1 /* $OpenBSD: mld6.c,v 1.56 2018/11/30 09:28:34 claudio Exp $ */ 2 /* $KAME: mld6.c,v 1.26 2001/02/16 14:50:35 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1988 Stephen Deering. 35 * Copyright (c) 1992, 1993 36 * The Regents of the University of California. All rights reserved. 37 * 38 * This code is derived from software contributed to Berkeley by 39 * Stephen Deering of Stanford University. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the above copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 3. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)igmp.c 8.1 (Berkeley) 7/19/93 66 */ 67 68 #include <sys/param.h> 69 #include <sys/systm.h> 70 #include <sys/mbuf.h> 71 #include <sys/socket.h> 72 #include <sys/protosw.h> 73 #include <sys/syslog.h> 74 75 #include <net/if.h> 76 #include <net/if_var.h> 77 78 #include <netinet/in.h> 79 #include <netinet6/in6_var.h> 80 #include <netinet/ip6.h> 81 #include <netinet6/ip6_var.h> 82 #include <netinet/icmp6.h> 83 #include <netinet6/mld6.h> 84 #include <netinet6/mld6_var.h> 85 86 static struct ip6_pktopts ip6_opts; 87 static int mld_timers_are_running; 88 /* XXX: These are necessary for KAME's link-local hack */ 89 static struct in6_addr mld_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 90 static struct in6_addr mld_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 91 92 void mld6_checktimer(struct ifnet *); 93 static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *); 94 95 void 96 mld6_init(void) 97 { 98 static u_int8_t hbh_buf[8]; 99 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 100 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 101 102 mld_timers_are_running = 0; 103 104 /* ip6h_nxt will be fill in later */ 105 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */ 106 107 /* XXX: grotty hard coding... */ 108 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 109 hbh_buf[3] = 0; 110 hbh_buf[4] = IP6OPT_ROUTER_ALERT; 111 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 112 memcpy(&hbh_buf[6], (caddr_t)&rtalert_code, sizeof(u_int16_t)); 113 114 ip6_initpktopts(&ip6_opts); 115 ip6_opts.ip6po_hbh = hbh; 116 } 117 118 void 119 mld6_start_listening(struct in6_multi *in6m) 120 { 121 /* 122 * RFC2710 page 10: 123 * The node never sends a Report or Done for the link-scope all-nodes 124 * address. 125 * MLD messages are never sent for multicast addresses whose scope is 0 126 * (reserved) or 1 (node-local). 127 */ 128 mld_all_nodes_linklocal.s6_addr16[1] = htons(in6m->in6m_ifidx);/* XXX */ 129 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld_all_nodes_linklocal) || 130 __IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < __IPV6_ADDR_SCOPE_LINKLOCAL) { 131 in6m->in6m_timer = 0; 132 in6m->in6m_state = MLD_OTHERLISTENER; 133 } else { 134 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 135 in6m->in6m_timer = 136 MLD_RANDOM_DELAY(MLD_V1_MAX_RI * 137 PR_FASTHZ); 138 in6m->in6m_state = MLD_IREPORTEDLAST; 139 mld_timers_are_running = 1; 140 } 141 } 142 143 void 144 mld6_stop_listening(struct in6_multi *in6m) 145 { 146 mld_all_nodes_linklocal.s6_addr16[1] = htons(in6m->in6m_ifidx);/* XXX */ 147 mld_all_routers_linklocal.s6_addr16[1] = 148 htons(in6m->in6m_ifidx); /* XXX: necessary when mrouting */ 149 150 if (in6m->in6m_state == MLD_IREPORTEDLAST && 151 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld_all_nodes_linklocal)) && 152 __IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > __IPV6_ADDR_SCOPE_INTFACELOCAL) 153 mld6_sendpkt(in6m, MLD_LISTENER_DONE, 154 &mld_all_routers_linklocal); 155 } 156 157 void 158 mld6_input(struct mbuf *m, int off) 159 { 160 struct ip6_hdr *ip6; 161 struct mld_hdr *mldh; 162 struct ifnet *ifp; 163 struct in6_multi *in6m; 164 struct ifmaddr *ifma; 165 int timer; /* timer value in the MLD query header */ 166 167 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh)); 168 if (mldh == NULL) { 169 icmp6stat_inc(icp6s_tooshort); 170 return; 171 } 172 173 /* source address validation */ 174 ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */ 175 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 176 #if 0 177 char src[INET6_ADDRSTRLEN], grp[INET6_ADDRSTRLEN]; 178 179 log(LOG_ERR, 180 "mld_input: src %s is not link-local (grp=%s)\n", 181 inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src)), 182 inet_ntop(AF_INET6, &mldh->mld_addr, grp, sizeof(grp))); 183 #endif 184 /* 185 * spec (RFC2710) does not explicitly 186 * specify to discard the packet from a non link-local 187 * source address. But we believe it's expected to do so. 188 */ 189 m_freem(m); 190 return; 191 } 192 193 ifp = if_get(m->m_pkthdr.ph_ifidx); 194 if (ifp == NULL) { 195 m_freem(m); 196 return; 197 } 198 199 /* 200 * In the MLD6 specification, there are 3 states and a flag. 201 * 202 * In Non-Listener state, we simply don't have a membership record. 