1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * This file is part of UBIFS.
4  *
5  * Copyright (C) 2006-2008 Nokia Corporation.
6  *
7  * Authors: Artem Bityutskiy (Битюцкий Артём)
8  *          Adrian Hunter
9  */
10 
11 /*
12  * This file describes UBIFS on-flash format and contains definitions of all the
13  * relevant data structures and constants.
14  *
15  * All UBIFS on-flash objects are stored in the form of nodes. All nodes start
16  * with the UBIFS node magic number and have the same common header. Nodes
17  * always sit at 8-byte aligned positions on the media and node header sizes are
18  * also 8-byte aligned (except for the indexing node and the padding node).
19  */
20 
21 #ifndef __UBIFS_MEDIA_H__
22 #define __UBIFS_MEDIA_H__
23 
24 /* UBIFS node magic number (must not have the padding byte first or last) */
25 #define UBIFS_NODE_MAGIC  0x06101831
26 
27 /*
28  * UBIFS on-flash format version. This version is increased when the on-flash
29  * format is changing. If this happens, UBIFS is will support older versions as
30  * well. But older UBIFS code will not support newer formats. Format changes
31  * will be rare and only when absolutely necessary, e.g. to fix a bug or to add
32  * a new feature.
33  *
34  * UBIFS went into mainline kernel with format version 4. The older formats
35  * were development formats.
36  */
37 #define UBIFS_FORMAT_VERSION 5
38 
39 /*
40  * Read-only compatibility version. If the UBIFS format is changed, older UBIFS
41  * implementations will not be able to mount newer formats in read-write mode.
42  * However, depending on the change, it may be possible to mount newer formats
43  * in R/O mode. This is indicated by the R/O compatibility version which is
44  * stored in the super-block.
45  *
46  * This is needed to support boot-loaders which only need R/O mounting. With
47  * this flag it is possible to do UBIFS format changes without a need to update
48  * boot-loaders.
49  */
50 #define UBIFS_RO_COMPAT_VERSION 0
51 
52 /* Minimum logical eraseblock size in bytes */
53 #define UBIFS_MIN_LEB_SZ (15*1024)
54 
55 /* Initial CRC32 value used when calculating CRC checksums */
56 #define UBIFS_CRC32_INIT 0xFFFFFFFFU
57 
58 /*
59  * UBIFS does not try to compress data if its length is less than the below
60  * constant.
61  */
62 #define UBIFS_MIN_COMPR_LEN 128
63 
64 /*
65  * If compressed data length is less than %UBIFS_MIN_COMPRESS_DIFF bytes
66  * shorter than uncompressed data length, UBIFS prefers to leave this data
67  * node uncompress, because it'll be read faster.
68  */
69 #define UBIFS_MIN_COMPRESS_DIFF 64
70 
71 /* Root inode number */
72 #define UBIFS_ROOT_INO 1
73 
74 /* Lowest inode number used for regular inodes (not UBIFS-only internal ones) */
75 #define UBIFS_FIRST_INO 64
76 
77 /*
78  * Maximum file name and extended attribute length (must be a multiple of 8,
79  * minus 1).
80  */
81 #define UBIFS_MAX_NLEN 255
82 
83 /* Maximum number of data journal heads */
84 #define UBIFS_MAX_JHEADS 1
85 
86 /*
87  * Size of UBIFS data block. Note, UBIFS is not a block oriented file-system,
88  * which means that it does not treat the underlying media as consisting of
89  * blocks like in case of hard drives. Do not be confused. UBIFS block is just
90  * the maximum amount of data which one data node can have or which can be
91  * attached to an inode node.
92  */
93 #define UBIFS_BLOCK_SIZE  4096
94 #define UBIFS_BLOCK_SHIFT 12
95 
96 /* UBIFS padding byte pattern (must not be first or last byte of node magic) */
97 #define UBIFS_PADDING_BYTE 0xCE
98 
99 /* Maximum possible key length */
100 #define UBIFS_MAX_KEY_LEN 16
101 
102 /* Key length ("simple" format) */
103 #define UBIFS_SK_LEN 8
104 
105 /* Minimum index tree fanout */
106 #define UBIFS_MIN_FANOUT 3
107 
108 /* Maximum number of levels in UBIFS indexing B-tree */
109 #define UBIFS_MAX_LEVELS 512
110 
111 /* Maximum amount of data attached to an inode in bytes */
112 #define UBIFS_MAX_INO_DATA UBIFS_BLOCK_SIZE
113 
114 /* LEB Properties Tree fanout (must be power of 2) and fanout shift */
115 #define UBIFS_LPT_FANOUT 4
116 #define UBIFS_LPT_FANOUT_SHIFT 2
117 
118 /* LEB Properties Tree bit field sizes */
119 #define UBIFS_LPT_CRC_BITS 16
120 #define UBIFS_LPT_CRC_BYTES 2
121 #define UBIFS_LPT_TYPE_BITS 4
122 
123 /* The key is always at the same position in all keyed nodes */
124 #define UBIFS_KEY_OFFSET offsetof(struct ubifs_ino_node, key)
125 
126 /* Garbage collector journal head number */
127 #define UBIFS_GC_HEAD   0
128 /* Base journal head number */
129 #define UBIFS_BASE_HEAD 1
130 /* Data journal head number */
131 #define UBIFS_DATA_HEAD 2
132 
133 /*
134  * LEB Properties Tree node types.
