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Linux 2.6.17.7
[linux/fpc-iii.git] / fs / nfsd / nfs4acl.c
blobedb107e61b91d8583f18e1bc26fe8c63e066196a
1 /*
2 * fs/nfs4acl/acl.c
3 *
4 * Common NFSv4 ACL handling code.
5 *
6 * Copyright (c) 2002, 2003 The Regents of the University of Michigan.
7 * All rights reserved.
8 *
9 * Marius Aamodt Eriksen <marius@umich.edu>
10 * Jeff Sedlak <jsedlak@umich.edu>
11 * J. Bruce Fields <bfields@umich.edu>
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 *
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
22 * 3. Neither the name of the University nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
27 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
28 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
29 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
33 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 */
38
39 #include <linux/string.h>
40 #include <linux/slab.h>
41 #include <linux/list.h>
42 #include <linux/types.h>
43 #include <linux/fs.h>
44 #include <linux/module.h>
45 #include <linux/nfs_fs.h>
46 #include <linux/posix_acl.h>
47 #include <linux/nfs4.h>
48 #include <linux/nfs4_acl.h>
49
50
51 /* mode bit translations: */
52 #define NFS4_READ_MODE (NFS4_ACE_READ_DATA)
53 #define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA)
54 #define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE
55 #define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE)
56 #define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)
57
58 /* We don't support these bits; insist they be neither allowed nor denied */
59 #define NFS4_MASK_UNSUPP (NFS4_ACE_DELETE | NFS4_ACE_WRITE_OWNER \
60 | NFS4_ACE_READ_NAMED_ATTRS | NFS4_ACE_WRITE_NAMED_ATTRS)
61
62 /* flags used to simulate posix default ACLs */
63 #define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \
64 | NFS4_ACE_DIRECTORY_INHERIT_ACE | NFS4_ACE_INHERIT_ONLY_ACE)
65
66 #define MASK_EQUAL(mask1, mask2) \
67 ( ((mask1) & NFS4_ACE_MASK_ALL) == ((mask2) & NFS4_ACE_MASK_ALL) )
68
69 static u32
70 mask_from_posix(unsigned short perm, unsigned int flags)
71 {
72 int mask = NFS4_ANYONE_MODE;
73
74 if (flags & NFS4_ACL_OWNER)
75 mask |= NFS4_OWNER_MODE;
76 if (perm & ACL_READ)
77 mask |= NFS4_READ_MODE;
78 if (perm & ACL_WRITE)
79 mask |= NFS4_WRITE_MODE;
80 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
81 mask |= NFS4_ACE_DELETE_CHILD;
82 if (perm & ACL_EXECUTE)
83 mask |= NFS4_EXECUTE_MODE;
84 return mask;
85 }
86
87 static u32
88 deny_mask(u32 allow_mask, unsigned int flags)
89 {
90 u32 ret = ~allow_mask & ~NFS4_MASK_UNSUPP;
91 if (!(flags & NFS4_ACL_DIR))
92 ret &= ~NFS4_ACE_DELETE_CHILD;
93 return ret;
94 }
95
96 /* XXX: modify functions to return NFS errors; they're only ever
97 * used by nfs code, after all.... */
98
99 static int
100 mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
101 {
102 u32 ignore = 0;
103
104 if (!(flags & NFS4_ACL_DIR))
105 ignore |= NFS4_ACE_DELETE_CHILD; /* ignore it */
106 perm |= ignore;
107 *mode = 0;
108 if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE)
109 *mode |= ACL_READ;
110 if ((perm & NFS4_WRITE_MODE) == NFS4_WRITE_MODE)
111 *mode |= ACL_WRITE;
112 if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE)
113 *mode |= ACL_EXECUTE;
114 if (!MASK_EQUAL(perm, ignore|mask_from_posix(*mode, flags)))
