source: MondoRescue/branches/3.2/mindi-busybox/miscutils/crond.c@ 3186

Last change on this file since 3186 was 2725, checked in by Bruno Cornec, 13 years ago
  • Update mindi-busybox to 1.18.3 to avoid problems with the tar command which is now failing on recent versions with busybox 1.7.3
File size: 22.9 KB
Line 
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 GPLv2 or later, see file LICENSE in this source tree.
12 */
13
14#include "libbb.h"
15#include <syslog.h>
16
17/* glibc frees previous setenv'ed value when we do next setenv()
18 * of the same variable. uclibc does not do this! */
19#if (defined(__GLIBC__) && !defined(__UCLIBC__)) /* || OTHER_SAFE_LIBC... */
20# define SETENV_LEAKS 0
21#else
22# define SETENV_LEAKS 1
23#endif
24
25
26#define TMPDIR CONFIG_FEATURE_CROND_DIR
27#define CRONTABS CONFIG_FEATURE_CROND_DIR "/crontabs"
28#ifndef SENDMAIL
29# define SENDMAIL "sendmail"
30#endif
31#ifndef SENDMAIL_ARGS
32# define SENDMAIL_ARGS "-ti"
33#endif
34#ifndef CRONUPDATE
35# define CRONUPDATE "cron.update"
36#endif
37#ifndef MAXLINES
38# define MAXLINES 256 /* max lines in non-root crontabs */
39#endif
40
41
42typedef struct CronFile {
43 struct CronFile *cf_next;
44 struct CronLine *cf_lines;
45 char *cf_username;
46 smallint cf_wants_starting; /* bool: one or more jobs ready */
47 smallint cf_has_running; /* bool: one or more jobs running */
48 smallint cf_deleted; /* marked for deletion (but still has running jobs) */
49} CronFile;
50
51typedef struct CronLine {
52 struct CronLine *cl_next;
53 char *cl_cmd; /* shell command */
54 pid_t cl_pid; /* >0:running, <0:needs to be started in this minute, 0:dormant */
55#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
56 int cl_empty_mail_size; /* size of mail header only, 0 if no mailfile */
57 char *cl_mailto; /* whom to mail results, may be NULL */
58#endif
59 /* ordered by size, not in natural order. makes code smaller: */
60 char cl_Dow[7]; /* 0-6, beginning sunday */
61 char cl_Mons[12]; /* 0-11 */
62 char cl_Hrs[24]; /* 0-23 */
63 char cl_Days[32]; /* 1-31 */
64 char cl_Mins[60]; /* 0-59 */
65} CronLine;
66
67
68#define DAEMON_UID 0
69
70
71enum {
72 OPT_l = (1 << 0),
73 OPT_L = (1 << 1),
74 OPT_f = (1 << 2),
75 OPT_b = (1 << 3),
76 OPT_S = (1 << 4),
77 OPT_c = (1 << 5),
78 OPT_d = (1 << 6) * ENABLE_FEATURE_CROND_D,
79};
80#if ENABLE_FEATURE_CROND_D
81# define DebugOpt (option_mask32 & OPT_d)
82#else
83# define DebugOpt 0
84#endif
85
86
87struct globals {
88 unsigned log_level; /* = 8; */
89 time_t crontab_dir_mtime;
90 const char *log_filename;
91 const char *crontab_dir_name; /* = CRONTABS; */
92 CronFile *cron_files;
93#if SETENV_LEAKS
94 char *env_var_user;
95 char *env_var_home;
96#endif
97} FIX_ALIASING;
98#define G (*(struct globals*)&bb_common_bufsiz1)
99#define INIT_G() do { \
100 G.log_level = 8; \
101 G.crontab_dir_name = CRONTABS; \
102} while (0)
103
104
105/* 0 is the most verbose, default 8 */
106#define LVL5 "\x05"
107#define LVL7 "\x07"
108#define LVL8 "\x08"
109#define WARN9 "\x49"
110#define DIE9 "\xc9"
111/* level >= 20 is "error" */
112#define ERR20 "\x14"
113
114static void crondlog(const char *ctl, ...) __attribute__ ((format (printf, 1, 2)));
115static void crondlog(const char *ctl, ...)
