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7#include <linux/init.h>
8#include <linux/sched.h>
9#include <linux/slab.h>
10#include <linux/capability.h>
11#include <linux/fs.h>
12#include <linux/ext3_jbd.h>
13#include <linux/ext3_fs.h>
14#include "xattr.h"
15#include "acl.h"
16
17
18
19
20static struct posix_acl *
21ext3_acl_from_disk(const void *value, size_t size)
22{
23 const char *end = (char *)value + size;
24 int n, count;
25 struct posix_acl *acl;
26
27 if (!value)
28 return NULL;
29 if (size < sizeof(ext3_acl_header))
30 return ERR_PTR(-EINVAL);
31 if (((ext3_acl_header *)value)->a_version !=
32 cpu_to_le32(EXT3_ACL_VERSION))
33 return ERR_PTR(-EINVAL);
34 value = (char *)value + sizeof(ext3_acl_header);
35 count = ext3_acl_count(size);
36 if (count < 0)
37 return ERR_PTR(-EINVAL);
38 if (count == 0)
39 return NULL;
40 acl = posix_acl_alloc(count, GFP_NOFS);
41 if (!acl)
42 return ERR_PTR(-ENOMEM);
43 for (n=0; n < count; n++) {
44 ext3_acl_entry *entry =
45 (ext3_acl_entry *)value;
46 if ((char *)value + sizeof(ext3_acl_entry_short) > end)
47 goto fail;
48 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
49 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
50 switch(acl->a_entries[n].e_tag) {
51 case ACL_USER_OBJ:
52 case ACL_GROUP_OBJ:
53 case ACL_MASK:
54 case ACL_OTHER:
55 value = (char *)value +
56 sizeof(ext3_acl_entry_short);
57 acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
58 break;
59
60 case ACL_USER:
61 case ACL_GROUP:
62 value = (char *)value + sizeof(ext3_acl_entry);
63 if ((char *)value > end)
64 goto fail;
65 acl->a_entries[n].e_id =
66 le32_to_cpu(entry->e_id);
67 break;
68
69 default:
70 goto fail;
71 }
72 }
73 if (value != end)
74 goto fail;
75 return acl;
76
77fail:
78 posix_acl_release(acl);
79 return ERR_PTR(-EINVAL);
80}
81
82
83
84
85static void *
86ext3_acl_to_disk(const struct posix_acl *acl, size_t *size)
87{
88 ext3_acl_header *ext_acl;
89 char *e;
90 size_t n;
91
92 *size = ext3_acl_size(acl->a_count);
93 ext_acl = kmalloc(sizeof(ext3_acl_header) + acl->a_count *
94 sizeof(ext3_acl_entry), GFP_NOFS);
95 if (!ext_acl)
96 return ERR_PTR(-ENOMEM);
97 ext_acl->a_version = cpu_to_le32(EXT3_ACL_VERSION);
98 e = (char *)ext_acl + sizeof(ext3_acl_header);
99 for (n=0; n < acl->a_count; n++) {
100 ext3_acl_entry *entry = (ext3_acl_entry *)e;
101 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
102 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
103 switch(acl->a_entries[n].e_tag) {
104 case ACL_USER:
105 case ACL_GROUP:
106 entry->e_id =
107 cpu_to_le32(acl->a_entries[n].e_id);
108 e += sizeof(ext3_acl_entry);
109 break;
110
111 case ACL_USER_OBJ:
112 case ACL_GROUP_OBJ:
113 case ACL_MASK:
114 case ACL_OTHER:
115 e += sizeof(ext3_acl_entry_short);
116 break;
117
118 default:
119 goto fail;
120 }
121 }
122 return (char *)ext_acl;
123
124fail:
125 kfree(ext_acl);
126 return ERR_PTR(-EINVAL);
127}
128
129
130
131
132
133
134static struct posix_acl *
135ext3_get_acl(struct inode *inode, int type)
136{
137 int name_index;
138 char *value = NULL;
139 struct posix_acl *acl;
140 int retval;
141
142 if (!test_opt(inode->i_sb, POSIX_ACL))
143 return NULL;
144
145 acl = get_cached_acl(inode, type);
146 if (acl != ACL_NOT_CACHED)
147 return acl;
148
149 switch (type) {
150 case ACL_TYPE_ACCESS:
151 name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
152 break;
153 case ACL_TYPE_DEFAULT:
154 name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
155 break;
156 default:
157 BUG();
158 }
159
160 retval = ext3_xattr_get(inode, name_index, "", NULL, 0);
161 if (retval > 0) {
162 value = kmalloc(retval, GFP_NOFS);
163 if (!value)
164 return ERR_PTR(-ENOMEM);
165 retval = ext3_xattr_get(inode, name_index, "", value, retval);
166 }
167 if (retval > 0)
