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 "nfsfh.h" 40 #include "nfsd.h" 41 #include "acl.h" 42 #include "vfs.h" 43 44 #define NFS4_ACL_TYPE_DEFAULT 0x01 45 #define NFS4_ACL_DIR 0x02 46 #define NFS4_ACL_OWNER 0x04 47 48 /* mode bit translations: */ 49 #define NFS4_READ_MODE (NFS4_ACE_READ_DATA) 50 #define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA) 51 #define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE 52 #define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE) 53 #define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL) 54 55 /* We don't support these bits; insist they be neither allowed nor denied */ 56 #define NFS4_MASK_UNSUPP (NFS4_ACE_DELETE | NFS4_ACE_WRITE_OWNER \ 57 | NFS4_ACE_READ_NAMED_ATTRS | NFS4_ACE_WRITE_NAMED_ATTRS) 58 59 /* flags used to simulate posix default ACLs */ 60 #define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \ 61 | NFS4_ACE_DIRECTORY_INHERIT_ACE) 62 63 #define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \ 64 | NFS4_ACE_INHERIT_ONLY_ACE \ 65 | NFS4_ACE_IDENTIFIER_GROUP) 66 67 #define MASK_EQUAL(mask1, mask2) \ 68 ( ((mask1) & NFS4_ACE_MASK_ALL) == ((mask2) & NFS4_ACE_MASK_ALL) ) 69 70 static u32 71 mask_from_posix(unsigned short perm, unsigned int flags) 72 { 73 int mask = NFS4_ANYONE_MODE; 74 75 if (flags & NFS4_ACL_OWNER) 76 mask |= NFS4_OWNER_MODE; 77 if (perm & ACL_READ) 78 mask |= NFS4_READ_MODE; 79 if (perm & ACL_WRITE) 80 mask |= NFS4_WRITE_MODE; 81 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR)) 82 mask |= NFS4_ACE_DELETE_CHILD; 83 if (perm & ACL_EXECUTE) 84 mask |= NFS4_EXECUTE_MODE; 85 return mask; 86 } 87 88 static u32 89 deny_mask_from_posix(unsigned short perm, u32 flags) 90 { 91 u32 mask = 0; 92 93 if (perm & ACL_READ) 94 mask |= NFS4_READ_MODE; 95 if (perm & ACL_WRITE) 96 mask |= NFS4_WRITE_MODE; 97 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR)) 98 mask |= NFS4_ACE_DELETE_CHILD; 99 if (perm & ACL_EXECUTE) 100 mask |= NFS4_EXECUTE_MODE; 101 return mask; 102 } 103 104 /* XXX: modify functions to return NFS errors; they're only ever 105 * used by nfs code, after all.... */ 106 107 /* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the 108 * side of being more restrictive, so the mode bit mapping below is 109 * pessimistic. An optimistic version would be needed to handle DENY's, 110 * but we espect to coalesce all ALLOWs and DENYs before mapping to mode 111 * bits. */ 112 113 static void 114 low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags) 115 { 116 u32 write_mode = NFS4_WRITE_MODE; 117 118 if (flags & NFS4_ACL_DIR) 119 write_mode |= NFS4_ACE_DELETE_CHILD; 120 *mode = 0; 121 if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE) 122 *mode |= ACL_READ; 123 if ((perm & write_mode) == write_mode) 124 *mode |= ACL_WRITE; 125 if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE) 126 *mode |= ACL_EXECUTE; 127 } 128 129 struct ace_container { 130 struct nfs4_ace *ace; 131 struct list_head ace_l; 132 }; 133 134 static short ace2type(struct nfs4_ace *); 135 static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *, 136 unsigned int); 137 138 int 139 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, 140 struct nfs4_acl **acl) 141 { 142 struct inode *inode = dentry->d_inode; 143 int error = 0; 144 struct posix_acl *pacl = NULL, *dpacl = NULL; 145 unsigned int flags = 0; 146 int size = 0; 147 148 pacl = get_acl(inode, ACL_TYPE_ACCESS); 149 if (!pacl) { 150 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL); 151 if (IS_ERR(pacl)) 152 return