igmp.c revision 1.40
1 /* $NetBSD: igmp.c,v 1.40 2005/02/02 21:41:55 perry Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 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 * Internet Group Management Protocol (IGMP) routines. 34 * 35 * Written by Steve Deering, Stanford, May 1988. 36 * Modified by Rosen Sharma, Stanford, Aug 1994. 37 * Modified by Bill Fenner, Xerox PARC, Feb 1995. 38 * 39 * MULTICAST Revision: 1.3 40 */ 41 42 #include <sys/cdefs.h> 43 __KERNEL_RCSID(0, "$NetBSD: igmp.c,v 1.40 2005/02/02 21:41:55 perry Exp $"); 44 45 #include "opt_mrouting.h" 46 47 #include <sys/param.h> 48 #include <sys/mbuf.h> 49 #include <sys/socket.h> 50 #include <sys/protosw.h> 51 #include <sys/systm.h> 52 53 #include <net/if.h> 54 #include <net/route.h> 55 56 #include <netinet/in.h> 57 #include <netinet/in_var.h> 58 #include <netinet/in_systm.h> 59 #include <netinet/ip.h> 60 #include <netinet/ip_var.h> 61 #include <netinet/igmp.h> 62 #include <netinet/igmp_var.h> 63 64 #include <machine/stdarg.h> 65 66 #define IP_MULTICASTOPTS 0 67 68 POOL_INIT(igmp_rti_pool, sizeof(struct router_info), 0, 0, 0, "igmppl", NULL); 69 struct igmpstat igmpstat; 70 int igmp_timers_are_running; 71 static LIST_HEAD(, router_info) rti_head = LIST_HEAD_INITIALIZER(rti_head); 72 73 void igmp_sendpkt(struct in_multi *, int); 74 static int rti_fill(struct in_multi *); 75 static struct router_info *rti_find(struct ifnet *); 76 static void rti_delete(struct ifnet *); 77 78 static int 79 rti_fill(inm) 80 struct in_multi *inm; 81 { 82 struct router_info *rti; 83 84 LIST_FOREACH(rti, &rti_head, rti_link) { 85 if (rti->rti_ifp == inm->inm_ifp) { 86 inm->inm_rti = rti; 87 if (rti->rti_type == IGMP_v1_ROUTER) 88 return (IGMP_v1_HOST_MEMBERSHIP_REPORT); 89 else 90 return (IGMP_v2_HOST_MEMBERSHIP_REPORT); 91 } 92 } 93 94 rti = pool_get(&igmp_rti_pool, PR_NOWAIT); 95 if (rti == NULL) 96 return 0; 97 rti->rti_ifp = inm->inm_ifp; 98 rti->rti_type = IGMP_v2_ROUTER; 99 LIST_INSERT_HEAD(&rti_head, rti, rti_link); 100 inm->inm_rti = rti; 101 return (IGMP_v2_HOST_MEMBERSHIP_REPORT); 102 } 103 104 static struct router_info * 105 rti_find(ifp) 106 struct ifnet *ifp; 107 { 108 struct router_info *rti; 109 110 LIST_FOREACH(rti, &rti_head, rti_link) { 111 if (rti->rti_ifp == ifp) 112 return (rti); 113 } 114 115 rti = pool_get(&igmp_rti_pool, PR_NOWAIT); 116 if (rti == NULL) 117 return NULL; 118 rti->rti_ifp = ifp; 119 rti->rti_type = IGMP_v2_ROUTER; 120 LIST_INSERT_HEAD(&rti_head, rti, rti_link); 121 return (rti); 122 } 123 124 static void 125 rti_delete(ifp) 126 struct ifnet *ifp; 127 { 128 struct router_info *rti; 129 130 LIST_FOREACH(rti, &rti_head, rti_link) { 131 if (rti->rti_ifp == ifp) { 132 LIST_REMOVE(rti, rti_link); 133 pool_put(&igmp_rti_pool, rti); 134 return; 135 } 136 } 137 } 138 139 void 140 igmp_input(struct mbuf *m, ...) 141 { 142 int proto; 143 int iphlen; 144 struct ifnet *ifp = m->m_pkthdr.rcvif; 145 struct ip *ip = mtod(m, struct ip *); 146 struct igmp *igmp; 147 u_int minlen; 148 struct in_multi *inm; 149 struct in_multistep step; 150 struct router_info *rti; 151 struct in_ifaddr *ia; 152 u_int timer; 153 va_list ap; 154 u_int16_t ip_len; 155 156 va_start(ap, m); 157 iphlen = va_arg(ap, int); 158 proto = va_arg(ap, int); 159 va_end(ap); 160 161 ++igmpstat.igps_rcv_total; 162 163 /* 164 * Validate lengths 165 */ 166 minlen = iphlen + IGMP_MINLEN; 167 ip_len = ntohs(ip->ip_len); 168 if (ip_len < minlen) { 169 ++igmpstat.igps_rcv_tooshort; 170 m_freem(m); 171 return; 172 } 173 if (((m->m_flags & M_EXT) && (ip->ip_src.s_addr & IN_CLASSA_NET) == 0) 174 || m->m_len < minlen) { 175 if ((m = m_pullup(m, minlen)) == 0) { 176 ++igmpstat.igps_rcv_tooshort; 177 return; 178 } 179 ip = mtod(m, struct ip *); 180 } 181 182 /* 183 * Validate checksum 184 */ 185 m->m_data += iphlen; 186 m->m_len -= iphlen; 187 igmp = mtod(m, struct igmp *); 188 /* No need to assert alignment here. */ 189 if (in_cksum(m, ip_len - iphlen)) { 190 ++igmpstat.igps_rcv_badsum; 191 m_freem(m); 192 return; 193 } 194 m->m_data -= iphlen; 195 m->m_len += iphlen; 196 197 switch (igmp->igmp_type) { 198 199 case IGMP_HOST_MEMBERSHIP_QUERY: 200 ++igmpstat.igps_rcv_queries; 201 202 if (ifp->if_flags & IFF_LOOPBACK) 203 break; 204 205 if (igmp->igmp_code == 0) { 206 rti = rti_find(ifp); 207 if (rti == NULL) 208 break; 209 rti->rti_type = IGMP_v1_ROUTER; 210 rti->rti_age = 0; 211 212 if (ip->ip_dst.s_addr != INADDR_ALLHOSTS_GROUP) { 213 ++igmpstat.igps_rcv_badqueries; 214 m_freem(m); 215 return; 216 } 217 218 /* 219 * Start the timers in all of our membership records 220 * for the interface on which the query arrived, 221 * except those that are already running and those 222 * that belong to a "local" group (224.0.0.X). 223 */ 224 IN_FIRST_MULTI(step, inm); 225 while (inm != NULL) { 226 if (inm->inm_ifp == ifp && 227 inm->inm_timer == 0 && 228 !IN_LOCAL_GROUP(inm->inm_addr.s_addr)) { 229 inm->inm_state = IGMP_DELAYING_MEMBER; 230 inm->inm_timer = IGMP_RANDOM_DELAY( 231 IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); 232 igmp_timers_are_running = 1; 233 } 234 IN_NEXT_MULTI(step, inm); 235 } 236 } else { 237 if (!IN_MULTICAST(ip->ip_dst.s_addr)) { 238 ++igmpstat.igps_rcv_badqueries; 239 m_freem(m); 240 return; 241 } 242 243 timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE; 244 if (timer == 0) 245 timer =1; 246 247 /* 248 * Start the timers in all of our membership records 249 * for the interface on which the query arrived, 250 * except those that are already running and those 251 * that belong to a "local" group (224.0.0.X). For 252 * timers already running, check if they need to be 253 * reset. 254 */ 255 IN_FIRST_MULTI(step, inm); 256 while (inm != NULL) { 257 if (inm->inm_ifp == ifp && 258 !IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 259 (ip->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP || 260 in_hosteq(ip->ip_dst, inm->inm_addr))) { 261 switch (inm->inm_state) { 262 case IGMP_DELAYING_MEMBER: 263 if (inm->inm_timer <= timer) 264 break; 265 /* FALLTHROUGH */ 266 case IGMP_IDLE_MEMBER: 267 case IGMP_LAZY_MEMBER: 268 case IGMP_AWAKENING_MEMBER: 269 inm->inm_state = 270 IGMP_DELAYING_MEMBER; 271 inm->inm_timer = 272 IGMP_RANDOM_DELAY(timer); 273 igmp_timers_are_running = 1; 274 break; 275 case IGMP_SLEEPING_MEMBER: 276 inm->inm_state = 277 IGMP_AWAKENING_MEMBER; 278 break; 279 } 280 } 281 IN_NEXT_MULTI(step, inm); 282 } 283 } 284 285 break; 286 287 case IGMP_v1_HOST_MEMBERSHIP_REPORT: 288 ++igmpstat.igps_rcv_reports; 289 290 if (ifp->if_flags & IFF_LOOPBACK) 291 break; 292 293 if (!IN_MULTICAST(igmp->igmp_group.s_addr) || 294 !in_hosteq(igmp->igmp_group, ip->ip_dst)) { 295 ++igmpstat.igps_rcv_badreports; 296 m_freem(m); 297 return; 298 } 299 300 /* 301 * KLUDGE: if the IP source address of the report has an 302 * unspecified (i.e., zero) subnet number, as is allowed for 303 * a booting host, replace it with the correct subnet number 304 * so that a process-level multicast routing daemon can 305 * determine which subnet it arrived from. This is necessary 306 * to compensate for the lack of any way for a process to 307 * determine the arrival interface of an incoming packet. 