igmp.c revision 1.50
1 /* $NetBSD: igmp.c,v 1.50 2009/09/13 18:45:11 pooka 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 1.50 2009/09/13 18:45:11 pooka 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/socketvar.h> 51 #include <sys/protosw.h> 52 #include <sys/systm.h> 53 #include <sys/sysctl.h> 54 55 #include <net/if.h> 56 #include <net/route.h> 57 #include <net/net_stats.h> 58 59 #include <netinet/in.h> 60 #include <netinet/in_var.h> 61 #include <netinet/in_systm.h> 62 #include <netinet/ip.h> 63 #include <netinet/ip_var.h> 64 #include <netinet/igmp.h> 65 #include <netinet/igmp_var.h> 66 67 #include <machine/stdarg.h> 68 69 #define IP_MULTICASTOPTS 0 70 71 static struct pool igmp_rti_pool; 72 73 static percpu_t *igmpstat_percpu; 74 75 #define IGMP_STATINC(x) _NET_STATINC(igmpstat_percpu, x) 76 77 int igmp_timers_are_running; 78 static LIST_HEAD(, router_info) rti_head = LIST_HEAD_INITIALIZER(rti_head); 79 80 void igmp_sendpkt(struct in_multi *, int); 81 static int rti_fill(struct in_multi *); 82 static struct router_info *rti_find(struct ifnet *); 83 static void rti_delete(struct ifnet *); 84 85 static int 86 rti_fill(struct in_multi *inm) 87 { 88 struct router_info *rti; 89 90 /* this function is called at splsoftnet() */ 91 LIST_FOREACH(rti, &rti_head, rti_link) { 92 if (rti->rti_ifp == inm->inm_ifp) { 93 inm->inm_rti = rti; 94 if (rti->rti_type == IGMP_v1_ROUTER) 95 return (IGMP_v1_HOST_MEMBERSHIP_REPORT); 96 else 97 return (IGMP_v2_HOST_MEMBERSHIP_REPORT); 98 } 99 } 100 101 rti = pool_get(&igmp_rti_pool, PR_NOWAIT); 102 if (rti == NULL) 103 return 0; 104 rti->rti_ifp = inm->inm_ifp; 105 rti->rti_type = IGMP_v2_ROUTER; 106 LIST_INSERT_HEAD(&rti_head, rti, rti_link); 107 inm->inm_rti = rti; 108 return (IGMP_v2_HOST_MEMBERSHIP_REPORT); 109 } 110 111 static struct router_info * 112 rti_find(struct ifnet *ifp) 113 { 114 struct router_info *rti; 115 int s = splsoftnet(); 116 117 LIST_FOREACH(rti, &rti_head, rti_link) { 118 if (rti->rti_ifp == ifp) 119 return (rti); 120 } 121 122 rti = pool_get(&igmp_rti_pool, PR_NOWAIT); 123 if (rti == NULL) { 124 splx(s); 125 return NULL; 126 } 127 rti->rti_ifp = ifp; 128 rti->rti_type = IGMP_v2_ROUTER; 129 LIST_INSERT_HEAD(&rti_head, rti, rti_link); 130 splx(s); 131 return (rti); 132 } 133 134 static void 135 rti_delete(struct ifnet *ifp) /* MUST be called at splsoftnet */ 136 { 137 struct router_info *rti; 138 139 LIST_FOREACH(rti, &rti_head, rti_link) { 140 if (rti->rti_ifp == ifp) { 141 LIST_REMOVE(rti, rti_link); 142 pool_put(&igmp_rti_pool, rti); 143 return; 144 } 145 } 146 } 147 148 void 149 igmp_init(void) 150 { 151 152 pool_init(&igmp_rti_pool, sizeof(struct router_info), 0, 0, 0, 153 "igmppl", NULL, IPL_SOFTNET); 154 igmpstat_percpu = percpu_alloc(sizeof(uint64_t) * IGMP_NSTATS); 155 } 156 157 void 158 igmp_input(struct mbuf *m, ...) 