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); 151 152 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 (IS_ERR(dpacl)) { 162 error = PTR_ERR(dpacl); 163 goto rel_pacl; 164 } 165 166 if (dpacl) 167 size += 2 * dpacl->a_count; 168 } 169 170 *acl = kmalloc(nfs4_acl_bytes(size), GFP_KERNEL); 171 if (*acl == NULL) { 172 error = -ENOMEM; 173 goto out; 174 } 175 (*acl)->naces = 0; 176 177 _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT); 178 179 if (dpacl) 180 _posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT); 181 182 out: 183 posix_acl_release(dpacl); 184 rel_pacl: 185 posix_acl_release(pacl); 186 return error; 187 } 188 189 struct posix_acl_summary { 190 unsigned short owner; 191 unsigned short users; 192 unsigned short group; 193 unsigned short groups; 194 unsigned short other; 195 unsigned short mask; 196 }; 197 198 static void 199 summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas) 200 { 201 struct posix_acl_entry *pa, *pe; 202 203 /* 204 * Only pas.users and pas.groups need initialization; previous 205 * posix_acl_valid() calls ensure that the other fields will be 206 * initialized in the following loop. But, just to placate gcc: 207 */ 208 memset(pas, 0, sizeof(*pas)); 209 pas->mask = 07; 210 211 pe = acl->a_entries + acl->a_count; 212 213 FOREACH_ACL_ENTRY(pa, acl, pe) { 214 switch (pa->e_tag) { 215 case ACL_USER_OBJ: 216 pas->owner = pa->e_perm; 217 break; 218 case ACL_GROUP_OBJ: 219 pas->group = pa->e_perm; 220 break; 221 case ACL_USER: 222 pas->users |= pa->e_perm; 223 break; 224 case ACL_GROUP: 225 pas->groups |= pa->e_perm; 226 break; 227 case ACL_OTHER: 228 pas->other = pa->e_perm; 229 break; 230 case ACL_MASK: 231 pas->mask = pa->e_perm; 232 break; 233 } 234 } 235 /* We'll only care about effective permissions: */ 236 pas->users &= pas->mask; 237 pas->group &= pas->mask; 238 pas->groups &= pas->mask; 239 } 240 241 /* We assume the acl has been verified with posix_acl_valid. */ 242 static void 243 _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl, 244 unsigned int flags) 245 { 246 struct posix_acl_entry *pa, *group_owner_entry; 247 struct nfs4_ace *ace; 248 struct posix_acl_summary pas; 249 unsigned short deny; 250 int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ? 251 NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0); 252 253 BUG_ON(pacl->a_count < 3); 254 summarize_posix_acl(pacl, &pas); 255 256 pa = pacl->a_entries; 257 ace = acl->aces + acl->naces; 258 259 /* We could deny everything not granted by the owner: */ 260 deny = ~pas.owner; 261 /* 262 * but it is equivalent (and simpler) to deny only what is not 263 * granted by later entries: 264 */ 265 deny &= pas.users | pas.group | pas.groups | pas.other; 266 if (deny) { 267 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 268 ace->flag = eflag; 269 ace->access_mask = deny_mask_from_posix(deny, flags); 270 ace->whotype = NFS4_ACL_WHO_OWNER; 271 ace++; 272 acl->naces++; 273 } 274 275 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 276 ace->flag = eflag; 277 ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER); 278 ace->whotype = NFS4_ACL_WHO_OWNER; 279 ace++; 280 acl->naces++; 281 pa++; 282 283 while (pa->e_tag == ACL_USER) { 284 deny = ~(pa->e_perm & pas.mask); 285 deny &= pas.groups | pas.group | pas.other; 286 if (deny) { 287 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 288 ace->flag = eflag; 289 ace->access_mask = deny_mask_from_posix(deny, flags); 290 ace->whotype = NFS4_ACL_WHO_NAMED; 291 ace->who_uid = pa->e_uid; 292 ace++; 293 acl->naces++; 