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14#include <linux/kernel.h>
15#include <linux/slab.h>
16#include <linux/atomic.h>
17#include <linux/fs.h>
18#include <linux/sched.h>
19#include <linux/cred.h>
20#include <linux/posix_acl.h>
21#include <linux/posix_acl_xattr.h>
22#include <linux/xattr.h>
23#include <linux/export.h>
24#include <linux/user_namespace.h>
25
26static struct posix_acl **acl_by_type(struct inode *inode, int type)
27{
28 switch (type) {
29 case ACL_TYPE_ACCESS:
30 return &inode->i_acl;
31 case ACL_TYPE_DEFAULT:
32 return &inode->i_default_acl;
33 default:
34 BUG();
35 }
36}
37
38struct posix_acl *get_cached_acl(struct inode *inode, int type)
39{
40 struct posix_acl **p = acl_by_type(inode, type);
41 struct posix_acl *acl;
42
43 for (;;) {
44 rcu_read_lock();
45 acl = rcu_dereference(*p);
46 if (!acl || is_uncached_acl(acl) ||
47 refcount_inc_not_zero(&acl->a_refcount))
48 break;
49 rcu_read_unlock();
50 cpu_relax();
51 }
52 rcu_read_unlock();
53 return acl;
54}
55EXPORT_SYMBOL(get_cached_acl);
56
57struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type)
58{
59 return rcu_dereference(*acl_by_type(inode, type));
60}
61EXPORT_SYMBOL(get_cached_acl_rcu);
62
63void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl)
64{
65 struct posix_acl **p = acl_by_type(inode, type);
66 struct posix_acl *old;
67
68 old = xchg(p, posix_acl_dup(acl));
69 if (!is_uncached_acl(old))
70 posix_acl_release(old);
71}
72EXPORT_SYMBOL(set_cached_acl);
73
74static void __forget_cached_acl(struct posix_acl **p)
75{
76 struct posix_acl *old;
77
78 old = xchg(p, ACL_NOT_CACHED);
79 if (!is_uncached_acl(old))
80 posix_acl_release(old);
81}
82
83void forget_cached_acl(struct inode *inode, int type)
84{
85 __forget_cached_acl(acl_by_type(inode, type));
86}
87EXPORT_SYMBOL(forget_cached_acl);
88
89void forget_all_cached_acls(struct inode *inode)
90{
91 __forget_cached_acl(&inode->i_acl);
92 __forget_cached_acl(&inode->i_default_acl);
93}
94EXPORT_SYMBOL(forget_all_cached_acls);
95
96struct posix_acl *get_acl(struct inode *inode, int type)
97{
98 void *sentinel;
99 struct posix_acl **p;
100 struct posix_acl *acl;
101
102
103
104
105
106
107
108 acl = get_cached_acl(inode, type);
109 if (!is_uncached_acl(acl))
110 return acl;
111
112 if (!IS_POSIXACL(inode))
113 return NULL;
114
115 sentinel = uncached_acl_sentinel(current);
116 p = acl_by_type(inode, type);
117
118
119
120
121
122
123
124
125
126 if (cmpxchg(p, ACL_NOT_CACHED, sentinel) != ACL_NOT_CACHED)
127 ;
128
129
130
131
132
133
134
135
136
137 if (!inode->i_op->get_acl) {
138 set_cached_acl(inode, type, NULL);
139 return NULL;
140 }
141 acl = inode->i_op->get_acl(inode, type);
142
143 if (IS_ERR(acl)) {
144
145
146
147
148 cmpxchg(p, sentinel, ACL_NOT_CACHED);
149 return acl;
150 }
151
152
153
154
155 posix_acl_dup(acl);
156 if (unlikely(cmpxchg(p, sentinel, acl) != sentinel))
157 posix_acl_release(acl);
158 return acl;
159}
160EXPORT_SYMBOL(get_acl);
161
162
163
164
165void
166posix_acl_init(struct posix_acl *acl, int count)
167{
168 refcount_set(&acl->a_refcount, 1);
