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