-
Notifications
You must be signed in to change notification settings - Fork 604
/
ext2fs.c
3793 lines (3242 loc) · 128 KB
/
ext2fs.c
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
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
** The Sleuth Kit
**
** Brian Carrier [carrier <at> sleuthkit [dot] org]
** Copyright (c) 2006-2011 Brian Carrier, Basis Technology. All Rights reserved
** Copyright (c) 2003-2005 Brian Carrier. All rights reserved
**
** TASK
** Copyright (c) 2002-2003 Brian Carrier, @stake Inc. All rights reserved
**
** Copyright (c) 1997,1998,1999, International Business Machines
** Corporation and others. All Rights Reserved.
*/
/**
*\file ext2fs.c
* Contains the internal TSK ext2/ext3/ext4 file system functions.
*/
/* TCT
* LICENSE
* This software is distributed under the IBM Public License.
* AUTHOR(S)
* Wietse Venema
* IBM T.J. Watson Research
* P.O. Box 704
* Yorktown Heights, NY 10598, USA
--*/
#include "tsk_fs_i.h"
#include "tsk_ext2fs.h"
#include "tsk/base/crc.h"
#include <stddef.h>
//#define Ext4_DBG 1
//#define EXT4_CHECKSUMS 1
#ifdef Ext4_DBG
static uint8_t
debug_print_buf(unsigned char *buf, int len)
{
int i = 0;
for (i = 0; i < len; i++) {
if (i % 8 == 0)
printf("%08X:\t", i);
printf("0x%02X ", buf[i]);
if ((i + 1) % 8 == 0)
printf("\n");
}
printf("\n");
return 0;
}
#endif
/** \internal
test_root - tests to see if a is power of b
@param a the number being investigated
@param b the root
@return 1 if a is a power of b, otherwise 0
*/
static uint8_t
test_root(uint32_t a, uint32_t b)
{
if (a == 0) {
return b == 0;
}
else if (b == 0) {
return 0;
}
else if (a == 1) {
// anything to power of 0 is 1
return 1;
}
else if (b == 1) {
return 0;
}
// keep on multiplying b by itself
uint32_t b2;
for (b2 = b; b2 < a; b2 *= b) {}
// was it an exact match?
return b2 == a;
}
/** \internal
* Test if block group has a super block in it.
*
* @return 1 if block group has superblock, otherwise 0
*/
static uint32_t
ext2fs_is_super_bg(uint32_t feature_ro_compat, uint32_t group_block)
{
// if no sparse feature, then it has super block
if (!(feature_ro_compat & EXT2FS_FEATURE_RO_COMPAT_SPARSE_SUPER))
return 1;
// group 0 always has super block
if (group_block == 0)
return 1;
// Sparse FS put super blocks in groups that are powers of 3, 5, 7
if (test_root(group_block, 3) ||
(test_root(group_block, 5)) ||
(test_root(group_block, 7))) {
return 1;
}
return 0;
}
/* ext2fs_group_load - load 32-bit or 64-bit block group descriptor into cache
*
* Note: This routine assumes &ext2fs->lock is locked by the caller.
*
* return 1 on error and 0 on success. On success one of either ext2fs->grp_buf or ext2fs->ext4_grp_buf will
* be non-null and contain the valid data. Because Ext4 can have 32-bit group descriptors, check which buffer is
* non-null to determine what to read instead of duplicating the logic everywhere.
*
* */
static uint8_t
ext2fs_group_load(EXT2FS_INFO * ext2fs, EXT2_GRPNUM_T grp_num)
{
TSK_FS_INFO *fs = (TSK_FS_INFO *) ext2fs;
size_t gd_size = tsk_getu16(fs->endian, ext2fs->fs->s_desc_size);
/*
* Sanity check
*/
if (grp_num >= ext2fs->groups_count) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_ARG);
tsk_error_set_errstr
("ext2fs_group_load: invalid cylinder group number: %"
PRI_EXT2GRP "", grp_num);
return 1;
}
// already loaded
else if (ext2fs->grp_num == grp_num) {
return 0;
}
// 64-bit version.
