1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 *
4 * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
5 *
6 */
7
8 #include <linux/fs.h>
9
10 #include "debug.h"
11 #include "ntfs.h"
12 #include "ntfs_fs.h"
13
compare_attr(const struct ATTRIB * left,enum ATTR_TYPE type,const __le16 * name,u8 name_len,const u16 * upcase)14 static inline int compare_attr(const struct ATTRIB *left, enum ATTR_TYPE type,
15 const __le16 *name, u8 name_len,
16 const u16 *upcase)
17 {
18 /* First, compare the type codes. */
19 int diff = le32_to_cpu(left->type) - le32_to_cpu(type);
20
21 if (diff)
22 return diff;
23
24 /* They have the same type code, so we have to compare the names. */
25 return ntfs_cmp_names(attr_name(left), left->name_len, name, name_len,
26 upcase, true);
27 }
28
29 /*
30 * mi_new_attt_id
31 *
32 * Return: Unused attribute id that is less than mrec->next_attr_id.
33 */
mi_new_attt_id(struct mft_inode * mi)34 static __le16 mi_new_attt_id(struct mft_inode *mi)
35 {
36 u16 free_id, max_id, t16;
37 struct MFT_REC *rec = mi->mrec;
38 struct ATTRIB *attr;
39 __le16 id;
40
41 id = rec->next_attr_id;
42 free_id = le16_to_cpu(id);
43 if (free_id < 0x7FFF) {
44 rec->next_attr_id = cpu_to_le16(free_id + 1);
45 return id;
46 }
47
48 /* One record can store up to 1024/24 ~= 42 attributes. */
49 free_id = 0;
50 max_id = 0;
51
52 attr = NULL;
53
54 for (;;) {
55 attr = mi_enum_attr(mi, attr);
56 if (!attr) {
57 rec->next_attr_id = cpu_to_le16(max_id + 1);
58 mi->dirty = true;
59 return cpu_to_le16(free_id);
60 }
61
62 t16 = le16_to_cpu(attr->id);
63 if (t16 == free_id) {
64 free_id += 1;
65 attr = NULL;
66 } else if (max_id < t16)
67 max_id = t16;
68 }
69 }
70
mi_get(struct ntfs_sb_info * sbi,CLST rno,struct mft_inode ** mi)71 int mi_get(struct ntfs_sb_info *sbi, CLST rno, struct mft_inode **mi)
72 {
73 int err;
74 struct mft_inode *m = kzalloc(sizeof(struct mft_inode), GFP_NOFS);
75
76 if (!m)
77 return -ENOMEM;
78
79 err = mi_init(m, sbi, rno);
80 if (err) {
81 kfree(m);
82 return err;
83 }
84
85 err = mi_read(m, false);
86 if (err) {
87 mi_put(m);
88 return err;
89 }
90
91 *mi = m;
92 return 0;
93 }
94
mi_put(struct mft_inode * mi)95 void mi_put(struct mft_inode *mi)
96 {
97 mi_clear(mi);
98 kfree(mi);
99 }
100
mi_init(struct mft_inode * mi,struct ntfs_sb_info * sbi,CLST rno)101 int mi_init(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno)
102 {
103 mi->sbi = sbi;
104 mi->rno = rno;
105 mi->mrec = kmalloc(sbi->record_size, GFP_NOFS);
106 if (!mi->mrec)
107 return -ENOMEM;
108
109 return 0;
110 }
111
112 /*
113 * mi_read - Read MFT data.
