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 82 #include <net/if.h> 83 84 #include <netinet/in.h> 85 #include <netinet/in_var.h> 86 #include <netinet/ip6.h> 87 #include <netinet6/ip6_var.h> 88 #include <netinet/icmp6.h> 89 #include <netinet6/mld6_var.h> 90 91 #include <net/net_osdep.h> 92 93 /* 94 * Protocol constants 95 */ 96 97 /* denotes that the MLD max response delay field specifies time in milliseconds */ 98 #define MLD_TIMER_SCALE 1000 99 /* 100 * time between repetitions of a node's initial report of interest in a 101 * multicast address(in seconds) 102 */ 103 #define MLD_UNSOLICITED_REPORT_INTERVAL 10 104 105 static struct ip6_pktopts ip6_opts; 106 static int mld6_timers_are_running; 107 /* XXX: These are necessary for KAME's link-local hack */ 108 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 109 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 110 111 static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *); 112 113 void 114 mld6_init() 115 { 116 static u_int8_t hbh_buf[8]; 117 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 118 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 119 120 mld6_timers_are_running = 0; 121 122 /* ip6h_nxt will be fill in later */ 123 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */ 124 125 /* XXX: grotty hard coding... */ 126 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 127 hbh_buf[3] = 0; 128 hbh_buf[4] = IP6OPT_ROUTER_ALERT; 129 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 130 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 131 132 init_ip6pktopts(&ip6_opts); 133 ip6_opts.ip6po_hbh = hbh; 134 } 135 136 void 137 mld6_start_listening(in6m) 138 struct in6_multi *in6m; 139 { 140 int s = splnet(); 141 142 /* 143 * RFC2710 page 10: 144 * The node never sends a Report or Done for the link-scope all-nodes 145 * address. 146 * MLD messages are never sent for multicast addresses whose scope is 0 147 * (reserved) or 1 (node-local). 148 */ 149 mld6_all_nodes_linklocal.s6_addr16[1] = 150 htons(in6m->in6m_ifp->if_index); /* XXX */ 151 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) || 152 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 153 in6m->in6m_timer = 0; 154 in6m->in6m_state = MLD_OTHERLISTENER; 155 } else { 156 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 157 in6m->in6m_timer = 158 MLD_RANDOM_DELAY(MLD_UNSOLICITED_REPORT_INTERVAL * 159 PR_FASTHZ); 160 in6m->in6m_state = MLD_IREPORTEDLAST; 161 mld6_timers_are_running = 1; 162 } 163 splx(s); 164 } 165 166 void 167 mld6_stop_listening(in6m) 168 struct in6_multi *in6m; 169 { 170 mld6_all_nodes_linklocal.s6_addr16[1] = 171 htons(in6m->in6m_ifp->if_index); /* XXX */ 172 mld6_all_routers_linklocal.s6_addr16[1] = 173 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 174 175 if (in6m->in6m_state == MLD_IREPORTEDLAST && 176 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) && 177 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_INTFACELOCAL) 178 mld6_sendpkt(in6m, MLD_LISTENER_DONE, 179 &mld6_all_routers_linklocal); 180 } 181 182 void 183 mld6_input(m, off) 184 struct mbuf *m; 185 int off; 186 { 187 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 188 struct mld_hdr *mldh; 189 struct ifnet *ifp = m->m_pkthdr.rcvif; 190 struct in6_multi *in6m; 191 struct in6_ifaddr *ia; 192 struct ifmultiaddr *ifma; 193 int timer; /* timer value in the MLD query header */ 194 195 #ifndef PULLDOWN_TEST 196 IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),); 197 mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off); 198 #else 199 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh)); 200 if (mldh == NULL) { 201 icmp6stat.icp6s_tooshort++; 202 return; 203 } 204 #endif 205 206 /* source address validation */ 207 ip6 = mtod(m, struct ip6_hdr *); /* in case mpullup */ 208 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 209 log(LOG_ERR, 210 "mld6_input: src %s is not link-local (grp=%s)\n", 211 ip6_sprintf(&ip6->ip6_src), 212 ip6_sprintf(&mldh->mld_addr)); 213 /* 214 * spec (RFC2710) does not explicitly 215 * specify to discard the packet from a non link-local 216 * source address. But we believe it's expected to do so. 217 * XXX: do we have to allow :: as source? 