1/* vi: set sw=4 ts=4: */ 2/* 3 * crond -d[#] -c <crondir> -f -b 4 * 5 * run as root, but NOT setuid root 6 * 7 * Copyright 1994 Matthew Dillon (dillon@apollo.west.oic.com) 8 * (version 2.3.2) 9 * Vladimir Oleynik <dzo@simtreas.ru> (C) 2002 10 * 11 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. 12 */ 13 14#include <sys/syslog.h> 15#include "libbb.h" 16 17#ifndef CRONTABS 18#define CRONTABS "/var/spool/cron/crontabs" 19#endif 20#ifndef TMPDIR 21#define TMPDIR "/var/spool/cron" 22#endif 23#ifndef SENDMAIL 24#define SENDMAIL "sendmail" 25#endif 26#ifndef SENDMAIL_ARGS 27#define SENDMAIL_ARGS "-ti", "oem" 28#endif 29#ifndef CRONUPDATE 30#define CRONUPDATE "cron.update" 31#endif 32#ifndef MAXLINES 33#define MAXLINES 256 /* max lines in non-root crontabs */ 34#endif 35 36typedef struct CronFile { 37 struct CronFile *cf_Next; 38 struct CronLine *cf_LineBase; 39 char *cf_User; /* username */ 40 int cf_Ready; /* bool: one or more jobs ready */ 41 int cf_Running; /* bool: one or more jobs running */ 42 int cf_Deleted; /* marked for deletion, ignore */ 43} CronFile; 44 45typedef struct CronLine { 46 struct CronLine *cl_Next; 47 char *cl_Shell; /* shell command */ 48 pid_t cl_Pid; /* running pid, 0, or armed (-1) */ 49 int cl_MailFlag; /* running pid is for mail */ 50 int cl_MailPos; /* 'empty file' size */ 51 char cl_Mins[60]; /* 0-59 */ 52 char cl_Hrs[24]; /* 0-23 */ 53 char cl_Days[32]; /* 1-31 */ 54 char cl_Mons[12]; /* 0-11 */ 55 char cl_Dow[7]; /* 0-6, beginning sunday */ 56} CronLine; 57 58#define RUN_RANOUT 1 59#define RUN_RUNNING 2 60#define RUN_FAILED 3 61 62#define DaemonUid 0 63 64#if ENABLE_DEBUG_CROND_OPTION 65static unsigned DebugOpt; 66#endif 67 68static unsigned LogLevel = 8; 69static const char *LogFile; 70static const char *CDir = CRONTABS; 71 72static void startlogger(void); 73 74static void CheckUpdates(void); 75static void SynchronizeDir(void); 76static int TestJobs(time_t t1, time_t t2); 77static void RunJobs(void); 78static int CheckJobs(void); 79 80static void RunJob(const char *user, CronLine * line); 81 82#if ENABLE_FEATURE_CROND_CALL_SENDMAIL 83static void EndJob(const char *user, CronLine * line); 84#else 85#define EndJob(user, line) line->cl_Pid = 0 86#endif 87 88static void DeleteFile(const char *userName); 89 90static CronFile *FileBase; 91 92 93static void crondlog(const char *ctl, ...) 94{ 95 va_list va; 96 const char *fmt; 97 int level = (int) (ctl[0] & 0xf); 98 int type = level == 20 ? 99 LOG_ERR : ((ctl[0] & 0100) ? LOG_WARNING : LOG_NOTICE); 100 101 102 va_start(va, ctl); 103 fmt = ctl + 1; 104 if (level >= LogLevel) { 105 106#if ENABLE_DEBUG_CROND_OPTION 107 if (DebugOpt) { 108 vfprintf(stderr, fmt, va); 109 } else 110#endif 111 if (LogFile == 0) { 112 vsyslog(type, fmt, va); 113 } else { 114#if !ENABLE_DEBUG_CROND_OPTION 115 int logfd = open(LogFile, O_WRONLY | O_CREAT | O_APPEND, 0600); 116#else 117 int logfd = open3_or_warn(LogFile, O_WRONLY | O_CREAT | O_APPEND, 0600); 118#endif 119 if (logfd >= 0) { 120 vdprintf(logfd, fmt, va); 121 close(logfd); 122 } 123 } 124 } 125 va_end(va); 126 if (ctl[0] & 0200) { 127 exit(20); 128 } 129} 130 