1 /* $FreeBSD$ */ 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. All advertising materials mentioning features or use of this software 50 * must display the following acknowledgement: 51 * This product includes software developed by the University of 52 * California, Berkeley and its contributors. 53 * 4. Neither the name of the University nor the names of its contributors 54 * may be used to endorse or promote products derived from this software 55 * without specific prior written permission. 56 * 57 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 58 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 59 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 60 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 61 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 62 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 63 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 64 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 65 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 66 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 67 * SUCH DAMAGE. 68 * 69 * @(#)igmp.c 8.1 (Berkeley) 7/19/93 70 */ 71 72 #include "opt_inet.h" 73 #include "opt_inet6.h" 74 75 #include <sys/param.h> 76 #include <sys/systm.h> 77 #include <sys/mbuf.h> 78 #include <sys/socket.h> 79 #include <sys/protosw.h> 80 #include <sys/syslog.h> 81 #include <sys/malloc.h> 82 83 #include <net/if.h> 84 85 #include <netinet/in.h> 86 #include <netinet/in_var.h> 87 #include <netinet/ip6.h> 88 #include <netinet6/ip6_var.h> 89 #include <netinet/icmp6.h> 90 #include <netinet6/mld6_var.h> 91 92 #include <net/net_osdep.h> 93 94 /* 95 * Protocol constants 96 */ 97 98 /* denotes that the MLD max response delay field specifies time in milliseconds */ 99 #define MLD_TIMER_SCALE 1000 100 /* 101 * time between repetitions of a node's initial report of interest in a 102 * multicast address(in seconds) 103 */ 104 #define MLD_UNSOLICITED_REPORT_INTERVAL 10 105 106 static struct ip6_pktopts ip6_opts; 107 static int mld6_timers_are_running; 108 /* XXX: These are necessary for KAME's link-local hack */ 109 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 110 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 111 112 static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *); 113 114 void 115 mld6_init() 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_ROUTER_ALERT; 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(in6m) 139 struct in6_multi *in6m; 140 { 141 int s = splnet(); 142 143 /* 144 * RFC2710 page 10: 145 * The node never sends a Report or Done for the link-scope all-nodes 146 * address. 147 * MLD messages are never sent for multicast addresses whose scope is 0 148 * (reserved) or 1 (node-local). 149 */ 150 mld6_all_nodes_linklocal.s6_addr16[1] = 151 htons(in6m->in6m_ifp->if_index); /* XXX */ 152 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) || 153 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 154 in6m->in6m_timer = 0; 155 in6m->in6m_state = MLD_OTHERLISTENER; 156 } else { 157 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 158 in6m->in6m_timer = 159 MLD_RANDOM_DELAY(MLD_UNSOLICITED_REPORT_INTERVAL * 160 PR_FASTHZ); 161 in6m->in6m_state = MLD_IREPORTEDLAST; 162 mld6_timers_are_running = 1; 163 } 164 splx(s); 165 } 166 167 void 168 mld6_stop_listening(in6m) 169 struct in6_multi *in6m; 170 { 171 mld6_all_nodes_linklocal.s6_addr16[1] = 172 htons(in6m->in6m_ifp->if_index); /* XXX */ 173 mld6_all_routers_linklocal.s6_addr16[1] = 174 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 175 176 if (in6m->in6m_state == MLD_IREPORTEDLAST && 177 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) && 178 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_INTFACELOCAL) 179 mld6_sendpkt(in6m, MLD_LISTENER_DONE, 180 &mld6_all_routers_linklocal); 181 } 182 183 void 184 mld6_input(m, off) 185 struct mbuf *m; 186 int off; 187 { 188 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 189 struct mld_hdr *mldh; 190 struct ifnet *ifp = m->m_pkthdr.rcvif; 191 struct in6_multi *in6m; 192 struct in6_ifaddr *ia; 193 struct ifmultiaddr *ifma; 194 int timer; /* timer value in the MLD query header */ 195 196 #ifndef PULLDOWN_TEST 197 IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),); 198 mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off); 199 #else 200 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh)); 201 if (mldh == NULL) { 202 icmp6stat.icp6s_tooshort++; 203 return; 204 } 205 #endif 206 207 /* source address validation */ 208 ip6 = mtod(m, struct ip6_hdr *); /* in case mpullup */ 209 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 210 log(LOG_ERR, 211 "mld6_input: src %s is not link-local (grp=%s)\n", 212 ip6_sprintf(&ip6->ip6_src), 213 ip6_sprintf(&mldh->mld_addr)); 214 /* 215 * spec (RFC2710) does not explicitly 216 * specify to discard the packet from a non link-local 217 * source address. But we believe it's expected to do so. 218 * XXX: do we have to allow :: as source? 