1 /* 2 * Copyright (c) 2001-2002,2005 Silicon Graphics, Inc. 3 * All Rights Reserved. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it would be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 #include "xfs.h" 19 #include "xfs_fs.h" 20 #include "xfs_types.h" 21 #include "xfs_bit.h" 22 #include "xfs_inum.h" 23 #include "xfs_ag.h" 24 #include "xfs_dir2.h" 25 #include "xfs_bmap_btree.h" 26 #include "xfs_alloc_btree.h" 27 #include "xfs_ialloc_btree.h" 28 #include "xfs_dir2_sf.h" 29 #include "xfs_attr_sf.h" 30 #include "xfs_dinode.h" 31 #include "xfs_inode.h" 32 #include "xfs_btree.h" 33 #include "xfs_acl.h" 34 #include "xfs_attr.h" 35 #include "xfs_vnodeops.h" 36 37 #include <linux/capability.h> 38 #include <linux/posix_acl_xattr.h> 39 40 STATIC int xfs_acl_setmode(bhv_vnode_t *, xfs_acl_t *, int *); 41 STATIC void xfs_acl_filter_mode(mode_t, xfs_acl_t *); 42 STATIC void xfs_acl_get_endian(xfs_acl_t *); 43 STATIC int xfs_acl_access(uid_t, gid_t, xfs_acl_t *, mode_t, cred_t *); 44 STATIC int xfs_acl_invalid(xfs_acl_t *); 45 STATIC void xfs_acl_sync_mode(mode_t, xfs_acl_t *); 46 STATIC void xfs_acl_get_attr(bhv_vnode_t *, xfs_acl_t *, int, int, int *); 47 STATIC void xfs_acl_set_attr(bhv_vnode_t *, xfs_acl_t *, int, int *); 48 STATIC int xfs_acl_allow_set(bhv_vnode_t *, int); 49 50 kmem_zone_t *xfs_acl_zone; 51 52 53 /* 54 * Test for existence of access ACL attribute as efficiently as possible. 55 */ 56 int 57 xfs_acl_vhasacl_access( 58 bhv_vnode_t *vp) 59 { 60 int error; 61 62 xfs_acl_get_attr(vp, NULL, _ACL_TYPE_ACCESS, ATTR_KERNOVAL, &error); 63 return (error == 0); 64 } 65 66 /* 67 * Test for existence of default ACL attribute as efficiently as possible. 68 */ 69 int 70 xfs_acl_vhasacl_default( 71 bhv_vnode_t *vp) 72 { 73 int error; 74 75 if (!VN_ISDIR(vp)) 76 return 0; 77 xfs_acl_get_attr(vp, NULL, _ACL_TYPE_DEFAULT, ATTR_KERNOVAL, &error); 78 return (error == 0); 79 } 80 81 /* 82 * Convert from extended attribute representation to in-memory for XFS. 83 */ 84 STATIC int 85 posix_acl_xattr_to_xfs( 86 posix_acl_xattr_header *src, 87 size_t size, 88 xfs_acl_t *dest) 89 { 90 posix_acl_xattr_entry *src_entry; 91 xfs_acl_entry_t *dest_entry; 92 int n; 93 94 if (!src || !dest) 95 return EINVAL; 96 97 if (size < sizeof(posix_acl_xattr_header)) 98 return EINVAL; 99 100 if (src->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION)) 101 return EOPNOTSUPP; 102 103 memset(dest, 0, sizeof(xfs_acl_t)); 104 dest->acl_cnt = posix_acl_xattr_count(size); 105 if (dest->acl_cnt < 0 || dest->acl_cnt > XFS_ACL_MAX_ENTRIES) 106 return EINVAL; 107 108 /* 109 * acl_set_file(3) may request that we set default ACLs with 110 * zero length -- defend (gracefully) against that here. 111 */ 112 if (!dest->acl_cnt) 113 return 0; 114 115 src_entry = (posix_acl_xattr_entry *)((char *)src + sizeof(*src)); 116 dest_entry = &dest->acl_entry[0]; 117 118 for (n = 0; n < dest->acl_cnt; n++, src_entry++, dest_entry++) { 119 dest_entry->ae_perm = le16_to_cpu(src_entry->e_perm); 120 if (_ACL_PERM_INVALID(dest_entry->ae_perm)) 