fs/nfsd/nfs4acl.c

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This source file includes following definitions.
mask_from_posix
deny_mask_from_posix
low_mode_from_nfs4
nfsd4_get_nfs4_acl
summarize_posix_acl
_posix_to_nfsv4_one
pace_gt
sort_pacl_range
sort_pacl
init_state
free_state
add_to_mask
posix_state_to_acl
allow_bits
deny_bits
find_uid
find_gid
deny_bits_array
allow_bits_array
process_one_v4_ace
nfs4_acl_nfsv4_to_posix
nfsd4_set_nfs4_acl
ace2type
nfs4_acl_bytes
nfs4_acl_get_whotype
nfs4_acl_write_who
   1 /*
   2  *  Common NFSv4 ACL handling code.
   3  *
   4  *  Copyright (c) 2002, 2003 The Regents of the University of Michigan.
   5  *  All rights reserved.
   6  *
   7  *  Marius Aamodt Eriksen <marius@umich.edu>
   8  *  Jeff Sedlak <jsedlak@umich.edu>
   9  *  J. Bruce Fields <bfields@umich.edu>
  10  *
  11  *  Redistribution and use in source and binary forms, with or without
  12  *  modification, are permitted provided that the following conditions
  13  *  are met:
  14  *
  15  *  1. Redistributions of source code must retain the above copyright
  16  *     notice, this list of conditions and the following disclaimer.
  17  *  2. Redistributions in binary form must reproduce the above copyright
  18  *     notice, this list of conditions and the following disclaimer in the
  19  *     documentation and/or other materials provided with the distribution.
  20  *  3. Neither the name of the University nor the names of its
  21  *     contributors may be used to endorse or promote products derived
  22  *     from this software without specific prior written permission.
  23  *
  24  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  25  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  27  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  31  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  32  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  33  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  34  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  */
  36 
  37 #include <linux/fs.h>
  38 #include <linux/slab.h>
  39 #include <linux/posix_acl.h>
  40 
  41 #include "nfsfh.h"
  42 #include "nfsd.h"
  43 #include "acl.h"
  44 #include "vfs.h"
  45 
  46 #define NFS4_ACL_TYPE_DEFAULT   0x01
  47 #define NFS4_ACL_DIR            0x02
  48 #define NFS4_ACL_OWNER          0x04
  49 
  50 /* mode bit translations: */
  51 #define NFS4_READ_MODE (NFS4_ACE_READ_DATA)
  52 #define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA)
  53 #define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE
  54 #define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE)
  55 #define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)
  56 
  57 /* flags used to simulate posix default ACLs */
  58 #define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \
  59                 | NFS4_ACE_DIRECTORY_INHERIT_ACE)
  60 
  61 #define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \
  62                 | NFS4_ACE_INHERIT_ONLY_ACE \
  63                 | NFS4_ACE_IDENTIFIER_GROUP)
  64 
  65 static u32
  66 mask_from_posix(unsigned short perm, unsigned int flags)
  67 {
  68         int mask = NFS4_ANYONE_MODE;
  69 
  70         if (flags & NFS4_ACL_OWNER)
  71                 mask |= NFS4_OWNER_MODE;
  72         if (perm & ACL_READ)
  73                 mask |= NFS4_READ_MODE;
  74         if (perm & ACL_WRITE)
  75                 mask |= NFS4_WRITE_MODE;
  76         if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
  77                 mask |= NFS4_ACE_DELETE_CHILD;
  78         if (perm & ACL_EXECUTE)
  79                 mask |= NFS4_EXECUTE_MODE;
  80         return mask;
  81 }
  82 
  83 static u32
  84 deny_mask_from_posix(unsigned short perm, u32 flags)
  85 {
  86         u32 mask = 0;
  87 
  88         if (perm & ACL_READ)
  89                 mask |= NFS4_READ_MODE;
  90         if (perm & ACL_WRITE)
  91                 mask |= NFS4_WRITE_MODE;
  92         if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
  93                 mask |= NFS4_ACE_DELETE_CHILD;
  94         if (perm & ACL_EXECUTE)
  95                 mask |= NFS4_EXECUTE_MODE;
  96         return mask;
  97 }
  98 
  99 /* XXX: modify functions to return NFS errors; they're only ever
 100  * used by nfs code, after all.... */
 101 
 102 /* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the
 103  * side of being more restrictive, so the mode bit mapping below is
 104  * pessimistic.  An optimistic version would be needed to handle DENY's,
 105  * but we expect to coalesce all ALLOWs and DENYs before mapping to mode
 106  * bits. */
 107 
 108 static void
 109 low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
 110 {
 111         u32 write_mode = NFS4_WRITE_MODE;
