/*
* MAIN.C
*
* crond [-s dir] [-c dir] [-t dir] [-m user@host] [-M mailer] [-S|-L [file]] [-l level] [-b|-f|-d]
* run as root, but NOT setuid root
*
* Copyright 1994 Matthew Dillon (dillon@apollo.backplane.com)
* Copyright 2009-2011 James Pryor <profjim@jimpryor.net>
* May be distributed under the GNU General Public License
*/
#include "defs.h"
Prototype short DebugOpt;
Prototype short LogLevel;
Prototype short ForegroundOpt;
Prototype short SyslogOpt;
Prototype const char *CDir;
Prototype const char *SCDir;
Prototype const char *TSDir;
Prototype const char *LogFile;
Prototype const char *LogHeader;
Prototype uid_t DaemonUid;
Prototype pid_t DaemonPid;
Prototype const char *SendMail;
Prototype const char *Mailto;
Prototype char *TempDir;
Prototype char *TempFileFmt;
short DebugOpt = 0;
short LogLevel = LOG_LEVEL;
short ForegroundOpt = 0;
short SyslogOpt = 1;
const char *CDir = CRONTABS;
const char *SCDir = SCRONTABS;
const char *TSDir = CRONSTAMPS;
const char *LogFile = NULL; /* opened with mode 0600 */
const char *LogHeader = LOGHEADER;
const char *SendMail = NULL;
const char *Mailto = NULL;
char *TempDir;
char *TempFileFmt;
uid_t DaemonUid;
pid_t DaemonPid;
int
main(int ac, char **av)
{
const char *LevelAry[] = {
"emerg",
"alert",
"crit",
"err",
"warning",
"notice",
"info",
"debug",
"panic",
"error",
"warn",
NULL
};
int i;
/*
* parse options
*/
DaemonUid = getuid();
opterr = 0;
while ((i = getopt(ac,av,"dl:L:fbSc:s:m:M:t:")) != -1) {
switch (i) {
case 'l':
{
char *ptr;
int j;
ptr = optarg;
for (j = 0; LevelAry[j]; ++j) {
if (strncmp(ptr, LevelAry[j], strlen(LevelAry[j])) == 0) {
break;
}
}
switch(j) {
case 0:
case 8:
/* #define LOG_EMERG 0 [* system is unusable *] */
LogLevel = LOG_EMERG;
break;
case 1:
/* #define LOG_ALERT 1 [* action must be taken immediately *] */
LogLevel = LOG_ALERT;
break;
case 2:
/* #define LOG_CRIT 2 [* critical conditions *] */
LogLevel = LOG_CRIT;
break;
case 3:
case 9:
/* #define LOG_ERR 3 [* error conditions *] */
LogLevel = LOG_ERR;
break;
case 4:
case 10:
/* #define LOG_WARNING 4 [* warning conditions *] */
LogLevel = LOG_WARNING;
break;
case 5:
/* #define LOG_NOTICE 5 [* normal but significant condition *] */
LogLevel = LOG_NOTICE;
break;
case 6:
/* #define LOG_INFO 6 [* informational *] */
LogLevel = LOG_INFO;
break;
case 7:
/* #define LOG_DEBUG 7 [* debug-level messages *] */
LogLevel = LOG_DEBUG;
break;
default:
LogLevel = atoi(optarg);
}
}
break;
case 'd':
DebugOpt = 1;
LogLevel = LOG_DEBUG;
/* fall through to include f too */
case 'f':
ForegroundOpt = 1;
break;
case 'b':
ForegroundOpt = 0;
break;
case 'S': /* log through syslog */
SyslogOpt = 1;
break;
case 'L': /* use internal log formatter */
SyslogOpt = 0;
LogFile = optarg;
/* if LC_TIME is defined, we use it for logging to file instead of compiled-in TIMESTAMP_FMT */
if (getenv("LC_TIME") != NULL) {
LogHeader = LOCALE_LOGHEADER;
}
break;
case 'c':
if (*optarg != 0) CDir = optarg;
break;
case 's':
if (*optarg != 0) SCDir = optarg;
break;
case 't':
if (*optarg != 0) TSDir = optarg;
break;
case 'M':
if (*optarg != 0) SendMail = optarg;
break;
case 'm':
if (*optarg != 0) Mailto = optarg;
break;
default:
/*
* check for parse error
*/
printf("dillon's cron daemon " VERSION "\n");
printf("crond [-s dir] [-c dir] [-t dir] [-m user@host] [-M mailer] [-S|-L [file]] [-l level] [-b|-f|-d]\n");
printf("-s directory of system crontabs (defaults to %s)\n", SCRONTABS);
printf("-c directory of per-user crontabs (defaults to %s)\n", CRONTABS);
printf("-t directory of timestamps (defaults to %s)\n", CRONSTAMPS);
printf("-m user@host where should cron output be directed? (defaults to local user)\n");
printf("-M mailer (defaults to %s)\n", SENDMAIL);
printf("-S log to syslog using identity '%s' (default)\n", LOG_IDENT);
printf("-L file log to specified file instead of syslog\n");
printf("-l loglevel log events <= this level (defaults to %s (level %d))\n", LevelAry[LOG_LEVEL], LOG_LEVEL);
printf("-b run in background (default)\n");
printf("-f run in foreground\n");
printf("-d run in debugging mode\n");
exit(2);
}
}
/*
* close stdin and stdout.
