aboutsummaryrefslogtreecommitdiff
path: root/fs/f2fs/xattr.c
blob: 3ab07ecd86ca16b5aaaa4e89792e5fe0db22ffca (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
/*
 * fs/f2fs/xattr.c
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *             http://www.samsung.com/
 *
 * Portions of this code from linux/fs/ext2/xattr.c
 *
 * Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de>
 *
 * Fix by Harrison Xing <harrison@mountainviewdata.com>.
 * Extended attributes for symlinks and special files added per
 *  suggestion of Luka Renko <luka.renko@hermes.si>.
 * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
 *  Red Hat Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/rwsem.h>
#include <linux/f2fs_fs.h>
#include <linux/security.h>
#include "f2fs.h"
#include "xattr.h"

static size_t f2fs_xattr_generic_list(struct dentry *dentry, char *list,
		size_t list_size, const char *name, size_t name_len, int type)
{
	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
	int total_len, prefix_len = 0;
	const char *prefix = NULL;

	switch (type) {
	case F2FS_XATTR_INDEX_USER:
		if (!test_opt(sbi, XATTR_USER))
			return -EOPNOTSUPP;
		prefix = XATTR_USER_PREFIX;
		prefix_len = XATTR_USER_PREFIX_LEN;
		break;
	case F2FS_XATTR_INDEX_TRUSTED:
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		prefix = XATTR_TRUSTED_PREFIX;
		prefix_len = XATTR_TRUSTED_PREFIX_LEN;
		break;
	case F2FS_XATTR_INDEX_SECURITY:
		prefix = XATTR_SECURITY_PREFIX;
		prefix_len = XATTR_SECURITY_PREFIX_LEN;
		break;
	default:
		return -EINVAL;
	}

	total_len = prefix_len + name_len + 1;
	if (list && total_len <= list_size) {
		memcpy(list, prefix, prefix_len);
		memcpy(list + prefix_len, name, name_len);
		list[prefix_len + name_len] = '\0';
	}
	return total_len;
}

static int f2fs_xattr_generic_get(struct dentry *dentry, const char *name,
		void *buffer, size_t size, int type)
{
	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);

	switch (type) {
	case F2FS_XATTR_INDEX_USER:
		if (!test_opt(sbi, XATTR_USER))
			return -EOPNOTSUPP;
		break;
	case F2FS_XATTR_INDEX_TRUSTED:
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		break;
	case F2FS_XATTR_INDEX_SECURITY:
		break;
	default:
		return -EINVAL;
	}
	if (strcmp(name, "") == 0)
		return -EINVAL;
	return f2fs_getxattr(dentry->d_inode, type, name, buffer, size);
}

static int f2fs_xattr_generic_set(struct dentry *dentry, const char *name,
		const void *value, size_t size, int flags, int type)
{
	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);

	switch (type) {
	case F2FS_XATTR_INDEX_USER:
		if (!test_opt(sbi, XATTR_USER))
			return -EOPNOTSUPP;
		break;
	case F2FS_XATTR_INDEX_TRUSTED:
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		break;
	case F2FS_XATTR_INDEX_SECURITY:
		break;
	default:
		return -EINVAL;
	}
	if (strcmp(name, "") == 0)
		return -EINVAL;

	return f2fs_setxattr(dentry->d_inode, type, name, value, size, NULL);
}

static size_t f2fs_xattr_advise_list(struct dentry *dentry, char *list,
		size_t list_size, const char *name, size_t name_len, int type)
{
	const char *xname = F2FS_SYSTEM_ADVISE_PREFIX;
	size_t size;

	if (type != F2FS_XATTR_INDEX_ADVISE)
		return 0;

	size = strlen(xname) + 1;
	if (list && size <= list_size)
		memcpy(list, xname, size);
	return size;
}

static int f2fs_xattr_advise_get(struct dentry *dentry, const char *name,
		void *buffer, size_t size, int type)
{
	struct inode *inode = dentry->d_inode;

	if (strcmp(name, "") != 0)
		return -EINVAL;

	*((char *)buffer) = F2FS_I(inode)->i_advise;
	return sizeof(char);
}

static int f2fs_xattr_advise_set(struct dentry *dentry, const char *name,
		const void *value, size_t size, int flags, int type)
{
	struct inode *inode = dentry->d_inode;

	if (strcmp(name, "") != 0)
		return -EINVAL;
	if (!inode_owner_or_capable(inode))
		return -EPERM;
	if (value == NULL)
		return -EINVAL;

	F2FS_I(inode)->i_advise |= *(char *)value;
	return 0;
}

#ifdef CONFIG_F2FS_FS_SECURITY
static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
		void *page)
{
	const struct xattr *xattr;
	int err = 0;

