void udp_input(struct mbuf *m, int off) { int iphlen = off; struct ip *ip; struct udphdr *uh; struct ifnet *ifp; struct inpcb *inp; uint16_t len, ip_len; struct inpcbinfo *pcbinfo; struct ip save_ip; struct sockaddr_in udp_in; struct m_tag *fwd_tag; int cscov_partial; uint8_t pr; ifp = m->m_pkthdr.rcvif; UDPSTAT_INC(udps_ipackets); /* * Strip IP options, if any; should skip this, make available to * user, and use on returned packets, but we don't yet have a way to * check the checksum with options still present. */ if (iphlen > sizeof (struct ip)) { ip_stripoptions(m); iphlen = sizeof(struct ip); } /* * Get IP and UDP header together in first mbuf. */ ip = mtod(m, struct ip *); if (m->m_len < iphlen + sizeof(struct udphdr)) { if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == NULL) { UDPSTAT_INC(udps_hdrops); return; } ip = mtod(m, struct ip *); } uh = (struct udphdr *)((caddr_t)ip + iphlen); pr = ip->ip_p; cscov_partial = (pr == IPPROTO_UDPLITE) ? 1 : 0; /* * Destination port of 0 is illegal, based on RFC768. */ if (uh->uh_dport == 0) goto badunlocked; /* * Construct sockaddr format source address. Stuff source address * and datagram in user buffer. */ bzero(&udp_in, sizeof(udp_in)); udp_in.sin_len = sizeof(udp_in); udp_in.sin_family = AF_INET; udp_in.sin_port = uh->uh_sport; udp_in.sin_addr = ip->ip_src; /* * Make mbuf data length reflect UDP length. If not enough data to * reflect UDP length, drop. */ len = ntohs((u_short)uh->uh_ulen); ip_len = ntohs(ip->ip_len) - iphlen; if (pr == IPPROTO_UDPLITE && len == 0) { /* Zero means checksum over the complete packet. */ len = ip_len; cscov_partial = 0; } if (ip_len != len) { if (len > ip_len || len < sizeof(struct udphdr)) { UDPSTAT_INC(udps_badlen); goto badunlocked; } if (pr == IPPROTO_UDP) m_adj(m, len - ip_len); } /* * Save a copy of the IP header in case we want restore it for * sending an ICMP error message in response. */ if (!V_udp_blackhole) save_ip = *ip; else memset(&save_ip, 0, sizeof(save_ip)); /* * Checksum extended UDP header and data. */ if (uh->uh_sum) { u_short uh_sum; if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID) && !cscov_partial) { if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR) uh_sum = m->m_pkthdr.csum_data; else uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, htonl((u_short)len + m->m_pkthdr.csum_data + pr)); uh_sum ^= 0xffff; } else { char b[9]; bcopy(((struct ipovly *)ip)->ih_x1, b, 9); bzero(((struct ipovly *)ip)->ih_x1, 9); ((struct ipovly *)ip)->ih_len = (pr == IPPROTO_UDP) ? uh->uh_ulen : htons(ip_len); uh_sum = in_cksum(m, len + sizeof (struct ip)); bcopy(b, ((struct ipovly *)ip)->ih_x1, 9); } if (uh_sum) { UDPSTAT_INC(udps_badsum); m_freem(m); return; } } else UDPSTAT_INC(udps_nosum); pcbinfo = get_inpcbinfo(pr); if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || in_broadcast(ip->ip_dst, ifp)) { struct inpcb *last; struct inpcbhead *pcblist; struct ip_moptions *imo; INP_INFO_RLOCK(pcbinfo); pcblist = get_pcblist(pr); last = NULL; LIST_FOREACH(inp, pcblist, inp_list) { if (inp->inp_lport != uh->uh_dport) continue; #ifdef INET6 if ((inp->inp_vflag & INP_IPV4) == 0) continue; #endif if (inp->inp_laddr.s_addr != INADDR_ANY && inp->inp_laddr.s_addr != ip->ip_dst.s_addr) continue; if (inp->inp_faddr.s_addr != INADDR_ANY && inp->inp_faddr.s_addr != ip->ip_src.s_addr) continue; if (inp->inp_fport != 0 && inp->inp_fport != uh->uh_sport) continue; INP_RLOCK(inp); /* * XXXRW: Because we weren't holding either the inpcb * or the hash lock when we checked for a match * before, we should probably recheck now that the * inpcb lock is held. */ /* * Handle socket delivery policy for any-source * and source-specific multicast. [RFC3678] */ imo = inp->inp_moptions; if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { struct sockaddr_in group; int blocked; if (imo == NULL) { INP_RUNLOCK(inp); continue; } bzero(&group, sizeof(struct sockaddr_in)); group.sin_len = sizeof(struct sockaddr_in); group.sin_family = AF_INET; group.sin_addr = ip->ip_dst; blocked = imo_multi_filter(imo, ifp, (struct sockaddr *)&group, (struct sockaddr *)&udp_in); if (blocked != MCAST_PASS) { if (blocked == MCAST_NOTGMEMBER) IPSTAT_INC(ips_notmember); if (blocked == MCAST_NOTSMEMBER || blocked == MCAST_MUTED) UDPSTAT_INC(udps_filtermcast); INP_RUNLOCK(inp); continue; } } if (last != NULL) { struct mbuf *n; n = m_copy(m, 0, M_COPYALL); udp_append(last, ip, n, iphlen, &udp_in); INP_RUNLOCK(last); } last = inp; /* * Don't look for additional matches if this one does * not have either the SO_REUSEPORT or SO_REUSEADDR * socket options set. This heuristic avoids * searching through all pcbs in the common case of a * non-shared port. It assumes that an application * will never clear these options after setting them. */ if ((last->inp_socket->so_options & (SO_REUSEPORT|SO_REUSEADDR)) == 0) break; } if (last == NULL) { /* * No matching pcb found; discard datagram. (No need * to send an ICMP Port Unreachable for a broadcast * or multicast datgram.) */ UDPSTAT_INC(udps_noportbcast); if (inp) INP_RUNLOCK(inp); INP_INFO_RUNLOCK(pcbinfo); goto badunlocked; } udp_append(last, ip, m, iphlen, &udp_in); INP_RUNLOCK(last); INP_INFO_RUNLOCK(pcbinfo); return; } /* * Locate pcb for datagram. */ /* * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain. */ if ((m->m_flags & M_IP_NEXTHOP) && (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { struct sockaddr_in *next_hop; next_hop = (struct sockaddr_in *)(fwd_tag + 1); /* * Transparently forwarded. Pretend to be the destination. * Already got one like this? */ inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport, ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m); if (!inp) { /* * It's new. Try to find the ambushing socket. * Because we've rewritten the destination address, * any hardware-generated hash is ignored. */ inp = in_pcblookup(pcbinfo, ip->ip_src, uh->uh_sport, next_hop->sin_addr, next_hop->sin_port ? htons(next_hop->sin_port) : uh->uh_dport, INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, ifp); } /* Remove the tag from the packet. We don't need it anymore. */ m_tag_delete(m, fwd_tag); m->m_flags &= ~M_IP_NEXTHOP; } else inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport, ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, ifp, m); if (inp == NULL) { if (udp_log_in_vain) { char buf[4*sizeof "123"]; strcpy(buf, inet_ntoa(ip->ip_dst)); log(LOG_INFO, "Connection attempt to UDP %s:%d from %s:%d\n", buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src), ntohs(uh->uh_sport)); } UDPSTAT_INC(udps_noport); if (m->m_flags & (M_BCAST | M_MCAST)) { UDPSTAT_INC(udps_noportbcast); goto badunlocked; } if (V_udp_blackhole) goto badunlocked; if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0) goto badunlocked; *ip = save_ip; icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0); return; } /* * Check the minimum TTL for socket. */ INP_RLOCK_ASSERT(inp); if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) { INP_RUNLOCK(inp); m_freem(m); return; } if (cscov_partial) { struct udpcb *up; up = intoudpcb(inp); if (up->u_rxcslen > len) { INP_RUNLOCK(inp); m_freem(m); return; } } UDP_PROBE(receive, NULL, inp, ip, inp, uh); udp_append(inp, ip, m, iphlen, &udp_in); INP_RUNLOCK(inp); return; badunlocked: m_freem(m); }
