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 } 155 /* allocate for worst case: one (deny, allow) pair each: */ 156 size += 2 * pacl->a_count; 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 } 164 165 *acl = nfs4_acl_new(size); 166 if (*acl == NULL) { 167 error = -ENOMEM; 168 goto out; 169 } 170 171 _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT); 172 173 if (dpacl) 174 _posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT); 175 176 out: 177 posix_acl_release(pacl); 178 posix_acl_release(dpacl); 179 return error; 180 } 181 182 struct posix_acl_summary { 183 unsigned short owner; 184 unsigned short users; 185 unsigned short group; 186 unsigned short groups; 187 unsigned short other; 188 unsigned short mask; 189 }; 190 191 static void 192 summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas) 193 { 194 struct posix_acl_entry *pa, *pe; 195 196 /* 197 * Only pas.users and pas.groups need initialization; previous 198 * posix_acl_valid() calls ensure that the other fields will be 199 * initialized in the following loop. But, just to placate gcc: 200 */ 201 memset(pas, 0, sizeof(*pas)); 202 pas->mask = 07; 203 204 pe = acl->a_entries + acl->a_count; 205 206 FOREACH_ACL_ENTRY(pa, acl, pe) { 207 switch (pa->e_tag) { 208 case ACL_USER_OBJ: 209 pas->owner = pa->e_perm; 210 break; 211 case ACL_GROUP_OBJ: 212 pas->group = pa->e_perm; 213 break; 214 case ACL_USER: 215 pas->users |= pa->e_perm; 216 break; 217 case ACL_GROUP: 218 pas->groups |= pa->e_perm; 219 break; 220 case ACL_OTHER: 221 pas->other = pa->e_perm; 222 break; 223 case ACL_MASK: 224 pas->mask = pa->e_perm; 225 break; 226 } 227 } 228 /* We'll only care about effective permissions: */ 229 pas->users &= pas->mask; 230 pas->group &= pas->mask; 231 pas->groups &= pas->mask; 232 } 233 234 /* We assume the acl has been verified with posix_acl_valid. */ 235 static void 236 _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl, 237 unsigned int flags) 238 { 239 struct posix_acl_entry *pa, *group_owner_entry; 240 struct nfs4_ace *ace; 241 struct posix_acl_summary pas; 242 unsigned short deny; 243 int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ? 244 NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0); 245 246 BUG_ON(pacl->a_count < 3); 247 summarize_posix_acl(pacl, &pas); 248 249 pa = pacl->a_entries; 250 ace = acl->aces + acl->naces; 251 252 /* We could deny everything not granted by the owner: */ 253 deny = ~pas.owner; 254 /* 255 * but it is equivalent (and simpler) to deny only what is not 256 * granted by later entries: 257 */ 258 deny &= pas.users | pas.group | pas.groups | pas.other; 259 if (deny) { 260 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 261 ace->flag = eflag; 262 ace->access_mask = deny_mask_from_posix(deny, flags); 263 ace->whotype = NFS4_ACL_WHO_OWNER; 264 ace++; 265 acl->naces++; 266 } 267 268 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 269 ace->flag = eflag; 270 ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER); 271 ace->whotype = NFS4_ACL_WHO_OWNER; 272 ace++; 273 acl->naces++; 274 pa++; 275 276 while (pa->e_tag == ACL_USER) { 277 deny = ~(pa->e_perm & pas.mask); 278 deny &= pas.groups | pas.group | pas.other; 279 if (deny) { 280 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 281 ace->flag = eflag; 282 ace->access_mask = deny_mask_from_posix(deny, flags); 283 ace->whotype = NFS4_ACL_WHO_NAMED; 284 ace->who_uid = pa->e_uid; 285 ace++; 286 acl->naces++; 287 } 288 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 289 ace->flag = eflag; 290 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, 291 flags); 292 ace->whotype = NFS4_ACL_WHO_NAMED; 293 ace->who_uid = pa->e_uid; 294 ace++; 295 acl->naces++; 296 pa++; 297 } 298 299 /* In the case of groups, we apply allow ACEs first, then deny ACEs, 300 * since a user can be in more than one group. */ 301 302 /* allow ACEs */ 303 304 group_owner_entry = pa; 305 306 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 307 ace->flag = eflag; 308 ace->access_mask = mask_from_posix(pas.group, flags); 309 ace->whotype = NFS4_ACL_WHO_GROUP; 310 ace++; 311 acl->naces++; 312 pa++; 313 314 while (pa->e_tag == ACL_GROUP) { 315 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 316 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; 317 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, 318 flags); 319 ace->whotype = NFS4_ACL_WHO_NAMED; 320 ace->who_gid = pa->e_gid; 321 ace++; 322 acl->naces++; 323 pa++; 324 } 325 326 /* deny ACEs */ 327 328 pa = group_owner_entry; 329 330 deny = ~pas.group & pas.other; 331 if (deny) { 332 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 333 ace->flag = eflag; 334 ace->access_mask = deny_mask_from_posix(deny, flags); 335 ace->whotype = NFS4_ACL_WHO_GROUP; 336 ace++; 337 acl->naces++; 338 } 339 pa++; 340 341 while (pa->e_tag == ACL_GROUP) { 342 deny = ~(pa->e_perm & pas.mask); 343 deny &= pas.other; 344 if (deny) { 345 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 346 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; 347 ace->access_mask = deny_mask_from_posix(deny, flags); 348 ace->whotype = NFS4_ACL_WHO_NAMED; 349 ace->who_gid = pa->e_gid; 350 ace++; 351 acl->naces++; 352 } 353 pa++; 354 } 355 356 if (pa->e_tag == ACL_MASK) 357 pa++; 358 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 359 ace->flag = eflag; 360 ace->access_mask = mask_from_posix(pa->e_perm, flags); 361 ace->whotype = NFS4_ACL_WHO_EVERYONE; 362 acl->naces++; 363 } 364 365 static bool 366 pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2) 367 { 368 if (pace1->e_tag != pace2->e_tag) 369 return pace1->e_tag > pace2->e_tag; 370 if (pace1->e_tag == ACL_USER) 371 return uid_gt(pace1->e_uid, pace2->e_uid); 372 if (pace1->e_tag == ACL_GROUP) 373 return gid_gt(pace1->e_gid, pace2->e_gid); 374 return false; 375 } 376 377 static void 378 sort_pacl_range(struct posix_acl *pacl, int start, int end) { 379 int sorted = 0, i; 380 struct posix_acl_entry tmp; 381 382 /* We just do a bubble sort; easy to do in place, and we're not 383 * expecting acl's to be long enough to justify anything more. */ 384 while (!sorted) { 385 sorted = 1; 386 for (i = start; i < end; i++) { 387 if (pace_gt(&pacl->a_entries[i], 388 &pacl->a_entries[i+1])) { 389 sorted = 0; 390 tmp = pacl->a_entries[i]; 391 pacl->a_entries[i] = pacl->a_entries[i+1]; 392 pacl->a_entries[i+1] = tmp; 393 } 394 } 395 } 396 } 397 398 static void 399 sort_pacl(struct posix_acl *pacl) 400 { 401 /* posix_acl_valid requires that users and groups be in order 402 * by uid/gid. */ 403 int i, j; 404 405 /* no users or groups */ 406 if (!pacl || pacl->a_count <= 4) 407 return; 408 409 i = 1; 410 while (pacl->a_entries[i].e_tag == ACL_USER) 411 i++; 412 sort_pacl_range(pacl, 1, i-1); 413 414 BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ); 415 j = ++i; 416 while (pacl->a_entries[j].e_tag == ACL_GROUP) 417 j++; 418 sort_pacl_range(pacl, i, j-1); 419 return; 420 } 421 422 /* 423 * While processing the NFSv4 ACE, this maintains bitmasks representing 424 * which permission bits have been