extensions: add connlabel match

allows to "tag" connections with up to 128 label names.

Labels are defined in /etc/xtables/connlabel.conf, example:
0 from eth0
1 via eth0

Labels can then be attached to flows, e.g.

-A PREROUTING  -i eth0 -m connlabel --label "from eth0" --set

Signed-off-by: Florian Westphal <fw@strlen.de>
5 files changed