308 */ 309 if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { 310 IFP_TO_IA(ifp, ia); /* XXX */ 311 if (ia) 312 ip->ip_src.s_addr = ia->ia_subnet; 313 } 314 315 /* 316 * If we belong to the group being reported, stop 317 * our timer for that group. 318 */ 319 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 320 if (inm != NULL) { 321 inm->inm_timer = 0; 322 ++igmpstat.igps_rcv_ourreports; 323 324 switch (inm->inm_state) { 325 case IGMP_IDLE_MEMBER: 326 case IGMP_LAZY_MEMBER: 327 case IGMP_AWAKENING_MEMBER: 328 case IGMP_SLEEPING_MEMBER: 329 inm->inm_state = IGMP_SLEEPING_MEMBER; 330 break; 331 case IGMP_DELAYING_MEMBER: 332 if (inm->inm_rti->rti_type == IGMP_v1_ROUTER) 333 inm->inm_state = IGMP_LAZY_MEMBER; 334 else 335 inm->inm_state = IGMP_SLEEPING_MEMBER; 336 break; 337 } 338 } 339 340 break; 341 342 case IGMP_v2_HOST_MEMBERSHIP_REPORT: 343 #ifdef MROUTING 344 /* 345 * Make sure we don't hear our own membership report. Fast 346 * leave requires knowing that we are the only member of a 347 * group. 348 */ 349 IFP_TO_IA(ifp, ia); /* XXX */ 350 if (ia && in_hosteq(ip->ip_src, ia->ia_addr.sin_addr)) 351 break; 352 #endif 353 354 ++igmpstat.igps_rcv_reports; 355 356 if (ifp->if_flags & IFF_LOOPBACK) 357 break; 358 359 if (!IN_MULTICAST(igmp->igmp_group.s_addr) || 360 !in_hosteq(igmp->igmp_group, ip->ip_dst)) { 361 ++igmpstat.igps_rcv_badreports; 362 m_freem(m); 363 return; 364 } 365 366 /* 367 * KLUDGE: if the IP source address of the report has an 368 * unspecified (i.e., zero) subnet number, as is allowed for 369 * a booting host, replace it with the correct subnet number 370 * so that a process-level multicast routing daemon can 371 * determine which subnet it arrived from. This is necessary 372 * to compensate for the lack of any way for a process to 373 * determine the arrival interface of an incoming packet. 374 */ 375 if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { 376 #ifndef MROUTING 377 IFP_TO_IA(ifp, ia); /* XXX */ 378 #endif 379 if (ia) 380 ip->ip_src.s_addr = ia->ia_subnet; 381 } 382 383 /* 384 * If we belong to the group being reported, stop 385 * our timer for that group. 386 */ 387 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 388 if (inm != NULL) { 389 inm->inm_timer = 0; 390 ++igmpstat.igps_rcv_ourreports; 391 392 switch (inm->inm_state) { 393 case IGMP_DELAYING_MEMBER: 394 case IGMP_IDLE_MEMBER: 395 case IGMP_AWAKENING_MEMBER: 396 inm->inm_state = IGMP_LAZY_MEMBER; 397 break; 398 case IGMP_LAZY_MEMBER: 399 case IGMP_SLEEPING_MEMBER: 400 break; 401 } 402 } 403 404 break; 405 406 } 407 408 /* 409 * Pass all valid IGMP packets up to any process(es) listening 410 * on a raw IGMP socket. 411 */ 412 rip_input(m, iphlen, proto); 413 return; 414 } 415 416 int 417 igmp_joingroup(inm) 418 struct in_multi *inm; 419 { 420 int report_type; 421 int s = splsoftnet(); 422 423 inm->inm_state = IGMP_IDLE_MEMBER; 424 425 if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 426 (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) { 427 report_type = rti_fill(inm); 428 if (report_type == 0) { 429 splx(s); 430 return ENOMEM; 431 } 432 igmp_sendpkt(inm, report_type); 433 inm->inm_state = IGMP_DELAYING_MEMBER; 434 inm->inm_timer = IGMP_RANDOM_DELAY( 435 IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); 436 igmp_timers_are_running = 1; 437 } else 438 inm->inm_timer = 0; 439 splx(s); 440 return 0; 441 } 442 443 void 444 igmp_leavegroup(inm) 445 struct in_multi *inm; 