PTR_ERR(pacl); 153 } 154 /* allocate for worst case: one (deny, allow) pair each: */ 155 size += 2 * pacl->a_count; 156 157 if (S_ISDIR(inode->i_mode)) { 158 flags = NFS4_ACL_DIR; 159 dpacl = get_acl(inode, ACL_TYPE_DEFAULT); 160 if (dpacl) 161 size += 2 * dpacl->a_count; 162 } 163 164 *acl = nfs4_acl_new(size); 165 if (*acl == NULL) { 166 error = -ENOMEM; 167 goto out; 168 } 169 170 _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT); 171 172 if (dpacl) 173 _posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT); 174 175 out: 176 posix_acl_release(pacl); 177 posix_acl_release(dpacl); 178 return error; 179 } 180 181 struct posix_acl_summary { 182 unsigned short owner; 183 unsigned short users; 184 unsigned short group; 185 unsigned short groups; 186 unsigned short other; 187 unsigned short mask; 188 }; 189 190 static void 191 summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas) 192 { 193 struct posix_acl_entry *pa, *pe; 194 195 /* 196 * Only pas.users and pas.groups need initialization; previous 197 * posix_acl_valid() calls ensure that the other fields will be 198 * initialized in the following loop. But, just to placate gcc: 199 */ 200 memset(pas, 0, sizeof(*pas)); 201 pas->mask = 07; 202 203 pe = acl->a_entries + acl->a_count; 204 205 FOREACH_ACL_ENTRY(pa, acl, pe) { 206 switch (pa->e_tag) { 207 case ACL_USER_OBJ: 208 pas->owner = pa->e_perm; 209 break; 210 case ACL_GROUP_OBJ: 211 pas->group = pa->e_perm; 212 break; 213 case ACL_USER: 214 pas->users |= pa->e_perm; 215 break; 216 case ACL_GROUP: 217 pas->groups |= pa->e_perm; 218 break; 219 case ACL_OTHER: 220 pas->other = pa->e_perm; 221 break; 222 case ACL_MASK: 223 pas->mask = pa->e_perm; 224 break; 225 } 226 } 227 /* We'll only care about effective permissions: */ 228 pas->users &= pas->mask; 229 pas->group &= pas->mask; 230 pas->groups &= pas->mask; 231 } 232 233 /* We assume the acl has been verified with posix_acl_valid. */ 234 static void 235 _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl, 236 unsigned int flags) 237 { 238 struct posix_acl_entry *pa, *group_owner_entry; 239 struct nfs4_ace *ace; 240 struct posix_acl_summary pas; 241 unsigned short deny; 242 int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ? 243 NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0); 244 245 BUG_ON(pacl->a_count < 3); 246 summarize_posix_acl(pacl, &pas); 247 248 pa = pacl->a_entries; 249 ace = acl->aces + acl->naces; 250 251 /* We could deny everything not granted by the owner: */ 252 deny = ~pas.owner; 253 /* 254 * but it is equivalent (and simpler) to deny only what is not 255 * granted by later entries: 256 */ 257 deny &= pas.users | pas.group | pas.groups | pas.other; 258 if (deny) { 259 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 260 ace->flag = eflag; 261 ace->access_mask = deny_mask_from_posix(deny, flags); 262 ace->whotype = NFS4_ACL_WHO_OWNER; 263 ace++; 264 acl->naces++; 265 } 266 267 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 268 ace->flag = eflag; 269 ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER); 270 ace->whotype = NFS4_ACL_WHO_OWNER; 271 ace++; 272 acl->naces++; 273 pa++; 274 275 while (pa->e_tag == ACL_USER) { 276 deny = ~(pa->e_perm & pas.mask); 277 deny &= pas.groups | pas.group | pas.other; 278 if (deny) { 279 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 280 ace->flag = eflag; 281 ace->access_mask = deny_mask_from_posix(deny, flags); 282 ace->whotype = NFS4_ACL_WHO_NAMED; 283 ace->who_uid = pa->e_uid; 284 ace++; 285 acl->naces++; 286 } 287 