1 /* $NetBSD: mld6.c,v 1.29 2006/01/21 00:15:36 rpaulo Exp $ */ 2 /* $KAME: mld6.c,v 1.25 2001/01/16 14:14:18 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) 1992, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * This code is derived from software contributed to Berkeley by 38 * Stephen Deering of Stanford University. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. Neither the name of the University nor the names of its contributors 49 * may be used to endorse or promote products derived from this software 50 * without specific prior written permission. 51 * 52 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 55 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 62 * SUCH DAMAGE. 63 * 64 * @(#)igmp.c 8.1 (Berkeley) 7/19/93 65 */ 66 67 /* 68 * Copyright (c) 1988 Stephen Deering. 69 * 70 * This code is derived from software contributed to Berkeley by 71 * Stephen Deering of Stanford University. 72 * 73 * Redistribution and use in source and binary forms, with or without 74 * modification, are permitted provided that the following conditions 75 * are met: 76 * 1. Redistributions of source code must retain the above copyright 77 * notice, this list of conditions and the following disclaimer. 78 * 2. Redistributions in binary form must reproduce the above copyright 79 * notice, this list of conditions and the following disclaimer in the 80 * documentation and/or other materials provided with the distribution. 81 * 3. All advertising materials mentioning features or use of this software 82 * must display the following acknowledgement: 83 * This product includes software developed by the University of 84 * California, Berkeley and its contributors. 85 * 4. Neither the name of the University nor the names of its contributors 86 * may be used to endorse or promote products derived from this software 87 * without specific prior written permission. 88 * 89 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 90 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 91 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 92 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 93 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 94 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 95 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 96 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 97 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 98 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 99 * SUCH DAMAGE. 100 * 101 * @(#)igmp.c 8.1 (Berkeley) 7/19/93 102 */ 103 104 #include <sys/cdefs.h> 105 __KERNEL_RCSID(0, "$NetBSD: mld6.c,v 1.29 2006/01/21 00:15:36 rpaulo Exp $"); 106 107 #include "opt_inet.h" 108 109 #include <sys/param.h> 110 #include <sys/systm.h> 111 #include <sys/mbuf.h> 112 #include <sys/socket.h> 113 #include <sys/protosw.h> 114 #include <sys/syslog.h> 115 116 #include <net/if.h> 117 118 #include <netinet/in.h> 119 #include <netinet/in_var.h> 120 #include <netinet/ip6.h> 121 #include <netinet6/ip6_var.h> 122 #include <netinet6/scope6_var.h> 123 #include <netinet/icmp6.h> 124 #include <netinet6/mld6_var.h> 125 126 #include <net/net_osdep.h> 127 128 /* 129 * Protocol constants 130 */ 131 132 /* denotes that the MLD max response delay field specifies time in milliseconds */ 133 #define MLD_TIMER_SCALE 1000 134 /* 135 * time between repetitions of a node's initial report of interest in a 136 * multicast address(in seconds) 137 */ 138 #define MLD_UNSOLICITED_REPORT_INTERVAL 10 139 140 static struct ip6_pktopts ip6_opts; 141 static int mld_timers_are_running; 142 143 static void mld6_sendpkt __P((struct in6_multi *, int, const struct in6_addr *)); 144 145 void 146 mld6_init() 147 { 148 static u_int8_t hbh_buf[8]; 149 