1 /* $NetBSD: main.c,v 1.12 1999/06/06 03:27:06 thorpej Exp $ */ 2 3 /* 4 * The mrouted program is covered by the license in the accompanying file 5 * named "LICENSE". Use of the mrouted program represents acceptance of 6 * the terms and conditions listed in that file. 7 * 8 * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of 9 * Leland Stanford Junior University. 10 */ 11 12 /* 13 * Written by Steve Deering, Stanford University, February 1989. 14 * 15 * (An earlier version of DVMRP was implemented by David Waitzman of 16 * BBN STC by extending Berkeley's routed program. Some of Waitzman's 17 * extensions have been incorporated into mrouted, but none of the 18 * original routed code has been adopted.) 19 */ 20 21 22 #include "defs.h" 23 #ifdef __STDC__ 24 #include <stdarg.h> 25 #else 26 #include <varargs.h> 27 #endif 28 #include <fcntl.h> 29 30 #ifdef SNMP 31 #include "snmp.h" 32 #endif 33 34 #include <sys/cdefs.h> 35 #ifndef lint 36 __RCSID("@(#) $NetBSD: main.c,v 1.12 1999/06/06 03:27:06 thorpej Exp $"); 37 #endif 38 39 #include <err.h> 40 #include <util.h> 41 42 extern char *configfilename; 43 char versionstring[100]; 44 45 static char dumpfilename[] = _PATH_MROUTED_DUMP; 46 static char cachefilename[] = _PATH_MROUTED_CACHE; 47 static char genidfilename[] = _PATH_MROUTED_GENID; 48 49 int cache_lifetime = DEFAULT_CACHE_LIFETIME; 50 int max_prune_lifetime = DEFAULT_CACHE_LIFETIME * 2; 51 52 int debug = 0; 53 u_char pruning = 1; /* Enable pruning by default */ 54 55 #ifdef SNMP 56 #define NHANDLERS 34 57 #else 58 #define NHANDLERS 2 59 #endif 60 61 static struct ihandler { 62 int fd; /* File descriptor */ 63 ihfunc_t func; /* Function to call with &fd_set */ 64 } ihandlers[NHANDLERS]; 65 static int nhandlers = 0; 66 67 /* 68 * Forward declarations. 69 */ 70 static void fasttimer __P((int)); 71 static void done __P((int)); 72 static void dump __P((int)); 73 static void fdump __P((int)); 74 static void cdump __P((int)); 75 static void restart __P((int)); 76 static void timer __P((void)); 77 static void cleanup __P((void)); 78 static void resetlogging __P((void *)); 79 80 /* To shut up gcc -Wstrict-prototypes */ 81 int main __P((int argc, char **argv)); 82 83 int 84 register_input_handler(fd, func) 85 int fd; 86 ihfunc_t func; 87 { 88 if (nhandlers >= NHANDLERS) 89 return -1; 90 91 ihandlers[nhandlers].fd = fd; 92 ihandlers[nhandlers++].func = func; 93 94 return 0; 95 } 96 97 int 98 main(argc, argv) 99 int argc; 100 char *argv[]; 101 { 102 register int recvlen; 103 register int omask; 104 int dummy; 105 FILE *fp; 106 struct timeval tv; 107 u_int32_t prev_genid; 108 int vers; 109 fd_set rfds, readers; 110 int nfds, n, i; 111 #ifdef SNMP 112 struct timeval timeout, *tvp = &timeout; 113 struct timeval sched, *svp = &sched, now, *nvp = &now; 114 int index, block; 115 #endif 116 117 setlinebuf(stderr); 118 119 if (geteuid() != 0) { 120 fprintf(stderr, "must be root\n"); 121 exit(1); 122 } 123 124 argv++, argc--; 125 while (argc > 0 && *argv[0] == '-') { 126 if (strcmp(*argv, "-d") == 0) { 127 if (argc > 1 && isdigit(*(argv + 1)[0])) { 128 argv++, argc--; 129 debug = atoi(*argv); 130 } else 131 debug = DEFAULT_DEBUG; 132 } else if (strcmp(*argv, "-c") == 0) { 133 if (argc > 1) { 134 argv++, argc--; 135 configfilename = *argv; 136 } else 137 goto usage; 138 } else if (strcmp(*argv, "-p") == 0) { 139 pruning = 0; 140 #ifdef SNMP 141 } else if (strcmp(*argv, "-P") == 0) { 142 if (argc > 1 && isdigit(*(argv + 1)[0])) { 143 argv++, argc--; 