-/* Copyright (c) 2008, 2009, 2010 Nicira Networks, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <errno.h>
-#include <getopt.h>
-#include <signal.h>
-#include <sys/ioctl.h>
-#include <linux/types.h>
-#include <linux/watchdog.h>
-
-
-/* Default values for the interval and timer. In seconds. */
-#define DEFAULT_INTERVAL 1
-#define DEFAULT_TIMEOUT 30
-
-static int fd = -1;
-
-/* The WDT is automatically enabled when /dev/watchdog is opened. If we
- * do not send the magic value to the device first before exiting, the
- * system will reboot. This function allows the program to exit without
- * causing a reboot.
- */
-static void
-cleanup(void)
-{
- if (fd == -1) {
- return;
- }
-
- /* Writing the magic value "V" to the device is an indication that
- * the device is about to be closed. This causes the watchdog to be
- * disabled after the call to close.
- */
- if (write(fd, "V", 1) != 1) {
- fprintf(stderr, "Couldn't write magic val: %d\n", errno);
- return;
- }
- close(fd);
- fd = -1;
-}
-
-
-/* If we receive a SIGINT, cleanup first, which will disable the
- * watchdog timer.
- */
-static void
-sighandler(int signum)
-{
- cleanup();
- signal(signum, SIG_DFL);
- raise(signum);
-}
-
-static void
-setup_signal(void)
-{
- struct sigaction action;
-
- action.sa_handler = sighandler;
- sigemptyset(&action.sa_mask);
- action.sa_flags = 0;
-
- if (sigaction(SIGINT, &action, NULL) != 0) {
- fprintf(stderr, "Problem setting up SIGINT handler...\n");
- }
- if (sigaction(SIGTERM, &action, NULL) != 0) {
- fprintf(stderr, "Problem setting up SIGTERM handler...\n");
- }
-}
-
-
-/* Print information on the WDT hardware */
-static void
-print_wdt_info(void)
-{
- struct watchdog_info ident;
-
- if (ioctl(fd, WDIOC_GETSUPPORT, &ident) == -1) {
- fprintf(stderr, "Couldn't get version: %d\n", errno);
- cleanup();
- exit(-1);
- }
- printf("identity: %s, ver: %d, opt: %#x\n", ident.identity,
- ident.firmware_version, ident.options);
-}
-
-
-static void
-print_help(char *progname)
-{
- printf("%s: Watchdog timer utility\n", progname);
- printf("usage: %s [OPTIONS]\n\n", progname);
- printf("Options:\n");
- printf(" -t, --timeout=SECS expiration time of WDT (default: %d)\n",
- DEFAULT_TIMEOUT);
- printf(" -i, --interval=SECS interval to send keep-alives (default: %d)\n",
- DEFAULT_INTERVAL);
- printf(" -d, --disable disable the WDT and exit\n");
- printf(" -h, --help display this help message\n");
- printf(" -v, --verbose enable verbose printing\n");
- printf(" -V, --version display version information of WDT and exit\n");
-}
-
-
-int main(int argc, char *argv[])
-{
- int arg;
- int optc;
- int verbose = 0;
- int interval = DEFAULT_INTERVAL;
- int timeout = DEFAULT_TIMEOUT;
- static struct option const longopts[] =
- {
- {"timeout", required_argument, NULL, 't'},
- {"interval", required_argument, NULL, 'i'},
- {"disable", no_argument, NULL, 'd'},
- {"help", no_argument, NULL, 'h'},
- {"verbose", no_argument, NULL, 'v'},
- {"version", no_argument, NULL, 'V'},
- {NULL, 0, NULL, 0}
- };
-
- setup_signal();
-
- fd = open("/dev/watchdog", O_RDWR);
- if (fd == -1) {
- fprintf(stderr, "Couldn't open watchdog device: %s\n", strerror(errno));
- exit(-1);
- }
-
- while ((optc = getopt_long(argc, argv, "t:i:dh?vV", longopts, NULL)) != -1) {
- switch (optc) {
- case 't':
- timeout = strtol(optarg, NULL, 10);
- if (!timeout) {
- fprintf(stderr, "Invalid timeout: %s\n", optarg);
- goto error;
- }
- break;
-
- case 'i':
- interval = strtol(optarg, NULL, 10);
- if (!interval) {
- fprintf(stderr, "Invalid interval: %s\n", optarg);
- goto error;
- }
- break;
-
- case 'd':
- arg = WDIOS_DISABLECARD;
- if (ioctl(fd, WDIOC_SETOPTIONS, &arg) == -1) {
- fprintf(stderr, "Couldn't disable: %d\n", errno);
- goto error;
- }
- cleanup();
- exit(0);
- break;
-
- case 'h':
- print_help(argv[0]);
- cleanup();
- exit(0);
- break;
-
- case 'v':
- verbose = 1;
- break;
-
- case 'V':
- print_wdt_info();
- cleanup();
- exit(0);
- break;
-
- default:
- print_help(argv[0]);
- goto error;
- break;
- }
- }
-
- argc -= optind;
- argv += optind;
-
- /* Sanity-check the arguments */
- if (argc != 0) {
- fprintf(stderr, "Illegal argument: %s\n", argv[0]);
- goto error;
- }
-
- if (verbose) {
- print_wdt_info();
- printf("timeout: %d, interval: %d\n", timeout, interval);
- }
-
- /* Prevent the interval being greater than the timeout, since it
- * will always cause a reboot.
- */
- if (interval > timeout) {
- fprintf(stderr, "Interval greater than timeout: %d > %d\n",
- interval, timeout);
- goto error;
- }
-
- /* Always set the timeout */
- if (ioctl(fd, WDIOC_SETTIMEOUT, &timeout) == -1) {
- fprintf(stderr, "Couldn't set timeout: %d\n", errno);
- goto error;
- }
-
- /* Loop and send a keep-alive every "interval" seconds */
- while (1) {
- if (verbose) {
- if (ioctl(fd, WDIOC_GETTIMELEFT, &arg) == -1) {
- fprintf(stderr, "Couldn't get time left: %d\n", errno);
- goto error;
- }
- printf("Sending keep alive, time remaining: %d\n", arg);
- }
-
- /* Send a keep-alive. The argument is ignored */
- if (ioctl(fd, WDIOC_KEEPALIVE, &arg) == -1) {
- fprintf(stderr, "Couldn't keepalive: %d\n", errno);
- goto error;
- }
-
- sleep(interval);
- }
-
- /* Never directly reached... */
-error:
- cleanup();
- exit(-1);
-}