fs/nfsd/nfs4acl.c

   1 /*
   2  *  fs/nfs4acl/acl.c
   3  *
   4  *  Common NFSv4 ACL handling code.
   5  *
   6  *  Copyright (c) 2002, 2003 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Marius Aamodt Eriksen <marius@umich.edu>
  10  *  Jeff Sedlak <jsedlak@umich.edu>
  11  *  J. Bruce Fields <bfields@umich.edu>
  12  *
  13  *  Redistribution and use in source and binary forms, with or without
  14  *  modification, are permitted provided that the following conditions
  15  *  are met:
  16  *
  17  *  1. Redistributions of source code must retain the above copyright
  18  *     notice, this list of conditions and the following disclaimer.
  19  *  2. Redistributions in binary form must reproduce the above copyright
  20  *     notice, this list of conditions and the following disclaimer in the
  21  *     documentation and/or other materials provided with the distribution.
  22  *  3. Neither the name of the University nor the names of its
  23  *     contributors may be used to endorse or promote products derived
  24  *     from this software without specific prior written permission.
  25  *
  26  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  27  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  28  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  29  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  31  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  32  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  33  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  34  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  35  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  36  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  37  */
  38
  39 #include <linux/string.h>
  40 #include <linux/slab.h>
  41 #include <linux/list.h>
  42 #include <linux/types.h>
  43 #include <linux/fs.h>
  44 #include <linux/module.h>
  45 #include <linux/nfs_fs.h>
  46 #include <linux/posix_acl.h>
  47 #include <linux/nfs4.h>
  48 #include <linux/nfs4_acl.h>
  49
  50
  51 /* mode bit translations: */
  52 #define NFS4_READ_MODE (NFS4_ACE_READ_DATA)
  53 #define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA)
  54 #define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE
  55 #define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE)
  56 #define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)
  57
  58 /* We don't support these bits; insist they be neither allowed nor denied */
  59 #define NFS4_MASK_UNSUPP (NFS4_ACE_DELETE | NFS4_ACE_WRITE_OWNER \
  60                 | NFS4_ACE_READ_NAMED_ATTRS | NFS4_ACE_WRITE_NAMED_ATTRS)
  61
  62 /* flags used to simulate posix default ACLs */
  63 #define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \
  64                 | NFS4_ACE_DIRECTORY_INHERIT_ACE)
  65
  66 #define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \
  67                 | NFS4_ACE_INHERIT_ONLY_ACE \
  68                 | NFS4_ACE_IDENTIFIER_GROUP)
  69
  70 #define MASK_EQUAL(mask1, mask2) \
  71         ( ((mask1) & NFS4_ACE_MASK_ALL) == ((mask2) & NFS4_ACE_MASK_ALL) )
  72
  73 static u32
  74 mask_from_posix(unsigned short perm, unsigned int flags)
  75 {
  76         int mask = NFS4_ANYONE_MODE;
  77
  78         if (flags & NFS4_ACL_OWNER)
  79                 mask |= NFS4_OWNER_MODE;
  80         if (perm & ACL_READ)
  81                 mask |= NFS4_READ_MODE;
  82         if (perm & ACL_WRITE)
  83                 mask |= NFS4_WRITE_MODE;
  84         if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
  85                 mask |= NFS4_ACE_DELETE_CHILD;
  86         if (perm & ACL_EXECUTE)
  87                 mask |= NFS4_EXECUTE_MODE;
  88         return mask;
  89 }
  90
  91 static u32
  92 deny_mask(u32 allow_mask, unsigned int flags)
  93 {
  94         u32 ret = ~allow_mask & ~NFS4_MASK_UNSUPP;
