tcp_tun_port
m->m_pkthdr.tcp_tun_port = port;
port = m->m_pkthdr.tcp_tun_port;
port = m->m_pkthdr.tcp_tun_port;
m->m_pkthdr.tcp_tun_port = port = uh->uh_sport;
if (tp->t_port != m->m_pkthdr.tcp_tun_port) {