* 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.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
-#include <stdio.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <signal.h>
-#include "busybox.h"
+//usage:#define watchdog_trivial_usage
+//usage: "[-t N[ms]] [-T N[ms]] [-F] DEV"
+//usage:#define watchdog_full_usage "\n\n"
+//usage: "Periodically write to watchdog device DEV\n"
+//usage: "\n -T N Reboot after N seconds if not reset (default 60)"
+//usage: "\n -t N Reset every N seconds (default 30)"
+//usage: "\n -F Run in foreground"
+//usage: "\n"
+//usage: "\nUse 500ms to specify period in milliseconds"
-/* Userspace timer duration, in seconds */
-static unsigned int timer_duration = 30;
+#include "libbb.h"
+#include "linux/types.h" /* for __u32 */
+#include "linux/watchdog.h"
-/* Watchdog file descriptor */
-static int fd;
+#define OPT_FOREGROUND (1 << 0)
+#define OPT_STIMER (1 << 1)
+#define OPT_HTIMER (1 << 2)
-static void watchdog_shutdown(int ATTRIBUTE_UNUSED unused)
+static void watchdog_shutdown(int sig UNUSED_PARAM)
{
- write(fd, "V", 1); /* Magic */
- close(fd);
- exit(0);
+ static const char V = 'V';
+
+ remove_pidfile(CONFIG_PID_FILE_PATH "/watchdog.pid");
+ 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 },
+ { "", 0 }
+ };
+
+ 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);
+
+ /* 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);
- 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);
+ 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);
- /* We're only interested in the watchdog device .. */
- if (optind < argc - 1 || argc == 1)
- bb_show_usage();
+ bb_signals(BB_FATAL_SIGS, watchdog_shutdown);
- if (daemon(0, 1) < 0)
- bb_perror_msg_and_die("Failed forking watchdog daemon");
+ /* Use known fd # - avoid needing global 'int fd' */
+ xmove_fd(xopen(argv[argc - 1], O_WRONLY), 3);
- signal(SIGHUP, watchdog_shutdown);
- signal(SIGINT, watchdog_shutdown);
+ /* 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
- fd = bb_xopen(argv[argc - 1], O_WRONLY);
+ write_pidfile(CONFIG_PID_FILE_PATH "/watchdog.pid");
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(fd, "\0", 1);
- sleep(timer_duration);
+ write(3, "", 1); /* write zero byte */
+ usleep(stimer_duration * 1000L);
}
-
- watchdog_shutdown(0);
-
- return EXIT_SUCCESS;
+ return EXIT_SUCCESS; /* - not reached, but gcc 4.2.1 is too dumb! */
}
projects / platform / upstream / busybox.git / blobdiff