169 acl->a_count = count;
170}
171EXPORT_SYMBOL(posix_acl_init);
172
173
174
175
176struct posix_acl *
177posix_acl_alloc(int count, gfp_t flags)
178{
179 const size_t size = sizeof(struct posix_acl) +
180 count * sizeof(struct posix_acl_entry);
181 struct posix_acl *acl = kmalloc(size, flags);
182 if (acl)
183 posix_acl_init(acl, count);
184 return acl;
185}
186EXPORT_SYMBOL(posix_acl_alloc);
187
188
189
190
191static struct posix_acl *
192posix_acl_clone(const struct posix_acl *acl, gfp_t flags)
193{
194 struct posix_acl *clone = NULL;
195
196 if (acl) {
197 int size = sizeof(struct posix_acl) + acl->a_count *
198 sizeof(struct posix_acl_entry);
199 clone = kmemdup(acl, size, flags);
200 if (clone)
201 refcount_set(&clone->a_refcount, 1);
202 }
203 return clone;
204}
205
206
207
208
209int
210posix_acl_valid(struct user_namespace *user_ns, const struct posix_acl *acl)
211{
212 const struct posix_acl_entry *pa, *pe;
213 int state = ACL_USER_OBJ;
214 int needs_mask = 0;
215
216 FOREACH_ACL_ENTRY(pa, acl, pe) {
217 if (pa->e_perm & ~(ACL_READ|ACL_WRITE|ACL_EXECUTE))
218 return -EINVAL;
219 switch (pa->e_tag) {
220 case ACL_USER_OBJ:
221 if (state == ACL_USER_OBJ) {
222 state = ACL_USER;
223 break;
224 }
225 return -EINVAL;
226
227 case ACL_USER:
228 if (state != ACL_USER)
229 return -EINVAL;
230 if (!kuid_has_mapping(user_ns, pa->e_uid))
231 return -EINVAL;
232 needs_mask = 1;
233 break;
234
235 case ACL_GROUP_OBJ:
236 if (state == ACL_USER) {
237 state = ACL_GROUP;
238 break;
239 }
240 return -EINVAL;
241
242 case ACL_GROUP:
243 if (state != ACL_GROUP)
244 return -EINVAL;
245 if (!kgid_has_mapping(user_ns, pa->e_gid))
246 return -EINVAL;
247 needs_mask = 1;
248 break;
249
250 case ACL_MASK:
251 if (state != ACL_GROUP)
252 return -EINVAL;
253 state = ACL_OTHER;
254 break;
255
256 case ACL_OTHER:
257 if (state == ACL_OTHER ||
258 (state == ACL_GROUP && !needs_mask)) {
259 state = 0;
260 break;
261 }
262 return -EINVAL;
263
264 default:
265 return -EINVAL;
266 }
267 }
268 if (state == 0)
269 return 0;
270 return -EINVAL;
271}
272EXPORT_SYMBOL(posix_acl_valid);
273
274
275
276
277
278int
279posix_acl_equiv_mode(const struct posix_acl *acl, umode_t *mode_p)
280{
281 const struct posix_acl_entry *pa, *pe;
282 umode_t mode = 0;
283 int not_equiv = 0;
284
285
286
287
288 if (!acl)
289 return 0;
290
291 FOREACH_ACL_ENTRY(pa, acl, pe) {
292 switch (pa->e_tag) {
293 case ACL_USER_OBJ:
294 mode |= (pa->e_perm & S_IRWXO) << 6;
295 break;
296 case ACL_GROUP_OBJ:
297 mode |= (pa->e_perm & S_IRWXO) << 3;
298 break;
299 case ACL_OTHER:
300 mode |= pa->e_perm & S_IRWXO;
301 break;
302 case ACL_MASK:
303 mode = (mode & ~S_IRWXG) |
304 ((pa->e_perm & S_IRWXO) << 3);
305 not_equiv = 1;
306 break;
307 case ACL_USER:
308 case ACL_GROUP:
309 not_equiv = 1;
310 break;
311 default:
312 return -EINVAL;
313 }
314 }
315 if (mode_p)
316 *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
317 return not_equiv;
318}
319EXPORT_SYMBOL(posix_acl_equiv_mode);
320
321
322
323
324struct posix_acl *
325posix_acl_from_mode(umode_t mode, gfp_t flags)