135  *
136  * UBIFS_LPT_PNODE: LPT leaf node (contains LEB properties)
137  * UBIFS_LPT_NNODE: LPT internal node
138  * UBIFS_LPT_LTAB: LPT's own lprops table
139  * UBIFS_LPT_LSAVE: LPT's save table (big model only)
140  * UBIFS_LPT_NODE_CNT: count of LPT node types
141  * UBIFS_LPT_NOT_A_NODE: all ones (15 for 4 bits) is never a valid node type
142  */
143 enum {
144 	UBIFS_LPT_PNODE,
145 	UBIFS_LPT_NNODE,
146 	UBIFS_LPT_LTAB,
147 	UBIFS_LPT_LSAVE,
148 	UBIFS_LPT_NODE_CNT,
149 	UBIFS_LPT_NOT_A_NODE = (1 << UBIFS_LPT_TYPE_BITS) - 1,
150 };
151 
152 /*
153  * UBIFS inode types.
154  *
155  * UBIFS_ITYPE_REG: regular file
156  * UBIFS_ITYPE_DIR: directory
157  * UBIFS_ITYPE_LNK: soft link
158  * UBIFS_ITYPE_BLK: block device node
159  * UBIFS_ITYPE_CHR: character device node
160  * UBIFS_ITYPE_FIFO: fifo
161  * UBIFS_ITYPE_SOCK: socket
162  * UBIFS_ITYPES_CNT: count of supported file types
163  */
164 enum {
165 	UBIFS_ITYPE_REG,
166 	UBIFS_ITYPE_DIR,
167 	UBIFS_ITYPE_LNK,
168 	UBIFS_ITYPE_BLK,
169 	UBIFS_ITYPE_CHR,
170 	UBIFS_ITYPE_FIFO,
171 	UBIFS_ITYPE_SOCK,
172 	UBIFS_ITYPES_CNT,
173 };
174 
175 /*
176  * Supported key hash functions.
177  *
178  * UBIFS_KEY_HASH_R5: R5 hash
179  * UBIFS_KEY_HASH_TEST: test hash which just returns first 4 bytes of the name
180  */
181 enum {
182 	UBIFS_KEY_HASH_R5,
183 	UBIFS_KEY_HASH_TEST,
184 };
185 
186 /*
187  * Supported key formats.
188  *
189  * UBIFS_SIMPLE_KEY_FMT: simple key format
190  */
191 enum {
192 	UBIFS_SIMPLE_KEY_FMT,
193 };
194 
195 /*
196  * The simple key format uses 29 bits for storing UBIFS block number and hash
197  * value.
198  */
199 #define UBIFS_S_KEY_BLOCK_BITS 29
200 #define UBIFS_S_KEY_BLOCK_MASK 0x1FFFFFFF
201 #define UBIFS_S_KEY_HASH_BITS  UBIFS_S_KEY_BLOCK_BITS
202 #define UBIFS_S_KEY_HASH_MASK  UBIFS_S_KEY_BLOCK_MASK
203 
204 /*
205  * Key types.
