mld6.c revision 1.20
1 /* $NetBSD: mld6.c,v 1.20 2002/06/09 14:43:13 itojun Exp $ */ 2 /* $KAME: mld6.c,v 1.25 2001/01/16 14:14:18 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/cdefs.h> 73 __KERNEL_RCSID(0, "$NetBSD: mld6.c,v 1.20 2002/06/09 14:43:13 itojun Exp $"); 74 75 #include "opt_inet.h" 76 77 #include <sys/param.h> 78 #include <sys/systm.h> 79 #include <sys/mbuf.h> 80 #include <sys/socket.h> 81 #include <sys/protosw.h> 82 #include <sys/syslog.h> 83 84 #include <net/if.h> 85 86 #include <netinet/in.h> 87 #include <netinet/in_var.h> 88 #include <netinet/ip6.h> 89 #include <netinet6/ip6_var.h> 90 #include <netinet/icmp6.h> 91 #include <netinet6/mld6_var.h> 92 93 #include <net/net_osdep.h> 94 95 /* 96 * Protocol constants 97 */ 98 99 /* denotes that the MLD max response delay field specifies time in milliseconds */ 100 #define MLD6_TIMER_SCALE 1000 101 /* 102 * time between repetitions of a node's initial report of interest in a 103 * multicast address(in seconds) 104 */ 105 #define MLD6_UNSOLICITED_REPORT_INTERVAL 10 106 107 static struct ip6_pktopts ip6_opts; 108 static int mld6_timers_are_running; 109 /* XXX: These are necessary for KAME's link-local hack */ 110 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 111 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 112 113 static void mld6_sendpkt __P((struct in6_multi *, int, const struct in6_addr *)); 114 115 void 116 mld6_init() 117 { 118 static u_int8_t hbh_buf[8]; 119 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 120 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 121 122 mld6_timers_are_running = 0; 123 124 /* ip6h_nxt will be fill in later */ 125 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */ 126 127 /* XXX: grotty hard coding... */ 128 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 129 hbh_buf[3] = 0; 130 hbh_buf[4] = IP6OPT_RTALERT; 131 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 132 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 133 134 ip6_opts.ip6po_hbh = hbh; 135 /* We will specify the hoplimit by a multicast option. */ 136 ip6_opts.ip6po_hlim = -1; 137 } 138 139 void 140 mld6_start_listening(in6m) 141 struct in6_multi *in6m; 142 { 143 int s = splsoftnet(); 144 145 /* 146 * RFC2710 page 10: 147 * The node never sends a Report or Done for the link-scope all-nodes 148 * address. 149 * MLD messages are never sent for multicast addresses whose scope is 0 150 * (reserved) or 1 (node-local). 151 */ 152 mld6_all_nodes_linklocal.s6_addr16[1] = 153 htons(in6m->in6m_ifp->if_index); /* XXX */ 154 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) || 155 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 156 in6m->in6m_timer = 0; 157 in6m->in6m_state = MLD6_OTHERLISTENER; 158 } else { 159 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL); 160 in6m->in6m_timer = 161 MLD6_RANDOM_DELAY(MLD6_UNSOLICITED_REPORT_INTERVAL * 162 PR_FASTHZ); 163 in6m->in6m_state = MLD6_IREPORTEDLAST; 164 mld6_timers_are_running = 1; 165 } 166 splx(s); 167 } 168 169 void 170 mld6_stop_listening(in6m) 171 struct in6_multi *in6m; 172 { 173 mld6_all_nodes_linklocal.s6_addr16[1] = 174 htons(in6m->in6m_ifp->if_index); /* XXX */ 175 mld6_all_routers_linklocal.s6_addr16[1] = 176 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 177 178 if (in6m->in6m_state == MLD6_IREPORTEDLAST && 179 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) && 180 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL) 181 mld6_sendpkt(in6m, MLD6_LISTENER_DONE, 182 &mld6_all_routers_linklocal); 183 } 184 185 void 186 mld6_input(m, off) 187 struct mbuf *m; 188 int off; 189 { 190 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 191 struct mld6_hdr *mldh; 192 struct ifnet *ifp = m->m_pkthdr.rcvif; 193 struct in6_multi *in6m; 194 struct in6_ifaddr *ia; 195 int timer; /* timer value in the MLD query header */ 196 197 #ifndef PULLDOWN_TEST 198 IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),); 199 mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off); 200 #else 201 IP6_EXTHDR_GET(mldh, struct mld6_hdr *, m, off, sizeof(*mldh)); 202 if (mldh == NULL) { 203 icmp6stat.icp6s_tooshort++; 204 return; 205 } 206 #endif 207 208 /* source address validation */ 209 ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */ 210 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 211 #if 0 212 log(LOG_ERR, 213 "mld6_input: src %s is not link-local (grp=%s)\n", 214 ip6_sprintf(&ip6->ip6_src), 215 ip6_sprintf(&mldh->mld6_addr)); 216 #endif 217 /* 218 * spec (RFC2710) does not explicitly 219 * specify to discard the packet from a non link-local 220 * source address. But we believe it's expected to do so. 221 * XXX: do we have to allow :: as source? 