Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
5c8ebd57 | 2 | * Copyright (C) 2002,2003 by Andreas Gruenbacher <a.gruenbacher@computer.org> |
1da177e4 | 3 | * |
5c8ebd57 CH |
4 | * Fixes from William Schumacher incorporated on 15 March 2001. |
5 | * (Reported by Charles Bertsch, <CBertsch@microtest.com>). | |
1da177e4 LT |
6 | */ |
7 | ||
8 | /* | |
9 | * This file contains generic functions for manipulating | |
10 | * POSIX 1003.1e draft standard 17 ACLs. | |
11 | */ | |
12 | ||
13 | #include <linux/kernel.h> | |
14 | #include <linux/slab.h> | |
60063497 | 15 | #include <linux/atomic.h> |
1da177e4 LT |
16 | #include <linux/fs.h> |
17 | #include <linux/sched.h> | |
18 | #include <linux/posix_acl.h> | |
5c8ebd57 | 19 | #include <linux/posix_acl_xattr.h> |
2aeccbe9 | 20 | #include <linux/xattr.h> |
630d9c47 | 21 | #include <linux/export.h> |
5c8ebd57 | 22 | #include <linux/user_namespace.h> |
1da177e4 | 23 | |
0afaa120 AM |
24 | struct posix_acl **acl_by_type(struct inode *inode, int type) |
25 | { | |
26 | switch (type) { | |
27 | case ACL_TYPE_ACCESS: | |
28 | return &inode->i_acl; | |
29 | case ACL_TYPE_DEFAULT: | |
30 | return &inode->i_default_acl; | |
31 | default: | |
32 | BUG(); | |
33 | } | |
34 | } | |
35 | EXPORT_SYMBOL(acl_by_type); | |
36 | ||
37 | struct posix_acl *get_cached_acl(struct inode *inode, int type) | |
38 | { | |
39 | struct posix_acl **p = acl_by_type(inode, type); | |
b8a7a3a6 AG |
40 | struct posix_acl *acl; |
41 | ||
42 | for (;;) { | |
43 | rcu_read_lock(); | |
44 | acl = rcu_dereference(*p); | |
45 | if (!acl || is_uncached_acl(acl) || | |
46 | atomic_inc_not_zero(&acl->a_refcount)) | |
47 | break; | |
48 | rcu_read_unlock(); | |
49 | cpu_relax(); | |
0afaa120 | 50 | } |
b8a7a3a6 | 51 | rcu_read_unlock(); |
0afaa120 AM |
52 | return acl; |
53 | } | |
54 | EXPORT_SYMBOL(get_cached_acl); | |
55 | ||
56 | struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type) | |
57 | { | |
58 | return rcu_dereference(*acl_by_type(inode, type)); | |
59 | } | |
60 | EXPORT_SYMBOL(get_cached_acl_rcu); | |
61 | ||
62 | void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl) | |
63 | { | |
64 | struct posix_acl **p = acl_by_type(inode, type); | |
65 | struct posix_acl *old; | |
b8a7a3a6 AG |
66 | |
67 | old = xchg(p, posix_acl_dup(acl)); | |
68 | if (!is_uncached_acl(old)) | |
0afaa120 AM |
69 | posix_acl_release(old); |
70 | } | |
71 | EXPORT_SYMBOL(set_cached_acl); | |
72 | ||
b8a7a3a6 | 73 | static void __forget_cached_acl(struct posix_acl **p) |
0afaa120 | 74 | { |
0afaa120 | 75 | struct posix_acl *old; |
b8a7a3a6 AG |
76 | |
77 | old = xchg(p, ACL_NOT_CACHED); | |
78 | if (!is_uncached_acl(old)) | |
0afaa120 AM |
79 | posix_acl_release(old); |
80 | } | |
b8a7a3a6 AG |
81 | |
82 | void forget_cached_acl(struct inode *inode, int type) | |
83 | { | |
84 | __forget_cached_acl(acl_by_type(inode, type)); | |
85 | } | |
0afaa120 AM |
86 | EXPORT_SYMBOL(forget_cached_acl); |
87 | ||
88 | void forget_all_cached_acls(struct inode *inode) | |
89 | { | |
b8a7a3a6 AG |
90 | __forget_cached_acl(&inode->i_acl); |
91 | __forget_cached_acl(&inode->i_default_acl); | |
0afaa120 AM |
92 | } |
93 | EXPORT_SYMBOL(forget_all_cached_acls); | |
1da177e4 | 94 | |
2982baa2 CH |
95 | struct posix_acl *get_acl(struct inode *inode, int type) |
96 | { | |
b8a7a3a6 AG |
97 | void *sentinel; |
98 | struct posix_acl **p; | |
2982baa2 CH |
99 | struct posix_acl *acl; |
100 | ||
b8a7a3a6 AG |
101 | /* |
102 | * The sentinel is used to detect when another operation like | |
103 | * set_cached_acl() or forget_cached_acl() races with get_acl(). | |
104 | * It is guaranteed that is_uncached_acl(sentinel) is true. | |
105 | */ | |
106 | ||
