~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/nfsd/nfs4acl.c

Version: ~ [ linux-5.17-rc1 ] ~ [ linux-5.16.2 ] ~ [ linux-5.15.16 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.93 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.173 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.225 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.262 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.297 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.299 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 "acl.h"
 41 
 42 
 43 /* mode bit translations: */
 44 #define NFS4_READ_MODE (NFS4_ACE_READ_DATA)
 45 #define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA)
 46 #define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE
 47 #define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE)
 48 #define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)
 49 
 50 /* We don't support these bits; insist they be neither allowed nor denied */
 51 #define NFS4_MASK_UNSUPP (NFS4_ACE_DELETE | NFS4_ACE_WRITE_OWNER \
 52                 | NFS4_ACE_READ_NAMED_ATTRS | NFS4_ACE_WRITE_NAMED_ATTRS)
 53 
 54 /* flags used to simulate posix default ACLs */
 55 #define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \
 56                 | NFS4_ACE_DIRECTORY_INHERIT_ACE)
 57 
 58 #define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \
 59                 | NFS4_ACE_INHERIT_ONLY_ACE \
 60                 | NFS4_ACE_IDENTIFIER_GROUP)
 61 
 62 #define MASK_EQUAL(mask1, mask2) \
 63         ( ((mask1) & NFS4_ACE_MASK_ALL) == ((mask2) & NFS4_ACE_MASK_ALL) )
 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 espect 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 struct ace_container {
125         struct nfs4_ace  *ace;
126         struct list_head  ace_l;
127 };
128 
129 static short ace2type(struct nfs4_ace *);
130 static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *,
131                                 unsigned int);
132 
133 struct nfs4_acl *
134 nfs4_acl_posix_to_nfsv4(struct posix_acl *pacl, struct posix_acl *dpacl,
135                         unsigned int flags)
136 {
137         struct nfs4_acl *acl;
138         int size = 0;
139 
140         if (pacl) {
141                 if (posix_acl_valid(pacl) < 0)
142                         return ERR_PTR(-EINVAL);
143                 size += 2*pacl->a_count;
144         }
145         if (dpacl) {
146                 if (posix_acl_valid(dpacl) < 0)
147                         return ERR_PTR(-EINVAL);
148                 size += 2*dpacl->a_count;
149         }
150 
151         /* Allocate for worst case: one (deny, allow) pair each: */
152         acl = nfs4_acl_new(size);
153         if (acl == NULL)
154                 return ERR_PTR(-ENOMEM);
155 
156         if (pacl)
157                 _posix_to_nfsv4_one(pacl, acl, flags & ~NFS4_ACL_TYPE_DEFAULT);
158 
159         if (dpacl)
160                 _posix_to_nfsv4_one(dpacl, acl, flags | NFS4_ACL_TYPE_DEFAULT);
161 
162         return acl;
163 }
164 
165 struct posix_acl_summary {
166         unsigned short owner;
167         unsigned short users;
168         unsigned short group;
169         unsigned short groups;
170         unsigned short other;
171         unsigned short mask;
172 };
173 
174 static void
175 summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas)
176 {
177         struct posix_acl_entry *pa, *pe;
178 
179         /*
180          * Only pas.users and pas.groups need initialization; previous
181          * posix_acl_valid() calls ensure that the other fields will be
182          * initialized in the following loop.  But, just to placate gcc:
183          */
184         memset(pas, 0, sizeof(*pas));
185         pas->mask = 07;
186 
187         pe = acl->a_entries + acl->a_count;
188 
189         FOREACH_ACL_ENTRY(pa, acl, pe) {
190                 switch (pa->e_tag) {
191                         case ACL_USER_OBJ:
192                                 pas->owner = pa->e_perm;
193                                 break;
194                         case ACL_GROUP_OBJ:
195                                 pas->group = pa->e_perm;
196                                 break;
197                         case ACL_USER:
198                                 pas->users |= pa->e_perm;
199                                 break;
200                         case ACL_GROUP:
201                                 pas->groups |= pa->e_perm;
202                                 break;
203                         case ACL_OTHER:
204                                 pas->other = pa->e_perm;
205                                 break;
206                         case ACL_MASK:
207                                 pas->mask = pa->e_perm;
208                                 break;
209                 }
210         }
211         /* We'll only care about effective permissions: */
212         pas->users &= pas->mask;
213         pas->group &= pas->mask;
214         pas->groups &= pas->mask;
215 }
216 
217 /* We assume the acl has been verified with posix_acl_valid. */
218 static void
219 _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
220                                                 unsigned int flags)
221 {
222         struct posix_acl_entry *pa, *group_owner_entry;
223         struct nfs4_ace *ace;
224         struct posix_acl_summary pas;
225         unsigned short deny;
226         int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ?
