summaryrefslogtreecommitdiffstats
path: root/squashfs-tools/unsquash-2.c
blob: b2546d55687fbb07235fc72acfa8ed5d64d3f4c9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
/*
 * Unsquash a squashfs filesystem.  This is a highly compressed read only
 * filesystem.
 *
 * Copyright (c) 2009, 2010, 2013, 2019, 2021, 2022, 2023
 * Phillip Lougher <phillip@squashfs.org.uk>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2,
 * or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * unsquash-2.c
 */

#include "unsquashfs.h"
#include "squashfs_compat.h"
#include "compressor.h"

static squashfs_fragment_entry_2 *fragment_table;
static unsigned int *uid_table, *guid_table;
static squashfs_operations ops;
static int needs_sorting = FALSE;


static void read_block_list(unsigned int *block_list, long long start,
					unsigned int offset, int blocks)
{
	int res;

	TRACE("read_block_list: blocks %d\n", blocks);

	if(swap) {
		char *block_ptr = malloc(blocks * sizeof(unsigned int));
		if(block_ptr == NULL)
			MEM_ERROR();
		res = read_inode_data(block_ptr, &start, &offset, blocks * sizeof(unsigned int));
		if(res == FALSE)
			EXIT_UNSQUASH("read_block_list: failed to read "
				"inode index %lld:%d\n", start, offset);
		SQUASHFS_SWAP_INTS_3(block_list, block_ptr, blocks);
		free(block_ptr);
	} else {
		res = read_inode_data(block_list, &start, &offset, blocks * sizeof(unsigned int));
		if(res == FALSE)
			EXIT_UNSQUASH("read_block_list: failed to read "
				"inode index %lld:%d\n", start, offset);
	}
}


static int read_fragment_table(long long *table_start)
{
	/*
	 * Note on overflow limits:
	 * Size of SBlk.s.fragments is 2^32 (unsigned int)
	 * Max size of bytes is 2^32*8 or 2^35
	 * Max indexes is (2^32*8)/8K or 2^22
	 * Max length is ((2^32*8)/8K)*4 or 2^24 or 16M
	 */
	int res, i;
	long long bytes = SQUASHFS_FRAGMENT_BYTES_2((long long) sBlk.s.fragments);
	int indexes = SQUASHFS_FRAGMENT_INDEXES_2((long long) sBlk.s.fragments);
	int length = SQUASHFS_FRAGMENT_INDEX_BYTES_2((long long) sBlk.s.fragments);
	unsigned int *fragment_table_index;

	/*
	 * The size of the index table (length bytes) should match the
	 * table start and end points
	 */
	if(length != (*table_start- sBlk.s.fragment_table_start)) {
		ERROR("read_ids: Bad inode count in super block\n");
		return FALSE;
	}

	TRACE("read_fragment_table: %d fragments, reading %d fragment indexes "
		"from 0x%llx\n", sBlk.s.fragments, indexes,
		sBlk.s.fragment_table_start);

	fragment_table_index = malloc(length);
	if(fragment_table_index  == NULL)
		MEM_ERROR();

	fragment_table = malloc(bytes);
	if(fragment_table == NULL)
		MEM_ERROR();

	if(swap) {
		 unsigned int *sfragment_table_index = malloc(length);

		if(sfragment_table_index == NULL)
			MEM_ERROR();

		 res = read_fs_bytes(fd, sBlk.s.fragment_table_start,
			length, sfragment_table_index);
		if(res == FALSE) {
			ERROR("read_fragment_table: failed to read fragment "
				"table index\n");
			free(sfragment_table_index);
			goto failed;
		}
		SQUASHFS_SWAP_FRAGMENT_INDEXES_2(fragment_table_index,
			sfragment_table_index, indexes);
		free(sfragment_table_index);
	} else {
		res = read_fs_bytes(fd, sBlk.s.fragment_table_start,
			length, fragment_table_index);
		if(res == FALSE) {
			ERROR("read_fragment_table: failed to read fragment "
				"table index\n");
			goto failed;
		}
	}

