/* $NetBSD: wdogctl.c,v 1.7 2001/02/20 23:25:29 cgd Exp $ */ /*- * Copyright (c) 2000 Zembu Labs, Inc. * All rights reserved. * * Author: Jason R. Thorpe * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Zembu Labs, Inc. * 4. Neither the name of Zembu Labs nor the names of its employees may * be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY ZEMBU LABS, INC. ``AS IS'' AND ANY EXPRESS * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAR- * RANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DIS- * CLAIMED. IN NO EVENT SHALL ZEMBU LABS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #define _PATH_WATCHDOG "/dev/watchdog" int main(int, char *[]); void enable_kernel(const char *, u_int); void enable_user(const char *, u_int); void disable(void); void list_timers(void); void usage(void); int Aflag; int main(int argc, char *argv[]) { int cmds = 0, kflag = 0, uflag = 0, dflag = 0, ch; u_int period = WDOG_PERIOD_DEFAULT; while ((ch = getopt(argc, argv, "Adkp:u")) != -1) { switch (ch) { case 'A': if (cmds == 0 || dflag) usage(); Aflag = 1; break; case 'd': dflag = 1; cmds++; break; case 'k': kflag = 1; cmds++; break; case 'p': if (cmds == 0 || dflag) usage(); period = atoi(optarg); if (period == -1) usage(); break; case 'u': uflag = 1; cmds++; break; default: usage(); } } argc -= optind; argv += optind; if (cmds > 1) usage(); if (kflag) { if (argc != 1) usage(); enable_kernel(argv[0], period); } else if (uflag) { if (argc != 1) usage(); enable_user(argv[0], period); } else if (dflag) { if (argc != 0) usage(); disable(); } else list_timers(); exit(0); } void enable_kernel(const char *name, u_int period) { struct wdog_mode wm; int fd; if (strlen(name) >= WDOG_NAMESIZE) errx(1, "invalid watchdog timer name: %s", name); strcpy(wm.wm_name, name); wm.wm_mode = WDOG_MODE_KTICKLE; wm.wm_period = period; if (Aflag) wm.wm_mode |= WDOG_FEATURE_ALARM; fd = open(_PATH_WATCHDOG, O_RDWR, 0644); if (fd == -1) err(1, "open %s", _PATH_WATCHDOG); if (ioctl(fd, WDOGIOC_SMODE, &wm) == -1) err(1, "WDOGIOC_SMODE"); } void enable_user(const char *name, u_int period) { struct wdog_mode wm; struct timespec ts; pid_t tickler; int fd, rv; if (strlen(name) >= WDOG_NAMESIZE) errx(1, "invalid watchdog timer name: %s", name); strcpy(wm.wm_name, name); wm.wm_mode = WDOG_MODE_UTICKLE; wm.wm_period = period; if (Aflag) wm.wm_mode |= WDOG_FEATURE_ALARM; fd = open(_PATH_WATCHDOG, O_RDWR, 0644); if (fd == -1) err(1, "open %s", _PATH_WATCHDOG); /* ...so we can log failures to tickle the timer. */ openlog("wdogctl", LOG_PERROR|LOG_PID, LOG_DAEMON); /* * We fork a child process which detaches from the controlling * terminal once the timer is armed, and tickles the timer * until we send it a SIGTERM. */ tickler = fork(); if (tickler == -1) err(1, "unable to fork tickler process"); else if (tickler != 0) { if (ioctl(fd, WDOGIOC_SMODE, &wm) == -1) { err(1, "WDOGIOC_SMODE"); (void) kill(tickler, SIGTERM); } (void) close(fd); return; } /* * Wait for the watchdog to be armed. When it is, loop, * tickling the timer, then waiting 1/2 the period before * doing it again. * * If the parent fails to enable the watchdog, it will kill * us. */ do { rv = ioctl(fd, WDOGIOC_WHICH, &wm); } while (rv == -1); if (ioctl(fd, WDOGIOC_TICKLE) == -1) syslog(LOG_EMERG, "unable to tickle watchdog timer %s: %m", wm.wm_name); /* * Now detach from the controlling terminal, and just run * in the background. The kernel will keep track of who * we are, each time we tickle the timer. */ if (daemon(0, 0) == -1) { /* * We weren't able to go into the background. When * we exit, the kernel will disable the watchdog so * that the system won't die. */ err(1, "unable to detach from terminal"); } if (ioctl(fd, WDOGIOC_TICKLE) == -1) syslog(LOG_EMERG, "unable to tickle watchdog timer %s: %m", wm.wm_name); for (;;) { ts.tv_sec = wm.wm_period / 2; ts.tv_nsec = 0; (void) nanosleep(&ts, NULL); if (ioctl(fd, WDOGIOC_TICKLE) == -1) syslog(LOG_EMERG, "unable to tickle watchdog timer %s: %m", wm.wm_name); } /* NOTREACHED */ } void disable(void) { struct wdog_mode wm; pid_t tickler; int fd; fd = open(_PATH_WATCHDOG, O_RDWR, 0644); if (fd == -1) err(1, "open %s", _PATH_WATCHDOG); if (ioctl(fd, WDOGIOC_WHICH, &wm) == -1) { printf("No watchdog timer running.\n"); return; } /* * If the timer is running in UTICKLE mode, we need * to kill the wdogctl(8) process that is tickling * the timer. */ if (wm.wm_mode == WDOG_MODE_UTICKLE) { if (ioctl(fd, WDOGIOC_GTICKLER, &tickler) == -1) err(1, "WDOGIOC_GTICKLER"); (void) close(fd); (void) kill(tickler, SIGTERM); } else { wm.wm_mode = WDOG_MODE_DISARMED; if (ioctl(fd, WDOGIOC_SMODE, &wm) == -1) err(1, "unable to disarm watchdog %s", wm.wm_name); (void) close(fd); } } void list_timers(void) { struct wdog_conf wc; struct wdog_mode wm; char *buf, *cp; int fd, count, i; pid_t tickler; fd = open(_PATH_WATCHDOG, O_RDONLY, 0644); if (fd == -1) err(1, "open %s", _PATH_WATCHDOG); wc.wc_names = NULL; wc.wc_count = 0; if (ioctl(fd, WDOGIOC_GWDOGS, &wc) == -1) err(1, "ioctl WDOGIOC_GWDOGS for count"); count = wc.wc_count; if (count == 0) { printf("No watchdog timers present.\n"); goto out; } buf = malloc(count * WDOG_NAMESIZE); if (buf == NULL) err(1, "malloc %d byte for watchdog names", count * WDOG_NAMESIZE); wc.wc_names = buf; if (ioctl(fd, WDOGIOC_GWDOGS, &wc) == -1) err(1, "ioctl WDOGIOC_GWDOGS for names"); count = wc.wc_count; if (count == 0) { printf("No watchdog timers present.\n"); free(buf); goto out; } printf("Available watchdog timers:\n"); for (i = 0, cp = buf; i < count; i++, cp += WDOG_NAMESIZE) { cp[WDOG_NAMESIZE - 1] = '\0'; strcpy(wm.wm_name, cp); if (ioctl(fd, WDOGIOC_GMODE, &wm) == -1) wm.wm_mode = -1; else if (wm.wm_mode == WDOG_MODE_UTICKLE) { if (ioctl(fd, WDOGIOC_GTICKLER, &tickler) == -1) tickler = (pid_t) -1; } printf("\t%s, %u second period", cp, wm.wm_period); if (wm.wm_mode != WDOG_MODE_DISARMED) { printf(" [armed, %s tickle", wm.wm_mode == WDOG_MODE_KTICKLE ? "kernel" : "user"); if (wm.wm_mode == WDOG_MODE_UTICKLE && tickler != (pid_t) -1) printf(", pid %d", tickler); printf("]"); } printf("\n"); } out: (void) close(fd); } void usage(void) { fprintf(stderr, "Usage: %s\n", getprogname()); fprintf(stderr, " %s -k [-A] [-p seconds] timer\n", getprogname()); fprintf(stderr, " %s -u [-A] [-p seconds] timer\n", getprogname()); fprintf(stderr, " %s -d\n", getprogname()); exit(1); }