1 /* $OpenBSD: mld6.c,v 1.11 2001/12/07 09:16:07 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. 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 <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/mbuf.h> 75 #include <sys/socket.h> 76 #include <sys/protosw.h> 77 #include <sys/syslog.h> 78 #include <dev/rndvar.h> 79 80 #include <net/if.h> 81 82 #include <netinet/in.h> 83 #include <netinet/in_var.h> 84 #include <netinet/ip6.h> 85 #include <netinet6/ip6_var.h> 86 #include <netinet/icmp6.h> 87 #include <netinet6/mld6_var.h> 88 89 /* 90 * Protocol constants 91 */ 92 93 /* denotes that the MLD max response delay field specifies time in milliseconds */ 94 #define MLD6_TIMER_SCALE 1000 95 /* 96 * time between repetitions of a node's initial report of interest in a 97 * multicast address(in seconds) 98 */ 99 #define MLD6_UNSOLICITED_REPORT_INTERVAL 10 100 101 static struct ip6_pktopts ip6_opts; 102 static int mld6_timers_are_running; 103 /* XXX: These are necessary for KAME's link-local hack */ 104 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 105 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 106 107 static void mld6_sendpkt __P((struct in6_multi *, int, const struct in6_addr *)); 108 109 void 110 mld6_init() 111 { 112 static u_int8_t hbh_buf[8]; 113 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 114 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 115 116 mld6_timers_are_running = 0; 117 118 /* ip6h_nxt will be fill in later */ 119 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */ 120 121 /* XXX: grotty hard coding... */ 122 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 123 hbh_buf[3] = 0; 124 hbh_buf[4] = IP6OPT_RTALERT; 125 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 126 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 127 128 ip6_opts.ip6po_hbh = hbh; 129 /* We will specify the hoplimit by a multicast option. */ 130 ip6_opts.ip6po_hlim = -1; 131 } 132 133 void 134 mld6_start_listening(in6m) 135 struct in6_multi *in6m; 136 { 137 int s = splnet(); 138 139 /* 140 * RFC2710 page 10: 141 * The node never sends a Report or Done for the link-scope all-nodes 142 * address. 143 * MLD messages are never sent for multicast addresses whose scope is 0 144 * (reserved) or 1 (node-local). 145 */ 146 mld6_all_nodes_linklocal.s6_addr16[1] = 147 htons(in6m->in6m_ifp->if_index); /* XXX */ 148 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) || 149 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 150 in6m->in6m_timer = 0; 151 in6m->in6m_state = MLD6_OTHERLISTENER; 152 } else { 153 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL); 154 in6m->in6m_timer = MLD6_RANDOM_DELAY( 155 MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ); 156 in6m->in6m_state = MLD6_IREPORTEDLAST; 157 mld6_timers_are_running = 1; 158 } 159 splx(s); 160 } 161 162 void 163 mld6_stop_listening(in6m) 164 struct in6_multi *in6m; 165 { 166 mld6_all_nodes_linklocal.s6_addr16[1] = 167 htons(in6m->in6m_ifp->if_index); /* XXX */ 168 mld6_all_routers_linklocal.s6_addr16[1] = 169 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 170 171 if (in6m->in6m_state == MLD6_IREPORTEDLAST && 172 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) && 173 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL) 174 mld6_sendpkt(in6m, MLD6_LISTENER_DONE, 175 &mld6_all_routers_linklocal); 176 } 177 178 void 179 mld6_input(m, off) 180 struct mbuf *m; 181 int off; 182 { 183 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 184 struct mld6_hdr *mldh; 185 struct ifnet *ifp = m->m_pkthdr.rcvif; 186 struct in6_multi *in6m; 187 struct in6_ifaddr *ia; 188 int timer; /* timer value in the MLD query header */ 189 190 #ifndef PULLDOWN_TEST 191 IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),); 192 mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off); 193 #else 194 IP6_EXTHDR_GET(mldh, struct mld6_hdr *, m, off, sizeof(*mldh)); 195 if (mldh == NULL) { 196 icmp6stat.icp6s_tooshort++; 197 return; 198 } 199 #endif 200 