igmp.c revision 1.30
1 /* $NetBSD: igmp.c,v 1.30 2002/06/30 22:40:33 thorpej 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 1.30 2002/06/30 22:40:33 thorpej 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 /* No need to assert alignment here. */ 184 if (in_cksum(m, ip->ip_len - iphlen)) { 185 ++igmpstat.igps_rcv_badsum; 186 m_freem(m); 187 return; 188 } 189 m->m_data -= iphlen; 190 m->m_len += iphlen; 191 192 switch (igmp->igmp_type) { 193 194 case IGMP_HOST_MEMBERSHIP_QUERY: 195 ++igmpstat.igps_rcv_queries; 196 197 if (ifp->if_flags & IFF_LOOPBACK) 198 break; 199 200 if (igmp->igmp_code == 0) { 201 rti = rti_find(ifp); 202 rti->rti_type = IGMP_v1_ROUTER; 203 rti->rti_age = 0; 204 205 if (ip->ip_dst.s_addr != INADDR_ALLHOSTS_GROUP) { 206 ++igmpstat.igps_rcv_badqueries; 207 m_freem(m); 208 return; 209 } 210 211 /* 212 * Start the timers in all of our membership records 213 * for the interface on which the query arrived, 214 * except those that are already running and those 215 * that belong to a "local" group (224.0.0.X). 216 */ 217 IN_FIRST_MULTI(step, inm); 218 while (inm != NULL) { 219 if (inm->inm_ifp == ifp && 220 inm->inm_timer == 0 && 221 !IN_LOCAL_GROUP(inm->inm_addr.s_addr)) { 222 inm->inm_state = IGMP_DELAYING_MEMBER; 223 inm->inm_timer = IGMP_RANDOM_DELAY( 224 IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); 225 igmp_timers_are_running = 1; 226 } 227 IN_NEXT_MULTI(step, inm); 228 } 229 } else { 230 if (!IN_MULTICAST(ip->ip_dst.s_addr)) { 231 ++igmpstat.igps_rcv_badqueries; 232 m_freem(m); 233 return; 234 } 235 236 timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE; 237 if (timer == 0) 238 timer =1; 239 240 /* 241 * Start the timers in all of our membership records 242 * for the interface on which the query arrived, 243 * except those that are already running and those 244 * that belong to a "local" group (224.0.0.X). For 245 * timers already running, check if they need to be 246 * reset. 247 */ 248 IN_FIRST_MULTI(step, inm); 249 while (inm != NULL) { 250 if (inm->inm_ifp == ifp && 251 !IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 252 (ip->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP || 253 in_hosteq(ip->ip_dst, inm->inm_addr))) { 254 switch (inm->inm_state) { 255 case IGMP_DELAYING_MEMBER: 256 if (inm->inm_timer <= timer) 257 break; 258 /* FALLTHROUGH */ 259 case IGMP_IDLE_MEMBER: 260 case IGMP_LAZY_MEMBER: 261 case IGMP_AWAKENING_MEMBER: 262 inm->inm_state = 263 IGMP_DELAYING_MEMBER; 264 inm->inm_timer = 265 IGMP_RANDOM_DELAY(timer); 266 igmp_timers_are_running = 1; 267 break; 268 case IGMP_SLEEPING_MEMBER: 269 inm->inm_state = 270 IGMP_AWAKENING_MEMBER; 271 break; 272 } 273 } 274 IN_NEXT_MULTI(step, inm); 275 } 276 } 277 278 break; 279 280 case IGMP_v1_HOST_MEMBERSHIP_REPORT: 281 ++igmpstat.igps_rcv_reports; 282 283 if (ifp->if_flags & IFF_LOOPBACK) 284 break; 285 286 if (!IN_MULTICAST(igmp->igmp_group.s_addr) || 287 !in_hosteq(igmp->igmp_group, ip->ip_dst)) { 288 ++igmpstat.igps_rcv_badreports; 289 m_freem(m); 290 return; 291 } 292 293 /* 294 * KLUDGE: if the IP source address of the report has an 295 * unspecified (i.e., zero) subnet number, as is allowed for 296 * a booting host, replace it with the correct subnet number 297 * so that a process-level multicast routing daemon can 298 * determine which subnet it arrived from. This is necessary 299 * to compensate for the lack of any way for a process to 300 * determine the arrival interface of an incoming packet. 301 */ 302 if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { 303 IFP_TO_IA(ifp, ia); /* XXX */ 304 if (ia) 305 ip->ip_src.s_addr = ia->ia_subnet; 306 } 307 308 /* 309 * If we belong to the group being reported, stop 310 * our timer for that group. 311 */ 312 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 313 if (inm != NULL) { 314 inm->inm_timer = 0; 315 ++igmpstat.igps_rcv_ourreports; 316 317 switch (inm->inm_state) { 318 case IGMP_IDLE_MEMBER: 319 case IGMP_LAZY_MEMBER: 320 case IGMP_AWAKENING_MEMBER: 321 case IGMP_SLEEPING_MEMBER: 322 inm->inm_state = IGMP_SLEEPING_MEMBER; 323 break; 324 case IGMP_DELAYING_MEMBER: 325 if (inm->inm_rti->rti_type == IGMP_v1_ROUTER) 326 inm->inm_state = IGMP_LAZY_MEMBER; 327 else 328 inm->inm_state = IGMP_SLEEPING_MEMBER; 329 break; 330 } 331 } 332 333 break; 334 335 case IGMP_v2_HOST_MEMBERSHIP_REPORT: 336 #ifdef MROUTING 337 /* 338 * Make sure we don't hear our own membership report. Fast 339 * leave requires knowing that we are the only member of a 340 * group. 341 */ 342 IFP_TO_IA(ifp, ia); /* XXX */ 343 if (ia && in_hosteq(ip->ip_src, ia->ia_addr.sin_addr)) 344 break; 345 #endif 346 347 ++igmpstat.igps_rcv_reports; 348 349 if (ifp->if_flags & IFF_LOOPBACK) 350 break; 351 352 if (!IN_MULTICAST(igmp->igmp_group.s_addr) || 353 !in_hosteq(igmp->igmp_group, ip->ip_dst)) { 354 ++igmpstat.igps_rcv_badreports; 355 m_freem(m); 356 return; 357 } 358 359 /* 360 * KLUDGE: if the IP source address of the report has an 361 * unspecified (i.e., zero) subnet number, as is allowed for 362 * a booting host, replace it with the correct subnet number 363 * so that a process-level multicast routing daemon can 364 * determine which subnet it arrived from. This is necessary 365 * to compensate for the lack of any way for a process to 366 * determine the arrival interface of an incoming packet. 367 */ 368 if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { 369 #ifndef MROUTING 370 IFP_TO_IA(ifp, ia); /* XXX */ 371 #endif 372 if (ia) 373 ip->ip_src.s_addr = ia->ia_subnet; 374 } 375 376 /* 377 * If we belong to the group being reported, stop 378 * our timer for that group. 379 */ 380 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 381 if (inm != NULL) { 382 inm->inm_timer = 0; 383 ++igmpstat.igps_rcv_ourreports; 384 385 switch (inm->inm_state) { 386 case IGMP_DELAYING_MEMBER: 387 case IGMP_IDLE_MEMBER: 388 case IGMP_AWAKENING_MEMBER: 389 inm->inm_state = IGMP_LAZY_MEMBER; 390 break; 391 case IGMP_LAZY_MEMBER: 392 case IGMP_SLEEPING_MEMBER: 393 break; 394 } 395 } 396 397 break; 398 399 } 400 401 /* 402 * Pass all valid IGMP packets up to any process(es) listening 403 * on a raw IGMP socket. 404 */ 405 rip_input(m, iphlen, proto); 406 return; 407 } 408 409 void 410 igmp_joingroup(inm) 411 struct in_multi *inm; 412 { 413 int s = splsoftnet(); 414 415 inm->inm_state = IGMP_IDLE_MEMBER; 416 417 if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 418 (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) { 419 igmp_sendpkt(inm, rti_fill(inm)); 420 inm->inm_state = IGMP_DELAYING_MEMBER; 421 inm->inm_timer = IGMP_RANDOM_DELAY( 422 IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); 423 igmp_timers_are_running = 1; 424 } else 425 inm->inm_timer = 0; 426 splx(s); 427 } 428 429 void 430 igmp_leavegroup(inm) 431 struct in_multi *inm; 432 { 