mld6.c revision 1.7
1 /* $NetBSD: mld6.c,v 1.7 1999/12/13 15:17:23 itojun Exp $ */ 2 3 /* 4 * Copyright (C) 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 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 #if (defined(__FreeBSD__) && __FreeBSD__ >= 3) || defined(__NetBSD__) 72 #include "opt_inet.h" 73 #ifdef __NetBSD__ /*XXX*/ 74 #include "opt_ipsec.h" 75 #endif 76 #endif 77 78 #include <sys/param.h> 79 #include <sys/systm.h> 80 #include <sys/mbuf.h> 81 #include <sys/socket.h> 82 #include <sys/protosw.h> 83 #include <sys/syslog.h> 84 85 #include <net/if.h> 86 87 #include <netinet/in.h> 88 #include <netinet/in_var.h> 89 #include <netinet6/ip6.h> 90 #include <netinet6/ip6_var.h> 91 #include <netinet6/icmp6.h> 92 #include <netinet6/mld6_var.h> 93 94 #include <net/net_osdep.h> 95 96 /* 97 * Protocol constants 98 */ 99 100 /* denotes that the MLD max response delay field specifies time in milliseconds */ 101 #define MLD6_TIMER_SCALE 1000 102 /* 103 * time between repetitions of a node's initial report of interest in a 104 * multicast address(in seconds) 105 */ 106 #define MLD6_UNSOLICITED_REPORT_INTERVAL 10 107 108 static struct ip6_pktopts ip6_opts; 109 static int mld6_timers_are_running; 110 /* XXX: These are necessary for KAME's link-local hack */ 111 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 112 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 113 114 static void mld6_sendpkt __P((struct in6_multi *, int, const struct in6_addr *)); 115 116 void 117 mld6_init() 118 { 119 static u_int8_t hbh_buf[8]; 120 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 121 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 122 123 mld6_timers_are_running = 0; 124 125 /* ip6h_nxt will be fill in later */ 126 hbh->ip6h_len = 0; /* (8 >> 3) - 1*/ 127 128 /* XXX: grotty hard coding... */ 129 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 130 hbh_buf[3] = 0; 131 hbh_buf[4] = IP6OPT_RTALERT; 132 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 133 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 134 135 ip6_opts.ip6po_hbh = hbh; 136 /* We will specify the hoplimit by a multicast option. */ 137 ip6_opts.ip6po_hlim = -1; 138 } 139 140 void 141 mld6_start_listening(in6m) 142 struct in6_multi *in6m; 143 { 144 #ifdef __NetBSD__ 145 int s = splsoftnet(); 146 #else 147 int s = splnet(); 148 #endif 149 150 /* 151 * (draft-ietf-ipngwg-mld, page 10) 152 * The node never sends a Report or Done for the link-scope all-nodes 153 * address. 154 * MLD messages are never sent for multicast addresses whose scope is 0 155 * (reserved) or 1 (node-local). 156 */ 157 mld6_all_nodes_linklocal.s6_addr16[1] = 158 htons(in6m->in6m_ifp->if_index); /* XXX */ 159 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) || 160 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 161 in6m->in6m_timer = 0; 162 in6m->in6m_state = MLD6_OTHERLISTENER; 163 } else { 164 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL); 165 in6m->in6m_timer = MLD6_RANDOM_DELAY( 166 MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ); 167 in6m->in6m_state = MLD6_IREPORTEDLAST; 168 mld6_timers_are_running = 1; 169 } 170 splx(s); 171 } 172 173 void 174 mld6_stop_listening(in6m) 175 struct in6_multi *in6m; 176 { 177 mld6_all_nodes_linklocal.s6_addr16[1] = 178 htons(in6m->in6m_ifp->if_index); /* XXX */ 179 mld6_all_routers_linklocal.s6_addr16[1] = 180 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 181 182 if (in6m->in6m_state == MLD6_IREPORTEDLAST && 183 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) && 184 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL) 185 mld6_sendpkt(in6m, MLD6_LISTENER_DONE, 186 &mld6_all_routers_linklocal); 187 } 188 189 void 190 