allowed and which denied to a given 425 * entity: */ 426 struct posix_ace_state { 427 u32 allow; 428 u32 deny; 429 }; 430 431 struct posix_user_ace_state { 432 union { 433 kuid_t uid; 434 kgid_t gid; 435 }; 436 struct posix_ace_state perms; 437 }; 438 439 struct posix_ace_state_array { 440 int n; 441 struct posix_user_ace_state aces[]; 442 }; 443 444 /* 445 * While processing the NFSv4 ACE, this maintains the partial permissions 446 * calculated so far: */ 447 448 struct posix_acl_state { 449 int empty; 450 struct posix_ace_state owner; 451 struct posix_ace_state group; 452 struct posix_ace_state other; 453 struct posix_ace_state everyone; 454 struct posix_ace_state mask; /* Deny unused in this case */ 455 struct posix_ace_state_array *users; 456 struct posix_ace_state_array *groups; 457 }; 458 459 static int 460 init_state(struct posix_acl_state *state, int cnt) 461 { 462 int alloc; 463 464 memset(state, 0, sizeof(struct posix_acl_state)); 465 state->empty = 1; 466 /* 467 * In the worst case, each individual acl could be for a distinct 468 * named user or group, but we don't no which, so we allocate 469 * enough space for either: 470 */ 471 alloc = sizeof(struct posix_ace_state_array) 472 + cnt*sizeof(struct posix_user_ace_state); 473 state->users = kzalloc(alloc, GFP_KERNEL); 474 if (!state->users) 475 return -ENOMEM; 476 state->groups = kzalloc(alloc, GFP_KERNEL); 477 if (!state->groups) { 478 kfree(state->users); 479 return -ENOMEM; 480 } 481 return 0; 482 } 483 484 static void 485 free_state(struct posix_acl_state *state) { 486 kfree(state->users); 487 kfree(state->groups); 488 } 489 490 static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate) 491 { 492 state->mask.allow |= astate->allow; 493 } 494 495 /* 496 * Certain bits (SYNCHRONIZE, DELETE, WRITE_OWNER, READ/WRITE_NAMED_ATTRS, 497 * READ_ATTRIBUTES, READ_ACL) are currently unenforceable and don't translate 498 * to traditional read/write/execute permissions. 499 * 500 * It's problematic to reject acls that use certain mode bits, because it 501 * places the burden on users to learn the rules about which bits one 502 * particular server sets, without giving the user a lot of help--we return an 503 * error that could mean any number of different things. To make matters 504 * worse, the problematic bits might be introduced by some application that's 505 * automatically mapping from some other acl model. 506 * 507 * So wherever possible we accept anything, possibly erring on the side of 508 * denying more permissions than necessary. 509 * 510 * However we do reject *explicit* DENY's of a few bits representing 511 * permissions we could never deny: 512 */ 513 514 static inline int check_deny(u32 mask, int isowner) 515 { 516 if (mask & (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL)) 517 return -EINVAL; 518 if (!isowner) 519 return 0; 520 if (mask & (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)) 521 return -EINVAL; 522 return 0; 523 } 524 525 static struct posix_acl * 526 posix_state_to_acl(struct posix_acl_state *state, unsigned int flags) 527 { 528 struct posix_acl_entry *pace; 529 struct posix_acl *pacl; 530 int nace; 531 int i, error = 0; 532 533 /* 534 * ACLs with no ACEs are treated differently in the inheritable 535 * and effective cases: when there are no inheritable ACEs, 536 * calls ->set_acl with a NULL ACL structure. 