115 return -EINVAL;
116 return 0;
117 }
118
119 struct ace_container {
120 struct nfs4_ace *ace;
121 struct list_head ace_l;
122 };
123
124 static short ace2type(struct nfs4_ace *);
125 static int _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *, unsigned int);
126 static struct posix_acl *_nfsv4_to_posix_one(struct nfs4_acl *, unsigned int);
127 int nfs4_acl_add_ace(struct nfs4_acl *, u32, u32, u32, int, uid_t);
128 static int nfs4_acl_split(struct nfs4_acl *, struct nfs4_acl *);
129
130 struct nfs4_acl *
131 nfs4_acl_posix_to_nfsv4(struct posix_acl *pacl, struct posix_acl *dpacl,
132 unsigned int flags)
133 {
134 struct nfs4_acl *acl;
135 int error = -EINVAL;
136
137 if ((pacl != NULL &&
138 (posix_acl_valid(pacl) < 0 || pacl->a_count == 0)) ||
139 (dpacl != NULL &&
140 (posix_acl_valid(dpacl) < 0 || dpacl->a_count == 0)))
141 goto out_err;
142
143 acl = nfs4_acl_new();
144 if (acl == NULL) {
145 error = -ENOMEM;
146 goto out_err;
147 }
148
149 if (pacl != NULL) {
150 error = _posix_to_nfsv4_one(pacl, acl,
151 flags & ~NFS4_ACL_TYPE_DEFAULT);
152 if (error < 0)
153 goto out_acl;
154 }
155
156 if (dpacl != NULL) {
157 error = _posix_to_nfsv4_one(dpacl, acl,
158 flags | NFS4_ACL_TYPE_DEFAULT);
159 if (error < 0)
160 goto out_acl;
161 }
162
163 return acl;
164
165 out_acl:
166 nfs4_acl_free(acl);
167 out_err:
168 acl = ERR_PTR(error);
169
170 return acl;
171 }
172
173 static int
174 nfs4_acl_add_pair(struct nfs4_acl *acl, int eflag, u32 mask, int whotype,
175 uid_t owner, unsigned int flags)
176 {
177 int error;
178
179 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE,
180 eflag, mask, whotype, owner);
181 if (error < 0)
182 return error;
183 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
184 eflag, deny_mask(mask, flags), whotype, owner);
185 return error;
186 }
187
188 /* We assume the acl has been verified with posix_acl_valid. */
189 static int
190 _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
191 unsigned int flags)
192 {
193 struct posix_acl_entry *pa, *pe, *group_owner_entry;
194 int error = -EINVAL;
195 u32 mask, mask_mask;
196 int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ?
197 NFS4_INHERITANCE_FLAGS : 0);
198
199 BUG_ON(pacl->a_count < 3);
200 pe = pacl->a_entries + pacl->a_count;
201 pa = pe - 2; /* if mask entry exists, it's second from the last. */
202 if (pa->e_tag == ACL_MASK)
203 mask_mask = deny_mask(mask_from_posix(pa->e_perm, flags), flags);
204 else
205 mask_mask = 0;
206
207 pa = pacl->a_entries;
208 BUG_ON(pa->e_tag != ACL_USER_OBJ);
209 mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER);
210 error = nfs4_acl_add_pair(acl, eflag, mask, NFS4_ACL_WHO_OWNER, 0, flags);
211 if (error < 0)
212 goto out;
213 pa++;
214
215 while (pa->e_tag == ACL_USER) {
216 mask = mask_from_posix(pa->e_perm, flags);
217 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
218 eflag, mask_mask, NFS4_ACL_WHO_NAMED, pa->e_id);
219 if (error < 0)
220 goto out;
221
222
223 error = nfs4_acl_add_pair(acl, eflag, mask,
224 NFS4_ACL_WHO_NAMED, pa->e_id, flags);
225 if (error < 0)
226 goto out;
227 pa++;
228 }
229
230 /* In the case of groups, we apply allow ACEs first, then deny ACEs,
231 * since a user can be in more than one group. */
232
233 /* allow ACEs */
234
235 if (pacl->a_count > 3) {
236 BUG_ON(pa->e_tag != ACL_GROUP_OBJ);