if (((fs->ftype == TSK_FS_TYPE_EXT4)) && (EXT2FS_HAS_INCOMPAT_FEATURE(fs, ext2fs->fs,
EXT2FS_FEATURE_INCOMPAT_64BIT)
&& (tsk_getu16(fs->endian, ext2fs->fs->s_desc_size) >= 64))) {
TSK_OFF_T offs;
ssize_t cnt;
if (gd_size < (int)sizeof(ext4fs_gd))
gd_size = sizeof(ext4fs_gd);
if (ext2fs->ext4_grp_buf == NULL) {
if ((ext2fs->ext4_grp_buf = (ext4fs_gd *) tsk_malloc(gd_size)) == NULL)
return 1;
}
offs = ext2fs->groups_offset + grp_num * gd_size;
cnt = tsk_fs_read(&ext2fs->fs_info, offs, (char *) ext2fs->ext4_grp_buf, gd_size);
#ifdef Ext4_DBG
debug_print_buf((char *) ext2fs->ext4_grp_buf, gd_size);
#endif
if (cnt != (ssize_t) gd_size) {
if (cnt >= 0) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_READ);
}
tsk_error_set_errstr2("ext2fs_group_load: Group descriptor %"
PRI_EXT2GRP " at %" PRIdOFF, grp_num, offs);
return 1;
}
// sanity checks
if ((ext4_getu64(fs->endian,
ext2fs->ext4_grp_buf->bg_block_bitmap_hi,
ext2fs->ext4_grp_buf->bg_block_bitmap_lo) > fs->last_block) ||
(ext4_getu64(fs->endian,
ext2fs->ext4_grp_buf->bg_inode_bitmap_hi,
ext2fs->ext4_grp_buf->bg_inode_bitmap_lo) > fs->last_block) ||
(ext4_getu64(fs->endian,
ext2fs->ext4_grp_buf->bg_inode_table_hi,
ext2fs->ext4_grp_buf->bg_inode_table_lo) > fs->last_block)) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_CORRUPT);
tsk_error_set_errstr("extXfs_group_load: Ext4 Group %" PRI_EXT2GRP
" descriptor block locations too large at byte offset %"
PRIuDADDR, grp_num, offs);
return 1;
}
}
else {
TSK_OFF_T offs;
ssize_t cnt;
if (gd_size < (int)sizeof(ext2fs_gd))
gd_size = sizeof(ext2fs_gd);
if (ext2fs->grp_buf == NULL) {
if ((ext2fs->grp_buf = (ext2fs_gd *) tsk_malloc(gd_size)) == NULL)
return 1;
}
offs = ext2fs->groups_offset + grp_num * gd_size;
cnt = tsk_fs_read(&ext2fs->fs_info, offs, (char *) ext2fs->grp_buf, gd_size);
if (cnt != (ssize_t) gd_size) {
if (cnt >= 0) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_READ);
}
tsk_error_set_errstr2("ext2fs_group_load: Group descriptor %"
PRI_EXT2GRP " at %" PRIdOFF, grp_num, offs);
return 1;
}
// sanity checks
if ((tsk_getu32(fs->endian,
ext2fs->grp_buf->bg_block_bitmap) > fs->last_block) ||
(tsk_getu32(fs->endian,
ext2fs->grp_buf->bg_inode_bitmap) > fs->last_block) ||
(tsk_getu32(fs->endian,
ext2fs->grp_buf->bg_inode_table) > fs->last_block)) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_CORRUPT);
tsk_error_set_errstr("extXfs_group_load: Group %" PRI_EXT2GRP
" descriptor block locations too large at byte offset %"
PRIuDADDR, grp_num, offs);
return 1;
}
if (tsk_verbose) {
TSK_FS_INFO *fs = (TSK_FS_INFO *) & ext2fs->fs_info;
tsk_fprintf(stderr,
"\tgroup %" PRI_EXT2GRP ": %" PRIu16 "/%" PRIu16
" free blocks/inodes\n", grp_num, tsk_getu16(fs->endian,
ext2fs->grp_buf->bg_free_blocks_count),
tsk_getu16(fs->endian, ext2fs->grp_buf->bg_free_inodes_count));
}
}
ext2fs->grp_num = grp_num;
return 0;
}
#ifdef EXT4_CHECKSUMS
/**
* ext4_group_desc_csum - Calculates the checksum of a group descriptor
* Ported from linux/fs/ext4/super.c
* @ext4_sb: pointer to ext2 super block structure
* @block_group: group descriptor number
* @gdp: pointer to group descriptor to calculate checksum for
* returns the checksum value
*/
static uint16_t
ext4_group_desc_csum(ext2fs_sb * ext4_sb, uint32_t block_group,
struct ext4fs_gd *gdp)
{
cm_t CRC16_CTX;
CRC16_CTX.cm_width = 16;
CRC16_CTX.cm_poly = 0x8005L;
CRC16_CTX.cm_init = 0xFFFFL;
CRC16_CTX.cm_refin = TRUE;
CRC16_CTX.cm_refot = TRUE;
CRC16_CTX.cm_xorot = 0x0000L;
cm_ini(&CRC16_CTX);
if (*ext4_sb->s_feature_ro_compat & EXT2FS_FEATURE_RO_COMPAT_GDT_CSUM) {
int offset = offsetof(struct ext4fs_gd, bg_checksum);
uint32_t le_group = tsk_getu32(TSK_LIT_ENDIAN, &block_group);
crc16(&CRC16_CTX, ext4_sb->s_uuid, sizeof(ext4_sb->s_uuid));
crc16(&CRC16_CTX, (uint8_t *) & le_group, sizeof(le_group));
crc16(&CRC16_CTX, (uint8_t *) gdp, offset);
offset += sizeof(gdp->bg_checksum); /* skip checksum */
/* for checksum of struct ext4_group_desc do the rest... */
if ((*ext4_sb->s_feature_incompat &
EXT2FS_FEATURE_INCOMPAT_64BIT) &&
offset < *ext4_sb->s_desc_size) {
crc16(&CRC16_CTX, (uint8_t *) gdp + offset,
*ext4_sb->s_desc_size - offset);
}
}
return cm_crc(&CRC16_CTX);
}
#endif
/* ext2fs_print_map - print a bitmap */
static void
ext2fs_print_map(uint8_t * map, int len)
{
int i;
for (i = 0; i < len; i++) {
if (i > 0 && i % 10 == 0)
putc('|', stderr);
putc(isset(map, i) ? '1' : '.', stderr);
}
putc('\n', stderr);
}
#define INODE_TABLE_SIZE(ext2fs) \
((tsk_getu32(ext2fs->fs_info.endian, ext2fs->fs->s_inodes_per_group) * ext2fs->inode_size - 1) \
/ ext2fs->fs_info.block_size + 1)
/* ext2fs_bmap_load - look up block bitmap & load into cache
*
* Note: This routine assumes &ext2fs->lock is locked by the caller.
