mld6.c revision 1.3
1 /* $NetBSD: mld6.c,v 1.3 1999/07/03 21:30:19 thorpej 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 #endif 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 <netinet6/in6.h> 87 #include <netinet6/ip6.h> 88 #include <netinet6/ip6_var.h> 89 #include <netinet6/icmp6.h> 90 #include <netinet6/mld6_var.h> 91 92 /* 93 * Protocol constants 94 */ 95 96 /* denotes that the MLD max response delay field specifies time in milliseconds */ 97 #define MLD6_TIMER_SCALE 1000 98 /* 99 * time between repetitions of a node's initial report of interest in a 100 * multicast address(in seconds) 101 */ 102 #define MLD6_UNSOLICITED_REPORT_INTERVAL 10 103 104 static struct ip6_pktopts ip6_opts; 105 static int mld6_timers_are_running; 106 /* XXX: These are necessary for KAME's link-local hack */ 107 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 108 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 109 110 static void mld6_sendpkt __P((struct in6_multi *, int, const struct in6_addr *)); 111 112 void 113 mld6_init() 114 { 115 static u_int8_t hbh_buf[8]; 116 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf; 117 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD); 118 119 mld6_timers_are_running = 0; 120 121 /* ip6h_nxt will be fill in later */ 122 hbh->ip6h_len = 0; /* (8 >> 3) - 1*/ 123 124 /* XXX: grotty hard coding... */ 125 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */ 126 hbh_buf[3] = 0; 127 hbh_buf[4] = IP6OPT_RTALERT; 128 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 129 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 130 131 ip6_opts.ip6po_hbh = hbh; 132 /* We will specify the hoplimit by a multicast option. */ 133 ip6_opts.ip6po_hlim = -1; 134 } 135 136 void 137 mld6_start_listening(in6m) 138 struct in6_multi *in6m; 139 { 140 int s = splnet(); 141 142 /* 143 * (draft-ietf-ipngwg-mld, 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, MLD6_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(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_NODELOCAL) 177 mld6_sendpkt(in6m, MLD6_LISTENER_DONE, 178 &mld6_all_routers_linklocal); 179 } 180 181 void 182 mld6_input(m, off) 183 struct mbuf *m; 184 int off; 185 { 186 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 187 struct mld6_hdr *mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off); 188 struct ifnet *ifp = m->m_pkthdr.rcvif; 189 struct in6_multi *in6m; 190 struct in6_ifaddr *ia; 191 int timer; /* timer value in the MLD query header */ 192 193 /* source address validation */ 194 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 195 log(LOG_ERR, 196 "mld6_input: src %s is not link-local\n", 197 ip6_sprintf(&ip6->ip6_src)); 198 /* 199 * spec(draft-ietf-ipngwg-mld) does not explicitly 200 * specify to discard the packet from a non link-local 201 * source address. But we believe it's expected to do so. 202 */ 203 return; 204 } 205 206 /* 207 * In the MLD6 specification, there are 3 states and a flag. 208 * 209 * In Non-Listener state, we simply don't have a membership record. 210 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 211 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 212 * 213 * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if 214 * we have heard a report from another member, or MLD6_IREPORTEDLAST 215 * if we sent the last report. 216 */ 217 switch(mldh->mld6_type) { 218 case MLD6_LISTENER_QUERY: 219 if (ifp->if_flags & IFF_LOOPBACK) 220 break; 221 222 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) && 223 !IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 224 break; /* print error or log stat? */ 225 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 226 mldh->mld6_addr.s6_addr16[1] = 227 htons(ifp->if_index); /* XXX */ 228 229 /* 230 * - Start the timers in all of our membership records 231 * that the query applies to for the interface on 232 * which the query arrived excl. those that belong 233 * to the "all-nodes" group (ff02::1). 234 * - Restart any timer that is already running but has 235 * A value longer than the requested timeout. 236 * - Use the value specified in the query message as 237 * the maximum timeout. 238 */ 239 IFP_TO_IA6(ifp, ia); 240 if (ia == NULL) 241 break; 242 243 /* 244 * XXX: System timer resolution is too low to handle Max 245 * Response Delay, so set 1 to the internal timer even if 246 * the calculated value equals to zero when Max Response 247 * Delay is positive. 