int udp6_input(struct mbuf **mp, int *offp, int proto) { struct mbuf *m = *mp; struct ifnet *ifp; struct ip6_hdr *ip6; struct udphdr *uh; struct inpcb *inp; struct inpcbinfo *pcbinfo; struct udpcb *up; int off = *offp; int cscov_partial; int plen, ulen; struct sockaddr_in6 fromsa; struct m_tag *fwd_tag; uint16_t uh_sum; uint8_t nxt; ifp = m->m_pkthdr.rcvif; ip6 = mtod(m, struct ip6_hdr *); #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE); ip6 = mtod(m, struct ip6_hdr *); uh = (struct udphdr *)((caddr_t)ip6 + off); #else IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh)); if (!uh) return (IPPROTO_DONE); #endif UDPSTAT_INC(udps_ipackets); /* * Destination port of 0 is illegal, based on RFC768. */ if (uh->uh_dport == 0) goto badunlocked; plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6); ulen = ntohs((u_short)uh->uh_ulen); nxt = ip6->ip6_nxt; cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0; if (nxt == IPPROTO_UDPLITE) { /* Zero means checksum over the complete packet. */ if (ulen == 0) ulen = plen; if (ulen == plen) cscov_partial = 0; if ((ulen < sizeof(struct udphdr)) || (ulen > plen)) { /* XXX: What is the right UDPLite MIB counter? */ goto badunlocked; } if (uh->uh_sum == 0) { /* XXX: What is the right UDPLite MIB counter? */ goto badunlocked; } } else { if ((ulen < sizeof(struct udphdr)) || (plen != ulen)) { UDPSTAT_INC(udps_badlen); goto badunlocked; } if (uh->uh_sum == 0) { UDPSTAT_INC(udps_nosum); goto badunlocked; } } if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) && !cscov_partial) { if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR) uh_sum = m->m_pkthdr.csum_data; else uh_sum = in6_cksum_pseudo(ip6, ulen, nxt, m->m_pkthdr.csum_data); uh_sum ^= 0xffff; } else uh_sum = in6_cksum_partial(m, nxt, off, plen, ulen); if (uh_sum != 0) { UDPSTAT_INC(udps_badsum); goto badunlocked; } /* * Construct sockaddr format source address. */ init_sin6(&fromsa, m); fromsa.sin6_port = uh->uh_sport; pcbinfo = get_inpcbinfo(nxt); if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { struct inpcb *last; struct inpcbhead *pcblist; struct ip6_moptions *imo; INP_INFO_RLOCK(pcbinfo); /* * In the event that laddr should be set to the link-local * address (this happens in RIPng), the multicast address * specified in the received packet will not match laddr. To * handle this situation, matching is relaxed if the * receiving interface is the same as one specified in the * socket and if the destination multicast address matches * one of the multicast groups specified in the socket. */ /* * KAME note: traditionally we dropped udpiphdr from mbuf * here. We need udphdr for IPsec processing so we do that * later. */ pcblist = get_pcblist(nxt); last = NULL; LIST_FOREACH(inp, pcblist, inp_list) { if ((inp->inp_vflag & INP_IPV6) == 0) continue; if (inp->inp_lport != uh->uh_dport) continue; if (inp->inp_fport != 0 && inp->inp_fport != uh->uh_sport) continue; if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) { if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) continue; } if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) { if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src) || inp->inp_fport != uh->uh_sport) continue; } /* * XXXRW: Because we weren't holding either the inpcb * or the hash lock when we checked for a match * before, we should probably recheck now that the * inpcb lock is (supposed to be) held. */ /* * Handle socket delivery policy for any-source * and source-specific multicast. [RFC3678] */ imo = inp->in6p_moptions; if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { struct sockaddr_in6 mcaddr; int blocked; INP_RLOCK(inp); bzero(&mcaddr, sizeof(struct sockaddr_in6)); mcaddr.sin6_len = sizeof(struct sockaddr_in6); mcaddr.sin6_family = AF_INET6; mcaddr.sin6_addr = ip6->ip6_dst; blocked = im6o_mc_filter(imo, ifp, (struct sockaddr *)&mcaddr, (struct sockaddr *)&fromsa); if (blocked != MCAST_PASS) { if (blocked == MCAST_NOTGMEMBER) IP6STAT_INC(ip6s_notmember); if (blocked == MCAST_NOTSMEMBER || blocked == MCAST_MUTED) UDPSTAT_INC(udps_filtermcast); INP_RUNLOCK(inp); /* XXX */ continue; } INP_RUNLOCK(inp); } if (last != NULL) { struct mbuf *n; if ((n = m_copy(m, 0, M_COPYALL)) != NULL) { INP_RLOCK(last); UDP_PROBE(receive, NULL, last, ip6, last, uh); udp6_append(last, n, off, &fromsa); INP_RUNLOCK(last); } } last = inp; /* * Don't look for additional matches if this one does * not have either the SO_REUSEPORT or SO_REUSEADDR * socket options set. This heuristic avoids * searching through all pcbs in the common case of a * non-shared port. It assumes that an application * will never clear these options after setting them. */ if ((last->inp_socket->so_options & (SO_REUSEPORT|SO_REUSEADDR)) == 0) break; } if (last == NULL) { /* * No matching pcb found; discard datagram. (No need * to send an ICMP Port Unreachable for a broadcast * or multicast datgram.) */ UDPSTAT_INC(udps_noport); UDPSTAT_INC(udps_noportmcast); goto badheadlocked; } INP_RLOCK(last); INP_INFO_RUNLOCK(pcbinfo); UDP_PROBE(receive, NULL, last, ip6, last, uh); udp6_append(last, m, off, &fromsa); INP_RUNLOCK(last); return (IPPROTO_DONE); } /* * Locate pcb for datagram. */ /* * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain. */ if ((m->m_flags & M_IP6_NEXTHOP) && (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { struct sockaddr_in6 *next_hop6; next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1); /* * Transparently forwarded. Pretend to be the destination. * Already got one like this? */ inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src, uh->uh_sport, &ip6->ip6_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m); if (!inp) { /* * It's new. Try to find the ambushing socket. * Because we've rewritten the destination address, * any hardware-generated hash is ignored. */ inp = in6_pcblookup(pcbinfo, &ip6->ip6_src, uh->uh_sport, &next_hop6->sin6_addr, next_hop6->sin6_port ? htons(next_hop6->sin6_port) : uh->uh_dport, INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif); } /* Remove the tag from the packet. We don't need it anymore. */ m_tag_delete(m, fwd_tag); m->m_flags &= ~M_IP6_NEXTHOP; } else inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src, uh->uh_sport, &ip6->ip6_dst, uh->uh_dport, INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m); if (inp == NULL) { if (udp_log_in_vain) { char ip6bufs[INET6_ADDRSTRLEN]; char ip6bufd[INET6_ADDRSTRLEN]; log(LOG_INFO, "Connection attempt to UDP [%s]:%d from [%s]:%d\n", ip6_sprintf(ip6bufd, &ip6->ip6_dst), ntohs(uh->uh_dport), ip6_sprintf(ip6bufs, &ip6->ip6_src), ntohs(uh->uh_sport)); } UDPSTAT_INC(udps_noport); if (m->m_flags & M_MCAST) { printf("UDP6: M_MCAST is set in a unicast packet.\n"); UDPSTAT_INC(udps_noportmcast); goto badunlocked; } if (V_udp_blackhole) goto badunlocked; if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0) goto badunlocked; icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0); return (IPPROTO_DONE); } INP_RLOCK_ASSERT(inp); up = intoudpcb(inp); if (cscov_partial) { if (up->u_rxcslen == 0 || up->u_rxcslen > ulen) { INP_RUNLOCK(inp); m_freem(m); return (IPPROTO_DONE); } } UDP_PROBE(receive, NULL, inp, ip6, inp, uh); udp6_append(inp, m, off, &fromsa); INP_RUNLOCK(inp); return (IPPROTO_DONE); badheadlocked: INP_INFO_RUNLOCK(pcbinfo); badunlocked: if (m) m_freem(m); return (IPPROTO_DONE); }