igmp.c revision 1.28
1 /* $NetBSD: igmp.c,v 1.28 2002/05/12 20:33:50 matt 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 1.28 2002/05/12 20:33:50 matt 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 struct igmpstat igmpstat; 69 int igmp_timers_are_running; 70 static struct router_info *rti_head; 71 72 void igmp_sendpkt __P((struct in_multi *, int)); 73 static int rti_fill __P((struct in_multi *)); 74 static struct router_info * rti_find __P((struct ifnet *)); 75 76 void 77 igmp_init() 78 { 79 80 igmp_timers_are_running = 0; 81 rti_head = 0; 82 } 83 84 static int 85 rti_fill(inm) 86 struct in_multi *inm; 87 { 88 struct router_info *rti; 89 90 for (rti = rti_head; rti != 0; rti = rti->rti_next) { 91 if (rti->rti_ifp == inm->inm_ifp) { 92 inm->inm_rti = rti; 93 if (rti->rti_type == IGMP_v1_ROUTER) 94 return (IGMP_v1_HOST_MEMBERSHIP_REPORT); 95 else 96 return (IGMP_v2_HOST_MEMBERSHIP_REPORT); 97 } 98 } 99 100 rti = (struct router_info *)malloc(sizeof(struct router_info), 101 M_MRTABLE, M_NOWAIT); 102 rti->rti_ifp = inm->inm_ifp; 103 rti->rti_type = IGMP_v2_ROUTER; 104 rti->rti_next = rti_head; 105 rti_head = rti; 106 inm->inm_rti = rti; 107 return (IGMP_v2_HOST_MEMBERSHIP_REPORT); 108 } 109 110 static struct router_info * 111 rti_find(ifp) 112 struct ifnet *ifp; 113 { 114 struct router_info *rti; 115 116 for (rti = rti_head; rti != 0; rti = rti->rti_next) { 117 if (rti->rti_ifp == ifp) 118 return (rti); 119 } 120 121 rti = (struct router_info *)malloc(sizeof(struct router_info), 122 M_MRTABLE, M_NOWAIT); 123 rti->rti_ifp = ifp; 124 rti->rti_type = IGMP_v2_ROUTER; 125 rti->rti_next = rti_head; 126 rti_head = rti; 127 return (rti); 128 } 129 130 void 131 #if __STDC__ 132 igmp_input(struct mbuf *m, ...) 133 #else 134 igmp_input(m, va_alist) 135 struct mbuf *m; 136 va_dcl 137 #endif 138 { 139 int proto; 140 int iphlen; 141 struct ifnet *ifp = m->m_pkthdr.rcvif; 142 struct ip *ip = mtod(m, struct ip *); 143 struct igmp *igmp; 144 int minlen; 145 struct in_multi *inm; 146 struct in_multistep step; 147 struct router_info *rti; 148 struct in_ifaddr *ia; 149 int timer; 150 va_list ap; 151 152 va_start(ap, m); 153 iphlen = va_arg(ap, int); 154 proto = va_arg(ap, int); 155 va_end(ap); 156 157 ++igmpstat.igps_rcv_total; 158 159 /* 160 * Validate lengths 161 */ 162 minlen = iphlen + IGMP_MINLEN; 163 if (ip->ip_len < minlen) { 164 ++igmpstat.igps_rcv_tooshort; 165 m_freem(m); 166 return; 167 } 168 if (((m->m_flags & M_EXT) && (ip->ip_src.s_addr & IN_CLASSA_NET) == 0) 169 || m->m_len < minlen) { 170 if ((m = m_pullup(m, minlen)) == 0) { 171 ++igmpstat.igps_rcv_tooshort; 172 return; 173 } 174 ip = mtod(m, struct ip *); 175 } 176 177 /* 178 * Validate checksum 179 */ 180 m->m_data += iphlen; 181 m->m_len -= iphlen; 182 igmp = mtod(m, struct igmp *); 183 if (in_cksum(m, ip->ip_len - iphlen)) { 184 ++igmpstat.igps_rcv_badsum; 185 m_freem(m); 186 return; 187 } 188 m->m_data -= iphlen; 189 m->m_len += iphlen; 190 191 switch (igmp->igmp_type) { 192 193 case IGMP_HOST_MEMBERSHIP_QUERY: 194 ++igmpstat.igps_rcv_queries; 195 196 if (ifp->if_flags & IFF_LOOPBACK) 197 break; 198 199 if (igmp->igmp_code == 0) { 200 rti = rti_find(ifp); 201 rti->rti_type = IGMP_v1_ROUTER; 202 rti->rti_age = 0; 203 204 if (ip->ip_dst.s_addr != INADDR_ALLHOSTS_GROUP) { 205 ++igmpstat.igps_rcv_badqueries; 206 m_freem(m); 207 return; 208 } 209 210 /* 211 * Start the timers in all of our membership records 212 * for the interface on which the query arrived, 213 * except those that are already running and those 214 * that belong to a "local" group (224.0.0.X). 