Re: Need a cluebat (was: Bug#31243: cfingerd segfaults on multihomed server)

[Mike Goldman <whig@by.net>]

Martin Schulze wrote:

> I'm sorry to bother you but I need a cluebat now.  I appreciate if
> everybody could send me a hint why this error could happen.
>
> Martin Schulze wrote:
> > > Cfingerd is installed on a server with multiple names/IPs.  Primary is
> > > locke.adm.by.net, 209.195.180.3.  Alternate is mailbox.by.net,
> > > 209.195.180.7.  When finger is sent to primary address, cfingerd responds
> > > correctly.  When sent to the alternate address, segfault occurs.  Log
> > > attached for each instance.  This problem does not exist in hamm
> > > cfingerd-1.3.2-11.0.
> > >
> > > [whig@jefferson ~]$ finger whig@locke.adm.by.net
> > > [locke.adm.by.net]
> > > Username: whig                      In real life: Mike Goldman
> > >
> > > [whig@jefferson ~]$ finger whig@mailbox.by.net
> > > [mailbox.by.net]
> > > Signal "SIGSEGV": Segmentation violation signal
> > >
> > > Please report this bug to cfingerd@infodrom.north.de!
>
> There are .nofinger files disabling everything.
>
> > Please try to finger joey@infodrom.north.de and joey@artis.uni-oldenburg.de.
> > Both end up on the same machine but run on different IP numbers.
>
> And the problem is reproducable.  I already tried to use strace
> but it didn't give me a hint why cfingerd didn't like the multi-ip
> setup.
>
> This is a difference, but it shouldn't be responsible for such a damage.
>
> -getsockname(0, {sin_family=AF_INET, sin_port=htons(79), sin_addr=inet_addr("134.106.121.3")}, [16]) = 0
> -getpeername(0, {sin_family=AF_INET, sin_port=htons(27790), sin_addr=inet_addr("134.106.121.40")}, [16]) = 0
> +getsockname(0, {sin_family=AF_INET, sin_port=htons(79), sin_addr=inet_addr("134.106.121.2")}, [16]) = 0
> +getpeername(0, {sin_family=AF_INET, sin_port=htons(27787), sin_addr=inet_addr("134.106.121.40")}, [16]) = 0

To clarify:

My machine (locke.adm.by.net / mailbox.by.net) is a production server, and I have backed off to the hamm
version 1.3.2-11.0.  Therefore fingering my accounts now will demonstrate nothing, as with or without a
.nofinger, it will not segfault.  Try, instead, to finger joey@artis.uni-oldenburg.de or
joey@sibelius.artis.uni-oldenburg.de to see the error.  By contrast, finger joey@infodrom.north.de will work
fine, because this resolves the primary IP address of the multihomed host.

FWIW, .nofinger does not prevent the segfault in the slink version.