busybox/miscutils/watchdog.c

/* vi: set sw=4 ts=4: */
/*
 * Mini watchdog implementation for busybox
 *
 * Copyright (C) 2003  Paul Mundt <lethal@linux-sh.org>
 * Copyright (C) 2006  Bernhard Fischer <busybox@busybox.net>
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

#include "busybox.h"

#define OPT_FOREGROUND 0x01
#define OPT_TIMER      0x02

/* Watchdog file descriptor */
static int fd;

static void watchdog_shutdown(int ATTRIBUTE_UNUSED unused)
{
	write(fd, "V", 1);	/* Magic, see watchdog-api.txt in kernel */
	close(fd);
	exit(0);
}

int watchdog_main(int argc, char **argv)
{
	unsigned opts;
	unsigned timer_duration = 30; /* Userspace timer duration, in seconds */
	char *t_arg;

	opts = getopt32(argc, argv, "Ft:", &t_arg);

	if (opts & OPT_TIMER)
		timer_duration = xatou(t_arg);

	/* We're only interested in the watchdog device .. */
	if (optind < argc - 1 || argc == 1)
		bb_show_usage();

#ifdef BB_NOMMU
	if (!(opts & OPT_FOREGROUND))
		vfork_daemon_rexec(0, 1, argc, argv, "-F");
#else
	xdaemon(0, 1);
#endif

	signal(SIGHUP, watchdog_shutdown);
	signal(SIGINT, watchdog_shutdown);

	fd = 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;
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* Mini watchdog implementation for busybox
4	*
5	* Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org>
6	* Copyright (C) 2006 Bernhard Fischer <busybox@busybox.net>
7	*
8	* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
9	*/
10
11	#include "busybox.h"
12
13	#define OPT_FOREGROUND 0x01
14	#define OPT_TIMER 0x02
15
16	/* Watchdog file descriptor */
17	static int fd;
18
19	static void watchdog_shutdown(int ATTRIBUTE_UNUSED unused)
20	{
21	write(fd, "V", 1); /* Magic, see watchdog-api.txt in kernel */
22	close(fd);
23	exit(0);
24	}
25
26	int watchdog_main(int argc, char **argv)
27	{
28	unsigned opts;
29	unsigned timer_duration = 30; /* Userspace timer duration, in seconds */
30	char *t_arg;
31
32	opts = getopt32(argc, argv, "Ft:", &t_arg);
33
34	if (opts & OPT_TIMER)
35	timer_duration = xatou(t_arg);
36
37	/* We're only interested in the watchdog device .. */
38	if (optind < argc - 1 \|\| argc == 1)
39	bb_show_usage();
40
41	#ifdef BB_NOMMU
42	if (!(opts & OPT_FOREGROUND))
43	vfork_daemon_rexec(0, 1, argc, argv, "-F");
44	#else
45	xdaemon(0, 1);
46	#endif
47
48	signal(SIGHUP, watchdog_shutdown);
49	signal(SIGINT, watchdog_shutdown);
50
51	fd = xopen(argv[argc - 1], O_WRONLY);
52
53	while (1) {
54	/*
55	* Make sure we clear the counter before sleeping, as the counter value
56	* is undefined at this point -- PFM
57	*/
58	write(fd, "\0", 1);
59	sleep(timer_duration);
60	}
61
62	watchdog_shutdown(0);
63
64	return EXIT_SUCCESS;
65	}