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 | ||
1da177e4 LT |
129 | /* |
130 | * Inode operation get_posix_acl(). | |
131 | * | |
1b1dcc1b | 132 | * inode->i_mutex: don't care |
1da177e4 LT |
133 | */ |
134 | static struct posix_acl * | |
135 | ext3_get_acl(struct inode *inode, int type) | |
136 | { | |
1da177e4 LT |
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 | ||
073aaa1b AV |
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(); | |
1da177e4 | 158 | } |
073aaa1b | 159 | |
1da177e4 LT |
160 | retval = ext3_xattr_get(inode, name_index, "", NULL, 0); |
161 | if (retval > 0) { | |
c587f0c0 | 162 | value = kmalloc(retval, GFP_NOFS); |
1da177e4 LT |
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 | ||
073aaa1b AV |
175 | if (!IS_ERR(acl)) |
176 | set_cached_acl(inode, type, acl); | |
1da177e4 | 177 | |
1da177e4 LT |
178 | return acl; |
179 | } | |
180 | ||
181 | /* | |
182 | * Set the access or default ACL of an inode. | |
183 | * | |
1b1dcc1b | 184 | * inode->i_mutex: down unless called from ext3_new_inode |
1da177e4 LT |
185 | */ |
186 | static int | |
187 | ext3_set_acl(handle_t *handle, struct inode *inode, int type, | |
188 | struct posix_acl *acl) | |
189 | { | |
1da177e4 LT |
190 | int name_index; |
191 | void *value = NULL; | |
dfa08592 | 192 | size_t size = 0; |
1da177e4 LT |
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; | |
30e2bab2 | 208 | inode->i_ctime = CURRENT_TIME_SEC; |
1da177e4 LT |
209 | ext3_mark_inode_dirty(handle, inode); |
210 | if (error == 0) | |
211 | acl = NULL; | |
212 | } | |
213 | } | |
214 | break; | |
215 | ||
216 | case ACL_TYPE_DEFAULT: | |
217 | name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT; | |
218 | if (!S_ISDIR(inode->i_mode)) | |
219 | return acl ? -EACCES : 0; | |
220 | break; | |
221 | ||
222 | default: | |
223 | return -EINVAL; | |
224 | } | |
e9ad5620 | 225 | if (acl) { |
1da177e4 LT |
226 | value = ext3_acl_to_disk(acl, &size); |
227 | if (IS_ERR(value)) | |
228 | return (int)PTR_ERR(value); | |
229 | } | |
230 | ||
231 | error = ext3_xattr_set_handle(handle, inode, name_index, "", | |
232 | value, size, 0); | |
233 | ||
234 | kfree(value); | |
1da177e4 | 235 | |
073aaa1b AV |
236 | if (!error) |
237 | set_cached_acl(inode, type, acl); | |
238 | ||
1da177e4 LT |
239 | return error; |
240 | } | |
241 | ||
1d5ccd1c | 242 | int |
b74c79e9 | 243 | ext3_check_acl(struct inode *inode, int mask, unsigned int flags) |
1da177e4 | 244 | { |
b74c79e9 NP |
245 | struct posix_acl *acl; |
246 | ||
247 | if (flags & IPERM_FLAG_RCU) | |
248 | return -ECHILD; | |
1da177e4 | 249 | |
b74c79e9 | 250 | acl = ext3_get_acl(inode, ACL_TYPE_ACCESS); |
e493073d | 251 | if (IS_ERR(acl)) |
252 | return PTR_ERR(acl); | |
1da177e4 LT |
253 | if (acl) { |
254 | int error = posix_acl_permission(inode, acl, mask); | |
255 | posix_acl_release(acl); | |
256 | return error; | |
257 | } | |
258 | ||
259 | return -EAGAIN; | |
260 | } | |
261 | ||
1da177e4 LT |
262 | /* |
263 | * Initialize the ACLs of a new inode. Called from ext3_new_inode. | |
264 | * | |
1b1dcc1b JS |
265 | * dir->i_mutex: down |
266 | * inode->i_mutex: up (access to inode is still exclusive) | |
1da177e4 LT |
267 | */ |
268 | int | |
269 | ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir) | |
270 | { | |
271 | struct posix_acl *acl = NULL; | |
272 | int error = 0; | |
273 | ||
274 | if (!S_ISLNK(inode->i_mode)) { | |
275 | if (test_opt(dir->i_sb, POSIX_ACL)) { | |
276 | acl = ext3_get_acl(dir, ACL_TYPE_DEFAULT); | |
277 | if (IS_ERR(acl)) | |