294 } 295 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 296 ace->flag = eflag; 297 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, 298 flags); 299 ace->whotype = NFS4_ACL_WHO_NAMED; 300 ace->who_uid = pa->e_uid; 301 ace++; 302 acl->naces++; 303 pa++; 304 } 305 306 /* In the case of groups, we apply allow ACEs first, then deny ACEs, 307 * since a user can be in more than one group. */ 308 309 /* allow ACEs */ 310 311 group_owner_entry = pa; 312 313 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 314 ace->flag = eflag; 315 ace->access_mask = mask_from_posix(pas.group, flags); 316 ace->whotype = NFS4_ACL_WHO_GROUP; 317 ace++; 318 acl->naces++; 319 pa++; 320 321 while (pa->e_tag == ACL_GROUP) { 322 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 323 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; 324 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, 325 flags); 326 ace->whotype = NFS4_ACL_WHO_NAMED; 327 ace->who_gid = pa->e_gid; 328 ace++; 329 acl->naces++; 330 pa++; 331 } 332 333 /* deny ACEs */ 334 335 pa = group_owner_entry; 336 337 deny = ~pas.group & pas.other; 338 if (deny) { 339 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 340 ace->flag = eflag; 341 ace->access_mask = deny_mask_from_posix(deny, flags); 342 ace->whotype = NFS4_ACL_WHO_GROUP; 343 ace++; 344 acl->naces++; 345 } 346 pa++; 347 348 while (pa->e_tag == ACL_GROUP) { 349 deny = ~(pa->e_perm & pas.mask); 350 deny &= pas.other; 351 if (deny) { 352 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 353 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; 354 ace->access_mask = deny_mask_from_posix(deny, flags); 355 ace->whotype = NFS4_ACL_WHO_NAMED; 356 ace->who_gid = pa->e_gid; 357 ace++; 358 acl->naces++; 359 } 360 pa++; 361 } 362 363 if (pa->e_tag == ACL_MASK) 364 pa++; 365 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 366 ace->flag = eflag; 367 ace->access_mask = mask_from_posix(pa->e_perm, flags); 368 ace->whotype = NFS4_ACL_WHO_EVERYONE; 369 acl->naces++; 370 } 371 372 static bool 373 pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2) 374 { 375 if (pace1->e_tag != pace2->e_tag) 376 return pace1->e_tag > pace2->e_tag; 377 if (pace1->e_tag == ACL_USER) 378 return uid_gt(pace1->e_uid, pace2->e_uid); 379 if (pace1->e_tag == ACL_GROUP) 380 return gid_gt(pace1->e_gid, pace2->e_gid); 381 return false; 382 } 383 384 static void 385 sort_pacl_range(struct posix_acl *pacl, int start, int end) { 386 int sorted = 0, i; 387 struct posix_acl_entry tmp; 388 389 /* We just do a bubble sort; easy to do in place, and we're not 390 * expecting acl's to be long enough to justify anything more. */ 391 while (!sorted) { 392 sorted = 1; 393 for (i = start; i < end; i++) { 394 if (pace_gt(&pacl->a_entries[i], 395 &pacl->a_entries[i+1])) { 396 sorted = 0; 397 tmp = pacl->a_entries[i]; 398 pacl->a_entries[i] = pacl->a_entries[i+1]; 399 pacl->a_entries[i+1] = tmp; 400 } 401 } 402 } 403 } 404 405 static void 406 sort_pacl(struct posix_acl *pacl) 407 { 408 /* posix_acl_valid requires that users and groups be in order 409 * by uid/gid. */ 410 int i, j; 411 412 /* no users or groups */ 413 if (!pacl || pacl->a_count <= 4) 414 return; 415 416 i = 1; 417 while (pacl->a_entries[i].e_tag == ACL_USER) 418 i++; 419 sort_pacl_range(pacl, 1, i-1); 420 421 BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ); 422 j = ++i; 423 while (pacl->a_entries[j].e_tag == ACL_GROUP) 424 j++; 425 sort_pacl_range(pacl, i, j-1); 426 return; 427 } 428 429 /* 430 * While processing the NFSv4 ACE, this