bpf: every packet to host is marked as seen
bpf: every packet to host is marked as seen

Then we can easily tell if a packet was process by bpf or not and we can
use iptables to do some additional action on the (not) seen packets.

Metaswitch/calico,neiljerram/felix,neiljerram/felix,Metaswitch/calico,neiljerram/felix,neiljerram/felix