1 /* vi: set sw=4 ts=4: */
3 * run as root, but NOT setuid root
5 * Copyright 1994 Matthew Dillon (dillon@apollo.west.oic.com)
7 * Vladimir Oleynik <dzo@simtreas.ru> (C) 2002
9 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
12 //config: bool "crond (13 kb)"
14 //config: select FEATURE_SYSLOG
16 //config: Crond is a background daemon that parses individual crontab
17 //config: files and executes commands on behalf of the users in question.
18 //config: This is a port of dcron from slackware. It uses files of the
19 //config: format /var/spool/cron/crontabs/<username> files, for example:
20 //config: $ cat /var/spool/cron/crontabs/root
21 //config: # Run daily cron jobs at 4:40 every day:
22 //config: 40 4 * * * /etc/cron/daily > /dev/null 2>&1
24 //config:config FEATURE_CROND_D
25 //config: bool "Support -d (redirect output to stderr)"
26 //config: depends on CROND
29 //config: -d N sets loglevel (0:most verbose) and directs all output to stderr.
31 //config:config FEATURE_CROND_CALL_SENDMAIL
32 //config: bool "Report command output via email (using sendmail)"
34 //config: depends on CROND
36 //config: Command output will be sent to corresponding user via email.
38 //config:config FEATURE_CROND_SPECIAL_TIMES
39 //config: bool "Support special times (@reboot, @daily, etc) in crontabs"
41 //config: depends on CROND
43 //config: string meaning
44 //config: ------ -------
45 //config: @reboot Run once, at startup
46 //config: @yearly Run once a year: "0 0 1 1 *"
47 //config: @annually Same as @yearly: "0 0 1 1 *"
48 //config: @monthly Run once a month: "0 0 1 * *"
49 //config: @weekly Run once a week: "0 0 * * 0"
50 //config: @daily Run once a day: "0 0 * * *"
51 //config: @midnight Same as @daily: "0 0 * * *"
52 //config: @hourly Run once an hour: "0 * * * *"
54 //config:config FEATURE_CROND_DIR
55 //config: string "crond spool directory"
56 //config: default "/var/spool/cron"
57 //config: depends on CROND || CRONTAB
59 //config: Location of crond spool.
61 //applet:IF_CROND(APPLET(crond, BB_DIR_USR_SBIN, BB_SUID_DROP))
63 //kbuild:lib-$(CONFIG_CROND) += crond.o
65 //usage:#define crond_trivial_usage
66 //usage: "-fbS -l N " IF_FEATURE_CROND_D("-d N ") "-L LOGFILE -c DIR"
67 //usage:#define crond_full_usage "\n\n"
68 //usage: " -f Foreground"
69 //usage: "\n -b Background (default)"
70 //usage: "\n -S Log to syslog (default)"
71 //usage: "\n -l N Set log level. Most verbose 0, default 8"
72 //usage: IF_FEATURE_CROND_D(
73 //usage: "\n -d N Set log level, log to stderr"
75 //usage: "\n -L FILE Log to FILE"
76 //usage: "\n -c DIR Cron dir. Default:"CONFIG_FEATURE_CROND_DIR"/crontabs"
79 #include "common_bufsiz.h"
83 /* If libc tracks and reuses setenv()-allocated memory, ok to set this to 0 */
84 /* Neither glibc nor uclibc do that! */
85 # define SETENV_LEAKS 0
87 # define SETENV_LEAKS 1
91 #define CRON_DIR CONFIG_FEATURE_CROND_DIR
92 #define CRONTABS CONFIG_FEATURE_CROND_DIR "/crontabs"
93 #define CRON_REBOOT CONFIG_PID_FILE_PATH "/crond.reboot"
95 # define SENDMAIL "sendmail"
98 # define SENDMAIL_ARGS "-ti"
101 # define CRONUPDATE "cron.update"
104 # define MAXLINES 256 /* max lines in non-root crontabs */
108 typedef struct CronFile {
109 struct CronFile *cf_next;
110 struct CronLine *cf_lines;
112 smallint cf_wants_starting; /* bool: one or more jobs ready */
113 smallint cf_has_running; /* bool: one or more jobs running */
114 smallint cf_deleted; /* marked for deletion (but still has running jobs) */
117 typedef struct CronLine {
118 struct CronLine *cl_next;
119 char *cl_cmd; /* shell command */
120 pid_t cl_pid; /* >0:running, <0:needs to be started in this minute, 0:dormant */