537 */ 538 if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT)) 539 return NULL; 540 541 /* 542 * When there are no effective ACEs, the following will end 543 * up setting a 3-element effective posix ACL with all 544 * permissions zero. 545 */ 546 if (!state->users->n && !state->groups->n) 547 nace = 3; 548 else /* Note we also include a MASK ACE in this case: */ 549 nace = 4 + state->users->n + state->groups->n; 550 pacl = posix_acl_alloc(nace, GFP_KERNEL); 551 if (!pacl) 552 return ERR_PTR(-ENOMEM); 553 554 pace = pacl->a_entries; 555 pace->e_tag = ACL_USER_OBJ; 556 error = check_deny(state->owner.deny, 1); 557 if (error) 558 goto out_err; 559 low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags); 560 561 for (i=0; i < state->users->n; i++) { 562 pace++; 563 pace->e_tag = ACL_USER; 564 error = check_deny(state->users->aces[i].perms.deny, 0); 565 if (error) 566 goto out_err; 567 low_mode_from_nfs4(state->users->aces[i].perms.allow, 568 &pace->e_perm, flags); 569 pace->e_uid = state->users->aces[i].uid; 570 add_to_mask(state, &state->users->aces[i].perms); 571 } 572 573 pace++; 574 pace->e_tag = ACL_GROUP_OBJ; 575 error = check_deny(state->group.deny, 0); 576 if (error) 577 goto out_err; 578 low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags); 579 add_to_mask(state, &state->group); 580 581 for (i=0; i < state->groups->n; i++) { 582 pace++; 583 pace->e_tag = ACL_GROUP; 584 error = check_deny(state->groups->aces[i].perms.deny, 0); 585 if (error) 586 goto out_err; 587 low_mode_from_nfs4(state->groups->aces[i].perms.allow, 588 &pace->e_perm, flags); 589 pace->e_gid = state->groups->aces[i].gid; 590 add_to_mask(state, &state->groups->aces[i].perms); 591 } 592 593 if (state->users->n || state->groups->n) { 594 pace++; 595 pace->e_tag = ACL_MASK; 596 low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags); 597 } 598 599 pace++; 600 pace->e_tag = ACL_OTHER; 601 error = check_deny(state->other.deny, 0); 602 if (error) 603 goto out_err; 604 low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags); 605 606 return pacl; 607 out_err: 608 posix_acl_release(pacl); 609 return ERR_PTR(error); 610 } 611 612 static inline void allow_bits(struct posix_ace_state *astate, u32 mask) 613 { 614 /* Allow all bits in the mask not already denied: */ 615 astate->allow |= mask & ~astate->deny; 616 } 617 618 static inline void deny_bits(struct posix_ace_state *astate, u32 mask) 619 { 620 /* Deny all bits in the mask not already allowed: */ 621 astate->deny |= mask & ~astate->allow; 622 } 623 624 static int find_uid(struct posix_acl_state *state, kuid_t uid) 625 { 626 struct posix_ace_state_array *a = state->users; 627 int i; 628 629 for (i = 0; i < a->n; i++) 630 if (uid_eq(a->aces[i].uid, uid)) 631 return i; 632 /* Not found: */ 633 a->n++; 634 a->aces[i].uid = uid; 635 a->aces[i].perms.allow = state->everyone.allow; 636 a->aces[i].perms.deny = state->everyone.deny; 637 638 return i; 639 } 640 641 static int find_gid(struct posix_acl_state *state, kgid_t gid) 642 { 643 struct posix_ace_state_array *a = state->groups; 644 int i; 645 646 for (i = 0; i < a->n; i++) 647 if (gid_eq(a->aces[i].gid, gid)) 648 return i; 649 /* Not found: */ 650 a->n++; 651 a->aces[i].gid = gid; 652 a->aces[i].perms.allow = state->everyone.allow; 653 a->aces[i].perms.deny = state->everyone.deny; 654 655 return i; 656 } 657 658 static void deny_bits_array(struct posix_ace_state_array *a, u32 mask) 659 { 660 int i; 661 662 for (i=0; i < a->n; i++) 663 deny_bits(&a->aces[i].perms, mask); 664 } 665 666 static void allow_bits_array(struct posix_ace_state_array *a, u32 mask) 667 { 668 int i; 669 670 for (i=0; i < a->n; i++) 671 allow_bits(&a->aces[i].perms, mask); 672 } 673 674 static void process_one_v4_ace(struct posix_acl_state *state, 675 struct nfs4_ace *ace) 676 { 677 u32 mask = ace->access_mask; 678 int i; 679 680 state->empty = 0; 681 682 switch (ace2type(ace)) { 683 case ACL_USER_OBJ: 684 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 685 allow_bits(&state->owner, mask); 686 } else { 687 deny_bits(&state->owner, mask); 688 } 689 break; 690 case ACL_USER: 691 i = find_uid(state, ace->who_uid); 692 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 693 allow_bits(&state->users->aces[i].perms, mask); 694 } else { 695 deny_bits(&state->users->aces[i].perms, mask); 696 mask = state->users->aces[i].perms.deny; 697 deny_bits(&state->owner, mask); 698 } 699 break; 700 case ACL_GROUP_OBJ: 701 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 702 allow_bits(&state->group, mask); 703 } else { 704 deny_bits(&state->group, mask); 705 mask = state->group.deny; 706 deny_bits(&state->owner, mask); 707 deny_bits(&state->everyone, mask); 708 deny_bits_array(state->users, mask); 709 deny_bits_array(state->groups, mask); 710 } 711 break; 712 case ACL_GROUP: 713 i = find_gid(state, ace->who_gid); 714 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 715 allow_bits(&state->groups->aces[i].perms, mask); 716 } else { 717 deny_bits(&state->groups->aces[i].perms, mask); 718 mask = state->groups->aces[i].perms.deny; 719 deny_bits(&state->owner, mask); 720 deny_bits(&state->group, mask); 721 deny_bits(&state->everyone, mask); 722 deny_bits_array(state->users, mask); 723 deny_bits_array(state->groups, mask); 724 } 725 break; 726 case ACL_OTHER: 727 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 728 allow_bits(&state->owner, mask); 729 allow_bits(&state->group, mask); 730 allow_bits(&state->other, mask); 731 allow_bits(&state->everyone, mask); 732 allow_bits_array(state->users, mask); 733 allow_bits_array(state->groups, mask); 734 } else { 735 deny_bits(&state->owner, mask); 736 deny_bits(&state->group, mask); 737 deny_bits(&state->other, mask); 738 deny_bits(&state->everyone, mask); 739 deny_bits_array(state->users, mask); 740 deny_bits_array(state->groups, mask); 741 } 742 } 743 } 744 745 static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, 746 struct posix_acl **pacl, struct posix_acl **dpacl, 747 unsigned int flags) 748 { 749 struct posix_acl_state effective_acl_state, default_acl_state; 750 struct nfs4_ace *ace; 751 int ret; 752 753 ret = init_state(&effective_acl_state, acl->naces); 754 if (ret) 755 return ret; 756 ret = init_state(&default_acl_state, acl->naces); 757 if (ret) 758 goto out_estate; 759 ret = -EINVAL; 760 for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) { 761 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE && 762 ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE) 763 goto out_dstate; 764 if (ace->flag & ~NFS4_SUPPORTED_FLAGS) 765 goto out_dstate; 766 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) { 767 process_one_v4_ace(&effective_acl_state, ace); 768 continue; 769 } 770 if (!(flags & NFS4_ACL_DIR)) 771 goto out_dstate; 772 /* 773 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT 774 * is set, we're effectively turning on the other. That's OK, 775 * according to rfc 3530. 