[tor-bugs] #28458 [Core Tor/sbws]: Stop resolving domains locally and stop using non-exits as 2nd hop

Tor Bug Tracker & Wiki blackhole at torproject.org
Thu Nov 15 13:36:50 UTC 2018


#28458: Stop resolving domains locally and stop using non-exits as 2nd hop
---------------------------+------------------------------
 Reporter:  juga           |          Owner:  juga
     Type:  defect         |         Status:  needs_review
 Priority:  Medium         |      Milestone:
Component:  Core Tor/sbws  |        Version:  sbws: 1.0.0
 Severity:  Normal         |     Resolution:
 Keywords:                 |  Actual Points:
Parent ID:                 |         Points:
 Reviewer:                 |        Sponsor:
---------------------------+------------------------------

Comment (by pastly):

 Replying to [comment:3 teor]:
 >
 > What happens if sbws gets END_REASON_EXITPOLICY from the exit?
 > (END_REASON_EXITPOLICY is the response when an exit's policy won't allow
 the IP address that the exit resolved.)
 >
 > This can happen because:
 > * the exit has just changed its policy, and sbws has an old version
 > * the exit resolves a different IP address from sbws
 >
 > I think we should measure the relay as a non-exit in this case.
 >
 > What happens if the exit can't connect because the connection is
 refused, or times out?
 >
 > This can happen because:
 > * the exit is busy
 > * the exit is censored
 > * the remote site is down
 >
 > I think we should measure the relay as a non-exit in this case.
 >
 > We could cover all these cases by choosing to measure exits as non-exit
 relays at random. About half the time would work.

 I like the idea of recovering from END_REASON_EXITPOLICY better, but the
 50% probability idea is waaayyy easier to implement. The former is harder
 in part because IIRC we currently don't ever look at circuit/stream close
 reasons, so we should implement doing that in a clean way.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/28458#comment:4>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online


More information about the tor-bugs mailing list