lib/libc/gen/sysctlnametomib.c

   1 /*
   2  * Copyright 2001 The FreeBSD Project. All Rights Reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE FREEBSD PROJECT ``AS IS'' AND ANY
  15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  17  * DISCLAIMED.  IN NO EVENT SHALL THE FREEBSD PROJECT BE LIABLE FOR
  18  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/lib/libc/gen/sysctlnametomib.c,v 1.1.2.1 2001/03/05 08:13:28 obrien Exp $
  27  * $DragonFly: src/lib/libc/gen/sysctlnametomib.c,v 1.3 2005/11/19 22:32:53 swildner Exp $
  28  */
  29
  30 #include <sys/types.h>
  31 #include <sys/sysctl.h>
  32 #include <string.h>
  33
  34 /*
  35  * This function uses a presently undocumented interface to the kernel
  36  * to walk the tree and get the type so it can print the value.
  37  * This interface is under work and consideration, and should probably
  38  * be killed with a big axe by the first person who can find the time.
  39  * (be aware though, that the proper interface isn't as obvious as it
  40  * may seem, there are various conflicting requirements.
  41  */
  42 int
  43 sysctlnametomib(const char *name, int *mibp, size_t *sizep)
  44 {
  45         int oid[2];
  46         int error;
  47
  48         oid[0] = 0;
  49         oid[1] = 3;
  50
  51         *sizep *= sizeof (int);
  52         error = sysctl(oid, 2, mibp, sizep, (void *)name, strlen(name));
  53         *sizep /= sizeof (int);
  54         if (error < 0)
  55                 return (error);
  56         return (0);
  57 }