1 #ifndef SQUASHFS_FS
2 #define SQUASHFS_FS
3 /*
4  * Squashfs
5  *
6  * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
7  * Phillip Lougher <phillip@lougher.demon.co.uk>
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * as published by the Free Software Foundation; either version 2,
12  * or (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
22  *
23  * squashfs_fs.h
24  */
25 
26 #define SQUASHFS_CACHED_FRAGMENTS	CONFIG_SQUASHFS_FRAGMENT_CACHE_SIZE
27 #define SQUASHFS_MAJOR			4
28 #define SQUASHFS_MINOR			0
29 #define SQUASHFS_MAGIC			0x73717368
30 #define SQUASHFS_START			0
31 
32 /* size of metadata (inode and directory) blocks */
33 #define SQUASHFS_METADATA_SIZE		8192
34 #define SQUASHFS_METADATA_LOG		13
35 
36 /* default size of data blocks */
37 #define SQUASHFS_FILE_SIZE		131072
38 #define SQUASHFS_FILE_LOG		17
39 
40 #define SQUASHFS_FILE_MAX_SIZE		1048576
41 #define SQUASHFS_FILE_MAX_LOG		20
42 
43 /* Max number of uids and gids */
44 #define SQUASHFS_IDS			65536
45 
46 /* Max length of filename (not 255) */
47 #define SQUASHFS_NAME_LEN		256
48 
49 #define SQUASHFS_INVALID_FRAG		(0xffffffffU)
50 #define SQUASHFS_INVALID_BLK		(-1LL)
51 
52 /* Filesystem flags */
53 #define SQUASHFS_NOI			0
54 #define SQUASHFS_NOD			1
55 #define SQUASHFS_NOF			3
56 #define SQUASHFS_NO_FRAG		4
57 #define SQUASHFS_ALWAYS_FRAG		5
58 #define SQUASHFS_DUPLICATE		6
59 #define SQUASHFS_EXPORT			7
60 
61 #define SQUASHFS_BIT(flag, bit)		((flag >> bit) & 1)
62 
63 #define SQUASHFS_UNCOMPRESSED_INODES(flags)	SQUASHFS_BIT(flags, \
64 						SQUASHFS_NOI)
65 
66 #define SQUASHFS_UNCOMPRESSED_DATA(flags)	SQUASHFS_BIT(flags, \
67 						SQUASHFS_NOD)
68 
69 #define SQUASHFS_UNCOMPRESSED_FRAGMENTS(flags)	SQUASHFS_BIT(flags, \
70 						SQUASHFS_NOF)
71 
72 #define SQUASHFS_NO_FRAGMENTS(flags)		SQUASHFS_BIT(flags, \
73 						SQUASHFS_NO_FRAG)
74 
75 #define SQUASHFS_ALWAYS_FRAGMENTS(flags)	SQUASHFS_BIT(flags, \
76 						SQUASHFS_ALWAYS_FRAG)
77 
78 #define SQUASHFS_DUPLICATES(flags)		SQUASHFS_BIT(flags, \
79 						SQUASHFS_DUPLICATE)
80 
81 #define SQUASHFS_EXPORTABLE(flags)		SQUASHFS_BIT(flags, \
82 						SQUASHFS_EXPORT)
83 
84 /* Max number of types and file types */
85 #define SQUASHFS_DIR_TYPE		1
86 #define SQUASHFS_REG_TYPE		2
87 #define SQUASHFS_SYMLINK_TYPE		3
88 #define SQUASHFS_BLKDEV_TYPE		4
89 #define SQUASHFS_CHRDEV_TYPE		5
90 #define SQUASHFS_FIFO_TYPE		6
91 #define SQUASHFS_SOCKET_TYPE		7
92 #define SQUASHFS_LDIR_TYPE		8
93 #define SQUASHFS_LREG_TYPE		9
94 #define SQUASHFS_LSYMLINK_TYPE		10
95 #define SQUASHFS_LBLKDEV_TYPE		11
96 #define SQUASHFS_LCHRDEV_TYPE		12
97 #define SQUASHFS_LFIFO_TYPE		13
98 #define SQUASHFS_LSOCKET_TYPE		14
99 
100 /* Flag whether block is compressed or uncompressed, bit is set if block is
101  * uncompressed */
102 #define SQUASHFS_COMPRESSED_BIT		(1 << 15)
103 
104 #define SQUASHFS_COMPRESSED_SIZE(B)	(((B) & ~SQUASHFS_COMPRESSED_BIT) ? \
105 		(B) & ~SQUASHFS_COMPRESSED_BIT :  SQUASHFS_COMPRESSED_BIT)
106 
107 #define SQUASHFS_COMPRESSED(B)		(!((B) & SQUASHFS_COMPRESSED_BIT))
108 
109 #define SQUASHFS_COMPRESSED_BIT_BLOCK	(1 << 24)
110 
111 #define SQUASHFS_COMPRESSED_SIZE_BLOCK(B)	((B) & \
112 						~SQUASHFS_COMPRESSED_BIT_BLOCK)
113 
114 #define SQUASHFS_COMPRESSED_BLOCK(B)	(!((B) & SQUASHFS_COMPRESSED_BIT_BLOCK))
115 
116 /*
117  * Inode number ops.  Inodes consist of a compressed block number, and an
