igmp.c revision 1.37
1 /* $NetBSD: igmp.c,v 1.37 2004/04/25 16:42:42 simonb 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 1.37 2004/04/25 16:42:42 simonb 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 __P((struct in_multi *, int)); 74 static int rti_fill __P((struct in_multi *)); 75 static struct router_info *rti_find __P((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 #if __STDC__ 141 igmp_input(struct mbuf *m, ...) 142 #else 143 igmp_input(m, va_alist) 144 struct mbuf *m; 145 va_dcl 146 #endif 147 { 148 int proto; 149 int iphlen; 150 struct ifnet *ifp = m->m_pkthdr.rcvif; 151 struct ip *ip = mtod(m, struct ip *); 152 struct igmp *igmp; 153 u_int minlen; 154 struct in_multi *inm; 155 struct in_multistep step; 156 struct router_info *rti; 157 struct in_ifaddr *ia; 158 u_int timer; 159 va_list ap; 160 u_int16_t ip_len; 161 162 va_start(ap, m); 163 iphlen = va_arg(ap, int); 164 proto = va_arg(ap, int); 165 va_end(ap); 166 167 ++igmpstat.igps_rcv_total; 168 169 /* 170 * Validate lengths 171 */ 172 minlen = iphlen + IGMP_MINLEN; 173 ip_len = ntohs(ip->ip_len); 174 if (ip_len < minlen) { 175 ++igmpstat.igps_rcv_tooshort; 176 m_freem(m); 177 return; 178 } 179 if (((m->m_flags & M_EXT) && (ip->ip_src.s_addr & IN_CLASSA_NET) == 0) 180 || m->m_len < minlen) { 181 if ((m = m_pullup(m, minlen)) == 0) { 182 ++igmpstat.igps_rcv_tooshort; 183 return; 184 } 185 ip = mtod(m, struct ip *); 186 } 187 188 /* 189 * Validate checksum 190 */ 191 m->m_data += iphlen; 192 m->m_len -= iphlen; 193 igmp = mtod(m, struct igmp *); 194 /* No need to assert alignment here. */ 195 if (in_cksum(m, ip_len - iphlen)) { 196 ++igmpstat.igps_rcv_badsum; 197 m_freem(m); 198 return; 199 } 200 m->m_data -= iphlen; 201 m->m_len += iphlen; 202 203 switch (igmp->igmp_type) { 204 205 case IGMP_HOST_MEMBERSHIP_QUERY: 206 ++igmpstat.igps_rcv_queries; 207 208 if (ifp->if_flags & IFF_LOOPBACK) 209 break; 210 211 if (igmp->igmp_code == 0) { 212 rti = rti_find(ifp); 213 if (rti == NULL) 214 break; 215 rti->rti_type = IGMP_v1_ROUTER; 216 rti->rti_age = 0; 217 218 if (ip->ip_dst.s_addr != INADDR_ALLHOSTS_GROUP) { 219 ++igmpstat.igps_rcv_badqueries; 220 m_freem(m); 221 return; 222 } 223 224 /* 225 * Start the timers in all of our membership records 226 * for the interface on which the query arrived, 227 * except those that are already running and those 228 * that belong to a "local" group (224.0.0.X). 229 */ 230 IN_FIRST_MULTI(step, inm); 231 while (inm != NULL) { 232 if (inm->inm_ifp == ifp && 233 inm->inm_timer == 0 && 234 !IN_LOCAL_GROUP(inm->inm_addr.s_addr)) { 235 inm->inm_state = IGMP_DELAYING_MEMBER; 236 inm->inm_timer = IGMP_RANDOM_DELAY( 237 IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); 238 igmp_timers_are_running = 1; 239 } 240 IN_NEXT_MULTI(step, inm); 241 } 242 } else { 243 if (!IN_MULTICAST(ip->ip_dst.s_addr)) { 244 ++igmpstat.igps_rcv_badqueries; 245 m_freem(m); 246 return; 247 } 248 249 timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE; 250 if (timer == 0) 251 timer =1; 252 253 /* 254 * Start the timers in all of our membership records 255 * for the interface on which the query arrived, 256 * except those that are already running and those 257 * that belong to a "local" group (224.0.0.X). For 258 * timers already running, check if they need to be 259 * reset. 260 */ 261 IN_FIRST_MULTI(step, inm); 262 while (inm != NULL) { 263 if (inm->inm_ifp == ifp && 264 !IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 265 (ip->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP || 266 in_hosteq(ip->ip_dst, inm->inm_addr))) { 267 switch (inm->inm_state) { 268 case IGMP_DELAYING_MEMBER: 269 if (inm->inm_timer <= timer) 270 break; 271 /* FALLTHROUGH */ 272 case IGMP_IDLE_MEMBER: 273 case IGMP_LAZY_MEMBER: 274 case IGMP_AWAKENING_MEMBER: 275 inm->inm_state = 276 IGMP_DELAYING_MEMBER; 277 inm->inm_timer = 278 IGMP_RANDOM_DELAY(timer); 279 igmp_timers_are_running = 1; 280 break; 