227                 NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0);
228 
229         BUG_ON(pacl->a_count < 3);
230         summarize_posix_acl(pacl, &pas);
231 
232         pa = pacl->a_entries;
233         ace = acl->aces + acl->naces;
234 
235         /* We could deny everything not granted by the owner: */
236         deny = ~pas.owner;
237         /*
238          * but it is equivalent (and simpler) to deny only what is not
239          * granted by later entries:
240          */
241         deny &= pas.users | pas.group | pas.groups | pas.other;
242         if (deny) {
243                 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
244                 ace->flag = eflag;
245                 ace->access_mask = deny_mask_from_posix(deny, flags);
246                 ace->whotype = NFS4_ACL_WHO_OWNER;
247                 ace++;
248                 acl->naces++;
249         }
250 
251         ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
252         ace->flag = eflag;
253         ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER);
254         ace->whotype = NFS4_ACL_WHO_OWNER;
255         ace++;
256         acl->naces++;
257         pa++;
258 
259         while (pa->e_tag == ACL_USER) {
260                 deny = ~(pa->e_perm & pas.mask);
261                 deny &= pas.groups | pas.group | pas.other;
262                 if (deny) {
263                         ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
264                         ace->flag = eflag;
265                         ace->access_mask = deny_mask_from_posix(deny, flags);
266                         ace->whotype = NFS4_ACL_WHO_NAMED;
267                         ace->who_uid = pa->e_uid;
268                         ace++;
269                         acl->naces++;
270                 }
271                 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
272                 ace->flag = eflag;
273                 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
274                                                    flags);
275                 ace->whotype = NFS4_ACL_WHO_NAMED;
276                 ace->who_uid = pa->e_uid;
277                 ace++;
278                 acl->naces++;
279                 pa++;
280         }
281 
282         /* In the case of groups, we apply allow ACEs first, then deny ACEs,
283          * since a user can be in more than one group.  */
284 
285         /* allow ACEs */
286 
287         group_owner_entry = pa;
288 
289         ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
290         ace->flag = eflag;
291         ace->access_mask = mask_from_posix(pas.group, flags);
292         ace->whotype = NFS4_ACL_WHO_GROUP;
293         ace++;
294         acl->naces++;
295         pa++;
296 
297         while (pa->e_tag == ACL_GROUP) {
298                 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
299                 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
300                 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
301                                                    flags);
302                 ace->whotype = NFS4_ACL_WHO_NAMED;
303                 ace->who_gid = pa->e_gid;
304                 ace++;
305                 acl->naces++;
306                 pa++;
307         }
308 
309         /* deny ACEs */
310 
311         pa = group_owner_entry;
312 
313         deny = ~pas.group & pas.other;
314         if (deny) {
315                 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
316                 ace->flag = eflag;
317                 ace->access_mask = deny_mask_from_posix(deny, flags);
318                 ace->whotype = NFS4_ACL_WHO_GROUP;
319                 ace++;
320                 acl->naces++;
321         }
322         pa++;
323 
324         while (pa->e_tag == ACL_GROUP) {
325                 deny = ~(pa->e_perm & pas.mask);
326                 deny &= pas.other;
327                 if (deny) {
328                         ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
329                         ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
330                         ace->access_mask = deny_mask_from_posix(deny, flags);
331                         ace->whotype = NFS4_ACL_WHO_NAMED;
332                         ace->who_gid = pa->e_gid;
333                         ace++;
334                         acl->naces++;
335                 }
336                 pa++;
337         }
338 
339         if (pa->e_tag == ACL_MASK)
340                 pa++;
341         ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
342         ace->flag = eflag;
