1 /* 2 * Copyright (C) 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD$ 30 */ 31 32 /* 33 * Copyright (c) 1988 Stephen Deering. 34 * Copyright (c) 1992, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * This code is derived from software contributed to Berkeley by 38 * Stephen Deering of Stanford University. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. All advertising materials mentioning features or use of this software 49 * must display the following acknowledgement: 50 * This product includes software developed by the University of 51 * California, Berkeley and its contributors. 52 * 4. Neither the name of the University nor the names of its contributors 53 * may be used to endorse or promote products derived from this software 54 * without specific prior written permission. 55 * 56 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 57 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 58 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 59 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 60 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 61 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 62 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 63 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 64 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 65 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 66 * SUCH DAMAGE. 67 * 68 * @(#)igmp.c 8.1 (Berkeley) 7/19/93 69 */ 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/mbuf.h> 74 #include <sys/socket.h> 75 #include <sys/protosw.h> 76 #include <sys/syslog.h> 77 78 #include <net/if.h> 79 80 #include <netinet/in.h> 81 #include <netinet/in_var.h> 82 #include <netinet6/in6.h> 83 #include <netinet6/ip6.h> 84 #include <netinet6/ip6_var.h> 85 #include <netinet6/icmp6.h> 86 #include <netinet6/mld6_var.h> 87 88 #include <net/net_osdep.h> 89 90 /* 91 * Protocol constants 92 */ 93 94 /* denotes that the MLD max response delay field specifies time in milliseconds */ 95 #define MLD6_TIMER_SCALE 1000 96 /* 97 * time between repetitions of a node's initial report of interest in a 98 * multicast address(in seconds) 99 */ 100 #define MLD6_UNSOLICITED_REPORT_INTERVAL 10 101 102 static struct ip6_pktopts ip6_opts; 103 static int mld6_timers_are_running; 104 /* XXX: These are necessary for KAME's link-local hack */ 105 static struct in6_addr mld6_all_nodes_linklocal = 106 IN6ADDR_LINKLOCAL_ALLNODES_INIT; 107 static struct in6_addr mld6_all_routers_linklocal = 108 IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 109 110 static void mld6_sendpkt __P((struct in6_multi *, int, 111 const struct in6_addr *)); 112 113 void 114 mld6_init() 115 { 116 static u_int8_t hbh_buf[8]; 117 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 118 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 119 120 mld6_timers_are_running = 0; 121 122 /* ip6h_nxt will be fill in later */ 123 hbh->ip6h_len = 0; /* (8 >> 3) - 1*/ 124 125 /* XXX: grotty hard coding... */ 126 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 127 hbh_buf[3] = 0; 128 hbh_buf[4] = IP6OPT_RTALERT; 129 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 130 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 131 132 ip6_opts.ip6po_hbh = hbh; 133 /* We will specify the hoplimit by a multicast option. */ 134 ip6_opts.ip6po_hlim = -1; 135 } 136 137 void 138 mld6_start_listening(in6m) 139 struct in6_multi *in6m; 140 { 141 int s = splnet(); 142 143 /* 144 * (draft-ietf-ipngwg-mld, 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, MLD6_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, MLD6_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 mld6_hdr *mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off); 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 /* source address validation */ 196 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 197 log(LOG_ERR, 198 "mld6_input: src %s is not link-local\n", 199 ip6_sprintf(&ip6->ip6_src)); 200 /* 201 * spec(draft-ietf-ipngwg-mld) does not explicitly 202 * specify to discard the packet from a non link-local 203 * source address. But we believe it's expected to do so. 204 */ 205 return; 206 } 207 208 /* 209 * In the MLD6 specification, there are 3 states and a flag. 210 * 211 * In Non-Listener state, we simply don't have a membership record. 212 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 213 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 214 * 215 * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if 216 * we have heard a report from another member, or MLD6_IREPORTEDLAST 217 * if we sent the last report. 218 */ 219 switch(mldh->mld6_type) { 220 case MLD6_LISTENER_QUERY: 221 if (ifp->if_flags & IFF_LOOPBACK) 222 break; 223 224 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) && 225 !IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 226 break; /* print error or log stat? */ 227 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 228 mldh->mld6_addr.s6_addr16[1] = 229 htons(ifp->if_index); /* XXX */ 230 231 /* 232 * - Start the timers in all of our membership records 233 * that the query applies to for the interface on 234 * which the query arrived excl. those that belong 235 * to the "all-nodes" group (ff02::1). 236 * - Restart any timer that is already running but has 237 * A value longer than the requested timeout. 238 * - Use the value specified in the query message as 239 * the maximum timeout. 240 */ 241 IFP_TO_IA6(ifp, ia); 242 if (ia == NULL) 243 break; 244 245 /* 246 * XXX: System timer resolution is too low to handle Max 247 * Response Delay, so set 1 to the internal timer even if 248 * the calculated value equals to zero when Max Response 249 * Delay is positive. 