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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/fs.h>
38#include <linux/slab.h>
39#include <linux/posix_acl.h>
40
41#include "nfsfh.h"
42#include "nfsd.h"
43#include "acl.h"
44#include "vfs.h"
45
46#define NFS4_ACL_TYPE_DEFAULT 0x01
47#define NFS4_ACL_DIR 0x02
48#define NFS4_ACL_OWNER 0x04
49
50/* mode bit translations: */
51#define NFS4_READ_MODE (NFS4_ACE_READ_DATA)
52#define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA)
53#define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE
54#define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE)
55#define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)
56
57/* flags used to simulate posix default ACLs */
58#define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \
59 | NFS4_ACE_DIRECTORY_INHERIT_ACE)
60
61#define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \
62 | NFS4_ACE_INHERIT_ONLY_ACE \
63 | NFS4_ACE_IDENTIFIER_GROUP)
64
65static u32
66mask_from_posix(unsigned short perm, unsigned int flags)
67{
68 int mask = NFS4_ANYONE_MODE;
69
70 if (flags & NFS4_ACL_OWNER)
71 mask |= NFS4_OWNER_MODE;
72 if (perm & ACL_READ)
73 mask |= NFS4_READ_MODE;
74 if (perm & ACL_WRITE)
75 mask |= NFS4_WRITE_MODE;
76 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
77 mask |= NFS4_ACE_DELETE_CHILD;
78 if (perm & ACL_EXECUTE)
79 mask |= NFS4_EXECUTE_MODE;
80 return mask;
81}
82
83static u32
84deny_mask_from_posix(unsigned short perm, u32 flags)
85{
86 u32 mask = 0;
87
88 if (perm & ACL_READ)
89 mask |= NFS4_READ_MODE;
90 if (perm & ACL_WRITE)
91 mask |= NFS4_WRITE_MODE;
92 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
93 mask |= NFS4_ACE_DELETE_CHILD;
94 if (perm & ACL_EXECUTE)
95 mask |= NFS4_EXECUTE_MODE;
96 return mask;
97}
98
99/* XXX: modify functions to return NFS errors; they're only ever
100 * used by nfs code, after all.... */
101
102/* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the
103 * side of being more restrictive, so the mode bit mapping below is
104 * pessimistic. An optimistic version would be needed to handle DENY's,
105 * but we expect to coalesce all ALLOWs and DENYs before mapping to mode
106 * bits. */
107
108static void
109low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
110{
111 u32 write_mode = NFS4_WRITE_MODE;
112
113 if (flags & NFS4_ACL_DIR)
114 write_mode |= NFS4_ACE_DELETE_CHILD;
115 *mode = 0;
116 if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE)
117 *mode |= ACL_READ;
118 if ((perm & write_mode) == write_mode)
119 *mode |= ACL_WRITE;
120 if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE)
121 *mode |= ACL_EXECUTE;
122}
123
124static short ace2type(struct nfs4_ace *);
125static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *,
126 unsigned int);
127
128int
129nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
130 struct nfs4_acl **acl)
131{
132 struct inode *inode = d_inode(dentry);
133 int error = 0;
134 struct posix_acl *pacl = NULL, *dpacl = NULL;
135 unsigned int flags = 0;
136 int size = 0;
137
138 pacl = get_inode_acl(inode, ACL_TYPE_ACCESS);
139 if (!pacl)
140 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
141
142 if (IS_ERR(pacl))
143 return PTR_ERR(pacl);
144
145 /* allocate for worst case: one (deny, allow) pair each: */
146 size += 2 * pacl->a_count;
147
148 if (S_ISDIR(inode->i_mode)) {
149 flags = NFS4_ACL_DIR;
150 dpacl = get_inode_acl(inode, ACL_TYPE_DEFAULT);
151 if (IS_ERR(dpacl)) {
152 error = PTR_ERR(dpacl);
153 goto rel_pacl;
154 }
155
156 if (dpacl)
157 size += 2 * dpacl->a_count;
158 }
159
160 *acl = kmalloc(nfs4_acl_bytes(size), GFP_KERNEL);
161 if (*acl == NULL) {
162 error = -ENOMEM;
163 goto out;
164 }
165 (*acl)->naces = 0;
166
167 _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT);
168
169 if (dpacl)
170 _posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT);
171
172out:
173 posix_acl_release(dpacl);
174rel_pacl:
175 posix_acl_release(pacl);
176 return error;
177}
178
179struct posix_acl_summary {
180 unsigned short owner;
181 unsigned short users;
182 unsigned short group;
183 unsigned short groups;
184 unsigned short other;
185 unsigned short mask;
186};
187
188static void
189summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas)
190{
191 struct posix_acl_entry *pa, *pe;
192
193 /*
194 * Only pas.users and pas.groups need initialization; previous
195 * posix_acl_valid() calls ensure that the other fields will be
196 * initialized in the following loop. But, just to placate gcc:
197 */
198 memset(pas, 0, sizeof(*pas));
199 pas->mask = 07;
200
201 FOREACH_ACL_ENTRY(pa, acl, pe) {
202 switch (pa->e_tag) {
203 case ACL_USER_OBJ:
204 pas->owner = pa->e_perm;
205 break;
206 case ACL_GROUP_OBJ:
207 pas->group = pa->e_perm;
208 break;
209 case ACL_USER:
210 pas->users |= pa->e_perm;
211 break;
212 case ACL_GROUP:
213 pas->groups |= pa->e_perm;
214 break;
215 case ACL_OTHER:
216 pas->other = pa->e_perm;
217 break;
218 case ACL_MASK:
219 pas->mask = pa->e_perm;
220 break;
221 }
222 }
223 /* We'll only care about effective permissions: */
224 pas->users &= pas->mask;
225 pas->group &= pas->mask;
226 pas->groups &= pas->mask;
227}
228
229/* We assume the acl has been verified with posix_acl_valid. */
230static void
231_posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
232 unsigned int flags)
233{
234 struct posix_acl_entry *pa, *group_owner_entry;
235 struct nfs4_ace *ace;
236 struct posix_acl_summary pas;
237 unsigned short deny;
238 int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ?
