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  */
50 struct 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