mld6.c revision 1.5
1 /* $NetBSD: mld6.c,v 1.5 1999/07/09 22:57:29 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 #include "opt_ipsec.h" 74 #endif 75 76 #include <sys/param.h> 77 #include <sys/systm.h> 78 #include <sys/mbuf.h> 79 #include <sys/socket.h> 80 #include <sys/protosw.h> 81 #include <sys/syslog.h> 82 83 #include <net/if.h> 84 85 #include <netinet/in.h> 86 #include <netinet/in_var.h> 87 #include <netinet6/in6.h> 88 #include <netinet6/ip6.h> 89 #include <netinet6/ip6_var.h> 90 #include <netinet6/icmp6.h> 91 #include <netinet6/mld6_var.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 10 104 105 static struct ip6_pktopts ip6_opts; 106 static int mld6_timers_are_running; 107 /* XXX: These are necessary for KAME's link-local hack */ 108 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT; 109 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; 110 111 static void mld6_sendpkt __P((struct in6_multi *, int, const struct in6_addr *)); 112 113 void 114 mld6_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_RTALERT; 129 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2; 130 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t)); 131 132 ip6_opts.ip6po_hbh = hbh; 133 /* We will specify the hoplimit by a multicast option. */ 134 ip6_opts.ip6po_hlim = -1; 135 } 136 137 void 138 mld6_start_listening(in6m) 139 struct in6_multi *in6m; 140 { 141 int s = splsoftnet(); 142 143 /* 144 * (draft-ietf-ipngwg-mld, page 10) 145 * The node never sends a Report or Done for the link-scope all-nodes 146 * address. 147 * MLD messages are never sent for multicast addresses whose scope is 0 148 * (reserved) or 1 (node-local). 149 */ 150 mld6_all_nodes_linklocal.s6_addr16[1] = 151 htons(in6m->in6m_ifp->if_index); /* XXX */ 152 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) || 153 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) { 154 in6m->in6m_timer = 0; 155 in6m->in6m_state = MLD6_OTHERLISTENER; 156 } else { 157 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL); 158 in6m->in6m_timer = MLD6_RANDOM_DELAY( 159 MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ); 160 in6m->in6m_state = MLD6_IREPORTEDLAST; 161 mld6_timers_are_running = 1; 162 } 163 splx(s); 164 } 165 166 void 167 mld6_stop_listening(in6m) 168 struct in6_multi *in6m; 169 { 170 mld6_all_nodes_linklocal.s6_addr16[1] = 171 htons(in6m->in6m_ifp->if_index); /* XXX */ 172 mld6_all_routers_linklocal.s6_addr16[1] = 173 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */ 174 175 if (in6m->in6m_state == MLD6_IREPORTEDLAST && 176 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) && 177 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL) 178 mld6_sendpkt(in6m, MLD6_LISTENER_DONE, 179 &mld6_all_routers_linklocal); 180 } 181 182 void 183 mld6_input(m, off) 184 struct mbuf *m; 185 int off; 186 { 187 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 188 struct mld6_hdr *mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off); 189 struct ifnet *ifp = m->m_pkthdr.rcvif; 190 struct in6_multi *in6m; 191 struct in6_ifaddr *ia; 192 int timer; /* timer value in the MLD query header */ 193 194 /* source address validation */ 195 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) { 196 log(LOG_ERR, 197 "mld6_input: src %s is not link-local\n", 198 ip6_sprintf(&ip6->ip6_src)); 199 /* 200 * spec(draft-ietf-ipngwg-mld) does not explicitly 201 * specify to discard the packet from a non link-local 202 * source address. But we believe it's expected to do so. 203 */ 204 return; 205 } 206 207 /* 208 * In the MLD6 specification, there are 3 states and a flag. 209 * 210 * In Non-Listener state, we simply don't have a membership record. 211 * In Delaying Listener state, our timer is running (in6m->in6m_timer) 212 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0) 213 * 214 * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if 215 * we have heard a report from another member, or MLD6_IREPORTEDLAST 216 * if we sent the last report. 217 */ 218 switch(mldh->mld6_type) { 219 case MLD6_LISTENER_QUERY: 220 if (ifp->if_flags & IFF_LOOPBACK) 221 break; 222 223 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) && 224 !IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 225 break; /* print error or log stat? */ 226 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 227 mldh->mld6_addr.s6_addr16[1] = 228 htons(ifp->if_index); /* XXX */ 229 230 /* 231 * - Start the timers in all of our membership records 232 * that the query applies to for the interface on 233 * which the query arrived excl. those that belong 234 * to the "all-nodes" group (ff02::1). 235 * - Restart any timer that is already running but has 236 * A value longer than the requested timeout. 237 * - Use the value specified in the query message as 238 * the maximum timeout. 239 */ 240 IFP_TO_IA6(ifp, ia); 241 if (ia == NULL) 242 break; 243 244 /* 245 * XXX: System timer resolution is too low to handle Max 246 * Response Delay, so set 1 to the internal timer even if 247 * the calculated value equals to zero when Max Response 248 * Delay is positive. 