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 * 4. 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/mbuf.h> 74 #include <sys/socket.h> 75 #include <sys/protosw.h> 76 #include <sys/syslog.h> 77 #include <sys/malloc.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 MLD_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 MLD_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 void 111 mld6_init() 112 { 113 static u_int8_t hbh_buf[8]; 114 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 115 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 116 117 mld6_timers_are_running = 0; 118 119 /* ip6h_nxt will be fill in later */ 120 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */ 121 122 /* XXX: grotty hard coding... */ 123 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 124 hbh_buf[3] = 0; 125 hbh_buf[4] = IP6OPT_ROUTER_ALERT; 126 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 127 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 128 129 init_ip6pktopts(&ip6_opts); 130 ip6_opts.ip6po_hbh = hbh; 131 } 132 133 void 134 mld6_start_listening(in6m) 135 struct in6_multi *in6m; 136 { 137 int s = splnet(); 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 mld6_all_nodes_linklocal.s6_addr16[1] = 147 htons(in6m->in6m_ifp->if_index); /* XXX */ 148 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) || 149 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 150 in6m->in6m_timer = 0; 151 in6m->in6m_state = MLD_OTHERLISTENER; 152 } else { 153 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 154 in6m->in6m_timer = 155 MLD_RANDOM_DELAY(MLD_UNSOLICITED_REPORT_INTERVAL * 156 PR_FASTHZ); 157 in6m->in6m_state = MLD_IREPORTEDLAST; 158 mld6_timers_are_running = 1; 159 } 160 splx(s); 161 } 162 163 void 164 mld6_stop_listening(in6m) 165 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 == MLD_IREPORTEDLAST && 173 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) && 174 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_INTFACELOCAL) 175 mld6_sendpkt(in6m, MLD_LISTENER_DONE, 176 &mld6_all_routers_linklocal); 177 } 178 179 void 180 mld6_input(m, off) 181 struct mbuf *m; 182 int off; 183 { 184 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 185 struct mld_hdr *mldh; 186 struct ifnet *ifp = m->m_pkthdr.rcvif; 187 struct in6_multi *in6m; 188 struct in6_ifaddr *ia; 189 struct ifmultiaddr *ifma; 190 int timer; /* timer value in the MLD query header */ 191 192 #ifndef PULLDOWN_TEST 193 IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),); 194 mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off); 195 #else 196 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh)); 197 if (mldh == NULL) { 198 icmp6stat.icp6s_tooshort++; 199 return; 200 } 201 #endif 202 203 /* 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 return; 218 } 219 220 /* 221 * In the MLD6 specification, there are 3 states and a flag. 222 * 223 * In Non-Listener state, we simply don't have a membership record. 224 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 225 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 226 * 227 * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if 228 * we have heard a report from another member, or MLD_IREPORTEDLAST 229 * if we sent the last report. 230 */ 231 switch(mldh->mld_type) { 232 case MLD_LISTENER_QUERY: 233 if (ifp->if_flags & IFF_LOOPBACK) 234 break; 235 236 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) && 237 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 238 break; /* print error or log stat? */ 239 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 240 mldh->mld_addr.s6_addr16[1] = 241 htons(ifp->if_index); /* XXX */ 242 243 /* 244 * - Start the timers in all of our membership records 245 * that the query applies to for the interface on 246 * which the query arrived excl. those that belong 247 * to the "all-nodes" group (ff02::1). 248 * - Restart any timer that is already running but has 249 * A value longer than the requested timeout. 250 * - Use the value specified in the query message as 251 * the maximum timeout. 252 */ 253 IFP_TO_IA6(ifp, ia); 254 if (ia == NULL) 255 break; 256 257 /* 258 * XXX: System timer resolution is too low to handle Max 259 * Response Delay, so set 1 to the internal timer even if 260 * the calculated value equals to zero when Max Response 261 * Delay is positive. 