in6p_lport
if (in6p->in6p_lport ||
if (in6p->in6p_lport == 0) {
udp6->uh_sport = in6p->in6p_lport; /* lport is always set in the PCB */
if (in6p->in6p_lport != uh->uh_dport)
&inp->in6p_laddr, inp->in6p_lport);