1 /* $FreeBSD: src/sys/netinet6/mld6.c,v 1.4.2.4 2003/01/23 21:06:47 sam Exp $ */ 2 /* $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 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 "opt_inet.h" 69 #include "opt_inet6.h" 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/malloc.h> /* for M_NOWAIT */ 74 #include <sys/mbuf.h> 75 #include <sys/socket.h> 76 #include <sys/protosw.h> 77 #include <sys/syslog.h> 78 79 #include <net/if.h> 80 81 #include <netinet/in.h> 82 #include <netinet/in_var.h> 83 #include <netinet/ip6.h> 84 #include <netinet6/ip6_var.h> 85 #include <netinet/icmp6.h> 86 #include <netinet6/mld6_var.h> 87 88 #include <net/net_osdep.h> 89 90 /* 91 * Protocol constants 92 */ 93 94 /* denotes that the MLD max response delay field specifies time in milliseconds */ 95 #define MLD6_TIMER_SCALE 1000 96 /* 97 * time between repetitions of a node's initial report of interest in a 98 * multicast address(in seconds) 99 */ 100 #define MLD6_UNSOLICITED_REPORT_INTERVAL 10 101 102 static struct ip6_pktopts ip6_opts; 103 static int mld6_timers_are_running; 104 /* XXX: These are necessary for KAME's link-local hack */ 105 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 106 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 107 108 static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *); 109 110 static struct lwkt_token mld6_token = LWKT_TOKEN_INITIALIZER(mp_token); 111 112 113 void 114 mld6_init(void) 115 { 116 static u_int8_t hbh_buf[8]; 117 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 118 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 119 120 mld6_timers_are_running = 0; 121 122 /* ip6h_nxt will be fill in later */ 123 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */ 124 125 /* XXX: grotty hard coding... */ 126 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 127 hbh_buf[3] = 0; 128 hbh_buf[4] = IP6OPT_RTALERT; 129 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 130 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 131 132 init_ip6pktopts(&ip6_opts); 133 ip6_opts.ip6po_hbh = hbh; 134 } 135 136 void 137 mld6_start_listening(struct in6_multi *in6m) 138 { 139 /* 140 * RFC2710 page 10: 141 * The node never sends a Report or Done for the link-scope all-nodes 142 * address. 143 * MLD messages are never sent for multicast addresses whose scope is 0 144 * (reserved) or 1 (node-local). 145 */ 146 lwkt_gettoken(&mld6_token); 147 mld6_all_nodes_linklocal.s6_addr16[1] = 148 htons(in6m->in6m_ifp->if_index); /* XXX */ 149 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) || 150 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 151 in6m->in6m_timer = 0; 152 in6m->in6m_state = MLD6_OTHERLISTENER; 153 } else { 154 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 155 in6m->in6m_timer = MLD6_RANDOM_DELAY( 156 MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ); 157 in6m->in6m_state = MLD6_IREPORTEDLAST; 158 mld6_timers_are_running = 1; 159 } 160 lwkt_reltoken(&mld6_token); 161 } 162 163 void 164 mld6_stop_listening(struct in6_multi *in6m) 165 { 166 mld6_all_nodes_linklocal.s6_addr16[1] = 167 htons(in6m->in6m_ifp->if_index); /* XXX */ 168 mld6_all_routers_linklocal.s6_addr16[1] = 169 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 170 171 if (in6m->in6m_state == MLD6_IREPORTEDLAST && 172 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) && 173 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_INTFACELOCAL) 174 mld6_sendpkt(in6m, MLD_LISTENER_DONE, 175 &mld6_all_routers_linklocal); 176 } 177 178 void 179 mld6_input(struct mbuf *m, int off) 180 { 181 struct ip6_hdr *ip6; 182 struct mld_hdr *mldh; 183 struct ifnet *ifp = m->m_pkthdr.rcvif; 184 struct in6_multi *in6m; 185 struct in6_ifaddr *ia; 186 struct ifmultiaddr *ifma, mark; 187 struct sockaddr sa; 188 int timer; /* timer value in the MLD query header */ 189 190 #ifndef PULLDOWN_TEST 191 IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),); 192 mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off); 193 #else 194 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh)); 195 if (mldh == NULL) { 196 icmp6stat.icp6s_tooshort++; 197 return; 198 } 199 #endif 200 201 lwkt_gettoken(&mld6_token); 202 /* source address validation */ 203 ip6 = mtod(m, struct ip6_hdr *); /* in case mpullup */ 204 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 205 #if 0 206 log(LOG_ERR, 207 "mld6_input: src %s is not link-local (grp=%s)\n", 208 ip6_sprintf(&ip6->ip6_src), 209 ip6_sprintf(&mldh->mld_addr)); 210 #endif 211 /* 212 * spec (RFC2710) does not explicitly 213 * specify to discard the packet from a non link-local 214 * source address. But we believe it's expected to do so. 215 * XXX: do we have to allow :: as source? 