206  *
207  * UBIFS_INO_KEY: inode node key
208  * UBIFS_DATA_KEY: data node key
209  * UBIFS_DENT_KEY: directory entry node key
210  * UBIFS_XENT_KEY: extended attribute entry key
211  * UBIFS_KEY_TYPES_CNT: number of supported key types
212  */
213 enum {
214 	UBIFS_INO_KEY,
215 	UBIFS_DATA_KEY,
216 	UBIFS_DENT_KEY,
217 	UBIFS_XENT_KEY,
218 	UBIFS_KEY_TYPES_CNT,
219 };
220 
221 /* Count of LEBs reserved for the superblock area */
222 #define UBIFS_SB_LEBS 1
223 /* Count of LEBs reserved for the master area */
224 #define UBIFS_MST_LEBS 2
225 
226 /* First LEB of the superblock area */
227 #define UBIFS_SB_LNUM 0
228 /* First LEB of the master area */
229 #define UBIFS_MST_LNUM (UBIFS_SB_LNUM + UBIFS_SB_LEBS)
230 /* First LEB of the log area */
231 #define UBIFS_LOG_LNUM (UBIFS_MST_LNUM + UBIFS_MST_LEBS)
232 
233 /*
234  * The below constants define the absolute minimum values for various UBIFS
235  * media areas. Many of them actually depend of flash geometry and the FS
236  * configuration (number of journal heads, orphan LEBs, etc). This means that
237  * the smallest volume size which can be used for UBIFS cannot be pre-defined
238  * by these constants. The file-system that meets the below limitation will not
239  * necessarily mount. UBIFS does run-time calculations and validates the FS
240  * size.
241  */
242 
243 /* Minimum number of logical eraseblocks in the log */
244 #define UBIFS_MIN_LOG_LEBS 2
245 /* Minimum number of bud logical eraseblocks (one for each head) */
246 #define UBIFS_MIN_BUD_LEBS 3
247 /* Minimum number of journal logical eraseblocks */
248 #define UBIFS_MIN_JNL_LEBS (UBIFS_MIN_LOG_LEBS + UBIFS_MIN_BUD_LEBS)
249 /* Minimum number of LPT area logical eraseblocks */
250 #define UBIFS_MIN_LPT_LEBS 2
251 /* Minimum number of orphan area logical eraseblocks */
252 #define UBIFS_MIN_ORPH_LEBS 1
253 /*
254  * Minimum number of main area logical eraseblocks (buds, 3 for the index, 1
255  * for GC, 1 for deletions, and at least 1 for committed data).
256  */
257 #define UBIFS_MIN_MAIN_LEBS (UBIFS_MIN_BUD_LEBS + 6)
258 
259 /* Minimum number of logical eraseblocks */
260 #define UBIFS_MIN_LEB_CNT (UBIFS_SB_LEBS + UBIFS_MST_LEBS + \
261 			   UBIFS_MIN_LOG_LEBS + UBIFS_MIN_LPT_LEBS + \
262 			   UBIFS_MIN_ORPH_LEBS + UBIFS_MIN_MAIN_LEBS)
263 
264 /* Node sizes (N.B. these are guaranteed to be multiples of 8) */
265 #define UBIFS_CH_SZ        sizeof(struct ubifs_ch)
266 #define UBIFS_INO_NODE_SZ  sizeof(struct ubifs_ino_node)
267 #define UBIFS_DATA_NODE_SZ sizeof(struct ubifs_data_node)
268 #define UBIFS_DENT_NODE_SZ sizeof(struct ubifs_dent_node)
269 #define UBIFS_TRUN_NODE_SZ sizeof(struct ubifs_trun_node)
270 #define UBIFS_PAD_NODE_SZ  sizeof(struct ubifs_pad_node)
271 #define UBIFS_SB_NODE_SZ   sizeof(struct ubifs_sb_node)
272 #define UBIFS_MST_NODE_SZ  sizeof(struct ubifs_mst_node)
273 #define UBIFS_REF_NODE_SZ  sizeof(struct ubifs_ref_node)
274 #define UBIFS_IDX_NODE_SZ  sizeof(struct ubifs_idx_node)
275 #define UBIFS_CS_NODE_SZ   sizeof(struct ubifs_cs_node)
276 #define UBIFS_ORPH_NODE_SZ sizeof(struct ubifs_orph_node)
277 #define UBIFS_AUTH_NODE_SZ sizeof(struct ubifs_auth_node)
278 #define UBIFS_SIG_NODE_SZ  sizeof(struct ubifs_sig_node)
279 
280 /* Extended attribute entry nodes are identical to directory entry nodes */
281 #define UBIFS_XENT_NODE_SZ UBIFS_DENT_NODE_SZ
282 /* Only this does not have to be multiple of 8 bytes */
283 #define UBIFS_BRANCH_SZ    sizeof(struct ubifs_branch)
284 
285 /* Maximum node sizes (N.B. these are guaranteed to be multiples of 8) */
286 #define UBIFS_MAX_DATA_NODE_SZ  (UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE)
287 #define UBIFS_MAX_INO_NODE_SZ   (UBIFS_INO_NODE_SZ + UBIFS_MAX_INO_DATA)
288 #define UBIFS_MAX_DENT_NODE_SZ  (UBIFS_DENT_NODE_SZ + UBIFS_MAX_NLEN + 1)
289 #define UBIFS_MAX_XENT_NODE_SZ  UBIFS_MAX_DENT_NODE_SZ
290 
291 /* The largest UBIFS node */
292 #define UBIFS_MAX_NODE_SZ UBIFS_MAX_INO_NODE_SZ
293 
294 /* The maxmimum size of a hash, enough for sha512 */
295 #define UBIFS_MAX_HASH_LEN 64
296 
297 /* The maxmimum size of a hmac, enough for hmac(sha512) */
298 #define UBIFS_MAX_HMAC_LEN 64
299 
300 /*
301  * xattr name of UBIFS encryption context, we don't use a prefix
302  * nor a long name to not waste space on the flash.
