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getdevmajor.c revision 1.5.8.1 
      1 /*	$NetBSD: getdevmajor.c,v 1.5.8.1 2012/04/17 00:05:18 yamt 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 1.5.8.1 2012/04/17 00:05:18 yamt 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 }
    111