218 */ 219 m_freem(m); 220 return; 221 } 222 223 /* 224 * In the MLD6 specification, there are 3 states and a flag. 225 * 226 * In Non-Listener state, we simply don't have a membership record. 227 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 228 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 229 * 230 * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if 231 * we have heard a report from another member, or MLD_IREPORTEDLAST 232 * if we sent the last report. 233 */ 234 switch(mldh->mld_type) { 235 case MLD_LISTENER_QUERY: 236 if (ifp->if_flags & IFF_LOOPBACK) 237 break; 238 239 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) && 240 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 241 break; /* print error or log stat? */ 242 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 243 mldh->mld_addr.s6_addr16[1] = 244 htons(ifp->if_index); /* XXX */ 245 246 /* 247 * - Start the timers in all of our membership records 248 * that the query applies to for the interface on 249 * which the query arrived excl. those that belong 250 * to the "all-nodes" group (ff02::1). 251 * - Restart any timer that is already running but has 252 * A value longer than the requested timeout. 253 * - Use the value specified in the query message as 254 * the maximum timeout. 255 */ 256 IFP_TO_IA6(ifp, ia); 257 if (ia == NULL) 258 break; 259 260 /* 261 * XXX: System timer resolution is too low to handle Max 262 * Response Delay, so set 1 to the internal timer even if 263 * the calculated value equals to zero when Max Response 264 * Delay is positive. 265 */ 266 timer = ntohs(mldh->mld_maxdelay) * PR_FASTHZ / MLD_TIMER_SCALE; 267 if (timer == 0 && mldh->mld_maxdelay) 268 timer = 1; 269 mld6_all_nodes_linklocal.s6_addr16[1] = 270 htons(ifp->if_index); /* XXX */ 271 272 TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) { 273 if (ifma->ifma_addr->sa_family != AF_INET6) 274 continue; 275 in6m = (struct in6_multi *)ifma->ifma_protospec; 276 277 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 278 &mld6_all_nodes_linklocal) || 279 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 280 IPV6_ADDR_SCOPE_LINKLOCAL) 281 continue; 282 283 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) || 284 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr, 285 &in6m->in6m_addr)) 286 { 287 if (timer == 0) { 288 /* send a report immediately */ 289 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, 290 NULL); 291 in6m->in6m_timer = 0; /* reset timer */ 292 in6m->in6m_state = MLD_IREPORTEDLAST; 293 } 294 else if (in6m->in6m_timer == 0 || /*idle state*/ 295 in6m->in6m_timer > timer) { 296 in6m->in6m_timer = 297 MLD_RANDOM_DELAY(timer); 298 mld6_timers_are_running = 1; 299 } 300 } 301 } 302 303 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 304 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 305 break; 306 307 case MLD_LISTENER_REPORT: 308 /* 309 * For fast leave to work, we have to know that we are the 310 * last person to send a report for this group. Reports 311 * can potentially get looped back if we are a multicast 312 * router, so discard reports sourced by me. 313 * Note that it is impossible to check IFF_LOOPBACK flag of 314 * ifp for this purpose, since ip6_mloopback pass the physical 315 * interface to looutput. 316 */ 317 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 318 break; 319 320 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 321 break; 322 323 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 324 mldh->mld_addr.s6_addr16[1] = 325 htons(ifp->if_index); /* XXX */ 326 /* 327 * If we belong to the group being reported, stop 328 * our timer for that group. 