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IABSD.fr/src/sys/netinet6/mld6.c
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/* $OpenBSD: mld6.c,v 1.75 2026/03/29 18:08:07 bluhm Exp $ */ /* $KAME: mld6.c,v 1.26 2001/02/16 14:50:35 itojun Exp $ */ /* * Copyright (C) 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 8.1 (Berkeley) 7/19/93 */ #include <sys/param.h> #include <sys/systm.h> #include <sys/mbuf.h> #include <sys/socket.h> #include <sys/protosw.h> #include <net/if.h> #include <net/if_var.h> #include <netinet/in.h> #include <netinet6/in6_var.h> #include <netinet/ip6.h> #include <netinet6/ip6_var.h> #include <netinet/icmp6.h> #include <netinet6/mld6.h> #include <netinet6/mld6_var.h> static struct ip6_pktopts ip6_opts; int mld6_timers_are_running; /* [a] shortcut for fast timer */ int mld6_checktimer(struct ifnet *, struct mld6_pktlist *); void mld6_init(void) { static u_int8_t hbh_buf[8]; struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); mld6_timers_are_running = 0; /* ip6h_nxt will be fill in later */ hbh->ip6h_len = 0; /* (8 >> 3) - 1 */ /* XXX: grotty hard coding... */ hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ hbh_buf[3] = 0; hbh_buf[4] = IP6OPT_ROUTER_ALERT; hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; memcpy(&hbh_buf[6], (caddr_t)&rtalert_code, sizeof(u_int16_t)); ip6_initpktopts(&ip6_opts); ip6_opts.ip6po_hbh = hbh; } void mld6_start_listening(struct in6_multi *in6m, struct ifnet *ifp, struct mld6_pktinfo *pkt) { /* XXX: These are necessary for KAME's link-local hack */ struct in6_addr all_nodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT; int running = 0; rw_assert_wrlock(&ifp->if_maddrlock); /* * RFC2710 page 10: * The node never sends a Report or Done for the link-scope all-nodes * address. * MLD messages are never sent for multicast addresses whose scope is 0 * (reserved) or 1 (node-local). */ all_nodes.s6_addr16[1] = htons(in6m->in6m_ifidx); if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_nodes) || __IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < __IPV6_ADDR_SCOPE_LINKLOCAL) { in6m->in6m_state = MLD_OTHERLISTENER; in6m->in6m_timer = 0; } else { in6m->in6m_state = MLD_IREPORTEDLAST; in6m->in6m_timer = MLD_RANDOM_DELAY(MLD_V1_MAX_RI * PR_FASTHZ); pkt->mpi_addr = in6m->in6m_addr; pkt->mpi_rdomain = ifp->if_rdomain; pkt->mpi_ifidx = in6m->in6m_ifidx; pkt->mpi_type = MLD_LISTENER_REPORT; running = 1; } if (running) atomic_store_int(&mld6_timers_are_running, 1); } void mld6_stop_listening(struct in6_multi *in6m, struct ifnet *ifp, struct mld6_pktinfo *pkt) { /* XXX: These are necessary for KAME's link-local hack */ struct in6_addr all_nodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT; struct in6_addr all_routers = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; rw_assert_anylock(&ifp->if_maddrlock); all_nodes.s6_addr16[1] = htons(in6m->in6m_ifidx); /* XXX: necessary when mrouting */ all_routers.s6_addr16[1] = htons(in6m->in6m_ifidx); if (in6m->in6m_state == MLD_IREPORTEDLAST && (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_nodes)) && __IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > __IPV6_ADDR_SCOPE_INTFACELOCAL) { pkt->mpi_addr = all_routers; pkt->mpi_rdomain = ifp->if_rdomain; pkt->mpi_ifidx = in6m->in6m_ifidx; pkt->mpi_type = MLD_LISTENER_DONE; } } void mld6_input(struct mbuf *m, int off) { struct ip6_hdr *ip6; struct mld_hdr *mldh; struct ifnet *ifp; struct in6_multi *in6m; struct ifmaddr *ifma; int timer; /* timer value in the MLD query header */ int running = 0; /* XXX: These are necessary for KAME's link-local hack */ struct in6_addr all_nodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT; mldh = ip6_exthdr_get(&m, off, sizeof(*mldh)); if (mldh == NULL) { icmp6stat_inc(icp6s_tooshort); return; } /* source address validation */ ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */ if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { #if 0 char src[INET6_ADDRSTRLEN], grp[INET6_ADDRSTRLEN]; log(LOG_ERR, "mld_input: