[tor-bugs] #24367 [Core Tor/Tor]: Changing pluggable transports (during start-up) in Tor Browser is broken

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#24367: Changing pluggable transports (during start-up) in Tor Browser is broken
-------------------------------------------------+-------------------------
 Reporter:  gk                                   |          Owner:  (none)
     Type:  defect                               |         Status:
                                                 |  needs_information
 Priority:  Medium                               |      Milestone:  Tor:
                                                 |  0.3.2.x-final
Component:  Core Tor/Tor                         |        Version:  Tor:
                                                 |  0.3.0.1-alpha
 Severity:  Normal                               |     Resolution:
 Keywords:  030-backport, 031-backport,          |  Actual Points:
  regression, tor-bridge-client, s8-errors,      |
  tbb-wants                                      |
Parent ID:                                       |         Points:  0.5
 Reviewer:                                       |        Sponsor:
                                                 |  Sponsor8-can
-------------------------------------------------+-------------------------

Comment (by teor):

 After the bridges and PT are changed, this is what happens:
 {{{
 Dec 14 19:48:33.000 [info] register_client_proxy(): Successfully
 registered transport obfs2
 918     Dec 14 19:48:33.000 [info] register_client_proxy(): Successfully
 registered transport obfs3
 919     Dec 14 19:48:33.000 [info] register_client_proxy(): Successfully
 registered transport obfs4
 920     Dec 14 19:48:33.000 [info] register_client_proxy(): Successfully
 registered transport scramblesuit
 921     Dec 14 19:48:34.000 [notice] Our directory information is no
 longer up-to-date enough to build circuits: We're missing descriptors for
 2/2 of our primary entry guards (total microdescriptors: 6474/6486).
 922     Dec 14 19:48:34.000 [info] launch_descriptor_downloads():
 Launching 1 request for 12 microdescs, 12 at a time
 923     Dec 14 19:48:34.000 [info] select_entry_guard_for_circuit():
 Selected primary guard [bridge]
 ($00DC6C4FA49A65BD1472993CF6730D54F11E0DBB) at 154.35.22.12:80 for
 circuit.
 924     Dec 14 19:48:34.000 [notice] Ignoring directory request, since no
 bridge nodes are available yet.
 }}}

 Notice how we're missing bridge descriptors, but we try to fetch
 microdescriptors?

 So all that code asn wrote to fetch microdescs harder isn't going to help
 here. Instead, we need to try bridges harder when we are missing bridge
 descriptors. Maybe we should start by resetting their download statuses?

 Also, we should think about whether this code works when we are not using
 microdescriptors. DOes it specifically trigger a microdesc fetch? Or is it
 just triggering descriptor fetches?

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24367#comment:36>
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