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