BSD 4.4 Lite Kernel Sources

1 files changed, 313 insertions, 0 deletions

diff --git a/sys/netinet/igmp.c b/sys/netinet/igmp.c
new file mode 100644
index 0000000..78b426c
--- /dev/null
+++ b/sys/netinet/igmp.c
@@ -0,0 +1,313 @@
+/*
+ * Copyright (c) 1988 Stephen Deering.
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Stephen Deering of Stanford University.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)igmp.c	8.1 (Berkeley) 7/19/93
+ */
+
+/* Internet Group Management Protocol (IGMP) routines. */
+
+
+#include <sys/param.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/protosw.h>
+
+#include <net/if.h>
+#include <net/route.h>
+
+#include <netinet/in.h>
+#include <netinet/in_var.h>
+#include <netinet/in_systm.h>
+#include <netinet/ip.h>
+#include <netinet/ip_var.h>
+#include <netinet/igmp.h>
+#include <netinet/igmp_var.h>
+
+extern struct ifnet loif;
+
+static int igmp_timers_are_running = 0;
+static u_long igmp_all_hosts_group;
+
+static void igmp_sendreport __P((struct in_multi *));
+
+void
+igmp_init()
+{
+	/*
+	 * To avoid byte-swapping the same value over and over again.
+	 */
+	igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);
+}
+
+void
+igmp_input(m, iphlen)
+	register struct mbuf *m;
+	register int iphlen;
+{
+	register struct igmp *igmp;
+	register struct ip *ip;
+	register int igmplen;
+	register struct ifnet *ifp = m->m_pkthdr.rcvif;
+	register int minlen;
+	register struct in_multi *inm;
+	register struct in_ifaddr *ia;
+	struct in_multistep step;
+
+	++igmpstat.igps_rcv_total;
+
+	ip = mtod(m, struct ip *);
+	igmplen = ip->ip_len;
+
+	/*
+	 * Validate lengths
+	 */
+	if (igmplen < IGMP_MINLEN) {
+		++igmpstat.igps_rcv_tooshort;
+		m_freem(m);
+		return;
+	}
+	minlen = iphlen + IGMP_MINLEN;
+	if ((m->m_flags & M_EXT || m->m_len < minlen) &&
+	    (m = m_pullup(m, minlen)) == 0) {
+		++igmpstat.igps_rcv_tooshort;
+		return;
+	}
+
+	/*
+	 * Validate checksum
+	 */
+	m->m_data += iphlen;
+	m->m_len -= iphlen;
+	igmp = mtod(m, struct igmp *);
+	if (in_cksum(m, igmplen)) {
+		++igmpstat.igps_rcv_badsum;
+		m_freem(m);
+		return;
+	}
+	m->m_data -= iphlen;
+	m->m_len += iphlen;
+	ip = mtod(m, struct ip *);
+
+	switch (igmp->igmp_type) {
+
+	case IGMP_HOST_MEMBERSHIP_QUERY:
+		++igmpstat.igps_rcv_queries;
+
+		if (ifp == &loif)
+			break;
+
+		if (ip->ip_dst.s_addr != igmp_all_hosts_group) {
+			++igmpstat.igps_rcv_badqueries;
+			m_freem(m);
+			return;
+		}
+
+		/*
+		 * Start the timers in all of our membership records for
+		 * the interface on which the query arrived, except those
+		 * that are already running and those that belong to the
+		 * "all-hosts" group.
+		 */
+		IN_FIRST_MULTI(step, inm);
+		while (inm != NULL) {
+			if (inm->inm_ifp == ifp && inm->inm_timer == 0 &&
+			    inm->inm_addr.s_addr != igmp_all_hosts_group) {
+				inm->inm_timer =
+				    IGMP_RANDOM_DELAY(inm->inm_addr);
+				igmp_timers_are_running = 1;
+			}
+			IN_NEXT_MULTI(step, inm);
+		}
+
+		break;
+
+	case IGMP_HOST_MEMBERSHIP_REPORT:
+		++igmpstat.igps_rcv_reports;
+
+		if (ifp == &loif)
+			break;
+
+		if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr)) ||
+		    igmp->igmp_group.s_addr != ip->ip_dst.s_addr) {
+			++igmpstat.igps_rcv_badreports;
+			m_freem(m);
+			return;
+		}
+
+		/*
+		 * KLUDGE: if the IP source address of the report has an
+		 * unspecified (i.e., zero) subnet number, as is allowed for
+		 * a booting host, replace it with the correct subnet number
+		 * so that a process-level multicast routing demon can
+		 * determine which subnet it arrived from.  This is necessary
+		 * to compensate for the lack of any way for a process to
+		 * determine the arrival interface of an incoming packet.
