aboutsummaryrefslogtreecommitdiff
path: root/fs/f2fs/acl.c
blob: 137af4255da6dfab591e4d640821539663d01a7c (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
/*
 * fs/f2fs/acl.c
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *             http://www.samsung.com/
 *
 * Portions of this code from linux/fs/ext2/acl.c
 *
 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
 *
 * 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/f2fs_fs.h>
#include "f2fs.h"
#include "xattr.h"
#include "acl.h"

#define get_inode_mode(i)	((is_inode_flag_set(F2FS_I(i), FI_ACL_MODE)) ? \
					(F2FS_I(i)->i_acl_mode) : ((i)->i_mode))

static inline size_t f2fs_acl_size(int count)
{
	if (count <= 4) {
		return sizeof(struct f2fs_acl_header) +
			count * sizeof(struct f2fs_acl_entry_short);
	} else {
		return sizeof(struct f2fs_acl_header) +
			4 * sizeof(struct f2fs_acl_entry_short) +
			(count - 4) * sizeof(struct f2fs_acl_entry);
	}
}

static inline int f2fs_acl_count(size_t size)
{
	ssize_t s;
	size -= sizeof(struct f2fs_acl_header);
	s = size - 4 * sizeof(struct f2fs_acl_entry_short);
	if (s < 0) {
		if (size % sizeof(struct f2fs_acl_entry_short))
			return -1;
		return size / sizeof(struct f2fs_acl_entry_short);
	} else {
		if (s % sizeof(struct f2fs_acl_entry))
			return -1;
		return s / sizeof(struct f2fs_acl_entry) + 4;
	}
}

static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
{
	int i, count;
	struct posix_acl *acl;
	struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
	struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
	const char *end = value + size;

	if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
		return ERR_PTR(-EINVAL);

	count = f2fs_acl_count(size);
	if (count < 0)
		return ERR_PTR(-EINVAL);
	if (count == 0)
		return NULL;

	acl = posix_acl_alloc(count, GFP_KERNEL);
	if (!acl)
		return ERR_PTR(-ENOMEM);

	for (i = 0; i < count; i++) {

		if ((char *)entry > end)
			goto fail;

		acl->a_entries[i].e_tag  = le16_to_cpu(entry->e_tag);
		acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);

		switch (acl->a_entries[i].e_tag) {
		case ACL_USER_OBJ:
		case ACL_GROUP_OBJ:
		case ACL_MASK:
		case ACL_OTHER:
			entry = (struct f2fs_acl_entry *)((char *)entry +
					sizeof(struct f2fs_acl_entry_short));
			break;

		case ACL_USER:
			acl->a_entries[i].e_uid =
				make_kuid(&init_user_ns,
						le32_to_cpu(entry->e_id));
			entry = (struct f2fs_acl_entry *)((char *)entry +
					sizeof(struct f2fs_acl_entry));
			break;
		case ACL_GROUP:
			acl->a_entries[i].e_gid =
				make_kgid(&init_user_ns,
						le32_to_cpu(entry->e_id));
			entry = (struct f2fs_acl_entry *)((char *)entry +
					sizeof(struct f2fs_acl_entry));
			break;
		default:
			goto fail;
		}
	}
	if ((char *)entry != end)
		goto fail;
	return acl;
fail:
	posix_acl_release(acl);
	return ERR_PTR(-EINVAL);
}

static void *f2fs_acl_to_disk(const struct posix_acl *acl, size_t *size)
{
	struct f2fs_acl_header *f2fs_acl;
	struct f2fs_acl_entry *entry;
	int i;

	f2fs_acl = kmalloc(sizeof(struct f2fs_acl_header) + acl->a_count *
			sizeof(struct f2fs_acl_entry), GFP_KERNEL);
	if (!f2fs_acl)
		return ERR_PTR(-ENOMEM);

	f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
	entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);

	for (i = 0; i < acl->a_count; i++) {

		entry->e_tag  = cpu_to_le16(acl->a_entries[i].e_tag);
		entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);

		switch (acl->a_entries[i].e_tag) {
		case ACL_USER:
			entry->e_id = cpu_to_le32(
					from_kuid(&init_user_ns,
						acl->a_entries[i].e_uid));
			entry = (struct f2fs_acl_entry *)((char *)entry +
					sizeof(struct f2fs_acl_entry));
			break;
		case ACL_GROUP:
			entry->e_id = cpu_to_le32(
					from_kgid(&init_user_ns,
						acl->a_entries[i].e_gid));
			entry = (struct f2fs_acl_entry *)((char *)entry +
					sizeof(struct f2fs_acl_entry));
			break;
		case ACL_USER_OBJ:
		case ACL_GROUP_OBJ:
		case ACL_MASK:
		case ACL_OTHER:
			entry = (struct f2fs_acl_entry *)((char *)entry +
					sizeof(struct f2fs_acl_entry_short));
			break;
		default:
			goto fail;
		}
	}
	*size = f2fs_acl_size(acl->a_count);
	return (void *)f2fs_acl;

fail:
	kfree(f2fs_acl);
	return ERR_PTR(-EINVAL);
}

struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
{
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
	void *value = NULL;
	struct posix_acl *acl;
	int retval;

	if (!test_opt(sbi, POSIX_ACL))
		return NULL;

	acl = get_cached_acl(inode, type);
	if (acl != ACL_NOT_CACHED)
		return acl;

	if (type == ACL_TYPE_ACCESS)
		name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;

