Tor clients share their IP with the introducer

[leif]

I just found out that clients advertise their IP to the introducer!

Storage servers on a hidden service grid will set their tub.location to their .onion address and send that instead, but clients do not need to be connected to so they don't have their own hidden services and won't set tub.location. (edit: unless they do set it to an unreachable address, which configuration.rst actually does say Tor clients should do, I realized after submitting this ticket.)

I've been running a hidden service grid for a while and just now realized (via the screenshots in ​this comment) that the introducer has a list of clients. I have not yet restarted my introducer to enable its wui to confirm that Tor clients are listing their IPs there, but I don't see why they wouldn't be since they don't have tub.location set.

Is there any reason clients need to tell the introducer their addresses at all?

I think the section of configuration.rst that mentions hidden services should include a caveat about how Tahoe is not yet actually ready for anonymous use, mentioning this issue as well as #1942.

I'm setting the milestone to 1.10 in hopes that this documentation change can make the upcoming release.

[leif]

Actually, I just re-read configuration.rst and see I missed part of it before... it does actually say this:

    * Run a node behind a Tor proxy (perhaps via ``torsocks``), in
      client-only mode (i.e. we can make outbound connections, but other
      nodes will not be able to connect to us). The literal
      '``unreachable.example.org``' will not resolve, but will serve as a
      reminder to human observers that this node cannot be reached. "Don't
      call us.. we'll call you"::

        tub.port = 8098
        tub.location = unreachable.example.org:0

I still think the Tor configuration docs should be cleaned up, but the situation isn't as bad as I thought... I just failed at reading the docs. Apologies!

[zooko]

related: #517, #1942, #1086, #344, pipermail/tahoe-dev/2010-June/004451.html, FAQ 21, comment:18:ticket:1010