131int crond_main(int ac, char **av); 132int crond_main(int ac, char **av) 133{ 134 unsigned opt; 135 char *lopt, *Lopt, *copt; 136 USE_DEBUG_CROND_OPTION(char *dopt;) 137 138 opt_complementary = "f-b:b-f:S-L:L-S" USE_DEBUG_CROND_OPTION(":d-l"); 139 opterr = 0; /* disable getopt 'errors' message. */ 140 opt = getopt32(av, "l:L:fbSc:" USE_DEBUG_CROND_OPTION("d:"), 141 &lopt, &Lopt, &copt USE_DEBUG_CROND_OPTION(, &dopt)); 142 if (opt & 1) /* -l */ 143 LogLevel = xatou(lopt); 144 if (opt & 2) /* -L */ 145 if (*Lopt) 146 LogFile = Lopt; 147 if (opt & 32) /* -c */ 148 if (*copt) 149 CDir = copt; 150#if ENABLE_DEBUG_CROND_OPTION 151 if (opt & 64) { /* -d */ 152 DebugOpt = xatou(dopt); 153 LogLevel = 0; 154 } 155#endif 156 157 /* close stdin and stdout, stderr. 158 * close unused descriptors - don't need. 159 * optional detach from controlling terminal 160 */ 161 if (!(opt & 4)) 162 bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, av); 163 164 xchdir(CDir); 165 signal(SIGHUP, SIG_IGN); /* ? original crond dies on HUP... */ 166 167 startlogger(); /* need if syslog mode selected */ 168 169 /* 170 * main loop - synchronize to 1 second after the minute, minimum sleep 171 * of 1 second. 172 */ 173 crondlog("\011%s " BB_VER " started, log level %d\n", 174 applet_name, LogLevel); 175 176 SynchronizeDir(); 177 178 { 179 time_t t1 = time(NULL); 180 time_t t2; 181 long dt; 182 int rescan = 60; 183 short sleep_time = 60; 184 185 write_pidfile("/var/run/crond.pid"); 186 for (;;) { 187 sleep((sleep_time + 1) - (short) (time(NULL) % sleep_time)); 188 189 t2 = time(NULL); 190 dt = t2 - t1; 191 192 /* 193 * The file 'cron.update' is checked to determine new cron 194 * jobs. The directory is rescanned once an hour to deal 195 * with any screwups. 196 * 197 * check for disparity. Disparities over an hour either way 198 * result in resynchronization. A reverse-indexed disparity 199 * less then an hour causes us to effectively sleep until we 200 * match the original time (i.e. no re-execution of jobs that 201 * have just been run). A forward-indexed disparity less then 202 * an hour causes intermediate jobs to be run, but only once 203 * in the worst case. 204 * 205 * when running jobs, the inequality used is greater but not 206 * equal to t1, and less then or equal to t2. 207 */ 208 209 if (--rescan == 0) { 210 rescan = 60; 211 SynchronizeDir(); 212 } 213 CheckUpdates(); 214#if ENABLE_DEBUG_CROND_OPTION 215 if (DebugOpt) 216 crondlog("\005Wakeup dt=%d\n", dt); 217#endif 218 if (dt < -60 * 60 || dt > 60 * 60) { 219 t1 = t2; 220 crondlog("\111time disparity of %d minutes detected\n", dt / 60); 221 } else if (dt > 0) { 222 TestJobs(t1, t2); 223 RunJobs(); 224 sleep(5); 225 if (CheckJobs() > 0) { 226 sleep_time = 10; 227 } else { 228 sleep_time = 60; 229 } 230 t1 = t2; 231 } 232 } 233 } 234 return 0; /* not reached */ 235} 236 237static int ChangeUser(const char *user) 238{ 239 struct passwd *pas; 240 const char *err_msg; 241 242 /* 243 * Obtain password entry and change privileges 244 */ 245 pas = getpwnam(user); 246 if (pas == 0) { 247 crondlog("\011failed to get uid for %s", user); 248 return -1; 249 } 250 setenv("USER", pas->pw_name, 1); 251 setenv("HOME", pas->pw_dir, 1); 252 setenv("SHELL", DEFAULT_SHELL, 1); 253 254 /* 255 * Change running state to the user in question 256 */ 257 err_msg = change_identity_e2str(pas); 258 if (err_msg) { 259 crondlog("\011%s for user %s", err_msg, user); 260 return -1; 261 } 262 if (chdir(pas->pw_dir) < 0) { 263 crondlog("\011chdir failed: %s: %m", pas->pw_dir); 264 if (chdir(TMPDIR) < 0) { 265 crondlog("\011chdir failed: %s: %m", TMPDIR); 266 return -1; 267 } 268 } 269 return pas->pw_uid; 270} 271 272static void startlogger(void) 273{ 274 if (LogFile == 0) { 275 openlog(applet_name, LOG_CONS | LOG_PID, LOG_CRON); 276 } 277#if ENABLE_DEBUG_CROND_OPTION 278 else { /* test logfile */ 279 int logfd; 280 281 logfd = open3_or_warn(LogFile, O_WRONLY | O_CREAT | O_APPEND, 0600); 282 if (logfd >= 0) { 283 close(logfd); 284 } 285 } 286#endif 287} 288 289 290static const char DowAry[] ALIGN1 = 291 "sun""mon""tue""wed""thu""fri""sat" 292 /* "Sun""Mon""Tue""Wed""Thu""Fri""Sat" */ 293; 294 295static const char MonAry[] ALIGN1 = 296 "jan""feb""mar""apr""may""jun""jul""aug""sep""oct""nov""dec" 297 /* "Jan""Feb""Mar""Apr""May""Jun""Jul""Aug""Sep""Oct""Nov""Dec" */ 298; 299 300static char *ParseField(char *user, char *ary, int modvalue, int off, 301 const char *names, char *ptr) 302/* 'names' is a pointer to a set of 3-char abbreviations */ 303{ 304 char *base = ptr; 305 int n1 = -1; 306 int n2 = -1; 307 308 if (base == NULL) { 309 return NULL; 310 } 311 312 while (*ptr != ' ' && *ptr != '\t' && *ptr != '\n') { 313 int skip = 0; 314 315 /* Handle numeric digit or symbol or '*' */ 316 317 if (*ptr == '*') { 318 n1 = 0; /* everything will be filled */ 319 n2 = modvalue - 1; 320 skip = 1; 321 ++ptr; 322 } else if (*ptr >= '0' && *ptr <= '9') { 323 if (n1 < 0) { 324 n1 = strtol(ptr, &ptr, 10) + off; 325 } else { 326 n2 = strtol(ptr, &ptr, 10) + off; 327 } 328 skip = 1; 329 } else if (names) { 330 int i; 331 332 for (i = 0; names[i]; i += 3) { 333 /* was using strncmp before... */ 334 if (strncasecmp(ptr, &names[i], 3) == 0) { 335 ptr += 3; 336 if (n1 < 0) { 337 n1 = i / 3; 338 } else { 339 n2 = i / 3; 340 } 341 skip = 1; 342 break; 343 } 344 } 345 } 346 347 /* handle optional range '-' */ 348 349 if (skip == 0) { 350 crondlog("\111failed user %s parsing %s\n", user, base); 351 return NULL; 352 } 353 if (*ptr == '-' && n2 < 0) { 354 ++ptr; 355 continue; 356 } 357 358 /* 359 * collapse single-value ranges, handle skipmark, and fill 360 * in the character array appropriately. 361 */ 362 363 if (n2 < 0) { 364 n2 = n1; 365 } 366 if (*ptr == '/') { 367 skip = strtol(ptr + 1, &ptr, 10); 368 } 369 /* 370 * fill array, using a failsafe is the easiest way to prevent 371 * an endless loop 372 */ 373 374 { 375 int s0 = 1; 376 int failsafe = 1024; 377 378 --n1; 379 do { 380 n1 = (n1 + 1) % modvalue; 381 382 if (--s0 == 0) { 383 ary[n1 % modvalue] = 1; 384 s0 = skip; 385 } 386 } 387 while (n1 != n2 && --failsafe); 388 389 if (failsafe == 0) { 390 crondlog("\111failed user %s parsing %s\n", user, base); 391 return NULL; 392 } 393 } 394 if (*ptr != ',') { 395 