1 /* 2 * Copyright (c) 1988 Stephen Deering. 3 * Copyright (c) 1992, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Stephen Deering of Stanford University. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)igmp.c 8.1 (Berkeley) 7/19/93 38 * $Id: igmp.c,v 1.10 1995/05/16 01:28:29 davidg Exp $ 39 */ 40 41 /* 42 * Internet Group Management Protocol (IGMP) routines. 43 * 44 * Written by Steve Deering, Stanford, May 1988. 45 * Modified by Rosen Sharma, Stanford, Aug 1994. 46 * Modified by Bill Fenner, Xerox PARC, Feb 1995. 47 * 48 * MULTICAST Revision: 3.3.1.2 49 */ 50 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/mbuf.h> 54 #include <sys/socket.h> 55 #include <sys/protosw.h> 56 #include <sys/proc.h> /* XXX needed for sysctl.h */ 57 #include <vm/vm.h> /* XXX needed for sysctl.h */ 58 #include <sys/sysctl.h> 59 60 #include <net/if.h> 61 #include <net/route.h> 62 63 #include <netinet/in.h> 64 #include <netinet/in_var.h> 65 #include <netinet/in_systm.h> 66 #include <netinet/ip.h> 67 #include <netinet/ip_var.h> 68 #include <netinet/igmp.h> 69 #include <netinet/igmp_var.h> 70 71 struct igmpstat igmpstat; 72 73 static int igmp_timers_are_running; 74 static u_long igmp_all_hosts_group; 75 static u_long igmp_local_group; 76 static u_long igmp_local_group_mask; 77 static struct router_info *Head; 78 79 static void igmp_sendpkt(struct in_multi *, int); 80 static void igmp_sendleave(struct in_multi *); 81 82 void 83 igmp_init() 84 { 85 /* 86 * To avoid byte-swapping the same value over and over again. 87 */ 88 igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP); 89 igmp_local_group = htonl(0xe0000000); /* 224.0.0.0 */ 90 igmp_local_group_mask = htonl(0xffffff00); /* ........^ */ 91 92 igmp_timers_are_running = 0; 93 94 Head = (struct router_info *) 0; 95 } 96 97 int 98 fill_rti(inm) 99 struct in_multi *inm; 100 { 101 register struct router_info *rti = Head; 102 103 #ifdef IGMP_DEBUG 104 printf("[igmp.c, _fill_rti] --> entering \n"); 105 #endif 106 while (rti) { 107 if (rti->ifp == inm->inm_ifp) { 108 inm->inm_rti = rti; 109 #ifdef IGMP_DEBUG 110 printf("[igmp.c, _fill_rti] --> found old entry \n"); 111 #endif 112 if (rti->type == IGMP_OLD_ROUTER) 113 return IGMP_HOST_MEMBERSHIP_REPORT; 114 else 115 return IGMP_HOST_NEW_MEMBERSHIP_REPORT; 116 } 117 rti = rti->next; 118 } 119 MALLOC(rti, struct router_info *, sizeof *rti, M_MRTABLE, M_NOWAIT); 120 rti->ifp = inm->inm_ifp; 121 rti->type = IGMP_NEW_ROUTER; 122 rti->time = IGMP_AGE_THRESHOLD; 123 rti->next = Head; 124 Head = rti; 125 inm->inm_rti = rti; 126 #ifdef IGMP_DEBUG 127 printf("[igmp.c, _fill_rti] --> created new entry \n"); 128 #endif 129 return IGMP_HOST_NEW_MEMBERSHIP_REPORT; 130 } 131 132 struct router_info * 133 find_rti(ifp) 134 struct ifnet *ifp; 135 { 136 register struct router_info *rti = Head; 137 138 #ifdef IGMP_DEBUG 139 printf("[igmp.c, _find_rti] --> entering \n"); 140 #endif 141 while (rti) { 142 if (rti->ifp == ifp) { 143 #ifdef IGMP_DEBUG 144 printf("[igmp.c, _find_rti] --> found old entry \n"); 145 #endif 146 return