st_proto
if (s1->st_proto > s2->st_proto)
if (s1->st_proto < s2->st_proto)
#define IPFW_STATE_TCPCLOSED(s) ((s)->st_proto == IPPROTO_TCP && \
ioc_id->u.ip.proto = s->st_proto;
if (s->st_proto != IPPROTO_TCP)