248 */ 249 timer = ntohs(mldh->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE; 250 if (timer == 0 && mldh->mld6_maxdelay) 251 timer = 1; 252 mld6_all_nodes_linklocal.s6_addr16[1] = 253 htons(ifp->if_index); /* XXX */ 254 255 for (in6m = ia->ia6_multiaddrs.lh_first; 256 in6m; 257 in6m = in6m->in6m_entry.le_next) { 258 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 259 &mld6_all_nodes_linklocal) || 260 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 261 IPV6_ADDR_SCOPE_LINKLOCAL) 262 continue; 263 264 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) || 265 IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr, 266 &in6m->in6m_addr)) { 267 if (timer == 0) { 268 /* send a report immediately */ 269 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, 270 NULL); 271 in6m->in6m_timer = 0; /* reset timer */ 272 in6m->in6m_state = MLD6_IREPORTEDLAST; 273 } 274 else if (in6m->in6m_timer == 0 || /*idle state*/ 275 in6m->in6m_timer > timer) { 276 in6m->in6m_timer = 277 MLD6_RANDOM_DELAY(timer); 278 mld6_timers_are_running = 1; 279 } 280 } 281 } 282 283 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 284 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 285 break; 286 case MLD6_LISTENER_REPORT: 287 /* 288 * For fast leave to work, we have to know that we are the 289 * last person to send a report for this group. Reports 290 * can potentially get looped back if we are a multicast 291 * router, so discard reports sourced by me. 292 * Note that it is impossible to check IFF_LOOPBACK flag of 293 * ifp for this purpose, since ip6_mloopback pass the physical 294 * interface to looutput. 295 */ 296 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 297 break; 298 299 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 300 break; 301 302 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 303 mldh->mld6_addr.s6_addr16[1] = 304 htons(ifp->if_index); /* XXX */ 305 /* 306 * If we belong to the group being reported, stop 307 * our timer for that group. 308 */ 309 IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m); 310 if (in6m) { 311 in6m->in6m_timer = 0; /* transit to idle state */ 312 in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */ 313 } 314 315 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 316 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 317 break; 318 default: /* this is impossible */ 319 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type); 320 break; 321 } 322 } 323 324 void 325 mld6_fasttimeo() 326 { 327 register struct in6_multi *in6m; 328 struct in6_multistep step; 329 int s; 330 331 /* 332 * Quick check to see if any work needs to be done, in order 333 * to minimize the overhead of fasttimo processing. 334 */ 335 if (!mld6_timers_are_running) 336 return; 337 338 s = splnet(); 339 mld6_timers_are_running = 0; 340 IN6_FIRST_MULTI(step, in6m); 341 while (in6m != NULL) { 342 if (in6m->in6m_timer == 0) { 343 /* do nothing */ 344 } else if (--in6m->in6m_timer == 0) { 345 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL); 346 in6m->in6m_state = MLD6_IREPORTEDLAST; 347 } else { 348 mld6_timers_are_running = 1; 349 } 350 IN6_NEXT_MULTI(step, in6m); 351 } 352 splx(s); 353 } 354 355 static void 356 mld6_sendpkt(in6m, type, dst) 357 struct in6_multi *in6m; 358 int type; 359 const struct in6_addr *dst; 360 { 361 struct mbuf *mh, *md; 362 struct mld6_hdr *mldh; 363 struct ip6_hdr *ip6; 364 struct ip6_moptions im6o; 365 struct in6_ifaddr *ia; 366 struct ifnet *ifp = in6m->in6m_ifp; 367 368 /* 369 * At first, find a link local address on the outgoing interface 370 * to use as the source address of the MLD packet. 371 */ 372 if ((ia = in6ifa_ifpforlinklocal(ifp)) == NULL) 373 return; 374 375 /* 376 * Allocate mbufs to store ip6 header and MLD header. 377 * We allocate 2 mbufs and make chain in advance because 378 * it is more convenient when inserting the hop-by-hop option later. 379 */ 380 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 381 if (mh == NULL) 382 return; 383 MGET(md, M_DONTWAIT, MT_DATA); 384 if (md == NULL) { 385 m_free(mh); 386 return; 387 } 388 mh->m_next = md; 389 390 #ifdef IPSEC 391 mh->m_pkthdr.rcvif = NULL; 392 #endif 393 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_hdr); 394 mh->m_len = sizeof(struct ip6_hdr); 395 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 396 397 /* fill in the ip6 header */ 398 ip6 = mtod(mh, struct ip6_hdr *); 399 ip6->ip6_flow = 0; 400 ip6->ip6_vfc = IPV6_VERSION; 401 /* ip6_plen will be set later */ 402 ip6->ip6_nxt = IPPROTO_ICMPV6; 403 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 404 ip6->ip6_src = ia->ia_addr.sin6_addr; 405 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 406 407 /* fill in the MLD header */ 408 md->m_len = sizeof(struct mld6_hdr); 409 mldh = mtod(md, struct mld6_hdr *); 410 mldh->mld6_type = type; 411 mldh->mld6_code = 0; 412 mldh->mld6_cksum = 0; 413 /* XXX: we assume the function will not be called for query messages */ 414 mldh->mld6_maxdelay = 0; 415 mldh->mld6_reserved = 0; 416 mldh->mld6_addr = in6m->in6m_addr; 417 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 418 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 419 mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 420 sizeof(struct mld6_hdr)); 421 422 /* construct multicast option */ 423 bzero(&im6o, sizeof(im6o)); 424 im6o.im6o_multicast_ifp = ifp; 425 im6o.im6o_multicast_hlim = 1; 426 427 /* 428 * Request loopback of the report if we are acting as a multicast 429 * router, so that the process-level routing daemon can hear it. 430 */ 431 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 432 433 /* increment output statictics */ 434 icmp6stat.icp6s_outhist[type]++; 435 436 ip6_output(mh, &ip6_opts, NULL, 0, &im6o); 437 } 438
Indexes created Sun Sep 21 20:09:37 GMT 2025