1 /* $NetBSD: main.c,v 1.6 1995/12/10 10:07:05 mycroft 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 #include <stdarg.h> 24 #include <fcntl.h> 25 #include <util.h> 26 27 #ifdef SNMP 28 #include "snmp.h" 29 #endif 30 31 #ifndef lint 32 static char rcsid[] = 33 "@(#) $Id: main.c,v 1.14 2003/11/26 01:17:12 millert Exp $"; 34 #endif 35 36 extern char *configfilename; 37 char versionstring[100]; 38 39 static char dumpfilename[] = _PATH_MROUTED_DUMP; 40 static char cachefilename[] = _PATH_MROUTED_CACHE; 41 static char genidfilename[] = _PATH_MROUTED_GENID; 42 43 int cache_lifetime = DEFAULT_CACHE_LIFETIME; 44 int max_prune_lifetime = DEFAULT_CACHE_LIFETIME * 2; 45 46 int debug = 0; 47 u_char pruning = 1; /* Enable pruning by default */ 48 49 #ifdef SNMP 50 #define NHANDLERS 34 51 #else 52 #define NHANDLERS 2 53 #endif 54 55 static struct ihandler { 56 int fd; /* File descriptor */ 57 ihfunc_t func; /* Function to call with &fd_set */ 58 } ihandlers[NHANDLERS]; 59 static int nhandlers = 0; 60 61 /* 62 * Forward declarations. 63 */ 64 static void fasttimer(int); 65 static void done(int); 66 static void dump(int); 67 static void fdump(int); 68 static void cdump(int); 69 static void restart(int); 70 static void timer(void); 71 static void cleanup(void); 72 static void resetlogging(void *); 73 74 int 75 register_input_handler(int fd, ihfunc_t func) 76 { 77 if (nhandlers >= NHANDLERS) 78 return -1; 79 80 ihandlers[nhandlers].fd = fd; 81 ihandlers[nhandlers++].func = func; 82 83 return 0; 84 } 85 86 int 87 main(int argc, char *argv[]) 88 { 89 register int recvlen; 90 int dummy; 91 FILE *fp; 92 struct timeval tv; 93 u_int32_t prev_genid; 94 int vers; 95 fd_set rfds, readers; 96 int nfds, n, i; 97 sigset_t mask, omask; 98 #ifdef SNMP 99 struct timeval timeout, *tvp = &timeout; 100 struct timeval sched, *svp = &sched, now, *nvp = &now; 101 int index, block; 102 #endif 103 104 if (geteuid() != 0) { 105 fprintf(stderr, "must be root\n"); 106 exit(1); 107 } 108 setlinebuf(stderr); 109 110 argv++, argc--; 111 while (argc > 0 && *argv[0] == '-') { 112 if (strcmp(*argv, "-d") == 0) { 113 if (argc > 1 && isdigit(*(argv + 1)[0])) { 114 argv++, argc--; 115 debug = atoi(*argv); 116 } else 117 debug = DEFAULT_DEBUG; 118 } else if (strcmp(*argv, "-c") == 0) { 119 if (argc > 1) { 120 argv++, argc--; 121 configfilename = *argv; 122 } else 123 goto usage; 124 } else if (strcmp(*argv, "-p") == 0) { 125 pruning = 0; 126 #ifdef SNMP 127 } else if (strcmp(*argv, "-P") == 0) { 128 if (argc > 1 && isdigit(*(argv + 1)[0])) { 129 argv++, argc--; 130 dest_port = atoi(*argv); 131 } else 132 dest_port = DEFAULT_PORT; 133 #endif 134 } else 135 goto usage; 136 argv++, argc--; 137 } 138 139 if (argc > 0) { 140 usage: fprintf(stderr, 141 "usage: mrouted [-p] [-c configfile] [-d [debug_level]]\n"); 142 exit(1); 143 } 144 145 if (debug == 0) { 146 /* 147 * Detach from the terminal 148 */ 149 int t; 150 151 if (fork()) exit(0); 152 (void)close(0); 153 (void)close(1); 154 (void)close(2); 155 (void)open("/", 0); 156 (void)dup2(0, 1); 157 (void)dup2(0, 2); 158 #ifdef SYSV 159 (void)setpgrp(); 160 #else 161 #ifdef TIOCNOTTY 162 t = open("/dev/tty", 2); 163 if (t >= 0) { 164 (void)ioctl(t, TIOCNOTTY, (char *)0); 165 (void)close(t); 166 } 167 #else 168 if (setsid() < 0) 169 perror("setsid"); 170 #endif 171 #endif 172 } 173 else 174 fprintf(stderr, "debug level %u\n", debug); 175 176 #ifdef LOG_DAEMON 177 (void)openlog("mrouted", LOG_PID, LOG_DAEMON); 178 (void)setlogmask(LOG_UPTO(LOG_NOTICE)); 179 #else 180 (void)openlog("mrouted", LOG_PID); 181 #endif 182 snprintf(versionstring, sizeof versionstring, "mrouted version %d.