2982baa2 | 107 | acl = get_cached_acl(inode, type); |
b8a7a3a6 | 108 | if (!is_uncached_acl(acl)) |
2982baa2 CH |
109 | return acl; |
110 | ||
111 | if (!IS_POSIXACL(inode)) | |
112 | return NULL; | |
113 | ||
b8a7a3a6 AG |
114 | sentinel = uncached_acl_sentinel(current); |
115 | p = acl_by_type(inode, type); | |
116 | ||
117 | /* | |
118 | * If the ACL isn't being read yet, set our sentinel. Otherwise, the | |
119 | * current value of the ACL will not be ACL_NOT_CACHED and so our own | |
120 | * sentinel will not be set; another task will update the cache. We | |
121 | * could wait for that other task to complete its job, but it's easier | |
122 | * to just call ->get_acl to fetch the ACL ourself. (This is going to | |
123 | * be an unlikely race.) | |
124 | */ | |
125 | if (cmpxchg(p, ACL_NOT_CACHED, sentinel) != ACL_NOT_CACHED) | |
126 | /* fall through */ ; | |
127 | ||
2982baa2 | 128 | /* |
b8a7a3a6 AG |
129 | * Normally, the ACL returned by ->get_acl will be cached. |
130 | * A filesystem can prevent that by calling | |
131 | * forget_cached_acl(inode, type) in ->get_acl. | |
2982baa2 CH |
132 | * |
133 | * If the filesystem doesn't have a get_acl() function at all, we'll | |
134 | * just create the negative cache entry. | |
135 | */ | |
136 | if (!inode->i_op->get_acl) { | |
137 | set_cached_acl(inode, type, NULL); | |
138 | return NULL; | |
139 | } | |
b8a7a3a6 AG |
140 | acl = inode->i_op->get_acl(inode, type); |
141 | ||
142 | if (IS_ERR(acl)) { | |
143 | /* | |
144 | * Remove our sentinel so that we don't block future attempts | |
145 | * to cache the ACL. | |
146 | */ | |
147 | cmpxchg(p, sentinel, ACL_NOT_CACHED); | |
148 | return acl; | |
149 | } | |
150 | ||
151 | /* | |
152 | * Cache the result, but only if our sentinel is still in place. | |
153 | */ | |
154 | posix_acl_dup(acl); | |
155 | if (unlikely(cmpxchg(p, sentinel, acl) != sentinel)) | |
156 | posix_acl_release(acl); | |
157 | return acl; | |
2982baa2 CH |
158 | } |
159 | EXPORT_SYMBOL(get_acl); | |
160 | ||
f61f6da0 CL |
161 | /* |
162 | * Init a fresh posix_acl | |
163 | */ | |
164 | void | |
165 | posix_acl_init(struct posix_acl *acl, int count) | |
166 | { | |
167 | atomic_set(&acl->a_refcount, 1); | |
168 | acl->a_count = count; | |
169 | } | |
0afaa120 | 170 | EXPORT_SYMBOL(posix_acl_init); |
f61f6da0 | 171 | |
1da177e4 LT |
172 | /* |
173 | * Allocate a new ACL with the specified number of entries. | |
174 | */ | |
175 | struct posix_acl * | |
dd0fc66f | 176 | posix_acl_alloc(int count, gfp_t flags) |
1da177e4 LT |
177 | { |
178 | const size_t size = sizeof(struct posix_acl) + | |
179 | count * sizeof(struct posix_acl_entry); | |
180 | struct posix_acl *acl = kmalloc(size, flags); | |
f61f6da0 CL |
181 | if (acl) |
182 | posix_acl_init(acl, count); | |
1da177e4 LT |
183 | return acl; |
184 | } | |
0afaa120 | 185 | EXPORT_SYMBOL(posix_acl_alloc); |
1da177e4 LT |
186 | |
187 | /* | |
188 | * Clone an ACL. | |
189 | */ | |
edde854e | 190 | static struct posix_acl * |
dd0fc66f | 191 | posix_acl_clone(const struct posix_acl *acl, gfp_t flags) |
1da177e4 LT |
192 | { |
193 | struct posix_acl *clone = NULL; | |
194 | ||
195 | if (acl) { | |
196 | int size = sizeof(struct posix_acl) + acl->a_count * | |
197 | sizeof(struct posix_acl_entry); | |
52978be6 AD |
198 | clone = kmemdup(acl, size, flags); |
199 | if (clone) | |
1da177e4 | 200 | atomic_set(&clone->a_refcount, 1); |
1da177e4 LT |
201 | } |
202 | return clone; | |
203 | } | |
204 | ||
205 | /* | |
206 | * Check if an acl is valid. Returns 0 if it is, or -E... otherwise. | |
207 | */ | |
208 | int | |
209 | posix_acl_valid(const struct posix_acl *acl) | |
210 | { | |
211 | const struct posix_acl_entry *pa, *pe; | |
