1/* $NetBSD: statd.c,v 1.28 2007/12/15 19:44:56 perry 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 1.28 2007/12/15 19:44:56 perry 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#include <sys/wait.h> 49 50#include <err.h> 51#include <ctype.h> 52#include <errno.h> 53#include <fcntl.h> 54#include <signal.h> 55#include <stdio.h> 56#include <stdlib.h> 57#include <string.h> 58#include <syslog.h> 59#include <unistd.h> 60#include <util.h> 61#include <db.h> 62#include <netconfig.h> 63 64#include <rpc/rpc.h> 65 66#include "statd.h" 67 68struct sigaction sa; 69int debug = 0; /* Controls syslog() for debug msgs */ 70int _rpcsvcdirty = 0; /* XXX ??? */ 71static DB *db; /* Database file */ 72 73Header status_info; 74 75static char undefdata[] = "\0\1\2\3\4\5\6\7"; 76static DBT undefkey = { 77 undefdata, 78 sizeof(undefdata) 79}; 80 81 82/* statd.c */ 83static int walk_one __P((int (*fun )__P ((DBT *, HostInfo *, void *)), DBT *, DBT *, void *)); 84static int walk_db __P((int (*fun )__P ((DBT *, HostInfo *, void *)), void *)); 85static int reset_host __P((DBT *, HostInfo *, void *)); 86static int check_work __P((DBT *, HostInfo *, void *)); 87static int unmon_host __P((DBT *, HostInfo *, void *)); 88static int notify_one __P((DBT *, HostInfo *, void *)); 89static void init_file __P((const char *)); 90static int notify_one_host __P((const char *)); 91static void die __P((int)) __dead; 92 93int main __P((int, char **)); 94 95int 96main(argc, argv) 97 int argc; 98 char **argv; 99{ 100 int ch; 101 struct sigaction nsa; 102 int maxrec = RPC_MAXDATASIZE; 103 104 while ((ch = getopt(argc, argv, "d")) != (-1)) { 105 switch (ch) { 106 case 'd': 107 debug = 1; 108 break; 109 default: 110 case '?': 111 (void)fprintf(stderr, "usage: %s [-d]\n", 112 getprogname()); 113 exit(1); 114 /* NOTREACHED */ 115 } 116 } 117 (void)rpcb_unset(SM_PROG, SM_VERS, NULL); 118 119 rpc_control(RPC_SVC_CONNMAXREC_SET, &maxrec); 120 121 if (!svc_create(sm_prog_1, SM_PROG, SM_VERS, "udp")) { 122 errx(1, "cannot create udp service."); 123 /* NOTREACHED */ 124 } 125 if (!svc_create(sm_prog_1, SM_PROG, SM_VERS, "tcp")) { 126 errx(1, "cannot create udp service."); 127 /* NOTREACHED */ 128 } 129 130 init_file("/var/db/statd.status"); 131 132 /* 133 * Note that it is NOT sensible to run this program from inetd - the 134 * protocol assumes that it will run immediately at boot time. 135 */ 136 if (!debug) 137 daemon(0, 0); 138 139 sigemptyset(&nsa.sa_mask); 140 nsa.sa_flags = SA_NOCLDSTOP|SA_NOCLDWAIT; 141 nsa.sa_handler = SIG_IGN; 142 (void)sigaction(SIGCHLD, &nsa, NULL); 143 144 pidfile(NULL); 145 openlog("rpc.statd", 0, LOG_DAEMON); 146 if (debug) 147 syslog(LOG_INFO, "Starting - debug enabled"); 148 else 149 syslog(LOG_INFO, "Starting"); 150 151 sa.sa_handler = die; 152 sa.sa_flags = 0; 153 sigemptyset(&sa.sa_mask); 154 (void)sigaction(SIGTERM, &sa, NULL); 155 (void)sigaction(SIGQUIT, &sa, NULL); 156 (void)sigaction(SIGHUP, &sa, NULL); 157 (void)sigaction(SIGINT, &sa, NULL); 158 159 sa.sa_handler = SIG_IGN; 160 sa.sa_flags = SA_RESTART; 161 sigemptyset(&sa.sa_mask); 162 sigaddset(&sa.sa_mask, SIGALRM); 163 164 /* Initialisation now complete - start operating */ 165 166 /* Notify hosts that need it */ 167 notify_handler(0); 168 169 while (1) 170 svc_run(); /* Should never return */ 171 die(0); 172} 173 174/* notify_handler ---------------------------------------------------------- */ 175/* 176 * Purpose: Catch SIGALRM and collect process status 177 * Returns: Nothing. 