Hurd support in libpcap

[Richard Braun]

Hello,

A while ago, I added support for Hurd (actually Mach) network devices
in libpcap. I've refreshed this work so that it now tries to fetch
data from netdde before trying a Mach device, just like pfinet does.
Debian packages built with the patch [1] are available from my
repository for tests :

deb http://ftp.sceen.net/debian-hurd-i386 experimental/
deb-src http://ftp.sceen.net/debian-hurd-i386 experimental/

The first issue that can be noticed is that, despite the filter being
filled with both NETF_IN and NETF_OUT, only incoming packets seem
to be captured. This is probably a minor bug in libbpf but I didn't
investigate yet.

-- 
Richard Braun

[1] 
http://darnassus.sceen.net/~rbraun/0001-Debian-GNU-Hurd-with-NETDDE-support.patch