343         ace->access_mask = mask_from_posix(pa->e_perm, flags);
344         ace->whotype = NFS4_ACL_WHO_EVERYONE;
345         acl->naces++;
346 }
347 
348 static bool
349 pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2)
350 {
351         if (pace1->e_tag != pace2->e_tag)
352                 return pace1->e_tag > pace2->e_tag;
353         if (pace1->e_tag == ACL_USER)
354                 return uid_gt(pace1->e_uid, pace2->e_uid);
355         if (pace1->e_tag == ACL_GROUP)
356                 return gid_gt(pace1->e_gid, pace2->e_gid);
357         return false;
358 }
359 
360 static void
361 sort_pacl_range(struct posix_acl *pacl, int start, int end) {
362         int sorted = 0, i;
363         struct posix_acl_entry tmp;
364 
365         /* We just do a bubble sort; easy to do in place, and we're not
366          * expecting acl's to be long enough to justify anything more. */
367         while (!sorted) {
368                 sorted = 1;
369                 for (i = start; i < end; i++) {
370                         if (pace_gt(&pacl->a_entries[i],
371                                     &pacl->a_entries[i+1])) {
372                                 sorted = 0;
373                                 tmp = pacl->a_entries[i];
374                                 pacl->a_entries[i] = pacl->a_entries[i+1];
375                                 pacl->a_entries[i+1] = tmp;
376                         }
377                 }
378         }
379 }
380 
381 static void
382 sort_pacl(struct posix_acl *pacl)
383 {
384         /* posix_acl_valid requires that users and groups be in order
385          * by uid/gid. */
386         int i, j;
387 
388         /* no users or groups */
389         if (!pacl || pacl->a_count <= 4)
390                 return;
391 
392         i = 1;
393         while (pacl->a_entries[i].e_tag == ACL_USER)
394                 i++;
395         sort_pacl_range(pacl, 1, i-1);
396 
397         BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ);
398         j = ++i;
399         while (pacl->a_entries[j].e_tag == ACL_GROUP)
400                 j++;
401         sort_pacl_range(pacl, i, j-1);
402         return;
403 }
404 
405 /*
406  * While processing the NFSv4 ACE, this maintains bitmasks representing
407  * which permission bits have been allowed and which denied to a given
408  * entity: */
409 struct posix_ace_state {
410         u32 allow;
411         u32 deny;
412 };
413 
414 struct posix_user_ace_state {
415         union {
416                 kuid_t uid;
417                 kgid_t gid;
418         };
419         struct posix_ace_state perms;
420 };
421 
422 struct posix_ace_state_array {
423         int n;
424         struct posix_user_ace_state aces[];
425 };
426 
427 /*
428  * While processing the NFSv4 ACE, this maintains the partial permissions
429  * calculated so far: */
430 
431 struct posix_acl_state {
432         int empty;
433         struct posix_ace_state owner;
434         struct posix_ace_state group;
435         struct posix_ace_state other;
436         struct posix_ace_state everyone;
437         struct posix_ace_state mask; /* Deny unused in this case */
438         struct posix_ace_state_array *users;
439         struct posix_ace_state_array *groups;
440 };
441 
442 static int
443 init_state(struct posix_acl_state *state, int cnt)
444 {
445         int alloc;
446 
447         memset(state, 0, sizeof(struct posix_acl_state));
448         state->empty = 1;
449         /*
450          * In the worst case, each individual acl could be for a distinct
451          * named user or group, but we don't no which, so we allocate
452          * enough space for either:
453          */
454         alloc = sizeof(struct posix_ace_state_array)
455                 + cnt*sizeof(struct posix_user_ace_state);
456         state->users = kzalloc(alloc, GFP_KERNEL);
457         if (!state->users)
458                 return -ENOMEM;
459         state->groups = kzalloc(alloc, GFP_KERNEL);
460         if (!state->groups) {
461                 kfree(state->users);
462                 return -ENOMEM;
463         }
464         return 0;
465 }
466 
467 static void
468 free_state(struct posix_acl_state *state) {
469         kfree(state->users);
470         kfree(state->groups);
471 }
472 
473 static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate)
474 {
475         state->mask.allow |= astate->allow;
476 }
477 
478 /*
479  * Certain bits (SYNCHRONIZE, DELETE, WRITE_OWNER, READ/WRITE_NAMED_ATTRS,
480  * READ_ATTRIBUTES, READ_ACL) are currently unenforceable and don't translate
481  * to traditional read/write/execute permissions.
