/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2003-2004 Sean M. Kelly * Copyright (c) 2013 iXsystems.com, * author: Alfred Perlstein * * 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 #include #include #include #include #include #include #include #include #include static long fetchtimeout(int opt, const char *longopt, const char *myoptarg, int zero_ok); static void parseargs(int, char *[]); static int seconds_to_pow2ns(int); static void sighandler(int); static void watchdog_loop(void); static int watchdog_init(void); static int watchdog_onoff(int onoff); static int watchdog_patpat(u_int timeout); static void usage(void); static int tstotv(struct timeval *tv, struct timespec *ts); static int tvtohz(struct timeval *tv); static int debugging = 0; static int end_program = 0; static const char *pidfile = _PATH_VARRUN "watchdogd.pid"; static u_int timeout = WD_TO_128SEC; static u_int exit_timeout = WD_TO_NEVER; static u_int pretimeout = 0; static u_int timeout_sec; static u_int nap = 10; static int passive = 0; static int is_daemon = 0; static int is_dry_run = 0; /* do not arm the watchdog, only report on timing of the watch program */ static int do_timedog = 0; static int do_syslog = 1; static int fd = -1; static int carp_thresh_seconds = -1; static char *test_cmd = NULL; static const char *getopt_shortopts; static int pretimeout_set; static int pretimeout_act; static int pretimeout_act_set; static int softtimeout_set; static int softtimeout_act; static int softtimeout_act_set; static struct option longopts[] = { { "debug", no_argument, &debugging, 1 }, { "pretimeout", required_argument, &pretimeout_set, 1 }, { "pretimeout-action", required_argument, &pretimeout_act_set, 1 }, { "softtimeout", no_argument, &softtimeout_set, 1 }, { "softtimeout-action", required_argument, &softtimeout_act_set, 1 }, { NULL, 0, NULL, 0} }; /* * Periodically pat the watchdog, preventing it from firing. */ int main(int argc, char *argv[]) { struct rtprio rtp; struct pidfh *pfh; pid_t otherpid; if (getuid() != 0) errx(EX_SOFTWARE, "not super user"); parseargs(argc, argv); if (do_syslog) openlog("watchdogd", LOG_CONS|LOG_NDELAY|LOG_PERROR, LOG_DAEMON); rtp.type = RTP_PRIO_REALTIME; rtp.prio = 0; if (rtprio(RTP_SET, 0, &rtp) == -1) err(EX_OSERR, "rtprio"); if (!is_dry_run && watchdog_init() == -1) errx(EX_SOFTWARE, "unable to initialize watchdog"); if (is_daemon) { if (watchdog_onoff(1) == -1) err(EX_OSERR, "patting the dog"); pfh = pidfile_open(pidfile, 0600, &otherpid); if (pfh == NULL) { if (errno == EEXIST) { watchdog_onoff(0); errx(EX_SOFTWARE, "%s already running, pid: %d", getprogname(), otherpid); } warn("Cannot open or create pidfile"); } if (debugging == 0 && daemon(0, 0) == -1) { watchdog_onoff(0); pidfile_remove(pfh); err(EX_OSERR, "daemon"); } signal(SIGHUP, SIG_IGN); signal(SIGINT, sighandler); signal(SIGTERM, sighandler); pidfile_write(pfh); if (madvise(0, 0, MADV_PROTECT) != 0) warn("madvise failed"); if (mlockall(MCL_CURRENT | MCL_FUTURE) != 0) warn("mlockall failed"); watchdog_loop(); /* exiting */ pidfile_remove(pfh); return (EX_OK); } else { if (passive) timeout |= WD_PASSIVE; else timeout |= WD_ACTIVE; if (watchdog_patpat(timeout) < 0) err(EX_OSERR, "patting the dog"); return (EX_OK); } } static void pow2ns_to_ts(int pow2ns, struct timespec *ts) { uint64_t ns; ns = 1ULL << pow2ns; ts->tv_sec = ns / 1000000000ULL; ts->tv_nsec = ns % 1000000000ULL; } /* * Convert a timeout in seconds to N where 2^N nanoseconds is close to * "seconds". * * The kernel expects the timeouts for watchdogs in "2^N nanosecond format". */ static u_int parse_timeout_to_pow2ns(char opt, const char *longopt, const char *myoptarg) { double a; u_int rv; struct timespec ts; struct timeval tv; int ticks; char shortopt[] = "- "; if (!longopt) shortopt[1] = opt; a = fetchtimeout(opt, longopt, myoptarg, 1); if (a == 0) rv = WD_TO_NEVER; else rv = seconds_to_pow2ns(a); pow2ns_to_ts(rv, &ts); tstotv(&tv, &ts); ticks = tvtohz(&tv); if (debugging) { printf("Timeout for %s%s " "is 2^%d nanoseconds " "(in: %s sec -> out: %jd sec %ld ns -> %d ticks)\n", longopt ? "-" : "", longopt ? longopt : shortopt, rv, myoptarg, (intmax_t)ts.tv_sec, ts.tv_nsec, ticks); } if (ticks <= 0) { errx(1, "Timeout for %s%s is too small, please choose a higher timeout.", longopt ? "-" : "", longopt ? longopt : shortopt); } return (rv); } /* * Catch signals and begin shutdown process. */ static void sighandler(int signum) { if (signum == SIGINT || signum == SIGTERM) end_program = 1; } /* * Open the watchdog device. */ static int watchdog_init(void) { if (is_dry_run) return 0; fd = open("/dev/" _PATH_WATCHDOG, O_RDWR); if (fd >= 0) return (0); warn("Could not open watchdog device"); return (-1); } /* * If we are doing timing, then get the time. */ static int watchdog_getuptime(struct timespec *tp) { int error; if (!do_timedog) return 0; error = clock_gettime(CLOCK_UPTIME_FAST, tp); if (error) warn("clock_gettime"); return (error); } static long watchdog_check_dogfunction_time(struct timespec *tp_start, struct timespec *tp_end) { struct timeval tv_start, tv_end, tv_now, tv; const char *cmd_prefix, *cmd; struct timespec tp_now; int sec; if (!do_timedog) return (0); TIMESPEC_TO_TIMEVAL(&tv_start, tp_start); TIMESPEC_TO_TIMEVAL(&tv_end, tp_end); timersub(&tv_end, &tv_start, &tv); sec = tv.tv_sec; if (sec < carp_thresh_seconds) return (sec); if (test_cmd) { cmd_prefix = "Watchdog program"; cmd = test_cmd; } else { cmd_prefix = "Watchdog operation"; cmd = "stat(\"/etc\", &sb)"; } if (do_syslog) syslog(LOG_CRIT, "%s: '%s' took too long: " "%d.%06ld seconds >= %d seconds threshold", cmd_prefix, cmd, sec, (long)tv.tv_usec, carp_thresh_seconds); else warnx("%s: '%s' took too long: " "%d.%06ld seconds >= %d seconds threshold", cmd_prefix, cmd, sec, (long)tv.tv_usec, carp_thresh_seconds); /* * Adjust the sleep interval again in case syslog(3) took a non-trivial * amount of time to run. */ if (watchdog_getuptime(&tp_now)) return (sec); TIMESPEC_TO_TIMEVAL(&tv_now, &tp_now); timersub(&tv_now, &tv_start, &tv); sec = tv.tv_sec; return (sec); } /* * Main program loop which is iterated every second. */ static void watchdog_loop(void) { struct timespec ts_start, ts_end; struct stat sb; long waited; int error, failed; while (end_program != 2) { failed = 0; error = watchdog_getuptime(&ts_start); if (error) { end_program = 1; goto try_end; } if (test_cmd != NULL) failed = system(test_cmd); else failed = stat("/etc", &sb); error = watchdog_getuptime(&ts_end); if (error) { end_program = 1; goto try_end; } if (failed == 0) watchdog_patpat(timeout|WD_ACTIVE); waited = watchdog_check_dogfunction_time(&ts_start, &ts_end); if (nap - waited > 0) sleep(nap - waited); try_end: if (end_program != 0) { if (watchdog_onoff(0) == 0) { end_program = 2; } else { warnx("Could not stop the watchdog, not exiting"); end_program = 0; } } } } /* * Reset the watchdog timer. This function must be called periodically * to keep the watchdog from firing. */ static int watchdog_patpat(u_int t) { if (is_dry_run) return 0; return ioctl(fd, WDIOCPATPAT, &t); } /* * Toggle the kernel's watchdog. This routine is used to enable and * disable the watchdog. */ static int watchdog_onoff(int onoff) { int error; /* fake successful watchdog op if a dry run */ if (is_dry_run) return 0; if (onoff) { /* * Call the WDIOC_SETSOFT regardless of softtimeout_set * because we'll need to turn it off if someone had turned * it on. */ error = ioctl(fd, WDIOC_SETSOFT, &softtimeout_set); if (error) { warn("setting