maintains bitmasks representing 431 * which permission bits have been allowed and which denied to a given 432 * entity: */ 433 struct posix_ace_state { 434 u32 allow; 435 u32 deny; 436 }; 437 438 struct posix_user_ace_state { 439 union { 440 kuid_t uid; 441 kgid_t gid; 442 }; 443 struct posix_ace_state perms; 444 }; 445 446 struct posix_ace_state_array { 447 int n; 448 struct posix_user_ace_state aces[]; 449 }; 450 451 /* 452 * While processing the NFSv4 ACE, this maintains the partial permissions 453 * calculated so far: */ 454 455 struct posix_acl_state { 456 int empty; 457 struct posix_ace_state owner; 458 struct posix_ace_state group; 459 struct posix_ace_state other; 460 struct posix_ace_state everyone; 461 struct posix_ace_state mask; /* Deny unused in this case */ 462 struct posix_ace_state_array *users; 463 struct posix_ace_state_array *groups; 464 }; 465 466 static int 467 init_state(struct posix_acl_state *state, int cnt) 468 { 469 int alloc; 470 471 memset(state, 0, sizeof(struct posix_acl_state)); 472 state->empty = 1; 473 /* 474 * In the worst case, each individual acl could be for a distinct 475 * named user or group, but we don't no which, so we allocate 476 * enough space for either: 477 */ 478 alloc = sizeof(struct posix_ace_state_array) 479 + cnt*sizeof(struct posix_user_ace_state); 480 state->users = kzalloc(alloc, GFP_KERNEL); 481 if (!state->users) 482 return -ENOMEM; 483 state->groups = kzalloc(alloc, GFP_KERNEL); 484 if (!state->groups) { 485 kfree(state->users); 486 return -ENOMEM; 487 } 488 return 0; 489 } 490 491 static void 492 free_state(struct posix_acl_state *state) { 493 kfree(state->users); 494 kfree(state->groups); 495 } 496 497 static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate) 498 { 499 state->mask.allow |= astate->allow; 500 } 501 502 /* 503 * Certain bits (SYNCHRONIZE, DELETE, WRITE_OWNER, READ/WRITE_NAMED_ATTRS, 504 * READ_ATTRIBUTES, READ_ACL) are currently unenforceable and don't translate 505 * to traditional read/write/execute permissions. 506 * 507 * It's problematic to reject acls that use certain mode bits, because it 508 * places the burden on users to learn the rules about which bits one 509 * particular server sets, without giving the user a lot of help--we return an 510 * error that could mean any number of different things. To make matters 511 * worse, the problematic bits might be introduced by some application that's 512 * automatically mapping from some other acl model. 513 * 514 * So wherever possible we accept anything, possibly erring on the side of 515 * denying more permissions than necessary. 516 * 517 * However we do reject *explicit* DENY's of a few bits representing 518 * permissions we could never deny: 519 */ 520 521 static inline int check_deny(u32 mask, int isowner) 522 { 523 if (mask & (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL)) 524 return -EINVAL; 525 if (!isowner) 526 return 0; 527 if (mask & (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)) 528 return -EINVAL; 529 return 0; 530 } 531 532 static struct posix_acl * 533 posix_state_to_acl(struct posix_acl_state *state, unsigned int flags) 534 { 535 struct posix_acl_entry *pace; 536 struct posix_acl *pacl; 537 int nace; 538 int i, error = 0; 539 540 /* 541 * ACLs with no ACEs are treated differently in the inheritable 542 * and effective cases: when there are no inheritable ACEs, 543 * calls ->set_acl with a NULL ACL structure. 