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1/*
2 * Common NFSv4 ACL handling code.
3 *
4 * Copyright (c) 2002, 2003 The Regents of the University of Michigan.
5 * All rights reserved.
6 *
7 * Marius Aamodt Eriksen <marius@umich.edu>
8 * Jeff Sedlak <jsedlak@umich.edu>
9 * J. Bruce Fields <bfields@umich.edu>
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 *
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its
21 * contributors may be used to endorse or promote products derived
22 * from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
25 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
26 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
27 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
31 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 */
36
37#include <linux/slab.h>
38#include <linux/nfs_fs.h>
39#include "acl.h"
40
41
42/* mode bit translations: */
43#define NFS4_READ_MODE (NFS4_ACE_READ_DATA)
44#define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA)
45#define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE
46#define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE)
47#define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)
48
49/* We don't support these bits; insist they be neither allowed nor denied */
50#define NFS4_MASK_UNSUPP (NFS4_ACE_DELETE | NFS4_ACE_WRITE_OWNER \
51 | NFS4_ACE_READ_NAMED_ATTRS | NFS4_ACE_WRITE_NAMED_ATTRS)
52
53/* flags used to simulate posix default ACLs */
54#define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \
55 | NFS4_ACE_DIRECTORY_INHERIT_ACE)
56
57#define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \
58 | NFS4_ACE_INHERIT_ONLY_ACE \
59 | NFS4_ACE_IDENTIFIER_GROUP)
60
61#define MASK_EQUAL(mask1, mask2) \
62 ( ((mask1) & NFS4_ACE_MASK_ALL) == ((mask2) & NFS4_ACE_MASK_ALL) )
63
64static u32
65mask_from_posix(unsigned short perm, unsigned int flags)
66{
67 int mask = NFS4_ANYONE_MODE;
68
69 if (flags & NFS4_ACL_OWNER)
70 mask |= NFS4_OWNER_MODE;
71 if (perm & ACL_READ)
72 mask |= NFS4_READ_MODE;
73 if (perm & ACL_WRITE)
74 mask |= NFS4_WRITE_MODE;
75 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
76 mask |= NFS4_ACE_DELETE_CHILD;
77 if (perm & ACL_EXECUTE)
78 mask |= NFS4_EXECUTE_MODE;
79 return mask;
80}
81
82static u32
83deny_mask_from_posix(unsigned short perm, u32 flags)
84{
85 u32 mask = 0;
86
87 if (perm & ACL_READ)
88 mask |= NFS4_READ_MODE;
89 if (perm & ACL_WRITE)
90 mask |= NFS4_WRITE_MODE;
91 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
92 mask |= NFS4_ACE_DELETE_CHILD;
93 if (perm & ACL_EXECUTE)
94 mask |= NFS4_EXECUTE_MODE;
95 return mask;
96}
97
98/* XXX: modify functions to return NFS errors; they're only ever
99 * used by nfs code, after all.... */
100
101/* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the
102 * side of being more restrictive, so the mode bit mapping below is
103 * pessimistic. An optimistic version would be needed to handle DENY's,
104 * but we espect to coalesce all ALLOWs and DENYs before mapping to mode
105 * bits. */
106
107static void
108low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
109{
110 u32 write_mode = NFS4_WRITE_MODE;
111
112 if (flags & NFS4_ACL_DIR)
113 write_mode |= NFS4_ACE_DELETE_CHILD;
114 *mode = 0;
115 if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE)
116 *mode |= ACL_READ;
117 if ((perm & write_mode) == write_mode)
118 *mode |= ACL_WRITE;
119 if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE)
120 *mode |= ACL_EXECUTE;
121}
122
123struct ace_container {
124 struct nfs4_ace *ace;
125 struct list_head ace_l;
126};
127
128static short ace2type(struct nfs4_ace *);
129static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *,
130 unsigned int);
131
132struct nfs4_acl *
133nfs4_acl_posix_to_nfsv4(struct posix_acl *pacl, struct posix_acl *dpacl,
134 unsigned int flags)
135{
136 struct nfs4_acl *acl;
137 int size = 0;
138
139 if (pacl) {
140 if (posix_acl_valid(pacl) < 0)
141 return ERR_PTR(-EINVAL);
142 size += 2*pacl->a_count;
143 }
144 if (dpacl) {
145 if (posix_acl_valid(dpacl) < 0)
146 return ERR_PTR(-EINVAL);
147 size += 2*dpacl->a_count;
148 }
149
150 /* Allocate for worst case: one (deny, allow) pair each: */
151 acl = nfs4_acl_new(size);
152 if (acl == NULL)
153 return ERR_PTR(-ENOMEM);
154
155 if (pacl)
156 _posix_to_nfsv4_one(pacl, acl, flags & ~NFS4_ACL_TYPE_DEFAULT);
157
158 if (dpacl)
159 _posix_to_nfsv4_one(dpacl, acl, flags | NFS4_ACL_TYPE_DEFAULT);
160
161 return acl;
162}
163
164struct posix_acl_summary {
165 unsigned short owner;
166 unsigned short users;
167 unsigned short group;
168 unsigned short groups;
169 unsigned short other;
170 unsigned short mask;
171};
172
173static void
174summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas)
175{
176 struct posix_acl_entry *pa, *pe;
177
178 /*
179 * Only pas.users and pas.groups need initialization; previous
180 * posix_acl_valid() calls ensure that the other fields will be
181 * initialized in the following loop. But, just to placate gcc:
182 */
183 memset(pas, 0, sizeof(*pas));
184 pas->mask = 07;
185
186 pe = acl->a_entries + acl->a_count;
187
188 FOREACH_ACL_ENTRY(pa, acl, pe) {
189 switch (pa->e_tag) {
190 case ACL_USER_OBJ:
191 pas->owner = pa->e_perm;
192 break;
193 case ACL_GROUP_OBJ:
194 pas->group = pa->e_perm;
195 break;
196 case ACL_USER:
197 pas->users |= pa->e_perm;
198 break;
199 case ACL_GROUP:
200 pas->groups |= pa->e_perm;
201 break;
202 case ACL_OTHER:
203 pas->other = pa->e_perm;
204 break;
205 case ACL_MASK:
206 pas->mask = pa->e_perm;
207 break;
208 }
209 }
210 /* We'll only care about effective permissions: */
211 pas->users &= pas->mask;
212 pas->group &= pas->mask;
213 pas->groups &= pas->mask;
214}
215
216/* We assume the acl has been verified with posix_acl_valid. */
217static void
218_posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
219 unsigned int flags)
220{
221 struct posix_acl_entry *pa, *group_owner_entry;
222 struct nfs4_ace *ace;
223 struct posix_acl_summary pas;
224 unsigned short deny;
225 int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ?
