1 /* $NetBSD: main.c,v 1.19 2003/05/16 18:10:38 itojun 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 26 #ifdef SNMP 27 #include "snmp.h" 28 #endif 29 30 #include <sys/cdefs.h> 31 #ifndef lint 32 __RCSID("@(#) $NetBSD: main.c,v 1.19 2003/05/16 18:10:38 itojun Exp $"); 33 #endif 34 35 #include <err.h> 36 #include <util.h> 37 38 extern char *configfilename; 39 char versionstring[100]; 40 41 static char dumpfilename[] = _PATH_MROUTED_DUMP; 42 static char cachefilename[] = _PATH_MROUTED_CACHE; 43 static char genidfilename[] = _PATH_MROUTED_GENID; 44 45 int cache_lifetime = DEFAULT_CACHE_LIFETIME; 46 int max_prune_lifetime = DEFAULT_CACHE_LIFETIME * 2; 47 48 int debug = 0; 49 u_char pruning = 1; /* Enable pruning by default */ 50 51 #ifdef SNMP 52 #define NHANDLERS 34 53 #else 54 #define NHANDLERS 2 55 #endif 56 57 static struct ihandler { 58 int fd; /* File descriptor */ 59 ihfunc_t func; /* Function to call with &fd_set */ 60 } ihandlers[NHANDLERS]; 61 static int nhandlers = 0; 62 63 /* 64 * Forward declarations. 65 */ 66 static void fasttimer(int); 67 static void done(int); 68 static void dump(int); 69 static void fdump(int); 70 static void cdump(int); 71 static void restart(int); 72 static void timer(void); 73 static void cleanup(void); 74 static void resetlogging(void *); 75 76 /* To shut up gcc -Wstrict-prototypes */ 77 int main(int argc, char *argv[]); 78 void logit(int severity, int syserr, const char *format, ...) 79 __attribute__((__format__(__printf__, 3, 4))); 80 81 int 82 register_input_handler(int fd, ihfunc_t func) 83 { 84 if (nhandlers >= NHANDLERS) 85 return -1; 86 87 ihandlers[nhandlers].fd = fd; 88 ihandlers[nhandlers++].func = func; 89 90 return 0; 91 } 92 93 int 94 main(int argc, char *argv[]) 95 { 96 int recvlen; 97 int omask; 98 int dummy; 99 FILE *fp; 100 struct timeval tv; 101 u_int32_t prev_genid; 102 int vers; 103 fd_set rfds, readers; 104 int nfds, n, i; 105 #ifdef SNMP 106 struct timeval timeout, *tvp = &timeout; 107 struct timeval sched, *svp = &sched, now, *nvp = &now; 108 int index, block; 109 #endif 110 111 setlinebuf(stderr); 112 113 if (geteuid() != 0) { 114 fprintf(stderr, "must be root\n"); 115 exit(1); 116 } 117 118 argv++, argc--; 119 while (argc > 0 && *argv[0] == '-') { 120 if (strcmp(*argv, "-d") == 0) { 121 if (argc > 1 && isdigit(*(argv + 1)[0])) { 122 argv++, argc--; 123 debug = atoi(*argv); 124 } else 125 debug = DEFAULT_DEBUG; 126 } else if (strcmp(*argv, "-c") == 0) { 127 if (argc > 1) { 128 argv++, argc--; 129 configfilename = *argv; 130 } else 131 goto usage; 132 } else if (strcmp(*argv, "-p") == 0) { 133 pruning = 0; 134 #ifdef SNMP 135 } else if (strcmp(*argv, "-P") == 0) { 136 if (argc > 1 && isdigit(*(argv + 1)[0])) { 137 argv++, argc--; 138 dest_port = atoi(*argv); 139 } else 140 dest_port = DEFAULT_PORT; 141 #endif 142 } else 143 goto usage; 144 argv++, argc--; 145 } 146 147 if (argc > 0) { 148 usage: fprintf(stderr, 149 "usage: mrouted [-p] [-c configfile] [-d [debug_level]]\n"); 150 exit(1); 151 } 152 153 if (debug == 0) { 154 /* 155 * Detach from the terminal 156 */ 157 if (daemon(0, 0)) 158 err(1, "can't fork"); 159 pidfile(NULL); 160 } 161 else 162 fprintf(stderr, "debug level %u\n", debug); 163 164 #ifdef LOG_DAEMON 165 (void)openlog("mrouted", LOG_PID, LOG_DAEMON); 166 (void)setlogmask(LOG_UPTO(LOG_NOTICE)); 167 #else 168 (void)openlog("mrouted", LOG_PID); 169 #endif 170 snprintf(versionstring, sizeof(versionstring), 171 "mrouted version %d.