1 /* $NetBSD: statd.c,v 1.14 1999/06/10 05:53:51 scottr Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Christos Zoulas. All rights reserved. 5 * Copyright (c) 1995 6 * A.R. Gordon (andrew.gordon@net-tel.co.uk). All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed for the FreeBSD project 19 * This product includes software developed by Christos Zoulas. 20 * 4. Neither the name of the author nor the names of any co-contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY ANDREW GORDON AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 */ 37 38 #include <sys/cdefs.h> 39 #ifndef lint 40 __RCSID("$NetBSD: statd.c,v 1.14 1999/06/10 05:53:51 scottr Exp $"); 41 #endif 42 43 /* main() function for status monitor daemon. Some of the code in this */ 44 /* file was generated by running rpcgen /usr/include/rpcsvc/sm_inter.x */ 45 /* The actual program logic is in the file procs.c */ 46 47 #include <sys/param.h> 48 49 #include <err.h> 50 #include <ctype.h> 51 #include <errno.h> 52 #include <fcntl.h> 53 #include <signal.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <syslog.h> 58 #include <unistd.h> 59 #include <util.h> 60 #include <db.h> 61 62 #include <rpc/rpc.h> 63 64 #include "statd.h" 65 66 struct sigaction sa; 67 int debug = 0; /* Controls syslog() for debug msgs */ 68 int _rpcsvcdirty = 0; /* XXX ??? */ 69 static DB *db; /* Database file */ 70 71 Header status_info; 72 73 static char undefdata[] = "\0\1\2\3\4\5\6\7"; 74 static DBT undefkey = { 75 undefdata, 76 sizeof(undefdata) 77 }; 78 extern char *__progname; 79 80 81 /* statd.c */ 82 static int walk_one __P((int (*fun )__P ((DBT *, DBT *, void *)), DBT *, DBT *, void *)); 83 static int walk_db __P((int (*fun )__P ((DBT *, DBT *, void *)), void *)); 84 static int reset_host __P((DBT *, DBT *, void *)); 85 static int check_work __P((DBT *, DBT *, void *)); 86 static int unmon_host __P((DBT *, DBT *, void *)); 87 static int notify_one __P((DBT *, DBT *, void *)); 88 static void init_file __P((char *)); 89 static int notify_one_host __P((char *)); 90 static void die __P((int)) __attribute__((__noreturn__)); 91 92 int main __P((int, char **)); 93 94 int 95 main(argc, argv) 96 int argc; 97 char **argv; 98 { 99 SVCXPRT *transp; 100 int ch; 101 102 while ((ch = getopt(argc, argv, "d")) != (-1)) { 103 switch (ch) { 104 case 'd': 105 debug = 1; 106 break; 107 default: 108 case '?': 109 (void)fprintf(stderr, "usage: %s [-d]\n", __progname); 110 exit(1); 111 /* NOTREACHED */ 112 } 113 } 114 (void)pmap_unset(SM_PROG, SM_VERS); 115 116 transp = svcudp_create(RPC_ANYSOCK); 117 if (transp == NULL) { 118 errx(1, "cannot create udp service."); 119 /* NOTREACHED */ 120 } 121 if (!svc_register(transp, SM_PROG, SM_VERS, sm_prog_1, IPPROTO_UDP)) { 122 errx(1, "unable to register (SM_PROG, SM_VERS, udp)."); 123 /* NOTREACHED */ 124 } 125 transp = svctcp_create(RPC_ANYSOCK, 0, 0); 126 if (transp == NULL) { 127 errx(1, "cannot create tcp service."); 128 /* NOTREACHED */ 129 } 130 if (!svc_register(transp, SM_PROG, SM_VERS, sm_prog_1, IPPROTO_TCP)) { 131 errx(1, "unable to register (SM_PROG, SM_VERS, tcp)."); 132 /* NOTREACHED */ 133 } 134 init_file("/var/db/statd.status"); 135 136 /* 137 * Note that it is NOT sensible to run this program from inetd - the 138 * protocol assumes that it will run immediately at boot time. 139 */ 140 if (!debug) 141 daemon(0, 0); 142 pidfile(NULL); 143 openlog("rpc.statd", 0, LOG_DAEMON); 144 if (debug) 145 syslog(LOG_INFO, "Starting - debug enabled"); 146 else 147 syslog(LOG_INFO, "Starting"); 148 149 sa.sa_handler = die; 150 sa.sa_flags = 0; 151 sigemptyset(&sa.sa_mask); 152 (void)sigaction(SIGTERM, &sa, NULL); 153 (void)sigaction(SIGQUIT, &sa, NULL); 154 (void)sigaction(SIGHUP, &sa, NULL); 155 (void)sigaction(SIGINT, &sa, NULL); 156 157 sa.sa_handler = SIG_IGN; 158 sa.sa_flags = SA_RESTART; 159 sigemptyset(&sa.sa_mask); 160 sigaddset(&sa.sa_mask, SIGALRM); 161 162 /* Initialisation now complete - start operating */ 163 164 /* Notify hosts that need it */ 165 notify_handler(0); 166 167 while (1) 168 svc_run(); /* Should never return */ 169 die(0); 170 } 171 172 /* notify_handler ---------------------------------------------------------- */ 173 /* 174 * Purpose: Catch SIGALRM and collect process status 175 * Returns: Nothing. 