1 /* $OpenBSD: mld6.c,v 1.25 2008/06/11 19:00:50 mcbride 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_ROUTER_ALERT; 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 } 126 127 void 128 mld6_start_listening(struct in6_multi *in6m) 129 { 130 int s = splsoftnet(); 131 132 /* 133 * RFC2710 page 10: 134 * The node never sends a Report or Done for the link-scope all-nodes 135 * address. 136 * MLD messages are never sent for multicast addresses whose scope is 0 137 * (reserved) or 1 (node-local). 138 */ 139 mld_all_nodes_linklocal.s6_addr16[1] = 140 htons(in6m->in6m_ifp->if_index); /* XXX */ 141 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld_all_nodes_linklocal) || 142 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 143 in6m->in6m_timer = 0; 144 in6m->in6m_state = MLD_OTHERLISTENER; 145 } else { 146 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 147 in6m->in6m_timer = 148 MLD_RANDOM_DELAY(MLD_UNSOLICITED_REPORT_INTERVAL * 149 PR_FASTHZ); 150 in6m->in6m_state = MLD_IREPORTEDLAST; 151 mld_timers_are_running = 1; 152 } 153 splx(s); 154 } 155 156 void 157 mld6_stop_listening(struct in6_multi *in6m) 158 { 159 mld_all_nodes_linklocal.s6_addr16[1] = 160 htons(in6m->in6m_ifp->if_index); /* XXX */ 161 mld_all_routers_linklocal.s6_addr16[1] = 162 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 163 164 if (in6m->in6m_state == MLD_IREPORTEDLAST && 165 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld_all_nodes_linklocal)) && 166 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_INTFACELOCAL) 167 mld6_sendpkt(in6m, MLD_LISTENER_DONE, 168 &mld_all_routers_linklocal); 169 } 170 171 void 172 mld6_input(struct mbuf *m, int off) 173 { 174 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 175 struct mld_hdr *mldh; 176 struct ifnet *ifp = m->m_pkthdr.rcvif; 177 struct in6_multi *in6m; 178 struct in6_ifaddr *ia; 179 int timer; /* timer value in the MLD query header */ 180 181 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh)); 182 if (mldh == NULL) { 183 icmp6stat.icp6s_tooshort++; 184 return; 185 } 186 187 /* source address validation */ 188 ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */ 189 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 190 #if 0 191 log(LOG_ERR, 192 "mld_input: src %s is not link-local (grp=%s)\n", 193 ip6_sprintf(&ip6->ip6_src), 194 ip6_sprintf(&mldh->mld_addr)); 195 #endif 196 /* 197 * spec (RFC2710) does not explicitly 198 * specify to discard the packet from a non link-local 199 * source address. But we believe it's expected to do so. 200 */ 201 m_freem(m); 202 return; 203 } 204 205 /* 206 * In the MLD6 specification, there are 3 states and a flag. 207 * 208 * In Non-Listener state, we simply don't have a membership record. 209 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 210 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 211 * 212 * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if 213 * we have heard a report from another member, or MLD_IREPORTEDLAST 214 * if we sent the last report. 215 */ 216 switch(mldh->mld_type) { 217 case MLD_LISTENER_QUERY: 218 if (ifp->if_flags & IFF_LOOPBACK) 219 break; 220 221 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) && 222 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 223 break; /* print error or log stat? */ 224 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 225 mldh->mld_addr.s6_addr16[1] = 226 htons(ifp->if_index); /* XXX */ 227 228 /* 229 * - Start the timers in all of our membership records 230 * that the query applies to for the interface on 231 * which the query arrived excl. those that belong 232 * to the "all-nodes" group (ff02::1). 233 * - Restart any timer that is already running but has 234 * A value longer than the requested timeout. 235 * - Use the value specified in the query message as 236 * the maximum timeout. 237 */ 238 IFP_TO_IA6(ifp, ia); 239 if (ia == NULL) 240 break; 241 242 /* 243 * XXX: System timer resolution is too low to handle Max 244 * Response Delay, so set 1 to the internal timer even if 245 * the calculated value equals to zero when Max Response 246 * Delay is positive. 247 */ 248 timer = ntohs(mldh->mld_maxdelay)*PR_FASTHZ/MLD_TIMER_SCALE; 249 if (timer == 0 && mldh->mld_maxdelay) 250 timer = 1; 251 mld_all_nodes_linklocal.s6_addr16[1] = 252 htons(ifp->if_index); /* XXX */ 253 254 LIST_FOREACH(in6m, &ia->ia6_multiaddrs, in6m_entry) { 255 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 256 &mld_all_nodes_linklocal) || 257 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 258 IPV6_ADDR_SCOPE_LINKLOCAL) 259 continue; 260 261 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) || 262 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr, 263 &in6m->in6m_addr)) 264 { 265 if (timer == 0) { 266 /* send a report immediately */ 267 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, 268 NULL); 269 in6m->in6m_timer = 0; /* reset timer */ 270 in6m->in6m_state = MLD_IREPORTEDLAST; 271 } else if (in6m->in6m_timer == 0 || /* idle */ 272 in6m->in6m_timer > timer) { 273 in6m->in6m_timer = 274 MLD_RANDOM_DELAY(timer); 275 mld_timers_are_running = 1; 276 } 277 } 278 } 279 280 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 281 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 282 break; 283 case MLD_LISTENER_REPORT: 284 /* 285 * For fast leave to work, we have to know that we are the 286 * last person to send a report for this group. Reports 287 * can potentially get looped back if we are a multicast 288 * router, so discard reports sourced by me. 289 * Note that it is impossible to check IFF_LOOPBACK flag of 290 * ifp for this purpose, since ip6_mloopback pass the physical 291 * interface to looutput. 