rti; 147 } 148 rti = rti->next; 149 } 150 MALLOC(rti, struct router_info *, sizeof *rti, M_MRTABLE, M_NOWAIT); 151 rti->ifp = ifp; 152 rti->type = IGMP_NEW_ROUTER; 153 rti->time = IGMP_AGE_THRESHOLD; 154 rti->next = Head; 155 Head = rti; 156 #ifdef IGMP_DEBUG 157 printf("[igmp.c, _find_rti] --> created an entry \n"); 158 #endif 159 return rti; 160 } 161 162 void 163 igmp_input(m, iphlen) 164 register struct mbuf *m; 165 register int iphlen; 166 { 167 register struct igmp *igmp; 168 register struct ip *ip; 169 register int igmplen; 170 register struct ifnet *ifp = m->m_pkthdr.rcvif; 171 register int minlen; 172 register struct in_multi *inm; 173 register struct in_ifaddr *ia; 174 struct in_multistep step; 175 struct router_info *rti; 176 177 int timer; /** timer value in the igmp query header **/ 178 179 ++igmpstat.igps_rcv_total; 180 181 ip = mtod(m, struct ip *); 182 igmplen = ip->ip_len; 183 184 /* 185 * Validate lengths 186 */ 187 if (igmplen < IGMP_MINLEN) { 188 ++igmpstat.igps_rcv_tooshort; 189 m_freem(m); 190 return; 191 } 192 minlen = iphlen + IGMP_MINLEN; 193 if ((m->m_flags & M_EXT || m->m_len < minlen) && 194 (m = m_pullup(m, minlen)) == 0) { 195 ++igmpstat.igps_rcv_tooshort; 196 return; 197 } 198 199 /* 200 * Validate checksum 201 */ 202 m->m_data += iphlen; 203 m->m_len -= iphlen; 204 igmp = mtod(m, struct igmp *); 205 if (in_cksum(m, igmplen)) { 206 ++igmpstat.igps_rcv_badsum; 207 m_freem(m); 208 return; 209 } 210 m->m_data -= iphlen; 211 m->m_len += iphlen; 212 213 ip = mtod(m, struct ip *); 214 timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE; 215 rti = find_rti(ifp); 216 217 switch (igmp->igmp_type) { 218 219 case IGMP_HOST_MEMBERSHIP_QUERY: 220 ++igmpstat.igps_rcv_queries; 221 222 if (ifp->if_flags & IFF_LOOPBACK) 223 break; 224 225 if (igmp->igmp_code == 0) { 226 227 rti->type = IGMP_OLD_ROUTER; rti->time = 0; 228 229 /* 230 ** Do exactly as RFC 1112 says 231 */ 232 233 if (ip->ip_dst.s_addr != igmp_all_hosts_group) { 234 ++igmpstat.igps_rcv_badqueries; 235 m_freem(m); 236 return; 237 } 238 239 /* 240 * Start the timers in all of our membership records for 241 * the interface on which the query arrived, except those 242 * that are already running and those that belong to a 243 * "local" group (224.0.0.X). 244 */ 245 IN_FIRST_MULTI(step, inm); 246 while (inm != NULL) { 247 if (inm->inm_ifp == ifp 248 && inm->inm_timer == 0 249 && ((inm->inm_addr.s_addr 250 & igmp_local_group_mask) 251 != igmp_local_group)) { 252 253 inm->inm_state = IGMP_DELAYING_MEMBER; 254 inm->inm_timer = IGMP_RANDOM_DELAY( 255 IGMP_MAX_HOST_REPORT_DELAY * PR_FASTHZ ); 256 257 igmp_timers_are_running = 1; 258 } 259 IN_NEXT_MULTI(step, inm); 260 } 261 } else { 262 /* 263 ** New Router 264 */ 265 266 if (!(m->m_flags & M_MCAST)) { 267 ++igmpstat.igps_rcv_badqueries; 268 m_freem(m); 269 return; 270 } 271 272 /* 273 * - Start the timers in all of our membership records 274 * that the query applies to for the interface on 275 * which the query arrived excl. those that belong 276 * to a "local" group (224.0.0.X) 277 * - For timers already running check if they need to 278 * be reset. 