116{
117 va_list va;
118 int level = (ctl[0] & 0x1f);
119
120 va_start(va, ctl);
121 if (level >= (int)G.log_level) {
122 /* Debug mode: all to (non-redirected) stderr, */
123 /* Syslog mode: all to syslog (logmode = LOGMODE_SYSLOG), */
124 if (!DebugOpt && G.log_filename) {
125 /* Otherwise (log to file): we reopen log file at every write: */
126 int logfd = open_or_warn(G.log_filename, O_WRONLY | O_CREAT | O_APPEND);
127 if (logfd >= 0)
128 xmove_fd(logfd, STDERR_FILENO);
129 }
130 /* When we log to syslog, level > 8 is logged at LOG_ERR
131 * syslog level, level <= 8 is logged at LOG_INFO. */
132 if (level > 8) {
133 bb_verror_msg(ctl + 1, va, /* strerr: */ NULL);
134 } else {
135 char *msg = NULL;
136 vasprintf(&msg, ctl + 1, va);
137 bb_info_msg("%s: %s", applet_name, msg);
138 free(msg);
139 }
140 }
141 va_end(va);
142 if (ctl[0] & 0x80)
143 exit(20);
144}
145
146static const char DowAry[] ALIGN1 =
147 "sun""mon""tue""wed""thu""fri""sat"
148 /* "Sun""Mon""Tue""Wed""Thu""Fri""Sat" */
149;
150
151static const char MonAry[] ALIGN1 =
152 "jan""feb""mar""apr""may""jun""jul""aug""sep""oct""nov""dec"
153 /* "Jan""Feb""Mar""Apr""May""Jun""Jul""Aug""Sep""Oct""Nov""Dec" */
154;
155
156static void ParseField(char *user, char *ary, int modvalue, int off,
157 const char *names, char *ptr)
158/* 'names' is a pointer to a set of 3-char abbreviations */
159{
160 char *base = ptr;
161 int n1 = -1;
162 int n2 = -1;
163
164 // this can't happen due to config_read()
165 /*if (base == NULL)
166 return;*/
167
168 while (1) {
169 int skip = 0;
170
171 /* Handle numeric digit or symbol or '*' */
172 if (*ptr == '*') {
173 n1 = 0; /* everything will be filled */
174 n2 = modvalue - 1;
175 skip = 1;
176 ++ptr;
177 } else if (isdigit(*ptr)) {
178 char *endp;
179 if (n1 < 0) {
180 n1 = strtol(ptr, &endp, 10) + off;
181 } else {
182 n2 = strtol(ptr, &endp, 10) + off;
183 }
184 ptr = endp; /* gcc likes temp var for &endp */
185 skip = 1;
186 } else if (names) {
187 int i;
188
189 for (i = 0; names[i]; i += 3) {
190 /* was using strncmp before... */
191 if (strncasecmp(ptr, &names[i], 3) == 0) {
192 ptr += 3;
193 if (n1 < 0) {
194 n1 = i / 3;
195 } else {
196 n2 = i / 3;
197 }
198 skip = 1;
199 break;
200 }
201 }
202 }
203
204 /* handle optional range '-' */
205 if (skip == 0) {
206 goto err;
207 }
208 if (*ptr == '-' && n2 < 0) {
209 ++ptr;
210 continue;
211 }
212
213 /*
214 * collapse single-value ranges, handle skipmark, and fill
215 * in the character array appropriately.