203 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 204 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 205 * 206 * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if 207 * we have heard a report from another member, or MLD_IREPORTEDLAST 208 * if we sent the last report. 209 */ 210 switch(mldh->mld_type) { 211 case MLD_LISTENER_QUERY: 212 if (ifp->if_flags & IFF_LOOPBACK) 213 break; 214 215 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) && 216 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 217 break; /* print error or log stat? */ 218 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 219 mldh->mld_addr.s6_addr16[1] = 220 htons(ifp->if_index); /* XXX */ 221 222 /* 223 * - Start the timers in all of our membership records 224 * that the query applies to for the interface on 225 * which the query arrived excl. those that belong 226 * to the "all-nodes" group (ff02::1). 227 * - Restart any timer that is already running but has 228 * A value longer than the requested timeout. 229 * - Use the value specified in the query message as 230 * the maximum timeout. 231 */ 232 233 /* 234 * XXX: System timer resolution is too low to handle Max 235 * Response Delay, so set 1 to the internal timer even if 236 * the calculated value equals to zero when Max Response 237 * Delay is positive. 238 */ 239 timer = ntohs(mldh->mld_maxdelay)*PR_FASTHZ/MLD_TIMER_SCALE; 240 if (timer == 0 && mldh->mld_maxdelay) 241 timer = 1; 242 mld_all_nodes_linklocal.s6_addr16[1] = 243 htons(ifp->if_index); /* XXX */ 244 245 TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) { 246 if (ifma->ifma_addr->sa_family != AF_INET6) 247 continue; 248 in6m = ifmatoin6m(ifma); 249 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 250 &mld_all_nodes_linklocal) || 251 __IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 252 __IPV6_ADDR_SCOPE_LINKLOCAL) 253 continue; 254 255 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) || 256 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr, 257 &in6m->in6m_addr)) 258 { 259 if (timer == 0) { 260 /* send a report immediately */ 261 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, 262 NULL); 263 in6m->in6m_timer = 0; /* reset timer */ 264 in6m->in6m_state = MLD_IREPORTEDLAST; 265 } else if (in6m->in6m_timer == 0 || /* idle */ 266 in6m->in6m_timer > timer) { 267 in6m->in6m_timer = 268 MLD_RANDOM_DELAY(timer); 269 mld_timers_are_running = 1; 270 } 271 } 272 } 273 274 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 275 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 276 break; 277 case MLD_LISTENER_REPORT: 278 /* 279 * For fast leave to work, we have to know that we are the 280 * last person to send a report for this group. Reports 281 * can potentially get looped back if we are a multicast 282 * router, so discard reports sourced by me. 283 * Note that it is impossible to check IFF_LOOPBACK flag of 284 * ifp for this purpose, since ip6_mloopback pass the physical 285 * interface to if_input_local(). 286 */ 287 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 288 break; 289 290 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 291 break; 292 293 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 294 mldh->mld_addr.s6_addr16[1] = 295 htons(ifp->if_index); /* XXX */ 296 /* 297 * If we belong to the group being reported, stop 298 * our timer for that group. 