144 dest_port = atoi(*argv); 145 } else 146 dest_port = DEFAULT_PORT; 147 #endif 148 } else 149 goto usage; 150 argv++, argc--; 151 } 152 153 if (argc > 0) { 154 usage: fprintf(stderr, 155 "usage: mrouted [-p] [-c configfile] [-d [debug_level]]\n"); 156 exit(1); 157 } 158 159 if (debug == 0) { 160 /* 161 * Detach from the terminal 162 */ 163 if (daemon(0, 0)) 164 err(1, "can't fork"); 165 pidfile(NULL); 166 } 167 else 168 fprintf(stderr, "debug level %u\n", debug); 169 170 #ifdef LOG_DAEMON 171 (void)openlog("mrouted", LOG_PID, LOG_DAEMON); 172 (void)setlogmask(LOG_UPTO(LOG_NOTICE)); 173 #else 174 (void)openlog("mrouted", LOG_PID); 175 #endif 176 sprintf(versionstring, "mrouted version %d.%d", 177 PROTOCOL_VERSION, MROUTED_VERSION); 178 179 log(LOG_NOTICE, 0, "%s", versionstring); 180 181 #ifdef SYSV 182 srand48(time(NULL)); 183 #else 184 srandom(gethostid()); 185 #endif 186 187 /* 188 * Get generation id 189 */ 190 gettimeofday(&tv, 0); 191 dvmrp_genid = tv.tv_sec; 192 193 fp = fopen(genidfilename, "r"); 194 if (fp != NULL) { 195 fscanf(fp, "%d", &prev_genid); 196 if (prev_genid == dvmrp_genid) 197 dvmrp_genid++; 198 (void) fclose(fp); 199 } 200 201 fp = fopen(genidfilename, "w"); 202 if (fp != NULL) { 203 fprintf(fp, "%d", dvmrp_genid); 204 (void) fclose(fp); 205 } 206 207 callout_init(); 208 init_igmp(); 209 init_routes(); 210 init_ktable(); 211 k_init_dvmrp(); /* enable DVMRP routing in kernel */ 212 213 #ifndef OLD_KERNEL 214 vers = k_get_version(); 215 /*XXX 216 * This function must change whenever the kernel version changes 217 */ 218 if ((((vers >> 8) & 0xff) != 3) || 219 ((vers & 0xff) != 5)) 220 log(LOG_ERR, 0, "kernel (v%d.%d)/mrouted (v%d.%d) version mismatch", 221 (vers >> 8) & 0xff, vers & 0xff, 222 PROTOCOL_VERSION, MROUTED_VERSION); 223 #endif 224 225 #ifdef SNMP 226 if (i = snmp_init()) 227 return i; 228 229 gettimeofday(nvp, 0); 230 if (nvp->tv_usec < 500000L){ 231 svp->tv_usec = nvp->tv_usec + 500000L; 232 svp->tv_sec = nvp->tv_sec; 233 } else { 234 svp->tv_usec = nvp->tv_usec - 500000L; 235 svp->tv_sec = nvp->tv_sec + 1; 236 } 237 #endif /* SNMP */ 238 239 init_vifs(); 240 241 #ifdef RSRR 242 rsrr_init(); 243 #endif /* RSRR */ 244 245 #if defined(__STDC__) || defined(__GNUC__) 246 /* 247 * Allow cleanup if unexpected exit. Apparently some architectures 248 * have a kernel bug where closing the socket doesn't do an 249 * ip_mrouter_done(), so we attempt to do it on exit. 250 */ 251 atexit(cleanup); 252 #endif 253 254 if (debug) 255 fprintf(stderr, "pruning %s\n", pruning ? "on" : "off"); 256 257 (void)signal(SIGALRM, fasttimer); 258 259 (void)signal(SIGHUP, restart); 260 (void)signal(SIGTERM, done); 261 (void)signal(SIGINT, done); 262 (void)signal(SIGUSR1, fdump); 263 (void)signal(SIGUSR2, cdump); 264 if (debug != 0) 265 (void)signal(SIGQUIT, dump); 266 267 FD_ZERO(&readers); 268 FD_SET(igmp_socket, &readers); 269 nfds = igmp_socket + 1; 270 for (i = 0; i < nhandlers; i++) { 271 FD_SET(ihandlers[i].fd, &readers); 272 if (ihandlers[i].fd >= nfds) 273 nfds = ihandlers[i].fd + 1; 274 } 275 276 /* 277 * Install the vifs in the kernel as late as possible in the 278 * initialization sequence. 