212 | int state = ACL_USER_OBJ; | |
1da177e4 LT |
213 | int needs_mask = 0; |
214 | ||
215 | FOREACH_ACL_ENTRY(pa, acl, pe) { | |
216 | if (pa->e_perm & ~(ACL_READ|ACL_WRITE|ACL_EXECUTE)) | |
217 | return -EINVAL; | |
218 | switch (pa->e_tag) { | |
219 | case ACL_USER_OBJ: | |
220 | if (state == ACL_USER_OBJ) { | |
1da177e4 LT |
221 | state = ACL_USER; |
222 | break; | |
223 | } | |
224 | return -EINVAL; | |
225 | ||
226 | case ACL_USER: | |
227 | if (state != ACL_USER) | |
228 | return -EINVAL; | |
2f6f0654 | 229 | if (!uid_valid(pa->e_uid)) |
1da177e4 | 230 | return -EINVAL; |
1da177e4 LT |
231 | needs_mask = 1; |
232 | break; | |
233 | ||
234 | case ACL_GROUP_OBJ: | |
235 | if (state == ACL_USER) { | |
1da177e4 LT |
236 | state = ACL_GROUP; |
237 | break; | |
238 | } | |
239 | return -EINVAL; | |
240 | ||
241 | case ACL_GROUP: | |
242 | if (state != ACL_GROUP) | |
243 | return -EINVAL; | |
2f6f0654 EB |
244 | if (!gid_valid(pa->e_gid)) |
245 | return -EINVAL; | |
1da177e4 LT |
246 | needs_mask = 1; |
247 | break; | |
248 | ||
249 | case ACL_MASK: | |
250 | if (state != ACL_GROUP) | |
251 | return -EINVAL; | |
252 | state = ACL_OTHER; | |
253 | break; | |
254 | ||
255 | case ACL_OTHER: | |
256 | if (state == ACL_OTHER || | |
257 | (state == ACL_GROUP && !needs_mask)) { | |
258 | state = 0; | |
259 | break; | |
260 | } | |
261 | return -EINVAL; | |
262 | ||
263 | default: | |
264 | return -EINVAL; | |
265 | } | |
266 | } | |
267 | if (state == 0) | |
268 | return 0; | |
269 | return -EINVAL; | |
270 | } | |
0afaa120 | 271 | EXPORT_SYMBOL(posix_acl_valid); |
1da177e4 LT |
272 | |
273 | /* | |
274 | * Returns 0 if the acl can be exactly represented in the traditional | |
275 | * file mode permission bits, or else 1. Returns -E... on error. | |
276 | */ | |
277 | int | |
d6952123 | 278 | posix_acl_equiv_mode(const struct posix_acl *acl, umode_t *mode_p) |
1da177e4 LT |
279 | { |
280 | const struct posix_acl_entry *pa, *pe; | |
d6952123 | 281 | umode_t mode = 0; |
1da177e4 LT |
282 | int not_equiv = 0; |
283 | ||
50c6e282 CH |
284 | /* |
285 | * A null ACL can always be presented as mode bits. | |
286 | */ | |
287 | if (!acl) | |
288 | return 0; | |
289 | ||
1da177e4 LT |
290 | FOREACH_ACL_ENTRY(pa, acl, pe) { |
291 | switch (pa->e_tag) { | |
292 | case ACL_USER_OBJ: | |
293 | mode |= (pa->e_perm & S_IRWXO) << 6; | |
294 | break; | |
295 | case ACL_GROUP_OBJ: | |
296 | mode |= (pa->e_perm & S_IRWXO) << 3; | |
297 | break; | |
298 | case ACL_OTHER: | |
299 | mode |= pa->e_perm & S_IRWXO; | |
300 | break; | |
301 | case ACL_MASK: | |
302 | mode = (mode & ~S_IRWXG) | | |
303 | ((pa->e_perm & S_IRWXO) << 3); | |
304 | not_equiv = 1; | |
305 | break; | |
306 | case ACL_USER: | |
307 | case ACL_GROUP: | |
308 | not_equiv = 1; | |
309 | break; | |
310 | default: | |
311 | return -EINVAL; | |
312 | } | |
313 | } | |
314 | if (mode_p) | |
315 | *mode_p = (*mode_p & ~S_IRWXUGO) | mode; | |
316 | return not_equiv; | |
317 | } | |
0afaa120 | 318 | EXPORT_SYMBOL(posix_acl_equiv_mode); |
1da177e4 LT |
319 | |
320 | /* | |
321 | * Create an ACL representing the file mode permission bits of an inode. | |
322 | */ | |
323 | struct posix_acl * | |
3a5fba19 | 324 | posix_acl_from_mode(umode_t mode, gfp_t flags) |
1da177e4 LT |
325 | { |
326 | struct posix_acl *acl = posix_acl_alloc(3, flags); | |
327 | if (!acl) | |
328 | return ERR_PTR(-ENOMEM); | |
329 | ||
330 | acl->a_entries[0].e_tag = ACL_USER_OBJ; | |
1da177e4 LT |
331 | acl->a_entries[0].e_perm = (mode & S_IRWXU) >> 6; |
332 | ||
333 | acl->a_entries[1].e_tag = ACL_GROUP_OBJ; | |
1da177e4 LT |
334 | acl->a_entries[1].e_perm = (mode & S_IRWXG) >> 3; |
335 | ||
