[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:                
-------------------------+--------------------------------------------------
Changes (by asn):

  * status:  needs_review => needs_revision


Comment:

 Thanks for all the code, karsten!

 I skimmed over the code while I was in the subway, here is a quick and
 dirty code review:

 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.

 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.

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

 Thanks for the code again!

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/5083#comment:6>
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