1 /* $OpenBSD: mld6.c,v 1.10 2001/06/09 06:43:38 angelos 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 * XXX: do we have to allow :: as source? 213 */ 214 m_freem(m); 215 return; 216 } 217 218 /* 219 * In the MLD6 specification, there are 3 states and a flag. 220 * 221 * In Non-Listener state, we simply don't have a membership record. 222 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 223 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 224 * 225 * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if 226 * we have heard a report from another member, or MLD6_IREPORTEDLAST 227 * if we sent the last report. 228 */ 229 switch(mldh->mld6_type) { 230 case MLD6_LISTENER_QUERY: 231 if (ifp->if_flags & IFF_LOOPBACK) 232 break; 233 234 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) && 235 !IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 236 break; /* print error or log stat? */ 237 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 238 mldh->mld6_addr.s6_addr16[1] = 239 htons(ifp->if_index); /* XXX */ 240 241 /* 242 * - Start the timers in all of our membership records 243 * that the query applies to for the interface on 244 * which the query arrived excl. those that belong 245 * to the "all-nodes" group (ff02::1). 246 * - Restart any timer that is already running but has 247 * A value longer than the requested timeout. 248 * - Use the value specified in the query message as 249 * the maximum timeout. 250 */ 251 IFP_TO_IA6(ifp, ia); 252 if (ia == NULL) 253 break; 254 255 /* 256 * XXX: System timer resolution is too low to handle Max 257 * Response Delay, so set 1 to the internal timer even if 258 * the calculated value equals to zero when Max Response 259 * Delay is positive. 260 */ 261 timer = ntohs(mldh->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE; 262 if (timer == 0 && mldh->mld6_maxdelay) 263 timer = 1; 264 mld6_all_nodes_linklocal.s6_addr16[1] = 265 htons(ifp->if_index); /* XXX */ 266 267 for (in6m = ia->ia6_multiaddrs.lh_first; 268 in6m; 269 in6m = in6m->in6m_entry.le_next) 270 { 271 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 272 &mld6_all_nodes_linklocal) || 273 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 274 IPV6_ADDR_SCOPE_LINKLOCAL) 275 continue; 276 277 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) || 278 IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr, 279 &in6m->in6m_addr)) 280 { 281 if (timer == 0) { 282 /* send a report immediately */ 283 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, 284 NULL); 285 in6m->in6m_timer = 0; /* reset timer */ 286 in6m->in6m_state = MLD6_IREPORTEDLAST; 287 } 288 else if (in6m->in6m_timer == 0 || /*idle state*/ 289 in6m->in6m_timer > timer) { 290 in6m->in6m_timer = 291 MLD6_RANDOM_DELAY(timer); 292 mld6_timers_are_running = 1; 293 } 294 } 295 } 296 297 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 298 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 299 break; 300 case MLD6_LISTENER_REPORT: 301 /* 302 * For fast leave to work, we have to know that we are the 303 * last person to send a report for this group. Reports 304 * can potentially get looped back if we are a multicast 305 * router, so discard reports sourced by me. 306 * Note that it is impossible to check IFF_LOOPBACK flag of 307 * ifp for this purpose, since ip6_mloopback pass the physical 308 * interface to looutput. 309 */ 310 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 311 break; 312 313 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 314 break; 315 316 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 317 mldh->mld6_addr.s6_addr16[1] = 318 htons(ifp->if_index); /* XXX */ 319 /* 320 * If we belong to the group being reported, stop 321 * our timer for that group. 