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/fs.h> 38 #include <linux/slab.h> 39 #include <linux/posix_acl.h> 40 41 #include "nfsfh.h" 42 #include "nfsd.h" 43 #include "acl.h" 44 #include "vfs.h" 45 46 #define NFS4_ACL_TYPE_DEFAULT 0x01 47 #define NFS4_ACL_DIR 0x02 48 #define NFS4_ACL_OWNER 0x04 49 50 /* mode bit translations: */ 51 #define NFS4_READ_MODE (NFS4_ACE_READ_DATA) 52 #define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA) 53 #define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE 54 #define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE) 55 #define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL) 56 57 /* flags used to simulate posix default ACLs */ 58 #define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \ 59 | NFS4_ACE_DIRECTORY_INHERIT_ACE) 60 61 #define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \ 62 | NFS4_ACE_INHERIT_ONLY_ACE \ 63 | NFS4_ACE_IDENTIFIER_GROUP) 64 65 static u32 66 mask_from_posix(unsigned short perm, unsigned int flags) 67 { 68 int mask = NFS4_ANYONE_MODE; 69 70 if (flags & NFS4_ACL_OWNER) 71 mask |= NFS4_OWNER_MODE; 72 if (perm & ACL_READ) 73 mask |= NFS4_READ_MODE; 74 if (perm & ACL_WRITE) 75 mask |= NFS4_WRITE_MODE; 76 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR)) 77 mask |= NFS4_ACE_DELETE_CHILD; 78 if (perm & ACL_EXECUTE) 79 mask |= NFS4_EXECUTE_MODE; 80 return mask; 81 } 82 83 static u32 84 deny_mask_from_posix(unsigned short perm, u32 flags) 85 { 86 u32 mask = 0; 87 88 if (perm & ACL_READ) 89 mask |= NFS4_READ_MODE; 90 if (perm & ACL_WRITE) 91 mask |= NFS4_WRITE_MODE; 92 if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR)) 93 mask |= NFS4_ACE_DELETE_CHILD; 94 if (perm & ACL_EXECUTE) 95 mask |= NFS4_EXECUTE_MODE; 96 return mask; 97 } 98 99 /* XXX: modify functions to return NFS errors; they're only ever 100 * used by nfs code, after all.... */ 101 102 /* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the 103 * side of being more restrictive, so the mode bit mapping below is 104 * pessimistic. An optimistic version would be needed to handle DENY's, 105 * but we expect to coalesce all ALLOWs and DENYs before mapping to mode 106 * bits. */ 107 108 static void 109 low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags) 110 { 111 u32 write_mode = NFS4_WRITE_MODE; 112 113 if (flags & NFS4_ACL_DIR) 114 write_mode |= NFS4_ACE_DELETE_CHILD; 115 *mode = 0; 116 if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE) 117 *mode |= ACL_READ; 118 if ((perm & write_mode) == write_mode) 119 *mode |= ACL_WRITE; 120 if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE) 121 *mode |= ACL_EXECUTE; 122 } 123 124 static short ace2type(struct nfs4_ace *); 125 static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *, 126 unsigned int); 127 128 int 129 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, 130 struct nfs4_acl **acl) 131 { 132 struct inode *inode = d_inode(dentry); 133 int error = 0; 134 struct posix_acl *pacl = NULL, *dpacl = NULL; 135 unsigned int flags = 0; 136 int size = 0; 137 138 pacl = get_inode_acl(inode, ACL_TYPE_ACCESS); 139 if (!pacl) 140 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL); 141 142 if (IS_ERR(pacl)) 143 return PTR_ERR(pacl); 144 145 /* allocate for worst case: one (deny, allow) pair each: */ 146 size += 2 * pacl->a_count; 147 148 if (S_ISDIR(inode->i_mode)) { 149 flags = NFS4_ACL_DIR; 150 dpacl = get_inode_acl(inode, ACL_TYPE_DEFAULT); 151 if (IS_ERR(dpacl)) { 152 error = PTR_ERR(dpacl); 153 goto rel_pacl; 154 } 155 156 if (dpacl) 157 size += 2 * dpacl->a_count; 158 } 159 160 *acl = kmalloc(nfs4_acl_bytes(size), GFP_KERNEL); 161 if (*acl == NULL) { 162 error = -ENOMEM; 163 goto out; 164 } 165 (*acl)->naces = 0; 166 167 _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT); 