	for(i = 0; i < indexes; i++) {
		int expected = (i + 1) != indexes ? SQUASHFS_METADATA_SIZE :
					bytes & (SQUASHFS_METADATA_SIZE - 1);
		int length = read_block(fd, fragment_table_index[i], NULL,
			expected, ((char *) fragment_table) + ((long long) i *
			SQUASHFS_METADATA_SIZE));
		TRACE("Read fragment table block %d, from 0x%x, length %d\n", i,
			fragment_table_index[i], length);
		if(length == FALSE) {
			ERROR("read_fragment_table: failed to read fragment "
				"table block\n");
			goto failed;
		}
	}

	if(swap) {
		squashfs_fragment_entry_2 sfragment;
		for(i = 0; i < sBlk.s.fragments; i++) {
			SQUASHFS_SWAP_FRAGMENT_ENTRY_2((&sfragment),
				(&fragment_table[i]));
			memcpy((char *) &fragment_table[i], (char *) &sfragment,
				sizeof(squashfs_fragment_entry_2));
		}
	}

	*table_start = fragment_table_index[0];
	free(fragment_table_index);

	return TRUE;

failed:
	free(fragment_table_index);
	return FALSE;
}


static void read_fragment(unsigned int fragment, long long *start_block, int *size)
{
	TRACE("read_fragment: reading fragment %d\n", fragment);

	squashfs_fragment_entry_2 *fragment_entry = &fragment_table[fragment];
	*start_block = fragment_entry->start_block;
	*size = fragment_entry->size;
}


static struct inode *read_inode(unsigned int start_block, unsigned int offset)
{
	static union squashfs_inode_header_2 header;
	long long start = sBlk.s.inode_table_start + start_block;
	long long st = start;
	unsigned int off = offset;
	static struct inode i;
	int res;

	TRACE("read_inode: reading inode [%d:%d]\n", start_block,  offset);

	if(swap) {
		squashfs_base_inode_header_2 sinode;
		res = read_inode_data(&sinode, &st, &off, sizeof(sinode));
		if(res)
			SQUASHFS_SWAP_BASE_INODE_HEADER_2(&header.base, &sinode,
				sizeof(squashfs_base_inode_header_2));
	} else
		res = read_inode_data(&header.base, &st, &off, sizeof(header.base));

	if(res == FALSE)
		EXIT_UNSQUASH("read_inode: failed to read inode %lld:%d\n", st, off);

	i.xattr = SQUASHFS_INVALID_XATTR;

	if(header.base.uid >= sBlk.no_uids)
		EXIT_UNSQUASH("File system corrupted - uid index in inode too large (uid: %u)\n", header.base.uid);

	i.uid = (uid_t) uid_table[header.base.uid];

	if(header.base.guid == SQUASHFS_GUIDS)
		i.gid = i.uid;
	else if(header.base.guid >= sBlk.no_guids)
		EXIT_UNSQUASH("File system corrupted - gid index in inode too large (gid: %d)\n", header.base.guid);
	else
		i.gid = (uid_t) guid_table[header.base.guid];

	if(header.base.inode_type < 1 || header.base.inode_type > 8)
		EXIT_UNSQUASH("File system corrupted - invalid type in inode (type: %u)\n", header.base.inode_type);

	i.mode = lookup_type[header.base.inode_type] | header.base.mode;
	i.type = header.base.inode_type;
	i.inode_number = inode_number++;

	switch(header.base.inode_type) {
		case SQUASHFS_DIR_TYPE: {
			squashfs_dir_inode_header_2 *inode = &header.dir;

			if(swap) {
				squashfs_dir_inode_header_2 sinode;
				res = read_inode_data(&sinode, &start, &offset, sizeof(sinode));
				if(res)
					SQUASHFS_SWAP_DIR_INODE_HEADER_2(&header.dir,
						&sinode);
			} else
				res = read_inode_data(inode, &start, &offset, sizeof(*inode));

			if(res == FALSE)
				EXIT_UNSQUASH("read_inode: failed to read "
					"inode %lld:%d\n", start, offset);

			i.data = inode->file_size;
			i.offset = inode->offset;
			i.start = inode->start_block;
			if(time_opt)
				i.time = timeval;
			else
				i.time = inode->mtime;
			break;
		}
		case SQUASHFS_LDIR_TYPE: {
			squashfs_ldir_inode_header_2 *inode = &header.ldir;