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 150 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 151 152 mld_timers_are_running = 0; 153 154 /* ip6h_nxt will be fill in later */ 155 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */ 156 157 /* XXX: grotty hard coding... */ 158 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 159 hbh_buf[3] = 0; 160 hbh_buf[4] = IP6OPT_RTALERT; 161 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 162 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 163 164 ip6_opts.ip6po_hbh = hbh; 165 /* We will specify the hoplimit by a multicast option. */ 166 ip6_opts.ip6po_hlim = -1; 167 } 168 169 void 170 mld6_start_listening(in6m) 171 struct in6_multi *in6m; 172 { 173 struct in6_addr all_in6; 174 175 /* 176 * RFC2710 page 10: 177 * The node never sends a Report or Done for the link-scope all-nodes 178 * address. 179 * MLD messages are never sent for multicast addresses whose scope is 0 180 * (reserved) or 1 (node-local). 181 */ 182 all_in6 = in6addr_linklocal_allnodes; 183 if (in6_setscope(&all_in6, in6m->in6m_ifp, NULL)) { 184 /* XXX: this should not happen! */ 185 in6m->in6m_timer = 0; 186 in6m->in6m_state = MLD_OTHERLISTENER; 187 } 188 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_in6) || 189 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 190 in6m->in6m_timer = 0; 191 in6m->in6m_state = MLD_OTHERLISTENER; 192 } else { 193 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 194 in6m->in6m_timer = 195 MLD_RANDOM_DELAY(MLD_UNSOLICITED_REPORT_INTERVAL * 196 PR_FASTHZ); 197 in6m->in6m_state = MLD_IREPORTEDLAST; 198 mld_timers_are_running = 1; 199 } 200 } 201 202 void 203 mld6_stop_listening(in6m) 204 struct in6_multi *in6m; 205 { 206 struct in6_addr allnode, allrouter; 207 208 allnode = in6addr_linklocal_allnodes; 209 if (in6_setscope(&allnode, in6m->in6m_ifp, NULL)) { 210 /* XXX: this should not happen! */ 211 return; 212 } 213 allrouter = in6addr_linklocal_allrouters; 214 if (in6_setscope(&allrouter, in6m->in6m_ifp, NULL)) { 215 /* XXX impossible */ 216 return; 217 } 218 219 if (in6m->in6m_state == MLD_IREPORTEDLAST && 220 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &allnode)) && 221 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > 222 IPV6_ADDR_SCOPE_INTFACELOCAL) { 223 mld6_sendpkt(in6m, MLD_LISTENER_DONE, &allrouter); 224 } 225 } 226 227 void 228 mld6_input(m, off) 229 struct mbuf *m; 230 int off; 231 { 232 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 233 struct mld_hdr *mldh; 234 struct ifnet *ifp = m->m_pkthdr.rcvif; 235 struct in6_multi *in6m; 236 struct in6_addr mld_addr, all_in6; 237 struct in6_ifaddr *ia; 238 int timer; /* timer value in the MLD query header */ 239 240 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh)); 241 if (mldh == NULL) { 242 icmp6stat.icp6s_tooshort++; 243 return; 244 } 245 246 /* source address validation */ 247 ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */ 248 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 249 #if 0 250 log(LOG_ERR, 251 "mld_input: src %s is not link-local (grp=%s)\n", 252 ip6_sprintf(&ip6->ip6_src), 253 ip6_sprintf(&mldh->mld_addr)); 254 #endif 255 /* 256 * spec (RFC2710) does not explicitly 257 * specify to discard the packet from a non link-local 258 * source address. But we believe it's expected to do so. 259 * XXX: do we have to allow :: as source? 260 */ 261 m_freem(m); 262 return; 263 } 264 265 /* 266 * make a copy for local work (in6_setscope() may modify the 1st arg) 267 */ 268 mld_addr = mldh->mld_addr; 269 if (in6_setscope(&mld_addr, ifp, NULL)) { 270 /* XXX: this should not happen! */ 271 m_free(m); 272 return; 273 } 274 275 /* 276 * In the MLD6 specification, there are 3 states and a flag. 277 * 278 * In Non-Listener state, we simply don't have a membership record. 