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 #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 #ifndef lint 35 static char rcsid[] = 36 "@(#) $Id: main.c,v 1.6 2001/09/04 23:35:59 millert Exp $"; 37 #endif 38 39 extern char *configfilename; 40 char versionstring[100]; 41 42 static char pidfilename[] = _PATH_MROUTED_PID; 43 static char dumpfilename[] = _PATH_MROUTED_DUMP; 44 static char cachefilename[] = _PATH_MROUTED_CACHE; 45 static char genidfilename[] = _PATH_MROUTED_GENID; 46 47 int cache_lifetime = DEFAULT_CACHE_LIFETIME; 48 int max_prune_lifetime = DEFAULT_CACHE_LIFETIME * 2; 49 50 int debug = 0; 51 u_char pruning = 1; /* Enable pruning by default */ 52 53 #ifdef SNMP 54 #define NHANDLERS 34 55 #else 56 #define NHANDLERS 2 57 #endif 58 59 static struct ihandler { 60 int fd; /* File descriptor */ 61 ihfunc_t func; /* Function to call with &fd_set */ 62 } ihandlers[NHANDLERS]; 63 static int nhandlers = 0; 64 65 /* 66 * Forward declarations. 67 */ 68 static void fasttimer __P((int)); 69 static void done __P((int)); 70 static void dump __P((int)); 71 static void fdump __P((int)); 72 static void cdump __P((int)); 73 static void restart __P((int)); 74 static void timer __P((void)); 75 static void cleanup __P((void)); 76 static void resetlogging __P((void *)); 77 78 /* To shut up gcc -Wstrict-prototypes */ 79 int main __P((int argc, char **argv)); 80 81 int 82 register_input_handler(fd, func) 83 int fd; 84 ihfunc_t func; 85 { 86 if (nhandlers >= NHANDLERS) 87 return -1; 88 89 ihandlers[nhandlers].fd = fd; 90 ihandlers[nhandlers++].func = func; 91 92 return 0; 93 } 94 95 int 96 main(argc, argv) 97 int argc; 98 char *argv[]; 99 { 100 register int recvlen; 101 int dummy; 102 FILE *fp; 103 struct timeval tv; 104 u_int32_t prev_genid; 105 int vers; 106 fd_set rfds, readers; 107 int nfds, n, i; 108 sigset_t mask, omask; 109 #ifdef SNMP 110 struct timeval timeout, *tvp = &timeout; 111 struct timeval sched, *svp = &sched, now, *nvp = &now; 112 int index, block; 113 #endif 114 115 if (geteuid() != 0) { 116 fprintf(stderr, "must be root\n"); 117 exit(1); 118 } 119 setlinebuf(stderr); 120 121 argv++, argc--; 122 while (argc > 0 && *argv[0] == '-') { 123 if (strcmp(*argv, "-d") == 0) { 124 if (argc > 1 && isdigit(*(argv + 1)[0])) { 125 argv++, argc--; 126 debug = atoi(*argv); 127 } else 128 debug = DEFAULT_DEBUG; 129 } else if (strcmp(*argv, "-c") == 0) { 130 if (argc > 1) { 131 argv++, argc--; 132 configfilename = *argv; 133 } else 134 goto usage; 135 } else if (strcmp(*argv, "-p") == 0) { 136 pruning = 0; 137 #ifdef SNMP 138 } else if (strcmp(*argv, "-P") == 0) { 139 if (argc > 1 && isdigit(*(argv + 1)[0])) { 140 argv++, argc--; 141 dest_port = atoi(*argv); 142 } else 143 dest_port = DEFAULT_PORT; 144 #endif 145 } else 146 goto usage; 147 argv++, argc--; 148 } 149 150 if (argc > 0) { 151 usage: fprintf(stderr, 152 "usage: mrouted [-p] [-c configfile] [-d [debug_level]]\n"); 153 exit(1); 154 } 155 156 if (debug == 0) { 157 /* 158 * Detach from the terminal 159 */ 160 int t; 161 162 if (fork()) exit(0); 163 (void)close(0); 164 (void)close(1); 165 (void)close(2); 166 (void)open("/", 0); 167 (void)dup2(0, 1); 168 (void)dup2(0, 2); 169 #ifdef SYSV 170 (void)setpgrp(); 171 #else 172 #ifdef TIOCNOTTY 173 t = open("/dev/tty", 2); 174 if (t >= 0) { 175 (void)ioctl(t, TIOCNOTTY, (char *)0); 176 (void)close(t); 177 } 178 #else 179 if (setsid() < 0) 180 perror("setsid"); 181 #endif 182 #endif 183 } 184 else 185 fprintf(stderr, "debug level %u\n", debug); 186 187 #ifdef LOG_DAEMON 188 (void)openlog("mrouted", LOG_PID, LOG_DAEMON); 189 (void)setlogmask(LOG_UPTO(LOG_NOTICE)); 190 #else 191 (void)openlog("mrouted", LOG_PID); 192 #endif 193 sprintf(versionstring, "mrouted version %d.