279 * - Use the igmp->igmp_code field as the maximum 280 * delay possible 281 */ 282 IN_FIRST_MULTI(step, inm); 283 while (inm != NULL) { 284 if (inm->inm_ifp == ifp && 285 (inm->inm_addr.s_addr & igmp_local_group_mask) != 286 igmp_local_group && 287 (ip->ip_dst.s_addr == igmp_all_hosts_group || 288 ip->ip_dst.s_addr == inm->inm_addr.s_addr)) { 289 switch(inm->inm_state) { 290 case IGMP_IDLE_MEMBER: 291 case IGMP_LAZY_MEMBER: 292 case IGMP_AWAKENING_MEMBER: 293 inm->inm_timer = IGMP_RANDOM_DELAY(timer); 294 igmp_timers_are_running = 1; 295 inm->inm_state = IGMP_DELAYING_MEMBER; 296 break; 297 case IGMP_DELAYING_MEMBER: 298 if (inm->inm_timer > timer) { 299 inm->inm_timer = IGMP_RANDOM_DELAY(timer); 300 igmp_timers_are_running = 1; 301 inm->inm_state = IGMP_DELAYING_MEMBER; 302 } 303 break; 304 case IGMP_SLEEPING_MEMBER: 305 inm->inm_state = IGMP_AWAKENING_MEMBER; 306 break; 307 } 308 } 309 IN_NEXT_MULTI(step, inm); 310 } 311 } 312 313 break; 314 315 case IGMP_HOST_MEMBERSHIP_REPORT: 316 /* 317 * an old report 318 */ 319 ++igmpstat.igps_rcv_reports; 320 321 if (ifp->if_flags & IFF_LOOPBACK) 322 break; 323 324 if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr)) || 325 igmp->igmp_group.s_addr != ip->ip_dst.s_addr) { 326 ++igmpstat.igps_rcv_badreports; 327 m_freem(m); 328 return; 329 } 330 331 /* 332 * KLUDGE: if the IP source address of the report has an 333 * unspecified (i.e., zero) subnet number, as is allowed for 334 * a booting host, replace it with the correct subnet number 335 * so that a process-level multicast routing demon can 336 * determine which subnet it arrived from. This is necessary 337 * to compensate for the lack of any way for a process to 338 * determine the arrival interface of an incoming packet. 339 */ 340 if ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) == 0) { 341 IFP_TO_IA(ifp, ia); 342 if (ia) ip->ip_src.s_addr = htonl(ia->ia_subnet); 343 } 344 345 /* 346 * If we belong to the group being reported, stop 347 * our timer for that group. 348 */ 349 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 350 351 if (inm != NULL) { 352 inm->inm_timer = 0; 353 ++igmpstat.igps_rcv_ourreports; 354 355 switch(inm->inm_state){ 356 case IGMP_IDLE_MEMBER: 357 case IGMP_LAZY_MEMBER: 358 case IGMP_AWAKENING_MEMBER: 359 case IGMP_SLEEPING_MEMBER: 360 inm->inm_state = IGMP_SLEEPING_MEMBER; 361 break; 362 case IGMP_DELAYING_MEMBER: 363 if (inm->inm_rti->type == IGMP_OLD_ROUTER) 364 inm->inm_state = IGMP_LAZY_MEMBER; 365 else 366 inm->inm_state = IGMP_SLEEPING_MEMBER; 367 break; 368 } 369 } 370 371 break; 372 373 case IGMP_HOST_NEW_MEMBERSHIP_REPORT: 374 /* 375 * a new report 376 */ 377 378 /* 379 * We can get confused and think there's someone 380 * else out there if we are a multicast router. 381 * For fast leave to work, we have to know that 382 * we are the only member. 