239 NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0);
240
241 BUG_ON(pacl->a_count < 3);
242 summarize_posix_acl(pacl, &pas);
243
244 pa = pacl->a_entries;
245 ace = acl->aces + acl->naces;
246
247 /* We could deny everything not granted by the owner: */
248 deny = ~pas.owner;
249 /*
250 * but it is equivalent (and simpler) to deny only what is not
251 * granted by later entries:
252 */
253 deny &= pas.users | pas.group | pas.groups | pas.other;
254 if (deny) {
255 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
256 ace->flag = eflag;
257 ace->access_mask = deny_mask_from_posix(deny, flags);
258 ace->whotype = NFS4_ACL_WHO_OWNER;
259 ace++;
260 acl->naces++;
261 }
262
263 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
264 ace->flag = eflag;
265 ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER);
266 ace->whotype = NFS4_ACL_WHO_OWNER;
267 ace++;
268 acl->naces++;
269 pa++;
270
271 while (pa->e_tag == ACL_USER) {
272 deny = ~(pa->e_perm & pas.mask);
273 deny &= pas.groups | pas.group | pas.other;
274 if (deny) {
275 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
276 ace->flag = eflag;
277 ace->access_mask = deny_mask_from_posix(deny, flags);
278 ace->whotype = NFS4_ACL_WHO_NAMED;
279 ace->who_uid = pa->e_uid;
280 ace++;
281 acl->naces++;
282 }
283 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
284 ace->flag = eflag;
285 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
286 flags);
287 ace->whotype = NFS4_ACL_WHO_NAMED;
288 ace->who_uid = pa->e_uid;
289 ace++;
290 acl->naces++;
291 pa++;
292 }
293
294 /* In the case of groups, we apply allow ACEs first, then deny ACEs,
295 * since a user can be in more than one group. */
296
297 /* allow ACEs */
298
299 group_owner_entry = pa;
300
301 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
302 ace->flag = eflag;
303 ace->access_mask = mask_from_posix(pas.group, flags);
304 ace->whotype = NFS4_ACL_WHO_GROUP;
305 ace++;
306 acl->naces++;
307 pa++;
308
309 while (pa->e_tag == ACL_GROUP) {
310 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
311 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
312 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
313 flags);
314 ace->whotype = NFS4_ACL_WHO_NAMED;
315 ace->who_gid = pa->e_gid;
316 ace++;
317 acl->naces++;
318 pa++;
319 }
320
321 /* deny ACEs */
322
323 pa = group_owner_entry;
324
325 deny = ~pas.group & pas.other;
326 if (deny) {
327 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
328 ace->flag = eflag;
329 ace->access_mask = deny_mask_from_posix(deny, flags);
330 ace->whotype = NFS4_ACL_WHO_GROUP;
331 ace++;
332 acl->naces++;
333 }
334 pa++;
335
336 while (pa->e_tag == ACL_GROUP) {
337 deny = ~(pa->e_perm & pas.mask);
338 deny &= pas.other;
339 if (deny) {
340 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
341 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
342 ace->access_mask = deny_mask_from_posix(deny, flags);
343 ace->whotype = NFS4_ACL_WHO_NAMED;
344 ace->who_gid = pa->e_gid;
345 ace++;
346 acl->naces++;
347 }
348 pa++;
349 }
350
351 if (pa->e_tag == ACL_MASK)
352 pa++;
353 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
354 ace->flag = eflag;
355 ace->access_mask = mask_from_posix(pa->e_perm, flags);
356 ace->whotype = NFS4_ACL_WHO_EVERYONE;
357 acl->naces++;
358}
359
360static bool
361pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2)
362{
363 if (pace1->e_tag != pace2->e_tag)
364 return pace1->e_tag > pace2->e_tag;
365 if (pace1->e_tag == ACL_USER)
366 return uid_gt(pace1->e_uid, pace2->e_uid);
367 if (pace1->e_tag == ACL_GROUP)
368 return gid_gt(pace1->e_gid, pace2->e_gid);
369 return false;
370}
371
372static void
373sort_pacl_range(struct posix_acl *pacl, int start, int end) {
374 int sorted = 0, i;
375
376 /* We just do a bubble sort; easy to do in place, and we're not
377 * expecting acl's to be long enough to justify anything more. */
378 while (!sorted) {
379 sorted = 1;
380 for (i = start; i < end; i++) {
381 if (pace_gt(&pacl->a_entries[i],
382 &pacl->a_entries[i+1])) {
383 sorted = 0;
384 swap(pacl->a_entries[i],
385 pacl->a_entries[i + 1]);
386 }
387 }
388 }
389}
390
391static void
392sort_pacl(struct posix_acl *pacl)
393{
394 /* posix_acl_valid requires that users and groups be in order
395 * by uid/gid. */
396 int i, j;
397
398 /* no users or groups */
399 if (!pacl || pacl->a_count <= 4)
400 return;
401
402 i = 1;
403 while (pacl->a_entries[i].e_tag == ACL_USER)
404 i++;
405 sort_pacl_range(pacl, 1, i-1);
406
407 BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ);
408 j = ++i;
409 while (pacl->a_entries[j].e_tag == ACL_GROUP)
410 j++;
411 sort_pacl_range(pacl, i, j-1);
412 return;
413}
414
415/*
416 * While processing the NFSv4 ACE, this maintains bitmasks representing
417 * which permission bits have been allowed and which denied to a given
418 * entity: */
419struct posix_ace_state {
420 u32 allow;
421 u32 deny;
422};
423
424struct posix_user_ace_state {
425 union {
426 kuid_t uid;
427 kgid_t gid;
428 };
429 struct posix_ace_state perms;
430};
431
432struct posix_ace_state_array {
433 int n;
434 struct posix_user_ace_state aces[];
435};
436
437/*
438 * While processing the NFSv4 ACE, this maintains the partial permissions
439 * calculated so far: */
440
441struct posix_acl_state {
442 unsigned char valid;
443 struct posix_ace_state owner;
444 struct posix_ace_state group;
445 struct posix_ace_state other;
446 struct posix_ace_state everyone;
447 struct posix_ace_state mask; /* Deny unused in this case */
448 struct posix_ace_state_array *users;
449 struct posix_ace_state_array *groups;
450};
451
452static int
453init_state(struct posix_acl_state *state, int cnt)
454{
455 int alloc;
456
457 memset(state, 0, sizeof(struct posix_acl_state));
458 /*
459 * In the worst case, each individual acl could be for a distinct
460 * named user or group, but we don't know which, so we allocate
461 * enough space for either:
462 */
463 alloc = sizeof(struct posix_ace_state_array)
464 + cnt*sizeof(struct posix_user_ace_state);
465 state->users = kzalloc(alloc, GFP_KERNEL);
466 if (!state->users)
467 return -ENOMEM;
468 state->groups = kzalloc(alloc, GFP_KERNEL);
469 if (!state->groups) {
470 kfree(state->users);
471 return -ENOMEM;
472 }
473 return 0;
474}
475
476static void
477free_state(struct posix_acl_state *state) {
478 kfree(state->users);
479 kfree(state->groups);
480}
481
482static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate)
483{
484 state->mask.allow |= astate->allow;
485}
486
487static struct posix_acl *
488posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
489{
490 struct posix_acl_entry *pace;
491 struct posix_acl *pacl;
492 int nace;
493 int i;
494
495 /*
496 * ACLs with no ACEs are treated differently in the inheritable
497 * and effective cases: when there are no inheritable ACEs,
498 * calls ->set_acl with a NULL ACL structure.