%d", 194 PROTOCOL_VERSION, MROUTED_VERSION); 195 196 log(LOG_NOTICE, 0, "%s", versionstring); 197 198 #ifdef SYSV 199 srand48(time(NULL)); 200 #else 201 srandom(gethostid()); 202 #endif 203 204 /* 205 * Get generation id 206 */ 207 gettimeofday(&tv, 0); 208 dvmrp_genid = tv.tv_sec; 209 210 fp = fopen(genidfilename, "r"); 211 if (fp != NULL) { 212 fscanf(fp, "%d", &prev_genid); 213 if (prev_genid == dvmrp_genid) 214 dvmrp_genid++; 215 (void) fclose(fp); 216 } 217 218 fp = fopen(genidfilename, "w"); 219 if (fp != NULL) { 220 fprintf(fp, "%d", dvmrp_genid); 221 (void) fclose(fp); 222 } 223 224 callout_init(); 225 init_igmp(); 226 init_routes(); 227 init_ktable(); 228 k_init_dvmrp(); /* enable DVMRP routing in kernel */ 229 230 #ifndef OLD_KERNEL 231 vers = k_get_version(); 232 /*XXX 233 * This function must change whenever the kernel version changes 234 */ 235 if ((((vers >> 8) & 0xff) != 3) || 236 ((vers & 0xff) != 5)) 237 log(LOG_ERR, 0, "kernel (v%d.%d)/mrouted (v%d.%d) version mismatch", 238 (vers >> 8) & 0xff, vers & 0xff, 239 PROTOCOL_VERSION, MROUTED_VERSION); 240 #endif 241 242 #ifdef SNMP 243 if (i = snmp_init()) 244 return i; 245 246 gettimeofday(nvp, 0); 247 if (nvp->tv_usec < 500000L){ 248 svp->tv_usec = nvp->tv_usec + 500000L; 249 svp->tv_sec = nvp->tv_sec; 250 } else { 251 svp->tv_usec = nvp->tv_usec - 500000L; 252 svp->tv_sec = nvp->tv_sec + 1; 253 } 254 #endif /* SNMP */ 255 256 init_vifs(); 257 258 #ifdef RSRR 259 rsrr_init(); 260 #endif /* RSRR */ 261 262 #if defined(__STDC__) || defined(__GNUC__) 263 /* 264 * Allow cleanup if unexpected exit. Apparently some architectures 265 * have a kernel bug where closing the socket doesn't do an 266 * ip_mrouter_done(), so we attempt to do it on exit. 267 */ 268 atexit(cleanup); 269 #endif 270 271 if (debug) 272 fprintf(stderr, "pruning %s\n", pruning ? "on" : "off"); 273 274 fp = fopen(pidfilename, "w"); 275 if (fp != NULL) { 276 fprintf(fp, "%d\n", (int)getpid()); 277 (void) fclose(fp); 278 } 279 280 (void)signal(SIGALRM, fasttimer); 281 282 (void)signal(SIGHUP, restart); 283 (void)signal(SIGTERM, done); 284 (void)signal(SIGINT, done); 285 (void)signal(SIGUSR1, fdump); 286 (void)signal(SIGUSR2, cdump); 287 if (debug != 0) 288 (void)signal(SIGQUIT, dump); 289 290 FD_ZERO(&readers); 291 FD_SET(igmp_socket, &readers); 292 nfds = igmp_socket + 1; 293 for (i = 0; i < nhandlers; i++) { 294 FD_SET(ihandlers[i].fd, &readers); 295 if (ihandlers[i].fd >= nfds) 296 nfds = ihandlers[i].fd + 1; 297 } 298 299 /* 300 * Install the vifs in the kernel as late as possible in the 301 * initialization sequence. 