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(struct inode *, 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(struct inode *, xfs_acl_t *, int, int, int *); 47 STATIC void xfs_acl_set_attr(struct inode *, xfs_acl_t *, int, int *); 48 STATIC int xfs_acl_allow_set(struct inode *, 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 struct inode *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 struct inode *vp) 72 { 73 int error; 74 75 if (!S_ISDIR(vp->i_mode)) 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 struct inode *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 if(size) { 221 if (!(_ACL_ALLOC(xfs_acl))) { 222 error = ENOMEM; 223 goto out; 224 } 225 memset(xfs_acl, 0, sizeof(xfs_acl_t)); 226 } else 227 flags = ATTR_KERNOVAL; 228 229 xfs_acl_get_attr(vp, xfs_acl, kind, flags, &error); 230 if (error) 231 goto out; 232 233 if (!size) { 234 error = -posix_acl_xattr_size(XFS_ACL_MAX_ENTRIES); 235 } else { 236 if (xfs_acl_invalid(xfs_acl)) { 237 error = EINVAL; 238 goto out; 239 } 240 if (kind == _ACL_TYPE_ACCESS) 241 xfs_acl_sync_mode(XFS_I(vp)->i_d.di_mode, xfs_acl); 242 error = -posix_acl_xfs_to_xattr(xfs_acl, ext_acl, size); 243 } 244 out: 245 if(xfs_acl) 246 _ACL_FREE(xfs_acl); 247 return -error; 248 } 249 250 int 251 xfs_acl_vremove( 252 struct inode *vp, 253 int kind) 254 { 255 int error; 256 257 error = xfs_acl_allow_set(vp, kind); 258 if (!error) { 259 error = xfs_attr_remove(XFS_I(vp), 260 kind == _ACL_TYPE_DEFAULT? 261 SGI_ACL_DEFAULT: SGI_ACL_FILE, 262 ATTR_ROOT); 263 if (error == ENOATTR) 264 error = 0; /* 'scool */ 265 } 266 return -error; 267 } 268 269 int 270 xfs_acl_vset( 271 struct inode *vp, 272 void *acl, 273 size_t size, 274 int kind) 275 { 276 posix_acl_xattr_header *ext_acl = acl; 277 xfs_acl_t *xfs_acl; 278 int error; 279 int basicperms = 0; /* more than std unix perms? */ 280 281 if (!acl) 282 return -EINVAL; 283 284 if (!(_ACL_ALLOC(xfs_acl))) 285 return -ENOMEM; 286 287 error = posix_acl_xattr_to_xfs(ext_acl, size, xfs_acl); 288 if (error) { 289 _ACL_FREE(xfs_acl); 290 return -error; 291 } 292 if (!xfs_acl->acl_cnt) { 293 _ACL_FREE(xfs_acl); 294 return 0; 295 } 296 297 error = xfs_acl_allow_set(vp, kind); 298 299 /* Incoming ACL exists, set file mode based on its value */ 300 if (!error && kind == _ACL_TYPE_ACCESS) 301 error = xfs_acl_setmode(vp, xfs_acl, &basicperms); 302 303 if (error) 304 goto out; 305 306 /* 307 * If we have more than std unix permissions, set up the actual attr. 308 * Otherwise, delete any existing attr. This prevents us from 309 * having actual attrs for permissions that can be stored in the 310 * standard permission bits. 311 */ 312 if (!basicperms) { 313 xfs_acl_set_attr(vp, xfs_acl, kind, &error); 314 } else { 315 error = -xfs_acl_vremove(vp, _ACL_TYPE_ACCESS); 316 } 317 318 out: 319 _ACL_FREE(xfs_acl); 320 return -error; 321 } 322 323 int 324 xfs_acl_iaccess( 325 xfs_inode_t *ip, 326 mode_t mode, 327 cred_t *cr) 328 { 329 xfs_acl_t *acl; 330 int rval; 331 struct xfs_name acl_name = {SGI_ACL_FILE, SGI_ACL_FILE_SIZE}; 332 333 if (!(_ACL_ALLOC(acl))) 334 return -1; 335 336 /* If the file has no ACL return -1. */ 337 rval = sizeof(xfs_acl_t); 338 if (xfs_attr_fetch(ip, &acl_name, (char *)acl, &rval, ATTR_ROOT)) { 339 _ACL_FREE(acl); 340 return -1; 341 } 342 xfs_acl_get_endian(acl); 343 344 /* If the file has an empty ACL return -1. */ 345 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) { 346 _ACL_FREE(acl); 347 return -1; 348 } 349 350 /* Synchronize ACL with mode bits */ 351 xfs_acl_sync_mode(ip->i_d.di_mode, acl); 352 353 rval = xfs_acl_access(ip->i_d.di_uid, ip->i_d.di_gid, acl, mode, cr); 354 _ACL_FREE(acl); 355 return rval; 356 } 357 358 STATIC int 359 xfs_acl_allow_set( 360 struct inode *vp, 361 int kind) 362 { 363 if (vp->i_flags & (S_IMMUTABLE|S_APPEND)) 364 return EPERM; 365 if (kind == _ACL_TYPE_DEFAULT && !S_ISDIR(vp->i_mode)) 366 return ENOTDIR; 367 if (vp->i_sb->s_flags & MS_RDONLY) 368 return EROFS; 369 if (XFS_I(vp)->i_d.di_uid != current->fsuid && !capable(CAP_FOWNER)) 370 return EPERM; 371 return 0; 372 } 373 374 /* 375 * Note: cr is only used here for the capability check if the ACL test fails. 