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 288 ace->flag = eflag; 289 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, 290 flags); 291 ace->whotype = NFS4_ACL_WHO_NAMED; 292 ace->who_uid = pa->e_uid; 293 ace++; 294 acl->naces++; 295 pa++; 296 } 297 298 /* In the case of groups, we apply allow ACEs first, then deny ACEs, 299 * since a user can be in more than one group. */ 300 301 /* allow ACEs */ 302 303 group_owner_entry = pa; 304 305 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 306 ace->flag = eflag; 307 ace->access_mask = mask_from_posix(pas.group, flags); 308 ace->whotype = NFS4_ACL_WHO_GROUP; 309 ace++; 310 acl->naces++; 311 pa++; 312 313 while (pa->e_tag == ACL_GROUP) { 314 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 315 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; 316 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, 317 flags); 318 ace->whotype = NFS4_ACL_WHO_NAMED; 319 ace->who_gid = pa->e_gid; 320 ace++; 321 acl->naces++; 322 pa++; 323 } 324 325 /* deny ACEs */ 326 327 pa = group_owner_entry; 328 329 deny = ~pas.group & pas.other; 330 if (deny) { 331 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 332 ace->flag = eflag; 333 ace->access_mask = deny_mask_from_posix(deny, flags); 334 ace->whotype = NFS4_ACL_WHO_GROUP; 335 ace++; 336 acl->naces++; 337 } 338 pa++; 339 340 while (pa->e_tag == ACL_GROUP) { 341 deny = ~(pa->e_perm & pas.mask); 342 deny &= pas.other; 343 if (deny) { 344 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 345 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; 346 ace->access_mask = deny_mask_from_posix(deny, flags); 347 ace->whotype = NFS4_ACL_WHO_NAMED; 348 ace->who_gid = pa->e_gid; 349 ace++; 350 acl->naces++; 351 } 352 pa++; 353 } 354 355 if (pa->e_tag == ACL_MASK) 356 pa++; 357 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 358 ace->flag = eflag; 359 ace->access_mask = mask_from_posix(pa->e_perm, flags); 360 ace->whotype = NFS4_ACL_WHO_EVERYONE; 361 acl->naces++; 362 } 363 364 static bool 365 pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2) 366 { 367 if (pace1->e_tag != pace2->e_tag) 368 return pace1->e_tag > pace2->e_tag; 369 if (pace1->e_tag == ACL_USER) 370 return uid_gt(pace1->e_uid, pace2->e_uid); 371 if (pace1->e_tag == ACL_GROUP) 372 return gid_gt(pace1->e_gid, pace2->e_gid); 373 return false; 374 } 375 376 static void 377 sort_pacl_range(struct posix_acl *pacl, int start, int end) { 378 int sorted = 0, i; 379 struct posix_acl_entry tmp; 380 381 /* We just do a bubble sort; easy to do in place, and we're not 382 * expecting acl's to be long enough to justify anything more. */ 383 while (!sorted) { 384 sorted = 1; 385 for (i = start; i < end; i++) { 386 if (pace_gt(&pacl->a_entries[i], 387 &pacl->a_entries[i+1])) { 388 sorted = 0; 389 tmp = pacl->a_entries[i]; 390 pacl->a_entries[i] = pacl->a_entries[i+1]; 391 pacl->a_entries[i+1] = tmp; 392 } 393 } 394 } 395 } 396 397 static void 398 sort_pacl(struct posix_acl *pacl) 399 { 400 /* posix_acl_valid requires that users and groups be in order 401 * by uid/gid. */ 402 int i, j; 403 404 /* no users or groups */ 405 if (!pacl || pacl->a_count <= 4) 406 return; 407 408 i = 1; 409 while (pacl->a_entries[i].e_tag == ACL_USER) 410 i++; 411 sort_pacl_range(pacl, 1, i-1); 412 413 BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ); 414 j = ++i; 415 while (pacl->a_entries[j].e_tag == ACL_GROUP) 416 j++; 417 sort_pacl_range(pacl, i, j-1); 418 return; 419 } 420 421 /* 422 * While processing the NFSv4 ACE, this maintains bitmasks