• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /**
2  * ntfsck - Part of the Linux-NTFS project.
3  *
4  * Copyright (c) 2006 Yuval Fledel
5  *
6  * This utility will check and fix errors on an NTFS volume.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program (in the main directory of the Linux-NTFS
20  * distribution in the file COPYING); if not, write to the Free Software
21  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
22  */
23 
24 
25 #include "config.h"
26 
27 #ifdef HAVE_STDIO_H
28 #include <stdio.h>
29 #endif
30 #ifdef HAVE_STDLIB_H
31 #include <stdlib.h>
32 #endif
33 #ifdef HAVE_STRING_H
34 #include <string.h>
35 #endif
36 #ifdef HAVE_FCNTL_H
37 #include <fcntl.h>
38 #endif
39 
40 #include <layout.h>
41 #include <bitmap.h>
42 #include <endians.h>
43 #include <bootsect.h>
44 #include <misc.h>
45 
46 #include "cluster.h"
47 #include "utils.h"
48 
49 #define RETURN_FS_ERRORS_CORRECTED (1)
50 #define RETURN_SYSTEM_NEEDS_REBOOT (2)
51 #define RETURN_FS_ERRORS_LEFT_UNCORRECTED (4)
52 #define RETURN_OPERATIONAL_ERROR (8)
53 #define RETURN_USAGE_OR_SYNTAX_ERROR (16)
54 #define RETURN_CANCELLED_BY_USER (32)
55 /* Where did 64 go? */
56 #define RETURN_SHARED_LIBRARY_ERROR (128)
57 
58 /* todo: command line: (everything is optional)
59  *  fsck-frontend options:
60  *	-C [fd]	: display progress bar (send it to the file descriptor if specified)
61  *	-T	: don't show the title on startup
62  *  fsck-checker options:
63  *	-a	: auto-repair. no questions. (optional: if marked clean and -f not specified, just check if mounable)
64  *	-p	: auto-repair safe. no questions (optional: same)
65  *	-n	: only check. no repair.
66  *	-r	: interactively repair.
67  *	-y	: always yes.
68  *	-v	: verbose.
69  *	-V	: version.
70  *  taken from fsck.ext2
71  *	-b sb	: use the superblock from sb. For corrupted volumes. (do we want separete boot/mft options?)
72  *	-c	: use badblocks(8) to find bad blocks (R/O mode) and add the findings to $Bad.
73  *	-C fd	: write competion info to fd. If 0, print a completion bar.
74  *	-d	: debugging output.
75  *	-D	: rebalance indices.
76  *	-f	: force checking even if marked clean.
77  *	-F	: flush buffers before beginning. (for time-benchmarking)
78  *	-k	: When used with -c, don't erase previous $Bad items.
79  *	-n	: Open fs as readonly. assume always no. (why is it needed if -r is not specified?)
80  *	-t	: Print time statistics.
81  *  taken from fsck.reiserfs
82  *	--rebuild-sb	: try to find $MFT start and rebuild the boot sector.
83  *	--rebuild-tree	: scan for items and rebuild the indices that point to them (0x30, $SDS, etc.)
84  *	--clean-reserved: zero rezerved fields. (use with care!)
85  *	--adjust-size -z: insert a sparse hole if the data_size is larger than the size marked in the runlist.
86  *	--logfile file	: report corruptions (unlike other errors) to a file instead of stderr.
87  *	--nolog		: don't report corruptions at all.
88  *	--quiet -q	: no progress bar.
89  *  taken from fsck.msdos
90  *	-w	: flush after every write.
91  *	- do n passes. (only 2 in fsck.msdos. second should not report errors. Bonus: stop when error list does not change)
92  *  taken from fsck.jfs
93  *	--omit-journal-reply: self-descriptive (why would someone do that?)
94  *	--replay-journal-only: self-descriptive. don't check otherwise.
95  *  taken from fsck.xfs
96  *	-s	: only serious errors should be reported.
97  *	-i ino	: verbose behaviour only for inode ino.
98  *	-b bno	: verbose behaviour only for cluster bno.
99  *	-L	: zero log.
100  *  inspired by others
101  *	- don't do cluster accounting.
102  *	- don't do mft record accounting.
103  *	- don't do file names accounting.
104  *	- don't do security_id accounting.
105  *	- don't check acl inheritance problems.
106  *	- undelete unused mft records. (bonus: different options for 100% salvagable and less)
107  *	- error-level-report n: only report errors above this error level
108  *	- error-level-repair n: only repair errors below this error level
109  *	- don't fail on ntfsclone metadata pruning.
110  *  signals:
111  *	SIGUSR1	: start displaying progress bar
112  *	SIGUSR2	: stop displaying progress bar.