482  *
483  * It's problematic to reject acls that use certain mode bits, because it
484  * places the burden on users to learn the rules about which bits one
485  * particular server sets, without giving the user a lot of help--we return an
486  * error that could mean any number of different things.  To make matters
487  * worse, the problematic bits might be introduced by some application that's
488  * automatically mapping from some other acl model.
489  *
490  * So wherever possible we accept anything, possibly erring on the side of
491  * denying more permissions than necessary.
492  *
493  * However we do reject *explicit* DENY's of a few bits representing
494  * permissions we could never deny:
495  */
496 
497 static inline int check_deny(u32 mask, int isowner)
498 {
499         if (mask & (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL))
500                 return -EINVAL;
501         if (!isowner)
502                 return 0;
503         if (mask & (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL))
504                 return -EINVAL;
505         return 0;
506 }
507 
508 static struct posix_acl *
509 posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
510 {
511         struct posix_acl_entry *pace;
512         struct posix_acl *pacl;
513         int nace;
514         int i, error = 0;
515 
516         /*
517          * ACLs with no ACEs are treated differently in the inheritable
518          * and effective cases: when there are no inheritable ACEs,
519          * calls ->set_acl with a NULL ACL structure.
520          */
521         if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT))
522                 return NULL;
523 
524         /*
525          * When there are no effective ACEs, the following will end
526          * up setting a 3-element effective posix ACL with all
527          * permissions zero.
528          */
529         nace = 4 + state->users->n + state->groups->n;
530         pacl = posix_acl_alloc(nace, GFP_KERNEL);
531         if (!pacl)
532                 return ERR_PTR(-ENOMEM);
533 
534         pace = pacl->a_entries;
535         pace->e_tag = ACL_USER_OBJ;
536         error = check_deny(state->owner.deny, 1);
537         if (error)
538                 goto out_err;
539         low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
540 
541         for (i=0; i < state->users->n; i++) {
542                 pace++;
543                 pace->e_tag = ACL_USER;
544                 error = check_deny(state->users->aces[i].perms.deny, 0);
545                 if (error)
546                         goto out_err;
547                 low_mode_from_nfs4(state->users->aces[i].perms.allow,
548                                         &pace->e_perm, flags);
549                 pace->e_uid = state->users->aces[i].uid;
550                 add_to_mask(state, &state->users->aces[i].perms);
551         }
552 
553         pace++;
554         pace->e_tag = ACL_GROUP_OBJ;
555         error = check_deny(state->group.deny, 0);
556         if (error)
557                 goto out_err;
558         low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
559         add_to_mask(state, &state->group);
560 
561         for (i=0; i < state->groups->n; i++) {
562                 pace++;
563                 pace->e_tag = ACL_GROUP;
564                 error = check_deny(state->groups->aces[i].perms.deny, 0);
565                 if (error)
566                         goto out_err;
567                 low_mode_from_nfs4(state->groups->aces[i].perms.allow,
568                                         &pace->e_perm, flags);
569                 pace->e_gid = state->groups->aces[i].gid;
570                 add_to_mask(state, &state->groups->aces[i].perms);
571         }
572 
573         pace++;
574         pace->e_tag = ACL_MASK;
575         low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
576 
577         pace++;
578         pace->e_tag = ACL_OTHER;
579         error = check_deny(state->other.deny, 0);
580         if (error)
581                 goto out_err;
582         low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
583 
584         return pacl;
585 out_err:
586         posix_acl_release(pacl);
587         return ERR_PTR(error);
588 }
589 
590 static inline void allow_bits(struct posix_ace_state *astate, u32 mask)
591 {
592         /* Allow all bits in the mask not already denied: */
593         astate->allow |= mask & ~astate->deny;
594 }
595 
596 static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
597 {
598         /* Deny all bits in the mask not already allowed: */
599         astate->deny |= mask & ~astate->allow;
600 }
601 
602 static int find_uid(struct posix_acl_state *state, kuid_t uid)
603 {
604         struct posix_ace_state_array *a = state->users;
605         int i;
606 
607         for (i = 0; i < a->n; i++)
608                 if (uid_eq(a->aces[i].uid, uid))
609                         return i;
610         /* Not found: */
611         a->n++;
612         a->aces[i].uid = uid;
613         a->aces[i].perms.allow = state->everyone.allow;
614         a->aces[i].perms.deny  = state->everyone.deny;
615 
616         return i;
617 }
618 
619 static int find_gid(struct posix_acl_state *state, kgid_t gid)
620 {
621         struct posix_ace_state_array *a = state->groups;
622         int i;
623 
624         for (i = 0; i < a->n; i++)
625                 if (gid_eq(a->aces[i].gid, gid))
626                         return i;
627         /* Not found: */