292 */ 293 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 294 break; 295 296 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 297 break; 298 299 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 300 mldh->mld_addr.s6_addr16[1] = 301 htons(ifp->if_index); /* XXX */ 302 /* 303 * If we belong to the group being reported, stop 304 * our timer for that group. 305 */ 306 IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m); 307 if (in6m) { 308 in6m->in6m_timer = 0; /* transit to idle state */ 309 in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */ 310 } 311 312 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 313 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 314 break; 315 default: /* this is impossible */ 316 #if 0 317 /* 318 * this case should be impossible because of filtering in 319 * icmp6_input(). But we explicitly disabled this part 320 * just in case. 321 */ 322 log(LOG_ERR, "mld_input: illegal type(%d)", mldh->mld_type); 323 #endif 324 break; 325 } 326 327 m_freem(m); 328 } 329 330 void 331 mld6_fasttimeo() 332 { 333 struct in6_multi *in6m; 334 struct in6_multistep step; 335 int s; 336 337 /* 338 * Quick check to see if any work needs to be done, in order 339 * to minimize the overhead of fasttimo processing. 340 */ 341 if (!mld_timers_are_running) 342 return; 343 344 s = splsoftnet(); 345 mld_timers_are_running = 0; 346 IN6_FIRST_MULTI(step, in6m); 347 while (in6m != NULL) { 348 if (in6m->in6m_timer == 0) { 349 /* do nothing */ 350 } else if (--in6m->in6m_timer == 0) { 351 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 352 in6m->in6m_state = MLD_IREPORTEDLAST; 353 } else { 354 mld_timers_are_running = 1; 355 } 356 IN6_NEXT_MULTI(step, in6m); 357 } 358 splx(s); 359 } 360 361 static void 362 mld6_sendpkt(struct in6_multi *in6m, int type, const struct in6_addr *dst) 363 { 364 struct mbuf *mh, *md; 365 struct mld_hdr *mldh; 366 struct ip6_hdr *ip6; 367 struct ip6_moptions im6o; 368 struct in6_ifaddr *ia; 369 struct ifnet *ifp = in6m->in6m_ifp; 370 int ignflags; 371 372 /* 373 * At first, find a link local address on the outgoing interface 374 * to use as the source address of the MLD packet. 375 * We do not reject tentative addresses for MLD report to deal with 376 * the case where we first join a link-local address. 377 */ 378 ignflags = (IN6_IFF_NOTREADY|IN6_IFF_ANYCAST) & ~IN6_IFF_TENTATIVE; 379 if ((ia = in6ifa_ifpforlinklocal(ifp, ignflags)) == NULL) 380 return; 381 if ((ia->ia6_flags & IN6_IFF_TENTATIVE)) 382 ia = NULL; 383 384 /* 385 * Allocate mbufs to store ip6 header and MLD header. 386 * We allocate 2 mbufs and make chain in advance because 387 * it is more convenient when inserting the hop-by-hop option later. 388 */ 389 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 390 if (mh == NULL) 391 return; 392 MGET(md, M_DONTWAIT, MT_DATA); 393 if (md == NULL) { 394 m_free(mh); 395 return; 396 } 397 mh->m_next = md; 398 399 mh->m_pkthdr.rcvif = NULL; 400 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr); 401 mh->m_len = sizeof(struct ip6_hdr); 402 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 403 404 /* fill in the ip6 header */ 405 ip6 = mtod(mh, struct ip6_hdr *); 406 ip6->ip6_flow = 0; 407 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 408 ip6->ip6_vfc |= IPV6_VERSION; 409 /* ip6_plen will be set later */ 410 ip6->ip6_nxt = IPPROTO_ICMPV6; 411 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 412 ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any; 413 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 414 415 /* fill in the MLD header */ 416 md->m_len = sizeof(struct mld_hdr); 417 mldh = mtod(md, struct mld_hdr *); 418 mldh->mld_type = type; 419 mldh->mld_code = 0; 420 mldh->mld_cksum = 0; 421 /* XXX: we assume the function will not be called for query messages */ 422 mldh->mld_maxdelay = 0; 423 mldh->mld_reserved = 0; 424 mldh->mld_addr = in6m->in6m_addr; 425 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 426 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 427 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 428 sizeof(struct mld_hdr)); 429 430 /* construct multicast option */ 431 bzero(&im6o, sizeof(im6o)); 432 im6o.im6o_multicast_ifp = ifp; 433 im6o.im6o_multicast_hlim = 1; 434 435 /* 436 * Request loopback of the report if we are acting as a multicast 437 * router, so that the process-level routing daemon can hear it. 438 */ 439 #ifdef MROUTING 440 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 441 #endif 442 443 /* increment output statictics */ 444 icmp6stat.icp6s_outhist[type]++; 445 icmp6_ifstat_inc(ifp, ifs6_out_msg); 446 switch (type) { 447 case MLD_LISTENER_QUERY: 448 icmp6_ifstat_inc(ifp, ifs6_out_mldquery); 449 break; 450 case MLD_LISTENER_REPORT: 451 icmp6_ifstat_inc(ifp, ifs6_out_mldreport); 452 break; 453 case MLD_LISTENER_DONE: 454 icmp6_ifstat_inc(ifp, ifs6_out_mlddone); 455 break; 456 } 457 458 ip6_output(mh, &ip6_opts, NULL, ia ? 0 : IPV6_UNSPECSRC, &im6o, NULL, 459 NULL); 460 } 461