[tor-bugs] #25899 [Core Tor/Tor]: Only run retry_dns() and check_dns_honesty() on exits

[Tor Bug Tracker & Wiki]

#25899: Only run retry_dns() and check_dns_honesty() on exits
---------------------------------+------------------------------------
 Reporter:  nickm                |          Owner:  dgoulet
     Type:  enhancement          |         Status:  needs_revision
 Priority:  Medium               |      Milestone:  Tor: 0.3.5.x-final
Component:  Core Tor/Tor         |        Version:
 Severity:  Normal               |     Resolution:
 Keywords:  034-roadmap-subtask  |  Actual Points:
Parent ID:  #25500               |         Points:
 Reviewer:                       |        Sponsor:
---------------------------------+------------------------------------
Changes (by dgoulet):

 * reviewer:  dgoulet =>
 * milestone:  Tor: 0.3.4.x-final => Tor: 0.3.5.x-final


Comment:

 Ok turns out that DNS and Exit Policy settings are kind of linked
 together...

 For instance, when building our routerinfo object, we append "reject *" if
 our DNS init failed but this patch is about trying to initializing the DNS
 by looking if we are configured as an Exit... so the approach gets a bit
 more complicated.

 Furthermore, `check_dns_honesty_event()` can be launched through the
 `dns_init()` code path which means it somehow needs to be enabled which
 only gets called in the initialized event callback which is _after_ the
 first dns_init() call in `do_main_loop()`....

 Bottom line, there seems to be some complexity with this one so deferring
 to 035. Not too big of a deal if a non-Exit relay launches those events.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/25899#comment:11>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online