121 #define START_ME_REBOOT -2
122 #define START_ME_NORMAL -1
123 #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
124 int cl_empty_mail_size; /* size of mail header only, 0 if no mailfile */
125 char *cl_mailto; /* whom to mail results, may be NULL */
128 /* ordered by size, not in natural order. makes code smaller: */
129 char cl_Dow[7]; /* 0-6, beginning sunday */
130 char cl_Mons[12]; /* 0-11 */
131 char cl_Hrs[24]; /* 0-23 */
132 char cl_Days[32]; /* 1-31 */
133 char cl_Mins[60]; /* 0-59 */
147 OPT_d = (1 << 6) * ENABLE_FEATURE_CROND_D,
151 unsigned log_level; /* = 8; */
152 time_t crontab_dir_mtime;
153 const char *log_filename;
154 const char *crontab_dir_name; /* = CRONTABS; */
155 CronFile *cron_files;
161 char *env_var_logname;
164 #define G (*(struct globals*)bb_common_bufsiz1)
165 #define INIT_G() do { \
166 setup_common_bufsiz(); \
168 G.crontab_dir_name = CRONTABS; \
172 * 0 is the most verbose, default 8.
173 * For some reason, in fact only 5, 7 and 8 are used.
175 static void crondlog(unsigned level, const char *msg, va_list va)
177 if (level >= G.log_level) {
179 * We are called only for info meesages.
180 * Warnings/errors use plain bb_[p]error_msg's, which
181 * need not touch syslog_level
182 * (they are ok with LOG_ERR default).
184 syslog_level = LOG_INFO;
185 bb_verror_msg(msg, va, /* strerr: */ NULL);
186 syslog_level = LOG_ERR;
190 static void log5(const char *msg, ...)
194 crondlog(4, msg, va);
198 static void log7(const char *msg, ...)
202 crondlog(7, msg, va);
206 static void log8(const char *msg, ...)
210 crondlog(8, msg, va);
215 static const char DowAry[] ALIGN1 =
216 "sun""mon""tue""wed""thu""fri""sat"
219 static const char MonAry[] ALIGN1 =
220 "jan""feb""mar""apr""may""jun""jul""aug""sep""oct""nov""dec"
223 static void ParseField(char *user, char *ary, int modvalue, int off,
224 const char *names, char *ptr)
225 /* 'names' is a pointer to a set of 3-char abbreviations */
231 // this can't happen due to config_read()
238 /* Handle numeric digit or symbol or '*' */
240 n1 = 0; /* everything will be filled */
244 } else if (isdigit(*ptr)) {
247 n1 = strtol(ptr, &endp, 10) + off;
249 n2 = strtol(ptr, &endp, 10) + off;
251 ptr = endp; /* gcc likes temp var for &endp */
256 for (i = 0; names[i]; i += 3) {
257 /* was using strncmp before... */
258 if (strncasecmp(ptr, &names[i], 3) == 0) {
271 /* handle optional range '-' */
275 if (*ptr == '-' && n2 < 0) {
281 * collapse single-value ranges, handle skipmark, and fill
282 * in the character array appropriately.
289 skip = strtol(ptr + 1, &endp, 10);
290 ptr = endp; /* gcc likes temp var for &endp */
294 * fill array, using a failsafe is the easiest way to prevent
303 n1 = (n1 + 1) % modvalue;
306 ary[n1 % modvalue] = 1;
309 if (--failsafe == 0) {
324 bb_error_msg("user %s: parse error at %s", user, base);
328 /* can't use log5 (it inserts newlines), open-coding it */
329 if (G.log_level <= 5 && logmode != LOGMODE_SYSLOG) {
331 for (i = 0; i < modvalue; ++i)
332 fprintf(stderr, "%d", (unsigned char)ary[i]);
333 bb_putchar_stderr('\n');
337 static void FixDayDow(CronLine *line)
343 for (i = 0; i < ARRAY_SIZE(line->cl_Dow); ++i) {
344 if (line->cl_Dow[i] == 0) {
349 for (i = 0; i < ARRAY_SIZE(line->cl_Days); ++i) {
350 if (line->cl_Days[i] == 0) {
355 if (weekUsed != daysUsed) {
357 memset(line->cl_Days, 0, sizeof(line->cl_Days));
359 memset(line->cl_Dow, 0, sizeof(line->cl_Dow));
364 * delete_cronfile() - delete user database
366 * Note: multiple entries for same user may exist if we were unable to
367 * completely delete a database due to running processes.