113  */
114 
115 /* Assuming NO_NTFS_DEVICE_DEFAULT_IO_OPS is not set */
116 
117 static int errors = 0;
118 static int unsupported = 0;
119 
120 static short bytes_per_sector, sectors_per_cluster;
121 //static s64 mft_offset, mftmirr_offset;
122 static s64 current_mft_record;
123 
124 /**
125  * This is just a preliminary volume.
126  * Filled while checking the boot sector and used in the preliminary MFT check.
127  */
128 //static ntfs_volume vol;
129 
130 static runlist_element *mft_rl, *mft_bitmap_rl;
131 
132 #define check_failed(FORMAT, ARGS...) \
133 	do { \
134 		errors++; \
135 		ntfs_log_redirect(__FUNCTION__,__FILE__,__LINE__, \
136 				NTFS_LOG_LEVEL_ERROR,NULL,FORMAT,##ARGS); \
137 	} while (0);
138 
139 /**
140  * 0 success.
141  * 1 fail.
142  */
assert_u32_equal(u32 val,u32 ok,const char * name)143 static int assert_u32_equal(u32 val, u32 ok, const char *name)
144 {
145 	if (val!=ok) {
146 		check_failed("Assertion failed for '%lld:%s'. should be 0x%x, "
147 			"was 0x%x.\n", (long long)current_mft_record, name,
148 			(int)ok, (int)val);
149 		//errors++;
150 		return 1;
151 	}
152 	return 0;
153 }
154 
assert_u32_noteq(u32 val,u32 wrong,const char * name)155 static int assert_u32_noteq(u32 val, u32 wrong, const char *name)
156 {
157 	if (val==wrong) {
158 		check_failed("Assertion failed for '%lld:%s'. should not be "
159 			"0x%x.\n", (long long)current_mft_record, name,
160 			(int)wrong);
161 		return 1;
162 	}
163 	return 0;
164 }
165 
assert_u32_lesseq(u32 val1,u32 val2,const char * name)166 static int assert_u32_lesseq(u32 val1, u32 val2, const char *name)
167 {
168 	if (val1 > val2) {
169 		check_failed("Assertion failed for '%s'. 0x%x > 0x%x\n",
170 			name, (int)val1, (int)val2);
171 		//errors++;
172 		return 1;
173 	}
174 	return 0;
175 }
176 
assert_u32_less(u32 val1,u32 val2,const char * name)177 static int assert_u32_less(u32 val1, u32 val2, const char *name)
178 {
179 	if (val1 >= val2) {
180 		check_failed("Assertion failed for '%s'. 0x%x >= 0x%x\n",
181 			name, (int)val1, (int)val2);
182 		//errors++;
183 		return 1;
184 	}
185 	return 0;
186 }
187 
188 /**
189  * Return: 0 ok, 1 error.
190  *
191  * todo: may we use ntfs_boot_sector_is_ntfs() instead?
192  *	It already does the checks but will not be able to fix anything.
193  */
verify_boot_sector(struct ntfs_device * dev,ntfs_volume * rawvol)194 static BOOL verify_boot_sector(struct ntfs_device *dev, ntfs_volume *rawvol)
195 {
196 	u8 buf[512];
197 	NTFS_BOOT_SECTOR *ntfs_boot = (NTFS_BOOT_SECTOR *)&buf;
198 	//u32 bytes_per_cluster;
199 
200 	current_mft_record = 9;
201 
202 	if (ntfs_pread(dev, 0, sizeof(buf), buf) != sizeof(buf)) {
203 		check_failed("Failed to read boot sector.\n");
204 		return 1;
205 	}
206 
207 	if ((buf[0]!=0xeb) ||
208 			((buf[1]!=0x52) && (buf[1]!=0x5b)) ||
209 			(buf[2]!=0x90)) {
210 		check_failed("Boot sector: Bad jump.\n");
211 	}
212 	if (ntfs_boot->oem_id != magicNTFS) {
213 		check_failed("Boot sector: Bad NTFS magic.\n");
214 	}
215 	bytes_per_sector = le16_to_cpu(ntfs_boot->bpb.bytes_per_sector);
216 	if (!bytes_per_sector) {
217 		check_failed("Boot sector: Bytes per sector is 0.\n");
218 	}
219 	if (bytes_per_sector%512) {
220 		check_failed("Boot sector: Bytes per sector is not a multiple"
221 					" of 512.\n");
222 	}
223 	sectors_per_cluster = ntfs_boot->bpb.sectors_per_cluster;
224 
225 	// todo: if partition, query bios and match heads/tracks? */
226 
227 	// Initialize some values into rawvol. We will need those later.
228 	rawvol->dev = dev;
229 	ntfs_boot_sector_parse(rawvol, (NTFS_BOOT_SECTOR *)buf);
230 
231 	return 0;
232 }
233 
234 /**
235  * Load the runlist of the <attr_type> attribute.
236  *
237  * Return NULL if an error.
238  * The caller is responsible on freeing the allocated memory if the result is not NULL.