226 NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0);
227
228 BUG_ON(pacl->a_count < 3);
229 summarize_posix_acl(pacl, &pas);
230
231 pa = pacl->a_entries;
232 ace = acl->aces + acl->naces;
233
234 /* We could deny everything not granted by the owner: */
235 deny = ~pas.owner;
236 /*
237 * but it is equivalent (and simpler) to deny only what is not
238 * granted by later entries:
239 */
240 deny &= pas.users | pas.group | pas.groups | pas.other;
241 if (deny) {
242 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
243 ace->flag = eflag;
244 ace->access_mask = deny_mask_from_posix(deny, flags);
245 ace->whotype = NFS4_ACL_WHO_OWNER;
246 ace++;
247 acl->naces++;
248 }
249
250 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
251 ace->flag = eflag;
252 ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER);
253 ace->whotype = NFS4_ACL_WHO_OWNER;
254 ace++;
255 acl->naces++;
256 pa++;
257
258 while (pa->e_tag == ACL_USER) {
259 deny = ~(pa->e_perm & pas.mask);
260 deny &= pas.groups | pas.group | pas.other;
261 if (deny) {
262 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
263 ace->flag = eflag;
264 ace->access_mask = deny_mask_from_posix(deny, flags);
265 ace->whotype = NFS4_ACL_WHO_NAMED;
266 ace->who = pa->e_id;
267 ace++;
268 acl->naces++;
269 }
270 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
271 ace->flag = eflag;
272 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
273 flags);
274 ace->whotype = NFS4_ACL_WHO_NAMED;
275 ace->who = pa->e_id;
276 ace++;
277 acl->naces++;
278 pa++;
279 }
280
281 /* In the case of groups, we apply allow ACEs first, then deny ACEs,
282 * since a user can be in more than one group. */
283
284 /* allow ACEs */
285
286 group_owner_entry = pa;
287
288 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
289 ace->flag = eflag;
290 ace->access_mask = mask_from_posix(pas.group, flags);
291 ace->whotype = NFS4_ACL_WHO_GROUP;
292 ace++;
293 acl->naces++;
294 pa++;
295
296 while (pa->e_tag == ACL_GROUP) {
297 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
298 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
299 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
300 flags);
301 ace->whotype = NFS4_ACL_WHO_NAMED;
302 ace->who = pa->e_id;
303 ace++;
304 acl->naces++;
305 pa++;
306 }
307
308 /* deny ACEs */
309
310 pa = group_owner_entry;
311
312 deny = ~pas.group & pas.other;
313 if (deny) {
314 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
315 ace->flag = eflag;
316 ace->access_mask = deny_mask_from_posix(deny, flags);
317 ace->whotype = NFS4_ACL_WHO_GROUP;
318 ace++;
319 acl->naces++;
320 }
321 pa++;
322
323 while (pa->e_tag == ACL_GROUP) {
324 deny = ~(pa->e_perm & pas.mask);
325 deny &= pas.other;
326 if (deny) {
327 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
328 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
329 ace->access_mask = deny_mask_from_posix(deny, flags);
330 ace->whotype = NFS4_ACL_WHO_NAMED;
331 ace->who = pa->e_id;
332 ace++;
333 acl->naces++;
334 }
335 pa++;
336 }
337
338 if (pa->e_tag == ACL_MASK)
339 pa++;
340 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
341 ace->flag = eflag;
342 ace->access_mask = mask_from_posix(pa->e_perm, flags);
343 ace->whotype = NFS4_ACL_WHO_EVERYONE;
344 acl->naces++;
345}
346
347static void
348sort_pacl_range(struct posix_acl *pacl, int start, int end) {
349 int sorted = 0, i;
350 struct posix_acl_entry tmp;
351
352 /* We just do a bubble sort; easy to do in place, and we're not
353 * expecting acl's to be long enough to justify anything more. */
354 while (!sorted) {
355 sorted = 1;
356 for (i = start; i < end; i++) {
357 if (pacl->a_entries[i].e_id
358 > pacl->a_entries[i+1].e_id) {
359 sorted = 0;
360 tmp = pacl->a_entries[i];
361 pacl->a_entries[i] = pacl->a_entries[i+1];
362 pacl->a_entries[i+1] = tmp;
363 }
364 }
365 }
366}
367
368static void
369sort_pacl(struct posix_acl *pacl)
370{
371 /* posix_acl_valid requires that users and groups be in order
372 * by uid/gid. */
373 int i, j;
374
375 if (pacl->a_count <= 4)
376 return; /* no users or groups */
377 i = 1;
378 while (pacl->a_entries[i].e_tag == ACL_USER)
379 i++;
380 sort_pacl_range(pacl, 1, i-1);
381
382 BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ);
383 j = ++i;
384 while (pacl->a_entries[j].e_tag == ACL_GROUP)
385 j++;
386 sort_pacl_range(pacl, i, j-1);
387 return;
388}
389
390/*
391 * While processing the NFSv4 ACE, this maintains bitmasks representing
392 * which permission bits have been allowed and which denied to a given
393 * entity: */
394struct posix_ace_state {
395 u32 allow;
396 u32 deny;
397};
398
399struct posix_user_ace_state {
400 uid_t uid;
401 struct posix_ace_state perms;
402};
403
404struct posix_ace_state_array {
405 int n;
406 struct posix_user_ace_state aces[];
407};
408
409/*
410 * While processing the NFSv4 ACE, this maintains the partial permissions
411 * calculated so far: */
412
413struct posix_acl_state {
414 int empty;
415 struct posix_ace_state owner;
416 struct posix_ace_state group;
417 struct posix_ace_state other;
418 struct posix_ace_state everyone;
419 struct posix_ace_state mask; /* Deny unused in this case */
420 struct posix_ace_state_array *users;
421 struct posix_ace_state_array *groups;
422};
423
424static int
425init_state(struct posix_acl_state *state, int cnt)
426{
427 int alloc;
428
429 memset(state, 0, sizeof(struct posix_acl_state));
430 state->empty = 1;
431 /*
432 * In the worst case, each individual acl could be for a distinct
433 * named user or group, but we don't no which, so we allocate
434 * enough space for either:
435 */
436 alloc = sizeof(struct posix_ace_state_array)
437 + cnt*sizeof(struct posix_user_ace_state);
438 state->users = kzalloc(alloc, GFP_KERNEL);
439 if (!state->users)
440 return -ENOMEM;
441 state->groups = kzalloc(alloc, GFP_KERNEL);
442 if (!state->groups) {
443 kfree(state->users);
444 return -ENOMEM;
445 }
446 return 0;
447}
448
449static void
450free_state(struct posix_acl_state *state) {
451 kfree(state->users);
452 kfree(state->groups);
453}
454
455static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate)
456{
457 state->mask.allow |= astate->allow;
458}
459
460/*
461 * Certain bits (SYNCHRONIZE, DELETE, WRITE_OWNER, READ/WRITE_NAMED_ATTRS,
462 * READ_ATTRIBUTES, READ_ACL) are currently unenforceable and don't translate
463 * to traditional read/write/execute permissions.