326{
327 struct posix_acl *acl = posix_acl_alloc(3, flags);
328 if (!acl)
329 return ERR_PTR(-ENOMEM);
330
331 acl->a_entries[0].e_tag = ACL_USER_OBJ;
332 acl->a_entries[0].e_perm = (mode & S_IRWXU) >> 6;
333
334 acl->a_entries[1].e_tag = ACL_GROUP_OBJ;
335 acl->a_entries[1].e_perm = (mode & S_IRWXG) >> 3;
336
337 acl->a_entries[2].e_tag = ACL_OTHER;
338 acl->a_entries[2].e_perm = (mode & S_IRWXO);
339 return acl;
340}
341EXPORT_SYMBOL(posix_acl_from_mode);
342
343
344
345
346
347int
348posix_acl_permission(struct user_namespace *mnt_userns, struct inode *inode,
349 const struct posix_acl *acl, int want)
350{
351 const struct posix_acl_entry *pa, *pe, *mask_obj;
352 int found = 0;
353 kuid_t uid;
354 kgid_t gid;
355
356 want &= MAY_READ | MAY_WRITE | MAY_EXEC;
357
358 FOREACH_ACL_ENTRY(pa, acl, pe) {
359 switch(pa->e_tag) {
360 case ACL_USER_OBJ:
361
362 uid = i_uid_into_mnt(mnt_userns, inode);
363 if (uid_eq(uid, current_fsuid()))
364 goto check_perm;
365 break;
366 case ACL_USER:
367 uid = kuid_into_mnt(mnt_userns, pa->e_uid);
368 if (uid_eq(uid, current_fsuid()))
369 goto mask;
370 break;
371 case ACL_GROUP_OBJ:
372 gid = i_gid_into_mnt(mnt_userns, inode);
373 if (in_group_p(gid)) {
374 found = 1;
375 if ((pa->e_perm & want) == want)
376 goto mask;
377 }
378 break;
379 case ACL_GROUP:
380 gid = kgid_into_mnt(mnt_userns, pa->e_gid);
381 if (in_group_p(gid)) {
382 found = 1;
383 if ((pa->e_perm & want) == want)
384 goto mask;
385 }
386 break;
387 case ACL_MASK:
388 break;
389 case ACL_OTHER:
390 if (found)
391 return -EACCES;
392 else
393 goto check_perm;
394 default:
395 return -EIO;
396 }
397 }
398 return -EIO;
399
400mask:
401 for (mask_obj = pa+1; mask_obj != pe; mask_obj++) {
402 if (mask_obj->e_tag == ACL_MASK) {
403 if ((pa->e_perm & mask_obj->e_perm & want) == want)
404 return 0;
405 return -EACCES;
406 }
407 }
408
409check_perm:
410 if ((pa->e_perm & want) == want)
411 return 0;
412 return -EACCES;
413}
414
415
416
417
418
419
420
421
422
423static int posix_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
424{
425 struct posix_acl_entry *pa, *pe;
426 struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
427 umode_t mode = *mode_p;
428 int not_equiv = 0;
429
430
431
432 FOREACH_ACL_ENTRY(pa, acl, pe) {
433 switch(pa->e_tag) {
434 case ACL_USER_OBJ:
435 pa->e_perm &= (mode >> 6) | ~S_IRWXO;
436 mode &= (pa->e_perm << 6) | ~S_IRWXU;
437 break;
438
439 case ACL_USER:
440 case ACL_GROUP:
441 not_equiv = 1;
442 break;
443
444 case ACL_GROUP_OBJ:
445 group_obj = pa;
446 break;
447
448 case ACL_OTHER:
449 pa->e_perm &= mode | ~S_IRWXO;
450 mode &= pa->e_perm | ~S_IRWXO;
451 break;
452
453 case ACL_MASK:
454 mask_obj = pa;
455 not_equiv = 1;
456 break;
457
458 default:
459 return -EIO;
460 }
461 }
462
463 if (mask_obj) {
464 mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
465 mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
466 } else {
467 if (!group_obj)
468 return -EIO;
469 group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
470 mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