446 { 447 448 switch (inm->inm_state) { 449 case IGMP_DELAYING_MEMBER: 450 case IGMP_IDLE_MEMBER: 451 if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 452 (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) 453 if (inm->inm_rti->rti_type != IGMP_v1_ROUTER) 454 igmp_sendpkt(inm, IGMP_HOST_LEAVE_MESSAGE); 455 break; 456 case IGMP_LAZY_MEMBER: 457 case IGMP_AWAKENING_MEMBER: 458 case IGMP_SLEEPING_MEMBER: 459 break; 460 } 461 } 462 463 void 464 igmp_fasttimo() 465 { 466 struct in_multi *inm; 467 struct in_multistep step; 468 int s; 469 470 /* 471 * Quick check to see if any work needs to be done, in order 472 * to minimize the overhead of fasttimo processing. 473 */ 474 if (!igmp_timers_are_running) 475 return; 476 477 s = splsoftnet(); 478 igmp_timers_are_running = 0; 479 IN_FIRST_MULTI(step, inm); 480 while (inm != NULL) { 481 if (inm->inm_timer == 0) { 482 /* do nothing */ 483 } else if (--inm->inm_timer == 0) { 484 if (inm->inm_state == IGMP_DELAYING_MEMBER) { 485 if (inm->inm_rti->rti_type == IGMP_v1_ROUTER) 486 igmp_sendpkt(inm, 487 IGMP_v1_HOST_MEMBERSHIP_REPORT); 488 else 489 igmp_sendpkt(inm, 490 IGMP_v2_HOST_MEMBERSHIP_REPORT); 491 inm->inm_state = IGMP_IDLE_MEMBER; 492 } 493 } else { 494 igmp_timers_are_running = 1; 495 } 496 IN_NEXT_MULTI(step, inm); 497 } 498 splx(s); 499 } 500 501 void 502 igmp_slowtimo() 503 { 504 struct router_info *rti; 505 int s; 506 507 s = splsoftnet(); 508 LIST_FOREACH(rti, &rti_head, rti_link) { 509 if (rti->rti_type == IGMP_v1_ROUTER && 510 ++rti->rti_age >= IGMP_AGE_THRESHOLD) { 511 rti->rti_type = IGMP_v2_ROUTER; 512 } 513 } 514 splx(s); 515 } 516 517 void 518 igmp_sendpkt(inm, type) 519 struct in_multi *inm; 520 int type; 521 { 522 struct mbuf *m; 523 struct igmp *igmp; 524 struct ip *ip; 525 struct ip_moptions imo; 526 #ifdef MROUTING 527 extern struct socket *ip_mrouter; 528 #endif /* MROUTING */ 529 530 MGETHDR(m, M_DONTWAIT, MT_HEADER); 531 if (m == NULL) 532 return; 533 /* 534 * Assume max_linkhdr + sizeof(struct ip) + IGMP_MINLEN 535 * is smaller than mbuf size returned by MGETHDR. 536 */ 537 m->m_data += max_linkhdr; 538 m->m_len = sizeof(struct ip) + IGMP_MINLEN; 539 m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN; 540 541 ip = mtod(m, struct ip *); 542 ip->ip_tos = 0; 543 ip->ip_len = htons(sizeof(struct ip) + IGMP_MINLEN); 544 ip->ip_off = htons(0); 545 ip->ip_p = IPPROTO_IGMP; 546 ip->ip_src = zeroin_addr; 547 ip->ip_dst = inm->inm_addr; 548 549 m->m_data += sizeof(struct ip); 550 m->m_len -= sizeof(struct ip); 551 igmp = mtod(m, struct igmp *); 552 igmp->igmp_type = type; 553 igmp->igmp_code = 0; 554 igmp->igmp_group = inm->inm_addr; 555 igmp->igmp_cksum = 0; 556 igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN); 557 m->m_data -= sizeof(struct ip); 558 m->m_len += sizeof(struct ip); 559 560 imo.imo_multicast_ifp = inm->inm_ifp; 561 imo.imo_multicast_ttl = 1; 562 #ifdef RSVP_ISI 563 imo.imo_multicast_vif = -1; 564 #endif 565 /* 566 * Request loopback of the report if we are acting as a multicast 567 * router, so that the process-level routing demon can hear it. 568 */ 569 #ifdef MROUTING 570 imo.imo_multicast_loop = (ip_mrouter != NULL); 571 #else 572 imo.imo_multicast_loop = 0; 573 #endif /* MROUTING */ 574 575 ip_output(m, (struct mbuf *)NULL, (struct route *)NULL, 576 IP_MULTICASTOPTS, &imo, (struct socket *)NULL); 577 578 ++igmpstat.igps_snd_reports; 579 } 580 581 void 582 igmp_purgeif(ifp) 583 struct ifnet *ifp; 584 { 585 586 rti_delete(ifp); 587 } 588
Indexes created Wed Sep 24 05:09:52 GMT 2025