1 /* $FreeBSD: src/sys/netinet6/mld6.c,v 1.4.2.4 2003/01/23 21:06:47 sam Exp $ */ 2 /* $DragonFly: src/sys/netinet6/mld6.c,v 1.6 2005/06/03 19:56:08 eirikn Exp $ */ 3 /* $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $ */ 4 5 /* 6 * Copyright (C) 1998 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 /* 35 * Copyright (c) 1988 Stephen Deering. 36 * Copyright (c) 1992, 1993 37 * The Regents of the University of California. All rights reserved. 38 * 39 * This code is derived from software contributed to Berkeley by 40 * Stephen Deering of Stanford University. 41 * 42 * Redistribution and use in source and binary forms, with or without 43 * modification, are permitted provided that the following conditions 44 * are met: 45 * 1. Redistributions of source code must retain the above copyright 46 * notice, this list of conditions and the following disclaimer. 47 * 2. Redistributions in binary form must reproduce the above copyright 48 * notice, this list of conditions and the following disclaimer in the 49 * documentation and/or other materials provided with the distribution. 50 * 3. Neither the name of the University nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 64 * SUCH DAMAGE. 65 * 66 * @(#)igmp.c 8.1 (Berkeley) 7/19/93 67 */ 68 69 #include "opt_inet.h" 70 #include "opt_inet6.h" 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/mbuf.h> 75 #include <sys/socket.h> 76 #include <sys/protosw.h> 77 #include <sys/syslog.h> 78 #include <sys/thread2.h> 79 80 #include <net/if.h> 81 82 #include <netinet/in.h> 83 #include <netinet/in_var.h> 84 #include <netinet/ip6.h> 85 #include <netinet6/ip6_var.h> 86 #include <netinet/icmp6.h> 87 #include <netinet6/mld6_var.h> 88 89 #include <net/net_osdep.h> 90 91 /* 92 * Protocol constants 93 */ 94 95 /* denotes that the MLD max response delay field specifies time in milliseconds */ 96 #define MLD6_TIMER_SCALE 1000 97 /* 98 * time between repetitions of a node's initial report of interest in a 99 * multicast address(in seconds) 100 */ 101 #define MLD6_UNSOLICITED_REPORT_INTERVAL 10 102 103 static struct ip6_pktopts ip6_opts; 104 static int mld6_timers_are_running; 105 /* XXX: These are necessary for KAME's link-local hack */ 106 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 107 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 108 109 static void mld6_sendpkt (struct in6_multi *, int, const struct in6_addr *); 110 111 static struct lwkt_token mld6_token = LWKT_TOKEN_INITIALIZER(mp_token); 112 113 114 void 115 mld6_init(void) 116 { 117 static u_int8_t hbh_buf[8]; 118 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 119 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 120 121 mld6_timers_are_running = 0; 122 123 /* ip6h_nxt will be fill in later */ 124 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */ 125 126 /* XXX: grotty hard coding... */ 127 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 128 hbh_buf[3] = 0; 129 hbh_buf[4] = IP6OPT_RTALERT; 130 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 131 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 132 133 init_ip6pktopts(&ip6_opts); 134 ip6_opts.ip6po_hbh = hbh; 135 } 136 137 void 138 mld6_start_listening(struct in6_multi *in6m) 139 { 140 /* 141 * RFC2710 page 10: 142 * The node never sends a Report or Done for the link-scope all-nodes 143 * address. 144 * MLD messages are never sent for multicast addresses whose scope is 0 145 * (reserved) or 1 (node-local). 146 */ 147 lwkt_gettoken(&mld6_token); 148 mld6_all_nodes_linklocal.s6_addr16[1] = 149 htons(in6m->in6m_ifp->if_index); /* XXX */ 150 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) || 151 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 152 in6m->in6m_timer = 0; 153 in6m->in6m_state = MLD6_OTHERLISTENER; 154 } else { 155 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 156 in6m->in6m_timer = MLD6_RANDOM_DELAY( 157 MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ); 158 in6m->in6m_state = MLD6_IREPORTEDLAST; 159 mld6_timers_are_running = 1; 160 } 161 lwkt_reltoken(&mld6_token); 162 } 163 164 void 165 mld6_stop_listening(struct in6_multi *in6m) 166 { 167 mld6_all_nodes_linklocal.s6_addr16[1] = 168 htons(in6m->in6m_ifp->if_index); /* XXX */ 169 mld6_all_routers_linklocal.s6_addr16[1] = 170 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 171 172 if (in6m->in6m_state == MLD6_IREPORTEDLAST && 173 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) && 174 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL) 175 mld6_sendpkt(in6m, MLD_LISTENER_DONE, 176 &mld6_all_routers_linklocal); 177 } 178 179 void 180 mld6_input(struct mbuf *m, int off) 181 { 182 struct ip6_hdr *ip6; 183 struct mld_hdr *mldh; 184 struct ifnet *ifp = m->m_pkthdr.rcvif; 185 struct in6_multi *in6m; 186 