201 /* source address validation */ 202 ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */ 203 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 204 log(LOG_ERR, 205 "mld6_input: src %s is not link-local (grp=%s)\n", 206 ip6_sprintf(&ip6->ip6_src), 207 ip6_sprintf(&mldh->mld6_addr)); 208 /* 209 * spec (RFC2710) does not explicitly 210 * specify to discard the packet from a non link-local 211 * source address. But we believe it's expected to do so. 212 */ 213 m_freem(m); 214 return; 215 } 216 217 /* 218 * In the MLD6 specification, there are 3 states and a flag. 219 * 220 * In Non-Listener state, we simply don't have a membership record. 221 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 222 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 223 * 224 * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if 225 * we have heard a report from another member, or MLD6_IREPORTEDLAST 226 * if we sent the last report. 227 */ 228 switch(mldh->mld6_type) { 229 case MLD6_LISTENER_QUERY: 230 if (ifp->if_flags & IFF_LOOPBACK) 231 break; 232 233 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) && 234 !IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 235 break; /* print error or log stat? */ 236 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 237 mldh->mld6_addr.s6_addr16[1] = 238 htons(ifp->if_index); /* XXX */ 239 240 /* 241 * - Start the timers in all of our membership records 242 * that the query applies to for the interface on 243 * which the query arrived excl. those that belong 244 * to the "all-nodes" group (ff02::1). 245 * - Restart any timer that is already running but has 246 * A value longer than the requested timeout. 247 * - Use the value specified in the query message as 248 * the maximum timeout. 249 */ 250 IFP_TO_IA6(ifp, ia); 251 if (ia == NULL) 252 break; 253 254 /* 255 * XXX: System timer resolution is too low to handle Max 256 * Response Delay, so set 1 to the internal timer even if 257 * the calculated value equals to zero when Max Response 258 * Delay is positive. 259 */ 260 timer = ntohs(mldh->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE; 261 if (timer == 0 && mldh->mld6_maxdelay) 262 timer = 1; 263 mld6_all_nodes_linklocal.s6_addr16[1] = 264 htons(ifp->if_index); /* XXX */ 265 266 for (in6m = ia->ia6_multiaddrs.lh_first; 267 in6m; 268 in6m = in6m->in6m_entry.le_next) 269 { 270 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 271 &mld6_all_nodes_linklocal) || 272 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 273 IPV6_ADDR_SCOPE_LINKLOCAL) 274 continue; 275 276 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) || 277 IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr, 278 &in6m->in6m_addr)) 279 { 280 if (timer == 0) { 281 /* send a report immediately */ 282 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, 283 NULL); 284 in6m->in6m_timer = 0; /* reset timer */ 285 in6m->in6m_state = MLD6_IREPORTEDLAST; 286 } 287 else if (in6m->in6m_timer == 0 || /* idle */ 288 in6m->in6m_timer > timer) { 289 in6m->in6m_timer = 290 MLD6_RANDOM_DELAY(timer); 291 mld6_timers_are_running = 1; 292 } 293 } 294 } 295 296 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 297 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 298 break; 299 case MLD6_LISTENER_REPORT: 300 /* 301 * For fast leave to work, we have to know that we are the 302 * last person to send a report for this group. Reports 303 * can potentially get looped back if we are a multicast 304 * router, so discard reports sourced by me. 305 * Note that it is impossible to check IFF_LOOPBACK flag of 306 * ifp for this purpose, since ip6_mloopback pass the physical 307 * interface to looutput. 308 */ 309 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 310 break; 311 312 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 313 break; 314 315 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 316 mldh->mld6_addr.s6_addr16[1] = 317 htons(ifp->if_index); /* XXX */ 318 /* 319 * If we belong to the group being reported, stop 320 * our timer for that group. 