302 */ 303 init_installvifs(); 304 305 if (debug >= 2) dump(0); 306 307 /* Start up the log rate-limiter */ 308 resetlogging(NULL); 309 310 (void)alarm(1); /* schedule first timer interrupt */ 311 312 /* 313 * Main receive loop. 314 */ 315 dummy = 0; 316 for(;;) { 317 bcopy((char *)&readers, (char *)&rfds, sizeof(rfds)); 318 #ifdef SNMP 319 gettimeofday(nvp, 0); 320 if (nvp->tv_sec > svp->tv_sec 321 || (nvp->tv_sec == svp->tv_sec && nvp->tv_usec > svp->tv_usec)){ 322 alarmTimer(nvp); 323 eventTimer(nvp); 324 if (nvp->tv_usec < 500000L){ 325 svp->tv_usec = nvp->tv_usec + 500000L; 326 svp->tv_sec = nvp->tv_sec; 327 } else { 328 svp->tv_usec = nvp->tv_usec - 500000L; 329 svp->tv_sec = nvp->tv_sec + 1; 330 } 331 } 332 333 tvp = &timeout; 334 tvp->tv_sec = 0; 335 tvp->tv_usec = 500000L; 336 337 block = 0; 338 snmp_select_info(&nfds, &rfds, tvp, &block); 339 if (block == 1) 340 tvp = NULL; /* block without timeout */ 341 if ((n = select(nfds, &rfds, NULL, NULL, tvp)) < 0) 342 #else 343 if ((n = select(nfds, &rfds, NULL, NULL, NULL)) < 0) 344 #endif 345 { 346 if (errno != EINTR) /* SIGALRM is expected */ 347 log(LOG_WARNING, errno, "select failed"); 348 continue; 349 } 350 351 if (FD_ISSET(igmp_socket, &rfds)) { 352 recvlen = recvfrom(igmp_socket, recv_buf, RECV_BUF_SIZE, 353 0, NULL, &dummy); 354 if (recvlen < 0) { 355 if (errno != EINTR) log(LOG_ERR, errno, "recvfrom"); 356 continue; 357 } 358 (void)sigemptyset(&mask); 359 (void)sigaddset(&mask, SIGALRM); 360 if (sigprocmask(SIG_BLOCK, &mask, &omask) < 0) 361 log(LOG_ERR, errno, "sigprocmask"); 362 accept_igmp(recvlen); 363 (void)sigprocmask(SIG_SETMASK, &omask, NULL); 364 } 365 366 for (i = 0; i < nhandlers; i++) { 367 if (FD_ISSET(ihandlers[i].fd, &rfds)) { 368 (*ihandlers[i].func)(ihandlers[i].fd, &rfds); 369 } 370 } 371 372 #ifdef SNMP 373 snmp_read(&rfds); 374 snmp_timeout(); /* poll */ 375 #endif 376 } 377 } 378 379 380 /* 381 * routine invoked every second. Its main goal is to cycle through 382 * the routing table and send partial updates to all neighbors at a 383 * rate that will cause the entire table to be sent in ROUTE_REPORT_INTERVAL 384 * seconds. Also, every TIMER_INTERVAL seconds it calls timer() to 385 * do all the other time-based processing. 386 */ 387 static void 388 fasttimer(i) 389 int i; 390 { 391 static unsigned int tlast; 392 static unsigned int nsent; 393 register unsigned int t = tlast + 1; 394 register int n; 395 396 /* 397 * if we're in the last second, send everything that's left. 398 * otherwise send at least the fraction we should have sent by now. 399 */ 400 if (t >= ROUTE_REPORT_INTERVAL) { 401 register int nleft = nroutes - nsent; 402 while (nleft > 0) { 403 if ((n = report_next_chunk()) <= 0) 404 break; 405 nleft -= n; 406 } 407 tlast = 0; 408 nsent = 0; 409 } else { 410 register unsigned int ncum = nroutes * t / ROUTE_REPORT_INTERVAL; 411 while (nsent < ncum) { 412 if ((n = report_next_chunk()) <= 0) 413 break; 414 nsent += n; 415 } 416 tlast = t; 417 } 418 if ((t % TIMER_INTERVAL) == 0) 419 timer(); 420 421 age_callout_queue();/* Advance the timer for the callout queue 422 for groups */ 423 alarm(1); 424 } 425 426 /* 427 * The 'virtual_time' variable is initialized to a value that will cause the 428 * first invocation of timer() to send a probe or route report to all vifs 429 * and send group membership queries to all subnets for which this router is 430 * querier. This first invocation occurs approximately TIMER_INTERVAL seconds 431 * after the router starts up. Note that probes for neighbors and queries 432 * for group memberships are also sent at start-up time, as part of initial- 433 * ization. This repetition after a short interval is desirable for quickly 434 * building up topology and membership information in the presence of possible 435 * packet loss. 436 * 437 * 'virtual_time' advances at a rate that is only a crude approximation of 438 * real time, because it does not take into account any time spent processing, 439 * and because the timer intervals are sometimes shrunk by a random amount to 440 * avoid unwanted synchronization with other routers. 