/* * 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: igmp.c,v 1.13 1995/11/14 20:33:52 phk Exp $ */ /* * 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. * * MULTICAST Revision: 3.3.1.2 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern int fill_rti __P((struct in_multi *inm)); extern struct router_info * find_rti __P((struct ifnet *ifp)); 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_local_group; static u_long igmp_local_group_mask; static struct router_info *Head; static void igmp_sendpkt(struct in_multi *, int); static void igmp_sendleave(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); igmp_local_group = htonl(0xe0000000); /* 224.0.0.0 */ igmp_local_group_mask = htonl(0xffffff00); /* ........^ */ igmp_timers_are_running = 0; Head = (struct router_info *) 0; } int fill_rti(inm) struct in_multi *inm; { register struct router_info *rti = Head; #ifdef IGMP_DEBUG printf("[igmp.c, _fill_rti] --> entering \n"); #endif while (rti) { if (rti->ifp == inm->inm_ifp) { inm->inm_rti = rti; #ifdef IGMP_DEBUG printf("[igmp.c, _fill_rti] --> found old entry \n"); #endif if (rti->type == IGMP_OLD_ROUTER) return IGMP_HOST_MEMBERSHIP_REPORT; else return IGMP_HOST_NEW_MEMBERSHIP_REPORT; } rti = rti->next; } MALLOC(rti, struct router_info *, sizeof *rti, M_MRTABLE, M_NOWAIT); rti->ifp = inm->inm_ifp; rti->type = IGMP_NEW_ROUTER; rti->time = IGMP_AGE_THRESHOLD; rti->next = Head; Head = rti; inm->inm_rti = rti; #ifdef IGMP_DEBUG printf("[igmp.c, _fill_rti] --> created new entry \n"); #endif return IGMP_HOST_NEW_MEMBERSHIP_REPORT; } 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->ifp == ifp) { #ifdef IGMP_DEBUG printf("[igmp.c, _find_rti] --> found old entry \n"); #endif return rti; } rti = rti->next; } MALLOC(rti, struct router_info *, sizeof *rti, M_MRTABLE, M_NOWAIT); rti->ifp = ifp; rti->type = IGMP_NEW_ROUTER; rti->time = IGMP_AGE_THRESHOLD; 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); switch (igmp->igmp_type) { case IGMP_HOST_MEMBERSHIP_QUERY: ++igmpstat.igps_rcv_queries; if (ifp->if_flags & IFF_LOOPBACK) break; if (igmp->igmp_code == 0) { rti->type = IGMP_OLD_ROUTER; rti->time = 0; /* ** Do exactly as RFC 1112 says */ 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 a * "local" group (224.0.0.X). */ IN_FIRST_MULTI(step, inm); while (inm != NULL) { if (inm->inm_ifp == ifp && inm->inm_timer == 0 && ((inm->inm_addr.s_addr & igmp_local_group_mask) != igmp_local_group)) { inm->inm_state = IGMP_DELAYING_MEMBER; inm->inm_timer = IGMP_RANDOM_DELAY( IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ ); igmp_timers_are_running = 1; } IN_NEXT_MULTI(step, inm); } } else { /* ** New Router */ if (!(m->m_flags & M_MCAST)) { ++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 a "local" group (224.0.0.X) * - For timers already running check if they need to * be reset. * - Use the igmp->igmp_code field as the maximum * delay possible */ IN_FIRST_MULTI(step, inm); while (inm != NULL) { if (inm->inm_ifp == ifp && (inm->inm_addr.s_addr & igmp_local_group_mask) != igmp_local_group && (ip->ip_dst.s_addr == igmp_all_hosts_group || ip->ip_dst.s_addr == inm->inm_addr.s_addr)) { switch(inm->inm_state) { case IGMP_IDLE_MEMBER: case IGMP_LAZY_MEMBER: case IGMP_AWAKENING_MEMBER: inm->inm_timer = IGMP_RANDOM_DELAY(timer); igmp_timers_are_running = 1; inm->inm_state = IGMP_DELAYING_MEMBER; break; case IGMP_DELAYING_MEMBER: if (inm->inm_timer > timer) { inm->inm_timer = IGMP_RANDOM_DELAY(timer); igmp_timers_are_running = 1; inm->inm_state = IGMP_DELAYING_MEMBER; } break; case IGMP_SLEEPING_MEMBER: inm->inm_state = IGMP_AWAKENING_MEMBER; break; } } IN_NEXT_MULTI(step, inm); } } break; case IGMP_HOST_MEMBERSHIP_REPORT: /* * an old report */ ++igmpstat.igps_rcv_reports; if (ifp->if_flags & IFF_LOOPBACK) 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; switch(inm->inm_state){ case IGMP_IDLE_MEMBER: case IGMP_LAZY_MEMBER: case IGMP_AWAKENING_MEMBER: case IGMP_SLEEPING_MEMBER: inm->inm_state = IGMP_SLEEPING_MEMBER; break; case IGMP_DELAYING_MEMBER: if (inm->inm_rti->type == IGMP_OLD_ROUTER) inm->inm_state = IGMP_LAZY_MEMBER; else inm->inm_state = IGMP_SLEEPING_MEMBER; break; } } break; case IGMP_HOST_NEW_MEMBERSHIP_REPORT: /* * a new report */ /* * We can get confused and think there's someone * else out there if we are a multicast router. * For fast leave to work, we have to know that * we are the only member. */ 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)) || 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) { /* #ifndef MROUTING XXX - I don't think the ifdef is necessary */ IFP_TO_IA(ifp, ia); /* #endif */ 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; switch(inm->inm_state){ case IGMP_DELAYING_MEMBER: case IGMP_IDLE_MEMBER: inm->inm_state = IGMP_LAZY_MEMBER; break; case IGMP_AWAKENING_MEMBER: inm->inm_state = IGMP_LAZY_MEMBER; break; case IGMP_LAZY_MEMBER: case IGMP_SLEEPING_MEMBER: 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; { int s = splnet(); inm->inm_state = IGMP_IDLE_MEMBER; if ((inm->inm_addr.s_addr & igmp_local_group_mask) == igmp_local_group || inm->inm_ifp->if_flags & IFF_LOOPBACK) inm->inm_timer = 0; else { igmp_sendpkt(inm,fill_rti(inm)); inm->inm_timer = IGMP_RANDOM_DELAY( IGMP_MAX_HOST_REPORT_DELAY*PR_FASTHZ); inm->inm_state = IGMP_DELAYING_MEMBER; igmp_timers_are_running = 1; } splx(s); } void igmp_leavegroup(inm) struct in_multi *inm; { switch(inm->inm_state) { case IGMP_DELAYING_MEMBER: case IGMP_IDLE_MEMBER: if (((inm->inm_addr.s_addr & igmp_local_group_mask) != igmp_local_group) && !(inm->inm_ifp->if_flags & IFF_LOOPBACK)) if (inm->inm_rti->type != IGMP_OLD_ROUTER) igmp_sendleave(inm); break; case IGMP_LAZY_MEMBER: case IGMP_AWAKENING_MEMBER: case IGMP_SLEEPING_MEMBER: break; } } 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) { if (inm->inm_state == IGMP_DELAYING_MEMBER) { if (inm->inm_rti->type == IGMP_OLD_ROUTER) igmp_sendpkt(inm, IGMP_HOST_MEMBERSHIP_REPORT); else igmp_sendpkt(inm, IGMP_HOST_NEW_MEMBERSHIP_REPORT); inm->inm_state = IGMP_IDLE_MEMBER; } } 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) { rti->time ++; if (rti->time >= IGMP_AGE_THRESHOLD){ rti->type = IGMP_NEW_ROUTER; rti->time = IGMP_AGE_THRESHOLD; } rti = rti->next; } #ifdef IGMP_DEBUG printf("[igmp.c,_slowtimo] -- > exiting \n"); #endif splx(s); } static void igmp_sendpkt(inm, type) struct in_multi *inm; int type; { struct mbuf *m; struct igmp *igmp; struct ip *ip; struct ip_moptions *imo; MGETHDR(m, M_DONTWAIT, MT_HEADER); if (m == NULL) return; MALLOC(imo, struct ip_moptions *, sizeof *imo, M_IPMOPTS, M_DONTWAIT); if (!imo) { m_free(m); 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 = igmp->igmp_group; 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); ip_output(m, (struct mbuf *)0, (struct route *)0, 0, imo); FREE(imo, M_IPMOPTS); ++igmpstat.igps_snd_reports; } static void igmp_sendleave(inm) struct in_multi *inm; { igmp_sendpkt(inm, IGMP_HOST_LEAVE_MESSAGE); }