114 */
mi_read(struct mft_inode * mi,bool is_mft)115 int mi_read(struct mft_inode *mi, bool is_mft)
116 {
117 int err;
118 struct MFT_REC *rec = mi->mrec;
119 struct ntfs_sb_info *sbi = mi->sbi;
120 u32 bpr = sbi->record_size;
121 u64 vbo = (u64)mi->rno << sbi->record_bits;
122 struct ntfs_inode *mft_ni = sbi->mft.ni;
123 struct runs_tree *run = mft_ni ? &mft_ni->file.run : NULL;
124 struct rw_semaphore *rw_lock = NULL;
125
126 if (is_mounted(sbi)) {
127 if (!is_mft && mft_ni) {
128 rw_lock = &mft_ni->file.run_lock;
129 down_read(rw_lock);
130 }
131 }
132
133 err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
134 if (rw_lock)
135 up_read(rw_lock);
136 if (!err)
137 goto ok;
138
139 if (err == -E_NTFS_FIXUP) {
140 mi->dirty = true;
141 goto ok;
142 }
143
144 if (err != -ENOENT)
145 goto out;
146
147 if (rw_lock) {
148 ni_lock(mft_ni);
149 down_write(rw_lock);
150 }
151 err = attr_load_runs_vcn(mft_ni, ATTR_DATA, NULL, 0, run,
152 vbo >> sbi->cluster_bits);
153 if (rw_lock) {
154 up_write(rw_lock);
155 ni_unlock(mft_ni);
156 }
157 if (err)
158 goto out;
159
160 if (rw_lock)
161 down_read(rw_lock);
162 err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
163 if (rw_lock)
164 up_read(rw_lock);
165
166 if (err == -E_NTFS_FIXUP) {
167 mi->dirty = true;
168 goto ok;
169 }
170 if (err)
171 goto out;
172
173 ok:
174 /* Check field 'total' only here. */
175 if (le32_to_cpu(rec->total) != bpr) {
176 err = -EINVAL;
177 goto out;
178 }
179
180 return 0;
181
182 out:
183 if (err == -E_NTFS_CORRUPT) {
184 ntfs_err(sbi->sb, "mft corrupted");
185 ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
186 err = -EINVAL;
187 }
188
189 return err;
190 }
191
mi_enum_attr(struct mft_inode * mi,struct ATTRIB * attr)192 struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
193 {
194 const struct MFT_REC *rec = mi->mrec;
195 u32 used = le32_to_cpu(rec->used);
196 u32 t32, off, asize;
197 u16 t16;
198
199 if (!attr) {
200 u32 total = le32_to_cpu(rec->total);
201
202 off = le16_to_cpu(rec->attr_off);
203
204 if (used > total)
205 return NULL;
206
207 if (off >= used || off < MFTRECORD_FIXUP_OFFSET_1 ||
208 !IS_ALIGNED(off, 4)) {
209 return NULL;
210 }
211
212 /* Skip non-resident records. */
213 if (!is_rec_inuse(rec))
214 return NULL;
215
216 attr = Add2Ptr(rec, off);
217 } else {
218 /* Check if input attr inside record. */
219 off = PtrOffset(rec, attr);
220 if (off >= used)
221 return NULL;
222
223 asize = le32_to_cpu(attr->size);
224 if (asize < SIZEOF_RESIDENT) {
225 /* Impossible 'cause we should not return such attribute. */
226 return NULL;
227 }
228
229 attr = Add2Ptr(attr, asize);
230 off += asize;
231 }
232
233 asize = le32_to_cpu(attr->size);
234
235 /* Can we use the first field (attr->type). */
236 if (off + 8 > used) {
237 static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8);
238 return NULL;
239 }
240
241 if (attr->type == ATTR_END) {
242 /* End of enumeration. */
243 return NULL;
244 }
245
246 /* 0x100 is last known attribute for now. */
247 t32 = le32_to_cpu(attr->type);
248 if ((t32 & 0xf) || (t32 > 0x100))
249 return NULL;
250
251 /* Check overflow and boundary. */
252 if (off + asize < off || off + asize > used)
253 return NULL;
254
255 /* Check size of attribute. */
256 if (!attr->non_res) {
257 if (asize < SIZEOF_RESIDENT)
258 return NULL;
259
260 t16 = le16_to_cpu(attr->res.data_off);
261
262 if (t16 > asize)
263 return NULL;
264
265 t32 = le32_to_cpu(attr->res.data_size);
266 if (t16 + t32 > asize)
267 return NULL;
268
269 if (attr->name_len &&
270 le16_to_cpu(attr->name_off) + sizeof(short) * attr->name_len > t16) {
271 return NULL;
272 }
273
274 return attr;
275 }
276
277 /* Check some nonresident fields. */
278 if (attr->name_len &&
279 le16_to_cpu(attr->name_off) + sizeof(short) * attr->name_len >
280 le16_to_cpu(attr->nres.run_off)) {
281 return NULL;
282 }
283
284 if (attr->nres.svcn || !is_attr_ext(attr)) {
285 if (asize + 8 < SIZEOF_NONRESIDENT)
286 return NULL;
287
288 if (attr->nres.c_unit)
289 return NULL;
290 } else if (asize + 8 < SIZEOF_NONRESIDENT_EX)
291 return NULL;
292
293 return attr;
294 }
295
296 /*
297 * mi_find_attr - Find the attribute by type and name and id.
