]>
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 | |
37d3c4d6 | 174 | posix_acl_valid(struct user_namespace *user_ns, const struct posix_acl *acl) |
1da177e4 LT |
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; | |
37d3c4d6 | 194 | if (!kuid_has_mapping(user_ns, 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; | |
37d3c4d6 | 209 | if (!kgid_has_mapping(user_ns, pa->e_gid)) |
2f6f0654 | 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 | ||
50c6e282 CH |
249 | /* |
250 | * A null ACL can always be presented as mode bits. | |
251 | */ | |
252 | if (!acl) | |
253 | return 0; | |
254 | ||
1da177e4 LT |
255 | FOREACH_ACL_ENTRY(pa, acl, pe) { |
256 | switch (pa->e_tag) { | |
257 | case ACL_USER_OBJ: | |
258 | mode |= (pa->e_perm & S_IRWXO) << 6; | |
259 | break; | |
260 | case ACL_GROUP_OBJ: | |
261 | mode |= (pa->e_perm & S_IRWXO) << 3; | |
262 | break; | |
263 | case ACL_OTHER: | |
264 | mode |= pa->e_perm & S_IRWXO; | |
265 | break; | |
266 | case ACL_MASK: | |
267 | mode = (mode & ~S_IRWXG) | | |
268 | ((pa->e_perm & S_IRWXO) << 3); | |
269 | not_equiv = 1; | |
270 | break; | |
271 | case ACL_USER: | |
272 | case ACL_GROUP: | |
273 | not_equiv = 1; | |
274 | break; | |
275 | default: | |
276 | return -EINVAL; | |
277 | } | |
278 | } | |
279 | if (mode_p) | |
280 | *mode_p = (*mode_p & ~S_IRWXUGO) | mode; | |
281 | return not_equiv; | |
282 | } | |
0afaa120 | 283 | EXPORT_SYMBOL(posix_acl_equiv_mode); |
1da177e4 LT |
284 | |
285 | /* | |
286 | * Create an ACL representing the file mode permission bits of an inode. | |
287 | */ | |
288 | struct posix_acl * | |
3a5fba19 | 289 | posix_acl_from_mode(umode_t mode, gfp_t flags) |
1da177e4 LT |
290 | { |
291 | struct posix_acl *acl = posix_acl_alloc(3, flags); | |
292 | if (!acl) | |
293 | return ERR_PTR(-ENOMEM); | |
294 | ||
295 | acl->a_entries[0].e_tag = ACL_USER_OBJ; | |
1da177e4 LT |
296 | acl->a_entries[0].e_perm = (mode & S_IRWXU) >> 6; |
297 | ||
298 | acl->a_entries[1].e_tag = ACL_GROUP_OBJ; | |
1da177e4 LT |
299 | acl->a_entries[1].e_perm = (mode & S_IRWXG) >> 3; |
300 | ||
301 | acl->a_entries[2].e_tag = ACL_OTHER; | |
1da177e4 LT |
302 | acl->a_entries[2].e_perm = (mode & S_IRWXO); |
303 | return acl; | |
304 | } | |
0afaa120 | 305 | EXPORT_SYMBOL(posix_acl_from_mode); |
1da177e4 LT |
306 | |
307 | /* | |
308 | * Return 0 if current is granted want access to the inode | |
309 | * by the acl. Returns -E... otherwise. | |
310 | */ | |
311 | int | |
312 | posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want) | |
313 | { | |
314 | const struct posix_acl_entry *pa, *pe, *mask_obj; | |
315 | int found = 0; | |
316 | ||
d124b60a AG |
317 | want &= MAY_READ | MAY_WRITE | MAY_EXEC | MAY_NOT_BLOCK; |
318 | ||
1da177e4 LT |
319 | FOREACH_ACL_ENTRY(pa, acl, pe) { |
320 | switch(pa->e_tag) { | |
321 | case ACL_USER_OBJ: | |
322 | /* (May have been checked already) */ | |
2f6f0654 | 323 | if (uid_eq(inode->i_uid, current_fsuid())) |
1da177e4 LT |
324 | goto check_perm; |
325 | break; | |
326 | case ACL_USER: | |
2f6f0654 | 327 | if (uid_eq(pa->e_uid, current_fsuid())) |
1da177e4 LT |
328 | goto mask; |
329 | break; | |
330 | case ACL_GROUP_OBJ: | |
331 | if (in_group_p(inode->i_gid)) { | |
332 | found = 1; | |
333 | if ((pa->e_perm & want) == want) | |
334 | goto mask; | |