*
* return 1 on error and 0 on success
* */
static uint8_t
ext2fs_bmap_load(EXT2FS_INFO * ext2fs, EXT2_GRPNUM_T grp_num)
{
TSK_FS_INFO *fs = (TSK_FS_INFO *) & ext2fs->fs_info;
ssize_t cnt;
TSK_DADDR_T addr;
/*
* Look up the group descriptor info. The load will do the sanity check.
*/
if (ext2fs_group_load(ext2fs, grp_num)) {
return 1;
}
if (ext2fs->bmap_buf == NULL) {
if ((ext2fs->bmap_buf =
(uint8_t *) tsk_malloc(fs->block_size)) == NULL) {
return 1;
}
}
else if (ext2fs->bmap_grp_num == grp_num) {
return 0;
}
if (ext2fs->ext4_grp_buf != NULL) {
addr = ext4_getu64(fs->endian,
ext2fs->ext4_grp_buf->bg_block_bitmap_hi,
ext2fs->ext4_grp_buf->bg_block_bitmap_lo);
}
else {
addr = (TSK_DADDR_T) tsk_getu32(fs->endian, ext2fs->grp_buf->bg_block_bitmap);
}
if (addr > fs->last_block) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_BLK_NUM);
tsk_error_set_errstr
("ext2fs_bmap_load: Block too large for image: %" PRIu64, addr);
return 1;
}
cnt = tsk_fs_read(fs, addr * fs->block_size,
(char *) ext2fs->bmap_buf, ext2fs->fs_info.block_size);
if (cnt != ext2fs->fs_info.block_size) {
if (cnt >= 0) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_READ);
}
tsk_error_set_errstr2("ext2fs_bmap_load: block bitmap %"
PRI_EXT2GRP " at %" PRIu64, grp_num, addr);
return 1;
}
ext2fs->bmap_grp_num = grp_num;
if (tsk_verbose > 1)
ext2fs_print_map(ext2fs->bmap_buf,
tsk_getu32(fs->endian, ext2fs->fs->s_blocks_per_group));
return 0;
}
/* ext2fs_imap_load - look up inode bitmap & load into cache
*
* Note: This routine assumes &ext2fs->lock is locked by the caller.
*
* return 0 on success and 1 on error
* */
static uint8_t
ext2fs_imap_load(EXT2FS_INFO * ext2fs, EXT2_GRPNUM_T grp_num)
{
TSK_FS_INFO *fs = (TSK_FS_INFO *) & ext2fs->fs_info;
ssize_t cnt;
TSK_DADDR_T addr;
/*
* Look up the group descriptor info.
*/
if (ext2fs_group_load(ext2fs, grp_num)) {
return 1;
}
/* Allocate the cache buffer and exit if map is already loaded */
if (ext2fs->imap_buf == NULL) {
if ((ext2fs->imap_buf =
(uint8_t *) tsk_malloc(fs->block_size)) == NULL) {
return 1;
}
}
else if (ext2fs->imap_grp_num == grp_num) {
return 0;
}
/*
* Look up the inode allocation bitmap.
