1 /* $OpenBSD: mld6.c,v 1.19 2003/06/11 02:54:02 itojun Exp $ */ 2 /* $KAME: mld6.c,v 1.26 2001/02/16 14:50:35 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. 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 <sys/param.h> 69 #include <sys/systm.h> 70 #include <sys/mbuf.h> 71 #include <sys/socket.h> 72 #include <sys/protosw.h> 73 #include <sys/syslog.h> 74 #include <dev/rndvar.h> 75 76 #include <net/if.h> 77 78 #include <netinet/in.h> 79 #include <netinet/in_var.h> 80 #include <netinet/ip6.h> 81 #include <netinet6/ip6_var.h> 82 #include <netinet/icmp6.h> 83 #include <netinet6/mld6_var.h> 84 85 /* 86 * Protocol constants 87 */ 88 89 /* denotes that the MLD max response delay field specifies time in milliseconds */ 90 #define MLD_TIMER_SCALE 1000 91 /* 92 * time between repetitions of a node's initial report of interest in a 93 * multicast address(in seconds) 94 */ 95 #define MLD_UNSOLICITED_REPORT_INTERVAL 10 96 97 static struct ip6_pktopts ip6_opts; 98 static int mld_timers_are_running; 99 /* XXX: These are necessary for KAME's link-local hack */ 100 static struct in6_addr mld_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 101 static struct in6_addr mld_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 102 103 static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *); 104 105 void 106 mld6_init() 107 { 108 static u_int8_t hbh_buf[8]; 109 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 110 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 111 112 mld_timers_are_running = 0; 113 114 /* ip6h_nxt will be fill in later */ 115 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */ 116 117 /* XXX: grotty hard coding... */ 118 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 119 hbh_buf[3] = 0; 120 hbh_buf[4] = IP6OPT_RTALERT; 121 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 122 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 123 124 ip6_opts.ip6po_hbh = hbh; 125 /* We will specify the hoplimit by a multicast option. */ 126 ip6_opts.ip6po_hlim = -1; 127 } 128 129 void 130 mld6_start_listening(in6m) 131 struct in6_multi *in6m; 132 { 133 int s = splsoftnet(); 134 135 /* 136 * RFC2710 page 10: 137 * The node never sends a Report or Done for the link-scope all-nodes 138 * address. 139 * MLD messages are never sent for multicast addresses whose scope is 0 140 * (reserved) or 1 (node-local). 141 */ 142 mld_all_nodes_linklocal.s6_addr16[1] = 143 htons(in6m->in6m_ifp->if_index); /* XXX */ 144 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld_all_nodes_linklocal) || 145 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 146 in6m->in6m_timer = 0; 147 in6m->in6m_state = MLD_OTHERLISTENER; 148 } else { 149 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 150 in6m->in6m_timer = 151 MLD_RANDOM_DELAY(MLD_UNSOLICITED_REPORT_INTERVAL * 152 PR_FASTHZ); 153 in6m->in6m_state = MLD_IREPORTEDLAST; 154 mld_timers_are_running = 1; 155 } 156 splx(s); 157 } 158 159 void 160 mld6_stop_listening(in6m) 161 struct in6_multi *in6m; 162 { 163 mld_all_nodes_linklocal.s6_addr16[1] = 164 htons(in6m->in6m_ifp->if_index); /* XXX */ 165 mld_all_routers_linklocal.s6_addr16[1] = 166 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 167 168 if (in6m->in6m_state == MLD_IREPORTEDLAST && 169 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld_all_nodes_linklocal)) && 170 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL) 171 mld6_sendpkt(in6m, MLD_LISTENER_DONE, 172 &mld_all_routers_linklocal); 173 } 174 175 void 176 mld6_input(m, off) 177 struct mbuf *m; 178 int off; 179 { 180 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 181 struct mld_hdr *mldh; 182 struct ifnet *ifp = m->m_pkthdr.rcvif; 183 struct in6_multi *in6m; 184 struct in6_ifaddr *ia; 185 int timer; /* timer value in the MLD query header */ 186 187 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh)); 188 if (mldh == NULL) { 189 icmp6stat.icp6s_tooshort++; 190 return; 191 } 192 193 /* source address validation */ 194 ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */ 195 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 196 #if 0 197 log(LOG_ERR, 198 "mld_input: src %s is not link-local (grp=%s)\n", 199 ip6_sprintf(&ip6->ip6_src), 200 ip6_sprintf(&mldh->mld_addr)); 201 #endif 202 /* 203 * spec (RFC2710) does not explicitly 204 * specify to discard the packet from a non link-local 205 * source address. But we believe it's expected to do so. 206 */ 207 m_freem(m); 208 return; 209 } 210 211 /* 212 * In the MLD6 specification, there are 3 states and a flag. 213 * 214 * In Non-Listener state, we simply don't have a membership record. 