[tor-bugs] #13593 [Tor]: Is "Link 1 2" in the descriptors obsolete?

[Tor Bug Tracker & Wiki]

#13593: Is "Link 1 2" in the descriptors obsolete?
------------------------+------------------------------
     Reporter:  arma    |      Owner:
         Type:  defect  |     Status:  new
     Priority:  normal  |  Milestone:  Tor: unspecified
    Component:  Tor     |    Version:
   Resolution:          |   Keywords:
Actual Points:          |  Parent ID:
       Points:          |
------------------------+------------------------------
Description changed by arma:

Old description:

> It looks like we're up to link protocol 4 in practice, but the
> descriptors still write this static string:
> {{{
>                     "protocols Link 1 2 Circuit 1\n"
> }}}
>
> dir-spec.txt tells us
> {{{
>        Both lists are space-separated sequences of numbers, to indicate
> which
>        protocols the server supports.  As of 30 Mar 2008, specified
>        protocols are "Link 1 2 Circuit 1".  See section 4.1 of tor-
> spec.txt
>        for more information about link protocol versions.
> }}}
>
> but Section 4.1 of tor-spec.txt indeed admits to link protocols 3 and 4.
>
> It looks like nothing in routerparse.c or anywhere else looks at the
> 'protocols' line of the descriptor. Heck, normal clients don't even get
> the descriptor anymore.
>
> I assume the last Tor version to not understand link protocol 2 is way
> obsolete (Tor 0.2.0.x era I think).
>
> And if clients never see the descriptors, it's hard to imagine how we'll
> be able to tell them a different Circuit protocol anyway.
>
> Should we dump this line? Have we accidentally lost anything here?

New description:

 It looks like we're up to link protocol 4 in practice, but the descriptors
 still write this static string:
 {{{
                     "protocols Link 1 2 Circuit 1\n"
 }}}

 dir-spec.txt tells us
 {{{
        Both lists are space-separated sequences of numbers, to indicate
 which
        protocols the server supports.  As of 30 Mar 2008, specified
        protocols are "Link 1 2 Circuit 1".  See section 4.1 of tor-
 spec.txt
        for more information about link protocol versions.
 }}}

 but Section 4.1 of tor-spec.txt indeed admits to link protocols 3 and 4.

 It looks like nothing in routerparse.c or anywhere else looks at the
 'protocols' line of the descriptor. Heck, normal clients don't even get
 the descriptor anymore.

 I assume the last Tor version to not understand link protocol 2 is way
 obsolete (Tor 0.2.0.x era I think).

 And if clients never see the descriptors, it's hard to imagine how we'll
 be able to tell them a different Circuit protocol either.

 Should we dump this line? Have we accidentally lost anything here?

--

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/13593#comment:1>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online