Line data    Source code

       1             : /*      $OpenBSD: kern_watchdog.c,v 1.13 2017/01/09 17:58:44 mpi 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           0 : wdog_register(int (*cb)(void *, int), void *cb_arg)
      42             : {
      43           0 :         if (wdog_ctl_cb != NULL)
      44             :                 return;
      45             : 
      46           0 :         wdog_ctl_cb = cb;
      47           0 :         wdog_ctl_cb_arg = cb_arg;
      48           0 :         timeout_set(&wdog_timeout, wdog_tickle, NULL);
      49           0 : }
      50             : 
      51             : void
      52           0 : wdog_tickle(void *arg)
      53             : {
      54           0 :         if (wdog_ctl_cb == NULL)
      55             :                 return;
      56           0 :         (void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, wdog_period);
      57           0 :         timeout_add(&wdog_timeout, wdog_period * hz / 2);
      58           0 : }
      59             : 
      60             : void
      61           0 : wdog_shutdown(void *arg)
      62             : {
      63           0 :         if (wdog_ctl_cb == NULL || wdog_ctl_cb_arg != arg)
      64             :                 return;
      65           0 :         timeout_del(&wdog_timeout);
      66           0 :         (void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, 0);
      67           0 :         wdog_ctl_cb = NULL;
      68           0 :         wdog_period = 0;
      69           0 :         wdog_auto = 1;
      70           0 : }
      71             : 
      72             : int
      73           0 : sysctl_wdog(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
      74             :     size_t newlen)
      75             : {
      76           0 :         int error, period;
      77             : 
      78           0 :         if (wdog_ctl_cb == NULL)
      79           0 :                 return (EOPNOTSUPP);
      80             : 
      81           0 :         switch (name[0]) {
      82             :         case KERN_WATCHDOG_PERIOD:
      83           0 :                 period = wdog_period;
      84           0 :                 error = sysctl_int(oldp, oldlenp, newp, newlen, &period);
      85           0 :                 if (error)
      86           0 :                         return (error);
      87           0 :                 if (newp) {
      88           0 :                         timeout_del(&wdog_timeout);
      89           0 :                         wdog_period = (*wdog_ctl_cb)(wdog_ctl_cb_arg, period);
      90           0 :                 }
      91             :                 break;
      92             :         case KERN_WATCHDOG_AUTO:
      93           0 :                 error = sysctl_int(oldp, oldlenp, newp, newlen, &wdog_auto);
      94           0 :                 if (error)
      95           0 :                         return (error);
      96             :                 break;
      97             :         default:
      98           0 :                 return (EINVAL);
      99             :         }
     100             : 
     101           0 :         if (wdog_auto && wdog_period > 0) {
     102           0 :                 (void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, wdog_period);
     103           0 :                 timeout_add(&wdog_timeout, wdog_period * hz / 2);
     104           0 :         } else
     105           0 :                 timeout_del(&wdog_timeout);
     106             : 
     107           0 :         return (error);
     108           0 : }