	retval = f2fs_getxattr(inode, name_index, "", NULL, 0);
	if (retval > 0) {
		value = kmalloc(retval, GFP_KERNEL);
		if (!value)
			return ERR_PTR(-ENOMEM);
		retval = f2fs_getxattr(inode, name_index, "", value, retval);
	}

	if (retval > 0)
		acl = f2fs_acl_from_disk(value, retval);
	else if (retval == -ENODATA)
		acl = NULL;
	else
		acl = ERR_PTR(retval);
	kfree(value);

	if (!IS_ERR(acl))
		set_cached_acl(inode, type, acl);

	return acl;
}

static int f2fs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
{
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	struct f2fs_inode_info *fi = F2FS_I(inode);
	int name_index;
	void *value = NULL;
	size_t size = 0;
	int error;

	if (!test_opt(sbi, POSIX_ACL))
		return 0;
	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;

	switch (type) {
	case ACL_TYPE_ACCESS:
		name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
		if (acl) {
			error = posix_acl_equiv_mode(acl, &inode->i_mode);
			if (error < 0)
				return error;
			set_acl_inode(fi, inode->i_mode);
			if (error == 0)
				acl = NULL;
		}
		break;

	case ACL_TYPE_DEFAULT:
		name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
		if (!S_ISDIR(inode->i_mode))
			return acl ? -EACCES : 0;
		break;

	default:
		return -EINVAL;
	}

	if (acl) {
		value = f2fs_acl_to_disk(acl, &size);
		if (IS_ERR(value)) {
			cond_clear_inode_flag(fi, FI_ACL_MODE);
			return (int)PTR_ERR(value);
		}
	}

	error = f2fs_setxattr(inode, name_index, "", value, size);

	kfree(value);
	if (!error)
		set_cached_acl(inode, type, acl);

	cond_clear_inode_flag(fi, FI_ACL_MODE);
	return error;
}

int f2fs_init_acl(struct inode *inode, struct inode *dir)
{
	struct posix_acl *acl = NULL;
	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
	int error = 0;

	if (!S_ISLNK(inode->i_mode)) {
		if (test_opt(sbi, POSIX_ACL)) {
			acl = f2fs_get_acl(dir, ACL_TYPE_DEFAULT);
			if (IS_ERR(acl))
				return PTR_ERR(acl);
		}
		if (!acl)
			inode->i_mode &= ~current_umask();
	}

	if (test_opt(sbi, POSIX_ACL) && acl) {

		if (S_ISDIR(inode->i_mode)) {
			error = f2fs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
			if (error)
				goto cleanup;
		}
		error = posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode);
		if (error < 0)
			return error;
		if (error > 0)
			error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl);
	}
cleanup:
	posix_acl_release(acl);
	return error;
}

int f2fs_acl_chmod(struct inode *inode)
{
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	struct posix_acl *acl;
	int error;
	mode_t mode = get_inode_mode(inode);

	if (!test_opt(sbi, POSIX_ACL))
		return 0;
	if (S_ISLNK(mode))
		return -EOPNOTSUPP;

	acl = f2fs_get_acl(inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl) || !acl)
		return PTR_ERR(acl);

	error = posix_acl_chmod(&acl, GFP_KERNEL, mode);
	if (error)
		return error;
	error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl);
	posix_acl_release(acl);
	return error;
}

static size_t f2fs_xattr_list_acl(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);
	const char *xname = POSIX_ACL_XATTR_DEFAULT;
	size_t size;

	if (!test_opt(sbi, POSIX_ACL))
		return 0;

	if (type == ACL_TYPE_ACCESS)
		xname = POSIX_ACL_XATTR_ACCESS;

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

static int f2fs_xattr_get_acl(struct dentry *dentry, const char *name,
		void *buffer, size_t size, int type)
{
	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
	struct posix_acl *acl;
	int error;

	if (strcmp(name, "") != 0)
		return -EINVAL;
	if (!test_opt(sbi, POSIX_ACL))
		return -EOPNOTSUPP;

	acl = f2fs_get_acl(dentry->d_inode, type);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (!acl)
		return -ENODATA;
	error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
	posix_acl_release(acl);

	return error;
}

static int f2fs_xattr_set_acl(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);
	struct inode *inode = dentry->d_inode;
	struct posix_acl *acl = NULL;
	int error;

	if (strcmp(name, "") != 0)
		return -EINVAL;
	if (!test_opt(sbi, POSIX_ACL))
		return -EOPNOTSUPP;
	if (!inode_owner_or_capable(inode))
		return -EPERM;

	if (value) {
		acl = posix_acl_from_xattr(&init_user_ns, value, size);
		if (IS_ERR(acl))
			return PTR_ERR(acl);
		if (acl) {
			error = posix_acl_valid(acl);
			if (error)
				goto release_and_out;
		}
	} else {
		acl = NULL;
	}

	error = f2fs_set_acl(inode, type, acl);

release_and_out:
	posix_acl_release(acl);
	return error;
}

const struct xattr_handler f2fs_xattr_acl_default_handler = {
	.prefix = POSIX_ACL_XATTR_DEFAULT,
	.flags = ACL_TYPE_DEFAULT,
	.list = f2fs_xattr_list_acl,
	.get = f2fs_xattr_get_acl,
	.set = f2fs_xattr_set_acl,
};

const struct xattr_handler f2fs_xattr_acl_access_handler = {
	.prefix = POSIX_ACL_XATTR_ACCESS,
	.flags = ACL_TYPE_ACCESS,
	.list = f2fs_xattr_list_acl,
	.get = f2fs_xattr_get_acl,
	.set = f2fs_xattr_set_acl,
};