1 /* 2 * Common NFSv4 ACL handling code. 3 * 4 * Copyright (c) 2002, 2003 The Regents of the University of Michigan. 5 * All rights reserved. 6 * 7 * Marius Aamodt Eriksen <marius@umich.edu> 8 * Jeff Sedlak <jsedlak@umich.edu> 9 * J. Bruce Fields <bfields@umich.edu> 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its 21 * contributors may be used to endorse or promote products derived 22 * from this software without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 25 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 26 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 27 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 31 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 32 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 33 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 34 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 35 */ 36 37 #include <linux/slab.h> 38 #include <linux/nfs_fs.h> 39 #include <linux/export.h> 40 #include "acl.h" 41 42 43 /* mode bit translations: */ 44 #define NFS4_READ_MODE (NFS4_ACE_READ_DATA) 45 #define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA) 46 #define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE 47 #define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE) 48 #define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL) 49 50 /* We don't support these bits; insist they be neither allowed nor denied */ 51 #define NFS4_MASK_UNSUPP (NFS4_ACE_DELETE | NFS4_ACE_WRITE_OWNER \ 52 | NFS4_ACE_READ_NAMED_ATTRS | NFS4_ACE_WRITE_NAMED_ATTRS) 53 54 /* flags used to simulate posix default ACLs */ 55 #define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \ 56 | NFS4_ACE_DIRECTORY_INHERIT_ACE) 57 58 #define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \ 59 | NFS4_ACE_INHERIT_ONLY_ACE \ 60 | NFS4_ACE_IDENTIFIER_GROUP) 61 62 #define MASK_EQUAL(mask1, mask2) \ 63 ( ((mask1) & NFS4_ACE_MASK_ALL) == ((mask2) & NFS4_ACE_MASK_ALL) ) 64 65 static u32 66 mask_from_posix(unsigned short perm, unsigned int flags) 67 { 68 int mask = NFS4_ANYONE_MODE; 69 70 if (flags & NFS4_ACL_OWNER) 71 mask |= NFS4_OWNER_MODE; 72 if (perm & ACL_READ) 73 mask |= NFS4_READ_MODE; 74 if (perm & ACL_WRITE) 75 mask |= NFS4_WRITE_MODE; 76 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR)) 77 mask |= NFS4_ACE_DELETE_CHILD; 78 if (perm & ACL_EXECUTE) 79 mask |= NFS4_EXECUTE_MODE; 80 return mask; 81 } 82 83 static u32 84 deny_mask_from_posix(unsigned short perm, u32 flags) 85 { 86 u32 mask = 0; 87 88 if (perm & ACL_READ) 89 mask |= NFS4_READ_MODE; 90 if (perm & ACL_WRITE) 91 mask |= NFS4_WRITE_MODE; 92 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR)) 93 mask |= NFS4_ACE_DELETE_CHILD; 94 if (perm & ACL_EXECUTE) 95 mask |= NFS4_EXECUTE_MODE; 96 return mask; 97 } 98 99 /* XXX: modify functions to return NFS errors; they're only ever 100 * used by nfs code, after all.... */ 101 102 /* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the 103 * side of being more restrictive, so the mode bit mapping below is 104 * pessimistic. An optimistic version would be needed to handle DENY's, 105 * but we espect to coalesce all ALLOWs and DENYs before mapping to mode 106 * bits. */ 107 108 static void 109 low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags) 110 { 111 u32 write_mode = NFS4_WRITE_MODE; 112 113 if (flags & NFS4_ACL_DIR) 114 write_mode |= NFS4_ACE_DELETE_CHILD; 115 *mode = 0; 116 