Commit | Line | Data |
---|---|---|
ac27a0ec | 1 | /* |
617ba13b | 2 | * linux/fs/ext4/acl.c |
ac27a0ec DK |
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> | |
10 | #include <linux/capability.h> | |
11 | #include <linux/fs.h> | |
3dcf5451 CH |
12 | #include "ext4_jbd2.h" |
13 | #include "ext4.h" | |
ac27a0ec DK |
14 | #include "xattr.h" |
15 | #include "acl.h" | |
16 | ||
17 | /* | |
18 | * Convert from filesystem to in-memory representation. | |
19 | */ | |
20 | static struct posix_acl * | |
617ba13b | 21 | ext4_acl_from_disk(const void *value, size_t size) |
ac27a0ec DK |
22 | { |
23 | const char *end = (char *)value + size; | |
24 | int n, count; | |
25 | struct posix_acl *acl; | |
26 | ||
27 | if (!value) | |
28 | return NULL; | |
617ba13b | 29 | if (size < sizeof(ext4_acl_header)) |
ac27a0ec | 30 | return ERR_PTR(-EINVAL); |
617ba13b MC |
31 | if (((ext4_acl_header *)value)->a_version != |
32 | cpu_to_le32(EXT4_ACL_VERSION)) | |
ac27a0ec | 33 | return ERR_PTR(-EINVAL); |
617ba13b MC |
34 | value = (char *)value + sizeof(ext4_acl_header); |
35 | count = ext4_acl_count(size); | |
ac27a0ec DK |
36 | if (count < 0) |
37 | return ERR_PTR(-EINVAL); | |
38 | if (count == 0) | |
39 | return NULL; | |
216553c4 | 40 | acl = posix_acl_alloc(count, GFP_NOFS); |
ac27a0ec DK |
41 | if (!acl) |
42 | return ERR_PTR(-ENOMEM); | |
2b2d6d01 | 43 | for (n = 0; n < count; n++) { |
617ba13b MC |
44 | ext4_acl_entry *entry = |
45 | (ext4_acl_entry *)value; | |
46 | if ((char *)value + sizeof(ext4_acl_entry_short) > end) | |
ac27a0ec DK |
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); | |
2b2d6d01 TT |
50 | |
51 | switch (acl->a_entries[n].e_tag) { | |
52 | case ACL_USER_OBJ: | |
53 | case ACL_GROUP_OBJ: | |
54 | case ACL_MASK: | |
55 | case ACL_OTHER: | |
56 | value = (char *)value + | |
57 | sizeof(ext4_acl_entry_short); | |
58 | acl->a_entries[n].e_id = ACL_UNDEFINED_ID; | |
59 | break; | |
60 | ||
61 | case ACL_USER: | |
62 | case ACL_GROUP: | |
63 | value = (char *)value + sizeof(ext4_acl_entry); | |
64 | if ((char *)value > end) | |
ac27a0ec | 65 | goto fail; |
2b2d6d01 TT |
66 | acl->a_entries[n].e_id = |
67 | le32_to_cpu(entry->e_id); | |
68 | break; | |
69 | ||
70 | default: | |
71 | goto fail; | |
ac27a0ec DK |
72 | } |
73 | } | |
74 | if (value != end) | |
75 | goto fail; | |
76 | return acl; | |
77 | ||
78 | fail: | |
79 | posix_acl_release(acl); | |
80 | return ERR_PTR(-EINVAL); | |
81 | } | |
82 | ||
83 | /* | |
84 | * Convert from in-memory to filesystem representation. | |
85 | */ | |
86 | static void * | |
617ba13b | 87 | ext4_acl_to_disk(const struct posix_acl *acl, size_t *size) |
ac27a0ec | 88 | { |
617ba13b | 89 | ext4_acl_header *ext_acl; |
ac27a0ec DK |
90 | char *e; |
91 | size_t n; | |
92 | ||
617ba13b MC |
93 | *size = ext4_acl_size(acl->a_count); |
94 | ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count * | |
216553c4 | 95 | sizeof(ext4_acl_entry), GFP_NOFS); |
ac27a0ec DK |
96 | if (!ext_acl) |
97 | return ERR_PTR(-ENOMEM); | |
617ba13b MC |
98 | ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION); |
99 | e = (char *)ext_acl + sizeof(ext4_acl_header); | |
2b2d6d01 | 100 | for (n = 0; n < acl->a_count; n++) { |
617ba13b | 101 | ext4_acl_entry *entry = (ext4_acl_entry *)e; |
ac27a0ec DK |
102 | entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); |
