1/*	$NetBSD: ext2fs_dir.h,v 1.17 2009/09/12 14:59:59 tsutsui Exp $	*/
2
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 *	@(#)dir.h	8.4 (Berkeley) 8/10/94
37 * Modified for ext2fs by Manuel Bouyer.
38 */
39
40/*
41 * Copyright (c) 1997 Manuel Bouyer.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 *    notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 *    notice, this list of conditions and the following disclaimer in the
50 *    documentation and/or other materials provided with the distribution.
51 *
52 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
53 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
54 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
55 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
56 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
57 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
58 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
59 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
60 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
61 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
62 *
63 *	@(#)dir.h	8.4 (Berkeley) 8/10/94
64 * Modified for ext2fs by Manuel Bouyer.
65 */
66
67#ifndef _UFS_EXT2FS_EXT2FS_DIR_H_
68#define	_UFS_EXT2FS_EXT2FS_DIR_H_
69
70/*
71 * Theoretically, directories can be more than 2Gb in length, however, in
72 * practice this seems unlikely. So, we define the type doff_t as a 32-bit
73 * quantity to keep down the cost of doing lookup on a 32-bit machine.
74 */
75#define	doff_t			int32_t
76#define	EXT2FS_MAXDIRSIZE	INT32_MAX
77
78/*
79 * A directory consists of some number of blocks of e2fs_bsize bytes.
80 *
81 * Each block contains some number of directory entry
82 * structures, which are of variable length.  Each directory entry has
83 * a struct direct at the front of it, containing its inode number,
84 * the length of the entry, and the length of the name contained in
85 * the entry.  These are followed by the name padded to a 4 byte boundary
86 * with null bytes.  All names are guaranteed null terminated.
87 * The maximum length of a name in a directory is EXT2FS_MAXNAMLEN.
88 *
89 * The macro EXT2FS_DIRSIZ(fmt, dp) gives the amount of space required to
90 * represent a directory entry.  Free space in a directory is represented by
91 * entries which have dp->e2d_reclen > DIRSIZ(fmt, dp).  All d2fs_bsize bytes
92 * in a directory block are claimed by the directory entries.  This
93 * usually results in the last entry in a directory having a large
94 * dp->e2d_reclen.  When entries are deleted from a directory, the
95 * space is returned to the previous entry in the same directory
96 * block by increasing its dp->e2d_reclen.  If the first entry of
97 * a directory block is free, then its dp->e2d_ino is set to 0.
98 * Entries other than the first in a directory do not normally have
99 * dp->e2d_ino set to 0.
100 * Ext2 rev 0 has a 16 bits e2d_namlen. For Ext2 vev 1 this has been split
101 * into a 8 bits e2d_namlen and 8 bits e2d_type (looks like ffs, isnt't it ? :)
102 * It's safe to use this for rev 0 as well because all ext2 are little-endian.
103 */
104
105#define	EXT2FS_MAXNAMLEN	255
106
107struct	ext2fs_direct {
108	uint32_t e2d_ino;		/* inode number of entry */
109	uint16_t e2d_reclen;		/* length of this record */
110	uint8_t e2d_namlen;		/* length of string in d_name */
111	uint8_t e2d_type;		/* file type */
112	char e2d_name[EXT2FS_MAXNAMLEN];/* name with length<=EXT2FS_MAXNAMLEN */
113};
114
115/* Ext2 directory file types (not the same as FFS. Sigh.) */
116#define EXT2_FT_UNKNOWN         0
117#define EXT2_FT_REG_FILE        1
118#define EXT2_FT_DIR             2
119#define EXT2_FT_CHRDEV          3
120#define EXT2_FT_BLKDEV          4
121#define EXT2_FT_FIFO            5
122#define EXT2_FT_SOCK            6
123#define EXT2_FT_SYMLINK         7
124
125#define EXT2_FT_MAX             8
126
127#define E2IFTODT(mode)    (((mode) & 0170000) >> 12)
128
129static __inline uint8_t inot2ext2dt(uint16_t) __unused;
130static __inline uint8_t
131inot2ext2dt(uint16_t type)
132{
133
134	switch (type) {
135	case E2IFTODT(EXT2_IFIFO):
136		return EXT2_FT_FIFO;
137	case E2IFTODT(EXT2_IFCHR):
138		return EXT2_FT_CHRDEV;
139	case E2IFTODT(EXT2_IFDIR):
140		return EXT2_FT_DIR;
141	case E2IFTODT(EXT2_IFBLK):
142		return EXT2_FT_BLKDEV;
143	case E2IFTODT(EXT2_IFREG):
144		return EXT2_FT_REG_FILE;
145	case E2IFTODT(EXT2_IFLNK):
146		return EXT2_FT_SYMLINK;
147	case E2IFTODT(EXT2_IFSOCK):
148		return EXT2_FT_SOCK;
149	default:
150		return 0;
151	}
152}
153
154/*
155 * The EXT2FS_DIRSIZ macro gives the minimum record length which will hold
156 * the directory entryfor a name len "len" (without the terminating null byte).
157 * This requires the amount of space in struct direct
158 * without the d_name field, plus enough space for the name without a
159 * terminating null byte, rounded up to a 4 byte boundary.
160 */
161#define EXT2FS_DIRSIZ(len)	roundup2(8 + len, 4)
162
163/*
164 * Template for manipulating directories.  Should use struct direct's,
165 * but the name field is EXT2FS_MAXNAMLEN - 1, and this just won't do.
166 */
167struct ext2fs_dirtemplate {
168	uint32_t	dot_ino;
169	int16_t		dot_reclen;
170	uint8_t		dot_namlen;
171	uint8_t		dot_type;
172	char		dot_name[4];	/* must be multiple of 4 */
173	uint32_t	dotdot_ino;
174	int16_t		dotdot_reclen;
175	uint8_t		dotdot_namlen;
176	uint8_t		dotdot_type;
177	char		dotdot_name[4];	/* ditto */
178};
179
180#endif /* !_UFS_EXT2FS_EXT2FS_DIR_H_ */
181