Merge remote-tracking branch 'tor-gitlab/mr/474' into main

  o Major bugfixes (bridges):

    - Make Tor work reliably again when you have multiple bridges

      configured and one or more of them are unreachable. The problem

      came because we require that we have bridge descriptors for both

      of our first two bridges (else we refuse to try to connect), but

      in some cases we would wait three hours before trying to fetch

      these missing descriptors, and/or never recover when we do try

      to fetch them. Fixes bugs 40396 and 40495; bugfix on 0.3.0.5-rc

      and 0.3.2.1-alpha.

  o Minor bugfixes (logging):

    - When we no longer have enough directory information to use the

      network, we would log a notice-level message -- but we would not

      reliably log a message when we recovered and resumed using the

      network. Now make sure there is always a corresponding message

      about recovering. Fixes bug 40496; bugfix on 0.3.5.1-alpha.

  o Minor bugfixes (bridges):

    - When we don't yet have a descriptor for one of our bridges, disable

      the entry guard retry schedule on that bridge. The entry guard retry

      schedule and the bridge descriptor retry schedule can conflict,

      e.g. where we mark a bridge as "maybe up" yet we don't try to fetch

      its descriptor yet, leading Tor to wait (refusing to do anything)

      until it becomes time to fetch the descriptor. Fixes bug 40497;

      bugfix on 0.3.0.3-alpha.

[[TestingAuthKeySlop]] **TestingAuthKeySlop** __N__ **seconds**|**minutes**|**hours** +

[[TestingBridgeBootstrapDownloadInitialDelay]] **TestingBridgeBootstrapDownloadInitialDelay** __N__::

    Initial delay in seconds for when clients should download each bridge descriptor when they

    have just started, or when they can not contact any of their bridges.

    Initial delay in seconds for how long clients should wait before

    downloading a bridge descriptor for a new bridge.

    Changing this requires that **TestingTorNetwork** is set. (Default: 0)

[[TestingBridgeDownloadInitialDelay]] **TestingBridgeDownloadInitialDelay** __N__::

    Initial delay in seconds for when clients should download each bridge descriptor when they

    know that one or more of their configured bridges are running. Changing

    this requires that **TestingTorNetwork** is set. (Default: 10800)

    How long to wait (in seconds) once clients have successfully

    downloaded a bridge descriptor, before trying another download for

    that same bridge. Changing this requires that **TestingTorNetwork**

    is set. (Default: 10800)

[[TestingClientConsensusDownloadInitialDelay]] **TestingClientConsensusDownloadInitialDelay** __N__::

    Initial delay in seconds for when clients should download consensuses. Changing this

}

/** We just learned a descriptor for a bridge. See if that

 * digest is in our entry guard list, and add it if not. */

 * digest is in our entry guard list, and add it if not. Schedule the

 * next fetch for a long time from now, and initiate any follow-up

 * activities like continuing to bootstrap.

 *

 * <b>from_cache</b> * tells us whether we fetched it from disk (else

 * the network)

 *

 * <b>desc_is_new</b> tells us if we preferred it to the old version we

 * had, if any. */

void

learned_bridge_descriptor(routerinfo_t *ri, int from_cache)

learned_bridge_descriptor(routerinfo_t *ri, int from_cache, int desc_is_new)

{

  tor_assert(ri);

  tor_assert(ri->purpose == ROUTER_PURPOSE_BRIDGE);

    if (bridge) { /* if we actually want to use this one */

      node_t *node;

      /* it's here; schedule its re-fetch for a long time from now. */

      if (!from_cache) {

        /* This schedules the re-fetch at a constant interval, which produces

         * a pattern of bridge traffic. But it's better than trying all

         * configured bridges several times in the first few minutes. */

        download_status_reset(&bridge->fetch_status);

        /* it's here; schedule its re-fetch for a long time from now. */

        bridge->fetch_status.next_attempt_at +=

          get_options()->TestingBridgeDownloadInitialDelay;

      }

      node = node_get_mutable_by_id(ri->cache_info.identity_digest);

      entry_guard_learned_bridge_identity(&bridge->addrport_configured,

                              (const uint8_t*)ri->cache_info.identity_digest);

      log_notice(LD_DIR, "new bridge descriptor '%s' (%s): %s", ri->nickname,

      if (desc_is_new)

        log_notice(LD_DIR, "new bridge descriptor '%s' (%s): %s",

                   ri->nickname,

                   from_cache ? "cached" : "fresh", router_describe(ri));

      /* If we didn't have a reachable bridge before this one, try directory

       * documents again. */