237 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
238 NFS4_ACE_IDENTIFIER_GROUP | eflag, mask_mask,
239 NFS4_ACL_WHO_GROUP, 0);
240 if (error < 0)
241 goto out;
242 }
243 group_owner_entry = pa;
244 mask = mask_from_posix(pa->e_perm, flags);
245 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE,
246 NFS4_ACE_IDENTIFIER_GROUP | eflag, mask,
247 NFS4_ACL_WHO_GROUP, 0);
248 if (error < 0)
249 goto out;
250 pa++;
251
252 while (pa->e_tag == ACL_GROUP) {
253 mask = mask_from_posix(pa->e_perm, flags);
254 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
255 NFS4_ACE_IDENTIFIER_GROUP | eflag, mask_mask,
256 NFS4_ACL_WHO_NAMED, pa->e_id);
257 if (error < 0)
258 goto out;
259
260 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE,
261 NFS4_ACE_IDENTIFIER_GROUP | eflag, mask,
262 NFS4_ACL_WHO_NAMED, pa->e_id);
263 if (error < 0)
264 goto out;
265 pa++;
266 }
267
268 /* deny ACEs */
269
270 pa = group_owner_entry;
271 mask = mask_from_posix(pa->e_perm, flags);
272 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
273 NFS4_ACE_IDENTIFIER_GROUP | eflag,
274 deny_mask(mask, flags), NFS4_ACL_WHO_GROUP, 0);
275 if (error < 0)
276 goto out;
277 pa++;
278 while (pa->e_tag == ACL_GROUP) {
279 mask = mask_from_posix(pa->e_perm, flags);
280 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
281 NFS4_ACE_IDENTIFIER_GROUP | eflag,
282 deny_mask(mask, flags), NFS4_ACL_WHO_NAMED, pa->e_id);
283 if (error < 0)
284 goto out;
285 pa++;
286 }
287
288 if (pa->e_tag == ACL_MASK)
289 pa++;
290 BUG_ON(pa->e_tag != ACL_OTHER);
291 mask = mask_from_posix(pa->e_perm, flags);
292 error = nfs4_acl_add_pair(acl, eflag, mask, NFS4_ACL_WHO_EVERYONE, 0, flags);
293
294 out:
295 return error;
296 }
297
298 static void
299 sort_pacl_range(struct posix_acl *pacl, int start, int end) {
300 int sorted = 0, i;
301 struct posix_acl_entry tmp;
302
303 /* We just do a bubble sort; easy to do in place, and we're not
304 * expecting acl's to be long enough to justify anything more. */
305 while (!sorted) {
306 sorted = 1;
307 for (i = start; i < end; i++) {
308 if (pacl->a_entries[i].e_id
309 > pacl->a_entries[i+1].e_id) {
310 sorted = 0;
311 tmp = pacl->a_entries[i];
312 pacl->a_entries[i] = pacl->a_entries[i+1];
313 pacl->a_entries[i+1] = tmp;
314 }
315 }
316 }
317 }
318
319 static void
320 sort_pacl(struct posix_acl *pacl)
321 {
322 /* posix_acl_valid requires that users and groups be in order
323 * by uid/gid. */
324 int i, j;
325
326 if (pacl->a_count <= 4)
327 return; /* no users or groups */
328 i = 1;
329 while (pacl->a_entries[i].e_tag == ACL_USER)
330 i++;
331 sort_pacl_range(pacl, 1, i-1);
332
333 BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ);
334 j = i++;
335 while (pacl->a_entries[j].e_tag == ACL_GROUP)
336 j++;
337 sort_pacl_range(pacl, i, j-1);
338 return;
339 }
340
341 static int
342 write_pace(struct nfs4_ace *ace, struct posix_acl *pacl,
343 struct posix_acl_entry **pace, short tag, unsigned int flags)
344 {
345 struct posix_acl_entry *this = *pace;
346
347 if (*pace == pacl->a_entries + pacl->a_count)
348 return -EINVAL; /* fell off the end */
349 (*pace)++;
350 this->e_tag = tag;
351 if (tag == ACL_USER_OBJ)
352 flags |= NFS4_ACL_OWNER;
353 if (mode_from_nfs4(ace->access_mask, &this->e_perm, flags))
354 return -EINVAL;
355 this->e_id = (tag == ACL_USER || tag == ACL_GROUP ?