464 *
465 * It's problematic to reject acls that use certain mode bits, because it
466 * places the burden on users to learn the rules about which bits one
467 * particular server sets, without giving the user a lot of help--we return an
468 * error that could mean any number of different things. To make matters
469 * worse, the problematic bits might be introduced by some application that's
470 * automatically mapping from some other acl model.
471 *
472 * So wherever possible we accept anything, possibly erring on the side of
473 * denying more permissions than necessary.
474 *
475 * However we do reject *explicit* DENY's of a few bits representing
476 * permissions we could never deny:
477 */
478
479static inline int check_deny(u32 mask, int isowner)
480{
481 if (mask & (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL))
482 return -EINVAL;
483 if (!isowner)
484 return 0;
485 if (mask & (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL))
486 return -EINVAL;
487 return 0;
488}
489
490static struct posix_acl *
491posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
492{
493 struct posix_acl_entry *pace;
494 struct posix_acl *pacl;
495 int nace;
496 int i, error = 0;
497
498 /*
499 * ACLs with no ACEs are treated differently in the inheritable
500 * and effective cases: when there are no inheritable ACEs, we
501 * set a zero-length default posix acl:
502 */
503 if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT)) {
504 pacl = posix_acl_alloc(0, GFP_KERNEL);
505 return pacl ? pacl : ERR_PTR(-ENOMEM);
506 }
507 /*
508 * When there are no effective ACEs, the following will end
509 * up setting a 3-element effective posix ACL with all
510 * permissions zero.
511 */
512 nace = 4 + state->users->n + state->groups->n;
513 pacl = posix_acl_alloc(nace, GFP_KERNEL);
514 if (!pacl)
515 return ERR_PTR(-ENOMEM);
516
517 pace = pacl->a_entries;
518 pace->e_tag = ACL_USER_OBJ;
519 error = check_deny(state->owner.deny, 1);
520 if (error)
521 goto out_err;
522 low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
523 pace->e_id = ACL_UNDEFINED_ID;
524
525 for (i=0; i < state->users->n; i++) {
526 pace++;
527 pace->e_tag = ACL_USER;
528 error = check_deny(state->users->aces[i].perms.deny, 0);
529 if (error)
530 goto out_err;
531 low_mode_from_nfs4(state->users->aces[i].perms.allow,
532 &pace->e_perm, flags);
533 pace->e_id = state->users->aces[i].uid;
534 add_to_mask(state, &state->users->aces[i].perms);
535 }
536
537 pace++;
538 pace->e_tag = ACL_GROUP_OBJ;
539 error = check_deny(state->group.deny, 0);
540 if (error)
541 goto out_err;
542 low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
543 pace->e_id = ACL_UNDEFINED_ID;
544 add_to_mask(state, &state->group);
545
546 for (i=0; i < state->groups->n; i++) {
547 pace++;
548 pace->e_tag = ACL_GROUP;
549 error = check_deny(state->groups->aces[i].perms.deny, 0);
550 if (error)
551 goto out_err;
552 low_mode_from_nfs4(state->groups->aces[i].perms.allow,
553 &pace->e_perm, flags);
554 pace->e_id = state->groups->aces[i].uid;
555 add_to_mask(state, &state->groups->aces[i].perms);
556 }
557
558 pace++;
559 pace->e_tag = ACL_MASK;
560 low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
561 pace->e_id = ACL_UNDEFINED_ID;
562
563 pace++;
564 pace->e_tag = ACL_OTHER;
565 error = check_deny(state->other.deny, 0);
566 if (error)
567 goto out_err;
568 low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
569 pace->e_id = ACL_UNDEFINED_ID;
570
571 return pacl;
572out_err:
573 posix_acl_release(pacl);
574 return ERR_PTR(error);
575}
576
577static inline void allow_bits(struct posix_ace_state *astate, u32 mask)
578{
579 /* Allow all bits in the mask not already denied: */
580 astate->allow |= mask & ~astate->deny;
581}
582
583static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
584{
585 /* Deny all bits in the mask not already allowed: */
586 astate->deny |= mask & ~astate->allow;
587}
588
589static int find_uid(struct posix_acl_state *state, struct posix_ace_state_array *a, uid_t uid)
590{
591 int i;
592
593 for (i = 0; i < a->n; i++)
594 if (a->aces[i].uid == uid)
595 return i;
596 /* Not found: */
597 a->n++;
598 a->aces[i].uid = uid;
599 a->aces[i].perms.allow = state->everyone.allow;
600 a->aces[i].perms.deny = state->everyone.deny;
601
602 return i;
603}
604
605static void deny_bits_array(struct posix_ace_state_array *a, u32 mask)
606{
607 int i;
608
609 for (i=0; i < a->n; i++)
610 deny_bits(&a->aces[i].perms, mask);
611}
612
613static void allow_bits_array(struct posix_ace_state_array *a, u32 mask)
614{
615 int i;
616
617 for (i=0; i < a->n; i++)
618 allow_bits(&a->aces[i].perms, mask);
619}
620
621static void process_one_v4_ace(struct posix_acl_state *state,
622 struct nfs4_ace *ace)
623{
624 u32 mask = ace->access_mask;
625 int i;
626
627 state->empty = 0;
628
629 switch (ace2type(ace)) {
630 case ACL_USER_OBJ:
631 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
632 allow_bits(&state->owner, mask);
633 } else {
634 deny_bits(&state->owner, mask);
635 }
636 break;
637 case ACL_USER:
638 i = find_uid(state, state->users, ace->who);
639 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
640 allow_bits(&state->users->aces[i].perms, mask);
641 } else {
642 deny_bits(&state->users->aces[i].perms, mask);
643 mask = state->users->aces[i].perms.deny;
644 deny_bits(&state->owner, mask);
645 }
646 break;
647 case ACL_GROUP_OBJ:
648 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
649 allow_bits(&state->group, mask);
650 } else {
651 deny_bits(&state->group, mask);
652 mask = state->group.deny;
653 deny_bits(&state->owner, mask);
654 deny_bits(&state->everyone, mask);
655 deny_bits_array(state->users, mask);
656 deny_bits_array(state->groups, mask);
657 }
658 break;
659 case ACL_GROUP:
660 i = find_uid(state, state->groups, ace->who);
661 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
662 allow_bits(&state->groups->aces[i].perms, mask);
663 } else {
664 deny_bits(&state->groups->aces[i].perms, mask);
665 mask = state->groups->aces[i].perms.deny;
666 deny_bits(&state->owner, mask);
667 deny_bits(&state->group, mask);
668 deny_bits(&state->everyone, mask);
669 deny_bits_array(state->users, mask);
670 deny_bits_array(state->groups, mask);
671 }
672 break;
673 case ACL_OTHER:
674 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
675 allow_bits(&state->owner, mask);
676 allow_bits(&state->group, mask);
677 allow_bits(&state->other, mask);
678 allow_bits(&state->everyone, mask);
679 allow_bits_array(state->users, mask);
680 allow_bits_array(state->groups, mask);
681 } else {
682 deny_bits(&state->owner, mask);
683 deny_bits(&state->group, mask);
684 deny_bits(&state->other, mask);
685 deny_bits(&state->everyone, mask);
686 deny_bits_array(state->users, mask);
687 deny_bits_array(state->groups, mask);
688 }
689 }
690}
691
692int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, struct posix_acl **pacl,
693 struct posix_acl **dpacl, unsigned int flags)
694{
695 struct posix_acl_state effective_acl_state, default_acl_state;
696 struct nfs4_ace *ace;
697 int ret;
698
699 ret = init_state(&effective_acl_state, acl->naces);
700 if (ret)
701 return ret;
702 ret = init_state(&default_acl_state, acl->naces);
703 if (ret)
704 goto out_estate;
705 ret = -EINVAL;
706 for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
707 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
708 ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
709 goto out_dstate;
710 if (ace->flag & ~NFS4_SUPPORTED_FLAGS)
711 goto out_dstate;
712 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) {
713 process_one_v4_ace(&effective_acl_state, ace);
714 continue;
715 }
716 if (!(flags & NFS4_ACL_DIR))
717 goto out_dstate;
718 /*
719 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT
720 * is set, we're effectively turning on the other. That's OK,
721 * according to rfc 3530.
