[tor-bugs] #21084 [Core Tor/Tor]: sometimes we call circuit has_opened() more than 2 times on client side

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#21084: sometimes we call circuit has_opened() more than 2 times on client side
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 Reporter:  s7r           |          Owner:
     Type:  defect        |         Status:  needs_information
 Priority:  Medium        |      Milestone:  Tor: 0.3.0.x-final
Component:  Core Tor/Tor  |        Version:  Tor: 0.3.0.1-alpha
 Severity:  Normal        |     Resolution:
 Keywords:  tor-hs        |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:
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Changes (by dgoulet):

 * status:  new => needs_information


Comment:

 So intro points have this interesting behavior which is if you get a NACK
 client side, the client will reuse the circuit (a 3 hops circuit) and re-
 extend it to another intro point making the circuit 4 hops. It will do
 that until the circuit reaches its hard limit of 7 hops. But if this
 happens, you should see that log statement in your logs:

 {{{
     log_info(LD_REND, "Got nack for %s from %s...",
         safe_str_client(rend_data_get_address(circ->rend_data)),
 safe_str_client(extend_info_describe(circ->build_state->chosen_exit)));
 }}}

 Else, I can see that it opens 2 times on a cannibalize circuit which is 3
 hops and then extended to 4 hops. However, a 5 hops circuit, apart from
 the behavior described above, I'm not sure it's normal for both a service
 or client...?

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/21084#comment:2>
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