mld6.c revision 121472
1/* $FreeBSD: head/sys/netinet6/mld6.c 121472 2003-10-24 18:26:30Z ume $ */ 2/* $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 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 "opt_inet.h" 73#include "opt_inet6.h" 74 75#include <sys/param.h> 76#include <sys/systm.h> 77#include <sys/mbuf.h> 78#include <sys/socket.h> 79#include <sys/protosw.h> 80#include <sys/syslog.h> 81 82#include <net/if.h> 83 84#include <netinet/in.h> 85#include <netinet/in_var.h> 86#include <netinet/ip6.h> 87#include <netinet6/ip6_var.h> 88#include <netinet/icmp6.h> 89#include <netinet6/mld6_var.h> 90 91#include <net/net_osdep.h> 92 93/* 94 * Protocol constants 95 */ 96 97/* denotes that the MLD max response delay field specifies time in milliseconds */ 98#define MLD6_TIMER_SCALE 1000 99/* 100 * time between repetitions of a node's initial report of interest in a 101 * multicast address(in seconds) 102 */ 103#define MLD6_UNSOLICITED_REPORT_INTERVAL 10 104 105static struct ip6_pktopts ip6_opts; 106static int mld6_timers_are_running; 107/* XXX: These are necessary for KAME's link-local hack */ 108static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 109static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 110 111static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *); 112 113void 114mld6_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_ROUTER_ALERT; 129 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 130 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 131 132 init_ip6pktopts(&ip6_opts); 133 ip6_opts.ip6po_hbh = hbh; 134} 135 136void 137mld6_start_listening(in6m) 138 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 165void 166mld6_stop_listening(in6m) 167 struct in6_multi *in6m; 168{ 169 mld6_all_nodes_linklocal.s6_addr16[1] = 170 htons(in6m->in6m_ifp->if_index); /* XXX */ 171 mld6_all_routers_linklocal.s6_addr16[1] = 172 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 173 174 if (in6m->in6m_state == MLD6_IREPORTEDLAST && 175 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) && 176 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_INTFACELOCAL) 177 mld6_sendpkt(in6m, MLD_LISTENER_DONE, 178 &mld6_all_routers_linklocal); 179} 180 181void 182mld6_input(m, off) 183 struct mbuf *m; 184 int off; 185{ 186 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 187 struct mld_hdr *mldh; 188 struct ifnet *ifp = m->m_pkthdr.rcvif; 189 struct in6_multi *in6m; 190 struct in6_ifaddr *ia; 191 struct ifmultiaddr *ifma; 192 int timer; /* timer value in the MLD query header */ 193 194#ifndef PULLDOWN_TEST 195 IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),); 196 mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off); 197#else 198 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh)); 199 if (mldh == NULL) { 200 icmp6stat.icp6s_tooshort++; 201 return; 202 } 203#endif 204 205 /* source address validation */ 206 ip6 = mtod(m, struct ip6_hdr *); /* in case mpullup */ 207 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 208 log(LOG_ERR, 209 "mld6_input: src %s is not link-local (grp=%s)\n", 210 ip6_sprintf(&ip6->ip6_src), 211 ip6_sprintf(&mldh->mld_addr)); 212 /* 213 * spec (RFC2710) does not explicitly 214 * specify to discard the packet from a non link-local 215 * source address. But we believe it's expected to do so. 216 * XXX: do we have to allow :: as source? 217 */ 218 m_freem(m); 219 return; 220 } 221 222 /* 223 * In the MLD6 specification, there are 3 states and a flag. 224 * 225 * In Non-Listener state, we simply don't have a membership record. 226 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 227 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 228 * 229 * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if 230 * we have heard a report from another member, or MLD6_IREPORTEDLAST 231 * if we sent the last report. 232 */ 233 switch(mldh->mld_type) { 234 case MLD_LISTENER_QUERY: 235 if (ifp->if_flags & IFF_LOOPBACK) 236 break; 237 238 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) && 239 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr)) 240 break; /* print error or log stat? */ 241 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 242 mldh->mld_addr.s6_addr16[1] = 243 htons(ifp->if_index); /* XXX */ 244 245 /* 246 * - Start the timers in all of our membership records 247 * that the query applies to for the interface on 248 * which the query arrived excl. those that belong 249 * to the "all-nodes" group (ff02::1). 250 * - Restart any timer that is already running but has 251 * A value longer than the requested timeout. 252 * - Use the value specified in the query message as 253 * the maximum timeout. 254 */ 255 IFP_TO_IA6(ifp, ia); 256 if (ia == NULL) 257 break; 258 259 /* 260 * XXX: System timer resolution is too low to handle Max 261 * Response Delay, so set 1 to the internal timer even if 262 * the calculated value equals to zero when Max Response 263 * Delay is positive. 