[3320] | 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 Reutner-Fischer <busybox@busybox.net>
|
---|
| 7 | * Copyright (C) 2008 Darius Augulis <augulis.darius@gmail.com>
|
---|
| 8 | *
|
---|
| 9 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
|
---|
| 10 | */
|
---|
| 11 |
|
---|
| 12 | #include "libbb.h"
|
---|
| 13 | #include "linux/types.h" /* for __u32 */
|
---|
| 14 | #include "linux/watchdog.h"
|
---|
| 15 |
|
---|
| 16 | #define OPT_FOREGROUND (1 << 0)
|
---|
| 17 | #define OPT_STIMER (1 << 1)
|
---|
| 18 | #define OPT_HTIMER (1 << 2)
|
---|
| 19 |
|
---|
| 20 | static void watchdog_shutdown(int sig UNUSED_PARAM)
|
---|
| 21 | {
|
---|
| 22 | static const char V = 'V';
|
---|
| 23 |
|
---|
| 24 | write(3, &V, 1); /* Magic, see watchdog-api.txt in kernel */
|
---|
| 25 | if (ENABLE_FEATURE_CLEAN_UP)
|
---|
| 26 | close(3);
|
---|
| 27 | _exit(EXIT_SUCCESS);
|
---|
| 28 | }
|
---|
| 29 |
|
---|
| 30 | int watchdog_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
---|
| 31 | int watchdog_main(int argc, char **argv)
|
---|
| 32 | {
|
---|
| 33 | static const struct suffix_mult suffixes[] = {
|
---|
| 34 | { "ms", 1 },
|
---|
| 35 | { "", 1000 },
|
---|
| 36 | { "", 0 }
|
---|
| 37 | };
|
---|
| 38 |
|
---|
| 39 | unsigned opts;
|
---|
| 40 | unsigned stimer_duration; /* how often to restart */
|
---|
| 41 | unsigned htimer_duration = 60000; /* reboots after N ms if not restarted */
|
---|
| 42 | char *st_arg;
|
---|
| 43 | char *ht_arg;
|
---|
| 44 |
|
---|
| 45 | opt_complementary = "=1"; /* must have exactly 1 argument */
|
---|
| 46 | opts = getopt32(argv, "Ft:T:", &st_arg, &ht_arg);
|
---|
| 47 |
|
---|
| 48 | /* We need to daemonize *before* opening the watchdog as many drivers
|
---|
| 49 | * will only allow one process at a time to do so. Since daemonizing
|
---|
| 50 | * is not perfect (child may run before parent finishes exiting), we
|
---|
| 51 | * can't rely on parent exiting before us (let alone *cleanly* releasing
|
---|
| 52 | * the watchdog fd -- something else that may not even be allowed).
|
---|
| 53 | */
|
---|
| 54 | if (!(opts & OPT_FOREGROUND))
|
---|
| 55 | bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
|
---|
| 56 |
|
---|
| 57 | if (opts & OPT_HTIMER)
|
---|
| 58 | htimer_duration = xatou_sfx(ht_arg, suffixes);
|
---|
| 59 | stimer_duration = htimer_duration / 2;
|
---|
| 60 | if (opts & OPT_STIMER)
|
---|
| 61 | stimer_duration = xatou_sfx(st_arg, suffixes);
|
---|
| 62 |
|
---|
| 63 | bb_signals(BB_FATAL_SIGS, watchdog_shutdown);
|
---|
| 64 |
|
---|
| 65 | /* Use known fd # - avoid needing global 'int fd' */
|
---|
| 66 | xmove_fd(xopen(argv[argc - 1], O_WRONLY), 3);
|
---|
| 67 |
|
---|
| 68 | /* WDIOC_SETTIMEOUT takes seconds, not milliseconds */
|
---|
| 69 | htimer_duration = htimer_duration / 1000;
|
---|
| 70 | #ifndef WDIOC_SETTIMEOUT
|
---|
| 71 | # error WDIOC_SETTIMEOUT is not defined, cannot compile watchdog applet
|
---|
| 72 | #else
|
---|
| 73 | # if defined WDIOC_SETOPTIONS && defined WDIOS_ENABLECARD
|
---|
| 74 | {
|
---|
| 75 | static const int enable = WDIOS_ENABLECARD;
|
---|
| 76 | ioctl_or_warn(3, WDIOC_SETOPTIONS, (void*) &enable);
|
---|
| 77 | }
|
---|
| 78 | # endif
|
---|
| 79 | ioctl_or_warn(3, WDIOC_SETTIMEOUT, &htimer_duration);
|
---|
| 80 | #endif
|
---|
| 81 |
|
---|
| 82 | #if 0
|
---|
| 83 | ioctl_or_warn(3, WDIOC_GETTIMEOUT, &htimer_duration);
|
---|
| 84 | printf("watchdog: SW timer is %dms, HW timer is %ds\n",
|
---|
| 85 | stimer_duration, htimer_duration * 1000);
|
---|
| 86 | #endif
|
---|
| 87 |
|
---|
| 88 | while (1) {
|
---|
| 89 | /*
|
---|
| 90 | * Make sure we clear the counter before sleeping,
|
---|
| 91 | * as the counter value is undefined at this point -- PFM
|
---|
| 92 | */
|
---|
| 93 | write(3, "", 1); /* write zero byte */
|
---|
| 94 | usleep(stimer_duration * 1000L);
|
---|
| 95 | }
|
---|
| 96 | return EXIT_SUCCESS; /* - not reached, but gcc 4.2.1 is too dumb! */
|
---|
| 97 | }
|
---|