1 files changed, 80 insertions, 0 deletions
diff --git a/miscutils/watchdog.c b/miscutils/watchdog.c
new file mode 100644
index 0000000..75a399f
--- /dev/null
+++ b/miscutils/watchdog.c
@@ -0,0 +1,80 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Mini watchdog implementation for busybox
+ *
+ * Copyright (C) 2003  Paul Mundt <lethal@linux-sh.org>
+ * Copyright (C) 2006  Bernhard Reutner-Fischer <busybox@busybox.net>
+ * Copyright (C) 2008  Darius Augulis <augulis.darius@gmail.com>
+ *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ */
+
+#include "libbb.h"
+#include "linux/watchdog.h"
+
+#define OPT_FOREGROUND  (1 << 0)
+#define OPT_STIMER      (1 << 1)
+#define OPT_HTIMER      (1 << 2)
+
+static void watchdog_shutdown(int sig UNUSED_PARAM)
+{
+	static const char V = 'V';
+
+	write(3, &V, 1);	/* Magic, see watchdog-api.txt in kernel */
+	if (ENABLE_FEATURE_CLEAN_UP)
+		close(3);
+	exit(EXIT_SUCCESS);
+}
+
+int watchdog_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int watchdog_main(int argc, char **argv)
+{
+	static const struct suffix_mult suffixes[] = {
+		{ "ms", 1 },
+		{ "", 1000 },
+		{ }
+	};
+
+	unsigned opts;
+	unsigned stimer_duration; /* how often to restart */
+	unsigned htimer_duration = 60000; /* reboots after N ms if not restarted */
+	char *st_arg;
+	char *ht_arg;
+
+	opt_complementary = "=1"; /* must have exactly 1 argument */
+	opts = getopt32(argv, "Ft:T:", &st_arg, &ht_arg);
+
+	if (opts & OPT_HTIMER)
+		htimer_duration = xatou_sfx(ht_arg, suffixes);
+	stimer_duration = htimer_duration / 2;
+	if (opts & OPT_STIMER)
+		stimer_duration = xatou_sfx(st_arg, suffixes);
+
+	bb_signals(BB_FATAL_SIGS, watchdog_shutdown);
+
+	/* Use known fd # - avoid needing global 'int fd' */
+	xmove_fd(xopen(argv[argc - 1], O_WRONLY), 3);
+
+	/* WDIOC_SETTIMEOUT takes seconds, not milliseconds */
+	htimer_duration = htimer_duration / 1000;
+	ioctl_or_warn(3, WDIOC_SETTIMEOUT, &htimer_duration);
+#if 0
+	ioctl_or_warn(3, WDIOC_GETTIMEOUT, &htimer_duration);
+	printf("watchdog: SW timer is %dms, HW timer is %dms\n",
+		stimer_duration, htimer_duration * 1000);
+#endif
+
+	if (!(opts & OPT_FOREGROUND)) {
+		bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
+	}
+
+	while (1) {
+		/*
+		 * Make sure we clear the counter before sleeping, as the counter value
+		 * is undefined at this point -- PFM
+		 */
+		write(3, "", 1); /* write zero byte */
+		usleep(stimer_duration * 1000L);
+	}
+	return EXIT_SUCCESS; /* - not reached, but gcc 4.2.1 is too dumb! */
+}