335 | } | |
336 | break; | |
337 | case ACL_GROUP: | |
2f6f0654 | 338 | if (in_group_p(pa->e_gid)) { |
1da177e4 LT |
339 | found = 1; |
340 | if ((pa->e_perm & want) == want) | |
341 | goto mask; | |
342 | } | |
343 | break; | |
344 | case ACL_MASK: | |
345 | break; | |
346 | case ACL_OTHER: | |
347 | if (found) | |
348 | return -EACCES; | |
349 | else | |
350 | goto check_perm; | |
351 | default: | |
352 | return -EIO; | |
353 | } | |
354 | } | |
355 | return -EIO; | |
356 | ||
357 | mask: | |
358 | for (mask_obj = pa+1; mask_obj != pe; mask_obj++) { | |
359 | if (mask_obj->e_tag == ACL_MASK) { | |
360 | if ((pa->e_perm & mask_obj->e_perm & want) == want) | |
361 | return 0; | |
362 | return -EACCES; | |
363 | } | |
364 | } | |
365 | ||
366 | check_perm: | |
367 | if ((pa->e_perm & want) == want) | |
368 | return 0; | |
369 | return -EACCES; | |
370 | } | |
371 | ||
372 | /* | |
373 | * Modify acl when creating a new inode. The caller must ensure the acl is | |
374 | * only referenced once. | |
375 | * | |
376 | * mode_p initially must contain the mode parameter to the open() / creat() | |
377 | * system calls. All permissions that are not granted by the acl are removed. | |
378 | * The permissions in the acl are changed to reflect the mode_p parameter. | |
379 | */ | |
d3fb6120 | 380 | static int posix_acl_create_masq(struct posix_acl *acl, umode_t *mode_p) |
1da177e4 LT |
381 | { |
382 | struct posix_acl_entry *pa, *pe; | |
383 | struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; | |
d3fb6120 | 384 | umode_t mode = *mode_p; |
1da177e4 LT |
385 | int not_equiv = 0; |
386 | ||
387 | /* assert(atomic_read(acl->a_refcount) == 1); */ | |
388 | ||
389 | FOREACH_ACL_ENTRY(pa, acl, pe) { | |
390 | switch(pa->e_tag) { | |
391 | case ACL_USER_OBJ: | |
392 | pa->e_perm &= (mode >> 6) | ~S_IRWXO; | |
393 | mode &= (pa->e_perm << 6) | ~S_IRWXU; | |
394 | break; | |
395 | ||
396 | case ACL_USER: | |
397 | case ACL_GROUP: | |
398 | not_equiv = 1; | |
399 | break; | |
400 | ||
401 | case ACL_GROUP_OBJ: | |
402 | group_obj = pa; | |
403 | break; | |
404 | ||
405 | case ACL_OTHER: | |
406 | pa->e_perm &= mode | ~S_IRWXO; | |
407 | mode &= pa->e_perm | ~S_IRWXO; | |
408 | break; | |
409 | ||
410 | case ACL_MASK: | |
411 | mask_obj = pa; | |
412 | not_equiv = 1; | |
413 | break; | |
414 | ||
415 | default: | |
416 | return -EIO; | |
417 | } | |
418 | } | |
419 | ||
420 | if (mask_obj) { | |
421 | mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO; | |
422 | mode &= (mask_obj->e_perm << 3) | ~S_IRWXG; | |
423 | } else { | |
424 | if (!group_obj) | |
425 | return -EIO; | |
426 | group_obj->e_perm &= (mode >> 3) | ~S_IRWXO; | |
427 | mode &= (group_obj->e_perm << 3) | ~S_IRWXG; | |
428 | } | |
429 | ||
430 | *mode_p = (*mode_p & ~S_IRWXUGO) | mode; | |
431 | return not_equiv; | |
432 | } | |
433 | ||
434 | /* | |
435 | * Modify the ACL for the chmod syscall. | |
436 | */ | |
5bf3258f | 437 | static int __posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode) |
1da177e4 LT |
438 | { |
439 | struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; | |
440 | struct posix_acl_entry *pa, *pe; | |
441 | ||
442 | /* assert(atomic_read(acl->a_refcount) == 1); */ | |
443 | ||
444 | FOREACH_ACL_ENTRY(pa, acl, pe) { | |
445 | switch(pa->e_tag) { | |