279 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 280 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 281 * 282 * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if 283 * we have heard a report from another member, or MLD_IREPORTEDLAST 284 * if we sent the last report. 285 */ 286 switch (mldh->mld_type) { 287 case MLD_LISTENER_QUERY: 288 if (ifp->if_flags & IFF_LOOPBACK) 289 break; 290 291 if (!IN6_IS_ADDR_UNSPECIFIED(&mld_addr) && 292 !IN6_IS_ADDR_MULTICAST(&mld_addr)) 293 break; /* print error or log stat? */ 294 295 all_in6 = in6addr_linklocal_allnodes; 296 if (in6_setscope(&all_in6, ifp, NULL)) { 297 /* XXX: this should not happen! */ 298 break; 299 } 300 301 /* 302 * - Start the timers in all of our membership records 303 * that the query applies to for the interface on 304 * which the query arrived excl. those that belong 305 * to the "all-nodes" group (ff02::1). 306 * - Restart any timer that is already running but has 307 * A value longer than the requested timeout. 308 * - Use the value specified in the query message as 309 * the maximum timeout. 310 */ 311 IFP_TO_IA6(ifp, ia); 312 if (ia == NULL) 313 break; 314 315 /* 316 * XXX: System timer resolution is too low to handle Max 317 * Response Delay, so set 1 to the internal timer even if 318 * the calculated value equals to zero when Max Response 319 * Delay is positive. 320 */ 321 timer = ntohs(mldh->mld_maxdelay)*PR_FASTHZ/MLD_TIMER_SCALE; 322 if (timer == 0 && mldh->mld_maxdelay) 323 timer = 1; 324 325 for (in6m = ia->ia6_multiaddrs.lh_first; 326 in6m; 327 in6m = in6m->in6m_entry.le_next) 328 { 329 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_in6) || 330 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 331 IPV6_ADDR_SCOPE_LINKLOCAL) 332 continue; 333 334 if (IN6_IS_ADDR_UNSPECIFIED(&mld_addr) || 335 IN6_ARE_ADDR_EQUAL(&mld_addr, &in6m->in6m_addr)) { 336 if (timer == 0) { 337 /* send a report immediately */ 338 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, 339 NULL); 340 in6m->in6m_timer = 0; /* reset timer */ 341 in6m->in6m_state = MLD_IREPORTEDLAST; 342 } 343 else if (in6m->in6m_timer == 0 || /*idle state*/ 344 in6m->in6m_timer > timer) { 345 in6m->in6m_timer = 346 MLD_RANDOM_DELAY(timer); 347 mld_timers_are_running = 1; 348 } 349 } 350 } 351 break; 352 353 case MLD_LISTENER_REPORT: 354 /* 355 * For fast leave to work, we have to know that we are the 356 * last person to send a report for this group. Reports 357 * can potentially get looped back if we are a multicast 358 * router, so discard reports sourced by me. 359 * Note that it is impossible to check IFF_LOOPBACK flag of 360 * ifp for this purpose, since ip6_mloopback pass the physical 361 * interface to looutput. 362 */ 363 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 364 break; 365 366 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 367 break; 368 369 /* 370 * If we belong to the group being reported, stop 371 * our timer for that group. 372 */ 373 IN6_LOOKUP_MULTI(mld_addr, ifp, in6m); 374 if (in6m) { 375 in6m->in6m_timer = 0; /* transit to idle state */ 376 in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */ 377 } 378 break; 379 default: /* this is impossible */ 380 #if 0 381 /* 382 * this case should be impossible because of filtering in 383 * icmp6_input(). But we explicitly disabled this part 384 * just in case. 385 */ 386 log(LOG_ERR, "mld_input: illegal type(%d)", mldh->mld6_type); 387 #endif 388 break; 389 } 390 391 m_freem(m); 392 } 393 394 void 395 mld6_fasttimeo() 396 { 397 struct in6_multi *in6m; 398 struct in6_multistep step; 399 int s; 400 /* 401 * Quick check to see if any work needs to be done, in order 402 * to minimize the overhead of fasttimo processing. 