mirror of
https://github.com/sheumann/hush.git
synced 2024-12-27 01:32:08 +00:00
64 lines
1.3 KiB
C
64 lines
1.3 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* Mini watchdog implementation for busybox
|
|
*
|
|
* Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org>
|
|
*
|
|
* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <fcntl.h>
|
|
#include <unistd.h>
|
|
#include <stdlib.h>
|
|
#include <signal.h>
|
|
#include "busybox.h"
|
|
|
|
/* Userspace timer duration, in seconds */
|
|
static unsigned int timer_duration = 30;
|
|
|
|
/* Watchdog file descriptor */
|
|
static int fd;
|
|
|
|
static void watchdog_shutdown(int ATTRIBUTE_UNUSED unused)
|
|
{
|
|
write(fd, "V", 1); /* Magic */
|
|
close(fd);
|
|
exit(0);
|
|
}
|
|
|
|
int watchdog_main(int argc, char **argv)
|
|
{
|
|
|
|
char *t_arg;
|
|
unsigned long flags;
|
|
flags = bb_getopt_ulflags(argc, argv, "t:", &t_arg);
|
|
if (flags & 1)
|
|
timer_duration = bb_xgetlarg(t_arg, 10, 0, INT_MAX);
|
|
|
|
/* We're only interested in the watchdog device .. */
|
|
if (optind < argc - 1 || argc == 1)
|
|
bb_show_usage();
|
|
|
|
if (daemon(0, 1) < 0)
|
|
bb_perror_msg_and_die("Failed forking watchdog daemon");
|
|
|
|
signal(SIGHUP, watchdog_shutdown);
|
|
signal(SIGINT, watchdog_shutdown);
|
|
|
|
fd = bb_xopen(argv[argc - 1], O_WRONLY);
|
|
|
|
while (1) {
|
|
/*
|
|
* Make sure we clear the counter before sleeping, as the counter value
|
|
* is undefined at this point -- PFM
|
|
*/
|
|
write(fd, "\0", 1);
|
|
sleep(timer_duration);
|
|
}
|
|
|
|
watchdog_shutdown(0);
|
|
|
|
return EXIT_SUCCESS;
|
|
}
|