281 case IGMP_SLEEPING_MEMBER: 282 inm->inm_state = 283 IGMP_AWAKENING_MEMBER; 284 break; 285 } 286 } 287 IN_NEXT_MULTI(step, inm); 288 } 289 } 290 291 break; 292 293 case IGMP_v1_HOST_MEMBERSHIP_REPORT: 294 ++igmpstat.igps_rcv_reports; 295 296 if (ifp->if_flags & IFF_LOOPBACK) 297 break; 298 299 if (!IN_MULTICAST(igmp->igmp_group.s_addr) || 300 !in_hosteq(igmp->igmp_group, ip->ip_dst)) { 301 ++igmpstat.igps_rcv_badreports; 302 m_freem(m); 303 return; 304 } 305 306 /* 307 * KLUDGE: if the IP source address of the report has an 308 * unspecified (i.e., zero) subnet number, as is allowed for 309 * a booting host, replace it with the correct subnet number 310 * so that a process-level multicast routing daemon can 311 * determine which subnet it arrived from. This is necessary 312 * to compensate for the lack of any way for a process to 313 * determine the arrival interface of an incoming packet. 314 */ 315 if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { 316 IFP_TO_IA(ifp, ia); /* XXX */ 317 if (ia) 318 ip->ip_src.s_addr = ia->ia_subnet; 319 } 320 321 /* 322 * If we belong to the group being reported, stop 323 * our timer for that group. 324 */ 325 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 326 if (inm != NULL) { 327 inm->inm_timer = 0; 328 ++igmpstat.igps_rcv_ourreports; 329 330 switch (inm->inm_state) { 331 case IGMP_IDLE_MEMBER: 332 case IGMP_LAZY_MEMBER: 333 case IGMP_AWAKENING_MEMBER: 334 case IGMP_SLEEPING_MEMBER: 335 inm->inm_state = IGMP_SLEEPING_MEMBER; 336 break; 337 case IGMP_DELAYING_MEMBER: 338 if (inm->inm_rti->rti_type == IGMP_v1_ROUTER) 339 inm->inm_state = IGMP_LAZY_MEMBER; 340 else 341 inm->inm_state = IGMP_SLEEPING_MEMBER; 342 break; 343 } 344 } 345 346 break; 347 348 case IGMP_v2_HOST_MEMBERSHIP_REPORT: 349 #ifdef MROUTING 350 /* 351 * Make sure we don't hear our own membership report. Fast 352 * leave requires knowing that we are the only member of a 353 * group. 354 */ 355 IFP_TO_IA(ifp, ia); /* XXX */ 356 if (ia && in_hosteq(ip->ip_src, ia->ia_addr.sin_addr)) 357 break; 358 #endif 359 360 ++igmpstat.igps_rcv_reports; 361 362 if (ifp->if_flags & IFF_LOOPBACK) 363 break; 364 365 if (!IN_MULTICAST(igmp->igmp_group.s_addr) || 366 !in_hosteq(igmp->igmp_group, ip->ip_dst)) { 367 ++igmpstat.igps_rcv_badreports; 368 m_freem(m); 369 return; 370 } 371 372 /* 373 * KLUDGE: if the IP source address of the report has an 374 * unspecified (i.e., zero) subnet number, as is allowed for 375 * a booting host, replace it with the correct subnet number 376 * so that a process-level multicast routing daemon can 377 * determine which subnet it arrived from. This is necessary 378 * to compensate for the lack of any way for a process to 379 * determine the arrival interface of an incoming packet. 380 */ 381 if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { 382 #ifndef MROUTING 383 IFP_TO_IA(ifp, ia); /* XXX */ 384 #endif 385 if (ia) 386 ip->ip_src.s_addr = ia->ia_subnet; 387 } 388 389 /* 390 * If we belong to the group being reported, stop 391 * our timer for that group. 392 */ 393 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 394 if (inm != NULL) { 395 inm->inm_timer = 0; 396 ++igmpstat.igps_rcv_ourreports; 397 398 switch (inm->inm_state) { 399 case IGMP_DELAYING_MEMBER: 400 case IGMP_IDLE_MEMBER: 401 case IGMP_AWAKENING_MEMBER: 402 inm->inm_state = IGMP_LAZY_MEMBER; 403 break; 404 case IGMP_LAZY_MEMBER: 405 case IGMP_SLEEPING_MEMBER: 406 break; 407 } 408 } 409 410 break; 411 412 } 413 414 /* 415 * Pass all valid IGMP packets up to any process(es) listening 416 * on a raw IGMP socket. 