tcp_signature
if (tcp_signature(tdb, tp->pf, m, th, iphlen, 1, sig) < 0)
if (tcp_signature(tdb, sc->sc_src.sa.sa_family, m, th,
if (tcp_signature(tdb, tp->pf, m, th, iphlen, 0,
int tcp_signature(struct tdb *, int, struct mbuf *, struct tcphdr *,