%d", PROTOCOL_VERSION, MROUTED_VERSION); 172 173 logit(LOG_NOTICE, 0, "%s", versionstring); 174 175 #ifdef SYSV 176 srand48(time(NULL)); 177 #else 178 srandom(gethostid()); 179 #endif 180 181 /* 182 * Get generation id 183 */ 184 gettimeofday(&tv, 0); 185 dvmrp_genid = tv.tv_sec; 186 187 fp = fopen(genidfilename, "r"); 188 if (fp != NULL) { 189 fscanf(fp, "%d", &prev_genid); 190 if (prev_genid == dvmrp_genid) 191 dvmrp_genid++; 192 (void) fclose(fp); 193 } 194 195 fp = fopen(genidfilename, "w"); 196 if (fp != NULL) { 197 fprintf(fp, "%d", dvmrp_genid); 198 (void) fclose(fp); 199 } 200 201 callout_init(); 202 init_igmp(); 203 init_routes(); 204 init_ktable(); 205 k_init_dvmrp(); /* enable DVMRP routing in kernel */ 206 207 #ifndef OLD_KERNEL 208 vers = k_get_version(); 209 /*XXX 210 * This function must change whenever the kernel version changes 211 */ 212 if ((((vers >> 8) & 0xff) != 3) || 213 ((vers & 0xff) != 5)) 214 logit(LOG_ERR, 0, "kernel (v%d.%d)/mrouted (v%d.%d) version mismatch", 215 (vers >> 8) & 0xff, vers & 0xff, 216 PROTOCOL_VERSION, MROUTED_VERSION); 217 #endif 218 219 #ifdef SNMP 220 if (i = snmp_init()) 221 return i; 222 223 gettimeofday(nvp, 0); 224 if (nvp->tv_usec < 500000L){ 225 svp->tv_usec = nvp->tv_usec + 500000L; 226 svp->tv_sec = nvp->tv_sec; 227 } else { 228 svp->tv_usec = nvp->tv_usec - 500000L; 229 svp->tv_sec = nvp->tv_sec + 1; 230 } 231 #endif /* SNMP */ 232 233 init_vifs(); 234 235 #ifdef RSRR 236 rsrr_init(); 237 #endif /* RSRR */ 238 239 /* 240 * Allow cleanup if unexpected exit. Apparently some architectures 241 * have a kernel bug where closing the socket doesn't do an 242 * ip_mrouter_done(), so we attempt to do it on exit. 243 */ 244 atexit(cleanup); 245 246 if (debug) 247 fprintf(stderr, "pruning %s\n", pruning ? "on" : "off"); 248 249 (void)signal(SIGALRM, fasttimer); 250 251 (void)signal(SIGHUP, restart); 252 (void)signal(SIGTERM, done); 253 (void)signal(SIGINT, done); 254 (void)signal(SIGUSR1, fdump); 255 (void)signal(SIGUSR2, cdump); 256 if (debug != 0) 257 (void)signal(SIGQUIT, dump); 258 259 FD_ZERO(&readers); 260 if (igmp_socket >= FD_SETSIZE) 261 logit(LOG_ERR, 0, "descriptor too big"); 262 FD_SET(igmp_socket, &readers); 263 nfds = igmp_socket + 1; 264 for (i = 0; i < nhandlers; i++) { 265 if (ihandlers[i].fd >= FD_SETSIZE) 266 logit(LOG_ERR, 0, "descriptor too big"); 267 FD_SET(ihandlers[i].fd, &readers); 268 if (ihandlers[i].fd >= nfds) 269 nfds = ihandlers[i].fd + 1; 270 } 271 272 /* 273 * Install the vifs in the kernel as late as possible in the 274 * initialization sequence. 275 */ 276 init_installvifs(); 277 278 if (debug >= 2) dump(0); 279 280 /* Start up the log rate-limiter */ 281 resetlogging(NULL); 282 283 (void)alarm(1); /* schedule first timer interrupt */ 284 285 /* 286 * Main receive loop. 287 */ 288 dummy = 0; 289 for(;;) { 290 #ifdef SYSV 291 sigset_t block, oblock; 292 #endif 293 bcopy((char *)&readers, (char *)&rfds, sizeof(rfds)); 294 #ifdef SNMP 295 gettimeofday(nvp, 0); 296 if (nvp->tv_sec > svp->tv_sec 297 || (nvp->tv_sec == svp->tv_sec && nvp->tv_usec > svp->tv_usec)){ 298 