356 ace->who : ACL_UNDEFINED_ID);
357 return 0;
358 }
359
360 static struct nfs4_ace *
361 get_next_v4_ace(struct list_head **p, struct list_head *head)
362 {
363 struct nfs4_ace *ace;
364
365 *p = (*p)->next;
366 if (*p == head)
367 return NULL;
368 ace = list_entry(*p, struct nfs4_ace, l_ace);
369
370 return ace;
371 }
372
373 int
374 nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, struct posix_acl **pacl,
375 struct posix_acl **dpacl, unsigned int flags)
376 {
377 struct nfs4_acl *dacl;
378 int error = -ENOMEM;
379
380 *pacl = NULL;
381 *dpacl = NULL;
382
383 dacl = nfs4_acl_new();
384 if (dacl == NULL)
385 goto out;
386
387 error = nfs4_acl_split(acl, dacl);
388 if (error < 0)
389 goto out_acl;
390
391 if (pacl != NULL) {
392 if (acl->naces == 0) {
393 error = -ENODATA;
394 goto try_dpacl;
395 }
396
397 *pacl = _nfsv4_to_posix_one(acl, flags);
398 if (IS_ERR(*pacl)) {
399 error = PTR_ERR(*pacl);
400 *pacl = NULL;
401 goto out_acl;
402 }
403 }
404
405 try_dpacl:
406 if (dpacl != NULL) {
407 if (dacl->naces == 0) {
408 if (pacl == NULL || *pacl == NULL)
409 error = -ENODATA;
410 goto out_acl;
411 }
412
413 error = 0;
414 *dpacl = _nfsv4_to_posix_one(dacl, flags);
415 if (IS_ERR(*dpacl)) {
416 error = PTR_ERR(*dpacl);
417 *dpacl = NULL;
418 goto out_acl;
419 }
420 }
421
422 out_acl:
423 if (error && pacl) {
424 posix_acl_release(*pacl);
425 *pacl = NULL;
426 }
427 nfs4_acl_free(dacl);
428 out:
429 return error;
430 }
431
432 static int
433 same_who(struct nfs4_ace *a, struct nfs4_ace *b)
434 {
435 return a->whotype == b->whotype &&
436 (a->whotype != NFS4_ACL_WHO_NAMED || a->who == b->who);
437 }
438
439 static int
440 complementary_ace_pair(struct nfs4_ace *allow, struct nfs4_ace *deny,
441 unsigned int flags)
442 {
443 int ignore = 0;
444 if (!(flags & NFS4_ACL_DIR))
445 ignore |= NFS4_ACE_DELETE_CHILD;
446 return MASK_EQUAL(ignore|deny_mask(allow->access_mask, flags),
447 ignore|deny->access_mask) &&
448 allow->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
449 deny->type == NFS4_ACE_ACCESS_DENIED_ACE_TYPE &&
450 allow->flag == deny->flag &&
451 same_who(allow, deny);
452 }
453
454 static inline int
455 user_obj_from_v4(struct nfs4_acl *n4acl, struct list_head **p,
456 struct posix_acl *pacl, struct posix_acl_entry **pace,
457 unsigned int flags)
458 {
459 int error = -EINVAL;
460 struct nfs4_ace *ace, *ace2;
461
462 ace = get_next_v4_ace(p, &n4acl->ace_head);
463 if (ace == NULL)
464 goto out;
465 if (ace2type(ace) != ACL_USER_OBJ)
466 goto out;
467 error = write_pace(ace, pacl, pace, ACL_USER_OBJ, flags);
468 if (error < 0)
469 goto out;
470 error = -EINVAL;
471 ace2 = get_next_v4_ace(p, &n4acl->ace_head);
472 if (ace2 == NULL)
473 goto out;
474 if (!complementary_ace_pair(ace, ace2, flags))
475 goto out;
476 error = 0;
477 out:
478 return error;