			if(swap) {
				squashfs_ldir_inode_header_2 sinode;
				res = read_inode_data(&sinode, &start, &offset, sizeof(sinode));
				if(res)
					SQUASHFS_SWAP_LDIR_INODE_HEADER_2(&header.ldir,
						&sinode);
			} else
				res = read_inode_data(inode, &start, &offset, sizeof(*inode));

			if(res == FALSE)
				EXIT_UNSQUASH("read_inode: failed to read "
					"inode %lld:%d\n", start, offset);

			i.data = inode->file_size;
			i.offset = inode->offset;
			i.start = inode->start_block;
			if(time_opt)
				i.time = timeval;
			else
				i.time = inode->mtime;
			break;
		}
		case SQUASHFS_FILE_TYPE: {
			squashfs_reg_inode_header_2 *inode = &header.reg;

			if(swap) {
				squashfs_reg_inode_header_2 sinode;
				res = read_inode_data(&sinode, &start, &offset, sizeof(sinode));
				if(res)
					SQUASHFS_SWAP_REG_INODE_HEADER_2(inode,
						&sinode);
			} else
				res = read_inode_data(inode, &start, &offset, sizeof(*inode));

			if(res == FALSE)
				EXIT_UNSQUASH("read_inode: failed to read "
					"inode %lld:%d\n", start, offset);

			i.data = inode->file_size;
			if(time_opt)
				i.time = timeval;
			else
				i.time = inode->mtime;
			i.frag_bytes = inode->fragment == SQUASHFS_INVALID_FRAG
				?  0 : inode->file_size % sBlk.s.block_size;
			i.fragment = inode->fragment;
			i.offset = inode->offset;
			i.blocks = inode->fragment == SQUASHFS_INVALID_FRAG ?
				(i.data + sBlk.s.block_size - 1) >>
				sBlk.s.block_log : i.data >>
				sBlk.s.block_log;
			i.start = inode->start_block;
			i.block_start = start;
			i.block_offset = offset;
			i.sparse = 0;
			break;
		}	
		case SQUASHFS_SYMLINK_TYPE: {
			squashfs_symlink_inode_header_2 *inodep =
				&header.symlink;

			if(swap) {
				squashfs_symlink_inode_header_2 sinodep;
				res = read_inode_data(&sinodep, &start, &offset, sizeof(sinodep));
				if(res)
					SQUASHFS_SWAP_SYMLINK_INODE_HEADER_2(inodep,
						&sinodep);
			} else
				res = read_inode_data(inodep, &start, &offset, sizeof(*inodep));

			if(res == FALSE)
				EXIT_UNSQUASH("read_inode: failed to read "
					"inode %lld:%d\n", start, offset);

			i.symlink = malloc(inodep->symlink_size + 1);
			if(i.symlink == NULL)
				MEM_ERROR();

			res = read_inode_data(i.symlink, &start, &offset, inodep->symlink_size);
			if(res == FALSE)
				EXIT_UNSQUASH("read_inode: failed to read "
					"inode symbolic link %lld:%d\n", start, offset);
			i.symlink[inodep->symlink_size] = '\0';
			i.data = inodep->symlink_size;
			if(time_opt)
				i.time = timeval;
			else
				i.time = sBlk.s.mkfs_time;
			break;
		}
 		case SQUASHFS_BLKDEV_TYPE:
	 	case SQUASHFS_CHRDEV_TYPE: {
			squashfs_dev_inode_header_2 *inodep = &header.dev;

			if(swap) {
				squashfs_dev_inode_header_2 sinodep;
				res = read_inode_data(&sinodep, &start, &offset, sizeof(sinodep));
				if(res)
					SQUASHFS_SWAP_DEV_INODE_HEADER_2(inodep,
						&sinodep);
			} else
				res = read_inode_data(inodep, &start, &offset, sizeof(*inodep));

			if(res == FALSE)
				EXIT_UNSQUASH("read_inode: failed to read "
					"inode %lld:%d\n", start, offset);

			i.data = inodep->rdev;
			if(time_opt)
				i.time = timeval;
			else
				i.time = sBlk.s.mkfs_time;
			break;
			}
		case SQUASHFS_FIFO_TYPE:
		case SQUASHFS_SOCKET_TYPE:
			i.data = 0;
			if(time_opt)
				i.time = timeval;
			else
				i.time = sBlk.s.mkfs_time;
			break;
		default:
			EXIT_UNSQUASH("Unknown inode type %d in "
				"read_inode_header_2!\n",
				header.base.inode_type);
	}
	return &i;
}