303  */
304 #define UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT "c"
305 
306 /* Type field in ubifs_sig_node */
307 #define UBIFS_SIGNATURE_TYPE_PKCS7	1
308 
309 /*
310  * On-flash inode flags.
311  *
312  * UBIFS_COMPR_FL: use compression for this inode
313  * UBIFS_SYNC_FL:  I/O on this inode has to be synchronous
314  * UBIFS_IMMUTABLE_FL: inode is immutable
315  * UBIFS_APPEND_FL: writes to the inode may only append data
316  * UBIFS_DIRSYNC_FL: I/O on this directory inode has to be synchronous
317  * UBIFS_XATTR_FL: this inode is the inode for an extended attribute value
318  * UBIFS_CRYPT_FL: use encryption for this inode
319  *
320  * Note, these are on-flash flags which correspond to ioctl flags
321  * (@FS_COMPR_FL, etc). They have the same values now, but generally, do not
322  * have to be the same.
323  */
324 enum {
325 	UBIFS_COMPR_FL     = 0x01,
326 	UBIFS_SYNC_FL      = 0x02,
327 	UBIFS_IMMUTABLE_FL = 0x04,
328 	UBIFS_APPEND_FL    = 0x08,
329 	UBIFS_DIRSYNC_FL   = 0x10,
330 	UBIFS_XATTR_FL     = 0x20,
331 	UBIFS_CRYPT_FL     = 0x40,
332 };
333 
334 /* Inode flag bits used by UBIFS */
335 #define UBIFS_FL_MASK 0x0000001F
336 
337 /*
338  * UBIFS compression algorithms.
339  *
340  * UBIFS_COMPR_NONE: no compression
341  * UBIFS_COMPR_LZO: LZO compression
342  * UBIFS_COMPR_ZLIB: ZLIB compression
343  * UBIFS_COMPR_ZSTD: ZSTD compression
344  * UBIFS_COMPR_TYPES_CNT: count of supported compression types
345  */
346 enum {
347 	UBIFS_COMPR_NONE,
348 	UBIFS_COMPR_LZO,
349 	UBIFS_COMPR_ZLIB,
350 	UBIFS_COMPR_ZSTD,
351 	UBIFS_COMPR_TYPES_CNT,
352 };
353 
354 /*
355  * UBIFS node types.
356  *
357  * UBIFS_INO_NODE: inode node
358  * UBIFS_DATA_NODE: data node
359  * UBIFS_DENT_NODE: directory entry node
360  * UBIFS_XENT_NODE: extended attribute node
361  * UBIFS_TRUN_NODE: truncation node
362  * UBIFS_PAD_NODE: padding node
363  * UBIFS_SB_NODE: superblock node
364  * UBIFS_MST_NODE: master node
365  * UBIFS_REF_NODE: LEB reference node
366  * UBIFS_IDX_NODE: index node
367  * UBIFS_CS_NODE: commit start node
368  * UBIFS_ORPH_NODE: orphan node
369  * UBIFS_AUTH_NODE: authentication node
370  * UBIFS_SIG_NODE: signature node
371  * UBIFS_NODE_TYPES_CNT: count of supported node types
372  *
373  * Note, we index arrays by these numbers, so keep them low and contiguous.
374  * Node type constants for inodes, direntries and so on have to be the same as
375  * corresponding key type constants.
376  */
377 enum {
378 	UBIFS_INO_NODE,
379 	UBIFS_DATA_NODE,
380 	UBIFS_DENT_NODE,
381 	UBIFS_XENT_NODE,
382 	UBIFS_TRUN_NODE,
383 	UBIFS_PAD_NODE,
384 	UBIFS_SB_NODE,
385 	UBIFS_MST_NODE,
386 	UBIFS_REF_NODE,
387 	UBIFS_IDX_NODE,
388 	UBIFS_CS_NODE,
389 	UBIFS_ORPH_NODE,
390 	UBIFS_AUTH_NODE,
391 	UBIFS_SIG_NODE,
392 	UBIFS_NODE_TYPES_CNT,
393 };
394 
395 /*
396  * Master node flags.
