[tor-bugs] #5083 [Obfsproxy]: Implement heartbeat message in obfsproxy

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#5083: Implement heartbeat message in obfsproxy
-------------------------+--------------------------------------------------
 Reporter:  karsten      |          Owner:  asn           
     Type:  enhancement  |         Status:  needs_revision
 Priority:  normal       |      Milestone:                
Component:  Obfsproxy    |        Version:                
 Keywords:               |         Parent:                
   Points:               |   Actualpoints:                
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Comment(by karsten):

 Replying to [comment:6 asn]:
 > The check
 > {{{
 >   p = strrchr(addrport, ':');
 >   if (p < 0)
 >     return;
 > }}}
 >  in `status_note_connection()` seems wrong. `strrchr()` returns a
 pointer, so `if (!p)` is probably better than `if (p < 0)`. I wonder if we
 should use `strchr()` like `util.c:resolve_address_port()` does; but it
 probably doesn't really matter.

 Ah, there's the code I was looking for.  I'm going to steal it from there.

 > b) Should we use a hash table or something to query whether a connection
 has been seen before? It seems that `smartlist_string_isin()` does a
 linear search over a smartlist, and some obfsproxy bridge operators are
 currently seeing 1500~ or so unique IPs. I'm not sure if that would cause
 lots of load, but a hash table (I think that's a `strmap_t` in
 `container.c`) might be better.

 Oh.  You're right.  strmap_t it is.

 > c) Are unique IPs and connections information useful/meaningful in the
 case of obfsproxy clients?

 They're the most basic statistics that we have about obfsproxy usage.  I'd
 prefer having a GeoIP database in obfsproxy and resolve both connections
 and unique addresses to country codes.  But that requires more coding,
 reviewing, and time that we don't have.

 > Thanks for the code again!

 Thanks for the review!  I'll make the changes hopefully later today,
 otherwise tomorrow morning.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/5083#comment:7>
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