215 */ 216 IN_FIRST_MULTI(step, inm); 217 while (inm != NULL) { 218 if (inm->inm_ifp == ifp && 219 inm->inm_timer == 0 && 220 !IN_LOCAL_GROUP(inm->inm_addr.s_addr)) { 221 inm->inm_state = IGMP_DELAYING_MEMBER; 222 inm->inm_timer = IGMP_RANDOM_DELAY( 223 IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); 224 igmp_timers_are_running = 1; 225 } 226 IN_NEXT_MULTI(step, inm); 227 } 228 } else { 229 if (!IN_MULTICAST(ip->ip_dst.s_addr)) { 230 ++igmpstat.igps_rcv_badqueries; 231 m_freem(m); 232 return; 233 } 234 235 timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE; 236 if (timer == 0) 237 timer =1; 238 239 /* 240 * Start the timers in all of our membership records 241 * for the interface on which the query arrived, 242 * except those that are already running and those 243 * that belong to a "local" group (224.0.0.X). For 244 * timers already running, check if they need to be 245 * reset. 246 */ 247 IN_FIRST_MULTI(step, inm); 248 while (inm != NULL) { 249 if (inm->inm_ifp == ifp && 250 !IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 251 (ip->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP || 252 in_hosteq(ip->ip_dst, inm->inm_addr))) { 253 switch (inm->inm_state) { 254 case IGMP_DELAYING_MEMBER: 255 if (inm->inm_timer <= timer) 256 break; 257 /* FALLTHROUGH */ 258 case IGMP_IDLE_MEMBER: 259 case IGMP_LAZY_MEMBER: 260 case IGMP_AWAKENING_MEMBER: 261 inm->inm_state = 262 IGMP_DELAYING_MEMBER; 263 inm->inm_timer = 264 IGMP_RANDOM_DELAY(timer); 265 igmp_timers_are_running = 1; 266 break; 267 case IGMP_SLEEPING_MEMBER: 268 inm->inm_state = 269 IGMP_AWAKENING_MEMBER; 270 break; 271 } 272 } 273 IN_NEXT_MULTI(step, inm); 274 } 275 } 276 277 break; 278 279 case IGMP_v1_HOST_MEMBERSHIP_REPORT: 280 ++igmpstat.igps_rcv_reports; 281 282 if (ifp->if_flags & IFF_LOOPBACK) 283 break; 284 285 if (!IN_MULTICAST(igmp->igmp_group.s_addr) || 286 !in_hosteq(igmp->igmp_group, ip->ip_dst)) { 287 ++igmpstat.igps_rcv_badreports; 288 m_freem(m); 289 return; 290 } 291 292 /* 293 * KLUDGE: if the IP source address of the report has an 294 * unspecified (i.e., zero) subnet number, as is allowed for 295 * a booting host, replace it with the correct subnet number 296 * so that a process-level multicast routing daemon can 297 * determine which subnet it arrived from. This is necessary 298 * to compensate for the lack of any way for a process to 299 * determine the arrival interface of an incoming packet. 300 */ 301 if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { 302 IFP_TO_IA(ifp, ia); /* XXX */ 303 if (ia) 304 ip->ip_src.s_addr = ia->ia_subnet; 305 } 306 307 /* 308 * If we belong to the group being reported, stop 309 * our timer for that group. 