+		 */
+		if ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) == 0) {
+			IFP_TO_IA(ifp, ia);
+			if (ia) ip->ip_src.s_addr = htonl(ia->ia_subnet);
+		}
+
+		/*
+		 * If we belong to the group being reported, stop
+		 * our timer for that group.
+		 */
+		IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
+		if (inm != NULL) {
+			inm->inm_timer = 0;
+			++igmpstat.igps_rcv_ourreports;
+		}
+
+		break;
+	}
+
+	/*
+	 * Pass all valid IGMP packets up to any process(es) listening
+	 * on a raw IGMP socket.
+	 */
+	rip_input(m);
+}
+
+void
+igmp_joingroup(inm)
+	struct in_multi *inm;
+{
+	register int s = splnet();
+
+	if (inm->inm_addr.s_addr == igmp_all_hosts_group ||
+	    inm->inm_ifp == &loif)
+		inm->inm_timer = 0;
+	else {
+		igmp_sendreport(inm);
+		inm->inm_timer = IGMP_RANDOM_DELAY(inm->inm_addr);
+		igmp_timers_are_running = 1;
+	}
+	splx(s);
+}
+
+void
+igmp_leavegroup(inm)
+	struct in_multi *inm;
+{
+	/*
+	 * No action required on leaving a group.
+	 */
+}
+
+void
+igmp_fasttimo()
+{
+	register struct in_multi *inm;
+	register int s;
+	struct in_multistep step;
+
+	/*
+	 * Quick check to see if any work needs to be done, in order
+	 * to minimize the overhead of fasttimo processing.
+	 */
+	if (!igmp_timers_are_running)
+		return;
+
+	s = splnet();
+	igmp_timers_are_running = 0;
+	IN_FIRST_MULTI(step, inm);
+	while (inm != NULL) {
+		if (inm->inm_timer == 0) {
+			/* do nothing */
+		} else if (--inm->inm_timer == 0) {
+			igmp_sendreport(inm);
+		} else {
+			igmp_timers_are_running = 1;
+		}
+		IN_NEXT_MULTI(step, inm);
+	}
+	splx(s);
+}
+
+static void
+igmp_sendreport(inm)
+	register struct in_multi *inm;
+{
+	register struct mbuf *m;
+	register struct igmp *igmp;
+	register struct ip *ip;
+	register struct ip_moptions *imo;
+	struct ip_moptions simo;
+
+	MGETHDR(m, M_DONTWAIT, MT_HEADER);
+	if (m == NULL)
+		return;
+	/*
+	 * Assume max_linkhdr + sizeof(struct ip) + IGMP_MINLEN
+	 * is smaller than mbuf size returned by MGETHDR.
+	 */
+	m->m_data += max_linkhdr;
+	m->m_len = sizeof(struct ip) + IGMP_MINLEN;
+	m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;
+
+	ip = mtod(m, struct ip *);
+	ip->ip_tos = 0;
+	ip->ip_len = sizeof(struct ip) + IGMP_MINLEN;
+	ip->ip_off = 0;
+	ip->ip_p = IPPROTO_IGMP;
+	ip->ip_src.s_addr = INADDR_ANY;
+	ip->ip_dst = inm->inm_addr;
+
+	igmp = (struct igmp *)(ip + 1);
+	igmp->igmp_type = IGMP_HOST_MEMBERSHIP_REPORT;
+	igmp->igmp_code = 0;
+	igmp->igmp_group = inm->inm_addr;
+	igmp->igmp_cksum = 0;
+	igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN);
+
+	imo = &simo;
+	bzero((caddr_t)imo, sizeof(*imo));
+	imo->imo_multicast_ifp = inm->inm_ifp;
+	imo->imo_multicast_ttl = 1;
+	/*
+	 * Request loopback of the report if we are acting as a multicast
+	 * router, so that the process-level routing demon can hear it.
+	 */
+#ifdef MROUTING
+    {
+	extern struct socket *ip_mrouter;
+	imo->imo_multicast_loop = (ip_mrouter != NULL);
+    }
+#endif
+	ip_output(m, NULL, NULL, 0, imo);
+
+	++igmpstat.igps_snd_reports;
+}