* Mini watchdog implementation for busybox
*
* Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org>
- * Copyright (C) 2006 Bernhard Fischer <busybox@busybox.net>
+ * 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/types.h" /* for __u32 */
+#include "linux/watchdog.h"
-#define OPT_FOREGROUND 0x01
-#define OPT_TIMER 0x02
+#define OPT_FOREGROUND (1 << 0)
+#define OPT_STIMER (1 << 1)
+#define OPT_HTIMER (1 << 2)
static void watchdog_shutdown(int sig UNUSED_PARAM)
{
int watchdog_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int watchdog_main(int argc, char **argv)
{
- unsigned opts;
- unsigned timer_duration = 30000; /* Userspace timer duration, in milliseconds */
- char *t_arg;
+ static const struct suffix_mult suffixes[] = {
+ { "ms", 1 },
+ { "", 1000 },
+ { "", 0 }
+ };
- opt_complementary = "=1"; /* must have 1 argument */
- opts = getopt32(argv, "Ft:", &t_arg);
+ 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;
- if (opts & OPT_TIMER) {
- static const struct suffix_mult suffixes[] = {
- { "ms", 1 },
- { "", 1000 },
- { }
- };
- timer_duration = xatou_sfx(t_arg, suffixes);
- }
+ opt_complementary = "=1"; /* must have exactly 1 argument */
+ opts = getopt32(argv, "Ft:T:", &st_arg, &ht_arg);
- if (!(opts & OPT_FOREGROUND)) {
+ /* We need to daemonize *before* opening the watchdog as many drivers
+ * will only allow one process at a time to do so. Since daemonizing
+ * is not perfect (child may run before parent finishes exiting), we
+ * can't rely on parent exiting before us (let alone *cleanly* releasing
+ * the watchdog fd -- something else that may not even be allowed).
+ */
+ if (!(opts & OPT_FOREGROUND))
bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
- }
+
+ 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);
-// TODO?
-// if (!(opts & OPT_TIMER)) {
-// if (ioctl(fd, WDIOC_GETTIMEOUT, &timer_duration) == 0)
-// timer_duration *= 500;
-// else
-// timer_duration = 30000;
-// }
+ /* WDIOC_SETTIMEOUT takes seconds, not milliseconds */
+ htimer_duration = htimer_duration / 1000;
+#ifndef WDIOC_SETTIMEOUT
+# error WDIOC_SETTIMEOUT is not defined, cannot compile watchdog applet
+#else
+# if defined WDIOC_SETOPTIONS && defined WDIOS_ENABLECARD
+ {
+ static const int enable = WDIOS_ENABLECARD;
+ ioctl_or_warn(3, WDIOC_SETOPTIONS, (void*) &enable);
+ }
+# endif
+ ioctl_or_warn(3, WDIOC_SETTIMEOUT, &htimer_duration);
+#endif
+
+#if 0
+ ioctl_or_warn(3, WDIOC_GETTIMEOUT, &htimer_duration);
+ printf("watchdog: SW timer is %dms, HW timer is %ds\n",
+ stimer_duration, htimer_duration * 1000);
+#endif
while (1) {
/*
- * Make sure we clear the counter before sleeping, as the counter value
- * is undefined at this point -- PFM
+ * 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(timer_duration * 1000L);
+ usleep(stimer_duration * 1000L);
}
return EXIT_SUCCESS; /* - not reached, but gcc 4.2.1 is too dumb! */
}