329 */ 330 IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m); 331 if (in6m) { 332 in6m->in6m_timer = 0; /* transit to idle state */ 333 in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */ 334 } 335 336 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 337 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 338 break; 339 default: /* this is impossible */ 340 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type); 341 break; 342 } 343 344 m_freem(m); 345 } 346 347 void 348 mld6_fasttimeo() 349 { 350 struct in6_multi *in6m; 351 struct in6_multistep step; 352 int s; 353 354 /* 355 * Quick check to see if any work needs to be done, in order 356 * to minimize the overhead of fasttimo processing. 357 */ 358 if (!mld6_timers_are_running) 359 return; 360 361 s = splnet(); 362 363 mld6_timers_are_running = 0; 364 IN6_FIRST_MULTI(step, in6m); 365 while (in6m != NULL) { 366 if (in6m->in6m_timer == 0) { 367 /* do nothing */ 368 } else if (--in6m->in6m_timer == 0) { 369 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 370 in6m->in6m_state = MLD_IREPORTEDLAST; 371 } else { 372 mld6_timers_are_running = 1; 373 } 374 IN6_NEXT_MULTI(step, in6m); 375 } 376 377 splx(s); 378 } 379 380 static void 381 mld6_sendpkt(in6m, type, dst) 382 struct in6_multi *in6m; 383 int type; 384 const struct in6_addr *dst; 385 { 386 struct mbuf *mh, *md; 387 struct mld_hdr *mldh; 388 struct ip6_hdr *ip6; 389 struct ip6_moptions im6o; 390 struct in6_ifaddr *ia; 391 struct ifnet *ifp = in6m->in6m_ifp; 392 struct ifnet *outif = NULL; 393 394 /* 395 * At first, find a link local address on the outgoing interface 396 * to use as the source address of the MLD packet. 397 */ 398 if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST)) 399 == NULL) 400 return; 401 402 /* 403 * Allocate mbufs to store ip6 header and MLD header. 404 * We allocate 2 mbufs and make chain in advance because 405 * it is more convenient when inserting the hop-by-hop option later. 406 */ 407 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 408 if (mh == NULL) 409 return; 410 MGET(md, M_DONTWAIT, MT_DATA); 411 if (md == NULL) { 412 m_free(mh); 413 return; 414 } 415 mh->m_next = md; 416 417 mh->m_pkthdr.rcvif = NULL; 418 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr); 419 mh->m_len = sizeof(struct ip6_hdr); 420 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 421 422 /* fill in the ip6 header */ 423 ip6 = mtod(mh, struct ip6_hdr *); 424 ip6->ip6_flow = 0; 425 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 426 ip6->ip6_vfc |= IPV6_VERSION; 427 /* ip6_plen will be set later */ 428 ip6->ip6_nxt = IPPROTO_ICMPV6; 429 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 430 ip6->ip6_src = ia->ia_addr.sin6_addr; 431 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 432 433 /* fill in the MLD header */ 434 md->m_len = sizeof(struct mld_hdr); 435 mldh = mtod(md, struct mld_hdr *); 436 mldh->mld_type = type; 437 mldh->mld_code = 0; 438 mldh->mld_cksum = 0; 439 /* XXX: we assume the function will not be called for query messages */ 440 mldh->mld_maxdelay = 0; 441 mldh->mld_reserved = 0; 442 mldh->mld_addr = in6m->in6m_addr; 443 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 444 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 445 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 446 sizeof(struct mld_hdr)); 447 448 /* construct multicast option */ 449 bzero(&im6o, sizeof(im6o)); 450 im6o.im6o_multicast_ifp = ifp; 451 im6o.im6o_multicast_hlim = 1; 452 453 /* 454 * Request loopback of the report if we are acting as a multicast 455 * router, so that the process-level routing daemon can hear it. 456 */ 457 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 458 459 /* increment output statictics */ 460 icmp6stat.icp6s_outhist[type]++; 461 462 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL); 463 if (outif) { 464 icmp6_ifstat_inc(outif, ifs6_out_msg); 465 switch (type) { 466 case MLD_LISTENER_QUERY: 467 icmp6_ifstat_inc(outif, ifs6_out_mldquery); 468 break; 469 case MLD_LISTENER_REPORT: 470 icmp6_ifstat_inc(outif, ifs6_out_mldreport); 471 break; 472 case MLD_LISTENER_DONE: 473 icmp6_ifstat_inc(outif, ifs6_out_mlddone); 474 break; 475 } 476 } 477 } 478