1 /* $NetBSD: mld6.c,v 1.26 2004/03/28 08:28:50 christos 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 1.26 2004/03/28 08:28:50 christos 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 <netinet/icmp6.h> 123 #include <netinet6/mld6_var.h> 124 125 #include <net/net_osdep.h> 126 127 /* 128 * Protocol constants 129 */ 130 131 /* denotes that the MLD max response delay field specifies time in milliseconds */ 132 #define MLD_TIMER_SCALE 1000 133 /* 134 * time between repetitions of a node's initial report of interest in a 135 * multicast address(in seconds) 136 */ 137 #define MLD_UNSOLICITED_REPORT_INTERVAL 10 138 139 static struct ip6_pktopts ip6_opts; 140 static int mld_timers_are_running; 141 /* XXX: These are necessary for KAME's link-local hack */ 142 static struct in6_addr mld_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 143 static struct in6_addr mld_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 144 145 static void mld6_sendpkt __P((struct in6_multi *, int, const struct in6_addr *)); 146 147 void 148 mld6_init() 149 { 150 static u_int8_t hbh_buf[8]; 151 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 152 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 153 154 mld_timers_are_running = 0; 155 156 /* ip6h_nxt will be fill in later */ 157 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */ 158 159 /* XXX: grotty hard coding... */ 160 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 161 hbh_buf[3] = 0; 162 hbh_buf[4] = IP6OPT_RTALERT; 163 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 164 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 165 166 ip6_opts.ip6po_hbh = hbh; 167 /* We will specify the hoplimit by a multicast option. */ 168 ip6_opts.ip6po_hlim = -1; 169 } 170 171 void 172 mld6_start_listening(in6m) 173 struct in6_multi *in6m; 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 mld_all_nodes_linklocal.s6_addr16[1] = 183 htons(in6m->in6m_ifp->if_index); /* XXX */ 184 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld_all_nodes_linklocal) || 185 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 186 in6m->in6m_timer = 0; 187 in6m->in6m_state = MLD_OTHERLISTENER; 188 } else { 189 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 190 in6m->in6m_timer = 191 MLD_RANDOM_DELAY(MLD_UNSOLICITED_REPORT_INTERVAL * 192 PR_FASTHZ); 193 in6m->in6m_state = MLD_IREPORTEDLAST; 194 mld_timers_are_running = 1; 195 } 196 } 197 198 void 199 mld6_stop_listening(in6m) 200 struct in6_multi *in6m; 201 { 202 mld_all_nodes_linklocal.s6_addr16[1] = 203 htons(in6m->in6m_ifp->if_index); /* XXX */ 204 mld_all_routers_linklocal.s6_addr16[1] = 205 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 206 207 if (in6m->in6m_state == MLD_IREPORTEDLAST && 208 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld_all_nodes_linklocal)) && 209 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL) 210 mld6_sendpkt(in6m, MLD_LISTENER_DONE, 211 &mld_all_routers_linklocal); 212 } 213 214 void 215 mld6_input(m, off) 216 struct mbuf *m; 217 int off; 218 { 219 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 220 struct mld_hdr *mldh; 221 struct ifnet *ifp = m->m_pkthdr.rcvif; 222 struct in6_multi *in6m; 223 struct in6_ifaddr *ia; 224 int timer; /* timer value in the MLD query header */ 225 226 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh)); 227 if (mldh == NULL) { 228 icmp6stat.icp6s_tooshort++; 229 return; 230 } 231 232 /* source address validation */ 233 ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */ 234 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 235 #if 0 236 log(LOG_ERR, 237 "mld_input: src %s is not link-local (grp=%s)\n", 238 ip6_sprintf(&ip6->ip6_src), 239 ip6_sprintf(&mldh->mld_addr)); 240 #endif 241 /* 242 * spec (RFC2710) does not explicitly 243 * specify to discard the packet from a non link-local 244 * source address. But we believe it's expected to do so. 245 * XXX: do we have to allow :: as source? 246 */ 247 m_freem(m); 248 return; 249 } 250 251 /* 252 * In the MLD6 specification, there are 3 states and a flag. 253 * 254 * In Non-Listener state, we simply don't have a membership record. 