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Diffstat (limited to 'utilities/ovs-wdt.c')
| -rw-r--r-- | utilities/ovs-wdt.c | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/utilities/ovs-wdt.c b/utilities/ovs-wdt.c new file mode 100644 index 000000000..3c5d797c0 --- /dev/null +++ b/utilities/ovs-wdt.c @@ -0,0 +1,263 @@ +/* Copyright (c) 2008, 2009 Nicira Networks, Inc. + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * In addition, as a special exception, Nicira Networks gives permission + * to link the code of its release of vswitchd with the OpenSSL project's + * "OpenSSL" library (or with modified versions of it that use the same + * license as the "OpenSSL" library), and distribute the linked + * executables. You must obey the GNU General Public License in all + * respects for all of the code used other than "OpenSSL". If you modify + * this file, you may extend this exception to your version of the file, + * but you are not obligated to do so. If you do not wish to do so, + * delete this exception statement from your version. + * + */ + +#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 + +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'}, + {0, 0, 0, 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); +} |