1/* $NetBSD: dirent.h,v 1.30 2016/01/22 23:31:30 dholland Exp $ */
2
3/*-
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * @(#)dirent.h 8.3 (Berkeley) 8/10/94
32 */
33
34#ifndef _SYS_DIRENT_H_
35#define _SYS_DIRENT_H_
36
37#include <sys/cdefs.h>
38#include <sys/featuretest.h>
39
40/*
41 * The dirent structure defines the format of directory entries returned by
42 * the getdents(2) system call.
43 *
44 * A directory entry has a struct dirent at the front of it, containing its
45 * inode number, the length of the entry, and the length of the name
46 * contained in the entry. These are followed by the name padded to
47 * _DIRENT_ALIGN() byte boundary with null bytes. All names are guaranteed
48 * NUL terminated. The maximum length of a name in a directory is MAXNAMLEN.
49 */
50struct dirent {
51 ino_t d_fileno; /* file number of entry */
52 uint16_t d_reclen; /* length of this record */
53 uint16_t d_namlen; /* length of string in d_name */
54 uint8_t d_type; /* file type, see below */
55#if defined(_NETBSD_SOURCE)
56#define MAXNAMLEN 511 /* must be kept in sync with NAME_MAX */
57 char d_name[MAXNAMLEN + 1]; /* name must be no longer than this */
58#else
59 char d_name[511 + 1]; /* name must be no longer than this */
60#endif
61};
62
63#if defined(_NETBSD_SOURCE)
64/*
65 * File types
66 */
67#define DT_UNKNOWN 0
68#define DT_FIFO 1
69#define DT_CHR 2
70#define DT_DIR 4
71#define DT_BLK 6
72#define DT_REG 8
73#define DT_LNK 10
74#define DT_SOCK 12
75#define DT_WHT 14
76
77/*
78 * Caution: the following macros are used by the ufs/ffs code on ffs's
79 * struct direct as well as the exposed struct dirent. The two
80 * structures are not the same, so it's important (until ufs is fixed,
81 * XXX) that the macro definitions remain type-polymorphic.
82 */
83
84/*
85 * The _DIRENT_ALIGN macro returns the alignment of struct dirent.
86 * struct direct and struct dirent12 used 4 byte alignment but
87 * struct dirent uses 8.
88 */
89#define _DIRENT_ALIGN(dp) (sizeof((dp)->d_fileno) - 1)
90/*
91 * The _DIRENT_NAMEOFF macro returns the offset of the d_name field in
92 * struct dirent
93 */
94#if __GNUC_PREREQ__(4, 0)
95#define _DIRENT_NAMEOFF(dp) __builtin_offsetof(__typeof__(*(dp)), d_name)
96#else
97#define _DIRENT_NAMEOFF(dp) \
98 ((char *)(void *)&(dp)->d_name - (char *)(void *)dp)
99#endif
100/*
101 * The _DIRENT_RECLEN macro gives the minimum record length which will hold
102 * a name of size "namlen". This requires the amount of space in struct dirent
103 * without the d_name field, plus enough space for the name with a terminating
104 * null byte (namlen+1), rounded up to a the appropriate byte boundary.
105 */
106#define _DIRENT_RECLEN(dp, namlen) \
107 ((_DIRENT_NAMEOFF(dp) + (namlen) + 1 + _DIRENT_ALIGN(dp)) & \
108 ~_DIRENT_ALIGN(dp))
109/*
110 * The _DIRENT_SIZE macro returns the minimum record length required for
111 * name name stored in the current record.
112 */
113#define _DIRENT_SIZE(dp) _DIRENT_RECLEN(dp, (dp)->d_namlen)
114/*
115 * The _DIRENT_NEXT macro advances to the next dirent record.
116 */
117#define _DIRENT_NEXT(dp) ((void *)((char *)(void *)(dp) + (dp)->d_reclen))
118/*
119 * The _DIRENT_MINSIZE returns the size of an empty (invalid) record.
120 */
121#define _DIRENT_MINSIZE(dp) _DIRENT_RECLEN(dp, 0)
122
123/*
124 * Convert between stat structure types and directory types.
125 */
126#define IFTODT(mode) (((mode) & 0170000) >> 12)
127#define DTTOIF(dirtype) ((dirtype) << 12)
128#endif
129
130#endif /* !_SYS_DIRENT_H_ */
131