397  *
398  * UBIFS_MST_DIRTY: rebooted uncleanly - master node is dirty
399  * UBIFS_MST_NO_ORPHS: no orphan inodes present
400  * UBIFS_MST_RCVRY: written by recovery
401  */
402 enum {
403 	UBIFS_MST_DIRTY = 1,
404 	UBIFS_MST_NO_ORPHS = 2,
405 	UBIFS_MST_RCVRY = 4,
406 };
407 
408 /*
409  * Node group type (used by recovery to recover whole group or none).
410  *
411  * UBIFS_NO_NODE_GROUP: this node is not part of a group
412  * UBIFS_IN_NODE_GROUP: this node is a part of a group
413  * UBIFS_LAST_OF_NODE_GROUP: this node is the last in a group
414  */
415 enum {
416 	UBIFS_NO_NODE_GROUP = 0,
417 	UBIFS_IN_NODE_GROUP,
418 	UBIFS_LAST_OF_NODE_GROUP,
419 };
420 
421 /*
422  * Superblock flags.
423  *
424  * UBIFS_FLG_BIGLPT: if "big" LPT model is used if set
425  * UBIFS_FLG_SPACE_FIXUP: first-mount "fixup" of free space within LEBs needed
426  * UBIFS_FLG_DOUBLE_HASH: store a 32bit cookie in directory entry nodes to
427  *			  support 64bit cookies for lookups by hash
428  * UBIFS_FLG_ENCRYPTION: this filesystem contains encrypted files
429  * UBIFS_FLG_AUTHENTICATION: this filesystem contains hashes for authentication
430  */
431 enum {
432 	UBIFS_FLG_BIGLPT = 0x02,
433 	UBIFS_FLG_SPACE_FIXUP = 0x04,
434 	UBIFS_FLG_DOUBLE_HASH = 0x08,
435 	UBIFS_FLG_ENCRYPTION = 0x10,
436 	UBIFS_FLG_AUTHENTICATION = 0x20,
437 };
438 
439 #define UBIFS_FLG_MASK (UBIFS_FLG_BIGLPT | UBIFS_FLG_SPACE_FIXUP | \
440 		UBIFS_FLG_DOUBLE_HASH | UBIFS_FLG_ENCRYPTION | \
441 		UBIFS_FLG_AUTHENTICATION)
442 
443 /**
444  * struct ubifs_ch - common header node.
445  * @magic: UBIFS node magic number (%UBIFS_NODE_MAGIC)
446  * @crc: CRC-32 checksum of the node header
447  * @sqnum: sequence number
448  * @len: full node length
449  * @node_type: node type
450  * @group_type: node group type
451  * @padding: reserved for future, zeroes
452  *
453  * Every UBIFS node starts with this common part. If the node has a key, the
454  * key always goes next.
455  */
456 struct ubifs_ch {
457 	__le32 magic;
458 	__le32 crc;
459 	__le64 sqnum;
460 	__le32 len;
461 	__u8 node_type;
462 	__u8 group_type;
463 	__u8 padding[2];
464 } __packed;
465 
466 /**
467  * union ubifs_dev_desc - device node descriptor.
468  * @new: new type device descriptor
469  * @huge: huge type device descriptor
470  *
471  * This data structure describes major/minor numbers of a device node. In an
472  * inode is a device node then its data contains an object of this type. UBIFS
473  * uses standard Linux "new" and "huge" device node encodings.
474  */
475 union ubifs_dev_desc {
476 	__le32 new;
477 	__le64 huge;
478 } __packed;
479 
480 /**
481  * struct ubifs_ino_node - inode node.
482  * @ch: common header
483  * @key: node key
484  * @creat_sqnum: sequence number at time of creation
485  * @size: inode size in bytes (amount of uncompressed data)
486  * @atime_sec: access time seconds
487  * @ctime_sec: creation time seconds
488  * @mtime_sec: modification time seconds
489  * @atime_nsec: access time nanoseconds
490  * @ctime_nsec: creation time nanoseconds
491  * @mtime_nsec: modification time nanoseconds
492  * @nlink: number of hard links
493  * @uid: owner ID
494  * @gid: group ID
495  * @mode: access flags
496  * @flags: per-inode flags (%UBIFS_COMPR_FL, %UBIFS_SYNC_FL, etc)
497  * @data_len: inode data length
498  * @xattr_cnt: count of extended attributes this inode has
499  * @xattr_size: summarized size of all extended attributes in bytes
500  * @padding1: reserved for future, zeroes
501  * @xattr_names: sum of lengths of all extended attribute names belonging to
502  *               this inode
503  * @compr_type: compression type used for this inode
504  * @padding2: reserved for future, zeroes
505  * @data: data attached to the inode
506  *
507  * Note, even though inode compression type is defined by @compr_type, some
508  * nodes of this inode may be compressed with different compressor - this
509  * happens if compression type is changed while the inode already has data
510  * nodes. But @compr_type will be use for further writes to the inode.