121 return EINVAL; 122 dest_entry->ae_tag = le16_to_cpu(src_entry->e_tag); 123 switch(dest_entry->ae_tag) { 124 case ACL_USER: 125 case ACL_GROUP: 126 dest_entry->ae_id = le32_to_cpu(src_entry->e_id); 127 break; 128 case ACL_USER_OBJ: 129 case ACL_GROUP_OBJ: 130 case ACL_MASK: 131 case ACL_OTHER: 132 dest_entry->ae_id = ACL_UNDEFINED_ID; 133 break; 134 default: 135 return EINVAL; 136 } 137 } 138 if (xfs_acl_invalid(dest)) 139 return EINVAL; 140 141 return 0; 142 } 143 144 /* 145 * Comparison function called from xfs_sort(). 146 * Primary key is ae_tag, secondary key is ae_id. 147 */ 148 STATIC int 149 xfs_acl_entry_compare( 150 const void *va, 151 const void *vb) 152 { 153 xfs_acl_entry_t *a = (xfs_acl_entry_t *)va, 154 *b = (xfs_acl_entry_t *)vb; 155 156 if (a->ae_tag == b->ae_tag) 157 return (a->ae_id - b->ae_id); 158 return (a->ae_tag - b->ae_tag); 159 } 160 161 /* 162 * Convert from in-memory XFS to extended attribute representation. 163 */ 164 STATIC int 165 posix_acl_xfs_to_xattr( 166 xfs_acl_t *src, 167 posix_acl_xattr_header *dest, 168 size_t size) 169 { 170 int n; 171 size_t new_size = posix_acl_xattr_size(src->acl_cnt); 172 posix_acl_xattr_entry *dest_entry; 173 xfs_acl_entry_t *src_entry; 174 175 if (size < new_size) 176 return -ERANGE; 177 178 /* Need to sort src XFS ACL by <ae_tag,ae_id> */ 179 xfs_sort(src->acl_entry, src->acl_cnt, sizeof(src->acl_entry[0]), 180 xfs_acl_entry_compare); 181 182 dest->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION); 183 dest_entry = &dest->a_entries[0]; 184 src_entry = &src->acl_entry[0]; 185 for (n = 0; n < src->acl_cnt; n++, dest_entry++, src_entry++) { 186 dest_entry->e_perm = cpu_to_le16(src_entry->ae_perm); 187 if (_ACL_PERM_INVALID(src_entry->ae_perm)) 188 return -EINVAL; 189 dest_entry->e_tag = cpu_to_le16(src_entry->ae_tag); 190 switch (src_entry->ae_tag) { 191 case ACL_USER: 192 case ACL_GROUP: 193 dest_entry->e_id = cpu_to_le32(src_entry->ae_id); 194 break; 195 case ACL_USER_OBJ: 196 case ACL_GROUP_OBJ: 197 case ACL_MASK: 198 case ACL_OTHER: 199 dest_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID); 200 break; 201 default: 202 return -EINVAL; 203 } 204 } 205 return new_size; 206 } 207 208 int 209 xfs_acl_vget( 210 bhv_vnode_t *vp, 211 void *acl, 212 size_t size, 213 int kind) 214 { 215 int error; 216 xfs_acl_t *xfs_acl = NULL; 217 posix_acl_xattr_header *ext_acl = acl; 218 int flags = 0; 219 220 VN_HOLD(vp); 221 if(size) { 222 if (!(_ACL_ALLOC(xfs_acl))) { 223 error = ENOMEM; 224 goto out; 225 } 226 memset(xfs_acl, 0, sizeof(xfs_acl_t)); 227 } else 228 flags = ATTR_KERNOVAL; 229 230 xfs_acl_get_attr(vp, xfs_acl, kind, flags, &error); 231 if (error) 232 goto out; 233 234 if (!size) { 235 error = -posix_acl_xattr_size(XFS_ACL_MAX_ENTRIES); 236 } else { 237 if (xfs_acl_invalid(xfs_acl)) { 238 error = EINVAL; 239 goto out; 240 } 241 if (kind == _ACL_TYPE_ACCESS) { 242 bhv_vattr_t va; 243 244 va.va_mask = XFS_AT_MODE; 245 error = xfs_getattr(xfs_vtoi(vp), &va, 0); 246 if (error) 247 goto out; 248 xfs_acl_sync_mode(va.va_mode, xfs_acl); 249 } 250 error = -posix_acl_xfs_to_xattr(xfs_acl, ext_acl, size); 251 } 252 out: 253 VN_RELE(vp); 254 if(xfs_acl) 255 _ACL_FREE(xfs_acl); 256 return -error; 257 } 258 259 int 260 xfs_acl_vremove( 261 bhv_vnode_t *vp, 262 int kind) 263 { 264 int error; 265 266 VN_HOLD(vp); 267 error = xfs_acl_allow_set(vp, kind); 268 if (!error) { 269 error = xfs_attr_remove(xfs_vtoi(vp), 270 kind == _ACL_TYPE_DEFAULT? 