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82 lines
2.0 KiB
C
82 lines
2.0 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Mini watchdog implementation for busybox
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*
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* Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <stdio.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <signal.h>
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#include "busybox.h"
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/* Userspace timer duration, in seconds */
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static unsigned int timer_duration = 30;
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/* Watchdog file descriptor */
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static int fd;
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static void watchdog_shutdown(int unused)
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{
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write(fd, "V", 1); /* Magic */
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close(fd);
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exit(0);
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}
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extern int watchdog_main(int argc, char **argv)
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{
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int opt;
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while ((opt = getopt(argc, argv, "t:")) > 0) {
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switch (opt) {
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case 't':
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timer_duration = bb_xgetlarg(optarg, 10, 0, INT_MAX);
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break;
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default:
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bb_show_usage();
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}
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}
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/* We're only interested in the watchdog device .. */
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if (optind < argc - 1 || argc == 1)
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bb_show_usage();
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if (daemon(0, 1) < 0)
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bb_perror_msg_and_die("Failed forking watchdog daemon");
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signal(SIGHUP, watchdog_shutdown);
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signal(SIGINT, watchdog_shutdown);
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fd = bb_xopen(argv[argc - 1], O_WRONLY);
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while (1) {
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/*
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* Make sure we clear the counter before sleeping, as the counter value
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* is undefined at this point -- PFM
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*/
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write(fd, "\0", 1);
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sleep(timer_duration);
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}
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watchdog_shutdown(0);
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return EXIT_SUCCESS;
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}
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