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 | NFS4_ACE_INHERIT_ONLY_ACE)
  65
  66 #define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS | NFS4_ACE_IDENTIFIER_GROUP)
  67
  68 #define MASK_EQUAL(mask1, mask2) \
  69         ( ((mask1) & NFS4_ACE_MASK_ALL) == ((mask2) & NFS4_ACE_MASK_ALL) )
  70
  71 static u32
  72 mask_from_posix(unsigned short perm, unsigned int flags)
  73 {
  74         int mask = NFS4_ANYONE_MODE;
  75
  76         if (flags & NFS4_ACL_OWNER)
  77                 mask |= NFS4_OWNER_MODE;
  78         if (perm & ACL_READ)
  79                 mask |= NFS4_READ_MODE;
  80         if (perm & ACL_WRITE)
  81                 mask |= NFS4_WRITE_MODE;
  82         if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
  83                 mask |= NFS4_ACE_DELETE_CHILD;
  84         if (perm & ACL_EXECUTE)
  85                 mask |= NFS4_EXECUTE_MODE;
  86         return mask;
  87 }
  88
  89 static u32
  90 deny_mask(u32 allow_mask, unsigned int flags)
  91 {
  92         u32 ret = ~allow_mask & ~NFS4_MASK_UNSUPP;
  93         if (!(flags & NFS4_ACL_DIR))
  94                 ret &= ~NFS4_ACE_DELETE_CHILD;
  95         return ret;
  96 }
  97
  98 /* XXX: modify functions to return NFS errors; they're only ever
  99  * used by nfs code, after all.... */
 100
 101 /* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the
 102  * side of being more restrictive, so the mode bit mapping below is
 103  * pessimistic.  An optimistic version would be needed to handle DENY's,
 104  * but we espect to coalesce all ALLOWs and DENYs before mapping to mode
 105  * bits. */
 106
 107 static void
 108 low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
 109 {
 110         u32 write_mode = NFS4_WRITE_MODE;
 111
 112         if (flags & NFS4_ACL_DIR)
 113                 write_mode |= NFS4_ACE_DELETE_CHILD;
 114         *mode = 0;
 115         if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE)
 116                 *mode |= ACL_READ;
 117         if ((perm & write_mode) == write_mode)
 118                 *mode |= ACL_WRITE;
 119         if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE)
 120                 *mode |= ACL_EXECUTE;
 121 }
 122
 123 struct ace_container {
 124         struct nfs4_ace  *ace;
 125         struct list_head  ace_l;
 126 };
 127
 128 static short ace2type(struct nfs4_ace *);
 129 static int _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *, unsigned int);
 130 static struct posix_acl *_nfsv4_to_posix_one(struct nfs4_acl *, unsigned int);
 131 int nfs4_acl_add_ace(struct nfs4_acl *, u32, u32, u32, int, uid_t);
 132 static int nfs4_acl_split(struct nfs4_acl *, struct nfs4_acl *);
 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 int
 346 nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, struct posix_acl **pacl,
 347                 struct posix_acl **dpacl, unsigned int flags)
 348 {
 349         struct nfs4_acl *dacl;
 350         int error = -ENOMEM;
 351
 352         *pacl = NULL;
 353         *dpacl = NULL;
 354
 355         dacl = nfs4_acl_new();
 356         if (dacl == NULL)
 357                 goto out;
 358
 359         error = nfs4_acl_split(acl, dacl);
 360         if (error)
 361                 goto out_acl;
 362
 363         *pacl = _nfsv4_to_posix_one(acl, flags);
 364         if (IS_ERR(*pacl)) {
 365                 error = PTR_ERR(*pacl);
 366                 *pacl = NULL;