479 }
480
481 static inline int
482 users_from_v4(struct nfs4_acl *n4acl, struct list_head **p,
483 struct nfs4_ace **mask_ace,
484 struct posix_acl *pacl, struct posix_acl_entry **pace,
485 unsigned int flags)
486 {
487 int error = -EINVAL;
488 struct nfs4_ace *ace, *ace2;
489
490 ace = get_next_v4_ace(p, &n4acl->ace_head);
491 if (ace == NULL)
492 goto out;
493 while (ace2type(ace) == ACL_USER) {
494 if (ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
495 goto out;
496 if (*mask_ace &&
497 !MASK_EQUAL(ace->access_mask, (*mask_ace)->access_mask))
498 goto out;
499 *mask_ace = ace;
500 ace = get_next_v4_ace(p, &n4acl->ace_head);
501 if (ace == NULL)
502 goto out;
503 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE)
504 goto out;
505 error = write_pace(ace, pacl, pace, ACL_USER, flags);
506 if (error < 0)
507 goto out;
508 error = -EINVAL;
509 ace2 = get_next_v4_ace(p, &n4acl->ace_head);
510 if (ace2 == NULL)
511 goto out;
512 if (!complementary_ace_pair(ace, ace2, flags))
513 goto out;
514 if ((*mask_ace)->flag != ace2->flag ||
515 !same_who(*mask_ace, ace2))
516 goto out;
517 ace = get_next_v4_ace(p, &n4acl->ace_head);
518 if (ace == NULL)
519 goto out;
520 }
521 error = 0;
522 out:
523 return error;
524 }
525
526 static inline int
527 group_obj_and_groups_from_v4(struct nfs4_acl *n4acl, struct list_head **p,
528 struct nfs4_ace **mask_ace,
529 struct posix_acl *pacl, struct posix_acl_entry **pace,
530 unsigned int flags)
531 {
532 int error = -EINVAL;
533 struct nfs4_ace *ace, *ace2;
534 struct ace_container *ac;
535 struct list_head group_l;
536
537 INIT_LIST_HEAD(&group_l);
538 ace = list_entry(*p, struct nfs4_ace, l_ace);
539
540 /* group owner (mask and allow aces) */
541
542 if (pacl->a_count != 3) {
543 /* then the group owner should be preceded by mask */
544 if (ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
545 goto out;
546 if (*mask_ace &&
547 !MASK_EQUAL(ace->access_mask, (*mask_ace)->access_mask))
548 goto out;
549 *mask_ace = ace;
550 ace = get_next_v4_ace(p, &n4acl->ace_head);
551 if (ace == NULL)
552 goto out;
553
554 if ((*mask_ace)->flag != ace->flag || !same_who(*mask_ace, ace))
555 goto out;
556 }
557
558 if (ace2type(ace) != ACL_GROUP_OBJ)
559 goto out;
560
561 ac = kmalloc(sizeof(*ac), GFP_KERNEL);
562 error = -ENOMEM;
563 if (ac == NULL)
564 goto out;
565 ac->ace = ace;
566 list_add_tail(&ac->ace_l, &group_l);
567
568 error = -EINVAL;
569 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE)
570 goto out;
571
572 error = write_pace(ace, pacl, pace, ACL_GROUP_OBJ, flags);
573 if (error < 0)
574 goto out;
575
576 error = -EINVAL;
577 ace = get_next_v4_ace(p, &n4acl->ace_head);
578 if (ace == NULL)
579 goto out;
580
581 /* groups (mask and allow aces) */
582
583 while (ace2type(ace) == ACL_GROUP) {
584 if (*mask_ace == NULL)
