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-rw-r--r--c/src/lib/libnetworking/netinet/igmp.c479
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diff --git a/c/src/lib/libnetworking/netinet/igmp.c b/c/src/lib/libnetworking/netinet/igmp.c
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+++ b/c/src/lib/libnetworking/netinet/igmp.c
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+/*
+ * 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
+ * $Id$
+ */
+
+/*
+ * Internet Group Management Protocol (IGMP) routines.
+ *
+ * Written by Steve Deering, Stanford, May 1988.
+ * Modified by Rosen Sharma, Stanford, Aug 1994.
+ * Modified by Bill Fenner, Xerox PARC, Feb 1995.
+ * Modified to fully comply to IGMPv2 by Bill Fenner, Oct 1995.
+ *
+ * MULTICAST Revision: 3.5.1.4
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/protosw.h>
+#include <sys/kernel.h>
+#include <sys/sysctl.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>
+
+static struct router_info *
+ find_rti __P((struct ifnet *ifp));
+
+static struct igmpstat igmpstat;
+
+SYSCTL_STRUCT(_net_inet_igmp, IGMPCTL_STATS, stats, CTLFLAG_RD,
+ &igmpstat, igmpstat, "");
+
+static int igmp_timers_are_running;
+static u_long igmp_all_hosts_group;
+static u_long igmp_all_rtrs_group;
+static struct mbuf *router_alert;
+static struct router_info *Head;
+
+static void igmp_sendpkt(struct in_multi *, int, unsigned long);
+
+void
+igmp_init()
+{
+ struct ipoption *ra;
+
+ /*
+ * To avoid byte-swapping the same value over and over again.
+ */
+ igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);
+ igmp_all_rtrs_group = htonl(INADDR_ALLRTRS_GROUP);
+
+ igmp_timers_are_running = 0;
+
+ /*
+ * Construct a Router Alert option to use in outgoing packets
+ */
+ MGET(router_alert, M_DONTWAIT, MT_DATA);
+ ra = mtod(router_alert, struct ipoption *);
+ ra->ipopt_dst.s_addr = 0;
+ ra->ipopt_list[0] = IPOPT_RA; /* Router Alert Option */
+ ra->ipopt_list[1] = 0x04; /* 4 bytes long */
+ ra->ipopt_list[2] = 0x00;
+ ra->ipopt_list[3] = 0x00;
+ router_alert->m_len = sizeof(ra->ipopt_dst) + ra->ipopt_list[1];
+
+ Head = (struct router_info *) 0;
+}
+
+static struct router_info *
+find_rti(ifp)
+ struct ifnet *ifp;
+{
+ register struct router_info *rti = Head;
+
+#ifdef IGMP_DEBUG
+ printf("[igmp.c, _find_rti] --> entering \n");
+#endif
+ while (rti) {
+ if (rti->rti_ifp == ifp) {
+#ifdef IGMP_DEBUG
+ printf("[igmp.c, _find_rti] --> found old entry \n");
+#endif
+ return rti;
+ }
+ rti = rti->rti_next;
+ }
+ MALLOC(rti, struct router_info *, sizeof *rti, M_MRTABLE, M_NOWAIT);
+ rti->rti_ifp = ifp;
+ rti->rti_type = IGMP_V2_ROUTER;
+ rti->rti_time = 0;
+ rti->rti_next = Head;
+ Head = rti;
+#ifdef IGMP_DEBUG
+ printf("[igmp.c, _find_rti] --> created an entry \n");
+#endif
+ return rti;
+}
+
+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;
+ struct router_info *rti;
+
+ int timer; /** timer value in the igmp query header **/
+
+ ++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 *);
+ timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE;
+ rti = find_rti(ifp);
+
+ /*
+ * In the IGMPv2 specification, there are 3 states and a flag.
+ *
+ * In Non-Member state, we simply don't have a membership record.