239  *
240  * Set size_of_file_record to some reasonable size when in doubt (the Windows default is 1024.)
241  *
242  * attr_type must be little endian.
243  *
244  * This function has code duplication with check_file_record() and
245  * check_attr_record() but its goal is to be less strict. Thus the
246  * duplicated checks are the minimal required for not crashing.
247  *
248  * Assumes dev is open.
249  */
load_runlist(ntfs_volume * rawvol,s64 offset_to_file_record,ATTR_TYPES attr_type,u32 size_of_file_record)250 static runlist *load_runlist(ntfs_volume *rawvol, s64 offset_to_file_record, ATTR_TYPES attr_type, u32 size_of_file_record)
251 {
252 	u8 *buf;
253 	u16 attrs_offset;
254 	u32 length;
255 	ATTR_RECORD *attr_rec;
256 
257 	if (size_of_file_record<22) // offset to attrs_offset
258 		return NULL;
259 
260 	buf = (u8*)ntfs_malloc(size_of_file_record);
261 	if (!buf)
262 		return NULL;
263 
264 	if (ntfs_pread(rawvol->dev, offset_to_file_record, size_of_file_record, buf) !=
265 			size_of_file_record) {
266 		check_failed("Failed to read file record at offset %lld (0x%llx).\n",
267 					(long long)offset_to_file_record,
268 					(long long)offset_to_file_record);
269 		return NULL;
270 	}
271 
272 	attrs_offset = le16_to_cpu(((MFT_RECORD*)buf)->attrs_offset);
273 	// first attribute must be after the header.
274 	if (attrs_offset<42) {
275 		check_failed("First attribute must be after the header (%u).\n", (int)attrs_offset);
276 	}
277 	attr_rec = (ATTR_RECORD *)(buf + attrs_offset);
278 	//printf("uv1.\n");
279 
280 	while ((u8*)attr_rec<=buf+size_of_file_record-4) {
281 
282 		//printf("Attr type: 0x%x.\n", attr_rec->type);
283 		// Check attribute record. (Only what is in the buffer)
284 		if (attr_rec->type==AT_END) {
285 			check_failed("Attribute 0x%x not found in file record at offset %lld (0x%llx).\n", (int)le32_to_cpu(attr_rec->type),
286 					(long long)offset_to_file_record,
287 					(long long)offset_to_file_record);
288 			return NULL;
289 		}
290 		if ((u8*)attr_rec>buf+size_of_file_record-8) {
291 			// not AT_END yet no room for the length field.
292 			check_failed("Attribute 0x%x is not AT_END, yet no "
293 					"room for the length field.\n",
294 					(int)le32_to_cpu(attr_rec->type));
295 			return NULL;
296 		}
297 
298 		length = le32_to_cpu(attr_rec->length);
299 
300 		// Check that this attribute does not overflow the mft_record
301 		if ((u8*)attr_rec+length >= buf+size_of_file_record) {
302 			check_failed("Attribute (0x%x) is larger than FILE record at offset %lld (0x%llx).\n",
303 					(int)le32_to_cpu(attr_rec->type),
304 					(long long)offset_to_file_record,
305 					(long long)offset_to_file_record);
306 			return NULL;
307 		}
308 		// todo: what ATTRIBUTE_LIST (0x20)?
309 
310 		if (attr_rec->type==attr_type) {
311 			// Eurika!
312 
313 			// ntfs_mapping_pairs_decompress only use two values from vol. Just fake it.
314 			// todo: it will also use vol->major_ver if defined(DEBUG). But only for printing purposes.
315 
316 			// Assume ntfs_boot_sector_parse() was called.
317 			return ntfs_mapping_pairs_decompress(rawvol, attr_rec, NULL);
318 		}
319 
320 		attr_rec = (ATTR_RECORD*)((u8*)attr_rec+length);
321 	}
322 	// If we got here, there was an overflow.
323 	check_failed("file record corrupted at offset %lld (0x%llx).\n",
324 			(long long)offset_to_file_record,
325 			(long long)offset_to_file_record);
326 	return NULL;
327 }
328 
329 /**
330  * Return: >=0 last VCN
331  *	   LCN_EINVAL error.
332  */
get_last_vcn(runlist * rl)333 static VCN get_last_vcn(runlist *rl)
334 {
335 	VCN res;
336 
337 	if (!rl)
338 		return LCN_EINVAL;
339 
340 	res = LCN_EINVAL;
341 	while (rl->length) {
342 		ntfs_log_verbose("vcn: %lld, length: %lld.\n",
343 				(long long)rl->vcn, (long long)rl->length);
344 		if (rl->vcn<0)
345 			res = rl->vcn;
346 		else
347 			res = rl->vcn + rl->length;
348 		rl++;
349 	}
350 
351 	return res;
352 }
353 
354 static u32 mft_bitmap_records;
355 static u8 *mft_bitmap_buf;
356 
357 /**
358  * Assumes mft_bitmap_rl is initialized.