310 */ 311 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 312 if (inm != NULL) { 313 inm->inm_timer = 0; 314 ++igmpstat.igps_rcv_ourreports; 315 316 switch (inm->inm_state) { 317 case IGMP_IDLE_MEMBER: 318 case IGMP_LAZY_MEMBER: 319 case IGMP_AWAKENING_MEMBER: 320 case IGMP_SLEEPING_MEMBER: 321 inm->inm_state = IGMP_SLEEPING_MEMBER; 322 break; 323 case IGMP_DELAYING_MEMBER: 324 if (inm->inm_rti->rti_type == IGMP_v1_ROUTER) 325 inm->inm_state = IGMP_LAZY_MEMBER; 326 else 327 inm->inm_state = IGMP_SLEEPING_MEMBER; 328 break; 329 } 330 } 331 332 break; 333 334 case IGMP_v2_HOST_MEMBERSHIP_REPORT: 335 #ifdef MROUTING 336 /* 337 * Make sure we don't hear our own membership report. Fast 338 * leave requires knowing that we are the only member of a 339 * group. 340 */ 341 IFP_TO_IA(ifp, ia); /* XXX */ 342 if (ia && in_hosteq(ip->ip_src, ia->ia_addr.sin_addr)) 343 break; 344 #endif 345 346 ++igmpstat.igps_rcv_reports; 347 348 if (ifp->if_flags & IFF_LOOPBACK) 349 break; 350 351 if (!IN_MULTICAST(igmp->igmp_group.s_addr) || 352 !in_hosteq(igmp->igmp_group, ip->ip_dst)) { 353 ++igmpstat.igps_rcv_badreports; 354 m_freem(m); 355 return; 356 } 357 358 /* 359 * KLUDGE: if the IP source address of the report has an 360 * unspecified (i.e., zero) subnet number, as is allowed for 361 * a booting host, replace it with the correct subnet number 362 * so that a process-level multicast routing daemon can 363 * determine which subnet it arrived from. This is necessary 364 * to compensate for the lack of any way for a process to 365 * determine the arrival interface of an incoming packet. 366 */ 367 if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { 368 #ifndef MROUTING 369 IFP_TO_IA(ifp, ia); /* XXX */ 370 #endif 371 if (ia) 372 ip->ip_src.s_addr = ia->ia_subnet; 373 } 374 375 /* 376 * If we belong to the group being reported, stop 377 * our timer for that group. 378 */ 379 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 380 if (inm != NULL) { 381 inm->inm_timer = 0; 382 ++igmpstat.igps_rcv_ourreports; 383 384 switch (inm->inm_state) { 385 case IGMP_DELAYING_MEMBER: 386 case IGMP_IDLE_MEMBER: 387 case IGMP_AWAKENING_MEMBER: 388 inm->inm_state = IGMP_LAZY_MEMBER; 389 break; 390 case IGMP_LAZY_MEMBER: 391 case IGMP_SLEEPING_MEMBER: 392 break; 393 } 394 } 395 396 break; 397 398 } 399 400 /* 401 * Pass all valid IGMP packets up to any process(es) listening 402 * on a raw IGMP socket. 403 */ 404 rip_input(m, iphlen, proto); 405 return; 406 } 407 408 void 409 igmp_joingroup(inm) 410 struct in_multi *inm; 411 { 412 int s = splsoftnet(); 413 414 inm->inm_state = IGMP_IDLE_MEMBER; 415 416 if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 417 (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) { 418 igmp_sendpkt(inm, rti_fill(inm)); 419 inm->inm_state = IGMP_DELAYING_MEMBER; 420 inm->inm_timer = IGMP_RANDOM_DELAY( 421 IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); 422 igmp_timers_are_running = 1; 423 } else 424 inm->inm_timer = 0; 425 splx(s); 426 } 427 428 void 429 igmp_leavegroup(inm) 430 struct in_multi *inm; 431 { 432 433 switch (inm->inm_state) { 434 case IGMP_DELAYING_MEMBER: 435 case IGMP_IDLE_MEMBER: 436 if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 437 (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) 438 if (inm->inm_rti->rti_type != IGMP_v1_ROUTER) 439 igmp_sendpkt(inm, IGMP_HOST_LEAVE_MESSAGE); 440 break; 441 case IGMP_LAZY_MEMBER: 442 case IGMP_AWAKENING_MEMBER: 443 case IGMP_SLEEPING_MEMBER: 444 break; 445 } 446 } 447 448 void 449 igmp_fasttimo() 450 { 451 struct in_multi *inm; 452 struct in_multistep step; 453 int s; 454 455 /* 456 * Quick check to see if any work needs to be done, in order 457 * to minimize the overhead of fasttimo processing. 