159 { 160 int proto; 161 int iphlen; 162 struct ifnet *ifp = m->m_pkthdr.rcvif; 163 struct ip *ip = mtod(m, struct ip *); 164 struct igmp *igmp; 165 u_int minlen; 166 struct in_multi *inm; 167 struct in_multistep step; 168 struct router_info *rti; 169 struct in_ifaddr *ia; 170 u_int timer; 171 va_list ap; 172 u_int16_t ip_len; 173 174 va_start(ap, m); 175 iphlen = va_arg(ap, int); 176 proto = va_arg(ap, int); 177 va_end(ap); 178 179 IGMP_STATINC(IGMP_STAT_RCV_TOTAL); 180 181 /* 182 * Validate lengths 183 */ 184 minlen = iphlen + IGMP_MINLEN; 185 ip_len = ntohs(ip->ip_len); 186 if (ip_len < minlen) { 187 IGMP_STATINC(IGMP_STAT_RCV_TOOSHORT); 188 m_freem(m); 189 return; 190 } 191 if (((m->m_flags & M_EXT) && (ip->ip_src.s_addr & IN_CLASSA_NET) == 0) 192 || m->m_len < minlen) { 193 if ((m = m_pullup(m, minlen)) == 0) { 194 IGMP_STATINC(IGMP_STAT_RCV_TOOSHORT); 195 return; 196 } 197 ip = mtod(m, struct ip *); 198 } 199 200 /* 201 * Validate checksum 202 */ 203 m->m_data += iphlen; 204 m->m_len -= iphlen; 205 igmp = mtod(m, struct igmp *); 206 /* No need to assert alignment here. */ 207 if (in_cksum(m, ip_len - iphlen)) { 208 IGMP_STATINC(IGMP_STAT_RCV_BADSUM); 209 m_freem(m); 210 return; 211 } 212 m->m_data -= iphlen; 213 m->m_len += iphlen; 214 215 switch (igmp->igmp_type) { 216 217 case IGMP_HOST_MEMBERSHIP_QUERY: 218 IGMP_STATINC(IGMP_STAT_RCV_QUERIES); 219 220 if (ifp->if_flags & IFF_LOOPBACK) 221 break; 222 223 if (igmp->igmp_code == 0) { 224 rti = rti_find(ifp); 225 if (rti == NULL) 226 break; 227 rti->rti_type = IGMP_v1_ROUTER; 228 rti->rti_age = 0; 229 230 if (ip->ip_dst.s_addr != INADDR_ALLHOSTS_GROUP) { 231 IGMP_STATINC(IGMP_STAT_RCV_BADQUERIES); 232 m_freem(m); 233 return; 234 } 235 236 /* 237 * Start the timers in all of our membership records 238 * for the interface on which the query arrived, 239 * except those that are already running and those 240 * that belong to a "local" group (224.0.0.X). 241 */ 242 IN_FIRST_MULTI(step, inm); 243 while (inm != NULL) { 244 if (inm->inm_ifp == ifp && 245 inm->inm_timer == 0 && 246 !IN_LOCAL_GROUP(inm->inm_addr.s_addr)) { 247 inm->inm_state = IGMP_DELAYING_MEMBER; 248 inm->inm_timer = IGMP_RANDOM_DELAY( 249 IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); 250 igmp_timers_are_running = 1; 251 } 252 IN_NEXT_MULTI(step, inm); 253 } 254 } else { 255 if (!IN_MULTICAST(ip->ip_dst.s_addr)) { 256 IGMP_STATINC(IGMP_STAT_RCV_BADQUERIES); 257 m_freem(m); 258 return; 259 } 260 261 timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE; 262 if (timer == 0) 263 timer =1; 264 265 /* 266 * Start the timers in all of our membership records 267 * for the interface on which the query arrived, 268 * except those that are already running and those 269 * that belong to a "local" group (224.0.0.X). For 270 * timers already running, check if they need to be 271 * reset. 