[tor-bugs] #22453 [Core Tor/Tor]: Relays should regularly do a larger bandwidth self-test

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#22453: Relays should regularly do a larger bandwidth self-test
-------------------------------------------------+-------------------------
 Reporter:  arma                                 |          Owner:  juga
     Type:  enhancement                          |         Status:
                                                 |  assigned
 Priority:  Medium                               |      Milestone:  Tor:
                                                 |  unspecified
Component:  Core Tor/Tor                         |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  034-triage-20180328,                 |  Actual Points:
  034-removed-20180328, tor-bwauth               |
Parent ID:  #25925                               |         Points:
 Reviewer:                                       |        Sponsor:
-------------------------------------------------+-------------------------

Comment (by juga):

 Diving into the code i found that the function where the relay bandwidth
 is compared with `options->AuthDirGuardBWGuarantee` is in
 `set_routerstatus_from_routerinfo` [0].

 To obtain the relay bandwidth, that function calls
 `dirserv_get_credible_bandwidth_kb` [1] which seems to be using either the
 measured bandwidth (by bwauths) or the self advertised bandwidth, but not
 any self measured bandwidth.

 If i understand it correctly, the self measured bandwidth
 (`bandwidthcapacity`) is obtained by `rep_hist_bandwidth_assess` [2].

 The function that is making use of the circuits to test the bandwidth is
 `router_perform_bandwidth_test` [3] but i don't see how it is storing the
 results or how is related with the previous.

 So, should `dirserv_get_credible_bandwidth_kb` make use of the bandwidth
 calculated by self tests?, which are the self tests here to be used?

 Where in the code should go the `times out after 30-60`?, and the `12-24
 hours, at random`?

 [0] https://gitweb.torproject.org/tor.git/tree/src/or/dirserv.c#n2058
 [1] https://gitweb.torproject.org/tor.git/tree/src/or/dirserv.c#n1780
 [2] https://gitweb.torproject.org/tor.git/tree/src/or/rephist.c#n1207
 [3] https://gitweb.torproject.org/tor.git/tree/src/or/router.c#n1626

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/22453#comment:16>
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