299 */ 300 IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m); 301 if (in6m) { 302 in6m->in6m_timer = 0; /* transit to idle state */ 303 in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */ 304 } 305 306 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 307 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 308 break; 309 default: /* this is impossible */ 310 #if 0 311 /* 312 * this case should be impossible because of filtering in 313 * icmp6_input(). But we explicitly disabled this part 314 * just in case. 315 */ 316 log(LOG_ERR, "mld_input: illegal type(%d)", mldh->mld_type); 317 #endif 318 break; 319 } 320 if_put(ifp); 321 322 m_freem(m); 323 } 324 325 void 326 mld6_fasttimeo(void) 327 { 328 struct ifnet *ifp; 329 330 NET_LOCK(); 331 332 /* 333 * Quick check to see if any work needs to be done, in order 334 * to minimize the overhead of fasttimo processing. 335 */ 336 if (!mld_timers_are_running) 337 goto out; 338 339 mld_timers_are_running = 0; 340 TAILQ_FOREACH(ifp, &ifnet, if_list) 341 mld6_checktimer(ifp); 342 343 out: 344 NET_UNLOCK(); 345 } 346 347 void 348 mld6_checktimer(struct ifnet *ifp) 349 { 350 struct in6_multi *in6m; 351 struct ifmaddr *ifma; 352 353 NET_ASSERT_LOCKED(); 354 355 TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) { 356 if (ifma->ifma_addr->sa_family != AF_INET6) 357 continue; 358 in6m = ifmatoin6m(ifma); 359 if (in6m->in6m_timer == 0) { 360 /* do nothing */ 361 } else if (--in6m->in6m_timer == 0) { 362 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 363 in6m->in6m_state = MLD_IREPORTEDLAST; 364 } else { 365 mld_timers_are_running = 1; 366 } 367 } 368 } 369 370 static void 371 mld6_sendpkt(struct in6_multi *in6m, int type, const struct in6_addr *dst) 372 { 373 struct mbuf *mh, *md; 374 struct mld_hdr *mldh; 375 struct ip6_hdr *ip6; 376 struct ip6_moptions im6o; 377 struct in6_ifaddr *ia6; 378 struct ifnet *ifp; 379 int ignflags; 380 381 ifp = if_get(in6m->in6m_ifidx); 382 if (ifp == NULL) 383 return; 384 385 /* 386 * At first, find a link local address on the outgoing interface 387 * to use as the source address of the MLD packet. 388 * We do not reject tentative addresses for MLD report to deal with 389 * the case where we first join a link-local address. 390 */ 391 ignflags = IN6_IFF_DUPLICATED|IN6_IFF_ANYCAST; 392 if ((ia6 = in6ifa_ifpforlinklocal(ifp, ignflags)) == NULL) { 393 if_put(ifp); 394 return; 395 } 396 if ((ia6->ia6_flags & IN6_IFF_TENTATIVE)) 397 ia6 = NULL; 398 399 /* 400 * Allocate mbufs to store ip6 header and MLD header. 401 * We allocate 2 mbufs and make chain in advance because 402 * it is more convenient when inserting the hop-by-hop option later. 403 */ 404 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 405 if (mh == NULL) { 406 if_put(ifp); 407 return; 408 } 409 MGET(md, M_DONTWAIT, MT_DATA); 410 if (md == NULL) { 411 m_free(mh); 412 if_put(ifp); 413 return; 414 } 415 mh->m_next = md; 416 417 mh->m_pkthdr.ph_ifidx = 0; 418 mh->m_pkthdr.ph_rtableid = ifp->if_rdomain; 419 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr); 420 mh->m_len = sizeof(struct ip6_hdr); 421 m_align(mh, sizeof(struct ip6_hdr)); 422 423 /* fill in the ip6 header */ 424 ip6 = mtod(mh, struct ip6_hdr *); 425 ip6->ip6_flow = 0; 426 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 427 ip6->ip6_vfc |= IPV6_VERSION; 428 /* ip6_plen will be set later */ 429 ip6->ip6_nxt = IPPROTO_ICMPV6; 430 /* ip6_hlim will be set by im6o.im6o_hlim */ 431 ip6->ip6_src = ia6 ? ia6->ia_addr.sin6_addr : in6addr_any; 432 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 433 434 /* fill in the MLD header */ 435 md->m_len = sizeof(struct mld_hdr); 436 mldh = mtod(md, struct mld_hdr *); 437 mldh->mld_type = type; 438 mldh->mld_code = 0; 439 mldh->mld_cksum = 0; 440 /* XXX: we assume the function will not be called for query messages */ 441 mldh->mld_maxdelay = 0; 442 mldh->mld_reserved = 0; 443 mldh->mld_addr = in6m->in6m_addr; 444 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 445 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 446 mh->m_pkthdr.csum_flags |= M_ICMP_CSUM_OUT; 447 448 /* construct multicast option */ 449 bzero(&im6o, sizeof(im6o)); 450 im6o.im6o_ifidx = ifp->if_index; 451 im6o.im6o_hlim = 1; 452 453 /* 454 * Request loopback of the report if we are acting as a multicast 455 * router, so that the process-level routing daemon can hear it. 456 */ 457 #ifdef MROUTING 458 im6o.im6o_loop = (ip6_mrouter[ifp->if_rdomain] != NULL); 459 #endif 460 if_put(ifp); 461 462 icmp6stat_inc(icp6s_outhist + type); 463 ip6_output(mh, &ip6_opts, NULL, ia6 ? 0 : IPV6_UNSPECSRC, &im6o, 464 NULL); 465 } 466