if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE) 117 *mode |= ACL_READ; 118 if ((perm & write_mode) == write_mode) 119 *mode |= ACL_WRITE; 120 if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE) 121 *mode |= ACL_EXECUTE; 122 } 123 124 struct ace_container { 125 struct nfs4_ace *ace; 126 struct list_head ace_l; 127 }; 128 129 static short ace2type(struct nfs4_ace *); 130 static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *, 131 unsigned int); 132 133 struct nfs4_acl * 134 nfs4_acl_posix_to_nfsv4(struct posix_acl *pacl, struct posix_acl *dpacl, 135 unsigned int flags) 136 { 137 struct nfs4_acl *acl; 138 int size = 0; 139 140 if (pacl) { 141 if (posix_acl_valid(pacl) < 0) 142 return ERR_PTR(-EINVAL); 143 size += 2*pacl->a_count; 144 } 145 if (dpacl) { 146 if (posix_acl_valid(dpacl) < 0) 147 return ERR_PTR(-EINVAL); 148 size += 2*dpacl->a_count; 149 } 150 151 /* Allocate for worst case: one (deny, allow) pair each: */ 152 acl = nfs4_acl_new(size); 153 if (acl == NULL) 154 return ERR_PTR(-ENOMEM); 155 156 if (pacl) 157 _posix_to_nfsv4_one(pacl, acl, flags & ~NFS4_ACL_TYPE_DEFAULT); 158 159 if (dpacl) 160 _posix_to_nfsv4_one(dpacl, acl, flags | NFS4_ACL_TYPE_DEFAULT); 161 162 return acl; 163 } 164 165 struct posix_acl_summary { 166 unsigned short owner; 167 unsigned short users; 168 unsigned short group; 169 unsigned short groups; 170 unsigned short other; 171 unsigned short mask; 172 }; 173 174 static void 175 summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas) 176 { 177 struct posix_acl_entry *pa, *pe; 178 179 /* 180 * Only pas.users and pas.groups need initialization; previous 181 * posix_acl_valid() calls ensure that the other fields will be 182 * initialized in the following loop. But, just to placate gcc: 183 */ 184 memset(pas, 0, sizeof(*pas)); 185 pas->mask = 07; 186 187 pe = acl->a_entries + acl->a_count; 188 189 FOREACH_ACL_ENTRY(pa, acl, pe) { 190 switch (pa->e_tag) { 191 case ACL_USER_OBJ: 192 pas->owner = pa->e_perm; 193 break; 194 case ACL_GROUP_OBJ: 195 pas->group = pa->e_perm; 196 break; 197 case ACL_USER: 198 pas->users |= pa->e_perm; 199 break; 200 case ACL_GROUP: 201 pas->groups |= pa->e_perm; 202 break; 203 case ACL_OTHER: 204 pas->other = pa->e_perm; 205 break; 206 case ACL_MASK: 207 pas->mask = pa->e_perm; 208 break; 209 } 210 } 211 /* We'll only care about effective permissions: */ 212 pas->users &= pas->mask; 213 pas->group &= pas->mask; 214 pas->groups &= pas->mask; 215 } 216 217 /* We assume the acl has been verified with posix_acl_valid. */ 218 static void 219 _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl, 220 unsigned int flags) 221 { 222 struct posix_acl_entry *pa, *group_owner_entry; 223 struct nfs4_ace *ace; 224 struct posix_acl_summary pas; 225 unsigned short deny; 226 int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ? 227 NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0); 228 229 BUG_ON(pacl->a_count < 3); 230 summarize_posix_acl(pacl, &pas); 231 232 pa = pacl->a_entries; 233 ace = acl->aces + acl->naces; 234 235 /* We could deny everything not granted by the owner: */ 236 deny = ~pas.owner; 237 /* 238 * but it is equivalent (and simpler) to deny only what is not 239 * granted by later entries: 240 */ 241 deny &= pas.users | pas.group | pas.groups | pas.other; 242 if (deny) { 243 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 244 ace->flag = eflag; 245 ace->access_mask = deny_mask_from_posix(deny, flags); 246 ace->whotype = NFS4_ACL_WHO_OWNER; 247 ace++; 248 acl->naces++; 249 } 250 251 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 252 ace->flag = eflag; 253 ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER); 254 ace->whotype = NFS4_ACL_WHO_OWNER; 255 ace++; 256 acl->naces++; 257 pa++; 258 259 while (pa->e_tag == ACL_USER) { 260 deny = ~(pa->e_perm & pas.mask); 261 deny &= pas.groups | pas.group | pas.other; 262 if (deny) { 263 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 264 ace->flag = eflag; 265 ace->access_mask = deny_mask_from_posix(deny, flags); 266 ace->whotype = NFS4_ACL_WHO_NAMED; 267 ace->who_uid = pa->e_uid; 268 ace++; 269 acl->naces++; 270 } 271 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 272 ace->flag = eflag; 273 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, 274 flags); 275 ace->whotype = NFS4_ACL_WHO_NAMED; 276 ace->who_uid = pa->e_uid; 277 ace++; 278 acl->naces++; 279 pa++; 280 } 281 282 /* In the case of groups, we apply allow ACEs first, then deny ACEs, 283 * since a user can be in more than one group. */ 284 285 /* allow ACEs */ 286 287 group_owner_entry = pa; 288 289 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 290 ace->flag = eflag; 291 ace->access_mask = mask_from_posix(pas.group, flags); 292 ace->whotype = NFS4_ACL_WHO_GROUP; 293 ace++; 294 acl->naces++; 295 pa++; 296 297 while (pa->e_tag == ACL_GROUP) { 298 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 299 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; 300 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, 301 flags); 302 ace->whotype = NFS4_ACL_WHO_NAMED; 303 ace->who_gid = pa->e_gid; 304 ace++; 305 acl->naces++; 306 pa++; 307 } 308 309 /* deny ACEs */ 310 311 pa = group_owner_entry; 312 313 deny = ~pas.group & pas.other; 314 if (deny) { 315 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 316 ace->flag = eflag; 317 ace->access_mask = deny_mask_from_posix(deny, flags); 318 ace->whotype = NFS4_ACL_WHO_GROUP; 319 ace++; 320 acl->naces++; 321 } 322 pa++; 323 324 while (pa->e_tag == ACL_GROUP) { 325 deny = ~(pa->e_perm & pas.mask); 326 deny &= pas.other; 327 if (deny) { 328 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 329 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; 330 ace->access_mask = deny_mask_from_posix(deny, flags); 331 ace->whotype = NFS4_ACL_WHO_NAMED; 332 ace->who_gid = pa->e_gid; 333 ace++; 334 acl->naces++; 335 } 336 pa++; 337 } 338 339 if (pa->e_tag == ACL_MASK) 340 pa++; 341 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 342 ace->flag = eflag; 343 ace->access_mask = mask_from_posix(pa->e_perm, flags); 344 ace->whotype = NFS4_ACL_WHO_EVERYONE; 345 acl->naces++; 346 } 347 348 static bool 349 pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2) 350 { 351 if (pace1->e_tag != pace2->e_tag) 352 return pace1->e_tag > pace2->e_tag; 353 if (pace1->e_tag == ACL_USER) 354 return uid_gt(pace1->e_uid, pace2->e_uid); 355 if (pace1->e_tag == ACL_GROUP) 356 return gid_gt(pace1->e_gid, pace2->e_gid); 357 return false; 358 } 359 360 static void 361 sort_pacl_range(struct posix_acl *pacl, int start, int end) { 362 int sorted = 0, i; 363 struct posix_acl_entry tmp; 364 365 /* We just do a bubble sort; easy to do in place, and we're not 366 * expecting acl's to be long enough to justify anything more. */ 367 while (!sorted) { 368 sorted = 1; 369 for (i = start; i < end; i++) { 