262 */ 263 timer = ntohs(mldh->mld_maxdelay) * PR_FASTHZ / MLD_TIMER_SCALE; 264 if (timer == 0 && mldh->mld_maxdelay) 265 timer = 1; 266 mld6_all_nodes_linklocal.s6_addr16[1] = 267 htons(ifp->if_index); /* XXX */ 268 269 TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) { 270 if (ifma->ifma_addr->sa_family != AF_INET6) 271 continue; 272 in6m = (struct in6_multi *)ifma->ifma_protospec; 273 274 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 275 &mld6_all_nodes_linklocal) || 276 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 277 IPV6_ADDR_SCOPE_LINKLOCAL) 278 continue; 279 280 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) || 281 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr, 282 &in6m->in6m_addr)) 283 { 284 if (timer == 0) { 285 /* send a report immediately */ 286 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, 287 NULL); 288 in6m->in6m_timer = 0; /* reset timer */ 289 in6m->in6m_state = MLD_IREPORTEDLAST; 290 } 291 else if (in6m->in6m_timer == 0 || /*idle state*/ 292 in6m->in6m_timer > timer) { 293 in6m->in6m_timer = 294 MLD_RANDOM_DELAY(timer); 295 mld6_timers_are_running = 1; 296 } 297 } 298 } 299 300 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 301 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 302 break; 303 304 case MLD_LISTENER_REPORT: 305 /* 306 * For fast leave to work, we have to know that we are the 307 * last person to send a report for this group. Reports 308 * can potentially get looped back if we are a multicast 309 * router, so discard reports sourced by me. 310 * Note that it is impossible to check IFF_LOOPBACK flag of 311 * ifp for this purpose, since ip6_mloopback pass the physical 312 * interface to looutput. 313 */ 314 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 315 break; 316 317 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 318 break; 319 320 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 321 mldh->mld_addr.s6_addr16[1] = 322 htons(ifp->if_index); /* XXX */ 323 /* 324 * If we belong to the group being reported, stop 325 * our timer for that group. 326 */ 327 IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m); 328 if (in6m) { 329 in6m->in6m_timer = 0; /* transit to idle state */ 330 in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */ 331 } 332 333 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 334 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 335 break; 336 default: /* this is impossible */ 337 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type); 338 break; 339 } 340 341 m_freem(m); 342 } 343 344 void 345 mld6_fasttimeo() 346 { 347 struct in6_multi *in6m; 348 struct in6_multistep step; 349 int s; 350 351 /* 352 * Quick check to see if any work needs to be done, in order 353 * to minimize the overhead of fasttimo processing. 354 */ 355 if (!mld6_timers_are_running) 356 return; 357 358 s = splnet(); 359 360 mld6_timers_are_running = 0; 361 IN6_FIRST_MULTI(step, in6m); 362 while (in6m != NULL) { 363 if (in6m->in6m_timer == 0) { 364 /* do nothing */ 365 } else if (--in6m->in6m_timer == 0) { 366 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 367 in6m->in6m_state = MLD_IREPORTEDLAST; 368 } else { 369 mld6_timers_are_running = 1; 370 } 371 IN6_NEXT_MULTI(step, in6m); 372 } 373 374 splx(s); 375 } 376 377 static void 378 mld6_sendpkt(in6m, type, dst) 379 struct in6_multi *in6m; 380 int type; 381 const struct in6_addr *dst; 382 { 383 struct mbuf *mh, *md; 384 struct mld_hdr *mldh; 385 struct ip6_hdr *ip6; 386 struct ip6_moptions im6o; 387 struct in6_ifaddr *ia; 388 struct ifnet *ifp = in6m->in6m_ifp; 389 struct ifnet *outif = NULL; 390 391 /* 392 * At first, find a link local address on the outgoing interface 393 * to use as the source address of the MLD packet. 