 367                 goto out_acl;
 368         }
 369
 370         *dpacl = _nfsv4_to_posix_one(dacl, flags);
 371         if (IS_ERR(*dpacl)) {
 372                 error = PTR_ERR(*dpacl);
 373                 *dpacl = NULL;
 374         }
 375 out_acl:
 376         if (error) {
 377                 posix_acl_release(*pacl);
 378                 *pacl = NULL;
 379         }
 380         nfs4_acl_free(dacl);
 381 out:
 382         return error;
 383 }
 384
 385 /*
 386  * While processing the NFSv4 ACE, this maintains bitmasks representing
 387  * which permission bits have been allowed and which denied to a given
 388  * entity: */
 389 struct posix_ace_state {
 390         u32 allow;
 391         u32 deny;
 392 };
 393
 394 struct posix_user_ace_state {
 395         uid_t uid;
 396         struct posix_ace_state perms;
 397 };
 398
 399 struct posix_ace_state_array {
 400         int n;
 401         struct posix_user_ace_state aces[];
 402 };
 403
 404 /*
 405  * While processing the NFSv4 ACE, this maintains the partial permissions
 406  * calculated so far: */
 407
 408 struct posix_acl_state {
 409         struct posix_ace_state owner;
 410         struct posix_ace_state group;
 411         struct posix_ace_state other;
 412         struct posix_ace_state everyone;
 413         struct posix_ace_state mask; /* Deny unused in this case */
 414         struct posix_ace_state_array *users;
 415         struct posix_ace_state_array *groups;
 416 };
 417
 418 static int
 419 init_state(struct posix_acl_state *state, int cnt)
 420 {
 421         int alloc;
 422
 423         memset(state, 0, sizeof(struct posix_acl_state));
 424         /*
 425          * In the worst case, each individual acl could be for a distinct
 426          * named user or group, but we don't no which, so we allocate
 427          * enough space for either:
 428          */
 429         alloc = sizeof(struct posix_ace_state_array)
 430                 + cnt*sizeof(struct posix_ace_state);
 431         state->users = kzalloc(alloc, GFP_KERNEL);
 432         if (!state->users)
 433                 return -ENOMEM;
 434         state->groups = kzalloc(alloc, GFP_KERNEL);
 435         if (!state->groups) {
 436                 kfree(state->users);
 437                 return -ENOMEM;
 438         }
 439         return 0;
 440 }
 441
 442 static void
 443 free_state(struct posix_acl_state *state) {
 444         kfree(state->users);
 445         kfree(state->groups);
 446 }
 447
 448 static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate)
 449 {
 450         state->mask.allow |= astate->allow;
 451 }
 452
 453 /*
 454  * Certain bits (SYNCHRONIZE, DELETE, WRITE_OWNER, READ/WRITE_NAMED_ATTRS,
 455  * READ_ATTRIBUTES, READ_ACL) are currently unenforceable and don't translate
 456  * to traditional read/write/execute permissions.
 457  *
 458  * It's problematic to reject acls that use certain mode bits, because it
 459  * places the burden on users to learn the rules about which bits one
 460  * particular server sets, without giving the user a lot of help--we return an
 461  * error that could mean any number of different things.  To make matters
 462  * worse, the problematic bits might be introduced by some application that's
 463  * automatically mapping from some other acl model.
 464  *
 465  * So wherever possible we accept anything, possibly erring on the side of
 466  * denying more permissions than necessary.
