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 mask_from_posix(unsigned short perm,unsigned int flags)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 deny_mask_from_posix(unsigned short perm,u32 flags)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 low_mode_from_nfs4(u32 perm,unsigned short * mode,unsigned int flags)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 nfsd4_get_nfs4_acl(struct svc_rqst * rqstp,struct dentry * dentry,struct nfs4_acl ** acl)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 summarize_posix_acl(struct posix_acl * acl,struct posix_acl_summary * pas)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 pe = acl->a_entries + acl->a_count; 202 203 FOREACH_ACL_ENTRY(pa, acl, pe) { 204 switch (pa->e_tag) { 205 case ACL_USER_OBJ: 206 pas->owner = pa->e_perm; 207 break; 208 case ACL_GROUP_OBJ: 209 pas->group = pa->e_perm; 210 break; 211 case ACL_USER: 212 pas->users |= pa->e_perm; 213 break; 214 case ACL_GROUP: 215 pas->groups |= pa->e_perm; 216 break; 217 case ACL_OTHER: 218 pas->other = pa->e_perm; 219 break; 220 case ACL_MASK: 221 pas->mask = pa->e_perm; 222 break; 223 } 224 } 225 /* We'll only care about effective permissions: */ 226 pas->users &= pas->mask; 227 pas->group &= pas->mask; 228 pas->groups &= pas->mask; 229 } 230 231 /* We assume the acl has been verified with posix_acl_valid. */ 232 static void _posix_to_nfsv4_one(struct posix_acl * pacl,struct nfs4_acl * acl,unsigned int flags)233 _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl, 234 unsigned int flags) 235 { 236 struct posix_acl_entry *pa, *group_owner_entry; 237 struct nfs4_ace *ace; 238 struct posix_acl_summary pas; 239 unsigned short deny; 240 int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ? 241 NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0); 242 243 BUG_ON(pacl->a_count < 3); 244 summarize_posix_acl(pacl, &pas); 245 246 pa = pacl->a_entries; 247 ace = acl->aces + acl->naces; 248 249 /* We could deny everything not granted by the owner: */ 250 deny = ~pas.owner; 251 /* 252 * but it is equivalent (and simpler) to deny only what is not 253 * granted by later entries: 254 */ 255 deny &= pas.users | pas.group | pas.groups | pas.other; 256 if (deny) { 257 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 258 ace->flag = eflag; 259 ace->access_mask = deny_mask_from_posix(deny, flags); 260 ace->whotype = NFS4_ACL_WHO_OWNER; 261 ace++; 262 acl->naces++; 263 } 264 265 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 266 ace->flag = eflag; 267 ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER); 268 ace->whotype = NFS4_ACL_WHO_OWNER; 269 ace++; 270 acl->naces++; 271 pa++; 272 273 while (pa->e_tag == ACL_USER) { 274 deny = ~(pa->e_perm & pas.mask); 275 deny &= pas.groups | pas.group | pas.other; 276 if (deny) { 277 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 278 ace->flag = eflag; 279 ace->access_mask = deny_mask_from_posix(deny, flags); 280 ace->whotype = NFS4_ACL_WHO_NAMED; 281 ace->who_uid = pa->e_uid; 282 ace++; 283 acl->naces++; 284 } 285 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 286 ace->flag = eflag; 287 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, 288 flags); 289 ace->whotype = NFS4_ACL_WHO_NAMED; 290 ace->who_uid = pa->e_uid; 291 ace++; 292 acl->naces++; 293 pa++; 294 } 295 296 /* In the case of groups, we apply allow ACEs first, then deny ACEs, 