static struct dir *squashfs_opendir(unsigned int block_start, unsigned int offset,
	struct inode **i)
{
	squashfs_dir_header_2 dirh;
	char buffer[sizeof(squashfs_dir_entry_2) + SQUASHFS_NAME_LEN + 1]
		__attribute__((aligned));
	squashfs_dir_entry_2 *dire = (squashfs_dir_entry_2 *) buffer;
	long long start;
	int bytes = 0;
	int dir_count, size, res;
	struct dir_ent *ent, *cur_ent = NULL;
	struct dir *dir;

	TRACE("squashfs_opendir: inode start block %d, offset %d\n",
		block_start, offset);

	*i = read_inode(block_start, offset);

	dir = malloc(sizeof(struct dir));
	if(dir == NULL)
		MEM_ERROR();

	dir->dir_count = 0;
	dir->cur_entry = NULL;
	dir->mode = (*i)->mode;
	dir->uid = (*i)->uid;
	dir->guid = (*i)->gid;
	dir->mtime = (*i)->time;
	dir->xattr = (*i)->xattr;
	dir->dirs = NULL;

	if ((*i)->data == 0)
		/*
		 * if the directory is empty, skip the unnecessary
		 * lookup_entry, this fixes the corner case with
		 * completely empty filesystems where lookup_entry correctly
		 * returning -1 is incorrectly treated as an error
		 */
		return dir;

	start = sBlk.s.directory_table_start + (*i)->start;
	offset = (*i)->offset;
	size = (*i)->data + bytes;

	while(bytes < size) {
		if(swap) {
			squashfs_dir_header_2 sdirh;
			res = read_directory_data(&sdirh, &start, &offset, sizeof(sdirh));
			if(res)
				SQUASHFS_SWAP_DIR_HEADER_2(&dirh, &sdirh);
		} else
			res = read_directory_data(&dirh, &start, &offset, sizeof(dirh));

		if(res == FALSE)
			goto corrupted;

		dir_count = dirh.count + 1;
		TRACE("squashfs_opendir: Read directory header @ byte position "
			"%d, %d directory entries\n", bytes, dir_count);
		bytes += sizeof(dirh);

		/* dir_count should never be larger than SQUASHFS_DIR_COUNT */
		if(dir_count > SQUASHFS_DIR_COUNT) {
			ERROR("File system corrupted: too many entries in directory\n");
			goto corrupted;
		}

		while(dir_count--) {
			if(swap) {
				squashfs_dir_entry_2 sdire;
				res = read_directory_data(&sdire, &start,
					&offset, sizeof(sdire));
				if(res)
					SQUASHFS_SWAP_DIR_ENTRY_2(dire, &sdire);
			} else
				res = read_directory_data(dire, &start,
					&offset, sizeof(*dire));

			if(res == FALSE)
				goto corrupted;

			bytes += sizeof(*dire);

			/* size should never be SQUASHFS_NAME_LEN or larger */
			if(dire->size >= SQUASHFS_NAME_LEN) {
				ERROR("File system corrupted: filename too long\n");
				goto corrupted;
			}

			res = read_directory_data(dire->name, &start, &offset,
								dire->size + 1);

			if(res == FALSE)
				goto corrupted;

			dire->name[dire->size + 1] = '\0';

			/* check name for invalid characters (i.e /, ., ..) */
			if(check_name(dire->name, dire->size + 1) == FALSE) {
				ERROR("File system corrupted: invalid characters in name\n");
				goto corrupted;
			}

			TRACE("squashfs_opendir: directory entry %s, inode "
				"%d:%d, type %d\n", dire->name,
				dirh.start_block, dire->offset, dire->type);

			ent = malloc(sizeof(struct dir_ent));
			if(ent == NULL)
				MEM_ERROR();

			ent->name = strdup(dire->name);
			ent->start_block = dirh.start_block;
			ent->offset = dire->offset;
			ent->type = dire->type;
			ent->next = NULL;
			if(cur_ent == NULL)
				dir->dirs = ent;
			else
				cur_ent->next = ent;
			cur_ent = ent;
			dir->dir_count ++;
			bytes += dire->size + 1;
		}
	}

	if(needs_sorting)
		sort_directory(&(dir->dirs), dir->dir_count);