279 */ 280 init_installvifs(); 281 282 if (debug >= 2) dump(0); 283 284 /* Start up the log rate-limiter */ 285 resetlogging(NULL); 286 287 (void)alarm(1); /* schedule first timer interrupt */ 288 289 /* 290 * Main receive loop. 291 */ 292 dummy = 0; 293 for(;;) { 294 #ifdef SYSV 295 sigset_t block, oblock; 296 #endif 297 bcopy((char *)&readers, (char *)&rfds, sizeof(rfds)); 298 #ifdef SNMP 299 gettimeofday(nvp, 0); 300 if (nvp->tv_sec > svp->tv_sec 301 || (nvp->tv_sec == svp->tv_sec && nvp->tv_usec > svp->tv_usec)){ 302 alarmTimer(nvp); 303 eventTimer(nvp); 304 if (nvp->tv_usec < 500000L){ 305 svp->tv_usec = nvp->tv_usec + 500000L; 306 svp->tv_sec = nvp->tv_sec; 307 } else { 308 svp->tv_usec = nvp->tv_usec - 500000L; 309 svp->tv_sec = nvp->tv_sec + 1; 310 } 311 } 312 313 tvp = &timeout; 314 tvp->tv_sec = 0; 315 tvp->tv_usec = 500000L; 316 317 block = 0; 318 snmp_select_info(&nfds, &rfds, tvp, &block); 319 if (block == 1) 320 tvp = NULL; /* block without timeout */ 321 if ((n = select(nfds, &rfds, NULL, NULL, tvp)) < 0) 322 #else 323 if ((n = select(nfds, &rfds, NULL, NULL, NULL)) < 0) 324 #endif 325 { 326 if (errno != EINTR) /* SIGALRM is expected */ 327 log(LOG_WARNING, errno, "select failed"); 328 continue; 329 } 330 331 if (FD_ISSET(igmp_socket, &rfds)) { 332 recvlen = recvfrom(igmp_socket, recv_buf, RECV_BUF_SIZE, 333 0, NULL, &dummy); 334 if (recvlen < 0) { 335 if (errno != EINTR) log(LOG_ERR, errno, "recvfrom"); 336 continue; 337 } 338 #ifdef SYSV 339 (void)sigemptyset(&block); 340 (void)sigaddset(&block, SIGALRM); 341 if (sigprocmask(SIG_BLOCK, &block, &oblock) < 0) 342 log(LOG_ERR, errno, "sigprocmask"); 343 #else 344 omask = sigblock(sigmask(SIGALRM)); 345 #endif 346 accept_igmp(recvlen); 347 #ifdef SYSV 348 (void)sigprocmask(SIG_SETMASK, &oblock, (sigset_t *)NULL); 349 #else 350 (void)sigsetmask(omask); 351 #endif 352 } 353 354 for (i = 0; i < nhandlers; i++) { 355 if (FD_ISSET(ihandlers[i].fd, &rfds)) { 356 (*ihandlers[i].func)(ihandlers[i].fd, &rfds); 357 } 358 } 359 360 #ifdef SNMP 361 snmp_read(&rfds); 362 snmp_timeout(); /* poll */ 363 #endif 364 } 365 } 366 367 368 /* 369 * routine invoked every second. Its main goal is to cycle through 370 * the routing table and send partial updates to all neighbors at a 371 * rate that will cause the entire table to be sent in ROUTE_REPORT_INTERVAL 372 * seconds. Also, every TIMER_INTERVAL seconds it calls timer() to 373 * do all the other time-based processing. 374 */ 375 static void 376 fasttimer(i) 377 int i; 378 { 379 static unsigned int tlast; 380 static unsigned int nsent; 381 register unsigned int t = tlast + 1; 382 register int n; 383 384 /* 385 * if we're in the last second, send everything that's left. 386 * otherwise send at least the fraction we should have sent by now. 387 */ 388 if (t >= ROUTE_REPORT_INTERVAL) { 389 register int nleft = nroutes - nsent; 390 while (nleft > 0) { 391 if ((n = report_next_chunk()) <= 0) 392 break; 393 nleft -= n; 394 } 395 tlast = 0; 396 nsent = 0; 397 } else { 398 register unsigned int ncum = nroutes * t / ROUTE_REPORT_INTERVAL; 399 while (nsent < ncum) { 400 if ((n = report_next_chunk()) <= 0) 401 break; 402 nsent += n; 403 } 404 tlast = t; 405 } 406 if ((t % TIMER_INTERVAL) == 0) 407 timer(); 408 409 age_callout_queue();/* Advance the timer for the callout queue 410 for groups */ 411 alarm(1); 412 } 413 414 /* 415 * The 'virtual_time' variable is initialized to a value that will cause the 416 * first invocation of timer() to send a probe or route report to all vifs 417 * and send group membership queries to all subnets for which this router is 418 * querier. This first invocation occurs approximately TIMER_INTERVAL seconds 419 * after the router starts up. Note that probes for neighbors and queries 420 * for group memberships are also sent at start-up time, as part of initial- 421 * ization. This repetition after a short interval is desirable for quickly 422 * building up topology and membership information in the presence of possible 423 * packet loss. 424 * 425 * 'virtual_time' advances at a rate that is only a crude approximation of 426 * real time, because it does not take into account any time spent processing, 427 * and because the timer intervals are sometimes shrunk by a random amount to 428 * avoid unwanted synchronization with other routers. 