%d", 183 PROTOCOL_VERSION, MROUTED_VERSION); 184 185 logit(LOG_NOTICE, 0, "%s", versionstring); 186 187 #ifdef SYSV 188 srand48(time(NULL)); 189 #else 190 srandom(gethostid()); 191 #endif 192 193 /* 194 * Get generation id 195 */ 196 gettimeofday(&tv, 0); 197 dvmrp_genid = tv.tv_sec; 198 199 fp = fopen(genidfilename, "r"); 200 if (fp != NULL) { 201 fscanf(fp, "%d", &prev_genid); 202 if (prev_genid == dvmrp_genid) 203 dvmrp_genid++; 204 (void) fclose(fp); 205 } 206 207 fp = fopen(genidfilename, "w"); 208 if (fp != NULL) { 209 fprintf(fp, "%d", dvmrp_genid); 210 (void) fclose(fp); 211 } 212 213 callout_init(); 214 init_igmp(); 215 init_routes(); 216 init_ktable(); 217 k_init_dvmrp(); /* enable DVMRP routing in kernel */ 218 219 #ifndef OLD_KERNEL 220 vers = k_get_version(); 221 /*XXX 222 * This function must change whenever the kernel version changes 223 */ 224 if ((((vers >> 8) & 0xff) != 3) || 225 ((vers & 0xff) != 5)) 226 logit(LOG_ERR, 0, "kernel (v%d.%d)/mrouted (v%d.%d) version mismatch", 227 (vers >> 8) & 0xff, vers & 0xff, 228 PROTOCOL_VERSION, MROUTED_VERSION); 229 #endif 230 231 #ifdef SNMP 232 if (i = snmp_init()) 233 return i; 234 235 gettimeofday(nvp, 0); 236 if (nvp->tv_usec < 500000L){ 237 svp->tv_usec = nvp->tv_usec + 500000L; 238 svp->tv_sec = nvp->tv_sec; 239 } else { 240 svp->tv_usec = nvp->tv_usec - 500000L; 241 svp->tv_sec = nvp->tv_sec + 1; 242 } 243 #endif /* SNMP */ 244 245 init_vifs(); 246 247 #ifdef RSRR 248 rsrr_init(); 249 #endif /* RSRR */ 250 251 /* 252 * Allow cleanup if unexpected exit. Apparently some architectures 253 * have a kernel bug where closing the socket doesn't do an 254 * ip_mrouter_done(), so we attempt to do it on exit. 255 */ 256 atexit(cleanup); 257 258 if (debug) 259 fprintf(stderr, "pruning %s\n", pruning ? "on" : "off"); 260 261 pidfile(NULL); 262 263 (void)signal(SIGALRM, fasttimer); 264 265 (void)signal(SIGHUP, restart); 266 (void)signal(SIGTERM, done); 267 (void)signal(SIGINT, done); 268 (void)signal(SIGUSR1, fdump); 269 (void)signal(SIGUSR2, cdump); 270 if (debug != 0) 271 (void)signal(SIGQUIT, dump); 272 273 FD_ZERO(&readers); 274 if (igmp_socket >= FD_SETSIZE) 275 logit(LOG_ERR, 0, "descriptor too big"); 276 FD_SET(igmp_socket, &readers); 277 nfds = igmp_socket + 1; 278 for (i = 0; i < nhandlers; i++) { 279 if (ihandlers[i].fd >= FD_SETSIZE) 280 logit(LOG_ERR, 0, "descriptor too big"); 281 FD_SET(ihandlers[i].fd, &readers); 282 if (ihandlers[i].fd >= nfds) 283 nfds = ihandlers[i].fd + 1; 284 } 285 286 /* 287 * Install the vifs in the kernel as late as possible in the 288 * initialization sequence. 