 112 
 113         if (flags & NFS4_ACL_DIR)
 114                 write_mode |= NFS4_ACE_DELETE_CHILD;
 115         *mode = 0;
 116         if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE)
 117                 *mode |= ACL_READ;
 118         if ((perm & write_mode) == write_mode)
 119                 *mode |= ACL_WRITE;
 120         if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE)
 121                 *mode |= ACL_EXECUTE;
 122 }
 123 
 124 static short ace2type(struct nfs4_ace *);
 125 static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *,
 126                                 unsigned int);
 127 
 128 int
 129 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
 130                 struct nfs4_acl **acl)
 131 {
 132         struct inode *inode = d_inode(dentry);
 133         int error = 0;
 134         struct posix_acl *pacl = NULL, *dpacl = NULL;
 135         unsigned int flags = 0;
 136         int size = 0;
 137 
 138         pacl = get_acl(inode, ACL_TYPE_ACCESS);
 139         if (!pacl)
 140                 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
 141 
 142         if (IS_ERR(pacl))
 143                 return PTR_ERR(pacl);
 144 
 145         /* allocate for worst case: one (deny, allow) pair each: */
 146         size += 2 * pacl->a_count;
 147 
 148         if (S_ISDIR(inode->i_mode)) {
 149                 flags = NFS4_ACL_DIR;
 150                 dpacl = get_acl(inode, ACL_TYPE_DEFAULT);
 151                 if (IS_ERR(dpacl)) {
 152                         error = PTR_ERR(dpacl);
 153                         goto rel_pacl;
 154                 }
 155 
 156                 if (dpacl)
 157                         size += 2 * dpacl->a_count;
 158         }
 159 
 160         *acl = kmalloc(nfs4_acl_bytes(size), GFP_KERNEL);
 161         if (*acl == NULL) {
 162                 error = -ENOMEM;
 163                 goto out;
 164         }
 165         (*acl)->naces = 0;
 166 
 167         _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT);
 168 
 169         if (dpacl)
 170                 _posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT);
 171 
 172 out:
 173         posix_acl_release(dpacl);
 174 rel_pacl:
 175         posix_acl_release(pacl);
 176         return error;
 177 }
 178 
 179 struct posix_acl_summary {
 180         unsigned short owner;
 181         unsigned short users;
 182         unsigned short group;
 183         unsigned short groups;
 184         unsigned short other;
 185         unsigned short mask;
 186 };
 187 
 188 static void
 189 summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas)
 190 {
 191         struct posix_acl_entry *pa, *pe;
 192 
 193         /*
 194          * Only pas.users and pas.groups need initialization; previous
 195          * posix_acl_valid() calls ensure that the other fields will be
 196          * initialized in the following loop.  But, just to placate gcc:
 197          */
 198         memset(pas, 0, sizeof(*pas));
 199         pas->mask = 07;
 200 
 201         pe = acl->a_entries + acl->a_count;
 202 
 203         FOREACH_ACL_ENTRY(pa, acl, pe) {
 204                 switch (pa->e_tag) {
 205                         case ACL_USER_OBJ:
 206                                 pas->owner = pa->e_perm;
 207                                 break;
 208                         case ACL_GROUP_OBJ:
 209                                 pas->group = pa->e_perm;
 210                                 break;
 211                         case ACL_USER:
 212                                 pas->users |= pa->e_perm;
 213                                 break;
 214                         case ACL_GROUP:
 215                                 pas->groups |= pa->e_perm;
 216                                 break;
 217                         case ACL_OTHER:
 218                                 pas->other = pa->e_perm;
 219                                 break;
 220                         case ACL_MASK:
 221                                 pas->mask = pa->e_perm;
 222                                 break;
 223                 }
 224         }
 225         /* We'll only care about effective permissions: */
 226         pas->users &= pas->mask;
 227         pas->group &= pas->mask;
 228         pas->groups &= pas->mask;
 229 }
 230 
 231 /* We assume the acl has been verified with posix_acl_valid. */
 232 static void
 233 _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
 234                                                 unsigned int flags)
 235 {
 236         struct posix_acl_entry *pa, *group_owner_entry;
 237         struct nfs4_ace *ace;
 238         struct posix_acl_summary pas;
 239         unsigned short deny;
 240         int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ?
