1 /* $OpenBSD: dir.h,v 1.10 2005/06/18 18:09:43 millert Exp $ */
2 /* $NetBSD: dir.h,v 1.8 1996/03/09 19:42:41 scottr Exp $ */
3
4 /*
5 * Copyright (c) 1982, 1986, 1989, 1993
6 * The Regents of the University of California. All rights reserved.
7 * (c) UNIX System Laboratories, Inc.
8 * All or some portions of this file are derived from material licensed
9 * to the University of California by American Telephone and Telegraph
10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
11 * the permission of UNIX System Laboratories, Inc.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * @(#)dir.h 8.4 (Berkeley) 8/10/94
38 */
39
40 #ifndef _DIR_H_
41 #define _DIR_H_
42
43 /*
44 * Theoretically, directories can be more than 2Gb in length, however, in
45 * practice this seems unlikely. So, we define the type doff_t as a 32-bit
46 * quantity to keep down the cost of doing lookup on a 32-bit machine.
47 */
48 #define doff_t int32_t
49 #define MAXDIRSIZE (0x7fffffff)
50
51 /*
52 * A directory consists of some number of blocks of DIRBLKSIZ
53 * bytes, where DIRBLKSIZ is chosen such that it can be transferred
54 * to disk in a single atomic operation (e.g. 512 bytes on most machines).
55 *
56 * Each DIRBLKSIZ byte block contains some number of directory entry
57 * structures, which are of variable length. Each directory entry has
58 * a struct direct at the front of it, containing its inode number,
59 * the length of the entry, and the length of the name contained in
60 * the entry. These are followed by the name padded to a 4 byte boundary
61 * with null bytes. All names are guaranteed null terminated.
62 * The maximum length of a name in a directory is MAXNAMLEN.
63 *
64 * The macro DIRSIZ(fmt, dp) gives the amount of space required to represent
65 * a directory entry. Free space in a directory is represented by
66 * entries which have dp->d_reclen > DIRSIZ(fmt, dp). All DIRBLKSIZ bytes
67 * in a directory block are claimed by the directory entries. This
68 * usually results in the last entry in a directory having a large
69 * dp->d_reclen. When entries are deleted from a directory, the
70 * space is returned to the previous entry in the same directory
71 * block by increasing its dp->d_reclen. If the first entry of
72 * a directory block is free, then its dp->d_ino is set to 0.
73 * Entries other than the first in a directory do not normally have
74 * dp->d_ino set to 0.
75 */
76 #define DIRBLKSIZ DEV_BSIZE
77 #define MAXNAMLEN 255
78
79 struct direct {
80 u_int32_t d_ino; /* inode number of entry */
81 u_int16_t d_reclen; /* length of this record */
82 u_int8_t d_type; /* file type, see below */
83 u_int8_t d_namlen; /* length of string in d_name */
84 char d_name[MAXNAMLEN + 1];/* name with length <= MAXNAMLEN */
85 };
86
87 /*
88 * File types
89 */
90 #define DT_UNKNOWN 0
91 #define DT_FIFO 1
92 #define DT_CHR 2
93 #define DT_DIR 4
94 #define DT_BLK 6
95 #define DT_REG 8
96 #define DT_LNK 10
97 #define DT_SOCK 12
98
99 /*
100 * Convert between stat structure types and directory types.
101 */
102 #define IFTODT(mode) (((mode) & 0170000) >> 12)
103 #define DTTOIF(dirtype) ((dirtype) << 12)
104
105 /*
106 * The DIRSIZ macro gives the minimum record length which will hold
107 * the directory entry. This requires the amount of space in struct direct
108 * without the d_name field, plus enough space for the name with a terminating
109 * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
110 */
111 #define DIRECTSIZ(namlen) \
112 (((int)&((struct direct *)0)->d_name + \
113 ((namlen)+1)*sizeof(((struct direct *)0)->d_name[0]) + 3) & ~3)
114 #if (BYTE_ORDER == LITTLE_ENDIAN)
115 #define DIRSIZ(oldfmt, dp) \
116 ((oldfmt) ? \
117 ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_type+1 + 3) &~ 3)) : \
118 ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3)))
119 #else
120 #define DIRSIZ(oldfmt, dp) \
121 ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))
122 #endif
123 #define OLDDIRFMT 1
124 #define NEWDIRFMT 0
125
126 /*
127 * Template for manipulating directories. Should use struct direct's,
128 * but the name field is MAXNAMLEN - 1, and this just won't do.
129 */
130 struct dirtemplate {
131 u_int32_t dot_ino;
132 int16_t dot_reclen;
133 u_int8_t dot_type;
134 u_int8_t dot_namlen;
135 char dot_name[4]; /* must be multiple of 4 */
136 u_int32_t dotdot_ino;
137 int16_t dotdot_reclen;
138 u_int8_t dotdot_type;
139 u_int8_t dotdot_namlen;
140 char dotdot_name[4]; /* ditto */
141 };
142
143 /*
144 * This is the old format of directories, sanz type element.
145 */
146 struct odirtemplate {
147 u_int32_t dot_ino;
148 int16_t dot_reclen;
149 u_int16_t dot_namlen;
150 char dot_name[4]; /* must be multiple of 4 */
151 u_int32_t dotdot_ino;
152 int16_t dotdot_reclen;
153 u_int16_t dotdot_namlen;
154 char dotdot_name[4]; /* ditto */
155 };
156 #endif /* !_DIR_H_ */