297 * since a user can be in more than one group. */ 298 299 /* allow ACEs */ 300 301 group_owner_entry = pa; 302 303 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 304 ace->flag = eflag; 305 ace->access_mask = mask_from_posix(pas.group, flags); 306 ace->whotype = NFS4_ACL_WHO_GROUP; 307 ace++; 308 acl->naces++; 309 pa++; 310 311 while (pa->e_tag == ACL_GROUP) { 312 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 313 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; 314 ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, 315 flags); 316 ace->whotype = NFS4_ACL_WHO_NAMED; 317 ace->who_gid = pa->e_gid; 318 ace++; 319 acl->naces++; 320 pa++; 321 } 322 323 /* deny ACEs */ 324 325 pa = group_owner_entry; 326 327 deny = ~pas.group & pas.other; 328 if (deny) { 329 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 330 ace->flag = eflag; 331 ace->access_mask = deny_mask_from_posix(deny, flags); 332 ace->whotype = NFS4_ACL_WHO_GROUP; 333 ace++; 334 acl->naces++; 335 } 336 pa++; 337 338 while (pa->e_tag == ACL_GROUP) { 339 deny = ~(pa->e_perm & pas.mask); 340 deny &= pas.other; 341 if (deny) { 342 ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; 343 ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; 344 ace->access_mask = deny_mask_from_posix(deny, flags); 345 ace->whotype = NFS4_ACL_WHO_NAMED; 346 ace->who_gid = pa->e_gid; 347 ace++; 348 acl->naces++; 349 } 350 pa++; 351 } 352 353 if (pa->e_tag == ACL_MASK) 354 pa++; 355 ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; 356 ace->flag = eflag; 357 ace->access_mask = mask_from_posix(pa->e_perm, flags); 358 ace->whotype = NFS4_ACL_WHO_EVERYONE; 359 acl->naces++; 360 } 361 362 static bool pace_gt(struct posix_acl_entry * pace1,struct posix_acl_entry * pace2)363 pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2) 364 { 365 if (pace1->e_tag != pace2->e_tag) 366 return pace1->e_tag > pace2->e_tag; 367 if (pace1->e_tag == ACL_USER) 368 return uid_gt(pace1->e_uid, pace2->e_uid); 369 if (pace1->e_tag == ACL_GROUP) 370 return gid_gt(pace1->e_gid, pace2->e_gid); 371 return false; 372 } 373 374 static void sort_pacl_range(struct posix_acl * pacl,int start,int end)375 sort_pacl_range(struct posix_acl *pacl, int start, int end) { 376 int sorted = 0, i; 377 378 /* We just do a bubble sort; easy to do in place, and we're not 379 * expecting acl's to be long enough to justify anything more. */ 380 while (!sorted) { 381 sorted = 1; 382 for (i = start; i < end; i++) { 383 if (pace_gt(&pacl->a_entries[i], 384 &pacl->a_entries[i+1])) { 385 sorted = 0; 386 swap(pacl->a_entries[i], 387 pacl->a_entries[i + 1]); 388 } 389 } 390 } 391 } 392 393 static void sort_pacl(struct posix_acl * pacl)394 sort_pacl(struct posix_acl *pacl) 395 { 396 /* posix_acl_valid requires that users and groups be in order 397 * by uid/gid. */ 398 int i, j; 399 400 /* no users or groups */ 401 if (!pacl || pacl->a_count <= 4) 402 return; 403 404 i = 1; 405 while (pacl->a_entries[i].e_tag == ACL_USER) 406 i++; 407 sort_pacl_range(pacl, 1, i-1); 408 409 BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ); 410 j = ++i; 411 while (pacl->a_entries[j].e_tag == ACL_GROUP) 412 j++; 413 sort_pacl_range(pacl, i, j-1); 414 return; 415 } 416 417 /* 418 * While processing the NFSv4 ACE, this maintains bitmasks representing 419 * which permission bits have been allowed and which denied to a given 420 * entity: */ 421 struct posix_ace_state { 422 u32 allow; 423 u32 deny; 424 }; 425 426 struct posix_user_ace_state { 427 union { 428 kuid_t uid; 429 kgid_t gid; 430 }; 431 struct posix_ace_state perms; 432 }; 433 434 struct posix_ace_state_array { 435 int n; 436 struct posix_user_ace_state aces[]; 437 }; 438 439 /* 440 * While processing the NFSv4 ACE, this maintains the partial permissions 441 * calculated so far: */ 442 443 struct posix_acl_state { 444 unsigned char valid; 445 struct posix_ace_state owner; 446 struct posix_ace_state group; 447 struct posix_ace_state other; 448 struct posix_ace_state everyone; 449 struct posix_ace_state mask; /* Deny unused in this case */ 450 struct posix_ace_state_array *users; 451 struct posix_ace_state_array *groups; 452 }; 453 454 static int init_state(struct posix_acl_state * state,int cnt)455 init_state(struct posix_acl_state *state, int cnt) 456 { 457 int alloc; 458 459 memset(state, 0, sizeof(struct posix_acl_state)); 460 /* 461 * In the worst case, each individual acl could be for a distinct 462 * named user or group, but we don't know which, so we allocate 463 * enough space for either: 464 */ 465 alloc = sizeof(struct posix_ace_state_array) 466 + cnt*sizeof(struct posix_user_ace_state); 467 state->users = kzalloc(alloc, GFP_KERNEL); 468 if (!state->users) 469 return -ENOMEM; 470 state->groups = kzalloc(alloc, GFP_KERNEL); 471 if (!state->groups) { 472 kfree(state->users); 473 return -ENOMEM; 474 } 475 return 0; 476 } 477 478 static void free_state(struct posix_acl_state * state)479 free_state(struct posix_acl_state *state) { 480 kfree(state->users); 481 kfree(state->groups); 482 } 483 add_to_mask(struct posix_acl_state * state,struct posix_ace_state * astate)484 static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate) 485 { 486 state->mask.allow |= astate->allow; 487 } 488 489 static struct posix_acl * posix_state_to_acl(struct posix_acl_state * state,unsigned int flags)490 posix_state_to_acl(struct posix_acl_state *state, unsigned int flags) 491 { 492 struct posix_acl_entry *pace; 493 struct posix_acl *pacl; 494 int nace; 495 int i; 496 497 /* 498 * ACLs with no ACEs are treated differently in the inheritable 499 * and effective cases: when there are no inheritable ACEs, 500 * calls ->set_acl with a NULL ACL structure. 501 */ 502 if (!state->valid && (flags & NFS4_ACL_TYPE_DEFAULT)) 503 return NULL; 504 505 /* 506 * When there are no effective ACEs, the following will end 507 * up setting a 3-element effective posix ACL with all 508 * permissions zero. 509 */ 510 if (!state->users->n && !state->groups->n) 511 nace = 3; 512 else /* Note we also include a MASK ACE in this case: */ 513 nace = 4 + state->users->n + state->groups->n; 514 pacl = posix_acl_alloc(nace, GFP_KERNEL); 515 if (!pacl) 516 return ERR_PTR(-ENOMEM); 517 518 pace = pacl->a_entries; 519 pace->e_tag = ACL_USER_OBJ; 520 low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags); 521 522 for (i=0; i < state->users->n; i++) { 523 pace++; 524 pace->e_tag = ACL_USER; 525 low_mode_from_nfs4(state->users->aces[i].perms.allow, 526 &pace->e_perm, flags); 527 pace->e_uid = state->users->aces[i].uid; 528 add_to_mask(state, &state->users->aces[i].perms); 529 } 530 531 pace++; 532 pace->e_tag = ACL_GROUP_OBJ; 533 low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags); 534 add_to_mask(state, &state->group); 535 536 for (i=0; i < state->groups->n; i++) { 537 pace++; 538 pace->e_tag = ACL_GROUP; 539 low_mode_from_nfs4(state->groups->aces[i].perms.allow, 540 &pace->e_perm, flags); 541 pace->e_gid = state->groups->aces[i].gid; 542 add_to_mask(state, &state->groups->aces[i].perms); 543 } 544 545 if (state->users->n || state->groups->n) { 546 pace++; 547 pace->e_tag = ACL_MASK; 548 low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags); 549 } 550 551 pace++; 552 pace->e_tag = ACL_OTHER; 553 low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags); 554 555 return pacl; 556 } 557 allow_bits(struct posix_ace_state * astate,u32 mask)558 static inline void allow_bits(struct posix_ace_state *astate, u32 mask) 559 { 560 /* Allow all bits in the mask not already denied: */ 561 astate->allow |= mask & ~astate->deny; 562 } 563 deny_bits(struct posix_ace_state * astate,u32 mask)564 static inline void deny_bits(struct posix_ace_state *astate, u32 mask) 565 { 566 /* Deny all bits in the mask not already allowed: */ 567 astate->deny |= mask & ~astate->allow; 568 } 569 find_uid(struct posix_acl_state * state,kuid_t uid)570 static int find_uid(struct posix_acl_state *state, kuid_t uid) 571 { 572 struct posix_ace_state_array *a = state->users; 573 int i; 574 575 for (i = 0; i < a->n; i++) 576 if (uid_eq(a->aces[i].uid, uid)) 577 return i; 578 /* Not found: */ 579 a->n++; 580 a->aces[i].uid = uid; 581 a->aces[i].perms.allow = state->everyone.allow; 582 a->aces[i].perms.deny = state->everyone.deny; 583 584 return i; 585 } 586 find_gid(struct posix_acl_state * state,kgid_t gid)587 static int find_gid(struct posix_acl_state *state, kgid_t gid) 588 { 589 struct posix_ace_state_array *a = state->groups; 590 int i; 591 592 for (i = 0; i < a->n; i++) 593 if (gid_eq(a->aces[i].gid, gid)) 594 return i; 595 /* Not found: */ 596 a->n++; 597 a->aces[i].gid = gid; 598 a->aces[i].perms.allow = state->everyone.allow; 599 a->aces[i].perms.deny = state->everyone.deny; 600 601 return i; 602 } 603 deny_bits_array(struct posix_ace_state_array * a,u32 mask)604 static void deny_bits_array(struct posix_ace_state_array *a, u32 mask) 605 { 606 int i; 607 608 for (i=0; i < a->n; i++) 609 deny_bits(&a->aces[i].perms, mask); 610 } 611 allow_bits_array(struct posix_ace_state_array * a,u32 mask)612 static void allow_bits_array(struct posix_ace_state_array *a, u32 mask) 613 { 614 int i; 615 616 for (i=0; i < a->n; i++) 617 allow_bits(&a->aces[i].perms, mask); 618 } 619 process_one_v4_ace(struct posix_acl_state * state,struct nfs4_ace * ace)620 static void process_one_v4_ace(struct posix_acl_state *state, 621 struct nfs4_ace *ace) 622 { 623 u32 mask = ace->access_mask; 624 short type = ace2type(ace); 625 int i; 626 627 state->valid |= type; 628 629 switch (type) { 630 case ACL_USER_OBJ: 631 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 632 allow_bits(&state->owner, mask); 633 } else { 634 deny_bits(&state->owner, mask); 635 } 636 break; 637 case ACL_USER: 638 i = find_uid(state, ace->who_uid); 639 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 640 allow_bits(&state->users->aces[i].perms, mask); 641 } else { 642 deny_bits(&state->users->aces[i].perms, mask); 643 mask = state->users->aces[i].perms.deny; 644 deny_bits(&state->owner, mask); 645 } 646 break; 647 case ACL_GROUP_OBJ: 648 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 649 allow_bits(&state->group, mask); 650 } else { 651 