628         a->n++;
629         a->aces[i].gid = gid;
630         a->aces[i].perms.allow = state->everyone.allow;
631         a->aces[i].perms.deny  = state->everyone.deny;
632 
633         return i;
634 }
635 
636 static void deny_bits_array(struct posix_ace_state_array *a, u32 mask)
637 {
638         int i;
639 
640         for (i=0; i < a->n; i++)
641                 deny_bits(&a->aces[i].perms, mask);
642 }
643 
644 static void allow_bits_array(struct posix_ace_state_array *a, u32 mask)
645 {
646         int i;
647 
648         for (i=0; i < a->n; i++)
649                 allow_bits(&a->aces[i].perms, mask);
650 }
651 
652 static void process_one_v4_ace(struct posix_acl_state *state,
653                                 struct nfs4_ace *ace)
654 {
655         u32 mask = ace->access_mask;
656         int i;
657 
658         state->empty = 0;
659 
660         switch (ace2type(ace)) {
661         case ACL_USER_OBJ:
662                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
663                         allow_bits(&state->owner, mask);
664                 } else {
665                         deny_bits(&state->owner, mask);
666                 }
667                 break;
668         case ACL_USER:
669                 i = find_uid(state, ace->who_uid);
670                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
671                         allow_bits(&state->users->aces[i].perms, mask);
672                 } else {
673                         deny_bits(&state->users->aces[i].perms, mask);
674                         mask = state->users->aces[i].perms.deny;
675                         deny_bits(&state->owner, mask);
676                 }
677                 break;
678         case ACL_GROUP_OBJ:
679                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
680                         allow_bits(&state->group, mask);
681                 } else {
682                         deny_bits(&state->group, mask);
683                         mask = state->group.deny;
684                         deny_bits(&state->owner, mask);
685                         deny_bits(&state->everyone, mask);
686                         deny_bits_array(state->users, mask);
687                         deny_bits_array(state->groups, mask);
688                 }
689                 break;
690         case ACL_GROUP:
691                 i = find_gid(state, ace->who_gid);
692                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
693                         allow_bits(&state->groups->aces[i].perms, mask);
694                 } else {
695                         deny_bits(&state->groups->aces[i].perms, mask);
696                         mask = state->groups->aces[i].perms.deny;
697                         deny_bits(&state->owner, mask);
698                         deny_bits(&state->group, mask);
699                         deny_bits(&state->everyone, mask);
700                         deny_bits_array(state->users, mask);
701                         deny_bits_array(state->groups, mask);
702                 }
703                 break;
704         case ACL_OTHER:
705                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
706                         allow_bits(&state->owner, mask);
707                         allow_bits(&state->group, mask);
708                         allow_bits(&state->other, mask);
709                         allow_bits(&state->everyone, mask);
710                         allow_bits_array(state->users, mask);
711                         allow_bits_array(state->groups, mask);
712                 } else {
713                         deny_bits(&state->owner, mask);
714                         deny_bits(&state->group, mask);
715                         deny_bits(&state->other, mask);
716                         deny_bits(&state->everyone, mask);
717                         deny_bits_array(state->users, mask);
718                         deny_bits_array(state->groups, mask);
719                 }
720         }
721 }
722 
723 int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, struct posix_acl **pacl,
724                             struct posix_acl **dpacl, unsigned int flags)
725 {
726         struct posix_acl_state effective_acl_state, default_acl_state;
727         struct nfs4_ace *ace;
728         int ret;
729 
730         ret = init_state(&effective_acl_state, acl->naces);
731         if (ret)
732                 return ret;
733         ret = init_state(&default_acl_state, acl->naces);
734         if (ret)
735                 goto out_estate;
736         ret = -EINVAL;
737         for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
738                 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
739                     ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
740                         goto out_dstate;
741                 if (ace->flag & ~NFS4_SUPPORTED_FLAGS)
742                         goto out_dstate;
743                 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) {
744                         process_one_v4_ace(&effective_acl_state, ace);
745                         continue;
746                 }
747                 if (!(flags & NFS4_ACL_DIR))
748                         goto out_dstate;
749                 /*
750                  * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT
751                  * is set, we're effectively turning on the other.  That's OK,
752                  * according to rfc 3530.
