mld6.c revision 1.6
1 /* $NetBSD: mld6.c,v 1.6 1999/07/31 18:41:17 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/in6.h> 90 #include <netinet6/ip6.h> 91 #include <netinet6/ip6_var.h> 92 #include <netinet6/icmp6.h> 93 #include <netinet6/mld6_var.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 * (draft-ietf-ipngwg-mld, 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 = MLD6_RANDOM_DELAY( 161 MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ); 162 in6m->in6m_state = MLD6_IREPORTEDLAST; 163 mld6_timers_are_running = 1; 164 } 165 splx(s); 166 } 167 168 void 169 mld6_stop_listening(in6m) 170 struct in6_multi *in6m; 171 { 172 mld6_all_nodes_linklocal.s6_addr16[1] = 173 htons(in6m->in6m_ifp->if_index); /* XXX */ 174 mld6_all_routers_linklocal.s6_addr16[1] = 175 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 176 177 if (in6m->in6m_state == MLD6_IREPORTEDLAST && 178 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) && 179 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL) 180 mld6_sendpkt(in6m, MLD6_LISTENER_DONE, 181 &mld6_all_routers_linklocal); 182 } 183 184 void 185 mld6_input(m, off) 186 struct mbuf *m; 187 int off; 188 { 189 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 190 struct mld6_hdr *mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off); 191 struct ifnet *ifp = m->m_pkthdr.rcvif; 192 struct in6_multi *in6m; 193 struct in6_ifaddr *ia; 194 int timer; /* timer value in the MLD query header */ 195 196 /* source address validation */ 197 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 198 log(LOG_ERR, 199 "mld6_input: src %s is not link-local\n", 200 ip6_sprintf(&ip6->ip6_src)); 201 /* 202 * spec(draft-ietf-ipngwg-mld) does not explicitly 203 * specify to discard the packet from a non link-local 204 * source address. But we believe it's expected to do so. 205 */ 206 return; 207 } 208 209 /* 210 * In the MLD6 specification, there are 3 states and a flag. 211 * 212 * In Non-Listener state, we simply don't have a membership record. 213 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 214 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 215 * 216 * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if 217 * we have heard a report from another member, or MLD6_IREPORTEDLAST 218 * if we sent the last report. 219 */ 220 switch(mldh->mld6_type) { 221 case MLD6_LISTENER_QUERY: 222 if (ifp->if_flags & IFF_LOOPBACK) 223 break; 224 225 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) && 226 !IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 227 break; /* print error or log stat? */ 228 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 229 mldh->mld6_addr.s6_addr16[1] = 230 htons(ifp->if_index); /* XXX */ 231 232 /* 233 * - Start the timers in all of our membership records 234 * that the query applies to for the interface on 235 * which the query arrived excl. those that belong 236 * to the "all-nodes" group (ff02::1). 237 * - Restart any timer that is already running but has 238 * A value longer than the requested timeout. 239 * - Use the value specified in the query message as 240 * the maximum timeout. 241 */ 242 IFP_TO_IA6(ifp, ia); 243 if (ia == NULL) 244 break; 245 246 /* 247 * XXX: System timer resolution is too low to handle Max 248 * Response Delay, so set 1 to the internal timer even if 249 * the calculated value equals to zero when Max Response 250 * Delay is positive. 251 */ 252 timer = ntohs(mldh->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE; 253 if (timer == 0 && mldh->mld6_maxdelay) 254 timer = 1; 255 mld6_all_nodes_linklocal.s6_addr16[1] = 256 htons(ifp->if_index); /* XXX */ 257 258 for (in6m = ia->ia6_multiaddrs.lh_first; 259 in6m; 260 in6m = in6m->in6m_entry.le_next) { 261 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 262 &mld6_all_nodes_linklocal) || 263 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 264 IPV6_ADDR_SCOPE_LINKLOCAL) 265 continue; 266 267 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) || 268 IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr, 269 &in6m->in6m_addr)) { 270 if (timer == 0) { 271 /* send a report immediately */ 272 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, 273 NULL); 274 in6m->in6m_timer = 0; /* reset timer */ 275 in6m->in6m_state = MLD6_IREPORTEDLAST; 276 } 277 else if (in6m->in6m_timer == 0 || /*idle state*/ 278 in6m->in6m_timer > timer) { 279 in6m->in6m_timer = 280 MLD6_RANDOM_DELAY(timer); 281 mld6_timers_are_running = 1; 282 } 283 } 284 } 285 286 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 287 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 288 break; 289 case MLD6_LISTENER_REPORT: 290 /* 291 * For fast leave to work, we have to know that we are the 292 * last person to send a report for this group. Reports 293 * can potentially get looped back if we are a multicast 294 * router, so discard reports sourced by me. 295 * Note that it is impossible to check IFF_LOOPBACK flag of 296 * ifp for this purpose, since ip6_mloopback pass the physical 297 * interface to looutput. 