499 */
500 if (!state->valid && (flags & NFS4_ACL_TYPE_DEFAULT))
501 return NULL;
502
503 /*
504 * When there are no effective ACEs, the following will end
505 * up setting a 3-element effective posix ACL with all
506 * permissions zero.
507 */
508 if (!state->users->n && !state->groups->n)
509 nace = 3;
510 else /* Note we also include a MASK ACE in this case: */
511 nace = 4 + state->users->n + state->groups->n;
512 pacl = posix_acl_alloc(nace, GFP_KERNEL);
513 if (!pacl)
514 return ERR_PTR(-ENOMEM);
515
516 pace = pacl->a_entries;
517 pace->e_tag = ACL_USER_OBJ;
518 low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
519
520 for (i=0; i < state->users->n; i++) {
521 pace++;
522 pace->e_tag = ACL_USER;
523 low_mode_from_nfs4(state->users->aces[i].perms.allow,
524 &pace->e_perm, flags);
525 pace->e_uid = state->users->aces[i].uid;
526 add_to_mask(state, &state->users->aces[i].perms);
527 }
528
529 pace++;
530 pace->e_tag = ACL_GROUP_OBJ;
531 low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
532 add_to_mask(state, &state->group);
533
534 for (i=0; i < state->groups->n; i++) {
535 pace++;
536 pace->e_tag = ACL_GROUP;
537 low_mode_from_nfs4(state->groups->aces[i].perms.allow,
538 &pace->e_perm, flags);
539 pace->e_gid = state->groups->aces[i].gid;
540 add_to_mask(state, &state->groups->aces[i].perms);
541 }
542
543 if (state->users->n || state->groups->n) {
544 pace++;
545 pace->e_tag = ACL_MASK;
546 low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
547 }
548
549 pace++;
550 pace->e_tag = ACL_OTHER;
551 low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
552
553 return pacl;
554}
555
556static inline void allow_bits(struct posix_ace_state *astate, u32 mask)
557{
558 /* Allow all bits in the mask not already denied: */
559 astate->allow |= mask & ~astate->deny;
560}
561
562static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
563{
564 /* Deny all bits in the mask not already allowed: */
565 astate->deny |= mask & ~astate->allow;
566}
567
568static int find_uid(struct posix_acl_state *state, kuid_t uid)
569{
570 struct posix_ace_state_array *a = state->users;
571 int i;
572
573 for (i = 0; i < a->n; i++)
574 if (uid_eq(a->aces[i].uid, uid))
575 return i;
576 /* Not found: */
577 a->n++;
578 a->aces[i].uid = uid;
579 a->aces[i].perms.allow = state->everyone.allow;
580 a->aces[i].perms.deny = state->everyone.deny;
581
582 return i;
583}
584
585static int find_gid(struct posix_acl_state *state, kgid_t gid)
586{
587 struct posix_ace_state_array *a = state->groups;
588 int i;
589
590 for (i = 0; i < a->n; i++)
591 if (gid_eq(a->aces[i].gid, gid))
592 return i;
593 /* Not found: */
594 a->n++;
595 a->aces[i].gid = gid;
596 a->aces[i].perms.allow = state->everyone.allow;
597 a->aces[i].perms.deny = state->everyone.deny;
598
599 return i;
600}
601
602static void deny_bits_array(struct posix_ace_state_array *a, u32 mask)
603{
604 int i;
605
606 for (i=0; i < a->n; i++)
607 deny_bits(&a->aces[i].perms, mask);
608}
609
610static void allow_bits_array(struct posix_ace_state_array *a, u32 mask)
611{
612 int i;
613
614 for (i=0; i < a->n; i++)
615 allow_bits(&a->aces[i].perms, mask);
616}
617
618static void process_one_v4_ace(struct posix_acl_state *state,
619 struct nfs4_ace *ace)
620{
621 u32 mask = ace->access_mask;
622 short type = ace2type(ace);
623 int i;
624
625 state->valid |= type;
626
627 switch (type) {
628 case ACL_USER_OBJ:
629 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
630 allow_bits(&state->owner, mask);
631 } else {
632 deny_bits(&state->owner, mask);
633 }
634 break;
635 case ACL_USER:
636 i = find_uid(state, ace->who_uid);
637 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
638 allow_bits(&state->users->aces[i].perms, mask);
639 } else {
640 deny_bits(&state->users->aces[i].perms, mask);
641 mask = state->users->aces[i].perms.deny;
642 deny_bits(&state->owner, mask);
643 }
644 break;
645 case ACL_GROUP_OBJ:
646 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
647 allow_bits(&state->group, mask);
648 } else {
649 deny_bits(&state->group, mask);
650 mask = state->group.deny;
651 deny_bits(&state->owner, mask);
652 deny_bits(&state->everyone, mask);
653 deny_bits_array(state->users, mask);
654 deny_bits_array(state->groups, mask);
655 }
656 break;
657 case ACL_GROUP:
658 i = find_gid(state, ace->who_gid);
659 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
660 allow_bits(&state->groups->aces[i].perms, mask);
661 } else {
662 deny_bits(&state->groups->aces[i].perms, mask);
663 mask = state->groups->aces[i].perms.deny;