215 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 216 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 217 * 218 * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if 219 * we have heard a report from another member, or MLD_IREPORTEDLAST 220 * if we sent the last report. 221 */ 222 switch(mldh->mld_type) { 223 case MLD_LISTENER_QUERY: 224 if (ifp->if_flags & IFF_LOOPBACK) 225 break; 226 227 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) && 228 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 229 break; /* print error or log stat? */ 230 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 231 mldh->mld_addr.s6_addr16[1] = 232 htons(ifp->if_index); /* XXX */ 233 234 /* 235 * - Start the timers in all of our membership records 236 * that the query applies to for the interface on 237 * which the query arrived excl. those that belong 238 * to the "all-nodes" group (ff02::1). 239 * - Restart any timer that is already running but has 240 * A value longer than the requested timeout. 241 * - Use the value specified in the query message as 242 * the maximum timeout. 243 */ 244 IFP_TO_IA6(ifp, ia); 245 if (ia == NULL) 246 break; 247 248 /* 249 * XXX: System timer resolution is too low to handle Max 250 * Response Delay, so set 1 to the internal timer even if 251 * the calculated value equals to zero when Max Response 252 * Delay is positive. 253 */ 254 timer = ntohs(mldh->mld_maxdelay)*PR_FASTHZ/MLD_TIMER_SCALE; 255 if (timer == 0 && mldh->mld_maxdelay) 256 timer = 1; 257 mld_all_nodes_linklocal.s6_addr16[1] = 258 htons(ifp->if_index); /* XXX */ 259 260 for (in6m = ia->ia6_multiaddrs.lh_first; 261 in6m; 262 in6m = in6m->in6m_entry.le_next) 263 { 264 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 265 &mld_all_nodes_linklocal) || 266 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 267 IPV6_ADDR_SCOPE_LINKLOCAL) 268 continue; 269 270 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) || 271 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr, 272 &in6m->in6m_addr)) 273 { 274 if (timer == 0) { 275 /* send a report immediately */ 276 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, 277 NULL); 278 in6m->in6m_timer = 0; /* reset timer */ 279 in6m->in6m_state = MLD_IREPORTEDLAST; 280 } else if (in6m->in6m_timer == 0 || /* idle */ 281 in6m->in6m_timer > timer) { 282 in6m->in6m_timer = 283 MLD_RANDOM_DELAY(timer); 284 mld_timers_are_running = 1; 285 } 286 } 287 } 288 289 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 290 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 291 break; 292 case MLD_LISTENER_REPORT: 293 /* 294 * For fast leave to work, we have to know that we are the 295 * last person to send a report for this group. Reports 296 * can potentially get looped back if we are a multicast 297 * router, so discard reports sourced by me. 298 * Note that it is impossible to check IFF_LOOPBACK flag of 299 * ifp for this purpose, since ip6_mloopback pass the physical 300 * interface to looutput. 301 */ 302 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 303 break; 304 305 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 306 break; 307 308 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 309 mldh->mld_addr.s6_addr16[1] = 310 htons(ifp->if_index); /* XXX */ 311 /* 312 * If we belong to the group being reported, stop 313 * our timer for that group. 