255 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 256 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 257 * 258 * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if 259 * we have heard a report from another member, or MLD_IREPORTEDLAST 260 * if we sent the last report. 261 */ 262 switch (mldh->mld_type) { 263 case MLD_LISTENER_QUERY: 264 if (ifp->if_flags & IFF_LOOPBACK) 265 break; 266 267 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) && 268 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 269 break; /* print error or log stat? */ 270 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 271 mldh->mld_addr.s6_addr16[1] = 272 htons(ifp->if_index); /* XXX */ 273 274 /* 275 * - Start the timers in all of our membership records 276 * that the query applies to for the interface on 277 * which the query arrived excl. those that belong 278 * to the "all-nodes" group (ff02::1). 279 * - Restart any timer that is already running but has 280 * A value longer than the requested timeout. 281 * - Use the value specified in the query message as 282 * the maximum timeout. 283 */ 284 IFP_TO_IA6(ifp, ia); 285 if (ia == NULL) 286 break; 287 288 /* 289 * XXX: System timer resolution is too low to handle Max 290 * Response Delay, so set 1 to the internal timer even if 291 * the calculated value equals to zero when Max Response 292 * Delay is positive. 293 */ 294 timer = ntohs(mldh->mld_maxdelay)*PR_FASTHZ/MLD_TIMER_SCALE; 295 if (timer == 0 && mldh->mld_maxdelay) 296 timer = 1; 297 mld_all_nodes_linklocal.s6_addr16[1] = 298 htons(ifp->if_index); /* XXX */ 299 300 for (in6m = ia->ia6_multiaddrs.lh_first; 301 in6m; 302 in6m = in6m->in6m_entry.le_next) 303 { 304 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 305 &mld_all_nodes_linklocal) || 306 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 307 IPV6_ADDR_SCOPE_LINKLOCAL) 308 continue; 309 310 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) || 311 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr, 312 &in6m->in6m_addr)) 313 { 314 if (timer == 0) { 315 /* send a report immediately */ 316 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, 317 NULL); 318 in6m->in6m_timer = 0; /* reset timer */ 319 in6m->in6m_state = MLD_IREPORTEDLAST; 320 } 321 else if (in6m->in6m_timer == 0 || /*idle state*/ 322 in6m->in6m_timer > timer) { 323 in6m->in6m_timer = 324 MLD_RANDOM_DELAY(timer); 325 mld_timers_are_running = 1; 326 } 327 } 328 } 329 330 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 331 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 332 break; 333 case MLD_LISTENER_REPORT: 334 /* 335 * For fast leave to work, we have to know that we are the 336 * last person to send a report for this group. Reports 337 * can potentially get looped back if we are a multicast 338 * router, so discard reports sourced by me. 339 * Note that it is impossible to check IFF_LOOPBACK flag of 340 * ifp for this purpose, since ip6_mloopback pass the physical 341 * interface to looutput. 342 */ 343 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 344 break; 345 346 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 347 break; 348 349 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 350 mldh->mld_addr.s6_addr16[1] = 351 htons(ifp->if_index); /* XXX */ 352 /* 353 * If we belong to the group being reported, stop 354 * our timer for that group. 355 */ 356 IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m); 357 if (in6m) { 358 in6m->in6m_timer = 0; /* transit to idle state */ 359 in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */ 360 } 361 362 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 363 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 364 break; 365 default: /* this is impossible */ 366 #if 0 367 /* 368 * this case should be impossible because of filtering in 369 * icmp6_input(). But we explicitly disabled this part 370 * just in case. 371 */ 372 log(LOG_ERR, "mld_input: illegal type(%d)", mldh->mld6_type); 373 #endif 374 break; 375 } 376 377 m_freem(m); 378 } 379 380 void 381 mld6_fasttimeo() 382 { 383 struct in6_multi *in6m; 384 struct in6_multistep step; 385 int s; 386 /* 387 * Quick check to see if any work needs to be done, in order 388 * to minimize the overhead of fasttimo processing. 