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