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      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