key_portfromsaddr
udp->uh_sport = key_portfromsaddr(&saidx->src);
udp->uh_dport = key_portfromsaddr(&saidx->dst);
key_portfromsaddr(&sav->sah->saidx.dst),
key_portfromsaddr(&sav->sah->saidx.src),
u_int16_t key_portfromsaddr(const union sockaddr_union *);