Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/ext3/acl.c | |
3 | * | |
4 | * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> | |
5 | */ | |
6 | ||
7 | #include <linux/init.h> | |
8 | #include <linux/sched.h> | |
9 | #include <linux/slab.h> | |
16f7e0fe | 10 | #include <linux/capability.h> |
1da177e4 LT |
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 | * Convert from filesystem to in-memory representation. | |
19 | */ | |
20 | static struct posix_acl * | |
21 | ext3_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; | |
c587f0c0 | 40 | acl = posix_acl_alloc(count, GFP_NOFS); |
1da177e4 LT |
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 | ||
77 | fail: | |
78 | posix_acl_release(acl); | |
79 | return ERR_PTR(-EINVAL); | |
80 | } | |
81 | ||
82 | /* | |
83 | * Convert from in-memory to filesystem representation. | |
84 | */ | |
85 | static void * | |
86 | ext3_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); | |
f52720ca | 93 | ext_acl = kmalloc(sizeof(ext3_acl_header) + acl->a_count * |
c587f0c0 | 94 | sizeof(ext3_acl_entry), GFP_NOFS); |
1da177e4 LT |
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 | ||
124 | fail: | |
125 | kfree(ext_acl); | |
126 | return ERR_PTR(-EINVAL); | |
127 | } | |
128 | ||
129 | static inline struct posix_acl * | |
130 | ext3_iget_acl(struct inode *inode, struct posix_acl **i_acl) | |
131 | { | |
9c64daff | 132 | struct posix_acl *acl = ACCESS_ONCE(*i_acl); |
1da177e4 | 133 | |
9c64daff LT |
134 | if (acl) { |
135 | spin_lock(&inode->i_lock); | |
136 | acl = *i_acl; | |
6582a0e6 | 137 | if (acl != ACL_NOT_CACHED) |
9c64daff LT |
138 | acl = posix_acl_dup(acl); |
139 | spin_unlock(&inode->i_lock); | |
140 | } | |
1da177e4 LT |
141 | |
142 | return acl; | |
143 | } | |
144 | ||
145 | static inline void | |
146 | ext3_iset_acl(struct inode *inode, struct posix_acl **i_acl, | |
147 | struct posix_acl *acl) | |
148 | { | |
149 | spin_lock(&inode->i_lock); | |
6582a0e6 | 150 | if (*i_acl != ACL_NOT_CACHED) |
1da177e4 LT |
151 | posix_acl_release(*i_acl); |
152 | *i_acl = posix_acl_dup(acl); | |
153 | spin_unlock(&inode->i_lock); | |
154 | } | |
155 | ||
156 | /* | |
157 | * Inode operation get_posix_acl(). | |
158 | * | |
1b1dcc1b | 159 | * inode->i_mutex: don't care |
1da177e4 LT |
160 | */ |
161 | static struct posix_acl * | |
162 | ext3_get_acl(struct inode *inode, int type) | |
163 | { | |
1da177e4 LT |
164 | int name_index; |
165 | char *value = NULL; | |
166 | struct posix_acl *acl; | |
167 | int retval; | |
168 | ||
169 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
170 | return NULL; | |
171 | ||
172 | switch(type) { | |
173 | case ACL_TYPE_ACCESS: | |
6582a0e6 AV |
174 | acl = ext3_iget_acl(inode, &inode->i_acl); |
175 | if (acl != ACL_NOT_CACHED) | |
1da177e4 LT |
176 | return acl; |
177 | name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS; | |
178 | break; | |
179 | ||
180 | case ACL_TYPE_DEFAULT: | |
6582a0e6 AV |
181 | acl = ext3_iget_acl(inode, &inode->i_default_acl); |
182 | if (acl != ACL_NOT_CACHED) | |
1da177e4 LT |
183 | return acl; |
184 | name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT; | |
185 | break; | |
186 | ||
187 | default: | |
188 | return ERR_PTR(-EINVAL); | |
189 | } | |
190 | retval = ext3_xattr_get(inode, name_index, "", NULL, 0); | |
191 | if (retval > 0) { | |
c587f0c0 | 192 | value = kmalloc(retval, GFP_NOFS); |
1da177e4 LT |
193 | if (!value) |
194 | return ERR_PTR(-ENOMEM); | |
195 | retval = ext3_xattr_get(inode, name_index, "", value, retval); | |
196 | } | |
197 | if (retval > 0) | |
198 | acl = ext3_acl_from_disk(value, retval); | |
199 | else if (retval == -ENODATA || retval == -ENOSYS) | |
200 | acl = NULL; | |
201 | else | |
202 | acl = ERR_PTR(retval); | |
203 | kfree(value); | |
