You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

567 lines
9.9 KiB

/* See LICENSE file for copyright and license details. */
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <limits.h>
#include <signal.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <syslog.h>
#include <time.h>
#include <unistd.h>
#include "queue.h"
#include "util.h"
struct field {
enum {
ERROR,
WILDCARD,
NUMBER,
RANGE,
REPEAT,
LIST
} type;
long *val;
int len;
};
struct ctabentry {
struct field min;
struct field hour;
struct field mday;
struct field mon;
struct field wday;
char *cmd;
TAILQ_ENTRY(ctabentry) entry;
};
struct jobentry {
char *cmd;
pid_t pid;
TAILQ_ENTRY(jobentry) entry;
};
static sig_atomic_t chldreap;
static sig_atomic_t reload;
static sig_atomic_t quit;
static TAILQ_HEAD(, ctabentry) ctabhead = TAILQ_HEAD_INITIALIZER(ctabhead);
static TAILQ_HEAD(, jobentry) jobhead = TAILQ_HEAD_INITIALIZER(jobhead);
static char *config = "/etc/crontab";
static char *pidfile = "/var/run/crond.pid";
static int nflag;
static void
loginfo(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
if (nflag == 0)
vsyslog(LOG_INFO, fmt, ap);
else
vfprintf(stdout, fmt, ap);
fflush(stdout);
va_end(ap);
}
static void
logwarn(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
if (nflag == 0)
vsyslog(LOG_WARNING, fmt, ap);
else
vfprintf(stderr, fmt, ap);
va_end(ap);
}
static void
logerr(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
if (nflag == 0)
vsyslog(LOG_ERR, fmt, ap);
else
vfprintf(stderr, fmt, ap);
va_end(ap);
}
static void
runjob(char *cmd)
{
struct jobentry *je;
time_t t;
pid_t pid;
t = time(NULL);
/* If command is already running, skip it */
TAILQ_FOREACH(je, &jobhead, entry) {
if (strcmp(je->cmd, cmd) == 0) {
loginfo("already running %s pid: %d at %s",
je->cmd, je->pid, ctime(&t));
return;
}
}
switch ((pid = fork())) {
case -1:
logerr("error: failed to fork job: %s time: %s",
cmd, ctime(&t));
return;
case 0:
setsid();
loginfo("run: %s pid: %d at %s",
cmd, getpid(), ctime(&t));
execl("/bin/sh", "/bin/sh", "-c", cmd, (char *)NULL);
logerr("error: failed to execute job: %s time: %s",
cmd, ctime(&t));
_exit(1);
default:
je = emalloc(sizeof(*je));
je->cmd = estrdup(cmd);
je->pid = pid;
TAILQ_INSERT_TAIL(&jobhead, je, entry);
}
}
static void
waitjob(void)
{
struct jobentry *je, *tmp;
int status;
time_t t;
pid_t pid;
t = time(NULL);
while ((pid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
je = NULL;
TAILQ_FOREACH(tmp, &jobhead, entry) {
if (tmp->pid == pid) {
je = tmp;
break;
}
}
if (je) {
TAILQ_REMOVE(&jobhead, je, entry);
free(je->cmd);
free(je);
}
if (WIFEXITED(status) == 1)
loginfo("complete: pid: %d returned: %d time: %s",
pid, WEXITSTATUS(status), ctime(&t));
else if (WIFSIGNALED(status) == 1)
loginfo("complete: pid: %d terminated by signal: %s time: %s",
pid, strsignal(WTERMSIG(status)), ctime(&t));
else if (WIFSTOPPED(status) == 1)
loginfo("complete: pid: %d stopped by signal: %s time: %s",
pid, strsignal(WSTOPSIG(status)), ctime(&t));
}
}
static int
isleap(int year)
{
if (year % 400 == 0)
return 1;
if (year % 100 == 0)
return 0;