272 */ 273 IN_FIRST_MULTI(step, inm); 274 while (inm != NULL) { 275 if (inm->inm_ifp == ifp && 276 !IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 277 (ip->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP || 278 in_hosteq(ip->ip_dst, inm->inm_addr))) { 279 switch (inm->inm_state) { 280 case IGMP_DELAYING_MEMBER: 281 if (inm->inm_timer <= timer) 282 break; 283 /* FALLTHROUGH */ 284 case IGMP_IDLE_MEMBER: 285 case IGMP_LAZY_MEMBER: 286 case IGMP_AWAKENING_MEMBER: 287 inm->inm_state = 288 IGMP_DELAYING_MEMBER; 289 inm->inm_timer = 290 IGMP_RANDOM_DELAY(timer); 291 igmp_timers_are_running = 1; 292 break; 293 case IGMP_SLEEPING_MEMBER: 294 inm->inm_state = 295 IGMP_AWAKENING_MEMBER; 296 break; 297 } 298 } 299 IN_NEXT_MULTI(step, inm); 300 } 301 } 302 303 break; 304 305 case IGMP_v1_HOST_MEMBERSHIP_REPORT: 306 IGMP_STATINC(IGMP_STAT_RCV_REPORTS); 307 308 if (ifp->if_flags & IFF_LOOPBACK) 309 break; 310 311 if (!IN_MULTICAST(igmp->igmp_group.s_addr) || 312 !in_hosteq(igmp->igmp_group, ip->ip_dst)) { 313 IGMP_STATINC(IGMP_STAT_RCV_BADREPORTS); 314 m_freem(m); 315 return; 316 } 317 318 /* 319 * KLUDGE: if the IP source address of the report has an 320 * unspecified (i.e., zero) subnet number, as is allowed for 321 * a booting host, replace it with the correct subnet number 322 * so that a process-level multicast routing daemon can 323 * determine which subnet it arrived from. This is necessary 324 * to compensate for the lack of any way for a process to 325 * determine the arrival interface of an incoming packet. 326 */ 327 if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { 328 IFP_TO_IA(ifp, ia); /* XXX */ 329 if (ia) 330 ip->ip_src.s_addr = ia->ia_subnet; 331 } 332 333 /* 334 * If we belong to the group being reported, stop 335 * our timer for that group. 336 */ 337 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 338 if (inm != NULL) { 339 inm->inm_timer = 0; 340 IGMP_STATINC(IGMP_STAT_RCV_OURREPORTS); 341 342 switch (inm->inm_state) { 343 case IGMP_IDLE_MEMBER: 344 case IGMP_LAZY_MEMBER: 345 case IGMP_AWAKENING_MEMBER: 346 case IGMP_SLEEPING_MEMBER: 347 inm->inm_state = IGMP_SLEEPING_MEMBER; 348 break; 349 case IGMP_DELAYING_MEMBER: 350 if (inm->inm_rti->rti_type == IGMP_v1_ROUTER) 351 inm->inm_state = IGMP_LAZY_MEMBER; 352 else 353 inm->inm_state = IGMP_SLEEPING_MEMBER; 354 break; 355 } 356 } 357 358 break; 359 360 case IGMP_v2_HOST_MEMBERSHIP_REPORT: 361 #ifdef MROUTING 362 /* 363 * Make sure we don't hear our own membership report. Fast 364 * leave requires knowing that we are the only member of a 365 * group. 366 */ 367 IFP_TO_IA(ifp, ia); /* XXX */ 368 if (ia && in_hosteq(ip->ip_src, ia->ia_addr.sin_addr)) 369 break; 370 #endif 371 372 IGMP_STATINC(IGMP_STAT_RCV_REPORTS); 373 374 if (ifp->if_flags & IFF_LOOPBACK) 375 break; 376 377 if (!IN_MULTICAST(igmp->igmp_group.s_addr) || 378 !in_hosteq(igmp->igmp_group, ip->ip_dst)) { 379 IGMP_STATINC(IGMP_STAT_RCV_BADREPORTS); 380 m_freem(m); 381 return; 382 } 383 384 /* 385 * KLUDGE: if the IP source address of the report has an 386 * unspecified (i.e., zero) subnet number, as is allowed for 387 * a booting host, replace it with the correct subnet number 388 * so that a process-level multicast routing daemon can 389 * determine which subnet it arrived from. This is necessary 390 * to compensate for the lack of any way for a process to 391 * determine the arrival interface of an incoming packet. 