+ * In Delaying Member state, our timer is running (inm->inm_timer)
+ * In Idle Member state, our timer is not running (inm->inm_timer==0)
+ *
+ * The flag is inm->inm_state, it is set to IGMP_OTHERMEMBER if
+ * we have heard a report from another member, or IGMP_IREPORTEDLAST
+ * if I sent the last report.
+ */
+ switch (igmp->igmp_type) {
+
+ case IGMP_MEMBERSHIP_QUERY:
+ ++igmpstat.igps_rcv_queries;
+
+ if (ifp->if_flags & IFF_LOOPBACK)
+ break;
+
+ if (igmp->igmp_code == 0) {
+ /*
+ * Old router. Remember that the querier on this
+ * interface is old, and set the timer to the
+ * value in RFC 1112.
+ */
+
+ rti->rti_type = IGMP_V1_ROUTER;
+ rti->rti_time = 0;
+
+ timer = IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ;
+
+ if (ip->ip_dst.s_addr != igmp_all_hosts_group ||
+ igmp->igmp_group.s_addr != 0) {
+ ++igmpstat.igps_rcv_badqueries;
+ m_freem(m);
+ return;
+ }
+ } else {
+ /*
+ * New router. Simply do the new validity check.
+ */
+
+ if (igmp->igmp_group.s_addr != 0 &&
+ !IN_MULTICAST(ntohl(igmp->igmp_group.s_addr))) {
+ ++igmpstat.igps_rcv_badqueries;
+ m_freem(m);
+ return;
+ }
+ }
+
+ /*
+ * - Start the timers in all of our membership records
+ * that the query applies to for the interface on
+ * which the query arrived excl. those that belong
+ * to the "all-hosts" group (224.0.0.1).
+ * - Restart any timer that is already running but has
+ * a value longer than the requested timeout.
+ * - Use the value specified in the query message as
+ * the maximum timeout.
+ */
+ IN_FIRST_MULTI(step, inm);
+ while (inm != NULL) {
+ if (inm->inm_ifp == ifp &&
+ inm->inm_addr.s_addr != igmp_all_hosts_group &&
+ (igmp->igmp_group.s_addr == 0 ||
+ igmp->igmp_group.s_addr == inm->inm_addr.s_addr)) {
+ if (inm->inm_timer == 0 ||
+ inm->inm_timer > timer) {
+ inm->inm_timer =
+ IGMP_RANDOM_DELAY(timer);
+ igmp_timers_are_running = 1;
+ }
+ }
+ IN_NEXT_MULTI(step, inm);
+ }
+
+ break;
+
+ case IGMP_V1_MEMBERSHIP_REPORT:
+ case IGMP_V2_MEMBERSHIP_REPORT:
+ /*
+ * For fast leave to work, we have to know that we are the
+ * last person to send a report for this group. Reports
+ * can potentially get looped back if we are a multicast
+ * router, so discard reports sourced by me.
+ */
+ IFP_TO_IA(ifp, ia);
+ if (ia && ip->ip_src.s_addr == IA_SIN(ia)->sin_addr.s_addr)
+ break;
+
+ ++igmpstat.igps_rcv_reports;
+
+ if (ifp->if_flags & IFF_LOOPBACK)
+ break;
+
+ if (!IN_MULTICAST(ntohl(igmp->igmp_group.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)
+ 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;
+
+ inm->inm_state = IGMP_OTHERMEMBER;
+ }
+
+ break;
+ }
+
+ /*
+ * Pass all valid IGMP packets up to any process(es) listening
+ * on a raw IGMP socket.