336 | acl->a_entries[2].e_tag = ACL_OTHER; | |
1da177e4 LT |
337 | acl->a_entries[2].e_perm = (mode & S_IRWXO); |
338 | return acl; | |
339 | } | |
0afaa120 | 340 | EXPORT_SYMBOL(posix_acl_from_mode); |
1da177e4 LT |
341 | |
342 | /* | |
343 | * Return 0 if current is granted want access to the inode | |
344 | * by the acl. Returns -E... otherwise. | |
345 | */ | |
346 | int | |
347 | posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want) | |
348 | { | |
349 | const struct posix_acl_entry *pa, *pe, *mask_obj; | |
350 | int found = 0; | |
351 | ||
d124b60a AG |
352 | want &= MAY_READ | MAY_WRITE | MAY_EXEC | MAY_NOT_BLOCK; |
353 | ||
1da177e4 LT |
354 | FOREACH_ACL_ENTRY(pa, acl, pe) { |
355 | switch(pa->e_tag) { | |
356 | case ACL_USER_OBJ: | |
357 | /* (May have been checked already) */ | |
2f6f0654 | 358 | if (uid_eq(inode->i_uid, current_fsuid())) |
1da177e4 LT |
359 | goto check_perm; |
360 | break; | |
361 | case ACL_USER: | |
2f6f0654 | 362 | if (uid_eq(pa->e_uid, current_fsuid())) |
1da177e4 LT |
363 | goto mask; |
364 | break; | |
365 | case ACL_GROUP_OBJ: | |
366 | if (in_group_p(inode->i_gid)) { | |
367 | found = 1; | |
368 | if ((pa->e_perm & want) == want) | |
369 | goto mask; | |
370 | } | |
371 | break; | |
372 | case ACL_GROUP: | |
2f6f0654 | 373 | if (in_group_p(pa->e_gid)) { |
1da177e4 LT |
374 | found = 1; |
375 | if ((pa->e_perm & want) == want) | |
376 | goto mask; | |
377 | } | |
378 | break; | |
379 | case ACL_MASK: | |
380 | break; | |
381 | case ACL_OTHER: | |
382 | if (found) | |
383 | return -EACCES; | |
384 | else | |
385 | goto check_perm; | |
386 | default: | |
387 | return -EIO; | |
388 | } | |
389 | } | |
390 | return -EIO; | |
391 | ||
392 | mask: | |
393 | for (mask_obj = pa+1; mask_obj != pe; mask_obj++) { | |
394 | if (mask_obj->e_tag == ACL_MASK) { | |
395 | if ((pa->e_perm & mask_obj->e_perm & want) == want) | |
396 | return 0; | |
397 | return -EACCES; | |
398 | } | |
399 | } | |
400 | ||
401 | check_perm: | |
402 | if ((pa->e_perm & want) == want) | |
403 | return 0; | |
404 | return -EACCES; | |
405 | } | |
406 | ||
407 | /* | |
408 | * Modify acl when creating a new inode. The caller must ensure the acl is | |
409 | * only referenced once. | |
410 | * | |
411 | * mode_p initially must contain the mode parameter to the open() / creat() | |
412 | * system calls. All permissions that are not granted by the acl are removed. | |
413 | * The permissions in the acl are changed to reflect the mode_p parameter. | |
414 | */ | |
d3fb6120 | 415 | static int posix_acl_create_masq(struct posix_acl *acl, umode_t *mode_p) |
1da177e4 LT |
416 | { |
417 | struct posix_acl_entry *pa, *pe; | |
418 | struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; | |
d3fb6120 | 419 | umode_t mode = *mode_p; |
1da177e4 LT |
420 | int not_equiv = 0; |
421 | ||
422 | /* assert(atomic_read(acl->a_refcount) == 1); */ | |
423 | ||
424 | FOREACH_ACL_ENTRY(pa, acl, pe) { | |
425 | switch(pa->e_tag) { | |
426 | case ACL_USER_OBJ: | |
427 | pa->e_perm &= (mode >> 6) | ~S_IRWXO; | |
428 | mode &= (pa->e_perm << 6) | ~S_IRWXU; | |
429 | break; | |
430 | ||
431 | case ACL_USER: | |
432 | case ACL_GROUP: | |
433 | not_equiv = 1; | |
434 | break; | |
435 | ||
436 | case ACL_GROUP_OBJ: | |
437 | group_obj = pa; | |
438 | break; | |
439 | ||
440 | case ACL_OTHER: | |
441 | pa->e_perm &= mode | ~S_IRWXO; | |
442 | mode &= pa->e_perm | ~S_IRWXO; | |
443 | break; | |
444 | ||
445 | case ACL_MASK: | |
446 | mask_obj = pa; | |
447 | not_equiv = 1; | |
448 | break; | |
449 | ||
450 | default: | |
451 | return -EIO; | |
452 | } | |
453 | } | |
454 | ||
455 | if (mask_obj) { | |
456 | mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO; | |
