[tor-bugs] #6031 [Tor Hidden Services]: Distinguish when a Tor HS is "not found" vs "not reachable" (exists / does not exists)

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#6031: Distinguish when a Tor HS is "not found" vs "not reachable" (exists / does
not exists)
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 Reporter:  naif                 |          Owner:     
     Type:  enhancement          |         Status:  new
 Priority:  normal               |      Milestone:     
Component:  Tor Hidden Services  |        Version:     
 Keywords:                       |         Parent:     
   Points:                       |   Actualpoints:     
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Comment(by naif):

 Well,

 i think that the various way to check this could be:

 a) SOCKS level
    Given that there is no documented specific reply for that, we could use
 reply
              o  X'09' to X'FF' unassigned
    that are unassigned by the RFC and give the meaning of "Host not
 found".

    This means that the socks client must manage this new REP code.

 b) Tor CP level
    Extend messages so that if a Circuit is created manually from Tor
 Control Port, a Tor CP client can know if a TorHS exists or not

    This would mean that a client, before connecting to a TorHS host,
 should go trough Tor CP and manually establish a circuit.

 c) Tor DNS Resolver level
    We may leverage the DNS Resolver of Tor, to handle such situation when
 we have a configuration like:
      VirtualAddrNetwork 10.192.0.0/10
      AutomapHostsOnResolve 1
      DNSPort 53

    In that case we may handle the "Host Not Found" condition case.

    This would mean that a client, before connecting to a TorHS host,
 should go trough DNS query.


 I would suggest to goes for an unassigned SOCKS REP code.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/6031#comment:6>
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