WDIOC_SETSOFT %d", softtimeout_set); return (error); } error = watchdog_patpat((timeout|WD_ACTIVE)); if (error) { warn("watchdog_patpat failed"); goto failsafe; } if (softtimeout_act_set) { error = ioctl(fd, WDIOC_SETSOFTTIMEOUTACT, &softtimeout_act); if (error) { warn("setting WDIOC_SETSOFTTIMEOUTACT %d", softtimeout_act); goto failsafe; } } if (pretimeout_set) { error = ioctl(fd, WDIOC_SETPRETIMEOUT, &pretimeout); if (error) { warn("setting WDIOC_SETPRETIMEOUT %d", pretimeout); goto failsafe; } } if (pretimeout_act_set) { error = ioctl(fd, WDIOC_SETPRETIMEOUTACT, &pretimeout_act); if (error) { warn("setting WDIOC_SETPRETIMEOUTACT %d", pretimeout_act); goto failsafe; } } /* pat one more time for good measure */ return watchdog_patpat((timeout|WD_ACTIVE)); } else { return watchdog_patpat(exit_timeout); } failsafe: watchdog_patpat(exit_timeout); return (error); } /* * Tell user how to use the program. */ static void usage(void) { if (is_daemon) fprintf(stderr, "usage:\n" " watchdogd [-dnSw] [-e cmd] [-I pidfile] [-s sleep] [-t timeout]\n" " [-T script_timeout] [-x exit_timeout]\n" " [--debug]\n" " [--pretimeout seconds] [-pretimeout-action action]\n" " [--softtimeout] [-softtimeout-action action]\n" ); else fprintf(stderr, "usage: watchdog [-d] [-t timeout]\n"); exit(EX_USAGE); } static long fetchtimeout(int opt, const char *longopt, const char *myoptarg, int zero_ok) { const char *errstr; char *p; long rv; errstr = NULL; p = NULL; errno = 0; rv = strtol(myoptarg, &p, 0); if ((p != NULL && *p != '\0') || errno != 0) errstr = "is not a number"; if (rv < 0 || (!zero_ok && rv == 0)) errstr = "must be greater than zero"; if (errstr) { if (longopt) errx(EX_USAGE, "--%s argument %s", longopt, errstr); else errx(EX_USAGE, "-%c argument %s", opt, errstr); } return (rv); } struct act_tbl { const char *at_act; int at_value; }; static const struct act_tbl act_tbl[] = { { "panic", WD_SOFT_PANIC }, { "ddb", WD_SOFT_DDB }, { "log", WD_SOFT_LOG }, { "printf", WD_SOFT_PRINTF }, { NULL, 0 } }; static void timeout_act_error(const char *lopt, const char *badact) { char *opts, *oldopts; int i; opts = NULL; for (i = 0; act_tbl[i].at_act != NULL; i++) { oldopts = opts; if (asprintf(&opts, "%s%s%s", oldopts == NULL ? "" : oldopts, oldopts == NULL ? "" : ", ", act_tbl[i].at_act) == -1) err(EX_OSERR, "malloc"); free(oldopts); } warnx("bad --%s argument '%s' must be one of (%s).", lopt, badact, opts); usage(); } /* * Take a comma separated list of actions and or the flags * together for the ioctl. */ static int timeout_act_str2int(const char *lopt, const char *acts) { int i; char *dupacts, *tofree; char *o; int rv = 0; tofree = dupacts = strdup(acts); if (!tofree) err(EX_OSERR, "malloc"); while ((o = strsep(&dupacts, ",")) != NULL) { for (i = 0; act_tbl[i].at_act != NULL; i++) { if (!strcmp(o, act_tbl[i].at_act)) { rv |= act_tbl[i].at_value; break; } } if (act_tbl[i].at_act == NULL) timeout_act_error(lopt, o); } free(tofree); return rv; } int tstotv(struct timeval *tv, struct timespec *ts) { tv->tv_sec = ts->tv_sec; tv->tv_usec = ts->tv_nsec / 1000; return 0; } /* * Convert a timeval to a number of ticks. * Mostly copied from the kernel. */ int tvtohz(struct timeval *tv) { register unsigned long ticks; register long sec, usec; int hz; size_t hzsize; int error; int tick; hzsize = sizeof(hz); error = sysctlbyname("kern.hz", &hz, &hzsize, NULL, 0); if (error) err(1, "sysctlbyname kern.hz"); tick = 1000000 / hz; /* * If the number of usecs in the whole seconds part of the time * difference fits in a long, then the total number of usecs will * fit in an unsigned long. Compute the total and convert it to * ticks, rounding up and adding 1 to allow for the current tick * to expire. Rounding also depends on unsigned long arithmetic * to