204 | ||
205 | if (!IS_ERR(acl)) { | |
206 | switch(type) { | |
207 | case ACL_TYPE_ACCESS: | |
6582a0e6 | 208 | ext3_iset_acl(inode, &inode->i_acl, acl); |
1da177e4 LT |
209 | break; |
210 | ||
211 | case ACL_TYPE_DEFAULT: | |
6582a0e6 | 212 | ext3_iset_acl(inode, &inode->i_default_acl, acl); |
1da177e4 LT |
213 | break; |
214 | } | |
215 | } | |
216 | return acl; | |
217 | } | |
218 | ||
219 | /* | |
220 | * Set the access or default ACL of an inode. | |
221 | * | |
1b1dcc1b | 222 | * inode->i_mutex: down unless called from ext3_new_inode |
1da177e4 LT |
223 | */ |
224 | static int | |
225 | ext3_set_acl(handle_t *handle, struct inode *inode, int type, | |
226 | struct posix_acl *acl) | |
227 | { | |
1da177e4 LT |
228 | int name_index; |
229 | void *value = NULL; | |
dfa08592 | 230 | size_t size = 0; |
1da177e4 LT |
231 | int error; |
232 | ||
233 | if (S_ISLNK(inode->i_mode)) | |
234 | return -EOPNOTSUPP; | |
235 | ||
236 | switch(type) { | |
237 | case ACL_TYPE_ACCESS: | |
238 | name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS; | |
239 | if (acl) { | |
240 | mode_t mode = inode->i_mode; | |
241 | error = posix_acl_equiv_mode(acl, &mode); | |
242 | if (error < 0) | |
243 | return error; | |
244 | else { | |
245 | inode->i_mode = mode; | |
246 | ext3_mark_inode_dirty(handle, inode); | |
247 | if (error == 0) | |
248 | acl = NULL; | |
249 | } | |
250 | } | |
251 | break; | |
252 | ||
253 | case ACL_TYPE_DEFAULT: | |
254 | name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT; | |
255 | if (!S_ISDIR(inode->i_mode)) | |
256 | return acl ? -EACCES : 0; | |
257 | break; | |
258 | ||
259 | default: | |
260 | return -EINVAL; | |
261 | } | |
e9ad5620 | 262 | if (acl) { |
1da177e4 LT |
263 | value = ext3_acl_to_disk(acl, &size); |
264 | if (IS_ERR(value)) | |
265 | return (int)PTR_ERR(value); | |
266 | } | |
267 | ||
268 | error = ext3_xattr_set_handle(handle, inode, name_index, "", | |
269 | value, size, 0); | |
270 | ||
271 | kfree(value); | |
272 | if (!error) { | |
273 | switch(type) { | |
274 | case ACL_TYPE_ACCESS: | |
6582a0e6 | 275 | ext3_iset_acl(inode, &inode->i_acl, acl); |
1da177e4 LT |
276 | break; |
277 | ||
278 | case ACL_TYPE_DEFAULT: | |
6582a0e6 | 279 | ext3_iset_acl(inode, &inode->i_default_acl, acl); |
1da177e4 LT |
280 | break; |
281 | } | |
282 | } | |
283 | return error; | |
284 | } | |
285 | ||
286 | static int | |
287 | ext3_check_acl(struct inode *inode, int mask) | |
288 | { | |
289 | struct posix_acl *acl = ext3_get_acl(inode, ACL_TYPE_ACCESS); | |
290 | ||
e493073d | 291 | if (IS_ERR(acl)) |
292 | return PTR_ERR(acl); | |
1da177e4 LT |
293 | if (acl) { |
294 | int error = posix_acl_permission(inode, acl, mask); | |
295 | posix_acl_release(acl); | |
296 | return error; | |
297 | } | |
298 | ||
299 | return -EAGAIN; | |
300 | } | |
301 | ||
302 | int | |
e6305c43 | 303 | ext3_permission(struct inode *inode, int mask) |
1da177e4 LT |
304 | { |
305 | return generic_permission(inode, mask, ext3_check_acl); | |
306 | } | |
307 | ||
308 | /* | |
309 | * Initialize the ACLs of a new inode. Called from ext3_new_inode. | |
310 | * | |
1b1dcc1b JS |
311 | * dir->i_mutex: down |
312 | * inode->i_mutex: up (access to inode is still exclusive) | |
1da177e4 LT |
313 | */ |
314 | int | |
315 | ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir) | |
316 | { | |
317 | struct posix_acl *acl = NULL; | |
318 | int error = 0; | |
319 | ||
320 | if (!S_ISLNK(inode->i_mode)) { | |
321 | if (test_opt(dir->i_sb, POSIX_ACL)) { | |
322 | acl = ext3_get_acl(dir, ACL_TYPE_DEFAULT); | |
323 | if (IS_ERR(acl)) | |
324 | return PTR_ERR(acl); | |
325 | } | |
326 | if (!acl) | |
ce3b0f8d | 327 | inode->i_mode &= ~current_umask(); |
1da177e4 LT |
328 | } |
329 | if (test_opt(inode->i_sb, POSIX_ACL) && acl) { | |
330 | struct posix_acl *clone; | |
331 | mode_t mode; | |
332 | ||
333 | if (S_ISDIR(inode->i_mode)) { | |
334 | error = ext3_set_acl(handle, inode, | |
335 | ACL_TYPE_DEFAULT, acl); | |
336 | if (error) | |
337 | goto cleanup; | |
338 | } | |
c587f0c0 | 339 | clone = posix_acl_clone(acl, GFP_NOFS); |
1da177e4 LT |
340 | error = -ENOMEM; |
341 | if (!clone) | |
342 | goto cleanup; | |
343 | ||
344 | mode = inode->i_mode; | |
345 | error = posix_acl_create_masq(clone, &mode); | |
346 | if (error >= 0) { | |
347 | inode->i_mode = mode; | |
348 | if (error > 0) { | |
349 | /* This is an extended ACL */ | |
350 | error = ext3_set_acl(handle, inode, | |
351 | ACL_TYPE_ACCESS, clone); | |
352 | } | |
353 | } | |
354 | posix_acl_release(clone); | |
355 | } | |
356 | cleanup: | |
357 | posix_acl_release(acl); | |
358 | return error; | |
359 | } | |
360 | ||
361 | /* | |
362 | * Does chmod for an inode that may have an Access Control List. The | |
363 | * inode->i_mode field must be updated to the desired value by the caller | |
364 | * before calling this function. | |
365 | * Returns 0 on success, or a negative error number. | |
366 | * | |
367 | * We change the ACL rather than storing some ACL entries in the file | |
368 | * mode permission bits (which would be more efficient), because that | |
369 | * would break once additional permissions (like ACL_APPEND, ACL_DELETE | |
370 | * for directories) are added. There are no more bits available in the | |
371 | * file mode. | |
372 | * | |
1b1dcc1b | 373 | * inode->i_mutex: down |
1da177e4 LT |
374 | */ |
375 | int | |
376 | ext3_acl_chmod(struct inode *inode) | |
377 | { | |
378 | struct posix_acl *acl, *clone; | |
379 | int error; | |
380 | ||
381 | if (S_ISLNK(inode->i_mode)) | |
382 | return -EOPNOTSUPP; | |
383 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
384 | return 0; | |
385 | acl = ext3_get_acl(inode, ACL_TYPE_ACCESS); | |
386 | if (IS_ERR(acl) || !acl) | |
387 | return PTR_ERR(acl); | |
388 | clone = posix_acl_clone(acl, GFP_KERNEL); | |
389 | posix_acl_release(acl); | |
390 | if (!clone) | |
391 | return -ENOMEM; | |
392 | error = posix_acl_chmod_masq(clone, inode->i_mode); | |
393 | if (!error) { | |
394 | handle_t *handle; | |
395 | int retries = 0; | |
396 | ||
397 | retry: | |
1f54587b JK |
398 | handle = ext3_journal_start(inode, |
399 | EXT3_DATA_TRANS_BLOCKS(inode->i_sb)); | |
1da177e4 LT |
400 | if (IS_ERR(handle)) { |
401 | error = PTR_ERR(handle); | |
402 | ext3_std_error(inode->i_sb, error); | |
403 | goto out; | |
404 | } | |
405 | error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, clone); | |
406 | ext3_journal_stop(handle); | |
407 | if (error == -ENOSPC && | |
408 | ext3_should_retry_alloc(inode->i_sb, &retries)) | |
409 | goto retry; | |
410 | } | |
411 | out: | |
412 | posix_acl_release(clone); | |
413 | return error; | |
414 | } | |
415 | ||
416 | /* | |
417 | * Extended attribute handlers | |
418 | */ | |
419 | static size_t | |
420 | ext3_xattr_list_acl_access(struct inode *inode, char *list, size_t list_len, | |
421 | const char *name, size_t name_len) | |
422 | { | |
9a59f452 | 423 | const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS); |
1da177e4 LT |
424 | |
425 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
426 | return 0; | |
427 | if (list && size <= list_len) | |
9a59f452 | 428 | memcpy(list, POSIX_ACL_XATTR_ACCESS, size); |
1da177e4 LT |
429 | return size; |
430 | } | |
431 | ||
432 | static size_t | |
433 | ext3_xattr_list_acl_default(struct inode *inode, char *list, size_t list_len, | |
434 | const char *name, size_t name_len) | |
435 | { | |
9a59f452 | 436 | const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT); |
1da177e4 LT |
437 | |
438 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
439 | return 0; | |
