icmp_error
icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
icmp_error(m0, type, code, 0, 0);
icmp_error(m0, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG, 0,
icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
void icmp_error (struct mbuf *, int, int, n_long, int);
icmp_error(m, type, code, 0, 0);
icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
icmp_error(mcopy, type, code, dest, destmtu);
icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);