/* $OpenBSD: igmp.c,v 1.85 2024/08/20 07:46:27 mvs Exp $ */ /* $NetBSD: igmp.c,v 1.15 1996/02/13 23:41:25 christos Exp $ */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * All rights reserved. * * 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. Neither the name of the project 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 PROJECT 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 PROJECT 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. */ /* * 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. 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 8.2 (Berkeley) 5/3/95 */ /* * 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: 1.3 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define IP_MULTICASTOPTS 0 int igmp_timers_are_running; /* [a] shortcut for fast timer */ static LIST_HEAD(, router_info) rti_head; static struct mbuf *router_alert; struct cpumem *igmpcounters; int igmp_checktimer(struct ifnet *); void igmp_sendpkt(struct ifnet *, struct in_multi *, int, in_addr_t); int rti_fill(struct in_multi *); struct router_info * rti_find(struct ifnet *); int igmp_input_if(struct ifnet *, struct mbuf **, int *, int, int); int igmp_sysctl_igmpstat(void *, size_t *, void *); void igmp_init(void) { struct ipoption *ra; igmp_timers_are_running = 0; LIST_INIT(&rti_head); igmpcounters = counters_alloc(igps_ncounters); router_alert = m_get(M_WAIT, MT_DATA); /* * Construct a Router Alert option (RAO) to use in report * messages as required by RFC2236. This option has the * following format: * * | 10010100 | 00000100 | 2 octet value | * * where a value of "0" indicates that routers shall examine * the packet. */ ra = mtod(router_alert, struct ipoption *); ra->ipopt_dst.s_addr = INADDR_ANY; ra->ipopt_list[0] = IPOPT_RA; ra->ipopt_list[1] = 0x04; ra->ipopt_list[2] = 0x00; ra->ipopt_list[3] = 0x00; router_alert->m_len = sizeof(ra->ipopt_dst) + ra->ipopt_list[1]; } int rti_fill(struct in_multi *inm) { struct router_info *rti; LIST_FOREACH(rti, &rti_head, rti_list) { if (rti->rti_ifidx == inm->inm_ifidx) { inm->inm_rti = rti; if (rti->rti_type == IGMP_v1_ROUTER) return (IGMP_v1_HOST_MEMBERSHIP_REPORT); else return (IGMP_v2_HOST_MEMBERSHIP_REPORT); } } rti = malloc(sizeof(*rti), M_MRTABLE, M_WAITOK); rti->rti_ifidx = inm->inm_ifidx; rti->rti_type = IGMP_v2_ROUTER; LIST_INSERT_HEAD(&rti_head, rti, rti_list); inm->inm_rti = rti; return (IGMP_v2_HOST_MEMBERSHIP_REPORT); } struct router_info * rti_find(struct ifnet *ifp) { struct router_info *rti; KERNEL_ASSERT_LOCKED(); LIST_FOREACH(rti, &rti_head, rti_list) { if (rti->rti_ifidx == ifp->if_index) return (rti); } rti = malloc(sizeof(*rti), M_MRTABLE, M_NOWAIT); if (rti == NULL) return (NULL); rti->rti_ifidx = ifp->if_index; rti->rti_type = IGMP_v2_ROUTER; LIST_INSERT_HEAD(&rti_head, rti, rti_list); return (rti); } void rti_delete(struct ifnet *ifp) { struct router_info *rti, *trti; LIST_FOREACH_SAFE(rti, &rti_head, rti_list, trti) { if (rti->rti_ifidx == ifp->if_index) { LIST_REMOVE(rti, rti_list); free(rti, M_MRTABLE, sizeof(*rti)); break; } } } int igmp_input(struct mbuf **mp, int *offp, int proto, int af) { struct ifnet *ifp; igmpstat_inc(igps_rcv_total); ifp = if_get((*mp)->m_pkthdr.ph_ifidx); if (ifp == NULL) { m_freemp(mp); return IPPROTO_DONE; } KERNEL_LOCK(); proto = igmp_input_if(ifp, mp, offp, proto, af); KERNEL_UNLOCK(); if_put(ifp); return proto; } int igmp_input_if(struct ifnet *ifp, struct mbuf **mp, int *offp, int proto, int af) { struct mbuf *m = *mp; int iphlen = *offp; struct ip *ip = mtod(m, struct ip *); struct igmp *igmp; int igmplen; int minlen; struct ifmaddr *ifma; struct in_multi *inm; struct router_info *rti; struct in_ifaddr *ia; int timer, running = 0; igmplen = ntohs(ip->ip_len) - iphlen; /* * Validate lengths */ if (igmplen < IGMP_MINLEN) { igmpstat_inc(igps_rcv_tooshort); m_freem(m); return IPPROTO_DONE; } minlen = iphlen + IGMP_MINLEN; if ((m->m_flags & M_EXT || m->m_len < minlen) && (m = *mp = m_pullup(m, minlen)) == NULL) { igmpstat_inc(igps_rcv_tooshort); return IPPROTO_DONE; } /* * Validate checksum */ m->m_data += iphlen; m->m_len -= iphlen; igmp = mtod(m, struct igmp *); if (in_cksum(m, igmplen)) { igmpstat_inc(igps_rcv_badsum); m_freem(m); return IPPROTO_DONE; } m->m_data -= iphlen; m->m_len += iphlen; ip = mtod(m, struct ip *); switch (igmp->igmp_type) { case IGMP_HOST_MEMBERSHIP_QUERY: igmpstat_inc(igps_rcv_queries); if (ifp->if_flags & IFF_LOOPBACK) break; if (igmp->igmp_code == 0) { rti = rti_find(ifp); if (rti == NULL) { m_freem(m); return IPPROTO_DONE; } rti->rti_type = IGMP_v1_ROUTER; rti->rti_age = 0; if (ip->ip_dst.s_addr != INADDR_ALLHOSTS_GROUP) { igmpstat_inc(igps_rcv_badqueries); m_freem(m); return IPPROTO_DONE; } /* * 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). */ TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) { if (ifma->ifma_addr->sa_family != AF_INET) continue; inm = ifmatoinm(ifma); if (inm->inm_timer == 0 && !IN_LOCAL_GROUP(inm->inm_addr.s_addr)) { inm->inm_state = IGMP_DELAYING_MEMBER; inm->inm_timer = IGMP_RANDOM_DELAY( IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); running = 1; } } } else { if (!IN_MULTICAST(ip->ip_dst.s_addr)) { igmpstat_inc(igps_rcv_badqueries); m_freem(m); return IPPROTO_DONE; } timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE; if (timer == 0) timer = 1; /* * 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). For * timers already running, check if they need to be * reset. */ TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) { if (ifma->ifma_addr->sa_family != AF_INET) continue; inm = ifmatoinm(ifma); if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && (ip->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP || ip->ip_dst.s_addr == inm->inm_addr.s_addr)) { switch (inm->inm_state) { case IGMP_DELAYING_MEMBER: if (inm->inm_timer <= timer) break; /* FALLTHROUGH */ case IGMP_IDLE_MEMBER: case IGMP_LAZY_MEMBER: case IGMP_AWAKENING_MEMBER: inm->inm_state = IGMP_DELAYING_MEMBER; inm->inm_timer = IGMP_RANDOM_DELAY(timer); running = 1; break; case IGMP_SLEEPING_MEMBER: inm->inm_state = IGMP_AWAKENING_MEMBER; break; } } } } break; case IGMP_v1_HOST_MEMBERSHIP_REPORT: igmpstat_inc(igps_rcv_reports); if (ifp->if_flags & IFF_LOOPBACK) break; if (!IN_MULTICAST(igmp->igmp_group.s_addr) || igmp->igmp_group.s_addr != ip->ip_dst.s_addr) { igmpstat_inc(igps_rcv_badreports); m_freem(m); return IPPROTO_DONE; } /* * 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 daemon 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 ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { IFP_TO_IA(ifp, ia); if (ia) ip->ip_src.s_addr = ia->ia_net; } /* * 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_inc(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->rti_type == IGMP_v1_ROUTER) inm->inm_state = IGMP_LAZY_MEMBER; else inm->inm_state = IGMP_SLEEPING_MEMBER; break; } } break; case IGMP_v2_HOST_MEMBERSHIP_REPORT: #ifdef MROUTING /* * Make sure we don't hear our own membership report. Fast * leave requires knowing that we are the only member of a * group. */ IFP_TO_IA(ifp, ia); if (ia && ip->ip_src.s_addr == ia->ia_addr.sin_addr.s_addr) break; #endif igmpstat_inc(igps_rcv_reports); if (ifp->if_flags & IFF_LOOPBACK) break; if (!IN_MULTICAST(igmp->igmp_group.s_addr) || igmp->igmp_group.s_addr != ip->ip_dst.s_addr) { igmpstat_inc(igps_rcv_badreports); m_freem(m); return IPPROTO_DONE; } /* * 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 daemon 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 ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { #ifndef MROUTING IFP_TO_IA(ifp, ia); #endif if (ia) ip->ip_src.s_addr = ia->ia_net; } /* * 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_inc(igps_rcv_ourreports); switch (inm->inm_state) { case IGMP_DELAYING_MEMBER: case IGMP_IDLE_MEMBER: case IGMP_AWAKENING_MEMBER: inm->inm_state = IGMP_LAZY_MEMBER; break; case IGMP_LAZY_MEMBER: case IGMP_SLEEPING_MEMBER: break; } } break; } if (running) { membar_producer(); atomic_store_int(&igmp_timers_are_running, running); } /* * Pass all valid IGMP packets up to any process(es) listening * on a raw IGMP socket. */ return rip_input(mp, offp, proto, af); } void igmp_joingroup(struct in_multi *inm, struct ifnet *ifp) { int i, running = 0; inm->inm_state = IGMP_IDLE_MEMBER; if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && (ifp->if_flags & IFF_LOOPBACK) == 0) { i = rti_fill(inm); igmp_sendpkt(ifp, inm, i, 0); inm->inm_state = IGMP_DELAYING_MEMBER; inm->inm_timer = IGMP_RANDOM_DELAY( IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); running = 1; } else inm->inm_timer = 0; if (running) { membar_producer(); atomic_store_int(&igmp_timers_are_running, running); } } void igmp_leavegroup(struct in_multi *inm, struct ifnet *ifp) { switch (inm->inm_state) { case IGMP_DELAYING_MEMBER: case IGMP_IDLE_MEMBER: if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && (ifp->if_flags & IFF_LOOPBACK) == 0) if (inm->inm_rti->rti_type != IGMP_v1_ROUTER) igmp_sendpkt(ifp, inm, IGMP_HOST_LEAVE_MESSAGE, INADDR_ALLROUTERS_GROUP); break; case IGMP_LAZY_MEMBER: case IGMP_AWAKENING_MEMBER: case IGMP_SLEEPING_MEMBER: break; } } void igmp_fasttimo(void) { struct ifnet *ifp; int running = 0; /* * Quick check to see if any work needs to be done, in order * to minimize the overhead of fasttimo processing. * Variable igmp_timers_are_running is read atomically, but without * lock intentionally. In case it is not set due to MP races, we may * miss to check the timers. Then run the loop at next fast timeout. */ if (!atomic_load_int(&igmp_timers_are_running)) return; membar_consumer(); NET_LOCK(); TAILQ_FOREACH(ifp, &ifnetlist, if_list) { if (igmp_checktimer(ifp)) running = 1; } membar_producer(); atomic_store_int(&igmp_timers_are_running, running); NET_UNLOCK(); } int igmp_checktimer(struct ifnet *ifp) { struct in_multi *inm; struct ifmaddr *ifma; int running = 0; NET_ASSERT_LOCKED(); TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) { if (ifma->ifma_addr->sa_family != AF_INET) continue; inm = ifmatoinm(ifma); if (inm->inm_timer == 0) { /* do nothing */ } else if (--inm->inm_timer == 0) { if (inm->inm_state == IGMP_DELAYING_MEMBER) { if (inm->inm_rti->rti_type == IGMP_v1_ROUTER) igmp_sendpkt(ifp, inm, IGMP_v1_HOST_MEMBERSHIP_REPORT, 0); else igmp_sendpkt(ifp, inm, IGMP_v2_HOST_MEMBERSHIP_REPORT, 0); inm->inm_state = IGMP_IDLE_MEMBER; } } else { running = 1; } } return (running); } void igmp_slowtimo(void) { struct router_info *rti; NET_LOCK(); LIST_FOREACH(rti, &rti_head, rti_list) { if (rti->rti_type == IGMP_v1_ROUTER && ++rti->rti_age >= IGMP_AGE_THRESHOLD) { rti->rti_type = IGMP_v2_ROUTER; } } NET_UNLOCK(); } void igmp_sendpkt(struct ifnet *ifp, struct in_multi *inm, int type, in_addr_t addr) { struct mbuf *m; struct igmp *igmp; struct ip *ip; struct ip_moptions imo; 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 = htons(sizeof(struct ip) + IGMP_MINLEN); ip->ip_off = 0; ip->ip_p = IPPROTO_IGMP; ip->ip_src.s_addr = INADDR_ANY; if (addr) { ip->ip_dst.s_addr = addr; } else { ip->ip_dst = inm->inm_addr; } m->m_data += sizeof(struct ip); m->m_len -= sizeof(struct ip); 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); m->m_pkthdr.ph_rtableid = ifp->if_rdomain; imo.imo_ifidx = inm->inm_ifidx; imo.imo_ttl = 1; /* * Request loopback of the report if we are acting as a multicast * router, so that the process-level routing daemon can hear it. */ #ifdef MROUTING imo.imo_loop = (ip_mrouter[ifp->if_rdomain] != NULL); #else imo.imo_loop = 0; #endif /* MROUTING */ ip_output(m, router_alert, NULL, IP_MULTICASTOPTS, &imo, NULL, 0); igmpstat_inc(igps_snd_reports); } /* * Sysctl for igmp variables. */ int igmp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen) { /* All sysctl names at this level are terminal. */ if (namelen != 1) return (ENOTDIR); switch (name[0]) { case IGMPCTL_STATS: return (igmp_sysctl_igmpstat(oldp, oldlenp, newp)); default: return (EOPNOTSUPP); } /* NOTREACHED */ } int igmp_sysctl_igmpstat(void *oldp, size_t *oldlenp, void *newp) { uint64_t counters[igps_ncounters]; struct igmpstat igmpstat; u_long *words = (u_long *)&igmpstat; int i; CTASSERT(sizeof(igmpstat) == (nitems(counters) * sizeof(u_long))); memset(&igmpstat, 0, sizeof igmpstat); counters_read(igmpcounters, counters, nitems(counters), NULL); for (i = 0; i < nitems(counters); i++) words[i] = (u_long)counters[i]; return (sysctl_rdstruct(oldp, oldlenp, newp, &igmpstat, sizeof(igmpstat))); }