representing 423 * which permission bits have been allowed and which denied to a given 424 * entity: */ 425 struct posix_ace_state { 426 u32 allow; 427 u32 deny; 428 }; 429 430 struct posix_user_ace_state { 431 union { 432 kuid_t uid; 433 kgid_t gid; 434 }; 435 struct posix_ace_state perms; 436 }; 437 438 struct posix_ace_state_array { 439 int n; 440 struct posix_user_ace_state aces[]; 441 }; 442 443 /* 444 * While processing the NFSv4 ACE, this maintains the partial permissions 445 * calculated so far: */ 446 447 struct posix_acl_state { 448 int empty; 449 struct posix_ace_state owner; 450 struct posix_ace_state group; 451 struct posix_ace_state other; 452 struct posix_ace_state everyone; 453 struct posix_ace_state mask; /* Deny unused in this case */ 454 struct posix_ace_state_array *users; 455 struct posix_ace_state_array *groups; 456 }; 457 458 static int 459 init_state(struct posix_acl_state *state, int cnt) 460 { 461 int alloc; 462 463 memset(state, 0, sizeof(struct posix_acl_state)); 464 state->empty = 1; 465 /* 466 * In the worst case, each individual acl could be for a distinct 467 * named user or group, but we don't no which, so we allocate 468 * enough space for either: 469 */ 470 alloc = sizeof(struct posix_ace_state_array) 471 + cnt*sizeof(struct posix_user_ace_state); 472 state->users = kzalloc(alloc, GFP_KERNEL); 473 if (!state->users) 474 return -ENOMEM; 475 state->groups = kzalloc(alloc, GFP_KERNEL); 476 if (!state->groups) { 477 kfree(state->users); 478 return -ENOMEM; 479 } 480 return 0; 481 } 482 483 static void 484 free_state(struct posix_acl_state *state) { 485 kfree(state->users); 486 kfree(state->groups); 487 } 488 489 static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate) 490 { 491 state->mask.allow |= astate->allow; 492 } 493 494 /* 495 * Certain bits (SYNCHRONIZE, DELETE, WRITE_OWNER, READ/WRITE_NAMED_ATTRS, 496 * READ_ATTRIBUTES, READ_ACL) are currently unenforceable and don't translate 497 * to traditional read/write/execute permissions. 498 * 499 * It's problematic to reject acls that use certain mode bits, because it 500 * places the burden on users to learn the rules about which bits one 501 * particular server sets, without giving the user a lot of help--we return an 502 * error that could mean any number of different things. To make matters 503 * worse, the problematic bits might be introduced by some application that's 504 * automatically mapping from some other acl model. 505 * 506 * So wherever possible we accept anything, possibly erring on the side of 507 * denying more permissions than necessary. 508 * 509 * However we do reject *explicit* DENY's of a few bits representing 510 * permissions we could never deny: 511 */ 512 513 static inline int check_deny(u32 mask, int isowner) 514 { 515 if (mask & (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL)) 516 return -EINVAL; 517 if (!isowner) 518 return 0; 519 if (mask & (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)) 520 return -EINVAL; 521 return 0; 522 } 523 524 static struct posix_acl * 525 posix_state_to_acl(struct posix_acl_state *state, unsigned int flags) 526 { 527 struct posix_acl_entry *pace; 528 struct posix_acl *pacl; 529 int nace; 530 int i, error = 0; 531 532 /* 533 * ACLs with no ACEs are treated differently in the inheritable 534 * and effective cases: when there are no inheritable ACEs, 535 * calls ->set_acl with a NULL ACL structure. 