Eric Andersen | ffde867 | 2001-01-25 23:40:32 +0000 | [diff] [blame] | 1 | /* vi: set sw=4 ts=4: */ |
| 2 | /* |
| 3 | * Mini watchdog implementation for busybox |
| 4 | * |
Eric Andersen | cde8f53 | 2003-07-22 07:39:18 +0000 | [diff] [blame] | 5 | * Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org> |
Bernhard Reutner-Fischer | 5f6d67b | 2006-06-03 20:53:18 +0000 | [diff] [blame] | 6 | * Copyright (C) 2006 Bernhard Fischer <busybox@busybox.net> |
Eric Andersen | ffde867 | 2001-01-25 23:40:32 +0000 | [diff] [blame] | 7 | * |
Rob Landley | 1b751c8 | 2005-10-28 09:24:33 +0000 | [diff] [blame] | 8 | * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. |
Eric Andersen | ffde867 | 2001-01-25 23:40:32 +0000 | [diff] [blame] | 9 | */ |
| 10 | |
Bernhard Reutner-Fischer | c89982d | 2006-06-03 19:49:21 +0000 | [diff] [blame] | 11 | #include "busybox.h" |
Eric Andersen | ffde867 | 2001-01-25 23:40:32 +0000 | [diff] [blame] | 12 | #include <stdio.h> |
| 13 | #include <fcntl.h> |
Eric Andersen | ed3ef50 | 2001-01-27 08:24:39 +0000 | [diff] [blame] | 14 | #include <unistd.h> |
| 15 | #include <stdlib.h> |
Eric Andersen | cde8f53 | 2003-07-22 07:39:18 +0000 | [diff] [blame] | 16 | #include <signal.h> |
Eric Andersen | ffde867 | 2001-01-25 23:40:32 +0000 | [diff] [blame] | 17 | |
Eric Andersen | cde8f53 | 2003-07-22 07:39:18 +0000 | [diff] [blame] | 18 | /* Watchdog file descriptor */ |
| 19 | static int fd; |
| 20 | |
Bernhard Reutner-Fischer | 20f4000 | 2006-01-30 17:17:14 +0000 | [diff] [blame] | 21 | static void watchdog_shutdown(int ATTRIBUTE_UNUSED unused) |
Eric Andersen | cde8f53 | 2003-07-22 07:39:18 +0000 | [diff] [blame] | 22 | { |
| 23 | write(fd, "V", 1); /* Magic */ |
| 24 | close(fd); |
| 25 | exit(0); |
| 26 | } |
| 27 | |
Rob Landley | 1b751c8 | 2005-10-28 09:24:33 +0000 | [diff] [blame] | 28 | int watchdog_main(int argc, char **argv) |
Eric Andersen | ffde867 | 2001-01-25 23:40:32 +0000 | [diff] [blame] | 29 | { |
Bernhard Reutner-Fischer | 5f6d67b | 2006-06-03 20:53:18 +0000 | [diff] [blame] | 30 | unsigned long timer_duration = 30; /* Userspace timer duration, in seconds */ |
Rob Landley | 1b751c8 | 2005-10-28 09:24:33 +0000 | [diff] [blame] | 31 | char *t_arg; |
Bernhard Reutner-Fischer | 5f6d67b | 2006-06-03 20:53:18 +0000 | [diff] [blame] | 32 | |
| 33 | if (bb_getopt_ulflags(argc, argv, "t:", &t_arg)) |
Rob Landley | 1b751c8 | 2005-10-28 09:24:33 +0000 | [diff] [blame] | 34 | timer_duration = bb_xgetlarg(t_arg, 10, 0, INT_MAX); |
Eric Andersen | cde8f53 | 2003-07-22 07:39:18 +0000 | [diff] [blame] | 35 | |
| 36 | /* We're only interested in the watchdog device .. */ |
| 37 | if (optind < argc - 1 || argc == 1) |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 38 | bb_show_usage(); |
Eric Andersen | ffde867 | 2001-01-25 23:40:32 +0000 | [diff] [blame] | 39 | |
Bernhard Reutner-Fischer | 2c99851 | 2006-04-12 18:09:26 +0000 | [diff] [blame] | 40 | bb_xdaemon(0, 1); |
Eric Andersen | cde8f53 | 2003-07-22 07:39:18 +0000 | [diff] [blame] | 41 | |
| 42 | signal(SIGHUP, watchdog_shutdown); |
| 43 | signal(SIGINT, watchdog_shutdown); |
| 44 | |
| 45 | fd = bb_xopen(argv[argc - 1], O_WRONLY); |
Eric Andersen | ffde867 | 2001-01-25 23:40:32 +0000 | [diff] [blame] | 46 | |
| 47 | while (1) { |
Eric Andersen | c7bda1c | 2004-03-15 08:29:22 +0000 | [diff] [blame] | 48 | /* |
Eric Andersen | cde8f53 | 2003-07-22 07:39:18 +0000 | [diff] [blame] | 49 | * Make sure we clear the counter before sleeping, as the counter value |
| 50 | * is undefined at this point -- PFM |
| 51 | */ |
Eric Andersen | ffde867 | 2001-01-25 23:40:32 +0000 | [diff] [blame] | 52 | write(fd, "\0", 1); |
Eric Andersen | cde8f53 | 2003-07-22 07:39:18 +0000 | [diff] [blame] | 53 | sleep(timer_duration); |
Eric Andersen | ffde867 | 2001-01-25 23:40:32 +0000 | [diff] [blame] | 54 | } |
| 55 | |
Eric Andersen | cde8f53 | 2003-07-22 07:39:18 +0000 | [diff] [blame] | 56 | watchdog_shutdown(0); |
| 57 | |
| 58 | return EXIT_SUCCESS; |
Eric Andersen | ffde867 | 2001-01-25 23:40:32 +0000 | [diff] [blame] | 59 | } |