753                  */
754                 process_one_v4_ace(&default_acl_state, ace);
755 
756                 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE))
757                         process_one_v4_ace(&effective_acl_state, ace);
758         }
759         *pacl = posix_state_to_acl(&effective_acl_state, flags);
760         if (IS_ERR(*pacl)) {
761                 ret = PTR_ERR(*pacl);
762                 *pacl = NULL;
763                 goto out_dstate;
764         }
765         *dpacl = posix_state_to_acl(&default_acl_state,
766                                                 flags | NFS4_ACL_TYPE_DEFAULT);
767         if (IS_ERR(*dpacl)) {
768                 ret = PTR_ERR(*dpacl);
769                 *dpacl = NULL;
770                 posix_acl_release(*pacl);
771                 *pacl = NULL;
772                 goto out_dstate;
773         }
774         sort_pacl(*pacl);
775         sort_pacl(*dpacl);
776         ret = 0;
777 out_dstate:
778         free_state(&default_acl_state);
779 out_estate:
780         free_state(&effective_acl_state);
781         return ret;
782 }
783 
784 static short
785 ace2type(struct nfs4_ace *ace)
786 {
787         switch (ace->whotype) {
788                 case NFS4_ACL_WHO_NAMED:
789                         return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ?
790                                         ACL_GROUP : ACL_USER);
791                 case NFS4_ACL_WHO_OWNER:
792                         return ACL_USER_OBJ;
793                 case NFS4_ACL_WHO_GROUP:
794                         return ACL_GROUP_OBJ;
795                 case NFS4_ACL_WHO_EVERYONE:
796                         return ACL_OTHER;
797         }
798         BUG();
799         return -1;
800 }
801 
802 EXPORT_SYMBOL(nfs4_acl_posix_to_nfsv4);
803 EXPORT_SYMBOL(nfs4_acl_nfsv4_to_posix);
804 
805 struct nfs4_acl *
806 nfs4_acl_new(int n)
807 {
808         struct nfs4_acl *acl;
809 
810         acl = kmalloc(sizeof(*acl) + n*sizeof(struct nfs4_ace), GFP_KERNEL);
811         if (acl == NULL)
812                 return NULL;
813         acl->naces = 0;
814         return acl;
815 }
816 
817 static struct {
818         char *string;
819         int   stringlen;
820         int type;
821 } s2t_map[] = {
822         {
823                 .string    = "OWNER@",
824                 .stringlen = sizeof("OWNER@") - 1,
825                 .type      = NFS4_ACL_WHO_OWNER,
826         },
827         {
828                 .string    = "GROUP@",
829                 .stringlen = sizeof("GROUP@") - 1,
830                 .type      = NFS4_ACL_WHO_GROUP,
831         },
832         {
833                 .string    = "EVERYONE@",
834                 .stringlen = sizeof("EVERYONE@") - 1,
835                 .type      = NFS4_ACL_WHO_EVERYONE,
836         },
837 };
838 
839 int
840 nfs4_acl_get_whotype(char *p, u32 len)
841 {
842         int i;
843 
844         for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
845                 if (s2t_map[i].stringlen == len &&
846                                 0 == memcmp(s2t_map[i].string, p, len))
847                         return s2t_map[i].type;
848         }
849         return NFS4_ACL_WHO_NAMED;
850 }
851 
852 int
853 nfs4_acl_write_who(int who, char *p)
854 {
855         int i;
856 
857         for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
858                 if (s2t_map[i].type == who) {
859                         memcpy(p, s2t_map[i].string, s2t_map[i].stringlen);
860                         return s2t_map[i].stringlen;
861                 }
862         }
863         BUG();
864         return -1;
865 }
866 
867 EXPORT_SYMBOL(nfs4_acl_new);
868 EXPORT_SYMBOL(nfs4_acl_get_whotype);
869 EXPORT_SYMBOL(nfs4_acl_write_who);
870 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp