Error computing fingerprint");
 +      goto done;
 +    }
 +  } else {
 +    if (crypto_pk_get_hashed_fingerprint(get_server_identity_key(),
 +                                         fingerprint) < 0) {
 +      log_err(LD_GENERAL,"Error computing hashed fingerprint");
 +      goto done;
 +    }
 +  }
 +
 +  tor_asprintf(&fingerprint_line, "%s %s\n", options->Nickname, fingerprint);
 +
 +  /* Check whether we need to write the (hashed-)fingerprint file. */
 +
 +  cp = read_file_to_str(keydir, RFTS_IGNORE_MISSING, NULL);
 +  if (!cp || strcmp(cp, fingerprint_line)) {
 +    if (write_str_to_file(keydir, fingerprint_line, 0)) {
 +      log_err(LD_FS, "Error writing %sfingerprint line to file",
 +              hashed ? "hashed " : "");
 +      goto done;
 +    }
 +  }
 +
 +  log_notice(LD_GENERAL, "Your Tor %s identity key fingerprint is '%s %s'",
 +             hashed ? "bridge's hashed" : "server's", options->Nickname,
 +             fingerprint);
 +
 +  result = 0;
 + done:
 +  tor_free(cp);
 +  tor_free(keydir);
 +  tor_free(fingerprint_line);
 +  return result;
 +}
 +
 +static int
 +init_keys_common(void)
 +{
 +  if (!key_lock)
 +    key_lock = tor_mutex_new();
 +
 +  /* There are a couple of paths that put us here before we've asked
 +   * openssl to initialize itself. */
 +  if (crypto_global_init(get_options()->HardwareAccel,
 +                         get_options()->AccelName,
 +                         get_options()->AccelDir)) {
 +    log_err(LD_BUG, "Unable to initialize OpenSSL. Exiting.");
 +    return -1;
 +  }
 +
 +  return 0;
 +}
 +
 +int
 +init_keys_client(void)
 +{
 +  crypto_pk_t *prkey;
 +  if (init_keys_common() < 0)
 +    return -1;
 +
 +  if (!(prkey = crypto_pk_new()))
 +    return -1;
 +  if (crypto_pk_generate_key(prkey)) {
 +    crypto_pk_free(prkey);
 +    return -1;
 +  }
 +  set_client_identity_key(prkey);
 +  /* Create a TLS context. */
 +  if (router_initialize_tls_context() < 0) {
 +    log_err(LD_GENERAL,"Error creating TLS context for Tor client.");
 +    return -1;
 +  }
 +  return 0;
 +}
 +
 +/** Initialize all OR private keys, and the TLS context, as necessary.
 + * On OPs, this only initializes the tls context. Return 0 on success,
 + * or -1 if Tor should die.
 + */
 +int
 +init_keys(void)
 +{
 +  char *keydir;
 +  const char *mydesc;
 +  crypto_pk_t *prkey;
 +  char digest[DIGEST_LEN];
 +  char v3_digest[DIGEST_LEN];
 +  const or_options_t *options = get_options();
 +  dirinfo_type_t type;
 +  time_t now = time(NULL);
 +  dir_server_t *ds;
 +  int v3_digest_set = 0;
 +  authority_cert_t *cert = NULL;
 +
 +  /* OP's don't need persistent keys; just make up an identity and
 +   * initialize the TLS context. */
 +  if (!server_mode(options)) {
 +    return init_keys_client();
 +  }
 +  if (init_keys_common() < 0)
 +    return -1;
 +
 +  if (create_keys_directory(options) < 0)
 +    return -1;
 +
 +  /* 1a. Read v3 directory authority key/cert information. */
 +  memset(v3_digest, 0, sizeof(v3_digest));
 +  if (authdir_mode_v3(options)) {
 +    if (init_v3_authority_keys()<0) {
 +      log_err(LD_GENERAL, "We're configured as a V3 authority, but we "
 +              "were unable to load our v3 authority keys and certificate! "
 +              "Use tor-gencert to generate them. Dying.");
 +      return -1;
 +    }
 +    cert = get_my_v3_authority_cert();
 +    if (cert) {
 +      if (crypto_pk_get_digest(get_my_v3_authority_cert()->identity_key,
 +                               v3_digest) < 0) {
 +        log_err(LD_BUG, "Couldn't compute my v3 authority identity key "
 +                "digest.");
 +        return -1;
 +      }
 +      v3_digest_set = 1;
 +    }
 +  }
 +
 +  /* 1b. Read identity key. Make it if none is found. */
 +  keydir = get_keydir_fname("secret_id_key");
 +  log_info(LD_GENERAL,"Reading/making identity key \"%s\"...",keydir);
 +  bool created = false;
 +  prkey = init_key_from_file(keydir, 1, LOG_ERR, &created);
 +  tor_free(keydir);
 +  if (!prkey) return -1;
 +  if (created)
 +    log_new_relay_greeting();
 +  set_server_identity_key(prkey);
 +
 +  /* 1c. If we are configured as a bridge, generate a client key;
 +   * otherwise, set the server identity key as our client identity
 +   * key. */
 +  if (public_server_mode(options)) {
 +    set_client_identity_key(crypto_pk_dup_key(prkey)); /* set above */
 +  } else {
 +    if (!(prkey = crypto_pk_new()))
 +      return -1;
 +    if (crypto_pk_generate_key(prkey)) {
 +      crypto_pk_free(prkey);
 +      return -1;
 +    }
 +    set_client_identity_key(prkey);
 +  }
 +
 +  /* 1d. Load all ed25519 keys */
 +  const int new_signing_key = load_ed_keys(options,now);
 +  if (new_signing_key < 0)
 +    return -1;
 +
 +  /* 2. Read onion key.  Make it if none is found. */
 +  keydir = get_keydir_fname("secret_onion_key");
 +  log_info(LD_GENERAL,"Reading/making onion key \"%s\"...",keydir);
 +  prkey = init_key_from_file(keydir, 1, LOG_ERR, &created);
 +  if (created)
 +    log_new_relay_greeting();
 +  tor_free(keydir);
 +  if (!prkey) return -1;
 +  set_onion_key(prkey);
 +  if (options->command == CMD_RUN_TOR) {
 +    /* only mess with the state file if we're actually running Tor */
 +    or_state_t *state = get_or_state();
 +    if (state->LastRotatedOnionKey > 100 && state->LastRotatedOnionKey < now) {
 +      /* We allow for some parsing slop, but we don't want to risk accepting
 +       * values in the distant future.  If we did, we might never rotate the
 +       * onion key. */
 +      onionkey_set_at = state->LastRotatedOnionKey;
 +    } else {
 +      /* We have no LastRotatedOnionKey set; either we just created the key
 +       * or it's a holdover from 0.1.2.4-alpha-dev or earlier.  In either case,
 +       * start the clock ticking now so that we will eventually rotate it even
 +       * if we don't stay up for the full lifetime of an onion key. */
 +      state->LastRotatedOnionKey = onionkey_set_at = now;
 +      or_state_mark_dirty(state, options->AvoidDiskWrites ?
 +                                   time(NULL)+3600 : 0);
 +    }
 +  }
 +
 +  keydir = get_keydir_fname("secret_onion_key.old");
 +  if (!lastonionkey && file_status(keydir) == FN_FILE) {
 +    /* Load keys from non-empty files only.
 +     * Missing old keys won't be replaced with freshly generated keys. */
 +    prkey = init_key_from_file(keydir, 0, LOG_ERR, 0);
 +    if (prkey)
 +      lastonionkey = prkey;
 +  }
 +  tor_free(keydir);
 +
 +  {
 +    /* 2b. Load curve25519 onion keys. */
 +    int r;
 +    keydir = get_keydir_fname("secret_onion_key_ntor");
 +    r = init_curve25519_keypair_from_file(&curve25519_onion_key,
 +                                          keydir, 1, LOG_ERR, "onion");
 +    tor_free(keydir);
 +    if (r<0)
 +      return -1;
 +
 +    keydir = get_keydir_fname("secret_onion_key_ntor.old");
 +    if (tor_mem_is_zero((const char *)
 +                           last_curve25519_onion_key.pubkey.public_key,
 +                        CURVE25519_PUBKEY_LEN) &&
 +        file_status(keydir) == FN_FILE) {
 +      /* Load keys from non-empty files only.
 +       * Missing old keys won't be replaced with freshly generated keys. */
 +      init_curve25519_keypair_from_file(&last_curve25519_onion_key,
 +                                        keydir, 0, LOG_ERR, "onion");
 +    }
 +    tor_free(keydir);
 +  }
 +
 +  /* 3. Initialize link key and TLS context. */
 +  if (router_initialize_tls_context() < 0) {
 +    log_err(LD_GENERAL,"Error initializing TLS context");
 +    return -1;
 +  }
 +
 +  /* 3b. Get an ed25519 link certificate.  Note that we need to do this
 +   * after we set up the TLS context */
 +  if (generate_ed_link_cert(options, now, new_signing_key > 0) < 0) {
 +    log_err(LD_GENERAL,"Couldn't make link cert");
 +    return -1;
 +  }
 +
 +  /* 4. Build our router descriptor. */
 +  /* Must be called after keys are initialized. */
 +  mydesc = router_get_my_descriptor();
 +  if (authdir_mode_v3(options)) {
 +    const char *m = NULL;
 +    routerinfo_t *ri;
 +    /* We need to add our own fingerprint so it gets recognized. */
 +    if (dirserv_add_own_fingerprint(get_server_identity_key())) {
 +      log_err(LD_GENERAL,"Error adding own fingerprint to set of relays");
 +      return -1;
 +    }
 +    if (mydesc) {
 +      was_router_added_t added;
 +      ri = router_parse_entry_from_string(mydesc, NULL, 1, 0, NULL, NULL);
 +      if (!ri) {
 +        log_err(LD_GENERAL,"Generated a routerinfo we couldn't parse.");
 +        return -1;
 +      }
 +      added = dirserv_add_descriptor(ri, &m, "self");
 +      if (!WRA_WAS_ADDED(added)) {
 +        if (!WRA_WAS_OUTDATED(added)) {
 +          log_err(LD_GENERAL, "Unable to add own descriptor to directory: %s",
 +                  m?m:"<unknown error>");
 +          return -1;
 +        } else {
 +          /* If the descriptor was outdated, that's ok. This can happen
 +           * when some config options are toggled that affect workers, but
 +           * we don't really need new keys yet so the descriptor doesn't
 +           * change and the old one is still fresh. */
 +          log_info(LD_GENERAL, "Couldn't add own descriptor to directory "
 +                   "after key init: %s This is usually not a problem.",
 +                   m?m:"<unknown error>");
 +        }
 +      }
 +    }
 +  }
 +
 +  /* 5. Dump fingerprint and possibly hashed fingerprint to files. */
 +  if (router_write_fingerprint(0)) {
 +    log_err(LD_FS, "Error writing fingerprint to file");
 +    return -1;
 +  }
 +  if (!public_server_mode(options) && router_write_fingerprint(1)) {
 +    log_err(LD_FS, "Error writing hashed fingerprint to file");
 +    return -1;
 +  }
 +
 +  if (!authdir_mode(options))
 +    return 0;
 +  /* 6. [authdirserver only] load approved-routers file */
 +  if (dirserv_load_fingerprint_file() < 0) {
 +    log_err(LD_GENERAL,"Error loading fingerprints");
 +    return -1;
 +  }
 +  /* 6b. [authdirserver only] add own key to approved directories. */
 +  crypto_pk_get_digest(get_server_identity_key(), digest);
 +  type = ((options->V3AuthoritativeDir ?
 +               (V3_DIRINFO|MICRODESC_DIRINFO|EXTRAINFO_DIRINFO) : NO_DIRINFO) |
 +          (options->BridgeAuthoritativeDir ? BRIDGE_DIRINFO : NO_DIRINFO));
 +
 +  ds = router_get_trusteddirserver_by_digest(digest);
 +  if (!ds) {
 +    ds = trusted_dir_server_new(options->Nickname, NULL,
 +                                router_get_advertised_dir_port(options, 0),
 +                                router_get_advertised_or_port(options),
 +                                NULL,
 +                                digest,
 +                                v3_digest,
 +                                type, 0.0);
 +    if (!ds) {
 +      log_err(LD_GENERAL,"We want to be a directory authority, but we "
 +              "couldn't add ourselves to the authority list. Failing.");
 +      return -1;
 +    }
 +    dir_server_add(ds);
 +  }
 +  if (ds->type != type) {
 +    log_warn(LD_DIR,  "Configured authority type does not match authority "
 +             "type in DirAuthority list.  Adjusting. (%d v %d)",
 +             type, ds->type);
 +    ds->type = type;
 +  }
 +  if (v3_digest_set && (ds->type & V3_DIRINFO) &&
 +      tor_memneq(v3_digest, ds->v3_identity_digest, DIGEST_LEN)) {
 +    log_warn(LD_DIR, "V3 identity key does not match identity declared in "
 +             "DirAuthority line.  Adjusting.");
 +    memcpy(ds->v3_identity_digest, v3_digest, DIGEST_LEN);
 +  }
 +
 +  if (cert) { /* add my own cert to the list of known certs */
 +    log_info(LD_DIR, "adding my own v3 cert");
 +    if (trusted_dirs_load_certs_from_string(
 +                      cert->cache_info.signed_descriptor_body,
 +                      TRUSTED_DIRS_CERTS_SRC_SELF, 0,
 +                      NULL)<0) {
 +      log_warn(LD_DIR, "Unable to parse my own v3 cert! Failing.");
 +      return -1;
 +    }
 +  }
 +
 +  return 0; /* success */
 +}
 +
 +/** The lower threshold of remaining bandwidth required to advertise (or
 + * automatically provide) directory services */
 +/* XXX Should this be increased? */
 +#define MIN_BW_TO_ADVERTISE_DIRSERVER 51200
 +
 +/** Return true iff we have enough configured bandwidth to advertise or
 + * automatically provide directory services from cache directory
 + * information. */
 +int
 +router_has_bandwidth_to_be_dirserver(const or_options_t *options)
 +{
 +  if (options->BandwidthRate < MIN_BW_TO_ADVERTISE_DIRSERVER) {
 +    return 0;
 +  }
 +  if (options->RelayBandwidthRate > 0 &&
 +      options->RelayBandwidthRate < MIN_BW_TO_ADVERTISE_DIRSERVER) {
 +    return 0;
 +  }
 +  return 1;
 +}
 +
 +/** Helper: Return 1 if we have sufficient resources for serving directory
 + * requests, return 0 otherwise.
 + * dir_port is either 0 or the configured DirPort number.
 + * If AccountingMax is set less than our advertised bandwidth, then don't
 + * serve requests. Likewise, if our advertised bandwidth is less than
 + * MIN_BW_TO_ADVERTISE_DIRSERVER, don't bother trying to serve requests.
 + */
 +static int
 +router_should_be_dirserver(const or_options_t *options, int dir_port)
 +{
 +  static int advertising=1; /* start out assuming we will advertise */
 +  int new_choice=1;
 +  const char *reason = NULL;
 +
 +  if (accounting_is_enabled(options) &&
 +    get_options()->AccountingRule != ACCT_IN) {
 +    /* Don't spend bytes for directory traffic if we could end up hibernating,
 +     * but allow DirPort otherwise. Some relay operators set AccountingMax
 +     * because they're confused or to get statistics. Directory traffic has a
 +     * much larger effect on output than input so there is no reason to turn it
 +     * off if using AccountingRule in. */
 +    int interval_length = accounting_get_interval_length();
 +    uint32_t effective_bw = get_effective_bwrate(options);
 +    uint64_t acc_bytes;
 +    if (!interval_length) {
 +      log_warn(LD_BUG, "An accounting interval is not allowed to be zero "
 +                       "seconds long. Raising to 1.");
 +      interval_length = 1;
 +    }
 +    log_info(LD_GENERAL, "Calculating whether to advertise %s: effective "
 +                         "bwrate: %u, AccountingMax: %"PRIu64", "
 +                         "accounting interval length %d",
 +                         dir_port ? "dirport" : "begindir",
 +                         effective_bw, (options->AccountingMax),
 +                         interval_length);
 +
 +    acc_bytes = options->AccountingMax;
 +    if (get_options()->AccountingRule == ACCT_SUM)
 +      acc_bytes /= 2;
 +    if (effective_bw >=
 +        acc_bytes / interval_length) {
 +      new_choice = 0;
 +      reason = "AccountingMax enabled";
 +    }
 +  } else if (! router_has_bandwidth_to_be_dirserver(options)) {
 +    /* if we're advertising a small amount */
 +    new_choice = 0;
 +    reason = "BandwidthRate under 50KB";
 +  }
 +
 +  if (advertising != new_choice) {
 +    if (new_choice == 1) {
 +      if (dir_port > 0)
 +        log_notice(LD_DIR, "Advertising DirPort as %d", dir_port);
 +      else
 +        log_notice(LD_DIR, "Advertising directory service support");
 +    } else {
 +      tor_assert(reason);
 +      log_notice(LD_DIR, "Not advertising Dir%s (Reason: %s)",
 +                 dir_port ? "Port" : "ectory Service support", reason);
 +    }
 +    advertising = new_choice;
 +  }
 +
 +  return advertising;
 +}
 +
 +/** Look at a variety of factors, and return 0 if we don't want to
 + * advertise the fact that we have a DirPort open or begindir support, else
 + * return 1.
 + *
 + * Where dir_port or supports_tunnelled_dir_requests are not relevant, they
 + * must be 0.
 + *
 + * Log a helpful message if we change our mind about whether to publish.
 + */
 +static int
 +decide_to_advertise_dir_impl(const or_options_t *options,
 +                             uint16_t dir_port,
 +                             int supports_tunnelled_dir_requests)
 +{
 +  /* Part one: reasons to publish or not publish that aren't
 +   * worth mentioning to the user, either because they're obvious
 +   * or because they're normal behavior. */
 +
 +  /* short circuit the rest of the function */
 +  if (!dir_port && !supports_tunnelled_dir_requests)
 +    return 0;
 +  if (authdir_mode(options)) /* always publish */
 +    return 1;
 +  if (net_is_disabled())
 +    return 0;
 +  if (dir_port && !router_get_advertised_dir_port(options, dir_port))
 +    return 0;
 +  if (supports_tunnelled_dir_requests &&
 +      !router_get_advertised_or_port(options))
 +    return 0;
 +
 +  /* Part two: consider config options that could make us choose to
 +   * publish or not publish that the user might find surprising. */
 +  return router_should_be_dirserver(options, dir_port);
 +}
 +
 +/** Front-end to decide_to_advertise_dir_impl(): return 0 if we don't want to
 + * advertise the fact that we have a DirPort open, else return the
 + * DirPort we want to advertise.
 + */
 +int
 +router_should_advertise_dirport(const or_options_t *options, uint16_t dir_port)
 +{
 +  /* supports_tunnelled_dir_requests is not relevant, pass 0 */
 +  return decide_to_advertise_dir_impl(options, dir_port, 0) ? dir_port : 0;
 +}
 +
 +/** Front-end to decide_to_advertise_dir_impl(): return 0 if we don't want to
 + * advertise the fact that we support begindir requests, else return 1.
 + */
 +static int
 +router_should_advertise_begindir(const or_options_t *options,
 +                             int supports_tunnelled_dir_requests)
 +{
 +  /* dir_port is not relevant, pass 0 */
 +  return decide_to_advertise_dir_impl(options, 0,
 +                                      supports_tunnelled_dir_requests);
 +}
 +
 +/** Return true iff the combination of options in <b>options</b> and parameters
 + * in the consensus mean that we don't want to allow exits from circuits
 + * we got from addresses not known to be servers. */
 +int
 +should_refuse_unknown_exits(const or_options_t *options)
 +{
 +  if (options->RefuseUnknownExits != -1) {
 +    return options->RefuseUnknownExits;
 +  } else {
 +    return networkstatus_get_param(NULL, "refuseunknownexits", 1, 0, 1);
 +  }
 +}
 +
 +/** Decide if we're a publishable server. We are a publishable server if:
 + * - We don't have the ClientOnly option set
 + * and
 + * - We have the PublishServerDescriptor option set to non-empty
 + * and
 + * - We have ORPort set
 + * and
 + * - We believe our ORPort and DirPort (if present) are reachable from
 + *   the outside; or
 + * - We believe our ORPort is reachable from the outside, and we can't
 + *   check our DirPort because the consensus has no exits; or
 + * - We are an authoritative directory server.
 + */
 +static int
 +decide_if_publishable_server(void)
 +{
 +  const or_options_t *options = get_options();
 +
 +  if (options->ClientOnly)
 +    return 0;
 +  if (options->PublishServerDescriptor_ == NO_DIRINFO)
 +    return 0;
 +  if (!server_mode(options))
 +    return 0;
 +  if (authdir_mode(options))
 +    return 1;
 +  if (!router_get_advertised_or_port(options))
 +    return 0;
 +  if (!check_whether_orport_reachable(options))
 +    return 0;
 +  if (router_have_consensus_path() == CONSENSUS_PATH_INTERNAL) {
 +    /* All set: there are no exits in the consensus (maybe this is a tiny
 +     * test network), so we can't check our DirPort reachability. */
 +    return 1;
 +  } else {
 +    return check_whether_dirport_reachable(options);
 +  }
 +}
 +
 +/** Initiate server descriptor upload as reasonable (if server is publishable,
 + * etc).  <b>force</b> is as for router_upload_dir_desc_to_dirservers.
 + *
 + * We need to rebuild the descriptor if it's dirty even if we're not
 + * uploading, because our reachability testing *uses* our descriptor to
 + * determine what IP address and ports to test.
 + */
 +void
 +consider_publishable_server(int force)
 +{
 +  int rebuilt;
 +
 +  if (!server_mode(get_options()))
 +    return;
 +
 +  rebuilt = router_rebuild_descriptor(0);
 +  if (decide_if_publishable_server()) {
 +    set_server_advertised(1);
 +    if (rebuilt == 0)
 +      router_upload_dir_desc_to_dirservers(force);
 +  } else {
 +    set_server_advertised(0);
 +  }
 +}
 +
 +/** Return the port of the first active listener of type
 + *  <b>listener_type</b>. */
 +/** XXX not a very good interface. it's not reliable when there are
 +    multiple listeners. */
 +uint16_t
 +router_get_active_listener_port_by_type_af(int listener_type,
 +                                           sa_family_t family)
 +{
 +  /* Iterate all connections, find one of the right kind and return
 +     the port. Not very sophisticated or fast, but effective. */
 +  smartlist_t *conns = get_connection_array();
 +  SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
 +    if (conn->type == listener_type && !conn->marked_for_close &&
 +        conn->socket_family == family) {
 +      return conn->port;
 +    }
 +  } SMARTLIST_FOREACH_END(conn);
 +
 +  return 0;
 +}
 +
 +/** Return the port that we should advertise as our ORPort; this is either
 + * the one configured in the ORPort option, or the one we actually bound to
 + * if ORPort is "auto".
 + */
 +uint16_t
 +router_get_advertised_or_port(const or_options_t *options)
 +{
 +  return router_get_advertised_or_port_by_af(options, AF_INET);
 +}
 +
 +/** As router_get_advertised_or_port(), but allows an address family argument.
 + */
 +uint16_t
 +router_get_advertised_or_port_by_af(const or_options_t *options,
 +                                    sa_family_t family)
 +{
 +  int port = get_first_advertised_port_by_type_af(CONN_TYPE_OR_LISTENER,
 +                                                  family);
 +  (void)options;
 +
 +  /* If the port is in 'auto' mode, we have to use
 +     router_get_listener_port_by_type(). */
 +  if (port == CFG_AUTO_PORT)
 +    return router_get_active_listener_port_by_type_af(CONN_TYPE_OR_LISTENER,
 +                                                      family);
 +
 +  return port;
 +}
 +
 +/** Return the port that we should advertise as our DirPort;
 + * this is one of three possibilities:
 + * The one that is passed as <b>dirport</b> if the DirPort option is 0, or
 + * the one configured in the DirPort option,
 + * or the one we actually bound to if DirPort is "auto". */
 +uint16_t
 +router_get_advertised_dir_port(const or_options_t *options, uint16_t dirport)
 +{
 +  int dirport_configured = get_primary_dir_port();
 +  (void)options;
 +
 +  if (!dirport_configured)
 +    return dirport;
 +
 +  if (dirport_configured == CFG_AUTO_PORT)
 +    return router_get_active_listener_port_by_type_af(CONN_TYPE_DIR_LISTENER,
 +                                                      AF_INET);
 +
 +  return dirport_configured;
 +}
 +
 +/*
 + * OR descriptor generation.