break; 396 } 397 ++ptr; 398 n1 = -1; 399 n2 = -1; 400 } 401 402 if (*ptr != ' ' && *ptr != '\t' && *ptr != '\n') { 403 crondlog("\111failed user %s parsing %s\n", user, base); 404 return NULL; 405 } 406 407 while (*ptr == ' ' || *ptr == '\t' || *ptr == '\n') { 408 ++ptr; 409 } 410#if ENABLE_DEBUG_CROND_OPTION 411 if (DebugOpt) { 412 int i; 413 414 for (i = 0; i < modvalue; ++i) { 415 crondlog("\005%d", ary[i]); 416 } 417 crondlog("\005\n"); 418 } 419#endif 420 421 return ptr; 422} 423 424static void FixDayDow(CronLine * line) 425{ 426 int i; 427 int weekUsed = 0; 428 int daysUsed = 0; 429 430 for (i = 0; i < (int)(ARRAY_SIZE(line->cl_Dow)); ++i) { 431 if (line->cl_Dow[i] == 0) { 432 weekUsed = 1; 433 break; 434 } 435 } 436 for (i = 0; i < (int)(ARRAY_SIZE(line->cl_Days)); ++i) { 437 if (line->cl_Days[i] == 0) { 438 daysUsed = 1; 439 break; 440 } 441 } 442 if (weekUsed && !daysUsed) { 443 memset(line->cl_Days, 0, sizeof(line->cl_Days)); 444 } 445 if (daysUsed && !weekUsed) { 446 memset(line->cl_Dow, 0, sizeof(line->cl_Dow)); 447 } 448} 449 450 451 452static void SynchronizeFile(const char *fileName) 453{ 454 int maxEntries = MAXLINES; 455 int maxLines; 456 char buf[1024]; 457 458 if (strcmp(fileName, "root") == 0) { 459 maxEntries = 65535; 460 } 461 maxLines = maxEntries * 10; 462 463 if (fileName) { 464 FILE *fi; 465 466 DeleteFile(fileName); 467 468 fi = fopen(fileName, "r"); 469 if (fi != NULL) { 470 struct stat sbuf; 471 472 if (fstat(fileno(fi), &sbuf) == 0 && sbuf.st_uid == DaemonUid) { 473 CronFile *file = xzalloc(sizeof(CronFile)); 474 CronLine **pline; 475 476 file->cf_User = strdup(fileName); 477 pline = &file->cf_LineBase; 478 479 while (fgets(buf, sizeof(buf), fi) != NULL && --maxLines) { 480 CronLine line; 481 char *ptr; 482 483 trim(buf); 484 if (buf[0] == 0 || buf[0] == '#') { 485 continue; 486 } 487 if (--maxEntries == 0) { 488 break; 489 } 490 memset(&line, 0, sizeof(line)); 491 492#if ENABLE_DEBUG_CROND_OPTION 493 if (DebugOpt) { 494 crondlog("\111User %s Entry %s\n", fileName, buf); 495 } 496#endif 497 498 /* parse date ranges */ 499 ptr = ParseField(file->cf_User, line.cl_Mins, 60, 0, NULL, buf); 500 ptr = ParseField(file->cf_User, line.cl_Hrs, 24, 0, NULL, ptr); 501 ptr = ParseField(file->cf_User, line.cl_Days, 32, 0, NULL, ptr); 502 ptr = ParseField(file->cf_User, line.cl_Mons, 12, -1, MonAry, ptr); 503 ptr = ParseField(file->cf_User, line.cl_Dow, 7, 0, DowAry, ptr); 504 505 /* check failure */ 506 if (ptr == NULL) { 507 continue; 508 } 509 510 /* 511 * fix days and dow - if one is not * and the other 512 * is *, the other is set to 0, and vise-versa 513 */ 514 515 FixDayDow(&line); 516 517 *pline = xzalloc(sizeof(CronLine)); 518 **pline = line; 519 520 /* copy command */ 521 (*pline)->cl_Shell = strdup(ptr); 522 523#if ENABLE_DEBUG_CROND_OPTION 524 if (DebugOpt) { 525 crondlog("\111 Command %s\n", ptr); 526 } 527#endif 528 529 pline = &((*pline)->cl_Next); 530 } 531 *pline = NULL; 532 533 file->cf_Next = FileBase; 534 FileBase = file; 535 536 if (maxLines == 0 || maxEntries == 0) { 537 crondlog("\111Maximum number of lines reached for user %s\n", fileName); 