457 | mode &= (mask_obj->e_perm << 3) | ~S_IRWXG; | |
458 | } else { | |
459 | if (!group_obj) | |
460 | return -EIO; | |
461 | group_obj->e_perm &= (mode >> 3) | ~S_IRWXO; | |
462 | mode &= (group_obj->e_perm << 3) | ~S_IRWXG; | |
463 | } | |
464 | ||
465 | *mode_p = (*mode_p & ~S_IRWXUGO) | mode; | |
466 | return not_equiv; | |
467 | } | |
468 | ||
469 | /* | |
470 | * Modify the ACL for the chmod syscall. | |
471 | */ | |
5bf3258f | 472 | static int __posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode) |
1da177e4 LT |
473 | { |
474 | struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; | |
475 | struct posix_acl_entry *pa, *pe; | |
476 | ||
477 | /* assert(atomic_read(acl->a_refcount) == 1); */ | |
478 | ||
479 | FOREACH_ACL_ENTRY(pa, acl, pe) { | |
480 | switch(pa->e_tag) { | |
481 | case ACL_USER_OBJ: | |
482 | pa->e_perm = (mode & S_IRWXU) >> 6; | |
483 | break; | |
484 | ||
485 | case ACL_USER: | |
486 | case ACL_GROUP: | |
487 | break; | |
488 | ||
489 | case ACL_GROUP_OBJ: | |
490 | group_obj = pa; | |
491 | break; | |
492 | ||
493 | case ACL_MASK: | |
494 | mask_obj = pa; | |
495 | break; | |
496 | ||
497 | case ACL_OTHER: | |
498 | pa->e_perm = (mode & S_IRWXO); | |
499 | break; | |
500 | ||
501 | default: | |
502 | return -EIO; | |
503 | } | |
504 | } | |
505 | ||
506 | if (mask_obj) { | |
507 | mask_obj->e_perm = (mode & S_IRWXG) >> 3; | |
508 | } else { | |
509 | if (!group_obj) | |
510 | return -EIO; | |
511 | group_obj->e_perm = (mode & S_IRWXG) >> 3; | |
512 | } | |
513 | ||
514 | return 0; | |
515 | } | |
bc26ab5f | 516 | |
826cae2f | 517 | int |
37bc1539 | 518 | __posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p) |
826cae2f AV |
519 | { |
520 | struct posix_acl *clone = posix_acl_clone(*acl, gfp); | |
521 | int err = -ENOMEM; | |
522 | if (clone) { | |
523 | err = posix_acl_create_masq(clone, mode_p); | |
524 | if (err < 0) { | |
525 | posix_acl_release(clone); | |
526 | clone = NULL; | |
527 | } | |
528 | } | |
529 | posix_acl_release(*acl); | |
530 | *acl = clone; | |
531 | return err; | |
532 | } | |
37bc1539 | 533 | EXPORT_SYMBOL(__posix_acl_create); |
826cae2f | 534 | |
bc26ab5f | 535 | int |
5bf3258f | 536 | __posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode) |
bc26ab5f AV |
537 | { |
538 | struct posix_acl *clone = posix_acl_clone(*acl, gfp); | |
539 | int err = -ENOMEM; | |
540 | if (clone) { | |
5bf3258f | 541 | err = __posix_acl_chmod_masq(clone, mode); |
bc26ab5f AV |
542 | if (err) { |
543 | posix_acl_release(clone); | |
544 | clone = NULL; | |
545 | } | |
546 | } | |
547 | posix_acl_release(*acl); | |
548 | *acl = clone; | |
549 | return err; | |
550 | } | |
5bf3258f CH |
551 | EXPORT_SYMBOL(__posix_acl_chmod); |
552 | ||
553 | int | |
37bc1539 | 554 | posix_acl_chmod(struct inode *inode, umode_t mode) |
5bf3258f CH |
555 | { |
556 | struct posix_acl *acl; | |
557 | int ret = 0; | |
558 | ||
559 | if (!IS_POSIXACL(inode)) | |
560 | return 0; | |
561 | if (!inode->i_op->set_acl) | |
562 | return -EOPNOTSUPP; | |
563 | ||
564 | acl = get_acl(inode, ACL_TYPE_ACCESS); | |
789b663a TM |
565 | if (IS_ERR_OR_NULL(acl)) { |
566 | if (acl == ERR_PTR(-EOPNOTSUPP)) | |
567 | return 0; | |
5bf3258f | 568 | return PTR_ERR(acl); |
789b663a | 569 | } |
5bf3258f | 570 | |
37bc1539 | 571 | ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode); |
5bf3258f CH |
572 | if (ret) |
573 | return ret; | |
574 | ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS); | |
575 | posix_acl_release(acl); | |
576 | return ret; | |
577 | } | |
bc26ab5f | 578 | EXPORT_SYMBOL(posix_acl_chmod); |
5c8ebd57 | 579 | |
37bc1539 CH |
580 | int |
581 | posix_acl_create(struct inode *dir, umode_t *mode, | |