 + */
 +
 +/** My routerinfo. */
 +static routerinfo_t *desc_routerinfo = NULL;
 +/** My extrainfo */
 +static extrainfo_t *desc_extrainfo = NULL;
 +/** Why did we most recently decide to regenerate our descriptor?  Used to
 + * tell the authorities why we're sending it to them. */
 +static const char *desc_gen_reason = "uninitialized reason";
 +/** Since when has our descriptor been "clean"?  0 if we need to regenerate it
 + * now. */
 +static time_t desc_clean_since = 0;
 +/** Why did we mark the descriptor dirty? */
 +static const char *desc_dirty_reason = "Tor just started";
 +/** Boolean: do we need to regenerate the above? */
 +static int desc_needs_upload = 0;
 +
 +/** OR only: If <b>force</b> is true, or we haven't uploaded this
 + * descriptor successfully yet, try to upload our signed descriptor to
 + * all the directory servers we know about.
 + */
 +void
 +router_upload_dir_desc_to_dirservers(int force)
 +{
 +  const routerinfo_t *ri;
 +  extrainfo_t *ei;
 +  char *msg;
 +  size_t desc_len, extra_len = 0, total_len;
 +  dirinfo_type_t auth = get_options()->PublishServerDescriptor_;
 +
 +  ri = router_get_my_routerinfo();
 +  if (!ri) {
 +    log_info(LD_GENERAL, "No descriptor; skipping upload");
 +    return;
 +  }
 +  ei = router_get_my_extrainfo();
 +  if (auth == NO_DIRINFO)
 +    return;
 +  if (!force && !desc_needs_upload)
 +    return;
 +
 +  log_info(LD_OR, "Uploading relay descriptor to directory authorities%s",
 +           force ? " (forced)" : "");
 +
 +  desc_needs_upload = 0;
 +
 +  desc_len = ri->cache_info.signed_descriptor_len;
 +  extra_len = ei ? ei->cache_info.signed_descriptor_len : 0;
 +  total_len = desc_len + extra_len + 1;
 +  msg = tor_malloc(total_len);
 +  memcpy(msg, ri->cache_info.signed_descriptor_body, desc_len);
 +  if (ei) {
 +    memcpy(msg+desc_len, ei->cache_info.signed_descriptor_body, extra_len);
 +  }
 +  msg[desc_len+extra_len] = 0;
 +
 +  directory_post_to_dirservers(DIR_PURPOSE_UPLOAD_DIR,
 +                               (auth & BRIDGE_DIRINFO) ?
 +                                 ROUTER_PURPOSE_BRIDGE :
 +                                 ROUTER_PURPOSE_GENERAL,
 +                               auth, msg, desc_len, extra_len);
 +  tor_free(msg);
 +}
 +
 +/** OR only: Check whether my exit policy says to allow connection to
 + * conn.  Return 0 if we accept; non-0 if we reject.
 + */
 +int
 +router_compare_to_my_exit_policy(const tor_addr_t *addr, uint16_t port)
 +{
 +  const routerinfo_t *me = router_get_my_routerinfo();
 +  if (!me) /* make sure routerinfo exists */
 +    return -1;
 +
 +  /* make sure it's resolved to something. this way we can't get a
 +     'maybe' below. */
 +  if (tor_addr_is_null(addr))
 +    return -1;
 +
 +  /* look at router_get_my_routerinfo()->exit_policy for both the v4 and the
 +   * v6 policies.  The exit_policy field in router_get_my_routerinfo() is a
 +   * bit unusual, in that it contains IPv6 and IPv6 entries.  We don't want to
 +   * look at router_get_my_routerinfo()->ipv6_exit_policy, since that's a port
 +   * summary. */
 +  if ((tor_addr_family(addr) == AF_INET ||
 +       tor_addr_family(addr) == AF_INET6)) {
 +    return compare_tor_addr_to_addr_policy(addr, port,
 +                               me->exit_policy) != ADDR_POLICY_ACCEPTED;
 +#if 0
 +  } else if (tor_addr_family(addr) == AF_INET6) {
 +    return get_options()->IPv6Exit &&
 +      desc_routerinfo->ipv6_exit_policy &&
 +      compare_tor_addr_to_short_policy(addr, port,
 +                               me->ipv6_exit_policy) != ADDR_POLICY_ACCEPTED;
 +#endif /* 0 */
 +  } else {
 +    return -1;
 +  }
 +}
 +
 +/** Return true iff my exit policy is reject *:*.  Return -1 if we don't
 + * have a descriptor */
 +MOCK_IMPL(int,
 +router_my_exit_policy_is_reject_star,(void))
 +{
 +  const routerinfo_t *me = router_get_my_routerinfo();
 +  if (!me) /* make sure routerinfo exists */
 +    return -1;
 +
 +  return me->policy_is_reject_star;
 +}
 +
 +/** Return true iff I'm a server and <b>digest</b> is equal to
 + * my server identity key digest. */
 +int
 +router_digest_is_me(const char *digest)
 +{
 +  return (server_identitykey &&
 +          tor_memeq(server_identitykey_digest, digest, DIGEST_LEN));
 +}
 +
 +/** Return my identity digest. */
 +const uint8_t *
 +router_get_my_id_digest(void)
 +{
 +  return (const uint8_t *)server_identitykey_digest;
 +}
 +
 +/** Return true iff I'm a server and <b>digest</b> is equal to
 + * my identity digest. */
 +int
 +router_extrainfo_digest_is_me(const char *digest)
 +{
 +  extrainfo_t *ei = router_get_my_extrainfo();
 +  if (!ei)
 +    return 0;
 +
 +  return tor_memeq(digest,
 +                 ei->cache_info.signed_descriptor_digest,
 +                 DIGEST_LEN);
 +}
 +
 +/** A wrapper around router_digest_is_me(). */
 +int
 +router_is_me(const routerinfo_t *router)
 +{
 +  return router_digest_is_me(router->cache_info.identity_digest);
 +}
 +
 +/** Return a routerinfo for this OR, rebuilding a fresh one if
 + * necessary.  Return NULL on error, or if called on an OP. */
 +MOCK_IMPL(const routerinfo_t *,
 +router_get_my_routerinfo,(void))
 +{
 +  return router_get_my_routerinfo_with_err(NULL);
 +}
 +
 +/** Return routerinfo of this OR. Rebuild it from
 + * scratch if needed. Set <b>*err</b> to 0 on success or to
 + * appropriate TOR_ROUTERINFO_ERROR_* value on failure.
 + */
 +MOCK_IMPL(const routerinfo_t *,
 +router_get_my_routerinfo_with_err,(int *err))
 +{
 +  if (!server_mode(get_options())) {
 +    if (err)
 +      *err = TOR_ROUTERINFO_ERROR_NOT_A_SERVER;
 +
 +    return NULL;
 +  }
 +
 +  if (!desc_clean_since) {
 +    int rebuild_err = router_rebuild_descriptor(0);
 +    if (rebuild_err < 0) {
 +      if (err)
 +        *err = rebuild_err;
 +
 +      return NULL;
 +    }
 +  }
 +
 +  if (!desc_routerinfo) {
 +    if (err)
 +      *err = TOR_ROUTERINFO_ERROR_DESC_REBUILDING;
 +
 +    return NULL;
 +  }
 +
 +  if (err)
 +    *err = 0;
 +
 +  return desc_routerinfo;
 +}
 +
 +/** OR only: Return a signed server descriptor for this OR, rebuilding a fresh
 + * one if necessary.  Return NULL on error.
 + */
 +const char *
 +router_get_my_descriptor(void)
 +{
 +  const char *body;
 +  const routerinfo_t *me = router_get_my_routerinfo();
 +  if (! me)
 +    return NULL;
 +  tor_assert(me->cache_info.saved_location == SAVED_NOWHERE);
 +  body = signed_descriptor_get_body(&me->cache_info);
 +  /* Make sure this is nul-terminated. */
 +  tor_assert(!body[me->cache_info.signed_descriptor_len]);
 +  log_debug(LD_GENERAL,"my desc is '%s'", body);
 +  return body;
 +}
 +
 +/** Return the extrainfo document for this OR, or NULL if we have none.
 + * Rebuilt it (and the server descriptor) if necessary. */
 +extrainfo_t *
 +router_get_my_extrainfo(void)
 +{
 +  if (!server_mode(get_options()))
 +    return NULL;
 +  if (router_rebuild_descriptor(0))
 +    return NULL;
 +  return desc_extrainfo;
 +}
 +
 +/** Return a human-readable string describing what triggered us to generate
 + * our current descriptor, or NULL if we don't know. */
 +const char *
 +router_get_descriptor_gen_reason(void)
 +{
 +  return desc_gen_reason;
 +}
 +
 +/** A list of nicknames that we've warned about including in our family
 + * declaration verbatim rather than as digests. */
 +static smartlist_t *warned_nonexistent_family = NULL;
 +
 +static int router_guess_address_from_dir_headers(uint32_t *guess);
 +
 +/** Make a current best guess at our address, either because
 + * it's configured in torrc, or because we've learned it from
 + * dirserver headers. Place the answer in *<b>addr</b> and return
 + * 0 on success, else return -1 if we have no guess.
 + *
 + * If <b>cache_only</b> is true, just return any cached answers, and
 + * don't try to get any new answers.
 + */
 +MOCK_IMPL(int,
 +router_pick_published_address,(const or_options_t *options, uint32_t *addr,
 +                               int cache_only))
 +{
 +  /* First, check the cached output from resolve_my_address(). */
 +  *addr = get_last_resolved_addr();
 +  if (*addr)
 +    return 0;
 +
 +  /* Second, consider doing a resolve attempt right here. */
 +  if (!cache_only) {
 +    if (resolve_my_address(LOG_INFO, options, addr, NULL, NULL) >= 0) {
 +      log_info(LD_CONFIG,"Success: chose address '%s'.", fmt_addr32(*addr));
 +      return 0;
 +    }
 +  }
 +
 +  /* Third, check the cached output from router_new_address_suggestion(). */
 +  if (router_guess_address_from_dir_headers(addr) >= 0)
 +    return 0;
 +
 +  /* We have no useful cached answers. Return failure. */
 +  return -1;
 +}
 +
 +/* Like router_check_descriptor_address_consistency, but specifically for the
 + * ORPort or DirPort.
 + * listener_type is either CONN_TYPE_OR_LISTENER or CONN_TYPE_DIR_LISTENER. */
 +static void
 +router_check_descriptor_address_port_consistency(uint32_t ipv4h_desc_addr,
 +                                                 int listener_type)
 +{
 +  tor_assert(listener_type == CONN_TYPE_OR_LISTENER ||
 +             listener_type == CONN_TYPE_DIR_LISTENER);
 +
 +  /* The first advertised Port may be the magic constant CFG_AUTO_PORT.
 +   */
 +  int port_v4_cfg = get_first_advertised_port_by_type_af(listener_type,
 +                                                         AF_INET);
 +  if (port_v4_cfg != 0 &&
 +      !port_exists_by_type_addr32h_port(listener_type,
 +                                        ipv4h_desc_addr, port_v4_cfg, 1)) {
 +        const tor_addr_t *port_addr = get_first_advertised_addr_by_type_af(
 +                                                                listener_type,
 +                                                                AF_INET);
 +        /* If we're building a descriptor with no advertised address,
 +         * something is terribly wrong. */
 +        tor_assert(port_addr);
 +
 +        tor_addr_t desc_addr;
 +        char port_addr_str[TOR_ADDR_BUF_LEN];
 +        char desc_addr_str[TOR_ADDR_BUF_LEN];
 +
 +        tor_addr_to_str(port_addr_str, port_addr, TOR_ADDR_BUF_LEN, 0);
 +
 +        tor_addr_from_ipv4h(&desc_addr, ipv4h_desc_addr);
 +        tor_addr_to_str(desc_addr_str, &desc_addr, TOR_ADDR_BUF_LEN, 0);
 +
 +        const char *listener_str = (listener_type == CONN_TYPE_OR_LISTENER ?
