[tor-bugs] #31561 [Core Tor/Tor]: hs-v3: Service can keep unused intro points in its list

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#31561: hs-v3: Service can keep unused intro points in its list
---------------------------------------+-----------------------------------
 Reporter:  dgoulet                    |          Owner:  dgoulet
     Type:  defect                     |         Status:  needs_information
 Priority:  Medium                     |      Milestone:  Tor:
                                       |  0.4.2.x-final
Component:  Core Tor/Tor               |        Version:
 Severity:  Normal                     |     Resolution:
 Keywords:  tor-hs, hv-v3, 042-should  |  Actual Points:  0.1
Parent ID:  #30200                     |         Points:  0.2
 Reviewer:  asn, mikeperry             |        Sponsor:  Sponsor27-must
---------------------------------------+-----------------------------------

Comment (by asn):

 Replying to [comment:17 dgoulet]:
 > As per discussion on IRC, Mike spotted that
 `circuit_build_times_handle_completed_hop()` also can timeout a circuit.
 >
 > Which means, it would go through `circuit_change_purpose()` and the
 intro point would get retried instead of ditched.
 >
 > In other words, we have two different behaviors with this patch with
 regards to the intro circuit:
 >
 > 1. Time out: intro point is ditched, a new one is picked later.
 > 2. Closes/Re-purposed: intro point is set as "not established" and then
 will be retried later.
 >

 I am a bit confused by the above because
 `circuit_build_times_handle_completed_hop()` is also about "time out" and
 above you say that we retry instead of ditching, but (1) above says the
 opposite. What is the case?

 Maybe you want to distinguish between timeout while building a circuit,
 and timeout on a completed circuit? Or maybe I'm a bit confuse.


 > The change in behavior with this ticket is (1) which makes the service
 ditch an intro point on timeout issues instead of retrying it later.

 Hmm, I don't mind this behavior that much as long as we document it
 somewhere and we are OK with it. It does seem a bit arbitrary to me,
 because if we want to keep our intro points, then we should do it in this
 case too. Would it be hard to do?

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/31561#comment:19>
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