[tor-bugs] #12971 [Tor]: Invalid SOCKS5 response to UDP associate request

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#12971: Invalid SOCKS5 response to UDP associate request
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     Reporter:  yurivict271  |      Owner:
         Type:  defect       |     Status:  new
     Priority:  normal       |  Milestone:  Tor: 0.2.???
    Component:  Tor          |    Version:
   Resolution:               |   Keywords:  tor-client
Actual Points:               |  Parent ID:
       Points:               |
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Comment (by yawning):

 Replying to [comment:5 arma]:
 > Replying to [comment:4 yawning]:
 > > FWIW we do not support UDP ASSOCIATE at all, though this is still a
 bug.  The relevant location to change would be in
 connection_edge.c:connection_mark_unattached_ap_() I believe.
 >
 > I'd try to do it in parse_socks() when we say
 > {{{
 >         /* not a connect or resolve or a resolve_ptr? we don't support
 it. */
 >         log_warn(LD_APP,"socks5: command %d not recognized. Rejecting.",
 >                  req->command);
 >         return -1;
 > }}}
 >
 > Set req->reply and req->replylen and then
 connection_ap_handshake_process_socks() will send it for you.

 Indeed that is a better place to do this.  From looking through
 `parse_socks()`, it appears that our error handling has identical issues
 in other cases where we reject the request.

 If we don't decide to fix this as part of the refactor (which will happen
 $deity knows when):

  * Add `static void make_socks_error(socks_request_t *req, uint8_t
 reason);`
  * Call with the appropriate error codes before returning out of
 `parse_socks()`

 would be trivial to implement.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/12971#comment:6>
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