return (year % 4 == 0);
}
static int
daysinmon(int mon, int year)
{
int days[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
if (year < 1900)
year += 1900;
if (isleap(year))
days[1] = 29;
return days[mon];
}
static int
matchentry(struct ctabentry *cte, struct tm *tm)
{
struct {
struct field *f;
int tm;
int len;
} matchtbl[] = {
{ .f = &cte->min, .tm = tm->tm_min, .len = 60 },
{ .f = &cte->hour, .tm = tm->tm_hour, .len = 24 },
{ .f = &cte->mday, .tm = tm->tm_mday, .len = daysinmon(tm->tm_mon, tm->tm_year) },
{ .f = &cte->mon, .tm = tm->tm_mon, .len = 12 },
{ .f = &cte->wday, .tm = tm->tm_wday, .len = 7 },
};
size_t i;
int j;
for (i = 0; i < LEN(matchtbl); i++) {
switch (matchtbl[i].f->type) {
case WILDCARD:
continue;
case NUMBER:
if (matchtbl[i].f->val[0] == matchtbl[i].tm)
continue;
break;
case RANGE:
if (matchtbl[i].f->val[0] <= matchtbl[i].tm)
if (matchtbl[i].f->val[1] >= matchtbl[i].tm)
continue;
break;
case REPEAT:
if (matchtbl[i].tm > 0) {
if (matchtbl[i].tm % matchtbl[i].f->val[0] == 0)
continue;
} else {
if (matchtbl[i].len % matchtbl[i].f->val[0] == 0)
continue;
}
break;
case LIST:
for (j = 0; j < matchtbl[i].f->len; j++)
if (matchtbl[i].f->val[j] == matchtbl[i].tm)
break;
if (j < matchtbl[i].f->len)
continue;
break;
default:
break;
}
break;
}
if (i != LEN(matchtbl))
return 0;
return 1;
}
static int
parsefield(const char *field, long low, long high, struct field *f)
{
int i;
char *e1, *e2;
const char *p;
p = field;
while (isdigit(*p))
p++;
f->type = ERROR;
switch (*p) {
case '*':
if (strcmp(field, "*") == 0) {
f->val = NULL;
f->len = 0;
f->type = WILDCARD;
} else if (strncmp(field, "*/", 2) == 0) {
f->val = emalloc(sizeof(*f->val));
f->len = 1;
errno = 0;
f->val[0] = strtol(field + 2, &e1, 10);
if (e1[0] != '\0' || errno != 0 || f->val[0] == 0)
break;
f->type = REPEAT;
}
break;
case '\0':
f->val = emalloc(sizeof(*f->val));
f->len = 1;
errno = 0;
f->val[0] = strtol(field, &e1, 10);
if (e1[0] != '\0' || errno != 0)
break;
f->type = NUMBER;
break;
case '-':
f->val = emalloc(2 * sizeof(*f->val));
f->len = 2;
errno = 0;
f->val[0] = strtol(field, &e1, 10);
if (e1[0] != '-' || errno != 0)
break;
errno = 0;
f->val[1] = strtol(e1 + 1, &e2, 10);
if (e2[0] != '\0' || errno != 0)
break;
f->type = RANGE;
break;
case ',':
for (i = 1; isdigit(*p) || *p == ','; p++)
if (*p == ',')
i++;
f->val = emalloc(i * sizeof(*f->val));
f->len = i;
errno = 0;
f->val[0] = strtol(field, &e1, 10);
if (f->val[0] < low || f->val[0] > high)
break;
for (i = 1; *e1 == ',' && errno == 0; i++) {
errno = 0;
f->val[i] = strtol(e1 + 1, &e2, 10);
e1 = e2;
}
if (e1[0] != '\0' || errno != 0)
break;
f->type = LIST;
break;
default:
return -1;
}
for (i = 0; i < f->len; i++)
if (f->val[i] < low || f->val[i] > high)
f->type = ERROR;
if (f->type == ERROR) {
free(f->val);
return -1;
}
return 0;
}
static void
freecte(struct ctabentry *cte, int nfields)
{
switch (nfields) {
case 6:
free(cte->cmd);
case 5:
free(cte->wday.val);
case 4:
free(cte->mon.val);
case 3:
free(cte->mday.val);
case 2:
free(cte->hour.val);
case 1:
free(cte->min.val);
}
free(cte);
}
static void
unloadentries(void)
{
