[tor-bugs] #18620 [Core Tor/Tor]: HSFORGET command to clear cached client state for a HS

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#18620: HSFORGET command to clear cached client state for a HS
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 Reporter:  str4d                                |          Owner:  str4d
     Type:  enhancement                          |         Status:
 Priority:  Medium                               |  needs_revision
Component:  Core Tor/Tor                         |      Milestone:  Tor:
 Severity:  Normal                               |  0.2.9.x-final
 Keywords:  tor-hs, 029-accepted, review-        |        Version:  Tor:
  group-1                                        |  0.2.7.6
Parent ID:                                       |     Resolution:
 Reviewer:  asn                                  |  Actual Points:
                                                 |         Points:  small
                                                 |        Sponsor:
                                                 |  SponsorR-can
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Comment (by str4d):

 Thanks for the review asn! Apologies for the issues getting the patch to
 work - it was based on Tor 0.2.7.6 (which is the version Briar is
 currently using). I have ported the patch onto master (with associated
 changes per your review), and uploaded it here:

 https://github.com/str4d/tor/tree/18620-hsforget

 > Do you think that would be useful for this patch?

 I don't believe so, because the new `rend_cache_remove_entry()` function
 calls `rend_cache_entry_free(cache_entry)`, which calls
 `rend_service_descriptor_free(cache_entry->parsed)`, which contains:

 {{{
   if (desc->intro_nodes) {
     SMARTLIST_FOREACH(desc->intro_nodes, rend_intro_point_t *, intro,
       rend_intro_point_free(intro););
     smartlist_free(desc->intro_nodes);
   }
 }}}

 Thus the `rend_intro_point_t` objects are never reused.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/18620#comment:16>
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