1 /* $OpenBSD: ext2fs_dir.h,v 1.12 2024/01/09 03:16:00 guenther Exp $ */
2 /* $NetBSD: ext2fs_dir.h,v 1.4 2000/01/28 16:00:23 bouyer Exp $ */
3
4 /*
5 * Copyright (c) 1997 Manuel Bouyer.
6 * Copyright (c) 1982, 1986, 1989, 1993
7 * The Regents of the University of California. All rights reserved.
8 * (c) UNIX System Laboratories, Inc.
9 * All or some portions of this file are derived from material licensed
10 * to the University of California by American Telephone and Telegraph
11 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
12 * the permission of UNIX System Laboratories, Inc.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
22 * 3. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * @(#)dir.h 8.4 (Berkeley) 8/10/94
39 * Modified for ext2fs by Manuel Bouyer.
40 */
41
42 #ifndef _EXT2FS_DIR_H_
43 #define _EXT2FS_DIR_H_
44
45 /*
46 * Theoretically, directories can be more than 2Gb in length, however, in
47 * practice this seems unlikely. So, we define the type doff_t as a 32-bit
48 * quantity to keep down the cost of doing lookup on a 32-bit machine.
49 */
50 #define doff_t int32_t
51 #define EXT2FS_MAXDIRSIZE (0x7fffffff)
52
53 /*
54 * A directory consists of some number of blocks of e2fs_bsize bytes.
55 *
56 * Each block contains some number of directory entry
57 * structures, which are of variable length. Each directory entry has
58 * a struct direct at the front of it, containing its inode number,
59 * the length of the entry, and the length of the name contained in
60 * the entry. These are followed by the name padded to a 4 byte boundary
61 * with null bytes. All names are guaranteed null terminated.
62 * The maximum length of a name in a directory is EXT2FS_MAXNAMLEN.
63 *
64 * The macro EXT2FS_DIRSIZ(dp) gives the amount of space required to
65 * represent a directory entry. Free space in a directory is represented by
66 * entries which have dp->e2d_reclen > DIRSIZ(dp). All d2fs_bsize bytes
67 * in a directory block are claimed by the directory entries. This
68 * usually results in the last entry in a directory having a large
69 * dp->e2d_reclen. When entries are deleted from a directory, the
70 * space is returned to the previous entry in the same directory
71 * block by increasing its dp->e2d_reclen. If the first entry of
72 * a directory block is free, then its dp->e2d_ino is set to 0.
73 * Entries other than the first in a directory do not normally have
74 * dp->e2d_ino set to 0.
75 * Ext2 rev 0 has a 16 bits e2d_namlen. For Ext2 rev 1 this has been split
76 * into a 8 bits e2d_namlen and 8 bits e2d_type (looks like ffs, isnt't it ? :)
77 * It's safe to use this for rev 0 as well because all ext2 are little-endian.
78 */
79
80 #define EXT2FS_MAXNAMLEN 255
81
82 struct ext2fs_direct {
83 u_int32_t e2d_ino; /* inode number of entry */
84 u_int16_t e2d_reclen; /* length of this record */
85 u_int8_t e2d_namlen; /* length of string in d_name */
86 u_int8_t e2d_type; /* file type */
87 char e2d_name[EXT2FS_MAXNAMLEN];/* name with length <= EXT2FS_MAXNAMLEN */
88 };
89
90 enum slotstatus {
91 NONE,
92 COMPACT,
93 FOUND
94 };
95
96 struct ext2fs_searchslot {
97 enum slotstatus slotstatus;
98 doff_t slotoffset; /* offset of area with free space */
99 int slotsize; /* size of area at slotoffset */
100 int slotfreespace; /* amount of space free in slot */
101 int slotneeded; /* sizeof the entry we are seeking */
102 };
103
104 /* Ext2 directory file types (not the same as FFS. Sigh. */
105 #define EXT2_FT_UNKNOWN 0
106 #define EXT2_FT_REG_FILE 1
107 #define EXT2_FT_DIR 2
108 #define EXT2_FT_CHRDEV 3
109 #define EXT2_FT_BLKDEV 4
110 #define EXT2_FT_FIFO 5
111 #define EXT2_FT_SOCK 6
112 #define EXT2_FT_SYMLINK 7
113
114 #define EXT2_FT_MAX 8
115
116 #define E2IFTODT(mode) (((mode) & 0170000) >> 12)
117
118 static __inline__ u_int8_t inot2ext2dt(u_int16_t)
119 __attribute__((__unused__));
120 static __inline__ u_int8_t
inot2ext2dt(u_int16_t type)121 inot2ext2dt(u_int16_t type)
122 {
123 switch(type) {
124 case E2IFTODT(EXT2_IFIFO):
125 return EXT2_FT_FIFO;
126 case E2IFTODT(EXT2_IFCHR):
127 return EXT2_FT_CHRDEV;
128 case E2IFTODT(EXT2_IFDIR):
129 return EXT2_FT_DIR;
130 case E2IFTODT(EXT2_IFBLK):
131 return EXT2_FT_BLKDEV;
132 case E2IFTODT(EXT2_IFREG):
133 return EXT2_FT_REG_FILE;
134 case E2IFTODT(EXT2_IFLNK):
135 return EXT2_FT_SYMLINK;
136 case E2IFTODT(EXT2_IFSOCK):
137 return EXT2_FT_SOCK;
138 default:
139 return 0;
140 }
141 }
142
143 /*
144 * The EXT2FS_DIRSIZ macro gives the minimum record length which will hold
145 * the directory entryfor a name len "len" (without the terminating null byte).
146 * This requires the amount of space in struct direct
147 * without the d_name field, plus enough space for the name without a
148 * terminating null byte, rounded up to a 4 byte boundary.
149 */
150 #define EXT2FS_DIRSIZ(len) \
151 (( 8 + len + 3) &~ 3)
152
153 /*
154 * Template for manipulating directories. Should use struct direct's,
155 * but the name field is EXT2FS_MAXNAMLEN - 1, and this just won't do.
156 */
157 struct ext2fs_dirtemplate {
158 u_int32_t dot_ino;
159 int16_t dot_reclen;
160 u_int8_t dot_namlen;
161 u_int8_t dot_type;
162 char dot_name[4]; /* must be multiple of 4 */
163 u_int32_t dotdot_ino;
164 int16_t dotdot_reclen;
165 u_int8_t dotdot_namlen;
166 u_int8_t dotdot_type;
167 char dotdot_name[4]; /* ditto */
168 };
169
170 #endif /* !_EXT2FS_DIR_H_ */
171