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