  95         if (!(flags & NFS4_ACL_DIR))
  96                 ret &= ~NFS4_ACE_DELETE_CHILD;
  97         return ret;
  98 }
  99
 100 /* XXX: modify functions to return NFS errors; they're only ever
 101  * used by nfs code, after all.... */
 102
 103 /* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the
 104  * side of being more restrictive, so the mode bit mapping below is
 105  * pessimistic.  An optimistic version would be needed to handle DENY's,
 106  * but we espect to coalesce all ALLOWs and DENYs before mapping to mode
 107  * bits. */
 108
 109 static void
 110 low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
 111 {
 112         u32 write_mode = NFS4_WRITE_MODE;
 113
 114         if (flags & NFS4_ACL_DIR)
 115                 write_mode |= NFS4_ACE_DELETE_CHILD;
 116         *mode = 0;
 117         if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE)
 118                 *mode |= ACL_READ;
 119         if ((perm & write_mode) == write_mode)
 120                 *mode |= ACL_WRITE;
 121         if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE)
 122                 *mode |= ACL_EXECUTE;
 123 }
 124
 125 struct ace_container {
 126         struct nfs4_ace  *ace;
 127         struct list_head  ace_l;
 128 };
 129
 130 static short ace2type(struct nfs4_ace *);
 131 static int _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *, unsigned int);
 132 int nfs4_acl_add_ace(struct nfs4_acl *, u32, u32, u32, int, uid_t);
 133
 134 struct nfs4_acl *
 135 nfs4_acl_posix_to_nfsv4(struct posix_acl *pacl, struct posix_acl *dpacl,
 136                         unsigned int flags)
 137 {
 138         struct nfs4_acl *acl;
 139         int error = -EINVAL;
 140
 141         if ((pacl != NULL &&
 142                 (posix_acl_valid(pacl) < 0 || pacl->a_count == 0)) ||
 143             (dpacl != NULL &&
 144                 (posix_acl_valid(dpacl) < 0 || dpacl->a_count == 0)))
 145                 goto out_err;
 146
 147         acl = nfs4_acl_new();
 148         if (acl == NULL) {
 149                 error = -ENOMEM;
 150                 goto out_err;
 151         }
 152
 153         if (pacl != NULL) {
 154                 error = _posix_to_nfsv4_one(pacl, acl,
 155                                                 flags & ~NFS4_ACL_TYPE_DEFAULT);
 156                 if (error < 0)
 157                         goto out_acl;
 158         }
 159
 160         if (dpacl != NULL) {
 161                 error = _posix_to_nfsv4_one(dpacl, acl,
 162                                                 flags | NFS4_ACL_TYPE_DEFAULT);
 163                 if (error < 0)
 164                         goto out_acl;
 165         }
 166
 167         return acl;
 168
 169 out_acl:
 170         nfs4_acl_free(acl);
 171 out_err:
 172         acl = ERR_PTR(error);
 173
 174         return acl;
 175 }
 176
 177 static int
 178 nfs4_acl_add_pair(struct nfs4_acl *acl, int eflag, u32 mask, int whotype,
 179                 uid_t owner, unsigned int flags)
 180 {
 181         int error;
 182
 183         error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE,
 184                                  eflag, mask, whotype, owner);
 185         if (error < 0)
 186                 return error;
 187         error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
 188                                 eflag, deny_mask(mask, flags), whotype, owner);
 189         return error;
 190 }
 191
 192 /* We assume the acl has been verified with posix_acl_valid. */
 193 static int
 194 _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
 195                                                 unsigned int flags)
 196 {
 197         struct posix_acl_entry *pa, *pe, *group_owner_entry;
 198         int error = -EINVAL;
 199         u32 mask, mask_mask;
 200         int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ?