271 SGI_ACL_DEFAULT: SGI_ACL_FILE, 272 ATTR_ROOT); 273 if (error == ENOATTR) 274 error = 0; /* 'scool */ 275 } 276 VN_RELE(vp); 277 return -error; 278 } 279 280 int 281 xfs_acl_vset( 282 bhv_vnode_t *vp, 283 void *acl, 284 size_t size, 285 int kind) 286 { 287 posix_acl_xattr_header *ext_acl = acl; 288 xfs_acl_t *xfs_acl; 289 int error; 290 int basicperms = 0; /* more than std unix perms? */ 291 292 if (!acl) 293 return -EINVAL; 294 295 if (!(_ACL_ALLOC(xfs_acl))) 296 return -ENOMEM; 297 298 error = posix_acl_xattr_to_xfs(ext_acl, size, xfs_acl); 299 if (error) { 300 _ACL_FREE(xfs_acl); 301 return -error; 302 } 303 if (!xfs_acl->acl_cnt) { 304 _ACL_FREE(xfs_acl); 305 return 0; 306 } 307 308 VN_HOLD(vp); 309 error = xfs_acl_allow_set(vp, kind); 310 if (error) 311 goto out; 312 313 /* Incoming ACL exists, set file mode based on its value */ 314 if (kind == _ACL_TYPE_ACCESS) 315 xfs_acl_setmode(vp, xfs_acl, &basicperms); 316 317 /* 318 * If we have more than std unix permissions, set up the actual attr. 319 * Otherwise, delete any existing attr. This prevents us from 320 * having actual attrs for permissions that can be stored in the 321 * standard permission bits. 322 */ 323 if (!basicperms) { 324 xfs_acl_set_attr(vp, xfs_acl, kind, &error); 325 } else { 326 xfs_acl_vremove(vp, _ACL_TYPE_ACCESS); 327 } 328 329 out: 330 VN_RELE(vp); 331 _ACL_FREE(xfs_acl); 332 return -error; 333 } 334 335 int 336 xfs_acl_iaccess( 337 xfs_inode_t *ip, 338 mode_t mode, 339 cred_t *cr) 340 { 341 xfs_acl_t *acl; 342 int rval; 343 344 if (!(_ACL_ALLOC(acl))) 345 return -1; 346 347 /* If the file has no ACL return -1. */ 348 rval = sizeof(xfs_acl_t); 349 if (xfs_attr_fetch(ip, SGI_ACL_FILE, SGI_ACL_FILE_SIZE, 350 (char *)acl, &rval, ATTR_ROOT | ATTR_KERNACCESS, cr)) { 351 _ACL_FREE(acl); 352 return -1; 353 } 354 xfs_acl_get_endian(acl); 355 356 /* If the file has an empty ACL return -1. */ 357 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) { 358 _ACL_FREE(acl); 359 return -1; 360 } 361 362 /* Synchronize ACL with mode bits */ 363 xfs_acl_sync_mode(ip->i_d.di_mode, acl); 364 365 rval = xfs_acl_access(ip->i_d.di_uid, ip->i_d.di_gid, acl, mode, cr); 366 _ACL_FREE(acl); 367 return rval; 368 } 369 370 STATIC int 371 xfs_acl_allow_set( 372 bhv_vnode_t *vp, 373 int kind) 374 { 375 xfs_inode_t *ip = xfs_vtoi(vp); 376 bhv_vattr_t va; 377 int error; 378 379 if (vp->i_flags & (S_IMMUTABLE|S_APPEND)) 380 return EPERM; 381 if (kind == _ACL_TYPE_DEFAULT && !VN_ISDIR(vp)) 382 return ENOTDIR; 383 if (vp->i_sb->s_flags & MS_RDONLY) 384 return EROFS; 385 va.va_mask = XFS_AT_UID; 386 error = xfs_getattr(ip, &va, 0); 387 if (error) 388 return error; 389 if (va.va_uid != current->fsuid && !capable(CAP_FOWNER)) 390 return EPERM; 391 return error; 392 } 393 394 /* 395 * The access control process to determine the access permission: 396 * if uid == file owner id, use the file owner bits. 397 * if gid == file owner group id, use the file group bits. 398 * scan ACL for a matching user or group, and use matched entry 399 * permission. Use total permissions of all matching group entries, 400 * until all acl entries are exhausted. The final permission produced 401 * by matching acl entry or entries needs to be & with group permission. 402 * if not owner, owning group, or matching entry in ACL, use file 403 * other bits. 404 */ 405 STATIC int 406 xfs_acl_capability_check( 407 mode_t mode, 408 cred_t *cr) 409 { 410 if ((mode & ACL_READ) && !capable_cred(cr, CAP_DAC_READ_SEARCH)) 411 return EACCES; 412 if ((mode & ACL_WRITE) && !capable_cred(cr, CAP_DAC_OVERRIDE)) 413 return EACCES; 414 if ((mode & ACL_EXECUTE) && !capable_cred(cr, CAP_DAC_OVERRIDE)) 415 return EACCES; 416 417 return 0; 418 } 419 420 /* 421 * Note: cr is only used here for the capability check if the ACL test fails. 422 * It is not used to find out the credentials uid or groups etc, as was 423 * done in IRIX. It is assumed that the uid and groups for the current 424 * thread are taken from "current" instead of the cr parameter. 425 */ 426 STATIC int 427 xfs_acl_access( 428 uid_t fuid, 429 gid_t fgid, 430 xfs_acl_t *fap, 431 mode_t md, 432 cred_t *cr) 433 { 434 xfs_acl_entry_t matched; 435 int i, allows; 436 int maskallows = -1; /* true, but not 1, either */ 437 int seen_userobj = 0; 438 439 matched.ae_tag = 0; /* Invalid type */ 440 matched.ae_perm = 0; 441 md >>= 6; /* Normalize the bits for comparison */ 442 443 for (i = 0; i < fap->acl_cnt; i++) { 444 /* 445 * Break out if we've got a user_obj entry or 446 * a user entry and the mask (and have processed USER_OBJ) 447 */ 448 if (matched.ae_tag == ACL_USER_OBJ) 449 break; 450 if (matched.ae_tag == ACL_USER) { 451 if (maskallows != -1 && seen_userobj) 452 break; 453 if (fap->acl_entry[i].ae_tag != ACL_MASK && 454 fap->acl_entry[i].ae_tag != ACL_USER_OBJ) 455 continue; 456 } 457 /* True if this entry allows the requested access */ 458 allows = ((fap->acl_entry[i].ae_perm & md) == md); 459 460 switch (fap->acl_entry[i].ae_tag) { 461 case ACL_USER_OBJ: 462 seen_userobj = 1; 463 if (fuid != current->fsuid) 464 continue; 465 matched.ae_tag = ACL_USER_OBJ; 466 matched.ae_perm = allows; 467 break; 468 case ACL_USER: 469 if (fap->acl_entry[i].ae_id != current->fsuid) 470 continue; 471 matched.ae_tag = ACL_USER; 472 matched.ae_perm = allows; 473 break; 474 case ACL_GROUP_OBJ: 475 if ((matched.ae_tag == ACL_GROUP_OBJ || 476 matched.ae_tag == ACL_GROUP) && !allows) 477 continue; 478 if (!in_group_p(fgid)) 479 continue; 480 matched.ae_tag = ACL_GROUP_OBJ; 481 matched.ae_perm = allows; 482 break; 483 case ACL_GROUP: 484 if ((matched.ae_tag == ACL_GROUP_OBJ || 485 matched.ae_tag == ACL_GROUP) && !allows) 486 continue; 487 if (!in_group_p(fap->acl_entry[i].ae_id)) 488 continue; 489 matched.ae_tag = ACL_GROUP; 490 matched.ae_perm = allows; 491 break; 492 case ACL_MASK: 493 maskallows = allows; 494 break; 495 case ACL_OTHER: 496 if (matched.ae_tag != 0) 497 continue; 498 matched.ae_tag = ACL_OTHER; 499 matched.ae_perm = allows; 500 break; 501 } 502 } 503 /* 504 * First possibility is that no matched entry allows access. 505 * The capability to override DAC may exist, so check for it. 506 */ 507 switch (matched.ae_tag) { 508 case ACL_OTHER: 509 case ACL_USER_OBJ: 510 if (matched.ae_perm) 511 return 0; 512 break; 513 case ACL_USER: 514 case ACL_GROUP_OBJ: 515 case ACL_GROUP: 516 if (maskallows && matched.ae_perm) 517 return 0; 518 break; 519 case 0: 520 break; 521 } 522 523 return xfs_acl_capability_check(md, cr); 524 } 525 526 /* 527 * ACL validity checker. 528 * This acl validation routine checks each ACL entry read in makes sense. 529 */ 530 STATIC int 531 xfs_acl_invalid( 532 xfs_acl_t *aclp) 533 { 534 xfs_acl_entry_t *entry, *e; 535 int user = 0, group = 0, other = 0, mask = 0; 536 int mask_required = 0; 537 int i, j; 538 539 if (!aclp) 540 goto acl_invalid; 541 542 if (aclp->acl_cnt > XFS_ACL_MAX_ENTRIES) 543 goto acl_invalid; 544 545 for (i = 0; i < aclp->acl_cnt; i++) { 546 entry = &aclp->acl_entry[i]; 547 switch (entry->ae_tag) { 548 case ACL_USER_OBJ: 549 if (user++) 550 goto acl_invalid; 551 break; 552 case ACL_GROUP_OBJ: 553 if (group++) 554 goto acl_invalid; 555 break; 556 case ACL_OTHER: 557 if (other++) 558 goto acl_invalid; 559 break; 560 case ACL_USER: 561 case ACL_GROUP: 562 for (j = i + 1; j < aclp->acl_cnt; j++) { 563 e = &aclp->acl_entry[j]; 564 if (e->ae_id == entry->ae_id && 565 e->ae_tag == entry->ae_tag) 566 goto acl_invalid; 567 } 568 mask_required++; 569 break; 570 case ACL_MASK: 571 if (mask++) 572 goto acl_invalid; 573 break; 574 default: 575 goto acl_invalid; 576 } 577 } 578 if (!user || !group || !other || (mask_required && !mask)) 579 goto acl_invalid; 580 else 581 return 0; 582 acl_invalid: 583 return EINVAL; 584 } 585 586 /* 587 * Do ACL endian conversion. 588 */ 589 STATIC void 590 xfs_acl_get_endian( 591 xfs_acl_t *aclp) 592 { 593 xfs_acl_entry_t *ace, *end; 594 595 INT_SET(aclp->acl_cnt, ARCH_CONVERT, aclp->acl_cnt); 596 end = &aclp->acl_entry[0]+aclp->acl_cnt; 597 for (ace = &aclp->acl_entry[0]; ace < end; ace++) { 598 INT_SET(ace->ae_tag, ARCH_CONVERT, ace->ae_tag); 599 INT_SET(ace->ae_id, ARCH_CONVERT, ace->ae_id); 600 INT_SET(ace->ae_perm, ARCH_CONVERT, ace->ae_perm); 601 } 602 } 603 604 /* 605 * Get the ACL from the EA and do endian conversion. 606 */ 607 STATIC void 608 xfs_acl_get_attr( 609 bhv_vnode_t *vp, 610 xfs_acl_t *aclp, 611 int kind, 612 int flags, 613 int *error) 614 { 615 int len = sizeof(xfs_acl_t); 616 617 ASSERT((flags & ATTR_KERNOVAL) ? (aclp == NULL) : 1); 618 flags |= ATTR_ROOT; 619 *error = xfs_attr_get(xfs_vtoi(vp), 620 kind == _ACL_TYPE_ACCESS ? 