544 */ 545 if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT)) 546 return NULL; 547 548 /* 549 * When there are no effective ACEs, the following will end 550 * up setting a 3-element effective posix ACL with all 551 * permissions zero. 552 */ 553 if (!state->users->n && !state->groups->n) 554 nace = 3; 555 else /* Note we also include a MASK ACE in this case: */ 556 nace = 4 + state->users->n + state->groups->n; 557 pacl = posix_acl_alloc(nace, GFP_KERNEL); 558 if (!pacl) 559 return ERR_PTR(-ENOMEM); 560 561 pace = pacl->a_entries; 562 pace->e_tag = ACL_USER_OBJ; 563 error = check_deny(state->owner.deny, 1); 564 if (error) 565 goto out_err; 566 low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags); 567 568 for (i=0; i < state->users->n; i++) { 569 pace++; 570 pace->e_tag = ACL_USER; 571 error = check_deny(state->users->aces[i].perms.deny, 0); 572 if (error) 573 goto out_err; 574 low_mode_from_nfs4(state->users->aces[i].perms.allow, 575 &pace->e_perm, flags); 576 pace->e_uid = state->users->aces[i].uid; 577 add_to_mask(state, &state->users->aces[i].perms); 578 } 579 580 pace++; 581 pace->e_tag = ACL_GROUP_OBJ; 582 error = check_deny(state->group.deny, 0); 583 if (error) 584 goto out_err; 585 low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags); 586 add_to_mask(state, &state->group); 587 588 for (i=0; i < state->groups->n; i++) { 589 pace++; 590 pace->e_tag = ACL_GROUP; 591 error = check_deny(state->groups->aces[i].perms.deny, 0); 592 if (error) 593 goto out_err; 594 low_mode_from_nfs4(state->groups->aces[i].perms.allow, 595 &pace->e_perm, flags); 596 pace->e_gid = state->groups->aces[i].gid; 597 add_to_mask(state, &state->groups->aces[i].perms); 598 } 599 600 if (state->users->n || state->groups->n) { 601 pace++; 602 pace->e_tag = ACL_MASK; 603 low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags); 604 } 605 606 pace++; 607 pace->e_tag = ACL_OTHER; 608 error = check_deny(state->other.deny, 0); 609 if (error) 610 goto out_err; 611 low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags); 612 613 return pacl; 614 out_err: 615 posix_acl_release(pacl); 616 return ERR_PTR(error); 617 } 618 619 static inline void allow_bits(struct posix_ace_state *astate, u32 mask) 620 { 621 /* Allow all bits in the mask not already denied: */ 622 astate->allow |= mask & ~astate->deny; 623 } 624 625 static inline void deny_bits(struct posix_ace_state *astate, u32 mask) 626 { 627 /* Deny all bits in the mask not already allowed: */ 628 astate->deny |= mask & ~astate->allow; 629 } 630 631 static int find_uid(struct posix_acl_state *state, kuid_t uid) 632 { 633 struct posix_ace_state_array *a = state->users; 634 int i; 635 636 for (i = 0; i < a->n; i++) 637 if (uid_eq(a->aces[i].uid, uid)) 638 return i; 639 /* Not found: */ 640 a->n++; 641 a->aces[i].uid = uid; 642 a->aces[i].perms.allow = state->everyone.allow; 643 a->aces[i].perms.deny = state->everyone.deny; 644 645 return i; 646 } 647 648 static int find_gid(struct posix_acl_state *state, kgid_t gid) 649 { 650 struct posix_ace_state_array *a = state->groups; 651 int i; 652 653 for (i = 0; i < a->n; i++) 654 if (gid_eq(a->aces[i].gid, gid)) 655 return i; 656 /* Not found: */ 657 a->n++; 658 a->aces[i].gid = gid; 659 a->aces[i].perms.allow = state->everyone.allow; 660 a->aces[i].perms.deny = state->everyone.deny; 661 662 return i; 663 } 664 665 static void deny_bits_array(struct posix_ace_state_array *a, u32 mask) 666 { 667 int i; 668 669 for (i=0; i < a->n; i++) 670 deny_bits(&a->aces[i].perms, mask); 671 } 672 673 static void allow_bits_array(struct posix_ace_state_array *a, u32 mask) 674 { 675 int i; 676 677 for (i=0; i < a->n; i++) 678 