298 */
mi_find_attr(struct mft_inode * mi,struct ATTRIB * attr,enum ATTR_TYPE type,const __le16 * name,size_t name_len,const __le16 * id)299 struct ATTRIB *mi_find_attr(struct mft_inode *mi, struct ATTRIB *attr,
300 enum ATTR_TYPE type, const __le16 *name,
301 size_t name_len, const __le16 *id)
302 {
303 u32 type_in = le32_to_cpu(type);
304 u32 atype;
305
306 next_attr:
307 attr = mi_enum_attr(mi, attr);
308 if (!attr)
309 return NULL;
310
311 atype = le32_to_cpu(attr->type);
312 if (atype > type_in)
313 return NULL;
314
315 if (atype < type_in)
316 goto next_attr;
317
318 if (attr->name_len != name_len)
319 goto next_attr;
320
321 if (name_len && memcmp(attr_name(attr), name, name_len * sizeof(short)))
322 goto next_attr;
323
324 if (id && *id != attr->id)
325 goto next_attr;
326
327 return attr;
328 }
329
mi_write(struct mft_inode * mi,int wait)330 int mi_write(struct mft_inode *mi, int wait)
331 {
332 struct MFT_REC *rec;
333 int err;
334 struct ntfs_sb_info *sbi;
335
336 if (!mi->dirty)
337 return 0;
338
339 sbi = mi->sbi;
340 rec = mi->mrec;
341
342 err = ntfs_write_bh(sbi, &rec->rhdr, &mi->nb, wait);
343 if (err)
344 return err;
345
346 if (mi->rno < sbi->mft.recs_mirr)
347 sbi->flags |= NTFS_FLAGS_MFTMIRR;
348
349 mi->dirty = false;
350
351 return 0;
352 }
353
mi_format_new(struct mft_inode * mi,struct ntfs_sb_info * sbi,CLST rno,__le16 flags,bool is_mft)354 int mi_format_new(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno,
355 __le16 flags, bool is_mft)
356 {
357 int err;
358 u16 seq = 1;
359 struct MFT_REC *rec;
360 u64 vbo = (u64)rno << sbi->record_bits;
361
362 err = mi_init(mi, sbi, rno);
363 if (err)
364 return err;
365
366 rec = mi->mrec;
367
368 if (rno == MFT_REC_MFT) {
369 ;
370 } else if (rno < MFT_REC_FREE) {
371 seq = rno;
372 } else if (rno >= sbi->mft.used) {
373 ;
374 } else if (mi_read(mi, is_mft)) {
375 ;
376 } else if (rec->rhdr.sign == NTFS_FILE_SIGNATURE) {
377 /* Record is reused. Update its sequence number. */
378 seq = le16_to_cpu(rec->seq) + 1;
379 if (!seq)
380 seq = 1;
381 }
382
383 memcpy(rec, sbi->new_rec, sbi->record_size);
384
385 rec->seq = cpu_to_le16(seq);
386 rec->flags = RECORD_FLAG_IN_USE | flags;
387
388 mi->dirty = true;
389
390 if (!mi->nb.nbufs) {
391 struct ntfs_inode *ni = sbi->mft.ni;
392 bool lock = false;
393
394 if (is_mounted(sbi) && !is_mft) {
395 down_read(&ni->file.run_lock);
396 lock = true;
397 }
398
399 err = ntfs_get_bh(sbi, &ni->file.run, vbo, sbi->record_size,
400 &mi->nb);
401 if (lock)
402 up_read(&ni->file.run_lock);
403 }
404
405 return err;
406 }
407
408 /*
409 * mi_insert_attr - Reserve space for new attribute.