538 } 539 } 540 fclose(fi); 541 } 542 } 543} 544 545static void CheckUpdates(void) 546{ 547 FILE *fi; 548 char buf[256]; 549 550 fi = fopen(CRONUPDATE, "r"); 551 if (fi != NULL) { 552 remove(CRONUPDATE); 553 while (fgets(buf, sizeof(buf), fi) != NULL) { 554 SynchronizeFile(strtok(buf, " \t\r\n")); 555 } 556 fclose(fi); 557 } 558} 559 560static void SynchronizeDir(void) 561{ 562 /* Attempt to delete the database. */ 563 564 for (;;) { 565 CronFile *file; 566 567 for (file = FileBase; file && file->cf_Deleted; file = file->cf_Next); 568 if (file == NULL) { 569 break; 570 } 571 DeleteFile(file->cf_User); 572 } 573 574 /* 575 * Remove cron update file 576 * 577 * Re-chdir, in case directory was renamed & deleted, or otherwise 578 * screwed up. 579 * 580 * scan directory and add associated users 581 */ 582 583 remove(CRONUPDATE); 584 if (chdir(CDir) < 0) { 585 crondlog("\311cannot find %s\n", CDir); 586 } 587 { 588 DIR *dir = opendir("."); 589 struct dirent *den; 590 591 if (dir) { 592 while ((den = readdir(dir))) { 593 if (strchr(den->d_name, '.') != NULL) { 594 continue; 595 } 596 if (getpwnam(den->d_name)) { 597 SynchronizeFile(den->d_name); 598 } else { 599 crondlog("\007ignoring %s\n", den->d_name); 600 } 601 } 602 closedir(dir); 603 } else { 604 crondlog("\311cannot open current dir!\n"); 605 } 606 } 607} 608 609 610/* 611 * DeleteFile() - delete user database 612 * 613 * Note: multiple entries for same user may exist if we were unable to 614 * completely delete a database due to running processes. 615 */ 616 617static void DeleteFile(const char *userName) 618{ 619 CronFile **pfile = &FileBase; 620 CronFile *file; 621 622 while ((file = *pfile) != NULL) { 623 if (strcmp(userName, file->cf_User) == 0) { 624 CronLine **pline = &file->cf_LineBase; 625 CronLine *line; 626 627 file->cf_Running = 0; 628 file->cf_Deleted = 1; 629 630 while ((line = *pline) != NULL) { 631 if (line->cl_Pid > 0) { 632 file->cf_Running = 1; 633 pline = &line->cl_Next; 634 } else { 635 *pline = line->cl_Next; 636 free(line->cl_Shell); 637 free(line); 638 } 639 } 640 if (file->cf_Running == 0) { 641 *pfile = file->cf_Next; 642 free(file->cf_User); 643 free(file); 644 } else { 645 pfile = &file->cf_Next; 646 } 647 } else { 648 pfile = &file->cf_Next; 649 } 650 } 651} 652 653/* 654 * TestJobs() 655 * 656 * determine which jobs need to be run. Under normal conditions, the 657 * period is about a minute (one scan). Worst case it will be one 658 * hour (60 scans). 659 */ 660 661static int TestJobs(time_t t1, time_t t2) 662{ 663 int nJobs = 0; 664 time_t t; 665 666 /* Find jobs > t1 and <= t2 */ 667 668 for (t = t1 - t1 % 60; t <= t2; t += 60) { 669 if (t > t1) { 670 struct tm *tp = localtime(&t); 671 CronFile *file; 672 CronLine *line; 673 674 for (file = FileBase; file; file = file->cf_Next) { 675#if ENABLE_DEBUG_CROND_OPTION 676 if (DebugOpt) 677 crondlog("\005FILE %s:\n", file->cf_User); 678#endif 679 if (file->cf_Deleted) 680 continue; 681 for (line = file->cf_LineBase; line; line = line->cl_Next) { 682#if ENABLE_DEBUG_CROND_OPTION 683 if (DebugOpt) 684 crondlog("\005 LINE %s\n", line->cl_Shell); 