369 //FIXME: we will start a new job even if the old job is running
370 //if crontab was reloaded: crond thinks that "new" job is different from "old"
371 //even if they are in fact completely the same. Example
374 // 0-59 * * * * long_running_job2
375 //User edits crontab to:
376 // 0-59 * * * * job1_updated
377 // 0-59 * * * * long_running_job2
378 //Bug: crond can now start another long_running_job2 even if old one
380 //OTOH most other versions of cron do not wait for job termination anyway,
381 //they end up with multiple copies of jobs if they don't terminate soon enough.
382 static void delete_cronfile(const char *userName)
384 CronFile **pfile = &G.cron_files;
387 while ((file = *pfile) != NULL) {
388 if (strcmp(userName, file->cf_username) == 0) {
389 CronLine **pline = &file->cf_lines;
392 file->cf_has_running = 0;
393 file->cf_deleted = 1;
395 while ((line = *pline) != NULL) {
396 if (line->cl_pid > 0) {
397 file->cf_has_running = 1;
398 pline = &line->cl_next;
400 *pline = line->cl_next;
405 if (file->cf_has_running == 0) {
406 *pfile = file->cf_next;
407 free(file->cf_username);
412 pfile = &file->cf_next;
416 static void load_crontab(const char *fileName)
418 struct parser_t *parser;
422 #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
427 delete_cronfile(fileName);
429 if (!getpwnam(fileName)) {
430 log7("ignoring file '%s' (no such user)", fileName);
434 parser = config_open(fileName);
438 maxLines = (strcmp(fileName, "root") == 0) ? 65535 : MAXLINES;
440 if (fstat(fileno(parser->fp), &sbuf) == 0 && sbuf.st_uid == DAEMON_UID) {
441 CronFile *file = xzalloc(sizeof(CronFile));
445 file->cf_username = xstrdup(fileName);
446 pline = &file->cf_lines;
452 bb_error_msg("user %s: too many lines", fileName);
456 n = config_read(parser, tokens, 6, 1, "# \t", PARSE_NORMAL | PARSE_KEEP_COPY);
460 log5("user:%s entry:%s", fileName, parser->data);
462 /* check if line is setting MAILTO= */
463 if (is_prefixed_with(tokens[0], "MAILTO=")) {
464 #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
466 mailTo = (tokens[0][7]) ? xstrdup(&tokens[0][7]) : NULL;
467 #endif /* otherwise just ignore such lines */
470 if (is_prefixed_with(tokens[0], "SHELL=")) {
472 shell = xstrdup(&tokens[0][6]);
475 //TODO: handle HOME= too? "man crontab" says:
478 //where the spaces around the equal-sign (=) are optional, and any subsequent
479 //non-leading spaces in value will be part of the value assigned to name.
480 //The value string may be placed in quotes (single or double, but matching)
481 //to preserve leading or trailing blanks.
483 //Several environment variables are set up automatically by the cron(8) daemon.
484 //SHELL is set to /bin/sh, and LOGNAME and HOME are set from the /etc/passwd
485 //line of the crontab's owner. HOME and SHELL may be overridden by settings
486 //in the crontab; LOGNAME may not.
488 #if ENABLE_FEATURE_CROND_SPECIAL_TIMES
489 if (tokens[0][0] == '@') {
491 * "@daily /a/script/to/run PARAM1 PARAM2..."