664 deny_bits(&state->owner, mask);
665 deny_bits(&state->group, mask);
666 deny_bits(&state->everyone, mask);
667 deny_bits_array(state->users, mask);
668 deny_bits_array(state->groups, mask);
669 }
670 break;
671 case ACL_OTHER:
672 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
673 allow_bits(&state->owner, mask);
674 allow_bits(&state->group, mask);
675 allow_bits(&state->other, mask);
676 allow_bits(&state->everyone, mask);
677 allow_bits_array(state->users, mask);
678 allow_bits_array(state->groups, mask);
679 } else {
680 deny_bits(&state->owner, mask);
681 deny_bits(&state->group, mask);
682 deny_bits(&state->other, mask);
683 deny_bits(&state->everyone, mask);
684 deny_bits_array(state->users, mask);
685 deny_bits_array(state->groups, mask);
686 }
687 }
688}
689
690static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl,
691 struct posix_acl **pacl, struct posix_acl **dpacl,
692 unsigned int flags)
693{
694 struct posix_acl_state effective_acl_state, default_acl_state;
695 struct nfs4_ace *ace;
696 int ret;
697
698 ret = init_state(&effective_acl_state, acl->naces);
699 if (ret)
700 return ret;
701 ret = init_state(&default_acl_state, acl->naces);
702 if (ret)
703 goto out_estate;
704 ret = -EINVAL;
705 for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
706 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
707 ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
708 goto out_dstate;
709 if (ace->flag & ~NFS4_SUPPORTED_FLAGS)
710 goto out_dstate;
711 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) {
712 process_one_v4_ace(&effective_acl_state, ace);
713 continue;
714 }
715 if (!(flags & NFS4_ACL_DIR))
716 goto out_dstate;
717 /*
718 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT
719 * is set, we're effectively turning on the other. That's OK,
720 * according to rfc 3530.
721 */
722 process_one_v4_ace(&default_acl_state, ace);
723
724 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE))
725 process_one_v4_ace(&effective_acl_state, ace);
726 }
727
728 /*
729 * At this point, the default ACL may have zeroed-out entries for owner,
730 * group and other. That usually results in a non-sensical resulting ACL
731 * that denies all access except to any ACE that was explicitly added.
732 *
733 * The setfacl command solves a similar problem with this logic:
734 *
735 * "If a Default ACL entry is created, and the Default ACL contains
736 * no owner, owning group, or others entry, a copy of the ACL
737 * owner, owning group, or others entry is added to the Default ACL."
738 *
739 * Copy any missing ACEs from the effective set, if any ACEs were
740 * explicitly set.
741 */
742 if (default_acl_state.valid) {
743 if (!(default_acl_state.valid & ACL_USER_OBJ))
744 default_acl_state.owner = effective_acl_state.owner;
745 if (!(default_acl_state.valid & ACL_GROUP_OBJ))
746 default_acl_state.group = effective_acl_state.group;
747 if (!(default_acl_state.valid & ACL_OTHER))
748 default_acl_state.other = effective_acl_state.other;
749 }
750
751 *pacl = posix_state_to_acl(&effective_acl_state, flags);
752 if (IS_ERR(*pacl)) {
753 ret = PTR_ERR(*pacl);
754 *pacl = NULL;
755 goto out_dstate;
756 }
757 *dpacl = posix_state_to_acl(&default_acl_state,
758 flags | NFS4_ACL_TYPE_DEFAULT);
759 if (IS_ERR(*dpacl)) {
760 ret = PTR_ERR(*dpacl);
761 *dpacl = NULL;
762 posix_acl_release(*pacl);
763 *pacl = NULL;
764 goto out_dstate;
765 }
766 sort_pacl(*pacl);
767 sort_pacl(*dpacl);
768 ret = 0;
769out_dstate:
770 free_state(&default_acl_state);
771out_estate:
772 free_state(&effective_acl_state);
773 return ret;
774}
775
776__be32 nfsd4_acl_to_attr(enum nfs_ftype4 type, struct nfs4_acl *acl,
777 struct nfsd_attrs *attr)
778{
779 int host_error;
780 unsigned int flags = 0;
781
782 if (!acl)
783 return nfs_ok;
784
785 if (type == NF4DIR)
786 flags = NFS4_ACL_DIR;
787
788 host_error = nfs4_acl_nfsv4_to_posix(acl, &attr->na_pacl,
789 &attr->na_dpacl, flags);
790 if (host_error == -EINVAL)
791 return nfserr_attrnotsupp;
792 else
793 return nfserrno(host_error);
794}
795
796static short
797ace2type(struct nfs4_ace *ace)
798{
799 switch (ace->whotype) {
800 case NFS4_ACL_WHO_NAMED:
801 return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ?
802 ACL_GROUP : ACL_USER);
803 case NFS4_ACL_WHO_OWNER:
804 return ACL_USER_OBJ;
805 case NFS4_ACL_WHO_GROUP:
806 return ACL_GROUP_OBJ;
807 case NFS4_ACL_WHO_EVERYONE:
808 return ACL_OTHER;
809 }
810 BUG();
811 return -1;
812}
813
814/*
815 * return the size of the struct nfs4_acl required to represent an acl
816 * with @entries entries.
