mirror of
https://github.com/troglobit/finit.git
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134 lines
3.1 KiB
C
134 lines
3.1 KiB
C
/* Built-in watchdog daemon
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*
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* Copyright (c) 2016-2022 Joachim Wiberg <troglobit@gmail.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#include <config.h>
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#include <stdio.h>
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#include <string.h>
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#include <sysexits.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <errno.h>
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#include <signal.h>
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#include <syslog.h>
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#include <sys/ioctl.h>
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#include <linux/watchdog.h>
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#include "watchdog.h"
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int running = 1;
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int handover = 0;
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int shutdown = 0;
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static void sighandler(int signo)
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{
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if (signo == SIGTERM)
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handover = 1;
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if (signo == SIGPWR)
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shutdown = 1;
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running = 0;
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}
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static int init(char *progname, char *devnode)
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{
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int fd;
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sprintf(progname, "@finit-watchdog");
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signal(SIGTERM, sighandler);
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signal(SIGPWR, sighandler);
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openlog(&progname[1], LOG_CONS | LOG_PID, LOG_DAEMON);
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syslog(LOG_INFO, "Finit v%s watchdog %s starting ...", VERSION, devnode);
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fd = open(devnode, O_WRONLY);
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if (fd == -1)
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return -1;
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return fd;
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}
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static int loop(int fd, int timeout)
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{
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int dummy = 0;
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int period = timeout / 2;
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ioctl(fd, WDIOC_SETTIMEOUT, &timeout);
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while (running) {
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ioctl(fd, WDIOC_KEEPALIVE, &dummy);
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sleep(period);
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}
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/* System is going down, prepare to reboot system on TERM */
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if (shutdown) {
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timeout /= 3;
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ioctl(fd, WDIOC_SETTIMEOUT, &timeout);
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}
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/* External watchdogd wants to take over ... */
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if (handover) {
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syslog(LOG_INFO, "Handing over %s and exiting ...", WDT_DEVNODE);
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ioctl(fd, WDIOC_KEEPALIVE, &dummy);
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if (write(fd, "V", 1) == -1)
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return EX_IOERR;
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} else
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syslog(LOG_ALERT, "System going down ...");
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return EX_OK;
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}
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int main(int argc, char *argv[])
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{
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int fd, rc = EX_OK;
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fd = init(argv[0], WDT_DEVNODE);
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if (fd == -1) {
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syslog(LOG_CRIT, "Failed connecting to %s: %s", WDT_DEVNODE, strerror(errno));
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rc = EX_OSFILE;
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goto done;
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}
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rc = loop(fd, WDT_TIMEOUT);
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while (!handover) {
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/* Waiting for SIGTERM or WDT reset ... */
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sleep(1);
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/* Set lowest possible timeout on SIGPWR */
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ioctl(fd, WDIOC_SETTIMEOUT, &shutdown);
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}
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close(fd);
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done:
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closelog();
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return rc;
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}
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/**
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* Local Variables:
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* indent-tabs-mode: t
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* c-file-style: "linux"
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* End:
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*/
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