219 */ 220 m_freem(m); 221 return; 222 } 223 224 /* 225 * In the MLD6 specification, there are 3 states and a flag. 226 * 227 * In Non-Listener state, we simply don't have a membership record. 228 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 229 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 230 * 231 * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if 232 * we have heard a report from another member, or MLD_IREPORTEDLAST 233 * if we sent the last report. 234 */ 235 switch(mldh->mld_type) { 236 case MLD_LISTENER_QUERY: 237 if (ifp->if_flags & IFF_LOOPBACK) 238 break; 239 240 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) && 241 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 242 break; /* print error or log stat? */ 243 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 244 mldh->mld_addr.s6_addr16[1] = 245 htons(ifp->if_index); /* XXX */ 246 247 /* 248 * - Start the timers in all of our membership records 249 * that the query applies to for the interface on 250 * which the query arrived excl. those that belong 251 * to the "all-nodes" group (ff02::1). 252 * - Restart any timer that is already running but has 253 * A value longer than the requested timeout. 254 * - Use the value specified in the query message as 255 * the maximum timeout. 256 */ 257 IFP_TO_IA6(ifp, ia); 258 if (ia == NULL) 259 break; 260 261 /* 262 * XXX: System timer resolution is too low to handle Max 263 * Response Delay, so set 1 to the internal timer even if 264 * the calculated value equals to zero when Max Response 265 * Delay is positive. 266 */ 267 timer = ntohs(mldh->mld_maxdelay) * PR_FASTHZ / MLD_TIMER_SCALE; 268 if (timer == 0 && mldh->mld_maxdelay) 269 timer = 1; 270 mld6_all_nodes_linklocal.s6_addr16[1] = 271 htons(ifp->if_index); /* XXX */ 272 273 TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) { 274 if (ifma->ifma_addr->sa_family != AF_INET6) 275 continue; 276 in6m = (struct in6_multi *)ifma->ifma_protospec; 277 278 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 279 &mld6_all_nodes_linklocal) || 280 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 281 IPV6_ADDR_SCOPE_LINKLOCAL) 282 continue; 283 284 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) || 285 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr, 286 &in6m->in6m_addr)) 287 { 288 if (timer == 0) { 289 /* send a report immediately */ 290 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, 291 NULL); 292 in6m->in6m_timer = 0; /* reset timer */ 293 in6m->in6m_state = MLD_IREPORTEDLAST; 294 } 295 else if (in6m->in6m_timer == 0 || /*idle state*/ 296 in6m->in6m_timer > timer) { 297 in6m->in6m_timer = 298 MLD_RANDOM_DELAY(timer); 299 mld6_timers_are_running = 1; 300 } 301 } 302 } 303 304 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 305 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 306 break; 307 308 case MLD_LISTENER_REPORT: 309 /* 310 * For fast leave to work, we have to know that we are the 311 * last person to send a report for this group. Reports 312 * can potentially get looped back if we are a multicast 313 * router, so discard reports sourced by me. 314 * Note that it is impossible to check IFF_LOOPBACK flag of 315 * ifp for this purpose, since ip6_mloopback pass the physical 316 * interface to looutput. 317 */ 318 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 319 break; 320 321 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 322 break; 323 324 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 325 mldh->mld_addr.s6_addr16[1] = 326 htons(ifp->if_index); /* XXX */ 327 /* 328 * If we belong to the group being reported, stop 329 * our timer for that group. 330 */ 331 IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m); 332 if (in6m) { 333 in6m->in6m_timer = 0; /* transit to idle state */ 334 in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */ 335 } 336 337 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 338 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 339 break; 340 default: /* this is impossible */ 341 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type); 342 break; 343 } 344 345 m_freem(m); 346 } 347 348 void 349 mld6_fasttimeo() 350 { 351 struct in6_multi *in6m; 352 struct in6_multistep step; 353 int s; 354 355 /* 356 * Quick check to see if any work needs to be done, in order 357 * to minimize the overhead of fasttimo processing. 