359  * return: 0 ok.
360  *	   RETURN_OPERATIONAL_ERROR on error.
361  */
mft_bitmap_load(ntfs_volume * rawvol)362 static int mft_bitmap_load(ntfs_volume *rawvol)
363 {
364 	VCN vcn;
365 	u32 mft_bitmap_length;
366 
367 	vcn = get_last_vcn(mft_bitmap_rl);
368 	if (vcn<=LCN_EINVAL) {
369 		mft_bitmap_buf = NULL;
370 		/* This case should not happen, not even with on-disk errors */
371 		goto error;
372 	}
373 
374 	mft_bitmap_length = vcn * rawvol->cluster_size;
375 	mft_bitmap_records = 8 * mft_bitmap_length * rawvol->cluster_size /
376 		rawvol->mft_record_size;
377 
378 	//printf("sizes: %d, %d.\n", mft_bitmap_length, mft_bitmap_records);
379 
380 	mft_bitmap_buf = (u8*)ntfs_malloc(mft_bitmap_length);
381 	if (!mft_bitmap_buf)
382 		goto error;
383 	if (ntfs_rl_pread(rawvol, mft_bitmap_rl, 0, mft_bitmap_length,
384 			mft_bitmap_buf)!=mft_bitmap_length)
385 		goto error;
386 	return 0;
387 error:
388 	mft_bitmap_records = 0;
389 	ntfs_log_error("Could not load $MFT/Bitmap.\n");
390 	return RETURN_OPERATIONAL_ERROR;
391 }
392 
393 /**
394  * -1 Error.
395  *  0 Unused record
396  *  1 Used record
397  *
398  * Assumes mft_bitmap_rl was initialized.
399  */
mft_bitmap_get_bit(s64 mft_no)400 static int mft_bitmap_get_bit(s64 mft_no)
401 {
402 	if (mft_no>=mft_bitmap_records)
403 		return -1;
404 	return ntfs_bit_get(mft_bitmap_buf, mft_no);
405 }
406 
407 /**
408  * @attr_rec: The attribute record to check
409  * @mft_rec: The parent FILE record.
410  * @buflen: The size of the FILE record.
411  *
412  * Return:
413  *  NULL: Fatal error occured. Not sure where is the next record.
414  *  otherwise: pointer to the next attribute record.
415  *
416  * The function only check fields that are inside this attr record.
417  *
418  * Assumes mft_rec is current_mft_record.
419  */
check_attr_record(ATTR_REC * attr_rec,MFT_RECORD * mft_rec,u16 buflen)420 static ATTR_REC *check_attr_record(ATTR_REC *attr_rec, MFT_RECORD *mft_rec,
421 			u16 buflen)
422 {
423 	u16 name_offset;
424 	u16 attrs_offset = le16_to_cpu(mft_rec->attrs_offset);
425 	u32 attr_type = le32_to_cpu(attr_rec->type);
426 	u32 length = le32_to_cpu(attr_rec->length);
427 
428 	// Check that this attribute does not overflow the mft_record
429 	if ((u8*)attr_rec+length >= ((u8*)mft_rec)+buflen) {
430 		check_failed("Attribute (0x%x) is larger than FILE record (%lld).\n",
431 				(int)attr_type, (long long)current_mft_record);
432 		return NULL;
433 	}
434 
435 	// Attr type must be a multiple of 0x10 and 0x10<=x<=0x100.
436 	if ((attr_type & ~0x0F0) && (attr_type != 0x100)) {
437 		check_failed("Unknown attribute type 0x%x.\n",
438 			(int)attr_type);
439 		goto check_attr_record_next_attr;
440 	}
441 
442 	if (length<24) {
443 		check_failed("Attribute %lld:0x%x Length too short (%u).\n",
444 			(long long)current_mft_record, (int)attr_type,
445 			(int)length);
446 		goto check_attr_record_next_attr;
447 	}
448 
449 	// If this is the first attribute:
450 	// todo: instance number must be smaller than next_instance.
451 	if ((u8*)attr_rec == ((u8*)mft_rec) + attrs_offset) {
452 		if (!mft_rec->base_mft_record)
453 			assert_u32_equal(attr_type, 0x10,
454 				"First attribute type");
455 		// The following not always holds.
456 		// attr 0x10 becomes instance 1 and attr 0x40 becomes 0.
457 		//assert_u32_equal(attr_rec->instance, 0,
458 		//	"First attribute instance number");
459 	} else {
460 		assert_u32_noteq(attr_type, 0x10,
461 			"Not-first attribute type");
462 		// The following not always holds.
463 		//assert_u32_noteq(attr_rec->instance, 0,
464 		//	"Not-first attribute instance number");
465 	}
466 	//if (current_mft_record==938 || current_mft_record==1683 || current_mft_record==3152 || current_mft_record==22410)
467 	//printf("Attribute %lld:0x%x instance: %u isbase:%d.\n",
468 	//		current_mft_record, (int)attr_type, (int)le16_to_cpu(attr_rec->instance), (int)mft_rec->base_mft_record);
469 	// todo: instance is unique.