440 | if (list && size <= list_len) | |
9a59f452 | 441 | memcpy(list, POSIX_ACL_XATTR_DEFAULT, size); |
1da177e4 LT |
442 | return size; |
443 | } | |
444 | ||
445 | static int | |
446 | ext3_xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size) | |
447 | { | |
448 | struct posix_acl *acl; | |
449 | int error; | |
450 | ||
451 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
452 | return -EOPNOTSUPP; | |
453 | ||
454 | acl = ext3_get_acl(inode, type); | |
455 | if (IS_ERR(acl)) | |
456 | return PTR_ERR(acl); | |
457 | if (acl == NULL) | |
458 | return -ENODATA; | |
459 | error = posix_acl_to_xattr(acl, buffer, size); | |
460 | posix_acl_release(acl); | |
461 | ||
462 | return error; | |
463 | } | |
464 | ||
465 | static int | |
466 | ext3_xattr_get_acl_access(struct inode *inode, const char *name, | |
467 | void *buffer, size_t size) | |
468 | { | |
469 | if (strcmp(name, "") != 0) | |
470 | return -EINVAL; | |
471 | return ext3_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size); | |
472 | } | |
473 | ||
474 | static int | |
475 | ext3_xattr_get_acl_default(struct inode *inode, const char *name, | |
476 | void *buffer, size_t size) | |
477 | { | |
478 | if (strcmp(name, "") != 0) | |
479 | return -EINVAL; | |
480 | return ext3_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size); | |
481 | } | |
482 | ||
483 | static int | |
484 | ext3_xattr_set_acl(struct inode *inode, int type, const void *value, | |
485 | size_t size) | |
486 | { | |
487 | handle_t *handle; | |
488 | struct posix_acl *acl; | |
489 | int error, retries = 0; | |
490 | ||
491 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
492 | return -EOPNOTSUPP; | |
3bd858ab | 493 | if (!is_owner_or_cap(inode)) |
1da177e4 LT |
494 | return -EPERM; |
495 | ||
496 | if (value) { | |
497 | acl = posix_acl_from_xattr(value, size); | |
498 | if (IS_ERR(acl)) | |
499 | return PTR_ERR(acl); | |
500 | else if (acl) { | |
501 | error = posix_acl_valid(acl); | |
502 | if (error) | |
503 | goto release_and_out; | |
504 | } | |
505 | } else | |
506 | acl = NULL; | |
507 | ||
508 | retry: | |
1f54587b | 509 | handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb)); |
1da177e4 LT |
510 | if (IS_ERR(handle)) |
511 | return PTR_ERR(handle); | |
512 | error = ext3_set_acl(handle, inode, type, acl); | |
513 | ext3_journal_stop(handle); | |
514 | if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries)) | |
515 | goto retry; | |
516 | ||
517 | release_and_out: | |
518 | posix_acl_release(acl); | |
519 | return error; | |
520 | } | |
521 | ||
522 | static int | |
523 | ext3_xattr_set_acl_access(struct inode *inode, const char *name, | |
524 | const void *value, size_t size, int flags) | |
525 | { | |
526 | if (strcmp(name, "") != 0) | |
527 | return -EINVAL; | |
528 | return ext3_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size); | |
529 | } | |
530 | ||
531 | static int | |
532 | ext3_xattr_set_acl_default(struct inode *inode, const char *name, | |
533 | const void *value, size_t size, int flags) | |
534 | { | |
535 | if (strcmp(name, "") != 0) | |
536 | return -EINVAL; | |
537 | return ext3_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size); | |
538 | } | |
539 | ||
540 | struct xattr_handler ext3_xattr_acl_access_handler = { | |
9a59f452 | 541 | .prefix = POSIX_ACL_XATTR_ACCESS, |
1da177e4 LT |
542 | .list = ext3_xattr_list_acl_access, |
543 | .get = ext3_xattr_get_acl_access, | |
544 | .set = ext3_xattr_set_acl_access, | |
545 | }; | |
546 | ||
547 | struct xattr_handler ext3_xattr_acl_default_handler = { | |
9a59f452 | 548 | .prefix = POSIX_ACL_XATTR_DEFAULT, |
1da177e4 LT |
549 | .list = ext3_xattr_list_acl_default, |
550 | .get = ext3_xattr_get_acl_default, | |
551 | .set = ext3_xattr_set_acl_default, | |
552 | }; |