216 */ 217 m_freem(m); 218 lwkt_reltoken(&mld6_token); 219 return; 220 } 221 222 /* 223 * In the MLD6 specification, there are 3 states and a flag. 224 * 225 * In Non-Listener state, we simply don't have a membership record. 226 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 227 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 228 * 229 * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if 230 * we have heard a report from another member, or MLD6_IREPORTEDLAST 231 * if we sent the last report. 232 */ 233 switch(mldh->mld_type) { 234 case MLD_LISTENER_QUERY: 235 if (ifp->if_flags & IFF_LOOPBACK) 236 break; 237 238 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) && 239 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 240 break; /* print error or log stat? */ 241 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 242 mldh->mld_addr.s6_addr16[1] = 243 htons(ifp->if_index); /* XXX */ 244 245 /* 246 * - Start the timers in all of our membership records 247 * that the query applies to for the interface on 248 * which the query arrived excl. those that belong 249 * to the "all-nodes" group (ff02::1). 250 * - Restart any timer that is already running but has 251 * A value longer than the requested timeout. 252 * - Use the value specified in the query message as 253 * the maximum timeout. 254 */ 255 IFP_TO_IA6(ifp, ia); 256 if (ia == NULL) 257 break; 258 259 /* 260 * XXX: System timer resolution is too low to handle Max 261 * Response Delay, so set 1 to the internal timer even if 262 * the calculated value equals to zero when Max Response 263 * Delay is positive. 264 */ 265 timer = ntohs(mldh->mld_maxdelay) * PR_FASTHZ / 266 MLD6_TIMER_SCALE; 267 if (timer == 0 && mldh->mld_maxdelay) 268 timer = 1; 269 mld6_all_nodes_linklocal.s6_addr16[1] = 270 htons(ifp->if_index); /* XXX */ 271 272 bzero(&sa, sizeof(sa)); 273 sa.sa_family = AF_UNSPEC; 274 sa.sa_len = sizeof(sa); 275 276 bzero(&mark, sizeof(mark)); 277 mark.ifma_addr = &sa; 278 279 /* TODO: need ifnet_serialize_main */ 280 ifnet_serialize_all(ifp); 281 282 TAILQ_INSERT_HEAD(&ifp->if_multiaddrs, &mark, ifma_link); 283 while ((ifma = TAILQ_NEXT(&mark, ifma_link)) != NULL) { 284 TAILQ_REMOVE(&ifp->if_multiaddrs, &mark, ifma_link); 285 TAILQ_INSERT_AFTER(&ifp->if_multiaddrs, ifma, &mark, 286 ifma_link); 287 288 if (ifma->ifma_addr->sa_family != AF_INET6) 289 continue; 290 in6m = (struct in6_multi *)ifma->ifma_protospec; 291 292 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 293 &mld6_all_nodes_linklocal) || 294 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 295 IPV6_ADDR_SCOPE_LINKLOCAL) 296 continue; 297 298 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) || 299 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr, 300 &in6m->in6m_addr)) 301 { 302 if (timer == 0) { 303 /* 304 * Release serializer(s) temporarily, 305 * before sending report. 306 */ 307 ifnet_deserialize_all(ifp); 308 /* send a report immediately */ 309 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, 310 NULL); 311 ifnet_serialize_all(ifp); 312 in6m->in6m_timer = 0; /* reset timer */ 313 in6m->in6m_state = MLD6_IREPORTEDLAST; 314 } 315 else if (in6m->in6m_timer == 0 || /*idle state*/ 316 in6m->in6m_timer > timer) { 317 in6m->in6m_timer = 318 MLD6_RANDOM_DELAY(timer); 319 mld6_timers_are_running = 1; 320 } 321 } 322 } 323 TAILQ_REMOVE(&ifp->if_multiaddrs, &mark, ifma_link); 324 325 ifnet_deserialize_all(ifp); 326 327 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 328 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 329 break; 330 331 case MLD_LISTENER_REPORT: 332 /* 333 * For fast leave to work, we have to know that we are the 334 * last person to send a report for this group. Reports 335 * can potentially get looped back if we are a multicast 336 * router, so discard reports sourced by me. 337 * Note that it is impossible to check IFF_LOOPBACK flag of 338 * ifp for this purpose, since ip6_mloopback pass the physical 339 * interface to looutput. 