410 *
411 * Return: Not full constructed attribute or NULL if not possible to create.
412 */
mi_insert_attr(struct mft_inode * mi,enum ATTR_TYPE type,const __le16 * name,u8 name_len,u32 asize,u16 name_off)413 struct ATTRIB *mi_insert_attr(struct mft_inode *mi, enum ATTR_TYPE type,
414 const __le16 *name, u8 name_len, u32 asize,
415 u16 name_off)
416 {
417 size_t tail;
418 struct ATTRIB *attr;
419 __le16 id;
420 struct MFT_REC *rec = mi->mrec;
421 struct ntfs_sb_info *sbi = mi->sbi;
422 u32 used = le32_to_cpu(rec->used);
423 const u16 *upcase = sbi->upcase;
424 int diff;
425
426 /* Can we insert mi attribute? */
427 if (used + asize > mi->sbi->record_size)
428 return NULL;
429
430 /*
431 * Scan through the list of attributes to find the point
432 * at which we should insert it.
433 */
434 attr = NULL;
435 while ((attr = mi_enum_attr(mi, attr))) {
436 diff = compare_attr(attr, type, name, name_len, upcase);
437
438 if (diff < 0)
439 continue;
440
441 if (!diff && !is_attr_indexed(attr))
442 return NULL;
443 break;
444 }
445
446 if (!attr) {
447 tail = 8; /* Not used, just to suppress warning. */
448 attr = Add2Ptr(rec, used - 8);
449 } else {
450 tail = used - PtrOffset(rec, attr);
451 }
452
453 id = mi_new_attt_id(mi);
454
455 memmove(Add2Ptr(attr, asize), attr, tail);
456 memset(attr, 0, asize);
457
458 attr->type = type;
459 attr->size = cpu_to_le32(asize);
460 attr->name_len = name_len;
461 attr->name_off = cpu_to_le16(name_off);
462 attr->id = id;
463
464 memmove(Add2Ptr(attr, name_off), name, name_len * sizeof(short));
465 rec->used = cpu_to_le32(used + asize);
466
467 mi->dirty = true;
468
469 return attr;
470 }
471
472 /*
473 * mi_remove_attr - Remove the attribute from record.
474 *
475 * NOTE: The source attr will point to next attribute.
476 */
mi_remove_attr(struct ntfs_inode * ni,struct mft_inode * mi,struct ATTRIB * attr)477 bool mi_remove_attr(struct ntfs_inode *ni, struct mft_inode *mi,
478 struct ATTRIB *attr)
479 {
480 struct MFT_REC *rec = mi->mrec;
481 u32 aoff = PtrOffset(rec, attr);
482 u32 used = le32_to_cpu(rec->used);
483 u32 asize = le32_to_cpu(attr->size);
484
485 if (aoff + asize > used)
486 return false;
487
488 if (ni && is_attr_indexed(attr)) {
489 u16 links = le16_to_cpu(ni->mi.mrec->hard_links);
490 struct ATTR_FILE_NAME *fname =
491 attr->type != ATTR_NAME ?
