1 /* $OpenBSD: kern_watchdog.c,v 1.15 2021/01/09 20:59:23 gnezdo Exp $ */ 2 3 /* 4 * Copyright (c) 2003 Markus Friedl. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 #include <sys/param.h> 27 #include <sys/kernel.h> 28 #include <sys/systm.h> 29 #include <sys/timeout.h> 30 #include <sys/sysctl.h> 31 #include <sys/time.h> 32 33 void wdog_tickle(void *arg); 34 int (*wdog_ctl_cb)(void *, int) = NULL; 35 void *wdog_ctl_cb_arg = NULL; 36 int wdog_period = 0; 37 int wdog_auto = 1; 38 struct timeout wdog_timeout; 39 40 void 41 wdog_register(int (*cb)(void *, int), void *cb_arg) 42 { 43 if (wdog_ctl_cb != NULL) 44 return; 45 46 wdog_ctl_cb = cb; 47 wdog_ctl_cb_arg = cb_arg; 48 timeout_set(&wdog_timeout, wdog_tickle, NULL); 49 } 50 51 void 52 wdog_tickle(void *arg) 53 { 54 if (wdog_ctl_cb == NULL) 55 return; 56 (void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, wdog_period); 57 timeout_add_msec(&wdog_timeout, wdog_period * 1000 / 2); 58 } 59 60 void 61 wdog_shutdown(void *arg) 62 { 63 if (wdog_ctl_cb == NULL || wdog_ctl_cb_arg != arg) 64 return; 65 timeout_del(&wdog_timeout); 66 (void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, 0); 67 wdog_ctl_cb = NULL; 68 wdog_period = 0; 69 wdog_auto = 1; 70 } 71 72 int 73 sysctl_wdog(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 74 size_t newlen) 75 { 76 int error, period; 77 78 if (wdog_ctl_cb == NULL) 79 return (EOPNOTSUPP); 80 81 switch (name[0]) { 82 case KERN_WATCHDOG_PERIOD: 83 period = wdog_period; 84 error = sysctl_int_bounded(oldp, oldlenp, newp, newlen, 85 &period, 0, INT_MAX); 86 if (error) 87 return (error); 88 if (newp) { 89 timeout_del(&wdog_timeout); 90 wdog_period = (*wdog_ctl_cb)(wdog_ctl_cb_arg, period); 91 } 92 break; 93 case KERN_WATCHDOG_AUTO: 94 error = sysctl_int_bounded(oldp, oldlenp, newp, newlen, 95 &wdog_auto, 0, 1); 96 if (error) 97 return (error); 98 break; 99 default: 100 return (EINVAL); 101 } 102 103 if (wdog_auto && wdog_period > 0) { 104 (void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, wdog_period); 105 timeout_add_msec(&wdog_timeout, wdog_period * 1000 / 2); 106 } else 107 timeout_del(&wdog_timeout); 108 109 return (error); 110 } 111