289 */ 290 init_installvifs(); 291 292 if (debug >= 2) dump(0); 293 294 /* Start up the log rate-limiter */ 295 resetlogging(NULL); 296 297 (void)alarm(1); /* schedule first timer interrupt */ 298 299 /* 300 * Main receive loop. 301 */ 302 dummy = 0; 303 for(;;) { 304 bcopy((char *)&readers, (char *)&rfds, sizeof(rfds)); 305 #ifdef SNMP 306 gettimeofday(nvp, 0); 307 if (nvp->tv_sec > svp->tv_sec 308 || (nvp->tv_sec == svp->tv_sec && nvp->tv_usec > svp->tv_usec)){ 309 alarmTimer(nvp); 310 eventTimer(nvp); 311 if (nvp->tv_usec < 500000L){ 312 svp->tv_usec = nvp->tv_usec + 500000L; 313 svp->tv_sec = nvp->tv_sec; 314 } else { 315 svp->tv_usec = nvp->tv_usec - 500000L; 316 svp->tv_sec = nvp->tv_sec + 1; 317 } 318 } 319 320 tvp = &timeout; 321 tvp->tv_sec = 0; 322 tvp->tv_usec = 500000L; 323 324 block = 0; 325 snmp_select_info(&nfds, &rfds, tvp, &block); 326 if (block == 1) 327 tvp = NULL; /* block without timeout */ 328 if ((n = select(nfds, &rfds, NULL, NULL, tvp)) < 0) 329 #else 330 if ((n = select(nfds, &rfds, NULL, NULL, NULL)) < 0) 331 #endif 332 { 333 if (errno != EINTR) /* SIGALRM is expected */ 334 logit(LOG_WARNING, errno, "select failed"); 335 continue; 336 } 337 338 if (FD_ISSET(igmp_socket, &rfds)) { 339 recvlen = recvfrom(igmp_socket, recv_buf, RECV_BUF_SIZE, 340 0, NULL, &dummy); 341 if (recvlen < 0) { 342 if (errno != EINTR) logit(LOG_ERR, errno, "recvfrom"); 343 continue; 344 } 345 (void)sigemptyset(&mask); 346 (void)sigaddset(&mask, SIGALRM); 347 if (sigprocmask(SIG_BLOCK, &mask, &omask) < 0) 348 logit(LOG_ERR, errno, "sigprocmask"); 349 accept_igmp(recvlen); 350 (void)sigprocmask(SIG_SETMASK, &omask, NULL); 351 } 352 353 for (i = 0; i < nhandlers; i++) { 354 if (FD_ISSET(ihandlers[i].fd, &rfds)) { 355 (*ihandlers[i].func)(ihandlers[i].fd, &rfds); 356 } 357 } 358 359 #ifdef SNMP 360 snmp_read(&rfds); 361 snmp_timeout(); /* poll */ 362 #endif 363 } 364 } 365 366 367 /* 368 * routine invoked every second. Its main goal is to cycle through 369 * the routing table and send partial updates to all neighbors at a 370 * rate that will cause the entire table to be sent in ROUTE_REPORT_INTERVAL 371 * seconds. Also, every TIMER_INTERVAL seconds it calls timer() to 372 * do all the other time-based processing. 373 */ 374 static void 375 fasttimer(int i) 376 { 377 static unsigned int tlast; 378 static unsigned int nsent; 379 register unsigned int t = tlast + 1; 380 register int n; 381 382 /* 383 * if we're in the last second, send everything that's left. 384 * otherwise send at least the fraction we should have sent by now. 385 */ 386 if (t >= ROUTE_REPORT_INTERVAL) { 387 register int nleft = nroutes - nsent; 388 while (nleft > 0) { 389 if ((n = report_next_chunk()) <= 0) 390 break; 391 nleft -= n; 392 } 393 tlast = 0; 394 nsent = 0; 395 } else { 396 register unsigned int ncum = nroutes * t / ROUTE_REPORT_INTERVAL; 397 while (nsent < ncum) { 398 if ((n = report_next_chunk()) <= 0) 399 break; 400 nsent += n; 401 } 402 tlast = t; 403 } 404 if ((t % TIMER_INTERVAL) == 0) 405 timer(); 406 407 age_callout_queue();/* Advance the timer for the callout queue 408 for groups */ 409 alarm(1); 410 } 411 412 /* 413 * The 'virtual_time' variable is initialized to a value that will cause the 414 * first invocation of timer() to send a probe or route report to all vifs 415 * and send group membership queries to all subnets for which this router is 416 * querier. This first invocation occurs approximately TIMER_INTERVAL seconds 417 * after the router starts up. Note that probes for neighbors and queries 418 * for group memberships are also sent at start-up time, as part of initial- 419 * ization. This repetition after a short interval is desirable for quickly 420 * building up topology and membership information in the presence of possible 421 * packet loss. 422 * 423 * 'virtual_time' advances at a rate that is only a crude approximation of 424 * real time, because it does not take into account any time spent processing, 425 * and because the timer intervals are sometimes shrunk by a random amount to 426 * avoid unwanted synchronization with other routers. 427 */ 428 429 static u_long virtual_time = 0; 430 431 432 /* 433 * Timer routine. Performs periodic neighbor probing, route reporting, and 434 * group querying duties, and drives various timers in routing entries and 435 * virtual interface data structures. 436 */ 437 static void 438 timer(void) 439 { 440 age_routes(); /* Advance the timers in the route entries */ 441 age_vifs(); /* Advance the timers for neighbors */ 442 age_table_entry(); /* Advance the timers for the cache entries */ 443 444 if (virtual_time % GROUP_QUERY_INTERVAL == 0) { 445 /* 446 * Time to query the local group memberships on all subnets 447 * for which this router is the elected querier. 448 */ 449 query_groups(); 450 } 451 452 if (virtual_time % NEIGHBOR_PROBE_INTERVAL == 0) { 453 /* 454 * Time to send a probe on all vifs from which no neighbors have 455 * been heard. Also, check if any inoperative interfaces have now 456 * come up. (If they have, they will also be probed as part of 457 * their initialization.) 458 */ 459 probe_for_neighbors(); 460 461 if (vifs_down) 462 check_vif_state(); 463 } 464 465 delay_change_reports = FALSE; 466 if (routes_changed) { 467 /* 468 * Some routes have changed since the last timer interrupt, but 469 * have not been reported yet. Report the changed routes to all 470 * neighbors. 471 */ 472 report_to_all_neighbors(CHANGED_ROUTES); 473 } 474 475 #ifdef SNMP 476 sync_timer(); 477 #endif 478 479 /* 480 * Advance virtual time 481 */ 482 virtual_time += TIMER_INTERVAL; 483 } 484 485 486 /* 487 * On termination, let everyone know we're going away. 488 */ 489 static void 490 done(int i) 491 { 492 logit(LOG_NOTICE, 0, "%s exiting", versionstring); 493 cleanup(); 494 _exit(1); 495 } 496 497 static void 498 cleanup(void) 499 { 500 static in_cleanup = 0; 501 502 if (!in_cleanup) { 503 in_cleanup++; 504 #ifdef RSRR 505 rsrr_clean(); 506 #endif /* RSRR */ 507 expire_all_routes(); 508 report_to_all_neighbors(ALL_ROUTES); 509 k_stop_dvmrp(); 510 } 511 } 512 513 514 /* 515 * Dump internal data structures to stderr. 516 */ 517 static void 518 dump(int i) 519 { 520 dump_vifs(stderr); 521 dump_routes(stderr); 522 } 523 524 525 /* 526 * Dump internal data structures to a file. 527 */ 528 static void 529 fdump(int i) 530 { 531 FILE *fp; 532 533 fp = fopen(dumpfilename, "w"); 534 if (fp != NULL) { 535 dump_vifs(fp); 536 dump_routes(fp); 537 (void) fclose(fp); 538 } 539 } 540 541 542 /* 543 * Dump local cache contents to a file. 544 */ 545 static void 546 cdump(int i) 547 { 548 FILE *fp; 549 550 fp = fopen(cachefilename, "w"); 551 if (fp != NULL) { 552 dump_cache(fp); 553 (void) fclose(fp); 554 } 555 } 556 557 558 /* 559 * Restart mrouted 560 */ 561 static void 562 restart(int