[tor-bugs] #6799 [Tor]: Don't expire unused relay-to-relay TLS conns so quickly

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#6799: Don't expire unused relay-to-relay TLS conns so quickly
-------------------------+-------------------------------------------------
     Reporter:  arma     |      Owner:
         Type:  defect   |     Status:  needs_review
     Priority:  major    |  Milestone:  Tor: 0.2.5.x-final
    Component:  Tor      |    Version:
   Resolution:           |   Keywords:  tor-relay anonymity-attack
Actual Points:           |  025-triaged 024-backport andrea-review-0255
       Points:           |  Parent ID:
-------------------------+-------------------------------------------------

Comment (by nickm):

 So, randomization and idle timeouts seem to be correctly handled.  And
 non-canonical timeouts are getting killed by their idle timeouts:
 {{{
 net/nodes/004r/notice.log:May 15 17:06:24.000 [notice] Expiring non-used
 OR connection 0x7f103c1e6060 to fd 21 (127.0.0.1:49256) [idle 239, timeout
 239, canonical=0].
 net/nodes/004r/notice.log:May 15 17:28:17.000 [notice] Expiring non-used
 OR connection 0x7f103c1bb860 to fd 21 (127.0.0.1:49655) [idle 252, timeout
 252, canonical=0].
 net/nodes/004r/notice.log:May 15 17:40:21.000 [notice] Expiring non-used
 OR connection 0x7f103c259270 to fd 21 (127.0.0.1:49904) [idle 244, timeout
 244, canonical=0].
 net/nodes/006r/notice.log:May 15 17:14:04.000 [notice] Expiring non-used
 OR connection 0x7f018ab040c0 to fd 24 (127.0.0.1:51470) [idle 205, timeout
 205, canonical=0].
 }}}

 And likewise for canonical connections on relays:
 {{{
 net/nodes/002a/notice.log:May 15 17:18:36.000 [notice] Expiring non-used
 OR connection 0x7fe7b325a590 to fd 24 (127.0.0.1:5003) [idle 936, timeout
 936, canonical=1].
 net/nodes/003r/notice.log:May 15 16:31:03.000 [notice] Expiring non-used
 OR connection 0x7f5bc23cceb0 to fd 30 (127.0.0.1:5002) [idle 900, timeout
 900, canonical=1].
 net/nodes/003r/notice.log:May 15 17:47:16.000 [notice] Expiring non-used
 OR connection 0x7f5bc23d95d0 to fd 24 (127.0.0.1:5002) [idle 1249, timeout
 1249, canonical=1].
 net/nodes/007r/notice.log:May 15 17:12:31.000 [notice] Expiring non-used
 OR connection 0x7fda748dc6a0 to fd 22 (127.0.0.1:5001) [idle 1100, timeout
 1100, canonical=1].
 }}}

 But for canonical connections on clients, the idle timeouts seem to be
 somewhat irrelevant; something else in run_connection_housekeeping is
 keeping them alive for a long time past their idle timeouts:
 {{{
 net/nodes/009c/notice.log:May 15 15:31:19.000 [notice] Expiring non-used
 OR connection 0x7f9ec576e3e0 to fd 16 (127.0.0.1:5004) [idle 4556, timeout
 955, canonical=1].
 net/nodes/009c/notice.log:May 15 16:47:47.000 [notice] Expiring non-used
 OR connection 0x7f9ec5793180 to fd 5 (127.0.0.1:5002) [idle 3662, timeout
 1273, canonical=1].
 net/nodes/009c/notice.log:May 15 16:50:53.000 [notice] Expiring non-used
 OR connection 0x7f9ec5772bb0 to fd 13 (127.0.0.1:5006) [idle 7409, timeout
 907, canonical=1].
 net/nodes/009c/notice.log:May 15 16:53:59.000 [notice] Expiring non-used
 OR connection 0x7f9ec578b8b0 to fd 14 (127.0.0.1:5004) [idle 3677, timeout
 1274, canonical=1].
 }}}

 Will investigate further, unless something happens to know just what the
 issue is.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/6799#comment:16>
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