[tor-bugs] #10242 [Obfsproxy]: obfs-flash-client does not reconnect well when browser proxy reconnects

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#10242: obfs-flash-client does not reconnect well when browser proxy reconnects
-----------------------+---------------------
 Reporter:  infinity0  |          Owner:  asn
     Type:  defect     |         Status:  new
 Priority:  normal     |      Milestone:
Component:  Obfsproxy  |        Version:
 Keywords:             |  Actual Points:
Parent ID:             |         Points:
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 From [#ticket:7167:comment:42]; assigning to obfsproxy as that is our
 current theory.

 I've found a problem with the current set-up. I'm not sure why it's
 happening, but it's something special about our plugin composition.

 If I disconnect my browser proxy and reconnect it (by reloading the page),
 with flashproxy-client tor is able to recover and I can continue browsing.
 However, with obfs-flash-client, tor is unable to do this and I get a
 bunch of error messages like this:

 {{{
 Oct 11 19:32:59.000 [notice] We tried for 15 seconds to connect to
 '[scrubbed]' using exit X1 at A1. Retrying on a new circuit.
 [x4]
 Oct 11 19:33:14.000 [notice] We tried for 15 seconds to connect to
 '[scrubbed]' using exit X2 at A2. Retrying on a new circuit.
 [x4]
 Oct 11 19:33:29.000 [notice] We tried for 15 seconds to connect to
 '[scrubbed]' using exit X3 at A3. Retrying on a new circuit.
 [x4]
 }}}

 To reproduce: [the new facilitator is running in the standard location, so
 just use the standard torrc]

 edit: It does seem to recover after several more minutes though.

 Some later theorising:

 <dcf1> What I'd try first is probably enable debug logging on obfsproxy.
 <dcf1> flashproxy-client disconnects its LOCAL port when a REMOTE
 disappears. Usually LOCAL is Tor itself, which reconnects in such a
 situation.
 <dcf1> Maybe obfsproxy doesn't reconnect in the same way, or maybe
 flashproxy-client needs optionally not to disconnect LOCAL.
 <infinity0> ah
 <infinity0> sounds plausible
 <dcf1> It's a good find, as disconnecting flash proxies is certainly the
 norm.
 <dcf1> I would expect tor to make a new socks connection to obfsproxy,
 which should in turn make a fresh connection to the socks shim, but I'm
 not sure.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/10242>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online
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