536 */ 537 if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT)) 538 return NULL; 539 540 /* 541 * When there are no effective ACEs, the following will end 542 * up setting a 3-element effective posix ACL with all 543 * permissions zero. 544 */ 545 if (!state->users->n && !state->groups->n) 546 nace = 3; 547 else /* Note we also include a MASK ACE in this case: */ 548 nace = 4 + state->users->n + state->groups->n; 549 pacl = posix_acl_alloc(nace, GFP_KERNEL); 550 if (!pacl) 551 return ERR_PTR(-ENOMEM); 552 553 pace = pacl->a_entries; 554 pace->e_tag = ACL_USER_OBJ; 555 error = check_deny(state->owner.deny, 1); 556 if (error) 557 goto out_err; 558 low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags); 559 560 for (i=0; i < state->users->n; i++) { 561 pace++; 562 pace->e_tag = ACL_USER; 563 error = check_deny(state->users->aces[i].perms.deny, 0); 564 if (error) 565 goto out_err; 566 low_mode_from_nfs4(state->users->aces[i].perms.allow, 567 &pace->e_perm, flags); 568 pace->e_uid = state->users->aces[i].uid; 569 add_to_mask(state, &state->users->aces[i].perms); 570 } 571 572 pace++; 573 pace->e_tag = ACL_GROUP_OBJ; 574 error = check_deny(state->group.deny, 0); 575 if (error) 576 goto out_err; 577 low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags); 578 add_to_mask(state, &state->group); 579 580 for (i=0; i < state->groups->n; i++) { 581 pace++; 582 pace->e_tag = ACL_GROUP; 583 error = check_deny(state->groups->aces[i].perms.deny, 0); 584 if (error) 585 goto out_err; 586 low_mode_from_nfs4(state->groups->aces[i].perms.allow, 587 &pace->e_perm, flags); 588 pace->e_gid = state->groups->aces[i].gid; 589 add_to_mask(state, &state->groups->aces[i].perms); 590 } 591 592 if (state->users->n || state->groups->n) { 593 pace++; 594 pace->e_tag = ACL_MASK; 595 low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags); 596 } 597 598 pace++; 599 pace->e_tag = ACL_OTHER; 600 error = check_deny(state->other.deny, 0); 601 if (error) 602 goto out_err; 603 low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags); 604 605 return pacl; 606 out_err: 607 posix_acl_release(pacl); 608 return ERR_PTR(error); 609 } 610 611 static inline void allow_bits(struct posix_ace_state *astate, u32 mask) 612 { 613 /* Allow all bits in the mask not already denied: */ 614 astate->allow |= mask & ~astate->deny; 615 } 616 617 static inline void deny_bits(struct posix_ace_state *astate, u32 mask) 618 { 619 /* Deny all bits in the mask not already allowed: */ 620 astate->deny |= mask & ~astate->allow; 621 } 622 623 static int find_uid(struct posix_acl_state *state, kuid_t uid) 624 { 625 struct posix_ace_state_array *a = state->users; 626 int i; 627 628 for (i = 0; i < a->n; i++) 629 if (uid_eq(a->aces[i].uid, uid)) 630 return i; 631 /* Not found: */ 632 a->n++; 633 a->aces[i].uid = uid; 634 a->aces[i].perms.allow = state->everyone.allow; 635 a->aces[i].perms.deny = state->everyone.deny; 636 637 return i; 638 } 639 640 static int find_gid(struct posix_acl_state *state, kgid_t gid) 641 { 642 struct posix_ace_state_array *a = state->groups; 643 int i; 644 645 for (i = 0; i < a->n; i++) 646 if (gid_eq(a->aces[i].gid, gid)) 647 return i; 648 /* Not found: */ 649 a->n++; 650 a->aces[i].gid = gid; 651 a->aces[i].perms.allow = state->everyone.allow; 652 a->aces[i].perms.deny = state->everyone.deny; 653 654 return i; 655 } 656 657 static void deny_bits_array(struct posix_ace_state_array *a, u32 mask) 658 { 659 int i; 660 661 for (i=0; i < a->n; i++) 662 deny_bits(&a->aces[i].perms, mask); 663 } 664 665 static void allow_bits_array(struct posix_ace_state_array *a, u32 mask) 666 { 667 int i; 668 669 for (i=0; i < a->n; i++) 670 