*/
if (ext2fs->ext4_grp_buf != NULL) {
addr = ext4_getu64(fs->endian,
ext2fs->ext4_grp_buf->bg_inode_bitmap_hi,
ext2fs->ext4_grp_buf->bg_inode_bitmap_lo);
}
else {
addr = (TSK_DADDR_T) tsk_getu32(fs->endian, ext2fs->grp_buf->bg_inode_bitmap);
}
if (addr > fs->last_block) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_BLK_NUM);
tsk_error_set_errstr
("ext2fs_imap_load: Block too large for image: %" PRIu64, addr);
return 1;
}
// Ensure the bitmap buffer is initialized.
memset(ext2fs->imap_buf, 0, fs->block_size);
cnt = tsk_fs_read(fs, addr * fs->block_size,
(char *) ext2fs->imap_buf, ext2fs->fs_info.block_size);
if (cnt != ext2fs->fs_info.block_size) {
if (cnt >= 0) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_READ);
}
tsk_error_set_errstr2("ext2fs_imap_load: Inode bitmap %"
PRI_EXT2GRP " at %" PRIu64, grp_num, addr);
return 1;
}
ext2fs->imap_grp_num = grp_num;
if (tsk_verbose > 1)
ext2fs_print_map(ext2fs->imap_buf,
tsk_getu32(fs->endian, ext2fs->fs->s_inodes_per_group));
return 0;
}
/* ext2fs_dinode_load - look up disk inode & load into ext2fs_inode structure
* @param ext2fs A ext2fs file system information structure
* @param dino_inum Metadata address
* @param dino_buf The buffer to store the block in (must be size of ext2fs->inode_size or larger)
* @param ea_buf The buffer to hold the extended attribute data
*
* return 1 on error and 0 on success
* */
static uint8_t
ext2fs_dinode_load(EXT2FS_INFO * ext2fs, TSK_INUM_T dino_inum,
ext2fs_inode * dino_buf, uint8_t ** ea_buf, size_t * ea_buf_len)
{
EXT2_GRPNUM_T grp_num;
TSK_OFF_T addr;
ssize_t cnt;
TSK_INUM_T rel_inum;
TSK_FS_INFO *fs = (TSK_FS_INFO *) & ext2fs->fs_info;
/*
* Sanity check.
* Use last_num-1 to account for virtual Orphan directory in last_inum.
*/
if ((dino_inum < fs->first_inum) || (dino_inum > fs->last_inum - 1)) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_INODE_NUM);
tsk_error_set_errstr("ext2fs_dinode_load: address: %" PRIuINUM,
dino_inum);
return 1;
}
if (dino_buf == NULL) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_ARG);
tsk_error_set_errstr("ext2fs_dinode_load: dino_buf is NULL");
return 1;
}
/*
* Look up the group descriptor for this inode.
*/
grp_num = (EXT2_GRPNUM_T) ((dino_inum - fs->first_inum) /
tsk_getu32(fs->endian, ext2fs->fs->s_inodes_per_group));
/* lock access to grp_buf */
tsk_take_lock(&ext2fs->lock);
if (ext2fs_group_load(ext2fs, grp_num)) {
tsk_release_lock(&ext2fs->lock);
return 1;
}
/*
* Look up the inode table block for this inode.
*/
rel_inum =
(dino_inum - 1) - tsk_getu32(fs->endian,
ext2fs->fs->s_inodes_per_group) * grp_num;
if (ext2fs->ext4_grp_buf != NULL) {
#ifdef Ext4_DBG
printf("DEBUG: d_inode_load 64bit gd_size=%d\n",
tsk_getu16(fs->endian, ext2fs->fs->s_desc_size));
#endif
/* Test for possible overflow */
if (ext4_getu64(fs->endian, ext2fs->ext4_grp_buf->bg_inode_table_hi, ext2fs->ext4_grp_buf->bg_inode_table_lo)
>= LLONG_MAX / fs->block_size) {
tsk_release_lock(&ext2fs->lock);
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_READ);
tsk_error_set_errstr
("ext2fs_dinode_load: Overflow when calculating address");
return 1;
}
addr =
(TSK_OFF_T) ext4_getu64(fs->endian,
ext2fs->ext4_grp_buf->bg_inode_table_hi,
ext2fs->ext4_grp_buf->bg_inode_table_lo)
* (TSK_OFF_T) fs->block_size +
rel_inum * (TSK_OFF_T) ext2fs->inode_size;
}
else {
addr =
(TSK_OFF_T) tsk_getu32(fs->endian,
ext2fs->grp_buf->bg_inode_table) * (TSK_OFF_T) fs->block_size +
rel_inum * (TSK_OFF_T) ext2fs->inode_size;
}
tsk_release_lock(&ext2fs->lock);