493 typedef struct SpecialEntry {
495 const char tokens[8];
497 static const SpecialEntry SpecAry[] = {
498 /* hour day month weekday */
499 { "yearly", "0\0" "1\0" "1\0" "*" },
500 { "annually", "0\0" "1\0" "1\0" "*" },
501 { "monthly", "0\0" "1\0" "*\0" "*" },
502 { "weekly", "0\0" "*\0" "*\0" "0" },
503 { "daily", "0\0" "*\0" "*\0" "*" },
504 { "midnight", "0\0" "*\0" "*\0" "*" },
505 { "hourly", "*\0" "*\0" "*\0" "*" },
508 const SpecialEntry *e = SpecAry;
513 if (strcmp(e->name, tokens[0] + 1) == 0) {
515 * tokens[1] is only the first word of command,
517 * find the entire command in unmodified string:
519 tokens[5] = skip_whitespace(
521 skip_whitespace(parser->data)));
523 char *et = (char*)e->tokens;
524 /* minute is "0" for all specials */
525 tokens[0] = (char*)"0";
537 continue; /* bad line (unrecognized '@foo') */
540 /* check if a minimum of tokens is specified */
543 IF_FEATURE_CROND_SPECIAL_TIMES(
546 *pline = line = xzalloc(sizeof(*line));
547 #if ENABLE_FEATURE_CROND_SPECIAL_TIMES
548 if (tokens[0][0] == '@') { /* "@reboot" line */
549 file->cf_wants_starting = 1;
550 line->cl_pid = START_ME_REBOOT; /* wants to start */
551 /* line->cl_Mins/Hrs/etc stay zero: never match any time */
555 /* parse date ranges */
556 ParseField(file->cf_username, line->cl_Mins, 60, 0, NULL, tokens[0]);
557 ParseField(file->cf_username, line->cl_Hrs, 24, 0, NULL, tokens[1]);
558 ParseField(file->cf_username, line->cl_Days, 32, 0, NULL, tokens[2]);
559 ParseField(file->cf_username, line->cl_Mons, 12, -1, MonAry, tokens[3]);
560 ParseField(file->cf_username, line->cl_Dow, 7, 0, DowAry, tokens[4]);
562 * fix days and dow - if one is not "*" and the other
563 * is "*", the other is set to 0, and vise-versa
567 #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
568 /* copy mailto (can be NULL) */
569 line->cl_mailto = xstrdup(mailTo);
571 line->cl_shell = xstrdup(shell);
573 line->cl_cmd = xstrdup(tokens[5]);
574 pline = &line->cl_next;
575 //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]);
579 file->cf_next = G.cron_files;
582 config_close(parser);
583 #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
589 static void process_cron_update_file(void)
594 fi = fopen_for_read(CRONUPDATE);
597 while (fgets(buf, sizeof(buf), fi) != NULL) {
598 /* use first word only */
599 skip_non_whitespace(buf)[0] = '\0';
606 static void rescan_crontab_dir(void)
610 /* Delete all files until we only have ones with running jobs (or none) */
612 for (file = G.cron_files; file; file = file->cf_next) {
613 if (!file->cf_deleted) {
614 delete_cronfile(file->cf_username);
619 /* Remove cron update file */
621 /* Re-chdir, in case directory was renamed & deleted */
622 xchdir(G.crontab_dir_name);
624 /* Scan directory and add associated users */
626 DIR *dir = opendir(".");
629 /* xopendir exists, but "can't open '.'" is not informative */
631 bb_error_msg_and_die("can't open '%s'", G.crontab_dir_name);
632 while ((den = readdir(dir)) != NULL) {
633 if (strchr(den->d_name, '.') != NULL) {
636 load_crontab(den->d_name);
643 /* We set environment *before* vfork (because we want to use vfork),
644 * so we cannot use setenv() - repeated calls to setenv() may leak memory!
645 * Using putenv(), and freeing memory after unsetenv() won't leak */
646 static void safe_setenv(char **pvar_val, const char *var, const char *val)
648 char *var_val = *pvar_val;
651 bb_unsetenv_and_free(var_val);
653 *pvar_val = xasprintf("%s=%s", var, val);
658 static void set_env_vars(struct passwd *pas, const char *shell)
660 /* POSIX requires crond to set up at least HOME, LOGNAME, PATH, SHELL.
661 * We assume crond inherited suitable PATH.