216 */
217 if (n2 < 0) {
218 n2 = n1;
219 }
220 if (*ptr == '/') {
221 char *endp;
222 skip = strtol(ptr + 1, &endp, 10);
223 ptr = endp; /* gcc likes temp var for &endp */
224 }
225
226 /*
227 * fill array, using a failsafe is the easiest way to prevent
228 * an endless loop
229 */
230 {
231 int s0 = 1;
232 int failsafe = 1024;
233
234 --n1;
235 do {
236 n1 = (n1 + 1) % modvalue;
237
238 if (--s0 == 0) {
239 ary[n1 % modvalue] = 1;
240 s0 = skip;
241 }
242 if (--failsafe == 0) {
243 goto err;
244 }
245 } while (n1 != n2);
246 }
247 if (*ptr != ',') {
248 break;
249 }
250 ++ptr;
251 n1 = -1;
252 n2 = -1;
253 }
254
255 if (*ptr) {
256 err:
257 crondlog(WARN9 "user %s: parse error at %s", user, base);
258 return;
259 }
260
261 if (DebugOpt && (G.log_level <= 5)) { /* like LVL5 */
262 /* can't use crondlog, it inserts '\n' */
263 int i;
264 for (i = 0; i < modvalue; ++i)
265 fprintf(stderr, "%d", (unsigned char)ary[i]);
266 bb_putchar_stderr('\n');
267 }
268}
269
270static void FixDayDow(CronLine *line)
271{
272 unsigned i;
273 int weekUsed = 0;
274 int daysUsed = 0;
275
276 for (i = 0; i < ARRAY_SIZE(line->cl_Dow); ++i) {
277 if (line->cl_Dow[i] == 0) {
278 weekUsed = 1;
279 break;
280 }
281 }
282 for (i = 0; i < ARRAY_SIZE(line->cl_Days); ++i) {
283 if (line->cl_Days[i] == 0) {
284 daysUsed = 1;
285 break;
286 }
287 }
288 if (weekUsed != daysUsed) {
289 if (weekUsed)
290 memset(line->cl_Days, 0, sizeof(line->cl_Days));
291 else /* daysUsed */
292 memset(line->cl_Dow, 0, sizeof(line->cl_Dow));
293 }
294}
295
296/*
297 * delete_cronfile() - delete user database
298 *
299 * Note: multiple entries for same user may exist if we were unable to
300 * completely delete a database due to running processes.
301 */
302//FIXME: we will start a new job even if the old job is running
303//if crontab was reloaded: crond thinks that "new" job is different from "old"
304//even if they are in fact completely the same. Example
305//Crontab was:
306// 0-59 * * * * job1
307// 0-59 * * * * long_running_job2
308//User edits crontab to:
309// 0-59 * * * * job1_updated
310// 0-59 * * * * long_running_job2
311//Bug: crond can now start another long_running_job2 even if old one
312//is still running.
313//OTOH most other versions of cron do not wait for job termination anyway,
314//they end up with multiple copies of jobs if they don't terminate soon enough.
315static void delete_cronfile(const char *userName)
316{
317 CronFile **pfile = &G.cron_files;
318 CronFile *file;
319
320 while ((file = *pfile) != NULL) {
321 if (strcmp(userName, file->cf_username) == 0) {
322 CronLine **pline = &file->cf_lines;
323 CronLine *line;
324
325 file->cf_has_running = 0;
326 file->cf_deleted = 1;
327
328 while ((line = *pline) != NULL) {
329 if (line->cl_pid > 0) {
330 file->cf_has_running = 1;
331 pline = &line->cl_next;
332 } else {
333 *pline = line->cl_next;
334 free(line->cl_cmd);
335 free(line);
336 }
337 }
338 if (file->cf_has_running == 0) {
339 *pfile = file->cf_next;
340 free(file->cf_username);
341 free(file);
342 continue;
343 }
344 }
345 pfile = &file->cf_next;
346 }
347}
348
349static void load_crontab(const char *fileName)
350{
351 struct parser_t *parser;
352 struct stat sbuf;
353 int maxLines;
354 char *tokens[6];
355#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
356 char *mailTo = NULL;
357#endif
358
359 delete_cronfile(fileName);
360
361 if (!getpwnam(fileName)) {
362 crondlog(LVL7 "ignoring file '%s' (no such user)", fileName);
363 return;
364 }
365
366 parser = config_open(fileName);
367 if (!parser)
368 return;
369