	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
		err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
				xattr->name, xattr->value,
				xattr->value_len, (struct page *)page);
		if (err < 0)
			break;
	}
	return err;
}

int f2fs_init_security(struct inode *inode, struct inode *dir,
				const struct qstr *qstr, struct page *ipage)
{
	return security_inode_init_security(inode, dir, qstr,
				&f2fs_initxattrs, ipage);
}
#endif

const struct xattr_handler f2fs_xattr_user_handler = {
	.prefix	= XATTR_USER_PREFIX,
	.flags	= F2FS_XATTR_INDEX_USER,
	.list	= f2fs_xattr_generic_list,
	.get	= f2fs_xattr_generic_get,
	.set	= f2fs_xattr_generic_set,
};

const struct xattr_handler f2fs_xattr_trusted_handler = {
	.prefix	= XATTR_TRUSTED_PREFIX,
	.flags	= F2FS_XATTR_INDEX_TRUSTED,
	.list	= f2fs_xattr_generic_list,
	.get	= f2fs_xattr_generic_get,
	.set	= f2fs_xattr_generic_set,
};

const struct xattr_handler f2fs_xattr_advise_handler = {
	.prefix = F2FS_SYSTEM_ADVISE_PREFIX,
	.flags	= F2FS_XATTR_INDEX_ADVISE,
	.list   = f2fs_xattr_advise_list,
	.get    = f2fs_xattr_advise_get,
	.set    = f2fs_xattr_advise_set,
};

const struct xattr_handler f2fs_xattr_security_handler = {
	.prefix	= XATTR_SECURITY_PREFIX,
	.flags	= F2FS_XATTR_INDEX_SECURITY,
	.list	= f2fs_xattr_generic_list,
	.get	= f2fs_xattr_generic_get,
	.set	= f2fs_xattr_generic_set,
};

static const struct xattr_handler *f2fs_xattr_handler_map[] = {
	[F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler,
#ifdef CONFIG_F2FS_FS_POSIX_ACL
	[F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &f2fs_xattr_acl_access_handler,
	[F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &f2fs_xattr_acl_default_handler,
#endif
	[F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
#ifdef CONFIG_F2FS_FS_SECURITY
	[F2FS_XATTR_INDEX_SECURITY] = &f2fs_xattr_security_handler,
#endif
	[F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler,
};

const struct xattr_handler *f2fs_xattr_handlers[] = {
	&f2fs_xattr_user_handler,
#ifdef CONFIG_F2FS_FS_POSIX_ACL
	&f2fs_xattr_acl_access_handler,
	&f2fs_xattr_acl_default_handler,
#endif
	&f2fs_xattr_trusted_handler,
#ifdef CONFIG_F2FS_FS_SECURITY
	&f2fs_xattr_security_handler,
#endif
	&f2fs_xattr_advise_handler,
	NULL,
};

static inline const struct xattr_handler *f2fs_xattr_handler(int name_index)
{
	const struct xattr_handler *handler = NULL;

	if (name_index > 0 && name_index < ARRAY_SIZE(f2fs_xattr_handler_map))
		handler = f2fs_xattr_handler_map[name_index];
	return handler;
}

int f2fs_getxattr(struct inode *inode, int name_index, const char *name,
		void *buffer, size_t buffer_size)
{
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	struct f2fs_inode_info *fi = F2FS_I(inode);
	struct f2fs_xattr_entry *entry;
	struct page *page;
	void *base_addr;
	int error = 0, found = 0;
	size_t value_len, name_len;

	if (name == NULL)
		return -EINVAL;
	name_len = strlen(name);

	if (!fi->i_xattr_nid)
		return -ENODATA;

	page = get_node_page(sbi, fi->i_xattr_nid);
	if (IS_ERR(page))
		return PTR_ERR(page);
	base_addr = page_address(page);

	list_for_each_xattr(entry, base_addr) {
		if (entry->e_name_index != name_index)
			continue;
		if (entry->e_name_len != name_len)
			continue;
		if (!memcmp(entry->e_name, name, name_len)) {
			found = 1;
			break;
		}
	}
	if (!found) {
		error = -ENODATA;
		goto cleanup;
	}

	value_len = le16_to_cpu(entry->e_value_size);

	if (buffer && value_len > buffer_size) {
		error = -ERANGE;
		goto cleanup;
	}

	if (buffer) {
		char *pval = entry->e_name + entry->e_name_len;
		memcpy(buffer, pval, value_len);
	}
	error = value_len;

cleanup:
	f2fs_put_page(page, 1);
	return error;
}

ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
{
	struct inode *inode = dentry->d_inode;
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	struct f2fs_inode_info *fi = F2FS_I(inode);
	struct f2fs_xattr_entry *entry;
	struct page *page;
	void *base_addr;
	int error = 0;
	size_t rest = buffer_size;

	if (!fi->i_xattr_nid)
		return 0;

	page = get_node_page(sbi, fi->i_xattr_nid);
	if (IS_ERR(page))
		return PTR_ERR(page);
	base_addr = page_address(page);