340 */ 341 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 342 break; 343 344 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 345 break; 346 347 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 348 mldh->mld_addr.s6_addr16[1] = 349 htons(ifp->if_index); /* XXX */ 350 /* 351 * If we belong to the group being reported, stop 352 * our timer for that group. 353 */ 354 in6m = IN6_LOOKUP_MULTI(&mldh->mld_addr, ifp); 355 if (in6m) { 356 in6m->in6m_timer = 0; /* transit to idle state */ 357 in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */ 358 } 359 360 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 361 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 362 break; 363 default: /* this is impossible */ 364 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type); 365 break; 366 } 367 368 m_freem(m); 369 lwkt_reltoken(&mld6_token); 370 } 371 372 void 373 mld6_fasttimeo(void) 374 { 375 struct in6_multi *in6m; 376 struct in6_multistep step; 377 378 /* 379 * Quick check to see if any work needs to be done, in order 380 * to minimize the overhead of fasttimo processing. 381 */ 382 lwkt_gettoken(&mld6_token); 383 384 if (!mld6_timers_are_running) { 385 lwkt_reltoken(&mld6_token); 386 return; 387 } 388 389 mld6_timers_are_running = 0; 390 IN6_FIRST_MULTI(step, in6m); 391 while (in6m != NULL) { 392 if (in6m->in6m_timer == 0) { 393 /* do nothing */ 394 } else if (--in6m->in6m_timer == 0) { 395 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 396 in6m->in6m_state = MLD6_IREPORTEDLAST; 397 } else { 398 mld6_timers_are_running = 1; 399 } 400 IN6_NEXT_MULTI(step, in6m); 401 } 402 403 lwkt_reltoken(&mld6_token); 404 } 405 406 static void 407 mld6_sendpkt(struct in6_multi *in6m, int type, const struct in6_addr *dst) 408 { 409 struct mbuf *mh, *md; 410 struct mld_hdr *mldh; 411 struct ip6_hdr *ip6; 412 struct ip6_moptions im6o; 413 struct in6_ifaddr *ia; 414 struct ifnet *ifp = in6m->in6m_ifp; 415 struct ifnet *outif = NULL; 416 417 /* 418 * At first, find a link local address on the outgoing interface 419 * to use as the source address of the MLD packet. 420 */ 421 if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST)) 422 == NULL) 423 return; 424 425 /* 426 * Allocate mbufs to store ip6 header and MLD header. 427 * We allocate 2 mbufs and make chain in advance because 428 * it is more convenient when inserting the hop-by-hop option later. 429 */ 430 MGETHDR(mh, M_NOWAIT, MT_HEADER); 431 if (mh == NULL) 432 return; 433 MGET(md, M_NOWAIT, MT_DATA); 434 if (md == NULL) { 435 m_free(mh); 436 return; 437 } 438 mh->m_next = md; 439 440 mh->m_pkthdr.rcvif = NULL; 441 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr); 442 mh->m_len = sizeof(struct ip6_hdr); 443 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 444 445 /* fill in the ip6 header */ 446 ip6 = mtod(mh, struct ip6_hdr *); 447 ip6->ip6_flow = 0; 448 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 449 ip6->ip6_vfc |= IPV6_VERSION; 450 /* ip6_plen will be set later */ 451 ip6->ip6_nxt = IPPROTO_ICMPV6; 452 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 453 ip6->ip6_src = ia->ia_addr.sin6_addr; 454 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 455 456 /* fill in the MLD header */ 457 md->m_len = sizeof(struct mld_hdr); 458 mldh = mtod(md, struct mld_hdr *); 459 mldh->mld_type = type; 460 mldh->mld_code = 0; 461 mldh->mld_cksum = 0; 462 /* XXX: we assume the function will not be called for query messages */ 463 mldh->mld_maxdelay = 0; 464 mldh->mld_reserved = 0; 465 mldh->mld_addr = in6m->in6m_addr; 466 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 467 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 468 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 469 sizeof(struct mld_hdr)); 470 471 /* construct multicast option */ 472 bzero(&im6o, sizeof(im6o)); 473 im6o.im6o_multicast_ifp = ifp; 474 im6o.im6o_multicast_hlim = 1; 475 476 /* 477 * Request loopback of the report if we are acting as a multicast 478 * router, so that the process-level routing daemon can hear it. 479 */ 480 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 481 482 /* increment output statictics */ 483 icmp6stat.icp6s_outhist[type]++; 484 485 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL); 486 if (outif) { 487 icmp6_ifstat_inc(outif, ifs6_out_msg); 488 switch (type) { 489 case MLD_LISTENER_QUERY: 490 icmp6_ifstat_inc(outif, ifs6_out_mldquery); 491 break; 492 case MLD_LISTENER_REPORT: 493 icmp6_ifstat_inc(outif, ifs6_out_mldreport); 494 break; 495 case MLD_LISTENER_DONE: 496 icmp6_ifstat_inc(outif, ifs6_out_mlddone); 497 break; 498 } 499 } 500 } 501