 +                                    "OR" : "Dir");
 +        log_warn(LD_CONFIG, "The IPv4 %sPort address %s does not match the "
 +                 "descriptor address %s. If you have a static public IPv4 "
 +                 "address, use 'Address <IPv4>' and 'OutboundBindAddress "
 +                 "<IPv4>'. If you are behind a NAT, use two %sPort lines: "
 +                 "'%sPort <PublicPort> NoListen' and '%sPort <InternalPort> "
 +                 "NoAdvertise'.",
 +                 listener_str, port_addr_str, desc_addr_str, listener_str,
 +                 listener_str, listener_str);
 +      }
 +}
 +
 +/* Tor relays only have one IPv4 address in the descriptor, which is derived
 + * from the Address torrc option, or guessed using various methods in
 + * router_pick_published_address().
 + * Warn the operator if there is no ORPort on the descriptor address
 + * ipv4h_desc_addr.
 + * Warn the operator if there is no DirPort on the descriptor address.
 + * This catches a few common config errors:
 + *  - operators who expect ORPorts and DirPorts to be advertised on the
 + *    ports' listen addresses, rather than the torrc Address (or guessed
 + *    addresses in the absence of an Address config). This includes
 + *    operators who attempt to put their ORPort and DirPort on different
 + *    addresses;
 + *  - discrepancies between guessed addresses and configured listen
 + *    addresses (when the Address option isn't set).
 + * If a listener is listening on all IPv4 addresses, it is assumed that it
 + * is listening on the configured Address, and no messages are logged.
 + * If an operators has specified NoAdvertise ORPorts in a NAT setting,
 + * no messages are logged, unless they have specified other advertised
 + * addresses.
 + * The message tells operators to configure an ORPort and DirPort that match
 + * the Address (using NoListen if needed).
 + */
 +static void
 +router_check_descriptor_address_consistency(uint32_t ipv4h_desc_addr)
 +{
 +  router_check_descriptor_address_port_consistency(ipv4h_desc_addr,
 +                                                   CONN_TYPE_OR_LISTENER);
 +  router_check_descriptor_address_port_consistency(ipv4h_desc_addr,
 +                                                   CONN_TYPE_DIR_LISTENER);
 +}
 +
 +/** Build a fresh routerinfo, signed server descriptor, and extra-info document
 + * for this OR. Set r to the generated routerinfo, e to the generated
 + * extra-info document. Return 0 on success, -1 on temporary error. Failure to
 + * generate an extra-info document is not an error and is indicated by setting
 + * e to NULL. Caller is responsible for freeing generated documents if 0 is
 + * returned.
 + */
 +int
 +router_build_fresh_descriptor(routerinfo_t **r, extrainfo_t **e)
 +{
 +  routerinfo_t *ri;
 +  extrainfo_t *ei;
 +  uint32_t addr;
 +  char platform[256];
 +  int hibernating = we_are_hibernating();
 +  const or_options_t *options = get_options();
 +
 +  if (router_pick_published_address(options, &addr, 0) < 0) {
 +    log_warn(LD_CONFIG, "Don't know my address while generating descriptor");
 +    return TOR_ROUTERINFO_ERROR_NO_EXT_ADDR;
 +  }
 +
 +  /* Log a message if the address in the descriptor doesn't match the ORPort
 +   * and DirPort addresses configured by the operator. */
 +  router_check_descriptor_address_consistency(addr);
 +
 +  ri = tor_malloc_zero(sizeof(routerinfo_t));
 +  ri->cache_info.routerlist_index = -1;
 +  ri->nickname = tor_strdup(options->Nickname);
 +  ri->addr = addr;
 +  ri->or_port = router_get_advertised_or_port(options);
 +  ri->dir_port = router_get_advertised_dir_port(options, 0);
 +  ri->supports_tunnelled_dir_requests =
 +    directory_permits_begindir_requests(options);
 +  ri->cache_info.published_on = time(NULL);
 +  /* get_onion_key() must invoke from main thread */
 +  router_set_rsa_onion_pkey(get_onion_key(), &ri->onion_pkey,
 +                            &ri->onion_pkey_len);
 +
 +  ri->onion_curve25519_pkey =
 +    tor_memdup(&get_current_curve25519_keypair()->pubkey,
 +               sizeof(curve25519_public_key_t));
 +
 +  /* For now, at most one IPv6 or-address is being advertised. */
 +  {
 +    const port_cfg_t *ipv6_orport = NULL;
 +    SMARTLIST_FOREACH_BEGIN(get_configured_ports(), const port_cfg_t *, p) {
 +      if (p->type == CONN_TYPE_OR_LISTENER &&
 +          ! p->server_cfg.no_advertise &&
 +          ! p->server_cfg.bind_ipv4_only &&
 +          tor_addr_family(&p->addr) == AF_INET6) {
 +        /* Like IPv4, if the relay is configured using the default
 +         * authorities, disallow internal IPs. Otherwise, allow them. */
 +        const int default_auth = using_default_dir_authorities(options);
 +        if (! tor_addr_is_internal(&p->addr, 0) || ! default_auth) {
 +          ipv6_orport = p;
 +          break;
 +        } else {
 +          char addrbuf[TOR_ADDR_BUF_LEN];
 +          log_warn(LD_CONFIG,
 +                   "Unable to use configured IPv6 address \"%s\" in a "
 +                   "descriptor. Skipping it. "
 +                   "Try specifying a globally reachable address explicitly.",
 +                   tor_addr_to_str(addrbuf, &p->addr, sizeof(addrbuf), 1));
 +        }
 +      }
 +    } SMARTLIST_FOREACH_END(p);
 +    if (ipv6_orport) {
 +      tor_addr_copy(&ri->ipv6_addr, &ipv6_orport->addr);
 +      ri->ipv6_orport = ipv6_orport->port;
 +    }
 +  }
 +
 +  ri->identity_pkey = crypto_pk_dup_key(get_server_identity_key());
 +  if (BUG(crypto_pk_get_digest(ri->identity_pkey,
 +                           ri->cache_info.identity_digest) < 0)) {
 +    routerinfo_free(ri);
 +    return TOR_ROUTERINFO_ERROR_DIGEST_FAILED;
 +  }
 +  ri->cache_info.signing_key_cert =
 +    tor_cert_dup(get_master_signing_key_cert());
 +
 +  get_platform_str(platform, sizeof(platform));
 +  ri->platform = tor_strdup(platform);
 +
 +  ri->protocol_list = tor_strdup(protover_get_supported_protocols());
 +
 +  /* compute ri->bandwidthrate as the min of various options */
 +  ri->bandwidthrate = get_effective_bwrate(options);
 +
 +  /* and compute ri->bandwidthburst similarly */
 +  ri->bandwidthburst = get_effective_bwburst(options);
 +
 +  /* Report bandwidth, unless we're hibernating or shutting down */
 +  ri->bandwidthcapacity = hibernating ? 0 : rep_hist_bandwidth_assess();
 +
 +  if (dns_seems_to_be_broken() || has_dns_init_failed()) {
 +    /* DNS is screwed up; don't claim to be an exit. */
 +    policies_exit_policy_append_reject_star(&ri->exit_policy);
 +  } else {
 +    policies_parse_exit_policy_from_options(options,ri->addr,&ri->ipv6_addr,
 +                                            &ri->exit_policy);
 +  }
 +  ri->policy_is_reject_star =
 +    policy_is_reject_star(ri->exit_policy, AF_INET, 1) &&
 +    policy_is_reject_star(ri->exit_policy, AF_INET6, 1);
 +
 +  if (options->IPv6Exit) {
 +    char *p_tmp = policy_summarize(ri->exit_policy, AF_INET6);
 +    if (p_tmp)
 +      ri->ipv6_exit_policy = parse_short_policy(p_tmp);
 +    tor_free(p_tmp);
 +  }
 +
 +  if (options->MyFamily && ! options->BridgeRelay) {
 +    if (!warned_nonexistent_family)
 +      warned_nonexistent_family = smartlist_new();
 +    ri->declared_family = smartlist_new();
 +    config_line_t *family;
 +    for (family = options->MyFamily; family; family = family->next) {
 +       char *name = family->value;
 +       const node_t *member;
 +       if (!strcasecmp(name, options->Nickname))
 +         continue; /* Don't list ourself, that's redundant */
 +       else
 +         member = node_get_by_nickname(name, 0);
 +       if (!member) {
 +         int is_legal = is_legal_nickname_or_hexdigest(name);
 +         if (!smartlist_contains_string(warned_nonexistent_family, name) &&
 +             !is_legal_hexdigest(name)) {
 +           if (is_legal)
 +             log_warn(LD_CONFIG,
 +                      "I have no descriptor for the router named \"%s\" in my "
 +                      "declared family; I'll use the nickname as is, but "
 +                      "this may confuse clients.", name);
 +           else
 +             log_warn(LD_CONFIG, "There is a router named \"%s\" in my "
 +                      "declared family, but that isn't a legal nickname. "
 +                      "Skipping it.", escaped(name));
 +           smartlist_add_strdup(warned_nonexistent_family, name);
 +         }
 +         if (is_legal) {
 +           smartlist_add_strdup(ri->declared_family, name);
 +         }
 +       } else if (router_digest_is_me(member->identity)) {
 +         /* Don't list ourself in our own family; that's redundant */
 +         /* XXX shouldn't be possible */
 +       } else {
 +         char *fp = tor_malloc(HEX_DIGEST_LEN+2);
 +         fp[0] = '$';
 +         base16_encode(fp+1,HEX_DIGEST_LEN+1,
 +                       member->identity, DIGEST_LEN);
 +         smartlist_add(ri->declared_family, fp);
 +         if (smartlist_contains_string(warned_nonexistent_family, name))
 +           smartlist_string_remove(warned_nonexistent_family, name);
 +       }
 +    }
 +
 +    /* remove duplicates from the list */
 +    smartlist_sort_strings(ri->declared_family);
 +    smartlist_uniq_strings(ri->declared_family);
 +  }
 +
 +  /* Now generate the extrainfo. */
 +  ei = tor_malloc_zero(sizeof(extrainfo_t));
 +  ei->cache_info.is_extrainfo = 1;
 +  strlcpy(ei->nickname, get_options()->Nickname, sizeof(ei->nickname));
 +  ei->cache_info.published_on = ri->cache_info.published_on;
 +  ei->cache_info.signing_key_cert =
 +    tor_cert_dup(get_master_signing_key_cert());
 +
 +  memcpy(ei->cache_info.identity_digest, ri->cache_info.identity_digest,
 +         DIGEST_LEN);
 +  if (extrainfo_dump_to_string(&ei->cache_info.signed_descriptor_body,
 +                               ei, get_server_identity_key(),
 +                               get_master_signing_keypair()) < 0) {
 +    log_warn(LD_BUG, "Couldn't generate extra-info descriptor.");
 +    extrainfo_free(ei);
 +    ei = NULL;
 +  } else {
 +    ei->cache_info.signed_descriptor_len =
 +      strlen(ei->cache_info.signed_descriptor_body);
 +    router_get_extrainfo_hash(ei->cache_info.signed_descriptor_body,
 +                              ei->cache_info.signed_descriptor_len,
 +                              ei->cache_info.signed_descriptor_digest);
 +    crypto_digest256((char*) ei->digest256,
 +                     ei->cache_info.signed_descriptor_body,
 +                     ei->cache_info.signed_descriptor_len,
 +                     DIGEST_SHA256);
 +  }
 +
 +  /* Now finish the router descriptor. */
 +  if (ei) {
 +    memcpy(ri->cache_info.extra_info_digest,
 +           ei->cache_info.signed_descriptor_digest,
 +           DIGEST_LEN);
 +    memcpy(ri->cache_info.extra_info_digest256,
 +           ei->digest256,
 +           DIGEST256_LEN);
 +  } else {
 +    /* ri was allocated with tor_malloc_zero, so there is no need to
 +     * zero ri->cache_info.extra_info_digest here. */
 +  }
 +  if (! (ri->cache_info.signed_descriptor_body =
 +          router_dump_router_to_string(ri, get_server_identity_key(),
 +                                       get_onion_key(),
 +                                       get_current_curve25519_keypair(),
 +                                       get_master_signing_keypair())) ) {
 +    log_warn(LD_BUG, "Couldn't generate router descriptor.");
 +    routerinfo_free(ri);
 +    extrainfo_free(ei);
 +    return TOR_ROUTERINFO_ERROR_CANNOT_GENERATE;
 +  }
 +  ri->cache_info.signed_descriptor_len =
 +    strlen(ri->cache_info.signed_descriptor_body);
 +
 +  ri->purpose =
 +    options->BridgeRelay ? ROUTER_PURPOSE_BRIDGE : ROUTER_PURPOSE_GENERAL;
 +  if (options->BridgeRelay) {
 +    /* Bridges shouldn't be able to send their descriptors unencrypted,
 +       anyway, since they don't have a DirPort, and always connect to the
 +       bridge authority anonymously.  But just in case they somehow think of
 +       sending them on an unencrypted connection, don't allow them to try. */
 +    ri->cache_info.send_unencrypted = 0;
 +    if (ei)
 +      ei->cache_info.send_unencrypted = 0;
 +  } else {
 +    ri->cache_info.send_unencrypted = 1;
 +    if (ei)
 +      ei->cache_info.send_unencrypted = 1;
 +  }
 +
 +  router_get_router_hash(ri->cache_info.signed_descriptor_body,
 +                         strlen(ri->cache_info.signed_descriptor_body),
 +                         ri->cache_info.signed_descriptor_digest);
 +
 +  if (ei) {
 +    tor_assert(!