168 acl = ext3_acl_from_disk(value, retval);
169 else if (retval == -ENODATA || retval == -ENOSYS)
170 acl = NULL;
171 else
172 acl = ERR_PTR(retval);
173 kfree(value);
174
175 if (!IS_ERR(acl))
176 set_cached_acl(inode, type, acl);
177
178 return acl;
179}
180
181
182
183
184
185
186static int
187ext3_set_acl(handle_t *handle, struct inode *inode, int type,
188 struct posix_acl *acl)
189{
190 int name_index;
191 void *value = NULL;
192 size_t size = 0;
193 int error;
194
195 if (S_ISLNK(inode->i_mode))
196 return -EOPNOTSUPP;
197
198 switch(type) {
199 case ACL_TYPE_ACCESS:
200 name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
201 if (acl) {
202 mode_t mode = inode->i_mode;
203 error = posix_acl_equiv_mode(acl, &mode);
204 if (error < 0)
205 return error;
206 else {
207 inode->i_mode = mode;
208 ext3_mark_inode_dirty(handle, inode);
209 if (error == 0)
210 acl = NULL;
211 }
212 }
213 break;
214
215 case ACL_TYPE_DEFAULT:
216 name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
217 if (!S_ISDIR(inode->i_mode))
218 return acl ? -EACCES : 0;
219 break;
220
221 default:
222 return -EINVAL;
223 }
224 if (acl) {
225 value = ext3_acl_to_disk(acl, &size);
226 if (IS_ERR(value))
227 return (int)PTR_ERR(value);
228 }
229
230 error = ext3_xattr_set_handle(handle, inode, name_index, "",
231 value, size, 0);
232
233 kfree(value);
234
235 if (!error)
236 set_cached_acl(inode, type, acl);
237
238 return error;
239}
240
241int
242ext3_check_acl(struct inode *inode, int mask)
243{
244 struct posix_acl *acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
245
246 if (IS_ERR(acl))
247 return PTR_ERR(acl);
248 if (acl) {
249 int error = posix_acl_permission(inode, acl, mask);
250 posix_acl_release(acl);
251 return error;
252 }
253
254 return -EAGAIN;
255}
256
257
258
259
260
261
262
263int
264ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
265{
266 struct posix_acl *acl = NULL;
267 int error = 0;
268
269 if (!S_ISLNK(inode->i_mode)) {
270 if (test_opt(dir->i_sb, POSIX_ACL)) {
271 acl = ext3_get_acl(dir, ACL_TYPE_DEFAULT);
272 if (IS_ERR(acl))
273 return PTR_ERR(acl);
274 }
275 if (!acl)
276 inode->i_mode &= ~current_umask();
277 }
278 if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
279 struct posix_acl *clone;
280 mode_t mode;
281
282 if (S_ISDIR(inode->i_mode)) {
283 error = ext3_set_acl(handle, inode,
284 ACL_TYPE_DEFAULT, acl);
285 if (error)
286 goto cleanup;
287 }
288 clone = posix_acl_clone(acl, GFP_NOFS);
289 error = -ENOMEM;
290 if (!clone)
291 goto cleanup;
292
293 mode = inode->i_mode;
294 error = posix_acl_create_masq(clone, &mode);
295 if (error >= 0) {
296 inode->i_mode = mode;
297 if (error > 0) {
298
299 error = ext3_set_acl(handle, inode,
300 ACL_TYPE_ACCESS, clone);
301 }
302 }
303 posix_acl_release(clone);
304 }
305cleanup:
306 posix_acl_release(acl);
307 return error;
308}
309
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319
320
321
322
323
324int
325ext3_acl_chmod(struct inode *inode)
326{
327 struct posix_acl *acl, *clone;
328 int error;
329
330 if (S_ISLNK(inode->i_mode))
331 return -EOPNOTSUPP;
332 if (!test_opt(inode->i_sb, POSIX_ACL))
333 return 0;
334 acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
335 if (IS_ERR(acl) || !acl)
336 return PTR_ERR(acl);
337 clone = posix_acl_clone(acl, GFP_KERNEL);
338 posix_acl_release(acl);
339 if (!clone)
340 return -ENOMEM;
341 error = posix_acl_chmod_masq(clone, inode->i_mode);
342 if (!error) {
343 handle_t *handle;
344 int retries = 0;
345
346 retry:
347 handle = ext3_journal_start(inode,
348 EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
349 if (IS_ERR(handle)) {
350 error = PTR_ERR(handle);
351 ext3_std_error(inode->i_sb, error);
352 goto out;
353 }
354 error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, clone);
355 ext3_journal_stop(handle);
356 if (error == -ENOSPC &&
357 ext3_should_retry_alloc(inode->i_sb, &retries))
358 goto retry;
359 }
360out:
361 posix_acl_release(clone);
362 return error;
363}
364
365
366
367
368static size_t
369ext3_xattr_list_acl_access(struct inode *inode, char *list, size_t list_len,
370 const char *name, size_t name_len)
371{
372 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
373
374 if (!test_opt(inode->i_sb, POSIX_ACL))
375 return 0;
376 if (list && size <= list_len)
377 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
378 return size;
379}
380
381static size_t
382ext3_xattr_list_acl_default(struct inode *inode, char *list, size_t list_len,
383 const char *name, size_t name_len)
384{
385 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
386
387 if (!test_opt(inode->i_sb, POSIX_ACL))
388 return 0;
389 if (list && size <= list_len)
390 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
391 return size;
392}
393
394static int
395ext3_xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size)
396{
397 struct posix_acl *acl;
398 int error;
399
400 if (!test_opt(inode->i_sb, POSIX_ACL))
401 return -EOPNOTSUPP;
402
403 acl = ext3_get_acl(inode, type);
404 if (IS_ERR(acl))
405 return PTR_ERR(acl);
406 if (acl == NULL)
407 return -ENODATA;
408 error = posix_acl_to_xattr(acl, buffer, size);
409 posix_acl_release(acl);
410
411 return error;
412}
413
414static int
415ext3_xattr_get_acl_access(struct inode *inode, const char *name,
416 void *buffer, size_t size)
417{
418 if (strcmp(name, "") != 0)
419 return -EINVAL;
420 return ext3_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
421}
422
423static int
424ext3_xattr_get_acl_default(struct inode *inode, const char *name,
425 void *buffer, size_t size)
426{
427 if (strcmp(name, "") != 0)
428 return -EINVAL;
429 return ext3_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
430}
431
432static int
433ext3_xattr_set_acl(struct inode *inode, int type, const void *value,
434 size_t size)
435{
436 handle_t *handle;
437 struct posix_acl *acl;
438 int error, retries = 0;
439
440 if (!test_opt(inode->i_sb, POSIX_ACL))
441 return -EOPNOTSUPP;
442 if (!is_owner_or_cap(inode))
443 return -EPERM;
444
445 if (value) {
446 acl = posix_acl_from_xattr(value, size);
447 if (IS_ERR(acl))
448 return PTR_ERR(acl);
449 else if (acl) {
450 error = posix_acl_valid(acl);
451 if (error)
452 goto release_and_out;
453 }
454 } else
455 acl = NULL;
456
457retry:
458 handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
459 if (IS_ERR(handle))
460 return PTR_ERR(handle);
461 error = ext3_set_acl(handle, inode, type, acl);
462 ext3_journal_stop(handle);
463 if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
464 goto retry;
465
466release_and_out:
467 posix_acl_release(acl);
468 return error;
469}
470
471static int
472ext3_xattr_set_acl_access(struct inode *inode, const char *name,
473 const void *value, size_t size, int flags)
474{
475 if (strcmp(name, "") != 0)
476 return -EINVAL;
477 return ext3_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
478}
479
480static int
481ext3_xattr_set_acl_default(struct inode *inode, const char *name,
482 const void *value, size_t size, int flags)
483{
484 if (strcmp(name, "") != 0)
485 return -EINVAL;
486 return ext3_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
487}
488
489struct xattr_handler ext3_xattr_acl_access_handler = {
490 .prefix = POSIX_ACL_XATTR_ACCESS,
491 .list = ext3_xattr_list_acl_access,
492 .get = ext3_xattr_get_acl_access,
493 .set = ext3_xattr_set_acl_access,
494};
495
496struct xattr_handler ext3_xattr_acl_default_handler = {
497 .prefix = POSIX_ACL_XATTR_DEFAULT,
498 .list = ext3_xattr_list_acl_default,
499 .get = ext3_xattr_get_acl_default,
500 .set = ext3_xattr_set_acl_default,
501};
502
