1 /* $NetBSD: main.c,v 1.5 1995/10/09 03:51:44 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 #include <string.h> 24 #include <varargs.h> 25 26 #ifdef SNMP 27 #include "snmp.h" 28 #endif 29 30 extern char *configfilename; 31 32 static char pidfilename[] = _PATH_MROUTED_PID; 33 static char dumpfilename[] = _PATH_MROUTED_DUMP; 34 static char cachefilename[] = _PATH_MROUTED_CACHE; 35 static char genidfilename[] = _PATH_MROUTED_GENID; 36 37 int cache_lifetime = DEFAULT_CACHE_LIFETIME; 38 int max_prune_lifetime = DEFAULT_CACHE_LIFETIME * 2; 39 40 int debug = 0; 41 u_char pruning = 1; /* Enable pruning by default */ 42 43 #define NHANDLERS 2 44 45 static struct ihandler { 46 int fd; /* File descriptor */ 47 void (*func)(); /* Function to call with &fd_set */ 48 } ihandlers[NHANDLERS]; 49 static int nhandlers = 0; 50 51 /* 52 * Forward declarations. 53 */ 54 static void fasttimer(); 55 static void timer(); 56 static void cleanup(); 57 static void done(); 58 static void dump(); 59 static void fdump(); 60 static void cdump(); 61 static void restart(); 62 63 int 64 register_input_handler(fd, func) 65 int fd; 66 void (*func)(); 67 { 68 if (nhandlers >= NHANDLERS) 69 return -1; 70 71 ihandlers[nhandlers].fd = fd; 72 ihandlers[nhandlers++].func = func; 73 74 return 0; 75 } 76 77 int main(argc, argv) 78 int argc; 79 char *argv[]; 80 { 81 register int recvlen; 82 register int omask; 83 int dummy; 84 FILE *fp; 85 extern uid_t geteuid(); 86 struct timeval tv; 87 u_long prev_genid; 88 int vers; 89 fd_set rfds, readers; 90 int nfds, n, i; 91 #ifdef SNMP 92 char *myname; 93 fd_set wfds; 94 95 96 if (myname = strrchr(argv[0], '/')) 97 myname++; 98 if (myname == NULL || *myname == 0) 99 myname = argv[0]; 100 isodetailor (myname, 0); 101 #endif 102 103 #ifdef SYSV 104 setvbuf(stderr, NULL, _IOLBF, 0); 105 #else 106 setlinebuf(stderr); 107 #endif 108 109 if (geteuid() != 0) { 110 fprintf(stderr, "must be root\n"); 111 exit(1); 112 } 113 114 argv++, argc--; 115 while (argc > 0 && *argv[0] == '-') { 116 if (strcmp(*argv, "-d") == 0) { 117 if (argc > 1 && isdigit(*(argv + 1)[0])) { 118 argv++, argc--; 119 debug = atoi(*argv); 120 } else 121 debug = DEFAULT_DEBUG; 122 } else if (strcmp(*argv, "-c") == 0) { 123 if (argc > 1) { 124 argv++, argc--; 125 configfilename = *argv; 126 } else 127 goto usage; 128 } else if (strcmp(*argv, "-p") == 0) { 129 pruning = 0; 130 } else 131 goto usage; 132 argv++, argc--; 133 } 134 135 if (argc > 0) { 136 usage: fprintf(stderr, 137 "usage: mrouted [-p] [-c configfile] [-d [debug_level]]\n"); 138 exit(1); 139 } 140 141 if (debug == 0) { 142 /* 143 * Detach from the terminal 144 */ 145 int t; 146 147 if (fork()) exit(0); 148 (void)close(0); 149 (void)close(1); 150 (void)close(2); 151 (void)open("/", 0); 152 (void)dup2(0, 1); 153 (void)dup2(0, 2); 154 #ifdef TIOCNOTTY 155 t = open("/dev/tty", 2); 156 if (t >= 0) { 157 (void)ioctl(t, TIOCNOTTY, (char *)0); 158 (void)close(t); 159 } 160 #else 161 if (setsid() < 0) 162 perror("setsid"); 163 #endif 164 } 165 else 166 fprintf(stderr, "debug level %u\n", debug); 167 168 #ifdef LOG_DAEMON 169 (void)openlog("mrouted", LOG_PID, LOG_DAEMON); 170 (void)setlogmask(LOG_UPTO(LOG_NOTICE)); 171 #else 172 (void)openlog("mrouted", LOG_PID); 173 #endif 174 log(LOG_NOTICE, 0, "mrouted version %d.