417 */ 418 rip_input(m, iphlen, proto); 419 return; 420 } 421 422 int 423 igmp_joingroup(inm) 424 struct in_multi *inm; 425 { 426 int report_type; 427 int s = splsoftnet(); 428 429 inm->inm_state = IGMP_IDLE_MEMBER; 430 431 if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 432 (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) { 433 report_type = rti_fill(inm); 434 if (report_type == 0) 435 return ENOMEM; 436 igmp_sendpkt(inm, report_type); 437 inm->inm_state = IGMP_DELAYING_MEMBER; 438 inm->inm_timer = IGMP_RANDOM_DELAY( 439 IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); 440 igmp_timers_are_running = 1; 441 } else 442 inm->inm_timer = 0; 443 splx(s); 444 return 0; 445 } 446 447 void 448 igmp_leavegroup(inm) 449 struct in_multi *inm; 450 { 451 452 switch (inm->inm_state) { 453 case IGMP_DELAYING_MEMBER: 454 case IGMP_IDLE_MEMBER: 455 if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 456 (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) 457 if (inm->inm_rti->rti_type != IGMP_v1_ROUTER) 458 igmp_sendpkt(inm, IGMP_HOST_LEAVE_MESSAGE); 459 break; 460 case IGMP_LAZY_MEMBER: 461 case IGMP_AWAKENING_MEMBER: 462 case IGMP_SLEEPING_MEMBER: 463 break; 464 } 465 } 466 467 void 468 igmp_fasttimo() 469 { 470 struct in_multi *inm; 471 struct in_multistep step; 472 int s; 473 474 /* 475 * Quick check to see if any work needs to be done, in order 476 * to minimize the overhead of fasttimo processing. 477 */ 478 if (!igmp_timers_are_running) 479 return; 480 481 s = splsoftnet(); 482 igmp_timers_are_running = 0; 483 IN_FIRST_MULTI(step, inm); 484 while (inm != NULL) { 485 if (inm->inm_timer == 0) { 486 /* do nothing */ 487 } else if (--inm->inm_timer == 0) { 488 if (inm->inm_state == IGMP_DELAYING_MEMBER) { 489 if (inm->inm_rti->rti_type == IGMP_v1_ROUTER) 490 igmp_sendpkt(inm, 491 IGMP_v1_HOST_MEMBERSHIP_REPORT); 492 else 493 igmp_sendpkt(inm, 494 IGMP_v2_HOST_MEMBERSHIP_REPORT); 495 inm->inm_state = IGMP_IDLE_MEMBER; 496 } 497 } else { 498 igmp_timers_are_running = 1; 499 } 500 IN_NEXT_MULTI(step, inm); 501 } 502 splx(s); 503 } 504 505 void 506 igmp_slowtimo() 507 { 508 struct router_info *rti; 509 int s; 510 511 s = splsoftnet(); 512 LIST_FOREACH(rti, &rti_head, rti_link) { 513 if (rti->rti_type == IGMP_v1_ROUTER && 514 ++rti->rti_age >= IGMP_AGE_THRESHOLD) { 515 rti->rti_type = IGMP_v2_ROUTER; 516 } 517 } 518 splx(s); 519 } 520 521 void 522 igmp_sendpkt(inm, type) 523 struct in_multi *inm; 524 int type; 525 { 526 struct mbuf *m; 527 struct igmp *igmp; 528 struct ip *ip; 529 struct ip_moptions imo; 530 #ifdef MROUTING 531 extern struct socket *ip_mrouter; 532 #endif /* MROUTING */ 533 534 MGETHDR(m, M_DONTWAIT, MT_HEADER); 535 if (m == NULL) 536 return; 537 /* 538 * Assume max_linkhdr + sizeof(struct ip) + IGMP_MINLEN 539 * is smaller than mbuf size returned by MGETHDR. 540 */ 541 m->m_data += max_linkhdr; 542 m->m_len = sizeof(struct ip) + IGMP_MINLEN; 543 m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN; 544 545 ip = mtod(m, struct ip *); 546 ip->ip_tos = 0; 547 ip->ip_len = htons(sizeof(struct ip) + IGMP_MINLEN); 548 ip->ip_off = htons(0); 549 ip->ip_p = IPPROTO_IGMP; 550 ip->ip_src = zeroin_addr; 551 ip->ip_dst = inm->inm_addr; 552 553 m->m_data += sizeof(struct ip); 554 m->m_len -= sizeof(struct ip); 555 igmp = mtod(m, struct igmp *); 556 igmp->igmp_type = type; 557 igmp->igmp_code = 0; 558 igmp->igmp_group = inm->inm_addr; 559 igmp->igmp_cksum = 0; 560 igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN); 561 m->m_data -= sizeof(struct ip); 562 m->m_len += sizeof(struct ip); 563 564 imo.imo_multicast_ifp = inm->inm_ifp; 565 imo.imo_multicast_ttl = 1; 566 #ifdef RSVP_ISI 567 imo.imo_multicast_vif = -1; 568 #endif 569 /* 570 * Request loopback of the report if we are acting as a multicast 571 * router, so that the process-level routing demon can hear it. 572 */ 573 #ifdef MROUTING 574 imo.imo_multicast_loop = (ip_mrouter != NULL); 575 #else 576 imo.imo_multicast_loop = 0; 577 #endif /* MROUTING */ 578 579 ip_output(m, (struct mbuf *)NULL, (struct route *)NULL, 580 IP_MULTICASTOPTS, &imo, (struct socket *)NULL); 581 582 ++igmpstat.igps_snd_reports; 583 } 584 585 void 586 igmp_purgeif(ifp) 587 struct ifnet *ifp; 588 { 589 590 rti_delete(ifp); 591 } 592
Indexes created Mon Sep 22 13:09:51 GMT 2025