1 /* $FreeBSD: src/sys/netinet6/mld6.c,v 1.4.2.4 2003/01/23 21:06:47 sam Exp $ */ 2 /* $DragonFly: src/sys/netinet6/mld6.c,v 1.3 2003/08/23 11:02:45 rob Exp $ */ 3 /* $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $ */ 4 5 /* 6 * Copyright (C) 1998 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 /* 35 * Copyright (c) 1988 Stephen Deering. 36 * Copyright (c) 1992, 1993 37 * The Regents of the University of California. All rights reserved. 38 * 39 * This code is derived from software contributed to Berkeley by 40 * Stephen Deering of Stanford University. 41 * 42 * Redistribution and use in source and binary forms, with or without 43 * modification, are permitted provided that the following conditions 44 * are met: 45 * 1. Redistributions of source code must retain the above copyright 46 * notice, this list of conditions and the following disclaimer. 47 * 2. Redistributions in binary form must reproduce the above copyright 48 * notice, this list of conditions and the following disclaimer in the 49 * documentation and/or other materials provided with the distribution. 50 * 3. All advertising materials mentioning features or use of this software 51 * must display the following acknowledgement: 52 * This product includes software developed by the University of 53 * California, Berkeley and its contributors. 54 * 4. Neither the name of the University nor the names of its contributors 55 * may be used to endorse or promote products derived from this software 56 * without specific prior written permission. 57 * 58 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 59 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 60 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 61 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 62 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 63 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 64 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 65 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 66 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 67 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 68 * SUCH DAMAGE. 69 * 70 * @(#)igmp.c 8.1 (Berkeley) 7/19/93 71 */ 72 73 #include "opt_inet.h" 74 #include "opt_inet6.h" 75 76 #include <sys/param.h> 77 #include <sys/systm.h> 78 #include <sys/mbuf.h> 79 #include <sys/socket.h> 80 #include <sys/protosw.h> 81 #include <sys/syslog.h> 82 83 #include <net/if.h> 84 85 #include <netinet/in.h> 86 #include <netinet/in_var.h> 87 #include <netinet/ip6.h> 88 #include <netinet6/ip6_var.h> 89 #include <netinet/icmp6.h> 90 #include <netinet6/mld6_var.h> 91 92 #include <net/net_osdep.h> 93 94 /* 95 * Protocol constants 96 */ 97 98 /* denotes that the MLD max response delay field specifies time in milliseconds */ 99 #define MLD6_TIMER_SCALE 1000 100 /* 101 * time between repetitions of a node's initial report of interest in a 102 * multicast address(in seconds) 103 */ 104 #define MLD6_UNSOLICITED_REPORT_INTERVAL 10 105 106 static struct ip6_pktopts ip6_opts; 107 static int mld6_timers_are_running; 108 /* XXX: These are necessary for KAME's link-local hack */ 109 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 110 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 111 112 static void mld6_sendpkt (struct in6_multi *, int, const struct in6_addr *); 113 114 void 115 mld6_init() 116 { 117 static u_int8_t hbh_buf[8]; 118 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 119 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 120 121 mld6_timers_are_running = 0; 122 123 /* ip6h_nxt will be fill in later */ 124 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */ 125 126 /* XXX: grotty hard coding... */ 127 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 128 hbh_buf[3] = 0; 129 hbh_buf[4] = IP6OPT_RTALERT; 130 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 131 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 132 133 init_ip6pktopts(&ip6_opts); 134 ip6_opts.ip6po_hbh = hbh; 135 } 136 137 void 138 mld6_start_listening(in6m) 139 struct in6_multi *in6m; 140 { 141 int s = splnet(); 142 143 /* 144 * RFC2710 page 10: 145 * The node never sends a Report or Done for the link-scope all-nodes 146 * address. 147 * MLD messages are never sent for multicast addresses whose scope is 0 148 * (reserved) or 1 (node-local). 149 */ 150 mld6_all_nodes_linklocal.s6_addr16[1] = 151 htons(in6m->in6m_ifp->if_index); /* XXX */ 152 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) || 153 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 154 in6m->in6m_timer = 0; 155 in6m->in6m_state = MLD6_OTHERLISTENER; 156 } else { 157 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 158 in6m->in6m_timer = MLD6_RANDOM_DELAY( 159 MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ); 160 in6m->in6m_state = MLD6_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 == MLD6_IREPORTEDLAST && 176 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) && 177 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL) 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 MLD6_OTHERLISTENER if 231 * we have heard a report from another member, or MLD6_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/MLD6_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 LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) 273 { 274 if (ifma->ifma_addr->sa_family != AF_INET6) 275 continue; 276 in6m = (struct in6_multi *)ifma->ifma_protospec; 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 = MLD6_IREPORTEDLAST; 293 } 294 else if (in6m->in6m_timer == 0 || /*idle state*/ 295 in6m->in6m_timer > timer) { 296 in6m->in6m_timer = 297 MLD6_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 case MLD_LISTENER_REPORT: 307 /* 308 * For fast leave to work, we have to know that we are the 309 * last person to send a report for this group. Reports 310 * can potentially get looped back if we are a multicast 311 * router, so discard reports sourced by me. 312 * Note that it is impossible to check IFF_LOOPBACK flag of 313 * ifp for this purpose, since ip6_mloopback pass the physical 314 * interface to looutput. 