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