817 */
818int nfs4_acl_bytes(int entries)
819{
820 return sizeof(struct nfs4_acl) + entries * sizeof(struct nfs4_ace);
821}
822
823static struct {
824 char *string;
825 int stringlen;
826 int type;
827} s2t_map[] = {
828 {
829 .string = "OWNER@",
830 .stringlen = sizeof("OWNER@") - 1,
831 .type = NFS4_ACL_WHO_OWNER,
832 },
833 {
834 .string = "GROUP@",
835 .stringlen = sizeof("GROUP@") - 1,
836 .type = NFS4_ACL_WHO_GROUP,
837 },
838 {
839 .string = "EVERYONE@",
840 .stringlen = sizeof("EVERYONE@") - 1,
841 .type = NFS4_ACL_WHO_EVERYONE,
842 },
843};
844
845int
846nfs4_acl_get_whotype(char *p, u32 len)
847{
848 int i;
849
850 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
851 if (s2t_map[i].stringlen == len &&
852 0 == memcmp(s2t_map[i].string, p, len))
853 return s2t_map[i].type;
854 }
855 return NFS4_ACL_WHO_NAMED;
856}
857
858__be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who)
859{
860 __be32 *p;
861 int i;
862
863 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
864 if (s2t_map[i].type != who)
865 continue;
866 p = xdr_reserve_space(xdr, s2t_map[i].stringlen + 4);
867 if (!p)
868 return nfserr_resource;
869 p = xdr_encode_opaque(p, s2t_map[i].string,
870 s2t_map[i].stringlen);
871 return 0;
872 }
873 WARN_ON_ONCE(1);
874 return nfserr_serverfault;
875}
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/fs.h>
38#include <linux/slab.h>
39#include <linux/posix_acl.h>
40
41#include "nfsfh.h"
42#include "nfsd.h"
43#include "acl.h"
44#include "vfs.h"
45
46#define NFS4_ACL_TYPE_DEFAULT 0x01
47#define NFS4_ACL_DIR 0x02
48#define NFS4_ACL_OWNER 0x04
49
50/* mode bit translations: */
51#define NFS4_READ_MODE (NFS4_ACE_READ_DATA)
52#define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA)
53#define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE
54#define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE)
55#define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)
56
57/* flags used to simulate posix default ACLs */
58#define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \
59 | NFS4_ACE_DIRECTORY_INHERIT_ACE)
60
61#define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \
62 | NFS4_ACE_INHERIT_ONLY_ACE \
63 | NFS4_ACE_IDENTIFIER_GROUP)
64
65static u32
66mask_from_posix(unsigned short perm, unsigned int flags)
67{
68 int mask = NFS4_ANYONE_MODE;
69
70 if (flags & NFS4_ACL_OWNER)
71 mask |= NFS4_OWNER_MODE;
72 if (perm & ACL_READ)
73 mask |= NFS4_READ_MODE;
74 if (perm & ACL_WRITE)
75 mask |= NFS4_WRITE_MODE;
76 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
77 mask |= NFS4_ACE_DELETE_CHILD;
78 if (perm & ACL_EXECUTE)
79 mask |= NFS4_EXECUTE_MODE;
80 return mask;
81}
82
83static u32
84deny_mask_from_posix(unsigned short perm, u32 flags)
85{
86 u32 mask = 0;
87
88 if (perm & ACL_READ)
89 mask |= NFS4_READ_MODE;
90 if (perm & ACL_WRITE)
91 mask |= NFS4_WRITE_MODE;
92 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
93 mask |= NFS4_ACE_DELETE_CHILD;
94 if (perm & ACL_EXECUTE)
95 mask |= NFS4_EXECUTE_MODE;
96 return mask;
97}
98
99/* XXX: modify functions to return NFS errors; they're only ever
100 * used by nfs code, after all.... */
101
102/* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the
103 * side of being more restrictive, so the mode bit mapping below is
104 * pessimistic. An optimistic version would be needed to handle DENY's,
105 * but we expect to coalesce all ALLOWs and DENYs before mapping to mode
106 * bits. */
107
108static void
109low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
110{
111 u32 write_mode = NFS4_WRITE_MODE;
112
113 if (flags & NFS4_ACL_DIR)
114 write_mode |= NFS4_ACE_DELETE_CHILD;
115 *mode = 0;
116 if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE)
117 *mode |= ACL_READ;
118 if ((perm & write_mode) == write_mode)
119 *mode |= ACL_WRITE;
120 if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE)
121 *mode |= ACL_EXECUTE;
122}
123
124static short ace2type(struct nfs4_ace *);
125static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *,
126 unsigned int);
127
128int
129nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
130 struct nfs4_acl **acl)
131{
132 struct inode *inode = d_inode(dentry);
133 int error = 0;
134 struct posix_acl *pacl = NULL, *dpacl = NULL;
135 unsigned int flags = 0;
136 int size = 0;
137
138 pacl = get_acl(inode, ACL_TYPE_ACCESS);
139 if (!pacl)
140 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
141
142 if (IS_ERR(pacl))
143 return PTR_ERR(pacl);
144
145 /* allocate for worst case: one (deny, allow) pair each: */
146 size += 2 * pacl->a_count;
147
148 if (S_ISDIR(inode->i_mode)) {
149 flags = NFS4_ACL_DIR;
150 dpacl = get_acl(inode, ACL_TYPE_DEFAULT);
151 if (IS_ERR(dpacl)) {
152 error = PTR_ERR(dpacl);
153 goto rel_pacl;
154 }
155
156 if (dpacl)
157 size += 2 * dpacl->a_count;
158 }
159
160 *acl = kmalloc(nfs4_acl_bytes(size), GFP_KERNEL);
161 if (*acl == NULL) {
162 error = -ENOMEM;
163 goto out;
164 }
165 (*acl)->naces = 0;
166
167 _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT);
168
169 if (dpacl)
170 _posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT);
171
172out:
173 posix_acl_release(dpacl);
174rel_pacl:
175 posix_acl_release(pacl);
176 return error;
177}
178
179struct posix_acl_summary {
180 unsigned short owner;
181 unsigned short users;
182 unsigned short group;
183 unsigned short groups;
184 unsigned short other;
185 unsigned short mask;
186};
187
188static void
189summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas)
190{
191 struct posix_acl_entry *pa, *pe;
192
193 /*
194 * Only pas.users and pas.groups need initialization; previous
195 * posix_acl_valid() calls ensure that the other fields will be
196 * initialized in the following loop. But, just to placate gcc:
197 */
198 memset(pas, 0, sizeof(*pas));
199 pas->mask = 07;
200
201 pe = acl->a_entries + acl->a_count;