 +          routerinfo_incompatible_with_extrainfo(ri->identity_pkey, ei,
 +                                                 &ri->cache_info, NULL));
 +  }
 +
 +  *r = ri;
 +  *e = ei;
 +  return 0;
 +}
 +
 +/** If <b>force</b> is true, or our descriptor is out-of-date, rebuild a fresh
 + * routerinfo, signed server descriptor, and extra-info document for this OR.
 + * Return 0 on success, -1 on temporary error.
 + */
 +int
 +router_rebuild_descriptor(int force)
 +{
 +  int err = 0;
 +  routerinfo_t *ri;
 +  extrainfo_t *ei;
 +  uint32_t addr;
 +  const or_options_t *options = get_options();
 +
 +  if (desc_clean_since && !force)
 +    return 0;
 +
 +  if (router_pick_published_address(options, &addr, 0) < 0 ||
 +      router_get_advertised_or_port(options) == 0) {
 +    /* Stop trying to rebuild our descriptor every second. We'll
 +     * learn that it's time to try again when ip_address_changed()
 +     * marks it dirty. */
 +    desc_clean_since = time(NULL);
 +    return TOR_ROUTERINFO_ERROR_DESC_REBUILDING;
 +  }
 +
 +  log_info(LD_OR, "Rebuilding relay descriptor%s", force ? " (forced)" : "");
 +
 +  err = router_build_fresh_descriptor(&ri, &ei);
 +  if (err < 0) {
 +    return err;
 +  }
 +
 +  routerinfo_free(desc_routerinfo);
 +  desc_routerinfo = ri;
 +  extrainfo_free(desc_extrainfo);
 +  desc_extrainfo = ei;
 +
 +  desc_clean_since = time(NULL);
 +  desc_needs_upload = 1;
 +  desc_gen_reason = desc_dirty_reason;
 +  if (BUG(desc_gen_reason == NULL)) {
 +    desc_gen_reason = "descriptor was marked dirty earlier, for no reason.";
 +  }
 +  desc_dirty_reason = NULL;
 +  control_event_my_descriptor_changed();
 +  return 0;
 +}
 +
 +/** If our router descriptor ever goes this long without being regenerated
 + * because something changed, we force an immediate regenerate-and-upload. */
 +#define FORCE_REGENERATE_DESCRIPTOR_INTERVAL (18*60*60)
 +
 +/** If our router descriptor seems to be missing or unacceptable according
 + * to the authorities, regenerate and reupload it _this_ often. */
 +#define FAST_RETRY_DESCRIPTOR_INTERVAL (90*60)
 +
 +/** Mark descriptor out of date if it's been "too long" since we last tried
 + * to upload one. */
 +void
 +mark_my_descriptor_dirty_if_too_old(time_t now)
 +{
 +  networkstatus_t *ns;
 +  const routerstatus_t *rs;
 +  const char *retry_fast_reason = NULL; /* Set if we should retry frequently */
 +  const time_t slow_cutoff = now - FORCE_REGENERATE_DESCRIPTOR_INTERVAL;
 +  const time_t fast_cutoff = now - FAST_RETRY_DESCRIPTOR_INTERVAL;
 +
 +  /* If it's already dirty, don't mark it. */
 +  if (! desc_clean_since)
 +    return;
 +
 +  /* If it's older than FORCE_REGENERATE_DESCRIPTOR_INTERVAL, it's always
 +   * time to rebuild it. */
 +  if (desc_clean_since < slow_cutoff) {
 +    mark_my_descriptor_dirty("time for new descriptor");
 +    return;
 +  }
 +  /* Now we see whether we want to be retrying frequently or no.  The
 +   * rule here is that we'll retry frequently if we aren't listed in the
 +   * live consensus we have, or if the publication time of the
 +   * descriptor listed for us in the consensus is very old. */
 +  ns = networkstatus_get_live_consensus(now);
 +  if (ns) {
 +    rs = networkstatus_vote_find_entry(ns, server_identitykey_digest);
 +    if (rs == NULL)
 +      retry_fast_reason = "not listed in consensus";
 +    else if (rs->published_on < slow_cutoff)
 +      retry_fast_reason = "version listed in consensus is quite old";
 +  }
 +
 +  if (retry_fast_reason && desc_clean_since < fast_cutoff)
 +    mark_my_descriptor_dirty(retry_fast_reason);
 +}
 +
 +/** Call when the current descriptor is out of date. */
 +void
 +mark_my_descriptor_dirty(const char *reason)
 +{
 +  const or_options_t *options = get_options();
 +  if (BUG(reason == NULL)) {
 +    reason = "marked descriptor dirty for unspecified reason";
 +  }
 +  if (server_mode(options) && options->PublishServerDescriptor_)
 +    log_info(LD_OR, "Decided to publish new relay descriptor: %s", reason);
 +  desc_clean_since = 0;
 +  if (!desc_dirty_reason)
 +    desc_dirty_reason = reason;
 +}
 +
 +/** How frequently will we republish our descriptor because of large (factor
 + * of 2) shifts in estimated bandwidth? Note: We don't use this constant
 + * if our previous bandwidth estimate was exactly 0. */
 +#define MAX_BANDWIDTH_CHANGE_FREQ (3*60*60)
 +
 +/** Maximum uptime to republish our descriptor because of large shifts in
 + * estimated bandwidth. */
 +#define MAX_UPTIME_BANDWIDTH_CHANGE (24*60*60)
 +
 +/** By which factor bandwidth shifts have to change to be considered large. */
 +#define BANDWIDTH_CHANGE_FACTOR 2
 +
 +/** Check whether bandwidth has changed a lot since the last time we announced
 + * bandwidth while the uptime is smaller than MAX_UPTIME_BANDWIDTH_CHANGE.
 + * If so, mark our descriptor dirty. */
 +void
 +check_descriptor_bandwidth_changed(time_t now)
 +{
 +  static time_t last_changed = 0;
 +  uint64_t prev, cur;
 +  const int hibernating = we_are_hibernating();
 +
 +  /* If the relay uptime is bigger than MAX_UPTIME_BANDWIDTH_CHANGE,
 +   * the next regularly scheduled descriptor update (18h) will be enough */
 +  if (get_uptime() > MAX_UPTIME_BANDWIDTH_CHANGE && !hibernating)
 +    return;
 +
 +  const routerinfo_t *my_ri = router_get_my_routerinfo();
 +
 +  if (!my_ri)
 +    return;
 +
 +  prev = my_ri->bandwidthcapacity;
 +
 +  /* Consider ourselves to have zero bandwidth if we're hibernating or
 +   * shutting down. */
 +  cur = hibernating ? 0 : rep_hist_bandwidth_assess();
 +
 +  if ((prev != cur && (!prev || !cur)) ||
 +      cur > (prev * BANDWIDTH_CHANGE_FACTOR) ||
 +      cur < (prev / BANDWIDTH_CHANGE_FACTOR) ) {
 +    if (last_changed+MAX_BANDWIDTH_CHANGE_FREQ < now || !prev) {
 +      log_info(LD_GENERAL,
 +               "Measured bandwidth has changed; rebuilding descriptor.");
 +      mark_my_descriptor_dirty("bandwidth has changed");
 +      last_changed = now;
 +    }
 +  }
 +}
 +
 +/** Note at log level severity that our best guess of address has changed from
 + * <b>prev</b> to <b>cur</b>. */
 +static void
 +log_addr_has_changed(int severity,
 +                     const tor_addr_t *prev,
 +                     const tor_addr_t *cur,
 +                     const char *source)
 +{
 +  char addrbuf_prev[TOR_ADDR_BUF_LEN];
 +  char addrbuf_cur[TOR_ADDR_BUF_LEN];
 +
 +  if (BUG(!server_mode(get_options())))
 +    return;
 +
 +  if (tor_addr_to_str(addrbuf_prev, prev, sizeof(addrbuf_prev), 1) == NULL)
 +    strlcpy(addrbuf_prev, "???", TOR_ADDR_BUF_LEN);
 +  if (tor_addr_to_str(addrbuf_cur, cur, sizeof(addrbuf_cur), 1) == NULL)
 +    strlcpy(addrbuf_cur, "???", TOR_ADDR_BUF_LEN);
 +
 +  if (!tor_addr_is_null(prev))
 +    log_fn(severity, LD_GENERAL,
 +           "Our IP Address has changed from %s to %s; "
 +           "rebuilding descriptor (source: %s).",
 +           addrbuf_prev, addrbuf_cur, source);
 +  else
 +    log_notice(LD_GENERAL,
 +             "Guessed our IP address as %s (source: %s).",
 +             addrbuf_cur, source);
 +}
 +
 +/** Check whether our own address as defined by the Address configuration
 + * has changed. This is for routers that get their address from a service
 + * like dyndns. If our address has changed, mark our descriptor dirty. */
 +void
 +check_descriptor_ipaddress_changed(time_t now)
 +{
 +  uint32_t prev, cur;
 +  const or_options_t *options = get_options();
 +  const char *method = NULL;
 +  char *hostname = NULL;
 +  const routerinfo_t *my_ri = router_get_my_routerinfo();
 +
 +  (void) now;
 +
 +  if (my_ri == NULL) /* make sure routerinfo exists */
 +    return;
 +
 +  /* XXXX ipv6 */
 +  prev = my_ri->addr;
 +  if (resolve_my_address(LOG_INFO, options, &cur, &method, &hostname) < 0) {
 +    log_info(LD_CONFIG,"options->Address didn't resolve into an IP.");
 +    return;
 +  }
 +
 +  if (prev != cur) {
 +    char *source;
 +    tor_addr_t tmp_prev, tmp_cur;
 +
 +    tor_addr_from_ipv4h(&tmp_prev, prev);
 +    tor_addr_from_ipv4h(&tmp_cur, cur);
 +
 +    tor_asprintf(&source, "METHOD=%s%s%s", method,
 +                 hostname ? " HOSTNAME=" : "",
 +                 hostname ? hostname : "");
 +
 +    log_addr_has_changed(LOG_NOTICE, &tmp_prev, &tmp_cur, source);
 +    tor_free(source);
 +
 +    ip_address_changed(0);
 +  }
 +
 +  tor_free(hostname);
 +}
 +
 +/** The most recently guessed value of our IP address, based on directory
 + * headers. */
 +static tor_addr_t last_guessed_ip = TOR_ADDR_NULL;
 +
 +/** A directory server <b>d_conn</b> told us our IP address is
 + * <b>suggestion</b>.