403 */ 404 if (!mld_timers_are_running) 405 return; 406 407 s = splsoftnet(); 408 mld_timers_are_running = 0; 409 IN6_FIRST_MULTI(step, in6m); 410 while (in6m != NULL) { 411 if (in6m->in6m_timer == 0) { 412 /* do nothing */ 413 } else if (--in6m->in6m_timer == 0) { 414 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 415 in6m->in6m_state = MLD_IREPORTEDLAST; 416 } else { 417 mld_timers_are_running = 1; 418 } 419 IN6_NEXT_MULTI(step, in6m); 420 } 421 splx(s); 422 } 423 424 static void 425 mld6_sendpkt(in6m, type, dst) 426 struct in6_multi *in6m; 427 int type; 428 const struct in6_addr *dst; 429 { 430 struct mbuf *mh, *md; 431 struct mld_hdr *mldh; 432 struct ip6_hdr *ip6; 433 struct ip6_moptions im6o; 434 struct in6_ifaddr *ia; 435 struct ifnet *ifp = in6m->in6m_ifp; 436 int ignflags; 437 438 /* 439 * At first, find a link local address on the outgoing interface 440 * to use as the source address of the MLD packet. 441 * We do not reject tentative addresses for MLD report to deal with 442 * the case where we first join a link-local address. 443 */ 444 ignflags = (IN6_IFF_NOTREADY|IN6_IFF_ANYCAST) & ~IN6_IFF_TENTATIVE; 445 if ((ia = in6ifa_ifpforlinklocal(ifp, ignflags)) == NULL) 446 return; 447 if ((ia->ia6_flags & IN6_IFF_TENTATIVE)) 448 ia = NULL; 449 450 /* 451 * Allocate mbufs to store ip6 header and MLD header. 452 * We allocate 2 mbufs and make chain in advance because 453 * it is more convenient when inserting the hop-by-hop option later. 454 */ 455 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 456 if (mh == NULL) 457 return; 458 MGET(md, M_DONTWAIT, MT_DATA); 459 if (md == NULL) { 460 m_free(mh); 461 return; 462 } 463 mh->m_next = md; 464 465 mh->m_pkthdr.rcvif = NULL; 466 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr); 467 mh->m_len = sizeof(struct ip6_hdr); 468 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 469 470 /* fill in the ip6 header */ 471 ip6 = mtod(mh, struct ip6_hdr *); 472 ip6->ip6_flow = 0; 473 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 474 ip6->ip6_vfc |= IPV6_VERSION; 475 /* ip6_plen will be set later */ 476 ip6->ip6_nxt = IPPROTO_ICMPV6; 477 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 478 ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any; 479 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 480 481 /* fill in the MLD header */ 482 md->m_len = sizeof(struct mld_hdr); 483 mldh = mtod(md, struct mld_hdr *); 484 mldh->mld_type = type; 485 mldh->mld_code = 0; 486 mldh->mld_cksum = 0; 487 /* XXX: we assume the function will not be called for query messages */ 488 mldh->mld_maxdelay = 0; 489 mldh->mld_reserved = 0; 490 mldh->mld_addr = in6m->in6m_addr; 491 in6_clearscope(&mldh->mld_addr); /* XXX */ 492 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 493 sizeof(struct mld_hdr)); 494 495 /* construct multicast option */ 496 bzero(&im6o, sizeof(im6o)); 497 im6o.im6o_multicast_ifp = ifp; 498 im6o.im6o_multicast_hlim = 1; 499 500 /* 501 * Request loopback of the report if we are acting as a multicast 502 * router, so that the process-level routing daemon can hear it. 503 */ 504 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 505 506 /* increment output statictics */ 507 icmp6stat.icp6s_outhist[type]++; 508 icmp6_ifstat_inc(ifp, ifs6_out_msg); 509 switch (type) { 510 case MLD_LISTENER_QUERY: 511 icmp6_ifstat_inc(ifp, ifs6_out_mldquery); 512 break; 513 case MLD_LISTENER_REPORT: 514 icmp6_ifstat_inc(ifp, ifs6_out_mldreport); 515 break; 516 case MLD_LISTENER_DONE: 517 icmp6_ifstat_inc(ifp, ifs6_out_mlddone); 518 break; 519 } 520 521 ip6_output(mh, &ip6_opts, NULL, ia ? 0 : IPV6_UNSPECSRC, 522 &im6o, (struct socket *)NULL, NULL); 523 } 524