168 169 if (dpacl) 170 _posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT); 171 172 out: 173 posix_acl_release(dpacl); 174 rel_pacl: 175 posix_acl_release(pacl); 176 return error; 177 } 178 179 struct posix_acl_summary { 180 unsigned short owner; 181 unsigned short users; 182 unsigned short group; 183 unsigned short groups; 184 unsigned short other; 185 unsigned short mask; 186 }; 187 188 static void 189 summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas) 190 { 191 struct posix_acl_entry *pa, *pe; 192 193 /* 194 * Only pas.users and pas.groups need initialization; previous 195 * posix_acl_valid() calls ensure that the other fields will be 196 * initialized in the following loop. But, just to placate gcc: 197 */ 198 memset(pas, 0, sizeof(*pas)); 199 pas->mask = 07; 200 201 FOREACH_ACL_ENTRY(pa, acl, pe) { 202 switch (pa->e_tag) { 203 case ACL_USER_OBJ: 204 pas->owner = pa->e_perm; 205 break; 206 case ACL_GROUP_OBJ: 207 pas->group = pa->e_perm; 208 break; 209 case ACL_USER: 210 pas->users |= pa->e_perm; 211 break; 212 case ACL_GROUP: 213 pas->groups |= pa->e_perm; 214 break; 215 case ACL_OTHER: 216 pas->other = pa->e_perm; 217 break; 218 case ACL_MASK: 219 pas->mask = pa->e_perm; 220 break; 221 } 222 } 223 /* We'll only care about effective permissions: */ 224 pas->users &= pas->mask; 225 pas->group &= pas->mask; 226 pas->groups &= pas->mask; 227 } 228 229 /* We assume the acl has been verified with posix_acl_valid. */ 230 static void 231 _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl, 232 unsigned int flags) 233 { 234 struct posix_acl_entry *pa, *group_owner_entry; 235 struct nfs4_ace *ace; 236 struct posix_acl_summary pas; 237 unsigned short deny; 238 int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ? 239 NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0); 240 241 BUG_ON(pacl->a_count < 3); 242 summarize_posix_acl(pacl, &pas); 243 244 pa = pacl->a_entries; 245 ace = acl->aces + acl->naces; 246 247 /* We could deny everything not granted by the owner: */ 248 deny = ~pas.owner; 249 /* 250 * but it is equivalent (and simpler) to deny only what is not 251 * granted by later entries: 252 */ 253 deny &= pas.users | pas.group | pas.groups | pas.other; 254 if (deny) { 255 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 256 ace->flag = eflag; 257 ace->access_mask = deny_mask_from_posix(deny, flags); 258 ace->whotype = NFS4_ACL_WHO_OWNER; 259 ace++; 260 acl->naces++; 261 } 262 263 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 264 ace->flag = eflag; 265 ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER); 266 ace->whotype = NFS4_ACL_WHO_OWNER; 267 ace++; 268 acl->naces++; 269 pa++; 270 271 while (pa->e_tag == ACL_USER) { 272 deny = ~(pa->e_perm & pas.mask); 273 deny &= pas.groups | pas.group | pas.other; 274 if (deny) { 275 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 276 ace->flag = eflag; 277 ace->access_mask = deny_mask_from_posix(deny, flags); 278 ace->whotype = NFS4_ACL_WHO_NAMED; 279 ace->who_uid = pa->e_uid; 280 ace++; 281 acl->naces++; 282 } 283 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 284 ace->flag = eflag; 285 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, 286 flags); 287 ace->whotype = NFS4_ACL_WHO_NAMED; 288 ace->who_uid = pa->e_uid; 289 ace++; 290 acl->naces++; 291 pa++; 292 } 293 294 /* In the case of groups, we apply allow ACEs first, then deny ACEs, 295 * since a user can be in more than one group. */ 296 297 /* allow ACEs */ 298 299 group_owner_entry = pa; 300 301 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 302 ace->flag = eflag; 303 ace->access_mask = mask_from_posix(pas.group, flags); 304 ace->whotype = NFS4_ACL_WHO_GROUP; 305 ace++; 306 acl->naces++; 307 pa++; 308 309 while (pa->e_tag == ACL_GROUP) { 310 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 311 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; 312 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, 313 flags); 314 ace->whotype = NFS4_ACL_WHO_NAMED; 315 ace->who_gid = pa->e_gid; 316 ace++; 317 acl->naces++; 318 pa++; 319 } 320 321 /* deny ACEs */ 322 323 pa = group_owner_entry; 324 325 deny = ~pas.group & pas.other; 326 if (deny) { 327 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 328 ace->flag = eflag; 329 ace->access_mask = deny_mask_from_posix(deny, flags); 330 ace->whotype = NFS4_ACL_WHO_GROUP; 331 ace++; 332 acl->naces++; 333 } 334 pa++; 335 336 while (pa->e_tag == ACL_GROUP) { 337 deny = ~(pa->e_perm & pas.mask); 338 deny &= pas.other; 339 if (deny) { 340 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 341 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; 342 ace->access_mask = deny_mask_from_posix(deny, flags); 343 ace->whotype = NFS4_ACL_WHO_NAMED; 344 ace->who_gid = pa->e_gid; 345 ace++; 346 acl->naces++; 347 } 348 pa++; 349 } 350 351 if (pa->e_tag == ACL_MASK) 352 pa++; 353 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 354 ace->flag = eflag; 355 ace->access_mask = mask_from_posix(pa->e_perm, flags); 356 ace->whotype = NFS4_ACL_WHO_EVERYONE; 357 acl->naces++; 358 } 359 360 static bool 361 pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2) 362 { 363 if (pace1->e_tag != pace2->e_tag) 364 return pace1->e_tag > pace2->e_tag; 365 if (pace1->e_tag == ACL_USER) 366 return uid_gt(pace1->e_uid, pace2->e_uid); 367 if (pace1->e_tag == ACL_GROUP) 368 return gid_gt(pace1->e_gid, pace2->e_gid); 369 return false; 370 } 371 372 /** 373 * sort_pacl_range - sort a range of POSIX ACL entries by tag and id 374 * @pacl: POSIX ACL containing entries to sort 375 * @start: starting index of range to sort 376 * @end: ending index of range to sort (inclusive) 377 * 378 * Sorts ACL entries in place so that USER entries are ordered by UID 379 * and GROUP entries are ordered by GID. Required before calling 380 * posix_acl_valid(). 381 */ 382 void sort_pacl_range(struct posix_acl *pacl, int start, int end) 383 { 384 int sorted = 0, i; 385 386 /* Bubble sort: acceptable here because ACLs are typically short. */ 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 swap(pacl->a_entries[i], 394 pacl->a_entries[i + 1]); 395 } 396 } 397 } 398 } 399 400 static void 401 sort_pacl(struct posix_acl *pacl) 402 { 403 /* posix_acl_valid requires that users and groups be in order 404 * by uid/gid. */ 405 int i, j; 406 407 /* no users or groups */ 408 if (!pacl || pacl->a_count <= 4) 409 return; 410 411 i = 1; 412 while (pacl->a_entries[i].e_tag == ACL_USER) 413 i++; 414 sort_pacl_range(pacl, 1, i-1); 415 416 BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ); 417 j = ++i; 418 while (pacl->a_entries[j].e_tag == ACL_GROUP) 419 j++; 420 sort_pacl_range(pacl, i, j-1); 421 return; 422 } 423 424 /* 425 * While processing the NFSv4 ACE, this maintains bitmasks representing 426 * which permission bits have been allowed and which denied to a given 427 * entity: */ 428 struct posix_ace_state { 429 u32 allow; 430 u32 deny; 431 }; 432 433 struct posix_user_ace_state { 434 union { 435 kuid_t uid; 436 kgid_t gid; 437 }; 438 struct posix_ace_state perms; 439 }; 440 441 struct posix_ace_state_array { 442 int n; 443 struct posix_user_ace_state aces[]; 444 }; 445 446 /* 447 * While processing the NFSv4 ACE, this maintains the partial permissions 448 * calculated so far: */ 449 450 struct posix_acl_state { 451 unsigned char valid; 452 struct posix_ace_state owner; 453 struct posix_ace_state group; 454 struct posix_ace_state other; 455 struct posix_ace_state everyone; 456 struct posix_ace_state mask; /* Deny unused in this case */ 457 struct posix_ace_state_array *users; 458 struct posix_ace_state_array *groups; 459 }; 460 461 static int 462 init_state(struct posix_acl_state *state, int cnt) 463 { 464 int alloc; 465 466 memset(state, 0, sizeof(struct posix_acl_state)); 467 /* 468 * In the worst case, each individual acl could be for a distinct 469 * named user or group, but we don't know 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 static struct posix_acl * 497 posix_state_to_acl(struct posix_acl_state *state, unsigned int flags) 498 { 499 struct posix_acl_entry *pace; 500 struct posix_acl *pacl; 501 int nace; 502 int i; 503 504 /* 505 * ACLs with no ACEs are treated differently in the inheritable 506 * and effective cases: when there are no inheritable ACEs, 507 * calls ->set_acl with a NULL ACL structure. 508 */ 509 if (!state->valid && (flags & NFS4_ACL_TYPE_DEFAULT)) 510 return NULL; 511 512 /* 513 * When there are no effective ACEs, the following will end 514 * up setting a 3-element effective posix ACL with all 515 * permissions zero. 516 */ 517 if (!state->users->n && !state->groups->n) 518 nace = 3; 519 else /* Note we also include a MASK ACE in this case: */ 520 nace = 4 + state->users->n + state->groups->n; 521 pacl = posix_acl_alloc(nace, GFP_KERNEL); 522 if (!pacl) 523 return ERR_PTR(-ENOMEM); 524 525 pace = pacl->a_entries; 526 pace->e_tag = ACL_USER_OBJ; 527 low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags); 528 529 for (i=0; i < state->users->n; i++) { 530 pace++; 531 pace->e_tag = ACL_USER; 532 low_mode_from_nfs4(state->users->aces[i].perms.allow, 533 &pace->e_perm, flags); 534 pace->e_uid = state->users->aces[i].uid; 535 add_to_mask(state, &state->users->aces[i].perms); 536 } 537 538 pace++; 539 pace->e_tag = ACL_GROUP_OBJ; 540 low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags); 541 add_to_mask(state, &state->group); 542 543 for (i=0; i < state->groups->n; i++) { 544 pace++; 545 pace->e_tag = ACL_GROUP; 546 low_mode_from_nfs4(state->groups->aces[i].perms.allow, 547 &pace->e_perm, flags); 548 pace->e_gid = state->groups->aces[i].gid; 549 add_to_mask(state, &state->groups->aces[i].perms); 550 } 551 552 if (state->users->n || state->groups->n) { 553 pace++; 554 pace->e_tag = ACL_MASK; 555 low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags); 556 } 557 558 pace++; 559 pace->e_tag = ACL_OTHER; 560 low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags); 561 562 return pacl; 563 } 564 565 static inline void allow_bits(struct posix_ace_state *astate, u32 mask) 566 { 567 /* Allow all bits in the mask not already denied: */ 568 astate->allow |= mask & ~astate->deny; 569 } 570 571 static inline void deny_bits(struct posix_ace_state *astate, u32 mask) 572 { 573 /* Deny all bits in the mask not already allowed: */ 574 astate->deny |= mask & ~astate->allow; 575 } 576 577 static int find_uid(struct posix_acl_state *state, kuid_t uid) 578 { 579 struct posix_ace_state_array *a = state->users; 580 int i; 581 582 for (i = 0; i < a->n; i++) 583 if (uid_eq(a->aces[i].uid, uid)) 584 return i; 585 /* Not found: */ 586 a->n++; 587 a->aces[i].uid = uid; 588 a->aces[i].perms.allow = state->everyone.allow; 589 a->aces[i].perms.deny = state->everyone.deny; 590 591 return i; 592 } 593 594 static int find_gid(struct posix_acl_state *state, kgid_t gid) 595 { 596 struct posix_ace_state_array *a = state->groups; 597 int i; 598 599 for (i = 0; i < a->n; i++) 600 if (gid_eq(a->aces[i].gid, gid)) 601 return i; 602 /* Not found: */ 603 a->n++; 604 a->aces[i].gid = gid; 605 a->aces[i].perms.allow = state->everyone.allow; 606 a->aces[i].perms.deny = state->everyone.deny; 607 608 return i; 609 } 610 611 static void deny_bits_array(struct posix_ace_state_array *a, u32 mask) 612 { 613 int i; 614 615 for (i=0; i < a->n; i++) 616 deny_bits(&a->aces[i].perms, mask); 617 } 618 619 static void allow_bits_array(struct posix_ace_state_array *a, u32 mask) 620 { 621 int i; 622 623 for (i=0; i < a->n; i++) 624 allow_bits(&a->aces[i].perms, mask); 625 } 626 627 static void process_one_v4_ace(struct posix_acl_state *state, 628 struct nfs4_ace *ace) 629 { 630 u32 mask = ace->access_mask; 631 short type = ace2type(ace); 632 int i; 633 634 state->valid |= type; 635 636 switch (type) { 637 case ACL_USER_OBJ: 638 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 639 allow_bits(&state->owner, mask); 640 } else { 641 deny_bits(&state->owner, mask); 642 } 643 break; 644 case ACL_USER: 645 i = find_uid(state, ace->who_uid); 646 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 647 allow_bits(&state->users->aces[i].perms, mask); 648 } else { 649 deny_bits(&state->users->aces[i].perms, mask); 650 mask = state->users->aces[i].perms.deny; 651 deny_bits(&state->owner, mask); 652 } 653 break; 654 case ACL_GROUP_OBJ: 655 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 656 allow_bits(&state->group, mask); 657 } else { 658 deny_bits(&state->group, mask); 659 mask = state->group.deny; 660 deny_bits(&state->owner, mask); 661 deny_bits(&state->everyone, mask); 662 deny_bits_array(state->users, mask); 663 deny_bits_array(state->groups, mask); 664 } 665 break; 666 case ACL_GROUP: 667 i = find_gid(state, ace->who_gid); 668 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 669 allow_bits(&state->groups->aces[i].perms, mask); 670 } else { 671 deny_bits(&state->groups->aces[i].perms, mask); 672 mask = state->groups->aces[i].perms.deny; 673 deny_bits(&state->owner, mask); 674 deny_bits(&state->group, mask); 675 deny_bits(&state->everyone, mask); 676 deny_bits_array(state->users, mask); 677 deny_bits_array(state->groups, mask); 678 } 679 break; 680 case ACL_OTHER: 681 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 682 allow_bits(&state->owner, mask); 683 allow_bits(&state->group, mask); 684 allow_bits(&state->other, mask); 685 allow_bits(&state->everyone, mask); 686 allow_bits_array(state->users, mask); 687 allow_bits_array(state->groups, mask); 688 } else { 689 deny_bits(&state->owner, mask); 690 deny_bits(&state->group, mask); 691 deny_bits(&state->other, mask); 692 deny_bits(&state->everyone, mask); 693 deny_bits_array(state->users, mask); 694 deny_bits_array(state->groups, mask); 695 } 696 } 697 } 698 699 static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, 700 struct posix_acl **pacl, struct posix_acl **dpacl, 701 unsigned int flags) 702 { 703 struct posix_acl_state effective_acl_state, default_acl_state; 704 struct nfs4_ace *ace; 705 int ret; 706 707 ret = init_state(&effective_acl_state, acl->naces); 708 if (ret) 709 return ret; 710 ret = init_state(&default_acl_state, acl->naces); 711 if (ret) 712 goto out_estate; 713 ret = -EINVAL; 714 for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) { 715 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE && 716 ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE) 717 goto out_dstate; 718 if (ace->flag & ~NFS4_SUPPORTED_FLAGS) 719 goto out_dstate; 720 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) { 721 process_one_v4_ace(&effective_acl_state, ace); 722 continue; 723 } 724 if (!(flags & NFS4_ACL_DIR)) 725 goto out_dstate; 726 /* 727 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT 728 * is set, we're effectively turning on the other. That's OK, 729 * according to rfc 3530. 730 */ 731 process_one_v4_ace(&default_acl_state, ace); 732 733 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE)) 734 process_one_v4_ace(&effective_acl_state, ace); 735 } 736 737 /* 738 * At this point, the default ACL may have zeroed-out entries for owner, 739 * group and other. That usually results in a non-sensical resulting ACL 740 * that denies all access except to any ACE that was explicitly added. 