776 */ 777 process_one_v4_ace(&default_acl_state, ace); 778 779 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE)) 780 process_one_v4_ace(&effective_acl_state, ace); 781 } 782 *pacl = posix_state_to_acl(&effective_acl_state, flags); 783 if (IS_ERR(*pacl)) { 784 ret = PTR_ERR(*pacl); 785 *pacl = NULL; 786 goto out_dstate; 787 } 788 *dpacl = posix_state_to_acl(&default_acl_state, 789 flags | NFS4_ACL_TYPE_DEFAULT); 790 if (IS_ERR(*dpacl)) { 791 ret = PTR_ERR(*dpacl); 792 *dpacl = NULL; 793 posix_acl_release(*pacl); 794 *pacl = NULL; 795 goto out_dstate; 796 } 797 sort_pacl(*pacl); 798 sort_pacl(*dpacl); 799 ret = 0; 800 out_dstate: 801 free_state(&default_acl_state); 802 out_estate: 803 free_state(&effective_acl_state); 804 return ret; 805 } 806 807 __be32 808 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, 809 struct nfs4_acl *acl) 810 { 811 __be32 error; 812 int host_error; 813 struct dentry *dentry; 814 struct inode *inode; 815 struct posix_acl *pacl = NULL, *dpacl = NULL; 816 unsigned int flags = 0; 817 818 /* Get inode */ 819 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_SATTR); 820 if (error) 821 return error; 822 823 dentry = fhp->fh_dentry; 824 inode = dentry->d_inode; 825 826 if (!inode->i_op->set_acl || !IS_POSIXACL(inode)) 827 return nfserr_attrnotsupp; 828 829 if (S_ISDIR(inode->i_mode)) 830 flags = NFS4_ACL_DIR; 831 832 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); 833 if (host_error == -EINVAL) 834 return nfserr_attrnotsupp; 835 if (host_error < 0) 836 goto out_nfserr; 837 838 host_error = inode->i_op->set_acl(inode, pacl, ACL_TYPE_ACCESS); 839 if (host_error < 0) 840 goto out_release; 841 842 if (S_ISDIR(inode->i_mode)) { 843 host_error = inode->i_op->set_acl(inode, dpacl, 844 ACL_TYPE_DEFAULT); 845 } 846 847 out_release: 848 posix_acl_release(pacl); 849 posix_acl_release(dpacl); 850 out_nfserr: 851 if (host_error == -EOPNOTSUPP) 852 return nfserr_attrnotsupp; 853 else 854 return nfserrno(host_error); 855 } 856 857 858 static short 859 ace2type(struct nfs4_ace *ace) 860 { 861 switch (ace->whotype) { 862 case NFS4_ACL_WHO_NAMED: 863 return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ? 864 ACL_GROUP : ACL_USER); 865 case NFS4_ACL_WHO_OWNER: 866 return ACL_USER_OBJ; 867 case NFS4_ACL_WHO_GROUP: 868 return ACL_GROUP_OBJ; 869 case NFS4_ACL_WHO_EVERYONE: 870 return ACL_OTHER; 871 } 872 BUG(); 873 return -1; 874 } 875 876 struct nfs4_acl * 877 nfs4_acl_new(int n) 878 { 879 struct nfs4_acl *acl; 880 881 acl = kmalloc(sizeof(*acl) + n*sizeof(struct nfs4_ace), GFP_KERNEL); 882 if (acl == NULL) 883 return NULL; 884 acl->naces = 0; 885 return acl; 886 } 887 888 static struct { 889 char *string; 890 int stringlen; 891 int type; 892 } s2t_map[] = { 893 { 894 .string = "OWNER@", 895 .stringlen = sizeof("OWNER@") - 1, 896 .type = NFS4_ACL_WHO_OWNER, 897 }, 898 { 899 .string = "GROUP@", 900 .stringlen = sizeof("GROUP@") - 1, 901 .type = NFS4_ACL_WHO_GROUP, 902 }, 903 { 904 .string = "EVERYONE@", 905 .stringlen = sizeof("EVERYONE@") - 1, 906 .type = NFS4_ACL_WHO_EVERYONE, 907 }, 908 }; 909 910 int 911 nfs4_acl_get_whotype(char *p, u32 len) 912 { 913 int i; 914 915 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 916 if (s2t_map[i].stringlen == len && 917 0 == memcmp(s2t_map[i].string, p, len)) 918 return s2t_map[i].type; 919 } 920 return NFS4_ACL_WHO_NAMED; 921 } 922 923 __be32 nfs4_acl_write_who(int who, __be32 **p, int *len) 924 { 925 int i; 926 int bytes; 927 928 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 929 if (s2t_map[i].type != who) 930 continue; 931 bytes = 4 + (XDR_QUADLEN(s2t_map[i].stringlen) << 2); 932 if (bytes > *len) 933 return nfserr_resource; 934 *p = xdr_encode_opaque(*p, s2t_map[i].string, 935 s2t_map[i].stringlen); 936 *len -= bytes; 937 return 0; 938 } 939 WARN_ON_ONCE(1); 940 return -1; 941 } 942