	list_for_each_xattr(entry, base_addr) {
		const struct xattr_handler *handler =
			f2fs_xattr_handler(entry->e_name_index);
		size_t size;

		if (!handler)
			continue;

		size = handler->list(dentry, buffer, rest, entry->e_name,
				entry->e_name_len, handler->flags);
		if (buffer && size > rest) {
			error = -ERANGE;
			goto cleanup;
		}

		if (buffer)
			buffer += size;
		rest -= size;
	}
	error = buffer_size - rest;
cleanup:
	f2fs_put_page(page, 1);
	return error;
}

int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
			const void *value, size_t value_len, struct page *ipage)
{
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	struct f2fs_inode_info *fi = F2FS_I(inode);
	struct f2fs_xattr_header *header = NULL;
	struct f2fs_xattr_entry *here, *last;
	struct page *page;
	void *base_addr;
	int error, found, free, newsize;
	size_t name_len;
	char *pval;
	int ilock;

	if (name == NULL)
		return -EINVAL;

	if (value == NULL)
		value_len = 0;

	name_len = strlen(name);

	if (name_len > F2FS_NAME_LEN || value_len > MAX_VALUE_LEN)
		return -ERANGE;

	f2fs_balance_fs(sbi);

	ilock = mutex_lock_op(sbi);

	if (!fi->i_xattr_nid) {
		/* Allocate new attribute block */
		struct dnode_of_data dn;

		if (!alloc_nid(sbi, &fi->i_xattr_nid)) {
			error = -ENOSPC;
			goto exit;
		}
		set_new_dnode(&dn, inode, NULL, NULL, fi->i_xattr_nid);
		mark_inode_dirty(inode);

		page = new_node_page(&dn, XATTR_NODE_OFFSET, ipage);
		if (IS_ERR(page)) {
			alloc_nid_failed(sbi, fi->i_xattr_nid);
			fi->i_xattr_nid = 0;
			error = PTR_ERR(page);
			goto exit;
		}

		alloc_nid_done(sbi, fi->i_xattr_nid);
		base_addr = page_address(page);
		header = XATTR_HDR(base_addr);
		header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
		header->h_refcount = cpu_to_le32(1);
	} else {
		/* The inode already has an extended attribute block. */
		page = get_node_page(sbi, fi->i_xattr_nid);
		if (IS_ERR(page)) {
			error = PTR_ERR(page);
			goto exit;
		}

		base_addr = page_address(page);
		header = XATTR_HDR(base_addr);
	}

	if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
		error = -EIO;
		goto cleanup;
	}

	/* find entry with wanted name. */
	found = 0;
	list_for_each_xattr(here, base_addr) {
		if (here->e_name_index != name_index)
			continue;
		if (here->e_name_len != name_len)
			continue;
		if (!memcmp(here->e_name, name, name_len)) {
			found = 1;
			break;
		}
	}

	last = here;

	while (!IS_XATTR_LAST_ENTRY(last))
		last = XATTR_NEXT_ENTRY(last);

	newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) +
			name_len + value_len);

	/* 1. Check space */
	if (value) {
		/* If value is NULL, it is remove operation.
		 * In case of update operation, we caculate free.
		 */
		free = MIN_OFFSET - ((char *)last - (char *)header);
		if (found)
			free = free - ENTRY_SIZE(here);

		if (free < newsize) {
			error = -ENOSPC;
			goto cleanup;
		}
	}

	/* 2. Remove old entry */
	if (found) {
		/* If entry is found, remove old entry.
		 * If not found, remove operation is not needed.
		 */
		struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here);
		int oldsize = ENTRY_SIZE(here);

		memmove(here, next, (char *)last - (char *)next);
		last = (struct f2fs_xattr_entry *)((char *)last - oldsize);
		memset(last, 0, oldsize);
	}

	/* 3. Write new entry */
	if (value) {
		/* Before we come here, old entry is removed.
		 * We just write new entry. */
		memset(last, 0, newsize);
		last->e_name_index = name_index;
		last->e_name_len = name_len;
		memcpy(last->e_name, name, name_len);
		pval = last->e_name + name_len;
		memcpy(pval, value, value_len);
		last->e_value_size = cpu_to_le16(value_len);
	}

	set_page_dirty(page);
	f2fs_put_page(page, 1);

	if (is_inode_flag_set(fi, FI_ACL_MODE)) {
		inode->i_mode = fi->i_acl_mode;
		inode->i_ctime = CURRENT_TIME;
		clear_inode_flag(fi, FI_ACL_MODE);
	}
	if (ipage)
		update_inode(inode, ipage);
	else
		update_inode_page(inode);
	mutex_unlock_op(sbi, ilock);

	return 0;
cleanup:
	f2fs_put_page(page, 1);
exit:
	mutex_unlock_op(sbi, ilock);
	return error;
}