 241                 NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0);
 242 
 243         BUG_ON(pacl->a_count < 3);
 244         summarize_posix_acl(pacl, &pas);
 245 
 246         pa = pacl->a_entries;
 247         ace = acl->aces + acl->naces;
 248 
 249         /* We could deny everything not granted by the owner: */
 250         deny = ~pas.owner;
 251         /*
 252          * but it is equivalent (and simpler) to deny only what is not
 253          * granted by later entries:
 254          */
 255         deny &= pas.users | pas.group | pas.groups | pas.other;
 256         if (deny) {
 257                 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
 258                 ace->flag = eflag;
 259                 ace->access_mask = deny_mask_from_posix(deny, flags);
 260                 ace->whotype = NFS4_ACL_WHO_OWNER;
 261                 ace++;
 262                 acl->naces++;
 263         }
 264 
 265         ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
 266         ace->flag = eflag;
 267         ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER);
 268         ace->whotype = NFS4_ACL_WHO_OWNER;
 269         ace++;
 270         acl->naces++;
 271         pa++;
 272 
 273         while (pa->e_tag == ACL_USER) {
 274                 deny = ~(pa->e_perm & pas.mask);
 275                 deny &= pas.groups | pas.group | pas.other;
 276                 if (deny) {
 277                         ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
 278                         ace->flag = eflag;
 279                         ace->access_mask = deny_mask_from_posix(deny, flags);
 280                         ace->whotype = NFS4_ACL_WHO_NAMED;
 281                         ace->who_uid = pa->e_uid;
 282                         ace++;
 283                         acl->naces++;
 284                 }
 285                 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
 286                 ace->flag = eflag;
 287                 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
 288                                                    flags);
 289                 ace->whotype = NFS4_ACL_WHO_NAMED;
 290                 ace->who_uid = pa->e_uid;
 291                 ace++;
 292                 acl->naces++;
 293                 pa++;
 294         }
 295 
 296         /* In the case of groups, we apply allow ACEs first, then deny ACEs,
 297          * since a user can be in more than one group.  */
 298 
 299         /* allow ACEs */
 300 
 301         group_owner_entry = pa;
 302 
 303         ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
 304         ace->flag = eflag;
 305         ace->access_mask = mask_from_posix(pas.group, flags);
 306         ace->whotype = NFS4_ACL_WHO_GROUP;
 307         ace++;
 308         acl->naces++;
 309         pa++;
 310 
 311         while (pa->e_tag == ACL_GROUP) {
 312                 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
 313                 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
 314                 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
 315                                                    flags);
 316                 ace->whotype = NFS4_ACL_WHO_NAMED;
 317                 ace->who_gid = pa->e_gid;
 318                 ace++;
 319                 acl->naces++;
 320                 pa++;
 321         }
 322 
 323         /* deny ACEs */
 324 
 325         pa = group_owner_entry;
 326 
 327         deny = ~pas.group & pas.other;
 328         if (deny) {
 329                 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
 330                 ace->flag = eflag;
 331                 ace->access_mask = deny_mask_from_posix(deny, flags);
 332                 ace->whotype = NFS4_ACL_WHO_GROUP;
 333                 ace++;
 334                 acl->naces++;
 335         }
 336         pa++;
 337 
 338         while (pa->e_tag == ACL_GROUP) {
 339                 deny = ~(pa->e_perm & pas.mask);
 340                 deny &= pas.other;
 341                 if (deny) {