222 */ 223 m_freem(m); 224 return; 225 } 226 227 /* 228 * In the MLD6 specification, there are 3 states and a flag. 229 * 230 * In Non-Listener state, we simply don't have a membership record. 231 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 232 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 233 * 234 * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if 235 * we have heard a report from another member, or MLD6_IREPORTEDLAST 236 * if we sent the last report. 237 */ 238 switch (mldh->mld6_type) { 239 case MLD6_LISTENER_QUERY: 240 if (ifp->if_flags & IFF_LOOPBACK) 241 break; 242 243 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) && 244 !IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 245 break; /* print error or log stat? */ 246 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 247 mldh->mld6_addr.s6_addr16[1] = 248 htons(ifp->if_index); /* XXX */ 249 250 /* 251 * - Start the timers in all of our membership records 252 * that the query applies to for the interface on 253 * which the query arrived excl. those that belong 254 * to the "all-nodes" group (ff02::1). 255 * - Restart any timer that is already running but has 256 * A value longer than the requested timeout. 257 * - Use the value specified in the query message as 258 * the maximum timeout. 259 */ 260 IFP_TO_IA6(ifp, ia); 261 if (ia == NULL) 262 break; 263 264 /* 265 * XXX: System timer resolution is too low to handle Max 266 * Response Delay, so set 1 to the internal timer even if 267 * the calculated value equals to zero when Max Response 268 * Delay is positive. 269 */ 270 timer = ntohs(mldh->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE; 271 if (timer == 0 && mldh->mld6_maxdelay) 272 timer = 1; 273 mld6_all_nodes_linklocal.s6_addr16[1] = 274 htons(ifp->if_index); /* XXX */ 275 276 for (in6m = ia->ia6_multiaddrs.lh_first; 277 in6m; 278 in6m = in6m->in6m_entry.le_next) 279 { 280 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 281 &mld6_all_nodes_linklocal) || 282 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 283 IPV6_ADDR_SCOPE_LINKLOCAL) 284 continue; 285 286 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) || 287 IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr, 288 &in6m->in6m_addr)) 289 { 290 if (timer == 0) { 291 /* send a report immediately */ 292 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, 293 NULL); 294 in6m->in6m_timer = 0; /* reset timer */ 295 in6m->in6m_state = MLD6_IREPORTEDLAST; 296 } 297 else if (in6m->in6m_timer == 0 || /*idle state*/ 298 in6m->in6m_timer > timer) { 299 in6m->in6m_timer = 300 MLD6_RANDOM_DELAY(timer); 301 mld6_timers_are_running = 1; 302 } 303 } 304 } 305 306 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 307 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 308 break; 309 case MLD6_LISTENER_REPORT: 310 /* 311 * For fast leave to work, we have to know that we are the 312 * last person to send a report for this group. Reports 313 * can potentially get looped back if we are a multicast 314 * router, so discard reports sourced by me. 315 * Note that it is impossible to check IFF_LOOPBACK flag of 316 * ifp for this purpose, since ip6_mloopback pass the physical 317 * interface to looutput. 318 */ 319 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 320 break; 321 322 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 323 break; 324 325 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 326 mldh->mld6_addr.s6_addr16[1] = 327 htons(ifp->if_index); /* XXX */ 328 /* 329 * If we belong to the group being reported, stop 330 * our timer for that group. 