664 safe_setenv(&G.env_var_logname, "LOGNAME", pas->pw_name);
665 safe_setenv(&G.env_var_user, "USER", pas->pw_name);
666 safe_setenv(&G.env_var_home, "HOME", pas->pw_dir);
667 safe_setenv(&G.env_var_shell, "SHELL", shell);
669 xsetenv("LOGNAME", pas->pw_name);
670 xsetenv("USER", pas->pw_name);
671 xsetenv("HOME", pas->pw_dir);
672 xsetenv("SHELL", shell);
676 static void change_user(struct passwd *pas)
678 /* careful: we're after vfork! */
679 change_identity(pas); /* - initgroups, setgid, setuid */
680 if (chdir(pas->pw_dir) < 0) {
681 bb_error_msg("can't change directory to '%s'", pas->pw_dir);
686 // TODO: sendmail should be _run-time_ option, not compile-time!
687 #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
690 fork_job(const char *user, int mailFd, CronLine *line, bool run_sendmail)
693 const char *shell, *prog;
697 /* prepare things before vfork */
698 pas = getpwnam(user);
700 bb_error_msg("can't get uid for %s", user);
704 shell = line->cl_shell ? line->cl_shell : G.default_shell;
705 prog = run_sendmail ? SENDMAIL : shell;
707 set_env_vars(pas, shell);
709 sv_logmode = logmode;
713 /* initgroups, setgid, setuid, and chdir to home or CRON_DIR */
715 log5("child running %s", prog);
717 xmove_fd(mailFd, run_sendmail ? 0 : 1);
720 /* crond 3.0pl1-100 puts tasks in separate process groups */
723 execlp(prog, prog, "-c", line->cl_cmd, (char *) NULL);
725 execlp(prog, prog, SENDMAIL_ARGS, (char *) NULL);
727 * I want this error message on stderr too,
728 * even if other messages go only to syslog:
730 logmode |= LOGMODE_STDIO;
731 bb_error_msg_and_die("can't execute '%s' for user %s", prog, user);
733 logmode = sv_logmode;
736 bb_perror_msg("vfork");
739 } /* else: PARENT, FORK SUCCESS */
742 * Close the mail file descriptor.. we can't just leave it open in
743 * a structure, closing it later, because we might run out of descriptors
751 static pid_t start_one_job(const char *user, CronLine *line)
757 line->cl_empty_mail_size = 0;
759 if (line->cl_mailto) {
760 /* Open mail file (owner is root so nobody can screw with it) */
761 snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", CRON_DIR, user, getpid());
762 mailFd = open(mailFile, O_CREAT | O_TRUNC | O_WRONLY | O_EXCL | O_APPEND, 0600);
765 fdprintf(mailFd, "To: %s\nSubject: cron: %s\n\n", line->cl_mailto,
767 line->cl_empty_mail_size = lseek(mailFd, 0, SEEK_CUR);
769 bb_error_msg("can't create mail file %s for user %s, "
770 "discarding output", mailFile, user);
774 line->cl_pid = fork_job(user, mailFd, line, /*sendmail?*/ 0);
776 if (line->cl_pid <= 0) {
779 /* rename mail-file based on pid of process */
780 char *mailFile2 = xasprintf("%s/cron.%s.%d", CRON_DIR, user, (int)line->cl_pid);
781 rename(mailFile, mailFile2); // TODO: xrename?
790 * process_finished_job - called when job terminates and when mail terminates
792 static void process_finished_job(const char *user, CronLine *line)
805 if (line->cl_empty_mail_size <= 0) {
806 /* End of job and no mail file, or end of sendmail job */
811 * End of primary job - check for mail file.
812 * If size has changed and the file is still valid, we send it.
