[tor-bugs] #31652 [Core Tor/Tor]: hs-v3: Service circuit retry limit should not close a valid circuit

[Tor Bug Tracker & Wiki]

#31652: hs-v3: Service circuit retry limit should not close a valid circuit
-------------------------------------------------+-------------------------
 Reporter:  dgoulet                              |          Owner:  neel
     Type:  defect                               |         Status:
                                                 |  needs_revision
 Priority:  Medium                               |      Milestone:  Tor:
                                                 |  0.4.2.x-final
Component:  Core Tor/Tor                         |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  tor-hs, tor-circuit, 042-should,     |  Actual Points:
  dgoulet-merge                                  |
Parent ID:  #30200                               |         Points:  0.1
 Reviewer:  asn                                  |        Sponsor:
                                                 |  Sponsor27-must
-------------------------------------------------+-------------------------
Changes (by dgoulet):

 * status:  merge_ready => needs_revision


Comment:

 I think we can _not_ do this:

 {{{
   if (hs_circ_service_get_intro_circ(ip) && over_max_retries) {
     return true;
   }
 }}}

 If we have a pending intro circuit for that `ip` and we are over the max
 retries, this means that the pending intro circuit is the one that will be
 used or will fail.

 So returning `true` means that it will be removed from the service list
 and will lead to a lost lingering intro circuit that once established,
 we'll hit an error because we can't find the "ip" object.

 If we have one established or in the process of establishing one, NEVER
 remove the IP is what I think we should do.

 If we have no circuits at all and we are over the limit, remove it.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/31652#comment:23>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online