 342                         ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
 343                         ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
 344                         ace->access_mask = deny_mask_from_posix(deny, flags);
 345                         ace->whotype = NFS4_ACL_WHO_NAMED;
 346                         ace->who_gid = pa->e_gid;
 347                         ace++;
 348                         acl->naces++;
 349                 }
 350                 pa++;
 351         }
 352 
 353         if (pa->e_tag == ACL_MASK)
 354                 pa++;
 355         ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
 356         ace->flag = eflag;
 357         ace->access_mask = mask_from_posix(pa->e_perm, flags);
 358         ace->whotype = NFS4_ACL_WHO_EVERYONE;
 359         acl->naces++;
 360 }
 361 
 362 static bool
 363 pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2)
 364 {
 365         if (pace1->e_tag != pace2->e_tag)
 366                 return pace1->e_tag > pace2->e_tag;
 367         if (pace1->e_tag == ACL_USER)
 368                 return uid_gt(pace1->e_uid, pace2->e_uid);
 369         if (pace1->e_tag == ACL_GROUP)
 370                 return gid_gt(pace1->e_gid, pace2->e_gid);
 371         return false;
 372 }
 373 
 374 static void
 375 sort_pacl_range(struct posix_acl *pacl, int start, int end) {
 376         int sorted = 0, i;
 377 
 378         /* We just do a bubble sort; easy to do in place, and we're not
 379          * expecting acl's to be long enough to justify anything more. */
 380         while (!sorted) {
 381                 sorted = 1;
 382                 for (i = start; i < end; i++) {
 383                         if (pace_gt(&pacl->a_entries[i],
 384                                     &pacl->a_entries[i+1])) {
 385                                 sorted = 0;
 386                                 swap(pacl->a_entries[i],
 387                                      pacl->a_entries[i + 1]);
 388                         }
 389                 }
 390         }
 391 }
 392 
 393 static void
 394 sort_pacl(struct posix_acl *pacl)
 395 {
 396         /* posix_acl_valid requires that users and groups be in order
 397          * by uid/gid. */
 398         int i, j;
 399 
 400         /* no users or groups */
 401         if (!pacl || pacl->a_count <= 4)
 402                 return;
 403 
 404         i = 1;
 405         while (pacl->a_entries[i].e_tag == ACL_USER)
 406                 i++;
 407         sort_pacl_range(pacl, 1, i-1);
 408 
 409         BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ);
 410         j = ++i;
 411         while (pacl->a_entries[j].e_tag == ACL_GROUP)
 412                 j++;
 413         sort_pacl_range(pacl, i, j-1);
 414         return;
 415 }
 416 
 417 /*
 418  * While processing the NFSv4 ACE, this maintains bitmasks representing
 419  * which permission bits have been allowed and which denied to a given
 420  * entity: */
 421 struct posix_ace_state {
 422         u32 allow;
 423         u32 deny;
 424 };
 425 
 426 struct posix_user_ace_state {
 427         union {
 428                 kuid_t uid;
 429                 kgid_t gid;
 430         };
 431         struct posix_ace_state perms;
 432 };
 433 
 434 struct posix_ace_state_array {
 435         int n;
 436         struct posix_user_ace_state aces[];
 437 };
 438 
 439 /*
 440  * While processing the NFSv4 ACE, this maintains the partial permissions
 441  * calculated so far: */
 442 
 443 struct posix_acl_state {
 444         int empty;
 445         struct posix_ace_state owner;
 446         struct posix_ace_state group;
 447         struct posix_ace_state other;
 448         struct posix_ace_state everyone;
 449         struct posix_ace_state mask; /* Deny unused in this case */
 450         struct posix_ace_state_array *users;
 451         struct posix_ace_state_array *groups;
 452 };
 453 
 454 static int
 455 init_state(struct posix_acl_state *state, int cnt)
 456 {
 457         int alloc;
 458 
