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 <poll.h> 26 #include <err.h> 27 28 extern char *configfilename; 29 char versionstring[100]; 30 31 static char dumpfilename[] = _PATH_MROUTED_DUMP; 32 static char cachefilename[] = _PATH_MROUTED_CACHE; 33 static char genidfilename[] = _PATH_MROUTED_GENID; 34 35 int cache_lifetime = DEFAULT_CACHE_LIFETIME; 36 int max_prune_lifetime = DEFAULT_CACHE_LIFETIME * 2; 37 38 int debug = 0; 39 u_char pruning = 1; /* Enable pruning by default */ 40 41 #define NHANDLERS 2 42 43 static struct ihandler { 44 int fd; /* File descriptor */ 45 ihfunc_t func; /* Function to call */ 46 } ihandlers[NHANDLERS]; 47 static int nhandlers = 0; 48 49 /* 50 * Forward declarations. 51 */ 52 static void fasttimer(int); 53 static void done(int); 54 static void dump(int); 55 static void fdump(int); 56 static void cdump(int); 57 static void restart(int); 58 static void timer(void); 59 static void cleanup(void); 60 static void resetlogging(void *); 61 62 int 63 register_input_handler(int fd, ihfunc_t func) 64 { 65 if (nhandlers >= NHANDLERS) 66 return -1; 67 68 ihandlers[nhandlers].fd = fd; 69 ihandlers[nhandlers++].func = func; 70 71 return 0; 72 } 73 74 int 75 main(int argc, char *argv[]) 76 { 77 int recvlen; 78 int dummy; 79 FILE *fp; 80 struct timeval now; 81 u_int32_t prev_genid; 82 struct pollfd *pfd; 83 int vers, n, i, ch; 84 sigset_t mask, omask; 85 const char *errstr; 86 87 if (geteuid() != 0) { 88 fprintf(stderr, "must be root\n"); 89 exit(1); 90 } 91 setvbuf(stderr, NULL, _IOLBF, 0); 92 93 while ((ch = getopt(argc, argv, "c:d::p")) != -1) { 94 switch (ch) { 95 case 'c': 96 configfilename = optarg; 97 break; 98 case 'd': 99 if (!optarg) 100 debug = DEFAULT_DEBUG; 101 else { 102 debug = strtonum(optarg, 0, 3, &errstr); 103 if (errstr) { 104 warnx("debug level %s", errstr); 105 debug = DEFAULT_DEBUG; 106 } 107 } 108 break; 109 case 'p': 110 pruning = 0; 111 break; 112 default: 113 goto usage; 114 } 115 } 116 argc -= optind; 117 argv += optind; 118 119 if (argc > 0) { 120 usage: fprintf(stderr, 121 "usage: mrouted [-p] [-c config_file] [-d[debug_level]]\n"); 122 exit(1); 123 } 124 125 if (debug == 0) { 126 /* 127 * Detach from the terminal 128 */ 129 int t; 130 131 if (fork()) exit(0); 132 (void)close(0); 133 (void)close(1); 134 (void)close(2); 135 (void)open("/dev/null", O_RDONLY); 136 (void)dup2(0, 1); 137 (void)dup2(0, 2); 138 #ifdef TIOCNOTTY 139 t = open("/dev/tty", O_RDWR); 140 if (t >= 0) { 141 (void)ioctl(t, TIOCNOTTY, (char *)0); 142 (void)close(t); 143 } 144 #else 145 if (setsid() == -1) 146 perror("setsid"); 147 #endif 148 } 149 else 150 fprintf(stderr, "debug level %u\n", debug); 151 152 #ifdef LOG_DAEMON 153 (void)openlog("mrouted", LOG_PID, LOG_DAEMON); 154 (void)setlogmask(LOG_UPTO(LOG_NOTICE)); 155 #else 156 (void)openlog("mrouted", LOG_PID); 157 #endif 158 snprintf(versionstring, sizeof versionstring, "mrouted version %d.%d", 159 PROTOCOL_VERSION, MROUTED_VERSION); 160 161 logit(LOG_NOTICE, 0, "%s", versionstring); 162 163 /* 164 * Get generation id 165 */ 166 gettimeofday(&now, NULL); 167 dvmrp_genid = (u_int32_t)now.tv_sec; /* for a while after 2038 */ 168 169 fp = fopen(genidfilename, "r"); 170 if (fp != NULL) { 171 fscanf(fp, "%d", &prev_genid); 172 if (prev_genid == dvmrp_genid) 173 dvmrp_genid++; 174 (void) fclose(fp); 175 } 176 177 fp = fopen(genidfilename, "w"); 178 if (fp != NULL) { 179 fprintf(fp, "%d", dvmrp_genid); 180 (void) fclose(fp); 181 } 182 183 callout_init(); 184 init_igmp(); 185 init_routes(); 186 init_ktable(); 187 k_init_dvmrp(); /* enable DVMRP routing in kernel */ 188 189 #ifndef OLD_KERNEL 190 vers = k_get_version(); 191 /*XXX 192 * This function must change whenever the kernel version changes 193 */ 194 if ((((vers >> 8) & 0xff) != 3) || 195 ((vers & 0xff) != 5)) 196 logit(LOG_ERR, 0, "kernel (v%d.