178 * Notes: No special action required, other than to collect the 179 * process status and hence allow the child to die: 180 * we only use child processes for asynchronous transmission 181 * of SM_NOTIFY to other systems, so it is normal for the 182 * children to exit when they have done their work. 183 */ 184void 185notify_handler(sig) 186 int sig; 187{ 188 time_t now; 189 190 NO_ALARM; 191 sa.sa_handler = SIG_IGN; 192 (void)sigaction(SIGALRM, &sa, NULL); 193 194 now = time(NULL); 195 196 (void) walk_db(notify_one, &now); 197 198 if (walk_db(check_work, &now) == 0) { 199 /* 200 * No more work to be done. 201 */ 202 CLR_ALARM; 203 return; 204 } 205 sync_file(); 206 ALARM; 207 alarm(5); 208} 209 210/* sync_file --------------------------------------------------------------- */ 211/* 212 * Purpose: Packaged call of msync() to flush changes to mmap()ed file 213 * Returns: Nothing. Errors to syslog. 214 */ 215void 216sync_file() 217{ 218 DBT data; 219 220 data.data = &status_info; 221 data.size = sizeof(status_info); 222 switch ((*db->put)(db, &undefkey, &data, 0)) { 223 case 0: 224 return; 225 case -1: 226 goto bad; 227 default: 228 abort(); 229 } 230 if ((*db->sync)(db, 0) == -1) { 231bad: 232 syslog(LOG_ERR, "database corrupted %m"); 233 die(1); 234 } 235} 236 237/* change_host -------------------------------------------------------------- */ 238/* 239 * Purpose: Update/Create an entry for host 240 * Returns: Nothing 241 * Notes: 242 * 243 */ 244void 245change_host(hostnamep, hp) 246 char *hostnamep; 247 HostInfo *hp; 248{ 249 DBT key, data; 250 char *ptr; 251 char hostname[MAXHOSTNAMELEN + 1]; 252 HostInfo h; 253 254 strncpy(hostname, hostnamep, MAXHOSTNAMELEN + 1); 255 h = *hp; 256 257 for (ptr = hostname; *ptr; ptr++) 258 if (isupper((unsigned char) *ptr)) 259 *ptr = tolower((unsigned char) *ptr); 260 261 key.data = hostname; 262 key.size = ptr - hostname + 1; 263 data.data = &h; 264 data.size = sizeof(h); 265 266 switch ((*db->put)(db, &key, &data, 0)) { 267 case -1: 268 syslog(LOG_ERR, "database corrupted %m"); 269 die(1); 270 case 0: 271 return; 272 default: 273 abort(); 274 } 275} 276 277 278/* find_host -------------------------------------------------------------- */ 279/* 280 * Purpose: Find the entry in the status file for a given host 281 * Returns: Copy of entry in hd, or NULL 282 * Notes: 283 * 284 */ 285HostInfo * 286find_host(hostname, hp) 287 char *hostname; 288 HostInfo *hp; 289{ 290 DBT key, data; 291 char *ptr; 292 293 for (ptr = hostname; *ptr; ptr++) 294 if (isupper((unsigned char) *ptr)) 295 *ptr = tolower((unsigned char) *ptr); 296 297 key.data = hostname; 298 key.size = ptr - hostname + 1; 299 switch ((*db->get)(db, &key, &data, 0)) { 300 case 0: 301 if (data.size != sizeof(*hp)) 302 goto bad; 303 return memcpy(hp, data.data, sizeof(*hp)); 304 case 1: 305 return NULL; 306 case -1: 307 goto bad; 308 default: 309 abort(); 310 } 311 312bad: 313 syslog(LOG_ERR, "Database corrupted %m"); 314 return NULL; 315} 316 317/* walk_one ------------------------------------------------------------- */ 318/* 319 * Purpose: Call the given function if the element is valid 320 * Returns: Nothing - exits on error 321 * Notes: 322 */ 323static int 324walk_one(fun, key, data, ptr) 325 int (*fun) __P((DBT *, HostInfo *, void *)); 326 DBT *key, *data; 327 void *ptr; 328{ 329 HostInfo h; 330 if (key->size == undefkey.size && 331 memcmp(key->data, undefkey.data, key->size) == 0) 332 return 0; 