[tor-bugs] #24875 [Obfuscation/meek]: meek-client doesn't exit on close of stdin if there are no active handlers running

[Tor Bug Tracker & Wiki]

#24875: meek-client doesn't exit on close of stdin if there are no active handlers
running
----------------------------------+-----------------
     Reporter:  dcf               |      Owner:  dcf
         Type:  defect            |     Status:  new
     Priority:  Medium            |  Milestone:
    Component:  Obfuscation/meek  |    Version:
     Severity:  Normal            |   Keywords:
Actual Points:                    |  Parent ID:
       Points:                    |   Reviewer:
      Sponsor:                    |
----------------------------------+-----------------
 If you give meek-client an EOF while it's not currently handling any
 connections, it says it is terminating but doesn't quite terminate.
 {{{
 $ TOR_PT_EXIT_ON_STDIN_CLOSE=1 TOR_PT_MANAGED_TRANSPORT_VER=1
 TOR_PT_CLIENT_TRANSPORTS=meek ./meek-client < /dev/null
 VERSION 1
 CMETHOD meek socks5 127.0.0.1:35831
 2018/01/11 22:03:23 listening on 127.0.0.1:35831
 CMETHODS DONE
 2018/01/11 22:03:23 synthesizing SIGTERM because of stdin close
 2018/01/11 22:03:23 got signal terminated
 2018/01/11 22:03:23 error in AcceptSocks: accept tcp 127.0.0.1:35831: use
 of closed network connection
 }}}
 It's stuck in this loop, because it only checks `numHandlers == 0` inside
 the loop and not before entering.
 {{{
         for n := range handlerChan {
                 numHandlers += n
                 if numHandlers == 0 {
                         break
                 }
         }
 }}}

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24875>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online