 459         memset(state, 0, sizeof(struct posix_acl_state));
 460         state->empty = 1;
 461         /*
 462          * In the worst case, each individual acl could be for a distinct
 463          * named user or group, but we don't know which, so we allocate
 464          * enough space for either:
 465          */
 466         alloc = sizeof(struct posix_ace_state_array)
 467                 + cnt*sizeof(struct posix_user_ace_state);
 468         state->users = kzalloc(alloc, GFP_KERNEL);
 469         if (!state->users)
 470                 return -ENOMEM;
 471         state->groups = kzalloc(alloc, GFP_KERNEL);
 472         if (!state->groups) {
 473                 kfree(state->users);
 474                 return -ENOMEM;
 475         }
 476         return 0;
 477 }
 478 
 479 static void
 480 free_state(struct posix_acl_state *state) {
 481         kfree(state->users);
 482         kfree(state->groups);
 483 }
 484 
 485 static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate)
 486 {
 487         state->mask.allow |= astate->allow;
 488 }
 489 
 490 static struct posix_acl *
 491 posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
 492 {
 493         struct posix_acl_entry *pace;
 494         struct posix_acl *pacl;
 495         int nace;
 496         int i;
 497 
 498         /*
 499          * ACLs with no ACEs are treated differently in the inheritable
 500          * and effective cases: when there are no inheritable ACEs,
 501          * calls ->set_acl with a NULL ACL structure.
 502          */
 503         if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT))
 504                 return NULL;
 505 
 506         /*
 507          * When there are no effective ACEs, the following will end
 508          * up setting a 3-element effective posix ACL with all
 509          * permissions zero.
 510          */
 511         if (!state->users->n && !state->groups->n)
 512                 nace = 3;
 513         else /* Note we also include a MASK ACE in this case: */
 514                 nace = 4 + state->users->n + state->groups->n;
 515         pacl = posix_acl_alloc(nace, GFP_KERNEL);
 516         if (!pacl)
 517                 return ERR_PTR(-ENOMEM);
 518 
 519         pace = pacl->a_entries;
 520         pace->e_tag = ACL_USER_OBJ;
 521         low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
 522 
 523         for (i=0; i < state->users->n; i++) {
 524                 pace++;
 525                 pace->e_tag = ACL_USER;
 526                 low_mode_from_nfs4(state->users->aces[i].perms.allow,
 527                                         &pace->e_perm, flags);
 528                 pace->e_uid = state->users->aces[i].uid;
 529                 add_to_mask(state, &state->users->aces[i].perms);
 530         }
 531 
 532         pace++;
 533         pace->e_tag = ACL_GROUP_OBJ;
 534         low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
 535         add_to_mask(state, &state->group);
 536 
 537         for (i=0; i < state->groups->n; i++) {
 538                 pace++;
 539                 pace->e_tag = ACL_GROUP;
 540                 low_mode_from_nfs4(state->groups->aces[i].perms.allow,
 541                                         &pace->e_perm, flags);
 542                 pace->e_gid = state->groups->aces[i].gid;
 543                 add_to_mask(state, &state->groups->aces[i].perms);
 544         }
 545 
 546         if (state->users->n || state->groups->n) {
 547                 pace++;
 548                 pace->e_tag = ACL_MASK;
 549                 low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
 550         }
 551 
 552         pace++;
 553         pace->e_tag = ACL_OTHER;
 554         low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
 555 
 556         return pacl;
 557 }
 558 
 559 static inline void allow_bits(struct posix_ace_state *astate, u32 mask)
 560 {
 561         /* Allow all bits in the mask not already denied: */
 562         astate->allow |= mask & ~astate->deny;
 563 }
 564 
 565 static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