118  * uncompressed offset within that block
119  */
120 #define SQUASHFS_INODE_BLK(A)		((unsigned int) ((A) >> 16))
121 
122 #define SQUASHFS_INODE_OFFSET(A)	((unsigned int) ((A) & 0xffff))
123 
124 #define SQUASHFS_MKINODE(A, B)		((long long)(((long long) (A)\
125 					<< 16) + (B)))
126 
127 /* Translate between VFS mode and squashfs mode */
128 #define SQUASHFS_MODE(A)		((A) & 0xfff)
129 
130 /* fragment and fragment table defines */
131 #define SQUASHFS_FRAGMENT_BYTES(A)	\
132 				((A) * sizeof(struct squashfs_fragment_entry))
133 
134 #define SQUASHFS_FRAGMENT_INDEX(A)	(SQUASHFS_FRAGMENT_BYTES(A) / \
135 					SQUASHFS_METADATA_SIZE)
136 
137 #define SQUASHFS_FRAGMENT_INDEX_OFFSET(A)	(SQUASHFS_FRAGMENT_BYTES(A) % \
138 						SQUASHFS_METADATA_SIZE)
139 
140 #define SQUASHFS_FRAGMENT_INDEXES(A)	((SQUASHFS_FRAGMENT_BYTES(A) + \
141 					SQUASHFS_METADATA_SIZE - 1) / \
142 					SQUASHFS_METADATA_SIZE)
143 
144 #define SQUASHFS_FRAGMENT_INDEX_BYTES(A)	(SQUASHFS_FRAGMENT_INDEXES(A) *\
145 						sizeof(u64))
146 
147 /* inode lookup table defines */
148 #define SQUASHFS_LOOKUP_BYTES(A)	((A) * sizeof(u64))
149 
150 #define SQUASHFS_LOOKUP_BLOCK(A)	(SQUASHFS_LOOKUP_BYTES(A) / \
151 					SQUASHFS_METADATA_SIZE)
152 
153 #define SQUASHFS_LOOKUP_BLOCK_OFFSET(A)	(SQUASHFS_LOOKUP_BYTES(A) % \
154 					SQUASHFS_METADATA_SIZE)
155 
156 #define SQUASHFS_LOOKUP_BLOCKS(A)	((SQUASHFS_LOOKUP_BYTES(A) + \
157 					SQUASHFS_METADATA_SIZE - 1) / \
158 					SQUASHFS_METADATA_SIZE)
159 
160 #define SQUASHFS_LOOKUP_BLOCK_BYTES(A)	(SQUASHFS_LOOKUP_BLOCKS(A) *\
161 					sizeof(u64))
162 
163 /* uid/gid lookup table defines */
164 #define SQUASHFS_ID_BYTES(A)		((A) * sizeof(unsigned int))
165 
166 #define SQUASHFS_ID_BLOCK(A)		(SQUASHFS_ID_BYTES(A) / \
167 					SQUASHFS_METADATA_SIZE)
168 
169 #define SQUASHFS_ID_BLOCK_OFFSET(A)	(SQUASHFS_ID_BYTES(A) % \
170 					SQUASHFS_METADATA_SIZE)
171 
172 #define SQUASHFS_ID_BLOCKS(A)		((SQUASHFS_ID_BYTES(A) + \
173 					SQUASHFS_METADATA_SIZE - 1) / \
174 					SQUASHFS_METADATA_SIZE)
175 
176 #define SQUASHFS_ID_BLOCK_BYTES(A)	(SQUASHFS_ID_BLOCKS(A) *\
177 					sizeof(u64))
178 
179 /* cached data constants for filesystem */
180 #define SQUASHFS_CACHED_BLKS		8
181 
182 #define SQUASHFS_MAX_FILE_SIZE_LOG	64
183 
184 #define SQUASHFS_MAX_FILE_SIZE		(1LL << \
185 					(SQUASHFS_MAX_FILE_SIZE_LOG - 2))
186 
187 #define SQUASHFS_MARKER_BYTE		0xff
188 
189 /* meta index cache */
190 #define SQUASHFS_META_INDEXES	(SQUASHFS_METADATA_SIZE / sizeof(unsigned int))
191 #define SQUASHFS_META_ENTRIES	127
192 #define SQUASHFS_META_SLOTS	8
193 
194 struct meta_entry {
195 	u64			data_block;
196 	unsigned int		index_block;
197 	unsigned short		offset;
198 	unsigned short		pad;
199 };
200 
201 struct meta_index {
202 	unsigned int		inode_number;
203 	unsigned int		offset;
204 	unsigned short		entries;
205 	unsigned short		skip;
206 	unsigned short		locked;
207 	unsigned short		pad;
208 	struct meta_entry	meta_entry[SQUASHFS_META_ENTRIES];
209 };
210 
211 
212 /*
213  * definitions for structures on disk
214  */
215 #define ZLIB_COMPRESSION	 1
216 
217 struct squashfs_super_block {
218 	__le32			s_magic;
219 	__le32			inodes;
220 	__le32			mkfs_time;
221 	__le32			block_size;
222 	__le32			fragments;
223 	__le16			compression;
224 	__le16			block_log;
225 	__le16			flags;
226 	__le16			no_ids;
227 	__le16			s_major;
228 	__le16			s_minor;
