+ if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
+ in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) {
+ struct socket *last;
+ /*
+ * Deliver a multicast or broadcast datagram to *all* sockets
+ * for which the local and remote addresses and ports match
+ * those of the incoming datagram. This allows more than
+ * one process to receive multi/broadcasts on the same port.
+ * (This really ought to be done for unicast datagrams as
+ * well, but that would cause problems with existing
+ * applications that open both address-specific sockets and
+ * a wildcard socket listening to the same port -- they would
+ * end up receiving duplicates of every unicast datagram.
+ * Those applications open the multiple sockets to overcome an
+ * inadequacy of the UDP socket interface, but for backwards
+ * compatibility we avoid the problem here rather than
+ * fixing the interface. Maybe 4.5BSD will remedy this?)
+ */
+
+ /*
+ * Construct sockaddr format source address.
+ */
+ udp_in.sin_port = uh->uh_sport;
+ udp_in.sin_addr = ip->ip_src;
+ m->m_len -= sizeof (struct udpiphdr);
+ m->m_data += sizeof (struct udpiphdr);
+ /*
+ * Locate pcb(s) for datagram.
+ * (Algorithm copied from raw_intr().)
+ */
+ last = NULL;
+ for (inp = udb.inp_next; inp != &udb; inp = inp->inp_next) {
+ if (inp->inp_lport != uh->uh_dport)
+ continue;
+ if (inp->inp_laddr.s_addr != INADDR_ANY) {
+ if (inp->inp_laddr.s_addr !=
+ ip->ip_dst.s_addr)
+ continue;
+ }
+ if (inp->inp_faddr.s_addr != INADDR_ANY) {
+ if (inp->inp_faddr.s_addr !=
+ ip->ip_src.s_addr ||
+ inp->inp_fport != uh->uh_sport)
+ continue;
+ }
+
+ if (last != NULL) {
+ struct mbuf *n;
+
+ if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
+ if (sbappendaddr(&last->so_rcv,
+ (struct sockaddr *)&udp_in,
+ n, (struct mbuf *)0) == 0) {
+ m_freem(n);
+ udpstat.udps_fullsock++;
+ } else
+ sorwakeup(last);
+ }
+ }
+ last = inp->inp_socket;
+ /*
+ * Don't look for additional matches if this one
+ * does not have the SO_REUSEPORT socket option 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
+ * the SO_REUSEPORT option after setting it.
+ */
+ if ((last->so_options & SO_REUSEPORT) == 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.udps_noportbcast++;
+ goto bad;
+ }
+ if (sbappendaddr(&last->so_rcv, (struct sockaddr *)&udp_in,
+ m, (struct mbuf *)0) == 0) {
+ udpstat.udps_fullsock++;
+ goto bad;
+ }
+ sorwakeup(last);
+ return;
+ }
projects / unix-history / blobdiff