/* vi: set sw=4 ts=4: */ /* * Mini watchdog implementation for busybox * * Copyright (C) 2003 Paul Mundt * Copyright (C) 2006 Bernhard Fischer * * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. */ #include "busybox.h" #define OPT_FOREGROUND 0x01 #define OPT_TIMER 0x02 static void watchdog_shutdown(int ATTRIBUTE_UNUSED sig) ATTRIBUTE_NORETURN; static void watchdog_shutdown(int ATTRIBUTE_UNUSED sig) { write(3, "V", 1); /* Magic, see watchdog-api.txt in kernel */ if (ENABLE_FEATURE_CLEAN_UP) close(3); exit(0); } int watchdog_main(int argc, char **argv); int watchdog_main(int argc, char **argv) { unsigned opts; unsigned timer_duration = 30; /* Userspace timer duration, in seconds */ char *t_arg; opts = getopt32(argc, argv, "Ft:", &t_arg); if (opts & OPT_TIMER) timer_duration = xatou(t_arg); /* We're only interested in the watchdog device .. */ if (optind < argc - 1 || argc == 1) bb_show_usage(); #ifdef BB_NOMMU if (!(opts & OPT_FOREGROUND)) vfork_daemon_rexec(0, 1, argc, argv, "-F"); #else xdaemon(0, 1); #endif signal(SIGHUP, watchdog_shutdown); signal(SIGINT, watchdog_shutdown); /* Use known fd # - avoid needing global 'int fd' */ dup2(xopen(argv[argc - 1], O_WRONLY), 3); while (1) { /* * Make sure we clear the counter before sleeping, as the counter value * is undefined at this point -- PFM */ write(3, "", 1); sleep(timer_duration); } watchdog_shutdown(0); /* return EXIT_SUCCESS; */ }