cnt = tsk_fs_read(fs, addr, (char *) dino_buf, ext2fs->inode_size);
if (cnt != ext2fs->inode_size) {
if (cnt >= 0) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_READ);
}
tsk_error_set_errstr2("ext2fs_dinode_load: Inode %" PRIuINUM
" from %" PRIdOFF, dino_inum, addr);
return 1;
}
//DEBUG printf("Inode Size: %d, %d, %d, %d\n", sizeof(ext2fs_inode), *ext2fs->fs->s_inode_size, ext2fs->inode_size, *ext2fs->fs->s_want_extra_isize);
//DEBUG debug_print_buf((char *)dino_buf, ext2fs->inode_size);
// Check if we have an extended attribute in the inode
if (ext2fs->inode_size > EXT2_EA_INODE_OFFSET) {
// The extended attribute data immediatly follows the standard inode data
*ea_buf = (char*)dino_buf + EXT2_EA_INODE_OFFSET;
*ea_buf_len = ext2fs->inode_size - EXT2_EA_INODE_OFFSET;
}
else {
*ea_buf = NULL;
}
if (tsk_verbose) {
tsk_fprintf(stderr,
"%" PRIuINUM " m/l/s=%o/%d/%" PRIu32
" u/g=%d/%d macd=%" PRIu32 "/%" PRIu32 "/%" PRIu32 "/%" PRIu32
"\n", dino_inum, tsk_getu16(fs->endian, dino_buf->i_mode),
tsk_getu16(fs->endian, dino_buf->i_nlink),
(tsk_getu32(fs->endian,
dino_buf->i_size) + (tsk_getu16(fs->endian,
dino_buf->i_mode) & EXT2_IN_REG) ? (uint64_t)
tsk_getu32(fs->endian, dino_buf->i_size_high) << 32 : 0),
tsk_getu16(fs->endian,
dino_buf->i_uid) + (tsk_getu16(fs->endian,
dino_buf->i_uid_high) << 16), tsk_getu16(fs->endian,
dino_buf->i_gid) + (tsk_getu16(fs->endian,
dino_buf->i_gid_high) << 16), tsk_getu32(fs->endian,
dino_buf->i_mtime), tsk_getu32(fs->endian,
dino_buf->i_atime), tsk_getu32(fs->endian,
dino_buf->i_ctime), tsk_getu32(fs->endian,
dino_buf->i_dtime));
}
return 0;
}
/**
* \internal
* Loads attribute for Ext4 inline storage method.
* @param fs_file File to load attrs
* @param ea_buf Extended attribute buffer
* @param ea_buf_len Extended attribute buffer length
* @returns 0 on success, 1 otherwise
*/
static uint8_t
ext4_load_attrs_inline(TSK_FS_FILE *fs_file, const uint8_t * ea_buf, size_t ea_buf_len)
{
TSK_FS_META *fs_meta = fs_file->meta;
TSK_FS_ATTR *fs_attr;
// see if we have already loaded the attr
if ((fs_meta->attr != NULL)
&& (fs_meta->attr_state == TSK_FS_META_ATTR_STUDIED)) {
return 0;
}
if (fs_meta->attr_state == TSK_FS_META_ATTR_ERROR) {
return 1;
}
// First load the data from the extended attr (if present)
const char *ea_inline_data = NULL;
uint32_t ea_inline_data_len = 0;
if ((ea_buf != NULL) && (ea_buf_len > 4 + sizeof(ext2fs_ea_entry))
&& (tsk_getu32(fs_file->fs_info->endian, ea_buf) == EXT2_EA_MAGIC)) {
// First entry starts after the four byte header
size_t index = 4;
ext2fs_ea_entry *ea_entry = (ext2fs_ea_entry*) &(ea_buf[index]);
// The end of the list of entries is marked by two null bytes
while ((ea_entry->nlen != 0) || (ea_entry->nidx != 0)) {
// It looks like the continuation of inline data is stored in system.data.
// Make sure we have room to read the attr name 'data'.
if ((ea_entry->nidx == EXT2_EA_IDX_SYSTEM)
&& (ea_entry->nlen == 4)
&& (index + sizeof(ext2fs_ea_entry) + strlen("data") < ea_buf_len)
&& (strncmp(&(ea_entry->name), "data", 4)) == 0) {
// This is the right attribute. Check that the length and offset are valid.
// The offset is from the beginning of the entries, i.e., four bytes into the buffer.
uint16_t offset = tsk_getu16(fs_file->fs_info->endian, ea_entry->val_off);
uint32_t size = tsk_getu32(fs_file->fs_info->endian, ea_entry->val_size);
if ((ea_buf_len >= 4) && (offset < ea_buf_len - 4) && (size <= ea_buf_len - 4 - offset)) {
ea_inline_data = &(ea_buf[4 + offset]);
ea_inline_data_len = size;
break;
}
}
// Prepare to load the next entry.
