xref: /freebsd/sys/sys/dirent.h (revision 0957b409)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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  * $FreeBSD$
33  */
34 
35 #ifndef	_SYS_DIRENT_H_
36 #define	_SYS_DIRENT_H_
37 
38 #include <sys/cdefs.h>
39 #include <sys/_types.h>
40 
41 #ifndef _INO_T_DECLARED
42 typedef	__ino_t		ino_t;
43 #define	_INO_T_DECLARED
44 #endif
45 
46 #ifndef _OFF_T_DECLARED
47 typedef	__off_t		off_t;
48 #define	_OFF_T_DECLARED
49 #endif
50 
51 /*
52  * The dirent structure defines the format of directory entries returned by
53  * the getdirentries(2) system call.
54  *
55  * A directory entry has a struct dirent at the front of it, containing its
56  * inode number, the length of the entry, and the length of the name
57  * contained in the entry.  These are followed by the name padded to an 8
58  * byte boundary with null bytes.  All names are guaranteed null terminated.
59  * The maximum length of a name in a directory is MAXNAMLEN.
60  *
61  * Explicit padding between the last member of the header (d_namlen) and
62  * d_name avoids ABI padding at the end of dirent on LP64 architectures.
63  * There is code depending on d_name being last.
64  */
65 
66 struct dirent {
67 	ino_t      d_fileno;		/* file number of entry */
68 	off_t      d_off;		/* directory offset of entry */
69 	__uint16_t d_reclen;		/* length of this record */
70 	__uint8_t  d_type;		/* file type, see below */
71 	__uint8_t  d_pad0;
72 	__uint16_t d_namlen;		/* length of string in d_name */
73 	__uint16_t d_pad1;
74 #if __BSD_VISIBLE
75 #define	MAXNAMLEN	255
76 	char	d_name[MAXNAMLEN + 1];	/* name must be no longer than this */
77 #else
78 	char	d_name[255 + 1];	/* name must be no longer than this */
79 #endif
80 };
81 
82 #if defined(_WANT_FREEBSD11_DIRENT) || defined(_KERNEL)
83 struct freebsd11_dirent {
84 	__uint32_t d_fileno;		/* file number of entry */
85 	__uint16_t d_reclen;		/* length of this record */
86 	__uint8_t  d_type;		/* file type, see below */
87 	__uint8_t  d_namlen;		/* length of string in d_name */
88 	char	d_name[255 + 1];	/* name must be no longer than this */
89 };
90 #endif /* _WANT_FREEBSD11_DIRENT || _KERNEL */
91 
92 #if __BSD_VISIBLE
93 
94 /*
95  * File types
96  */
97 #define	DT_UNKNOWN	 0
98 #define	DT_FIFO		 1
99 #define	DT_CHR		 2
100 #define	DT_DIR		 4
101 #define	DT_BLK		 6
102 #define	DT_REG		 8
103 #define	DT_LNK		10
104 #define	DT_SOCK		12
105 #define	DT_WHT		14
106 
107 /*
108  * Convert between stat structure types and directory types.
109  */
110 #define	IFTODT(mode)	(((mode) & 0170000) >> 12)
111 #define	DTTOIF(dirtype)	((dirtype) << 12)
112 
113 /*
114  * The _GENERIC_DIRSIZ macro gives the minimum record length which will hold
115  * the directory entry.  This returns the amount of space in struct dirent
116  * without the d_name field, plus enough space for the name with a terminating
117  * null byte (dp->d_namlen+1), rounded up to a 8 byte boundary.
118  *
119  * XXX although this macro is in the implementation namespace, it requires
120  * a manifest constant that is not.
121  */
122 #define	_GENERIC_DIRLEN(namlen)					\
123 	((__offsetof(struct dirent, d_name) + (namlen) + 1 + 7) & ~7)
124 #define	_GENERIC_DIRSIZ(dp)	_GENERIC_DIRLEN((dp)->d_namlen)
125 #endif /* __BSD_VISIBLE */
126 
127 #ifdef _KERNEL
128 #define	GENERIC_DIRSIZ(dp)	_GENERIC_DIRSIZ(dp)
129 
130 /*
131  * Ensure that padding bytes are zeroed and that the name is NUL-terminated.
132  */
133 static inline void
134 dirent_terminate(struct dirent *dp)
135 {
136 
137 	dp->d_pad0 = 0;
138 	dp->d_pad1 = 0;
139 	memset(dp->d_name + dp->d_namlen, 0,
140 	    dp->d_reclen - (__offsetof(struct dirent, d_name) + dp->d_namlen));
141 }
142 #endif
143 
144 #endif /* !_SYS_DIRENT_H_ */
145