summaryrefslogtreecommitdiffstats
path: root/fs/ntfs3/attrlist.c
blob: 42631b31adf17f39c635eacd3c0a8a033583d96b (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
// SPDX-License-Identifier: GPL-2.0
/*
 *
 * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
 *
 */

#include <linux/fs.h>

#include "debug.h"
#include "ntfs.h"
#include "ntfs_fs.h"

/*
 * al_is_valid_le
 *
 * Return: True if @le is valid.
 */
static inline bool al_is_valid_le(const struct ntfs_inode *ni,
				  struct ATTR_LIST_ENTRY *le)
{
	if (!le || !ni->attr_list.le || !ni->attr_list.size)
		return false;

	return PtrOffset(ni->attr_list.le, le) + le16_to_cpu(le->size) <=
	       ni->attr_list.size;
}

void al_destroy(struct ntfs_inode *ni)
{
	run_close(&ni->attr_list.run);
	kfree(ni->attr_list.le);
	ni->attr_list.le = NULL;
	ni->attr_list.size = 0;
	ni->attr_list.dirty = false;
}

/*
 * ntfs_load_attr_list
 *
 * This method makes sure that the ATTRIB list, if present,
 * has been properly set up.
 */
int ntfs_load_attr_list(struct ntfs_inode *ni, struct ATTRIB *attr)
{
	int err;
	size_t lsize;
	void *le = NULL;

	if (ni->attr_list.size)
		return 0;

	if (!attr->non_res) {
		lsize = le32_to_cpu(attr->res.data_size);
		le = kmalloc(al_aligned(lsize), GFP_NOFS | __GFP_NOWARN);
		if (!le) {
			err = -ENOMEM;
			goto out;
		}
		memcpy(le, resident_data(attr), lsize);
	} else if (attr->nres.svcn) {
		err = -EINVAL;
		goto out;
	} else {
		u16 run_off = le16_to_cpu(attr->nres.run_off);

		lsize = le64_to_cpu(attr->nres.data_size);

		run_init(&ni->attr_list.run);

		if (run_off > le32_to_cpu(attr->size)) {
			err = -EINVAL;
			goto out;
		}

		err = run_unpack_ex(&ni->attr_list.run, ni->mi.sbi, ni->mi.rno,
				    0, le64_to_cpu(attr->nres.evcn), 0,
				    Add2Ptr(attr, run_off),
				    le32_to_cpu(attr->size) - run_off);
		if (err < 0)
			goto out;

		le = kmalloc(al_aligned(lsize), GFP_NOFS | __GFP_NOWARN);
		if (!le) {
			err = -ENOMEM;
			goto out;
		}

		err = ntfs_read_run_nb(ni->mi.sbi, &ni->attr_list.run, 0, le,
				       lsize, NULL);
		if (err)
			goto out;
	}

	ni->attr_list.size = lsize;
	ni->attr_list.le = le;

	return 0;

out:
	ni->attr_list.le = le;
	al_destroy(ni);

	return err;
}

/*
 * al_enumerate
 *
 * Return:
 * * The next list le.
 * * If @le is NULL then return the first le.
 */
struct ATTR_LIST_ENTRY *al_enumerate(struct ntfs_inode *ni,
				     struct ATTR_LIST_ENTRY *le)
{
	size_t off;
	u16 sz;

	if (!le) {
		le = ni->attr_list.le;
	} else {
		sz = le16_to_cpu(le->size);
		if (sz < sizeof(struct ATTR_LIST_ENTRY)) {
			/* Impossible 'cause we should not return such le. */
			return NULL;
		}
		le = Add2Ptr(le, sz);
	}

	/* Check boundary. */
	off = PtrOffset(ni->attr_list.le, le);
	if (off + sizeof(struct ATTR_LIST_ENTRY) > ni->attr_list.size) {
		/* The regular end of list. */
		return NULL;
	}

	sz = le16_to_cpu(le->size);