333 if (data->size != sizeof(HostInfo)) { 334 syslog(LOG_ERR, "Bad data in database"); 335 die(1); 336 } 337 memcpy(&h, data->data, sizeof(h)); 338 return (*fun)(key, &h, ptr); 339} 340 341/* walk_db -------------------------------------------------------------- */ 342/* 343 * Purpose: Iterate over all elements calling the given function 344 * Returns: -1 if function failed, 0 on success 345 * Notes: 346 */ 347static int 348walk_db(fun, ptr) 349 int (*fun) __P((DBT *, HostInfo *, void *)); 350 void *ptr; 351{ 352 DBT key, data; 353 354 switch ((*db->seq)(db, &key, &data, R_FIRST)) { 355 case -1: 356 goto bad; 357 case 1: 358 /* We should have at least the magic entry at this point */ 359 abort(); 360 case 0: 361 if (walk_one(fun, &key, &data, ptr) == -1) 362 return -1; 363 break; 364 default: 365 abort(); 366 } 367 368 369 for (;;) 370 switch ((*db->seq)(db, &key, &data, R_NEXT)) { 371 case -1: 372 goto bad; 373 case 0: 374 if (walk_one(fun, &key, &data, ptr) == -1) 375 return -1; 376 break; 377 case 1: 378 return 0; 379 default: 380 abort(); 381 } 382bad: 383 syslog(LOG_ERR, "Corrupted database %m"); 384 die(1); 385} 386 387/* reset_host ------------------------------------------------------------ */ 388/* 389 * Purpose: Clean up existing hosts in file. 390 * Returns: Always success 0. 391 * Notes: Clean-up of existing file - monitored hosts will have a 392 * pointer to a list of clients, which refers to memory in 393 * the previous incarnation of the program and so are 394 * meaningless now. These pointers are zeroed and the fact 395 * that the host was previously monitored is recorded by 396 * setting the notifyReqd flag, which will in due course 397 * cause a SM_NOTIFY to be sent. 398 * 399 * Note that if we crash twice in quick succession, some hosts 400 * may already have notifyReqd set, where we didn't manage to 401 * notify them before the second crash occurred. 402 */ 403static int 404reset_host(key, hi, ptr) 405 DBT *key; 406 HostInfo *hi; 407 void *ptr; 408{ 409 410 if (hi->monList) { 411 hi->notifyReqd = *(time_t *) ptr; 412 hi->attempts = 0; 413 hi->monList = NULL; 414 change_host((char *)key->data, hi); 415 } 416 return 0; 417} 418 419/* check_work ------------------------------------------------------------ */ 420/* 421 * Purpose: Check if there is work to be done. 422 * Returns: 0 if there is no work to be done -1 if there is. 423 * Notes: 424 */ 425static int 426check_work(key, hi, ptr) 427 DBT *key; 428 HostInfo *hi; 429 void *ptr; 430{ 431 return hi->notifyReqd ? -1 : 0; 432} 433 434/* unmon_host ------------------------------------------------------------ */ 435/* 436 * Purpose: Unmonitor a host 437 * Returns: 0 438 * Notes: 439 */ 440static int 441unmon_host(key, hi, ptr) 442 DBT *key; 443 HostInfo *hi; 444 void *ptr; 445{ 446 char *name = key->data; 447 448 if (do_unmon(name, hi, ptr)) 449 change_host(name, hi); 450 return 0; 451} 452 453/* notify_one ------------------------------------------------------------ */ 454/* 455 * Purpose: Notify one host. 456 * Returns: 0 if success -1 on failure 457 * Notes: 458 */ 459static int 460notify_one(key, hi, ptr) 461 DBT *key; 462 HostInfo *hi; 463 void *ptr; 464{ 465 time_t now = *(time_t *) ptr; 466 char *name = key->data; 467 int error; 468 469 if (hi->notifyReqd == 0 || hi->notifyReqd > now) 470 return 0; 471 472 /* 473 * If one of the initial attempts fails, we wait 474 * for a while and have another go. This is necessary 475 * because when we