1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1989, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#ifndef _UFS_UFS_DIR_H_
38#define	_UFS_UFS_DIR_H_
39
40/*
41 * Theoretically, directories can be more than 2Gb in length, however, in
42 * practice this seems unlikely. So, we define the type doff_t as a 32-bit
43 * quantity to keep down the cost of doing lookup on a 32-bit machine.
44 */
45#define	doff_t		int32_t
46#define	MAXDIRSIZE	(0x7fffffff)
47
48/*
49 * A directory consists of some number of blocks of DIRBLKSIZ
50 * bytes, where DIRBLKSIZ is chosen such that it can be transferred
51 * to disk in a single atomic operation (e.g. 512 bytes on most machines).
52 *
53 * Each DIRBLKSIZ byte block contains some number of directory entry
54 * structures, which are of variable length.  Each directory entry has
55 * a struct direct at the front of it, containing its inode number,
56 * the length of the entry, and the length of the name contained in
57 * the entry.  These are followed by the name padded to a 4 byte boundary
58 * with null bytes.  All names are guaranteed null terminated.
59 * The maximum length of a name in a directory is UFS_MAXNAMLEN.
60 *
61 * The macro DIRSIZ(fmt, dp) gives the amount of space required to represent
62 * a directory entry.  Free space in a directory is represented by
63 * entries which have dp->d_reclen > DIRSIZ(fmt, dp).  All DIRBLKSIZ bytes
64 * in a directory block are claimed by the directory entries.  This
65 * usually results in the last entry in a directory having a large
66 * dp->d_reclen.  When entries are deleted from a directory, the
67 * space is returned to the previous entry in the same directory
68 * block by increasing its dp->d_reclen.  If the first entry of
69 * a directory block is free, then its dp->d_ino is set to 0.
70 * Entries other than the first in a directory do not normally have
71 * dp->d_ino set to 0.
72 */
73#define	DIRBLKSIZ	DEV_BSIZE
74#define	UFS_MAXNAMLEN	255
75
76struct	direct {
77	uint32_t d_ino;		/* inode number of entry */
78	uint16_t d_reclen;		/* length of this record */
79	uint8_t  d_type; 		/* file type, see below */
80	uint8_t  d_namlen;		/* length of string in d_name */
81	char	  d_name[UFS_MAXNAMLEN + 1];
82					/* name with length <= UFS_MAXNAMLEN */
83};
84
85/*
86 * File types
87 */
88#define	DT_UNKNOWN	 0
89#define	DT_FIFO		 1
90#define	DT_CHR		 2
91#define	DT_DIR		 4
92#define	DT_BLK		 6
93#define	DT_REG		 8
94#define	DT_LNK		10
95#define	DT_SOCK		12
96#define	DT_WHT		14
97
98/*
99 * Convert between stat structure types and directory types.
100 */
101#define	IFTODT(mode)	(((mode) & 0170000) >> 12)
102#define	DTTOIF(dirtype)	((dirtype) << 12)
103
104/*
105 * The DIRSIZ macro gives the minimum record length which will hold
106 * the directory entry.  This requires the amount of space in struct direct
107 * without the d_name field, plus enough space for the name with a terminating
108 * null byte (dp->d_namlen + 1), rounded up to a 4 byte boundary.
109 */
110#define	DIR_ROUNDUP	4	/* Directory name roundup size */
111#define	DIRECTSIZ(namlen) \
112    (roundup2(__offsetof(struct direct, d_name) + (namlen) + 1, DIR_ROUNDUP))
113#if (BYTE_ORDER == LITTLE_ENDIAN)
114#define	DIRSIZ(oldfmt, dp) \
115    ((oldfmt) ? DIRECTSIZ((dp)->d_type) : DIRECTSIZ((dp)->d_namlen))
116#else
117#define	DIRSIZ(oldfmt, dp) \
118    DIRECTSIZ((dp)->d_namlen)
119#endif
120#define	OLDDIRFMT	1
121#define	NEWDIRFMT	0
122
123/*
124 * Template for manipulating directories.  Should use struct direct's,
125 * but the name field is UFS_MAXNAMLEN - 1, and this just won't do.
126 */
127struct dirtemplate {
128	uint32_t	dot_ino;
129	int16_t		dot_reclen;
130	uint8_t	dot_type;
131	uint8_t	dot_namlen;
132	char		dot_name[4];	/* must be multiple of 4 */
133	uint32_t	dotdot_ino;
134	int16_t		dotdot_reclen;
135	uint8_t	dotdot_type;
136	uint8_t	dotdot_namlen;
137	char		dotdot_name[4];	/* ditto */
138};
139
140/*
141 * This is the old format of directories, sanz type element.
142 */
143struct odirtemplate {
144	uint32_t	dot_ino;
145	int16_t		dot_reclen;
146	uint16_t	dot_namlen;
147	char		dot_name[4];	/* must be multiple of 4 */
148	uint32_t	dotdot_ino;
149	int16_t		dotdot_reclen;
150	uint16_t	dotdot_namlen;
151	char		dotdot_name[4];	/* ditto */
152};
153#endif /* !_DIR_H_ */
154