 566 {
 567         /* Deny all bits in the mask not already allowed: */
 568         astate->deny |= mask & ~astate->allow;
 569 }
 570 
 571 static int find_uid(struct posix_acl_state *state, kuid_t uid)
 572 {
 573         struct posix_ace_state_array *a = state->users;
 574         int i;
 575 
 576         for (i = 0; i < a->n; i++)
 577                 if (uid_eq(a->aces[i].uid, uid))
 578                         return i;
 579         /* Not found: */
 580         a->n++;
 581         a->aces[i].uid = uid;
 582         a->aces[i].perms.allow = state->everyone.allow;
 583         a->aces[i].perms.deny  = state->everyone.deny;
 584 
 585         return i;
 586 }
 587 
 588 static int find_gid(struct posix_acl_state *state, kgid_t gid)
 589 {
 590         struct posix_ace_state_array *a = state->groups;
 591         int i;
 592 
 593         for (i = 0; i < a->n; i++)
 594                 if (gid_eq(a->aces[i].gid, gid))
 595                         return i;
 596         /* Not found: */
 597         a->n++;
 598         a->aces[i].gid = gid;
 599         a->aces[i].perms.allow = state->everyone.allow;
 600         a->aces[i].perms.deny  = state->everyone.deny;
 601 
 602         return i;
 603 }
 604 
 605 static void deny_bits_array(struct posix_ace_state_array *a, u32 mask)
 606 {
 607         int i;
 608 
 609         for (i=0; i < a->n; i++)
 610                 deny_bits(&a->aces[i].perms, mask);
 611 }
 612 
 613 static void allow_bits_array(struct posix_ace_state_array *a, u32 mask)
 614 {
 615         int i;
 616 
 617         for (i=0; i < a->n; i++)
 618                 allow_bits(&a->aces[i].perms, mask);
 619 }
 620 
 621 static void process_one_v4_ace(struct posix_acl_state *state,
 622                                 struct nfs4_ace *ace)
 623 {
 624         u32 mask = ace->access_mask;
 625         int i;
 626 
 627         state->empty = 0;
 628 
 629         switch (ace2type(ace)) {
 630         case ACL_USER_OBJ:
 631                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 632                         allow_bits(&state->owner, mask);
 633                 } else {
 634                         deny_bits(&state->owner, mask);
 635                 }
 636                 break;
 637         case ACL_USER:
 638                 i = find_uid(state, ace->who_uid);
 639                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 640                         allow_bits(&state->users->aces[i].perms, mask);
 641                 } else {
 642                         deny_bits(&state->users->aces[i].perms, mask);
 643                         mask = state->users->aces[i].perms.deny;
 644                         deny_bits(&state->owner, mask);
 645                 }
 646                 break;
 647         case ACL_GROUP_OBJ:
 648                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 649                         allow_bits(&state->group, mask);
 650                 } else {
 651                         deny_bits(&state->group, mask);
 652                         mask = state->group.deny;
 653                         deny_bits(&state->owner, mask);
 654                         deny_bits(&state->everyone, mask);
 655                         deny_bits_array(state->users, mask);
 656                         deny_bits_array(state->groups, mask);
 657                 }
 658                 break;
 659         case ACL_GROUP:
 660                 i = find_gid(state, ace->who_gid);
 661                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 662                         allow_bits(&state->groups->aces[i].perms, mask);
 663                 } else {
 664                         deny_bits(&state->groups->aces[i].perms, mask);
 665                         mask = state->groups->aces[i].perms.deny;
 666                         deny_bits(&state->owner, mask);
 667                         deny_bits(&state->group, mask);
 668                         deny_bits(&state->everyone, mask);
 669                         deny_bits_array(state->users, mask);