814 snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", CRON_DIR, user, (int)pid);
815 mailFd = open(mailFile, O_RDONLY);
821 if (fstat(mailFd, &sbuf) < 0
822 || sbuf.st_uid != DAEMON_UID
823 || sbuf.st_nlink != 0
824 || sbuf.st_size == line->cl_empty_mail_size
825 || !S_ISREG(sbuf.st_mode)
830 line->cl_empty_mail_size = 0;
831 /* if (line->cl_mailto) - always true if cl_empty_mail_size was nonzero */
832 line->cl_pid = fork_job(user, mailFd, line, /*sendmail?*/ 1);
835 #else /* !ENABLE_FEATURE_CROND_CALL_SENDMAIL */
837 static pid_t start_one_job(const char *user, CronLine *line)
843 pas = getpwnam(user);
845 bb_error_msg("can't get uid for %s", user);
849 /* Prepare things before vfork */
850 shell = line->cl_shell ? line->cl_shell : G.default_shell;
851 set_env_vars(pas, shell);
853 /* Fork as the user in question and run program */
857 /* initgroups, setgid, setuid, and chdir to home or CRON_DIR */
859 log5("child running %s", shell);
860 /* crond 3.0pl1-100 puts tasks in separate process groups */
862 execl(shell, shell, "-c", line->cl_cmd, (char *) NULL);
863 bb_error_msg_and_die("can't execute '%s' for user %s", shell, user);
866 bb_perror_msg("vfork");
874 #define process_finished_job(user, line) ((line)->cl_pid = 0)
876 #endif /* !ENABLE_FEATURE_CROND_CALL_SENDMAIL */
879 * Determine which jobs need to be run. Under normal conditions, the
880 * period is about a minute (one scan). Worst case it will be one
883 static void flag_starting_jobs(time_t t1, time_t t2)
887 /* Find jobs > t1 and <= t2 */
889 for (t = t1 - t1 % 60; t <= t2; t += 60) {
898 for (file = G.cron_files; file; file = file->cf_next) {
899 log5("file %s:", file->cf_username);
900 if (file->cf_deleted)
902 for (line = file->cf_lines; line; line = line->cl_next) {
903 log5(" line %s", line->cl_cmd);
904 if (line->cl_Mins[ptm->tm_min]
905 && line->cl_Hrs[ptm->tm_hour]
906 && (line->cl_Days[ptm->tm_mday] || line->cl_Dow[ptm->tm_wday])
907 && line->cl_Mons[ptm->tm_mon]
910 (int)line->cl_pid, line->cl_cmd);
911 if (line->cl_pid > 0) {
912 log8("user %s: process already running: %s",
913 file->cf_username, line->cl_cmd);
914 } else if (line->cl_pid == 0) {
915 line->cl_pid = START_ME_NORMAL;
916 file->cf_wants_starting = 1;
924 #if ENABLE_FEATURE_CROND_SPECIAL_TIMES
925 static int touch_reboot_file(void)
927 int fd = open(CRON_REBOOT, O_WRONLY | O_CREAT | O_EXCL | O_TRUNC, 0000);
932 /* File (presumably) exists - this is not the first run after reboot */
937 static void start_jobs(int wants_start)
942 for (file = G.cron_files; file; file = file->cf_next) {
943 if (!file->cf_wants_starting)
946 file->cf_wants_starting = 0;
947 for (line = file->cf_lines; line; line = line->cl_next) {
949 if (line->cl_pid != wants_start)
952 pid = start_one_job(file->cf_username, line);
953 log8("USER %s pid %3d cmd %s",
954 file->cf_username, (int)pid, line->cl_cmd);
956 file->cf_wants_starting = 1;
959 file->cf_has_running = 1;
966 * Check for job completion, return number of jobs still running after
969 static int check_completions(void)
973 int num_still_running = 0;
975 for (file = G.cron_files; file; file = file->cf_next) {
976 if (!file->cf_has_running)
979 file->cf_has_running = 0;
980 for (line = file->cf_lines; line; line = line->cl_next) {
983 if (line->cl_pid <= 0)
986 r = waitpid(line->cl_pid, NULL, WNOHANG);
987 if (r < 0 || r == line->cl_pid) {
988 process_finished_job(file->cf_username, line);
989 if (line->cl_pid == 0) {
990 /* sendmail was not started for it */
993 /* else: sendmail was started, job is still running, fall thru */
995 /* else: r == 0: "process is still running" */
996 file->cf_has_running = 1;
998 //FIXME: if !file->cf_has_running && file->deleted: delete it!
999 //otherwise deleted entries will stay forever, right?
