[tor-bugs] #28942 [Circumvention/Snowflake]: Evaluate pion WebRTC

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#28942: Evaluate pion WebRTC
-------------------------------------+-------------------------------
 Reporter:  backkem                  |          Owner:  cohosh
     Type:  enhancement              |         Status:  assigned
 Priority:  Medium                   |      Milestone:
Component:  Circumvention/Snowflake  |        Version:
 Severity:  Normal                   |     Resolution:
 Keywords:  ex-sponsor-19            |  Actual Points:
Parent ID:                           |         Points:
 Reviewer:                           |        Sponsor:  Sponsor28-can
-------------------------------------+-------------------------------

Comment (by cohosh):

 Looks like something's up with reading from the data channel. I put a
 version of `BytesSyncLogger` at the `proxy-go` instance and at the client
 but changed it to count totals and not reset the inbound and outbound
 counts. I'm finding that the `proxy-go` instance (which runs pion webrtc)
 is not receiving all of the messages that the `client` (running go-webrtc)
 sends:

 At the proxy:
 {{{
 2019/06/18 13:58:34 Traffic Bytes (in|out): 40279 | 650650 -- (34
 OnMessages, 97 Sends)
 2019/06/18 13:58:34 OnClose channel
 }}}
 At the client:
 {{{
 2019/06/18 13:58:24 Traffic Bytes (in|out): 650650 | 335191 -- (97
 OnMessages, 43 Sends)
 2019/06/18 13:58:53 Traffic Bytes (in|out): 650650 | 339361 -- (97
 OnMessages, 44 Sends)
 2019/06/18 13:58:53 WebRTC: No messages received for 30 seconds -- closing
 stale connection.
 2019/06/18 13:58:53 WebRTC: closing DataChannel
 }}}

 I'm going to dig into the pion/webrtc code to see if anything obvious
 comes up. As far as I can tell the datachannels being created are reliable
 just as before so maybe there's something weird with the signaling code
 they use to notify the datachannel that data has been read.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/28942#comment:8>
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