	/* Check le for errors. */
	if (sz < sizeof(struct ATTR_LIST_ENTRY) ||
	    off + sz > ni->attr_list.size ||
	    sz < le->name_off + le->name_len * sizeof(short)) {
		return NULL;
	}

	return le;
}

/*
 * al_find_le
 *
 * Find the first le in the list which matches type, name and VCN.
 *
 * Return: NULL if not found.
 */
struct ATTR_LIST_ENTRY *al_find_le(struct ntfs_inode *ni,
				   struct ATTR_LIST_ENTRY *le,
				   const struct ATTRIB *attr)
{
	CLST svcn = attr_svcn(attr);

	return al_find_ex(ni, le, attr->type, attr_name(attr), attr->name_len,
			  &svcn);
}

/*
 * al_find_ex
 *
 * Find the first le in the list which matches type, name and VCN.
 *
 * Return: NULL if not found.
 */
struct ATTR_LIST_ENTRY *al_find_ex(struct ntfs_inode *ni,
				   struct ATTR_LIST_ENTRY *le,
				   enum ATTR_TYPE type, const __le16 *name,
				   u8 name_len, const CLST *vcn)
{
	struct ATTR_LIST_ENTRY *ret = NULL;
	u32 type_in = le32_to_cpu(type);

	while ((le = al_enumerate(ni, le))) {
		u64 le_vcn;
		int diff = le32_to_cpu(le->type) - type_in;

		/* List entries are sorted by type, name and VCN. */
		if (diff < 0)
			continue;

		if (diff > 0)
			return ret;

		if (le->name_len != name_len)
			continue;

		le_vcn = le64_to_cpu(le->vcn);
		if (!le_vcn) {
			/*
			 * Compare entry names only for entry with vcn == 0.
			 */
			diff = ntfs_cmp_names(le_name(le), name_len, name,
					      name_len, ni->mi.sbi->upcase,
					      true);
			if (diff < 0)
				continue;

			if (diff > 0)
				return ret;
		}

		if (!vcn)
			return le;

		if (*vcn == le_vcn)
			return le;

		if (*vcn < le_vcn)
			return ret;

		ret = le;
	}

	return ret;
}

/*
 * al_find_le_to_insert
 *
 * Find the first list entry which matches type, name and VCN.
 */
static struct ATTR_LIST_ENTRY *al_find_le_to_insert(struct ntfs_inode *ni,
						    enum ATTR_TYPE type,
						    const __le16 *name,
						    u8 name_len, CLST vcn)
{
	struct ATTR_LIST_ENTRY *le = NULL, *prev;
	u32 type_in = le32_to_cpu(type);

	/* List entries are sorted by type, name and VCN. */
	while ((le = al_enumerate(ni, prev = le))) {
		int diff = le32_to_cpu(le->type) - type_in;

		if (diff < 0)
			continue;

		if (diff > 0)
			return le;

		if (!le->vcn) {
			/*
			 * Compare entry names only for entry with vcn == 0.
			 */
			diff = ntfs_cmp_names(le_name(le), le->name_len, name,
					      name_len, ni->mi.sbi->upcase,
					      true);
			if (diff < 0)
				continue;

			if (diff > 0)
				return le;
		}

		if (le64_to_cpu(le->vcn) >= vcn)
			return le;
	}

	return prev ? Add2Ptr(prev, le16_to_cpu(prev->size)) : ni->attr_list.le;
}

/*
 * al_add_le
 *
 * Add an "attribute list entry" to the list.
 */
int al_add_le(struct ntfs_inode *ni, enum ATTR_TYPE type, const __le16 *name,
	      u8 name_len, CLST svcn, __le16 id, const struct MFT_REF *ref,
	      struct ATTR_LIST_ENTRY **new_le)
{
	int err;
	struct ATTRIB *attr;
	struct ATTR_LIST_ENTRY *le;
	size_t off;
	u16 sz;
	size_t asize, new_asize, old_size;
	u64 new_size;
	typeof(ni->attr_list) *al = &ni->attr_list;

	/*
	 * Compute the size of the new 'le'
	 */
	sz = le_size(name_len);
	old_size = al->size;
	new_size = old_size + sz;
	asize = al_aligned(old_size);
	new_asize = al_aligned(new_size);