deny_bits(&state->group, mask); 652 mask = state->group.deny; 653 deny_bits(&state->owner, mask); 654 deny_bits(&state->everyone, mask); 655 deny_bits_array(state->users, mask); 656 deny_bits_array(state->groups, mask); 657 } 658 break; 659 case ACL_GROUP: 660 i = find_gid(state, ace->who_gid); 661 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 662 allow_bits(&state->groups->aces[i].perms, mask); 663 } else { 664 deny_bits(&state->groups->aces[i].perms, mask); 665 mask = state->groups->aces[i].perms.deny; 666 deny_bits(&state->owner, mask); 667 deny_bits(&state->group, mask); 668 deny_bits(&state->everyone, mask); 669 deny_bits_array(state->users, mask); 670 deny_bits_array(state->groups, mask); 671 } 672 break; 673 case ACL_OTHER: 674 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { 675 allow_bits(&state->owner, mask); 676 allow_bits(&state->group, mask); 677 allow_bits(&state->other, mask); 678 allow_bits(&state->everyone, mask); 679 allow_bits_array(state->users, mask); 680 allow_bits_array(state->groups, mask); 681 } else { 682 deny_bits(&state->owner, mask); 683 deny_bits(&state->group, mask); 684 deny_bits(&state->other, mask); 685 deny_bits(&state->everyone, mask); 686 deny_bits_array(state->users, mask); 687 deny_bits_array(state->groups, mask); 688 } 689 } 690 } 691 nfs4_acl_nfsv4_to_posix(struct nfs4_acl * acl,struct posix_acl ** pacl,struct posix_acl ** dpacl,unsigned int flags)692 static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, 693 struct posix_acl **pacl, struct posix_acl **dpacl, 694 unsigned int flags) 695 { 696 struct posix_acl_state effective_acl_state, default_acl_state; 697 struct nfs4_ace *ace; 698 int ret; 699 700 ret = init_state(&effective_acl_state, acl->naces); 701 if (ret) 702 return ret; 703 ret = init_state(&default_acl_state, acl->naces); 704 if (ret) 705 goto out_estate; 706 ret = -EINVAL; 707 for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) { 708 if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE && 709 ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE) 710 goto out_dstate; 711 if (ace->flag & ~NFS4_SUPPORTED_FLAGS) 712 goto out_dstate; 713 if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) { 714 process_one_v4_ace(&effective_acl_state, ace); 715 continue; 716 } 717 if (!(flags & NFS4_ACL_DIR)) 718 goto out_dstate; 719 /* 720 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT 721 * is set, we're effectively turning on the other. That's OK, 722 * according to rfc 3530. 723 */ 724 process_one_v4_ace(&default_acl_state, ace); 725 726 if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE)) 727 process_one_v4_ace(&effective_acl_state, ace); 728 } 729 730 /* 731 * At this point, the default ACL may have zeroed-out entries for owner, 732 * group and other. That usually results in a non-sensical resulting ACL 733 * that denies all access except to any ACE that was explicitly added. 734 * 735 * The setfacl command solves a similar problem with this logic: 736 * 737 * "If a Default ACL entry is created, and the Default ACL contains 738 * no owner, owning group, or others entry, a copy of the ACL 739 * owner, owning group, or others entry is added to the Default ACL." 740 * 741 * Copy any missing ACEs from the effective set, if any ACEs were 742 * explicitly set. 743 */ 744 if (default_acl_state.valid) { 745 if (!