458 */ 459 if (!igmp_timers_are_running) 460 return; 461 462 s = splsoftnet(); 463 igmp_timers_are_running = 0; 464 IN_FIRST_MULTI(step, inm); 465 while (inm != NULL) { 466 if (inm->inm_timer == 0) { 467 /* do nothing */ 468 } else if (--inm->inm_timer == 0) { 469 if (inm->inm_state == IGMP_DELAYING_MEMBER) { 470 if (inm->inm_rti->rti_type == IGMP_v1_ROUTER) 471 igmp_sendpkt(inm, 472 IGMP_v1_HOST_MEMBERSHIP_REPORT); 473 else 474 igmp_sendpkt(inm, 475 IGMP_v2_HOST_MEMBERSHIP_REPORT); 476 inm->inm_state = IGMP_IDLE_MEMBER; 477 } 478 } else { 479 igmp_timers_are_running = 1; 480 } 481 IN_NEXT_MULTI(step, inm); 482 } 483 splx(s); 484 } 485 486 void 487 igmp_slowtimo() 488 { 489 struct router_info *rti; 490 int s; 491 492 s = splsoftnet(); 493 for (rti = rti_head; rti != 0; rti = rti->rti_next) { 494 if (rti->rti_type == IGMP_v1_ROUTER && 495 ++rti->rti_age >= IGMP_AGE_THRESHOLD) { 496 rti->rti_type = IGMP_v2_ROUTER; 497 } 498 } 499 splx(s); 500 } 501 502 void 503 igmp_sendpkt(inm, type) 504 struct in_multi *inm; 505 int type; 506 { 507 struct mbuf *m; 508 struct igmp *igmp; 509 struct ip *ip; 510 struct ip_moptions imo; 511 #ifdef MROUTING 512 extern struct socket *ip_mrouter; 513 #endif /* MROUTING */ 514 515 MGETHDR(m, M_DONTWAIT, MT_HEADER); 516 if (m == NULL) 517 return; 518 /* 519 * Assume max_linkhdr + sizeof(struct ip) + IGMP_MINLEN 520 * is smaller than mbuf size returned by MGETHDR. 521 */ 522 m->m_data += max_linkhdr; 523 m->m_len = sizeof(struct ip) + IGMP_MINLEN; 524 m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN; 525 526 ip = mtod(m, struct ip *); 527 ip->ip_tos = 0; 528 ip->ip_len = sizeof(struct ip) + IGMP_MINLEN; 529 ip->ip_off = 0; 530 ip->ip_p = IPPROTO_IGMP; 531 ip->ip_src = zeroin_addr; 532 ip->ip_dst = inm->inm_addr; 533 534 m->m_data += sizeof(struct ip); 535 m->m_len -= sizeof(struct ip); 536 igmp = mtod(m, struct igmp *); 537 igmp->igmp_type = type; 538 igmp->igmp_code = 0; 539 igmp->igmp_group = inm->inm_addr; 540 igmp->igmp_cksum = 0; 541 igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN); 542 m->m_data -= sizeof(struct ip); 543 m->m_len += sizeof(struct ip); 544 545 imo.imo_multicast_ifp = inm->inm_ifp; 546 imo.imo_multicast_ttl = 1; 547 #ifdef RSVP_ISI 548 imo.imo_multicast_vif = -1; 549 #endif 550 /* 551 * Request loopback of the report if we are acting as a multicast 552 * router, so that the process-level routing demon can hear it. 553 */ 554 #ifdef MROUTING 555 imo.imo_multicast_loop = (ip_mrouter != NULL); 556 #else 557 imo.imo_multicast_loop = 0; 558 #endif /* MROUTING */ 559 560 ip_output(m, (struct mbuf *)0, (struct route *)0, IP_MULTICASTOPTS, 561 &imo); 562 563 ++igmpstat.igps_snd_reports; 564 } 565
Indexes created Wed Sep 24 14:09:57 GMT 2025