 + * If this address is different from the one we think we are now, and
 + * if our computer doesn't actually know its IP address, then switch. */
 +void
 +router_new_address_suggestion(const char *suggestion,
 +                              const dir_connection_t *d_conn)
 +{
 +  tor_addr_t addr;
 +  uint32_t cur = 0;             /* Current IPv4 address.  */
 +  const or_options_t *options = get_options();
 +
 +  /* first, learn what the IP address actually is */
 +  if (tor_addr_parse(&addr, suggestion) == -1) {
 +    log_debug(LD_DIR, "Malformed X-Your-Address-Is header %s. Ignoring.",
 +              escaped(suggestion));
 +    return;
 +  }
 +
 +  log_debug(LD_DIR, "Got X-Your-Address-Is: %s.", suggestion);
 +
 +  if (!server_mode(options)) {
 +    tor_addr_copy(&last_guessed_ip, &addr);
 +    return;
 +  }
 +
 +  /* XXXX ipv6 */
 +  cur = get_last_resolved_addr();
 +  if (cur ||
 +      resolve_my_address(LOG_INFO, options, &cur, NULL, NULL) >= 0) {
 +    /* We're all set -- we already know our address. Great. */
 +    tor_addr_from_ipv4h(&last_guessed_ip, cur); /* store it in case we
 +                                                   need it later */
 +    return;
 +  }
 +  if (tor_addr_is_internal(&addr, 0)) {
 +    /* Don't believe anybody who says our IP is, say, 127.0.0.1. */
 +    return;
 +  }
 +  if (tor_addr_eq(&d_conn->base_.addr, &addr)) {
 +    /* Don't believe anybody who says our IP is their IP. */
 +    log_debug(LD_DIR, "A directory server told us our IP address is %s, "
 +              "but they are just reporting their own IP address. Ignoring.",
 +              suggestion);
 +    return;
 +  }
 +
 +  /* Okay.  We can't resolve our own address, and X-Your-Address-Is is giving
 +   * us an answer different from what we had the last time we managed to
 +   * resolve it. */
 +  if (!tor_addr_eq(&last_guessed_ip, &addr)) {
 +    control_event_server_status(LOG_NOTICE,
 +                                "EXTERNAL_ADDRESS ADDRESS=%s METHOD=DIRSERV",
 +                                suggestion);
 +    log_addr_has_changed(LOG_NOTICE, &last_guessed_ip, &addr,
 +                         d_conn->base_.address);
 +    ip_address_changed(0);
 +    tor_addr_copy(&last_guessed_ip, &addr); /* router_rebuild_descriptor()
 +                                               will fetch it */
 +  }
 +}
 +
 +/** We failed to resolve our address locally, but we'd like to build
 + * a descriptor and publish / test reachability. If we have a guess
 + * about our address based on directory headers, answer it and return
 + * 0; else return -1. */
 +static int
 +router_guess_address_from_dir_headers(uint32_t *guess)
 +{
 +  if (!tor_addr_is_null(&last_guessed_ip)) {
 +    *guess = tor_addr_to_ipv4h(&last_guessed_ip);
 +    return 0;
 +  }
 +  return -1;
 +}
 +
 +/** Set <b>platform</b> (max length <b>len</b>) to a NUL-terminated short
 + * string describing the version of Tor and the operating system we're
 + * currently running on.
 + */
 +STATIC void
 +get_platform_str(char *platform, size_t len)
 +{
 +  tor_snprintf(platform, len, "Tor %s on %s",
 +               get_short_version(), get_uname());
 +}
 +
 +/* XXX need to audit this thing and count fenceposts. maybe
 + *     refactor so we don't have to keep asking if we're
 + *     near the end of maxlen?
 + */
 +#define DEBUG_ROUTER_DUMP_ROUTER_TO_STRING
 +
 +/** OR only: Given a routerinfo for this router, and an identity key to sign
 + * with, encode the routerinfo as a signed server descriptor and return a new
 + * string encoding the result, or NULL on failure.
 + */
 +char *
 +router_dump_router_to_string(routerinfo_t *router,
 +                             const crypto_pk_t *ident_key,
 +                             const crypto_pk_t *tap_key,
 +                             const curve25519_keypair_t *ntor_keypair,
 +                             const ed25519_keypair_t *signing_keypair)
 +{
 +  char *address = NULL;
 +  char *onion_pkey = NULL; /* Onion key, PEM-encoded. */
 +  crypto_pk_t *rsa_pubkey = NULL;
 +  char *identity_pkey = NULL; /* Identity key, PEM-encoded. */
 +  char digest[DIGEST256_LEN];
 +  char published[ISO_TIME_LEN+1];
 +  char fingerprint[FINGERPRINT_LEN+1];
 +  char *extra_info_line = NULL;
 +  size_t onion_pkeylen, identity_pkeylen;
 +  char *family_line = NULL;
 +  char *extra_or_address = NULL;
 +  const or_options_t *options = get_options();
 +  smartlist_t *chunks = NULL;
 +  char *output = NULL;
 +  const int emit_ed_sigs = signing_keypair &&
 +    router->cache_info.signing_key_cert;
 +  char *ed_cert_line = NULL;
 +  char *rsa_tap_cc_line = NULL;
 +  char *ntor_cc_line = NULL;
 +  char *proto_line = NULL;
 +
 +  /* Make sure the identity key matches the one in the routerinfo. */
 +  if (!crypto_pk_eq_keys(ident_key, router->identity_pkey)) {
 +    log_warn(LD_BUG,"Tried to sign a router with a private key that didn't "
 +             "match router's public key!");
 +    goto err;
 +  }
 +  if (emit_ed_sigs) {
 +    if (!router->cache_info.signing_key_cert->signing_key_included ||
 +        !ed25519_pubkey_eq(&router->cache_info.signing_key_cert->signed_key,
 +                           &signing_keypair->pubkey)) {
 +      log_warn(LD_BUG, "Tried to sign a router descriptor with a mismatched "
 +               "ed25519 key chain %d",
 +               router->cache_info.signing_key_cert->signing_key_included);
 +      goto err;
 +    }
 +  }
 +
 +  /* record our fingerprint, so we can include it in the descriptor */
 +  if (crypto_pk_get_fingerprint(router->identity_pkey, fingerprint, 1)<0) {
 +    log_err(LD_BUG,"Error computing fingerprint");
 +    goto err;
 +  }
 +
 +  if (emit_ed_sigs) {
 +    /* Encode ed25519 signing cert */
 +    char ed_cert_base64[256];
 +    char ed_fp_base64[ED25519_BASE64_LEN+1];
 +    if (base64_encode(ed_cert_base64, sizeof(ed_cert_base64),
 +                    (const char*)router->cache_info.signing_key_cert->encoded,
 +                    router->cache_info.signing_key_cert->encoded_len,
 +                    BASE64_ENCODE_MULTILINE) < 0) {
 +      log_err(LD_BUG,"Couldn't base64-encode signing key certificate!");
 +      goto err;
 +    }
 +    if (ed25519_public_to_base64(ed_fp_base64,
 +                       &router->cache_info.signing_key_cert->signing_key)<0) {
 +      log_err(LD_BUG,"Couldn't base64-encode identity key\n");
 +      goto err;
 +    }
 +    tor_asprintf(&ed_cert_line, "identity-ed25519\n"
 +                 "-----BEGIN ED25519 CERT-----\n"
 +                 "%s"
 +                 "-----END ED25519 CERT-----\n"
 +                 "master-key-ed25519 %s\n",
 +                 ed_cert_base64, ed_fp_base64);
 +  }
 +
 +  /* PEM-encode the onion key */
 +  rsa_pubkey = router_get_rsa_onion_pkey(router->onion_pkey,
 +                                         router->onion_pkey_len);
 +  if (crypto_pk_write_public_key_to_string(rsa_pubkey,
 +                                           &onion_pkey,&onion_pkeylen)<0) {
 +    log_warn(LD_BUG,"write onion_pkey to string failed!");
 +    goto err;
 +  }
 +
 +  /* PEM-encode the identity key */
 +  if (crypto_pk_write_public_key_to_string(router->identity_pkey,
 +                                        &identity_pkey,&identity_pkeylen)<0) {
 +    log_warn(LD_BUG,"write identity_pkey to string failed!");
 +    goto err;
 +  }
 +
 +  /* Cross-certify with RSA key */
 +  if (tap_key && router->cache_info.signing_key_cert &&
 +      router->cache_info.signing_key_cert->signing_key_included) {
 +    char buf[256];
 +    int tap_cc_len = 0;
 +    uint8_t *tap_cc =
 +      make_tap_onion_key_crosscert(tap_key,
 +                            &router->cache_info.signing_key_cert->signing_key,
 +                            router->identity_pkey,
 +                            &tap_cc_len);
 +    if (!tap_cc) {
 +      log_warn(LD_BUG,"make_tap_onion_key_crosscert failed!");
 +      goto err;
 +    }
 +
 +    if (base64_encode(buf, sizeof(buf), (const char*)tap_cc, tap_cc_len,
 +                      BASE64_ENCODE_MULTILINE) < 0) {
 +      log_warn(LD_BUG,"base64_encode(rsa_crosscert) failed!");
 +      tor_free(tap_cc);
 +      goto err;
 +    }
 +    tor_free(tap_cc);
 +
 +    tor_asprintf(&rsa_tap_cc_line,
 +                 "onion-key-crosscert\n"
 +                 "-----BEGIN CROSSCERT-----\n"
 +                 "%s"
 +                 "-----END CROSSCERT-----\n", buf);
 +  }
 +
 +  /* Cross-certify with onion keys */
 +  if (ntor_keypair && router->cache_info.signing_key_cert &&
 +      router->cache_info.signing_key_cert->signing_key_included) {
 +    int sign = 0;
 +    char buf[256];
 +    /* XXXX Base the expiration date on the actual onion key expiration time?*/
 +    tor_cert_t *cert =
 +      make_ntor_onion_key_crosscert(ntor_keypair,
 +                         &router->cache_info.signing_key_cert->signing_key,
 +                         router->cache_info.published_on,
 +                         get_onion_key_lifetime(), &sign);
 +    if (!cert) {
 +      log_warn(LD_BUG,"make_ntor_onion_key_crosscert failed!");
 +      goto err;
 +    }
 +    tor_assert(sign == 0 || sign == 1);
 +
 +    if (base64_encode(buf, sizeof(buf),
 +                      (const char*)cert->encoded, cert->encoded_len,
 +                      BASE64_ENCODE_MULTILINE)<0) {
 +      log_warn(LD_BUG,"base64_encode(ntor_crosscert) failed!");
 +      tor_cert_free(cert);
 +      goto err;
 +    }
 +    tor_cert_free(cert);
 +
 +    tor_asprintf(&ntor_cc_line,
 +                 "ntor-onion-key-crosscert %d\n"
 +                 "-----BEGIN ED25519 CERT-----\n"
 +                 "%s"
 +                 "-----END ED25519 CERT-----\n", sign, buf);
 +  }
 +
 +  /* Encode the publication time. */
 +  format_iso_time(published, router->cache_info.published_on);
 +
 +  if (router->declared_family && smartlist_len(router->declared_family)) {
 +    char *family = smartlist_join_strings(router->declared_family,
 +                                          " ", 0, NULL);
 +    tor_asprintf(&family_line, "family %s\n", family);
 +    tor_free(family);
 +  } else {
 +    family_line = tor_strdup("");
 +  }
 +
 +  if (!tor_digest_is_zero(router->cache_info.extra_info_digest)) {
 +    char extra_info_digest[HEX_DIGEST_LEN+1];
 +    base16_encode(extra_info_digest, sizeof(extra_info_digest),
 +                  router->cache_info.extra_info_digest, DIGEST_LEN);
 +    if (!tor_digest256_is_zero(router->cache_info.extra_info_digest256)) {
 +      char d256_64[BASE64_DIGEST256_LEN+1];
 +      digest256_to_base64(d256_64, router->cache_info.extra_info_digest256);
 +      tor_asprintf(&extra_info_line, "extra-info-digest %s %s\n",
 +                   extra_info_digest, d256_64);
 +    } else {
 +      tor_asprintf(&extra_info_line, "extra-info-digest %s\n",
 +                   extra_info_digest);
 +    }
 +  }
 +
 +  if (router->ipv6_orport &&
 +      tor_addr_family(&router->ipv6_addr) == AF_INET6) {
 +    char addr[TOR_ADDR_BUF_LEN];
 +    const char *a;
 +    a = tor_addr_to_str(addr, &router->ipv6_addr, sizeof(addr), 1);
 +    if (a) {
 +      tor_asprintf(&extra_or_address,
 +                   "or-address %s:%d\n", a, router->ipv6_orport);
 +      log_debug(LD_OR, "My or-address line is <%s>", extra_or_address);
 +    }
 +  }
 +
 +  if (router->protocol_list) {
 +    tor_asprintf(&proto_line, "proto %s\n", router->protocol_list);
 +  } else {
 +    proto_line = tor_strdup("");
 +  }
 +
 +  address = tor_dup_ip(router->addr);
 +  chunks = smartlist_new();
 +
 +  /* Generate the easy portion of the router descriptor. */
 +  smartlist_add_asprintf(chunks,
 +                    "router %s %s %d 0 %d\n"
 +                    "%s"
 +                    "%s"
 +                    "platform %s\n"
 +                    "%s"
 +                    "published %s\n"
 +                    "fingerprint %s\n"
 +                    "uptime %ld\n"
 +                    "bandwidth %d %d %d\n"
 +                    "%s%s"
 +                    "onion-key\n%s"
 +                    "signing-key\n%s"
 +                    "%s%s"
 +                    "%s%s%s",
 +    router->nickname,
 +    address,
 +    router->or_port,
 +    router_should_advertise_dirport(options, router->dir_port),
 +    ed_cert_line ? ed_cert_line : "",
 +    extra_or_address ? extra_or_address : "",
 +    router->platform,
 +    proto_line,
 +    published,
 +    fingerprint,
 +    get_uptime(),
 +    (int) router->bandwidthrate,
 +    (int) router->bandwidthburst,
 +    (int) router->bandwidthcapacity,
 +    extra_info_line ? extra_info_line : "",
 +    (options->DownloadExtraInfo || options->V3AuthoritativeDir) ?