370 if (pace_gt(&pacl->a_entries[i], 371 &pacl->a_entries[i+1])) { 372 sorted = 0; 373 tmp = pacl->a_entries[i]; 374 pacl->a_entries[i] = pacl->a_entries[i+1]; 375 pacl->a_entries[i+1] = tmp; 376 } 377 } 378 } 379 } 380 381 static void 382 sort_pacl(struct posix_acl *pacl) 383 { 384 /* posix_acl_valid requires that users and groups be in order 385 * by uid/gid. */ 386 int i, j; 387 388 if (pacl->a_count <= 4) 389 return; /* no users or groups */ 390 i = 1; 391 while (pacl->a_entries[i].e_tag == ACL_USER) 392 i++; 393 sort_pacl_range(pacl, 1, i-1); 394 395 BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ); 396 j = ++i; 397 while (pacl->a_entries[j].e_tag == ACL_GROUP) 398 j++; 399 sort_pacl_range(pacl, i, j-1); 400 return; 401 } 402 403 /* 404 * While processing the NFSv4 ACE, this maintains bitmasks representing 405 * which permission bits have been allowed and which denied to a given 406 * entity: */ 407 struct posix_ace_state { 408 u32 allow; 409 u32 deny; 410 }; 411 412 struct posix_user_ace_state { 413 union { 414 kuid_t uid; 415 kgid_t gid; 416 }; 417 struct posix_ace_state perms; 418 }; 419 420 struct posix_ace_state_array { 421 int n; 422 struct posix_user_ace_state aces[]; 423 }; 424 425 /* 426 * While processing the NFSv4 ACE, this maintains the partial permissions 427 * calculated so far: */ 428 429 struct posix_acl_state { 430 int empty; 431 struct posix_ace_state owner; 432 struct posix_ace_state group; 433 struct posix_ace_state other; 434 struct posix_ace_state everyone; 435 struct posix_ace_state mask; /* Deny unused in this case */ 436 struct posix_ace_state_array *users; 437 struct posix_ace_state_array *groups; 438 }; 439 440 static int 441 init_state(struct posix_acl_state *state, int cnt) 442 { 443 int alloc; 444 445 memset(state, 0, sizeof(struct posix_acl_state)); 446 state->empty = 1; 447 /* 448 * In the worst case, each individual acl could be for a distinct 449 * named user or group, but we don't no which, so we allocate 450 * enough space for either: 451 */ 452 alloc = sizeof(struct posix_ace_state_array) 453 + cnt*sizeof(struct posix_user_ace_state); 454 state->users = kzalloc(alloc, GFP_KERNEL); 455 if (!state->users) 456 return -ENOMEM; 457 state->groups = kzalloc(alloc, GFP_KERNEL); 458 if (!state->groups) { 459 kfree(state->users); 460 return -ENOMEM; 461 } 462 return 0; 463 } 464 465 static void 466 free_state(struct posix_acl_state *state) { 467 kfree(state->users); 468 kfree(state->groups); 469 } 470 471 static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate) 472 { 473 state->mask.allow |= astate->allow; 474 } 475 476 /* 477 * Certain bits (SYNCHRONIZE, DELETE, WRITE_OWNER, READ/WRITE_NAMED_ATTRS, 478 * READ_ATTRIBUTES, READ_ACL) are currently unenforceable and don't translate 479 * to traditional read/write/execute permissions. 480 * 481 * It's problematic to reject acls that use certain mode bits, because it 482 * places the burden on users to learn the rules about which bits one 483 * particular server sets, without giving the user a lot of help--we return an 484 * error that could mean any number of different things. To make matters 485 * worse, the problematic bits might be introduced by some application that's 486 * automatically mapping from some other acl model. 487 * 488 * So wherever possible we accept anything, possibly erring on the side of 489 * denying more permissions than necessary. 