370 maxLines = (strcmp(fileName, "root") == 0) ? 65535 : MAXLINES;
371
372 if (fstat(fileno(parser->fp), &sbuf) == 0 && sbuf.st_uid == DAEMON_UID) {
373 CronFile *file = xzalloc(sizeof(CronFile));
374 CronLine **pline;
375 int n;
376
377 file->cf_username = xstrdup(fileName);
378 pline = &file->cf_lines;
379
380 while (1) {
381 CronLine *line;
382
383 if (!--maxLines)
384 break;
385 n = config_read(parser, tokens, 6, 1, "# \t", PARSE_NORMAL | PARSE_KEEP_COPY);
386 if (!n)
387 break;
388
389 if (DebugOpt)
390 crondlog(LVL5 "user:%s entry:%s", fileName, parser->data);
391
392 /* check if line is setting MAILTO= */
393 if (0 == strncmp(tokens[0], "MAILTO=", 7)) {
394#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
395 free(mailTo);
396 mailTo = (tokens[0][7]) ? xstrdup(&tokens[0][7]) : NULL;
397#endif /* otherwise just ignore such lines */
398 continue;
399 }
400 /* check if a minimum of tokens is specified */
401 if (n < 6)
402 continue;
403 *pline = line = xzalloc(sizeof(*line));
404 /* parse date ranges */
405 ParseField(file->cf_username, line->cl_Mins, 60, 0, NULL, tokens[0]);
406 ParseField(file->cf_username, line->cl_Hrs, 24, 0, NULL, tokens[1]);
407 ParseField(file->cf_username, line->cl_Days, 32, 0, NULL, tokens[2]);
408 ParseField(file->cf_username, line->cl_Mons, 12, -1, MonAry, tokens[3]);
409 ParseField(file->cf_username, line->cl_Dow, 7, 0, DowAry, tokens[4]);
410 /*
411 * fix days and dow - if one is not "*" and the other
412 * is "*", the other is set to 0, and vise-versa
413 */
414 FixDayDow(line);
415#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
416 /* copy mailto (can be NULL) */
417 line->cl_mailto = xstrdup(mailTo);
418#endif
419 /* copy command */
420 line->cl_cmd = xstrdup(tokens[5]);
421 if (DebugOpt) {
422 crondlog(LVL5 " command:%s", tokens[5]);
423 }
424 pline = &line->cl_next;
425//bb_error_msg("M[%s]F[%s][%s][%s][%s][%s][%s]", mailTo, tokens[0], tokens[1], tokens[2], tokens[3], tokens[4], tokens[5]);
426 }
427 *pline = NULL;
428
429 file->cf_next = G.cron_files;
430 G.cron_files = file;
431
432 if (maxLines == 0) {
433 crondlog(WARN9 "user %s: too many lines", fileName);
434 }
435 }
436 config_close(parser);
437}
438
439static void process_cron_update_file(void)
440{
441 FILE *fi;
442 char buf[256];
443
444 fi = fopen_for_read(CRONUPDATE);
445 if (fi != NULL) {
446 unlink(CRONUPDATE);
447 while (fgets(buf, sizeof(buf), fi) != NULL) {
448 /* use first word only */
449 skip_non_whitespace(buf)[0] = '\0';
450 load_crontab(buf);
451 }
452 fclose(fi);
453 }
454}
455
456static void rescan_crontab_dir(void)
457{
458 CronFile *file;
459
460 /* Delete all files until we only have ones with running jobs (or none) */
461 again:
462 for (file = G.cron_files; file; file = file->cf_next) {
463 if (!file->cf_deleted) {
464 delete_cronfile(file->cf_username);
465 goto again;
466 }
467 }
468
469 /* Remove cron update file */
470 unlink(CRONUPDATE);
471 /* Re-chdir, in case directory was renamed & deleted */
472 if (chdir(G.crontab_dir_name) < 0) {
473 crondlog(DIE9 "chdir(%s)", G.crontab_dir_name);
474 }
475
476 /* Scan directory and add associated users */
477 {
478 DIR *dir = opendir(".");
479 struct dirent *den;
480
481 if (!dir)
482 crondlog(DIE9 "chdir(%s)", "."); /* exits */
483 while ((den = readdir(dir)) != NULL) {
484 if (strchr(den->d_name, '.') != NULL) {
485 continue;
486 }
487 load_crontab(den->d_name);
488 }
489 closedir(dir);
490 }
491}
492
493#if SETENV_LEAKS
494/* We set environment *before* vfork (because we want to use vfork),
495 * so we cannot use setenv() - repeated calls to setenv() may leak memory!