278 | return PTR_ERR(acl); | |
279 | } | |
280 | if (!acl) | |
ce3b0f8d | 281 | inode->i_mode &= ~current_umask(); |
1da177e4 LT |
282 | } |
283 | if (test_opt(inode->i_sb, POSIX_ACL) && acl) { | |
284 | struct posix_acl *clone; | |
285 | mode_t mode; | |
286 | ||
287 | if (S_ISDIR(inode->i_mode)) { | |
288 | error = ext3_set_acl(handle, inode, | |
289 | ACL_TYPE_DEFAULT, acl); | |
290 | if (error) | |
291 | goto cleanup; | |
292 | } | |
c587f0c0 | 293 | clone = posix_acl_clone(acl, GFP_NOFS); |
1da177e4 LT |
294 | error = -ENOMEM; |
295 | if (!clone) | |
296 | goto cleanup; | |
297 | ||
298 | mode = inode->i_mode; | |
299 | error = posix_acl_create_masq(clone, &mode); | |
300 | if (error >= 0) { | |
301 | inode->i_mode = mode; | |
302 | if (error > 0) { | |
303 | /* This is an extended ACL */ | |
304 | error = ext3_set_acl(handle, inode, | |
305 | ACL_TYPE_ACCESS, clone); | |
306 | } | |
307 | } | |
308 | posix_acl_release(clone); | |
309 | } | |
310 | cleanup: | |
311 | posix_acl_release(acl); | |
312 | return error; | |
313 | } | |
314 | ||
315 | /* | |
316 | * Does chmod for an inode that may have an Access Control List. The | |
317 | * inode->i_mode field must be updated to the desired value by the caller | |
318 | * before calling this function. | |
319 | * Returns 0 on success, or a negative error number. | |
320 | * | |
321 | * We change the ACL rather than storing some ACL entries in the file | |
322 | * mode permission bits (which would be more efficient), because that | |
323 | * would break once additional permissions (like ACL_APPEND, ACL_DELETE | |
324 | * for directories) are added. There are no more bits available in the | |
325 | * file mode. | |
326 | * | |
1b1dcc1b | 327 | * inode->i_mutex: down |
1da177e4 LT |
328 | */ |
329 | int | |
330 | ext3_acl_chmod(struct inode *inode) | |
331 | { | |
332 | struct posix_acl *acl, *clone; | |
333 | int error; | |
334 | ||
335 | if (S_ISLNK(inode->i_mode)) | |
336 | return -EOPNOTSUPP; | |
337 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
338 | return 0; | |
339 | acl = ext3_get_acl(inode, ACL_TYPE_ACCESS); | |
340 | if (IS_ERR(acl) || !acl) | |
341 | return PTR_ERR(acl); | |
342 | clone = posix_acl_clone(acl, GFP_KERNEL); | |
343 | posix_acl_release(acl); | |
344 | if (!clone) | |
345 | return -ENOMEM; | |
346 | error = posix_acl_chmod_masq(clone, inode->i_mode); | |
347 | if (!error) { | |
348 | handle_t *handle; | |
349 | int retries = 0; | |
350 | ||
351 | retry: | |
1f54587b JK |
352 | handle = ext3_journal_start(inode, |
353 | EXT3_DATA_TRANS_BLOCKS(inode->i_sb)); | |
1da177e4 LT |
354 | if (IS_ERR(handle)) { |
355 | error = PTR_ERR(handle); | |
356 | ext3_std_error(inode->i_sb, error); | |
357 | goto out; | |
358 | } | |
359 | error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, clone); | |
360 | ext3_journal_stop(handle); | |
361 | if (error == -ENOSPC && | |
362 | ext3_should_retry_alloc(inode->i_sb, &retries)) | |
363 | goto retry; | |
364 | } | |
365 | out: | |
366 | posix_acl_release(clone); | |
367 | return error; | |
368 | } | |
369 | ||
370 | /* | |
371 | * Extended attribute handlers | |
372 | */ | |
373 | static size_t | |
431547b3 CH |
374 | ext3_xattr_list_acl_access(struct dentry *dentry, char *list, size_t list_len, |
375 | const char *name, size_t name_len, int type) | |
1da177e4 | 376 | { |
9a59f452 | 377 | const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS); |
1da177e4 | 378 | |
431547b3 | 379 | if (!test_opt(dentry->d_sb, POSIX_ACL)) |
1da177e4 LT |
380 | return 0; |