// The entry size is the size of the struct plus the length of the name, minus one
// because the struct contains the first character of the name.
index += sizeof(ext2fs_ea_entry) + ea_entry->nlen - 1;
// Make sure there's room for the next entry plus the 'data' name we're looking for.
if (index + sizeof(ext2fs_ea_entry) + strlen("data") > ea_buf_len) {
break;
}
ea_entry = (ext2fs_ea_entry*) &(ea_buf[index]);
}
}
// Check if resident data size exceeds maximum inode size (1024) - ext4 inode resident data offset (156)
if ((fs_meta->size == 0) || (fs_meta->size > (1024 - 156))) {
return 1;
}
// Combine the two parts of the inline data for the resident attribute. For now, make a
// buffer for the full file size - this may be different than the length of the data
// from the inode if we have sparse data.
uint8_t *resident_data = (uint8_t*)tsk_malloc(fs_meta->size);
if (resident_data == NULL) {
return 1;
}
memset(resident_data, 0, fs_meta->size);
// Copy the data from the inode.
size_t inode_data_len = (fs_meta->size < EXT2_INLINE_MAX_DATA_LEN) ? fs_meta->size : EXT2_INLINE_MAX_DATA_LEN;
memcpy(resident_data, fs_meta->content_ptr, inode_data_len);
// If we need more data and found an extended attribute, append that data
if ((fs_meta->size > EXT2_INLINE_MAX_DATA_LEN) && (ea_inline_data_len > 0)) {
// Don't go beyond the size of the file
size_t ea_data_len = (ea_inline_data_len < (uint64_t)fs_meta->size - inode_data_len) ? ea_inline_data_len : fs_meta->size - inode_data_len;
memcpy(resident_data + inode_data_len, ea_inline_data, ea_data_len);
}
if (fs_meta->attr == NULL) {
fs_meta->attr = tsk_fs_attrlist_alloc();
}
if ((fs_attr =
tsk_fs_attrlist_getnew(fs_meta->attr,
TSK_FS_ATTR_RES)) == NULL) {
free(resident_data);
return 1;
}
// Set the details in the fs_attr structure
if (tsk_fs_attr_set_str(fs_file, fs_attr, "DATA",
TSK_FS_ATTR_TYPE_DEFAULT, TSK_FS_ATTR_ID_DEFAULT,
(void*)resident_data,
fs_meta->size)) {
free(resident_data);
fs_meta->attr_state = TSK_FS_META_ATTR_ERROR;
return 1;
}
free(resident_data);
fs_meta->attr_state = TSK_FS_META_ATTR_STUDIED;
return 0;
}
/* ext2fs_dinode_copy - copy cached disk inode into generic inode
*
* returns 1 on error and 0 on success
* */
static uint8_t
ext2fs_dinode_copy(EXT2FS_INFO * ext2fs, TSK_FS_FILE * fs_file,
TSK_INUM_T inum, const ext2fs_inode * dino_buf, const uint8_t * ea_buf, size_t ea_buf_len)
{
int i;
TSK_FS_INFO *fs = (TSK_FS_INFO *) & ext2fs->fs_info;
TSK_FS_META * fs_meta = fs_file->meta;
ext2fs_sb *sb = ext2fs->fs;
EXT2_GRPNUM_T grp_num;
TSK_INUM_T ibase = 0;
if (dino_buf == NULL) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_ARG);
tsk_error_set_errstr("ext2fs_dinode_copy: dino_buf is NULL");
return 1;
}
fs_meta->attr_state = TSK_FS_META_ATTR_EMPTY;
if (fs_meta->attr) {
tsk_fs_attrlist_markunused(fs_meta->attr);
}
// set the type
switch (tsk_getu16(fs->endian, dino_buf->i_mode) & EXT2_IN_FMT) {
case EXT2_IN_REG:
fs_meta->type = TSK_FS_META_TYPE_REG;
break;
case EXT2_IN_DIR:
fs_meta->type = TSK_FS_META_TYPE_DIR;
break;
case EXT2_IN_SOCK:
fs_meta->type = TSK_FS_META_TYPE_SOCK;
break;
case EXT2_IN_LNK:
fs_meta->type = TSK_FS_META_TYPE_LNK;
break;
case EXT2_IN_BLK:
fs_meta->type = TSK_FS_META_TYPE_BLK;
break;
case EXT2_IN_CHR:
fs_meta->type = TSK_FS_META_TYPE_CHR;
break;
case EXT2_IN_FIFO:
fs_meta->type = TSK_FS_META_TYPE_FIFO;
break;
default:
fs_meta->type = TSK_FS_META_TYPE_UNDEF;
break;
}
// set the mode
fs_meta->mode = 0;
