63 lines
2.2 KiB
C
63 lines
2.2 KiB
C
|
/*-
|
||
|
|
* Copyright (c) 2008 Yahoo!, Inc.
|
||
|
|
* All rights reserved.
|
||
|
|
* Written by: John Baldwin <jhb@FreeBSD.org>
|
||
|
|
*
|
||
|
|
* Redistribution and use in source and binary forms, with or without
|
||
|
|
* modification, are permitted provided that the following conditions
|
||
|
|
* are met:
|
||
|
|
* 1. Redistributions of source code must retain the above copyright
|
||
|
|
* notice, this list of conditions and the following disclaimer.
|
||
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
||
|
|
* notice, this list of conditions and the following disclaimer in the
|
||
|
|
* documentation and/or other materials provided with the distribution.
|
||
|
|
* 3. Neither the name of the author nor the names of any co-contributors
|
||
|
|
* may be used to endorse or promote products derived from this software
|
||
|
|
* without specific prior written permission.
|
||
|
|
*
|
||
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
||
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
||
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||
|
|
* SUCH DAMAGE.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <sys/cdefs.h>
|
||
|
|
__FBSDID("$FreeBSD$");
|
||
|
|
|
||
|
|
#include <sys/types.h>
|
||
|
|
#include <sys/sysctl.h>
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Returns true if the named feature is present in the currently
|
||
|
|
* running kernel. A feature's presence is indicated by an integer
|
||
|
|
* sysctl node called kern.feature.<feature> that is non-zero.
|
||
|
|
*/
|
||
|
|
int
|
||
|
|
feature_present(const char *feature)
|
||
|
|
{
|
||
|
|
char *mib;
|
||
|
|
size_t len;
|
||
|
|
int i;
|
||
|
|
|
||
|
|
if (asprintf(&mib, "kern.features.%s", feature) < 0)
|
||
|
|
return (0);
|
||
|
|
len = sizeof(i);
|
||
|
|
if (sysctlbyname(mib, &i, &len, NULL, 0) < 0) {
|
||
|
|
free(mib);
|
||
|
|
return (0);
|
||
|
|
}
|
||
|
|
free(mib);
|
||
|
|
if (len != sizeof(i))
|
||
|
|
return (0);
|
||
|
|
return (i != 0);
|
||
|
|
}
|