585 goto out;
586
587 if (ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE ||
588 !MASK_EQUAL(ace->access_mask, (*mask_ace)->access_mask))
589 goto out;
590 *mask_ace = ace;
591
592 ace = get_next_v4_ace(p, &n4acl->ace_head);
593 if (ace == NULL)
594 goto out;
595 ac = kmalloc(sizeof(*ac), GFP_KERNEL);
596 error = -ENOMEM;
597 if (ac == NULL)
598 goto out;
599 error = -EINVAL;
600 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE ||
601 !same_who(ace, *mask_ace))
602 goto out;
603
604 ac->ace = ace;
605 list_add_tail(&ac->ace_l, &group_l);
606
607 error = write_pace(ace, pacl, pace, ACL_GROUP, flags);
608 if (error < 0)
609 goto out;
610 error = -EINVAL;
611 ace = get_next_v4_ace(p, &n4acl->ace_head);
612 if (ace == NULL)
613 goto out;
614 }
615
616 /* group owner (deny ace) */
617
618 if (ace2type(ace) != ACL_GROUP_OBJ)
619 goto out;
620 ac = list_entry(group_l.next, struct ace_container, ace_l);
621 ace2 = ac->ace;
622 if (!complementary_ace_pair(ace2, ace, flags))
623 goto out;
624 list_del(group_l.next);
625 kfree(ac);
626
627 /* groups (deny aces) */
628
629 while (!list_empty(&group_l)) {
630 ace = get_next_v4_ace(p, &n4acl->ace_head);
631 if (ace == NULL)
632 goto out;
633 if (ace2type(ace) != ACL_GROUP)
634 goto out;
635 ac = list_entry(group_l.next, struct ace_container, ace_l);
636 ace2 = ac->ace;
637 if (!complementary_ace_pair(ace2, ace, flags))
638 goto out;
639 list_del(group_l.next);
640 kfree(ac);
641 }
642
643 ace = get_next_v4_ace(p, &n4acl->ace_head);
644 if (ace == NULL)
645 goto out;
646 if (ace2type(ace) != ACL_OTHER)
647 goto out;
648 error = 0;
649 out:
650 while (!list_empty(&group_l)) {
651 ac = list_entry(group_l.next, struct ace_container, ace_l);
652 list_del(group_l.next);
653 kfree(ac);
654 }
655 return error;
656 }
657
658 static inline int
659 mask_from_v4(struct nfs4_acl *n4acl, struct list_head **p,
660 struct nfs4_ace **mask_ace,
661 struct posix_acl *pacl, struct posix_acl_entry **pace,
662 unsigned int flags)
663 {
664 int error = -EINVAL;
665 struct nfs4_ace *ace;
666
667 ace = list_entry(*p, struct nfs4_ace, l_ace);
668 if (pacl->a_count != 3) {
669 if (*mask_ace == NULL)
670 goto out;
671 (*mask_ace)->access_mask = deny_mask((*mask_ace)->access_mask, flags);
672 write_pace(*mask_ace, pacl, pace, ACL_MASK, flags);
673 }
674 error = 0;
675 out:
676 return error;
677 }
678
679 static inline int
680 other_from_v4(struct nfs4_acl *n4acl, struct list_head **p,
681 struct posix_acl *pacl, struct posix_acl_entry **pace,
682 unsigned int flags)
683 {
684 int error = -EINVAL;
685 struct nfs4_ace *ace, *ace2;
686
687 ace = list_entry(*p, struct nfs4_ace, l_ace);
688 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE)
689 goto out;
690 error = write_pace(ace, pacl, pace, ACL_OTHER, flags);
691 if (error < 0)
692 goto out;