446 | case ACL_USER_OBJ: | |
447 | pa->e_perm = (mode & S_IRWXU) >> 6; | |
448 | break; | |
449 | ||
450 | case ACL_USER: | |
451 | case ACL_GROUP: | |
452 | break; | |
453 | ||
454 | case ACL_GROUP_OBJ: | |
455 | group_obj = pa; | |
456 | break; | |
457 | ||
458 | case ACL_MASK: | |
459 | mask_obj = pa; | |
460 | break; | |
461 | ||
462 | case ACL_OTHER: | |
463 | pa->e_perm = (mode & S_IRWXO); | |
464 | break; | |
465 | ||
466 | default: | |
467 | return -EIO; | |
468 | } | |
469 | } | |
470 | ||
471 | if (mask_obj) { | |
472 | mask_obj->e_perm = (mode & S_IRWXG) >> 3; | |
473 | } else { | |
474 | if (!group_obj) | |
475 | return -EIO; | |
476 | group_obj->e_perm = (mode & S_IRWXG) >> 3; | |
477 | } | |
478 | ||
479 | return 0; | |
480 | } | |
bc26ab5f | 481 | |
826cae2f | 482 | int |
37bc1539 | 483 | __posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p) |
826cae2f AV |
484 | { |
485 | struct posix_acl *clone = posix_acl_clone(*acl, gfp); | |
486 | int err = -ENOMEM; | |
487 | if (clone) { | |
488 | err = posix_acl_create_masq(clone, mode_p); | |
489 | if (err < 0) { | |
490 | posix_acl_release(clone); | |
491 | clone = NULL; | |
492 | } | |
493 | } | |
494 | posix_acl_release(*acl); | |
495 | *acl = clone; | |
496 | return err; | |
497 | } | |
37bc1539 | 498 | EXPORT_SYMBOL(__posix_acl_create); |
826cae2f | 499 | |
bc26ab5f | 500 | int |
5bf3258f | 501 | __posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode) |
bc26ab5f AV |
502 | { |
503 | struct posix_acl *clone = posix_acl_clone(*acl, gfp); | |
504 | int err = -ENOMEM; | |
505 | if (clone) { | |
5bf3258f | 506 | err = __posix_acl_chmod_masq(clone, mode); |
bc26ab5f AV |
507 | if (err) { |
508 | posix_acl_release(clone); | |
509 | clone = NULL; | |
510 | } | |
511 | } | |
512 | posix_acl_release(*acl); | |
513 | *acl = clone; | |
514 | return err; | |
515 | } | |
5bf3258f CH |
516 | EXPORT_SYMBOL(__posix_acl_chmod); |
517 | ||
518 | int | |
37bc1539 | 519 | posix_acl_chmod(struct inode *inode, umode_t mode) |
5bf3258f CH |
520 | { |
521 | struct posix_acl *acl; | |
522 | int ret = 0; | |
523 | ||
524 | if (!IS_POSIXACL(inode)) | |
525 | return 0; | |
526 | if (!inode->i_op->set_acl) | |
527 | return -EOPNOTSUPP; | |
528 | ||
529 | acl = get_acl(inode, ACL_TYPE_ACCESS); | |
789b663a TM |
530 | if (IS_ERR_OR_NULL(acl)) { |
531 | if (acl == ERR_PTR(-EOPNOTSUPP)) | |
532 | return 0; | |
5bf3258f | 533 | return PTR_ERR(acl); |
789b663a | 534 | } |
5bf3258f | 535 | |
37bc1539 | 536 | ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode); |
5bf3258f CH |
537 | if (ret) |
538 | return ret; | |
539 | ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS); | |
540 | posix_acl_release(acl); | |
541 | return ret; | |
542 | } | |
bc26ab5f | 543 | EXPORT_SYMBOL(posix_acl_chmod); |
5c8ebd57 | 544 | |
37bc1539 CH |
545 | int |
546 | posix_acl_create(struct inode *dir, umode_t *mode, | |
547 | struct posix_acl **default_acl, struct posix_acl **acl) | |
548 | { | |
549 | struct posix_acl *p; | |
c0c3a718 | 550 | struct posix_acl *clone; |
37bc1539 CH |
551 | int ret; |
552 | ||
c0c3a718 DC |
553 | *acl = NULL; |
554 | *default_acl = NULL; | |
555 | ||
37bc1539 | 556 | if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) |
c0c3a718 | 557 | return 0; |
37bc1539 CH |
558 | |
559 | p = get_acl(dir, ACL_TYPE_DEFAULT); | |