389 */ 390 if (!mld_timers_are_running) 391 return; 392 393 s = splsoftnet(); 394 mld_timers_are_running = 0; 395 IN6_FIRST_MULTI(step, in6m); 396 while (in6m != NULL) { 397 if (in6m->in6m_timer == 0) { 398 /* do nothing */ 399 } else if (--in6m->in6m_timer == 0) { 400 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 401 in6m->in6m_state = MLD_IREPORTEDLAST; 402 } else { 403 mld_timers_are_running = 1; 404 } 405 IN6_NEXT_MULTI(step, in6m); 406 } 407 splx(s); 408 } 409 410 static void 411 mld6_sendpkt(in6m, type, dst) 412 struct in6_multi *in6m; 413 int type; 414 const struct in6_addr *dst; 415 { 416 struct mbuf *mh, *md; 417 struct mld_hdr *mldh; 418 struct ip6_hdr *ip6; 419 struct ip6_moptions im6o; 420 struct in6_ifaddr *ia; 421 struct ifnet *ifp = in6m->in6m_ifp; 422 int ignflags; 423 424 /* 425 * At first, find a link local address on the outgoing interface 426 * to use as the source address of the MLD packet. 427 * We do not reject tentative addresses for MLD report to deal with 428 * the case where we first join a link-local address. 429 */ 430 ignflags = (IN6_IFF_NOTREADY|IN6_IFF_ANYCAST) & ~IN6_IFF_TENTATIVE; 431 if ((ia = in6ifa_ifpforlinklocal(ifp, ignflags)) == NULL) 432 return; 433 if ((ia->ia6_flags & IN6_IFF_TENTATIVE)) 434 ia = NULL; 435 436 /* 437 * Allocate mbufs to store ip6 header and MLD header. 438 * We allocate 2 mbufs and make chain in advance because 439 * it is more convenient when inserting the hop-by-hop option later. 440 */ 441 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 442 if (mh == NULL) 443 return; 444 MGET(md, M_DONTWAIT, MT_DATA); 445 if (md == NULL) { 446 m_free(mh); 447 return; 448 } 449 mh->m_next = md; 450 451 mh->m_pkthdr.rcvif = NULL; 452 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr); 453 mh->m_len = sizeof(struct ip6_hdr); 454 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 455 456 /* fill in the ip6 header */ 457 ip6 = mtod(mh, struct ip6_hdr *); 458 ip6->ip6_flow = 0; 459 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 460 ip6->ip6_vfc |= IPV6_VERSION; 461 /* ip6_plen will be set later */ 462 ip6->ip6_nxt = IPPROTO_ICMPV6; 463 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 464 ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any; 465 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 466 467 /* fill in the MLD header */ 468 md->m_len = sizeof(struct mld_hdr); 469 mldh = mtod(md, struct mld_hdr *); 470 mldh->mld_type = type; 471 mldh->mld_code = 0; 472 mldh->mld_cksum = 0; 473 /* XXX: we assume the function will not be called for query messages */ 474 mldh->mld_maxdelay = 0; 475 mldh->mld_reserved = 0; 476 mldh->mld_addr = in6m->in6m_addr; 477 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 478 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 479 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 480 sizeof(struct mld_hdr)); 481 482 /* construct multicast option */ 483 bzero(&im6o, sizeof(im6o)); 484 im6o.im6o_multicast_ifp = ifp; 485 im6o.im6o_multicast_hlim = 1; 486 487 /* 488 * Request loopback of the report if we are acting as a multicast 489 * router, so that the process-level routing daemon can hear it. 490 */ 491 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 492 493 /* increment output statictics */ 494 icmp6stat.icp6s_outhist[type]++; 495 icmp6_ifstat_inc(ifp, ifs6_out_msg); 496 switch (type) { 497 case MLD_LISTENER_QUERY: 498 icmp6_ifstat_inc(ifp, ifs6_out_mldquery); 499 break; 500 case MLD_LISTENER_REPORT: 501 icmp6_ifstat_inc(ifp, ifs6_out_mldreport); 502 break; 503 case MLD_LISTENER_DONE: 504 icmp6_ifstat_inc(ifp, ifs6_out_mlddone); 505 break; 506 } 507 508 ip6_output(mh, &ip6_opts, NULL, ia ? 0 : IPV6_UNSPECSRC, 509 &im6o, (struct socket *)NULL, NULL); 510 } 511