722 */
723 process_one_v4_ace(&default_acl_state, ace);
724
725 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE))
726 process_one_v4_ace(&effective_acl_state, ace);
727 }
728 *pacl = posix_state_to_acl(&effective_acl_state, flags);
729 if (IS_ERR(*pacl)) {
730 ret = PTR_ERR(*pacl);
731 *pacl = NULL;
732 goto out_dstate;
733 }
734 *dpacl = posix_state_to_acl(&default_acl_state,
735 flags | NFS4_ACL_TYPE_DEFAULT);
736 if (IS_ERR(*dpacl)) {
737 ret = PTR_ERR(*dpacl);
738 *dpacl = NULL;
739 posix_acl_release(*pacl);
740 *pacl = NULL;
741 goto out_dstate;
742 }
743 sort_pacl(*pacl);
744 sort_pacl(*dpacl);
745 ret = 0;
746out_dstate:
747 free_state(&default_acl_state);
748out_estate:
749 free_state(&effective_acl_state);
750 return ret;
751}
752
753static short
754ace2type(struct nfs4_ace *ace)
755{
756 switch (ace->whotype) {
757 case NFS4_ACL_WHO_NAMED:
758 return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ?
759 ACL_GROUP : ACL_USER);
760 case NFS4_ACL_WHO_OWNER:
761 return ACL_USER_OBJ;
762 case NFS4_ACL_WHO_GROUP:
763 return ACL_GROUP_OBJ;
764 case NFS4_ACL_WHO_EVERYONE:
765 return ACL_OTHER;
766 }
767 BUG();
768 return -1;
769}
770
771EXPORT_SYMBOL(nfs4_acl_posix_to_nfsv4);
772EXPORT_SYMBOL(nfs4_acl_nfsv4_to_posix);
773
774struct nfs4_acl *
775nfs4_acl_new(int n)
776{
777 struct nfs4_acl *acl;
778
779 acl = kmalloc(sizeof(*acl) + n*sizeof(struct nfs4_ace), GFP_KERNEL);
780 if (acl == NULL)
781 return NULL;
782 acl->naces = 0;
783 return acl;
784}
785
786static struct {
787 char *string;
788 int stringlen;
789 int type;
790} s2t_map[] = {
791 {
792 .string = "OWNER@",
793 .stringlen = sizeof("OWNER@") - 1,
794 .type = NFS4_ACL_WHO_OWNER,
795 },
796 {
797 .string = "GROUP@",
798 .stringlen = sizeof("GROUP@") - 1,
799 .type = NFS4_ACL_WHO_GROUP,
800 },
801 {
802 .string = "EVERYONE@",
803 .stringlen = sizeof("EVERYONE@") - 1,
804 .type = NFS4_ACL_WHO_EVERYONE,
805 },
806};
807
808int
809nfs4_acl_get_whotype(char *p, u32 len)
810{
811 int i;
812
813 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
814 if (s2t_map[i].stringlen == len &&
815 0 == memcmp(s2t_map[i].string, p, len))
816 return s2t_map[i].type;
817 }
818 return NFS4_ACL_WHO_NAMED;
819}
820
821int
822nfs4_acl_write_who(int who, char *p)
823{
824 int i;
825
826 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
827 if (s2t_map[i].type == who) {
828 memcpy(p, s2t_map[i].string, s2t_map[i].stringlen);
829 return s2t_map[i].stringlen;
830 }
831 }
832 BUG();
833 return -1;
834}
835
836EXPORT_SYMBOL(nfs4_acl_new);
837EXPORT_SYMBOL(nfs4_acl_get_whotype);
838EXPORT_SYMBOL(nfs4_acl_write_who);
1/*
2 * Common NFSv4 ACL handling code.
3 *
4 * Copyright (c) 2002, 2003 The Regents of the University of Michigan.
5 * All rights reserved.