avoid overflow. * * Otherwise, if the number of ticks in the whole seconds part of * the time difference fits in a long, then convert the parts to * ticks separately and add, using similar rounding methods and * overflow avoidance. This method would work in the previous * case but it is slightly slower and assumes that hz is integral. * * Otherwise, round the time difference down to the maximum * representable value. * * If ints have 32 bits, then the maximum value for any timeout in * 10ms ticks is 248 days. */ sec = tv->tv_sec; usec = tv->tv_usec; if (usec < 0) { sec--; usec += 1000000; } if (sec < 0) { #ifdef DIAGNOSTIC if (usec > 0) { sec++; usec -= 1000000; } printf("tvotohz: negative time difference %ld sec %ld usec\n", sec, usec); #endif ticks = 1; } else if (sec <= LONG_MAX / 1000000) ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1)) / tick + 1; else if (sec <= LONG_MAX / hz) ticks = sec * hz + ((unsigned long)usec + (tick - 1)) / tick + 1; else ticks = LONG_MAX; if (ticks > INT_MAX) ticks = INT_MAX; return ((int)ticks); } static int seconds_to_pow2ns(int seconds) { uint64_t power; uint64_t ns; uint64_t shifted; if (seconds <= 0) errx(1, "seconds %d < 0", seconds); ns = ((uint64_t)seconds) * 1000000000ULL; power = flsll(ns); shifted = 1ULL << power; if (shifted <= ns) { power++; } if (debugging) { printf("shifted %lld\n", (long long)shifted); printf("seconds_to_pow2ns: seconds: %d, ns %lld, power %d\n", seconds, (long long)ns, (int)power); } return (power); } /* * Handle the few command line arguments supported. */ static void parseargs(int argc, char *argv[]) { struct timespec ts; int longindex; int c; const char *lopt; /* Get the default value of timeout_sec from the default timeout. */ pow2ns_to_ts(timeout, &ts); timeout_sec = ts.tv_sec; /* * if we end with a 'd' aka 'watchdogd' then we are the daemon program, * otherwise run as a command line utility. */ c = strlen(argv[0]); if (argv[0][c - 1] == 'd') is_daemon = 1; if (is_daemon) getopt_shortopts = "I:de:ns:t:ST:wx:?"; else getopt_shortopts = "dt:?"; while ((c = getopt_long(argc, argv, getopt_shortopts, longopts, &longindex)) != -1) { switch (c) { case 'I': pidfile = optarg; break; case 'd': debugging = 1; break; case 'e': test_cmd = strdup(optarg); break; case 'n': is_dry_run = 1; break; #ifdef notyet case 'p': passive = 1; break; #endif case 's': nap = fetchtimeout(c, NULL, optarg, 0); break; case 'S': do_syslog = 0; break; case 't': timeout_sec = atoi(optarg); timeout = parse_timeout_to_pow2ns(c, NULL, optarg); if (debugging) printf("Timeout is 2^%d nanoseconds\n", timeout); break; case 'T': carp_thresh_seconds = fetchtimeout(c, "NULL", optarg, 0); break; case 'w': do_timedog = 1; break; case 'x': exit_timeout = parse_timeout_to_pow2ns(c, NULL, optarg); if (exit_timeout != 0) exit_timeout |= WD_ACTIVE; break; case 0: lopt = longopts[longindex].name; if (!strcmp(lopt, "pretimeout")) { pretimeout = fetchtimeout(0, lopt, optarg, 0); } else if (!strcmp(lopt, "pretimeout-action")) { pretimeout_act = timeout_act_str2int(lopt, optarg); } else if (!strcmp(lopt, "softtimeout-action")) { softtimeout_act = timeout_act_str2int(lopt, optarg); } else { /* warnx("bad option at index %d: %s", optind, argv[optind]); usage(); */ } break; case '?': default: usage(); /* NOTREACHED */ } } if (nap > timeout_sec / 2) nap = timeout_sec / 2; if (carp_thresh_seconds == -1) carp_thresh_seconds = nap; if (argc != optind) errx(EX_USAGE, "extra arguments."); if (is_daemon && timeout < WD_TO_1SEC) errx(EX_USAGE, "-t argument is less than one second."); if (pretimeout_set) { if (pretimeout >= timeout_sec) { errx(EX_USAGE, "pretimeout (%d) >= timeout (%d -> %ld)\n" "see manual section TIMEOUT RESOLUTION", pretimeout, timeout_sec, (long)ts.tv_sec); } } }