[tor-bugs] #15937 [Tor]: Clients fail on the 7th rapid SOCKS request to the same HS

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#15937: Clients fail on the 7th rapid SOCKS request to the same HS
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 Reporter:  teor      |          Owner:  dgoulet
     Type:  defect    |         Status:  needs_information
 Priority:  Low       |      Milestone:  Tor: 0.2.8.x-final
Component:  Tor       |        Version:
 Severity:  Normal    |     Resolution:
 Keywords:  tor-hs    |  Actual Points:
Parent ID:            |         Points:  small/medium
  Sponsor:  SponsorR  |
----------------------+------------------------------------
Changes (by dgoulet):

 * status:  assigned => needs_information
 * severity:   => Normal


Comment:

 Hrm ok it's a fun puzzle but I think I figured it out and the solution
 could be simple.

 In `rend_client_refetch_v2_renddesc()`, at the bottom if the fetch request
 fails by not finding a new HSDir because all 6 have been queried already,
 we call `rend_client_desc_trynow()` which closes all `RENDDESC_WAIT`
 connections for a .onion thus losing all previous 6.

 I can't figure out why we do that if we can't find an HSDir... so can we
 simply remove this?:
 {{{
   if (ret <= 0) {
     /* Close pending connections on error or if no hsdir can be found. */
     rend_client_desc_trynow(rend_query->onion_address);
   }
 }}}

 When the fetch succeeds (in `connection_dir_client_reached_eof()`), we
 already call that function to move to the next stage for HS connection so
 I propose we remove the above.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/15937#comment:12>
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