%d", 175 PROTOCOL_VERSION, MROUTED_VERSION); 176 177 #ifdef SYSV 178 srand48(time(NULL)); 179 #else 180 srandom(gethostid()); 181 #endif 182 183 /* 184 * Get generation id 185 */ 186 gettimeofday(&tv, 0); 187 dvmrp_genid = tv.tv_sec; 188 189 fp = fopen(genidfilename, "r"); 190 if (fp != NULL) { 191 fscanf(fp, "%d", &prev_genid); 192 if (prev_genid == dvmrp_genid) 193 dvmrp_genid++; 194 (void) fclose(fp); 195 } 196 197 fp = fopen(genidfilename, "w"); 198 if (fp != NULL) { 199 fprintf(fp, "%d", dvmrp_genid); 200 (void) fclose(fp); 201 } 202 203 callout_init(); 204 205 #ifdef SNMP 206 snmp_init(); 207 #endif 208 209 init_igmp(); 210 k_init_dvmrp(); /* enable DVMRP routing in kernel */ 211 212 #ifndef OLD_KERNEL 213 vers = k_get_version(); 214 if ((((vers >> 8) & 0xff) != PROTOCOL_VERSION) || 215 ((vers & 0xff) != MROUTED_VERSION)) 216 log(LOG_ERR, 0, "kernel (v%d.%d)/mrouted (v%d.%d) version mismatch", 217 (vers >> 8) & 0xff, vers & 0xff, 218 PROTOCOL_VERSION, MROUTED_VERSION); 219 #endif 220 221 init_routes(); 222 init_ktable(); 223 init_vifs(); 224 #ifdef RSRR 225 rsrr_init(); 226 #endif /* RSRR */ 227 228 #if defined(__STDC__) || defined(__GNUC__) 229 /* Allow cleanup if unexpected exit. Apparently some architectures 230 * have a kernel bug where closing the socket doesn't do an 231 * ip_mrouter_done(), so we attempt to do it on exit. 232 */ 233 atexit(cleanup); 234 #endif 235 236 if (debug) 237 fprintf(stderr, "pruning %s\n", pruning ? "on" : "off"); 238 239 fp = fopen(pidfilename, "w"); 240 if (fp != NULL) { 241 fprintf(fp, "%d\n", getpid()); 242 (void) fclose(fp); 243 } 244 245 if (debug >= 2) dump(); 246 247 (void)signal(SIGALRM, fasttimer); 248 249 (void)signal(SIGHUP, restart); 250 (void)signal(SIGTERM, done); 251 (void)signal(SIGINT, done); 252 (void)signal(SIGUSR1, fdump); 253 (void)signal(SIGUSR2, cdump); 254 if (debug != 0) 255 (void)signal(SIGQUIT, dump); 256 257 FD_ZERO(&readers); 258 FD_SET(igmp_socket, &readers); 259 nfds = igmp_socket + 1; 260 for (i = 0; i < nhandlers; i++) { 261 FD_SET(ihandlers[i].fd, &readers); 262 if (ihandlers[i].fd >= nfds) 263 nfds = ihandlers[i].fd + 1; 264 } 265 266 (void)alarm(1); /* schedule first timer interrupt */ 267 268 /* 269 * Main receive loop. 270 */ 271 dummy = 0; 272 for(;;) { 273 bcopy((char *)&readers, (char *)&rfds, sizeof(rfds)); 274 #ifdef SNMP 275 FD_ZERO(&wfds); 276 277 if (smux_fd != NOTOK) { 278 if (rock_and_roll) 279 FD_SET(smux_fd, &rfds); 280 else 281 FD_SET(smux_fd, &wfds); 282 if (smux_fd >= nfds) 283 nfds = smux_fd + 1; 284 } 285 286 if ((n = xselect(nfds, &rfds, &wfds, NULLFD, NOTOK))==NOTOK) { 287 #else 288 if ((n = select(nfds, &rfds, NULL, NULL, NULL)) < 0) { 289 #endif 290 if (errno != EINTR) /* SIGALRM is expected */ 291 log(LOG_WARNING, errno, "select failed"); 292 continue; 293 } 294 295 if (FD_ISSET(igmp_socket, &rfds)) { 296 recvlen = recvfrom(igmp_socket, recv_buf, RECV_BUF_SIZE, 297 0, NULL, &dummy); 298 if (recvlen < 0) { 299 if (errno != EINTR) log(LOG_ERR, errno, "recvfrom"); 300 continue; 301 } 302 omask = sigblock(sigmask(SIGALRM)); 303 accept_igmp(recvlen); 304 (void)sigsetmask(omask); 305 } 306 307 for (i = 0; i < nhandlers; i++) { 308 if (FD_ISSET(ihandlers[i].fd, &rfds)) { 309 (*ihandlers[i].func)(&rfds); 310 } 311 } 312 313 #ifdef SNMP 314 if (smux_fd != NOTOK) { 315 if (rock_and_roll) { 316 if (FD_ISSET(smux_fd, &rfds)) 317 doit_smux(); 318 } else if (FD_ISSET(smux_fd, &wfds)) 319 start_smux(); 320 } 321 #endif 322 } 323 } 324 325 326 /* 327 * routine invoked every second. Its main goal is to cycle through 328 * the routing table and send partial updates to all neighbors at a 329 * rate that will cause the entire table to be sent in ROUTE_REPORT_INTERVAL 330 * seconds. Also, every TIMER_INTERVAL seconds it calls timer() to 331 * do all the other time-based processing. 