[tor-bugs] #8596 [Tor]: Inconsistent addrmap events when resolving hostname (regression)

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#8596: Inconsistent addrmap events when resolving hostname (regression)
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 Reporter:  Desoxy                     |          Owner:                     
     Type:  defect                     |         Status:  new                
 Priority:  normal                     |      Milestone:  Tor: 0.2.4.x-final 
Component:  Tor                        |        Version:  Tor: 0.2.4.11-alpha
 Keywords:  tor-client controller dns  |         Parent:                     
   Points:                             |   Actualpoints:                     
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 Tor 0.2.3.x would generate an ADDRMAP event for all addresses added to the
 cache, and since all resolved IPv4 addresses were added to the cache, all
 IPv4 addresses generated an ADDRMAP event. Ticket #7570 introduced
 circuit-based separation of the DNS cache and "broke" that mechanism:
 Resolves generated via the DNSPort or a control connection do not end up
 in the cache and thus don't generate an ADDRMAP event. Also, when the
 cache is disabled by adding the `SocksPort 9050 NoCacheDNS` to the torrc,
 no ADDRMAP event is generated.

 Git-bisect shows commit 7536c40e9641a0724f0c9e6f994306d762d37e4d[1]
 introduced this problem.

 First, we should be clear about when to generate ADDRMAP events. From the
 control spec:

 {{{
 4.1.7. New Address mapping

   These events are generated when a new address mapping is entered in
   Tor's address map cache, or when the answer for a RESOLVE command is
   found.
 }}}

 This would mean that DNS data retrieved for DNSPort queries or when
 NoCacheDNS is set would not trigger an event. Do we want this behavior? Or
 do we want to trigger ADDRMAP events for any mapping that is not already
 in the cache, even if it is not going to be cached anyway?

 1:
 https://gitweb.torproject.org/tor.git/commitdiff/7536c40e9641a0724f0c9e6f994306d762d37e4d?hp=f33487668f16dbd7f95eaf8644865c28e1dd7036

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/8596>
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