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/* $OpenBSD: watchdogd.c,v 1.15 2015/01/16 06:40:22 deraadt Exp $ */ |
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/* |
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* Copyright (c) 2005 Marc Balmer <mbalmer@openbsd.org> |
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* |
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* Permission to use, copy, modify, and distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <sys/types.h> |
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#include <sys/resource.h> |
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#include <sys/signal.h> |
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#include <sys/sysctl.h> |
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#include <sys/mman.h> |
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#include <err.h> |
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#include <errno.h> |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <unistd.h> |
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volatile sig_atomic_t quit = 0; |
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__dead void usage(void); |
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void sighdlr(int); |
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int main(int, char *[]); |
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__dead void |
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usage(void) |
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{ |
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extern char *__progname; |
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fprintf(stderr, "usage: %s [-dnq] [-i interval] [-p period]\n", |
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__progname); |
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exit(1); |
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} |
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/* ARGSUSED */ |
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void |
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sighdlr(int signum) |
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{ |
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quit = 1; |
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} |
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int |
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main(int argc, char *argv[]) |
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{ |
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struct rlimit rlim; |
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const char *errstr; |
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size_t len; |
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u_int interval = 0, period = 30, nperiod; |
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int ch, trigauto, sauto, speriod; |
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int quiet = 0, daemonize = 1, retval = 1, do_restore = 1; |
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int mib[3]; |
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while ((ch = getopt(argc, argv, "di:np:q")) != -1) { |
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switch (ch) { |
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case 'd': |
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daemonize = 0; |
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break; |
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case 'i': |
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interval = (u_int)strtonum(optarg, 1LL, 86400LL, |
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&errstr); |
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if (errstr) |
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errx(1, "interval is %s: %s", errstr, optarg); |
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break; |
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case 'n': |
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do_restore = 0; |
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break; |
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case 'p': |
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period = (u_int)strtonum(optarg, 2LL, 86400LL, &errstr); |
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if (errstr) |
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errx(1, "period is %s: %s", errstr, optarg); |
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break; |
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case 'q': |
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quiet = 1; |
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break; |
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default: |
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usage(); |
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} |
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} |
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argc -= optind; |
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argv += optind; |
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if (argc > 0) |
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usage(); |
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if (interval == 0 && (interval = period / 3) == 0) |
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interval = 1; |
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if (period <= interval) |
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errx(1, "retrigger interval too long"); |
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/* save kern.watchdog.period and kern.watchdog.auto for restore */ |
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mib[0] = CTL_KERN; |
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mib[1] = KERN_WATCHDOG; |
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mib[2] = KERN_WATCHDOG_PERIOD; |
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len = sizeof(speriod); |
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if (sysctl(mib, 3, &speriod, &len, &period, sizeof(period)) == -1) { |
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if (errno == EOPNOTSUPP) |
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errx(1, "no watchdog timer available"); |
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else |
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err(1, "can't access kern.watchdog.period"); |
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} |
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mib[2] = KERN_WATCHDOG_AUTO; |
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len = sizeof(sauto); |
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trigauto = 0; |
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if (sysctl(mib, 3, &sauto, &len, &trigauto, sizeof(trigauto)) == -1) |
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err(1, "can't access kern.watchdog.auto"); |
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/* Double check the timeout period, some devices change the value */ |
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mib[2] = KERN_WATCHDOG_PERIOD; |
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len = sizeof(nperiod); |
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if (sysctl(mib, 3, &nperiod, &len, NULL, 0) == -1) { |
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warnx("can't read back kern.watchdog.period, " |
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"restoring original values"); |
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goto restore; |
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} |
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if (nperiod != period && !quiet) |
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warnx("period adjusted to %d by device", nperiod); |
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if (nperiod <= interval) { |
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warnx("retrigger interval %d too long, " |
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"restoring original values", interval); |
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goto restore; |
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} |
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if (daemonize && daemon(0, 0)) { |
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warn("can't daemonize, restoring original values"); |
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goto restore; |
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} |
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/* |
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* mlockall() below will wire the whole stack up to the limit |
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* thus we have to reduce stack size to avoid resource abuse |
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*/ |
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rlim.rlim_cur = 256 * 1024; |
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rlim.rlim_max = 256 * 1024; |
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(void)setrlimit(RLIMIT_STACK, &rlim); |
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(void)mlockall(MCL_CURRENT | MCL_FUTURE); |
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setpriority(PRIO_PROCESS, getpid(), -5); |
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signal(SIGTERM, sighdlr); |
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retval = 0; |
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while (!quit) { |
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if (sysctl(mib, 3, NULL, 0, &period, sizeof(period)) == -1) |
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quit = retval = 1; |
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sleep(interval); |
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} |
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if (do_restore) { |
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restore: sysctl(mib, 3, NULL, 0, &speriod, sizeof(speriod)); |
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mib[2] = KERN_WATCHDOG_AUTO; |
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sysctl(mib, 3, NULL, 0, &sauto, sizeof(sauto)); |
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} |
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return retval; |
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} |