xref: /illumos-gate/usr/src/lib/libc/port/gen/mkdev.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include "lint.h"
33 #include <sys/types.h>
34 #include <sys/mkdev.h>
35 #include <errno.h>
36 
37 /*
38  * Create a formatted device number
39  */
40 dev_t
41 __makedev(const int version, const major_t majdev, const minor_t mindev)
42 {
43 	dev_t devnum;
44 	switch (version) {
45 	case OLDDEV:
46 		if (majdev > OMAXMAJ || mindev > OMAXMIN) {
47 			errno = EINVAL;
48 			return ((o_dev_t)NODEV);
49 		}
50 		devnum = ((majdev << ONBITSMINOR) | mindev);
51 		break;
52 
53 	case NEWDEV:
54 #if MAXMAJ != 0xfffffffful	/* assumes major_t == uint32_t */
55 		if (majdev > MAXMAJ) {
56 			errno = EINVAL;
57 			return (NODEV);
58 		}
59 #endif
60 #if MAXMIN != 0xfffffffful	/* assumes minor_t == uint32_t */
61 		if (mindev > MAXMIN) {
62 			errno = EINVAL;
63 			return (NODEV);
64 		}
65 #endif
66 		if ((devnum = (((dev_t)majdev << NBITSMINOR) |
67 		    mindev)) == NODEV) {
68 			errno = EINVAL;
69 			return (NODEV);
70 		}
71 		break;
72 
73 	default:
74 		errno = EINVAL;
75 		return (NODEV);
76 	}
77 
78 	return (devnum);
79 }
80 
81 /*
82  * Return major number part of formatted device number
83  */
84 major_t
85 __major(const int version, const dev_t devnum)
86 {
87 	major_t maj;
88 
89 	switch (version) {
90 	case OLDDEV:
91 		maj = (devnum >> ONBITSMINOR);
92 		if (devnum == NODEV || maj > OMAXMAJ) {
93 			errno = EINVAL;
94 			return ((major_t)NODEV);
95 		}
96 		break;
97 
98 	case NEWDEV:
99 		maj = (devnum >> NBITSMINOR);
100 		if (devnum == NODEV) {
101 			errno = EINVAL;
102 			return ((major_t)NODEV);
103 		}
104 #if MAXMAJ != 0xfffffffful	/* assumes major_t == uint32_t */
105 		if (maj > MAXMAJ) {
106 			errno = EINVAL;
107 			return ((major_t)NODEV);
108 		}
109 #endif
110 		break;
111 
112 	default:
113 		errno = EINVAL;
114 		return ((major_t)NODEV);
115 	}
116 
117 	return (maj);
118 }
119 
120 
121 /*
122  * Return minor number part of formatted device number
123  */
124 minor_t
125 __minor(const int version, const dev_t devnum)
126 {
127 	switch (version) {
128 	case OLDDEV:
129 		if (devnum == NODEV) {
130 			errno = EINVAL;
131 			return ((minor_t)NODEV);
132 		}
133 		return (devnum & OMAXMIN);
134 
135 	case NEWDEV:
136 		if (devnum == NODEV) {
137 			errno = EINVAL;
138 			return ((minor_t)NODEV);
139 		}
140 		return (devnum & MAXMIN);
141 
142 	default:
143 		errno = EINVAL;
144 		return ((minor_t)NODEV);
145 	}
146 }
147