202
203 FOREACH_ACL_ENTRY(pa, acl, pe) {
204 switch (pa->e_tag) {
205 case ACL_USER_OBJ:
206 pas->owner = pa->e_perm;
207 break;
208 case ACL_GROUP_OBJ:
209 pas->group = pa->e_perm;
210 break;
211 case ACL_USER:
212 pas->users |= pa->e_perm;
213 break;
214 case ACL_GROUP:
215 pas->groups |= pa->e_perm;
216 break;
217 case ACL_OTHER:
218 pas->other = pa->e_perm;
219 break;
220 case ACL_MASK:
221 pas->mask = pa->e_perm;
222 break;
223 }
224 }
225 /* We'll only care about effective permissions: */
226 pas->users &= pas->mask;
227 pas->group &= pas->mask;
228 pas->groups &= pas->mask;
229}
230
231/* We assume the acl has been verified with posix_acl_valid. */
232static void
233_posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
234 unsigned int flags)
235{
236 struct posix_acl_entry *pa, *group_owner_entry;
237 struct nfs4_ace *ace;
238 struct posix_acl_summary pas;
239 unsigned short deny;
240 int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ?
241 NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0);
242
243 BUG_ON(pacl->a_count < 3);
244 summarize_posix_acl(pacl, &pas);
245
246 pa = pacl->a_entries;
247 ace = acl->aces + acl->naces;
248
249 /* We could deny everything not granted by the owner: */
250 deny = ~pas.owner;
251 /*
252 * but it is equivalent (and simpler) to deny only what is not
253 * granted by later entries:
254 */
255 deny &= pas.users | pas.group | pas.groups | pas.other;
256 if (deny) {
257 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
258 ace->flag = eflag;
259 ace->access_mask = deny_mask_from_posix(deny, flags);
260 ace->whotype = NFS4_ACL_WHO_OWNER;
261 ace++;
262 acl->naces++;
263 }
264
265 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
266 ace->flag = eflag;
267 ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER);
268 ace->whotype = NFS4_ACL_WHO_OWNER;
269 ace++;
270 acl->naces++;
271 pa++;
272
273 while (pa->e_tag == ACL_USER) {
274 deny = ~(pa->e_perm & pas.mask);
275 deny &= pas.groups | pas.group | pas.other;
276 if (deny) {
277 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
278 ace->flag = eflag;
279 ace->access_mask = deny_mask_from_posix(deny, flags);
280 ace->whotype = NFS4_ACL_WHO_NAMED;
281 ace->who_uid = pa->e_uid;
282 ace++;
283 acl->naces++;
284 }
285 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
286 ace->flag = eflag;
287 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
288 flags);
289 ace->whotype = NFS4_ACL_WHO_NAMED;
290 ace->who_uid = pa->e_uid;
291 ace++;
292 acl->naces++;
293 pa++;
294 }
295
296 /* In the case of groups, we apply allow ACEs first, then deny ACEs,
297 * since a user can be in more than one group. */
298
299 /* allow ACEs */
300
301 group_owner_entry = pa;
302
303 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
304 ace->flag = eflag;
305 ace->access_mask = mask_from_posix(pas.group, flags);
306 ace->whotype = NFS4_ACL_WHO_GROUP;
307 ace++;
308 acl->naces++;
309 pa++;
310
311 while (pa->e_tag == ACL_GROUP) {
312 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
313 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
314 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
315 flags);
316 ace->whotype = NFS4_ACL_WHO_NAMED;
317 ace->who_gid = pa->e_gid;
318 ace++;
319 acl->naces++;
320 pa++;
321 }
322
323 /* deny ACEs */
324
325 pa = group_owner_entry;
326
327 deny = ~pas.group & pas.other;
328 if (deny) {
329 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
330 ace->flag = eflag;
331 ace->access_mask = deny_mask_from_posix(deny, flags);
332 ace->whotype = NFS4_ACL_WHO_GROUP;
333 ace++;
334 acl->naces++;
335 }
336 pa++;
337
338 while (pa->e_tag == ACL_GROUP) {
339 deny = ~(pa->e_perm & pas.mask);
340 deny &= pas.other;
341 if (deny) {
342 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
343 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
344 ace->access_mask = deny_mask_from_posix(deny, flags);
345 ace->whotype = NFS4_ACL_WHO_NAMED;
346 ace->who_gid = pa->e_gid;
347 ace++;
348 acl->naces++;
349 }
350 pa++;
351 }
352
353 if (pa->e_tag == ACL_MASK)
354 pa++;
355 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
356 ace->flag = eflag;
357 ace->access_mask = mask_from_posix(pa->e_perm, flags);
358 ace->whotype = NFS4_ACL_WHO_EVERYONE;
359 acl->naces++;
360}
361
362static bool
363pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2)
364{
365 if (pace1->e_tag != pace2->e_tag)
366 return pace1->e_tag > pace2->e_tag;
367 if (pace1->e_tag == ACL_USER)
368 return uid_gt(pace1->e_uid, pace2->e_uid);
369 if (pace1->e_tag == ACL_GROUP)
370 return gid_gt(pace1->e_gid, pace2->e_gid);
371 return false;
372}
373
374static void
375sort_pacl_range(struct posix_acl *pacl, int start, int end) {
376 int sorted = 0, i;
377
378 /* We just do a bubble sort; easy to do in place, and we're not
379 * expecting acl's to be long enough to justify anything more. */
380 while (!sorted) {
381 sorted = 1;
382 for (i = start; i < end; i++) {
383 if (pace_gt(&pacl->a_entries[i],
384 &pacl->a_entries[i+1])) {
385 sorted = 0;
386 swap(pacl->a_entries[i],
387 pacl->a_entries[i + 1]);
388 }
389 }
390 }
391}
392
393static void
394sort_pacl(struct posix_acl *pacl)
395{
396 /* posix_acl_valid requires that users and groups be in order
397 * by uid/gid. */
398 int i, j;
399
400 /* no users or groups */
401 if (!pacl || pacl->a_count <= 4)
402 return;
403
404 i = 1;
405 while (pacl->a_entries[i].e_tag == ACL_USER)
406 i++;
407 sort_pacl_range(pacl, 1, i-1);
408
409 BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ);
410 j = ++i;
411 while (pacl->a_entries[j].e_tag == ACL_GROUP)
412 j++;
413 sort_pacl_range(pacl, i, j-1);
414 return;
415}
416
417/*
418 * While processing the NFSv4 ACE, this maintains bitmasks representing
419 * which permission bits have been allowed and which denied to a given
420 * entity: */
421struct posix_ace_state {