582 | struct posix_acl **default_acl, struct posix_acl **acl) | |
583 | { | |
584 | struct posix_acl *p; | |
c0c3a718 | 585 | struct posix_acl *clone; |
37bc1539 CH |
586 | int ret; |
587 | ||
c0c3a718 DC |
588 | *acl = NULL; |
589 | *default_acl = NULL; | |
590 | ||
37bc1539 | 591 | if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) |
c0c3a718 | 592 | return 0; |
37bc1539 CH |
593 | |
594 | p = get_acl(dir, ACL_TYPE_DEFAULT); | |
c0c3a718 DC |
595 | if (!p || p == ERR_PTR(-EOPNOTSUPP)) { |
596 | *mode &= ~current_umask(); | |
597 | return 0; | |
37bc1539 | 598 | } |
c0c3a718 DC |
599 | if (IS_ERR(p)) |
600 | return PTR_ERR(p); | |
37bc1539 | 601 | |
c0c3a718 DC |
602 | clone = posix_acl_clone(p, GFP_NOFS); |
603 | if (!clone) | |
fed0b588 | 604 | goto no_mem; |
37bc1539 | 605 | |
c0c3a718 | 606 | ret = posix_acl_create_masq(clone, mode); |
fed0b588 OS |
607 | if (ret < 0) |
608 | goto no_mem_clone; | |
37bc1539 | 609 | |
c0c3a718 DC |
610 | if (ret == 0) |
611 | posix_acl_release(clone); | |
612 | else | |
613 | *acl = clone; | |
37bc1539 | 614 | |
c0c3a718 | 615 | if (!S_ISDIR(*mode)) |
37bc1539 | 616 | posix_acl_release(p); |
c0c3a718 | 617 | else |
37bc1539 | 618 | *default_acl = p; |
37bc1539 | 619 | |
37bc1539 | 620 | return 0; |
fed0b588 OS |
621 | |
622 | no_mem_clone: | |
c0c3a718 | 623 | posix_acl_release(clone); |
fed0b588 OS |
624 | no_mem: |
625 | posix_acl_release(p); | |
626 | return -ENOMEM; | |
37bc1539 CH |
627 | } |
628 | EXPORT_SYMBOL_GPL(posix_acl_create); | |
629 | ||
5c8ebd57 CH |
630 | /* |
631 | * Fix up the uids and gids in posix acl extended attributes in place. | |
632 | */ | |
633 | static void posix_acl_fix_xattr_userns( | |
634 | struct user_namespace *to, struct user_namespace *from, | |
635 | void *value, size_t size) | |
636 | { | |
637 | posix_acl_xattr_header *header = (posix_acl_xattr_header *)value; | |
638 | posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end; | |
639 | int count; | |
640 | kuid_t uid; | |
641 | kgid_t gid; | |
642 | ||
643 | if (!value) | |
644 | return; | |
645 | if (size < sizeof(posix_acl_xattr_header)) | |
646 | return; | |
647 | if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION)) | |
648 | return; | |
649 | ||
650 | count = posix_acl_xattr_count(size); | |
651 | if (count < 0) | |
652 | return; | |
653 | if (count == 0) | |
654 | return; | |
655 | ||
656 | for (end = entry + count; entry != end; entry++) { | |
657 | switch(le16_to_cpu(entry->e_tag)) { | |
658 | case ACL_USER: | |
659 | uid = make_kuid(from, le32_to_cpu(entry->e_id)); | |
660 | entry->e_id = cpu_to_le32(from_kuid(to, uid)); | |
661 | break; | |
662 | case ACL_GROUP: | |
663 | gid = make_kgid(from, le32_to_cpu(entry->e_id)); | |
664 | entry->e_id = cpu_to_le32(from_kgid(to, gid)); | |
665 | break; | |
666 | default: | |
667 | break; | |
668 | } | |
669 | } | |
670 | } | |
671 | ||
672 | void posix_acl_fix_xattr_from_user(void *value, size_t size) | |
673 | { | |
674 | struct user_namespace *user_ns = current_user_ns(); | |
675 | if (user_ns == &init_user_ns) | |
676 | return; | |
677 | posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size); | |
678 | } | |
679 | ||
680 | void posix_acl_fix_xattr_to_user(void *value, size_t size) | |
681 | { | |
682 | struct user_namespace *user_ns = current_user_ns(); | |
683 | if (user_ns == &init_user_ns) | |
684 | return; | |
685 | posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size); | |
686 | } | |
687 | ||
688 | /* | |
689 | * Convert from extended attribute to in-memory representation. | |
690 | */ | |
691 | struct posix_acl * | |
692 | posix_acl_from_xattr(struct user_namespace *user_ns, | |
693 | const void *value, size_t size) | |