470 
471 	// Check flags.
472 	if (attr_rec->flags & ~(const_cpu_to_le16(0xc0ff))) {
473 		check_failed("Attribute %lld:0x%x Unknown flags (0x%x).\n",
474 			(long long)current_mft_record, (int)attr_type,
475 			(int)le16_to_cpu(attr_rec->flags));
476 	}
477 
478 	if (attr_rec->non_resident>1) {
479 		check_failed("Attribute %lld:0x%x Unknown non-resident "
480 			"flag (0x%x).\n", (long long)current_mft_record,
481 			(int)attr_type, (int)attr_rec->non_resident);
482 		goto check_attr_record_next_attr;
483 	}
484 
485 	name_offset = le16_to_cpu(attr_rec->name_offset);
486 	/*
487 	 * todo: name must be legal unicode.
488 	 * Not really, information below in urls is about filenames, but I
489 	 * believe it also applies to attribute names.  (Yura)
490 	 *  http://blogs.msdn.com/michkap/archive/2006/09/24/769540.aspx
491 	 *  http://blogs.msdn.com/michkap/archive/2006/09/10/748699.aspx
492 	 */
493 
494 	if (attr_rec->non_resident) {
495 		// Non-Resident
496 
497 		// Make sure all the fields exist.
498 		if (length<64) {
499 			check_failed("Non-resident attribute %lld:0x%x too short (%u).\n",
500 				(long long)current_mft_record, (int)attr_type,
501 				(int)length);
502 			goto check_attr_record_next_attr;
503 		}
504 		if (attr_rec->compression_unit && (length<72)) {
505 			check_failed("Compressed attribute %lld:0x%x too short (%u).\n",
506 				(long long)current_mft_record, (int)attr_type,
507 				(int)length);
508 			goto check_attr_record_next_attr;
509 		}
510 
511 		// todo: name comes before mapping pairs, and after the header.
512 		// todo: length==mapping_pairs_offset+length of compressed mapping pairs.
513 		// todo: mapping_pairs_offset is 8-byte aligned.
514 
515 		// todo: lowest vcn <= highest_vcn
516 		// todo: if base record -> lowest vcn==0
517 		// todo: lowest_vcn!=0 -> attribute list is used.
518 		// todo: lowest_vcn & highest_vcn are in the drive (0<=x<total clusters)
519 		// todo: mapping pairs agree with highest_vcn.
520 		// todo: compression unit == 0 or 4.
521 		// todo: reserved1 == 0.
522 		// todo: if not compressed nor sparse, initialized_size <= allocated_size and data_size <= allocated_size.
523 		// todo: if compressed or sparse, allocated_size <= initialized_size and allocated_size <= data_size
524 		// todo: if mft_no!=0 and not compressed/sparse, data_size==initialized_size.
525 		// todo: if mft_no!=0 and compressed/sparse, allocated_size==initialized_size.
526 		// todo: what about compressed_size if compressed?
527 		// todo: attribute must not be 0x10, 0x30, 0x40, 0x60, 0x70, 0x90, 0xd0 (not sure about 0xb0, 0xe0, 0xf0)
528 	} else {
529 		u16 value_offset = le16_to_cpu(attr_rec->value_offset);
530 		u32 value_length = le32_to_cpu(attr_rec->value_length);
531 		// Resident
532 		if (attr_rec->name_length) {
533 			if (name_offset < 24)
534 				check_failed("Resident attribute with "
535 					"name intersecting header.\n");
536 			if (value_offset < name_offset +
537 					attr_rec->name_length)
538 				check_failed("Named resident attribute "
539 					"with value before name.\n");
540 		}
541 		// if resident, length==value_length+value_offset
542 		//assert_u32_equal(le32_to_cpu(attr_rec->value_length)+
543 		//	value_offset, length,
544 		//	"length==value_length+value_offset");
545 		// if resident, length==value_length+value_offset
546 		if (value_length+value_offset > length) {
547 			check_failed("value_length(%d)+value_offset(%d)>length(%d) for attribute 0x%x.\n", (int)value_length, (int)value_offset, (int)length, (int)attr_type);
548 			return NULL;
549 		}
550 
551 		// Check resident_flags.
552 		if (attr_rec->resident_flags>0x01) {
553 			check_failed("Unknown resident flags (0x%x) for attribute 0x%x.\n", (int)attr_rec->resident_flags, (int)attr_type);
554 		} else if (attr_rec->resident_flags && (attr_type!=0x30)) {
555 			check_failed("Resident flags mark attribute 0x%x as indexed.\n", (int)attr_type);
556 		}
557 
558 		// reservedR is 0.
