igmp.c revision 1.24
1 /* $NetBSD: igmp.c,v 1.24 2000/03/30 13:24:54 augustss 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 "opt_mrouting.h" 43 44 #include <sys/param.h> 45 #include <sys/mbuf.h> 46 #include <sys/socket.h> 47 #include <sys/protosw.h> 48 #include <sys/systm.h> 49 50 #include <net/if.h> 51 #include <net/route.h> 52 53 #include <netinet/in.h> 54 #include <netinet/in_var.h> 55 #include <netinet/in_systm.h> 56 #include <netinet/ip.h> 57 #include <netinet/ip_var.h> 58 #include <netinet/igmp.h> 59 #include <netinet/igmp_var.h> 60 61 #include <machine/stdarg.h> 62 63 #define IP_MULTICASTOPTS 0 64 65 int igmp_timers_are_running; 66 static struct router_info *rti_head; 67 68 void igmp_sendpkt __P((struct in_multi *, int)); 69 static int rti_fill __P((struct in_multi *)); 70 static struct router_info * rti_find __P((struct ifnet *)); 71 72 void 73 igmp_init() 74 { 75 76 /* 77 * To avoid byte-swapping the same value over and over again. 78 */ 79 igmp_timers_are_running = 0; 80 rti_head = 0; 81 } 82 83 static int 84 rti_fill(inm) 85 struct in_multi *inm; 86 { 87 struct router_info *rti; 88 89 for (rti = rti_head; rti != 0; rti = rti->rti_next) { 90 if (rti->rti_ifp == inm->inm_ifp) { 91 inm->inm_rti = rti; 92 if (rti->rti_type == IGMP_v1_ROUTER) 93 return (IGMP_v1_HOST_MEMBERSHIP_REPORT); 94 else 95 return (IGMP_v2_HOST_MEMBERSHIP_REPORT); 96 } 97 } 98 99 rti = (struct router_info *)malloc(sizeof(struct router_info), 100 M_MRTABLE, M_NOWAIT); 101 rti->rti_ifp = inm->inm_ifp; 102 rti->rti_type = IGMP_v2_ROUTER; 103 rti->rti_next = rti_head; 104 rti_head = rti; 105 inm->inm_rti = rti; 106 return (IGMP_v2_HOST_MEMBERSHIP_REPORT); 107 } 108 109 static struct router_info * 110 rti_find(ifp) 111 struct ifnet *ifp; 112 { 113 struct router_info *rti; 114 115 for (rti = rti_head; rti != 0; rti = rti->rti_next) { 116 if (rti->rti_ifp == ifp) 117 return (rti); 118 } 119 120 rti = (struct router_info *)malloc(sizeof(struct router_info), 121 M_MRTABLE, M_NOWAIT); 122 rti->rti_ifp = ifp; 123 rti->rti_type = IGMP_v2_ROUTER; 124 rti->rti_next = rti_head; 125 rti_head = rti; 126 return (rti); 127 } 128 129 void 130 #if __STDC__ 131 igmp_input(struct mbuf *m, ...) 132 #else 133 igmp_input(m, va_alist) 134 struct mbuf *m; 135 va_dcl 136 #endif 137 { 138 int proto; 139 int iphlen; 140 struct ifnet *ifp = m->m_pkthdr.rcvif; 141 struct ip *ip = mtod(m, struct ip *); 142 struct igmp *igmp; 143 int minlen; 144 struct in_multi *inm; 145 struct in_multistep step; 146 struct router_info *rti; 147 struct in_ifaddr *ia; 148 int timer; 149 va_list ap; 150 151 va_start(ap, m); 152 iphlen = va_arg(ap, int); 153 proto = va_arg(ap, int); 154 va_end(ap); 155 156 ++igmpstat.igps_rcv_total; 157 158 /* 159 * Validate lengths 160 */ 161 minlen = iphlen + IGMP_MINLEN; 162 if (ip->ip_len < minlen) { 163 ++igmpstat.igps_rcv_tooshort; 164 m_freem(m); 165 return; 166 } 167 if ((m->m_flags & M_EXT || m->m_len < minlen) && 168 (m = m_pullup(m, minlen)) == 0) { 169 ++igmpstat.igps_rcv_tooshort; 170 return; 171 } 172 173 /* 174 * Validate checksum 175 */ 176 m->m_data += iphlen; 177 m->m_len -= iphlen; 178 igmp = mtod(m, struct igmp *); 179 if (in_cksum(m, ip->ip_len - iphlen)) { 180 ++igmpstat.igps_rcv_badsum; 181 m_freem(m); 