6 *
7 * Marius Aamodt Eriksen <marius@umich.edu>
8 * Jeff Sedlak <jsedlak@umich.edu>
9 * J. Bruce Fields <bfields@umich.edu>
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 *
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its
21 * contributors may be used to endorse or promote products derived
22 * from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
25 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
26 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
27 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
31 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 */
36
37#include <linux/slab.h>
38#include <linux/nfs_fs.h>
39#include <linux/export.h>
40#include "nfsfh.h"
41#include "nfsd.h"
42#include "acl.h"
43#include "vfs.h"
44
45#define NFS4_ACL_TYPE_DEFAULT 0x01
46#define NFS4_ACL_DIR 0x02
47#define NFS4_ACL_OWNER 0x04
48
49/* mode bit translations: */
50#define NFS4_READ_MODE (NFS4_ACE_READ_DATA)
51#define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA)
52#define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE
53#define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE)
54#define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)
55
56/* We don't support these bits; insist they be neither allowed nor denied */
57#define NFS4_MASK_UNSUPP (NFS4_ACE_DELETE | NFS4_ACE_WRITE_OWNER \
58 | NFS4_ACE_READ_NAMED_ATTRS | NFS4_ACE_WRITE_NAMED_ATTRS)
59
60/* flags used to simulate posix default ACLs */
61#define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \
62 | NFS4_ACE_DIRECTORY_INHERIT_ACE)
63
64#define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \
65 | NFS4_ACE_INHERIT_ONLY_ACE \
66 | NFS4_ACE_IDENTIFIER_GROUP)
67
68#define MASK_EQUAL(mask1, mask2) \
69 ( ((mask1) & NFS4_ACE_MASK_ALL) == ((mask2) & NFS4_ACE_MASK_ALL) )
70
71static u32
72mask_from_posix(unsigned short perm, unsigned int flags)
73{
74 int mask = NFS4_ANYONE_MODE;
75
76 if (flags & NFS4_ACL_OWNER)
77 mask |= NFS4_OWNER_MODE;
78 if (perm & ACL_READ)
79 mask |= NFS4_READ_MODE;
80 if (perm & ACL_WRITE)
81 mask |= NFS4_WRITE_MODE;
82 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
83 mask |= NFS4_ACE_DELETE_CHILD;
84 if (perm & ACL_EXECUTE)
85 mask |= NFS4_EXECUTE_MODE;
86 return mask;
87}
88
89static u32
90deny_mask_from_posix(unsigned short perm, u32 flags)
91{
92 u32 mask = 0;
93
94 if (perm & ACL_READ)
95 mask |= NFS4_READ_MODE;
96 if (perm & ACL_WRITE)
97 mask |= NFS4_WRITE_MODE;
98 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
99 mask |= NFS4_ACE_DELETE_CHILD;
100 if (perm & ACL_EXECUTE)
101 mask |= NFS4_EXECUTE_MODE;
102 return mask;
103}
104
105/* XXX: modify functions to return NFS errors; they're only ever
106 * used by nfs code, after all.... */
107
108/* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the
109 * side of being more restrictive, so the mode bit mapping below is
110 * pessimistic. An optimistic version would be needed to handle DENY's,
111 * but we espect to coalesce all ALLOWs and DENYs before mapping to mode
112 * bits. */
113
114static void
115low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
116{
117 u32 write_mode = NFS4_WRITE_MODE;
118
119 if (flags & NFS4_ACL_DIR)
120 write_mode |= NFS4_ACE_DELETE_CHILD;
121 *mode = 0;
122 if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE)
123 *mode |= ACL_READ;
124 if ((perm & write_mode) == write_mode)
125 *mode |= ACL_WRITE;
126 if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE)
127 *mode |= ACL_EXECUTE;
128}
129
130struct ace_container {
131 struct nfs4_ace *ace;
132 struct list_head ace_l;
133};
134
135static short ace2type(struct nfs4_ace *);
136static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *,
137 unsigned int);
138
139int
140nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
141 struct nfs4_acl **acl)
142{
143 struct inode *inode = dentry->d_inode;
144 int error = 0;
145 struct posix_acl *pacl = NULL, *dpacl = NULL;
146 unsigned int flags = 0;
147 int size = 0;
148
149 pacl = get_acl(inode, ACL_TYPE_ACCESS);
150 if (!pacl) {
151 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
152 if (IS_ERR(pacl))
153 return PTR_ERR(pacl);
154 }
155 /* allocate for worst case: one (deny, allow) pair each: */
156 size += 2 * pacl->a_count;
157
158 if (S_ISDIR(inode->i_mode)) {
159 flags = NFS4_ACL_DIR;
160 dpacl = get_acl(inode, ACL_TYPE_DEFAULT);
161 if (dpacl)
162 size += 2 * dpacl->a_count;
163 }
164
165 *acl = nfs4_acl_new(size);
166 if (*acl == NULL) {
167 error = -ENOMEM;
168 goto out;
169 }
170
171 _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT);
172
173 if (dpacl)
174 _posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT);
175
176 out:
177 posix_acl_release(pacl);
178 posix_acl_release(dpacl);
179 return error;
180}
181
182struct posix_acl_summary {
183 unsigned short owner;
184 unsigned short users;
185 unsigned short group;
186 unsigned short groups;
187 unsigned short other;
188 unsigned short mask;
189};
190
191static void
192summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas)
193{
194 struct posix_acl_entry *pa, *pe;
195
196 /*
197 * Only pas.users and pas.groups need initialization; previous
198 * posix_acl_valid() calls ensure that the other fields will be
199 * initialized in the following loop. But, just to placate gcc:
200 */
201 memset(pas, 0, sizeof(*pas));
202 pas->mask = 07;
203
204 pe = acl->a_entries + acl->a_count;
205
206 FOREACH_ACL_ENTRY(pa, acl, pe) {
207 switch (pa->e_tag) {
208 case ACL_USER_OBJ:
209 pas->owner = pa->e_perm;
210 break;
211 case ACL_GROUP_OBJ:
212 pas->group = pa->e_perm;
213 break;
214 case ACL_USER:
215 pas->users |= pa->e_perm;
216 break;
217 case ACL_GROUP:
218 pas->groups |= pa->e_perm;
219 break;
220 case ACL_OTHER:
221 pas->other = pa->e_perm;
222 break;
223 case ACL_MASK:
224 pas->mask = pa->e_perm;
225 break;
226 }
227 }
228 /* We'll only care about effective permissions: */
229 pas->users &= pas->mask;
230 pas->group &= pas->mask;
231 pas->groups &= pas->mask;
232}
233
234/* We assume the acl has been verified with posix_acl_valid. */
235static void
236_posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
237 unsigned int flags)
238{
239 struct posix_acl_entry *pa, *group_owner_entry;
240 struct nfs4_ace *ace;
241 struct posix_acl_summary pas;
242 unsigned short deny;
243 int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ?