 467  *
 468  * However we do reject *explicit* DENY's of a few bits representing
 469  * permissions we could never deny:
 470  */
 471
 472 static inline int check_deny(u32 mask, int isowner)
 473 {
 474         if (mask & (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL))
 475                 return -EINVAL;
 476         if (!isowner)
 477                 return 0;
 478         if (mask & (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL))
 479                 return -EINVAL;
 480         return 0;
 481 }
 482
 483 static struct posix_acl *
 484 posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
 485 {
 486         struct posix_acl_entry *pace;
 487         struct posix_acl *pacl;
 488         int nace;
 489         int i, error = 0;
 490
 491         nace = 4 + state->users->n + state->groups->n;
 492         pacl = posix_acl_alloc(nace, GFP_KERNEL);
 493         if (!pacl)
 494                 return ERR_PTR(-ENOMEM);
 495
 496         pace = pacl->a_entries;
 497         pace->e_tag = ACL_USER_OBJ;
 498         error = check_deny(state->owner.deny, 1);
 499         if (error)
 500                 goto out_err;
 501         low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
 502         pace->e_id = ACL_UNDEFINED_ID;
 503
 504         for (i=0; i < state->users->n; i++) {
 505                 pace++;
 506                 pace->e_tag = ACL_USER;
 507                 error = check_deny(state->users->aces[i].perms.deny, 0);
 508                 if (error)
 509                         goto out_err;
 510                 low_mode_from_nfs4(state->users->aces[i].perms.allow,
 511                                         &pace->e_perm, flags);
 512                 pace->e_id = state->users->aces[i].uid;
 513                 add_to_mask(state, &state->users->aces[i].perms);
 514         }
 515
 516         pace++;
 517         pace->e_tag = ACL_GROUP_OBJ;
 518         error = check_deny(state->group.deny, 0);
 519         if (error)
 520                 goto out_err;
 521         low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
 522         pace->e_id = ACL_UNDEFINED_ID;
 523         add_to_mask(state, &state->group);
 524
 525         for (i=0; i < state->groups->n; i++) {
 526                 pace++;
 527                 pace->e_tag = ACL_GROUP;
 528                 error = check_deny(state->groups->aces[i].perms.deny, 0);
 529                 if (error)
 530                         goto out_err;
 531                 low_mode_from_nfs4(state->groups->aces[i].perms.allow,
 532                                         &pace->e_perm, flags);
 533                 pace->e_id = state->groups->aces[i].uid;
 534                 add_to_mask(state, &state->groups->aces[i].perms);
 535         }
 536
 537         pace++;
 538         pace->e_tag = ACL_MASK;
 539         low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
 540         pace->e_id = ACL_UNDEFINED_ID;
 541
 542         pace++;
 543         pace->e_tag = ACL_OTHER;
 544         error = check_deny(state->other.deny, 0);
 545         if (error)
 546                 goto out_err;
 547         low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
 548         pace->e_id = ACL_UNDEFINED_ID;
 549
 550         return pacl;
 551 out_err:
 552         posix_acl_release(pacl);
 553         return ERR_PTR(error);
 554 }
 555
 556 static inline void allow_bits(struct posix_ace_state *astate, u32 mask)
 557 {
 558         /* Allow all bits in the mask not already denied: */
 559         astate->allow |= mask & ~astate->deny;
 560 }
 561
 562 static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
 563 {
 564         /* Deny all bits in the mask not already allowed: */
 565         astate->deny |= mask & ~astate->allow;
 566 }
 567
 568 static int find_uid(struct posix_acl_state *state, struct posix_ace_state_array *a, uid_t uid)
 569 {
 570         int i;
 571
 572         for (i = 0; i < a->n; i++)
 573                 if (a->aces[i].uid == uid)
 574                         return i;
 575         /* Not found: */
 576         a->n++;
 577         a->aces[i].uid = uid;
 578         a->aces[i].perms.allow = state->everyone.allow;
 579         a->aces[i].perms.deny  = state->everyone.deny;
 580
 581         return i;
 582 }
 583
 584 static void deny_bits_array(struct posix_ace_state_array *a, u32 mask)
 585 {
 586         int i;
 587
 588         for (i=0; i < a->n; i++)
 589                 deny_bits(&a->aces[i].perms, mask);
 590 }
 591
 592 static void allow_bits_array(struct posix_ace_state_array *a, u32 mask)
 593 {
 594         int i;
 595
 596         for (i=0; i < a->n; i++)
 597                 allow_bits(&a->aces[i].perms, mask);
 598 }
 599
 600 static void process_one_v4_ace(struct posix_acl_state *state,
 601                                 struct nfs4_ace *ace)
 602 {
 603         u32 mask = ace->access_mask;
 604         int i;
 605
 606         switch (ace2type(ace)) {
 607         case ACL_USER_OBJ:
 608                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 609                         allow_bits(&state->owner, mask);
 610                 } else {
 611                         deny_bits(&state->owner, mask);
 612                 }
 613                 break;
 614         case ACL_USER:
 615                 i = find_uid(state, state->users, ace->who);
 616                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 617                         allow_bits(&state->users->aces[i].perms, mask);
 618                 } else {
 619                         deny_bits(&state->users->aces[i].perms, mask);
 620                         mask = state->users->aces[i].perms.deny;
 621                         deny_bits(&state->owner, mask);
 622                 }
 623                 break;
 624         case ACL_GROUP_OBJ:
 625                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 626                         allow_bits(&state->group, mask);
 627                 } else {
 628                         deny_bits(&state->group, mask);
 629                         mask = state->group.deny;
 630                         deny_bits(&state->owner, mask);
 631                         deny_bits(&state->everyone, mask);
 632                         deny_bits_array(state->users, mask);
 633                         deny_bits_array(state->groups, mask);
 634                 }
 635                 break;
 636         case ACL_GROUP:
 637                 i = find_uid(state, state->groups, ace->who);
 638                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 639                         allow_bits(&state->groups->aces[i].perms, mask);
 640                 } else {
 641                         deny_bits(&state->groups->aces[i].perms, mask);
 642                         mask = state->groups->aces[i].perms.deny;
 643                         deny_bits(&state->owner, mask);
 644                         deny_bits(&state->group, mask);
 645                         deny_bits(&state->everyone, mask);
 646                         deny_bits_array(state->users, mask);
 647                         deny_bits_array(state->groups, mask);
 648                 }
 649                 break;
 650         case ACL_OTHER:
 651                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 652                         allow_bits(&state->owner, mask);
 653                         allow_bits(&state->group, mask);
 654                         allow_bits(&state->other, mask);
 655                         allow_bits(&state->everyone, mask);
 656                         allow_bits_array(state->users, mask);
 657                         allow_bits_array(state->groups, mask);
 658                 } else {
 659                         deny_bits(&state->owner, mask);
 660                         deny_bits(&state->group, mask);
 661                         deny_bits(&state->other, mask);
 662                         deny_bits(&state->everyone, mask);
 663                         deny_bits_array(state->users, mask);
 664                         deny_bits_array(state->groups, mask);
 665                 }
 666         }
 667 }
 668
 669 static struct posix_acl *
 670 _nfsv4_to_posix_one(struct nfs4_acl *n4acl, unsigned int flags)
 671 {
 672         struct posix_acl_state state;
 673         struct posix_acl *pacl;
 674         struct nfs4_ace *ace;
 675         int ret;
 676
 677         ret = init_state(&state, n4acl->naces);
 678         if (ret)
 679                 return ERR_PTR(ret);
 680
 681         list_for_each_entry(ace, &n4acl->ace_head, l_ace)
 682                 process_one_v4_ace(&state, ace);
 683
 684         pacl = posix_state_to_acl(&state, flags);
 685
 686         free_state(&state);
 687
 688         if (!IS_ERR(pacl))
 689                 sort_pacl(pacl);
 690         return pacl;
 691 }
 692