1000 num_still_running += file->cf_has_running;
1002 return num_still_running;
1005 static void reopen_logfile_to_stderr(void)
1007 if (G.log_filename) {
1008 int logfd = open_or_warn(G.log_filename, O_WRONLY | O_CREAT | O_APPEND);
1010 xmove_fd(logfd, STDERR_FILENO);
1014 int crond_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1015 int crond_main(int argc UNUSED_PARAM, char **argv)
1019 unsigned sleep_time;
1024 opts = getopt32(argv, "^"
1025 "l:L:fbSc:" IF_FEATURE_CROND_D("d:")
1027 /* "-b after -f is ignored", and so on for every pair a-b */
1028 "f-b:b-f:S-L:L-S" IF_FEATURE_CROND_D(":d-l")
1029 /* -l and -d have numeric param */
1030 ":l+" IF_FEATURE_CROND_D(":d+")
1032 &G.log_level, &G.log_filename, &G.crontab_dir_name
1033 IF_FEATURE_CROND_D(,&G.log_level)
1035 /* both -d N and -l N set the same variable: G.log_level */
1037 if (!(opts & OPT_f)) {
1038 /* close stdin, stdout, stderr.
1039 * close unused descriptors - don't need them. */
1040 bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv);
1043 if (!(opts & OPT_d) && G.log_filename == NULL) {
1044 /* logging to syslog */
1045 openlog(applet_name, LOG_CONS | LOG_PID, LOG_CRON);
1046 logmode = LOGMODE_SYSLOG;
1049 //signal(SIGHUP, SIG_IGN); /* ? original crond dies on HUP... */
1051 reopen_logfile_to_stderr();
1052 xchdir(G.crontab_dir_name);
1053 /* $SHELL, or current UID's shell, or DEFAULT_SHELL */
1054 /* Useful on Android where DEFAULT_SHELL /bin/sh may not exist */
1055 G.default_shell = xstrdup(get_shell_name());
1057 log8("crond (busybox "BB_VER") started, log level %d", G.log_level);
1058 rescan_crontab_dir();
1059 write_pidfile(CONFIG_PID_FILE_PATH "/crond.pid");
1060 #if ENABLE_FEATURE_CROND_SPECIAL_TIMES
1061 if (touch_reboot_file())
1062 start_jobs(START_ME_REBOOT); /* start @reboot entries, if any */
1074 /* Synchronize to 1 minute, minimum 1 second */
1076 sleep(sleep_time - (time(NULL) % sleep_time));
1078 dt = (long)t2 - (long)t1;
1080 reopen_logfile_to_stderr();
1083 * The file 'cron.update' is checked to determine new cron
1084 * jobs. The directory is rescanned once an hour to deal
1085 * with any screwups.
1087 * Check for time jump. Disparities over an hour either way
1088 * result in resynchronization. A negative disparity
1089 * less than an hour causes us to effectively sleep until we
1090 * match the original time (i.e. no re-execution of jobs that
1091 * have just been run). A positive disparity less than
1092 * an hour causes intermediate jobs to be run, but only once
1093 * in the worst case.
1095 * When running jobs, the inequality used is greater but not
1096 * equal to t1, and less then or equal to t2.
1098 if (stat(G.crontab_dir_name, &sbuf) != 0)
1099 sbuf.st_mtime = 0; /* force update (once) if dir was deleted */
1100 if (G.crontab_dir_mtime != sbuf.st_mtime) {
1101 G.crontab_dir_mtime = sbuf.st_mtime;
1104 if (--rescan == 0) {
1106 rescan_crontab_dir();
1108 process_cron_update_file();
1109 log5("wakeup dt=%ld", dt);
1110 if (dt < -60 * 60 || dt > 60 * 60) {
1111 bb_error_msg("time disparity of %ld minutes detected", dt / 60);
1112 /* and we do not run any jobs in this case */
1113 } else if (dt > 0) {
1114 /* Usual case: time advances forward, as expected */
1115 flag_starting_jobs(t1, t2);
1116 start_jobs(START_ME_NORMAL);
1118 if (check_completions() > 0) {
1119 /* some jobs are still running */
1123 /* else: time jumped back, do not run any jobs */
1126 return 0; /* not reached */