176 * Notes: No special action required, other than to collect the 177 * process status and hence allow the child to die: 178 * we only use child processes for asynchronous transmission 179 * of SM_NOTIFY to other systems, so it is normal for the 180 * children to exit when they have done their work. 181 */ 182 void 183 notify_handler(sig) 184 int sig; 185 { 186 time_t now; 187 188 NO_ALARM; 189 sa.sa_handler = SIG_IGN; 190 (void)sigaction(SIGALRM, &sa, NULL); 191 192 now = time(NULL); 193 194 (void) walk_db(notify_one, &now); 195 196 if (walk_db(check_work, &now) == 0) { 197 /* 198 * No more work to be done. 199 */ 200 CLR_ALARM; 201 return; 202 } 203 sync_file(); 204 ALARM; 205 alarm(5); 206 } 207 208 /* sync_file --------------------------------------------------------------- */ 209 /* 210 * Purpose: Packaged call of msync() to flush changes to mmap()ed file 211 * Returns: Nothing. Errors to syslog. 212 */ 213 void 214 sync_file() 215 { 216 DBT data; 217 218 data.data = &status_info; 219 data.size = sizeof(status_info); 220 switch ((*db->put)(db, &undefkey, &data, 0)) { 221 case 0: 222 return; 223 case -1: 224 goto bad; 225 default: 226 abort(); 227 } 228 if ((*db->sync)(db, 0) == -1) { 229 bad: 230 syslog(LOG_ERR, "database corrupted %m"); 231 die(1); 232 } 233 } 234 235 /* change_host -------------------------------------------------------------- */ 236 /* 237 * Purpose: Update/Create an entry for host 238 * Returns: Nothing 239 * Notes: 240 * 241 */ 242 void 243 change_host(hostname, hp) 244 char *hostname; 245 HostInfo *hp; 246 { 247 DBT key, data; 248 char *ptr; 249 250 for (ptr = hostname; *ptr; ptr++) 251 if (isupper((unsigned char) *ptr)) 252 *ptr = tolower((unsigned char) *ptr); 253 254 key.data = hostname; 255 key.size = ptr - hostname + 1; 256 data.data = hp; 257 data.size = sizeof(*hp); 258 259 switch ((*db->put)(db, &key, &data, 0)) { 260 case -1: 261 syslog(LOG_ERR, "database corrupted %m"); 262 die(1); 263 case 0: 264 return; 265 default: 266 abort(); 267 } 268 } 269 270 271 /* find_host -------------------------------------------------------------- */ 272 /* 273 * Purpose: Find the entry in the status file for a given host 274 * Returns: Copy of entry in hd, or NULL 275 * Notes: 276 * 277 */ 278 HostInfo * 279 find_host(hostname, hp) 280 char *hostname; 281 HostInfo *hp; 282 { 283 DBT key, data; 284 char *ptr; 285 286 for (ptr = hostname; *ptr; ptr++) 287 if (isupper((unsigned char) *ptr)) 288 *ptr = tolower((unsigned char) *ptr); 289 290 key.data = hostname; 291 key.size = ptr - hostname + 1; 292 switch ((*db->get)(db, &key, &data, 0)) { 293 case 0: 294 if (data.size != sizeof(*hp)) 295 goto bad; 296 return memcpy(hp, data.data, sizeof(*hp)); 297 case 1: 298 return NULL; 299 case -1: 300 goto bad; 301 default: 302 abort(); 303 } 304 305 bad: 306 syslog(LOG_ERR, "Database corrupted %m"); 307 return NULL; 308 } 309 310 /* walk_one ------------------------------------------------------------- */ 311 /* 312 * Purpose: Call the given function if the element is valid 313 * Returns: Nothing - exits on error 314 * Notes: 315 */ 316 static int 317 walk_one(fun, key, data, ptr) 318 int (*fun) __P((DBT *, DBT *, void *)); 319 DBT *key, *data; 320 void *ptr; 321 { 322 if (key->size == undefkey.size && 323 memcmp(key->data, undefkey.data, key->size) == 0) 324 return 0; 325 if (data->size != sizeof(HostInfo)) { 326 syslog(LOG_ERR, "Bad data in database"); 327 die(1); 328 } 329 330 return (*fun)(key, data, ptr); 331 } 332 333 /* walk_db -------------------------------------------------------------- */ 