322 */ 323 IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m); 324 if (in6m) { 325 in6m->in6m_timer = 0; /* transit to idle state */ 326 in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */ 327 } 328 329 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 330 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 331 break; 332 default: /* this is impossible */ 333 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type); 334 break; 335 } 336 337 m_freem(m); 338 } 339 340 void 341 mld6_fasttimeo() 342 { 343 struct in6_multi *in6m; 344 struct in6_multistep step; 345 int s; 346 347 /* 348 * Quick check to see if any work needs to be done, in order 349 * to minimize the overhead of fasttimo processing. 350 */ 351 if (!mld6_timers_are_running) 352 return; 353 354 s = splnet(); 355 356 mld6_timers_are_running = 0; 357 IN6_FIRST_MULTI(step, in6m); 358 while (in6m != NULL) { 359 if (in6m->in6m_timer == 0) { 360 /* do nothing */ 361 } else if (--in6m->in6m_timer == 0) { 362 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL); 363 in6m->in6m_state = MLD6_IREPORTEDLAST; 364 } else { 365 mld6_timers_are_running = 1; 366 } 367 IN6_NEXT_MULTI(step, in6m); 368 } 369 splx(s); 370 } 371 372 static void 373 mld6_sendpkt(in6m, type, dst) 374 struct in6_multi *in6m; 375 int type; 376 const struct in6_addr *dst; 377 { 378 struct mbuf *mh, *md; 379 struct mld6_hdr *mldh; 380 struct ip6_hdr *ip6; 381 struct ip6_moptions im6o; 382 struct in6_ifaddr *ia; 383 struct ifnet *ifp = in6m->in6m_ifp; 384 struct ifnet *outif = NULL; 385 386 /* 387 * At first, find a link local address on the outgoing interface 388 * to use as the source address of the MLD packet. 389 */ 390 if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST)) 391 == NULL) 392 return; 393 394 /* 395 * Allocate mbufs to store ip6 header and MLD header. 396 * We allocate 2 mbufs and make chain in advance because 397 * it is more convenient when inserting the hop-by-hop option later. 398 */ 399 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 400 if (mh == NULL) 401 return; 402 MGET(md, M_DONTWAIT, MT_DATA); 403 if (md == NULL) { 404 m_free(mh); 405 return; 406 } 407 mh->m_next = md; 408 409 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_hdr); 410 mh->m_len = sizeof(struct ip6_hdr); 411 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 412 413 /* fill in the ip6 header */ 414 ip6 = mtod(mh, struct ip6_hdr *); 415 ip6->ip6_flow = 0; 416 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 417 ip6->ip6_vfc |= IPV6_VERSION; 418 /* ip6_plen will be set later */ 419 ip6->ip6_nxt = IPPROTO_ICMPV6; 420 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 421 ip6->ip6_src = ia->ia_addr.sin6_addr; 422 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 423 424 /* fill in the MLD header */ 425 md->m_len = sizeof(struct mld6_hdr); 426 mldh = mtod(md, struct mld6_hdr *); 427 mldh->mld6_type = type; 428 mldh->mld6_code = 0; 429 mldh->mld6_cksum = 0; 430 /* XXX: we assume the function will not be called for query messages */ 431 mldh->mld6_maxdelay = 0; 432 mldh->mld6_reserved = 0; 433 mldh->mld6_addr = in6m->in6m_addr; 434 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 435 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 436 mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 437 sizeof(struct mld6_hdr)); 438 439 /* construct multicast option */ 440 bzero(&im6o, sizeof(im6o)); 441 im6o.im6o_multicast_ifp = ifp; 442 im6o.im6o_multicast_hlim = 1; 443 444 /* 445 * Request loopback of the report if we are acting as a multicast 446 * router, so that the process-level routing daemon can hear it. 447 */ 448 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 449 450 /* increment output statictics */ 451 icmp6stat.icp6s_outhist[type]++; 452 453 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif); 454 if (outif) { 455 icmp6_ifstat_inc(outif, ifs6_out_msg); 456 switch (type) { 457 case MLD6_LISTENER_QUERY: 458 icmp6_ifstat_inc(outif, ifs6_out_mldquery); 459 break; 460 case MLD6_LISTENER_REPORT: 461 icmp6_ifstat_inc(outif, ifs6_out_mldreport); 462 break; 463 case MLD6_LISTENER_DONE: 464 icmp6_ifstat_inc(outif, ifs6_out_mlddone); 465 break; 466 } 467 } 468 } 469