c0c3a718 DC |
560 | if (!p || p == ERR_PTR(-EOPNOTSUPP)) { |
561 | *mode &= ~current_umask(); | |
562 | return 0; | |
37bc1539 | 563 | } |
c0c3a718 DC |
564 | if (IS_ERR(p)) |
565 | return PTR_ERR(p); | |
37bc1539 | 566 | |
c0c3a718 DC |
567 | clone = posix_acl_clone(p, GFP_NOFS); |
568 | if (!clone) | |
fed0b588 | 569 | goto no_mem; |
37bc1539 | 570 | |
c0c3a718 | 571 | ret = posix_acl_create_masq(clone, mode); |
fed0b588 OS |
572 | if (ret < 0) |
573 | goto no_mem_clone; | |
37bc1539 | 574 | |
c0c3a718 DC |
575 | if (ret == 0) |
576 | posix_acl_release(clone); | |
577 | else | |
578 | *acl = clone; | |
37bc1539 | 579 | |
c0c3a718 | 580 | if (!S_ISDIR(*mode)) |
37bc1539 | 581 | posix_acl_release(p); |
c0c3a718 | 582 | else |
37bc1539 | 583 | *default_acl = p; |
37bc1539 | 584 | |
37bc1539 | 585 | return 0; |
fed0b588 OS |
586 | |
587 | no_mem_clone: | |
c0c3a718 | 588 | posix_acl_release(clone); |
fed0b588 OS |
589 | no_mem: |
590 | posix_acl_release(p); | |
591 | return -ENOMEM; | |
37bc1539 CH |
592 | } |
593 | EXPORT_SYMBOL_GPL(posix_acl_create); | |
594 | ||
a665e1b4 JK |
595 | /** |
596 | * posix_acl_update_mode - update mode in set_acl | |
597 | * | |
598 | * Update the file mode when setting an ACL: compute the new file permission | |
599 | * bits based on the ACL. In addition, if the ACL is equivalent to the new | |
600 | * file mode, set *acl to NULL to indicate that no ACL should be set. | |
601 | * | |
602 | * As with chmod, clear the setgit bit if the caller is not in the owning group | |
603 | * or capable of CAP_FSETID (see inode_change_ok). | |
604 | * | |
605 | * Called from set_acl inode operations. | |
606 | */ | |
607 | int posix_acl_update_mode(struct inode *inode, umode_t *mode_p, | |
608 | struct posix_acl **acl) | |
609 | { | |
610 | umode_t mode = inode->i_mode; | |
611 | int error; | |
612 | ||
613 | error = posix_acl_equiv_mode(*acl, &mode); | |
614 | if (error < 0) | |
615 | return error; | |
616 | if (error == 0) | |
617 | *acl = NULL; | |
618 | if (!in_group_p(inode->i_gid) && | |
619 | !capable_wrt_inode_uidgid(inode, CAP_FSETID)) | |
620 | mode &= ~S_ISGID; | |
621 | *mode_p = mode; | |
622 | return 0; | |
623 | } | |
624 | EXPORT_SYMBOL(posix_acl_update_mode); | |
625 | ||
5c8ebd57 CH |
626 | /* |
627 | * Fix up the uids and gids in posix acl extended attributes in place. | |
628 | */ | |
2ccf1c9b | 629 | int posix_acl_fix_xattr_userns( |
5c8ebd57 CH |
630 | struct user_namespace *to, struct user_namespace *from, |
631 | void *value, size_t size) | |
632 | { | |
633 | posix_acl_xattr_header *header = (posix_acl_xattr_header *)value; | |
634 | posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end; | |
635 | int count; | |
2ccf1c9b SF |
636 | kuid_t kuid; |
637 | kgid_t kgid; | |
638 | uid_t uid; | |
639 | gid_t gid; | |
640 | int ret = 0; | |
5c8ebd57 | 641 | |
2ccf1c9b SF |
642 | if (to == from) |
643 | return 0; | |
5c8ebd57 | 644 | if (!value) |
2ccf1c9b | 645 | return 0; |
5c8ebd57 | 646 | if (size < sizeof(posix_acl_xattr_header)) |
2ccf1c9b | 647 | return -EINVAL; |
5c8ebd57 | 648 | if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION)) |
2ccf1c9b | 649 | return -EINVAL; |
5c8ebd57 CH |
650 | |
651 | count = posix_acl_xattr_count(size); | |
652 | if (count < 0) | |
2ccf1c9b | 653 | return -EINVAL; |
