[tor-bugs] #19191 [Core Tor/Tor]: {BUG} directory_send_command: Bug: Squid does not like URLs longer than 4095 bytes, and this one is 20515 bytes long

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#19191: {BUG} directory_send_command: Bug: Squid does not like URLs longer than
4095 bytes, and this one is 20515 bytes long
--------------------------+------------------------------------
 Reporter:  fk            |          Owner:
     Type:  defect        |         Status:  new
 Priority:  Medium        |      Milestone:  Tor: 0.2.8.x-final
Component:  Core Tor/Tor  |        Version:  Tor: 0.2.8.3-alpha
 Severity:  Normal        |     Resolution:
 Keywords:  regression    |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:
--------------------------+------------------------------------

Comment (by nickm):

 So, it appears that max_dl_per_request is now happily returning a big
 number...
 {{{
   /* If we're going to tunnel our connections, we can ask for a lot more
    * in a request. */
   if (!directory_fetches_from_authorities(options)) {
     max = 500;
   }
 }}}

 ... but we still run our squid-check code on all (non-tunneled) directory
 connections, since conceivably they will hit a transparent proxy with a
 size limit:
 {{{
   /* warn in the non-tunneled case */
   if (direct && (strlen(proxystring) + strlen(url) >= 4096)) {
     log_warn(LD_BUG,
              "Squid does not like URLs longer than 4095 bytes, and this "
              "one is %d bytes long: %s%s",
              (int)(strlen(proxystring) + strlen(url)), proxystring, url);
   }
 }}}

 So I think there are a couple possible "real problems" I can think of
 here:
   * The "real problem" might be that max_dl_per_request should be checking
 something other than directory_fetches_from_authorities() to predict
 whether we'll be tunneling the connection.
   * The "real problem" might be that we're not tunneling this connection,
 even though we don't fetch from authorities.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/19191#comment:2>
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