471 }
472
473 *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
474 return not_equiv;
475}
476
477
478
479
480static int __posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode)
481{
482 struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
483 struct posix_acl_entry *pa, *pe;
484
485
486
487 FOREACH_ACL_ENTRY(pa, acl, pe) {
488 switch(pa->e_tag) {
489 case ACL_USER_OBJ:
490 pa->e_perm = (mode & S_IRWXU) >> 6;
491 break;
492
493 case ACL_USER:
494 case ACL_GROUP:
495 break;
496
497 case ACL_GROUP_OBJ:
498 group_obj = pa;
499 break;
500
501 case ACL_MASK:
502 mask_obj = pa;
503 break;
504
505 case ACL_OTHER:
506 pa->e_perm = (mode & S_IRWXO);
507 break;
508
509 default:
510 return -EIO;
511 }
512 }
513
514 if (mask_obj) {
515 mask_obj->e_perm = (mode & S_IRWXG) >> 3;
516 } else {
517 if (!group_obj)
518 return -EIO;
519 group_obj->e_perm = (mode & S_IRWXG) >> 3;
520 }
521
522 return 0;
523}
524
525int
526__posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p)
527{
528 struct posix_acl *clone = posix_acl_clone(*acl, gfp);
529 int err = -ENOMEM;
530 if (clone) {
531 err = posix_acl_create_masq(clone, mode_p);
532 if (err < 0) {
533 posix_acl_release(clone);
534 clone = NULL;
535 }
536 }
537 posix_acl_release(*acl);
538 *acl = clone;
539 return err;
540}
541EXPORT_SYMBOL(__posix_acl_create);
542
543int
544__posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode)
545{
546 struct posix_acl *clone = posix_acl_clone(*acl, gfp);
547 int err = -ENOMEM;
548 if (clone) {
549 err = __posix_acl_chmod_masq(clone, mode);
550 if (err) {
551 posix_acl_release(clone);
552 clone = NULL;
553 }
554 }
555 posix_acl_release(*acl);
556 *acl = clone;
557 return err;
558}
559EXPORT_SYMBOL(__posix_acl_chmod);
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574int
575 posix_acl_chmod(struct user_namespace *mnt_userns, struct inode *inode,
576 umode_t mode)
577{
578 struct posix_acl *acl;
579 int ret = 0;
580
581 if (!IS_POSIXACL(inode))
582 return 0;
583 if (!inode->i_op->set_acl)
584 return -EOPNOTSUPP;
585
586 acl = get_acl(inode, ACL_TYPE_ACCESS);
587 if (IS_ERR_OR_NULL(acl)) {
588 if (acl == ERR_PTR(-EOPNOTSUPP))
589 return 0;
590 return PTR_ERR(acl);
591 }
592
593 ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode);
594 if (ret)
595 return ret;
596 ret = inode->i_op->set_acl(mnt_userns, inode, acl, ACL_TYPE_ACCESS);
597 posix_acl_release(acl);
598 return ret;
599}
600EXPORT_SYMBOL(posix_acl_chmod);
601
602int
603posix_acl_create(struct inode *dir, umode_t *mode,
604 struct posix_acl **default_acl, struct posix_acl **acl)
605{
606 struct posix_acl *p;
607 struct posix_acl *clone;
608 int ret;
609
610 *acl = NULL;
611 *default_acl = NULL;
612
613 if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
614 return 0;
615
616 p = get_acl(dir, ACL_TYPE_DEFAULT);
617 if (!p || p == ERR_PTR(-EOPNOTSUPP)) {
618 *mode &= ~current_umask();
619 return 0;
620 }
621 if (IS_ERR(p))
622 return PTR_ERR(p);
623
624 ret = -ENOMEM;
625 clone = posix_acl_clone(p, GFP_NOFS);
626 if (!clone)
627 goto err_release;
628