103 | entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); | |
2b2d6d01 TT |
104 | switch (acl->a_entries[n].e_tag) { |
105 | case ACL_USER: | |
106 | case ACL_GROUP: | |
107 | entry->e_id = cpu_to_le32(acl->a_entries[n].e_id); | |
108 | e += sizeof(ext4_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(ext4_acl_entry_short); | |
116 | break; | |
117 | ||
118 | default: | |
119 | goto fail; | |
ac27a0ec DK |
120 | } |
121 | } | |
122 | return (char *)ext_acl; | |
123 | ||
124 | fail: | |
125 | kfree(ext_acl); | |
126 | return ERR_PTR(-EINVAL); | |
127 | } | |
128 | ||
ac27a0ec DK |
129 | /* |
130 | * Inode operation get_posix_acl(). | |
131 | * | |
132 | * inode->i_mutex: don't care | |
133 | */ | |
134 | static struct posix_acl * | |
617ba13b | 135 | ext4_get_acl(struct inode *inode, int type) |
ac27a0ec | 136 | { |
ac27a0ec DK |
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 | ||
2b2d6d01 TT |
149 | switch (type) { |
150 | case ACL_TYPE_ACCESS: | |
2b2d6d01 TT |
151 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS; |
152 | break; | |
2b2d6d01 | 153 | case ACL_TYPE_DEFAULT: |
2b2d6d01 TT |
154 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT; |
155 | break; | |
2b2d6d01 | 156 | default: |
073aaa1b | 157 | BUG(); |
ac27a0ec | 158 | } |
617ba13b | 159 | retval = ext4_xattr_get(inode, name_index, "", NULL, 0); |
ac27a0ec | 160 | if (retval > 0) { |
216553c4 | 161 | value = kmalloc(retval, GFP_NOFS); |
ac27a0ec DK |
162 | if (!value) |
163 | return ERR_PTR(-ENOMEM); | |
617ba13b | 164 | retval = ext4_xattr_get(inode, name_index, "", value, retval); |
ac27a0ec DK |
165 | } |
166 | if (retval > 0) | |
617ba13b | 167 | acl = ext4_acl_from_disk(value, retval); |
ac27a0ec DK |
168 | else if (retval == -ENODATA || retval == -ENOSYS) |
169 | acl = NULL; | |
170 | else | |
171 | acl = ERR_PTR(retval); | |
172 | kfree(value); | |
173 | ||
073aaa1b AV |
174 | if (!IS_ERR(acl)) |
175 | set_cached_acl(inode, type, acl); | |
2b2d6d01 | 176 | |
ac27a0ec DK |
177 | return acl; |
178 | } | |
179 | ||
180 | /* | |
181 | * Set the access or default ACL of an inode. | |
182 | * | |
617ba13b | 183 | * inode->i_mutex: down unless called from ext4_new_inode |
ac27a0ec DK |
184 | */ |
185 | static int | |
617ba13b | 186 | ext4_set_acl(handle_t *handle, struct inode *inode, int type, |
ac27a0ec DK |
187 | struct posix_acl *acl) |
188 | { | |
ac27a0ec DK |
189 | int name_index; |
190 | void *value = NULL; | |
191 | size_t size = 0; | |
192 | int error; | |
193 | ||
194 | if (S_ISLNK(inode->i_mode)) | |
195 | return -EOPNOTSUPP; | |
196 | ||
2b2d6d01 TT |
197 | switch (type) { |
198 | case ACL_TYPE_ACCESS: | |
199 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS; | |
200 | if (acl) { | |
201 | mode_t mode = inode->i_mode; | |
202 | error = posix_acl_equiv_mode(acl, &mode); | |
203 | if (error < 0) | |
204 | return error; | |
205 | else { | |
206 | inode->i_mode = mode; | |
207 | ext4_mark_inode_dirty(handle, inode); | |
208 | if (error == 0) | |
209 | acl = NULL; | |
ac27a0ec | 210 | } |
2b2d6d01 TT |
211 | } |
212 | break; | |
ac27a0ec | 213 | |
2b2d6d01 TT |
214 | case ACL_TYPE_DEFAULT: |
215 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT; | |
216 | if (!S_ISDIR(inode->i_mode)) | |
217 | return acl ? -EACCES : 0; | |
218 | break; | |
ac27a0ec | 219 | |
2b2d6d01 TT |