struct ctabentry *cte, *tmp;
for (cte = TAILQ_FIRST(&ctabhead); cte; cte = tmp) {
tmp = TAILQ_NEXT(cte, entry);
TAILQ_REMOVE(&ctabhead, cte, entry);
freecte(cte, 6);
}
}
static int
loadentries(void)
{
struct ctabentry *cte;
FILE *fp;
char *line = NULL, *p, *col;
int r = 0, y;
size_t size = 0;
ssize_t len;
struct fieldlimits {
char *name;
long min;
long max;
struct field *f;
} flim[] = {
{ "min", 0, 59, NULL },
{ "hour", 0, 23, NULL },
{ "mday", 1, 31, NULL },
{ "mon", 1, 12, NULL },
{ "wday", 0, 6, NULL }
};
size_t x;
if ((fp = fopen(config, "r")) == NULL) {
logerr("error: can't open %s: %s\n", config, strerror(errno));
return -1;
}
for (y = 0; (len = getline(&line, &size, fp)) != -1; y++) {
p = line;
if (line[0] == '#' || line[0] == '\n' || line[0] == '\0')
continue;
cte = emalloc(sizeof(*cte));
flim[0].f = &cte->min;
flim[1].f = &cte->hour;
flim[2].f = &cte->mday;
flim[3].f = &cte->mon;
flim[4].f = &cte->wday;
for (x = 0; x < LEN(flim); x++) {
do
col = strsep(&p, "\t\n ");
while (col && col[0] == '\0');
if (!col || parsefield(col, flim[x].min, flim[x].max, flim[x].f) < 0) {
logerr("error: failed to parse `%s' field on line %d\n",
flim[x].name, y + 1);
freecte(cte, x);
r = -1;
break;
}
}
if (r == -1)
break;
col = strsep(&p, "\n");
if (col)
while (col[0] == '\t' || col[0] == ' ')
col++;
if (!col || col[0] == '\0') {
logerr("error: missing `cmd' field on line %d\n",
y + 1);
freecte(cte, 5);
r = -1;
break;
}
cte->cmd = estrdup(col);
TAILQ_INSERT_TAIL(&ctabhead, cte, entry);
}
if (r < 0)
unloadentries();
free(line);
fclose(fp);
return r;
}
static void
reloadentries(void)
{
unloadentries();
if (loadentries() < 0)
logwarn("warning: discarding old crontab entries\n");
}
static void
sighandler(int sig)
{
switch (sig) {
case SIGCHLD:
chldreap = 1;
break;
case SIGHUP:
reload = 1;
break;
case SIGTERM:
quit = 1;
break;
}
}
static void
usage(void)
{
eprintf("usage: %s [-f file] [-n]\n", argv0);
}
int
main(int argc, char *argv[])
{
FILE *fp;
struct ctabentry *cte;
time_t t;
struct tm *tm;
struct sigaction sa;
ARGBEGIN {
case 'n':
nflag = 1;
break;
case 'f':
config = EARGF(usage());
break;
default:
usage();
} ARGEND
if (argc > 0)
usage();
if (nflag == 0) {
openlog(argv[0], LOG_CONS | LOG_PID, LOG_CRON);
if (daemon(1, 0) < 0) {
logerr("error: failed to daemonize %s\n", strerror(errno));
return 1;
}
if ((fp = fopen(pidfile, "w"))) {
fprintf(fp, "%d\n", getpid());
fclose(fp);
}
}
sa.sa_handler = sighandler;
sigfillset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
sigaction(SIGCHLD, &sa, NULL);
sigaction(SIGHUP, &sa, NULL);
sigaction(SIGTERM, &sa, NULL);
loadentries();
while (1) {
t = time(NULL);
sleep(60 - t % 60);
if (quit == 1) {
if (nflag == 0)
unlink(pidfile);
unloadentries();
/* Don't wait or kill forked processes, just exit */
break;
}
if (reload == 1 || chldreap == 1) {
if (reload == 1) {
reloadentries();
reload = 0;
}
if (chldreap == 1) {
waitjob();
chldreap = 0;
}
continue;
}
TAILQ_FOREACH(cte, &ctabhead, entry) {
t = time(NULL);
tm = localtime(&t);
if (matchentry(cte, tm) == 1)
runjob(cte->cmd);
}
}
if (nflag == 0)
closelog();
return 0;
}