392 */ 393 if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { 394 #ifndef MROUTING 395 IFP_TO_IA(ifp, ia); /* XXX */ 396 #endif 397 if (ia) 398 ip->ip_src.s_addr = ia->ia_subnet; 399 } 400 401 /* 402 * If we belong to the group being reported, stop 403 * our timer for that group. 404 */ 405 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 406 if (inm != NULL) { 407 inm->inm_timer = 0; 408 IGMP_STATINC(IGMP_STAT_RCV_OURREPORTS); 409 410 switch (inm->inm_state) { 411 case IGMP_DELAYING_MEMBER: 412 case IGMP_IDLE_MEMBER: 413 case IGMP_AWAKENING_MEMBER: 414 inm->inm_state = IGMP_LAZY_MEMBER; 415 break; 416 case IGMP_LAZY_MEMBER: 417 case IGMP_SLEEPING_MEMBER: 418 break; 419 } 420 } 421 422 break; 423 424 } 425 426 /* 427 * Pass all valid IGMP packets up to any process(es) listening 428 * on a raw IGMP socket. 429 */ 430 rip_input(m, iphlen, proto); 431 return; 432 } 433 434 int 435 igmp_joingroup(struct in_multi *inm) 436 { 437 int report_type; 438 int s = splsoftnet(); 439 440 inm->inm_state = IGMP_IDLE_MEMBER; 441 442 if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 443 (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) { 444 report_type = rti_fill(inm); 445 if (report_type == 0) { 446 splx(s); 447 return ENOMEM; 448 } 449 igmp_sendpkt(inm, report_type); 450 inm->inm_state = IGMP_DELAYING_MEMBER; 451 inm->inm_timer = IGMP_RANDOM_DELAY( 452 IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); 453 igmp_timers_are_running = 1; 454 } else 455 inm->inm_timer = 0; 456 splx(s); 457 return 0; 458 } 459 460 void 461 igmp_leavegroup(struct in_multi *inm) 462 { 463 464 switch (inm->inm_state) { 465 case IGMP_DELAYING_MEMBER: 466 case IGMP_IDLE_MEMBER: 467 if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 468 (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) 469 if (inm->inm_rti->rti_type != IGMP_v1_ROUTER) 470 igmp_sendpkt(inm, IGMP_HOST_LEAVE_MESSAGE); 471 break; 472 case IGMP_LAZY_MEMBER: 473 case IGMP_AWAKENING_MEMBER: 474 case IGMP_SLEEPING_MEMBER: 475 break; 476 } 477 } 478 479 void 480 igmp_fasttimo(void) 481 { 482 struct in_multi *inm; 483 struct in_multistep step; 484 485 /* 486 * Quick check to see if any work needs to be done, in order 487 * to minimize the overhead of fasttimo processing. 488 */ 489 if (!igmp_timers_are_running) 490 return; 491 492 mutex_enter(softnet_lock); 493 KERNEL_LOCK(1, NULL); 494 495 igmp_timers_are_running = 0; 496 IN_FIRST_MULTI(step, inm); 497 while (inm != NULL) { 498 if (inm->inm_timer == 0) { 499 /* do nothing */ 500 } else if (--inm->inm_timer == 0) { 501 if (inm->inm_state == IGMP_DELAYING_MEMBER) { 502 if (inm->inm_rti->rti_type == IGMP_v1_ROUTER) 503 igmp_sendpkt(inm, 504 IGMP_v1_HOST_MEMBERSHIP_REPORT); 505 else 506 igmp_sendpkt(inm, 507 IGMP_v2_HOST_MEMBERSHIP_REPORT); 508 inm->inm_state = IGMP_IDLE_MEMBER; 509 } 510 } else { 511 igmp_timers_are_running = 1; 512 } 513 IN_NEXT_MULTI(step, inm); 514 } 515 516 KERNEL_UNLOCK_ONE(NULL); 517 mutex_exit(softnet_lock); 518 } 519 520 void 521 igmp_slowtimo(void) 522 { 523 struct router_info *rti; 524 525 mutex_enter(softnet_lock); 526 KERNEL_LOCK(1, NULL); 527 LIST_FOREACH(rti, &rti_head, rti_link) { 528 if (rti->rti_type == IGMP_v1_ROUTER && 529 ++rti->rti_age >= IGMP_AGE_THRESHOLD) { 530 rti->rti_type = IGMP_v2_ROUTER; 531 } 532 } 533 KERNEL_UNLOCK_ONE(NULL); 534 mutex_exit(softnet_lock); 535 } 536 537 void 538 igmp_sendpkt(struct in_multi *inm, int type) 539 { 540 struct mbuf *m; 541 struct igmp *igmp; 542 struct ip *ip; 543 struct ip_moptions imo; 544 #ifdef MROUTING 545 extern struct socket *ip_mrouter; 546 #endif /* MROUTING */ 547 548 MGETHDR(m, M_DONTWAIT, MT_HEADER); 549 if (m == NULL) 550 return; 551 /* 552 * Assume max_linkhdr + sizeof(struct ip) + IGMP_MINLEN 553 * is smaller than mbuf size returned by MGETHDR. 554 */ 555 m->m_data += max_linkhdr; 556 m->m_len = sizeof(struct ip) + IGMP_MINLEN; 557 m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN; 558 559 ip = mtod(m, struct ip *); 560 ip->ip_tos = 0; 561 ip->ip_len = htons(sizeof(struct ip) + IGMP_MINLEN); 562 ip->ip_off = htons(0); 563 ip->ip_p = IPPROTO_IGMP; 564 ip->ip_src = zeroin_addr; 565 ip->ip_dst = inm->inm_addr; 566 567 m->m_data += sizeof(struct ip); 568 m->m_len -= sizeof(struct ip); 569 igmp = mtod(m, struct igmp *); 570 igmp->igmp_type = type; 571 igmp->igmp_code = 0; 572 igmp->igmp_group = inm->inm_addr; 573 igmp->igmp_cksum = 0; 574 igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN); 575 m->m_data -= sizeof(struct ip); 576 m->m_len += sizeof(struct ip); 577 578 imo.imo_multicast_ifp = inm->inm_ifp; 579 imo.imo_multicast_ttl = 1; 580 #ifdef RSVP_ISI 581 imo.imo_multicast_vif = -1; 582 #endif 583 /* 584 * Request loopback of the report if we are acting as a multicast 585 * router, so that the process-level routing demon can hear it. 586 */ 587 #ifdef MROUTING 588 imo.imo_multicast_loop = (ip_mrouter != NULL); 589 #else 590 imo.imo_multicast_loop = 0; 591 #endif /* MROUTING */ 592 593 ip_output(m, NULL, NULL, IP_MULTICASTOPTS, &imo, NULL); 594 595 IGMP_STATINC(IGMP_STAT_SND_REPORTS); 596 } 597 598 void 599 igmp_purgeif(struct ifnet *ifp) /* MUST be called at splsoftnet() */ 600 { 601 rti_delete(ifp); /* manipulates pools */ 602 } 603 604 static int 605 sysctl_net_inet_igmp_stats(SYSCTLFN_ARGS) 606 { 607 608 return (NETSTAT_SYSCTL(igmpstat_percpu, IGMP_NSTATS)); 609 } 610 611 SYSCTL_SETUP(sysctl_net_inet_igmp_setup, "sysctl net.inet.igmp subtree setup") 612 { 613 614 sysctl_createv(clog, 0, NULL, NULL, 615 CTLFLAG_PERMANENT, 616 CTLTYPE_NODE, "net", NULL, 617 NULL, 0, NULL, 0, 618 CTL_NET, CTL_EOL); 619 sysctl_createv(clog, 0, NULL, NULL, 620 CTLFLAG_PERMANENT, 621 CTLTYPE_NODE, "inet", NULL, 622 NULL, 0, NULL, 0, 623 CTL_NET, PF_INET, CTL_EOL); 624 sysctl_createv(clog, 0, NULL, NULL, 625 CTLFLAG_PERMANENT, 626 CTLTYPE_NODE, "igmp", 627 SYSCTL_DESCR("Internet Group Management Protocol"), 628 NULL, 0, NULL, 0, 629 CTL_NET, PF_INET, IPPROTO_IGMP, CTL_EOL); 630 631 sysctl_createv(clog, 0, NULL, NULL, 632 CTLFLAG_PERMANENT, 633 CTLTYPE_STRUCT, "stats", 634 SYSCTL_DESCR("IGMP statistics"), 635 sysctl_net_inet_igmp_stats, 0, NULL, 0, 636 CTL_NET, PF_INET, IPPROTO_IGMP, CTL_CREATE, CTL_EOL); 637 } 638
Indexes created Mon Sep 22 21:09:42 GMT 2025