1 /* $OpenBSD: kern_watchdog.c,v 1.1 2003/01/21 16:59:23 markus 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/sysctl.h> 30 #include <sys/time.h> 31 32 void wdog_init(void); 33 void wdog_tickle(void *arg); 34 void wdog_shutdown(void *arg); 35 int (*wdog_ctl_cb)(void *, int) = NULL; 36 void *wdog_ctl_cb_arg = NULL; 37 int wdog_period = 0; 38 int wdog_auto = 1; 39 struct timeout wdog_timeout; 40 41 void 42 wdog_init(void) 43 { 44 timeout_set(&wdog_timeout, wdog_tickle, NULL); 45 shutdownhook_establish(wdog_shutdown, NULL); 46 } 47 48 void 49 wdog_register(void *cb_arg, int (*cb)(void *, int)) 50 { 51 if (wdog_ctl_cb != NULL) 52 return; 53 wdog_init(); 54 wdog_ctl_cb = cb; 55 wdog_ctl_cb_arg = cb_arg; 56 } 57 58 void 59 wdog_tickle(void *arg) 60 { 61 if (wdog_ctl_cb == NULL) 62 return; 63 (void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, wdog_period); 64 timeout_add(&wdog_timeout, wdog_period * hz / 2); 65 } 66 67 void 68 wdog_shutdown(void *arg) 69 { 70 if (wdog_ctl_cb == NULL) 71 return; 72 timeout_del(&wdog_timeout); 73 (void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, 0); 74 } 75 76 int 77 sysctl_wdog(name, namelen, oldp, oldlenp, newp, newlen) 78 int *name; 79 u_int namelen; 80 void *oldp; 81 size_t *oldlenp; 82 void *newp; 83 size_t newlen; 84 { 85 int error, period; 86 87 if (wdog_ctl_cb == NULL) 88 return (EOPNOTSUPP); 89 90 switch (name[0]) { 91 case KERN_WATCHDOG_PERIOD: 92 period = wdog_period; 93 error = sysctl_int(oldp, oldlenp, newp, newlen, &period); 94 if (error) 95 return (error); 96 if (newp) { 97 timeout_del(&wdog_timeout); 98 wdog_period = (*wdog_ctl_cb)(wdog_ctl_cb_arg, period); 99 } 100 break; 101 case KERN_WATCHDOG_AUTO: 102 error = sysctl_int(oldp, oldlenp, newp, newlen, &wdog_auto); 103 if (error) 104 return (error); 105 break; 106 default: 107 return (EINVAL); 108 } 109 110 timeout_del(&wdog_timeout); 111 if (wdog_auto && wdog_period > 0) { 112 (void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, wdog_period); 113 timeout_add(&wdog_timeout, wdog_period * hz / 2); 114 } 115 return (error); 116 } 117