mld6_input(m, off) 191 struct mbuf *m; 192 int off; 193 { 194 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 195 struct mld6_hdr *mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off); 196 struct ifnet *ifp = m->m_pkthdr.rcvif; 197 struct in6_multi *in6m; 198 struct in6_ifaddr *ia; 199 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 200 struct ifmultiaddr *ifma; 201 #endif 202 int timer; /* timer value in the MLD query header */ 203 204 /* source address validation */ 205 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 206 log(LOG_ERR, 207 "mld6_input: src %s is not link-local\n", 208 ip6_sprintf(&ip6->ip6_src)); 209 /* 210 * spec(draft-ietf-ipngwg-mld) 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 */ 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 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 267 LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) 268 #else 269 for (in6m = ia->ia6_multiaddrs.lh_first; 270 in6m; 271 in6m = in6m->in6m_entry.le_next) 272 #endif 273 { 274 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 275 if (ifma->ifma_addr->sa_family != AF_INET6) 276 continue; 277 in6m = (struct in6_multi *)ifma->ifma_protospec; 278 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 279 &mld6_all_nodes_linklocal) || 280 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 281 IPV6_ADDR_SCOPE_LINKLOCAL) 282 continue; 283 #else 284 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 285 &mld6_all_nodes_linklocal) || 286 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 287 IPV6_ADDR_SCOPE_LINKLOCAL) 288 continue; 289 #endif 290 291 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) || 292 IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr, 293 &in6m->in6m_addr)) 294 { 295 if (timer == 0) { 296 /* send a report immediately */ 297 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, 298 NULL); 299 in6m->in6m_timer = 0; /* reset timer */ 300 in6m->in6m_state = MLD6_IREPORTEDLAST; 301 } 302 else if (in6m->in6m_timer == 0 || /*idle state*/ 303 in6m->in6m_timer > timer) { 304 in6m->in6m_timer = 305 MLD6_RANDOM_DELAY(timer); 306 mld6_timers_are_running = 1; 307 } 308 } 309 } 310 311 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 312 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 313 break; 314 case MLD6_LISTENER_REPORT: 315 /* 316 * For fast leave to work, we have to know that we are the 317 * last person to send a report for this group. Reports 318 * can potentially get looped back if we are a multicast 319 * router, so discard reports sourced by me. 320 * Note that it is impossible to check IFF_LOOPBACK flag of 321 * ifp for this purpose, since ip6_mloopback pass the physical 322 * interface to looutput. 323 */ 324 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 325 break; 326 327 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 328 break; 329 330 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 331 mldh->mld6_addr.s6_addr16[1] = 332 htons(ifp->if_index); /* XXX */ 333 /* 334 * If we belong to the group being reported, stop 335 * our timer for that group. 336 */ 337 IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m); 338 if (in6m) { 339 in6m->in6m_timer = 0; /* transit to idle state */ 340 in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */ 341 } 342 343 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 344 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 345 break; 346 default: /* this is impossible */ 347 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type); 348 break; 349 } 350 } 351 352 void 353 mld6_fasttimeo() 354 { 355 register struct in6_multi *in6m; 356 struct in6_multistep step; 357 int s; 358 359 /* 360 * Quick check to see if any work needs to be done, in order 361 * to minimize the overhead of fasttimo processing. 