gen/FreeBSD/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
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD: src/lib/libc/gen/sysctlnametomib.c,v 1.4 2003/01/04 00:11:11 tjr Exp $");
  29
  30 #include <sys/types.h>
  31 #include <sys/sysctl.h>
  32 #include <string.h>
  33
  34 extern int __sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
  35                                         void *newp, size_t newlen);
  36
  37 /*
  38  * This function uses a presently undocumented interface to the kernel
  39  * to walk the tree and get the type so it can print the value.
  40  * This interface is under work and consideration, and should probably
  41  * be killed with a big axe by the first person who can find the time.
  42  * (be aware though, that the proper interface isn't as obvious as it
  43  * may seem, there are various conflicting requirements.
  44  */
  45 int
  46 sysctlnametomib(const char *name, int *mibp, size_t *sizep)
  47 {
  48         int oid[2];
  49         int error;
  50
  51         oid[0] = 0;
  52         oid[1] = 3;
  53
  54         *sizep *= sizeof (int);
  55         error = __sysctl(oid, 2, mibp, sizep, (void *)name, strlen(name));
  56         *sizep /= sizeof (int);
  57         return (error);
  58 }