182 return; 183 } 184 m->m_data -= iphlen; 185 m->m_len += iphlen; 186 ip = mtod(m, struct ip *); 187 188 switch (igmp->igmp_type) { 189 190 case IGMP_HOST_MEMBERSHIP_QUERY: 191 ++igmpstat.igps_rcv_queries; 192 193 if (ifp->if_flags & IFF_LOOPBACK) 194 break; 195 196 if (igmp->igmp_code == 0) { 197 rti = rti_find(ifp); 198 rti->rti_type = IGMP_v1_ROUTER; 199 rti->rti_age = 0; 200 201 if (ip->ip_dst.s_addr != INADDR_ALLHOSTS_GROUP) { 202 ++igmpstat.igps_rcv_badqueries; 203 m_freem(m); 204 return; 205 } 206 207 /* 208 * Start the timers in all of our membership records 209 * for the interface on which the query arrived, 210 * except those that are already running and those 211 * that belong to a "local" group (224.0.0.X). 212 */ 213 IN_FIRST_MULTI(step, inm); 214 while (inm != NULL) { 215 if (inm->inm_ifp == ifp && 216 inm->inm_timer == 0 && 217 !IN_LOCAL_GROUP(inm->inm_addr.s_addr)) { 218 inm->inm_state = IGMP_DELAYING_MEMBER; 219 inm->inm_timer = IGMP_RANDOM_DELAY( 220 IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); 221 igmp_timers_are_running = 1; 222 } 223 IN_NEXT_MULTI(step, inm); 224 } 225 } else { 226 if (!IN_MULTICAST(ip->ip_dst.s_addr)) { 227 ++igmpstat.igps_rcv_badqueries; 228 m_freem(m); 229 return; 230 } 231 232 timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE; 233 if (timer == 0) 234 timer =1; 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). For 241 * timers already running, check if they need to be 242 * reset. 243 */ 244 IN_FIRST_MULTI(step, inm); 245 while (inm != NULL) { 246 if (inm->inm_ifp == ifp && 247 !IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 248 (ip->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP || 249 in_hosteq(ip->ip_dst, inm->inm_addr))) { 250 switch (inm->inm_state) { 251 case IGMP_DELAYING_MEMBER: 252 if (inm->inm_timer <= timer) 253 break; 254 /* FALLTHROUGH */ 255 case IGMP_IDLE_MEMBER: 256 case IGMP_LAZY_MEMBER: 257 case IGMP_AWAKENING_MEMBER: 258 inm->inm_state = 259 IGMP_DELAYING_MEMBER; 260 inm->inm_timer = 261 IGMP_RANDOM_DELAY(timer); 262 igmp_timers_are_running = 1; 263 break; 264 case IGMP_SLEEPING_MEMBER: 265 inm->inm_state = 266 IGMP_AWAKENING_MEMBER; 267 break; 268 } 269 } 270 IN_NEXT_MULTI(step, inm); 271 } 272 } 273 274 break; 275 276 case IGMP_v1_HOST_MEMBERSHIP_REPORT: 277 ++igmpstat.igps_rcv_reports; 278 279 if (ifp->if_flags & IFF_LOOPBACK) 280 break; 281 282 if (!IN_MULTICAST(igmp->igmp_group.s_addr) || 283 !in_hosteq(igmp->igmp_group, ip->ip_dst)) { 284 ++igmpstat.igps_rcv_badreports; 285 m_freem(m); 286 return; 287 } 288 289 /* 290 * KLUDGE: if the IP source address of the report has an 291 * unspecified (i.e., zero) subnet number, as is allowed for 292 * a booting host, replace it with the correct subnet number 293 * so that a process-level multicast routing daemon can 294 * determine which subnet it arrived from. This is necessary 295 * to compensate for the lack of any way for a process to 296 * determine the arrival interface of an incoming packet. 297 */ 298 if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { 299 IFP_TO_IA(ifp, ia); /* XXX */ 300 if (ia) 301 ip->ip_src.s_addr = ia->ia_subnet; 302 } 303 304 /* 305 * If we belong to the group being reported, stop 306 * our timer for that group. 