244 NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0);
245
246 BUG_ON(pacl->a_count < 3);
247 summarize_posix_acl(pacl, &pas);
248
249 pa = pacl->a_entries;
250 ace = acl->aces + acl->naces;
251
252 /* We could deny everything not granted by the owner: */
253 deny = ~pas.owner;
254 /*
255 * but it is equivalent (and simpler) to deny only what is not
256 * granted by later entries:
257 */
258 deny &= pas.users | pas.group | pas.groups | pas.other;
259 if (deny) {
260 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
261 ace->flag = eflag;
262 ace->access_mask = deny_mask_from_posix(deny, flags);
263 ace->whotype = NFS4_ACL_WHO_OWNER;
264 ace++;
265 acl->naces++;
266 }
267
268 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
269 ace->flag = eflag;
270 ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER);
271 ace->whotype = NFS4_ACL_WHO_OWNER;
272 ace++;
273 acl->naces++;
274 pa++;
275
276 while (pa->e_tag == ACL_USER) {
277 deny = ~(pa->e_perm & pas.mask);
278 deny &= pas.groups | pas.group | pas.other;
279 if (deny) {
280 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
281 ace->flag = eflag;
282 ace->access_mask = deny_mask_from_posix(deny, flags);
283 ace->whotype = NFS4_ACL_WHO_NAMED;
284 ace->who_uid = pa->e_uid;
285 ace++;
286 acl->naces++;
287 }
288 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
289 ace->flag = eflag;
290 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
291 flags);
292 ace->whotype = NFS4_ACL_WHO_NAMED;
293 ace->who_uid = pa->e_uid;
294 ace++;
295 acl->naces++;
296 pa++;
297 }
298
299 /* In the case of groups, we apply allow ACEs first, then deny ACEs,
300 * since a user can be in more than one group. */
301
302 /* allow ACEs */
303
304 group_owner_entry = pa;
305
306 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
307 ace->flag = eflag;
308 ace->access_mask = mask_from_posix(pas.group, flags);
309 ace->whotype = NFS4_ACL_WHO_GROUP;
310 ace++;
311 acl->naces++;
312 pa++;
313
314 while (pa->e_tag == ACL_GROUP) {
315 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
316 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
317 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
318 flags);
319 ace->whotype = NFS4_ACL_WHO_NAMED;
320 ace->who_gid = pa->e_gid;
321 ace++;
322 acl->naces++;
323 pa++;
324 }
325
326 /* deny ACEs */
327
328 pa = group_owner_entry;
329
330 deny = ~pas.group & pas.other;
331 if (deny) {
332 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
333 ace->flag = eflag;
334 ace->access_mask = deny_mask_from_posix(deny, flags);
335 ace->whotype = NFS4_ACL_WHO_GROUP;
336 ace++;
337 acl->naces++;
338 }
339 pa++;
340
341 while (pa->e_tag == ACL_GROUP) {
342 deny = ~(pa->e_perm & pas.mask);
343 deny &= pas.other;
344 if (deny) {
345 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
346 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
347 ace->access_mask = deny_mask_from_posix(deny, flags);
348 ace->whotype = NFS4_ACL_WHO_NAMED;
349 ace->who_gid = pa->e_gid;
350 ace++;
351 acl->naces++;
352 }
353 pa++;
354 }
355
356 if (pa->e_tag == ACL_MASK)
357 pa++;
358 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
359 ace->flag = eflag;
360 ace->access_mask = mask_from_posix(pa->e_perm, flags);
361 ace->whotype = NFS4_ACL_WHO_EVERYONE;
362 acl->naces++;
363}
364
365static bool
366pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2)
367{
368 if (pace1->e_tag != pace2->e_tag)
369 return pace1->e_tag > pace2->e_tag;
370 if (pace1->e_tag == ACL_USER)
371 return uid_gt(pace1->e_uid, pace2->e_uid);
372 if (pace1->e_tag == ACL_GROUP)
373 return gid_gt(pace1->e_gid, pace2->e_gid);
374 return false;
375}
376
377static void
378sort_pacl_range(struct posix_acl *pacl, int start, int end) {
379 int sorted = 0, i;
380 struct posix_acl_entry tmp;
381
382 /* We just do a bubble sort; easy to do in place, and we're not
383 * expecting acl's to be long enough to justify anything more. */
384 while (!sorted) {
385 sorted = 1;
386 for (i = start; i < end; i++) {
387 if (pace_gt(&pacl->a_entries[i],
388 &pacl->a_entries[i+1])) {
389 sorted = 0;
390 tmp = pacl->a_entries[i];
391 pacl->a_entries[i] = pacl->a_entries[i+1];
392 pacl->a_entries[i+1] = tmp;
393 }
394 }
395 }
396}
397
398static void
399sort_pacl(struct posix_acl *pacl)
400{
401 /* posix_acl_valid requires that users and groups be in order
402 * by uid/gid. */
403 int i, j;
404
405 /* no users or groups */
406 if (!pacl || pacl->a_count <= 4)
407 return;
408
409 i = 1;
410 while (pacl->a_entries[i].e_tag == ACL_USER)
411 i++;
412 sort_pacl_range(pacl, 1, i-1);
413
414 BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ);
415 j = ++i;
416 while (pacl->a_entries[j].e_tag == ACL_GROUP)
417 j++;
418 sort_pacl_range(pacl, i, j-1);
419 return;
420}
421
422/*
423 * While processing the NFSv4 ACE, this maintains bitmasks representing
424 * which permission bits have been allowed and which denied to a given
425 * entity: */
426struct posix_ace_state {
427 u32 allow;
428 u32 deny;
429};
430
431struct posix_user_ace_state {
432 union {
433 kuid_t uid;
434 kgid_t gid;
435 };
436 struct posix_ace_state perms;
437};
438
439struct posix_ace_state_array {
440 int n;
441 struct posix_user_ace_state aces[];
442};
443
444/*
445 * While processing the NFSv4 ACE, this maintains the partial permissions
446 * calculated so far: */
447
448struct posix_acl_state {
449 int empty;
450 struct posix_ace_state owner;
451 struct posix_ace_state group;
452 struct posix_ace_state other;
453 struct posix_ace_state everyone;
454 struct posix_ace_state mask; /* Deny unused in this case */
455 struct posix_ace_state_array *users;
456 struct posix_ace_state_array *groups;
457};
458
459static int
460init_state(struct posix_acl_state *state, int cnt)
461{
462 int alloc;
463
464 memset(state, 0, sizeof(struct posix_acl_state));
465 state->empty = 1;
466 /*
467 * In the worst case, each individual acl could be for a distinct
468 * named user or group, but we don't no which, so we allocate
469 * enough space for either:
470 */
471 alloc = sizeof(struct posix_ace_state_array)
472 + cnt*sizeof(struct posix_user_ace_state);
473 state->users = kzalloc(alloc, GFP_KERNEL);
474 if (!state->users)
475 return -ENOMEM;
476 state->groups = kzalloc(alloc, GFP_KERNEL);
477 if (!state->groups) {
478 kfree(state->users);
479 return -ENOMEM;
480 }
481 return 0;
482}
483
484static void
485free_state(struct posix_acl_state *state) {
486 kfree(state->users);
487 kfree(state->groups);
488}
489
490static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate)
491{
492 state->mask.allow |= astate->allow;
493}
494
495/*
496 * Certain bits (SYNCHRONIZE, DELETE, WRITE_OWNER, READ/WRITE_NAMED_ATTRS,
497 * READ_ATTRIBUTES, READ_ACL) are currently unenforceable and don't translate
498 * to traditional read/write/execute permissions.