629 ret = posix_acl_create_masq(clone, mode);
630 if (ret < 0)
631 goto err_release_clone;
632
633 if (ret == 0)
634 posix_acl_release(clone);
635 else
636 *acl = clone;
637
638 if (!S_ISDIR(*mode))
639 posix_acl_release(p);
640 else
641 *default_acl = p;
642
643 return 0;
644
645err_release_clone:
646 posix_acl_release(clone);
647err_release:
648 posix_acl_release(p);
649 return ret;
650}
651EXPORT_SYMBOL_GPL(posix_acl_create);
652
653
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655
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663
664
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669
670
671
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673
674
675int posix_acl_update_mode(struct user_namespace *mnt_userns,
676 struct inode *inode, umode_t *mode_p,
677 struct posix_acl **acl)
678{
679 umode_t mode = inode->i_mode;
680 int error;
681
682 error = posix_acl_equiv_mode(*acl, &mode);
683 if (error < 0)
684 return error;
685 if (error == 0)
686 *acl = NULL;
687 if (!in_group_p(i_gid_into_mnt(mnt_userns, inode)) &&
688 !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
689 mode &= ~S_ISGID;
690 *mode_p = mode;
691 return 0;
692}
693EXPORT_SYMBOL(posix_acl_update_mode);
694
695
696
697
698static void posix_acl_fix_xattr_userns(
699 struct user_namespace *to, struct user_namespace *from,
700 struct user_namespace *mnt_userns,
701 void *value, size_t size, bool from_user)
702{
703 struct posix_acl_xattr_header *header = value;
704 struct posix_acl_xattr_entry *entry = (void *)(header + 1), *end;
705 int count;
706 kuid_t uid;
707 kgid_t gid;
708
709 if (!value)
710 return;
711 if (size < sizeof(struct posix_acl_xattr_header))
712 return;
713 if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
714 return;
715
716 count = posix_acl_xattr_count(size);
717 if (count < 0)
718 return;
719 if (count == 0)
720 return;
721
722 for (end = entry + count; entry != end; entry++) {
723 switch(le16_to_cpu(entry->e_tag)) {
724 case ACL_USER:
725 uid = make_kuid(from, le32_to_cpu(entry->e_id));
726 if (from_user)
727 uid = kuid_from_mnt(mnt_userns, uid);
728 else
729 uid = kuid_into_mnt(mnt_userns, uid);
730 entry->e_id = cpu_to_le32(from_kuid(to, uid));
731 break;
732 case ACL_GROUP:
733 gid = make_kgid(from, le32_to_cpu(entry->e_id));
734 if (from_user)
735 gid = kgid_from_mnt(mnt_userns, gid);
736 else
737 gid = kgid_into_mnt(mnt_userns, gid);
738 entry->e_id = cpu_to_le32(from_kgid(to, gid));
739 break;
740 default:
741 break;
742 }
743 }
744}
745
746void posix_acl_fix_xattr_from_user(struct user_namespace *mnt_userns,
747 void *value, size_t size)
748{
749 struct user_namespace *user_ns = current_user_ns();
750 if ((user_ns == &init_user_ns) && (mnt_userns == &init_user_ns))
751 return;
752 posix_acl_fix_xattr_userns(&init_user_ns, user_ns, mnt_userns, value,
753 size, true);
754}
755
756void posix_acl_fix_xattr_to_user(struct user_namespace *mnt_userns,
757 void *value, size_t size)
758{
759 struct user_namespace *user_ns = current_user_ns();
760 if ((user_ns == &init_user_ns) && (mnt_userns == &init_user_ns))
