[tor-bugs] #21054 [Core Tor/Tor]: hs: BUG() is triggered with ephemeral service on config reload

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#21054: hs: BUG() is triggered with ephemeral service on config reload
-------------------------------------------------+-------------------------
 Reporter:  dgoulet                              |          Owner:  dgoulet
     Type:  defect                               |         Status:
                                                 |  needs_review
 Priority:  High                                 |      Milestone:  Tor:
                                                 |  0.3.0.x-final
Component:  Core Tor/Tor                         |        Version:  Tor:
                                                 |  0.3.0.1-alpha
 Severity:  Normal                               |     Resolution:
 Keywords:  tor-hs, prop224, refactoring,        |  Actual Points:
  review-group-14                                |
Parent ID:                                       |         Points:  0.5
 Reviewer:  asn                                  |        Sponsor:
                                                 |  SponsorR-can
-------------------------------------------------+-------------------------

Comment (by asn):

 Replying to [comment:5 dgoulet]:
 > Replying to [comment:4 asn]:
 > > Initial review:
 > >
 > > Changes look reasonable to me. One question, why does
 `circuit_get_next_service_intro_circ()` need the `start` argument?
 > >
 > > In the old code, we just iterated from the beginning of the
 circuitlist everytime. Why do we now begin from `start`? Is it an
 optimization?
 >
 > Yes. It is also to basically follow the `circuit_get_next_by_*` API that
 uses that technique. Without it, we can't return a circuit from the middle
 of the list matching our requirements and then continuing the loop at that
 circuit. Else, the other options is for the function to return a list of
 matching circuits. No strong preferences here, I would be fine with
 either.
 >

 I think the way you have it is fine!

 > >
 > > Also, BTW I didn't manage to reproduce the original bug. How do we do
 it? I started up a Tor with a normal HS, then I added an ADD_ONION, and
 then I HUPed. Am I missing a step?
 >
 > Yes, normal service then you do `ADD_ONION NEW:BEST Port=8161` and then
 HUP or `SIGNAL RELOAD`, you should hit the BUG. Btw, it won't be on
 console if you setup logging and should look like this (I just reproduced
 it on master):
 >
 > {{{
 > Jan 09 09:23:44.000 [warn] tor_bug_occurred_(): Bug:
 src/or/rendservice.c:839: rend_config_services: Non-fatal assertion
 !(rend_service_is_ephemeral(new)) failed. (on Tor 0.3.0.1-alpha-dev
 655ffeadd53833d9)
 > Jan 09 09:23:44.000 [warn] Bug: Non-fatal assertion
 !(rend_service_is_ephemeral(new)) failed in rend_config_services at
 src/or/rendservice.c:839. Stack trace: (on Tor 0.3.0.1-alpha-dev
 655ffeadd53833d9)
 > [...]
 > }}}

 Hmm, I'm still unable to repro this with carml. I tried with unpatched
 `df87812` and Tor will just successfuly HUP with no issues. Here is my
 torrc:
 {{{
 SocksPort auto
 ControlPort auto

 HiddenServiceDir /tmp/hidden_service
 HiddenServicePort 6667 127.0.0.1:6667

 CookieAuthentication 1
 CookieAuthFileGroupReadable 1
 ControlPort 9051
 }}}

 And then I just do:
 {{{
 $ ./bin/carml --connect tcp:127.0.0.1:9051 -q cmd ADD_ONION NEW:BEST
 Port=8161
 $ ./bin/carml --connect tcp:127.0.0.1:9051 -q cmd SIGNAL RELOAD
 }}}
 but Tor seems to handle it just fine:
 {{{
 Jan 12 13:16:53.000 [notice] Tor 0.3.0.1-alpha-dev (git-df87812b41abccd6)
 opening log file.
 Jan 12 13:16:57.000 [notice] New control connection opened from 127.0.0.1.
 Jan 12 13:16:58.000 [notice] New control connection opened from 127.0.0.1.
 Jan 12 13:16:58.000 [notice] Received reload signal (hup). Reloading
 config and resetting internal state.
 Jan 12 13:16:58.000 [notice] Read configuration file
 "/home/f/Computers/tor/mytor/../confs/bug21054".
 Jan 12 13:16:58.000 [warn] CookieAuthFileGroupReadable is set, but will
 have no effect: you must specify an explicit CookieAuthFile to have it
 group-readable.
 }}}

 What am I doing wrong?

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/21054#comment:6>
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