307 */ 308 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 309 if (inm != NULL) { 310 inm->inm_timer = 0; 311 ++igmpstat.igps_rcv_ourreports; 312 313 switch (inm->inm_state) { 314 case IGMP_IDLE_MEMBER: 315 case IGMP_LAZY_MEMBER: 316 case IGMP_AWAKENING_MEMBER: 317 case IGMP_SLEEPING_MEMBER: 318 inm->inm_state = IGMP_SLEEPING_MEMBER; 319 break; 320 case IGMP_DELAYING_MEMBER: 321 if (inm->inm_rti->rti_type == IGMP_v1_ROUTER) 322 inm->inm_state = IGMP_LAZY_MEMBER; 323 else 324 inm->inm_state = IGMP_SLEEPING_MEMBER; 325 break; 326 } 327 } 328 329 break; 330 331 case IGMP_v2_HOST_MEMBERSHIP_REPORT: 332 #ifdef MROUTING 333 /* 334 * Make sure we don't hear our own membership report. Fast 335 * leave requires knowing that we are the only member of a 336 * group. 337 */ 338 IFP_TO_IA(ifp, ia); /* XXX */ 339 if (ia && in_hosteq(ip->ip_src, ia->ia_addr.sin_addr)) 340 break; 341 #endif 342 343 ++igmpstat.igps_rcv_reports; 344 345 if (ifp->if_flags & IFF_LOOPBACK) 346 break; 347 348 if (!IN_MULTICAST(igmp->igmp_group.s_addr) || 349 !in_hosteq(igmp->igmp_group, ip->ip_dst)) { 350 ++igmpstat.igps_rcv_badreports; 351 m_freem(m); 352 return; 353 } 354 355 /* 356 * KLUDGE: if the IP source address of the report has an 357 * unspecified (i.e., zero) subnet number, as is allowed for 358 * a booting host, replace it with the correct subnet number 359 * so that a process-level multicast routing daemon can 360 * determine which subnet it arrived from. This is necessary 361 * to compensate for the lack of any way for a process to 362 * determine the arrival interface of an incoming packet. 363 */ 364 if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) { 365 #ifndef MROUTING 366 IFP_TO_IA(ifp, ia); /* XXX */ 367 #endif 368 if (ia) 369 ip->ip_src.s_addr = ia->ia_subnet; 370 } 371 372 /* 373 * If we belong to the group being reported, stop 374 * our timer for that group. 375 */ 376 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 377 if (inm != NULL) { 378 inm->inm_timer = 0; 379 ++igmpstat.igps_rcv_ourreports; 380 381 switch (inm->inm_state) { 382 case IGMP_DELAYING_MEMBER: 383 case IGMP_IDLE_MEMBER: 384 case IGMP_AWAKENING_MEMBER: 385 inm->inm_state = IGMP_LAZY_MEMBER; 386 break; 387 case IGMP_LAZY_MEMBER: 388 case IGMP_SLEEPING_MEMBER: 389 break; 390 } 391 } 392 393 break; 394 395 } 396 397 /* 398 * Pass all valid IGMP packets up to any process(es) listening 399 * on a raw IGMP socket. 400 */ 401 rip_input(m, iphlen, proto); 402 return; 403 } 404 405 void 406 igmp_joingroup(inm) 407 struct in_multi *inm; 408 { 409 int s = splsoftnet(); 410 411 inm->inm_state = IGMP_IDLE_MEMBER; 412 413 if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 414 (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) { 415 igmp_sendpkt(inm, rti_fill(inm)); 416 inm->inm_state = IGMP_DELAYING_MEMBER; 417 inm->inm_timer = IGMP_RANDOM_DELAY( 418 IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ); 419 igmp_timers_are_running = 1; 420 } else 421 inm->inm_timer = 0; 422 splx(s); 423 } 424 425 void 426 igmp_leavegroup(inm) 427 struct in_multi *inm; 428 { 429 430 switch (inm->inm_state) { 431 case IGMP_DELAYING_MEMBER: 432 case IGMP_IDLE_MEMBER: 433 if (!IN_LOCAL_GROUP(inm->inm_addr.s_addr) && 434 (inm->inm_ifp->if_flags & IFF_LOOPBACK) == 0) 435 if (inm->inm_rti->rti_type != IGMP_v1_ROUTER) 436 igmp_sendpkt(inm, IGMP_HOST_LEAVE_MESSAGE); 437 break; 438 case IGMP_LAZY_MEMBER: 439 case IGMP_AWAKENING_MEMBER: 440 case IGMP_SLEEPING_MEMBER: 441 break; 442 } 443 } 444 445 void 446 igmp_fasttimo() 447 { 448 struct in_multi *inm; 449 struct in_multistep step; 450 int s; 451 452 /* 453 * Quick check to see if any work needs to be done, in order 454 * to minimize the overhead of fasttimo processing. 455 */ 456 if (!igmp_timers_are_running) 457 return; 458 459 s = splsoftnet(); 460 igmp_timers_are_running = 0; 461 IN_FIRST_MULTI(step, inm); 462 while (inm != NULL) { 463 if (inm->inm_timer == 0) { 464 /* do nothing */ 465 } else if (--inm->inm_timer == 0) { 466 if (inm->inm_state == IGMP_DELAYING_MEMBER) { 467 if (inm->inm_rti->rti_type == IGMP_v1_ROUTER) 468 igmp_sendpkt(inm, 469 IGMP_v1_HOST_MEMBERSHIP_REPORT); 470 else 471 igmp_sendpkt(inm, 472 IGMP_v2_HOST_MEMBERSHIP_REPORT); 473 inm->inm_state = IGMP_IDLE_MEMBER; 474 } 475 } else { 476 igmp_timers_are_running = 1; 477 } 478 IN_NEXT_MULTI(step, inm); 479 } 480 splx(s); 481 } 482 483 void 484 igmp_slowtimo() 485 { 486 struct router_info *rti; 487 int s; 488 489 s = splsoftnet(); 490 for (rti = rti_head; rti != 0; rti = rti->rti_next) { 491 if (rti->rti_type == IGMP_v1_ROUTER && 492 ++rti->rti_age >= IGMP_AGE_THRESHOLD) { 493 rti->rti_type = IGMP_v2_ROUTER; 494 } 495 } 496 splx(s); 497 } 498 499 void 500 igmp_sendpkt(inm, type) 501 struct in_multi *inm; 502 int type; 503 { 504 struct mbuf *m; 505 struct igmp *igmp; 506 struct ip *ip; 507 struct ip_moptions imo; 508 #ifdef MROUTING 509 extern struct socket *ip_mrouter; 510 #endif /* MROUTING */ 511 512 MGETHDR(m, M_DONTWAIT, MT_HEADER); 513 if (m == NULL) 514 return; 515 /* 516 * Assume max_linkhdr + sizeof(struct ip) + IGMP_MINLEN 517 * is smaller than mbuf size returned by MGETHDR. 518 */ 519 m->m_data += max_linkhdr; 520 m->m_len = sizeof(struct ip) + IGMP_MINLEN; 521 m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN; 522 523 ip = mtod(m, struct ip *); 524 ip->ip_tos = 0; 525 ip->ip_len = sizeof(struct ip) + IGMP_MINLEN; 526 ip->ip_off = 0; 527 ip->ip_p = IPPROTO_IGMP; 528 ip->ip_src = zeroin_addr; 529 ip->ip_dst = inm->inm_addr; 530 531 m->m_data += sizeof(struct ip); 532 m->m_len -= sizeof(struct ip); 533 igmp = mtod(m, struct igmp *); 534 igmp->igmp_type = type; 535 igmp->igmp_code = 0; 536 igmp->igmp_group = inm->inm_addr; 537 igmp->igmp_cksum = 0; 538 igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN); 539 m->m_data -= sizeof(struct ip); 540 m->m_len += sizeof(struct ip); 541 542 imo.imo_multicast_ifp = inm->inm_ifp; 543 imo.imo_multicast_ttl = 1; 544 #ifdef RSVP_ISI 545 imo.imo_multicast_vif = -1; 546 #endif 547 /* 548 * Request loopback of the report if we are acting as a multicast 549 * router, so that the process-level routing demon can hear it. 550 */ 551 #ifdef MROUTING 552 imo.imo_multicast_loop = (ip_mrouter != NULL); 553 #else 554 imo.imo_multicast_loop = 0; 555 #endif /* MROUTING */ 556 557 ip_output(m, (struct mbuf *)0, (struct route *)0, IP_MULTICASTOPTS, 558 &imo); 559 560 ++igmpstat.igps_snd_reports; 561 } 562
Indexes created Tue Sep 23 13:09:54 GMT 2025