%d)/mrouted (v%d.%d) version mismatch", 197 (vers >> 8) & 0xff, vers & 0xff, 198 PROTOCOL_VERSION, MROUTED_VERSION); 199 #endif 200 201 init_vifs(); 202 203 #ifdef RSRR 204 rsrr_init(); 205 #endif /* RSRR */ 206 207 /* 208 * Allow cleanup if unexpected exit. Apparently some architectures 209 * have a kernel bug where closing the socket doesn't do an 210 * ip_mrouter_done(), so we attempt to do it on exit. 211 */ 212 atexit(cleanup); 213 214 if (debug) 215 fprintf(stderr, "pruning %s\n", pruning ? "on" : "off"); 216 217 (void)signal(SIGALRM, fasttimer); 218 219 (void)signal(SIGHUP, restart); 220 (void)signal(SIGTERM, done); 221 (void)signal(SIGINT, done); 222 (void)signal(SIGUSR1, fdump); 223 (void)signal(SIGUSR2, cdump); 224 if (debug != 0) 225 (void)signal(SIGQUIT, dump); 226 227 pfd = calloc(sizeof(struct pollfd), 1 + nhandlers); 228 pfd[0].fd = igmp_socket; 229 pfd[0].events = POLLIN; 230 for (i = 0; i < nhandlers; i++) { 231 pfd[i + 1].fd = ihandlers[i].fd; 232 pfd[i + 1].events = POLLIN; 233 } 234 235 /* 236 * Install the vifs in the kernel as late as possible in the 237 * initialization sequence. 238 */ 239 init_installvifs(); 240 241 if (debug >= 2) dump(0); 242 243 /* Start up the log rate-limiter */ 244 resetlogging(NULL); 245 246 (void)alarm(1); /* schedule first timer interrupt */ 247 248 /* 249 * Main receive loop. 250 */ 251 dummy = 0; 252 for(;;) { 253 if ((n = poll(pfd, nhandlers + 1, -1)) == -1) { 254 if (errno != EINTR) /* SIGALRM is expected */ 255 logit(LOG_WARNING, errno, "poll failed"); 256 continue; 257 } 258 259 if (pfd[0].revents & POLLIN) { 260 recvlen = recvfrom(igmp_socket, recv_buf, RECV_BUF_SIZE, 261 0, NULL, &dummy); 262 if (recvlen == -1) { 263 if (errno != EINTR) logit(LOG_ERR, errno, "recvfrom"); 264 continue; 265 } 266 (void)sigemptyset(&mask); 267 (void)sigaddset(&mask, SIGALRM); 268 if (sigprocmask(SIG_BLOCK, &mask, &omask) == -1) 269 logit(LOG_ERR, errno, "sigprocmask"); 270 accept_igmp(recvlen); 271 (void)sigprocmask(SIG_SETMASK, &omask, NULL); 272 } 273 274 for (i = 0; i < nhandlers; i++) { 275 if (pfd[i + 1].revents & POLLIN) { 276 (*ihandlers[i].func)(ihandlers[i].fd); 277 } 278 } 279 } 280 } 281 282 283 /* 284 * routine invoked every second. Its main goal is to cycle through 285 * the routing table and send partial updates to all neighbors at a 286 * rate that will cause the entire table to be sent in ROUTE_REPORT_INTERVAL 287 * seconds. Also, every TIMER_INTERVAL seconds it calls timer() to 288 * do all the other time-based processing. 289 */ 290 /* XXX signal race */ 291 static void 292 fasttimer(int i) 293 { 294 static unsigned int tlast; 295 static unsigned int nsent; 296 unsigned int t = tlast + 1; 297 int n; 298 299 /* 300 * if we're in the last second, send everything that's left. 301 * otherwise send at least the fraction we should have sent by now. 302 */ 303 if (t >= ROUTE_REPORT_INTERVAL) { 304 int nleft = nroutes - nsent; 305 while (nleft > 0) { 306 if ((n = report_next_chunk()) <= 0) 307 break; 308 nleft -= n; 309 } 310 tlast = 0; 311 nsent = 0; 312 } else { 313 unsigned int ncum = nroutes * t / ROUTE_REPORT_INTERVAL; 314 while (nsent < ncum) { 315 if ((n = report_next_chunk()) <= 0) 316 break; 317 nsent += n; 318 } 319 tlast = t; 320 } 321 if ((t % TIMER_INTERVAL) == 0) 322 timer(); 323 324 