362 */ 363 if (!mld6_timers_are_running) 364 return; 365 366 #ifdef __NetBSD__ 367 s = splsoftnet(); 368 #else 369 s = splnet(); 370 #endif 371 mld6_timers_are_running = 0; 372 IN6_FIRST_MULTI(step, in6m); 373 while (in6m != NULL) { 374 if (in6m->in6m_timer == 0) { 375 /* do nothing */ 376 } else if (--in6m->in6m_timer == 0) { 377 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL); 378 in6m->in6m_state = MLD6_IREPORTEDLAST; 379 } else { 380 mld6_timers_are_running = 1; 381 } 382 IN6_NEXT_MULTI(step, in6m); 383 } 384 splx(s); 385 } 386 387 static void 388 mld6_sendpkt(in6m, type, dst) 389 struct in6_multi *in6m; 390 int type; 391 const struct in6_addr *dst; 392 { 393 struct mbuf *mh, *md; 394 struct mld6_hdr *mldh; 395 struct ip6_hdr *ip6; 396 struct ip6_moptions im6o; 397 struct in6_ifaddr *ia; 398 struct ifnet *ifp = in6m->in6m_ifp; 399 struct ifnet *outif = NULL; 400 401 /* 402 * At first, find a link local address on the outgoing interface 403 * to use as the source address of the MLD packet. 404 */ 405 if ((ia = in6ifa_ifpforlinklocal(ifp)) == NULL) 406 return; 407 408 /* 409 * Allocate mbufs to store ip6 header and MLD header. 410 * We allocate 2 mbufs and make chain in advance because 411 * it is more convenient when inserting the hop-by-hop option later. 412 */ 413 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 414 if (mh == NULL) 415 return; 416 MGET(md, M_DONTWAIT, MT_DATA); 417 if (md == NULL) { 418 m_free(mh); 419 return; 420 } 421 mh->m_next = md; 422 423 #ifdef IPSEC 424 #ifndef __OpenBSD__ /*KAME IPSEC*/ 425 mh->m_pkthdr.rcvif = NULL; 426 #endif 427 #endif 428 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_hdr); 429 mh->m_len = sizeof(struct ip6_hdr); 430 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 431 432 /* fill in the ip6 header */ 433 ip6 = mtod(mh, struct ip6_hdr *); 434 ip6->ip6_flow = 0; 435 ip6->ip6_vfc = IPV6_VERSION; 436 /* ip6_plen will be set later */ 437 ip6->ip6_nxt = IPPROTO_ICMPV6; 438 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 439 ip6->ip6_src = ia->ia_addr.sin6_addr; 440 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 441 442 /* fill in the MLD header */ 443 md->m_len = sizeof(struct mld6_hdr); 444 mldh = mtod(md, struct mld6_hdr *); 445 mldh->mld6_type = type; 446 mldh->mld6_code = 0; 447 mldh->mld6_cksum = 0; 448 /* XXX: we assume the function will not be called for query messages */ 449 mldh->mld6_maxdelay = 0; 450 mldh->mld6_reserved = 0; 451 mldh->mld6_addr = in6m->in6m_addr; 452 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 453 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 454 mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 455 sizeof(struct mld6_hdr)); 456 457 /* construct multicast option */ 458 bzero(&im6o, sizeof(im6o)); 459 im6o.im6o_multicast_ifp = ifp; 460 im6o.im6o_multicast_hlim = 1; 461 462 /* 463 * Request loopback of the report if we are acting as a multicast 464 * router, so that the process-level routing daemon can hear it. 465 */ 466 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 467 468 /* increment output statictics */ 469 icmp6stat.icp6s_outhist[type]++; 470 471 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif); 472 if (outif) { 473 icmp6_ifstat_inc(outif, ifs6_out_msg); 474 switch(type) { 475 case MLD6_LISTENER_QUERY: 476 icmp6_ifstat_inc(outif, ifs6_out_mldquery); 477 break; 478 case MLD6_LISTENER_REPORT: 479 icmp6_ifstat_inc(outif, ifs6_out_mldreport); 480 break; 481 case MLD6_LISTENER_DONE: 482 icmp6_ifstat_inc(outif, ifs6_out_mlddone); 483 break; 484 } 485 } 486 } 487
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