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Linux/fs/nfsd/nfs4acl.c

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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 
 65 static u32
 66 mask_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 
 83 static u32
 84 deny_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 
108 static void
109 low_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 
124 static short ace2type(struct nfs4_ace *);
125 static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *,
126                                 unsigned int);
127 
128 int
129 nfsd4_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 
172 out:
173         posix_acl_release(dpacl);
174 rel_pacl:
175         posix_acl_release(pacl);
176         return error;
177 }
178 
179 struct 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 
188 static void
189 summarize_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. */
232 static 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 
362 static bool
363 pace_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 
374 static void
375 sort_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 
393 static void
394 sort_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: */
421 struct posix_ace_state {
422         u32 allow;
423         u32 deny;
424 };
425 
426 struct posix_user_ace_state {
427         union {
428                 kuid_t uid;
429                 kgid_t gid;
430         };
431         struct posix_ace_state perms;
432 };
433 
434 struct 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 
443 struct 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 
454 static int
455 init_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 
479 static void
480 free_state(struct posix_acl_state *state) {
481         kfree(state->users);
482         kfree(state->groups);
483 }
484 
485 static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate)
486 {
487         state->mask.allow |= astate->allow;
488 }
489 
490 static struct posix_acl *
491 posix_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 
559 static 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 
565 static 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 
571 static 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 
588 static 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 
605 static 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 
613 static 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 
621 static 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 
692 static 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;
747 out_dstate:
748         free_state(&default_acl_state);
749 out_estate:
750         free_state(&effective_acl_state);
751         return ret;
752 }
753 
754 __be32
755 nfsd4_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 
792 out_drop_lock:
793         fh_unlock(fhp);
794 
795         posix_acl_release(pacl);
796         posix_acl_release(dpacl);
797 out_nfserr:
798         if (host_error == -EOPNOTSUPP)
799                 return nfserr_attrnotsupp;
800         else
801                 return nfserrno(host_error);
802 }
803 
804 
805 static short
806 ace2type(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  */
827 int nfs4_acl_bytes(int entries)
828 {
829         return sizeof(struct nfs4_acl) + entries * sizeof(struct nfs4_ace);
830 }
831 
832 static 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 
854 int
855 nfs4_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 }
885 

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