 201                                         NFS4_INHERITANCE_FLAGS : 0);
 202
 203         BUG_ON(pacl->a_count < 3);
 204         pe = pacl->a_entries + pacl->a_count;
 205         pa = pe - 2; /* if mask entry exists, it's second from the last. */
 206         if (pa->e_tag == ACL_MASK)
 207                 mask_mask = deny_mask(mask_from_posix(pa->e_perm, flags), flags);
 208         else
 209                 mask_mask = 0;
 210
 211         pa = pacl->a_entries;
 212         BUG_ON(pa->e_tag != ACL_USER_OBJ);
 213         mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER);
 214         error = nfs4_acl_add_pair(acl, eflag, mask, NFS4_ACL_WHO_OWNER, 0, flags);
 215         if (error < 0)
 216                 goto out;
 217         pa++;
 218
 219         while (pa->e_tag == ACL_USER) {
 220                 mask = mask_from_posix(pa->e_perm, flags);
 221                 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
 222                                 eflag,  mask_mask, NFS4_ACL_WHO_NAMED, pa->e_id);
 223                 if (error < 0)
 224                         goto out;
 225
 226
 227                 error = nfs4_acl_add_pair(acl, eflag, mask,
 228                                 NFS4_ACL_WHO_NAMED, pa->e_id, flags);
 229                 if (error < 0)
 230                         goto out;
 231                 pa++;
 232         }
 233
 234         /* In the case of groups, we apply allow ACEs first, then deny ACEs,
 235          * since a user can be in more than one group.  */
 236
 237         /* allow ACEs */
 238
 239         if (pacl->a_count > 3) {
 240                 BUG_ON(pa->e_tag != ACL_GROUP_OBJ);
 241                 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
 242                                 NFS4_ACE_IDENTIFIER_GROUP | eflag, mask_mask,
 243                                 NFS4_ACL_WHO_GROUP, 0);
 244                 if (error < 0)
 245                         goto out;
 246         }
 247         group_owner_entry = pa;
 248         mask = mask_from_posix(pa->e_perm, flags);
 249         error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE,
 250                         NFS4_ACE_IDENTIFIER_GROUP | eflag, mask,
 251                         NFS4_ACL_WHO_GROUP, 0);
 252         if (error < 0)
 253                 goto out;
 254         pa++;
 255
 256         while (pa->e_tag == ACL_GROUP) {
 257                 mask = mask_from_posix(pa->e_perm, flags);
 258                 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
 259                                 NFS4_ACE_IDENTIFIER_GROUP | eflag, mask_mask,
 260                                 NFS4_ACL_WHO_NAMED, pa->e_id);
 261                 if (error < 0)
 262                         goto out;
 263
 264                 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE,
 265                                 NFS4_ACE_IDENTIFIER_GROUP | eflag, mask,
 266                                 NFS4_ACL_WHO_NAMED, pa->e_id);
 267                 if (error < 0)
 268                         goto out;
 269                 pa++;
 270         }
 271
 272         /* deny ACEs */
 273
 274         pa = group_owner_entry;
 275         mask = mask_from_posix(pa->e_perm, flags);
 276         error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
 277                         NFS4_ACE_IDENTIFIER_GROUP | eflag,
 278                         deny_mask(mask, flags), NFS4_ACL_WHO_GROUP, 0);
 279         if (error < 0)
 280                 goto out;
 281         pa++;
 282         while (pa->e_tag == ACL_GROUP) {
 283                 mask = mask_from_posix(pa->e_perm, flags);
 284                 error = nfs4_acl_add_ace(acl, NFS4_ACE_ACCESS_DENIED_ACE_TYPE,
 285                                 NFS4_ACE_IDENTIFIER_GROUP | eflag,
 286                                 deny_mask(mask, flags), NFS4_ACL_WHO_NAMED, pa->e_id);
 287                 if (error < 0)
 288                         goto out;
 289                 pa++;
 290         }
 291
 292         if (pa->e_tag == ACL_MASK)
 293                 pa++;
 294         BUG_ON(pa->e_tag != ACL_OTHER);
 295         mask = mask_from_posix(pa->e_perm, flags);
 296         error = nfs4_acl_add_pair(acl, eflag, mask, NFS4_ACL_WHO_EVERYONE, 0, flags);
 297
 298 out:
 299         return error;
 300 }
 301
 302 static void
 303 sort_pacl_range(struct posix_acl *pacl, int start, int end) {
 304         int sorted = 0, i;
 305         struct posix_acl_entry tmp;
 306
 307         /* We just do a bubble sort; easy to do in place, and we're not
 308          * expecting acl's to be long enough to justify anything more. */
 309         while (!sorted) {
 310                 sorted = 1;
 311                 for (i = start; i < end; i++) {
 312                         if (pacl->a_entries[i].e_id
 313                                         > pacl->a_entries[i+1].e_id) {
 314                                 sorted = 0;
 315                                 tmp = pacl->a_entries[i];
 316                                 pacl->a_entries[i] = pacl->a_entries[i+1];
 317                                 pacl->a_entries[i+1] = tmp;
 318                         }
 319                 }
 320         }
 321 }
 322
 323 static void
 324 sort_pacl(struct posix_acl *pacl)
 325 {
 326         /* posix_acl_valid requires that users and groups be in order
 327          * by uid/gid. */
 328         int i, j;
 329
 330         if (pacl->a_count <= 4)
 331                 return; /* no users or groups */
 332         i = 1;
 333         while (pacl->a_entries[i].e_tag == ACL_USER)
 334                 i++;
 335         sort_pacl_range(pacl, 1, i-1);
 336
 337         BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ);
 338         j = i++;
 339         while (pacl->a_entries[j].e_tag == ACL_GROUP)
 340                 j++;
 341         sort_pacl_range(pacl, i, j-1);
 342         return;
 343 }
 344
 345 /*
 346  * While processing the NFSv4 ACE, this maintains bitmasks representing
 347  * which permission bits have been allowed and which denied to a given
 348  * entity: */
 349 struct posix_ace_state {
 350         u32 allow;
 351         u32 deny;
 352 };
 353
 354 struct posix_user_ace_state {
 355         uid_t uid;
 356         struct posix_ace_state perms;
 357 };
 358
 359 struct posix_ace_state_array {
 360         int n;
 361         struct posix_user_ace_state aces[];
 362 };
 363
 364 /*
 365  * While processing the NFSv4 ACE, this maintains the partial permissions
 366  * calculated so far: */
 367
 368 struct posix_acl_state {
 369         struct posix_ace_state owner;
 370         struct posix_ace_state group;
 371         struct posix_ace_state other;
 372         struct posix_ace_state everyone;
 373         struct posix_ace_state mask; /* Deny unused in this case */
 374         struct posix_ace_state_array *users;
 375         struct posix_ace_state_array *groups;
 376 };
 377
 378 static int
 379 init_state(struct posix_acl_state *state, int cnt)
 380 {
 381         int alloc;
 382
 383         memset(state, 0, sizeof(struct posix_acl_state));
 384         /*
 385          * In the worst case, each individual acl could be for a distinct
 386          * named user or group, but we don't no which, so we allocate
 387          * enough space for either:
 388          */
 389         alloc = sizeof(struct posix_ace_state_array)
 390                 + cnt*sizeof(struct posix_ace_state);
 391         state->users = kzalloc(alloc, GFP_KERNEL);
 392         if (!state->users)
 393                 return -ENOMEM;
 394         state->groups = kzalloc(alloc, GFP_KERNEL);
 395         if (!state->groups) {
 396                 kfree(state->users);
 397                 return -ENOMEM;
 398         }
 399         return 0;
 400 }
 401
 402 static void
 403 free_state(struct posix_acl_state *state) {
 404         kfree(state->users);
 405         kfree(state->groups);
 406 }
 407
 408 static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate)
 409 {
 410         state->mask.allow |= astate->allow;
 411 }
 412
 413 /*
 414  * Certain bits (SYNCHRONIZE, DELETE, WRITE_OWNER, READ/WRITE_NAMED_ATTRS,
 415  * READ_ATTRIBUTES, READ_ACL) are currently unenforceable and don't translate
 416  * to traditional read/write/execute permissions.
 417  *
 418  * It's problematic to reject acls that use certain mode bits, because it
 419  * places the burden on users to learn the rules about which bits one
 420  * particular server sets, without giving the user a lot of help--we return an
 421  * error that could mean any number of different things.  To make matters
 422  * worse, the problematic bits might be introduced by some application that's
 423  * automatically mapping from some other acl model.
 424  *
 425  * So wherever possible we accept anything, possibly erring on the side of
 426  * denying more permissions than necessary.