694 | { | |
695 | posix_acl_xattr_header *header = (posix_acl_xattr_header *)value; | |
696 | posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end; | |
697 | int count; | |
698 | struct posix_acl *acl; | |
699 | struct posix_acl_entry *acl_e; | |
700 | ||
701 | if (!value) | |
702 | return NULL; | |
703 | if (size < sizeof(posix_acl_xattr_header)) | |
704 | return ERR_PTR(-EINVAL); | |
705 | if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION)) | |
706 | return ERR_PTR(-EOPNOTSUPP); | |
707 | ||
708 | count = posix_acl_xattr_count(size); | |
709 | if (count < 0) | |
710 | return ERR_PTR(-EINVAL); | |
711 | if (count == 0) | |
712 | return NULL; | |
713 | ||
714 | acl = posix_acl_alloc(count, GFP_NOFS); | |
715 | if (!acl) | |
716 | return ERR_PTR(-ENOMEM); | |
717 | acl_e = acl->a_entries; | |
718 | ||
719 | for (end = entry + count; entry != end; acl_e++, entry++) { | |
720 | acl_e->e_tag = le16_to_cpu(entry->e_tag); | |
721 | acl_e->e_perm = le16_to_cpu(entry->e_perm); | |
722 | ||
723 | switch(acl_e->e_tag) { | |
724 | case ACL_USER_OBJ: | |
725 | case ACL_GROUP_OBJ: | |
726 | case ACL_MASK: | |
727 | case ACL_OTHER: | |
728 | break; | |
729 | ||
730 | case ACL_USER: | |
731 | acl_e->e_uid = | |
732 | make_kuid(user_ns, | |
733 | le32_to_cpu(entry->e_id)); | |
734 | if (!uid_valid(acl_e->e_uid)) | |
735 | goto fail; | |
736 | break; | |
737 | case ACL_GROUP: | |
738 | acl_e->e_gid = | |
739 | make_kgid(user_ns, | |
740 | le32_to_cpu(entry->e_id)); | |
741 | if (!gid_valid(acl_e->e_gid)) | |
742 | goto fail; | |
743 | break; | |
744 | ||
745 | default: | |
746 | goto fail; | |
747 | } | |
748 | } | |
749 | return acl; | |
750 | ||
751 | fail: | |
752 | posix_acl_release(acl); | |
753 | return ERR_PTR(-EINVAL); | |
754 | } | |
755 | EXPORT_SYMBOL (posix_acl_from_xattr); | |
756 | ||
757 | /* | |
758 | * Convert from in-memory to extended attribute representation. | |
759 | */ | |
760 | int | |
761 | posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl, | |
762 | void *buffer, size_t size) | |
763 | { | |
764 | posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer; | |
47ba9734 | 765 | posix_acl_xattr_entry *ext_entry; |
5c8ebd57 CH |
766 | int real_size, n; |
767 | ||
768 | real_size = posix_acl_xattr_size(acl->a_count); | |
769 | if (!buffer) | |
770 | return real_size; | |
771 | if (real_size > size) | |
772 | return -ERANGE; | |
47ba9734 DC |
773 | |
774 | ext_entry = ext_acl->a_entries; | |
5c8ebd57 CH |
775 | ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION); |
776 | ||
777 | for (n=0; n < acl->a_count; n++, ext_entry++) { | |
778 | const struct posix_acl_entry *acl_e = &acl->a_entries[n]; | |
779 | ext_entry->e_tag = cpu_to_le16(acl_e->e_tag); | |
780 | ext_entry->e_perm = cpu_to_le16(acl_e->e_perm); | |
781 | switch(acl_e->e_tag) { | |
782 | case ACL_USER: | |
783 | ext_entry->e_id = | |
784 | cpu_to_le32(from_kuid(user_ns, acl_e->e_uid)); | |
785 | break; | |
786 | case ACL_GROUP: | |
787 | ext_entry->e_id = | |
788 | cpu_to_le32(from_kgid(user_ns, acl_e->e_gid)); | |
789 | break; | |
790 | default: | |
791 | ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID); | |
792 | break; | |
793 | } | |
794 | } | |
795 | return real_size; | |
796 | } | |
797 | EXPORT_SYMBOL (posix_acl_to_xattr); | |
2aeccbe9 CH |
798 | |
799 | static int | |
d9a82a04 AG |
800 | posix_acl_xattr_get(const struct xattr_handler *handler, |
801 | struct dentry *dentry, const char *name, | |
802 | void *value, size_t size) | |
2aeccbe9 CH |
803 | { |
804 | struct posix_acl *acl; | |
805 | int error; | |
806 | ||
bb668734 | 807 | if (!IS_POSIXACL(d_backing_inode(dentry))) |
2aeccbe9 | 808 | return -EOPNOTSUPP; |