496 * Using putenv(), and freeing memory after unsetenv() won't leak */
497static void safe_setenv(char **pvar_val, const char *var, const char *val)
498{
499 char *var_val = *pvar_val;
500
501 if (var_val) {
502 bb_unsetenv_and_free(var_val);
503 }
504 *pvar_val = xasprintf("%s=%s", var, val);
505 putenv(*pvar_val);
506}
507#endif
508
509static void set_env_vars(struct passwd *pas)
510{
511#if SETENV_LEAKS
512 safe_setenv(&G.env_var_user, "USER", pas->pw_name);
513 safe_setenv(&G.env_var_home, "HOME", pas->pw_dir);
514 /* if we want to set user's shell instead: */
515 /*safe_setenv(G.env_var_shell, "SHELL", pas->pw_shell);*/
516#else
517 xsetenv("USER", pas->pw_name);
518 xsetenv("HOME", pas->pw_dir);
519#endif
520 /* currently, we use constant one: */
521 /*setenv("SHELL", DEFAULT_SHELL, 1); - done earlier */
522}
523
524static void change_user(struct passwd *pas)
525{
526 /* careful: we're after vfork! */
527 change_identity(pas); /* - initgroups, setgid, setuid */
528 if (chdir(pas->pw_dir) < 0) {
529 crondlog(WARN9 "chdir(%s)", pas->pw_dir);
530 if (chdir(TMPDIR) < 0) {
531 crondlog(DIE9 "chdir(%s)", TMPDIR); /* exits */
532 }
533 }
534}
535
536// TODO: sendmail should be _run-time_ option, not compile-time!
537#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
538
539static pid_t
540fork_job(const char *user, int mailFd,
541 const char *prog,
542 const char *shell_cmd /* if NULL, we run sendmail */
543) {
544 struct passwd *pas;
545 pid_t pid;
546
547 /* prepare things before vfork */
548 pas = getpwnam(user);
549 if (!pas) {
550 crondlog(WARN9 "can't get uid for %s", user);
551 goto err;
552 }
553 set_env_vars(pas);
554
555 pid = vfork();
556 if (pid == 0) {
557 /* CHILD */
558 /* initgroups, setgid, setuid, and chdir to home or TMPDIR */
559 change_user(pas);
560 if (DebugOpt) {
561 crondlog(LVL5 "child running %s", prog);
562 }
563 if (mailFd >= 0) {
564 xmove_fd(mailFd, shell_cmd ? 1 : 0);
565 dup2(1, 2);
566 }
567 /* crond 3.0pl1-100 puts tasks in separate process groups */
568 bb_setpgrp();
569 execlp(prog, prog, (shell_cmd ? "-c" : SENDMAIL_ARGS), shell_cmd, (char *) NULL);
570 crondlog(ERR20 "can't execute '%s' for user %s", prog, user);
571 if (shell_cmd) {
572 fdprintf(1, "Exec failed: %s -c %s\n", prog, shell_cmd);
573 }
574 _exit(EXIT_SUCCESS);
575 }
576
577 if (pid < 0) {
578 /* FORK FAILED */
579 crondlog(ERR20 "can't vfork");
580 err:
581 pid = 0;
582 } /* else: PARENT, FORK SUCCESS */
583
584 /*
585 * Close the mail file descriptor.. we can't just leave it open in
586 * a structure, closing it later, because we might run out of descriptors
587 */
588 if (mailFd >= 0) {
589 close(mailFd);
590 }
591 return pid;
592}
593
594static void start_one_job(const char *user, CronLine *line)
595{
596 char mailFile[128];
597 int mailFd = -1;
598
599 line->cl_pid = 0;
600 line->cl_empty_mail_size = 0;
601
602 if (line->cl_mailto) {
603 /* Open mail file (owner is root so nobody can screw with it) */
604 snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", TMPDIR, user, getpid());
605 mailFd = open(mailFile, O_CREAT | O_TRUNC | O_WRONLY | O_EXCL | O_APPEND, 0600);
606
607 if (mailFd >= 0) {