 427  *
 428  * However we do reject *explicit* DENY's of a few bits representing
 429  * permissions we could never deny:
 430  */
 431
 432 static inline int check_deny(u32 mask, int isowner)
 433 {
 434         if (mask & (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL))
 435                 return -EINVAL;
 436         if (!isowner)
 437                 return 0;
 438         if (mask & (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL))
 439                 return -EINVAL;
 440         return 0;
 441 }
 442
 443 static struct posix_acl *
 444 posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
 445 {
 446         struct posix_acl_entry *pace;
 447         struct posix_acl *pacl;
 448         int nace;
 449         int i, error = 0;
 450
 451         nace = 4 + state->users->n + state->groups->n;
 452         pacl = posix_acl_alloc(nace, GFP_KERNEL);
 453         if (!pacl)
 454                 return ERR_PTR(-ENOMEM);
 455
 456         pace = pacl->a_entries;
 457         pace->e_tag = ACL_USER_OBJ;
 458         error = check_deny(state->owner.deny, 1);
 459         if (error)
 460                 goto out_err;
 461         low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
 462         pace->e_id = ACL_UNDEFINED_ID;
 463
 464         for (i=0; i < state->users->n; i++) {
 465                 pace++;
 466                 pace->e_tag = ACL_USER;
 467                 error = check_deny(state->users->aces[i].perms.deny, 0);
 468                 if (error)
 469                         goto out_err;
 470                 low_mode_from_nfs4(state->users->aces[i].perms.allow,
 471                                         &pace->e_perm, flags);
 472                 pace->e_id = state->users->aces[i].uid;
 473                 add_to_mask(state, &state->users->aces[i].perms);
 474         }
 475
 476         pace++;
 477         pace->e_tag = ACL_GROUP_OBJ;
 478         error = check_deny(state->group.deny, 0);
 479         if (error)
 480                 goto out_err;
 481         low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
 482         pace->e_id = ACL_UNDEFINED_ID;
 483         add_to_mask(state, &state->group);
 484
 485         for (i=0; i < state->groups->n; i++) {
 486                 pace++;
 487                 pace->e_tag = ACL_GROUP;
 488                 error = check_deny(state->groups->aces[i].perms.deny, 0);
 489                 if (error)
 490                         goto out_err;
 491                 low_mode_from_nfs4(state->groups->aces[i].perms.allow,
 492                                         &pace->e_perm, flags);
 493                 pace->e_id = state->groups->aces[i].uid;
 494                 add_to_mask(state, &state->groups->aces[i].perms);
 495         }
 496
 497         pace++;
 498         pace->e_tag = ACL_MASK;
 499         low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
 500         pace->e_id = ACL_UNDEFINED_ID;
 501
 502         pace++;
 503         pace->e_tag = ACL_OTHER;
 504         error = check_deny(state->other.deny, 0);
 505         if (error)
 506                 goto out_err;
 507         low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
 508         pace->e_id = ACL_UNDEFINED_ID;
 509
 510         return pacl;
 511 out_err:
 512         posix_acl_release(pacl);
 513         return ERR_PTR(error);
 514 }
 515
 516 static inline void allow_bits(struct posix_ace_state *astate, u32 mask)
 517 {
 518         /* Allow all bits in the mask not already denied: */
 519         astate->allow |= mask & ~astate->deny;
 520 }
 521
 522 static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
 523 {
 524         /* Deny all bits in the mask not already allowed: */
 525         astate->deny |= mask & ~astate->allow;
 526 }
 527
 528 static int find_uid(struct posix_acl_state *state, struct posix_ace_state_array *a, uid_t uid)
 529 {
 530         int i;
 531
 532         for (i = 0; i < a->n; i++)
 533                 if (a->aces[i].uid == uid)
 534                         return i;
 535         /* Not found: */
 536         a->n++;
 537         a->aces[i].uid = uid;
 538         a->aces[i].perms.allow = state->everyone.allow;
 539         a->aces[i].perms.deny  = state->everyone.deny;
 540
 541         return i;
 542 }
 543
 544 static void deny_bits_array(struct posix_ace_state_array *a, u32 mask)
 545 {
 546         int i;
 547
 548         for (i=0; i < a->n; i++)
 549                 deny_bits(&a->aces[i].perms, mask);
 550 }
 551
 552 static void allow_bits_array(struct posix_ace_state_array *a, u32 mask)
 553 {
 554         int i;
 555
 556         for (i=0; i < a->n; i++)
 557                 allow_bits(&a->aces[i].perms, mask);
 558 }
 559
 560 static void process_one_v4_ace(struct posix_acl_state *state,
 561                                 struct nfs4_ace *ace)
 562 {
 563         u32 mask = ace->access_mask;
 564         int i;
 565
 566         switch (ace2type(ace)) {
 567         case ACL_USER_OBJ:
 568                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 569                         allow_bits(&state->owner, mask);
 570                 } else {
 571                         deny_bits(&state->owner, mask);
 572                 }
 573                 break;
 574         case ACL_USER:
 575                 i = find_uid(state, state->users, ace->who);