alarmTimer(nvp); 299 eventTimer(nvp); 300 if (nvp->tv_usec < 500000L){ 301 svp->tv_usec = nvp->tv_usec + 500000L; 302 svp->tv_sec = nvp->tv_sec; 303 } else { 304 svp->tv_usec = nvp->tv_usec - 500000L; 305 svp->tv_sec = nvp->tv_sec + 1; 306 } 307 } 308 309 tvp = &timeout; 310 tvp->tv_sec = 0; 311 tvp->tv_usec = 500000L; 312 313 block = 0; 314 snmp_select_info(&nfds, &rfds, tvp, &block); 315 if (block == 1) 316 tvp = NULL; /* block without timeout */ 317 if ((n = select(nfds, &rfds, NULL, NULL, tvp)) < 0) 318 #else 319 if ((n = select(nfds, &rfds, NULL, NULL, NULL)) < 0) 320 #endif 321 { 322 if (errno != EINTR) /* SIGALRM is expected */ 323 logit(LOG_WARNING, errno, "select failed"); 324 continue; 325 } 326 327 if (FD_ISSET(igmp_socket, &rfds)) { 328 recvlen = recvfrom(igmp_socket, recv_buf, RECV_BUF_SIZE, 329 0, NULL, &dummy); 330 if (recvlen < 0) { 331 if (errno != EINTR) logit(LOG_ERR, errno, "recvfrom"); 332 continue; 333 } 334 #ifdef SYSV 335 (void)sigemptyset(&block); 336 (void)sigaddset(&block, SIGALRM); 337 if (sigprocmask(SIG_BLOCK, &block, &oblock) < 0) 338 logit(LOG_ERR, errno, "sigprocmask"); 339 #else 340 omask = sigblock(sigmask(SIGALRM)); 341 #endif 342 accept_igmp(recvlen); 343 #ifdef SYSV 344 (void)sigprocmask(SIG_SETMASK, &oblock, (sigset_t *)NULL); 345 #else 346 (void)sigsetmask(omask); 347 #endif 348 } 349 350 for (i = 0; i < nhandlers; i++) { 351 if (FD_ISSET(ihandlers[i].fd, &rfds)) { 352 (*ihandlers[i].func)(ihandlers[i].fd, &rfds); 353 } 354 } 355 356 #ifdef SNMP 357 snmp_read(&rfds); 358 snmp_timeout(); /* poll */ 359 #endif 360 } 361 } 362 363 364 /* 365 * routine invoked every second. Its main goal is to cycle through 366 * the routing table and send partial updates to all neighbors at a 367 * rate that will cause the entire table to be sent in ROUTE_REPORT_INTERVAL 368 * seconds. Also, every TIMER_INTERVAL seconds it calls timer() to 369 * do all the other time-based processing. 370 */ 371 static void 372 fasttimer(int i) 373 { 374 static unsigned int tlast; 375 static unsigned int nsent; 376 unsigned int t = tlast + 1; 377 int n; 378 379 /* 380 * if we're in the last second, send everything that's left. 381 * otherwise send at least the fraction we should have sent by now. 382 */ 383 if (t >= ROUTE_REPORT_INTERVAL) { 384 int nleft = nroutes - nsent; 385 while (nleft > 0) { 386 if ((n = report_next_chunk()) <= 0) 387 break; 388 nleft -= n; 389 } 390 tlast = 0; 391 nsent = 0; 392 } else { 393 unsigned int ncum = nroutes * t / ROUTE_REPORT_INTERVAL; 394 while (nsent < ncum) { 395 if ((n = report_next_chunk()) <= 0) 396 break; 397 nsent += n; 398 } 399 tlast = t; 400 } 401 if ((t % TIMER_INTERVAL) == 0) 402 timer(); 403 404 age_callout_queue();/* Advance the timer for the callout queue 405 for groups */ 406 alarm(1); 407 } 408 409 /* 410 * The 'virtual_time' variable is initialized to a value that will cause the 411 * first invocation of timer() to send a probe or route report to all vifs 412 * and send group membership queries to all subnets for which this router is 413 * querier. This first invocation occurs approximately TIMER_INTERVAL seconds 414 * after the router starts up. Note that probes for neighbors and queries 415 * for group memberships are also sent at start-up time, as part of initial- 416 * ization. This repetition after a short interval is desirable for quickly 417 * building up topology and membership information in the presence of possible 418 * packet loss. 419 * 420 * 'virtual_time' advances at a rate that is only a crude approximation of 421 * real time, because it does not take into account any time spent processing, 422 * and because the timer intervals are sometimes shrunk by a random amount to 423 * avoid unwanted synchronization with other routers. 