xref: /illumos-gate/usr/src/lib/libc/port/gen/mkdev.c (revision 9b9d39d2a32ff806d2431dbcc50968ef1e6d46b2)
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 /*
31  * Copyright 2024 Oxide Computer Company
32  */
33 
34 #include "lint.h"
35 #include <sys/types.h>
36 #include <sys/mkdev.h>
37 #include <errno.h>
38 
39 /*
40  * Create a formatted device number
41  */
42 dev_t
43 __makedev(const int version, const major_t majdev, const minor_t mindev)
44 {
45 	dev_t devnum;
46 	switch (version) {
47 	case OLDDEV:
48 		if (majdev > OMAXMAJ || mindev > OMAXMIN) {
49 			errno = EINVAL;
50 			return ((o_dev_t)NODEV);
51 		}
52 		devnum = ((majdev << ONBITSMINOR) | mindev);
53 		break;
54 
55 	case NEWDEV:
56 #if MAXMAJ != 0xfffffffful	/* assumes major_t == uint32_t */
57 		if (majdev > MAXMAJ) {
58 			errno = EINVAL;
59 			return (NODEV);
60 		}
61 #endif
62 #if MAXMIN != 0xfffffffful	/* assumes minor_t == uint32_t */
63 		if (mindev > MAXMIN) {
64 			errno = EINVAL;
65 			return (NODEV);
66 		}
67 #endif
68 		if ((devnum = (((dev_t)majdev << NBITSMINOR) |
69 		    mindev)) == NODEV) {
70 			errno = EINVAL;
71 			return (NODEV);
72 		}
73 		break;
74 	case COMPATDEV:
75 		if (majdev > MAXMAJ32 || mindev > MAXMIN32) {
76 			errno = EINVAL;
77 			return (NODEV);
78 		}
79 
80 		if ((devnum = (((dev_t)majdev << NBITSMINOR32) |
81 		    mindev)) == NODEV) {
82 			errno = EINVAL;
83 			return (NODEV);
84 		}
85 		break;
86 	default:
87 		errno = EINVAL;
88 		return (NODEV);
89 	}
90 
91 	return (devnum);
92 }
93 
94 /*
95  * Return major number part of formatted device number
96  */
97 major_t
98 __major(const int version, const dev_t devnum)
99 {
100 	major_t maj;
101 
102 	switch (version) {
103 	case OLDDEV:
104 		maj = (devnum >> ONBITSMINOR);
105 		if (devnum == NODEV || maj > OMAXMAJ) {
106 			errno = EINVAL;
107 			return ((major_t)NODEV);
108 		}
109 		break;
110 
111 	case NEWDEV:
112 		maj = (devnum >> NBITSMINOR);
113 		if (devnum == NODEV) {
114 			errno = EINVAL;
115 			return ((major_t)NODEV);
116 		}
117 #if MAXMAJ != 0xfffffffful	/* assumes major_t == uint32_t */
118 		if (maj > MAXMAJ) {
119 			errno = EINVAL;
120 			return ((major_t)NODEV);
121 		}
122 #endif
123 		break;
124 
125 	case COMPATDEV:
126 		maj = devnum >> NBITSMAJOR32;
127 		if (devnum == NODEV || maj > MAXMAJ32) {
128 			errno = EINVAL;
129 			return ((major_t)NODEV);
130 		}
131 		break;
132 
133 	default:
134 		errno = EINVAL;
135 		return ((major_t)NODEV);
136 	}
137 
138 	return (maj);
139 }
140 
141 
142 /*
143  * Return minor number part of formatted device number
144  */
145 minor_t
146 __minor(const int version, const dev_t devnum)
147 {
148 	if (devnum == NODEV) {
149 		errno = EINVAL;
150 		return ((minor_t)NODEV);
151 	}
152 
153 	switch (version) {
154 	case OLDDEV:
155 		return (devnum & OMAXMIN);
156 	case NEWDEV:
157 		return (devnum & MAXMIN);
158 	case COMPATDEV:
159 		return (devnum & MAXMIN32);
160 	default:
161 		errno = EINVAL;
162 		return ((minor_t)NODEV);
163 	}
164 }
165