741 * 742 * The setfacl command solves a similar problem with this logic: 743 * 744 * "If a Default ACL entry is created, and the Default ACL contains 745 * no owner, owning group, or others entry, a copy of the ACL 746 * owner, owning group, or others entry is added to the Default ACL." 747 * 748 * Copy any missing ACEs from the effective set, if any ACEs were 749 * explicitly set. 750 */ 751 if (default_acl_state.valid) { 752 if (!(default_acl_state.valid & ACL_USER_OBJ)) 753 default_acl_state.owner = effective_acl_state.owner; 754 if (!(default_acl_state.valid & ACL_GROUP_OBJ)) 755 default_acl_state.group = effective_acl_state.group; 756 if (!(default_acl_state.valid & ACL_OTHER)) 757 default_acl_state.other = effective_acl_state.other; 758 } 759 760 *pacl = posix_state_to_acl(&effective_acl_state, flags); 761 if (IS_ERR(*pacl)) { 762 ret = PTR_ERR(*pacl); 763 *pacl = NULL; 764 goto out_dstate; 765 } 766 *dpacl = posix_state_to_acl(&default_acl_state, 767 flags | NFS4_ACL_TYPE_DEFAULT); 768 if (IS_ERR(*dpacl)) { 769 ret = PTR_ERR(*dpacl); 770 *dpacl = NULL; 771 posix_acl_release(*pacl); 772 *pacl = NULL; 773 goto out_dstate; 774 } 775 sort_pacl(*pacl); 776 sort_pacl(*dpacl); 777 ret = 0; 778 out_dstate: 779 free_state(&default_acl_state); 780 out_estate: 781 free_state(&effective_acl_state); 782 return ret; 783 } 784 785 __be32 nfsd4_acl_to_attr(enum nfs_ftype4 type, struct nfs4_acl *acl, 786 struct nfsd_attrs *attr) 787 { 788 int host_error; 789 unsigned int flags = 0; 790 791 if (!acl) 792 return nfs_ok; 793 794 if (type == NF4DIR) 795 flags = NFS4_ACL_DIR; 796 797 host_error = nfs4_acl_nfsv4_to_posix(acl, &attr->na_pacl, 798 &attr->na_dpacl, flags); 799 if (host_error == -EINVAL) 800 return nfserr_attrnotsupp; 801 else 802 return nfserrno(host_error); 803 } 804 805 static short 806 ace2type(struct nfs4_ace *ace) 807 { 808 switch (ace->whotype) { 809 case NFS4_ACL_WHO_NAMED: 810 return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ? 811 ACL_GROUP : ACL_USER); 812 case NFS4_ACL_WHO_OWNER: 813 return ACL_USER_OBJ; 814 case NFS4_ACL_WHO_GROUP: 815 return ACL_GROUP_OBJ; 816 case NFS4_ACL_WHO_EVERYONE: 817 return ACL_OTHER; 818 } 819 BUG(); 820 return -1; 821 } 822 823 /* 824 * return the size of the struct nfs4_acl required to represent an acl 825 * with @entries entries. 826 */ 827 int nfs4_acl_bytes(int entries) 828 { 829 return sizeof(struct nfs4_acl) + entries * sizeof(struct nfs4_ace); 830 } 831 832 static struct { 833 char *string; 834 int stringlen; 835 int type; 836 } s2t_map[] = { 837 { 838 .string = "OWNER@", 839 .stringlen = sizeof("OWNER@") - 1, 840 .type = NFS4_ACL_WHO_OWNER, 841 }, 842 { 843 .string = "GROUP@", 844 .stringlen = sizeof("GROUP@") - 1, 845 .type = NFS4_ACL_WHO_GROUP, 846 }, 847 { 848 .string = "EVERYONE@", 849 .stringlen = sizeof("EVERYONE@") - 1, 850 .type = NFS4_ACL_WHO_EVERYONE, 851 }, 852 }; 853 854 int 855 nfs4_acl_get_whotype(char *p, u32 len) 856 { 857 int i; 858 859 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 860 if (s2t_map[i].stringlen == len && 861 0 == memcmp(s2t_map[i].string, p, len)) 862 return s2t_map[i].type; 863 } 864 return NFS4_ACL_WHO_NAMED; 865 } 866 867 __be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who) 868 { 869 __be32 *p; 870 int i; 871 872 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 873 if (s2t_map[i].type != who) 874 continue; 875 p = xdr_reserve_space(xdr, s2t_map[i].stringlen + 4); 876 if (!p) 877 return nfserr_resource; 878 p = xdr_encode_opaque(p, s2t_map[i].string, 879 s2t_map[i].stringlen); 880 return 0; 881 } 882 WARN_ON_ONCE(1); 883 return nfserr_serverfault; 884 } 885