if (tsk_getu16(fs->endian, dino_buf->i_mode) & EXT2_IN_ISUID)
fs_meta->mode |= TSK_FS_META_MODE_ISUID;
if (tsk_getu16(fs->endian, dino_buf->i_mode) & EXT2_IN_ISGID)
fs_meta->mode |= TSK_FS_META_MODE_ISGID;
if (tsk_getu16(fs->endian, dino_buf->i_mode) & EXT2_IN_ISVTX)
fs_meta->mode |= TSK_FS_META_MODE_ISVTX;
if (tsk_getu16(fs->endian, dino_buf->i_mode) & EXT2_IN_IRUSR)
fs_meta->mode |= TSK_FS_META_MODE_IRUSR;
if (tsk_getu16(fs->endian, dino_buf->i_mode) & EXT2_IN_IWUSR)
fs_meta->mode |= TSK_FS_META_MODE_IWUSR;
if (tsk_getu16(fs->endian, dino_buf->i_mode) & EXT2_IN_IXUSR)
fs_meta->mode |= TSK_FS_META_MODE_IXUSR;
if (tsk_getu16(fs->endian, dino_buf->i_mode) & EXT2_IN_IRGRP)
fs_meta->mode |= TSK_FS_META_MODE_IRGRP;
if (tsk_getu16(fs->endian, dino_buf->i_mode) & EXT2_IN_IWGRP)
fs_meta->mode |= TSK_FS_META_MODE_IWGRP;
if (tsk_getu16(fs->endian, dino_buf->i_mode) & EXT2_IN_IXGRP)
fs_meta->mode |= TSK_FS_META_MODE_IXGRP;
if (tsk_getu16(fs->endian, dino_buf->i_mode) & EXT2_IN_IROTH)
fs_meta->mode |= TSK_FS_META_MODE_IROTH;
if (tsk_getu16(fs->endian, dino_buf->i_mode) & EXT2_IN_IWOTH)
fs_meta->mode |= TSK_FS_META_MODE_IWOTH;
if (tsk_getu16(fs->endian, dino_buf->i_mode) & EXT2_IN_IXOTH)
fs_meta->mode |= TSK_FS_META_MODE_IXOTH;
fs_meta->nlink = tsk_getu16(fs->endian, dino_buf->i_nlink);
fs_meta->size = tsk_getu32(fs->endian, dino_buf->i_size);
fs_meta->addr = inum;
/* the general size value in the inode is only 32-bits,
* but the i_dir_acl value is used for regular files to
* hold the upper 32-bits
*
* The RO_COMPAT_LARGE_FILE flag in the super block will identify
* if there are any large files in the file system
*/
if ((fs_meta->type == TSK_FS_META_TYPE_REG) &&
(tsk_getu32(fs->endian, sb->s_feature_ro_compat) &
EXT2FS_FEATURE_RO_COMPAT_LARGE_FILE)) {
fs_meta->size +=
((uint64_t) tsk_getu32(fs->endian,
dino_buf->i_size_high) << 32);
}
fs_meta->uid =
tsk_getu16(fs->endian, dino_buf->i_uid) + ((TSK_UID_T)tsk_getu16(fs->endian,
dino_buf->i_uid_high) << 16);
fs_meta->gid =
tsk_getu16(fs->endian, dino_buf->i_gid) + ((TSK_GID_T)tsk_getu16(fs->endian,
dino_buf->i_gid_high) << 16);
fs_meta->mtime = tsk_getu32(fs->endian, dino_buf->i_mtime);
fs_meta->atime = tsk_getu32(fs->endian, dino_buf->i_atime);
fs_meta->ctime = tsk_getu32(fs->endian, dino_buf->i_ctime);
fs_meta->time2.ext2.dtime = tsk_getu32(fs->endian, dino_buf->i_dtime);
if (fs->ftype == TSK_FS_TYPE_EXT4) {
fs_meta->mtime_nano =
tsk_getu32(fs->endian, dino_buf->i_mtime_extra) >> 2;
fs_meta->atime_nano =
tsk_getu32(fs->endian, dino_buf->i_atime_extra) >> 2;
fs_meta->ctime_nano =
tsk_getu32(fs->endian, dino_buf->i_ctime_extra) >> 2;
fs_meta->crtime = tsk_getu32(fs->endian, dino_buf->i_crtime);
fs_meta->crtime_nano =
tsk_getu32(fs->endian, dino_buf->i_crtime_extra) >> 2;
}
else {
fs_meta->mtime_nano = fs_meta->atime_nano = fs_meta->ctime_nano = 0;
fs_meta->crtime = 0;
}
fs_meta->time2.ext2.dtime_nano = 0;
fs_meta->seq = 0;
if (fs_meta->link) {
free(fs_meta->link);
fs_meta->link = NULL;
}
if (fs_meta->content_len != EXT2FS_FILE_CONTENT_LEN) {
if ((fs_meta =
tsk_fs_meta_realloc(fs_meta,
EXT2FS_FILE_CONTENT_LEN)) == NULL) {
return 1;
}
}
if (tsk_getu32(fs->endian, dino_buf->i_flags) & EXT2_IN_EXTENTS) {
uint32_t *addr_ptr;
fs_meta->content_type = TSK_FS_META_CONTENT_TYPE_EXT4_EXTENTS;
/* NOTE TSK_DADDR_T != uint32_t, so lets make sure we use uint32_t */
addr_ptr = (uint32_t *) fs_meta->content_ptr;
for (i = 0; i < EXT2FS_NDADDR + EXT2FS_NIADDR; i++) {