499 *
500 * It's problematic to reject acls that use certain mode bits, because it
501 * places the burden on users to learn the rules about which bits one
502 * particular server sets, without giving the user a lot of help--we return an
503 * error that could mean any number of different things. To make matters
504 * worse, the problematic bits might be introduced by some application that's
505 * automatically mapping from some other acl model.
506 *
507 * So wherever possible we accept anything, possibly erring on the side of
508 * denying more permissions than necessary.
509 *
510 * However we do reject *explicit* DENY's of a few bits representing
511 * permissions we could never deny:
512 */
513
514static inline int check_deny(u32 mask, int isowner)
515{
516 if (mask & (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL))
517 return -EINVAL;
518 if (!isowner)
519 return 0;
520 if (mask & (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL))
521 return -EINVAL;
522 return 0;
523}
524
525static struct posix_acl *
526posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
527{
528 struct posix_acl_entry *pace;
529 struct posix_acl *pacl;
530 int nace;
531 int i, error = 0;
532
533 /*
534 * ACLs with no ACEs are treated differently in the inheritable
535 * and effective cases: when there are no inheritable ACEs,
536 * calls ->set_acl with a NULL ACL structure.
537 */
538 if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT))
539 return NULL;
540
541 /*
542 * When there are no effective ACEs, the following will end
543 * up setting a 3-element effective posix ACL with all
544 * permissions zero.
545 */
546 if (!state->users->n && !state->groups->n)
547 nace = 3;
548 else /* Note we also include a MASK ACE in this case: */
549 nace = 4 + state->users->n + state->groups->n;
550 pacl = posix_acl_alloc(nace, GFP_KERNEL);
551 if (!pacl)
552 return ERR_PTR(-ENOMEM);
553
554 pace = pacl->a_entries;
555 pace->e_tag = ACL_USER_OBJ;
556 error = check_deny(state->owner.deny, 1);
557 if (error)
558 goto out_err;
559 low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
560
561 for (i=0; i < state->users->n; i++) {
562 pace++;
563 pace->e_tag = ACL_USER;
564 error = check_deny(state->users->aces[i].perms.deny, 0);
565 if (error)
566 goto out_err;
567 low_mode_from_nfs4(state->users->aces[i].perms.allow,
568 &pace->e_perm, flags);
569 pace->e_uid = state->users->aces[i].uid;
570 add_to_mask(state, &state->users->aces[i].perms);
571 }
572
573 pace++;
574 pace->e_tag = ACL_GROUP_OBJ;
575 error = check_deny(state->group.deny, 0);
576 if (error)
577 goto out_err;
578 low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
579 add_to_mask(state, &state->group);
580
581 for (i=0; i < state->groups->n; i++) {
582 pace++;
583 pace->e_tag = ACL_GROUP;
584 error = check_deny(state->groups->aces[i].perms.deny, 0);
585 if (error)
586 goto out_err;
587 low_mode_from_nfs4(state->groups->aces[i].perms.allow,
588 &pace->e_perm, flags);
589 pace->e_gid = state->groups->aces[i].gid;
590 add_to_mask(state, &state->groups->aces[i].perms);
591 }
592
593 if (state->users->n || state->groups->n) {
594 pace++;
595 pace->e_tag = ACL_MASK;
596 low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
597 }
598
599 pace++;
600 pace->e_tag = ACL_OTHER;
601 error = check_deny(state->other.deny, 0);
602 if (error)
603 goto out_err;
604 low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
605
606 return pacl;
607out_err:
608 posix_acl_release(pacl);
609 return ERR_PTR(error);
610}
611
612static inline void allow_bits(struct posix_ace_state *astate, u32 mask)
613{
614 /* Allow all bits in the mask not already denied: */
615 astate->allow |= mask & ~astate->deny;
616}
617
618static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
619{
620 /* Deny all bits in the mask not already allowed: */
621 astate->deny |= mask & ~astate->allow;
622}
623
624static int find_uid(struct posix_acl_state *state, kuid_t uid)
625{
626 struct posix_ace_state_array *a = state->users;
627 int i;
628
629 for (i = 0; i < a->n; i++)
630 if (uid_eq(a->aces[i].uid, uid))
631 return i;
632 /* Not found: */
633 a->n++;
634 a->aces[i].uid = uid;
635 a->aces[i].perms.allow = state->everyone.allow;
636 a->aces[i].perms.deny = state->everyone.deny;
637
638 return i;
639}
640
641static int find_gid(struct posix_acl_state *state, kgid_t gid)
642{
643 struct posix_ace_state_array *a = state->groups;
644 int i;
645
646 for (i = 0; i < a->n; i++)
647 if (gid_eq(a->aces[i].gid, gid))
648 return i;
649 /* Not found: */
650 a->n++;
651 a->aces[i].gid = gid;
652 a->aces[i].perms.allow = state->everyone.allow;
653 a->aces[i].perms.deny = state->everyone.deny;
654
655 return i;
656}
657
658static void deny_bits_array(struct posix_ace_state_array *a, u32 mask)
659{
660 int i;
661
662 for (i=0; i < a->n; i++)
663 deny_bits(&a->aces[i].perms, mask);
664}
665
666static void allow_bits_array(struct posix_ace_state_array *a, u32 mask)
667{
668 int i;
669
670 for (i=0; i < a->n; i++)
671 allow_bits(&a->aces[i].perms, mask);
672}
673
674static void process_one_v4_ace(struct posix_acl_state *state,
675 struct nfs4_ace *ace)
676{
677 u32 mask = ace->access_mask;
678 int i;
679
680 state->empty = 0;
681
682 switch (ace2type(ace)) {
683 case ACL_USER_OBJ:
684 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
685 allow_bits(&state->owner, mask);
686 } else {
687 deny_bits(&state->owner, mask);
688 }
689 break;
690 case ACL_USER:
691 i = find_uid(state, ace->who_uid);
692 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
693 allow_bits(&state->users->aces[i].perms, mask);
694 } else {
695 deny_bits(&state->users->aces[i].perms, mask);
696 mask = state->users->aces[i].perms.deny;
697 deny_bits(&state->owner, mask);
698 }
699 break;
700 case ACL_GROUP_OBJ:
701 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
702 allow_bits(&state->group, mask);
703 } else {
704 deny_bits(&state->group, mask);
705 mask = state->group.deny;
706 deny_bits(&state->owner, mask);
707 deny_bits(&state->everyone, mask);
708 deny_bits_array(state->users, mask);
709 deny_bits_array(state->groups, mask);
710 }
711 break;
712 case ACL_GROUP:
713 i = find_gid(state, ace->who_gid);
714 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
715 allow_bits(&state->groups->aces[i].perms, mask);
716 } else {
717 deny_bits(&state->groups->aces[i].perms, mask);
718 mask = state->groups->aces[i].perms.deny;
719 deny_bits(&state->owner, mask);
720 deny_bits(&state->group, mask);
721 deny_bits(&state->everyone, mask);
722 deny_bits_array(state->users, mask);
723 deny_bits_array(state->groups, mask);
724 }
725 break;
726 case ACL_OTHER:
727 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
728 allow_bits(&state->owner, mask);
729 allow_bits(&state->group, mask);
730 allow_bits(&state->other, mask);
731 allow_bits(&state->everyone, mask);
732 allow_bits_array(state->users, mask);
733 allow_bits_array(state->groups, mask);
734 } else {
735 deny_bits(&state->owner, mask);
736 deny_bits(&state->group, mask);
737 deny_bits(&state->other, mask);
738 deny_bits(&state->everyone, mask);
739 deny_bits_array(state->users, mask);
740 deny_bits_array(state->groups, mask);
741 }
742 }
743}
744
745static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl,
746 struct posix_acl **pacl, struct posix_acl **dpacl,
747 unsigned int flags)
748{
749 struct posix_acl_state effective_acl_state, default_acl_state;
750 struct nfs4_ace *ace;
751 int ret;
752
753 ret = init_state(&effective_acl_state, acl->naces);
754 if (ret)
755 return ret;
756 ret = init_state(&default_acl_state, acl->naces);
757 if (ret)
758 goto out_estate;
759 ret = -EINVAL;
760 for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
761 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
762 ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
763 goto out_dstate;
764 if (ace->flag & ~NFS4_SUPPORTED_FLAGS)
765 goto out_dstate;
766 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) {
767 process_one_v4_ace(&effective_acl_state, ace);
768 continue;
769 }
770 if (!(flags & NFS4_ACL_DIR))
771 goto out_dstate;
772 /*
773 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT
774 * is set, we're effectively turning on the other. That's OK,
775 * according to rfc 3530.
