[tor-bugs] #7733 [Tor]: Two channels required for bootstrap

[Tor Bug Tracker & Wiki]

#7733: Two channels required for bootstrap
------------------------+-----------------------------------------------
     Reporter:  dcf     |      Owner:
         Type:  defect  |     Status:  new
     Priority:  normal  |  Milestone:  Tor: 0.2.5.x-final
    Component:  Tor     |    Version:
   Resolution:          |   Keywords:  tor-client flashproxy 025-triaged
Actual Points:          |  Parent ID:
       Points:          |
------------------------+-----------------------------------------------

Comment (by nickm):

 I mentiond that in the case where I have everything cached and I have a
 bridge with no specified ID, we launch two channels right at startup, one
 with ID==0 and one with ID set.  Here are the stack traces for those two
 launches.

 {{{
 ========================================
 This one happens with ID == 0.

 2   tor                                 0x000000010610370d
 channel_tls_connect + 477
 3   tor                                 0x000000010610be75
 circuit_handle_first_hop + 373
 4   tor                                 0x000000010610bb36
 circuit_establish_circuit + 3254
 5   tor                                 0x000000010611c7de
 circuit_launch_by_extend_info + 382
 6   tor                                 0x000000010611dbe8
 circuit_get_open_circ_or_launch + 1752
 7   tor                                 0x000000010611d0e7
 connection_ap_handshake_attach_circuit + 551
 8   tor                                 0x000000010613eaff
 connection_ap_make_link + 463
 9   tor                                 0x000000010615197f
 directory_initiate_command_rend + 751
 10  tor                                 0x0000000106151317
 directory_initiate_command + 87
 11  tor                                 0x0000000106177436
 launch_direct_bridge_descriptor_fetch + 246
 12  tor                                 0x00000001061776ba
 fetch_bridge_descriptors + 618
 13  tor                                 0x000000010617cf7b
 second_elapsed_callback + 923
 14  libevent-2.0.5.dylib                0x00000001062da997 event_base_loop
 + 1745
 15  tor                                 0x000000010617c935 do_main_loop +
 709
 16  tor                                 0x000000010617fb2e tor_main + 2558
 17  libdyld.dylib                       0x00007fff9885e5fd start + 1
 18  ???                                 0x0000000000000001 0x0 + 1


 ========================================
 This one happens with ID set

 2   tor                                 0x00000001020ad70d
 channel_tls_connect + 477
 3   tor                                 0x00000001020b5e75
 circuit_handle_first_hop + 373
 4   tor                                 0x00000001020b5b36
 circuit_establish_circuit + 3254
 5   tor                                 0x00000001020c67de
 circuit_launch_by_extend_info + 382
 6   tor                                 0x00000001020c7be8
 circuit_get_open_circ_or_launch + 1752
 7   tor                                 0x00000001020c70e7
 connection_ap_handshake_attach_circuit + 551
 8   tor                                 0x00000001020e8aff
 connection_ap_make_link + 463
 9   tor                                 0x00000001020fb97f
 directory_initiate_command_rend + 751
 10  tor                                 0x00000001020faf5f
 directory_get_from_dirserver + 671
 11  tor                                 0x000000010212f7c7
 update_consensus_networkstatus_downloads + 487
 12  tor                                 0x000000010212fcf8
 update_networkstatus_downloads + 104
 13  tor                                 0x000000010212743b
 second_elapsed_callback + 2139
 14  libevent-2.0.5.dylib                0x0000000102287997 event_base_loop
 + 1745
 15  tor                                 0x0000000102126935 do_main_loop +
 709
 16  tor                                 0x0000000102129b2e tor_main + 2558
 17  libdyld.dylib                       0x00007fff9885e5fd start + 1
 18  ???                                 0x0000000000000001 0x0 + 1
 }}}



 (Also what's confusing me a bit too is that we're launching these
 downloads at all, since we should already have a cached networkstatus and
 a cached bridge descriptor.)

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/7733#comment:7>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online