xref: /netbsd-src/sys/ufs/ext2fs/ext2fs_dir.h (revision 2980e352a13e8f0b545a366830c411e7a542ada8)
1 /*	$NetBSD: ext2fs_dir.h,v 1.15 2007/12/25 18:33:49 perry 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  * 3. All advertising materials mentioning features or use of this software
52  *    must display the following acknowledgement:
53  *	This product includes software developed by Manuel Bouyer.
54  * 4. The name of the author may not be used to endorse or promote products
55  *    derived from this software without specific prior written permission.
56  *
57  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
58  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
59  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
60  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
61  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
62  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
63  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
64  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
65  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
66  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
67  *
68  *	@(#)dir.h	8.4 (Berkeley) 8/10/94
69  * Modified for ext2fs by Manuel Bouyer.
70  */
71 
72 #ifndef _UFS_EXT2FS_EXT2FS_DIR_H_
73 #define	_UFS_EXT2FS_EXT2FS_DIR_H_
74 
75 /*
76  * Theoretically, directories can be more than 2Gb in length, however, in
77  * practice this seems unlikely. So, we define the type doff_t as a 32-bit
78  * quantity to keep down the cost of doing lookup on a 32-bit machine.
79  */
80 #define	doff_t			int32_t
81 #define	EXT2FS_MAXDIRSIZE	(0x7fffffff)
82 
83 /*
84  * A directory consists of some number of blocks of e2fs_bsize bytes.
85  *
86  * Each block contains some number of directory entry
87  * structures, which are of variable length.  Each directory entry has
88  * a struct direct at the front of it, containing its inode number,
89  * the length of the entry, and the length of the name contained in
90  * the entry.  These are followed by the name padded to a 4 byte boundary
91  * with null bytes.  All names are guaranteed null terminated.
92  * The maximum length of a name in a directory is EXT2FS_MAXNAMLEN.
93  *
94  * The macro EXT2FS_DIRSIZ(fmt, dp) gives the amount of space required to
95  * represent a directory entry.  Free space in a directory is represented by
96  * entries which have dp->e2d_reclen > DIRSIZ(fmt, dp).  All d2fs_bsize bytes
97  * in a directory block are claimed by the directory entries.  This
98  * usually results in the last entry in a directory having a large
99  * dp->e2d_reclen.  When entries are deleted from a directory, the
100  * space is returned to the previous entry in the same directory
101  * block by increasing its dp->e2d_reclen.  If the first entry of
102  * a directory block is free, then its dp->e2d_ino is set to 0.
103  * Entries other than the first in a directory do not normally have
104  * dp->e2d_ino set to 0.
105  * Ext2 rev 0 has a 16 bits e2d_namlen. For Ext2 vev 1 this has been split
106  * into a 8 bits e2d_namlen and 8 bits e2d_type (looks like ffs, isnt't it ? :)
107  * It's safe to use this for rev 0 as well because all ext2 are little-endian.
108  */
109 
110 #define	EXT2FS_MAXNAMLEN	255
111 
112 struct	ext2fs_direct {
113 	u_int32_t e2d_ino;		/* inode number of entry */
114 	u_int16_t e2d_reclen;		/* length of this record */
115 	u_int8_t e2d_namlen;		/* length of string in d_name */
116 	u_int8_t e2d_type;		/* file type */
117 	char e2d_name[EXT2FS_MAXNAMLEN];/* name with length<=EXT2FS_MAXNAMLEN */
118 };
119 
120 /* Ext2 directory file types (not the same as FFS. Sigh. */
121 #define EXT2_FT_UNKNOWN         0
122 #define EXT2_FT_REG_FILE        1
123 #define EXT2_FT_DIR             2
124 #define EXT2_FT_CHRDEV          3
125 #define EXT2_FT_BLKDEV          4
126 #define EXT2_FT_FIFO            5
127 #define EXT2_FT_SOCK            6
128 #define EXT2_FT_SYMLINK         7
129 
130 #define EXT2_FT_MAX             8
131 
132 #define E2IFTODT(mode)    (((mode) & 0170000) >> 12)
133 
134 static __inline u_int8_t inot2ext2dt(u_int16_t) __unused;
135 static __inline u_int8_t
136 inot2ext2dt(u_int16_t type)
137 {
138 	switch(type) {
139 	case E2IFTODT(EXT2_IFIFO):
140 		return EXT2_FT_FIFO;
141 	case E2IFTODT(EXT2_IFCHR):
142 		return EXT2_FT_CHRDEV;
143 	case E2IFTODT(EXT2_IFDIR):
144 		return EXT2_FT_DIR;
145 	case E2IFTODT(EXT2_IFBLK):
146 		return EXT2_FT_BLKDEV;
147 	case E2IFTODT(EXT2_IFREG):
148 		return EXT2_FT_REG_FILE;
149 	case E2IFTODT(EXT2_IFLNK):
150 		return EXT2_FT_SYMLINK;
151 	case E2IFTODT(EXT2_IFSOCK):
152 		return EXT2_FT_SOCK;
153 	default:
154 		return 0;
155 	}
156 }
157 
158 /*
159  * The EXT2FS_DIRSIZ macro gives the minimum record length which will hold
160  * the directory entryfor a name len "len" (without the terminating null byte).
161  * This requires the amount of space in struct direct
162  * without the d_name field, plus enough space for the name without a
163  * terminating null byte, rounded up to a 4 byte boundary.
164  */
165 #define EXT2FS_DIRSIZ(len)	(( 8 + len + 3) & ~3)
166 
167 /*
168  * Template for manipulating directories.  Should use struct direct's,
169  * but the name field is EXT2FS_MAXNAMLEN - 1, and this just won't do.
170  */
171 struct ext2fs_dirtemplate {
172 	u_int32_t	dot_ino;
173 	int16_t		dot_reclen;
174 	u_int8_t	dot_namlen;
175 	u_int8_t	dot_type;
176 	char		dot_name[4];	/* must be multiple of 4 */
177 	u_int32_t	dotdot_ino;
178 	int16_t		dotdot_reclen;
179 	u_int8_t	dotdot_namlen;
180 	u_int8_t	dotdot_type;
181 	char		dotdot_name[4];	/* ditto */
182 };
183 
184 #endif /* !_UFS_EXT2FS_EXT2FS_DIR_H_ */
185