250 */ 251 timer = ntohs(mldh->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE; 252 if (timer == 0 && mldh->mld6_maxdelay) 253 timer = 1; 254 mld6_all_nodes_linklocal.s6_addr16[1] = 255 htons(ifp->if_index); /* XXX */ 256 257 LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) 258 { 259 if (ifma->ifma_addr->sa_family != AF_INET6) 260 continue; 261 in6m = (struct in6_multi *)ifma->ifma_protospec; 262 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 263 &mld6_all_nodes_linklocal) || 264 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 265 IPV6_ADDR_SCOPE_LINKLOCAL) 266 continue; 267 268 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) || 269 IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr, 270 &in6m->in6m_addr)) 271 { 272 if (timer == 0) { 273 /* send a report immediately */ 274 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, 275 NULL); 276 in6m->in6m_timer = 0; /* reset timer */ 277 in6m->in6m_state = MLD6_IREPORTEDLAST; 278 } else if (in6m->in6m_timer == 0 || /*idle state*/ 279 in6m->in6m_timer > timer) { 280 in6m->in6m_timer = 281 MLD6_RANDOM_DELAY(timer); 282 mld6_timers_are_running = 1; 283 } 284 } 285 } 286 287 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 288 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 289 break; 290 case MLD6_LISTENER_REPORT: 291 /* 292 * For fast leave to work, we have to know that we are the 293 * last person to send a report for this group. Reports 294 * can potentially get looped back if we are a multicast 295 * router, so discard reports sourced by me. 296 * Note that it is impossible to check IFF_LOOPBACK flag of 297 * ifp for this purpose, since ip6_mloopback pass the physical 298 * interface to looutput. 299 */ 300 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 301 break; 302 303 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 304 break; 305 306 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 307 mldh->mld6_addr.s6_addr16[1] = 308 htons(ifp->if_index); /* XXX */ 309 /* 310 * If we belong to the group being reported, stop 311 * our timer for that group. 312 */ 313 IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m); 314 if (in6m) { 315 in6m->in6m_timer = 0; /* transit to idle state */ 316 in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */ 317 } 318 319 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 320 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 321 break; 322 default: /* this is impossible */ 323 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type); 324 break; 325 } 326 } 327 328 void 329 mld6_fasttimeo() 330 { 331 register struct in6_multi *in6m; 332 struct in6_multistep step; 333 int s; 334 335 /* 336 * Quick check to see if any work needs to be done, in order 337 * to minimize the overhead of fasttimo processing. 338 */ 339 if (!mld6_timers_are_running) 340 return; 341 342 s = splnet(); 343 mld6_timers_are_running = 0; 344 IN6_FIRST_MULTI(step, in6m); 345 while (in6m != NULL) { 346 if (in6m->in6m_timer == 0) { 347 /* do nothing */ 348 } else if (--in6m->in6m_timer == 0) { 349 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL); 350 in6m->in6m_state = MLD6_IREPORTEDLAST; 351 } else { 352 mld6_timers_are_running = 1; 353 } 354 IN6_NEXT_MULTI(step, in6m); 355 } 356 splx(s); 357 } 358 359 static void 360 mld6_sendpkt(in6m, type, dst) 361 struct in6_multi *in6m; 362 int type; 363 const struct in6_addr *dst; 364 { 365 struct mbuf *mh, *md; 366 struct mld6_hdr *mldh; 367 struct ip6_hdr *ip6; 368 struct ip6_moptions im6o; 369 struct in6_ifaddr *ia; 370 struct ifnet *ifp = in6m->in6m_ifp; 371 struct ifnet *outif = NULL; 372 373 /* 374 * At first, find a link local address on the outgoing interface 375 * to use as the source address of the MLD packet. 376 */ 377 if ((ia = in6ifa_ifpforlinklocal(ifp)) == NULL) 378 return; 379 380 /* 381 * Allocate mbufs to store ip6 header and MLD header. 382 * We allocate 2 mbufs and make chain in advance because 383 * it is more convenient when inserting the hop-by-hop option later. 384 */ 385 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 386 if (mh == NULL) 387 return; 388 MGET(md, M_DONTWAIT, MT_DATA); 389 if (md == NULL) { 390 m_free(mh); 391 return; 392 } 393 mh->m_next = md; 394 395 #ifdef IPSEC 396 mh->m_pkthdr.rcvif = NULL; 397 #endif 398 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_hdr); 399 mh->m_len = sizeof(struct ip6_hdr); 400 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 401 402 /* fill in the ip6 header */ 403 ip6 = mtod(mh, struct ip6_hdr *); 404 ip6->ip6_flow = 0; 405 ip6->ip6_vfc = IPV6_VERSION; 406 /* ip6_plen will be set later */ 407 ip6->ip6_nxt = IPPROTO_ICMPV6; 408 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 409 ip6->ip6_src = ia->ia_addr.sin6_addr; 410 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 411 412 /* fill in the MLD header */ 413 md->m_len = sizeof(struct mld6_hdr); 414 mldh = mtod(md, struct mld6_hdr *); 415 mldh->mld6_type = type; 416 mldh->mld6_code = 0; 417 mldh->mld6_cksum = 0; 418 /* XXX: we assume the function will not be called for query messages */ 419 mldh->mld6_maxdelay = 0; 420 mldh->mld6_reserved = 0; 421 mldh->mld6_addr = in6m->in6m_addr; 422 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 423 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 424 mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 425 sizeof(struct mld6_hdr)); 426 427 /* construct multicast option */ 428 bzero(&im6o, sizeof(im6o)); 429 im6o.im6o_multicast_ifp = ifp; 430 im6o.im6o_multicast_hlim = 1; 431 432 /* 433 * Request loopback of the report if we are acting as a multicast 434 * router, so that the process-level routing daemon can hear it. 435 */ 436 im6o.im6o_multicast_loop = 0; 437 438 /* increment output statictics */ 439 icmp6stat.icp6s_outhist[type]++; 440 441 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif); 442 if (outif) { 443 icmp6_ifstat_inc(outif, ifs6_out_msg); 444 switch(type) { 445 case MLD6_LISTENER_QUERY: 446 icmp6_ifstat_inc(outif, ifs6_out_mldquery); 447 break; 448 case MLD6_LISTENER_REPORT: 449 icmp6_ifstat_inc(outif, ifs6_out_mldreport); 450 break; 451 case MLD6_LISTENER_DONE: 452 icmp6_ifstat_inc(outif, ifs6_out_mlddone); 453 break; 454 } 455 } 456 } 457