1 /* $NetBSD: ext2fs_dir.h,v 1.23 2024/03/10 17:36:33 christos 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 #include <sys/dirent.h>
71 #include <ufs/ext2fs/ext2fs_dinode.h>
72
73 /*
74 * Theoretically, directories can be more than 2Gb in length, however, in
75 * practice this seems unlikely. So, we define the type doff_t as a 32-bit
76 * quantity to keep down the cost of doing lookup on a 32-bit machine.
77 */
78 #define doff_t int32_t
79 #define EXT2FS_MAXDIRSIZE INT32_MAX
80
81 /*
82 * A directory consists of some number of blocks of e2fs_bsize bytes.
83 *
84 * Each block contains some number of directory entry
85 * structures, which are of variable length. Each directory entry has
86 * a struct direct at the front of it, containing its inode number,
87 * the length of the entry, and the length of the name contained in
88 * the entry. These are followed by the name padded to a 4 byte boundary
89 * with null bytes. All names are guaranteed null terminated.
90 * The maximum length of a name in a directory is EXT2FS_MAXNAMLEN.
91 *
92 * The macro EXT2FS_DIRSIZ(fmt, dp) gives the amount of space required to
93 * represent a directory entry. Free space in a directory is represented by
94 * entries which have dp->e2d_reclen > DIRSIZ(fmt, dp). All d2fs_bsize bytes
95 * in a directory block are claimed by the directory entries. This
96 * usually results in the last entry in a directory having a large
97 * dp->e2d_reclen. When entries are deleted from a directory, the
98 * space is returned to the previous entry in the same directory
99 * block by increasing its dp->e2d_reclen. If the first entry of
100 * a directory block is free, then its dp->e2d_ino is set to 0.
101 * Entries other than the first in a directory do not normally have
102 * dp->e2d_ino set to 0.
103 * Ext2 rev 0 has a 16 bits e2d_namlen. For Ext2 vev 1 this has been split
104 * into a 8 bits e2d_namlen and 8 bits e2d_type (looks like ffs, isnt't it ? :)
105 * It's safe to use this for rev 0 as well because all ext2 are little-endian.
106 */
107
108 #define EXT2FS_MAXNAMLEN 255
109
110 struct ext2fs_direct {
111 uint32_t e2d_ino; /* inode number of entry */
112 uint16_t e2d_reclen; /* length of this record */
113 uint8_t e2d_namlen; /* length of string in d_name */
114 uint8_t e2d_type; /* file type */
115 char e2d_name[EXT2FS_MAXNAMLEN];/* name with length<=EXT2FS_MAXNAMLEN */
116 };
117
118 enum ext2fs_slotstatus {
119 NONE,
120 COMPACT,
121 FOUND
122 };
123
124 struct ext2fs_searchslot {
125 enum ext2fs_slotstatus slotstatus;
126 doff_t slotoffset; /* offset of area with free space */
127 int slotsize; /* size of area at slotoffset */
128 int slotfreespace; /* amount of space free in slot */
129 int slotneeded; /* sizeof the entry we are seeking */
130 };
131
132 /* Ext2 directory file types (not the same as FFS. Sigh.) */
133 #define EXT2_FT_UNKNOWN 0
134 #define EXT2_FT_REG_FILE 1
135 #define EXT2_FT_DIR 2
136 #define EXT2_FT_CHRDEV 3
137 #define EXT2_FT_BLKDEV 4
138 #define EXT2_FT_FIFO 5
139 #define EXT2_FT_SOCK 6
140 #define EXT2_FT_SYMLINK 7
141
142 #define EXT2_FT_MAX 8
143
144 #define E2IFTODT(mode) (((mode) & 0170000) >> 12)
145
146 static __inline uint8_t inot2ext2dt(uint16_t) __unused;
147 static __inline uint8_t
inot2ext2dt(uint16_t type)148 inot2ext2dt(uint16_t type)
149 {
150
151 switch (type) {
152 case E2IFTODT(EXT2_IFIFO):
153 return EXT2_FT_FIFO;
154 case E2IFTODT(EXT2_IFCHR):
155 return EXT2_FT_CHRDEV;
156 case E2IFTODT(EXT2_IFDIR):
157 return EXT2_FT_DIR;
158 case E2IFTODT(EXT2_IFBLK):
159 return EXT2_FT_BLKDEV;
160 case E2IFTODT(EXT2_IFREG):
161 return EXT2_FT_REG_FILE;
162 case E2IFTODT(EXT2_IFLNK):
163 return EXT2_FT_SYMLINK;
164 case E2IFTODT(EXT2_IFSOCK):
165 return EXT2_FT_SOCK;
166 default:
167 return 0;
168 }
169 }
170
171 static __inline uint8_t ext2dt2dt(uint8_t) __unused;
172 static __inline uint8_t
ext2dt2dt(uint8_t type)173 ext2dt2dt(uint8_t type)
174 {
175 switch (type) {
176 case EXT2_FT_REG_FILE:
177 return DT_REG;
178 case EXT2_FT_DIR:
179 return DT_DIR;
180 case EXT2_FT_CHRDEV:
181 return DT_CHR;
182 case EXT2_FT_BLKDEV:
183 return DT_BLK;
184 case EXT2_FT_FIFO:
185 return DT_FIFO;
186 case EXT2_FT_SOCK:
187 return DT_SOCK;
188 case EXT2_FT_SYMLINK:
189 return DT_LNK;
190 default:
191 return DT_UNKNOWN;
192 }
193 }
194
195 /*
196 * The EXT2FS_DIRSIZ macro gives the minimum record length which will hold
197 * the directory entryfor a name len "len" (without the terminating null byte).
198 * This requires the amount of space in struct direct
199 * without the d_name field, plus enough space for the name without a
200 * terminating null byte, rounded up to a 4 byte boundary.
201 */
202 #define EXT2FS_DIRSIZ(len) roundup2(8 + len, 4)
203
204 /*
205 * Template for manipulating directories. Should use struct direct's,
206 * but the name field is EXT2FS_MAXNAMLEN - 1, and this just won't do.
207 */
208 struct ext2fs_dirtemplate {
209 uint32_t dot_ino;
210 int16_t dot_reclen;
211 uint8_t dot_namlen;
212 uint8_t dot_type;
213 char dot_name[4]; /* must be multiple of 4 */
214 uint32_t dotdot_ino;
215 int16_t dotdot_reclen;
216 uint8_t dotdot_namlen;
217 uint8_t dotdot_type;
218 char dotdot_name[4]; /* ditto */
219 };
220
221 /*
222 * EXT2_DIR_PAD defines the directory entries boundaries
223 *
224 * NOTE: It must be a multiple of 4
225 */
226 #define EXT2_DIR_PAD 4
227 #define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1)
228 #define EXT2_DIR_REC_LEN(namelen) \
229 (((namelen) + 8 + EXT2_DIR_ROUND) & ~EXT2_DIR_ROUND)
230
231 #endif /* !_UFS_EXT2FS_EXT2FS_DIR_H_ */
232