age_callout_queue();/* Advance the timer for the callout queue 325 for groups */ 326 alarm(1); 327 } 328 329 /* 330 * The 'virtual_time' variable is initialized to a value that will cause the 331 * first invocation of timer() to send a probe or route report to all vifs 332 * and send group membership queries to all subnets for which this router is 333 * querier. This first invocation occurs approximately TIMER_INTERVAL seconds 334 * after the router starts up. Note that probes for neighbors and queries 335 * for group memberships are also sent at start-up time, as part of initial- 336 * ization. This repetition after a short interval is desirable for quickly 337 * building up topology and membership information in the presence of possible 338 * packet loss. 339 * 340 * 'virtual_time' advances at a rate that is only a crude approximation of 341 * real time, because it does not take into account any time spent processing, 342 * and because the timer intervals are sometimes shrunk by a random amount to 343 * avoid unwanted synchronization with other routers. 344 */ 345 346 static u_long virtual_time = 0; 347 348 349 /* 350 * Timer routine. Performs periodic neighbor probing, route reporting, and 351 * group querying duties, and drives various timers in routing entries and 352 * virtual interface data structures. 353 */ 354 static void 355 timer(void) 356 { 357 age_routes(); /* Advance the timers in the route entries */ 358 age_vifs(); /* Advance the timers for neighbors */ 359 age_table_entry(); /* Advance the timers for the cache entries */ 360 361 if (virtual_time % GROUP_QUERY_INTERVAL == 0) { 362 /* 363 * Time to query the local group memberships on all subnets 364 * for which this router is the elected querier. 365 */ 366 query_groups(); 367 } 368 369 if (virtual_time % NEIGHBOR_PROBE_INTERVAL == 0) { 370 /* 371 * Time to send a probe on all vifs from which no neighbors have 372 * been heard. Also, check if any inoperative interfaces have now 373 * come up. (If they have, they will also be probed as part of 374 * their initialization.) 375 */ 376 probe_for_neighbors(); 377 378 if (vifs_down) 379 check_vif_state(); 380 } 381 382 delay_change_reports = FALSE; 383 if (routes_changed) { 384 /* 385 * Some routes have changed since the last timer interrupt, but 386 * have not been reported yet. Report the changed routes to all 387 * neighbors. 388 */ 389 report_to_all_neighbors(CHANGED_ROUTES); 390 } 391 392 /* 393 * Advance virtual time 394 */ 395 virtual_time += TIMER_INTERVAL; 396 } 397 398 399 /* 400 * On termination, let everyone know we're going away. 401 */ 402 /* XXX signal race */ 403 static void 404 done(int i) 405 { 406 logit(LOG_NOTICE, 0, "%s exiting", versionstring); 407 cleanup(); 408 _exit(1); 409 } 410 411 /* XXX signal race, atexit race */ 412 static void 413 cleanup(void) 414 { 415 static int in_cleanup = 0; 416 417 if (!in_cleanup) { 418 in_cleanup++; 419 #ifdef RSRR 420 rsrr_clean(); 421 #endif /* RSRR */ 422 expire_all_routes(); 423 report_to_all_neighbors(ALL_ROUTES); 424 k_stop_dvmrp(); 425 } 426 } 427 428 429 /* 430 * Dump internal data structures to stderr. 