429 */ 430 431 static u_long virtual_time = 0; 432 433 434 /* 435 * Timer routine. Performs periodic neighbor probing, route reporting, and 436 * group querying duties, and drives various timers in routing entries and 437 * virtual interface data structures. 438 */ 439 static void 440 timer() 441 { 442 age_routes(); /* Advance the timers in the route entries */ 443 age_vifs(); /* Advance the timers for neighbors */ 444 age_table_entry(); /* Advance the timers for the cache entries */ 445 446 if (virtual_time % GROUP_QUERY_INTERVAL == 0) { 447 /* 448 * Time to query the local group memberships on all subnets 449 * for which this router is the elected querier. 450 */ 451 query_groups(); 452 } 453 454 if (virtual_time % NEIGHBOR_PROBE_INTERVAL == 0) { 455 /* 456 * Time to send a probe on all vifs from which no neighbors have 457 * been heard. Also, check if any inoperative interfaces have now 458 * come up. (If they have, they will also be probed as part of 459 * their initialization.) 460 */ 461 probe_for_neighbors(); 462 463 if (vifs_down) 464 check_vif_state(); 465 } 466 467 delay_change_reports = FALSE; 468 if (routes_changed) { 469 /* 470 * Some routes have changed since the last timer interrupt, but 471 * have not been reported yet. Report the changed routes to all 472 * neighbors. 473 */ 474 report_to_all_neighbors(CHANGED_ROUTES); 475 } 476 477 #ifdef SNMP 478 sync_timer(); 479 #endif 480 481 /* 482 * Advance virtual time 483 */ 484 virtual_time += TIMER_INTERVAL; 485 } 486 487 488 /* 489 * On termination, let everyone know we're going away. 490 */ 491 static void 492 done(i) 493 int i; 494 { 495 log(LOG_NOTICE, 0, "%s exiting", versionstring); 496 cleanup(); 497 _exit(1); 498 } 499 500 static void 501 cleanup() 502 { 503 static int in_cleanup = 0; 504 505 if (!in_cleanup) { 506 in_cleanup++; 507 #ifdef RSRR 508 rsrr_clean(); 509 #endif /* RSRR */ 510 expire_all_routes(); 511 report_to_all_neighbors(ALL_ROUTES); 512 k_stop_dvmrp(); 513 } 514 } 515 516 517 /* 518 * Dump internal data structures to stderr. 519 */ 520 static void 521 dump(i) 522 int i; 523 { 524 dump_vifs(stderr); 525 dump_routes(stderr); 526 } 527 528 529 /* 530 * Dump internal data structures to a file. 531 */ 532 static void 533 fdump(i) 534 int i; 535 { 536 FILE *fp; 537 538 fp = fopen(dumpfilename, "w"); 539 if (fp != NULL) { 540 dump_vifs(fp); 541 dump_routes(fp); 542 (void) fclose(fp); 543 } 544 } 545 546 547 /* 548 * Dump local cache contents to a file. 549 */ 550 static void 551 cdump(i) 552 int i; 553 { 554 FILE *fp; 555 556 fp = fopen(cachefilename, "w"); 557 if (fp != NULL) { 558 dump_cache(fp); 559 (void) fclose(fp); 560 } 561 } 562 563 564 /* 565 * Restart mrouted 566 */ 567 static void 568 restart(i) 569 int i; 570 { 571 register int omask; 572 #ifdef SYSV 573 sigset_t block, oblock; 574 #endif 575 576 log(LOG_NOTICE, 0, "%s restart", versionstring); 577 578 /* 579 * reset all the entries 580 */ 581 #ifdef SYSV 582 (void)sigemptyset(&block); 583 (void)sigaddset(&block, SIGALRM); 584 if (sigprocmask(SIG_BLOCK, &block, &oblock) < 0) 585 log(LOG_ERR, errno, "sigprocmask"); 586 #else 587 omask = sigblock(sigmask(SIGALRM)); 588 #endif 589 free_all_prunes(); 590 free_all_routes(); 591 stop_all_vifs(); 592 k_stop_dvmrp(); 593 close(igmp_socket); 594 close(udp_socket); 595 596 /* 597 * start processing again 598 */ 599 dvmrp_genid++; 600 pruning = 1; 601 602 init_igmp(); 603 init_routes(); 604 init_ktable(); 605 init_vifs(); 606 k_init_dvmrp(); /* enable DVMRP routing in kernel */ 607 init_installvifs(); 608 609 #ifdef SYSV 610 (void)sigprocmask(SIG_SETMASK, &oblock, (sigset_t *)NULL); 611 #else 612 (void)sigsetmask(omask); 613 #endif 614 } 615 616 #define LOG_MAX_MSGS 20 /* if > 20/minute then shut up for a while */ 617 #define LOG_SHUT_UP 600 /* shut up for 10 minutes */ 618 static int log_nmsgs = 0; 619 620 static void 621 resetlogging(arg) 622 void *arg; 623 { 624 int nxttime = 60; 625 void *narg = NULL; 626 627 if (arg == NULL && log_nmsgs > LOG_MAX_MSGS) { 628 nxttime = LOG_SHUT_UP; 629 narg = (void *)&log_nmsgs; /* just need some valid void * */ 630 syslog(LOG_WARNING, "logging too fast, shutting up for %d minutes", 631 LOG_SHUT_UP / 60); 632 } else { 633 log_nmsgs = 0; 634 } 635 636 timer_setTimer(nxttime, resetlogging, narg); 637 } 638 639 /* 640 * Log errors and other messages to the system log daemon and to stderr, 641 * according to the severity of the message and the current debug level. 642 * For errors of severity LOG_ERR or worse, terminate the program. 643 */ 644 #ifdef __STDC__ 645 void 646 log(int severity, int syserr, char *format, ...) 647 { 648 va_list ap; 649 static char fmt[211] = "warning - "; 650 char *msg; 651 char tbuf[20]; 652 struct timeval now; 653 struct tm *thyme; 654 time_t t; 655 656 va_start(ap, format); 657 #else 658 /*VARARGS3*/ 659 void 660 log(severity, syserr, format, va_alist) 661 int severity, syserr; 662 char *format; 663 va_dcl 664 { 665 va_list ap; 666 static char fmt[211] = "warning - "; 667 char *msg; 668 char tbuf[20]; 669 struct timeval now; 670 struct tm *thyme; 671 time_t t; 672 673 va_start(ap); 674 #endif 675 vsprintf(&fmt[10], format, ap); 676 va_end(ap); 677 msg = (severity == LOG_WARNING) ? fmt : &fmt[10]; 678 679 switch (debug) { 680 case 0: break; 681 case 1: if (severity > LOG_NOTICE) break; 682 case 2: if (severity > LOG_INFO ) break; 683 default: 684 gettimeofday(&now,NULL); 685 t = now.tv_sec; 686 thyme = localtime(&t); 687 strftime(tbuf, sizeof(tbuf), "%X.%%03d ", thyme); 688 fprintf(stderr, tbuf, now.tv_usec / 1000); 689 fprintf(stderr, "%s", msg); 690 if (syserr == 0) 691 fprintf(stderr, "\n"); 692 else 693 fprintf(stderr, ": %s\n", strerror(syserr)); 694 } 695 696 if (severity <= LOG_NOTICE) { 697 if (log_nmsgs++ < LOG_MAX_MSGS) { 698 if (syserr != 0) { 699 errno = syserr; 700 syslog(severity, "%s: %m", msg); 701 } else 702 syslog(severity, "%s", msg); 703 } 704 705 if (severity <= LOG_ERR) exit(-1); 706 } 707 } 708 709 #ifdef DEBUG_MFC 710 void 711 md_log(what, origin, mcastgrp) 712 int what; 713 u_int32_t origin, mcastgrp; 714 { 715 static FILE *f = NULL; 716 struct timeval tv; 717 u_int32_t buf[4]; 718 719 if (!f) { 720 if ((f = fopen("/tmp/mrouted.clog", "w")) == NULL) { 721 log(LOG_ERR, errno, "open /tmp/mrouted.clog"); 722 } 723 } 724 725 gettimeofday(&tv, NULL); 726 buf[0] = tv.tv_sec; 727 buf[1] = what; 728 buf[2] = origin; 729 buf[3] = mcastgrp; 730 731 fwrite(buf, sizeof(u_int32_t), 4, f); 732 } 733 #endif 734