298 */ 299 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 300 break; 301 302 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 303 break; 304 305 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 306 mldh->mld6_addr.s6_addr16[1] = 307 htons(ifp->if_index); /* XXX */ 308 /* 309 * If we belong to the group being reported, stop 310 * our timer for that group. 311 */ 312 IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m); 313 if (in6m) { 314 in6m->in6m_timer = 0; /* transit to idle state */ 315 in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */ 316 } 317 318 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 319 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 320 break; 321 default: /* this is impossible */ 322 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type); 323 break; 324 } 325 } 326 327 void 328 mld6_fasttimeo() 329 { 330 register struct in6_multi *in6m; 331 struct in6_multistep step; 332 int s; 333 334 /* 335 * Quick check to see if any work needs to be done, in order 336 * to minimize the overhead of fasttimo processing. 337 */ 338 if (!mld6_timers_are_running) 339 return; 340 341 s = splsoftnet(); 342 mld6_timers_are_running = 0; 343 IN6_FIRST_MULTI(step, in6m); 344 while (in6m != NULL) { 345 if (in6m->in6m_timer == 0) { 346 /* do nothing */ 347 } else if (--in6m->in6m_timer == 0) { 348 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL); 349 in6m->in6m_state = MLD6_IREPORTEDLAST; 350 } else { 351 mld6_timers_are_running = 1; 352 } 353 IN6_NEXT_MULTI(step, in6m); 354 } 355 splx(s); 356 } 357 358 static void 359 mld6_sendpkt(in6m, type, dst) 360 struct in6_multi *in6m; 361 int type; 362 const struct in6_addr *dst; 363 { 364 struct mbuf *mh, *md; 365 struct mld6_hdr *mldh; 366 struct ip6_hdr *ip6; 367 struct ip6_moptions im6o; 368 struct in6_ifaddr *ia; 369 struct ifnet *ifp = in6m->in6m_ifp; 370 371 /* 372 * At first, find a link local address on the outgoing interface 373 * to use as the source address of the MLD packet. 374 */ 375 if ((ia = in6ifa_ifpforlinklocal(ifp)) == NULL) 376 return; 377 378 /* 379 * Allocate mbufs to store ip6 header and MLD header. 380 * We allocate 2 mbufs and make chain in advance because 381 * it is more convenient when inserting the hop-by-hop option later. 382 */ 383 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 384 if (mh == NULL) 385 return; 386 MGET(md, M_DONTWAIT, MT_DATA); 387 if (md == NULL) { 388 m_free(mh); 389 return; 390 } 391 mh->m_next = md; 392 393 #ifdef IPSEC 394 mh->m_pkthdr.rcvif = NULL; 395 #endif 396 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_hdr); 397 mh->m_len = sizeof(struct ip6_hdr); 398 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 399 400 /* fill in the ip6 header */ 401 ip6 = mtod(mh, struct ip6_hdr *); 402 ip6->ip6_flow = 0; 403 ip6->ip6_vfc = IPV6_VERSION; 404 /* ip6_plen will be set later */ 405 ip6->ip6_nxt = IPPROTO_ICMPV6; 406 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 407 ip6->ip6_src = ia->ia_addr.sin6_addr; 408 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 409 410 /* fill in the MLD header */ 411 md->m_len = sizeof(struct mld6_hdr); 412 mldh = mtod(md, struct mld6_hdr *); 413 mldh->mld6_type = type; 414 mldh->mld6_code = 0; 415 mldh->mld6_cksum = 0; 416 /* XXX: we assume the function will not be called for query messages */ 417 mldh->mld6_maxdelay = 0; 418 mldh->mld6_reserved = 0; 419 mldh->mld6_addr = in6m->in6m_addr; 420 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 421 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 422 mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 423 sizeof(struct mld6_hdr)); 424 425 /* construct multicast option */ 426 bzero(&im6o, sizeof(im6o)); 427 im6o.im6o_multicast_ifp = ifp; 428 im6o.im6o_multicast_hlim = 1; 429 430 /* 431 * Request loopback of the report if we are acting as a multicast 432 * router, so that the process-level routing daemon can hear it. 433 */ 434 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 435 436 /* increment output statictics */ 437 icmp6stat.icp6s_outhist[type]++; 438 439 ip6_output(mh, &ip6_opts, NULL, 0, &im6o); 440 } 441
Indexes created Wed Oct 15 03:09:54 GMT 2025