685#endif 686 if (line->cl_Mins[tp->tm_min] && line->cl_Hrs[tp->tm_hour] && 687 (line->cl_Days[tp->tm_mday] || line->cl_Dow[tp->tm_wday]) 688 && line->cl_Mons[tp->tm_mon]) { 689#if ENABLE_DEBUG_CROND_OPTION 690 if (DebugOpt) { 691 crondlog("\005 JobToDo: %d %s\n", 692 line->cl_Pid, line->cl_Shell); 693 } 694#endif 695 if (line->cl_Pid > 0) { 696 crondlog("\010 process already running: %s %s\n", 697 file->cf_User, line->cl_Shell); 698 } else if (line->cl_Pid == 0) { 699 line->cl_Pid = -1; 700 file->cf_Ready = 1; 701 ++nJobs; 702 } 703 } 704 } 705 } 706 } 707 } 708 return nJobs; 709} 710 711static void RunJobs(void) 712{ 713 CronFile *file; 714 CronLine *line; 715 716 for (file = FileBase; file; file = file->cf_Next) { 717 if (file->cf_Ready) { 718 file->cf_Ready = 0; 719 720 for (line = file->cf_LineBase; line; line = line->cl_Next) { 721 if (line->cl_Pid < 0) { 722 723 RunJob(file->cf_User, line); 724 725 crondlog("\010USER %s pid %3d cmd %s\n", 726 file->cf_User, line->cl_Pid, line->cl_Shell); 727 if (line->cl_Pid < 0) { 728 file->cf_Ready = 1; 729 } 730 else if (line->cl_Pid > 0) { 731 file->cf_Running = 1; 732 } 733 } 734 } 735 } 736 } 737} 738 739/* 740 * CheckJobs() - check for job completion 741 * 742 * Check for job completion, return number of jobs still running after 743 * all done. 744 */ 745 746static int CheckJobs(void) 747{ 748 CronFile *file; 749 CronLine *line; 750 int nStillRunning = 0; 751 752 for (file = FileBase; file; file = file->cf_Next) { 753 if (file->cf_Running) { 754 file->cf_Running = 0; 755 756 for (line = file->cf_LineBase; line; line = line->cl_Next) { 757 if (line->cl_Pid > 0) { 758 int status; 759 int r = wait4(line->cl_Pid, &status, WNOHANG, NULL); 760 761 if (r < 0 || r == line->cl_Pid) { 762 EndJob(file->cf_User, line); 763 if (line->cl_Pid) { 764 file->cf_Running = 1; 765 } 766 } else if (r == 0) { 767 file->cf_Running = 1; 768 } 769 } 770 } 771 } 772 nStillRunning += file->cf_Running; 773 } 774 return nStillRunning; 775} 776 777 778#if ENABLE_FEATURE_CROND_CALL_SENDMAIL 779static void 780ForkJob(const char *user, CronLine * line, int mailFd, 781 const char *prog, const char *cmd, const char *arg, const char *mailf) 782{ 783 /* Fork as the user in question and run program */ 784 pid_t pid = fork(); 785 786 line->cl_Pid = pid; 787 if (pid == 0) { 788 /* CHILD */ 789 790 /* Change running state to the user in question */ 791 792 if (ChangeUser(user) < 0) { 793 exit(0); 794 } 795#if ENABLE_DEBUG_CROND_OPTION 796 if (DebugOpt) { 797 crondlog("\005Child Running %s\n", prog); 798 } 799#endif 800 801 if (mailFd >= 0) { 802 dup2(mailFd, mailf != NULL); 803 dup2((mailf ? mailFd : 1), 2); 804 close(mailFd); 805 } 806 execl(prog, prog, cmd, arg, NULL); 807 crondlog("\024cannot exec, user %s cmd %s %s %s\n", user, prog, cmd, arg); 808 if (mailf) { 809 fdprintf(1, "Exec failed: %s -c %s\n", prog, arg); 810 } 811 exit(0); 812 } else if (pid < 0) { 813 /* FORK FAILED */ 814 crondlog("\024cannot fork, user %s\n", user); 815 line->cl_Pid = 0; 816 if (mailf) { 817 remove(mailf); 818 } 819 } else if (mailf) { 820 /* PARENT, FORK SUCCESS 821 * rename mail-file based on pid of process 822 */ 823 char mailFile2[128]; 824 825 snprintf(mailFile2, sizeof(mailFile2), TMPDIR "/cron.