334 /* 335 * Purpose: Iterate over all elements calling the given function 336 * Returns: -1 if function failed, 0 on success 337 * Notes: 338 */ 339 static int 340 walk_db(fun, ptr) 341 int (*fun) __P((DBT *, DBT *, void *)); 342 void *ptr; 343 { 344 DBT key, data; 345 346 switch ((*db->seq)(db, &key, &data, R_FIRST)) { 347 case -1: 348 goto bad; 349 case 1: 350 /* We should have at least the magic entry at this point */ 351 abort(); 352 case 0: 353 if (walk_one(fun, &key, &data, ptr) == -1) 354 return -1; 355 break; 356 default: 357 abort(); 358 } 359 360 361 for (;;) 362 switch ((*db->seq)(db, &key, &data, R_NEXT)) { 363 case -1: 364 goto bad; 365 case 1: 366 if (walk_one(fun, &key, &data, ptr) == -1) 367 return -1; 368 break; 369 case 0: 370 return 0; 371 default: 372 abort(); 373 } 374 bad: 375 syslog(LOG_ERR, "Corrupted database %m"); 376 die(1); 377 } 378 379 /* reset_host ------------------------------------------------------------ */ 380 /* 381 * Purpose: Clean up existing hosts in file. 382 * Returns: Always success 0. 383 * Notes: Clean-up of existing file - monitored hosts will have a 384 * pointer to a list of clients, which refers to memory in 385 * the previous incarnation of the program and so are 386 * meaningless now. These pointers are zeroed and the fact 387 * that the host was previously monitored is recorded by 388 * setting the notifyReqd flag, which will in due course 389 * cause a SM_NOTIFY to be sent. 390 * 391 * Note that if we crash twice in quick succession, some hosts 392 * may already have notifyReqd set, where we didn't manage to 393 * notify them before the second crash occurred. 394 */ 395 static int 396 reset_host(key, data, ptr) 397 DBT *key, *data; 398 void *ptr; 399 { 400 HostInfo *hi = data->data; 401 402 if (hi->monList) { 403 hi->notifyReqd = *(time_t *) data; 404 hi->attempts = 0; 405 hi->monList = NULL; 406 } 407 return 0; 408 } 409 410 /* check_work ------------------------------------------------------------ */ 411 /* 412 * Purpose: Check if there is work to be done. 413 * Returns: 0 if there is no work to be done -1 if there is. 414 * Notes: 415 */ 416 static int 417 check_work(key, data, ptr) 418 DBT *key, *data; 419 void *ptr; 420 { 421 HostInfo *hi = data->data; 422 423 return hi->notifyReqd ? -1 : 0; 424 } 425 426 /* unmon_host ------------------------------------------------------------ */ 427 /* 428 * Purpose: Unmonitor a host 429 * Returns: 0 430 * Notes: 431 */ 432 static int 433 unmon_host(key, data, ptr) 434 DBT *key, *data; 435 void *ptr; 436 { 437 char *name = key->data; 438 HostInfo *hi = data->data; 439 440 if (do_unmon(name, hi, ptr)) 441 change_host(name, hi); 442 return 0; 443 } 444 445 /* notify_one ------------------------------------------------------------ */ 446 /* 447 * Purpose: Notify one host. 448 * Returns: 0 if success -1 on failure 449 * Notes: 450 */ 451 static int 452 notify_one(key, data, ptr) 453 DBT *key, *data; 454 void *ptr; 455 { 456 time_t now = *(time_t *) ptr; 457 char *name = key->data; 458 HostInfo *hi = data->data; 459 460 if (hi->notifyReqd == 0 || hi->notifyReqd > now) 461 return 0; 462 463 if (notify_one_host(name)) { 464 give_up: 465 hi->notifyReqd = 0; 466 hi->attempts = 0; 467 switch ((*db->put)(db, key, data, 0)) { 468 case -1: 469 syslog(LOG_ERR, "Error storing %s (%m)", name); 470 case 0: 471 return 0; 472 473 default: 474 abort(); 475 } 476 } 477 else { 478 /* 479 * If one of the initial attempts fails, we wait 480 * for a while and have another go. This is necessary 481 * because when we have crashed, (eg. a power outage) 482 * it is quite possible that we won't be able to 483 * contact all monitored hosts immediately on restart, 484 * either because they crashed too and take longer 485 * to come up (in which case the notification isn't 486 * really required), or more importantly if some 487 * router etc. needed to reach the monitored host 488 * has not come back up yet. In this case, we will 489 * be a bit late in re-establishing locks (after the 490 * grace period) but that is the best we can do. We 491 * try 10 times at 5 sec intervals, 10 more times at 492 * 1 minute intervals, then 24 more times at hourly 493 * intervals, finally giving up altogether if the 494 * host hasn't come back to life after 24 hours. 