433 434 switch (inm->inm_state) { 435 case IGMP_DELAYING_MEMBER: 436 case IGMP_IDLE_MEMBER: 437 if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 438 (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) 439 if (inm->inm_rti->rti_type != IGMP_v1_ROUTER) 440 igmp_sendpkt(inm, IGMP_HOST_LEAVE_MESSAGE); 441 break; 442 case IGMP_LAZY_MEMBER: 443 case IGMP_AWAKENING_MEMBER: 444 case IGMP_SLEEPING_MEMBER: 445 break; 446 } 447 } 448 449 void 450 igmp_fasttimo() 451 { 452 struct in_multi *inm; 453 struct in_multistep step; 454 int s; 455 456 /* 457 * Quick check to see if any work needs to be done, in order 458 * to minimize the overhead of fasttimo processing. 459 */ 460 if (!igmp_timers_are_running) 461 return; 462 463 s = splsoftnet(); 464 igmp_timers_are_running = 0; 465 IN_FIRST_MULTI(step, inm); 466 while (inm != NULL) { 467 if (inm->inm_timer == 0) { 468 /* do nothing */ 469 } else if (--inm->inm_timer == 0) { 470 if (inm->inm_state == IGMP_DELAYING_MEMBER) { 471 if (inm->inm_rti->rti_type == IGMP_v1_ROUTER) 472 igmp_sendpkt(inm, 473 IGMP_v1_HOST_MEMBERSHIP_REPORT); 474 else 475 igmp_sendpkt(inm, 476 IGMP_v2_HOST_MEMBERSHIP_REPORT); 477 inm->inm_state = IGMP_IDLE_MEMBER; 478 } 479 } else { 480 igmp_timers_are_running = 1; 481 } 482 IN_NEXT_MULTI(step, inm); 483 } 484 splx(s); 485 } 486 487 void 488 igmp_slowtimo() 489 { 490 struct router_info *rti; 491 int s; 492 493 s = splsoftnet(); 494 for (rti = rti_head; rti != 0; rti = rti->rti_next) { 495 if (rti->rti_type == IGMP_v1_ROUTER && 496 ++rti->rti_age >= IGMP_AGE_THRESHOLD) { 497 rti->rti_type = IGMP_v2_ROUTER; 498 } 499 } 500 splx(s); 501 } 502 503 void 504 igmp_sendpkt(inm, type) 505 struct in_multi *inm; 506 int type; 507 { 508 struct mbuf *m; 509 struct igmp *igmp; 510 struct ip *ip; 511 struct ip_moptions imo; 512 #ifdef MROUTING 513 extern struct socket *ip_mrouter; 514 #endif /* MROUTING */ 515 516 MGETHDR(m, M_DONTWAIT, MT_HEADER); 517 if (m == NULL) 518 return; 519 /* 520 * Assume max_linkhdr + sizeof(struct ip) + IGMP_MINLEN 521 * is smaller than mbuf size returned by MGETHDR. 522 */ 523 m->m_data += max_linkhdr; 524 m->m_len = sizeof(struct ip) + IGMP_MINLEN; 525 m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN; 526 527 ip = mtod(m, struct ip *); 528 ip->ip_tos = 0; 529 ip->ip_len = sizeof(struct ip) + IGMP_MINLEN; 530 ip->ip_off = 0; 531 ip->ip_p = IPPROTO_IGMP; 532 ip->ip_src = zeroin_addr; 533 ip->ip_dst = inm->inm_addr; 534 535 m->m_data += sizeof(struct ip); 536 m->m_len -= sizeof(struct ip); 537 igmp = mtod(m, struct igmp *); 538 igmp->igmp_type = type; 539 igmp->igmp_code = 0; 540 igmp->igmp_group = inm->inm_addr; 541 igmp->igmp_cksum = 0; 542 igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN); 543 m->m_data -= sizeof(struct ip); 544 m->m_len += sizeof(struct ip); 545 546 imo.imo_multicast_ifp = inm->inm_ifp; 547 imo.imo_multicast_ttl = 1; 548 #ifdef RSVP_ISI 549 imo.imo_multicast_vif = -1; 550 #endif 551 /* 552 * Request loopback of the report if we are acting as a multicast 553 * router, so that the process-level routing demon can hear it. 554 */ 555 #ifdef MROUTING 556 imo.imo_multicast_loop = (ip_mrouter != NULL); 557 #else 558 imo.imo_multicast_loop = 0; 559 #endif /* MROUTING */ 560 561 ip_output(m, (struct mbuf *)0, (struct route *)0, IP_MULTICASTOPTS, 562 &imo); 563 564 ++igmpstat.igps_snd_reports; 565 } 566
Indexes created Tue Sep 23 22:09:46 GMT 2025