allow_bits(&a->aces[i].perms, mask); 671 } 672 673 static void process_one_v4_ace(struct posix_acl_state *state, 674 struct nfs4_ace *ace) 675 { 676 u32 mask = ace->access_mask; 677 int i; 678 679 state->empty = 0; 680 681 switch (ace2type(ace)) { 682 case ACL_USER_OBJ: 683 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 684 allow_bits(&state->owner, mask); 685 } else { 686 deny_bits(&state->owner, mask); 687 } 688 break; 689 case ACL_USER: 690 i = find_uid(state, ace->who_uid); 691 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 692 allow_bits(&state->users->aces[i].perms, mask); 693 } else { 694 deny_bits(&state->users->aces[i].perms, mask); 695 mask = state->users->aces[i].perms.deny; 696 deny_bits(&state->owner, mask); 697 } 698 break; 699 case ACL_GROUP_OBJ: 700 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 701 allow_bits(&state->group, mask); 702 } else { 703 deny_bits(&state->group, mask); 704 mask = state->group.deny; 705 deny_bits(&state->owner, mask); 706 deny_bits(&state->everyone, mask); 707 deny_bits_array(state->users, mask); 708 deny_bits_array(state->groups, mask); 709 } 710 break; 711 case ACL_GROUP: 712 i = find_gid(state, ace->who_gid); 713 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 714 allow_bits(&state->groups->aces[i].perms, mask); 715 } else { 716 deny_bits(&state->groups->aces[i].perms, mask); 717 mask = state->groups->aces[i].perms.deny; 718 deny_bits(&state->owner, mask); 719 deny_bits(&state->group, mask); 720 deny_bits(&state->everyone, mask); 721 deny_bits_array(state->users, mask); 722 deny_bits_array(state->groups, mask); 723 } 724 break; 725 case ACL_OTHER: 726 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 727 allow_bits(&state->owner, mask); 728 allow_bits(&state->group, mask); 729 allow_bits(&state->other, mask); 730 allow_bits(&state->everyone, mask); 731 allow_bits_array(state->users, mask); 732 allow_bits_array(state->groups, mask); 733 } else { 734 deny_bits(&state->owner, mask); 735 deny_bits(&state->group, mask); 736 deny_bits(&state->other, mask); 737 deny_bits(&state->everyone, mask); 738 deny_bits_array(state->users, mask); 739 deny_bits_array(state->groups, mask); 740 } 741 } 742 } 743 744 static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, 745 struct posix_acl **pacl, struct posix_acl **dpacl, 746 unsigned int flags) 747 { 748 struct posix_acl_state effective_acl_state, default_acl_state; 749 struct nfs4_ace *ace; 750 int ret; 751 752 ret = init_state(&effective_acl_state, acl->naces); 753 if (ret) 754 return ret; 755 ret = init_state(&default_acl_state, acl->naces); 756 if (ret) 757 goto out_estate; 758 ret = -EINVAL; 759 for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) { 760 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE && 761 ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE) 762 goto out_dstate; 763 if (ace->flag & ~NFS4_SUPPORTED_FLAGS) 764 goto out_dstate; 765 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) { 766 process_one_v4_ace(&effective_acl_state, ace); 767 continue; 768 } 769 if (!(flags & NFS4_ACL_DIR)) 770 goto out_dstate; 771 /* 772 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT 773 * is set, we're effectively turning on the other. That's OK, 774 * according to rfc 3530. 