struct in6_ifaddr *ia; 187 struct ifmultiaddr *ifma, mark; 188 struct sockaddr sa; 189 int timer; /* timer value in the MLD query header */ 190 191 #ifndef PULLDOWN_TEST 192 IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),); 193 mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off); 194 #else 195 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh)); 196 if (mldh == NULL) { 197 icmp6stat.icp6s_tooshort++; 198 return; 199 } 200 #endif 201 202 lwkt_gettoken(&mld6_token); 203 /* source address validation */ 204 ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */ 205 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 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 /* 211 * spec (RFC2710) does not explicitly 212 * specify to discard the packet from a non link-local 213 * source address. But we believe it's expected to do so. 214 * XXX: do we have to allow :: as source? 215 */ 216 m_freem(m); 217 lwkt_reltoken(&mld6_token); 218 return; 219 } 220 221 /* 222 * In the MLD6 specification, there are 3 states and a flag. 223 * 224 * In Non-Listener state, we simply don't have a membership record. 225 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 226 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 227 * 228 * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if 229 * we have heard a report from another member, or MLD6_IREPORTEDLAST 230 * if we sent the last report. 231 */ 232 switch(mldh->mld_type) { 233 case MLD_LISTENER_QUERY: 234 if (ifp->if_flags & IFF_LOOPBACK) 235 break; 236 237 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) && 238 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 239 break; /* print error or log stat? */ 240 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 241 mldh->mld_addr.s6_addr16[1] = 242 htons(ifp->if_index); /* XXX */ 243 244 /* 245 * - Start the timers in all of our membership records 246 * that the query applies to for the interface on 247 * which the query arrived excl. those that belong 248 * to the "all-nodes" group (ff02::1). 249 * - Restart any timer that is already running but has 250 * A value longer than the requested timeout. 251 * - Use the value specified in the query message as 252 * the maximum timeout. 253 */ 254 IFP_TO_IA6(ifp, ia); 255 if (ia == NULL) 256 break; 257 258 /* 259 * XXX: System timer resolution is too low to handle Max 260 * Response Delay, so set 1 to the internal timer even if 261 * the calculated value equals to zero when Max Response 262 * Delay is positive. 263 */ 264 timer = ntohs(mldh->mld_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE; 265 if (timer == 0 && mldh->mld_maxdelay) 266 timer = 1; 267 mld6_all_nodes_linklocal.s6_addr16[1] = 268 htons(ifp->if_index); /* XXX */ 269 270 bzero(&sa, sizeof(sa)); 271 sa.sa_family = AF_UNSPEC; 272 sa.sa_len = sizeof(sa); 273 274 bzero(&mark, sizeof(mark)); 275 mark.ifma_addr = &sa; 276 277 /* TODO: need ifnet_serialize_main */ 278 ifnet_serialize_all(ifp); 279 280 TAILQ_INSERT_HEAD(&ifp->if_multiaddrs, &mark, ifma_link); 281 while ((ifma = TAILQ_NEXT(&mark, ifma_link)) != NULL) { 282 TAILQ_REMOVE(&ifp->if_multiaddrs, &mark, ifma_link); 283 TAILQ_INSERT_AFTER(&ifp->if_multiaddrs, ifma, &mark, 284 ifma_link); 285 286 if (ifma->ifma_addr->sa_family != AF_INET6) 287 continue; 288 in6m = (struct in6_multi *)ifma->ifma_protospec; 289 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 290 &mld6_all_nodes_linklocal) || 291 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 292 IPV6_ADDR_SCOPE_LINKLOCAL) 293 continue; 294 295 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) || 296 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr, 297 &in6m->in6m_addr)) 298 { 299 if (timer == 0) { 300 /* 301 * Release serializer(s) temporarily, 302 * before sending report. 303 */ 304 ifnet_deserialize_all(ifp); 305 /* send a report immediately */ 306 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, 307 NULL); 308 ifnet_serialize_all(ifp); 309 in6m->in6m_timer = 0; /* reset timer */ 310 in6m->in6m_state = MLD6_IREPORTEDLAST; 311 } 312 else if (in6m->in6m_timer == 0 || /*idle state*/ 313 in6m->in6m_timer > timer) { 314 in6m->in6m_timer = 315 MLD6_RANDOM_DELAY(timer); 316 mld6_timers_are_running = 1; 317 } 318 } 319 } 320 TAILQ_REMOVE(&ifp->if_multiaddrs, &mark, ifma_link); 321 322 ifnet_deserialize_all(ifp); 323 324 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 325 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 326 break; 327 case MLD_LISTENER_REPORT: 328 /* 329 * For fast leave to work, we have to know that we are the 330 * last person to send a report for this group. Reports 331 * can potentially get looped back if we are a multicast 332 * router, so discard reports sourced by me. 333 * Note that it is impossible to check IFF_LOOPBACK flag of 334 * ifp for this purpose, since ip6_mloopback pass the physical 335 * interface to looutput. 