511  *
512  * Note, do not forget to amend 'zero_ino_node_unused()' function when changing
513  * the padding fields.
514  */
515 struct ubifs_ino_node {
516 	struct ubifs_ch ch;
517 	__u8 key[UBIFS_MAX_KEY_LEN];
518 	__le64 creat_sqnum;
519 	__le64 size;
520 	__le64 atime_sec;
521 	__le64 ctime_sec;
522 	__le64 mtime_sec;
523 	__le32 atime_nsec;
524 	__le32 ctime_nsec;
525 	__le32 mtime_nsec;
526 	__le32 nlink;
527 	__le32 uid;
528 	__le32 gid;
529 	__le32 mode;
530 	__le32 flags;
531 	__le32 data_len;
532 	__le32 xattr_cnt;
533 	__le32 xattr_size;
534 	__u8 padding1[4]; /* Watch 'zero_ino_node_unused()' if changing! */
535 	__le32 xattr_names;
536 	__le16 compr_type;
537 	__u8 padding2[26]; /* Watch 'zero_ino_node_unused()' if changing! */
538 	__u8 data[];
539 } __packed;
540 
541 /**
542  * struct ubifs_dent_node - directory entry node.
543  * @ch: common header
544  * @key: node key
545  * @inum: target inode number
546  * @padding1: reserved for future, zeroes
547  * @type: type of the target inode (%UBIFS_ITYPE_REG, %UBIFS_ITYPE_DIR, etc)
548  * @nlen: name length
549  * @cookie: A 32bits random number, used to construct a 64bits
550  *          identifier.
551  * @name: zero-terminated name
552  *
553  * Note, do not forget to amend 'zero_dent_node_unused()' function when
554  * changing the padding fields.
555  */
556 struct ubifs_dent_node {
557 	struct ubifs_ch ch;
558 	__u8 key[UBIFS_MAX_KEY_LEN];
559 	__le64 inum;
560 	__u8 padding1;
561 	__u8 type;
562 	__le16 nlen;
563 	__le32 cookie;
564 	__u8 name[];
565 } __packed;
566 
567 /**
568  * struct ubifs_data_node - data node.
569  * @ch: common header
570  * @key: node key
571  * @size: uncompressed data size in bytes
572  * @compr_type: compression type (%UBIFS_COMPR_NONE, %UBIFS_COMPR_LZO, etc)
573  * @compr_size: compressed data size in bytes, only valid when data is encrypted
574  * @data: data
575  *
576  */
577 struct ubifs_data_node {
578 	struct ubifs_ch ch;
579 	__u8 key[UBIFS_MAX_KEY_LEN];
580 	__le32 size;
581 	__le16 compr_type;
582 	__le16 compr_size;
583 	__u8 data[];
584 } __packed;
585 
586 /**
587  * struct ubifs_trun_node - truncation node.
588  * @ch: common header
589  * @inum: truncated inode number
590  * @padding: reserved for future, zeroes
591  * @old_size: size before truncation
592  * @new_size: size after truncation
593  *
594  * This node exists only in the journal and never goes to the main area. Note,
595  * do not forget to amend 'zero_trun_node_unused()' function when changing the
596  * padding fields.
597  */
598 struct ubifs_trun_node {
599 	struct ubifs_ch ch;
600 	__le32 inum;
601 	__u8 padding[12]; /* Watch 'zero_trun_node_unused()' if changing! */
602 	__le64 old_size;
603 	__le64 new_size;
604 } __packed;
605 
606 /**
607  * struct ubifs_pad_node - padding node.
608  * @ch: common header
609  * @pad_len: how many bytes after this node are unused (because padded)
610  * @padding: reserved for future, zeroes
611  */
612 struct ubifs_pad_node {
613 	struct ubifs_ch ch;
614 	__le32 pad_len;
615 } __packed;
616 
617 /**
618  * struct ubifs_sb_node - superblock node.
