From 370c3cb57cb5163d6847a6824b2720554e33754a Mon Sep 17 00:00:00 2001 From: Sean Kelly Date: Thu, 26 Jun 2003 09:50:52 +0000 Subject: - Add a software watchdog facility. This commit has two pieces. One half is the watchdog kernel code which lives primarily in hardclock() in sys/kern/kern_clock.c. The other half is a userland daemon which, when run, will keep the watchdog from firing while the userland is intact and functioning. Approved by: jeff (mentor) --- usr.sbin/watchdogd/Makefile | 8 ++ usr.sbin/watchdogd/watchdogd.8 | 97 +++++++++++++++++ usr.sbin/watchdogd/watchdogd.c | 232 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 337 insertions(+) create mode 100644 usr.sbin/watchdogd/Makefile create mode 100644 usr.sbin/watchdogd/watchdogd.8 create mode 100644 usr.sbin/watchdogd/watchdogd.c (limited to 'usr.sbin/watchdogd') diff --git a/usr.sbin/watchdogd/Makefile b/usr.sbin/watchdogd/Makefile new file mode 100644 index 000000000000..bc8bfd24d4a6 --- /dev/null +++ b/usr.sbin/watchdogd/Makefile @@ -0,0 +1,8 @@ +# $FreeBSD$ + +PROG= watchdogd +SRCS= watchdogd.c +MAN= watchdogd.8 +WARNS= 6 + +.include diff --git a/usr.sbin/watchdogd/watchdogd.8 b/usr.sbin/watchdogd/watchdogd.8 new file mode 100644 index 000000000000..b8f7ce8ce0a3 --- /dev/null +++ b/usr.sbin/watchdogd/watchdogd.8 @@ -0,0 +1,97 @@ +.\" Copyright (c) 2003 Sean M. Kelly +.\" 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 REGENTS 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 REGENTS 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. +.\" +.\" $FreeBSD$ +.\" +.Dd June 25, 2003 +.Dt WATCHDOGD 8 +.Os +.Sh NAME +.Nm watchdogd +.Nd Software watchdog daemon +.Sh SYNOPSIS +.Nm +.Op Fl d +.Op Fl I Ar file +.Sh DESCRIPTION +The +.Nm +utility interfaces with the kernel's software watchdog facility to ensure +that the system is in a working state. +If +.Nm +is unable to interface with the kernel over a specific timeout, +the kernel will take actions to assist in debugging or restarting the computer. +.Pp +One possible circumstance which will cause a watchdog timeout is an interrupt +storm. +If this occurs, +.Nm +will no longer execute and thus the kernel's watchdog routines will take +action after a configurable timeout. +.Pp +Upon receiving the +.Dv SIGTERM +or +.Dv SIGINT +signals, +.Nm +will first instruct the kernel to no longer perform watchdog checks and then +will terminate. +.Pp +The +.Nm +utility recognizes the following runtime options: +.Bl -tag -width ".Fl I Ar file" +.It Fl I Ar file +Write the process id of the +.Nm +utility in the specified file. +.It Fl d +Don't fork. +When this option is specified, +.Nm +will not fork into the background at startup. +.El +.Sh FILES +.Bl -tag -width "/var/run/watchdogd.pid" -compact +.It Pa /var/run/watchdogd.pid +.El +.Sh SEE ALSO +.Xr watchdog 4 , +.Xr sysctl 8 +.Sh AUTHORS +.An -nosplit +The +.Nm +utility and manual page were written by +.An Sean Kelly Aq smkelly@FreeBSD.org . +.Pp +Some contributions made by +.An Jeff Roberson Aq jeff@FreeBSD.org . +.Sh HISTORY +The +.Nm +utility appeared in +.Fx 5.1 . diff --git a/usr.sbin/watchdogd/watchdogd.c b/usr.sbin/watchdogd/watchdogd.c new file mode 100644 index 000000000000..3dd2f528e14e --- /dev/null +++ b/usr.sbin/watchdogd/watchdogd.c @@ -0,0 +1,232 @@ +/* + * Copyright (c) 2003 Sean M. Kelly + * 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 +__FBSDID("$FreeBSD$"); + +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include + +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]; +int 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) + exit(EX_SOFTWARE); + + 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) { + fprintf(stderr, "Could not find reset OID: %s\n", + strerror(errno)); + 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 + int 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) { + fprintf(stderr, "Could not %s watchdog: %s\n", + (onoff > 0) ? "enable" : "disable", + strerror(errno)); + 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 */ + } + } +} -- cgit v1.2.3