 670                         deny_bits_array(state->groups, mask);
 671                 }
 672                 break;
 673         case ACL_OTHER:
 674                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 675                         allow_bits(&state->owner, mask);
 676                         allow_bits(&state->group, mask);
 677                         allow_bits(&state->other, mask);
 678                         allow_bits(&state->everyone, mask);
 679                         allow_bits_array(state->users, mask);
 680                         allow_bits_array(state->groups, mask);
 681                 } else {
 682                         deny_bits(&state->owner, mask);
 683                         deny_bits(&state->group, mask);
 684                         deny_bits(&state->other, mask);
 685                         deny_bits(&state->everyone, mask);
 686                         deny_bits_array(state->users, mask);
 687                         deny_bits_array(state->groups, mask);
 688                 }
 689         }
 690 }
 691 
 692 static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl,
 693                 struct posix_acl **pacl, struct posix_acl **dpacl,
 694                 unsigned int flags)
 695 {
 696         struct posix_acl_state effective_acl_state, default_acl_state;
 697         struct nfs4_ace *ace;
 698         int ret;
 699 
 700         ret = init_state(&effective_acl_state, acl->naces);
 701         if (ret)
 702                 return ret;
 703         ret = init_state(&default_acl_state, acl->naces);
 704         if (ret)
 705                 goto out_estate;
 706         ret = -EINVAL;
 707         for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
 708                 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
 709                     ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
 710                         goto out_dstate;
 711                 if (ace->flag & ~NFS4_SUPPORTED_FLAGS)
 712                         goto out_dstate;
 713                 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) {
 714                         process_one_v4_ace(&effective_acl_state, ace);
 715                         continue;
 716                 }
 717                 if (!(flags & NFS4_ACL_DIR))
 718                         goto out_dstate;
 719                 /*
 720                  * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT
 721                  * is set, we're effectively turning on the other.  That's OK,
 722                  * according to rfc 3530.
 723                  */
 724                 process_one_v4_ace(&default_acl_state, ace);
 725 
 726                 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE))
 727                         process_one_v4_ace(&effective_acl_state, ace);
 728         }
 729         *pacl = posix_state_to_acl(&effective_acl_state, flags);
 730         if (IS_ERR(*pacl)) {
 731                 ret = PTR_ERR(*pacl);
 732                 *pacl = NULL;
 733                 goto out_dstate;
 734         }
 735         *dpacl = posix_state_to_acl(&default_acl_state,
 736                                                 flags | NFS4_ACL_TYPE_DEFAULT);
 737         if (IS_ERR(*dpacl)) {
 738                 ret = PTR_ERR(*dpacl);
 739                 *dpacl = NULL;
 740                 posix_acl_release(*pacl);
 741                 *pacl = NULL;
 742                 goto out_dstate;
 743         }
 744         sort_pacl(*pacl);
 745         sort_pacl(*dpacl);
 746         ret = 0;
 747 out_dstate:
 748         free_state(&default_acl_state);
 749 out_estate:
 750         free_state(&effective_acl_state);
 751         return ret;
 752 }
 753 
 754 __be32
 755 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
 756                 struct nfs4_acl *acl)
 757 {
 758         __be32 error;
 759         int host_error;
 760         struct dentry *dentry;
 761         struct inode *inode;
 762         struct posix_acl *pacl = NULL, *dpacl = NULL;
