[tor-bugs] #17821 [metrics-lib]: adapt metrics-lib to actual tordnsel format

[Tor Bug Tracker & Wiki]

#17821: adapt metrics-lib to actual tordnsel format
-----------------------------+---------------------
     Reporter:  iwakeh       |      Owner:  karsten
         Type:  defect       |     Status:  new
     Priority:  Medium       |  Milestone:
    Component:  metrics-lib  |    Version:
     Severity:  Normal       |   Keywords:
Actual Points:               |  Parent ID:
       Points:               |    Sponsor:
-----------------------------+---------------------
 Currently metrics-lib only reads tordnsel descriptors that contain
 exactly one ExitAddress entry. This does not reflect the torperf data,
 which can contain several ExitAddress entries
 [https://collector.torproject.org/#exit-lists TorDNSEL description] (see
 also #17701), i.e.
 {{{
 ExitNode D41C2006D7C461BDC22B9D236CC93F5D366C1388
 Published 2015-12-11 12:28:41
 LastStatus 2015-12-11 13:02:32
 ExitAddress 37.48.65.71 2015-12-10 19:10:50
 ExitAddress 37.48.74.44 2015-12-11 13:06:36
 }}}

 === solution
 metrics-libs should process tordnsel descriptors with an arbitrary count
 (but finite ;-) of ExitAddress lines.

 (I could only find entries with one and two ExitAddress lines, but there
 is no limit stated in the spec.)

 === proposed changes
 The interface needs to be changed:
 I suggest that the current getExitAddress is marked deprecated and
 returns one of the addresses read for backward compatibility
 {{{
  /**
   * Return one IP address that was determined in the scan.
   * @deprecated use getExitAddresses()
   */
   public String getExitAddress();
 }}}

 In addition, a new method should be added
 {{{
  /* Return the IP addresses that were determined in the scan. */
   public List<String> getExitAddresses();
 }}}


 Is this ok? Should anything be added or changed?

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/17821>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online