315 */ 316 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 317 break; 318 319 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 320 break; 321 322 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 323 mldh->mld_addr.s6_addr16[1] = 324 htons(ifp->if_index); /* XXX */ 325 /* 326 * If we belong to the group being reported, stop 327 * our timer for that group. 328 */ 329 IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m); 330 if (in6m) { 331 in6m->in6m_timer = 0; /* transit to idle state */ 332 in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */ 333 } 334 335 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 336 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 337 break; 338 default: /* this is impossible */ 339 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type); 340 break; 341 } 342 343 m_freem(m); 344 } 345 346 void 347 mld6_fasttimeo() 348 { 349 struct in6_multi *in6m; 350 struct in6_multistep step; 351 int s; 352 353 /* 354 * Quick check to see if any work needs to be done, in order 355 * to minimize the overhead of fasttimo processing. 356 */ 357 if (!mld6_timers_are_running) 358 return; 359 360 s = splnet(); 361 mld6_timers_are_running = 0; 362 IN6_FIRST_MULTI(step, in6m); 363 while (in6m != NULL) { 364 if (in6m->in6m_timer == 0) { 365 /* do nothing */ 366 } else if (--in6m->in6m_timer == 0) { 367 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 368 in6m->in6m_state = MLD6_IREPORTEDLAST; 369 } else { 370 mld6_timers_are_running = 1; 371 } 372 IN6_NEXT_MULTI(step, in6m); 373 } 374 splx(s); 375 } 376 377 static void 378 mld6_sendpkt(in6m, type, dst) 379 struct in6_multi *in6m; 380 int type; 381 const struct in6_addr *dst; 382 { 383 struct mbuf *mh, *md; 384 struct mld_hdr *mldh; 385 struct ip6_hdr *ip6; 386 struct ip6_moptions im6o; 387 struct in6_ifaddr *ia; 388 struct ifnet *ifp = in6m->in6m_ifp; 389 struct ifnet *outif = NULL; 390 391 /* 392 * At first, find a link local address on the outgoing interface 393 * to use as the source address of the MLD packet. 394 */ 395 if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST)) 396 == NULL) 397 return; 398 399 /* 400 * Allocate mbufs to store ip6 header and MLD header. 401 * We allocate 2 mbufs and make chain in advance because 402 * it is more convenient when inserting the hop-by-hop option later. 403 */ 404 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 405 if (mh == NULL) 406 return; 407 MGET(md, M_DONTWAIT, MT_DATA); 408 if (md == NULL) { 409 m_free(mh); 410 return; 411 } 412 mh->m_next = md; 413 414 mh->m_pkthdr.rcvif = NULL; 415 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr); 416 mh->m_len = sizeof(struct ip6_hdr); 417 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 418 419 /* fill in the ip6 header */ 420 ip6 = mtod(mh, struct ip6_hdr *); 421 ip6->ip6_flow = 0; 422 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 423 ip6->ip6_vfc |= IPV6_VERSION; 424 /* ip6_plen will be set later */ 425 ip6->ip6_nxt = IPPROTO_ICMPV6; 426 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 427 ip6->ip6_src = ia->ia_addr.sin6_addr; 428 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 429 430 /* fill in the MLD header */ 431 md->m_len = sizeof(struct mld_hdr); 432 mldh = mtod(md, struct mld_hdr *); 433 mldh->mld_type = type; 434 mldh->mld_code = 0; 435 mldh->mld_cksum = 0; 436 /* XXX: we assume the function will not be called for query messages */ 437 mldh->mld_maxdelay = 0; 438 mldh->mld_reserved = 0; 439 mldh->mld_addr = in6m->in6m_addr; 440 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 441 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 442 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, 443 sizeof(struct ip6_hdr), 444 sizeof(struct mld_hdr)); 445 446 /* construct multicast option */ 447 bzero(&im6o, sizeof(im6o)); 448 im6o.im6o_multicast_ifp = ifp; 449 im6o.im6o_multicast_hlim = 1; 450 451 /* 452 * Request loopback of the report if we are acting as a multicast 453 * router, so that the process-level routing daemon can hear it. 454 */ 455 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 456 457 /* increment output statictics */ 458 icmp6stat.icp6s_outhist[type]++; 459 460 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL); 461 if (outif) { 462 icmp6_ifstat_inc(outif, ifs6_out_msg); 463 switch (type) { 464 case MLD_LISTENER_QUERY: 465 icmp6_ifstat_inc(outif, ifs6_out_mldquery); 466 break; 467 case MLD_LISTENER_REPORT: 468 icmp6_ifstat_inc(outif, ifs6_out_mldreport); 469 break; 470 case MLD_LISTENER_DONE: 471 icmp6_ifstat_inc(outif, ifs6_out_mlddone); 472 break; 473 } 474 } 475 } 476