559 		assert_u32_equal(attr_rec->reservedR, 0, "Resident Reserved");
560 
561 		// todo: attribute must not be 0xa0 (not sure about 0xb0, 0xe0, 0xf0)
562 		// todo: check content well-formness per attr_type.
563 	}
564 	return 0;
565 check_attr_record_next_attr:
566 	return (ATTR_REC *)(((u8 *)attr_rec) + length);
567 }
568 
569 /**
570  * All checks that can be satisfied only by data from the buffer.
571  * No other [MFT records/metadata files] are required.
572  *
573  * The buffer is changed by removing the Update Sequence.
574  *
575  * Return:
576  *	0	Everything's cool.
577  *	else	Consider this record as damaged.
578  */
check_file_record(u8 * buffer,u16 buflen)579 static BOOL check_file_record(u8 *buffer, u16 buflen)
580 {
581 	u16 usa_count, usa_ofs, attrs_offset, usa;
582 	u32 bytes_in_use, bytes_allocated, i;
583 	MFT_RECORD *mft_rec = (MFT_RECORD *)buffer;
584 	ATTR_REC *attr_rec;
585 
586 	// check record magic
587 	assert_u32_equal(le32_to_cpu(mft_rec->magic), le32_to_cpu(magic_FILE), "FILE record magic");
588 	// todo: records 16-23 must be filled in order.
589 	// todo: what to do with magic_BAAD?
590 
591 	// check usa_count+offset to update seq <= attrs_offset <
592 	//	bytes_in_use <= bytes_allocated <= buflen.
593 	usa_ofs = le16_to_cpu(mft_rec->usa_ofs);
594 	usa_count = le16_to_cpu(mft_rec->usa_count);
595 	attrs_offset = le16_to_cpu(mft_rec->attrs_offset);
596 	bytes_in_use = le32_to_cpu(mft_rec->bytes_in_use);
597 	bytes_allocated = le32_to_cpu(mft_rec->bytes_allocated);
598 	if (assert_u32_lesseq(usa_ofs+usa_count, attrs_offset,
599 				"usa_ofs+usa_count <= attrs_offset") ||
600 			assert_u32_less(attrs_offset, bytes_in_use,
601 				"attrs_offset < bytes_in_use") ||
602 			assert_u32_lesseq(bytes_in_use, bytes_allocated,
603 				"bytes_in_use <= bytes_allocated") ||
604 			assert_u32_lesseq(bytes_allocated, buflen,
605 				"bytes_allocated <= max_record_size")) {
606 		return 1;
607 	}
608 
609 
610 	// We should know all the flags.
611 	if (le16_to_cpu(mft_rec->flags) > 0xf) {
612 		check_failed("Unknown MFT record flags (0x%x).\n",
613 			(unsigned int)le16_to_cpu(mft_rec->flags));
614 	}
615 	// todo: flag in_use must be on.
616 
617 	// Remove update seq & check it.
618 	usa = *(u16*)(buffer+usa_ofs); // The value that should be at the end of every sector.
619 	if (assert_u32_equal(usa_count-1, buflen/NTFS_BLOCK_SIZE, "USA length"))
620 		return (1);
621 	for (i=1;i<usa_count;i++) {
622 		u16 *fixup = (u16*)(buffer+NTFS_BLOCK_SIZE*i-2); // the value at the end of the sector.
623 		u16 saved_val = *(u16*)(buffer+usa_ofs+2*i); // the actual data value that was saved in the us array.
624 
625 		assert_u32_equal(*fixup, usa, "fixup");
626 		*fixup = saved_val; // remove it.
627 	}
628 
629 	attr_rec = (ATTR_REC *)(buffer + attrs_offset);
630 	while ((u8*)attr_rec<=buffer+buflen-4) {
631 
632 		// Check attribute record. (Only what is in the buffer)
633 		if (attr_rec->type==AT_END) {
634 			// Done.
635 			return 0;
636 		}
637 		if ((u8*)attr_rec>buffer+buflen-8) {
638 			// not AT_END yet no room for the length field.
639 			check_failed("Attribute 0x%x is not AT_END, yet no "
640 					"room for the length field.\n",
641 					(int)le32_to_cpu(attr_rec->type));
642 			return 1;
643 		}
644 
645 		attr_rec = check_attr_record(attr_rec, mft_rec, buflen);
646 		if (!attr_rec)
647 			return 1;
648 	}
649 	// If we got here, there was an overflow.
650 	return 1;
651 
652 	// todo: an attribute should be at the offset to first attribute, and the offset should be inside the buffer. It should have the value of "next attribute id".
653 	// todo: if base record, it should start with attribute 0x10.
654 
655 	// Highlevel check of attributes.
656 	//  todo: Attributes are well-formed.
657 	//  todo: Room for next attribute in the end of the previous record.