 576                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 577                         allow_bits(&state->users->aces[i].perms, mask);
 578                 } else {
 579                         deny_bits(&state->users->aces[i].perms, mask);
 580                         mask = state->users->aces[i].perms.deny;
 581                         deny_bits(&state->owner, mask);
 582                 }
 583                 break;
 584         case ACL_GROUP_OBJ:
 585                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 586                         allow_bits(&state->group, mask);
 587                 } else {
 588                         deny_bits(&state->group, mask);
 589                         mask = state->group.deny;
 590                         deny_bits(&state->owner, mask);
 591                         deny_bits(&state->everyone, mask);
 592                         deny_bits_array(state->users, mask);
 593                         deny_bits_array(state->groups, mask);
 594                 }
 595                 break;
 596         case ACL_GROUP:
 597                 i = find_uid(state, state->groups, ace->who);
 598                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 599                         allow_bits(&state->groups->aces[i].perms, mask);
 600                 } else {
 601                         deny_bits(&state->groups->aces[i].perms, mask);
 602                         mask = state->groups->aces[i].perms.deny;
 603                         deny_bits(&state->owner, mask);
 604                         deny_bits(&state->group, mask);
 605                         deny_bits(&state->everyone, mask);
 606                         deny_bits_array(state->users, mask);
 607                         deny_bits_array(state->groups, mask);
 608                 }
 609                 break;
 610         case ACL_OTHER:
 611                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 612                         allow_bits(&state->owner, mask);
 613                         allow_bits(&state->group, mask);
 614                         allow_bits(&state->other, mask);
 615                         allow_bits(&state->everyone, mask);
 616                         allow_bits_array(state->users, mask);
 617                         allow_bits_array(state->groups, mask);
 618                 } else {
 619                         deny_bits(&state->owner, mask);
 620                         deny_bits(&state->group, mask);
 621                         deny_bits(&state->other, mask);
 622                         deny_bits(&state->everyone, mask);
 623                         deny_bits_array(state->users, mask);
 624                         deny_bits_array(state->groups, mask);
 625                 }
 626         }
 627 }
 628
 629 int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, struct posix_acl **pacl,
 630                             struct posix_acl **dpacl, unsigned int flags)
 631 {
 632         struct posix_acl_state effective_acl_state, default_acl_state;
 633         struct nfs4_ace *ace;
 634         int ret;
 635
 636         ret = init_state(&effective_acl_state, acl->naces);
 637         if (ret)
 638                 return ret;
 639         ret = init_state(&default_acl_state, acl->naces);
 640         if (ret)
 641                 goto out_estate;
 642         ret = -EINVAL;
 643         list_for_each_entry(ace, &acl->ace_head, l_ace) {
 644                 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
 645                     ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
 646                         goto out_dstate;
 647                 if (ace->flag & ~NFS4_SUPPORTED_FLAGS)
 648                         goto out_dstate;
 649                 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) {
 650                         process_one_v4_ace(&effective_acl_state, ace);
 651                         continue;
 652                 }
 653                 if (!(flags & NFS4_ACL_DIR))
 654                         goto out_dstate;
 655                 /*
 656                  * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT
 657                  * is set, we're effectively turning on the other.  That's OK,
 658                  * according to rfc 3530.
 659                  */
 660                 process_one_v4_ace(&default_acl_state, ace);
 661
 662                 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE))
 663                         process_one_v4_ace(&effective_acl_state, ace);
 664         }
 665         *pacl = posix_state_to_acl(&effective_acl_state, flags);
 666         if (IS_ERR(*pacl)) {
 667                 ret = PTR_ERR(*pacl);
 668                 goto out_dstate;
 669         }
 670         *dpacl = posix_state_to_acl(&default_acl_state, flags);
 671         if (IS_ERR(*dpacl)) {
 672                 ret = PTR_ERR(*dpacl);
 673                 posix_acl_release(*pacl);
 674                 goto out_dstate;
 675         }
 676         sort_pacl(*pacl);
 677         sort_pacl(*dpacl);
 678         ret = 0;
 679 out_dstate:
 680         free_state(&default_acl_state);
 681 out_estate:
 682         free_state(&effective_acl_state);
 683         return ret;
 684 }
 685
 686 static short
 687 ace2type(struct nfs4_ace *ace)
 688 {
 689         switch (ace->whotype) {
 690                 case NFS4_ACL_WHO_NAMED:
 691                         return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ?