	/* Scan forward to the point at which the new 'le' should be inserted. */
	le = al_find_le_to_insert(ni, type, name, name_len, svcn);
	off = PtrOffset(al->le, le);

	if (new_size > asize) {
		void *ptr = kmalloc(new_asize, GFP_NOFS);

		if (!ptr)
			return -ENOMEM;

		memcpy(ptr, al->le, off);
		memcpy(Add2Ptr(ptr, off + sz), le, old_size - off);
		le = Add2Ptr(ptr, off);
		kfree(al->le);
		al->le = ptr;
	} else {
		memmove(Add2Ptr(le, sz), le, old_size - off);
	}
	*new_le = le;

	al->size = new_size;

	le->type = type;
	le->size = cpu_to_le16(sz);
	le->name_len = name_len;
	le->name_off = offsetof(struct ATTR_LIST_ENTRY, name);
	le->vcn = cpu_to_le64(svcn);
	le->ref = *ref;
	le->id = id;
	memcpy(le->name, name, sizeof(short) * name_len);

	err = attr_set_size(ni, ATTR_LIST, NULL, 0, &al->run, new_size,
			    &new_size, true, &attr);
	if (err) {
		/* Undo memmove above. */
		memmove(le, Add2Ptr(le, sz), old_size - off);
		al->size = old_size;
		return err;
	}

	al->dirty = true;

	if (attr && attr->non_res) {
		err = ntfs_sb_write_run(ni->mi.sbi, &al->run, 0, al->le,
					al->size, 0);
		if (err)
			return err;
		al->dirty = false;
	}

	return 0;
}

/*
 * al_remove_le - Remove @le from attribute list.
 */
bool al_remove_le(struct ntfs_inode *ni, struct ATTR_LIST_ENTRY *le)
{
	u16 size;
	size_t off;
	typeof(ni->attr_list) *al = &ni->attr_list;

	if (!al_is_valid_le(ni, le))
		return false;

	/* Save on stack the size of 'le' */
	size = le16_to_cpu(le->size);
	off = PtrOffset(al->le, le);

	memmove(le, Add2Ptr(le, size), al->size - (off + size));

	al->size -= size;
	al->dirty = true;

	return true;
}

/*
 * al_delete_le - Delete first le from the list which matches its parameters.
 */
bool al_delete_le(struct ntfs_inode *ni, enum ATTR_TYPE type, CLST vcn,
		  const __le16 *name, u8 name_len, const struct MFT_REF *ref)
{
	u16 size;
	struct ATTR_LIST_ENTRY *le;
	size_t off;
	typeof(ni->attr_list) *al = &ni->attr_list;

	/* Scan forward to the first le that matches the input. */
	le = al_find_ex(ni, NULL, type, name, name_len, &vcn);
	if (!le)
		return false;

	off = PtrOffset(al->le, le);

next:
	if (off >= al->size)
		return false;
	if (le->type != type)
		return false;
	if (le->name_len != name_len)
		return false;
	if (name_len && ntfs_cmp_names(le_name(le), name_len, name, name_len,
				       ni->mi.sbi->upcase, true))
		return false;
	if (le64_to_cpu(le->vcn) != vcn)
		return false;

	/*
	 * The caller specified a segment reference, so we have to
	 * scan through the matching entries until we find that segment
	 * reference or we run of matching entries.
	 */
	if (ref && memcmp(ref, &le->ref, sizeof(*ref))) {
		off += le16_to_cpu(le->size);
		le = Add2Ptr(al->le, off);
		goto next;
	}

	/* Save on stack the size of 'le'. */
	size = le16_to_cpu(le->size);
	/* Delete the le. */
	memmove(le, Add2Ptr(le, size), al->size - (off + size));

	al->size -= size;
	al->dirty = true;

	return true;
}

int al_update(struct ntfs_inode *ni, int sync)
{
	int err;
	struct ATTRIB *attr;
	typeof(ni->attr_list) *al = &ni->attr_list;

	if (!al->dirty || !al->size)
		return 0;

	/*
	 * Attribute list increased on demand in al_add_le.
	 * Attribute list decreased here.
	 */
	err = attr_set_size(ni, ATTR_LIST, NULL, 0, &al->run, al->size, NULL,
			    false, &attr);
	if (err)
		goto out;

	if (!attr->non_res) {
		memcpy(resident_data(attr), al->le, al->size);
	} else {
		err = ntfs_sb_write_run(ni->mi.sbi, &al->run, 0, al->le,
					al->size, sync);
		if (err)
			goto out;

		attr->nres.valid_size = attr->nres.data_size;
	}

	ni->mi.dirty = true;
	al->dirty = false;

out:
	return err;
}