 693 static int
 694 nfs4_acl_split(struct nfs4_acl *acl, struct nfs4_acl *dacl)
 695 {
 696         struct list_head *h, *n;
 697         struct nfs4_ace *ace;
 698         int error = 0;
 699
 700         list_for_each_safe(h, n, &acl->ace_head) {
 701                 ace = list_entry(h, struct nfs4_ace, l_ace);
 702
 703                 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
 704                     ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
 705                         return -EINVAL;
 706
 707                 if (ace->flag & ~NFS4_SUPPORTED_FLAGS)
 708                         return -EINVAL;
 709
 710                 switch (ace->flag & NFS4_INHERITANCE_FLAGS) {
 711                 case 0:
 712                         /* Leave this ace in the effective acl: */
 713                         continue;
 714                 case NFS4_INHERITANCE_FLAGS:
 715                         /* Add this ace to the default acl and remove it
 716                          * from the effective acl: */
 717                         error = nfs4_acl_add_ace(dacl, ace->type, ace->flag,
 718                                 ace->access_mask, ace->whotype, ace->who);
 719                         if (error)
 720                                 return error;
 721                         list_del(h);
 722                         kfree(ace);
 723                         acl->naces--;
 724                         break;
 725                 case NFS4_INHERITANCE_FLAGS & ~NFS4_ACE_INHERIT_ONLY_ACE:
 726                         /* Add this ace to the default, but leave it in
 727                          * the effective acl as well: */
 728                         error = nfs4_acl_add_ace(dacl, ace->type, ace->flag,
 729                                 ace->access_mask, ace->whotype, ace->who);
 730                         if (error)
 731                                 return error;
 732                         break;
 733                 default:
 734                         return -EINVAL;
 735                 }
 736         }
 737         return 0;
 738 }
 739
 740 static short
 741 ace2type(struct nfs4_ace *ace)
 742 {
 743         switch (ace->whotype) {
 744                 case NFS4_ACL_WHO_NAMED:
 745                         return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ?
 746                                         ACL_GROUP : ACL_USER);
 747                 case NFS4_ACL_WHO_OWNER:
 748                         return ACL_USER_OBJ;
 749                 case NFS4_ACL_WHO_GROUP:
 750                         return ACL_GROUP_OBJ;
 751                 case NFS4_ACL_WHO_EVERYONE:
 752                         return ACL_OTHER;
 753         }
 754         BUG();
 755         return -1;
 756 }
 757
 758 EXPORT_SYMBOL(nfs4_acl_posix_to_nfsv4);
 759 EXPORT_SYMBOL(nfs4_acl_nfsv4_to_posix);
 760
 761 struct nfs4_acl *
 762 nfs4_acl_new(void)
 763 {
 764         struct nfs4_acl *acl;
 765
 766         if ((acl = kmalloc(sizeof(*acl), GFP_KERNEL)) == NULL)
 767                 return NULL;
 768
 769         acl->naces = 0;
 770         INIT_LIST_HEAD(&acl->ace_head);
 771
 772         return acl;
 773 }
 774
 775 void
 776 nfs4_acl_free(struct nfs4_acl *acl)
 777 {
 778         struct list_head *h;
 779         struct nfs4_ace *ace;
 780
 781         if (!acl)
 782                 return;
 783
 784         while (!list_empty(&acl->ace_head)) {
 785                 h = acl->ace_head.next;
 786                 list_del(h);
 787                 ace = list_entry(h, struct nfs4_ace, l_ace);
 788                 kfree(ace);
 789         }
 790
 791         kfree(acl);
 792
 793         return;
 794 }
 795
 796 int
 797 nfs4_acl_add_ace(struct nfs4_acl *acl, u32 type, u32 flag, u32 access_mask,
 798                 int whotype, uid_t who)
 799 {
 800         struct nfs4_ace *ace;
 801
 802         if ((ace = kmalloc(sizeof(*ace), GFP_KERNEL)) == NULL)
 803                 return -ENOMEM;
 804
 805         ace->type = type;
 806         ace->flag = flag;
 807         ace->access_mask = access_mask;
 808         ace->whotype = whotype;
 809         ace->who = who;
 810
 811         list_add_tail(&ace->l_ace, &acl->ace_head);
 812         acl->naces++;
 813
 814         return 0;
 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_free);
 869 EXPORT_SYMBOL(nfs4_acl_add_ace);
 870 EXPORT_SYMBOL(nfs4_acl_get_whotype);
 871 EXPORT_SYMBOL(nfs4_acl_write_who);