1 files changed, 65 insertions, 0 deletions

diff --git a/miscutils/watchdog.c b/miscutils/watchdog.c
new file mode 100644
index 000000000..e342c13f3
--- /dev/null
+++ b/miscutils/watchdog.c
@@ -0,0 +1,65 @@
+/* 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;
+}