492 NULL :
493 resident_data_ex(attr,
494 SIZEOF_ATTRIBUTE_FILENAME);
495 if (fname && fname->type == FILE_NAME_DOS) {
496 /* Do not decrease links count deleting DOS name. */
497 } else if (!links) {
498 /* minor error. Not critical. */
499 } else {
500 ni->mi.mrec->hard_links = cpu_to_le16(links - 1);
501 ni->mi.dirty = true;
502 }
503 }
504
505 used -= asize;
506 memmove(attr, Add2Ptr(attr, asize), used - aoff);
507 rec->used = cpu_to_le32(used);
508 mi->dirty = true;
509
510 return true;
511 }
512
513 /* bytes = "new attribute size" - "old attribute size" */
mi_resize_attr(struct mft_inode * mi,struct ATTRIB * attr,int bytes)514 bool mi_resize_attr(struct mft_inode *mi, struct ATTRIB *attr, int bytes)
515 {
516 struct MFT_REC *rec = mi->mrec;
517 u32 aoff = PtrOffset(rec, attr);
518 u32 total, used = le32_to_cpu(rec->used);
519 u32 nsize, asize = le32_to_cpu(attr->size);
520 u32 rsize = le32_to_cpu(attr->res.data_size);
521 int tail = (int)(used - aoff - asize);
522 int dsize;
523 char *next;
524
525 if (tail < 0 || aoff >= used)
526 return false;
527
528 if (!bytes)
529 return true;
530
531 total = le32_to_cpu(rec->total);
532 next = Add2Ptr(attr, asize);
533
534 if (bytes > 0) {
535 dsize = ALIGN(bytes, 8);
536 if (used + dsize > total)
537 return false;
538 nsize = asize + dsize;
539 /* Move tail */
540 memmove(next + dsize, next, tail);
541 memset(next, 0, dsize);
542 used += dsize;
543 rsize += dsize;
544 } else {
545 dsize = ALIGN(-bytes, 8);
546 if (dsize > asize)
547 return false;
548 nsize = asize - dsize;
549 memmove(next - dsize, next, tail);
550 used -= dsize;
551 rsize -= dsize;
552 }
553
554 rec->used = cpu_to_le32(used);
555 attr->size = cpu_to_le32(nsize);
556 if (!attr->non_res)
557 attr->res.data_size = cpu_to_le32(rsize);
558 mi->dirty = true;
559
560 return true;
561 }
562
mi_pack_runs(struct mft_inode * mi,struct ATTRIB * attr,struct runs_tree * run,CLST len)563 int mi_pack_runs(struct mft_inode *mi, struct ATTRIB *attr,
564 struct runs_tree *run, CLST len)
565 {
566 int err = 0;
567 struct ntfs_sb_info *sbi = mi->sbi;
568 u32 new_run_size;
569 CLST plen;
570 struct MFT_REC *rec = mi->mrec;
571 CLST svcn = le64_to_cpu(attr->nres.svcn);
572 u32 used = le32_to_cpu(rec->used);
573 u32 aoff = PtrOffset(rec, attr);
574 u32 asize = le32_to_cpu(attr->size);
575 char *next = Add2Ptr(attr, asize);
576 u16 run_off = le16_to_cpu(attr->nres.run_off);
577 u32 run_size = asize - run_off;
578 u32 tail = used - aoff - asize;
579 u32 dsize = sbi->record_size - used;
580
581 /* Make a maximum gap in current record. */
582 memmove(next + dsize, next, tail);
583
584 /* Pack as much as possible. */
585 err = run_pack(run, svcn, len, Add2Ptr(attr, run_off), run_size + dsize,
586 &plen);
587 if (err < 0) {
588 memmove(next, next + dsize, tail);
589 return err;
590 }
591
592 new_run_size = ALIGN(err, 8);
593
594 memmove(next + new_run_size - run_size, next + dsize, tail);
595
596 attr->size = cpu_to_le32(asize + new_run_size - run_size);
597 attr->nres.evcn = cpu_to_le64(svcn + plen - 1);
598 rec->used = cpu_to_le32(used + new_run_size - run_size);
599 mi->dirty = true;
600
601 return 0;
602 }
603