Bug#719960: libnet-arp-perl: Net::ARP::arp_lookup always fails (regression)

[Florian Schlichting]

severity 719960 normal
thanks

On Sat, Aug 17, 2013 at 11:33:31AM +0200, Olof Johansson wrote:
> On 2013-08-17 10:19 +0200, Vincent Lefevre wrote:
> > After the upgrade to libnet-arp-perl 1.0.8-1, Net::ARP::arp_lookup
> > always fails:
> > 
> > xvii:~> perl -MNet::ARP -e 'print "-> ".Net::ARP::arp_lookup(undef,"192.168.1.1")."\n"'
> > No valid device name found.
> > -> unknown
> 
> I can't seem to find any references to arp_lookup accepting undef as
> device in the manual. I can reproduce your issue, but actually setting
> device to something makes it work. I'm inclined to disagree on this
> being grave. Imho.
> 
> $ perl -MNet::ARP -E 'say Net::ARP::arp_lookup("wlan0", "192.168.1.1")'

The implementation changed between 1.0.4-1 and 1.0.8-1; whereas before,
it would just open /proc/net/arp and look for the IP address, matching
the device only when given, it now uses the SIOCGARP ioctl for which a
device name is mandatory.

So I think this "works as intended", but one could perhaps ask upstream
to provide an option to iterate over several / all available devices, or
amend the documentation to explain that undef values are not / no longer
supported.

Florian