Line data Source code
1 : /* $OpenBSD: ext2fs_dir.h,v 1.11 2014/07/11 07:59:04 pelikan 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(fmt, 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(fmt, 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
121 0 : inot2ext2dt(u_int16_t type)
122 : {
123 0 : switch(type) {
124 : case E2IFTODT(EXT2_IFIFO):
125 0 : return EXT2_FT_FIFO;
126 : case E2IFTODT(EXT2_IFCHR):
127 0 : return EXT2_FT_CHRDEV;
128 : case E2IFTODT(EXT2_IFDIR):
129 0 : return EXT2_FT_DIR;
130 : case E2IFTODT(EXT2_IFBLK):
131 0 : return EXT2_FT_BLKDEV;
132 : case E2IFTODT(EXT2_IFREG):
133 0 : return EXT2_FT_REG_FILE;
134 : case E2IFTODT(EXT2_IFLNK):
135 0 : return EXT2_FT_SYMLINK;
136 : case E2IFTODT(EXT2_IFSOCK):
137 0 : return EXT2_FT_SOCK;
138 : default:
139 0 : return 0;
140 : }
141 0 : }
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_ */
|
