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/*
* Copyright (c) 2003 Sean M. Kelly <smkelly@FreeBSD.org>
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS 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.
*/
/*
* Software watchdog daemon.
*/
#include <sys/types.h>
__FBSDID("$FreeBSD$");
#include <sys/rtprio.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <err.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sysexits.h>
#include <unistd.h>
static void parseargs(int, char *[]);
static void sighandler(int);
static void watchdog_loop(void);
static int watchdog_init(void);
static int watchdog_onoff(int onoff);
static int watchdog_tickle(void);
static void usage(void);
int debugging = 0;
int end_program = 0;
const char *pidfile = _PATH_VARRUN "watchdogd.pid";
int reset_mib[3];
size_t reset_miblen = 3;
/*
* Periodically write to the debug.watchdog.reset sysctl OID
* to keep the software watchdog from firing.
*/
int
main(int argc, char *argv[])
{
struct rtprio rtp;
FILE *fp;
if (getuid() != 0)
errx(EX_SOFTWARE, "not super user");
parseargs(argc, argv);
rtp.type = RTP_PRIO_REALTIME;
rtp.prio = 0;
if (rtprio(RTP_SET, 0, &rtp) == -1)
err(EX_OSERR, "rtprio");
if (watchdog_init() == -1)
errx(EX_SOFTWARE, "unable to initialize watchdog");
if (watchdog_onoff(1) == -1)
exit(EX_SOFTWARE);
if (debugging == 0 && daemon(0, 0) == -1) {
watchdog_onoff(0);
err(EX_OSERR, "daemon");
}
signal(SIGHUP, SIG_IGN);
signal(SIGINT, sighandler);
signal(SIGTERM, sighandler);
fp = fopen(pidfile, "w");
if (fp != NULL) {
fprintf(fp, "%d\n", getpid());
fclose(fp);
}
watchdog_loop();
/* exiting */
watchdog_onoff(0);
unlink(pidfile);
return (EX_OK);
}
/*
* Catch signals and begin shutdown process.
*/
static void
sighandler(int signum)
{
if (signum == SIGINT || signum == SIGTERM)
end_program = 1;
}
/*
* Locate the OID for the 'debug.watchdog.reset' sysctl setting.
* Upon finding it, do an initial reset on the watchdog.
*/
static int
watchdog_init()
{
int error;
error = sysctlnametomib("debug.watchdog.reset", reset_mib,
&reset_miblen);
if (error == -1) {
warn("could not find reset OID");
return (error);
}
return watchdog_tickle();
}
/*
* Main program loop which is iterated every second.
*/
static void
watchdog_loop(void)
{
struct stat sb;
int failed;
while (end_program == 0) {
failed = 0;
failed = stat("/etc", &sb);
if (failed == 0)
watchdog_tickle();
sleep(1);
}
}
/*
* Reset the watchdog timer. This function must be called periodically
* to keep the watchdog from firing.
*/
int
watchdog_tickle(void)
{
return sysctl(reset_mib, reset_miblen, NULL, NULL, NULL, 0);
}
/*
* Toggle the kernel's watchdog. This routine is used to enable and
* disable the watchdog.
*/
static int
watchdog_onoff(int onoff)
{
int mib[3];
int error;
size_t len;
len = 3;
error = sysctlnametomib("debug.watchdog.enabled", mib, &len);
if (error == 0)
error = sysctl(mib, len, NULL, NULL, &onoff, sizeof(onoff));
if (error == -1) {
warn("could not %s watchdog",
(onoff > 0) ? "enable" : "disable");
return (error);
}
return (0);
}
/*
* Tell user how to use the program.
*/
static void
usage()
{
fprintf(stderr, "usage: watchdogd [-d] [-I file]\n");
exit(EX_USAGE);
}
/*
* Handle the few command line arguments supported.
*/
static void
parseargs(int argc, char *argv[])
{
int c;
while ((c = getopt(argc, argv, "I:d?")) != -1) {
switch (c) {
case 'I':
pidfile = optarg;
break;
case 'd':
debugging = 1;
break;
case '?':
default:
usage();
/* NOTREACHED */
}
}
}
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