776 */
777 process_one_v4_ace(&default_acl_state, ace);
778
779 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE))
780 process_one_v4_ace(&effective_acl_state, ace);
781 }
782 *pacl = posix_state_to_acl(&effective_acl_state, flags);
783 if (IS_ERR(*pacl)) {
784 ret = PTR_ERR(*pacl);
785 *pacl = NULL;
786 goto out_dstate;
787 }
788 *dpacl = posix_state_to_acl(&default_acl_state,
789 flags | NFS4_ACL_TYPE_DEFAULT);
790 if (IS_ERR(*dpacl)) {
791 ret = PTR_ERR(*dpacl);
792 *dpacl = NULL;
793 posix_acl_release(*pacl);
794 *pacl = NULL;
795 goto out_dstate;
796 }
797 sort_pacl(*pacl);
798 sort_pacl(*dpacl);
799 ret = 0;
800out_dstate:
801 free_state(&default_acl_state);
802out_estate:
803 free_state(&effective_acl_state);
804 return ret;
805}
806
807__be32
808nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
809 struct nfs4_acl *acl)
810{
811 __be32 error;
812 int host_error;
813 struct dentry *dentry;
814 struct inode *inode;
815 struct posix_acl *pacl = NULL, *dpacl = NULL;
816 unsigned int flags = 0;
817
818 /* Get inode */
819 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_SATTR);
820 if (error)
821 return error;
822
823 dentry = fhp->fh_dentry;
824 inode = dentry->d_inode;
825
826 if (!inode->i_op->set_acl || !IS_POSIXACL(inode))
827 return nfserr_attrnotsupp;
828
829 if (S_ISDIR(inode->i_mode))
830 flags = NFS4_ACL_DIR;
831
832 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
833 if (host_error == -EINVAL)
834 return nfserr_attrnotsupp;
835 if (host_error < 0)
836 goto out_nfserr;
837
838 host_error = inode->i_op->set_acl(inode, pacl, ACL_TYPE_ACCESS);
839 if (host_error < 0)
840 goto out_release;
841
842 if (S_ISDIR(inode->i_mode)) {
843 host_error = inode->i_op->set_acl(inode, dpacl,
844 ACL_TYPE_DEFAULT);
845 }
846
847out_release:
848 posix_acl_release(pacl);
849 posix_acl_release(dpacl);
850out_nfserr:
851 if (host_error == -EOPNOTSUPP)
852 return nfserr_attrnotsupp;
853 else
854 return nfserrno(host_error);
855}
856
857
858static short
859ace2type(struct nfs4_ace *ace)
860{
861 switch (ace->whotype) {
862 case NFS4_ACL_WHO_NAMED:
863 return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ?
864 ACL_GROUP : ACL_USER);
865 case NFS4_ACL_WHO_OWNER:
866 return ACL_USER_OBJ;
867 case NFS4_ACL_WHO_GROUP:
868 return ACL_GROUP_OBJ;
869 case NFS4_ACL_WHO_EVERYONE:
870 return ACL_OTHER;
871 }
872 BUG();
873 return -1;
874}
875
876struct nfs4_acl *
877nfs4_acl_new(int n)
878{
879 struct nfs4_acl *acl;
880
881 acl = kmalloc(sizeof(*acl) + n*sizeof(struct nfs4_ace), GFP_KERNEL);
882 if (acl == NULL)
883 return NULL;
884 acl->naces = 0;
885 return acl;
886}
887
888static struct {
889 char *string;
890 int stringlen;
891 int type;
892} s2t_map[] = {
893 {
894 .string = "OWNER@",
895 .stringlen = sizeof("OWNER@") - 1,
896 .type = NFS4_ACL_WHO_OWNER,
897 },
898 {
899 .string = "GROUP@",
900 .stringlen = sizeof("GROUP@") - 1,
901 .type = NFS4_ACL_WHO_GROUP,
902 },
903 {
904 .string = "EVERYONE@",
905 .stringlen = sizeof("EVERYONE@") - 1,
906 .type = NFS4_ACL_WHO_EVERYONE,
907 },
908};
909
910int
911nfs4_acl_get_whotype(char *p, u32 len)
912{
913 int i;
914
915 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
916 if (s2t_map[i].stringlen == len &&
917 0 == memcmp(s2t_map[i].string, p, len))
918 return s2t_map[i].type;
919 }
920 return NFS4_ACL_WHO_NAMED;
921}
922
923__be32 nfs4_acl_write_who(int who, __be32 **p, int *len)
924{
925 int i;
926 int bytes;
927
928 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
929 if (s2t_map[i].type != who)
930 continue;
931 bytes = 4 + (XDR_QUADLEN(s2t_map[i].stringlen) << 2);
932 if (bytes > *len)
933 return nfserr_resource;
934 *p = xdr_encode_opaque(*p, s2t_map[i].string,
935 s2t_map[i].stringlen);
936 *len -= bytes;
937 return 0;
938 }
939 WARN_ON_ONCE(1);
940 return -1;
941}