	/* check directory for duplicate names and sorting */
	if(check_directory(dir) == FALSE) {
		if(needs_sorting)
			ERROR("File system corrupted: directory has duplicate names\n");
		else
			ERROR("File system corrupted: directory has duplicate names or is unsorted\n");
		goto corrupted;
	}
	return dir;

corrupted:
	squashfs_closedir(dir);
	return NULL;
}


static int read_filesystem_tables()
{
	long long table_start;

	/* Read uid and gid lookup tables */

	/* Sanity check super block contents */
	if(sBlk.no_guids) {
		if(sBlk.guid_start >= sBlk.s.bytes_used) {
			ERROR("read_filesystem_tables: gid start too large in super block\n");
			goto corrupted;
		}

		if(read_ids(sBlk.no_guids, sBlk.guid_start, sBlk.s.bytes_used, &guid_table) == FALSE)
			goto corrupted;

		table_start = sBlk.guid_start;
	} else {
		/* no guids, guid_start should be 0 */
		if(sBlk.guid_start != 0) {
			ERROR("read_filesystem_tables: gid start too large in super block\n");
			goto corrupted;
		}

		table_start = sBlk.s.bytes_used;
	}

	if(sBlk.uid_start >= table_start) {
		ERROR("read_filesystem_tables: uid start too large in super block\n");
		goto corrupted;
	}

	/* There should be at least one uid */
	if(sBlk.no_uids == 0) {
		ERROR("read_filesystem_tables: uid count bad in super block\n");
		goto corrupted;
	}

	if(read_ids(sBlk.no_uids, sBlk.uid_start, table_start, &uid_table) == FALSE)
		goto corrupted;

	table_start = sBlk.uid_start;

	/* Read fragment table */
	if(sBlk.s.fragments != 0) {

		/* Sanity check super block contents */
		if(sBlk.s.fragment_table_start >= table_start) {
			ERROR("read_filesystem_tables: fragment table start too large in super block\n");
			goto corrupted;
		}

		/* The number of fragments should not exceed the number of inodes */
		if(sBlk.s.fragments > sBlk.s.inodes) {
			ERROR("read_filesystem_tables: Bad fragment count in super block\n");
			goto corrupted;
		}

		if(read_fragment_table(&table_start) == FALSE)
			goto corrupted;
	} else {
		/*
		 * Sanity check super block contents - with 0 fragments,
		 * the fragment table should be empty
		 */
		if(sBlk.s.fragment_table_start != table_start) {
			ERROR("read_filesystem_tables: fragment table start invalid in super block\n");
			goto corrupted;
		}
	}

	/* Sanity check super block directory table values */
	if(sBlk.s.directory_table_start > table_start) {
		ERROR("read_filesystem_tables: directory table start too large in super block\n");
		goto corrupted;
	}

	/* Sanity check super block inode table values */
	if(sBlk.s.inode_table_start >= sBlk.s.directory_table_start) {
		ERROR("read_filesystem_tables: inode table start too large in super block\n");
		goto corrupted;
	}

	return TRUE;

corrupted:
	return FALSE;
}


int read_super_2(squashfs_operations **s_ops, void *s)
{
	 squashfs_super_block_3 *sBlk_3 = s;

	if(sBlk_3->s_magic != SQUASHFS_MAGIC || sBlk_3->s_major != 2 ||
							sBlk_3->s_minor > 1)
		return -1;

	sBlk.s.s_magic = sBlk_3->s_magic;
	sBlk.s.inodes = sBlk_3->inodes;
	sBlk.s.mkfs_time = sBlk_3->mkfs_time;
	sBlk.s.block_size = sBlk_3->block_size;
	sBlk.s.fragments = sBlk_3->fragments;
	sBlk.s.block_log = sBlk_3->block_log;
	sBlk.s.flags = sBlk_3->flags;
	sBlk.s.s_major = sBlk_3->s_major;
	sBlk.s.s_minor = sBlk_3->s_minor;
	sBlk.s.root_inode = sBlk_3->root_inode;
	sBlk.s.bytes_used = sBlk_3->bytes_used_2;
	sBlk.s.inode_table_start = sBlk_3->inode_table_start;
	sBlk.s.directory_table_start = sBlk_3->directory_table_start_2;
	sBlk.s.fragment_table_start = sBlk_3->fragment_table_start_2;
	sBlk.s.inode_table_start = sBlk_3->inode_table_start_2;
	sBlk.no_uids = sBlk_3->no_uids;
	sBlk.no_guids = sBlk_3->no_guids;
	sBlk.uid_start = sBlk_3->uid_start_2;
	sBlk.guid_start = sBlk_3->guid_start_2;
	sBlk.s.xattr_id_table_start = SQUASHFS_INVALID_BLK;