422 u32 allow;
423 u32 deny;
424};
425
426struct posix_user_ace_state {
427 union {
428 kuid_t uid;
429 kgid_t gid;
430 };
431 struct posix_ace_state perms;
432};
433
434struct posix_ace_state_array {
435 int n;
436 struct posix_user_ace_state aces[];
437};
438
439/*
440 * While processing the NFSv4 ACE, this maintains the partial permissions
441 * calculated so far: */
442
443struct posix_acl_state {
444 int empty;
445 struct posix_ace_state owner;
446 struct posix_ace_state group;
447 struct posix_ace_state other;
448 struct posix_ace_state everyone;
449 struct posix_ace_state mask; /* Deny unused in this case */
450 struct posix_ace_state_array *users;
451 struct posix_ace_state_array *groups;
452};
453
454static int
455init_state(struct posix_acl_state *state, int cnt)
456{
457 int alloc;
458
459 memset(state, 0, sizeof(struct posix_acl_state));
460 state->empty = 1;
461 /*
462 * In the worst case, each individual acl could be for a distinct
463 * named user or group, but we don't know which, so we allocate
464 * enough space for either:
465 */
466 alloc = sizeof(struct posix_ace_state_array)
467 + cnt*sizeof(struct posix_user_ace_state);
468 state->users = kzalloc(alloc, GFP_KERNEL);
469 if (!state->users)
470 return -ENOMEM;
471 state->groups = kzalloc(alloc, GFP_KERNEL);
472 if (!state->groups) {
473 kfree(state->users);
474 return -ENOMEM;
475 }
476 return 0;
477}
478
479static void
480free_state(struct posix_acl_state *state) {
481 kfree(state->users);
482 kfree(state->groups);
483}
484
485static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate)
486{
487 state->mask.allow |= astate->allow;
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;
497
498 /*
499 * ACLs with no ACEs are treated differently in the inheritable
500 * and effective cases: when there are no inheritable ACEs,
501 * calls ->set_acl with a NULL ACL structure.
502 */
503 if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT))
504 return NULL;
505
506 /*
507 * When there are no effective ACEs, the following will end
508 * up setting a 3-element effective posix ACL with all
509 * permissions zero.
510 */
511 if (!state->users->n && !state->groups->n)
512 nace = 3;
513 else /* Note we also include a MASK ACE in this case: */
514 nace = 4 + state->users->n + state->groups->n;
515 pacl = posix_acl_alloc(nace, GFP_KERNEL);
516 if (!pacl)
517 return ERR_PTR(-ENOMEM);
518
519 pace = pacl->a_entries;
520 pace->e_tag = ACL_USER_OBJ;
521 low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
522
523 for (i=0; i < state->users->n; i++) {
524 pace++;
525 pace->e_tag = ACL_USER;
526 low_mode_from_nfs4(state->users->aces[i].perms.allow,
527 &pace->e_perm, flags);
528 pace->e_uid = state->users->aces[i].uid;
529 add_to_mask(state, &state->users->aces[i].perms);
530 }
531
532 pace++;
533 pace->e_tag = ACL_GROUP_OBJ;
534 low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
535 add_to_mask(state, &state->group);
536
537 for (i=0; i < state->groups->n; i++) {
538 pace++;
539 pace->e_tag = ACL_GROUP;
540 low_mode_from_nfs4(state->groups->aces[i].perms.allow,
541 &pace->e_perm, flags);
542 pace->e_gid = state->groups->aces[i].gid;
543 add_to_mask(state, &state->groups->aces[i].perms);
544 }
545
546 if (state->users->n || state->groups->n) {
547 pace++;
548 pace->e_tag = ACL_MASK;
549 low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
550 }
551
552 pace++;
553 pace->e_tag = ACL_OTHER;
554 low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
555
556 return pacl;
557}
558
559static inline void allow_bits(struct posix_ace_state *astate, u32 mask)
560{
561 /* Allow all bits in the mask not already denied: */
562 astate->allow |= mask & ~astate->deny;
563}
564
565static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
566{
567 /* Deny all bits in the mask not already allowed: */
568 astate->deny |= mask & ~astate->allow;
569}
570
571static int find_uid(struct posix_acl_state *state, kuid_t uid)
572{
573 struct posix_ace_state_array *a = state->users;
574 int i;
575
576 for (i = 0; i < a->n; i++)
577 if (uid_eq(a->aces[i].uid, uid))
578 return i;
579 /* Not found: */
580 a->n++;
581 a->aces[i].uid = uid;
582 a->aces[i].perms.allow = state->everyone.allow;
583 a->aces[i].perms.deny = state->everyone.deny;
584
585 return i;
586}
587
588static int find_gid(struct posix_acl_state *state, kgid_t gid)
589{
590 struct posix_ace_state_array *a = state->groups;
591 int i;
592
593 for (i = 0; i < a->n; i++)
594 if (gid_eq(a->aces[i].gid, gid))
595 return i;
596 /* Not found: */
597 a->n++;
598 a->aces[i].gid = gid;
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, ace->who_uid);
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_gid(state, ace->who_gid);
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
692static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl,
693 struct posix_acl **pacl, struct posix_acl **dpacl,
694 unsigned int flags)
695{
696 struct posix_acl_state effective_acl_state, default_acl_state;
697 struct nfs4_ace *ace;
698 int ret;
699
700 ret = init_state(&effective_acl_state, acl->naces);
701 if (ret)
702 return ret;
703 ret = init_state(&default_acl_state, acl->naces);
704 if (ret)
705 goto out_estate;
706 ret = -EINVAL;
707 for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
708 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
709 ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
710 goto out_dstate;
711 if (ace->flag & ~NFS4_SUPPORTED_FLAGS)
712 goto out_dstate;
713 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) {
714 process_one_v4_ace(&effective_acl_state, ace);
715 continue;
716 }
717 if (!(flags & NFS4_ACL_DIR))
718 goto out_dstate;
719 /*
720 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT
721 * is set, we're effectively turning on the other. That's OK,
722 * according to rfc 3530.