249 */ 250 timer = ntohs(mldh->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE; 251 if (timer == 0 && mldh->mld6_maxdelay) 252 timer = 1; 253 mld6_all_nodes_linklocal.s6_addr16[1] = 254 htons(ifp->if_index); /* XXX */ 255 256 for (in6m = ia->ia6_multiaddrs.lh_first; 257 in6m; 258 in6m = in6m->in6m_entry.le_next) { 259 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, 260 &mld6_all_nodes_linklocal) || 261 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < 262 IPV6_ADDR_SCOPE_LINKLOCAL) 263 continue; 264 265 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) || 266 IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr, 267 &in6m->in6m_addr)) { 268 if (timer == 0) { 269 /* send a report immediately */ 270 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, 271 NULL); 272 in6m->in6m_timer = 0; /* reset timer */ 273 in6m->in6m_state = MLD6_IREPORTEDLAST; 274 } 275 else if (in6m->in6m_timer == 0 || /*idle state*/ 276 in6m->in6m_timer > timer) { 277 in6m->in6m_timer = 278 MLD6_RANDOM_DELAY(timer); 279 mld6_timers_are_running = 1; 280 } 281 } 282 } 283 284 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 285 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 286 break; 287 case MLD6_LISTENER_REPORT: 288 /* 289 * For fast leave to work, we have to know that we are the 290 * last person to send a report for this group. Reports 291 * can potentially get looped back if we are a multicast 292 * router, so discard reports sourced by me. 293 * Note that it is impossible to check IFF_LOOPBACK flag of 294 * ifp for this purpose, since ip6_mloopback pass the physical 295 * interface to looutput. 296 */ 297 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */ 298 break; 299 300 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr)) 301 break; 302 303 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 304 mldh->mld6_addr.s6_addr16[1] = 305 htons(ifp->if_index); /* XXX */ 306 /* 307 * If we belong to the group being reported, stop 308 * our timer for that group. 309 */ 310 IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m); 311 if (in6m) { 312 in6m->in6m_timer = 0; /* transit to idle state */ 313 in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */ 314 } 315 316 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 317 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 318 break; 319 default: /* this is impossible */ 320 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type); 321 break; 322 } 323 } 324 325 void 326 mld6_fasttimeo() 327 { 328 register struct in6_multi *in6m; 329 struct in6_multistep step; 330 int s; 331 332 /* 333 * Quick check to see if any work needs to be done, in order 334 * to minimize the overhead of fasttimo processing. 335 */ 336 if (!mld6_timers_are_running) 337 return; 338 339 s = splsoftnet(); 340 mld6_timers_are_running = 0; 341 IN6_FIRST_MULTI(step, in6m); 342 while (in6m != NULL) { 343 if (in6m->in6m_timer == 0) { 344 /* do nothing */ 345 } else if (--in6m->in6m_timer == 0) { 346 mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL); 347 in6m->in6m_state = MLD6_IREPORTEDLAST; 348 } else { 349 mld6_timers_are_running = 1; 350 } 351 IN6_NEXT_MULTI(step, in6m); 352 } 353 splx(s); 354 } 355 356 static void 357 mld6_sendpkt(in6m, type, dst) 358 struct in6_multi *in6m; 359 int type; 360 const struct in6_addr *dst; 361 { 362 struct mbuf *mh, *md; 363 struct mld6_hdr *mldh; 364 struct ip6_hdr *ip6; 365 struct ip6_moptions im6o; 366 struct in6_ifaddr *ia; 367 struct ifnet *ifp = in6m->in6m_ifp; 368 369 /* 370 * At first, find a link local address on the outgoing interface 371 * to use as the source address of the MLD packet. 372 */ 373 if ((ia = in6ifa_ifpforlinklocal(ifp)) == NULL) 374 return; 375 376 /* 377 * Allocate mbufs to store ip6 header and MLD header. 378 * We allocate 2 mbufs and make chain in advance because 379 * it is more convenient when inserting the hop-by-hop option later. 380 */ 381 MGETHDR(mh, M_DONTWAIT, MT_HEADER); 382 if (mh == NULL) 383 return; 384 MGET(md, M_DONTWAIT, MT_DATA); 385 if (md == NULL) { 386 m_free(mh); 387 return; 388 } 389 mh->m_next = md; 390 391 #ifdef IPSEC 392 mh->m_pkthdr.rcvif = NULL; 393 #endif 394 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_hdr); 395 mh->m_len = sizeof(struct ip6_hdr); 396 MH_ALIGN(mh, sizeof(struct ip6_hdr)); 397 398 /* fill in the ip6 header */ 399 ip6 = mtod(mh, struct ip6_hdr *); 400 ip6->ip6_flow = 0; 401 ip6->ip6_vfc = IPV6_VERSION; 402 /* ip6_plen will be set later */ 403 ip6->ip6_nxt = IPPROTO_ICMPV6; 404 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */ 405 ip6->ip6_src = ia->ia_addr.sin6_addr; 406 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr; 407 408 /* fill in the MLD header */ 409 md->m_len = sizeof(struct mld6_hdr); 410 mldh = mtod(md, struct mld6_hdr *); 411 mldh->mld6_type = type; 412 mldh->mld6_code = 0; 413 mldh->mld6_cksum = 0; 414 /* XXX: we assume the function will not be called for query messages */ 415 mldh->mld6_maxdelay = 0; 416 mldh->mld6_reserved = 0; 417 mldh->mld6_addr = in6m->in6m_addr; 418 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr)) 419 mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */ 420 mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), 421 sizeof(struct mld6_hdr)); 422 423 /* construct multicast option */ 424 bzero(&im6o, sizeof(im6o)); 425 im6o.im6o_multicast_ifp = ifp; 426 im6o.im6o_multicast_hlim = 1; 427 428 /* 429 * Request loopback of the report if we are acting as a multicast 430 * router, so that the process-level routing daemon can hear it. 431 */ 432 im6o.im6o_multicast_loop = (ip6_mrouter != NULL); 433 434 /* increment output statictics */ 435 icmp6stat.icp6s_outhist[type]++; 436 437 ip6_output(mh, &ip6_opts, NULL, 0, &im6o); 438 } 439
Indexes created Wed Oct 15 03:09:54 GMT 2025