229 	__le64			root_inode;
230 	__le64			bytes_used;
231 	__le64			id_table_start;
232 	__le64			xattr_table_start;
233 	__le64			inode_table_start;
234 	__le64			directory_table_start;
235 	__le64			fragment_table_start;
236 	__le64			lookup_table_start;
237 };
238 
239 struct squashfs_dir_index {
240 	__le32			index;
241 	__le32			start_block;
242 	__le32			size;
243 	unsigned char		name[0];
244 };
245 
246 struct squashfs_base_inode {
247 	__le16			inode_type;
248 	__le16			mode;
249 	__le16			uid;
250 	__le16			guid;
251 	__le32			mtime;
252 	__le32	 		inode_number;
253 };
254 
255 struct squashfs_ipc_inode {
256 	__le16			inode_type;
257 	__le16			mode;
258 	__le16			uid;
259 	__le16			guid;
260 	__le32			mtime;
261 	__le32	 		inode_number;
262 	__le32			nlink;
263 };
264 
265 struct squashfs_dev_inode {
266 	__le16			inode_type;
267 	__le16			mode;
268 	__le16			uid;
269 	__le16			guid;
270 	__le32			mtime;
271 	__le32	 		inode_number;
272 	__le32			nlink;
273 	__le32			rdev;
274 };
275 
276 struct squashfs_symlink_inode {
277 	__le16			inode_type;
278 	__le16			mode;
279 	__le16			uid;
280 	__le16			guid;
281 	__le32			mtime;
282 	__le32	 		inode_number;
283 	__le32			nlink;
284 	__le32			symlink_size;
285 	char			symlink[0];
286 };
287 
288 struct squashfs_reg_inode {
289 	__le16			inode_type;
290 	__le16			mode;
291 	__le16			uid;
292 	__le16			guid;
293 	__le32			mtime;
294 	__le32	 		inode_number;
295 	__le32			start_block;
296 	__le32			fragment;
297 	__le32			offset;
298 	__le32			file_size;
299 	__le16			block_list[0];
300 };
301 
302 struct squashfs_lreg_inode {
303 	__le16			inode_type;
304 	__le16			mode;
305 	__le16			uid;
306 	__le16			guid;
307 	__le32			mtime;
308 	__le32	 		inode_number;
309 	__le64			start_block;
310 	__le64			file_size;
311 	__le64			sparse;
312 	__le32			nlink;
313 	__le32			fragment;
314 	__le32			offset;
315 	__le32			xattr;
316 	__le16			block_list[0];
317 };
318 
319 struct squashfs_dir_inode {
320 	__le16			inode_type;
321 	__le16			mode;
322 	__le16			uid;
323 	__le16			guid;
324 	__le32			mtime;
325 	__le32	 		inode_number;
326 	__le32			start_block;
327 	__le32			nlink;
328 	__le16			file_size;
329 	__le16			offset;
330 	__le32			parent_inode;
331 };
332 
333 struct squashfs_ldir_inode {
334 	__le16			inode_type;
335 	__le16			mode;
336 	__le16			uid;
337 	__le16			guid;
338 	__le32			mtime;
339 	__le32	 		inode_number;
340 	__le32			nlink;
341 	__le32			file_size;
342 	__le32			start_block;
343 	__le32			parent_inode;
344 	__le16			i_count;
345 	__le16			offset;
346 	__le32			xattr;
347 	struct squashfs_dir_index	index[0];
348 };
349 
350 union squashfs_inode {
351 	struct squashfs_base_inode		base;
352 	struct squashfs_dev_inode		dev;
353 	struct squashfs_symlink_inode		symlink;
354 	struct squashfs_reg_inode		reg;
355 	struct squashfs_lreg_inode		lreg;
356 	struct squashfs_dir_inode		dir;
357 	struct squashfs_ldir_inode		ldir;
358 	struct squashfs_ipc_inode		ipc;
359 };
360 
361 struct squashfs_dir_entry {
362 	__le16			offset;
363 	__le16			inode_number;
364 	__le16			type;
365 	__le16			size;
366 	char			name[0];
367 };
368 
369 struct squashfs_dir_header {
370 	__le32			count;
371 	__le32			start_block;
372 	__le32			inode_number;
373 };
374 
375 struct squashfs_fragment_entry {
376 	__le64			start_block;
377 	__le32			size;
378 	unsigned int		unused;
379 };
380 
381 #endif
382