761 return;
762 posix_acl_fix_xattr_userns(user_ns, &init_user_ns, mnt_userns, value,
763 size, false);
764}
765
766
767
768
769struct posix_acl *
770posix_acl_from_xattr(struct user_namespace *user_ns,
771 const void *value, size_t size)
772{
773 const struct posix_acl_xattr_header *header = value;
774 const struct posix_acl_xattr_entry *entry = (const void *)(header + 1), *end;
775 int count;
776 struct posix_acl *acl;
777 struct posix_acl_entry *acl_e;
778
779 if (!value)
780 return NULL;
781 if (size < sizeof(struct posix_acl_xattr_header))
782 return ERR_PTR(-EINVAL);
783 if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
784 return ERR_PTR(-EOPNOTSUPP);
785
786 count = posix_acl_xattr_count(size);
787 if (count < 0)
788 return ERR_PTR(-EINVAL);
789 if (count == 0)
790 return NULL;
791
792 acl = posix_acl_alloc(count, GFP_NOFS);
793 if (!acl)
794 return ERR_PTR(-ENOMEM);
795 acl_e = acl->a_entries;
796
797 for (end = entry + count; entry != end; acl_e++, entry++) {
798 acl_e->e_tag = le16_to_cpu(entry->e_tag);
799 acl_e->e_perm = le16_to_cpu(entry->e_perm);
800
801 switch(acl_e->e_tag) {
802 case ACL_USER_OBJ:
803 case ACL_GROUP_OBJ:
804 case ACL_MASK:
805 case ACL_OTHER:
806 break;
807
808 case ACL_USER:
809 acl_e->e_uid =
810 make_kuid(user_ns,
811 le32_to_cpu(entry->e_id));
812 if (!uid_valid(acl_e->e_uid))
813 goto fail;
814 break;
815 case ACL_GROUP:
816 acl_e->e_gid =
817 make_kgid(user_ns,
818 le32_to_cpu(entry->e_id));
819 if (!gid_valid(acl_e->e_gid))
820 goto fail;
821 break;
822
823 default:
824 goto fail;
825 }
826 }
827 return acl;
828
829fail:
830 posix_acl_release(acl);
831 return ERR_PTR(-EINVAL);
832}
833EXPORT_SYMBOL (posix_acl_from_xattr);
834
835
836
837
838int
839posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl,
840 void *buffer, size_t size)
841{
842 struct posix_acl_xattr_header *ext_acl = buffer;
843 struct posix_acl_xattr_entry *ext_entry;
844 int real_size, n;
845
846 real_size = posix_acl_xattr_size(acl->a_count);
847 if (!buffer)
848 return real_size;
849 if (real_size > size)
850 return -ERANGE;
851
852 ext_entry = (void *)(ext_acl + 1);
853 ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
854
855 for (n=0; n < acl->a_count; n++, ext_entry++) {
856 const struct posix_acl_entry *acl_e = &acl->a_entries[n];
857 ext_entry->e_tag = cpu_to_le16(acl_e->e_tag);
858 ext_entry->e_perm = cpu_to_le16(acl_e->e_perm);
859 switch(acl_e->e_tag) {
860 case ACL_USER:
861 ext_entry->e_id =
862 cpu_to_le32(from_kuid(user_ns, acl_e->e_uid));
863 break;
864 case ACL_GROUP:
865 ext_entry->e_id =
866 cpu_to_le32(from_kgid(user_ns, acl_e->e_gid));
867 break;
868 default:
869 ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
870 break;
871 }
872 }
873 return real_size;
874}
875EXPORT_SYMBOL (posix_acl_to_xattr);
876
877static int
878posix_acl_xattr_get(const struct xattr_handler *handler,
879 struct dentry *unused, struct inode *inode,
880 const char *name, void *value, size_t size)
881{
882 struct posix_acl *acl;
883 int error;
884
885 if (!IS_POSIXACL(inode))
886 return -EOPNOTSUPP;