621 SGI_ACL_FILE : SGI_ACL_DEFAULT, 622 (char *)aclp, &len, flags, sys_cred); 623 if (*error || (flags & ATTR_KERNOVAL)) 624 return; 625 xfs_acl_get_endian(aclp); 626 } 627 628 /* 629 * Set the EA with the ACL and do endian conversion. 630 */ 631 STATIC void 632 xfs_acl_set_attr( 633 bhv_vnode_t *vp, 634 xfs_acl_t *aclp, 635 int kind, 636 int *error) 637 { 638 xfs_acl_entry_t *ace, *newace, *end; 639 xfs_acl_t *newacl; 640 int len; 641 642 if (!(_ACL_ALLOC(newacl))) { 643 *error = ENOMEM; 644 return; 645 } 646 647 len = sizeof(xfs_acl_t) - 648 (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt)); 649 end = &aclp->acl_entry[0]+aclp->acl_cnt; 650 for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0]; 651 ace < end; 652 ace++, newace++) { 653 INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag); 654 INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id); 655 INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm); 656 } 657 INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt); 658 *error = xfs_attr_set(xfs_vtoi(vp), 659 kind == _ACL_TYPE_ACCESS ? 660 SGI_ACL_FILE: SGI_ACL_DEFAULT, 661 (char *)newacl, len, ATTR_ROOT); 662 _ACL_FREE(newacl); 663 } 664 665 int 666 xfs_acl_vtoacl( 667 bhv_vnode_t *vp, 668 xfs_acl_t *access_acl, 669 xfs_acl_t *default_acl) 670 { 671 bhv_vattr_t va; 672 int error = 0; 673 674 if (access_acl) { 675 /* 676 * Get the Access ACL and the mode. If either cannot 677 * be obtained for some reason, invalidate the access ACL. 678 */ 679 xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error); 680 if (!error) { 681 /* Got the ACL, need the mode... */ 682 va.va_mask = XFS_AT_MODE; 683 error = xfs_getattr(xfs_vtoi(vp), &va, 0); 684 } 685 686 if (error) 687 access_acl->acl_cnt = XFS_ACL_NOT_PRESENT; 688 else /* We have a good ACL and the file mode, synchronize. */ 689 xfs_acl_sync_mode(va.va_mode, access_acl); 690 } 691 692 if (default_acl) { 693 xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error); 694 if (error) 695 default_acl->acl_cnt = XFS_ACL_NOT_PRESENT; 696 } 697 return error; 698 } 699 700 /* 701 * This function retrieves the parent directory's acl, processes it 702 * and lets the child inherit the acl(s) that it should. 703 */ 704 int 705 xfs_acl_inherit( 706 bhv_vnode_t *vp, 707 mode_t mode, 708 xfs_acl_t *pdaclp) 709 { 710 xfs_acl_t *cacl; 711 int error = 0; 712 int basicperms = 0; 713 714 /* 715 * If the parent does not have a default ACL, or it's an 716 * invalid ACL, we're done. 717 */ 718 if (!vp) 719 return 0; 720 if (!pdaclp || xfs_acl_invalid(pdaclp)) 721 return 0; 722 723 /* 724 * Copy the default ACL of the containing directory to 725 * the access ACL of the new file and use the mode that 726 * was passed in to set up the correct initial values for 727 * the u::,g::[m::], and o:: entries. This is what makes 728 * umask() "work" with ACL's. 729 */ 730 731 if (!