 +                         "caches-extra-info\n" : "",
 +    onion_pkey, identity_pkey,
 +    rsa_tap_cc_line ? rsa_tap_cc_line : "",
 +    ntor_cc_line ? ntor_cc_line : "",
 +    family_line,
 +    we_are_hibernating() ? "hibernating 1\n" : "",
 +    "hidden-service-dir\n");
 +
 +  if (options->ContactInfo && strlen(options->ContactInfo)) {
 +    const char *ci = options->ContactInfo;
 +    if (strchr(ci, '\n') || strchr(ci, '\r'))
 +      ci = escaped(ci);
 +    smartlist_add_asprintf(chunks, "contact %s\n", ci);
 +  }
 +
 +  if (options->BridgeRelay) {
 +    const char *bd;
 +    if (options->BridgeDistribution && strlen(options->BridgeDistribution)) {
 +      bd = options->BridgeDistribution;
 +    } else {
 +      bd = "any";
 +    }
 +    if (strchr(bd, '\n') || strchr(bd, '\r'))
 +      bd = escaped(bd);
 +    smartlist_add_asprintf(chunks, "bridge-distribution-request %s\n", bd);
 +  }
 +
 +  if (router->onion_curve25519_pkey) {
 +    char kbuf[128];
 +    base64_encode(kbuf, sizeof(kbuf),
 +                  (const char *)router->onion_curve25519_pkey->public_key,
 +                  CURVE25519_PUBKEY_LEN, BASE64_ENCODE_MULTILINE);
 +    smartlist_add_asprintf(chunks, "ntor-onion-key %s", kbuf);
 +  } else {
 +    /* Authorities will start rejecting relays without ntor keys in 0.2.9 */
 +    log_err(LD_BUG, "A relay must have an ntor onion key");
 +    goto err;
 +  }
 +
 +  /* Write the exit policy to the end of 's'. */
 +  if (!router->exit_policy || !smartlist_len(router->exit_policy)) {
 +    smartlist_add_strdup(chunks, "reject *:*\n");
 +  } else if (router->exit_policy) {
 +    char *exit_policy = router_dump_exit_policy_to_string(router,1,0);
 +
 +    if (!exit_policy)
 +      goto err;
 +
 +    smartlist_add_asprintf(chunks, "%s\n", exit_policy);
 +    tor_free(exit_policy);
 +  }
 +
 +  if (router->ipv6_exit_policy) {
 +    char *p6 = write_short_policy(router->ipv6_exit_policy);
 +    if (p6 && strcmp(p6, "reject 1-65535")) {
 +      smartlist_add_asprintf(chunks,
 +                            "ipv6-policy %s\n", p6);
 +    }
 +    tor_free(p6);
 +  }
 +
 +  if (router_should_advertise_begindir(options,
 +                                   router->supports_tunnelled_dir_requests)) {
 +    smartlist_add_strdup(chunks, "tunnelled-dir-server\n");
 +  }
 +
 +  /* Sign the descriptor with Ed25519 */
 +  if (emit_ed_sigs)  {
 +    smartlist_add_strdup(chunks, "router-sig-ed25519 ");
 +    crypto_digest_smartlist_prefix(digest, DIGEST256_LEN,
 +                                   ED_DESC_SIGNATURE_PREFIX,
 +                                   chunks, "", DIGEST_SHA256);
 +    ed25519_signature_t sig;
 +    char buf[ED25519_SIG_BASE64_LEN+1];
 +    if (ed25519_sign(&sig, (const uint8_t*)digest, DIGEST256_LEN,
 +                     signing_keypair) < 0)
 +      goto err;
 +    if (ed25519_signature_to_base64(buf, &sig) < 0)
 +      goto err;
 +
 +    smartlist_add_asprintf(chunks, "%s\n", buf);
 +  }
 +
 +  /* Sign the descriptor with RSA */
 +  smartlist_add_strdup(chunks, "router-signature\n");
 +
 +  crypto_digest_smartlist(digest, DIGEST_LEN, chunks, "", DIGEST_SHA1);
 +
 +  {
 +    char *sig;
 +    if (!(sig = router_get_dirobj_signature(digest, DIGEST_LEN, ident_key))) {
 +      log_warn(LD_BUG, "Couldn't sign router descriptor");
 +      goto err;
 +    }
 +    smartlist_add(chunks, sig);
 +  }
 +
 +  /* include a last '\n' */
 +  smartlist_add_strdup(chunks, "\n");
 +
 +  output = smartlist_join_strings(chunks, "", 0, NULL);
 +
 +#ifdef DEBUG_ROUTER_DUMP_ROUTER_TO_STRING
 +  {
 +    char *s_dup;
 +    const char *cp;
 +    routerinfo_t *ri_tmp;
 +    cp = s_dup = tor_strdup(output);
 +    ri_tmp = router_parse_entry_from_string(cp, NULL, 1, 0, NULL, NULL);
 +    if (!ri_tmp) {
 +      log_err(LD_BUG,
 +              "We just generated a router descriptor we can't parse.");
 +      log_err(LD_BUG, "Descriptor was: <<%s>>", output);
 +      goto err;
 +    }
 +    tor_free(s_dup);
 +    routerinfo_free(ri_tmp);
 +  }
 +#endif /* defined(DEBUG_ROUTER_DUMP_ROUTER_TO_STRING) */
 +
 +  goto done;
 +
 + err:
 +  tor_free(output); /* sets output to NULL */
 + done:
 +  if (chunks) {
 +    SMARTLIST_FOREACH(chunks, char *, cp, tor_free(cp));
 +    smartlist_free(chunks);
 +  }
 +  crypto_pk_free(rsa_pubkey);
 +  tor_free(address);
 +  tor_free(family_line);
 +  tor_free(onion_pkey);
 +  tor_free(identity_pkey);
 +  tor_free(extra_or_address);
 +  tor_free(ed_cert_line);
 +  tor_free(rsa_tap_cc_line);
 +  tor_free(ntor_cc_line);
 +  tor_free(extra_info_line);
 +  tor_free(proto_line);
 +
 +  return output;
 +}
 +
 +/**
 + * OR only: Given <b>router</b>, produce a string with its exit policy.
 + * If <b>include_ipv4</b> is true, include IPv4 entries.
 + * If <b>include_ipv6</b> is true, include IPv6 entries.
 + */
 +char *
 +router_dump_exit_policy_to_string(const routerinfo_t *router,
 +                                  int include_ipv4,
 +                                  int include_ipv6)
 +{
 +  if ((!router->exit_policy) || (router->policy_is_reject_star)) {
 +    return tor_strdup("reject *:*");
 +  }
 +
 +  return policy_dump_to_string(router->exit_policy,
 +                               include_ipv4,
 +                               include_ipv6);
 +}
 +
 +/** Load the contents of <b>filename</b>, find the last line starting with
 + * <b>end_line</b>, ensure that its timestamp is not more than 25 hours in
 + * the past or more than 1 hour in the future with respect to <b>now</b>,
 + * and write the file contents starting with that line to *<b>out</b>.
