in_dport
np->in_dport = htons(np->in_dport);
if (np->in_dport != 0) {
s = portname(np->in_p, ntohs(np->in_dport));
nat->in_dport = htons($3);
} else if ($3 != nat->in_dport) {
nat->in_dport = pnum;
| daddr IPNY_PORT portstuff { nat->in_dport = $3.p1;
nat->in_dport = nat->in_pnext;
nat->in_dport = htons(nat->in_dport);
nat->in_pmin = nat->in_dport;
(np->in_dport != tcp->th_dport))
(np->in_dport != tcp->th_dport))
u_short dport = nat->in_dport;
ipn->in_dport = htons(port);