314 */ 315 IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m); 316 if (in6m) { 317 in6m->in6m_timer = 0; /* transit to idle state */ 318 in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */ 319 } 320 321 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 322 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 323 break; 324 default: /* this is impossible */ 325 #if 0 326 /* 327 * this case should be impossible because of filtering in 328 * icmp6_input(). But we explicitly disabled this part 329 * just in case. 330 */ 331 log(LOG_ERR, "mld_input: illegal type(%d)", mldh->mld_type); 332 #endif 333 break; 334 } 335 336 m_freem(m); 337 } 338 339 void 340 mld6_fasttimeo() 341 { 342 struct in6_multi *in6m; 343 struct in6_multistep step; 344 int s; 345 346 /* 347 * Quick check to see if any work needs to be done, in order 348 * to minimize the overhead of fasttimo processing. 349 */ 350 if (!mld_timers_are_running) 351 return; 352 353 s = splsoftnet(); 354 mld_timers_are_running = 0; 355 IN6_FIRST_MULTI(step, in6m); 356 while (in6m != NULL) { 357 if (in6m->in6m_timer == 0) { 358 /* do nothing */ 359 } else if (--in6m->in6m_timer == 0) { 360 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 361 in6m->in6m_state = MLD_IREPORTEDLAST; 362 } else { 363 mld_timers_are_running = 1; 364 } 365 IN6_NEXT_MULTI(step, in6m); 366 } 367 splx(s); 368 } 369 370 static void 371 mld6_sendpkt(in6m, type, dst) 372 struct in6_multi *in6m; 373 int type; 374 const struct in6_addr *dst; 375 { 376 struct mbuf *mh, *md; 377 struct mld_hdr *mldh; 378 struct ip6_hdr *ip6; 379 struct ip6_moptions im6o; 380 struct in6_ifaddr *ia; 381 struct ifnet *ifp = in6m->in6m_ifp; 382 int ignflags; 383 384 /* 385 * At first, find a link local address on the outgoing interface 386 * to use as the source address of the MLD packet. 387 * We do not reject tentative addresses for MLD report to deal with 388 * the case where we first join a link-local address. 389 */ 390 ignflags = (IN6_IFF_NOTREADY|IN6_IFF_ANYCAST) & ~IN6_IFF_TENTATIVE; 391 if ((ia = in6ifa_ifpforlinklocal(ifp, ignflags)) == NULL) 392 return; 393 if ((ia->ia6_flags & IN6_IFF_TENTATIVE)) 394 ia = NULL; 395 396 /* 397 * Allocate mbufs to store ip6 header and MLD header. 398 * We allocate 2 mbufs and make chain in advance because 399 * it is more convenient when inserting the hop-by-hop option later. 400 */ 401 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 402 if (mh == NULL) 403 return; 404 MGET(md, M_DONTWAIT, MT_DATA); 405 if (md == NULL) { 406 m_free(mh); 407 return; 408 } 409 mh->m_next = md; 410 411 mh->m_pkthdr.rcvif = NULL; 412 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr); 413 mh->m_len = sizeof(struct ip6_hdr); 414 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 415 416 /* fill in the ip6 header */ 417 ip6 = mtod(mh, struct ip6_hdr *); 418 ip6->ip6_flow = 0; 419 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 420 ip6->ip6_vfc |= IPV6_VERSION; 421 /* ip6_plen will be set later */ 422 ip6->ip6_nxt = IPPROTO_ICMPV6; 423 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 424 ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any; 425 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 426 427 /* fill in the MLD header */ 428 md->m_len = sizeof(struct mld_hdr); 429 mldh = mtod(md, struct mld_hdr *); 430 mldh->mld_type = type; 431 mldh->mld_code = 0; 432 mldh->mld_cksum = 0; 433 /* XXX: we assume the function will not be called for query messages */ 434 mldh->mld_maxdelay = 0; 435 mldh->mld_reserved = 0; 436 mldh->mld_addr = in6m->in6m_addr; 437 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 438 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 439 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 440 sizeof(struct mld_hdr)); 441 442 /* construct multicast option */ 443 bzero(&im6o, sizeof(im6o)); 444 im6o.im6o_multicast_ifp = ifp; 445 im6o.im6o_multicast_hlim = 1; 446 447 /* 448 * Request loopback of the report if we are acting as a multicast 449 * router, so that the process-level routing daemon can hear it. 450 */ 451 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 452 453 /* increment output statictics */ 454 icmp6stat.icp6s_outhist[type]++; 455 icmp6_ifstat_inc(ifp, ifs6_out_msg); 456 switch (type) { 457 case MLD_LISTENER_QUERY: 458 icmp6_ifstat_inc(ifp, ifs6_out_mldquery); 459 break; 460 case MLD_LISTENER_REPORT: 461 icmp6_ifstat_inc(ifp, ifs6_out_mldreport); 462 break; 463 case MLD_LISTENER_DONE: 464 icmp6_ifstat_inc(ifp, ifs6_out_mlddone); 465 break; 466 } 467 468 ip6_output(mh, &ip6_opts, NULL, ia ? 0 : IPV6_UNSPECSRC, &im6o, NULL); 469 } 470