 + * Return 1 for success, 0 if the file does not exist or is empty, or -1
 + * if the file does not contain a line matching these criteria or other
 + * failure. */
 +static int
 +load_stats_file(const char *filename, const char *end_line, time_t now,
 +                char **out)
 +{
 +  int r = -1;
 +  char *fname = get_datadir_fname(filename);
 +  char *contents, *start = NULL, *tmp, timestr[ISO_TIME_LEN+1];
 +  time_t written;
 +  switch (file_status(fname)) {
 +    case FN_FILE:
 +      /* X022 Find an alternative to reading the whole file to memory. */
 +      if ((contents = read_file_to_str(fname, 0, NULL))) {
 +        tmp = strstr(contents, end_line);
 +        /* Find last block starting with end_line */
 +        while (tmp) {
 +          start = tmp;
 +          tmp = strstr(tmp + 1, end_line);
 +        }
 +        if (!start)
 +          goto notfound;
 +        if (strlen(start) < strlen(end_line) + 1 + sizeof(timestr))
 +          goto notfound;
 +        strlcpy(timestr, start + 1 + strlen(end_line), sizeof(timestr));
 +        if (parse_iso_time(timestr, &written) < 0)
 +          goto notfound;
 +        if (written < now - (25*60*60) || written > now + (1*60*60))
 +          goto notfound;
 +        *out = tor_strdup(start);
 +        r = 1;
 +      }
 +     notfound:
 +      tor_free(contents);
 +      break;
 +    /* treat empty stats files as if the file doesn't exist */
 +    case FN_NOENT:
 +    case FN_EMPTY:
 +      r = 0;
 +      break;
 +    case FN_ERROR:
 +    case FN_DIR:
 +    default:
 +      break;
 +  }
 +  tor_free(fname);
 +  return r;
 +}
 +
 +/** Write the contents of <b>extrainfo</b> and aggregated statistics to
 + * *<b>s_out</b>, signing them with <b>ident_key</b>. Return 0 on
 + * success, negative on failure. */
 +int
 +extrainfo_dump_to_string(char **s_out, extrainfo_t *extrainfo,
 +                         crypto_pk_t *ident_key,
 +                         const ed25519_keypair_t *signing_keypair)
 +{
 +  const or_options_t *options = get_options();
 +  char identity[HEX_DIGEST_LEN+1];
 +  char published[ISO_TIME_LEN+1];
 +  char digest[DIGEST_LEN];
 +  char *bandwidth_usage;
 +  int result;
 +  static int write_stats_to_extrainfo = 1;
 +  char sig[DIROBJ_MAX_SIG_LEN+1];
 +  char *s = NULL, *pre, *contents, *cp, *s_dup = NULL;
 +  time_t now = time(NULL);
 +  smartlist_t *chunks = smartlist_new();
 +  extrainfo_t *ei_tmp = NULL;
 +  const int emit_ed_sigs = signing_keypair &&
 +    extrainfo->cache_info.signing_key_cert;
 +  char *ed_cert_line = NULL;
 +
 +  base16_encode(identity, sizeof(identity),
 +                extrainfo->cache_info.identity_digest, DIGEST_LEN);
 +  format_iso_time(published, extrainfo->cache_info.published_on);
 +  bandwidth_usage = rep_hist_get_bandwidth_lines();
 +  if (emit_ed_sigs) {
 +    if (!extrainfo->cache_info.signing_key_cert->signing_key_included ||
 +        !ed25519_pubkey_eq(&extrainfo->cache_info.signing_key_cert->signed_key,
 +                           &signing_keypair->pubkey)) {
 +      log_warn(LD_BUG, "Tried to sign a extrainfo descriptor with a "
 +               "mismatched ed25519 key chain %d",
 +               extrainfo->cache_info.signing_key_cert->signing_key_included);
 +      goto err;
 +    }
 +    char ed_cert_base64[256];
 +    if (base64_encode(ed_cert_base64, sizeof(ed_cert_base64),
 +                 (const char*)extrainfo->cache_info.signing_key_cert->encoded,
 +                 extrainfo->cache_info.signing_key_cert->encoded_len,
 +                 BASE64_ENCODE_MULTILINE) < 0) {
 +      log_err(LD_BUG,"Couldn't base64-encode signing key certificate!");
 +      goto err;
 +    }
 +    tor_asprintf(&ed_cert_line, "identity-ed25519\n"
 +                 "-----BEGIN ED25519 CERT-----\n"
 +                 "%s"
 +                 "-----END ED25519 CERT-----\n", ed_cert_base64);
 +  } else {
 +    ed_cert_line = tor_strdup("");
 +  }
 +
 +  tor_asprintf(&pre, "extra-info %s %s\n%spublished %s\n%s",
 +               extrainfo->nickname, identity,
 +               ed_cert_line,
 +               published, bandwidth_usage);
 +  smartlist_add(chunks, pre);
 +
 +  if (geoip_is_loaded(AF_INET))
 +    smartlist_add_asprintf(chunks, "geoip-db-digest %s\n",
 +                           geoip_db_digest(AF_INET));
 +  if (geoip_is_loaded(AF_INET6))
 +    smartlist_add_asprintf(chunks, "geoip6-db-digest %s\n",
 +                           geoip_db_digest(AF_INET6));
 +
 +  if (options->ExtraInfoStatistics && write_stats_to_extrainfo) {
 +    log_info(LD_GENERAL, "Adding stats to extra-info descriptor.");
 +    if (options->DirReqStatistics &&
 +        load_stats_file("stats"PATH_SEPARATOR"dirreq-stats",
 +                        "dirreq-stats-end", now, &contents) > 0) {
 +      smartlist_add(chunks, contents);
 +    }
 +    if (options->HiddenServiceStatistics &&
 +        load_stats_file("stats"PATH_SEPARATOR"hidserv-stats",
 +                        "hidserv-stats-end", now, &contents) > 0) {
 +      smartlist_add(chunks, contents);
 +    }
 +    if (options->EntryStatistics &&
 +        load_stats_file("stats"PATH_SEPARATOR"entry-stats",
 +                        "entry-stats-end", now, &contents) > 0) {
 +      smartlist_add(chunks, contents);
 +    }
 +    if (options->CellStatistics &&
 +        load_stats_file("stats"PATH_SEPARATOR"buffer-stats",
 +                        "cell-stats-end", now, &contents) > 0) {
 +      smartlist_add(chunks, contents);
 +    }
 +    if (options->ExitPortStatistics &&
 +        load_stats_file("stats"PATH_SEPARATOR"exit-stats",
 +                        "exit-stats-end", now, &contents) > 0) {
 +      smartlist_add(chunks, contents);
 +    }
 +    if (options->ConnDirectionStatistics &&
 +        load_stats_file("stats"PATH_SEPARATOR"conn-stats",
 +                        "conn-bi-direct", now, &contents) > 0) {
 +      smartlist_add(chunks, contents);
 +    }
-   }
- 
-   if (options->PaddingStatistics) {
-     contents = rep_hist_get_padding_count_lines();
-     if (contents)
-       smartlist_add(chunks, contents);
++    if (options->PaddingStatistics) {
++      contents = rep_hist_get_padding_count_lines();
++      if (contents)
++        smartlist_add(chunks, contents);
++    }
 +  }
 +
 +  /* Add information about the pluggable transports we support. */
 +  if (options->ServerTransportPlugin) {
 +    char *pluggable_transports = pt_get_extra_info_descriptor_string();
 +    if (pluggable_transports)
 +      smartlist_add(chunks, pluggable_transports);
 +  }
 +
 +  if (should_record_bridge_info(options) && write_stats_to_extrainfo) {
 +    const char *bridge_stats = geoip_get_bridge_stats_extrainfo(now);
 +    if (bridge_stats) {
 +      smartlist_add_strdup(chunks, bridge_stats);
 +    }
 +  }
 +
 +  if (emit_ed_sigs) {
 +    char sha256_digest[DIGEST256_LEN];
 +    smartlist_add_strdup(chunks, "router-sig-ed25519 ");
 +    crypto_digest_smartlist_prefix(sha256_digest, DIGEST256_LEN,
 +                                   ED_DESC_SIGNATURE_PREFIX,
 +                                   chunks, "", DIGEST_SHA256);
 +    ed25519_signature_t ed_sig;
 +    char buf[ED25519_SIG_BASE64_LEN+1];
 +    if (ed25519_sign(&ed_sig, (const uint8_t*)sha256_digest, DIGEST256_LEN,
 +                     signing_keypair) < 0)
 +      goto err;
 +    if (ed25519_signature_to_base64(buf, &ed_sig) < 0)
 +      goto err;
 +
 +    smartlist_add_asprintf(chunks, "%s\n", buf);
 +  }
 +
 +  smartlist_add_strdup(chunks, "router-signature\n");
 +  s = smartlist_join_strings(chunks, "", 0, NULL);
 +
 +  while (strlen(s) > MAX_EXTRAINFO_UPLOAD_SIZE - DIROBJ_MAX_SIG_LEN) {
 +    /* So long as there are at least two chunks (one for the initial
 +     * extra-info line and one for the router-signature), we can keep removing
 +     * things. */
 +    if (smartlist_len(chunks) > 2) {
 +      /* We remove the next-to-last element (remember, len-1 is the last
 +         element), since we need to keep the router-signature element. */
 +      int idx = smartlist_len(chunks) - 2;
 +      char *e = smartlist_get(chunks, idx);
 +      smartlist_del_keeporder(chunks, idx);
 +      log_warn(LD_GENERAL, "We just generated an extra-info descriptor "
 +                           "with statistics that exceeds the 50 KB "
 +                           "upload limit. Removing last added "
 +                           "statistics.");
 +      tor_free(e);
 +      tor_free(s);
 +      s = smartlist_join_strings(chunks, "", 0, NULL);
 +    } else {
 +      log_warn(LD_BUG, "We just generated an extra-info descriptors that "
 +                       "exceeds the 50 KB upload limit.");
 +      goto err;
 +    }
 +  }
 +
 +  memset(sig, 0, sizeof(sig));
 +  if (router_get_extrainfo_hash(s, strlen(s), digest) < 0 ||
 +      router_append_dirobj_signature(sig, sizeof(sig), digest, DIGEST_LEN,
 +                                     ident_key) < 0) {
 +    log_warn(LD_BUG, "Could not append signature to extra-info "
 +                     "descriptor.");
 +    goto err;
 +  }
 +  smartlist_add_strdup(chunks, sig);
 +  tor_free(s);
 +  s = smartlist_join_strings(chunks, "", 0, NULL);
 +
 +  cp = s_dup = tor_strdup(s);
 +  ei_tmp = extrainfo_parse_entry_from_string(cp, NULL, 1, NULL, NULL);
 +  if (!ei_tmp) {
 +    if (write_stats_to_extrainfo) {
 +      log_warn(LD_GENERAL, "We just generated an extra-info descriptor "
 +                           "with statistics that we can't parse. Not "
 +                           "adding statistics to this or any future "
 +                           "extra-info descriptors.");
 +      write_stats_to_extrainfo = 0;
 +      result = extrainfo_dump_to_string(s_out, extrainfo, ident_key,
 +                                        signing_keypair);
 +      goto done;
 +    } else {
 +      log_warn(LD_BUG, "We just generated an extrainfo descriptor we "
 +                       "can't parse.");
 +      goto err;
 +    }
 +  }
 +
 +  *s_out = s;
 +  s = NULL; /* prevent free */
 +  result = 0;
 +  goto done;
 +
 + err:
 +  result = -1;
 +
 + done:
 +  tor_free(s);
 +  SMARTLIST_FOREACH(chunks, char *, chunk, tor_free(chunk));
 +  smartlist_free(chunks);
 +  tor_free(s_dup);
 +  tor_free(ed_cert_line);
 +  extrainfo_free(ei_tmp);
 +  tor_free(bandwidth_usage);
 +
 +  return result;
 +}
 +
 +/** Forget that we have issued any router-related warnings, so that we'll
 + * warn again if we see the same errors. */
 +void
 +router_reset_warnings(void)
 +{
 +  if (warned_nonexistent_family) {
 +    SMARTLIST_FOREACH(warned_nonexistent_family, char *, cp, tor_free(cp));
 +    smartlist_clear(warned_nonexistent_family);
 +  }
 +}
 +
 +/** Release all static resources held in router.c */
 +void
 +router_free_all(void)
 +{
 +  crypto_pk_free(onionkey);
 +  crypto_pk_free(lastonionkey);
 +  crypto_pk_free(server_identitykey);
 +  crypto_pk_free(client_identitykey);
 +
 +  tor_mutex_free(key_lock);
 +  routerinfo_free(desc_routerinfo);
 +  extrainfo_free(desc_extrainfo);
 +  crypto_pk_free(authority_signing_key);
 +  authority_cert_free(authority_key_certificate);
 +  crypto_pk_free(legacy_signing_key);
 +  authority_cert_free(legacy_key_certificate);
 +
 +  memwipe(&curve25519_onion_key, 0, sizeof(curve25519_onion_key));
 +  memwipe(&last_curve25519_onion_key, 0, sizeof(last_curve25519_onion_key));
 +
 +  if (warned_nonexistent_family) {
 +    SMARTLIST_FOREACH(warned_nonexistent_family, char *, cp, tor_free(cp));
 +    smartlist_free(warned_nonexistent_family);
 +  }
 +}
 +/* From the given RSA key object, convert it to ASN-1 encoded format and set
 + * the newly allocated object in onion_pkey_out. The length of the key is set
 + * in onion_pkey_len_out. */
 +void
 +router_set_rsa_onion_pkey(const crypto_pk_t *pk, char **onion_pkey_out,
 +                          size_t *onion_pkey_len_out)
 +{
 +  int len;
 +  char buf[1024];
 +
 +  tor_assert(pk);
 +  tor_assert(onion_pkey_out);
 +  tor_assert(onion_pkey_len_out);
 +
 +  len = crypto_pk_asn1_encode(pk, buf, sizeof(buf));
 +  if (BUG(len < 0)) {
 +    goto done;
 +  }
 +
 +  *onion_pkey_out = tor_memdup(buf, len);
 +  *onion_pkey_len_out = len;
 +
 + done:
 +  return;
 +}
 +
 +/* From an ASN-1 encoded onion pkey, return a newly allocated RSA key object.
 + * It is the caller responsability to free the returned object.
 + *
 + * Return NULL if the pkey is NULL, malformed or if the length is 0. */
 +crypto_pk_t *
 +router_get_rsa_onion_pkey(const char *pkey, size_t pkey_len)
 +{
 +  if (!pkey || pkey_len == 0) {
 +    return NULL;
 +  }
 +  return crypto_pk_asn1_decode(pkey, pkey_len);
 +}



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