658 
659 	return FALSE;
660 }
661 
replay_log(ntfs_volume * vol)662 static void replay_log(ntfs_volume *vol __attribute__((unused)))
663 {
664 	// At this time, only check that the log is fully replayed.
665 	ntfs_log_warning("Unsupported: replay_log()\n");
666 	// todo: if logfile is clean, return success.
667 	unsupported++;
668 }
669 
verify_mft_record(ntfs_volume * vol,s64 mft_num)670 static void verify_mft_record(ntfs_volume *vol, s64 mft_num)
671 {
672 	u8 *buffer;
673 	int is_used;
674 
675 	current_mft_record = mft_num;
676 
677 	is_used = mft_bitmap_get_bit(mft_num);
678 	if (is_used<0) {
679 		ntfs_log_error("Error getting bit value for record %lld.\n",
680 			(long long)mft_num);
681 	} else if (!is_used) {
682 		ntfs_log_verbose("Record %lld unused. Skipping.\n",
683 				(long long)mft_num);
684 		return;
685 	}
686 
687 	buffer = ntfs_malloc(vol->mft_record_size);
688 	if (!buffer)
689 		goto verify_mft_record_error;
690 
691 	ntfs_log_verbose("MFT record %lld\n", (long long)mft_num);
692 	if (ntfs_attr_pread(vol->mft_na, mft_num*vol->mft_record_size, vol->mft_record_size, buffer) < 0) {
693 		ntfs_log_perror("Couldn't read $MFT record %lld", (long long)mft_num);
694 		goto verify_mft_record_error;
695 	}
696 
697 	check_file_record(buffer, vol->mft_record_size);
698 	// todo: if offset to first attribute >= 0x30, number of mft record should match.
699 	// todo: Match the "record is used" with the mft bitmap.
700 	// todo: if this is not base, check that the parent is a base, and is in use, and pointing to this record.
701 
702 	// todo: if base record: for each extent record:
703 	//   todo: verify_file_record
704 	//   todo: hard link count should be the number of 0x30 attributes.
705 	//   todo: Order of attributes.
706 	//   todo: make sure compression_unit is the same.
707 
708 	return;
709 verify_mft_record_error:
710 
711 	if (buffer)
712 		free(buffer);
713 	errors++;
714 }
715 
716 /**
717  * This function serves as bootstraping for the more comprehensive checks.
718  * It will load the MFT runlist and MFT/Bitmap runlist.
719  * It should not depend on other checks or we may have a circular dependancy.
720  * Also, this loadng must be forgiving, unlike the comprehensive checks.
721  */
verify_mft_preliminary(ntfs_volume * rawvol)722 static int verify_mft_preliminary(ntfs_volume *rawvol)
723 {
724 	current_mft_record = 0;
725 	s64 mft_offset, mftmirr_offset;
726 	int res;
727 
728 	ntfs_log_trace("Entering verify_mft_preliminary().\n");
729 	// todo: get size_of_file_record from boot sector
730 	// Load the first segment of the $MFT/DATA runlist.
731 	mft_offset = rawvol->mft_lcn * rawvol->cluster_size;
732 	mftmirr_offset = rawvol->mftmirr_lcn * rawvol->cluster_size;
733 	mft_rl = load_runlist(rawvol, mft_offset, AT_DATA, 1024);
734 	if (!mft_rl) {
735 		check_failed("Loading $MFT runlist failed. Trying $MFTMirr.\n");
736 		mft_rl = load_runlist(rawvol, mftmirr_offset, AT_DATA, 1024);
737 	}
738 	if (!mft_rl) {
739 		check_failed("Loading $MFTMirr runlist failed too. Aborting.\n");
740 		return RETURN_FS_ERRORS_LEFT_UNCORRECTED | RETURN_OPERATIONAL_ERROR;
741 	}
742 	// TODO: else { recover $MFT } // Use $MFTMirr to recover $MFT.
743 	// todo: support loading the next runlist extents when ATTRIBUTE_LIST is used on $MFT.
744 	// If attribute list: Gradually load mft runlist. (parse runlist from first file record, check all referenced file records, continue with the next file record). If no attribute list, just load it.
745 
746 	// Load the runlist of $MFT/Bitmap.
747 	// todo: what about ATTRIBUTE_LIST? Can we reuse code?
748 	mft_bitmap_rl = load_runlist(rawvol, mft_offset, AT_BITMAP, 1024);
749 	if (!mft_bitmap_rl) {
750 		check_failed("Loading $MFT/Bitmap runlist failed. Trying $MFTMirr.\n");
751 		mft_bitmap_rl = load_runlist(rawvol, mftmirr_offset, AT_BITMAP, 1024);
752 	}
753 	if (!mft_bitmap_rl) {
754 		check_failed("Loading $MFTMirr/Bitmap runlist failed too. Aborting.\n");
755 		return RETURN_FS_ERRORS_LEFT_UNCORRECTED;
756 		// todo: rebuild the bitmap by using the "in_use" file record flag or by filling it with 1's.
