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 1.5 2004/06/02 14:43:01 eirikn 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(void) 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(struct in6_multi *in6m) 139 { 140 int s = splnet(); 141 142 /* 143 * RFC2710 page 10: 144 * The node never sends a Report or Done for the link-scope all-nodes 145 * address. 146 * MLD messages are never sent for multicast addresses whose scope is 0 147 * (reserved) or 1 (node-local). 148 */ 149 mld6_all_nodes_linklocal.s6_addr16[1] = 150 htons(in6m->in6m_ifp->if_index); /* XXX */ 151 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) || 152 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 153 in6m->in6m_timer = 0; 154 in6m->in6m_state = MLD6_OTHERLISTENER; 155 } else { 156 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 157 in6m->in6m_timer = MLD6_RANDOM_DELAY( 158 MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ); 159 in6m->in6m_state = MLD6_IREPORTEDLAST; 160 mld6_timers_are_running = 1; 161 } 162 splx(s); 163 } 164 165 void 166 mld6_stop_listening(struct in6_multi *in6m) 167 { 168 mld6_all_nodes_linklocal.s6_addr16[1] = 169 htons(in6m->in6m_ifp->if_index); /* XXX */ 170 mld6_all_routers_linklocal.s6_addr16[1] = 171 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 172 173 if (in6m->in6m_state == MLD6_IREPORTEDLAST && 174 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) && 175 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL) 176 mld6_sendpkt(in6m, MLD_LISTENER_DONE, 177 &mld6_all_routers_linklocal); 178 } 179 180 void 181 mld6_input(struct mbuf *m, int off) 182 { 183 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 184 struct mld_hdr *mldh; 185 struct ifnet *ifp = m->m_pkthdr.rcvif; 186 struct in6_multi *in6m; 187 struct in6_ifaddr *ia; 188 struct ifmultiaddr *ifma; 189 int timer; /* timer value in the MLD query header */ 190 191 #ifndef PULLDOWN_TEST 192 IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),); 193 mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off); 194 #else 195 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh)); 196 if (mldh == NULL) { 197 icmp6stat.icp6s_tooshort++; 198 return; 199 } 200 #endif 201 202 /* source address validation */ 203 ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */ 204 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 205 log(LOG_ERR, 206 "mld6_input: src %s is not link-local (grp=%s)\n", 207 ip6_sprintf(&ip6->ip6_src), 208 ip6_sprintf(&mldh->mld_addr)); 209 /* 210 * spec (RFC2710) does not explicitly 211 * specify to discard the packet from a non link-local 212 * source address. But we believe it's expected to do so. 213 * XXX: do we have to allow :: as source? 214 */ 215 m_freem(m); 216 return; 217 } 218 219 /* 220 * In the MLD6 specification, there are 3 states and a flag. 221 * 222 * In Non-Listener state, we simply don't have a membership record. 223 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 224 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 225 * 226 * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if 227 * we have heard a report from another member, or MLD6_IREPORTEDLAST 228 * if we sent the last report. 229 */ 230 switch(mldh->mld_type) { 231 case MLD_LISTENER_QUERY: 232 if (ifp->if_flags & IFF_LOOPBACK) 233 break; 234 235 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) && 236 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 237 break; /* print error or log stat? */ 238 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 239 mldh->mld_addr.s6_addr16[1] = 240 htons(ifp->if_index); /* XXX */ 241 242 /* 243 * - Start the timers in all of our membership records 244 * that the query applies to for the interface on 245 * which the query arrived excl. those that belong 246 * to the "all-nodes" group (ff02::1). 247 * - Restart any timer that is already running but has 248 * A value longer than the requested timeout. 249 * - Use the value specified in the query message as 250 * the maximum timeout. 251 */ 252 IFP_TO_IA6(ifp, ia); 253 if (ia == NULL) 254 break; 255 256 /* 257 * XXX: System timer resolution is too low to handle Max 258 * Response Delay, so set 1 to the internal timer even if 259 * the calculated value equals to zero when Max Response 260 * Delay is positive. 