 763         unsigned int flags = 0;
 764 
 765         /* Get inode */
 766         error = fh_verify(rqstp, fhp, 0, NFSD_MAY_SATTR);
 767         if (error)
 768                 return error;
 769 
 770         dentry = fhp->fh_dentry;
 771         inode = d_inode(dentry);
 772 
 773         if (S_ISDIR(inode->i_mode))
 774                 flags = NFS4_ACL_DIR;
 775 
 776         host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
 777         if (host_error == -EINVAL)
 778                 return nfserr_attrnotsupp;
 779         if (host_error < 0)
 780                 goto out_nfserr;
 781 
 782         fh_lock(fhp);
 783 
 784         host_error = set_posix_acl(inode, ACL_TYPE_ACCESS, pacl);
 785         if (host_error < 0)
 786                 goto out_drop_lock;
 787 
 788         if (S_ISDIR(inode->i_mode)) {
 789                 host_error = set_posix_acl(inode, ACL_TYPE_DEFAULT, dpacl);
 790         }
 791 
 792 out_drop_lock:
 793         fh_unlock(fhp);
 794 
 795         posix_acl_release(pacl);
 796         posix_acl_release(dpacl);
 797 out_nfserr:
 798         if (host_error == -EOPNOTSUPP)
 799                 return nfserr_attrnotsupp;
 800         else
 801                 return nfserrno(host_error);
 802 }
 803 
 804 
 805 static short
 806 ace2type(struct nfs4_ace *ace)
 807 {
 808         switch (ace->whotype) {
 809                 case NFS4_ACL_WHO_NAMED:
 810                         return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ?
 811                                         ACL_GROUP : ACL_USER);
 812                 case NFS4_ACL_WHO_OWNER:
 813                         return ACL_USER_OBJ;
 814                 case NFS4_ACL_WHO_GROUP:
 815                         return ACL_GROUP_OBJ;
 816                 case NFS4_ACL_WHO_EVERYONE:
 817                         return ACL_OTHER;
 818         }
 819         BUG();
 820         return -1;
 821 }
 822 
 823 /*
 824  * return the size of the struct nfs4_acl required to represent an acl
 825  * with @entries entries.
 826  */
 827 int nfs4_acl_bytes(int entries)
 828 {
 829         return sizeof(struct nfs4_acl) + entries * sizeof(struct nfs4_ace);
 830 }
 831 
 832 static struct {
 833         char *string;
 834         int   stringlen;
 835         int type;
 836 } s2t_map[] = {
 837         {
 838                 .string    = "OWNER@",
 839                 .stringlen = sizeof("OWNER@") - 1,
 840                 .type      = NFS4_ACL_WHO_OWNER,
 841         },
 842         {
 843                 .string    = "GROUP@",
 844                 .stringlen = sizeof("GROUP@") - 1,
 845                 .type      = NFS4_ACL_WHO_GROUP,
 846         },
 847         {
 848                 .string    = "EVERYONE@",
 849                 .stringlen = sizeof("EVERYONE@") - 1,
 850                 .type      = NFS4_ACL_WHO_EVERYONE,
 851         },
 852 };
 853 
 854 int
 855 nfs4_acl_get_whotype(char *p, u32 len)
 856 {
 857         int i;
 858 
 859         for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
 860                 if (s2t_map[i].stringlen == len &&
 861                                 0 == memcmp(s2t_map[i].string, p, len))
 862                         return s2t_map[i].type;
 863         }
 864         return NFS4_ACL_WHO_NAMED;
 865 }
 866 
 867 __be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who)
 868 {
 869         __be32 *p;
 870         int i;
 871 
 872         for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
 873                 if (s2t_map[i].type != who)
 874                         continue;
 875                 p = xdr_reserve_space(xdr, s2t_map[i].stringlen + 4);
 876                 if (!p)
 877                         return nfserr_resource;
 878                 p = xdr_encode_opaque(p, s2t_map[i].string,
 879                                         s2t_map[i].stringlen);
 880                 return 0;
 881         }
 882         WARN_ON_ONCE(1);
 883         return nfserr_serverfault;
 884 }
/* [<][>][^][v][top][bottom][index][help] */
root/fs/nfsd/nfs4acl.c

DEFINITIONS