383 */ 384 IFP_TO_IA(ifp, ia); 385 if (ia && ip->ip_src.s_addr == IA_SIN(ia)->sin_addr.s_addr) 386 break; 387 388 ++igmpstat.igps_rcv_reports; 389 390 if (ifp->if_flags & IFF_LOOPBACK) 391 break; 392 393 if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr)) || 394 igmp->igmp_group.s_addr != ip->ip_dst.s_addr) { 395 ++igmpstat.igps_rcv_badreports; 396 m_freem(m); 397 return; 398 } 399 400 /* 401 * KLUDGE: if the IP source address of the report has an 402 * unspecified (i.e., zero) subnet number, as is allowed for 403 * a booting host, replace it with the correct subnet number 404 * so that a process-level multicast routing demon can 405 * determine which subnet it arrived from. This is necessary 406 * to compensate for the lack of any way for a process to 407 * determine the arrival interface of an incoming packet. 408 */ 409 if ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) == 0) { 410 /* #ifndef MROUTING XXX - I don't think the ifdef is necessary */ 411 IFP_TO_IA(ifp, ia); 412 /* #endif */ 413 if (ia) ip->ip_src.s_addr = htonl(ia->ia_subnet); 414 } 415 416 /* 417 * If we belong to the group being reported, stop 418 * our timer for that group. 419 */ 420 IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm); 421 if (inm != NULL) { 422 inm->inm_timer = 0; 423 ++igmpstat.igps_rcv_ourreports; 424 425 switch(inm->inm_state){ 426 case IGMP_DELAYING_MEMBER: 427 case IGMP_IDLE_MEMBER: 428 inm->inm_state = IGMP_LAZY_MEMBER; 429 break; 430 case IGMP_AWAKENING_MEMBER: 431 inm->inm_state = IGMP_LAZY_MEMBER; 432 break; 433 case IGMP_LAZY_MEMBER: 434 case IGMP_SLEEPING_MEMBER: 435 break; 436 } 437 } 438 } 439 440 /* 441 * Pass all valid IGMP packets up to any process(es) listening 442 * on a raw IGMP socket. 443 */ 444 rip_input(m); 445 } 446 447 void 448 igmp_joingroup(inm) 449 struct in_multi *inm; 450 { 451 int s = splnet(); 452 453 inm->inm_state = IGMP_IDLE_MEMBER; 454 455 if ((inm->inm_addr.s_addr & igmp_local_group_mask) == igmp_local_group 456 || inm->inm_ifp->if_flags & IFF_LOOPBACK) 457 inm->inm_timer = 0; 458 else { 459 igmp_sendpkt(inm,fill_rti(inm)); 460 inm->inm_timer = IGMP_RANDOM_DELAY( 461 IGMP_MAX_HOST_REPORT_DELAY*PR_FASTHZ); 462 inm->inm_state = IGMP_DELAYING_MEMBER; 463 igmp_timers_are_running = 1; 464 } 465 splx(s); 466 } 467 468 void 469 igmp_leavegroup(inm) 470 struct in_multi *inm; 471 { 472 switch(inm->inm_state) { 473 case IGMP_DELAYING_MEMBER: 474 case IGMP_IDLE_MEMBER: 475 if (((inm->inm_addr.s_addr & igmp_local_group_mask) 476 != igmp_local_group) 477 && !(inm->inm_ifp->if_flags & IFF_LOOPBACK)) 478 if (inm->inm_rti->type != IGMP_OLD_ROUTER) 479 igmp_sendleave(inm); 480 break; 481 case IGMP_LAZY_MEMBER: 482 case IGMP_AWAKENING_MEMBER: 483 case IGMP_SLEEPING_MEMBER: 484 break; 485 } 486 } 487 488 void 489 igmp_fasttimo() 490 { 491 register struct in_multi *inm; 492 struct in_multistep step; 493 int s; 494 495 /* 496 * Quick check to see if any work needs to be done, in order 497 * to minimize the overhead of fasttimo processing. 