[tor-bugs] #5298 [Tor Relay]: Relay does not pick the right IP addr of local node

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#5298: Relay does not pick the right IP addr of local node
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 Reporter:  ciaccio               |          Owner:                     
     Type:  defect                |         Status:  new                
 Priority:  normal                |      Milestone:                     
Component:  Tor Relay             |        Version:  Tor: 0.2.3.12-alpha
 Keywords:  multihomed, ppp0, 3G  |         Parent:                     
   Points:                        |   Actualpoints:                     
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Comment(by ciaccio):

 Replying to [comment:5 ciaccio]:
 > Replying to [comment:4 nickm]:
 >
 > > I'm trying to understand the actual functional change in config.c
 right now -- looking at it, I think I can see how it might help with your
 situation, but I haven't yet been able to convince myself that it doesn't
 somehow break some other category of usage.  If you can maybe explain what
 the functional change is supposed to be, that could help me figure it out.
 >
 > The proposed new version of resolve_my_address() should only differ in
 the way it "guesses" the local IP address when nothing is given as
 options->Address.
 >
 > But, during debug, I preferred to rearrange the entire routine because
 the original one was a mess IMHO -- it probably suffered from too many
 consecutive ad-hoc bug fixes.
 >
 > When guessing local IP address, the old resolve_my_address() routine
 tries by first inferring the local hostname (e.g. from /etc/hostname I
 think) and resolving that; on failure, it guesses from network interfaces
 directly.  This is OK when the host is a server with a fixed public IP
 address, but not for, say, a laptop with a dynamic IP address, where the
 local hostname might not correspond to anything at all; or, a laptop with
 both a eth0 and a ppp0, where the hostname is always bound to the eth0 IP
 address even when ppp0 is actually in use (this happens when I unplug my
 laptop from the office LAN and move to home, for instance).  The new
 resolve_my_address() always guesses the local IP address from network
 interfaces directly; so it always picks the one which is currently in use.

 ...still no answer after 5 weeks or so... :-(

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/5298#comment:6>
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