775 */ 776 process_one_v4_ace(&default_acl_state, ace); 777 778 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE)) 779 process_one_v4_ace(&effective_acl_state, ace); 780 } 781 *pacl = posix_state_to_acl(&effective_acl_state, flags); 782 if (IS_ERR(*pacl)) { 783 ret = PTR_ERR(*pacl); 784 *pacl = NULL; 785 goto out_dstate; 786 } 787 *dpacl = posix_state_to_acl(&default_acl_state, 788 flags | NFS4_ACL_TYPE_DEFAULT); 789 if (IS_ERR(*dpacl)) { 790 ret = PTR_ERR(*dpacl); 791 *dpacl = NULL; 792 posix_acl_release(*pacl); 793 *pacl = NULL; 794 goto out_dstate; 795 } 796 sort_pacl(*pacl); 797 sort_pacl(*dpacl); 798 ret = 0; 799 out_dstate: 800 free_state(&default_acl_state); 801 out_estate: 802 free_state(&effective_acl_state); 803 return ret; 804 } 805 806 __be32 807 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, 808 struct nfs4_acl *acl) 809 { 810 __be32 error; 811 int host_error; 812 struct dentry *dentry; 813 struct inode *inode; 814 struct posix_acl *pacl = NULL, *dpacl = NULL; 815 unsigned int flags = 0; 816 817 /* Get inode */ 818 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_SATTR); 819 if (error) 820 return error; 821 822 dentry = fhp->fh_dentry; 823 inode = dentry->d_inode; 824 825 if (!inode->i_op->set_acl || !IS_POSIXACL(inode)) 826 return nfserr_attrnotsupp; 827 828 if (S_ISDIR(inode->i_mode)) 829 flags = NFS4_ACL_DIR; 830 831 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); 832 if (host_error == -EINVAL) 833 return nfserr_attrnotsupp; 834 if (host_error < 0) 835 goto out_nfserr; 836 837 host_error = inode->i_op->set_acl(inode, pacl, ACL_TYPE_ACCESS); 838 if (host_error < 0) 839 goto out_release; 840 841 if (S_ISDIR(inode->i_mode)) { 842 host_error = inode->i_op->set_acl(inode, dpacl, 843 ACL_TYPE_DEFAULT); 844 } 845 846 out_release: 847 posix_acl_release(pacl); 848 posix_acl_release(dpacl); 849 out_nfserr: 850 if (host_error == -EOPNOTSUPP) 851 return nfserr_attrnotsupp; 852 else 853 return nfserrno(host_error); 854 } 855 856 857 static short 858 ace2type(struct nfs4_ace *ace) 859 { 860 switch (ace->whotype) { 861 case NFS4_ACL_WHO_NAMED: 862 return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ? 863 ACL_GROUP : ACL_USER); 864 case NFS4_ACL_WHO_OWNER: 865 return ACL_USER_OBJ; 866 case NFS4_ACL_WHO_GROUP: 867 return ACL_GROUP_OBJ; 868 case NFS4_ACL_WHO_EVERYONE: 869 return ACL_OTHER; 870 } 871 BUG(); 872 return -1; 873 } 874 875 struct nfs4_acl * 876 nfs4_acl_new(int n) 877 { 878 struct nfs4_acl *acl; 879 880 acl = kmalloc(sizeof(*acl) + n*sizeof(struct nfs4_ace), GFP_KERNEL); 881 if (acl == NULL) 882 return NULL; 883 acl->naces = 0; 884 return acl; 885 } 886 887 static struct { 888 char *string; 889 int stringlen; 890 int type; 891 } s2t_map[] = { 892 { 893 .string = "OWNER@", 894 .stringlen = sizeof("OWNER@") - 1, 895 .type = NFS4_ACL_WHO_OWNER, 896 }, 897 { 898 .string = "GROUP@", 899 .stringlen = sizeof("GROUP@") - 1, 900 .type = NFS4_ACL_WHO_GROUP, 901 }, 902 { 903 .string = "EVERYONE@", 904 .stringlen = sizeof("EVERYONE@") - 1, 905 .type = NFS4_ACL_WHO_EVERYONE, 906 }, 907 }; 908 909 int 910 nfs4_acl_get_whotype(char *p, u32 len) 911 { 912 int i; 913 914 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 915 if (s2t_map[i].stringlen == len && 916 0 == memcmp(s2t_map[i].string, p, len)) 917 return s2t_map[i].type; 918 } 919 return NFS4_ACL_WHO_NAMED; 920 } 921 922 __be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who) 923 { 924 __be32 *p; 925 int i; 926 927 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 928 if (s2t_map[i].type != who) 929 continue; 930 p = xdr_reserve_space(xdr, s2t_map[i].stringlen + 4); 931 if (!p) 932 return nfserr_resource; 933 p = xdr_encode_opaque(p, s2t_map[i].string, 934 s2t_map[i].stringlen); 935 return 0; 936 } 937 WARN_ON_ONCE(1); 938 return -1; 939 } 940