have crashed, (eg. a power outage) 476 * it is quite possible that we won't be able to 477 * contact all monitored hosts immediately on restart, 478 * either because they crashed too and take longer 479 * to come up (in which case the notification isn't 480 * really required), or more importantly if some 481 * router etc. needed to reach the monitored host 482 * has not come back up yet. In this case, we will 483 * be a bit late in re-establishing locks (after the 484 * grace period) but that is the best we can do. We 485 * try 10 times at 5 sec intervals, 10 more times at 486 * 1 minute intervals, then 24 more times at hourly 487 * intervals, finally giving up altogether if the 488 * host hasn't come back to life after 24 hours. 489 */ 490 if (notify_one_host(name) || hi->attempts++ >= 44) { 491 error = 0; 492 hi->notifyReqd = 0; 493 hi->attempts = 0; 494 } else { 495 error = -1; 496 if (hi->attempts < 10) 497 hi->notifyReqd += 5; 498 else if (hi->attempts < 20) 499 hi->notifyReqd += 60; 500 else 501 hi->notifyReqd += 60 * 60; 502 } 503 change_host(name, hi); 504 return error; 505} 506 507/* init_file -------------------------------------------------------------- */ 508/* 509 * Purpose: Open file, create if necessary, initialise it. 510 * Returns: Nothing - exits on error 511 * Notes: Called before process becomes daemon, hence logs to 512 * stderr rather than syslog. 513 * Opens the file, then mmap()s it for ease of access. 514 * Also performs initial clean-up of the file, zeroing 515 * monitor list pointers, setting the notifyReqd flag in 516 * all hosts that had a monitor list, and incrementing 517 * the state number to the next even value. 518 */ 519static void 520init_file(filename) 521 const char *filename; 522{ 523 DBT data; 524 525 db = dbopen(filename, O_RDWR|O_CREAT|O_NDELAY|O_EXLOCK, 0644, DB_HASH, 526 NULL); 527 if (db == NULL) 528 err(1, "Cannot open `%s'", filename); 529 530 switch ((*db->get)(db, &undefkey, &data, 0)) { 531 case 1: 532 /* New database */ 533 (void)memset(&status_info, 0, sizeof(status_info)); 534 sync_file(); 535 return; 536 537 case -1: 538 err(1, "error accessing database (%m)"); 539 case 0: 540 /* Existing database */ 541 if (data.size != sizeof(status_info)) 542 errx(1, "database corrupted %lu != %lu", 543 (u_long)data.size, (u_long)sizeof(status_info)); 544 memcpy(&status_info, data.data, data.size); 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 */ 560void 561reset_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 */ 579void 580unmon_hosts() 581{ 582 time_t now = time(NULL); 583 walk_db(unmon_host, &now); 584 sync_file(); 585} 586 587static int 588notify_one_host(hostname) 589 const 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 arg.mon_name = our_hostname; 600 arg.state = status_info.ourState; 601 602 if (debug) 603 syslog(LOG_DEBUG, "Sending SM_NOTIFY to host %s from %s", 604 hostname, our_hostname); 605 606 cli = clnt_create(hostname, SM_PROG, SM_VERS, "udp"); 607 if (!cli) { 608 syslog(LOG_ERR, "Failed to contact host %s%s", hostname, 609 clnt_spcreateerror("")); 610 return (FALSE); 611 } 612 if (clnt_call(cli, SM_NOTIFY, xdr_stat_chge, &arg, xdr_void, 613 &dummy, timeout) != RPC_SUCCESS) { 614 syslog(LOG_ERR, "Failed to contact rpc.statd at host %s", 615 hostname); 616 clnt_destroy(cli); 617 return (FALSE); 618 } 619 clnt_destroy(cli); 620 return (TRUE); 621} 622 623 624static void 625die(n) 626 int n; 627{ 628 (*db->close)(db); 629 exit(n); 630} 631