2140 	struct mbuf *copym;  in ip_mloopback()  local
2142 	copym = m_copypacket(m, M_DONTWAIT);  in ip_mloopback()
2143 	if (copym != NULL &&  in ip_mloopback()
2144 	    (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip)))  in ip_mloopback()
2145 		copym = m_pullup(copym, sizeof(struct ip));  in ip_mloopback()
2146 	if (copym == NULL)  in ip_mloopback()
2152 	ip = mtod(copym, struct ip *);  in ip_mloopback()
2154 	if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) {  in ip_mloopback()
2155 		in_undefer_cksum_tcpudp(copym);  in ip_mloopback()
2156 		copym->m_pkthdr.csum_flags &=  in ip_mloopback()
2161 	ip->ip_sum = in_cksum(copym, ip->ip_hl << 2);  in ip_mloopback()
2163 	(void)looutput(ifp, copym, sintocsa(dst), NULL);  in ip_mloopback()