allow_bits(&a->aces[i].perms, mask); 679 } 680 681 static void process_one_v4_ace(struct posix_acl_state *state, 682 struct nfs4_ace *ace) 683 { 684 u32 mask = ace->access_mask; 685 int i; 686 687 state->empty = 0; 688 689 switch (ace2type(ace)) { 690 case ACL_USER_OBJ: 691 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 692 allow_bits(&state->owner, mask); 693 } else { 694 deny_bits(&state->owner, mask); 695 } 696 break; 697 case ACL_USER: 698 i = find_uid(state, ace->who_uid); 699 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 700 allow_bits(&state->users->aces[i].perms, mask); 701 } else { 702 deny_bits(&state->users->aces[i].perms, mask); 703 mask = state->users->aces[i].perms.deny; 704 deny_bits(&state->owner, mask); 705 } 706 break; 707 case ACL_GROUP_OBJ: 708 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 709 allow_bits(&state->group, mask); 710 } else { 711 deny_bits(&state->group, mask); 712 mask = state->group.deny; 713 deny_bits(&state->owner, mask); 714 deny_bits(&state->everyone, mask); 715 deny_bits_array(state->users, mask); 716 deny_bits_array(state->groups, mask); 717 } 718 break; 719 case ACL_GROUP: 720 i = find_gid(state, ace->who_gid); 721 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 722 allow_bits(&state->groups->aces[i].perms, mask); 723 } else { 724 deny_bits(&state->groups->aces[i].perms, mask); 725 mask = state->groups->aces[i].perms.deny; 726 deny_bits(&state->owner, mask); 727 deny_bits(&state->group, mask); 728 deny_bits(&state->everyone, mask); 729 deny_bits_array(state->users, mask); 730 deny_bits_array(state->groups, mask); 731 } 732 break; 733 case ACL_OTHER: 734 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 735 allow_bits(&state->owner, mask); 736 allow_bits(&state->group, mask); 737 allow_bits(&state->other, mask); 738 allow_bits(&state->everyone, mask); 739 allow_bits_array(state->users, mask); 740 allow_bits_array(state->groups, mask); 741 } else { 742 deny_bits(&state->owner, mask); 743 deny_bits(&state->group, mask); 744 deny_bits(&state->other, mask); 745 deny_bits(&state->everyone, mask); 746 deny_bits_array(state->users, mask); 747 deny_bits_array(state->groups, mask); 748 } 749 } 750 } 751 752 static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, 753 struct posix_acl **pacl, struct posix_acl **dpacl, 754 unsigned int flags) 755 { 756 struct posix_acl_state effective_acl_state, default_acl_state; 757 struct nfs4_ace *ace; 758 int ret; 759 760 ret = init_state(&effective_acl_state, acl->naces); 761 if (ret) 762 return ret; 763 ret = init_state(&default_acl_state, acl->naces); 764 if (ret) 765 goto out_estate; 766 ret = -EINVAL; 767 for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) { 768 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE && 769 ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE) 770 goto out_dstate; 771 if (ace->flag & ~NFS4_SUPPORTED_FLAGS) 772 goto out_dstate; 773 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) { 774 process_one_v4_ace(&effective_acl_state, ace); 775 continue; 776 } 777 if (!(flags & NFS4_ACL_DIR)) 778 goto out_dstate; 779 /* 780 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT 781 * is set, we're effectively turning on the other. That's OK, 782 * according to rfc 3530. 