+ */
+ rip_input(m, iphlen);
+}
+
+void
+igmp_joingroup(inm)
+ struct in_multi *inm;
+{
+ int s = splnet();
+
+ if (inm->inm_addr.s_addr == igmp_all_hosts_group
+ || inm->inm_ifp->if_flags & IFF_LOOPBACK) {
+ inm->inm_timer = 0;
+ inm->inm_state = IGMP_OTHERMEMBER;
+ } else {
+ inm->inm_rti = find_rti(inm->inm_ifp);
+ igmp_sendpkt(inm, inm->inm_rti->rti_type, 0);
+ inm->inm_timer = IGMP_RANDOM_DELAY(
+ IGMP_MAX_HOST_REPORT_DELAY*PR_FASTHZ);
+ inm->inm_state = IGMP_IREPORTEDLAST;
+ igmp_timers_are_running = 1;
+ }
+ splx(s);
+}
+
+void
+igmp_leavegroup(inm)
+ struct in_multi *inm;
+{
+ if (inm->inm_state == IGMP_IREPORTEDLAST &&
+ inm->inm_addr.s_addr != igmp_all_hosts_group &&
+ !(inm->inm_ifp->if_flags & IFF_LOOPBACK) &&
+ inm->inm_rti->rti_type != IGMP_V1_ROUTER)
+ igmp_sendpkt(inm, IGMP_V2_LEAVE_GROUP, igmp_all_rtrs_group);
+}
+
+void
+igmp_fasttimo()
+{
+ register struct in_multi *inm;
+ struct in_multistep step;
+ int s;
+
+ /*
+ * 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_sendpkt(inm, inm->inm_rti->rti_type, 0);
+ inm->inm_state = IGMP_IREPORTEDLAST;
+ } else {
+ igmp_timers_are_running = 1;
+ }
+ IN_NEXT_MULTI(step, inm);
+ }
+ splx(s);
+}
+
+void
+igmp_slowtimo()
+{
+ int s = splnet();
+ register struct router_info *rti = Head;
+
+#ifdef IGMP_DEBUG
+ printf("[igmp.c,_slowtimo] -- > entering \n");
+#endif
+ while (rti) {
+ if (rti->rti_type == IGMP_V1_ROUTER) {
+ rti->rti_time++;
+ if (rti->rti_time >= IGMP_AGE_THRESHOLD) {
+ rti->rti_type = IGMP_V2_ROUTER;
+ }
+ }
+ rti = rti->rti_next;
+ }
+#ifdef IGMP_DEBUG
+ printf("[igmp.c,_slowtimo] -- > exiting \n");
+#endif
+ splx(s);
+}
+
+static struct route igmprt;
+
+static void
+igmp_sendpkt(inm, type, addr)
+ struct in_multi *inm;
+ int type;
+ unsigned long addr;
+{
+ struct mbuf *m;
+ struct igmp *igmp;
+ struct ip *ip;
+ struct ip_moptions imo;
+
+ MGETHDR(m, M_DONTWAIT, MT_HEADER);
+ if (m == NULL)
+ return;
+
+ m->m_pkthdr.rcvif = loif;
+ m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;
+ MH_ALIGN(m, IGMP_MINLEN + sizeof(struct ip));
+ m->m_data += sizeof(struct ip);
+ m->m_len = IGMP_MINLEN;
+ igmp = mtod(m, struct igmp *);
+ igmp->igmp_type = type;
+ igmp->igmp_code = 0;
+ igmp->igmp_group = inm->inm_addr;
+ igmp->igmp_cksum = 0;
+ igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN);
+
+ m->m_data -= sizeof(struct ip);
+ m->m_len += sizeof(struct ip);
+ 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.s_addr = addr ? addr : igmp->igmp_group.s_addr;
+
+ imo.imo_multicast_ifp = inm->inm_ifp;
+ imo.imo_multicast_ttl = 1;
+ imo.imo_multicast_vif = -1;
+ /*
+ * Request loopback of the report if we are acting as a multicast
+ * router, so that the process-level routing demon can hear it.
+ */
+ imo.imo_multicast_loop = (ip_mrouter != NULL);
+
+ /*
+ * XXX
+ * Do we have to worry about reentrancy here? Don't think so.
+ */
+ ip_output(m, router_alert, &igmprt, 0, &imo);
+
+ ++igmpstat.igps_snd_reports;
+}
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