441 */ 442 443 static u_long virtual_time = 0; 444 445 446 /* 447 * Timer routine. Performs periodic neighbor probing, route reporting, and 448 * group querying duties, and drives various timers in routing entries and 449 * virtual interface data structures. 450 */ 451 static void 452 timer() 453 { 454 age_routes(); /* Advance the timers in the route entries */ 455 age_vifs(); /* Advance the timers for neighbors */ 456 age_table_entry(); /* Advance the timers for the cache entries */ 457 458 if (virtual_time % GROUP_QUERY_INTERVAL == 0) { 459 /* 460 * Time to query the local group memberships on all subnets 461 * for which this router is the elected querier. 462 */ 463 query_groups(); 464 } 465 466 if (virtual_time % NEIGHBOR_PROBE_INTERVAL == 0) { 467 /* 468 * Time to send a probe on all vifs from which no neighbors have 469 * been heard. Also, check if any inoperative interfaces have now 470 * come up. (If they have, they will also be probed as part of 471 * their initialization.) 472 */ 473 probe_for_neighbors(); 474 475 if (vifs_down) 476 check_vif_state(); 477 } 478 479 delay_change_reports = FALSE; 480 if (routes_changed) { 481 /* 482 * Some routes have changed since the last timer interrupt, but 483 * have not been reported yet. Report the changed routes to all 484 * neighbors. 485 */ 486 report_to_all_neighbors(CHANGED_ROUTES); 487 } 488 489 #ifdef SNMP 490 sync_timer(); 491 #endif 492 493 /* 494 * Advance virtual time 495 */ 496 virtual_time += TIMER_INTERVAL; 497 } 498 499 500 /* 501 * On termination, let everyone know we're going away. 502 */ 503 static void 504 done(i) 505 int i; 506 { 507 log(LOG_NOTICE, 0, "%s exiting", versionstring); 508 cleanup(); 509 _exit(1); 510 } 511 512 static void 513 cleanup() 514 { 515 static in_cleanup = 0; 516 517 if (!in_cleanup) { 518 in_cleanup++; 519 #ifdef RSRR 520 rsrr_clean(); 521 #endif /* RSRR */ 522 expire_all_routes(); 523 report_to_all_neighbors(ALL_ROUTES); 524 k_stop_dvmrp(); 525 } 526 } 527 528 529 /* 530 * Dump internal data structures to stderr. 531 */ 532 static void 533 dump(i) 534 int i; 535 { 536 dump_vifs(stderr); 537 dump_routes(stderr); 538 } 539 540 541 /* 542 * Dump internal data structures to a file. 543 */ 544 static void 545 fdump(i) 546 int i; 547 { 548 FILE *fp; 549 550 fp = fopen(dumpfilename, "w"); 551 if (fp != NULL) { 552 dump_vifs(fp); 553 dump_routes(fp); 554 (void) fclose(fp); 555 } 556 } 557 558 559 /* 560 * Dump local cache contents to a file. 561 */ 562 static void 563 cdump(i) 564 int i; 565 { 566 FILE *fp; 567 568 fp = fopen(cachefilename, "w"); 569 if (fp != NULL) { 570 dump_cache(fp); 571 (void) fclose(fp); 572 } 573 } 574 575 576 /* 577 * Restart mrouted 578 */ 579 static void 580 restart(i) 581 int i; 582 { 583 sigset_t mask, omask; 584 585 log(LOG_NOTICE, 0, "%s restart", versionstring); 586 587 /* 588 * reset all the entries 589 */ 590 (void)sigemptyset(&mask); 591 (void)sigaddset(&mask, SIGALRM); 592 if (sigprocmask(SIG_BLOCK, &mask, &omask) < 