693 error = -EINVAL;
694 ace2 = get_next_v4_ace(p, &n4acl->ace_head);
695 if (ace2 == NULL)
696 goto out;
697 if (!complementary_ace_pair(ace, ace2, flags))
698 goto out;
699 error = 0;
700 out:
701 return error;
702 }
703
704 static int
705 calculate_posix_ace_count(struct nfs4_acl *n4acl)
706 {
707 if (n4acl->naces == 6) /* owner, owner group, and other only */
708 return 3;
709 else { /* Otherwise there must be a mask entry. */
710 /* Also, the remaining entries are for named users and
711 * groups, and come in threes (mask, allow, deny): */
712 if (n4acl->naces < 7)
713 return -EINVAL;
714 if ((n4acl->naces - 7) % 3)
715 return -EINVAL;
716 return 4 + (n4acl->naces - 7)/3;
717 }
718 }
719
720
721 static struct posix_acl *
722 _nfsv4_to_posix_one(struct nfs4_acl *n4acl, unsigned int flags)
723 {
724 struct posix_acl *pacl;
725 int error = -EINVAL, nace = 0;
726 struct list_head *p;
727 struct nfs4_ace *mask_ace = NULL;
728 struct posix_acl_entry *pace;
729
730 nace = calculate_posix_ace_count(n4acl);
731 if (nace < 0)
732 goto out_err;
733
734 pacl = posix_acl_alloc(nace, GFP_KERNEL);
735 error = -ENOMEM;
736 if (pacl == NULL)
737 goto out_err;
738
739 pace = &pacl->a_entries[0];
740 p = &n4acl->ace_head;
741
742 error = user_obj_from_v4(n4acl, &p, pacl, &pace, flags);
743 if (error)
744 goto out_acl;
745
746 error = users_from_v4(n4acl, &p, &mask_ace, pacl, &pace, flags);
747 if (error)
748 goto out_acl;
749
750 error = group_obj_and_groups_from_v4(n4acl, &p, &mask_ace, pacl, &pace,
751 flags);
752 if (error)
753 goto out_acl;
754
755 error = mask_from_v4(n4acl, &p, &mask_ace, pacl, &pace, flags);
756 if (error)
757 goto out_acl;
758 error = other_from_v4(n4acl, &p, pacl, &pace, flags);
759 if (error)
760 goto out_acl;
761
762 error = -EINVAL;
763 if (p->next != &n4acl->ace_head)
764 goto out_acl;
765 if (pace != pacl->a_entries + pacl->a_count)
766 goto out_acl;
767
768 sort_pacl(pacl);
769
770 return pacl;
771 out_acl:
772 posix_acl_release(pacl);
773 out_err:
774 pacl = ERR_PTR(error);
775 return pacl;
776 }
777
778 static int
779 nfs4_acl_split(struct nfs4_acl *acl, struct nfs4_acl *dacl)
780 {
781 struct list_head *h, *n;
782 struct nfs4_ace *ace;
783 int error = 0;
784
785 list_for_each_safe(h, n, &acl->ace_head) {
786 ace = list_entry(h, struct nfs4_ace, l_ace);
787
788 if ((ace->flag & NFS4_INHERITANCE_FLAGS)
789 != NFS4_INHERITANCE_FLAGS)
790 continue;
791
792 error = nfs4_acl_add_ace(dacl, ace->type, ace->flag,
793 ace->access_mask, ace->whotype, ace->who);
794 if (error < 0)
795 goto out;
796
797 list_del(h);
798 kfree(ace);
799 acl->naces--;
800 }
801
802 out:
803 return error;
804 }
805
806 static short
807 ace2type(struct nfs4_ace *ace)
808 {
809 switch (ace->whotype) {
810 case NFS4_ACL_WHO_NAMED:
811 return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ?
