lib/libc/gen/getdevmajor.c

   1 /*      $NetBSD: getdevmajor.c,v 1.6 2012/03/13 21:13:35 christos Exp $ */
   2
   3 /*-
   4  * Copyright (c) 2004 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Andrew Brown.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  32  * POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include <sys/cdefs.h>
  36 #if defined(LIBC_SCCS) && !defined(lint)
  37 __RCSID("$NetBSD: getdevmajor.c,v 1.6 2012/03/13 21:13:35 christos Exp $");
  38 #endif /* LIBC_SCCS and not lint */
  39
  40 #include "namespace.h"
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #include <sys/param.h>
  44 #include <sys/sysctl.h>
  45
  46 #include <errno.h>
  47 #include <string.h>
  48 #include <stdlib.h>
  49
  50 #ifdef __weak_alias
  51 __weak_alias(getdevmajor,_getdevmajor)
  52 #endif
  53
  54 /*
  55  * XXX temporary alias because getdevmajor() was renamed
  56  * in -current for some time
  57  */
  58 dev_t __getdevmajor50(const char *, mode_t);
  59 dev_t
  60 __getdevmajor50(const char *name, mode_t type)
  61 {
  62
  63         return (dev_t)getdevmajor(name, type);
  64 }
  65
  66 devmajor_t
  67 getdevmajor(const char *name, mode_t type)
  68 {
  69         struct kinfo_drivers kd[200], *kdp = &kd[0];
  70         size_t i, sz = sizeof(kd);
  71         int rc;
  72         devmajor_t n = NODEVMAJOR;
  73
  74         if (type != S_IFCHR && type != S_IFBLK) {
  75                 errno = EINVAL;
  76                 return n;
  77         }
  78
  79         do {
  80                 rc = sysctlbyname("kern.drivers", kdp, &sz, NULL, 0);
  81                 if (rc == -1) {
  82                         if (errno != ENOMEM)
  83                                 goto out;
  84                         if (kdp != &kd[0])
  85                                 free(kdp);
  86                         if ((kdp = malloc(sz)) == NULL)
  87                                 return n;
  88                 }
  89         } while (rc == -1);
  90
  91         sz /= sizeof(*kdp);
  92
  93         for (i = 0; i < sz; i++) {
  94                 if (strcmp(name, kdp[i].d_name) == 0) {
  95                         if (type == S_IFCHR)
  96                                 n = kdp[i].d_cmajor;
  97                         else
  98                                 n = kdp[i].d_bmajor;
  99                         break;
 100                 }
 101         }
 102         if (i >= sz)
 103                 errno = ENOENT;
 104
 105   out:
 106         if (kdp != &kd[0])
 107                 free(kdp);
 108
 109         return n;
 110 }