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nfs4acl.c
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linux-6.19.14/fs/nfsd/nfs4acl.c
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 65static u32 66mask_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 83static u32 84deny_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 108static void 109low_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 124static short ace2type(struct nfs4_ace *); 125static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *, 126 unsigned int); 127 128int 129nfsd4_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 172out: 173 posix_acl_release(dpacl); 174rel_pacl: 175 posix_acl_release(pacl); 176 return error; 177} 178 179struct 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 188static void 189summarize_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. */ 230static 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 360static bool 361pace_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 372static void 373sort_pacl_range(struct posix_acl *pacl, int start, int end) { 374 int sorted = 0, i; 375 376 /* We just do a bubble sort; easy to do in place, and we're not 377 * expecting acl's to be long enough to justify anything more. */ 378 while (!sorted) { 379 sorted = 1; 380 for (i = start; i < end; i++) { 381 if (pace_gt(&pacl->a_entries[i], 382 &pacl->a_entries[i+1])) { 383 sorted = 0; 384 swap(pacl->a_entries[i], 385 pacl->a_entries[i + 1]); 386 } 387 } 388 } 389} 390 391static void 392sort_pacl(struct posix_acl *pacl) 393{ 394 /* posix_acl_valid requires that users and groups be in order 395 * by uid/gid. */ 396 int i, j; 397 398 /* no users or groups */ 399 if (!pacl || pacl->a_count <= 4) 400 return; 401 402 i = 1; 403 while (pacl->a_entries[i].e_tag == ACL_USER) 404 i++; 405 sort_pacl_range(pacl, 1, i-1); 406 407 BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ); 408 j = ++i; 409 while (pacl->a_entries[j].e_tag == ACL_GROUP) 410 j++; 411 sort_pacl_range(pacl, i, j-1); 412 return; 413} 414 415/* 416 * While processing the NFSv4 ACE, this maintains bitmasks representing 417 * which permission bits have been allowed and which denied to a given 418 * entity: */ 419struct posix_ace_state { 420 u32 allow; 421 u32 deny; 422}; 423 424struct posix_user_ace_state { 425 union { 426 kuid_t uid; 427 kgid_t gid; 428 }; 429 struct posix_ace_state perms; 430}; 431 432struct posix_ace_state_array { 433 int n; 434 struct posix_user_ace_state aces[]; 435}; 436 437/* 438 * While processing the NFSv4 ACE, this maintains the partial permissions 439 * calculated so far: */ 440 441struct posix_acl_state { 442 unsigned char valid; 443 struct posix_ace_state owner; 444 struct posix_ace_state group; 445 struct posix_ace_state other; 446 struct posix_ace_state everyone; 447 struct posix_ace_state mask; /* Deny unused in this case */ 448 struct posix_ace_state_array *users; 449 struct posix_ace_state_array *groups; 450}; 451 452static int 453init_state(struct posix_acl_state *state, int cnt) 454{ 455 int alloc; 456 457 memset(state, 0, sizeof(struct posix_acl_state)); 458 /* 459 * In the worst case, each individual acl could be for a distinct 460 * named user or group, but we don't know which, so we allocate 461 * enough space for either: 462 */ 463 alloc = sizeof(struct posix_ace_state_array) 464 + cnt*sizeof(struct posix_user_ace_state); 465 state->users = kzalloc(alloc, GFP_KERNEL); 466 if (!state->users) 467 return -ENOMEM; 468 state->groups = kzalloc(alloc, GFP_KERNEL); 469 if (!state->groups) { 470 kfree(state->users); 471 return -ENOMEM; 472 } 473 return 0; 474} 475 476static void 477free_state(struct posix_acl_state *state) { 478 kfree(state->users); 479 kfree(state->groups); 480} 481 482static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate) 483{ 484 state->mask.allow |= astate->allow; 485} 486 487static struct posix_acl * 488posix_state_to_acl(struct posix_acl_state *state, unsigned int flags) 489{ 490 struct posix_acl_entry *pace; 491 struct posix_acl *pacl; 492 int nace; 493 int i; 494 495 /* 496 * ACLs with no ACEs are treated differently in the inheritable 497 * and effective cases: when there are no inheritable ACEs, 498 * calls ->set_acl with a NULL ACL structure. 499 */ 500 if (!state->valid && (flags & NFS4_ACL_TYPE_DEFAULT)) 501 return NULL; 502 503 /* 504 * When there are no effective ACEs, the following will end 505 * up setting a 3-element effective posix ACL with all 506 * permissions zero. 507 */ 508 if (!state->users->n && !state->groups->n) 509 nace = 3; 510 else /* Note we also include a MASK ACE in this case: */ 511 nace = 4 + state->users->n + state->groups->n; 512 pacl = posix_acl_alloc(nace, GFP_KERNEL); 513 if (!pacl) 514 return ERR_PTR(-ENOMEM); 515 516 pace = pacl->a_entries; 517 pace->e_tag = ACL_USER_OBJ; 518 low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags); 519 520 for (i=0; i < state->users->n; i++) { 521 pace++; 522 pace->e_tag = ACL_USER; 523 low_mode_from_nfs4(state->users->aces[i].perms.allow, 524 &pace->e_perm, flags); 525 pace->e_uid = state->users->aces[i].uid; 526 add_to_mask(state, &state->users->aces[i].perms); 527 } 528 529 pace++; 530 pace->e_tag = ACL_GROUP_OBJ; 531 low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags); 532 add_to_mask(state, &state->group); 533 534 for (i=0; i < state->groups->n; i++) { 535 pace++; 536 pace->e_tag = ACL_GROUP; 537 low_mode_from_nfs4(state->groups->aces[i].perms.allow, 538 &pace->e_perm, flags); 539 pace->e_gid = state->groups->aces[i].gid; 540 add_to_mask(state, &state->groups->aces[i].perms); 541 } 542 543 if (state->users->n || state->groups->n) { 544 pace++; 545 pace->e_tag = ACL_MASK; 546 low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags); 547 } 548 549 pace++; 550 pace->e_tag = ACL_OTHER; 551 low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags); 552 553 return pacl; 554} 555 556static inline void allow_bits(struct posix_ace_state *astate, u32 mask) 557{ 558 /* Allow all bits in the mask not already denied: */ 559 astate->allow |= mask & ~astate->deny; 560} 561 562static inline void deny_bits(struct posix_ace_state *astate, u32 mask) 563{ 564 /* Deny all bits in the mask not already allowed: */ 565 astate->deny |= mask & ~astate->allow; 566} 567 568static int find_uid(struct posix_acl_state *state, kuid_t uid) 569{ 570 struct posix_ace_state_array *a = state->users; 571 int i; 572 573 for (i = 0; i < a->n; i++) 574 if (uid_eq(a->aces[i].uid, uid)) 575 return i; 576 /* Not found: */ 577 a->n++; 578 a->aces[i].uid = uid; 579 a->aces[i].perms.allow = state->everyone.allow; 580 a->aces[i].perms.deny = state->everyone.deny; 581 582 return i; 583} 584 585static int find_gid(struct posix_acl_state *state, kgid_t gid) 586{ 587 struct posix_ace_state_array *a = state->groups; 588 int i; 589 590 for (i = 0; i < a->n; i++) 591 if (gid_eq(a->aces[i].gid, gid)) 592 return i; 593 /* Not found: */ 594 a->n++; 595 a->aces[i].gid = gid; 596 a->aces[i].perms.allow = state->everyone.allow; 597 a->aces[i].perms.deny = state->everyone.deny; 598 599 return i; 600} 601 602static void deny_bits_array(struct posix_ace_state_array *a, u32 mask) 603{ 604 int i; 605 606 for (i=0; i < a->n; i++) 607 deny_bits(&a->aces[i].perms, mask); 608} 609 610static void allow_bits_array(struct posix_ace_state_array *a, u32 mask) 611{ 612 int i; 613 614 for (i=0; i < a->n; i++) 615 allow_bits(&a->aces[i].perms, mask); 616} 617 618static void process_one_v4_ace(struct posix_acl_state *state, 619 struct nfs4_ace *ace) 620{ 621 u32 mask = ace->access_mask; 622 short type = ace2type(ace); 623 int i; 624 625 state->valid |= type; 626 627 switch (type) { 628 case ACL_USER_OBJ: 629 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 630 allow_bits(&state->owner, mask); 631 } else { 632 deny_bits(&state->owner, mask); 633 } 634 break; 635 case ACL_USER: 636 i = find_uid(state, ace->who_uid); 637 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 638 allow_bits(&state->users->aces[i].perms, mask); 639 } else { 640 deny_bits(&state->users->aces[i].perms, mask); 641 mask = state->users->aces[i].perms.deny; 642 deny_bits(&state->owner, mask); 643 } 644 break; 645 case ACL_GROUP_OBJ: 646 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 647 allow_bits(&state->group, mask); 648 } else { 649 deny_bits(&state->group, mask); 650 mask = state->group.deny; 651 deny_bits(&state->owner, mask); 652 deny_bits(&state->everyone, mask); 653 deny_bits_array(state->users, mask); 654 deny_bits_array(state->groups, mask); 655 } 656 break; 657 case ACL_GROUP: 658 i = find_gid(state, ace->who_gid); 659 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 660 allow_bits(&state->groups->aces[i].perms, mask); 661 } else { 662 deny_bits(&state->groups->aces[i].perms, mask); 663 mask = state->groups->aces[i].perms.deny; 664 deny_bits(&state->owner, mask); 665 deny_bits(&state->group, mask); 666 deny_bits(&state->everyone, mask); 667 deny_bits_array(state->users, mask); 668 deny_bits_array(state->groups, mask); 669 } 670 break; 671 case ACL_OTHER: 672 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 673 allow_bits(&state->owner, mask); 674 allow_bits(&state->group, mask); 675 allow_bits(&state->other, mask); 676 allow_bits(&state->everyone, mask); 677 allow_bits_array(state->users, mask); 678 allow_bits_array(state->groups, mask); 679 } else { 680 deny_bits(&state->owner, mask); 681 deny_bits(&state->group, mask); 682 deny_bits(&state->other, mask); 683 deny_bits(&state->everyone, mask); 684 deny_bits_array(state->users, mask); 685 deny_bits_array(state->groups, mask); 686 } 687 } 688} 689 690static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, 691 struct posix_acl **pacl, struct posix_acl **dpacl, 692 unsigned int flags) 693{ 694 struct posix_acl_state effective_acl_state, default_acl_state; 695 struct nfs4_ace *ace; 696 int ret; 697 698 ret = init_state(&effective_acl_state, acl->naces); 699 if (ret) 700 return ret; 701 ret = init_state(&default_acl_state, acl->naces); 702 if (ret) 703 goto out_estate; 704 ret = -EINVAL; 705 for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) { 706 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE && 707 ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE) 708 goto out_dstate; 709 if (ace->flag & ~NFS4_SUPPORTED_FLAGS) 710 goto out_dstate; 711 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) { 712 process_one_v4_ace(&effective_acl_state, ace); 713 continue; 714 } 715 if (!(flags & NFS4_ACL_DIR)) 716 goto out_dstate; 717 /* 718 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT 719 * is set, we're effectively turning on the other. That's OK, 720 * according to rfc 3530. 721 */ 722 process_one_v4_ace(&default_acl_state, ace); 723 724 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE)) 725 process_one_v4_ace(&effective_acl_state, ace); 726 } 727 728 /* 729 * At this point, the default ACL may have zeroed-out entries for owner, 730 * group and other. That usually results in a non-sensical resulting ACL 731 * that denies all access except to any ACE that was explicitly added. 