332 */ 333 static void 334 fasttimer() 335 { 336 static unsigned int tlast; 337 static unsigned int nsent; 338 register unsigned int t = tlast + 1; 339 register int n; 340 341 /* 342 * if we're in the last second, send everything that's left. 343 * otherwise send at least the fraction we should have sent by now. 344 */ 345 if (t >= ROUTE_REPORT_INTERVAL) { 346 register int nleft = nroutes - nsent; 347 while (nleft > 0) { 348 if ((n = report_next_chunk()) <= 0) 349 break; 350 nleft -= n; 351 } 352 tlast = 0; 353 nsent = 0; 354 } else { 355 register unsigned int ncum = nroutes * t / ROUTE_REPORT_INTERVAL; 356 while (nsent < ncum) { 357 if ((n = report_next_chunk()) <= 0) 358 break; 359 nsent += n; 360 } 361 tlast = t; 362 } 363 if ((t % TIMER_INTERVAL) == 0) 364 timer(); 365 366 age_callout_queue();/* Advance the timer for the callout queue 367 for groups */ 368 alarm(1); 369 } 370 371 /* 372 * The 'virtual_time' variable is initialized to a value that will cause the 373 * first invocation of timer() to send a probe or route report to all vifs 374 * and send group membership queries to all subnets for which this router is 375 * querier. This first invocation occurs approximately TIMER_INTERVAL seconds 376 * after the router starts up. Note that probes for neighbors and queries 377 * for group memberships are also sent at start-up time, as part of initial- 378 * ization. This repetition after a short interval is desirable for quickly 379 * building up topology and membership information in the presence of possible 380 * packet loss. 381 * 382 * 'virtual_time' advances at a rate that is only a crude approximation of 383 * real time, because it does not take into account any time spent processing, 384 * and because the timer intervals are sometimes shrunk by a random amount to 385 * avoid unwanted synchronization with other routers. 386 */ 387 388 static u_long virtual_time = 0; 389 390 391 /* 392 * Timer routine. Performs periodic neighbor probing, route reporting, and 393 * group querying duties, and drives various timers in routing entries and 394 * virtual interface data structures. 395 */ 396 static void 397 timer() 398 { 399 age_routes(); /* Advance the timers in the route entries */ 400 age_vifs(); /* Advance the timers for neighbors */ 401 age_table_entry(); /* Advance the timers for the cache entries */ 402 403 if (virtual_time % GROUP_QUERY_INTERVAL == 0) { 404 /* 405 * Time to query the local group memberships on all subnets 406 * for which this router is the elected querier. 407 */ 408 query_groups(); 409 } 410 411 if (virtual_time % NEIGHBOR_PROBE_INTERVAL == 0) { 412 /* 413 * Time to send a probe on all vifs from which no neighbors have 414 * been heard. Also, check if any inoperative interfaces have now 415 * come up. (If they have, they will also be probed as part of 416 * their initialization.) 417 */ 418 probe_for_neighbors(); 419 420 if (vifs_down) 421 check_vif_state(); 422 } 423 424 delay_change_reports = FALSE; 425 if (routes_changed) { 426 /* 427 * Some routes have changed since the last timer interrupt, but 428 * have not been reported yet. Report the changed routes to all 429 * neighbors. 