xnb_fill_eh_and_ip
static void xnb_fill_eh_and_ip(struct mbuf *m, uint16_t ip_len,
xnb_fill_eh_and_ip(mbufc, 84, 28, IPPROTO_ICMP, 0, 0);
xnb_fill_eh_and_ip(mbufc, 36, 4, IPPROTO_UDP, 0, 0xbaad);
xnb_fill_eh_and_ip(m, 60, 8, IPPROTO_TCP, IP_DF, 0);