812 ACL_GROUP : ACL_USER);
813 case NFS4_ACL_WHO_OWNER:
814 return ACL_USER_OBJ;
815 case NFS4_ACL_WHO_GROUP:
816 return ACL_GROUP_OBJ;
817 case NFS4_ACL_WHO_EVERYONE:
818 return ACL_OTHER;
819 }
820 BUG();
821 return -1;
822 }
823
824 EXPORT_SYMBOL(nfs4_acl_posix_to_nfsv4);
825 EXPORT_SYMBOL(nfs4_acl_nfsv4_to_posix);
826
827 struct nfs4_acl *
828 nfs4_acl_new(void)
829 {
830 struct nfs4_acl *acl;
831
832 if ((acl = kmalloc(sizeof(*acl), GFP_KERNEL)) == NULL)
833 return NULL;
834
835 acl->naces = 0;
836 INIT_LIST_HEAD(&acl->ace_head);
837
838 return acl;
839 }
840
841 void
842 nfs4_acl_free(struct nfs4_acl *acl)
843 {
844 struct list_head *h;
845 struct nfs4_ace *ace;
846
847 if (!acl)
848 return;
849
850 while (!list_empty(&acl->ace_head)) {
851 h = acl->ace_head.next;
852 list_del(h);
853 ace = list_entry(h, struct nfs4_ace, l_ace);
854 kfree(ace);
855 }
856
857 kfree(acl);
858
859 return;
860 }
861
862 int
863 nfs4_acl_add_ace(struct nfs4_acl *acl, u32 type, u32 flag, u32 access_mask,
864 int whotype, uid_t who)
865 {
866 struct nfs4_ace *ace;
867
868 if ((ace = kmalloc(sizeof(*ace), GFP_KERNEL)) == NULL)
869 return -ENOMEM;
870
871 ace->type = type;
872 ace->flag = flag;
873 ace->access_mask = access_mask;
874 ace->whotype = whotype;
875 ace->who = who;
876
877 list_add_tail(&ace->l_ace, &acl->ace_head);
878 acl->naces++;
879
880 return 0;
881 }
882
883 static struct {
884 char *string;
885 int stringlen;
886 int type;
887 } s2t_map[] = {
888 {
889 .string = "OWNER@",
890 .stringlen = sizeof("OWNER@") - 1,
891 .type = NFS4_ACL_WHO_OWNER,
892 },
893 {
894 .string = "GROUP@",
895 .stringlen = sizeof("GROUP@") - 1,
896 .type = NFS4_ACL_WHO_GROUP,
897 },
898 {
899 .string = "EVERYONE@",
900 .stringlen = sizeof("EVERYONE@") - 1,
901 .type = NFS4_ACL_WHO_EVERYONE,
902 },
903 };
904
905 int
906 nfs4_acl_get_whotype(char *p, u32 len)
907 {
908 int i;
909
910 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
911 if (s2t_map[i].stringlen == len &&
912 0 == memcmp(s2t_map[i].string, p, len))
913 return s2t_map[i].type;
914 }
915 return NFS4_ACL_WHO_NAMED;
916 }
917
918 int
919 nfs4_acl_write_who(int who, char *p)
920 {
921 int i;
922
923 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
924 if (s2t_map[i].type == who) {
925 memcpy(p, s2t_map[i].string, s2t_map[i].stringlen);
926 return s2t_map[i].stringlen;
927 }
928 }
929 BUG();
930 return -1;
931 }
932
933 static inline int
934 match_who(struct nfs4_ace *ace, uid_t owner, gid_t group, uid_t who)
935 {
936 switch (ace->whotype) {
937 case NFS4_ACL_WHO_NAMED:
938 return who == ace->who;
939 case NFS4_ACL_WHO_OWNER:
940 return who == owner;
941 case NFS4_ACL_WHO_GROUP:
942 return who == group;
943 case NFS4_ACL_WHO_EVERYONE:
944 return 1;
945 default:
946 return 0;
947 }
948 }
949
950 EXPORT_SYMBOL(nfs4_acl_new);
951 EXPORT_SYMBOL(nfs4_acl_free);
952 EXPORT_SYMBOL(nfs4_acl_add_ace);
953 EXPORT_SYMBOL(nfs4_acl_get_whotype);
954 EXPORT_SYMBOL(nfs4_acl_write_who);
Linux with added FPC-III support