381 | if (list && size <= list_len) | |
9a59f452 | 382 | memcpy(list, POSIX_ACL_XATTR_ACCESS, size); |
1da177e4 LT |
383 | return size; |
384 | } | |
385 | ||
386 | static size_t | |
431547b3 CH |
387 | ext3_xattr_list_acl_default(struct dentry *dentry, char *list, size_t list_len, |
388 | const char *name, size_t name_len, int type) | |
1da177e4 | 389 | { |
9a59f452 | 390 | const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT); |
1da177e4 | 391 | |
431547b3 | 392 | if (!test_opt(dentry->d_sb, POSIX_ACL)) |
1da177e4 LT |
393 | return 0; |
394 | if (list && size <= list_len) | |
9a59f452 | 395 | memcpy(list, POSIX_ACL_XATTR_DEFAULT, size); |
1da177e4 LT |
396 | return size; |
397 | } | |
398 | ||
399 | static int | |
431547b3 CH |
400 | ext3_xattr_get_acl(struct dentry *dentry, const char *name, void *buffer, |
401 | size_t size, int type) | |
1da177e4 LT |
402 | { |
403 | struct posix_acl *acl; | |
404 | int error; | |
405 | ||
431547b3 CH |
406 | if (strcmp(name, "") != 0) |
407 | return -EINVAL; | |
408 | if (!test_opt(dentry->d_sb, POSIX_ACL)) | |
1da177e4 LT |
409 | return -EOPNOTSUPP; |
410 | ||
431547b3 | 411 | acl = ext3_get_acl(dentry->d_inode, type); |
1da177e4 LT |
412 | if (IS_ERR(acl)) |
413 | return PTR_ERR(acl); | |
414 | if (acl == NULL) | |
415 | return -ENODATA; | |
416 | error = posix_acl_to_xattr(acl, buffer, size); | |
417 | posix_acl_release(acl); | |
418 | ||
419 | return error; | |
420 | } | |
421 | ||
422 | static int | |
431547b3 CH |
423 | ext3_xattr_set_acl(struct dentry *dentry, const char *name, const void *value, |
424 | size_t size, int flags, int type) | |
1da177e4 | 425 | { |
431547b3 | 426 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
427 | handle_t *handle; |
428 | struct posix_acl *acl; | |
429 | int error, retries = 0; | |
430 | ||
431547b3 CH |
431 | if (strcmp(name, "") != 0) |
432 | return -EINVAL; | |
1da177e4 LT |
433 | if (!test_opt(inode->i_sb, POSIX_ACL)) |
434 | return -EOPNOTSUPP; | |
3bd858ab | 435 | if (!is_owner_or_cap(inode)) |
1da177e4 LT |
436 | return -EPERM; |
437 | ||
438 | if (value) { | |
439 | acl = posix_acl_from_xattr(value, size); | |
440 | if (IS_ERR(acl)) | |
441 | return PTR_ERR(acl); | |
442 | else if (acl) { | |
443 | error = posix_acl_valid(acl); | |
444 | if (error) | |
445 | goto release_and_out; | |
446 | } | |
447 | } else | |
448 | acl = NULL; | |
449 | ||
450 | retry: | |
1f54587b | 451 | handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb)); |
1da177e4 LT |
452 | if (IS_ERR(handle)) |
453 | return PTR_ERR(handle); | |
454 | error = ext3_set_acl(handle, inode, type, acl); | |
455 | ext3_journal_stop(handle); | |
456 | if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries)) | |
457 | goto retry; | |
458 | ||
459 | release_and_out: | |
460 | posix_acl_release(acl); | |
461 | return error; | |
462 | } | |
463 | ||
d1f21049 | 464 | const struct xattr_handler ext3_xattr_acl_access_handler = { |
9a59f452 | 465 | .prefix = POSIX_ACL_XATTR_ACCESS, |
431547b3 | 466 | .flags = ACL_TYPE_ACCESS, |
1da177e4 | 467 | .list = ext3_xattr_list_acl_access, |
431547b3 CH |
468 | .get = ext3_xattr_get_acl, |
469 | .set = ext3_xattr_set_acl, | |
1da177e4 LT |
470 | }; |
471 | ||
d1f21049 | 472 | const struct xattr_handler ext3_xattr_acl_default_handler = { |
9a59f452 | 473 | .prefix = POSIX_ACL_XATTR_DEFAULT, |
431547b3 | 474 | .flags = ACL_TYPE_DEFAULT, |
1da177e4 | 475 | .list = ext3_xattr_list_acl_default, |
431547b3 CH |
476 | .get = ext3_xattr_get_acl, |
477 | .set = ext3_xattr_set_acl, | |
1da177e4 | 478 | }; |