430 */ 431 report_to_all_neighbors(CHANGED_ROUTES); 432 } 433 434 #ifdef SNMP 435 if (smux_fd == NOTOK && !dont_bother_anymore 436 && virtual_time % SNMPD_RETRY_INTERVAL == 0) { 437 /* 438 * Time to check for snmpd running. 439 */ 440 try_smux_init(); 441 } 442 #endif 443 444 /* 445 * Advance virtual time 446 */ 447 virtual_time += TIMER_INTERVAL; 448 } 449 450 451 /* 452 * On termination, let everyone know we're going away. 453 */ 454 static void 455 done() 456 { 457 log(LOG_NOTICE, 0, "mrouted version %d.%d exiting", 458 PROTOCOL_VERSION, MROUTED_VERSION); 459 cleanup(); 460 _exit(1); 461 } 462 463 static void 464 cleanup() 465 { 466 static in_cleanup = 0; 467 468 if (!in_cleanup) { 469 in_cleanup++; 470 #ifdef RSRR 471 rsrr_clean(); 472 #endif /* RSRR */ 473 expire_all_routes(); 474 report_to_all_neighbors(ALL_ROUTES); 475 k_stop_dvmrp(); 476 } 477 } 478 479 480 /* 481 * Dump internal data structures to stderr. 482 */ 483 static void 484 dump() 485 { 486 dump_vifs(stderr); 487 dump_routes(stderr); 488 } 489 490 491 /* 492 * Dump internal data structures to a file. 493 */ 494 static void 495 fdump() 496 { 497 FILE *fp; 498 499 fp = fopen(dumpfilename, "w"); 500 if (fp != NULL) { 501 dump_vifs(fp); 502 dump_routes(fp); 503 (void) fclose(fp); 504 } 505 } 506 507 508 /* 509 * Dump local cache contents to a file. 510 */ 511 static void 512 cdump() 513 { 514 FILE *fp; 515 516 fp = fopen(cachefilename, "w"); 517 if (fp != NULL) { 518 dump_cache(fp); 519 (void) fclose(fp); 520 } 521 } 522 523 524 /* 525 * Restart mrouted 526 */ 527 static void 528 restart() 529 { 530 register int omask; 531 532 log(LOG_NOTICE, 0, "mrouted version %d.%d restart", 533 PROTOCOL_VERSION, MROUTED_VERSION); 534 535 /* 536 * reset all the entries 537 */ 538 omask = sigblock(sigmask(SIGALRM)); 539 free_all_prunes(); 540 free_all_routes(); 541 stop_all_vifs(); 542 k_stop_dvmrp(); 543 close(igmp_socket); 544 close(udp_socket); 545 546 /* 547 * start processing again 548 */ 549 dvmrp_genid++; 550 pruning = 1; 551 552 init_igmp(); 553 k_init_dvmrp(); /* enable DVMRP routing in kernel */ 554 init_routes(); 555 init_ktable(); 556 init_vifs(); 557 558 (void)sigsetmask(omask); 559 } 560 561 562 /* 563 * Log errors and other messages to the system log daemon and to stderr, 564 * according to the severity of the message and the current debug level. 565 * For errors of severity LOG_ERR or worse, terminate the program. 566 */ 567 /*VARARGS3*/ 568 void 569 log(severity, syserr, format, va_alist) 570 int severity, syserr; 571 char *format; 572 va_dcl 573 { 574 va_list ap; 575 static char fmt[211] = "warning - "; 576 char *msg; 577 char tbuf[20]; 578 struct timeval now; 579 struct tm *thyme; 580 581 va_start(ap); 582 vsprintf(&fmt[10], format, ap); 583 va_end(ap); 584 msg = (severity == LOG_WARNING) ? fmt : &fmt[10]; 585 586 switch (debug) { 587 case 0: break; 588 case 1: if (severity > LOG_NOTICE) break; 589 case 2: if (severity > LOG_INFO ) break; 590 default: 591 gettimeofday(&now,NULL); 592 thyme = localtime((time_t *)&now.tv_sec); 593 strftime(tbuf, sizeof(tbuf), "%X.%%03d ", thyme); 594 fprintf(stderr, tbuf, now.tv_usec / 1000); 595 fprintf(stderr, "%s", msg); 596 if (syserr == 0) 597 fprintf(stderr, "\n"); 598 else 599 fprintf(stderr, ": %s\n", strerror(syserr)); 600 } 601 602 if (severity <= LOG_NOTICE) { 603 if (syserr != 0) { 604 errno = syserr; 605 syslog(severity, "%s: %m", msg); 606 } else 607 syslog(severity, "%s", msg); 608 609 if (severity <= LOG_ERR) exit(-1); 610 } 611 } 612