394 */ 395 if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST)) 396 == NULL) 397 return; 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 return; 407 MGET(md, M_DONTWAIT, MT_DATA); 408 if (md == NULL) { 409 m_free(mh); 410 return; 411 } 412 mh->m_next = md; 413 414 mh->m_pkthdr.rcvif = NULL; 415 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr); 416 mh->m_len = sizeof(struct ip6_hdr); 417 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 418 419 /* fill in the ip6 header */ 420 ip6 = mtod(mh, struct ip6_hdr *); 421 ip6->ip6_flow = 0; 422 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 423 ip6->ip6_vfc |= IPV6_VERSION; 424 /* ip6_plen will be set later */ 425 ip6->ip6_nxt = IPPROTO_ICMPV6; 426 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 427 ip6->ip6_src = ia->ia_addr.sin6_addr; 428 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 429 430 /* fill in the MLD header */ 431 md->m_len = sizeof(struct mld_hdr); 432 mldh = mtod(md, struct mld_hdr *); 433 mldh->mld_type = type; 434 mldh->mld_code = 0; 435 mldh->mld_cksum = 0; 436 /* XXX: we assume the function will not be called for query messages */ 437 mldh->mld_maxdelay = 0; 438 mldh->mld_reserved = 0; 439 mldh->mld_addr = in6m->in6m_addr; 440 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 441 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 442 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 443 sizeof(struct mld_hdr)); 444 445 /* construct multicast option */ 446 bzero(&im6o, sizeof(im6o)); 447 im6o.im6o_multicast_ifp = ifp; 448 im6o.im6o_multicast_hlim = 1; 449 450 /* 451 * Request loopback of the report if we are acting as a multicast 452 * router, so that the process-level routing daemon can hear it. 453 */ 454 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 455 456 /* increment output statictics */ 457 icmp6stat.icp6s_outhist[type]++; 458 459 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL); 460 if (outif) { 461 icmp6_ifstat_inc(outif, ifs6_out_msg); 462 switch (type) { 463 case MLD_LISTENER_QUERY: 464 icmp6_ifstat_inc(outif, ifs6_out_mldquery); 465 break; 466 case MLD_LISTENER_REPORT: 467 icmp6_ifstat_inc(outif, ifs6_out_mldreport); 468 break; 469 case MLD_LISTENER_DONE: 470 icmp6_ifstat_inc(outif, ifs6_out_mlddone); 471 break; 472 } 473 } 474 } 475 476 /* 477 * Add an address to the list of IP6 multicast addresses for a given interface. 478 * Add source addresses to the list also, if upstream router is MLDv2 capable 479 * and the number of source is not 0. 480 */ 481 struct in6_multi * 482 in6_addmulti(maddr6, ifp, errorp) 483 struct in6_addr *maddr6; 484 struct ifnet *ifp; 485 int *errorp; 486 { 487 struct in6_multi *in6m; 488 struct ifmultiaddr *ifma; 489 struct sockaddr_in6 sa6; 490 int s = splnet(); 491 492 *errorp = 0; 493 494 /* 495 * Call generic routine to add membership or increment 496 * refcount. It wants addresses in the form of a sockaddr, 497 * so we build one here (being careful to zero the unused bytes). 498 */ 499 bzero(&sa6, sizeof(sa6)); 500 sa6.sin6_family = AF_INET6; 501 sa6.sin6_len = sizeof(struct sockaddr_in6); 502 sa6.sin6_addr = *maddr6; 503 *errorp = if_addmulti(ifp, (struct sockaddr *)&sa6, &ifma); 504 if (*errorp) { 505 splx(s); 506 return 0; 507 } 508 509 /* 510 * If ifma->ifma_protospec is null, then if_addmulti() created 511 * a new record. Otherwise, we are done. 512 */ 513 if (ifma->ifma_protospec != 0) { 514 splx(s); 515 return ifma->ifma_protospec; 516 } 517 518 /* XXX - if_addmulti uses M_WAITOK. Can this really be called 519 at interrupt time? If so, need to fix if_addmulti. XXX */ 520 in6m = (struct in6_multi *)malloc(sizeof(*in6m), M_IPMADDR, M_NOWAIT); 521 if (in6m == NULL) { 522 splx(s); 523 return (NULL); 524 } 525 526 bzero(in6m, sizeof *in6m); 527 in6m->in6m_addr = *maddr6; 528 in6m->in6m_ifp = ifp; 529 in6m->in6m_refcount = 1; 530 in6m->in6m_ifma = ifma; 531 ifma->ifma_protospec = in6m; 532 LIST_INSERT_HEAD(&in6_multihead, in6m, in6m_entry); 533 534 /* 535 * Let MLD6 know that we have joined a new IPv6 multicast 536 * group. 537 */ 538 mld6_start_listening(in6m); 539 splx(s); 540 return (in6m); 541 } 542 543 /* 544 * Delete a multicast address record. 545 */ 546 void 547 in6_delmulti(in6m) 548 struct in6_multi *in6m; 549 { 550 struct ifmultiaddr *ifma = in6m->in6m_ifma; 551 int s = splnet(); 552 553 if (ifma->ifma_refcount == 1) { 554 /* 555 * No remaining claims to this record; let MLD6 know 556 * that we are leaving the multicast group. 557 */ 558 mld6_stop_listening(in6m); 559 ifma->ifma_protospec = 0; 560 LIST_REMOVE(in6m, in6m_entry); 561 free(in6m, M_IPMADDR); 562 } 563 /* XXX - should be separate API for when we have an ifma? */ 564 if_delmulti(ifma->ifma_ifp, ifma->ifma_addr); 565 splx(s); 566 } 567