619  * @ch: common header
620  * @padding: reserved for future, zeroes
621  * @key_hash: type of hash function used in keys
622  * @key_fmt: format of the key
623  * @flags: file-system flags (%UBIFS_FLG_BIGLPT, etc)
624  * @min_io_size: minimal input/output unit size
625  * @leb_size: logical eraseblock size in bytes
626  * @leb_cnt: count of LEBs used by file-system
627  * @max_leb_cnt: maximum count of LEBs used by file-system
628  * @max_bud_bytes: maximum amount of data stored in buds
629  * @log_lebs: log size in logical eraseblocks
630  * @lpt_lebs: number of LEBs used for lprops table
631  * @orph_lebs: number of LEBs used for recording orphans
632  * @jhead_cnt: count of journal heads
633  * @fanout: tree fanout (max. number of links per indexing node)
634  * @lsave_cnt: number of LEB numbers in LPT's save table
635  * @fmt_version: UBIFS on-flash format version
636  * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc)
637  * @padding1: reserved for future, zeroes
638  * @rp_uid: reserve pool UID
639  * @rp_gid: reserve pool GID
640  * @rp_size: size of the reserved pool in bytes
641  * @padding2: reserved for future, zeroes
642  * @time_gran: time granularity in nanoseconds
643  * @uuid: UUID generated when the file system image was created
644  * @ro_compat_version: UBIFS R/O compatibility version
645  * @hmac: HMAC to authenticate the superblock node
646  * @hmac_wkm: HMAC of a well known message (the string "UBIFS") as a convenience
647  *            to the user to check if the correct key is passed.
648  * @hash_algo: The hash algo used for this filesystem (one of enum hash_algo)
649  * @hash_mst: hash of the master node, only valid for signed images in which the
650  *            master node does not contain a hmac
651  */
652 struct ubifs_sb_node {
653 	struct ubifs_ch ch;
654 	__u8 padding[2];
655 	__u8 key_hash;
656 	__u8 key_fmt;
657 	__le32 flags;
658 	__le32 min_io_size;
659 	__le32 leb_size;
660 	__le32 leb_cnt;
661 	__le32 max_leb_cnt;
662 	__le64 max_bud_bytes;
663 	__le32 log_lebs;
664 	__le32 lpt_lebs;
665 	__le32 orph_lebs;
666 	__le32 jhead_cnt;
667 	__le32 fanout;
668 	__le32 lsave_cnt;
669 	__le32 fmt_version;
670 	__le16 default_compr;
671 	__u8 padding1[2];
672 	__le32 rp_uid;
673 	__le32 rp_gid;
674 	__le64 rp_size;
675 	__le32 time_gran;
676 	__u8 uuid[16];
677 	__le32 ro_compat_version;
678 	__u8 hmac[UBIFS_MAX_HMAC_LEN];
679 	__u8 hmac_wkm[UBIFS_MAX_HMAC_LEN];
680 	__le16 hash_algo;
681 	__u8 hash_mst[UBIFS_MAX_HASH_LEN];
682 	__u8 padding2[3774];
683 } __packed;
684 
685 /**
686  * struct ubifs_mst_node - master node.
687  * @ch: common header
688  * @highest_inum: highest inode number in the committed index
689  * @cmt_no: commit number
690  * @flags: various flags (%UBIFS_MST_DIRTY, etc)
691  * @log_lnum: start of the log
692  * @root_lnum: LEB number of the root indexing node
693  * @root_offs: offset within @root_lnum
694  * @root_len: root indexing node length
695  * @gc_lnum: LEB reserved for garbage collection (%-1 value means the LEB was
696  * not reserved and should be reserved on mount)
697  * @ihead_lnum: LEB number of index head
698  * @ihead_offs: offset of index head
699  * @index_size: size of index on flash
700  * @total_free: total free space in bytes
701  * @total_dirty: total dirty space in bytes
702  * @total_used: total used space in bytes (includes only data LEBs)
703  * @total_dead: total dead space in bytes (includes only data LEBs)
704  * @total_dark: total dark space in bytes (includes only data LEBs)
705  * @lpt_lnum: LEB number of LPT root nnode
706  * @lpt_offs: offset of LPT root nnode
707  * @nhead_lnum: LEB number of LPT head
708  * @nhead_offs: offset of LPT head
709  * @ltab_lnum: LEB number of LPT's own lprops table
710  * @ltab_offs: offset of LPT's own lprops table
711  * @lsave_lnum: LEB number of LPT's save table (big model only)