src %s is not link-local (grp=%s)\n", inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src)), inet_ntop(AF_INET6, &mldh->mld_addr, grp, sizeof(grp))); #endif /* * spec (RFC2710) does not explicitly * specify to discard the packet from a non link-local * source address. But we believe it's expected to do so. */ m_freem(m); return; } ifp = if_get(m->m_pkthdr.ph_ifidx); if (ifp == NULL) { m_freem(m); return; } /* * In the MLD6 specification, there are 3 states and a flag. * * In Non-Listener state, we simply don't have a membership record. * In Delaying Listener state, our timer is running (in6m->in6m_timer) * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) * * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if * we have heard a report from another member, or MLD_IREPORTEDLAST * if we sent the last report. */ switch(mldh->mld_type) { case MLD_LISTENER_QUERY: { struct mld6_pktlist pktlist; if (ifp->if_flags & IFF_LOOPBACK) break; if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) && !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) break; /* print error or log stat? */ if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) mldh->mld_addr.s6_addr16[1] = htons(ifp->if_index); /* XXX */ /* * - 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-nodes" group (ff02::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. */ /* * XXX: System timer resolution is too low to handle Max * Response Delay, so set 1 to the internal timer even if * the calculated value equals to zero when Max Response * Delay is positive. */ timer = ntohs(mldh->mld_maxdelay)*PR_FASTHZ/MLD_TIMER_SCALE; if (timer == 0 && mldh->mld_maxdelay) timer = 1; all_nodes.s6_addr16[1] = htons(ifp->if_index); rw_enter_write(&ifp->if_maddrlock); STAILQ_INIT(&pktlist); TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) { if (ifma->ifma_addr->sa_family != AF_INET6) continue; in6m = ifmatoin6m(ifma); if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_nodes) || __IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < __IPV6_ADDR_SCOPE_LINKLOCAL) continue; if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) || IN6_ARE_ADDR_EQUAL(&mldh->mld_addr, &in6m->in6m_addr)) { if (timer == 0) { /* send a report immediately */ struct mld6_pktinfo *pkt; in6m->in6m_state = MLD_IREPORTEDLAST; in6m->in6m_timer = 0; /* reset timer */ pkt = malloc(sizeof(*pkt), M_MRTABLE, M_NOWAIT); if (pkt == NULL) continue; pkt->mpi_addr = in6m->in6m_addr; pkt->mpi_rdomain = ifp->if_rdomain; pkt->mpi_ifidx = in6m->in6m_ifidx; pkt->mpi_type = MLD_LISTENER_REPORT; STAILQ_INSERT_TAIL(&pktlist, pkt, mpi_list); } else if (in6m->in6m_timer == 0 || /* idle */ in6m->in6m_timer > timer) { in6m->in6m_timer = MLD_RANDOM_DELAY(timer); running = 1; } } } rw_exit_write(&ifp->if_maddrlock); while (!STAILQ_EMPTY(&pktlist)) { struct mld6_pktinfo *pkt; pkt = STAILQ_FIRST(&pktlist); STAILQ_REMOVE_HEAD(&pktlist, mpi_list); mld6_sendpkt(pkt); free(pkt, M_MRTABLE, sizeof(*pkt)); } if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ break; } case MLD_LISTENER_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. * Note that it is impossible to check IFF_LOOPBACK flag of * ifp for this purpose, since ip6_mloopback pass the physical * interface to if_input_local(). */ if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ break; if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) break; if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) mldh->mld_addr.s6_addr16[1] = htons(ifp->if_index); /* XXX */ /* * If we belong to the group being reported, stop * our timer for that group. */ rw_enter_write(&ifp->if_maddrlock); in6m = in6_lookupmulti(&mldh->mld_addr, ifp); if (in6m) { in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */ in6m->in6m_timer = 0; /* transit to idle state */ } rw_exit_write(&ifp->if_maddrlock); if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ break; default: /* this is impossible */ #if 0 /* * this case should be impossible because of filtering in * icmp6_input(). But