498 */ 499 500 if (!igmp_timers_are_running) 501 return; 502 503 s = splnet(); 504 igmp_timers_are_running = 0; 505 IN_FIRST_MULTI(step, inm); 506 while (inm != NULL) { 507 if (inm->inm_timer == 0) { 508 /* do nothing */ 509 } else if (--inm->inm_timer == 0) { 510 if (inm->inm_state == IGMP_DELAYING_MEMBER) { 511 if (inm->inm_rti->type == IGMP_OLD_ROUTER) 512 igmp_sendpkt(inm, IGMP_HOST_MEMBERSHIP_REPORT); 513 else 514 igmp_sendpkt(inm, IGMP_HOST_NEW_MEMBERSHIP_REPORT); 515 inm->inm_state = IGMP_IDLE_MEMBER; 516 } 517 } else { 518 igmp_timers_are_running = 1; 519 } 520 IN_NEXT_MULTI(step, inm); 521 } 522 splx(s); 523 } 524 525 void 526 igmp_slowtimo() 527 { 528 int s = splnet(); 529 register struct router_info *rti = Head; 530 531 #ifdef IGMP_DEBUG 532 printf("[igmp.c,_slowtimo] -- > entering \n"); 533 #endif 534 while (rti) { 535 rti->time ++; 536 if (rti->time >= IGMP_AGE_THRESHOLD){ 537 rti->type = IGMP_NEW_ROUTER; 538 rti->time = IGMP_AGE_THRESHOLD; 539 } 540 rti = rti->next; 541 } 542 #ifdef IGMP_DEBUG 543 printf("[igmp.c,_slowtimo] -- > exiting \n"); 544 #endif 545 splx(s); 546 } 547 548 static void 549 igmp_sendpkt(inm, type) 550 struct in_multi *inm; 551 int type; 552 { 553 struct mbuf *m; 554 struct igmp *igmp; 555 struct ip *ip; 556 struct ip_moptions *imo; 557 558 MGETHDR(m, M_DONTWAIT, MT_HEADER); 559 if (m == NULL) 560 return; 561 562 MALLOC(imo, struct ip_moptions *, sizeof *imo, M_IPMOPTS, M_DONTWAIT); 563 if (!imo) { 564 m_free(m); 565 return; 566 } 567 568 m->m_pkthdr.rcvif = loif; 569 m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN; 570 MH_ALIGN(m, IGMP_MINLEN + sizeof(struct ip)); 571 m->m_data += sizeof(struct ip); 572 m->m_len = IGMP_MINLEN; 573 igmp = mtod(m, struct igmp *); 574 igmp->igmp_type = type; 575 igmp->igmp_code = 0; 576 igmp->igmp_group = inm->inm_addr; 577 igmp->igmp_cksum = 0; 578 igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN); 579 580 m->m_data -= sizeof(struct ip); 581 m->m_len += sizeof(struct ip); 582 ip = mtod(m, struct ip *); 583 ip->ip_tos = 0; 584 ip->ip_len = sizeof(struct ip) + IGMP_MINLEN; 585 ip->ip_off = 0; 586 ip->ip_p = IPPROTO_IGMP; 587 ip->ip_src.s_addr = INADDR_ANY; 588 ip->ip_dst = igmp->igmp_group; 589 590 imo->imo_multicast_ifp = inm->inm_ifp; 591 imo->imo_multicast_ttl = 1; 592 imo->imo_multicast_vif = -1; 593 /* 594 * Request loopback of the report if we are acting as a multicast 595 * router, so that the process-level routing demon can hear it. 596 */ 597 imo->imo_multicast_loop = (ip_mrouter != NULL); 598 599 ip_output(m, (struct mbuf *)0, (struct route *)0, 0, imo); 600 601 FREE(imo, M_IPMOPTS); 602 ++igmpstat.igps_snd_reports; 603 } 604 605 static void 606 igmp_sendleave(inm) 607 struct in_multi *inm; 608 { 609 igmp_sendpkt(inm, IGMP_HOST_LEAVE_MESSAGE); 610 } 611 612 int 613 igmp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, 614 void *newp, size_t newlen) 615 { 616 /* All sysctl names at this level are terminal. */ 617 if (namelen != 1) 618 return ENOTDIR; /* XXX overloaded */ 619 620 switch(name[0]) { 621 case IGMPCTL_STATS: 622 return sysctl_rdstruct(oldp, oldlenp, newp, &igmpstat, 623 sizeof igmpstat); 624 default: 625 return ENOPROTOOPT; 626 } 627 } 628