712  * @lsave_offs: offset of LPT's save table (big model only)
713  * @lscan_lnum: LEB number of last LPT scan
714  * @empty_lebs: number of empty logical eraseblocks
715  * @idx_lebs: number of indexing logical eraseblocks
716  * @leb_cnt: count of LEBs used by file-system
717  * @hash_root_idx: the hash of the root index node
718  * @hash_lpt: the hash of the LPT
719  * @hmac: HMAC to authenticate the master node
720  * @padding: reserved for future, zeroes
721  */
722 struct ubifs_mst_node {
723 	struct ubifs_ch ch;
724 	__le64 highest_inum;
725 	__le64 cmt_no;
726 	__le32 flags;
727 	__le32 log_lnum;
728 	__le32 root_lnum;
729 	__le32 root_offs;
730 	__le32 root_len;
731 	__le32 gc_lnum;
732 	__le32 ihead_lnum;
733 	__le32 ihead_offs;
734 	__le64 index_size;
735 	__le64 total_free;
736 	__le64 total_dirty;
737 	__le64 total_used;
738 	__le64 total_dead;
739 	__le64 total_dark;
740 	__le32 lpt_lnum;
741 	__le32 lpt_offs;
742 	__le32 nhead_lnum;
743 	__le32 nhead_offs;
744 	__le32 ltab_lnum;
745 	__le32 ltab_offs;
746 	__le32 lsave_lnum;
747 	__le32 lsave_offs;
748 	__le32 lscan_lnum;
749 	__le32 empty_lebs;
750 	__le32 idx_lebs;
751 	__le32 leb_cnt;
752 	__u8 hash_root_idx[UBIFS_MAX_HASH_LEN];
753 	__u8 hash_lpt[UBIFS_MAX_HASH_LEN];
754 	__u8 hmac[UBIFS_MAX_HMAC_LEN];
755 	__u8 padding[152];
756 } __packed;
757 
758 /**
759  * struct ubifs_ref_node - logical eraseblock reference node.
760  * @ch: common header
761  * @lnum: the referred logical eraseblock number
762  * @offs: start offset in the referred LEB
763  * @jhead: journal head number
764  * @padding: reserved for future, zeroes
765  */
766 struct ubifs_ref_node {
767 	struct ubifs_ch ch;
768 	__le32 lnum;
769 	__le32 offs;
770 	__le32 jhead;
771 	__u8 padding[28];
772 } __packed;
773 
774 /**
775  * struct ubifs_auth_node - node for authenticating other nodes
776  * @ch: common header
777  * @hmac: The HMAC
778  */
779 struct ubifs_auth_node {
780 	struct ubifs_ch ch;
781 	__u8 hmac[];
782 } __packed;
783 
784 /**
785  * struct ubifs_sig_node - node for signing other nodes
786  * @ch: common header
787  * @type: type of the signature, currently only UBIFS_SIGNATURE_TYPE_PKCS7
788  * supported
789  * @len: The length of the signature data
790  * @padding: reserved for future, zeroes
791  * @sig: The signature data
792  */
793 struct ubifs_sig_node {
794 	struct ubifs_ch ch;
795 	__le32 type;
796 	__le32 len;
797 	__u8 padding[32];
798 	__u8 sig[];
799 } __packed;
800 
801 /**
802  * struct ubifs_branch - key/reference/length branch
803  * @lnum: LEB number of the target node
804  * @offs: offset within @lnum
805  * @len: target node length
806  * @key: key
807  *
808  * In an authenticated UBIFS we have the hash of the referenced node after @key.
809  * This can't be added to the struct type definition because @key is a
810  * dynamically sized element already.
811  */
812 struct ubifs_branch {
813 	__le32 lnum;
814 	__le32 offs;
815 	__le32 len;
816 	__u8 key[];
817 } __packed;
818 
819 /**
820  * struct ubifs_idx_node - indexing node.
821  * @ch: common header
822  * @child_cnt: number of child index nodes
823  * @level: tree level
824  * @branches: LEB number / offset / length / key branches
825  */
826 struct ubifs_idx_node {
827 	struct ubifs_ch ch;
828 	__le16 child_cnt;
829 	__le16 level;
830 	__u8 branches[];
831 } __packed;
832 
833 /**
834  * struct ubifs_cs_node - commit start node.
835  * @ch: common header
836  * @cmt_no: commit number
837  */
838 struct ubifs_cs_node {
839 	struct ubifs_ch ch;
840 	__le64 cmt_no;
841 } __packed;
842 
843 /**
844  * struct ubifs_orph_node - orphan node.
845  * @ch: common header
846  * @cmt_no: commit number (also top bit is set on the last node of the commit)
847  * @inos: inode numbers of orphans
848  */
849 struct ubifs_orph_node {
850 	struct ubifs_ch ch;
851 	__le64 cmt_no;
852 	__le64 inos[];
853 } __packed;
854 
855 #endif /* __UBIFS_MEDIA_H__ */
856