we explicitly disabled this part * just in case. */ log(LOG_ERR, "mld_input: illegal type(%d)", mldh->mld_type); #endif break; } if (running) atomic_store_int(&mld6_timers_are_running, 1); if_put(ifp); m_freem(m); } void mld6_fasttimo(void) { struct mld6_pktlist pktlist; 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 mld6_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(&mld6_timers_are_running)) return; atomic_store_int(&mld6_timers_are_running, 0); NET_LOCK_SHARED(); STAILQ_INIT(&pktlist); TAILQ_FOREACH(ifp, &ifnetlist, if_list) { if (mld6_checktimer(ifp, &pktlist)) running = 1; } while (!STAILQ_EMPTY(&pktlist)) { struct mld6_pktinfo *pkt; pkt = STAILQ_FIRST(&pktlist); STAILQ_REMOVE_HEAD(&pktlist, mpi_list); mld6_sendpkt(pkt); free(pkt, M_MRTABLE, sizeof(*pkt)); } NET_UNLOCK_SHARED(); if (running) atomic_store_int(&mld6_timers_are_running, 1); } int mld6_checktimer(struct ifnet *ifp, struct mld6_pktlist *pktlist) { struct in6_multi *in6m; struct ifmaddr *ifma; int running = 0; rw_enter_write(&ifp->if_maddrlock); TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) { if (ifma->ifma_addr->sa_family != AF_INET6) continue; in6m = ifmatoin6m(ifma); if (in6m->in6m_timer == 0) { /* do nothing */ } else if (--in6m->in6m_timer == 0) { struct mld6_pktinfo *pkt; in6m->in6m_state = MLD_IREPORTEDLAST; pkt = malloc(sizeof(*pkt), M_MRTABLE, M_NOWAIT); if (pkt == NULL) continue; pkt->mpi_addr = in6m->in6m_addr; pkt->mpi_rdomain = ifp->if_rdomain; pkt->mpi_ifidx = in6m->in6m_ifidx; pkt->mpi_type = MLD_LISTENER_REPORT; STAILQ_INSERT_TAIL(pktlist, pkt, mpi_list); } else { running = 1; } } rw_exit_write(&ifp->if_maddrlock); return (running); } void mld6_sendpkt(const struct mld6_pktinfo *pkt) { struct mbuf *mh, *md; struct mld_hdr *mldh; struct ip6_hdr *ip6; struct ip6_moptions im6o; struct in6_ifaddr *ia6; struct ifnet *ifp; int ignflags; ifp = if_get(pkt->mpi_ifidx); if (ifp == NULL) return; /* * At first, find a link local address on the outgoing interface * to use as the source address of the MLD packet. * We do not reject tentative addresses for MLD report to deal with * the case where we first join a link-local address. */ ignflags = IN6_IFF_DUPLICATED|IN6_IFF_ANYCAST; if ((ia6 = in6ifa_ifpforlinklocal(ifp, ignflags)) == NULL) { if_put(ifp); return; } if ((ia6->ia6_flags & IN6_IFF_TENTATIVE)) ia6 = NULL; /* * Allocate mbufs to store ip6 header and MLD header. * We allocate 2 mbufs and make chain in advance because * it is more convenient when inserting the hop-by-hop option later. */ MGETHDR(mh, M_DONTWAIT, MT_HEADER); if (mh == NULL) { if_put(ifp); return; } MGET(md, M_DONTWAIT, MT_DATA); if (md == NULL) { m_free(mh); if_put(ifp); return; } mh->m_next = md; mh->m_pkthdr.ph_rtableid = pkt->mpi_rdomain; mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr); mh->m_len = sizeof(struct ip6_hdr); m_align(mh, sizeof(struct ip6_hdr)); /* fill in the ip6 header */ ip6 = mtod(mh, struct ip6_hdr *); ip6->ip6_flow = 0; ip6->ip6_vfc &= ~IPV6_VERSION_MASK; ip6->ip6_vfc |= IPV6_VERSION; /* ip6_plen will be set later */ ip6->ip6_nxt = IPPROTO_ICMPV6; /* ip6_hlim will be set by im6o.im6o_hlim */ ip6->ip6_src = ia6 ? ia6->ia_addr.sin6_addr : in6addr_any; ip6->ip6_dst = pkt->mpi_addr; /* fill in the MLD header */ md->m_len = sizeof(struct mld_hdr); mldh = mtod(md, struct mld_hdr *); mldh->mld_type = pkt->mpi_type; mldh->mld_code = 0; mldh->mld_cksum = 0; /* XXX: we assume the function will not be called for query messages */ mldh->mld_maxdelay = 0; mldh->mld_reserved = 0; mldh->mld_addr = pkt->mpi_addr; if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ mh->m_pkthdr.csum_flags |= M_ICMP_CSUM_OUT; /* construct multicast option */ bzero(&im6o, sizeof(im6o)); im6o.im6o_ifidx = pkt->mpi_ifidx; im6o.im6o_hlim = 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 im6o.im6o_loop = (ip6_mrouter[pkt->mpi_rdomain] != NULL); #endif if_put(ifp); icmp6stat_inc(icp6s_outhist + pkt->mpi_type); ip6_output(mh, &ip6_opts, NULL, ia6 ? 0 : IPV6_UNSPECSRC, &im6o, NULL); }