[tor-dev] Design for an exit relay scanner: feedback appreciated

[Philipp Winter]

On Thu, Oct 10, 2013 at 07:23:11AM +0000, Aaron wrote:
> I have been working on adding a "Tor Network Test Template" to
> ooni-probe; the basic concept is to extend the Tor controller
> library we use (txtorcon) to be able to build and attach
> circuits to specific streams, and iterate over the exits in
> the consensus.

I now have similar code which is based on stem:
https://github.com/NullHypothesis/exitmap

However, the problem with a parallel single-Tor-process design
is that there is no easy way for scanning modules to figure out
which exit relay they were attached to.  The Tor controller just
sees a bunch of incoming streams but once, one of these streams
spots something fishy, it is difficult to figure out which exit
relay is to blame.

Cheers,
Philipp