424 */ 425 426 static u_long virtual_time = 0; 427 428 429 /* 430 * Timer routine. Performs periodic neighbor probing, route reporting, and 431 * group querying duties, and drives various timers in routing entries and 432 * virtual interface data structures. 433 */ 434 static void 435 timer(void) 436 { 437 age_routes(); /* Advance the timers in the route entries */ 438 age_vifs(); /* Advance the timers for neighbors */ 439 age_table_entry(); /* Advance the timers for the cache entries */ 440 441 if (virtual_time % GROUP_QUERY_INTERVAL == 0) { 442 /* 443 * Time to query the local group memberships on all subnets 444 * for which this router is the elected querier. 445 */ 446 query_groups(); 447 } 448 449 if (virtual_time % NEIGHBOR_PROBE_INTERVAL == 0) { 450 /* 451 * Time to send a probe on all vifs from which no neighbors have 452 * been heard. Also, check if any inoperative interfaces have now 453 * come up. (If they have, they will also be probed as part of 454 * their initialization.) 455 */ 456 probe_for_neighbors(); 457 458 if (vifs_down) 459 check_vif_state(); 460 } 461 462 delay_change_reports = FALSE; 463 if (routes_changed) { 464 /* 465 * Some routes have changed since the last timer interrupt, but 466 * have not been reported yet. Report the changed routes to all 467 * neighbors. 468 */ 469 report_to_all_neighbors(CHANGED_ROUTES); 470 } 471 472 #ifdef SNMP 473 sync_timer(); 474 #endif 475 476 /* 477 * Advance virtual time 478 */ 479 virtual_time += TIMER_INTERVAL; 480 } 481 482 483 /* 484 * On termination, let everyone know we're going away. 485 */ 486 static void 487 done(int i) 488 { 489 logit(LOG_NOTICE, 0, "%s exiting", versionstring); 490 cleanup(); 491 _exit(1); 492 } 493 494 static void 495 cleanup(void) 496 { 497 static int in_cleanup = 0; 498 499 if (!in_cleanup) { 500 in_cleanup++; 501 #ifdef RSRR 502 rsrr_clean(); 503 #endif /* RSRR */ 504 expire_all_routes(); 505 report_to_all_neighbors(ALL_ROUTES); 506 k_stop_dvmrp(); 507 } 508 } 509 510 511 /* 512 * Dump internal data structures to stderr. 513 */ 514 static void 515 dump(int i) 516 { 517 dump_vifs(stderr); 518 dump_routes(stderr); 519 } 520 521 522 /* 523 * Dump internal data structures to a file. 524 */ 525 static void 526 fdump(int i) 527 { 528 FILE *fp; 529 530 fp = fopen(dumpfilename, "w"); 531 if (fp != NULL) { 532 dump_vifs(fp); 533 dump_routes(fp); 534 (void) fclose(fp); 535 } 536 } 537 538 539 /* 540 * Dump local cache contents to a file. 541 */ 542 static void 543 cdump(int i) 544 { 545 FILE *fp; 546 547 fp = fopen(cachefilename, "w"); 548 if (fp != NULL) { 549 dump_cache(fp); 550 (void) fclose(fp); 551 } 552 } 553 554 555 /* 556 * Restart mrouted 557 */ 558 static void 559 restart(int i) 560 { 561 int omask; 562 #ifdef SYSV 563 sigset_t block, oblock; 564 #endif 565 566 