0) 593 log(LOG_ERR, errno, "sigprocmask"); 594 free_all_prunes(); 595 free_all_routes(); 596 stop_all_vifs(); 597 k_stop_dvmrp(); 598 close(igmp_socket); 599 close(udp_socket); 600 601 /* 602 * start processing again 603 */ 604 dvmrp_genid++; 605 pruning = 1; 606 607 init_igmp(); 608 init_routes(); 609 init_ktable(); 610 init_vifs(); 611 k_init_dvmrp(); /* enable DVMRP routing in kernel */ 612 init_installvifs(); 613 614 (void)sigprocmask(SIG_SETMASK, &omask, NULL); 615 } 616 617 #define LOG_MAX_MSGS 20 /* if > 20/minute then shut up for a while */ 618 #define LOG_SHUT_UP 600 /* shut up for 10 minutes */ 619 static int log_nmsgs = 0; 620 621 static void 622 resetlogging(arg) 623 void *arg; 624 { 625 int nxttime = 60; 626 void *narg = NULL; 627 628 if (arg == NULL && log_nmsgs > LOG_MAX_MSGS) { 629 nxttime = LOG_SHUT_UP; 630 narg = (void *)&log_nmsgs; /* just need some valid void * */ 631 syslog(LOG_WARNING, "logging too fast, shutting up for %d minutes", 632 LOG_SHUT_UP / 60); 633 } else { 634 log_nmsgs = 0; 635 } 636 637 timer_setTimer(nxttime, resetlogging, narg); 638 } 639 640 /* 641 * Log errors and other messages to the system log daemon and to stderr, 642 * according to the severity of the message and the current debug level. 643 * For errors of severity LOG_ERR or worse, terminate the program. 644 */ 645 #ifdef __STDC__ 646 void 647 log(int severity, int syserr, char *format, ...) 648 { 649 va_list ap; 650 static char fmt[211] = "warning - "; 651 char *msg; 652 char tbuf[20]; 653 struct timeval now; 654 struct tm *thyme; 655 time_t t; 656 657 va_start(ap, format); 658 #else 659 /*VARARGS3*/ 660 void 661 log(severity, syserr, format, va_alist) 662 int severity, syserr; 663 char *format; 664 va_dcl 665 { 666 va_list ap; 667 static char fmt[211] = "warning - "; 668 char *msg; 669 char tbuf[20]; 670 struct timeval now; 671 struct tm *thyme; 672 time_t t; 673 674 va_start(ap); 675 #endif 676 vsprintf(&fmt[10], format, ap); 677 va_end(ap); 678 msg = (severity == LOG_WARNING) ? fmt : &fmt[10]; 679 680 switch (debug) { 681 case 0: break; 682 case 1: if (severity > LOG_NOTICE) break; 683 case 2: if (severity > LOG_INFO ) break; 684 default: 685 gettimeofday(&now,NULL); 686 t = now.tv_sec; 687 thyme = localtime(&t); 688 strftime(tbuf, sizeof(tbuf), "%X.%%03d ", thyme); 689 fprintf(stderr, tbuf, now.tv_usec / 1000); 690 fprintf(stderr, "%s", msg); 691 if (syserr == 0) 692 fprintf(stderr, "\n"); 693 else if (syserr < sys_nerr) 694 fprintf(stderr, ": %s\n", sys_errlist[syserr]); 695 else 696 fprintf(stderr, ": errno %d\n", syserr); 697 } 698 699 if (severity <= LOG_NOTICE) { 700 if (log_nmsgs++ < LOG_MAX_MSGS) { 701 if (syserr != 0) { 702 errno = syserr; 703 syslog(severity, "%s: %m", msg); 704 } else 705 syslog(severity, "%s", msg); 706 } 707 708 if (severity <= LOG_ERR) exit(1); 709 } 710 } 711 712 #ifdef DEBUG_MFC 713 void 714 md_log(what, origin, mcastgrp) 715 int what; 716 u_int32_t origin, mcastgrp; 717 { 718 static FILE *f = NULL; 719 struct timeval tv; 720 u_int32_t buf[4]; 721 722 if (!f) { 723 if ((f = fopen("/tmp/mrouted.clog", "w")) == NULL) { 724 log(LOG_ERR, errno, "open /tmp/mrouted.clog"); 725 } 726 } 727 728 gettimeofday(&tv, NULL); 729 buf[0] = tv.tv_sec; 730 buf[1] = what; 731 buf[2] = origin; 732 buf[3] = mcastgrp; 733 734 fwrite(buf, sizeof(u_int32_t), 4, f); 735 } 736 #endif 737