220 | default: |
221 | return -EINVAL; | |
ac27a0ec DK |
222 | } |
223 | if (acl) { | |
617ba13b | 224 | value = ext4_acl_to_disk(acl, &size); |
ac27a0ec DK |
225 | if (IS_ERR(value)) |
226 | return (int)PTR_ERR(value); | |
227 | } | |
228 | ||
617ba13b | 229 | error = ext4_xattr_set_handle(handle, inode, name_index, "", |
ac27a0ec DK |
230 | value, size, 0); |
231 | ||
232 | kfree(value); | |
073aaa1b AV |
233 | if (!error) |
234 | set_cached_acl(inode, type, acl); | |
2b2d6d01 | 235 | |
ac27a0ec DK |
236 | return error; |
237 | } | |
238 | ||
239 | static int | |
617ba13b | 240 | ext4_check_acl(struct inode *inode, int mask) |
ac27a0ec | 241 | { |
617ba13b | 242 | struct posix_acl *acl = ext4_get_acl(inode, ACL_TYPE_ACCESS); |
ac27a0ec DK |
243 | |
244 | if (IS_ERR(acl)) | |
245 | return PTR_ERR(acl); | |
246 | if (acl) { | |
247 | int error = posix_acl_permission(inode, acl, mask); | |
248 | posix_acl_release(acl); | |
249 | return error; | |
250 | } | |
251 | ||
252 | return -EAGAIN; | |
253 | } | |
254 | ||
255 | int | |
e6305c43 | 256 | ext4_permission(struct inode *inode, int mask) |
ac27a0ec | 257 | { |
617ba13b | 258 | return generic_permission(inode, mask, ext4_check_acl); |
ac27a0ec DK |
259 | } |
260 | ||
261 | /* | |
617ba13b | 262 | * Initialize the ACLs of a new inode. Called from ext4_new_inode. |
ac27a0ec DK |
263 | * |
264 | * dir->i_mutex: down | |
265 | * inode->i_mutex: up (access to inode is still exclusive) | |
266 | */ | |
267 | int | |
617ba13b | 268 | ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir) |
ac27a0ec DK |
269 | { |
270 | struct posix_acl *acl = NULL; | |
271 | int error = 0; | |
272 | ||
273 | if (!S_ISLNK(inode->i_mode)) { | |
274 | if (test_opt(dir->i_sb, POSIX_ACL)) { | |
617ba13b | 275 | acl = ext4_get_acl(dir, ACL_TYPE_DEFAULT); |
ac27a0ec DK |
276 | if (IS_ERR(acl)) |
277 | return PTR_ERR(acl); | |
278 | } | |
279 | if (!acl) | |
ce3b0f8d | 280 | inode->i_mode &= ~current_umask(); |
ac27a0ec DK |
281 | } |
282 | if (test_opt(inode->i_sb, POSIX_ACL) && acl) { | |
283 | struct posix_acl *clone; | |
284 | mode_t mode; | |
285 | ||
286 | if (S_ISDIR(inode->i_mode)) { | |
617ba13b | 287 | error = ext4_set_acl(handle, inode, |
ac27a0ec DK |
288 | ACL_TYPE_DEFAULT, acl); |
289 | if (error) | |
290 | goto cleanup; | |
291 | } | |
216553c4 | 292 | clone = posix_acl_clone(acl, GFP_NOFS); |
ac27a0ec DK |
293 | error = -ENOMEM; |
294 | if (!clone) | |
295 | goto cleanup; | |
296 | ||
297 | mode = inode->i_mode; | |
298 | error = posix_acl_create_masq(clone, &mode); | |
299 | if (error >= 0) { | |
300 | inode->i_mode = mode; | |
301 | if (error > 0) { | |
302 | /* This is an extended ACL */ | |
617ba13b | 303 | error = ext4_set_acl(handle, inode, |
ac27a0ec DK |
304 | ACL_TYPE_ACCESS, clone); |
305 | } | |
306 | } | |
307 | posix_acl_release(clone); | |
308 | } | |
309 | cleanup: | |
310 | posix_acl_release(acl); | |
311 | return error; | |
312 | } | |
313 | ||
314 | /* | |
315 | * Does chmod for an inode that may have an Access Control List. The | |
316 | * inode->i_mode field must be updated to the desired value by the caller | |
317 | * before calling this function. | |
318 | * Returns 0 on success, or a negative error number. | |
319 | * | |
320 | * We change the ACL rather than storing some ACL entries in the file | |
321 | * mode permission bits (which would be more efficient), because that | |
322 | * would break once additional permissions (like ACL_APPEND, ACL_DELETE | |
323 | * for directories) are added. There are no more bits available in the | |
324 | * file mode. | |
325 | * | |
326 | * inode->i_mutex: down | |
327 | */ | |
328 | int | |
617ba13b | 329 | ext4_acl_chmod(struct inode *inode) |
ac27a0ec DK |
330 | { |
331 | struct posix_acl *acl, *clone; | |
63f57933 | 332 | int error; |
ac27a0ec DK |
333 | |
334 | if (S_ISLNK(inode->i_mode)) | |
335 | return -EOPNOTSUPP; | |
336 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
337 | return 0; | |
617ba13b | 338 | acl = ext4_get_acl(inode, ACL_TYPE_ACCESS); |
ac27a0ec DK |
339 | if (IS_ERR(acl) || !acl) |
340 | return PTR_ERR(acl); | |
341 | clone = posix_acl_clone(acl, GFP_KERNEL); | |
342 | posix_acl_release(acl); | |
343 | if (!clone) | |
344 | return -ENOMEM; | |
345 | error = posix_acl_chmod_masq(clone, inode->i_mode); | |
346 | if (!error) { | |
347 | handle_t *handle; | |
348 | int retries = 0; | |
349 | ||
350 | retry: | |
617ba13b MC |
351 | handle = ext4_journal_start(inode, |
352 | EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); | |
ac27a0ec DK |
353 | if (IS_ERR(handle)) { |
354 | error = PTR_ERR(handle); | |
617ba13b | 355 | ext4_std_error(inode->i_sb, error); |
ac27a0ec DK |
356 | goto out; |
357 | } | |
617ba13b MC |
358 | error = ext4_set_acl(handle, inode, ACL_TYPE_ACCESS, clone); |
359 | ext4_journal_stop(handle); | |
ac27a0ec | 360 | if (error == -ENOSPC && |
617ba13b | 361 | ext4_should_retry_alloc(inode->i_sb, &retries)) |
ac27a0ec DK |
362 | goto retry; |
363 | } | |
364 | out: | |
365 | posix_acl_release(clone); | |
366 | return error; | |
367 | } | |
368 | ||
369 | /* | |
370 | * Extended attribute handlers | |
371 | */ | |
372 | static size_t | |
617ba13b | 373 | ext4_xattr_list_acl_access(struct inode *inode, char *list, size_t list_len, |
ac27a0ec DK |
374 | const char *name, size_t name_len) |
375 | { | |
376 | const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS); | |
377 | ||
378 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
379 | return 0; | |
380 | if (list && size <= list_len) | |
381 | memcpy(list, POSIX_ACL_XATTR_ACCESS, size); | |
382 | return size; | |
383 | } | |
384 | ||
385 | static size_t | |
617ba13b | 386 | ext4_xattr_list_acl_default(struct inode *inode, char *list, size_t list_len, |
ac27a0ec DK |
387 | const char *name, size_t name_len) |
388 | { | |
389 | const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT); | |
390 | ||
391 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
392 | return 0; | |
393 | if (list && size <= list_len) | |
394 | memcpy(list, POSIX_ACL_XATTR_DEFAULT, size); | |
395 | return size; | |
396 | } | |
397 | ||
398 | static int | |
617ba13b | 399 | ext4_xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size) |
ac27a0ec DK |
400 | { |
401 | struct posix_acl *acl; | |
402 | int error; | |
403 | ||
404 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
405 | return -EOPNOTSUPP; | |
406 | ||
617ba13b | 407 | acl = ext4_get_acl(inode, type); |
ac27a0ec DK |
408 | if (IS_ERR(acl)) |
409 | return PTR_ERR(acl); | |
410 | if (acl == NULL) | |
411 | return -ENODATA; | |
412 | error = posix_acl_to_xattr(acl, buffer, size); | |
413 | posix_acl_release(acl); | |