495 */ 496 if (hi->attempts++ >= 44) 497 goto give_up; 498 else if (hi->attempts < 10) 499 hi->notifyReqd += 5; 500 else if (hi->attempts < 20) 501 hi->notifyReqd += 60; 502 else 503 hi->notifyReqd += 60 * 60; 504 return -1; 505 } 506 } 507 508 /* init_file -------------------------------------------------------------- */ 509 /* 510 * Purpose: Open file, create if necessary, initialise it. 511 * Returns: Nothing - exits on error 512 * Notes: Called before process becomes daemon, hence logs to 513 * stderr rather than syslog. 514 * Opens the file, then mmap()s it for ease of access. 515 * Also performs initial clean-up of the file, zeroing 516 * monitor list pointers, setting the notifyReqd flag in 517 * all hosts that had a monitor list, and incrementing 518 * the state number to the next even value. 519 */ 520 static void 521 init_file(filename) 522 char *filename; 523 { 524 DBT data; 525 526 db = dbopen(filename, O_RDWR|O_CREAT|O_NDELAY|O_EXLOCK, 0644, DB_HASH, 527 NULL); 528 if (db == NULL) 529 err(1, "Cannot open `%s'", filename); 530 531 switch ((*db->get)(db, &undefkey, &data, 0)) { 532 case 1: 533 /* New database */ 534 (void)memset(&status_info, 0, sizeof(status_info)); 535 sync_file(); 536 return; 537 538 case -1: 539 err(1, "error accessing database (%m)"); 540 case 0: 541 /* Existing database */ 542 if (data.size != sizeof(status_info)) 543 errx(1, "database corrupted %lu != %lu", 544 (u_long)data.size, (u_long)sizeof(status_info)); 545 break; 546 default: 547 abort(); 548 } 549 550 reset_database(); 551 return; 552 } 553 554 /* reset_database --------------------------------------------------------- */ 555 /* 556 * Purpose: Clears the statd database 557 * Returns: Nothing 558 * Notes: If this is not called on reset, it will leak memory. 559 */ 560 void 561 reset_database() 562 { 563 time_t now = time(NULL); 564 walk_db(reset_host, &now); 565 566 /* Select the next higher even number for the state counter */ 567 status_info.ourState = 568 (status_info.ourState + 2) & 0xfffffffe; 569 status_info.ourState++; /* XXX - ??? */ 570 sync_file(); 571 } 572 573 /* unmon_hosts --------------------------------------------------------- */ 574 /* 575 * Purpose: Unmonitor all the hosts 576 * Returns: Nothing 577 * Notes: 578 */ 579 void 580 unmon_hosts() 581 { 582 time_t now = time(NULL); 583 walk_db(unmon_host, &now); 584 sync_file(); 585 } 586 587 static int 588 notify_one_host(hostname) 589 char *hostname; 590 { 591 struct timeval timeout = {20, 0}; /* 20 secs timeout */ 592 CLIENT *cli; 593 char dummy; 594 stat_chge arg; 595 char our_hostname[MAXHOSTNAMELEN + 1]; 596 597 gethostname(our_hostname, sizeof(our_hostname)); 598 our_hostname[sizeof(our_hostname) - 1] = '\0'; 599 our_hostname[SM_MAXSTRLEN] = '\0'; 600 arg.mon_name = our_hostname; 601 arg.state = status_info.ourState; 602 603 if (debug) 604 syslog(LOG_DEBUG, "Sending SM_NOTIFY to host %s from %s", 605 hostname, our_hostname); 606 607 cli = clnt_create(hostname, SM_PROG, SM_VERS, "udp"); 608 if (!cli) { 609 syslog(LOG_ERR, "Failed to contact host %s%s", hostname, 610 clnt_spcreateerror("")); 611 return (FALSE); 612 } 613 if (clnt_call(cli, SM_NOTIFY, xdr_stat_chge, &arg, xdr_void, 614 &dummy, timeout) != RPC_SUCCESS) { 615 syslog(LOG_ERR, "Failed to contact rpc.statd at host %s", 616 hostname); 617 clnt_destroy(cli); 618 return (FALSE); 619 } 620 clnt_destroy(cli); 621 return (TRUE); 622 } 623 624 625 static void 626 die(n) 627 int n; 628 { 629 (*db->close)(db); 630 exit(n); 631 } 632