358 */ 359 if (!mld6_timers_are_running) 360 return; 361 362 s = splnet(); 363 364 mld6_timers_are_running = 0; 365 IN6_FIRST_MULTI(step, in6m); 366 while (in6m != NULL) { 367 if (in6m->in6m_timer == 0) { 368 /* do nothing */ 369 } else if (--in6m->in6m_timer == 0) { 370 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 371 in6m->in6m_state = MLD_IREPORTEDLAST; 372 } else { 373 mld6_timers_are_running = 1; 374 } 375 IN6_NEXT_MULTI(step, in6m); 376 } 377 378 splx(s); 379 } 380 381 static void 382 mld6_sendpkt(in6m, type, dst) 383 struct in6_multi *in6m; 384 int type; 385 const struct in6_addr *dst; 386 { 387 struct mbuf *mh, *md; 388 struct mld_hdr *mldh; 389 struct ip6_hdr *ip6; 390 struct ip6_moptions im6o; 391 struct in6_ifaddr *ia; 392 struct ifnet *ifp = in6m->in6m_ifp; 393 struct ifnet *outif = NULL; 394 395 /* 396 * At first, find a link local address on the outgoing interface 397 * to use as the source address of the MLD packet. 398 */ 399 if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST)) 400 == NULL) 401 return; 402 403 /* 404 * Allocate mbufs to store ip6 header and MLD header. 405 * We allocate 2 mbufs and make chain in advance because 406 * it is more convenient when inserting the hop-by-hop option later. 407 */ 408 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 409 if (mh == NULL) 410 return; 411 MGET(md, M_DONTWAIT, MT_DATA); 412 if (md == NULL) { 413 m_free(mh); 414 return; 415 } 416 mh->m_next = md; 417 418 mh->m_pkthdr.rcvif = NULL; 419 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr); 420 mh->m_len = sizeof(struct ip6_hdr); 421 MH_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_multicast_hlim */ 431 ip6->ip6_src = ia->ia_addr.sin6_addr; 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 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 447 sizeof(struct mld_hdr)); 448 449 /* construct multicast option */ 450 bzero(&im6o, sizeof(im6o)); 451 im6o.im6o_multicast_ifp = ifp; 452 im6o.im6o_multicast_hlim = 1; 453 454 /* 455 * Request loopback of the report if we are acting as a multicast 456 * router, so that the process-level routing daemon can hear it. 457 */ 458 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 459 460 /* increment output statictics */ 461 icmp6stat.icp6s_outhist[type]++; 462 463 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL); 464 if (outif) { 465 icmp6_ifstat_inc(outif, ifs6_out_msg); 466 switch (type) { 467 case MLD_LISTENER_QUERY: 468 icmp6_ifstat_inc(outif, ifs6_out_mldquery); 469 break; 470 case MLD_LISTENER_REPORT: 471 icmp6_ifstat_inc(outif, ifs6_out_mldreport); 472 break; 473 case MLD_LISTENER_DONE: 474 icmp6_ifstat_inc(outif, ifs6_out_mlddone); 475 break; 476 } 477 } 478 } 479 480 /* 481 * Add an address to the list of IP6 multicast addresses for a given interface. 482 * Add source addresses to the list also, if upstream router is MLDv2 capable 483 * and the number of source is not 0. 484 */ 485 struct in6_multi * 486 in6_addmulti(maddr6, ifp, errorp) 487 struct in6_addr *maddr6; 488 struct ifnet *ifp; 489 int *errorp; 490 { 491 struct in6_multi *in6m; 492 struct ifmultiaddr *ifma; 493 struct sockaddr_in6 sa6; 494 int s = splnet(); 495 496 *errorp = 0; 497 498 /* 499 * Call generic routine to add membership or increment 500 * refcount. It wants addresses in the form of a sockaddr, 501 * so we build one here (being careful to zero the unused bytes). 502 */ 503 bzero(&sa6, sizeof(sa6)); 504 sa6.sin6_family = AF_INET6; 505 sa6.sin6_len = sizeof(struct sockaddr_in6); 506 sa6.sin6_addr = *maddr6; 507 *errorp = if_addmulti(ifp, (struct sockaddr *)&sa6, &ifma); 508 if (*errorp) { 509 splx(s); 510 return 0; 511 } 512 513 /* 514 * If ifma->ifma_protospec is null, then if_addmulti() created 515 * a new record. Otherwise, we are done. 516 */ 517 if (ifma->ifma_protospec != 0) { 518 splx(s); 519 return ifma->ifma_protospec; 520 } 521 522 /* XXX - if_addmulti uses M_WAITOK. Can this really be called 523 at interrupt time? If so, need to fix if_addmulti. XXX */ 524 in6m = (struct in6_multi *)malloc(sizeof(*in6m), M_IPMADDR, M_NOWAIT); 525 if (in6m == NULL) { 526 splx(s); 527 return (NULL); 528 } 529 530 bzero(in6m, sizeof *in6m); 531 in6m->in6m_addr = *maddr6; 532 in6m->in6m_ifp = ifp; 533 in6m->in6m_refcount = 1; 534 in6m->in6m_ifma = ifma; 535 ifma->ifma_protospec = in6m; 536 LIST_INSERT_HEAD(&in6_multihead, in6m, in6m_entry); 537 538 /* 539 * Let MLD6 know that we have joined a new IPv6 multicast 540 * group. 541 */ 542 mld6_start_listening(in6m); 543 splx(s); 544 return (in6m); 545 } 546 547 /* 548 * Delete a multicast address record. 549 */ 550 void 551 in6_delmulti(in6m) 552 struct in6_multi *in6m; 553 { 554 struct ifmultiaddr *ifma = in6m->in6m_ifma; 555 int s = splnet(); 556 557 if (ifma->ifma_refcount == 1) { 558 /* 559 * No remaining claims to this record; let MLD6 know 560 * that we are leaving the multicast group. 561 */ 562 mld6_stop_listening(in6m); 563 ifma->ifma_protospec = 0; 564 LIST_REMOVE(in6m, in6m_entry); 565 free(in6m, M_IPMADDR); 566 } 567 /* XXX - should be separate API for when we have an ifma? */ 568 if_delmulti(ifma->ifma_ifp, ifma->ifma_addr); 569 splx(s); 570 } 571