732 * 733 * The setfacl command solves a similar problem with this logic: 734 * 735 * "If a Default ACL entry is created, and the Default ACL contains 736 * no owner, owning group, or others entry, a copy of the ACL 737 * owner, owning group, or others entry is added to the Default ACL." 738 * 739 * Copy any missing ACEs from the effective set, if any ACEs were 740 * explicitly set. 741 */ 742 if (default_acl_state.valid) { 743 if (!(default_acl_state.valid & ACL_USER_OBJ)) 744 default_acl_state.owner = effective_acl_state.owner; 745 if (!(default_acl_state.valid & ACL_GROUP_OBJ)) 746 default_acl_state.group = effective_acl_state.group; 747 if (!(default_acl_state.valid & ACL_OTHER)) 748 default_acl_state.other = effective_acl_state.other; 749 } 750 751 *pacl = posix_state_to_acl(&effective_acl_state, flags); 752 if (IS_ERR(*pacl)) { 753 ret = PTR_ERR(*pacl); 754 *pacl = NULL; 755 goto out_dstate; 756 } 757 *dpacl = posix_state_to_acl(&default_acl_state, 758 flags | NFS4_ACL_TYPE_DEFAULT); 759 if (IS_ERR(*dpacl)) { 760 ret = PTR_ERR(*dpacl); 761 *dpacl = NULL; 762 posix_acl_release(*pacl); 763 *pacl = NULL; 764 goto out_dstate; 765 } 766 sort_pacl(*pacl); 767 sort_pacl(*dpacl); 768 ret = 0; 769out_dstate: 770 free_state(&default_acl_state); 771out_estate: 772 free_state(&effective_acl_state); 773 return ret; 774} 775 776__be32 nfsd4_acl_to_attr(enum nfs_ftype4 type, struct nfs4_acl *acl, 777 struct nfsd_attrs *attr) 778{ 779 int host_error; 780 unsigned int flags = 0; 781 782 if (!acl) 783 return nfs_ok; 784 785 if (type == NF4DIR) 786 flags = NFS4_ACL_DIR; 787 788 host_error = nfs4_acl_nfsv4_to_posix(acl, &attr->na_pacl, 789 &attr->na_dpacl, flags); 790 if (host_error == -EINVAL) 791 return nfserr_attrnotsupp; 792 else 793 return nfserrno(host_error); 794} 795 796static short 797ace2type(struct nfs4_ace *ace) 798{ 799 switch (ace->whotype) { 800 case NFS4_ACL_WHO_NAMED: 801 return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ? 802 ACL_GROUP : ACL_USER); 803 case NFS4_ACL_WHO_OWNER: 804 return ACL_USER_OBJ; 805 case NFS4_ACL_WHO_GROUP: 806 return ACL_GROUP_OBJ; 807 case NFS4_ACL_WHO_EVERYONE: 808 return ACL_OTHER; 809 } 810 BUG(); 811 return -1; 812} 813 814/* 815 * return the size of the struct nfs4_acl required to represent an acl 816 * with @entries entries. 817 */ 818int nfs4_acl_bytes(int entries) 819{ 820 return sizeof(struct nfs4_acl) + entries * sizeof(struct nfs4_ace); 821} 822 823static struct { 824 char *string; 825 int stringlen; 826 int type; 827} s2t_map[] = { 828 { 829 .string = "OWNER@", 830 .stringlen = sizeof("OWNER@") - 1, 831 .type = NFS4_ACL_WHO_OWNER, 832 }, 833 { 834 .string = "GROUP@", 835 .stringlen = sizeof("GROUP@") - 1, 836 .type = NFS4_ACL_WHO_GROUP, 837 }, 838 { 839 .string = "EVERYONE@", 840 .stringlen = sizeof("EVERYONE@") - 1, 841 .type = NFS4_ACL_WHO_EVERYONE, 842 }, 843}; 844 845int 846nfs4_acl_get_whotype(char *p, u32 len) 847{ 848 int i; 849 850 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 851 if (s2t_map[i].stringlen == len && 852 0 == memcmp(s2t_map[i].string, p, len)) 853 return s2t_map[i].type; 854 } 855 return NFS4_ACL_WHO_NAMED; 856} 857 858__be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who) 859{ 860 __be32 *p; 861 int i; 862 863 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 864 if (s2t_map[i].type != who) 865 continue; 866 p = xdr_reserve_space(xdr, s2t_map[i].stringlen + 4); 867 if (!p) 868 return nfserr_resource; 869 p = xdr_encode_opaque(p, s2t_map[i].string, 870 s2t_map[i].stringlen); 871 return 0; 872 } 873 WARN_ON_ONCE(1); 874 return nfserr_serverfault; 875}
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