e36cb0b8 | 809 | if (d_is_symlink(dentry)) |
2aeccbe9 CH |
810 | return -EOPNOTSUPP; |
811 | ||
d9a82a04 | 812 | acl = get_acl(d_backing_inode(dentry), handler->flags); |
2aeccbe9 CH |
813 | if (IS_ERR(acl)) |
814 | return PTR_ERR(acl); | |
815 | if (acl == NULL) | |
816 | return -ENODATA; | |
817 | ||
818 | error = posix_acl_to_xattr(&init_user_ns, acl, value, size); | |
819 | posix_acl_release(acl); | |
820 | ||
821 | return error; | |
822 | } | |
823 | ||
824 | static int | |
d9a82a04 AG |
825 | posix_acl_xattr_set(const struct xattr_handler *handler, |
826 | struct dentry *dentry, const char *name, | |
827 | const void *value, size_t size, int flags) | |
2aeccbe9 | 828 | { |
bb668734 | 829 | struct inode *inode = d_backing_inode(dentry); |
2aeccbe9 CH |
830 | struct posix_acl *acl = NULL; |
831 | int ret; | |
832 | ||
833 | if (!IS_POSIXACL(inode)) | |
834 | return -EOPNOTSUPP; | |
835 | if (!inode->i_op->set_acl) | |
836 | return -EOPNOTSUPP; | |
837 | ||
d9a82a04 | 838 | if (handler->flags == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) |
2aeccbe9 CH |
839 | return value ? -EACCES : 0; |
840 | if (!inode_owner_or_capable(inode)) | |
841 | return -EPERM; | |
842 | ||
843 | if (value) { | |
844 | acl = posix_acl_from_xattr(&init_user_ns, value, size); | |
845 | if (IS_ERR(acl)) | |
846 | return PTR_ERR(acl); | |
847 | ||
848 | if (acl) { | |
849 | ret = posix_acl_valid(acl); | |
850 | if (ret) | |
851 | goto out; | |
852 | } | |
853 | } | |
854 | ||
d9a82a04 | 855 | ret = inode->i_op->set_acl(inode, acl, handler->flags); |
2aeccbe9 CH |
856 | out: |
857 | posix_acl_release(acl); | |
858 | return ret; | |
859 | } | |
860 | ||
764a5c6b AG |
861 | static bool |
862 | posix_acl_xattr_list(struct dentry *dentry) | |
2aeccbe9 | 863 | { |
764a5c6b | 864 | return IS_POSIXACL(d_backing_inode(dentry)); |
2aeccbe9 CH |
865 | } |
866 | ||
867 | const struct xattr_handler posix_acl_access_xattr_handler = { | |
98e9cb57 | 868 | .name = XATTR_NAME_POSIX_ACL_ACCESS, |
2aeccbe9 CH |
869 | .flags = ACL_TYPE_ACCESS, |
870 | .list = posix_acl_xattr_list, | |
871 | .get = posix_acl_xattr_get, | |
872 | .set = posix_acl_xattr_set, | |
873 | }; | |
874 | EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler); | |
875 | ||
876 | const struct xattr_handler posix_acl_default_xattr_handler = { | |
98e9cb57 | 877 | .name = XATTR_NAME_POSIX_ACL_DEFAULT, |
2aeccbe9 CH |
878 | .flags = ACL_TYPE_DEFAULT, |
879 | .list = posix_acl_xattr_list, | |
880 | .get = posix_acl_xattr_get, | |
881 | .set = posix_acl_xattr_set, | |
882 | }; | |
883 | EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler); | |
feda821e CH |
884 | |
885 | int simple_set_acl(struct inode *inode, struct posix_acl *acl, int type) | |
886 | { | |
887 | int error; | |
888 | ||
889 | if (type == ACL_TYPE_ACCESS) { | |
890 | error = posix_acl_equiv_mode(acl, &inode->i_mode); | |
891 | if (error < 0) | |
892 | return 0; | |
893 | if (error == 0) | |
894 | acl = NULL; | |
895 | } | |
896 | ||
897 | inode->i_ctime = CURRENT_TIME; | |
898 | set_cached_acl(inode, type, acl); | |
899 | return 0; | |
900 | } | |
901 | ||
902 | int simple_acl_create(struct inode *dir, struct inode *inode) | |
903 | { | |
904 | struct posix_acl *default_acl, *acl; | |
905 | int error; | |
906 | ||
907 | error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); | |
908 | if (error) | |
909 | return error; | |
910 | ||
911 | set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl); | |
912 | set_cached_acl(inode, ACL_TYPE_ACCESS, acl); | |
913 | ||
914 | if (default_acl) | |
915 | posix_acl_release(default_acl); | |
916 | if (acl) | |
917 | posix_acl_release(acl); | |
918 | return 0; | |
919 | } |