608 fdprintf(mailFd, "To: %s\nSubject: cron: %s\n\n", line->cl_mailto,
609 line->cl_cmd);
610 line->cl_empty_mail_size = lseek(mailFd, 0, SEEK_CUR);
611 } else {
612 crondlog(ERR20 "can't create mail file %s for user %s, "
613 "discarding output", mailFile, user);
614 }
615 }
616
617 line->cl_pid = fork_job(user, mailFd, DEFAULT_SHELL, line->cl_cmd);
618 if (mailFd >= 0) {
619 if (line->cl_pid <= 0) {
620 unlink(mailFile);
621 } else {
622 /* rename mail-file based on pid of process */
623 char *mailFile2 = xasprintf("%s/cron.%s.%d", TMPDIR, user, (int)line->cl_pid);
624 rename(mailFile, mailFile2); // TODO: xrename?
625 free(mailFile2);
626 }
627 }
628}
629
630/*
631 * process_finished_job - called when job terminates and when mail terminates
632 */
633static void process_finished_job(const char *user, CronLine *line)
634{
635 pid_t pid;
636 int mailFd;
637 char mailFile[128];
638 struct stat sbuf;
639
640 pid = line->cl_pid;
641 line->cl_pid = 0;
642 if (pid <= 0) {
643 /* No job */
644 return;
645 }
646 if (line->cl_empty_mail_size <= 0) {
647 /* End of job and no mail file, or end of sendmail job */
648 return;
649 }
650
651 /*
652 * End of primary job - check for mail file.
653 * If size has changed and the file is still valid, we send it.
654 */
655 snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", TMPDIR, user, (int)pid);
656 mailFd = open(mailFile, O_RDONLY);
657 unlink(mailFile);
658 if (mailFd < 0) {
659 return;
660 }
661
662 if (fstat(mailFd, &sbuf) < 0
663 || sbuf.st_uid != DAEMON_UID
664 || sbuf.st_nlink != 0
665 || sbuf.st_size == line->cl_empty_mail_size
666 || !S_ISREG(sbuf.st_mode)
667 ) {
668 close(mailFd);
669 return;
670 }
671 line->cl_empty_mail_size = 0;
672 /* if (line->cl_mailto) - always true if cl_empty_mail_size was nonzero */
673 line->cl_pid = fork_job(user, mailFd, SENDMAIL, NULL);
674}
675
676#else /* !ENABLE_FEATURE_CROND_CALL_SENDMAIL */
677
678static void start_one_job(const char *user, CronLine *line)
679{
680 struct passwd *pas;
681 pid_t pid;
682
683 pas = getpwnam(user);
684 if (!pas) {
685 crondlog(WARN9 "can't get uid for %s", user);
686 goto err;
687 }
688
689 /* Prepare things before vfork */
690 set_env_vars(pas);
691
692 /* Fork as the user in question and run program */
693 pid = vfork();
694 if (pid == 0) {
695 /* CHILD */
696 /* initgroups, setgid, setuid, and chdir to home or TMPDIR */
697 change_user(pas);
698 if (DebugOpt) {
699 crondlog(LVL5 "child running %s", DEFAULT_SHELL);
700 }
701 /* crond 3.0pl1-100 puts tasks in separate process groups */
702 bb_setpgrp();
703 execl(DEFAULT_SHELL, DEFAULT_SHELL, "-c", line->cl_cmd, (char *) NULL);
704 crondlog(ERR20 "can't execute '%s' for user %s", DEFAULT_SHELL, user);
705 _exit(EXIT_SUCCESS);
706 }
707 if (pid < 0) {
708 /* FORK FAILED */
709 crondlog(ERR20 "can't vfork");
710 err:
711 pid = 0;
712 }
713 line->cl_pid = pid;
714}
715
716#define process_finished_job(user, line) ((line)->cl_pid = 0)
717
718#endif /* !ENABLE_FEATURE_CROND_CALL_SENDMAIL */
719
720/*
721 * Determine which jobs need to be run. Under normal conditions, the
722 * period is about a minute (one scan). Worst case it will be one
723 * hour (60 scans).
