xref: /freebsd/lib/libc/gen/sysctlnametomib.c (revision 38effe887ee979f91ad5abf42a2291558e7ff8d1)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright 2001 The FreeBSD Project. 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  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE FREEBSD PROJECT ``AS IS'' AND ANY
17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE FREEBSD PROJECT BE LIABLE FOR
20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/types.h>
33 #include <sys/sysctl.h>
34 #include <string.h>
35 
36 /*
37  * This function uses a presently undocumented interface to the kernel
38  * to walk the tree and get the type so it can print the value.
39  * This interface is under work and consideration, and should probably
40  * be killed with a big axe by the first person who can find the time.
41  * (be aware though, that the proper interface isn't as obvious as it
42  * may seem, there are various conflicting requirements.
43  */
44 int
45 sysctlnametomib(const char *name, int *mibp, size_t *sizep)
46 {
47 	int oid[2];
48 	int error;
49 
50 	oid[0] = CTL_SYSCTL;
51 	oid[1] = CTL_SYSCTL_NAME2OID;
52 
53 	*sizep *= sizeof(int);
54 	error = sysctl(oid, 2, mibp, sizep, name, strlen(name));
55 	*sizep /= sizeof(int);
56 	return (error);
57 }
58