264 */ 265 timer = ntohs(mldh->mld_maxdelay) * PR_FASTHZ / MLD6_TIMER_SCALE; 266 if (timer == 0 && mldh->mld_maxdelay) 267 timer = 1; 268 mld6_all_nodes_linklocal.s6_addr16[1] = 269 htons(ifp->if_index); /* XXX */ 270 271 TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) { 272 if (ifma->ifma_addr->sa_family != AF_INET6) 273 continue; 274 in6m = (struct in6_multi *)ifma->ifma_protospec; 275 276 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 277 &mld6_all_nodes_linklocal) || 278 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 279 IPV6_ADDR_SCOPE_LINKLOCAL) 280 continue; 281 282 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) || 283 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr, 284 &in6m->in6m_addr)) 285 { 286 if (timer == 0) { 287 /* send a report immediately */ 288 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, 289 NULL); 290 in6m->in6m_timer = 0; /* reset timer */ 291 in6m->in6m_state = MLD6_IREPORTEDLAST; 292 } 293 else if (in6m->in6m_timer == 0 || /*idle state*/ 294 in6m->in6m_timer > timer) { 295 in6m->in6m_timer = 296 MLD6_RANDOM_DELAY(timer); 297 mld6_timers_are_running = 1; 298 } 299 } 300 } 301 302 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 303 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 304 break; 305 306 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 346void 347mld6_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(); 361 362 mld6_timers_are_running = 0; 363 IN6_FIRST_MULTI(step, in6m); 364 while (in6m != NULL) { 365 if (in6m->in6m_timer == 0) { 366 /* do nothing */ 367 } else if (--in6m->in6m_timer == 0) { 368 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL); 369 in6m->in6m_state = MLD6_IREPORTEDLAST; 370 } else { 371 mld6_timers_are_running = 1; 372 } 373 IN6_NEXT_MULTI(step, in6m); 374 } 375 376 splx(s); 377} 378 379static void 380mld6_sendpkt(in6m, type, dst) 381 struct in6_multi *in6m; 382 int type; 383 const struct in6_addr *dst; 384{ 385 struct mbuf *mh, *md; 386 struct mld_hdr *mldh; 387 struct ip6_hdr *ip6; 388 struct ip6_moptions im6o; 389 struct in6_ifaddr *ia; 390 struct ifnet *ifp = in6m->in6m_ifp; 391 struct ifnet *outif = NULL; 392 393 /* 394 * At first, find a link local address on the outgoing interface 395 * to use as the source address of the MLD packet. 396 */ 397 if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST)) 398 == NULL) 399 return; 400 401 /* 402 * Allocate mbufs to store ip6 header and MLD header. 403 * We allocate 2 mbufs and make chain in advance because 404 * it is more convenient when inserting the hop-by-hop option later. 405 */ 406 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 407 if (mh == NULL) 408 return; 409 MGET(md, M_DONTWAIT, MT_DATA); 410 if (md == NULL) { 411 m_free(mh); 412 return; 413 } 414 mh->m_next = md; 415 416 mh->m_pkthdr.rcvif = NULL; 417 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr); 418 mh->m_len = sizeof(struct ip6_hdr); 419 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 420 421 /* fill in the ip6 header */ 422 ip6 = mtod(mh, struct ip6_hdr *); 423 ip6->ip6_flow = 0; 424 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 425 ip6->ip6_vfc |= IPV6_VERSION; 426 /* ip6_plen will be set later */ 427 ip6->ip6_nxt = IPPROTO_ICMPV6; 428 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 429 ip6->ip6_src = ia->ia_addr.sin6_addr; 430 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 431 432 /* fill in the MLD header */ 433 md->m_len = sizeof(struct mld_hdr); 434 mldh = mtod(md, struct mld_hdr *); 435 mldh->mld_type = type; 436 mldh->mld_code = 0; 437 mldh->mld_cksum = 0; 438 /* XXX: we assume the function will not be called for query messages */ 439 mldh->mld_maxdelay = 0; 440 mldh->mld_reserved = 0; 441 mldh->mld_addr = in6m->in6m_addr; 442 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr)) 443 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */ 444 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 445 sizeof(struct mld_hdr)); 446 447 /* construct multicast option */ 448 bzero(&im6o, sizeof(im6o)); 449 im6o.im6o_multicast_ifp = ifp; 450 im6o.im6o_multicast_hlim = 1; 451 452 /* 453 * Request loopback of the report if we are acting as a multicast 454 * router, so that the process-level routing daemon can hear it. 455 */ 456 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 457 458 /* increment output statictics */ 459 icmp6stat.icp6s_outhist[type]++; 460 461 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL); 462 if (outif) { 463 icmp6_ifstat_inc(outif, ifs6_out_msg); 464 switch (type) { 465 case MLD_LISTENER_QUERY: 466 icmp6_ifstat_inc(outif, ifs6_out_mldquery); 467 break; 468 case MLD_LISTENER_REPORT: 469 icmp6_ifstat_inc(outif, ifs6_out_mldreport); 470 break; 471 case MLD_LISTENER_DONE: 472 icmp6_ifstat_inc(outif, ifs6_out_mlddone); 473 break; 474 } 475 } 476} 477