%s.%d", user, pid); 826 rename(mailf, mailFile2); 827 } 828 /* 829 * Close the mail file descriptor.. we can't just leave it open in 830 * a structure, closing it later, because we might run out of descriptors 831 */ 832 833 if (mailFd >= 0) { 834 close(mailFd); 835 } 836} 837 838static void RunJob(const char *user, CronLine * line) 839{ 840 char mailFile[128]; 841 int mailFd; 842 843 line->cl_Pid = 0; 844 line->cl_MailFlag = 0; 845 846 /* open mail file - owner root so nobody can screw with it. */ 847 848 snprintf(mailFile, sizeof(mailFile), TMPDIR "/cron.%s.%d", user, getpid()); 849 mailFd = open(mailFile, O_CREAT | O_TRUNC | O_WRONLY | O_EXCL | O_APPEND, 0600); 850 851 if (mailFd >= 0) { 852 line->cl_MailFlag = 1; 853 fdprintf(mailFd, "To: %s\nSubject: cron: %s\n\n", user, 854 line->cl_Shell); 855 line->cl_MailPos = lseek(mailFd, 0, SEEK_CUR); 856 } else { 857 crondlog("\024cannot create mail file user %s file %s, output to /dev/null\n", user, mailFile); 858 } 859 860 ForkJob(user, line, mailFd, DEFAULT_SHELL, "-c", line->cl_Shell, mailFile); 861} 862 863/* 864 * EndJob - called when job terminates and when mail terminates 865 */ 866 867static void EndJob(const char *user, CronLine * line) 868{ 869 int mailFd; 870 char mailFile[128]; 871 struct stat sbuf; 872 873 /* No job */ 874 875 if (line->cl_Pid <= 0) { 876 line->cl_Pid = 0; 877 return; 878 } 879 880 /* 881 * End of job and no mail file 882 * End of sendmail job 883 */ 884 885 snprintf(mailFile, sizeof(mailFile), TMPDIR "/cron.%s.%d", user, line->cl_Pid); 886 line->cl_Pid = 0; 887 888 if (line->cl_MailFlag != 1) { 889 return; 890 } 891 line->cl_MailFlag = 0; 892 893 /* 894 * End of primary job - check for mail file. If size has increased and 895 * the file is still valid, we sendmail it. 896 */ 897 898 mailFd = open(mailFile, O_RDONLY); 899 remove(mailFile); 900 if (mailFd < 0) { 901 return; 902 } 903 904 if (fstat(mailFd, &sbuf) < 0 || sbuf.st_uid != DaemonUid 905 || sbuf.st_nlink != 0 || sbuf.st_size == line->cl_MailPos 906 || !S_ISREG(sbuf.st_mode) 907 ) { 908 close(mailFd); 909 return; 910 } 911 ForkJob(user, line, mailFd, SENDMAIL, SENDMAIL_ARGS, NULL); 912} 913#else 914/* crond without sendmail */ 915 916static void RunJob(const char *user, CronLine * line) 917{ 918 /* Fork as the user in question and run program */ 919 pid_t pid = fork(); 920 921 if (pid == 0) { 922 /* CHILD */ 923 924 /* Change running state to the user in question */ 925 926 if (ChangeUser(user) < 0) { 927 exit(0); 928 } 929#if ENABLE_DEBUG_CROND_OPTION 930 if (DebugOpt) { 931 crondlog("\005Child Running %s\n", DEFAULT_SHELL); 932 } 933#endif 934 935 execl(DEFAULT_SHELL, DEFAULT_SHELL, "-c", line->cl_Shell, NULL); 936 crondlog("\024cannot exec, user %s cmd %s -c %s\n", user, 937 DEFAULT_SHELL, line->cl_Shell); 938 exit(0); 939 } else if (pid < 0) { 940 /* FORK FAILED */ 941 crondlog("\024cannot, user %s\n", user); 942 pid = 0; 943 } 944 line->cl_Pid = pid; 945} 946#endif /* ENABLE_FEATURE_CROND_CALL_SENDMAIL */ 947