321 */ 322 IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m); 323 if (in6m) { 324 in6m->in6m_timer = 0; /* transit to idle state */ 325 in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */ 326 } 327 328 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 329 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 330 break; 331 default: /* this is impossible */ 332 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type); 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 (!mld6_timers_are_running) 351 return; 352 353 s = splnet(); 354 355 mld6_timers_are_running = 0; 356 IN6_FIRST_MULTI(step, in6m); 357 while (in6m != NULL) { 358 if (in6m->in6m_timer == 0) { 359 /* do nothing */ 360 } else if (--in6m->in6m_timer == 0) { 361 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL); 362 in6m->in6m_state = MLD6_IREPORTEDLAST; 363 } else { 364 mld6_timers_are_running = 1; 365 } 366 IN6_NEXT_MULTI(step, in6m); 367 } 368 splx(s); 369 } 370 371 static void 372 mld6_sendpkt(in6m, type, dst) 373 struct in6_multi *in6m; 374 int type; 375 const struct in6_addr *dst; 376 { 377 struct mbuf *mh, *md; 378 struct mld6_hdr *mldh; 379 struct ip6_hdr *ip6; 380 struct ip6_moptions im6o; 381 struct in6_ifaddr *ia; 382 struct ifnet *ifp = in6m->in6m_ifp; 383 struct ifnet *outif = NULL; 384 385 /* 386 * At first, find a link local address on the outgoing interface 387 * to use as the source address of the MLD packet. 388 */ 389 if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST)) 390 == NULL) 391 return; 392 393 /* 394 * Allocate mbufs to store ip6 header and MLD header. 395 * We allocate 2 mbufs and make chain in advance because 396 * it is more convenient when inserting the hop-by-hop option later. 397 */ 398 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 399 if (mh == NULL) 400 return; 401 MGET(md, M_DONTWAIT, MT_DATA); 402 if (md == NULL) { 403 m_free(mh); 404 return; 405 } 406 mh->m_next = md; 407 408 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_hdr); 409 mh->m_len = sizeof(struct ip6_hdr); 410 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 411 412 /* fill in the ip6 header */ 413 ip6 = mtod(mh, struct ip6_hdr *); 414 ip6->ip6_flow = 0; 415 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 416 ip6->ip6_vfc |= IPV6_VERSION; 417 /* ip6_plen will be set later */ 418 ip6->ip6_nxt = IPPROTO_ICMPV6; 419 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 420 ip6->ip6_src = ia->ia_addr.sin6_addr; 421 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 422 423 /* fill in the MLD header */ 424 md->m_len = sizeof(struct mld6_hdr); 425 mldh = mtod(md, struct mld6_hdr *); 426 mldh->mld6_type = type; 427 mldh->mld6_code = 0; 428 mldh->mld6_cksum = 0; 429 /* XXX: we assume the function will not be called for query messages */ 430 mldh->mld6_maxdelay = 0; 431 mldh->mld6_reserved = 0; 432 mldh->mld6_addr = in6m->in6m_addr; 433 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 434 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 435 mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 436 sizeof(struct mld6_hdr)); 437 438 /* construct multicast option */ 439 bzero(&im6o, sizeof(im6o)); 440 im6o.im6o_multicast_ifp = ifp; 441 im6o.im6o_multicast_hlim = 1; 442 443 /* 444 * Request loopback of the report if we are acting as a multicast 445 * router, so that the process-level routing daemon can hear it. 446 */ 447 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 448 449 /* increment output statictics */ 450 icmp6stat.icp6s_outhist[type]++; 451 452 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif); 453 if (outif) { 454 icmp6_ifstat_inc(outif, ifs6_out_msg); 455 switch (type) { 456 case MLD6_LISTENER_QUERY: 457 icmp6_ifstat_inc(outif, ifs6_out_mldquery); 458 break; 459 case MLD6_LISTENER_REPORT: 460 icmp6_ifstat_inc(outif, ifs6_out_mldreport); 461 break; 462 case MLD6_LISTENER_DONE: 463 icmp6_ifstat_inc(outif, ifs6_out_mlddone); 464 break; 465 } 466 } 467 } 468