331 */ 332 IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m); 333 if (in6m) { 334 in6m->in6m_timer = 0; /* transit to idle state */ 335 in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */ 336 } 337 338 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 339 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 340 break; 341 default: /* this is impossible */ 342 #if 0 343 /* 344 * this case should be impossible because of filtering in 345 * icmp6_input(). But we explicitly disabled this part 346 * just in case. 347 */ 348 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type); 349 #endif 350 break; 351 } 352 353 m_freem(m); 354 } 355 356 void 357 mld6_fasttimeo() 358 { 359 struct in6_multi *in6m; 360 struct in6_multistep step; 361 int s; 362 /* 363 * Quick check to see if any work needs to be done, in order 364 * to minimize the overhead of fasttimo processing. 365 */ 366 if (!mld6_timers_are_running) 367 return; 368 369 s = splsoftnet(); 370 mld6_timers_are_running = 0; 371 IN6_FIRST_MULTI(step, in6m); 372 while (in6m != NULL) { 373 if (in6m->in6m_timer == 0) { 374 /* do nothing */ 375 } else if (--in6m->in6m_timer == 0) { 376 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL); 377 in6m->in6m_state = MLD6_IREPORTEDLAST; 378 } else { 379 mld6_timers_are_running = 1; 380 } 381 IN6_NEXT_MULTI(step, in6m); 382 } 383 splx(s); 384 } 385 386 static void 387 mld6_sendpkt(in6m, type, dst) 388 struct in6_multi *in6m; 389 int type; 390 const struct in6_addr *dst; 391 { 392 struct mbuf *mh, *md; 393 struct mld6_hdr *mldh; 394 struct ip6_hdr *ip6; 395 struct ip6_moptions im6o; 396 struct in6_ifaddr *ia; 397 struct ifnet *ifp = in6m->in6m_ifp; 398 int ignflags; 399 400 /* 401 * At first, find a link local address on the outgoing interface 402 * to use as the source address of the MLD packet. 403 * We do not reject tentative addresses for MLD report to deal with 404 * the case where we first join a link-local address. 405 */ 406 ignflags = (IN6_IFF_NOTREADY|IN6_IFF_ANYCAST) & ~IN6_IFF_TENTATIVE; 407 if ((ia = in6ifa_ifpforlinklocal(ifp, ignflags)) == NULL) 408 return; 409 if ((ia->ia6_flags & IN6_IFF_TENTATIVE)) 410 ia = NULL; 411 412 /* 413 * Allocate mbufs to store ip6 header and MLD header. 414 * We allocate 2 mbufs and make chain in advance because 415 * it is more convenient when inserting the hop-by-hop option later. 416 */ 417 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 418 if (mh == NULL) 419 return; 420 MGET(md, M_DONTWAIT, MT_DATA); 421 if (md == NULL) { 422 m_free(mh); 423 return; 424 } 425 mh->m_next = md; 426 427 mh->m_pkthdr.rcvif = NULL; 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_MASK; 436 ip6->ip6_vfc |= IPV6_VERSION; 437 /* ip6_plen will be set later */ 438 ip6->ip6_nxt = IPPROTO_ICMPV6; 439 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 440 ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any; 441 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 442 443 /* fill in the MLD header */ 444 md->m_len = sizeof(struct mld6_hdr); 445 mldh = mtod(md, struct mld6_hdr *); 446 mldh->mld6_type = type; 447 mldh->mld6_code = 0; 448 mldh->mld6_cksum = 0; 449 /* XXX: we assume the function will not be called for query messages */ 450 mldh->mld6_maxdelay = 0; 451 mldh->mld6_reserved = 0; 452 mldh->mld6_addr = in6m->in6m_addr; 453 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 454 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 455 mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, 456 sizeof(struct ip6_hdr), 457 sizeof(struct mld6_hdr)); 458 459 /* construct multicast option */ 460 bzero(&im6o, sizeof(im6o)); 461 im6o.im6o_multicast_ifp = ifp; 462 im6o.im6o_multicast_hlim = 1; 463 464 /* 465 * Request loopback of the report if we are acting as a multicast 466 * router, so that the process-level routing daemon can hear it. 467 */ 468 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 469 470 /* increment output statictics */ 471 icmp6stat.icp6s_outhist[type]++; 472 icmp6_ifstat_inc(ifp, ifs6_out_msg); 473 switch (type) { 474 case MLD6_LISTENER_QUERY: 475 icmp6_ifstat_inc(ifp, ifs6_out_mldquery); 476 break; 477 case MLD6_LISTENER_REPORT: 478 icmp6_ifstat_inc(ifp, ifs6_out_mldreport); 479 break; 480 case MLD6_LISTENER_DONE: 481 icmp6_ifstat_inc(ifp, ifs6_out_mlddone); 482 break; 483 } 484 485 ip6_output(mh, &ip6_opts, NULL, ia ? 0 : IPV6_UNSPECSRC, &im6o, NULL); 486 } 487
Indexes created Tue Sep 23 07:09:52 GMT 2025