724 */
725static void flag_starting_jobs(time_t t1, time_t t2)
726{
727 time_t t;
728
729 /* Find jobs > t1 and <= t2 */
730
731 for (t = t1 - t1 % 60; t <= t2; t += 60) {
732 struct tm *ptm;
733 CronFile *file;
734 CronLine *line;
735
736 if (t <= t1)
737 continue;
738
739 ptm = localtime(&t);
740 for (file = G.cron_files; file; file = file->cf_next) {
741 if (DebugOpt)
742 crondlog(LVL5 "file %s:", file->cf_username);
743 if (file->cf_deleted)
744 continue;
745 for (line = file->cf_lines; line; line = line->cl_next) {
746 if (DebugOpt)
747 crondlog(LVL5 " line %s", line->cl_cmd);
748 if (line->cl_Mins[ptm->tm_min]
749 && line->cl_Hrs[ptm->tm_hour]
750 && (line->cl_Days[ptm->tm_mday] || line->cl_Dow[ptm->tm_wday])
751 && line->cl_Mons[ptm->tm_mon]
752 ) {
753 if (DebugOpt) {
754 crondlog(LVL5 " job: %d %s",
755 (int)line->cl_pid, line->cl_cmd);
756 }
757 if (line->cl_pid > 0) {
758 crondlog(LVL8 "user %s: process already running: %s",
759 file->cf_username, line->cl_cmd);
760 } else if (line->cl_pid == 0) {
761 line->cl_pid = -1;
762 file->cf_wants_starting = 1;
763 }
764 }
765 }
766 }
767 }
768}
769
770static void start_jobs(void)
771{
772 CronFile *file;
773 CronLine *line;
774
775 for (file = G.cron_files; file; file = file->cf_next) {
776 if (!file->cf_wants_starting)
777 continue;
778
779 file->cf_wants_starting = 0;
780 for (line = file->cf_lines; line; line = line->cl_next) {
781 pid_t pid;
782 if (line->cl_pid >= 0)
783 continue;
784
785 start_one_job(file->cf_username, line);
786 pid = line->cl_pid;
787 crondlog(LVL8 "USER %s pid %3d cmd %s",
788 file->cf_username, (int)pid, line->cl_cmd);
789 if (pid < 0) {
790 file->cf_wants_starting = 1;
791 }
792 if (pid > 0) {
793 file->cf_has_running = 1;
794 }
795 }
796 }
797}
798
799/*
800 * Check for job completion, return number of jobs still running after
801 * all done.
802 */
803static int check_completions(void)
804{
805 CronFile *file;
806 CronLine *line;
807 int num_still_running = 0;
808
809 for (file = G.cron_files; file; file = file->cf_next) {
810 if (!file->cf_has_running)
811 continue;
812
813 file->cf_has_running = 0;
814 for (line = file->cf_lines; line; line = line->cl_next) {
815 int r;
816
817 if (line->cl_pid <= 0)
818 continue;
819
820 r = waitpid(line->cl_pid, NULL, WNOHANG);
821 if (r < 0 || r == line->cl_pid) {
822 process_finished_job(file->cf_username, line);
823 if (line->cl_pid == 0) {
824 /* sendmail was not started for it */
825 continue;
826 }
827 /* else: sendmail was started, job is still running, fall thru */
828 }
829 /* else: r == 0: "process is still running" */
830 file->cf_has_running = 1;
831 }
832//FIXME: if !file->cf_has_running && file->deleted: delete it!
833//otherwise deleted entries will stay forever, right?