490 * 491 * However we do reject *explicit* DENY's of a few bits representing 492 * permissions we could never deny: 493 */ 494 495 static inline int check_deny(u32 mask, int isowner) 496 { 497 if (mask & (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL)) 498 return -EINVAL; 499 if (!isowner) 500 return 0; 501 if (mask & (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)) 502 return -EINVAL; 503 return 0; 504 } 505 506 static struct posix_acl * 507 posix_state_to_acl(struct posix_acl_state *state, unsigned int flags) 508 { 509 struct posix_acl_entry *pace; 510 struct posix_acl *pacl; 511 int nace; 512 int i, error = 0; 513 514 /* 515 * ACLs with no ACEs are treated differently in the inheritable 516 * and effective cases: when there are no inheritable ACEs, we 517 * set a zero-length default posix acl: 518 */ 519 if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT)) { 520 pacl = posix_acl_alloc(0, GFP_KERNEL); 521 return pacl ? pacl : ERR_PTR(-ENOMEM); 522 } 523 /* 524 * When there are no effective ACEs, the following will end 525 * up setting a 3-element effective posix ACL with all 526 * permissions zero. 527 */ 528 nace = 4 + state->users->n + state->groups->n; 529 pacl = posix_acl_alloc(nace, GFP_KERNEL); 530 if (!pacl) 531 return ERR_PTR(-ENOMEM); 532 533 pace = pacl->a_entries; 534 pace->e_tag = ACL_USER_OBJ; 535 error = check_deny(state->owner.deny, 1); 536 if (error) 537 goto out_err; 538 low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags); 539 540 for (i=0; i < state->users->n; i++) { 541 pace++; 542 pace->e_tag = ACL_USER; 543 error = check_deny(state->users->aces[i].perms.deny, 0); 544 if (error) 545 goto out_err; 546 low_mode_from_nfs4(state->users->aces[i].perms.allow, 547 &pace->e_perm, flags); 548 pace->e_uid = state->users->aces[i].uid; 549 add_to_mask(state, &state->users->aces[i].perms); 550 } 551 552 pace++; 553 pace->e_tag = ACL_GROUP_OBJ; 554 error = check_deny(state->group.deny, 0); 555 if (error) 556 goto out_err; 557 low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags); 558 add_to_mask(state, &state->group); 559 560 for (i=0; i < state->groups->n; i++) { 561 pace++; 562 pace->e_tag = ACL_GROUP; 563 error = check_deny(state->groups->aces[i].perms.deny, 0); 564 if (error) 565 goto out_err; 566 low_mode_from_nfs4(state->groups->aces[i].perms.allow, 567 &pace->e_perm, flags); 568 pace->e_gid = state->groups->aces[i].gid; 569 add_to_mask(state, &state->groups->aces[i].perms); 570 } 571 572 pace++; 573 pace->e_tag = ACL_MASK; 574 low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags); 575 576 pace++; 577 pace->e_tag = ACL_OTHER; 578 error = check_deny(state->other.deny, 0); 579 if (error) 580 goto out_err; 581 low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags); 582 583 return pacl; 584 out_err: 585 posix_acl_release(pacl); 586 return ERR_PTR(error); 587 } 588 589 static inline void allow_bits(struct posix_ace_state *astate, u32 mask) 590 { 591 /* Allow all bits in the mask not already denied: */ 592 astate->allow |= mask & ~astate->deny; 593 } 594 595 static inline void deny_bits(struct posix_ace_state *astate, u32 mask) 596 { 597 /* Deny all bits in the mask not already allowed: */ 598 astate->deny |= mask & ~astate->allow; 599 } 600 601 static int find_uid(struct posix_acl_state *state, kuid_t uid) 602 { 603 struct posix_ace_state_array *a = state->users; 604 int i; 605 606 for (i = 0; i < a->n; i++) 607 if (uid_eq(a->aces[i].uid, uid)) 608 return i; 609 /* Not found: */ 610 a->n++; 611 a->aces[i].uid = uid; 612 a->aces[i].perms.allow = state->everyone.allow; 613 a->aces[i].perms.deny = state->everyone.deny; 614 615 return i; 616 } 617 618 static int find_gid(struct posix_acl_state *state, kgid_t gid) 619 { 620 struct posix_ace_state_array *a = state->groups; 621 int i; 622 623 for (i = 0; i < a->n; i++) 624 if (gid_eq(a->aces[i].gid, gid)) 625 return i; 626 /* Not found: */ 627 a->n++; 628 a->aces[i].gid = gid; 629 a->aces[i].perms.allow = state->everyone.allow; 630 a->aces[i].perms.deny = state->everyone.deny; 631 632 return i; 633 } 634 635 static void deny_bits_array(struct posix_ace_state_array *a, u32 mask) 636 { 637 int i; 638 639 for (i=0; i < a->n; i++) 640 deny_bits(&a->aces[i].perms, mask); 641 } 642 643 static void allow_bits_array(struct posix_ace_state_array *a, u32 mask) 644 { 645 int i; 646 647 for (i=0; i < a->n; i++) 648 allow_bits(&a->aces[i].perms, mask); 649 } 650 651 static void process_one_v4_ace(struct posix_acl_state *state, 652 struct nfs4_ace *ace) 653 { 654 u32 mask = ace->access_mask; 655 int i; 656 657 state->empty = 0; 658 659 switch (ace2type(ace)) { 660 case ACL_USER_OBJ: 661 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 662 allow_bits(&state->owner, mask); 663 } else { 664 deny_bits(&state->owner, mask); 665 } 666 break; 667 case ACL_USER: 668 i = find_uid(state, ace->who_uid); 669 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 670 allow_bits(&state->users->aces[i].perms, mask); 671 } else { 672 deny_bits(&state->users->aces[i].perms, mask); 673 mask = state->users->aces[i].perms.deny; 674 deny_bits(&state->owner, mask); 675 } 676 break; 677 case ACL_GROUP_OBJ: 678 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 679 allow_bits(&state->group, mask); 680 } else { 681 deny_bits(&state->group, mask); 682 mask = state->group.deny; 683 deny_bits(&state->owner, mask); 684 deny_bits(&state->everyone, mask); 685 deny_bits_array(state->users, mask); 686 deny_bits_array(state->groups, mask); 687 } 688 break; 689 case ACL_GROUP: 690 i = find_gid(state, ace->who_gid); 691 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 692 allow_bits(&state->groups->aces[i].perms, mask); 693 } else { 694 deny_bits(&state->groups->aces[i].perms, mask); 695 mask = state->groups->aces[i].perms.deny; 696 deny_bits(&state->owner, mask); 697 deny_bits(&state->group, mask); 698 deny_bits(&state->everyone, mask); 699 deny_bits_array(state->users, mask); 700 deny_bits_array(state->groups, mask); 701 } 702 break; 703 case ACL_OTHER: 704 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 705 allow_bits(&state->owner, mask); 706 allow_bits(&state->group, mask); 707 allow_bits(&state->other, mask); 708 allow_bits(&state->everyone, mask); 709 allow_bits_array(state->users, mask); 710 allow_bits_array(state->groups, mask); 711 } else { 712 deny_bits(&state->owner, mask); 713 deny_bits(&state->group, mask); 714 deny_bits(&state->other, mask); 715 deny_bits(&state->everyone, mask); 716 deny_bits_array(state->users, mask); 717 deny_bits_array(state->groups, mask); 718 } 719 } 720 } 721 722 int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, struct posix_acl **pacl, 723 struct posix_acl **dpacl, unsigned int flags) 724 { 725 struct posix_acl_state effective_acl_state, default_acl_state; 726 struct nfs4_ace *ace; 727 int ret; 728 729 ret = init_state(&effective_acl_state, acl->naces); 730 if (ret) 731 return ret; 732 ret = init_state(&default_acl_state, acl->naces); 733 if (ret) 734 goto out_estate; 735 ret = -EINVAL; 736 for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) { 737 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE && 738 ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE) 739 goto out_dstate; 740 if (ace->flag & ~NFS4_SUPPORTED_FLAGS) 741 goto out_dstate; 742 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) { 743 process_one_v4_ace(&effective_acl_state, ace); 744 continue; 745 } 746 if (!(flags & NFS4_ACL_DIR)) 747 goto out_dstate; 748 /* 749 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT 750 * is set, we're effectively turning on the other. That's OK, 751 * according to rfc 3530. 752 */ 753 process_one_v4_ace(&default_acl_state, ace); 754 755 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE)) 756 process_one_v4_ace(&effective_acl_state, ace); 757 } 758 *pacl = posix_state_to_acl(&effective_acl_state, flags); 759 if (IS_ERR(*pacl)) { 760 ret = PTR_ERR(*pacl); 761 *pacl = NULL; 762 goto out_dstate; 763 } 764 *dpacl = posix_state_to_acl(&default_acl_state, 765 flags | NFS4_ACL_TYPE_DEFAULT); 766 if (IS_ERR(*dpacl)) { 767 ret = PTR_ERR(*dpacl); 768 *dpacl = NULL; 769 posix_acl_release(*pacl); 770 *pacl = NULL; 771 goto out_dstate; 772 } 773 sort_pacl(*pacl); 774 sort_pacl(*dpacl); 775 ret = 0; 776 out_dstate: 777 free_state(&default_acl_state); 778 out_estate: 779 free_state(&effective_acl_state); 780 return ret; 781 } 782 783 static short 784 ace2type(struct nfs4_ace *ace) 785 { 786 switch (ace->whotype) { 787 case NFS4_ACL_WHO_NAMED: 788 return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ? 789 ACL_GROUP : ACL_USER); 790 case NFS4_ACL_WHO_OWNER: 791 return ACL_USER_OBJ; 792 case NFS4_ACL_WHO_GROUP: 793 return ACL_GROUP_OBJ; 794 case NFS4_ACL_WHO_EVERYONE: 795 return ACL_OTHER; 796 } 797 BUG(); 798 return -1; 799 } 800 801 EXPORT_SYMBOL(nfs4_acl_posix_to_nfsv4); 802 EXPORT_SYMBOL(nfs4_acl_nfsv4_to_posix); 803 804 struct nfs4_acl * 805 nfs4_acl_new(int n) 806 { 807 struct nfs4_acl *acl; 808 809 acl = kmalloc(sizeof(*acl) + n*sizeof(struct nfs4_ace), GFP_KERNEL); 810 if (acl == NULL) 811 return NULL; 812 acl->naces = 0; 813 return acl; 814 } 815 816 static struct { 817 char *string; 818 int stringlen; 819 int type; 820 } s2t_map[] = { 821 { 822 .string = "OWNER@", 823 .stringlen = sizeof("OWNER@") - 1, 824 .type = NFS4_ACL_WHO_OWNER, 825 }, 826 { 827 .string = "GROUP@", 828 .stringlen = sizeof("GROUP@") - 1, 829 .type = NFS4_ACL_WHO_GROUP, 830 }, 831 { 832 .string = "EVERYONE@", 833 .stringlen = sizeof("EVERYONE@") - 1, 834 .type = NFS4_ACL_WHO_EVERYONE, 835 }, 836 }; 837 838 int 839 nfs4_acl_get_whotype(char *p, u32 len) 840 { 841 int i; 842 843 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 844 if (s2t_map[i].stringlen == len && 845 0 == memcmp(s2t_map[i].string, p, len)) 846 return s2t_map[i].type; 847 } 848 return NFS4_ACL_WHO_NAMED; 849 } 850 851 int 852 nfs4_acl_write_who(int who, char *p) 853 { 854 int i; 855 856 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 857 if (s2t_map[i].type == who) { 858 memcpy(p, s2t_map[i].string, s2t_map[i].stringlen); 859 return s2t_map[i].stringlen; 860 } 861 } 862 BUG(); 863 return -1; 864 } 865 866 EXPORT_SYMBOL(nfs4_acl_new); 867 EXPORT_SYMBOL(nfs4_acl_get_whotype); 868 EXPORT_SYMBOL(nfs4_acl_write_who); 869