887 if (S_ISLNK(inode->i_mode))
888 return -EOPNOTSUPP;
889
890 acl = get_acl(inode, handler->flags);
891 if (IS_ERR(acl))
892 return PTR_ERR(acl);
893 if (acl == NULL)
894 return -ENODATA;
895
896 error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
897 posix_acl_release(acl);
898
899 return error;
900}
901
902int
903set_posix_acl(struct user_namespace *mnt_userns, struct inode *inode,
904 int type, struct posix_acl *acl)
905{
906 if (!IS_POSIXACL(inode))
907 return -EOPNOTSUPP;
908 if (!inode->i_op->set_acl)
909 return -EOPNOTSUPP;
910
911 if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
912 return acl ? -EACCES : 0;
913 if (!inode_owner_or_capable(mnt_userns, inode))
914 return -EPERM;
915
916 if (acl) {
917 int ret = posix_acl_valid(inode->i_sb->s_user_ns, acl);
918 if (ret)
919 return ret;
920 }
921 return inode->i_op->set_acl(mnt_userns, inode, acl, type);
922}
923EXPORT_SYMBOL(set_posix_acl);
924
925static int
926posix_acl_xattr_set(const struct xattr_handler *handler,
927 struct user_namespace *mnt_userns,
928 struct dentry *unused, struct inode *inode,
929 const char *name, const void *value, size_t size,
930 int flags)
931{
932 struct posix_acl *acl = NULL;
933 int ret;
934
935 if (value) {
936 acl = posix_acl_from_xattr(&init_user_ns, value, size);
937 if (IS_ERR(acl))
938 return PTR_ERR(acl);
939 }
940 ret = set_posix_acl(mnt_userns, inode, handler->flags, acl);
941 posix_acl_release(acl);
942 return ret;
943}
944
945static bool
946posix_acl_xattr_list(struct dentry *dentry)
947{
948 return IS_POSIXACL(d_backing_inode(dentry));
949}
950
951const struct xattr_handler posix_acl_access_xattr_handler = {
952 .name = XATTR_NAME_POSIX_ACL_ACCESS,
953 .flags = ACL_TYPE_ACCESS,
954 .list = posix_acl_xattr_list,
955 .get = posix_acl_xattr_get,
956 .set = posix_acl_xattr_set,
957};
958EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler);
959
960const struct xattr_handler posix_acl_default_xattr_handler = {
961 .name = XATTR_NAME_POSIX_ACL_DEFAULT,
962 .flags = ACL_TYPE_DEFAULT,
963 .list = posix_acl_xattr_list,
964 .get = posix_acl_xattr_get,
965 .set = posix_acl_xattr_set,
966};
967EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler);
968
969int simple_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
970 struct posix_acl *acl, int type)
971{
972 int error;
973
974 if (type == ACL_TYPE_ACCESS) {
975 error = posix_acl_update_mode(mnt_userns, inode,
976 &inode->i_mode, &acl);
977 if (error)
978 return error;
979 }
980
981 inode->i_ctime = current_time(inode);
982 set_cached_acl(inode, type, acl);
983 return 0;
984}
985
986int simple_acl_create(struct inode *dir, struct inode *inode)
987{
988 struct posix_acl *default_acl, *acl;
989 int error;
990
991 error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
992 if (error)
993 return error;
994
995 set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl);
996 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
997
998 if (default_acl)
999 posix_acl_release(default_acl);
1000 if (acl)
1001 posix_acl_release(acl);
1002 return 0;
1003}
1004