757 	}
758 
759 	/* Load $MFT/Bitmap */
760 	if ((res = mft_bitmap_load(rawvol)))
761 		return res;
762 	return -1; /* FIXME: Just added to fix compiler warning without
763 			thinking about what should be here.  (Yura) */
764 }
765 
check_volume(ntfs_volume * vol)766 static void check_volume(ntfs_volume *vol)
767 {
768 	s64 mft_num, nr_mft_records;
769 
770 	ntfs_log_warning("Unsupported: check_volume()\n");
771 	unsupported++;
772 
773 	// For each mft record, verify that it contains a valid file record.
774 	nr_mft_records = vol->mft_na->initialized_size >>
775 			vol->mft_record_size_bits;
776 	ntfs_log_info("Checking %lld MFT records.\n", (long long)nr_mft_records);
777 
778 	for (mft_num=0; mft_num < nr_mft_records; mft_num++) {
779 	 	verify_mft_record(vol, mft_num);
780 	}
781 
782 	// todo: Check metadata files.
783 
784 	// todo: Second pass on mft records. Now check the contents as well.
785 	// todo: When going through runlists, build a bitmap.
786 
787 	// todo: cluster accounting.
788 	return;
789 }
790 
reset_dirty(ntfs_volume * vol)791 static int reset_dirty(ntfs_volume *vol)
792 {
793 	le16 flags;
794 
795 	if (!(vol->flags | VOLUME_IS_DIRTY))
796 		return 0;
797 
798 	ntfs_log_verbose("Resetting dirty flag.\n");
799 
800 	flags = vol->flags & ~VOLUME_IS_DIRTY;
801 
802 	if (ntfs_volume_write_flags(vol, flags)) {
803 		ntfs_log_error("Error setting volume flags.\n");
804 		return -1;
805 	}
806 	return 0;
807 }
808 
809 /**
810  * main - Does just what C99 claim it does.
811  *
812  * For more details on arguments and results, check the man page.
813  */
main(int argc,char ** argv)814 int main(int argc, char **argv)
815 {
816 	struct ntfs_device *dev;
817 	ntfs_volume rawvol;
818 	ntfs_volume *vol;
819 	const char *name;
820 	int ret;
821 
822 	if (argc != 2)
823 		return RETURN_USAGE_OR_SYNTAX_ERROR;
824 	name = argv[1];
825 
826 	ntfs_log_set_handler(ntfs_log_handler_outerr);
827 	//ntfs_log_set_levels(NTFS_LOG_LEVEL_DEBUG | NTFS_LOG_LEVEL_TRACE | NTFS_LOG_LEVEL_QUIET | NTFS_LOG_LEVEL_INFO | NTFS_LOG_LEVEL_VERBOSE | NTFS_LOG_LEVEL_PROGRESS);
828 
829 	/* Allocate an ntfs_device structure. */
830 	dev = ntfs_device_alloc(name, 0, &ntfs_device_default_io_ops, NULL);
831 	if (!dev)
832 		return RETURN_OPERATIONAL_ERROR;
833 	if (dev->d_ops->open(dev, O_RDONLY)) { //O_RDWR/O_RDONLY?
834 		ntfs_log_perror("Error opening partition device");
835 		ntfs_device_free(dev);
836 		return RETURN_OPERATIONAL_ERROR;
837 	}
838 
839 	if ((ret = verify_boot_sector(dev,&rawvol))) {
840 		dev->d_ops->close(dev);
841 		return ret;
842 	}
843 	ntfs_log_verbose("Boot sector verification complete. Proceeding to $MFT");
844 
845 	verify_mft_preliminary(&rawvol);
846 
847 	/* ntfs_device_mount() expects the device to be closed. */
848 	if (dev->d_ops->close(dev))
849 		ntfs_log_perror("Failed to close the device.");
850 
851 	// at this point we know that the volume is valid enough for mounting.
852 
853 	/* Call ntfs_device_mount() to do the actual mount. */
854 	vol = ntfs_device_mount(dev, NTFS_MNT_RDONLY);
855 	if (!vol) {
856 		ntfs_device_free(dev);
857 		return 2;
858 	}
859 
860 	replay_log(vol);
861 
862 	if (vol->flags & VOLUME_IS_DIRTY)
863 		ntfs_log_warning("Volume is dirty.\n");
864 
865 	check_volume(vol);
866 
867 	if (errors)
868 		ntfs_log_info("Errors found.\n");
869 	if (unsupported)
870 		ntfs_log_info("Unsupported cases found.\n");
871 
872 	if (!errors && !unsupported) {
873 		reset_dirty(vol);
874 	}
875 
876 	ntfs_umount(vol, FALSE);
877 
878 	if (errors)
879 		return 2;
880 	if (unsupported)
881 		return 1;
882 	return 0;
883 }
884 
885