#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <syslog.h>
#include "watchdog.h"

#define TIMEOUT_DEFAULT 60

int fd;

void sig_any() {
	syslog(LOG_EMERG, "feedthedog killed by untrapped signal. System will be rebooted by watchdog.");
	exit(0);
}

void sig_term() {
	syslog(LOG_NOTICE, "Exiting, shutting down watchdog...");
	if (write(fd, "V", 1) == -1) {
		syslog(LOG_NOTICE, "Failed!");
		exit(1);
	}
	if (close(fd) == -1) {
		syslog(LOG_NOTICE, "Failed!");
		exit(1);
	}
	syslog(LOG_NOTICE, "Watchdog successfully shut down!");
	exit(0);
}

void get_info() {
	int timeout;
	struct watchdog_info info;

    ioctl(fd, WDIOC_GETTIMEOUT, &timeout);
    syslog(LOG_INFO, "Watchdog timeout is %d seconds\n", timeout);

	ioctl(fd, WDIOC_GETSUPPORT, &info);
	syslog(LOG_INFO, "Watchdog options: 0x%04x", info.options);
	syslog(LOG_INFO, "Watchdog firmware ver: %d", info.firmware_version);
	syslog(LOG_INFO, "Watchdog type:%s", info.identity);
}

int main() {
	int i,timeout;

	openlog("feedthedog", LOG_PID, LOG_DAEMON);

	if ((fd = open("/dev/watchdog", O_WRONLY)) == -1) {
		perror("open");
		exit(1);
	}

	timeout = atoi(getenv("WATCHDOG_TIMEOUT"));
	if (timeout <= 0) {
		syslog(LOG_WARNING, "Timeout set to %d. Using default.", timeout);
		timeout = TIMEOUT_DEFAULT;
	}

	get_info();
	for (i=1;i<=_NSIG;i++) {
		switch (i) {
			case SIGSTOP:
			case SIGKILL:
				break;
			case SIGTERM:
				signal(SIGTERM, sig_term);
				break;
			default:
				signal(i, sig_any);
				break;
		}
	}

	if (fork())
		exit(0);

	syslog(LOG_INFO, "Watchdog feeder started");

	while (1) {
		write(fd, "\0", 1);
		sleep(10);
	}

	return 0;
}