261 */ 262 timer = ntohs(mldh->mld_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE; 263 if (timer == 0 && mldh->mld_maxdelay) 264 timer = 1; 265 mld6_all_nodes_linklocal.s6_addr16[1] = 266 htons(ifp->if_index); /* XXX */ 267 268 LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) 269 { 270 if (ifma->ifma_addr->sa_family != AF_INET6) 271 continue; 272 in6m = (struct in6_multi *)ifma->ifma_protospec; 273 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 274 &mld6_all_nodes_linklocal) || 275 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 276 IPV6_ADDR_SCOPE_LINKLOCAL) 277 continue; 278 279 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) || 280 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr, 281 &in6m->in6m_addr)) 282 { 283 if (timer == 0) { 284 /* send a report immediately */ 285 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, 286 NULL); 287 in6m->in6m_timer = 0; /* reset timer */ 288 in6m->in6m_state = MLD6_IREPORTEDLAST; 289 } 290 else if (in6m->in6m_timer == 0 || /*idle state*/ 291 in6m->in6m_timer > timer) { 292 in6m->in6m_timer = 293 MLD6_RANDOM_DELAY(timer); 294 mld6_timers_are_running = 1; 295 } 296 } 297 } 298 299 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 300 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 301 break; 302 case MLD_LISTENER_REPORT: 303 /* 304 * For fast leave to work, we have to know that we are the 305 * last person to send a report for this group. Reports 306 * can potentially get looped back if we are a multicast 307 * router, so discard reports sourced by me. 308 * Note that it is impossible to check IFF_LOOPBACK flag of 309 * ifp for this purpose, since ip6_mloopback pass the physical 310 * interface to looutput. 311 */ 312 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 313 break; 314 315 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 316 break; 317 318 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 319 mldh->mld_addr.s6_addr16[1] = 320 htons(ifp->if_index); /* XXX */ 321 /* 322 * If we belong to the group being reported, stop 323 * our timer for that group. 324 */ 325 IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m); 326 if (in6m) { 327 in6m->in6m_timer = 0; /* transit to idle state */ 328 in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */ 329 } 330 331 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 332 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 333 break; 334 default: /* this is impossible */ 335 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type); 336 break; 337 } 338 339 m_freem(m); 340 } 341 342 void 343 mld6_fasttimeo(void) 344 { 345 struct in6_multi *in6m; 346 struct in6_multistep step; 347 int s; 348 349 /* 350 * Quick check to see if any work needs to be done, in order 351 * to minimize the overhead of fasttimo processing. 352 */ 353 if (!mld6_timers_are_running) 354 return; 355 356 s = splnet(); 357 mld6_timers_are_running = 0; 358 IN6_FIRST_MULTI(step, in6m); 359 while (in6m != NULL) { 360 if (in6m->in6m_timer == 0) { 361 /* do nothing */ 362 } else if (--in6m->in6m_timer == 0) { 363 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 364 in6m->in6m_state = MLD6_IREPORTEDLAST; 365 } else { 366 mld6_timers_are_running = 1; 367 } 368 IN6_NEXT_MULTI(step, in6m); 369 } 370 splx(s); 371 } 372 373 static void 374 mld6_sendpkt(struct in6_multi *in6m, int type, 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 struct ifnet *outif = NULL; 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 */ 388 if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST)) 389 == NULL) 390 return; 391 392 /* 393 * Allocate mbufs to store ip6 header and MLD header. 394 * We allocate 2 mbufs and make chain in advance because 395 * it is more convenient when inserting the hop-by-hop option later. 396 */ 397 MGETHDR(mh, MB_DONTWAIT, MT_HEADER); 398 if (mh == NULL) 399 return; 400 MGET(md, MB_DONTWAIT, MT_DATA); 401 if (md == NULL) { 402 m_free(mh); 403 return; 404 } 405 mh->m_next = md; 406 407 mh->m_pkthdr.rcvif = NULL; 408 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_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 mld_hdr); 425 mldh = mtod(md, struct mld_hdr *); 426 mldh->mld_type = type; 427 mldh->mld_code = 0; 428 mldh->mld_cksum = 0; 429 /* XXX: we assume the function will not be called for query messages */ 430 mldh->mld_maxdelay = 0; 431 mldh->mld_reserved = 0; 432 mldh->mld_addr = in6m->in6m_addr; 433 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 434 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 435 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, 436 sizeof(struct ip6_hdr), 437 sizeof(struct mld_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, NULL); 454 if (outif) { 455 icmp6_ifstat_inc(outif, ifs6_out_msg); 456 switch (type) { 457 case MLD_LISTENER_QUERY: 458 icmp6_ifstat_inc(outif, ifs6_out_mldquery); 459 break; 460 case MLD_LISTENER_REPORT: 461 icmp6_ifstat_inc(outif, ifs6_out_mldreport); 462 break; 463 case MLD_LISTENER_DONE: 464 icmp6_ifstat_inc(outif, ifs6_out_mlddone); 465 break; 466 } 467 } 468 } 469