431 */ 432 /* XXX signal race */ 433 static void 434 dump(int i) 435 { 436 dump_vifs(stderr); 437 dump_routes(stderr); 438 } 439 440 441 /* 442 * Dump internal data structures to a file. 443 */ 444 static void 445 fdump(int i) 446 { 447 FILE *fp; 448 449 fp = fopen(dumpfilename, "w"); 450 if (fp != NULL) { 451 dump_vifs(fp); 452 dump_routes(fp); 453 (void) fclose(fp); 454 } 455 } 456 457 458 /* 459 * Dump local cache contents to a file. 460 */ 461 /* XXX signal race */ 462 static void 463 cdump(int i) 464 { 465 FILE *fp; 466 467 fp = fopen(cachefilename, "w"); 468 if (fp != NULL) { 469 dump_cache(fp); 470 (void) fclose(fp); 471 } 472 } 473 474 475 /* 476 * Restart mrouted 477 */ 478 /* XXX signal race */ 479 static void 480 restart(int i) 481 { 482 sigset_t mask, omask; 483 484 logit(LOG_NOTICE, 0, "%s restart", versionstring); 485 486 /* 487 * reset all the entries 488 */ 489 (void)sigemptyset(&mask); 490 (void)sigaddset(&mask, SIGALRM); 491 if (sigprocmask(SIG_BLOCK, &mask, &omask) == -1) 492 logit(LOG_ERR, errno, "sigprocmask"); 493 free_all_prunes(); 494 free_all_routes(); 495 stop_all_vifs(); 496 k_stop_dvmrp(); 497 close(igmp_socket); 498 close(udp_socket); 499 500 /* 501 * start processing again 502 */ 503 dvmrp_genid++; 504 pruning = 1; 505 506 init_igmp(); 507 init_routes(); 508 init_ktable(); 509 init_vifs(); 510 k_init_dvmrp(); /* enable DVMRP routing in kernel */ 511 init_installvifs(); 512 513 (void)sigprocmask(SIG_SETMASK, &omask, NULL); 514 } 515 516 #define LOG_MAX_MSGS 20 /* if > 20/minute then shut up for a while */ 517 #define LOG_SHUT_UP 600 /* shut up for 10 minutes */ 518 static int log_nmsgs = 0; 519 520 static void 521 resetlogging(void *arg) 522 { 523 int nxttime = 60; 524 void *narg = NULL; 525 526 if (arg == NULL && log_nmsgs > LOG_MAX_MSGS) { 527 nxttime = LOG_SHUT_UP; 528 narg = (void *)&log_nmsgs; /* just need some valid void * */ 529 syslog(LOG_WARNING, "logging too fast, shutting up for %d minutes", 530 LOG_SHUT_UP / 60); 531 } else { 532 log_nmsgs = 0; 533 } 534 535 timer_setTimer(nxttime, resetlogging, narg); 536 } 537 538 /* 539 * Log errors and other messages to the system log daemon and to stderr, 540 * according to the severity of the message and the current debug level. 541 * For errors of severity LOG_ERR or worse, terminate the program. 542 */ 543 void 544 logit(int severity, int syserr, char *format, ...) 545 { 546 va_list ap; 547 static char fmt[211] = "warning - "; 548 char *msg; 549 char tbuf[20]; 550 struct timeval now; 551 struct tm *thyme; 552 time_t t; 553 554 va_start(ap, format); 555 vsnprintf(&fmt[10], sizeof fmt - 10, format, ap); 556 va_end(ap); 557 msg = (severity == LOG_WARNING) ? fmt : &fmt[10]; 558 559 switch (debug) { 560 case 0: break; 561 case 1: if (severity > LOG_NOTICE) break; 562 case 2: if (severity > LOG_INFO ) break; 563 default: 564 gettimeofday(&now,NULL); 565 t = now.tv_sec; 566 thyme = localtime(&t); 567 strftime(tbuf, sizeof(tbuf), "%X.%%03d ", thyme); 568 fprintf(stderr, tbuf, now.tv_usec / 1000); 569 fprintf(stderr, "%s", msg); 570 if (syserr == 0) 571 fprintf(stderr, "\n"); 572 else if (syserr < sys_nerr) 573 fprintf(stderr, ": %s\n", sys_errlist[syserr]); 574 else 575 fprintf(stderr, ": errno %d\n", syserr); 576 } 577 578 if (severity <= LOG_NOTICE) { 579 if (log_nmsgs++ < LOG_MAX_MSGS) { 580 if (syserr != 0) { 581 errno = syserr; 582 syslog(severity, "%s: %m", msg); 583 } else 584 syslog(severity, "%s", msg); 585 } 586 587 if (severity <= LOG_ERR) exit(1); 588 } 589 } 590 591 #ifdef DEBUG_MFC 592 void 593 md_logit(int what, u_int32_t origin, u_int32_t mcastgrp) 594 { 595 static FILE *f = NULL; 596 struct timeval tv; 597 u_int32_t buf[4]; 598 599 if (!f) { 600 if ((f = fopen("/tmp/mrouted.clog", "w")) == NULL) { 601 logit(LOG_ERR, errno, "open /tmp/mrouted.clog"); 602 } 603 } 604 605 gettimeofday(&tv, NULL); 606 buf[0] = tv.tv_sec; 607 buf[1] = what; 608 buf[2] = origin; 609 buf[3] = mcastgrp; 610 611 fwrite(buf, sizeof(u_int32_t), 4, f); 612 } 613 #endif 614