(_ACL_ALLOC(cacl))) 732 return ENOMEM; 733 734 memcpy(cacl, pdaclp, sizeof(xfs_acl_t)); 735 xfs_acl_filter_mode(mode, cacl); 736 xfs_acl_setmode(vp, cacl, &basicperms); 737 738 /* 739 * Set the Default and Access ACL on the file. The mode is already 740 * set on the file, so we don't need to worry about that. 741 * 742 * If the new file is a directory, its default ACL is a copy of 743 * the containing directory's default ACL. 744 */ 745 if (VN_ISDIR(vp)) 746 xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error); 747 if (!error && !basicperms) 748 xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error); 749 _ACL_FREE(cacl); 750 return error; 751 } 752 753 /* 754 * Set up the correct mode on the file based on the supplied ACL. This 755 * makes sure that the mode on the file reflects the state of the 756 * u::,g::[m::], and o:: entries in the ACL. Since the mode is where 757 * the ACL is going to get the permissions for these entries, we must 758 * synchronize the mode whenever we set the ACL on a file. 759 */ 760 STATIC int 761 xfs_acl_setmode( 762 bhv_vnode_t *vp, 763 xfs_acl_t *acl, 764 int *basicperms) 765 { 766 bhv_vattr_t va; 767 xfs_acl_entry_t *ap; 768 xfs_acl_entry_t *gap = NULL; 769 int i, error, nomask = 1; 770 771 *basicperms = 1; 772 773 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) 774 return 0; 775 776 /* 777 * Copy the u::, g::, o::, and m:: bits from the ACL into the 778 * mode. The m:: bits take precedence over the g:: bits. 779 */ 780 va.va_mask = XFS_AT_MODE; 781 error = xfs_getattr(xfs_vtoi(vp), &va, 0); 782 if (error) 783 return error; 784 785 va.va_mask = XFS_AT_MODE; 786 va.va_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO); 787 ap = acl->acl_entry; 788 for (i = 0; i < acl->acl_cnt; ++i) { 789 switch (ap->ae_tag) { 790 case ACL_USER_OBJ: 791 va.va_mode |= ap->ae_perm << 6; 792 break; 793 case ACL_GROUP_OBJ: 794 gap = ap; 795 break; 796 case ACL_MASK: /* more than just standard modes */ 797 nomask = 0; 798 va.va_mode |= ap->ae_perm << 3; 799 *basicperms = 0; 800 break; 801 case ACL_OTHER: 802 va.va_mode |= ap->ae_perm; 803 break; 804 default: /* more than just standard modes */ 805 *basicperms = 0; 806 break; 807 } 808 ap++; 809 } 810 811 /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */ 812 if (gap && nomask) 813 va.va_mode |= gap->ae_perm << 3; 814 815 return xfs_setattr(xfs_vtoi(vp), &va, 0, sys_cred); 816 } 817 818 /* 819 * The permissions for the special ACL entries (u::, g::[m::], o::) are 820 * actually stored in the file mode (if there is both a group and a mask, 821 * the group is stored in the ACL entry and the mask is stored on the file). 822 * This allows the mode to remain automatically in sync with the ACL without 823 * the need for a call-back to the ACL system at every point where the mode 824 * could change. This function takes the permissions from the specified mode 825 * and places it in the supplied ACL. 826 * 827 * This implementation draws its validity from the fact that, when the ACL 828 * was assigned, the mode was copied from the ACL. 829 * If the mode did not change, therefore, the mode remains exactly what was 830 * taken from the special ACL entries at assignment. 