 692                                         ACL_GROUP : ACL_USER);
 693                 case NFS4_ACL_WHO_OWNER:
 694                         return ACL_USER_OBJ;
 695                 case NFS4_ACL_WHO_GROUP:
 696                         return ACL_GROUP_OBJ;
 697                 case NFS4_ACL_WHO_EVERYONE:
 698                         return ACL_OTHER;
 699         }
 700         BUG();
 701         return -1;
 702 }
 703
 704 EXPORT_SYMBOL(nfs4_acl_posix_to_nfsv4);
 705 EXPORT_SYMBOL(nfs4_acl_nfsv4_to_posix);
 706
 707 struct nfs4_acl *
 708 nfs4_acl_new(void)
 709 {
 710         struct nfs4_acl *acl;
 711
 712         if ((acl = kmalloc(sizeof(*acl), GFP_KERNEL)) == NULL)
 713                 return NULL;
 714
 715         acl->naces = 0;
 716         INIT_LIST_HEAD(&acl->ace_head);
 717
 718         return acl;
 719 }
 720
 721 void
 722 nfs4_acl_free(struct nfs4_acl *acl)
 723 {
 724         struct list_head *h;
 725         struct nfs4_ace *ace;
 726
 727         if (!acl)
 728                 return;
 729
 730         while (!list_empty(&acl->ace_head)) {
 731                 h = acl->ace_head.next;
 732                 list_del(h);
 733                 ace = list_entry(h, struct nfs4_ace, l_ace);
 734                 kfree(ace);
 735         }
 736
 737         kfree(acl);
 738
 739         return;
 740 }
 741
 742 int
 743 nfs4_acl_add_ace(struct nfs4_acl *acl, u32 type, u32 flag, u32 access_mask,
 744                 int whotype, uid_t who)
 745 {
 746         struct nfs4_ace *ace;
 747
 748         if ((ace = kmalloc(sizeof(*ace), GFP_KERNEL)) == NULL)
 749                 return -ENOMEM;
 750
 751         ace->type = type;
 752         ace->flag = flag;
 753         ace->access_mask = access_mask;
 754         ace->whotype = whotype;
 755         ace->who = who;
 756
 757         list_add_tail(&ace->l_ace, &acl->ace_head);
 758         acl->naces++;
 759
 760         return 0;
 761 }
 762
 763 static struct {
 764         char *string;
 765         int   stringlen;
 766         int type;
 767 } s2t_map[] = {
 768         {
 769                 .string    = "OWNER@",
 770                 .stringlen = sizeof("OWNER@") - 1,
 771                 .type      = NFS4_ACL_WHO_OWNER,
 772         },
 773         {
 774                 .string    = "GROUP@",
 775                 .stringlen = sizeof("GROUP@") - 1,
 776                 .type      = NFS4_ACL_WHO_GROUP,
 777         },
 778         {
 779                 .string    = "EVERYONE@",
 780                 .stringlen = sizeof("EVERYONE@") - 1,
 781                 .type      = NFS4_ACL_WHO_EVERYONE,
 782         },
 783 };
 784
 785 int
 786 nfs4_acl_get_whotype(char *p, u32 len)
 787 {
 788         int i;
 789
 790         for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
 791                 if (s2t_map[i].stringlen == len &&
 792                                 0 == memcmp(s2t_map[i].string, p, len))
 793                         return s2t_map[i].type;
 794         }
 795         return NFS4_ACL_WHO_NAMED;
 796 }
 797
 798 int
 799 nfs4_acl_write_who(int who, char *p)
 800 {
 801         int i;
 802
 803         for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
 804                 if (s2t_map[i].type == who) {
 805                         memcpy(p, s2t_map[i].string, s2t_map[i].stringlen);
 806                         return s2t_map[i].stringlen;
 807                 }
 808         }
 809         BUG();
 810         return -1;
 811 }
 812
 813 EXPORT_SYMBOL(nfs4_acl_new);
 814 EXPORT_SYMBOL(nfs4_acl_free);
 815 EXPORT_SYMBOL(nfs4_acl_add_ace);
 816 EXPORT_SYMBOL(nfs4_acl_get_whotype);
 817 EXPORT_SYMBOL(nfs4_acl_write_who);