5c8ebd57 | 654 | if (count == 0) |
2ccf1c9b | 655 | return 0; |
5c8ebd57 CH |
656 | |
657 | for (end = entry + count; entry != end; entry++) { | |
658 | switch(le16_to_cpu(entry->e_tag)) { | |
659 | case ACL_USER: | |
2ccf1c9b SF |
660 | kuid = make_kuid(from, le32_to_cpu(entry->e_id)); |
661 | uid = from_kuid(to, kuid); | |
662 | entry->e_id = cpu_to_le32(uid); | |
663 | if (uid == (uid_t)-1) | |
664 | ret = -EOVERFLOW; | |
5c8ebd57 CH |
665 | break; |
666 | case ACL_GROUP: | |
2ccf1c9b SF |
667 | kgid = make_kgid(from, le32_to_cpu(entry->e_id)); |
668 | gid = from_kgid(to, kgid); | |
669 | entry->e_id = cpu_to_le32(gid); | |
670 | if (gid == (gid_t)-1) | |
671 | ret = -EOVERFLOW; | |
5c8ebd57 CH |
672 | break; |
673 | default: | |
674 | break; | |
675 | } | |
676 | } | |
2ccf1c9b SF |
677 | |
678 | return ret; | |
5c8ebd57 | 679 | } |
2ccf1c9b | 680 | EXPORT_SYMBOL(posix_acl_fix_xattr_userns); |
5c8ebd57 | 681 | |
6969b7e0 | 682 | void posix_acl_fix_xattr_from_user(void *value, size_t size) |
5c8ebd57 | 683 | { |
6969b7e0 | 684 | struct user_namespace *user_ns = current_user_ns(); |
6969b7e0 | 685 | posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size); |
5c8ebd57 CH |
686 | } |
687 | ||
6969b7e0 | 688 | void posix_acl_fix_xattr_to_user(void *value, size_t size) |
5c8ebd57 | 689 | { |
6969b7e0 | 690 | struct user_namespace *user_ns = current_user_ns(); |
6969b7e0 | 691 | posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size); |
5c8ebd57 CH |
692 | } |
693 | ||
694 | /* | |
695 | * Convert from extended attribute to in-memory representation. | |
696 | */ | |
697 | struct posix_acl * | |
698 | posix_acl_from_xattr(struct user_namespace *user_ns, | |
699 | const void *value, size_t size) | |
700 | { | |
701 | posix_acl_xattr_header *header = (posix_acl_xattr_header *)value; | |
702 | posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end; | |
703 | int count; | |
704 | struct posix_acl *acl; | |
705 | struct posix_acl_entry *acl_e; | |
706 | ||
707 | if (!value) | |
708 | return NULL; | |
709 | if (size < sizeof(posix_acl_xattr_header)) | |
710 | return ERR_PTR(-EINVAL); | |
711 | if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION)) | |
712 | return ERR_PTR(-EOPNOTSUPP); | |
713 | ||
714 | count = posix_acl_xattr_count(size); | |
715 | if (count < 0) | |
716 | return ERR_PTR(-EINVAL); | |
717 | if (count == 0) | |
718 | return NULL; | |
719 | ||
720 | acl = posix_acl_alloc(count, GFP_NOFS); | |
721 | if (!acl) | |
722 | return ERR_PTR(-ENOMEM); | |
723 | acl_e = acl->a_entries; | |
724 | ||
725 | for (end = entry + count; entry != end; acl_e++, entry++) { | |
726 | acl_e->e_tag = le16_to_cpu(entry->e_tag); | |
727 | acl_e->e_perm = le16_to_cpu(entry->e_perm); | |
728 | ||
729 | switch(acl_e->e_tag) { | |
730 | case ACL_USER_OBJ: | |
731 | case ACL_GROUP_OBJ: | |
732 | case ACL_MASK: | |
733 | case ACL_OTHER: | |
734 | break; | |
735 | ||
736 | case ACL_USER: | |
737 | acl_e->e_uid = | |
738 | make_kuid(user_ns, | |
739 | le32_to_cpu(entry->e_id)); | |
740 | if (!uid_valid(acl_e->e_uid)) | |
741 | goto fail; | |
742 | break; | |
743 | case ACL_GROUP: | |
744 | acl_e->e_gid = | |
745 | make_kgid(user_ns, | |
746 | le32_to_cpu(entry->e_id)); | |
747 | if (!gid_valid(acl_e->e_gid)) | |
748 | goto fail; | |
749 | break; | |
750 | ||
751 | default: | |
752 | goto fail; | |
753 | } | |
754 | } | |
755 | return acl; | |
756 | ||
757 | fail: | |
758 | posix_acl_release(acl); | |
759 | return ERR_PTR(-EINVAL); | |
760 | } | |
761 | EXPORT_SYMBOL (posix_acl_from_xattr); | |
762 | ||
763 | /* | |
764 | * Convert from in-memory to extended attribute representation. | |
765 | */ | |
766 | int | |
767 | posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl, | |
768 | void *buffer, size_t size) | |
769 | { | |
770 | posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer; | |
47ba9734 | 771 | posix_acl_xattr_entry *ext_entry; |
5c8ebd57 CH |
772 | int real_size, n; |
773 | ||
774 | real_size = posix_acl_xattr_size(acl->a_count); | |
775 | if (!buffer) | |
776 | return real_size; | |
777 | if (real_size > size) | |
778 | return -ERANGE; | |
47ba9734 DC |
779 | |
780 | ext_entry = ext_acl->a_entries; | |
5c8ebd57 CH |
781 | ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION); |
782 | ||
783 | for (n=0; n < acl->a_count; n++, ext_entry++) { | |
784 | const struct posix_acl_entry *acl_e = &acl->a_entries[n]; | |
785 | ext_entry->e_tag = cpu_to_le16(acl_e->e_tag); | |
786 | ext_entry->e_perm = cpu_to_le16(acl_e->e_perm); | |
787 | switch(acl_e->e_tag) { | |
788 | case ACL_USER: | |
789 | ext_entry->e_id = | |
790 | cpu_to_le32(from_kuid(user_ns, acl_e->e_uid)); | |
791 | break; | |
792 | case ACL_GROUP: | |
793 | ext_entry->e_id = | |
794 | cpu_to_le32(from_kgid(user_ns, acl_e->e_gid)); | |
795 | break; | |
796 | default: | |
797 | ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID); | |
798 | break; | |
799 | } | |
800 | } | |
801 | return real_size; | |
802 | } | |
803 | EXPORT_SYMBOL (posix_acl_to_xattr); | |
2aeccbe9 CH |
804 | |
805 | static int | |
d9a82a04 AG |
806 | posix_acl_xattr_get(const struct xattr_handler *handler, |
807 | struct dentry *dentry, const char *name, | |
808 | void *value, size_t size) | |
2aeccbe9 CH |
809 | { |
810 | struct posix_acl *acl; | |
811 | int error; | |
812 | ||
c361016a AG |
813 | if (strcmp(name, "") != 0) |
814 | return -EINVAL; | |
bb668734 | 815 | if (!IS_POSIXACL(d_backing_inode(dentry))) |
2aeccbe9 | 816 | return -EOPNOTSUPP; |
e36cb0b8 | 817 | if (d_is_symlink(dentry)) |
2aeccbe9 CH |
818 | return -EOPNOTSUPP; |
819 | ||
d9a82a04 | 820 | acl = get_acl(d_backing_inode(dentry), handler->flags); |
2aeccbe9 CH |
821 | if (IS_ERR(acl)) |
822 | return PTR_ERR(acl); | |
823 | if (acl == NULL) | |
824 | return -ENODATA; | |
825 | ||
6969b7e0 | 826 | error = posix_acl_to_xattr(&init_user_ns, acl, value, size); |
2aeccbe9 CH |
827 | posix_acl_release(acl); |
828 | ||
829 | return error; | |
830 | } | |
831 | ||
12e4839a AG |
832 | int |
833 | set_posix_acl(struct inode *inode, int type, struct posix_acl *acl) | |
834 | { | |
835 | if (!IS_POSIXACL(inode)) | |
836 | return -EOPNOTSUPP; | |
837 | if (!inode->i_op->set_acl) | |
838 | return -EOPNOTSUPP; | |
839 | ||
840 | if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) | |
841 | return acl ? -EACCES : 0; | |
842 | if (!inode_owner_or_capable(inode)) | |
843 | return -EPERM; | |
844 | ||
845 | if (acl) { | |
37d3c4d6 | 846 | int ret = posix_acl_valid(inode->i_sb->s_user_ns, acl); |
12e4839a AG |
847 | if (ret) |
848 | return ret; | |
849 | } | |
850 | return inode->i_op->set_acl(inode, acl, type); | |
851 | } | |
852 | EXPORT_SYMBOL(set_posix_acl); | |
853 | ||
2aeccbe9 | 854 | static int |
d9a82a04 AG |
855 | posix_acl_xattr_set(const struct xattr_handler *handler, |
856 | struct dentry *dentry, const char *name, | |
857 | const void *value, size_t size, int flags) | |
2aeccbe9 | 858 | { |
bb668734 | 859 | struct inode *inode = d_backing_inode(dentry); |
2aeccbe9 CH |
860 | struct posix_acl *acl = NULL; |
861 | int ret; | |
862 | ||
c361016a AG |
863 | if (strcmp(name, "") != 0) |
864 | return -EINVAL; | |
2aeccbe9 CH |
865 | |
866 | if (value) { | |
6969b7e0 | 867 | acl = posix_acl_from_xattr(&init_user_ns, value, size); |
2aeccbe9 CH |
868 | if (IS_ERR(acl)) |
869 | return PTR_ERR(acl); | |
2aeccbe9 | 870 | } |
12e4839a | 871 | ret = set_posix_acl(inode, handler->flags, acl); |
2aeccbe9 CH |
872 | posix_acl_release(acl); |
873 | return ret; | |
874 | } | |
875 | ||
876 | static size_t | |
d9a82a04 AG |
877 | posix_acl_xattr_list(const struct xattr_handler *handler, |
878 | struct dentry *dentry, char *list, size_t list_size, | |
879 | const char *name, size_t name_len) | |
2aeccbe9 | 880 | { |
d9a82a04 | 881 | const char *xname = handler->prefix; |
2aeccbe9 CH |
882 | size_t size; |
883 | ||
bb668734 | 884 | if (!IS_POSIXACL(d_backing_inode(dentry))) |
dae5f57a | 885 | return 0; |
2aeccbe9 | 886 | |
2aeccbe9 CH |
887 | size = strlen(xname) + 1; |
888 | if (list && size <= list_size) | |
889 | memcpy(list, xname, size); | |
890 | return size; | |
891 | } | |
892 | ||
893 | const struct xattr_handler posix_acl_access_xattr_handler = { | |
894 | .prefix = POSIX_ACL_XATTR_ACCESS, | |
895 | .flags = ACL_TYPE_ACCESS, | |
896 | .list = posix_acl_xattr_list, | |
897 | .get = posix_acl_xattr_get, | |
898 | .set = posix_acl_xattr_set, | |
899 | }; | |
900 | EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler); | |
901 | ||
902 | const struct xattr_handler posix_acl_default_xattr_handler = { | |
903 | .prefix = POSIX_ACL_XATTR_DEFAULT, | |
904 | .flags = ACL_TYPE_DEFAULT, | |
905 | .list = posix_acl_xattr_list, | |
906 | .get = posix_acl_xattr_get, | |
907 | .set = posix_acl_xattr_set, | |
908 | }; | |
909 | EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler); | |
feda821e CH |
910 | |
911 | int simple_set_acl(struct inode *inode, struct posix_acl *acl, int type) | |
912 | { | |
913 | int error; | |
914 | ||
915 | if (type == ACL_TYPE_ACCESS) { | |
f4d9f3f8 GZ |
916 | error = posix_acl_update_mode(inode, |
917 | &inode->i_mode, &acl); | |
918 | if (error) | |
919 | return error; | |
feda821e CH |
920 | } |
921 | ||
922 | inode->i_ctime = CURRENT_TIME; | |
923 | set_cached_acl(inode, type, acl); | |
924 | return 0; | |
925 | } | |
926 | ||
927 | int simple_acl_create(struct inode *dir, struct inode *inode) | |
928 | { | |
929 | struct posix_acl *default_acl, *acl; | |
930 | int error; | |
931 | ||
932 | error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); | |
933 | if (error) | |
934 | return error; | |
935 | ||
936 | set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl); | |
937 | set_cached_acl(inode, ACL_TYPE_ACCESS, acl); | |
938 | ||
939 | if (default_acl) | |
940 | posix_acl_release(default_acl); | |
941 | if (acl) | |
942 | posix_acl_release(acl); | |
943 | return 0; | |
944 | } |