[tor-bugs] #33157 [Circumvention/Snowflake]: Client generates SDP with "IN IP4 0.0.0.0", causing proxy to send "client_ip=0.0.0.0" and bridge to send "USERADDR 0.0.0.0:1"

[Tor Bug Tracker & Wiki]

#33157: Client generates SDP with "IN IP4 0.0.0.0", causing proxy to send
"client_ip=0.0.0.0" and bridge to send "USERADDR 0.0.0.0:1"
-------------------------------------+------------------------
 Reporter:  dcf                      |          Owner:  (none)
     Type:  defect                   |         Status:  new
 Priority:  Medium                   |      Milestone:
Component:  Circumvention/Snowflake  |        Version:
 Severity:  Normal                   |     Resolution:
 Keywords:                           |  Actual Points:
Parent ID:                           |         Points:
 Reviewer:                           |        Sponsor:
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Comment (by arma):

 Replying to [comment:10 dcf]:
 > Since the fix in #33385 on 2020-02-20, only about 20–30% of connections
 at the bridge have a meaningful `client_ip`. I believe this is causing us
 to undercount clients and/or bandwidth, even though we no longer set
 `USERADDR` for those 0.0.0.0 connections. In the absence of `USERADDR`,
 tor will use a 127.0.0.1 address, which like 0.0.0.0 is ignored for the
 purpose of bandwidth accounting.

 I agree with your analysis.

 I've opened #33747 to handle this situation better on the Tor side. But I
 encourage you to continue regarding "we don't send a proper ip address
 along" as a bug on the Snowflake side.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/33157#comment:11>
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