addr_ptr[i] = tsk_gets32(fs->endian, dino_buf->i_block[i]);
}
}
else if (tsk_getu32(fs->endian, dino_buf->i_flags) & EXT2_INLINE_DATA) {
uint32_t *addr_ptr;
fs_meta->content_type = TSK_FS_META_CONTENT_TYPE_EXT4_INLINE;
addr_ptr = (uint32_t *)fs_meta->content_ptr;
for (i = 0; i < EXT2FS_NDADDR + EXT2FS_NIADDR; i++) {
addr_ptr[i] = tsk_gets32(fs->endian, dino_buf->i_block[i]);
}
// For inline data we create the default attribute now
ext4_load_attrs_inline(fs_file, ea_buf, ea_buf_len);
}
else {
TSK_DADDR_T *addr_ptr;
addr_ptr = (TSK_DADDR_T *) fs_meta->content_ptr;
for (i = 0; i < EXT2FS_NDADDR + EXT2FS_NIADDR; i++)
addr_ptr[i] = tsk_gets32(fs->endian, dino_buf->i_block[i]);
/* set the link string
* the size check prevents us from trying to allocate a huge amount of
* memory for a bad inode value
*/
if ((fs_meta->type == TSK_FS_META_TYPE_LNK)
&& (fs_meta->size < EXT2FS_MAXPATHLEN) && (fs_meta->size >= 0)) {
int i;
if ((fs_meta->link =
tsk_malloc((size_t) (fs_meta->size + 1))) == NULL)
return 1;
/* it is located directly in the pointers */
if (fs_meta->size < 4 * (EXT2FS_NDADDR + EXT2FS_NIADDR)) {
unsigned int j;
unsigned int count = 0;
for (i = 0; i < (EXT2FS_NDADDR + EXT2FS_NIADDR) &&
count < fs_meta->size; i++) {
char *a_ptr = (char *) &dino_buf->i_block[i];
for (j = 0; j < 4 && count < fs_meta->size; j++) {
fs_meta->link[count++] = a_ptr[j];
}
}
fs_meta->link[count] = '\0';
/* clear the content pointer data to avoid the prog from reading them */
memset(fs_meta->content_ptr, 0, fs_meta->content_len);
}
/* it is in blocks */
else {
TSK_FS_INFO *fs = (TSK_FS_INFO *) & ext2fs->fs_info;
char *data_buf = NULL;
char *a_ptr = fs_meta->link;
unsigned int total_read = 0;
TSK_DADDR_T *addr_ptr = fs_meta->content_ptr;;
if ((data_buf = tsk_malloc(fs->block_size)) == NULL) {
return 1;
}
/* we only need to do the direct blocks due to the limit
* on path length */
for (i = 0; i < EXT2FS_NDADDR && total_read < fs_meta->size;
i++) {
ssize_t cnt;
cnt = tsk_fs_read_block(fs,
addr_ptr[i], data_buf, fs->block_size);
if (cnt != fs->block_size) {
if (cnt >= 0) {
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_READ);
}
tsk_error_set_errstr2
("ext2fs_dinode_copy: symlink destination from %"
PRIuDADDR, addr_ptr[i]);
free(data_buf);
return 1;
}
int copy_len =
(fs_meta->size - total_read <
fs->block_size) ? (int) (fs_meta->size -
total_read) : (int) (fs->block_size);
memcpy(a_ptr, data_buf, copy_len);
total_read += copy_len;
a_ptr = (char *) ((uintptr_t) a_ptr + copy_len);
}
/* terminate the string */
*a_ptr = '\0';
free(data_buf);
}
/* Clean up name */
i = 0;
while (fs_meta->link[i] != '\0') {
if (TSK_IS_CNTRL(fs_meta->link[i]))
fs_meta->link[i] = '^';
i++;
}
}
}
/* Fill in the flags value */
grp_num = (EXT2_GRPNUM_T) ((inum - fs->first_inum) /
tsk_getu32(fs->endian, ext2fs->fs->s_inodes_per_group));
tsk_take_lock(&ext2fs->lock);
if (ext2fs_imap_load(ext2fs, grp_num)) {
tsk_release_lock(&ext2fs->lock);
return 1;
}
ibase =
grp_num * tsk_getu32(fs->endian,
ext2fs->fs->s_inodes_per_group) + fs->first_inum;
/*
* Ensure that inum - ibase refers to a valid bit offset in imap_buf.
*/
if ((ibase > inum) || (inum - ibase) >= (fs->block_size * 8)) {
tsk_release_lock(&ext2fs->lock);
tsk_error_reset();
tsk_error_set_errno(TSK_ERR_FS_WALK_RNG);
tsk_error_set_errstr("ext2fs_dinode_copy: Invalid offset into imap_buf (inum %" PRIuINUM " - ibase %" PRIuINUM ")",
inum, ibase);
return 1;
}