logit(LOG_NOTICE, 0, "%s restart", versionstring); 567 568 /* 569 * reset all the entries 570 */ 571 #ifdef SYSV 572 (void)sigemptyset(&block); 573 (void)sigaddset(&block, SIGALRM); 574 if (sigprocmask(SIG_BLOCK, &block, &oblock) < 0) 575 logit(LOG_ERR, errno, "sigprocmask"); 576 #else 577 omask = sigblock(sigmask(SIGALRM)); 578 #endif 579 free_all_prunes(); 580 free_all_routes(); 581 stop_all_vifs(); 582 k_stop_dvmrp(); 583 close(igmp_socket); 584 close(udp_socket); 585 586 /* 587 * start processing again 588 */ 589 dvmrp_genid++; 590 pruning = 1; 591 592 init_igmp(); 593 init_routes(); 594 init_ktable(); 595 init_vifs(); 596 k_init_dvmrp(); /* enable DVMRP routing in kernel */ 597 init_installvifs(); 598 599 #ifdef SYSV 600 (void)sigprocmask(SIG_SETMASK, &oblock, (sigset_t *)NULL); 601 #else 602 (void)sigsetmask(omask); 603 #endif 604 } 605 606 #define LOG_MAX_MSGS 20 /* if > 20/minute then shut up for a while */ 607 #define LOG_SHUT_UP 600 /* shut up for 10 minutes */ 608 static int log_nmsgs = 0; 609 610 static void 611 resetlogging(void *arg) 612 { 613 int nxttime = 60; 614 void *narg = NULL; 615 616 if (arg == NULL && log_nmsgs > LOG_MAX_MSGS) { 617 nxttime = LOG_SHUT_UP; 618 narg = (void *)&log_nmsgs; /* just need some valid void * */ 619 syslog(LOG_WARNING, "logging too fast, shutting up for %d minutes", 620 LOG_SHUT_UP / 60); 621 } else { 622 log_nmsgs = 0; 623 } 624 625 timer_setTimer(nxttime, resetlogging, narg); 626 } 627 628 /* 629 * Log errors and other messages to the system log daemon and to stderr, 630 * according to the severity of the message and the current debug level. 631 * For errors of severity LOG_ERR or worse, terminate the program. 632 */ 633 void 634 logit(int severity, int syserr, const char *format, ...) 635 { 636 va_list ap; 637 static char fmt[211] = "warning - "; 638 char *msg; 639 char tbuf[20]; 640 struct timeval now; 641 struct tm *thyme; 642 time_t t; 643 644 va_start(ap, format); 645 vsnprintf(&fmt[10], sizeof(fmt) - 10, format, ap); 646 va_end(ap); 647 msg = (severity == LOG_WARNING) ? fmt : &fmt[10]; 648 649 switch (debug) { 650 case 0: break; 651 case 1: if (severity > LOG_NOTICE) break; 652 case 2: if (severity > LOG_INFO ) break; 653 default: 654 gettimeofday(&now,NULL); 655 t = now.tv_sec; 656 thyme = localtime(&t); 657 strftime(tbuf, sizeof(tbuf), "%X", thyme); 658 fprintf(stderr, "%s.%03ld %s", tbuf, (long)now.tv_usec / 1000, 659 msg); 660 if (syserr == 0) 661 fprintf(stderr, "\n"); 662 else 663 fprintf(stderr, ": %s\n", strerror(syserr)); 664 } 665 666 if (severity <= LOG_NOTICE) { 667 if (log_nmsgs++ < LOG_MAX_MSGS) { 668 if (syserr != 0) { 669 errno = syserr; 670 syslog(severity, "%s: %m", msg); 671 } else 672 syslog(severity, "%s", msg); 673 } 674 675 if (severity <= LOG_ERR) exit(1); 676 } 677 } 678 679 #ifdef DEBUG_MFC 680 void 681 md_log(int what, u_int32_t origin, u_int32_t mcastgrp) 682 { 683 static FILE *f = NULL; 684 struct timeval tv; 685 u_int32_t buf[4]; 686 687 if (!f) { 688 if ((f = fopen("/tmp/mrouted.clog", "w")) == NULL) { 689 logit(LOG_ERR, errno, "open /tmp/mrouted.clog"); 690 } 691 } 692 693 gettimeofday(&tv, NULL); 694 buf[0] = tv.tv_sec; 695 buf[1] = what; 696 buf[2] = origin; 697 buf[3] = mcastgrp; 698 699 fwrite(buf, sizeof(u_int32_t), 4, f); 700 } 701 #endif 702