* close unused descriptors - don't need.
* optional detach from controlling terminal
*/
fclose(stdin);
fclose(stdout);
i = open("/dev/null", O_RDWR);
if (i < 0) {
perror("open: /dev/null");
exit(1);
}
dup2(i, 0);
dup2(i, 1);
/* create tempdir with permissions 0755 for cron output */
TempDir = strdup(TMPDIR "/cron.XXXXXX");
if (mkdtemp(TempDir) == NULL) {
perror("mkdtemp");
exit(1);
}
if (chmod(TempDir, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH)) {
perror("chmod");
exit(1);
}
if (!(TempFileFmt = concat(TempDir, "/cron.%s.%d", NULL))) {
errno = ENOMEM;
perror("main");
exit(1);
}
if (ForegroundOpt == 0) {
int fd;
int pid;
if ((pid = fork()) < 0) {
/* fork failed */
perror("fork");
exit(1);
} else if (pid > 0) {
/* parent */
exit(0);
}
/* child continues */
/* become session leader, detach from terminal */
if (setsid() < 0)
perror("setsid");
if ((fd = open("/dev/tty", O_RDWR)) >= 0) {
ioctl(fd, TIOCNOTTY, 0);
close(fd);
}
/* setup logging for backgrounded daemons */
if (SyslogOpt) {
/* start SIGHUP and SIGCHLD handling while stderr still open */
initsignals();
/* 2> /dev/null */
fclose(stderr);
dup2(1, 2);
/* open syslog */
openlog(LOG_IDENT, LOG_CONS|LOG_PID, LOG_CRON);
} else {
/* open logfile */
if ((fd = open(LogFile, O_WRONLY|O_CREAT|O_APPEND, 0600)) >= 0) {
/* start SIGHUP ignoring, SIGCHLD handling while stderr still open */
initsignals();
/* 2> LogFile */
fclose(stderr);
dup2(fd, 2);
} else {
int n = errno;
fdprintf(2, "failed to open logfile '%s', reason: %s", LogFile, strerror(n));
exit(n);
}
}
} else {
/* daemon in foreground */
/* stay in existing session, but start a new process group */
if (setpgid(0,0)) {
perror("setpgid");
exit(1);
}
/* stderr stays open, start SIGHUP ignoring, SIGCHLD handling */
initsignals();
}
/* close all other fds, including the ones we opened as /dev/null and LogFile */
for (i = 3; i < MAXOPEN; ++i) {
close(i);
}
/*
* main loop - synchronize to 1 second after the minute, minimum sleep
* of 1 second.
*/
printlogf(LOG_NOTICE,"%s " VERSION " dillon's cron daemon, started with loglevel %s\n", av[0], LevelAry[LogLevel]);
SynchronizeDir(CDir, NULL, 1);
SynchronizeDir(SCDir, "root", 1);
ReadTimestamps(NULL);
TestStartupJobs(); /* @startup jobs only run when crond is started, not when their crontab is loaded */
{
time_t t1 = time(NULL);
time_t t2;
long dt;
short rescan = 60;
short stime = 60;
for (;;) {
sleep((stime + 1) - (short)(time(NULL) % stime));
t2 = time(NULL);
dt = t2 - t1;
/*
* The file 'cron.update' is checked to determine new cron
* jobs. The directory is rescanned once an hour to deal
* with any screwups.
*
* check for disparity. Disparities over an hour either way
* result in resynchronization. A reverse-indexed disparity
* less then an hour causes us to effectively sleep until we
* match the original time (i.e. no re-execution of jobs that
* have just been run). A forward-indexed disparity less then
* an hour causes intermediate jobs to be run, but only once
* in the worst case.
*
* when running jobs, the inequality used is greater but not
* equal to t1, and less then or equal to t2.
*/
if (--rescan == 0) {
/*
* If we resynchronize while jobs are running, we'll clobber
* the job pids, so we won't know what's already running.
*/
if (CheckJobs() > 0) {
rescan = 1;
} else {
rescan = 60;
SynchronizeDir(CDir, NULL, 0);
SynchronizeDir(SCDir, "root", 0);
ReadTimestamps(NULL);
}
}
if (rescan < 60) {
CheckUpdates(CDir, NULL, t1, t2);
CheckUpdates(SCDir, "root", t1, t2);
}
if (DebugOpt)
printlogf(LOG_DEBUG, "Wakeup dt=%d\n", dt);
if (dt < -60*60 || dt > 60*60) {
t1 = t2;
printlogf(LOG_NOTICE,"time disparity of %d minutes detected\n", dt / 60);
} else if (dt > 0) {
TestJobs(t1, t2);
RunJobs();
sleep(5);
if (CheckJobs() > 0)
stime = 10;
else
stime = 60;
t1 = t2;
}
}
}
/* not reached */
}
Radix cross Linux
The main Radix cross Linux repository contains the build scripts of packages, which have the most complete and common functionality for desktop machines
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