414 | ||
415 | return error; | |
416 | } | |
417 | ||
418 | static int | |
617ba13b | 419 | ext4_xattr_get_acl_access(struct inode *inode, const char *name, |
ac27a0ec DK |
420 | void *buffer, size_t size) |
421 | { | |
422 | if (strcmp(name, "") != 0) | |
423 | return -EINVAL; | |
617ba13b | 424 | return ext4_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size); |
ac27a0ec DK |
425 | } |
426 | ||
427 | static int | |
617ba13b | 428 | ext4_xattr_get_acl_default(struct inode *inode, const char *name, |
ac27a0ec DK |
429 | void *buffer, size_t size) |
430 | { | |
431 | if (strcmp(name, "") != 0) | |
432 | return -EINVAL; | |
617ba13b | 433 | return ext4_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size); |
ac27a0ec DK |
434 | } |
435 | ||
436 | static int | |
617ba13b | 437 | ext4_xattr_set_acl(struct inode *inode, int type, const void *value, |
ac27a0ec DK |
438 | size_t size) |
439 | { | |
440 | handle_t *handle; | |
441 | struct posix_acl *acl; | |
442 | int error, retries = 0; | |
443 | ||
444 | if (!test_opt(inode->i_sb, POSIX_ACL)) | |
445 | return -EOPNOTSUPP; | |
3bd858ab | 446 | if (!is_owner_or_cap(inode)) |
ac27a0ec DK |
447 | return -EPERM; |
448 | ||
449 | if (value) { | |
450 | acl = posix_acl_from_xattr(value, size); | |
451 | if (IS_ERR(acl)) | |
452 | return PTR_ERR(acl); | |
453 | else if (acl) { | |
454 | error = posix_acl_valid(acl); | |
455 | if (error) | |
456 | goto release_and_out; | |
457 | } | |
458 | } else | |
459 | acl = NULL; | |
460 | ||
461 | retry: | |
617ba13b | 462 | handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); |
ac27a0ec DK |
463 | if (IS_ERR(handle)) |
464 | return PTR_ERR(handle); | |
617ba13b MC |
465 | error = ext4_set_acl(handle, inode, type, acl); |
466 | ext4_journal_stop(handle); | |
467 | if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) | |
ac27a0ec DK |
468 | goto retry; |
469 | ||
470 | release_and_out: | |
471 | posix_acl_release(acl); | |
472 | return error; | |
473 | } | |
474 | ||
475 | static int | |
617ba13b | 476 | ext4_xattr_set_acl_access(struct inode *inode, const char *name, |
ac27a0ec DK |
477 | const void *value, size_t size, int flags) |
478 | { | |
479 | if (strcmp(name, "") != 0) | |
480 | return -EINVAL; | |
617ba13b | 481 | return ext4_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size); |
ac27a0ec DK |
482 | } |
483 | ||
484 | static int | |
617ba13b | 485 | ext4_xattr_set_acl_default(struct inode *inode, const char *name, |
ac27a0ec DK |
486 | const void *value, size_t size, int flags) |
487 | { | |
488 | if (strcmp(name, "") != 0) | |
489 | return -EINVAL; | |
617ba13b | 490 | return ext4_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size); |
ac27a0ec DK |
491 | } |
492 | ||
617ba13b | 493 | struct xattr_handler ext4_xattr_acl_access_handler = { |
ac27a0ec | 494 | .prefix = POSIX_ACL_XATTR_ACCESS, |
617ba13b MC |
495 | .list = ext4_xattr_list_acl_access, |
496 | .get = ext4_xattr_get_acl_access, | |
497 | .set = ext4_xattr_set_acl_access, | |
ac27a0ec DK |
498 | }; |
499 | ||
617ba13b | 500 | struct xattr_handler ext4_xattr_acl_default_handler = { |
ac27a0ec | 501 | .prefix = POSIX_ACL_XATTR_DEFAULT, |
617ba13b MC |
502 | .list = ext4_xattr_list_acl_default, |
503 | .get = ext4_xattr_get_acl_default, | |
504 | .set = ext4_xattr_set_acl_default, | |
ac27a0ec | 505 | }; |