723 */
724 process_one_v4_ace(&default_acl_state, ace);
725
726 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE))
727 process_one_v4_ace(&effective_acl_state, ace);
728 }
729 *pacl = posix_state_to_acl(&effective_acl_state, flags);
730 if (IS_ERR(*pacl)) {
731 ret = PTR_ERR(*pacl);
732 *pacl = NULL;
733 goto out_dstate;
734 }
735 *dpacl = posix_state_to_acl(&default_acl_state,
736 flags | NFS4_ACL_TYPE_DEFAULT);
737 if (IS_ERR(*dpacl)) {
738 ret = PTR_ERR(*dpacl);
739 *dpacl = NULL;
740 posix_acl_release(*pacl);
741 *pacl = NULL;
742 goto out_dstate;
743 }
744 sort_pacl(*pacl);
745 sort_pacl(*dpacl);
746 ret = 0;
747out_dstate:
748 free_state(&default_acl_state);
749out_estate:
750 free_state(&effective_acl_state);
751 return ret;
752}
753
754__be32
755nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
756 struct nfs4_acl *acl)
757{
758 __be32 error;
759 int host_error;
760 struct dentry *dentry;
761 struct inode *inode;
762 struct posix_acl *pacl = NULL, *dpacl = NULL;
763 unsigned int flags = 0;
764
765 /* Get inode */
766 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_SATTR);
767 if (error)
768 return error;
769
770 dentry = fhp->fh_dentry;
771 inode = d_inode(dentry);
772
773 if (S_ISDIR(inode->i_mode))
774 flags = NFS4_ACL_DIR;
775
776 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
777 if (host_error == -EINVAL)
778 return nfserr_attrnotsupp;
779 if (host_error < 0)
780 goto out_nfserr;
781
782 fh_lock(fhp);
783
784 host_error = set_posix_acl(inode, ACL_TYPE_ACCESS, pacl);
785 if (host_error < 0)
786 goto out_drop_lock;
787
788 if (S_ISDIR(inode->i_mode)) {
789 host_error = set_posix_acl(inode, ACL_TYPE_DEFAULT, dpacl);
790 }
791
792out_drop_lock:
793 fh_unlock(fhp);
794
795 posix_acl_release(pacl);
796 posix_acl_release(dpacl);
797out_nfserr:
798 if (host_error == -EOPNOTSUPP)
799 return nfserr_attrnotsupp;
800 else
801 return nfserrno(host_error);
802}
803
804
805static short
806ace2type(struct nfs4_ace *ace)
807{
808 switch (ace->whotype) {
809 case NFS4_ACL_WHO_NAMED:
810 return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ?
811 ACL_GROUP : ACL_USER);
812 case NFS4_ACL_WHO_OWNER:
813 return ACL_USER_OBJ;
814 case NFS4_ACL_WHO_GROUP:
815 return ACL_GROUP_OBJ;
816 case NFS4_ACL_WHO_EVERYONE:
817 return ACL_OTHER;
818 }
819 BUG();
820 return -1;
821}
822
823/*
824 * return the size of the struct nfs4_acl required to represent an acl
825 * with @entries entries.
826 */
827int nfs4_acl_bytes(int entries)
828{
829 return sizeof(struct nfs4_acl) + entries * sizeof(struct nfs4_ace);
830}
831
832static struct {
833 char *string;
834 int stringlen;
835 int type;
836} s2t_map[] = {
837 {
838 .string = "OWNER@",
839 .stringlen = sizeof("OWNER@") - 1,
840 .type = NFS4_ACL_WHO_OWNER,
841 },
842 {
843 .string = "GROUP@",
844 .stringlen = sizeof("GROUP@") - 1,
845 .type = NFS4_ACL_WHO_GROUP,
846 },
847 {
848 .string = "EVERYONE@",
849 .stringlen = sizeof("EVERYONE@") - 1,
850 .type = NFS4_ACL_WHO_EVERYONE,
851 },
852};
853
854int
855nfs4_acl_get_whotype(char *p, u32 len)
856{
857 int i;
858
859 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
860 if (s2t_map[i].stringlen == len &&
861 0 == memcmp(s2t_map[i].string, p, len))
862 return s2t_map[i].type;
863 }
864 return NFS4_ACL_WHO_NAMED;
865}
866
867__be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who)
868{
869 __be32 *p;
870 int i;
871
872 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
873 if (s2t_map[i].type != who)
874 continue;
875 p = xdr_reserve_space(xdr, s2t_map[i].stringlen + 4);
876 if (!p)
877 return nfserr_resource;
878 p = xdr_encode_opaque(p, s2t_map[i].string,
879 s2t_map[i].stringlen);
880 return 0;
881 }
882 WARN_ON_ONCE(1);
883 return nfserr_serverfault;
884}