Add user-space code to support the new BPF iptables extension.
Pablo has mangled the original patch to:
* include a copy of include/linux/netfilter/xt_bpf.h in the tree.
* I have also remove the --bytecode-file option. The original
proposal was to accept BPF code in a file in human readable
format. Now, with the nfbpf_compile utility, it's very easy
to generate the filter using tcpdump-like syntax.
* I have remove the trailing comma in the backtick format, the
parser works just fine for me here.
* Fix error message if --bytecode is missing.
Signed-off-by: Willem de Bruijn <email@example.com>
Signed-off-by: Pablo Neira Ayuso <firstname.lastname@example.org>