i) 563 { 564 sigset_t mask, omask; 565 566 logit(LOG_NOTICE, 0, "%s restart", versionstring); 567 568 /* 569 * reset all the entries 570 */ 571 (void)sigemptyset(&mask); 572 (void)sigaddset(&mask, SIGALRM); 573 if (sigprocmask(SIG_BLOCK, &mask, &omask) < 0) 574 logit(LOG_ERR, errno, "sigprocmask"); 575 free_all_prunes(); 576 free_all_routes(); 577 stop_all_vifs(); 578 k_stop_dvmrp(); 579 close(igmp_socket); 580 close(udp_socket); 581 582 /* 583 * start processing again 584 */ 585 dvmrp_genid++; 586 pruning = 1; 587 588 init_igmp(); 589 init_routes(); 590 init_ktable(); 591 init_vifs(); 592 k_init_dvmrp(); /* enable DVMRP routing in kernel */ 593 init_installvifs(); 594 595 (void)sigprocmask(SIG_SETMASK, &omask, NULL); 596 } 597 598 #define LOG_MAX_MSGS 20 /* if > 20/minute then shut up for a while */ 599 #define LOG_SHUT_UP 600 /* shut up for 10 minutes */ 600 static int log_nmsgs = 0; 601 602 static void 603 resetlogging(void *arg) 604 { 605 int nxttime = 60; 606 void *narg = NULL; 607 608 if (arg == NULL && log_nmsgs > LOG_MAX_MSGS) { 609 nxttime = LOG_SHUT_UP; 610 narg = (void *)&log_nmsgs; /* just need some valid void * */ 611 syslog(LOG_WARNING, "logging too fast, shutting up for %d minutes", 612 LOG_SHUT_UP / 60); 613 } else { 614 log_nmsgs = 0; 615 } 616 617 timer_setTimer(nxttime, resetlogging, narg); 618 } 619 620 /* 621 * Log errors and other messages to the system log daemon and to stderr, 622 * according to the severity of the message and the current debug level. 623 * For errors of severity LOG_ERR or worse, terminate the program. 624 */ 625 void 626 logit(int severity, int syserr, char *format, ...) 627 { 628 va_list ap; 629 static char fmt[211] = "warning - "; 630 char *msg; 631 char tbuf[20]; 632 struct timeval now; 633 struct tm *thyme; 634 time_t t; 635 636 va_start(ap, format); 637 vsnprintf(&fmt[10], sizeof fmt - 10, format, ap); 638 va_end(ap); 639 msg = (severity == LOG_WARNING) ? fmt : &fmt[10]; 640 641 switch (debug) { 642 case 0: break; 643 case 1: if (severity > LOG_NOTICE) break; 644 case 2: if (severity > LOG_INFO ) break; 645 default: 646 gettimeofday(&now,NULL); 647 t = now.tv_sec; 648 thyme = localtime(&t); 649 strftime(tbuf, sizeof(tbuf), "%X.%%03d ", thyme); 650 fprintf(stderr, tbuf, now.tv_usec / 1000); 651 fprintf(stderr, "%s", msg); 652 if (syserr == 0) 653 fprintf(stderr, "\n"); 654 else if (syserr < sys_nerr) 655 fprintf(stderr, ": %s\n", sys_errlist[syserr]); 656 else 657 fprintf(stderr, ": errno %d\n", syserr); 658 } 659 660 if (severity <= LOG_NOTICE) { 661 if (log_nmsgs++ < LOG_MAX_MSGS) { 662 if (syserr != 0) { 663 errno = syserr; 664 syslog(severity, "%s: %m", msg); 665 } else 666 syslog(severity, "%s", msg); 667 } 668 669 if (severity <= LOG_ERR) exit(1); 670 } 671 } 672 673 #ifdef DEBUG_MFC 674 void 675 md_logit(int what, u_int32_t origin, u_int32_t mcastgrp) 676 { 677 static FILE *f = NULL; 678 struct timeval tv; 679 u_int32_t buf[4]; 680 681 if (!f) { 682 if ((f = fopen("/tmp/mrouted.clog", "w")) == NULL) { 683 logit(LOG_ERR, errno, "open /tmp/mrouted.clog"); 684 } 685 } 686 687 gettimeofday(&tv, NULL); 688 buf[0] = tv.tv_sec; 689 buf[1] = what; 690 buf[2] = origin; 691 buf[3] = mcastgrp; 692 693 fwrite(buf, sizeof(u_int32_t), 4, f); 694 } 695 #endif 696