783 */ 784 process_one_v4_ace(&default_acl_state, ace); 785 786 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE)) 787 process_one_v4_ace(&effective_acl_state, ace); 788 } 789 *pacl = posix_state_to_acl(&effective_acl_state, flags); 790 if (IS_ERR(*pacl)) { 791 ret = PTR_ERR(*pacl); 792 *pacl = NULL; 793 goto out_dstate; 794 } 795 *dpacl = posix_state_to_acl(&default_acl_state, 796 flags | NFS4_ACL_TYPE_DEFAULT); 797 if (IS_ERR(*dpacl)) { 798 ret = PTR_ERR(*dpacl); 799 *dpacl = NULL; 800 posix_acl_release(*pacl); 801 *pacl = NULL; 802 goto out_dstate; 803 } 804 sort_pacl(*pacl); 805 sort_pacl(*dpacl); 806 ret = 0; 807 out_dstate: 808 free_state(&default_acl_state); 809 out_estate: 810 free_state(&effective_acl_state); 811 return ret; 812 } 813 814 __be32 815 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, 816 struct nfs4_acl *acl) 817 { 818 __be32 error; 819 int host_error; 820 struct dentry *dentry; 821 struct inode *inode; 822 struct posix_acl *pacl = NULL, *dpacl = NULL; 823 unsigned int flags = 0; 824 825 /* Get inode */ 826 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_SATTR); 827 if (error) 828 return error; 829 830 dentry = fhp->fh_dentry; 831 inode = dentry->d_inode; 832 833 if (!inode->i_op->set_acl || !IS_POSIXACL(inode)) 834 return nfserr_attrnotsupp; 835 836 if (S_ISDIR(inode->i_mode)) 837 flags = NFS4_ACL_DIR; 838 839 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); 840 if (host_error == -EINVAL) 841 return nfserr_attrnotsupp; 842 if (host_error < 0) 843 goto out_nfserr; 844 845 host_error = inode->i_op->set_acl(inode, pacl, ACL_TYPE_ACCESS); 846 if (host_error < 0) 847 goto out_release; 848 849 if (S_ISDIR(inode->i_mode)) { 850 host_error = inode->i_op->set_acl(inode, dpacl, 851 ACL_TYPE_DEFAULT); 852 } 853 854 out_release: 855 posix_acl_release(pacl); 856 posix_acl_release(dpacl); 857 out_nfserr: 858 if (host_error == -EOPNOTSUPP) 859 return nfserr_attrnotsupp; 860 else 861 return nfserrno(host_error); 862 } 863 864 865 static short 866 ace2type(struct nfs4_ace *ace) 867 { 868 switch (ace->whotype) { 869 case NFS4_ACL_WHO_NAMED: 870 return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ? 871 ACL_GROUP : ACL_USER); 872 case NFS4_ACL_WHO_OWNER: 873 return ACL_USER_OBJ; 874 case NFS4_ACL_WHO_GROUP: 875 return ACL_GROUP_OBJ; 876 case NFS4_ACL_WHO_EVERYONE: 877 return ACL_OTHER; 878 } 879 BUG(); 880 return -1; 881 } 882 883 /* 884 * return the size of the struct nfs4_acl required to represent an acl 885 * with @entries entries. 886 */ 887 int nfs4_acl_bytes(int entries) 888 { 889 return sizeof(struct nfs4_acl) + entries * sizeof(struct nfs4_ace); 890 } 891 892 static struct { 893 char *string; 894 int stringlen; 895 int type; 896 } s2t_map[] = { 897 { 898 .string = "OWNER@", 899 .stringlen = sizeof("OWNER@") - 1, 900 .type = NFS4_ACL_WHO_OWNER, 901 }, 902 { 903 .string = "GROUP@", 904 .stringlen = sizeof("GROUP@") - 1, 905 .type = NFS4_ACL_WHO_GROUP, 906 }, 907 { 908 .string = "EVERYONE@", 909 .stringlen = sizeof("EVERYONE@") - 1, 910 .type = NFS4_ACL_WHO_EVERYONE, 911 }, 912 }; 913 914 int 915 nfs4_acl_get_whotype(char *p, u32 len) 916 { 917 int i; 918 919 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 920 if (s2t_map[i].stringlen == len && 921 0 == memcmp(s2t_map[i].string, p, len)) 922 return s2t_map[i].type; 923 } 924 return NFS4_ACL_WHO_NAMED; 925 } 926 927 __be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who) 928 { 929 __be32 *p; 930 int i; 931 932 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 933 if (s2t_map[i].type != who) 934 continue; 935 p = xdr_reserve_space(xdr, s2t_map[i].stringlen + 4); 936 if (!p) 937 return nfserr_resource; 938 p = xdr_encode_opaque(p, s2t_map[i].string, 939 s2t_map[i].stringlen); 940 return 0; 941 } 942 WARN_ON_ONCE(1); 943 return nfserr_serverfault; 944 } 945