Re: Issue about selection of Tor relays when using the default torrc configuration

[Roger Dingledine <arma@xxxxxxx>]

On Mon, Jun 01, 2009 at 05:38:43PM -0400, Sambuddho Chakravarty wrote:
> I am running tor-0.2.1.15-rc ; source downloaded from the tor website 
> .  For my purpose I am tapping into the function 
> circuituse.c:circuit_has_opened()  to determine which relays are being 
> used in a stream (assuming only one stream is using Tor).

One stream ever is probably a bad assumption. Tor generates streams to
do its directory lookups, for example.

A better place to instrument might be
connection_ap_handshake_send_begin().

But overall, as long as you're smart and check that it's really the
circuit and stream you think it is, you should be fine either way.

> However the IP 
> address of the relays I see here don't match the list of relays for the 
> stream when I determine them using
> 'get_info stream-status'. Which one should I rely upon to determine 
> which circuit is being used ? Common sense tells me to rely on 'get_info 
> stream_status'.

I dunno. Depends how you are doing things differently than we expected
you to. :) Perhaps some more details, of exactly what you're doing and
exactly what you expect and exactly what you get instead, would help us
guess.

> However , I see the client crash at times when I connect 
> to the control port .

Perhaps you introduced a bug when you made changes to Tor?

Or perhaps there is a crash bug in Tor when using it the way you're
trying to. If the latter, we'd love to hear more. There's a FAQ entry
that explains some of the ways you can help report:
https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ#ReportBug

Running it in gdb should help you get a backtrace, to pinpoint the
problem.

--Roger