336 */ 337 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 338 break; 339 340 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 341 break; 342 343 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 344 mldh->mld_addr.s6_addr16[1] = 345 htons(ifp->if_index); /* XXX */ 346 /* 347 * If we belong to the group being reported, stop 348 * our timer for that group. 349 */ 350 in6m = IN6_LOOKUP_MULTI(&mldh->mld_addr, ifp); 351 if (in6m) { 352 in6m->in6m_timer = 0; /* transit to idle state */ 353 in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */ 354 } 355 356 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 357 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 358 break; 359 default: /* this is impossible */ 360 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type); 361 break; 362 } 363 364 m_freem(m); 365 lwkt_reltoken(&mld6_token); 366 } 367 368 void 369 mld6_fasttimeo(void) 370 { 371 struct in6_multi *in6m; 372 struct in6_multistep step; 373 374 /* 375 * Quick check to see if any work needs to be done, in order 376 * to minimize the overhead of fasttimo processing. 377 */ 378 lwkt_gettoken(&mld6_token); 379 if (!mld6_timers_are_running) { 380 lwkt_reltoken(&mld6_token); 381 return; 382 } 383 384 mld6_timers_are_running = 0; 385 IN6_FIRST_MULTI(step, in6m); 386 while (in6m != NULL) { 387 if (in6m->in6m_timer == 0) { 388 /* do nothing */ 389 } else if (--in6m->in6m_timer == 0) { 390 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 391 in6m->in6m_state = MLD6_IREPORTEDLAST; 392 } else { 393 mld6_timers_are_running = 1; 394 } 395 IN6_NEXT_MULTI(step, in6m); 396 } 397 lwkt_reltoken(&mld6_token); 398 } 399 400 static void 401 mld6_sendpkt(struct in6_multi *in6m, int type, const struct in6_addr *dst) 402 { 403 struct mbuf *mh, *md; 404 struct mld_hdr *mldh; 405 struct ip6_hdr *ip6; 406 struct ip6_moptions im6o; 407 struct in6_ifaddr *ia; 408 struct ifnet *ifp = in6m->in6m_ifp; 409 struct ifnet *outif = NULL; 410 411 /* 412 * At first, find a link local address on the outgoing interface 413 * to use as the source address of the MLD packet. 414 */ 415 if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST)) 416 == NULL) 417 return; 418 419 /* 420 * Allocate mbufs to store ip6 header and MLD header. 421 * We allocate 2 mbufs and make chain in advance because 422 * it is more convenient when inserting the hop-by-hop option later. 423 */ 424 MGETHDR(mh, MB_DONTWAIT, MT_HEADER); 425 if (mh == NULL) 426 return; 427 MGET(md, MB_DONTWAIT, MT_DATA); 428 if (md == NULL) { 429 m_free(mh); 430 return; 431 } 432 mh->m_next = md; 433 434 mh->m_pkthdr.rcvif = NULL; 435 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr); 436 mh->m_len = sizeof(struct ip6_hdr); 437 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 438 439 /* fill in the ip6 header */ 440 ip6 = mtod(mh, struct ip6_hdr *); 441 ip6->ip6_flow = 0; 442 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 443 ip6->ip6_vfc |= IPV6_VERSION; 444 /* ip6_plen will be set later */ 445 ip6->ip6_nxt = IPPROTO_ICMPV6; 446 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 447 ip6->ip6_src = ia->ia_addr.sin6_addr; 448 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 449 450 /* fill in the MLD header */ 451 md->m_len = sizeof(struct mld_hdr); 452 mldh = mtod(md, struct mld_hdr *); 453 mldh->mld_type = type; 454 mldh->mld_code = 0; 455 mldh->mld_cksum = 0; 456 /* XXX: we assume the function will not be called for query messages */ 457 mldh->mld_maxdelay = 0; 458 mldh->mld_reserved = 0; 459 mldh->mld_addr = in6m->in6m_addr; 460 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 461 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 462 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, 463 sizeof(struct ip6_hdr), 464 sizeof(struct mld_hdr)); 465 466 /* construct multicast option */ 467 bzero(&im6o, sizeof(im6o)); 468 im6o.im6o_multicast_ifp = ifp; 469 im6o.im6o_multicast_hlim = 1; 470 471 /* 472 * Request loopback of the report if we are acting as a multicast 473 * router, so that the process-level routing daemon can hear it. 474 */ 475 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 476 477 /* increment output statictics */ 478 icmp6stat.icp6s_outhist[type]++; 479 480 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL); 481 if (outif) { 482 icmp6_ifstat_inc(outif, ifs6_out_msg); 483 switch (type) { 484 case MLD_LISTENER_QUERY: 485 icmp6_ifstat_inc(outif, ifs6_out_mldquery); 486 break; 487 case MLD_LISTENER_REPORT: 488 icmp6_ifstat_inc(outif, ifs6_out_mldreport); 489 break; 490 case MLD_LISTENER_DONE: 491 icmp6_ifstat_inc(outif, ifs6_out_mlddone); 492 break; 493 } 494 } 495 } 496