1 /* $OpenBSD: kern_watchdog.c,v 1.16 2022/08/14 01:58:27 jsg 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/systm.h>
28 #include <sys/timeout.h>
29 #include <sys/sysctl.h>
30
31 void wdog_tickle(void *arg);
32 int (*wdog_ctl_cb)(void *, int) = NULL;
33 void *wdog_ctl_cb_arg = NULL;
34 int wdog_period = 0;
35 int wdog_auto = 1;
36 struct timeout wdog_timeout;
37
38 void
wdog_register(int (* cb)(void *,int),void * cb_arg)39 wdog_register(int (*cb)(void *, int), void *cb_arg)
40 {
41 if (wdog_ctl_cb != NULL)
42 return;
43
44 wdog_ctl_cb = cb;
45 wdog_ctl_cb_arg = cb_arg;
46 timeout_set(&wdog_timeout, wdog_tickle, NULL);
47 }
48
49 void
wdog_tickle(void * arg)50 wdog_tickle(void *arg)
51 {
52 if (wdog_ctl_cb == NULL)
53 return;
54 (void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, wdog_period);
55 timeout_add_msec(&wdog_timeout, wdog_period * 1000 / 2);
56 }
57
58 void
wdog_shutdown(void * arg)59 wdog_shutdown(void *arg)
60 {
61 if (wdog_ctl_cb == NULL || wdog_ctl_cb_arg != arg)
62 return;
63 timeout_del(&wdog_timeout);
64 (void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, 0);
65 wdog_ctl_cb = NULL;
66 wdog_period = 0;
67 wdog_auto = 1;
68 }
69
70 int
sysctl_wdog(int * name,u_int namelen,void * oldp,size_t * oldlenp,void * newp,size_t newlen)71 sysctl_wdog(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
72 size_t newlen)
73 {
74 int error, period;
75
76 if (wdog_ctl_cb == NULL)
77 return (EOPNOTSUPP);
78
79 switch (name[0]) {
80 case KERN_WATCHDOG_PERIOD:
81 period = wdog_period;
82 error = sysctl_int_bounded(oldp, oldlenp, newp, newlen,
83 &period, 0, INT_MAX);
84 if (error)
85 return (error);
86 if (newp) {
87 timeout_del(&wdog_timeout);
88 wdog_period = (*wdog_ctl_cb)(wdog_ctl_cb_arg, period);
89 }
90 break;
91 case KERN_WATCHDOG_AUTO:
92 error = sysctl_int_bounded(oldp, oldlenp, newp, newlen,
93 &wdog_auto, 0, 1);
94 if (error)
95 return (error);
96 break;
97 default:
98 return (EINVAL);
99 }
100
101 if (wdog_auto && wdog_period > 0) {
102 (void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, wdog_period);
103 timeout_add_msec(&wdog_timeout, wdog_period * 1000 / 2);
104 } else
105 timeout_del(&wdog_timeout);
106
107 return (error);
108 }
109