	*s_ops = &ops;

	/*
	 * 2.x filesystems use gzip compression.
	 */
	comp = lookup_compressor("gzip");

	if(sBlk_3->s_minor == 0)
		needs_sorting = TRUE;

	return TRUE;
}


static void squashfs_stat(char *source)
{
	time_t mkfs_time = (time_t) sBlk.s.mkfs_time;
	struct tm *t = use_localtime ? localtime(&mkfs_time) :
					gmtime(&mkfs_time);
	char *mkfs_str = asctime(t);

#if __BYTE_ORDER == __BIG_ENDIAN
	printf("Found a valid %sSQUASHFS %d:%d superblock on %s.\n",
		swap ? "little endian " : "big endian ", sBlk.s.s_major,
		sBlk.s.s_minor, source);
#else
	printf("Found a valid %sSQUASHFS %d:%d superblock on %s.\n",
		swap ? "big endian " : "little endian ", sBlk.s.s_major,
		sBlk.s.s_minor, source);
#endif

	printf("Creation or last append time %s", mkfs_str ? mkfs_str :
		"failed to get time\n");
	printf("Filesystem size %llu bytes (%.2f Kbytes / %.2f Mbytes)\n",
		sBlk.s.bytes_used, sBlk.s.bytes_used / 1024.0,
		sBlk.s.bytes_used / (1024.0 * 1024.0));

	printf("Block size %d\n", sBlk.s.block_size);
	printf("Filesystem is %sexportable via NFS\n",
		SQUASHFS_EXPORTABLE(sBlk.s.flags) ? "" : "not ");
	printf("Inodes are %scompressed\n",
		SQUASHFS_UNCOMPRESSED_INODES(sBlk.s.flags) ? "un" : "");
	printf("Data is %scompressed\n",
		SQUASHFS_UNCOMPRESSED_DATA(sBlk.s.flags) ? "un" : "");

	if(SQUASHFS_NO_FRAGMENTS(sBlk.s.flags))
		printf("Fragments are not stored\n");
	else {
		printf("Fragments are %scompressed\n",
			SQUASHFS_UNCOMPRESSED_FRAGMENTS(sBlk.s.flags) ?  "un" : "");
		printf("Always-use-fragments option is %sspecified\n",
				SQUASHFS_ALWAYS_FRAGMENTS(sBlk.s.flags) ? "" : "not ");
	}

	printf("Check data is %spresent in the filesystem\n",
		SQUASHFS_CHECK_DATA(sBlk.s.flags) ? "" : "not ");
	printf("Duplicates are %sremoved\n", SQUASHFS_DUPLICATES(sBlk.s.flags) ? "" : "not ");
	printf("Number of fragments %d\n", sBlk.s.fragments);
	printf("Number of inodes %d\n", sBlk.s.inodes);
	printf("Number of uids %d\n", sBlk.no_uids);
	printf("Number of gids %d\n", sBlk.no_guids);

	TRACE("sBlk.s.inode_table_start 0x%llx\n", sBlk.s.inode_table_start);
	TRACE("sBlk.s.directory_table_start 0x%llx\n", sBlk.s.directory_table_start);
	TRACE("sBlk.s.fragment_table_start 0x%llx\n\n", sBlk.s.fragment_table_start);
	TRACE("sBlk.uid_start 0x%llx\n", sBlk.uid_start);
	TRACE("sBlk.guid_start 0x%llx\n", sBlk.guid_start);
}


static squashfs_operations ops = {
	.opendir = squashfs_opendir,
	.read_fragment = read_fragment,
	.read_block_list = read_block_list,
	.read_inode = read_inode,
	.read_filesystem_tables = read_filesystem_tables,
	.stat = squashfs_stat
};