834 num_still_running += file->cf_has_running;
835 }
836 return num_still_running;
837}
838
839int crond_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
840int crond_main(int argc UNUSED_PARAM, char **argv)
841{
842 time_t t2;
843 int rescan;
844 int sleep_time;
845 unsigned opts;
846
847 INIT_G();
848
849 /* "-b after -f is ignored", and so on for every pair a-b */
850 opt_complementary = "f-b:b-f:S-L:L-S" IF_FEATURE_CROND_D(":d-l")
851 ":l+:d+"; /* -l and -d have numeric param */
852 opts = getopt32(argv, "l:L:fbSc:" IF_FEATURE_CROND_D("d:"),
853 &G.log_level, &G.log_filename, &G.crontab_dir_name
854 IF_FEATURE_CROND_D(,&G.log_level));
855 /* both -d N and -l N set the same variable: G.log_level */
856
857 if (!(opts & OPT_f)) {
858 /* close stdin, stdout, stderr.
859 * close unused descriptors - don't need them. */
860 bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv);
861 }
862
863 if (!(opts & OPT_d) && G.log_filename == NULL) {
864 /* logging to syslog */
865 openlog(applet_name, LOG_CONS | LOG_PID, LOG_CRON);
866 logmode = LOGMODE_SYSLOG;
867 }
868
869 xchdir(G.crontab_dir_name);
870 //signal(SIGHUP, SIG_IGN); /* ? original crond dies on HUP... */
871 xsetenv("SHELL", DEFAULT_SHELL); /* once, for all future children */
872 crondlog(LVL8 "crond (busybox "BB_VER") started, log level %d", G.log_level);
873 rescan_crontab_dir();
874 write_pidfile("/var/run/crond.pid");
875
876 /* Main loop */
877 t2 = time(NULL);
878 rescan = 60;
879 sleep_time = 60;
880 for (;;) {
881 struct stat sbuf;
882 time_t t1;
883 long dt;
884
885 t1 = t2;
886
887 /* Synchronize to 1 minute, minimum 1 second */
888 sleep(sleep_time - (time(NULL) % sleep_time) + 1);
889
890 t2 = time(NULL);
891 dt = (long)t2 - (long)t1;
892
893 /*
894 * The file 'cron.update' is checked to determine new cron
895 * jobs. The directory is rescanned once an hour to deal
896 * with any screwups.
897 *
898 * Check for time jump. Disparities over an hour either way
899 * result in resynchronization. A negative disparity
900 * less than an hour causes us to effectively sleep until we
901 * match the original time (i.e. no re-execution of jobs that
902 * have just been run). A positive disparity less than
903 * an hour causes intermediate jobs to be run, but only once
904 * in the worst case.
905 *
906 * When running jobs, the inequality used is greater but not
907 * equal to t1, and less then or equal to t2.
908 */
909 if (stat(G.crontab_dir_name, &sbuf) != 0)
910 sbuf.st_mtime = 0; /* force update (once) if dir was deleted */
911 if (G.crontab_dir_mtime != sbuf.st_mtime) {
912 G.crontab_dir_mtime = sbuf.st_mtime;
913 rescan = 1;
914 }
915 if (--rescan == 0) {
916 rescan = 60;
917 rescan_crontab_dir();
918 }
919 process_cron_update_file();
920 if (DebugOpt)
921 crondlog(LVL5 "wakeup dt=%ld", dt);
922 if (dt < -60 * 60 || dt > 60 * 60) {
923 crondlog(WARN9 "time disparity of %ld minutes detected", dt / 60);
924 /* and we do not run any jobs in this case */
925 } else if (dt > 0) {
926 /* Usual case: time advances forward, as expected */
927 flag_starting_jobs(t1, t2);
928 start_jobs();
929 if (check_completions() > 0) {
930 /* some jobs are still running */
931 sleep_time = 10;
932 } else {
933 sleep_time = 60;
934 }
935 }
936 /* else: time jumped back, do not run any jobs */
937 } /* for (;;) */
938
939 return 0; /* not reached */
940}
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