831 * If a subsequent chmod() was done, the POSIX spec says that the change in 832 * mode must cause an update to the ACL seen at user level and used for 833 * access checks. Before and after a mode change, therefore, the file mode 834 * most accurately reflects what the special ACL entries should permit/deny. 835 * 836 * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly, 837 * the existing mode bits will override whatever is in the 838 * ACL. Similarly, if there is a pre-existing ACL that was 839 * never in sync with its mode (owing to a bug in 6.5 and 840 * before), it will now magically (or mystically) be 841 * synchronized. This could cause slight astonishment, but 842 * it is better than inconsistent permissions. 843 * 844 * The supplied ACL is a template that may contain any combination 845 * of special entries. These are treated as place holders when we fill 846 * out the ACL. This routine does not add or remove special entries, it 847 * simply unites each special entry with its associated set of permissions. 848 */ 849 STATIC void 850 xfs_acl_sync_mode( 851 mode_t mode, 852 xfs_acl_t *acl) 853 { 854 int i, nomask = 1; 855 xfs_acl_entry_t *ap; 856 xfs_acl_entry_t *gap = NULL; 857 858 /* 859 * Set ACL entries. POSIX1003.1eD16 requires that the MASK 860 * be set instead of the GROUP entry, if there is a MASK. 861 */ 862 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) { 863 switch (ap->ae_tag) { 864 case ACL_USER_OBJ: 865 ap->ae_perm = (mode >> 6) & 0x7; 866 break; 867 case ACL_GROUP_OBJ: 868 gap = ap; 869 break; 870 case ACL_MASK: 871 nomask = 0; 872 ap->ae_perm = (mode >> 3) & 0x7; 873 break; 874 case ACL_OTHER: 875 ap->ae_perm = mode & 0x7; 876 break; 877 default: 878 break; 879 } 880 } 881 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */ 882 if (gap && nomask) 883 gap->ae_perm = (mode >> 3) & 0x7; 884 } 885 886 /* 887 * When inheriting an Access ACL from a directory Default ACL, 888 * the ACL bits are set to the intersection of the ACL default 889 * permission bits and the file permission bits in mode. If there 890 * are no permission bits on the file then we must not give them 891 * the ACL. This is what what makes umask() work with ACLs. 892 */ 893 STATIC void 894 xfs_acl_filter_mode( 895 mode_t mode, 896 xfs_acl_t *acl) 897 { 898 int i, nomask = 1; 899 xfs_acl_entry_t *ap; 900 xfs_acl_entry_t *gap = NULL; 901 902 /* 903 * Set ACL entries. POSIX1003.1eD16 requires that the MASK 904 * be merged with GROUP entry, if there is a MASK. 905 */ 906 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) { 907 switch (ap->ae_tag) { 908 case ACL_USER_OBJ: 909 ap->ae_perm &= (mode >> 6) & 0x7; 910 break; 911 case ACL_GROUP_OBJ: 912 gap = ap; 913 break; 914 case ACL_MASK: 915 nomask = 0; 916 ap->ae_perm &= (mode >> 3) & 0x7; 917 break; 918 case ACL_OTHER: 919 ap->ae_perm &= mode & 0x7; 920 break; 921 default: 922 break; 923 } 924 } 925 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */ 926 if (gap && nomask) 927 gap->ae_perm &= (mode >> 3) & 0x7; 928 } 929