(default_acl_state.valid & ACL_USER_OBJ)) 746 default_acl_state.owner = effective_acl_state.owner; 747 if (!(default_acl_state.valid & ACL_GROUP_OBJ)) 748 default_acl_state.group = effective_acl_state.group; 749 if (!(default_acl_state.valid & ACL_OTHER)) 750 default_acl_state.other = effective_acl_state.other; 751 } 752 753 *pacl = posix_state_to_acl(&effective_acl_state, flags); 754 if (IS_ERR(*pacl)) { 755 ret = PTR_ERR(*pacl); 756 *pacl = NULL; 757 goto out_dstate; 758 } 759 *dpacl = posix_state_to_acl(&default_acl_state, 760 flags | NFS4_ACL_TYPE_DEFAULT); 761 if (IS_ERR(*dpacl)) { 762 ret = PTR_ERR(*dpacl); 763 *dpacl = NULL; 764 posix_acl_release(*pacl); 765 *pacl = NULL; 766 goto out_dstate; 767 } 768 sort_pacl(*pacl); 769 sort_pacl(*dpacl); 770 ret = 0; 771 out_dstate: 772 free_state(&default_acl_state); 773 out_estate: 774 free_state(&effective_acl_state); 775 return ret; 776 } 777 nfsd4_acl_to_attr(enum nfs_ftype4 type,struct nfs4_acl * acl,struct nfsd_attrs * attr)778 __be32 nfsd4_acl_to_attr(enum nfs_ftype4 type, struct nfs4_acl *acl, 779 struct nfsd_attrs *attr) 780 { 781 int host_error; 782 unsigned int flags = 0; 783 784 if (!acl) 785 return nfs_ok; 786 787 if (type == NF4DIR) 788 flags = NFS4_ACL_DIR; 789 790 host_error = nfs4_acl_nfsv4_to_posix(acl, &attr->na_pacl, 791 &attr->na_dpacl, flags); 792 if (host_error == -EINVAL) 793 return nfserr_attrnotsupp; 794 else 795 return nfserrno(host_error); 796 } 797 798 static short ace2type(struct nfs4_ace * ace)799 ace2type(struct nfs4_ace *ace) 800 { 801 switch (ace->whotype) { 802 case NFS4_ACL_WHO_NAMED: 803 return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ? 804 ACL_GROUP : ACL_USER); 805 case NFS4_ACL_WHO_OWNER: 806 return ACL_USER_OBJ; 807 case NFS4_ACL_WHO_GROUP: 808 return ACL_GROUP_OBJ; 809 case NFS4_ACL_WHO_EVERYONE: 810 return ACL_OTHER; 811 } 812 BUG(); 813 return -1; 814 } 815 816 /* 817 * return the size of the struct nfs4_acl required to represent an acl 818 * with @entries entries. 819 */ nfs4_acl_bytes(int entries)820 int nfs4_acl_bytes(int entries) 821 { 822 return sizeof(struct nfs4_acl) + entries * sizeof(struct nfs4_ace); 823 } 824 825 static struct { 826 char *string; 827 int stringlen; 828 int type; 829 } s2t_map[] = { 830 { 831 .string = "OWNER@", 832 .stringlen = sizeof("OWNER@") - 1, 833 .type = NFS4_ACL_WHO_OWNER, 834 }, 835 { 836 .string = "GROUP@", 837 .stringlen = sizeof("GROUP@") - 1, 838 .type = NFS4_ACL_WHO_GROUP, 839 }, 840 { 841 .string = "EVERYONE@", 842 .stringlen = sizeof("EVERYONE@") - 1, 843 .type = NFS4_ACL_WHO_EVERYONE, 844 }, 845 }; 846 847 int nfs4_acl_get_whotype(char * p,u32 len)848 nfs4_acl_get_whotype(char *p, u32 len) 849 { 850 int i; 851 852 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 853 if (s2t_map[i].stringlen == len && 854 0 == memcmp(s2t_map[i].string, p, len)) 855 return s2t_map[i].type; 856 } 857 return NFS4_ACL_WHO_NAMED; 858 } 859 nfs4_acl_write_who(struct xdr_stream * xdr,int who)860 __be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who) 861 { 862 __be32 *p; 863 int i; 864 865 for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { 866 if (s2t_map[i].type != who) 867 continue; 868 p = xdr_reserve_space(xdr, s2t_map[i].stringlen + 4); 869 if (!p) 870 return nfserr_resource; 871 p = xdr_encode_opaque(p, s2t_map[i].string, 872 s2t_map[i].stringlen); 873 return 0; 874 } 875 WARN_ON_ONCE(1); 876 return nfserr_serverfault; 877 } 878