376 * It is not used to find out the credentials uid or groups etc, as was 377 * done in IRIX. It is assumed that the uid and groups for the current 378 * thread are taken from "current" instead of the cr parameter. 379 */ 380 STATIC int 381 xfs_acl_access( 382 uid_t fuid, 383 gid_t fgid, 384 xfs_acl_t *fap, 385 mode_t md, 386 cred_t *cr) 387 { 388 xfs_acl_entry_t matched; 389 int i, allows; 390 int maskallows = -1; /* true, but not 1, either */ 391 int seen_userobj = 0; 392 393 matched.ae_tag = 0; /* Invalid type */ 394 matched.ae_perm = 0; 395 396 for (i = 0; i < fap->acl_cnt; i++) { 397 /* 398 * Break out if we've got a user_obj entry or 399 * a user entry and the mask (and have processed USER_OBJ) 400 */ 401 if (matched.ae_tag == ACL_USER_OBJ) 402 break; 403 if (matched.ae_tag == ACL_USER) { 404 if (maskallows != -1 && seen_userobj) 405 break; 406 if (fap->acl_entry[i].ae_tag != ACL_MASK && 407 fap->acl_entry[i].ae_tag != ACL_USER_OBJ) 408 continue; 409 } 410 /* True if this entry allows the requested access */ 411 allows = ((fap->acl_entry[i].ae_perm & md) == md); 412 413 switch (fap->acl_entry[i].ae_tag) { 414 case ACL_USER_OBJ: 415 seen_userobj = 1; 416 if (fuid != current->fsuid) 417 continue; 418 matched.ae_tag = ACL_USER_OBJ; 419 matched.ae_perm = allows; 420 break; 421 case ACL_USER: 422 if (fap->acl_entry[i].ae_id != current->fsuid) 423 continue; 424 matched.ae_tag = ACL_USER; 425 matched.ae_perm = allows; 426 break; 427 case ACL_GROUP_OBJ: 428 if ((matched.ae_tag == ACL_GROUP_OBJ || 429 matched.ae_tag == ACL_GROUP) && !allows) 430 continue; 431 if (!in_group_p(fgid)) 432 continue; 433 matched.ae_tag = ACL_GROUP_OBJ; 434 matched.ae_perm = allows; 435 break; 436 case ACL_GROUP: 437 if ((matched.ae_tag == ACL_GROUP_OBJ || 438 matched.ae_tag == ACL_GROUP) && !allows) 439 continue; 440 if (!in_group_p(fap->acl_entry[i].ae_id)) 441 continue; 442 matched.ae_tag = ACL_GROUP; 443 matched.ae_perm = allows; 444 break; 445 case ACL_MASK: 446 maskallows = allows; 447 break; 448 case ACL_OTHER: 449 if (matched.ae_tag != 0) 450 continue; 451 matched.ae_tag = ACL_OTHER; 452 matched.ae_perm = allows; 453 break; 454 } 455 } 456 /* 457 * First possibility is that no matched entry allows access. 458 * The capability to override DAC may exist, so check for it. 459 */ 460 switch (matched.ae_tag) { 461 case ACL_OTHER: 462 case ACL_USER_OBJ: 463 if (matched.ae_perm) 464 return 0; 465 break; 466 case ACL_USER: 467 case ACL_GROUP_OBJ: 468 case ACL_GROUP: 469 if (maskallows && matched.ae_perm) 470 return 0; 471 break; 472 case 0: 473 break; 474 } 475 476 /* EACCES tells generic_permission to check for capability overrides */ 477 return EACCES; 478 } 479 480 /* 481 * ACL validity checker. 482 * This acl validation routine checks each ACL entry read in makes sense. 483 */ 484 STATIC int 485 xfs_acl_invalid( 486 xfs_acl_t *aclp) 487 { 488 xfs_acl_entry_t *entry, *e; 489 int user = 0, group = 0, other = 0, mask = 0; 490 int mask_required = 0; 491 int i, j; 492 493 if (!aclp) 494 goto acl_invalid; 495 496 if (aclp->acl_cnt > XFS_ACL_MAX_ENTRIES) 497 goto acl_invalid; 498 499 for (i = 0; i < aclp->acl_cnt; i++) { 500 entry = &aclp->acl_entry[i]; 501 switch (entry->ae_tag) { 502 case ACL_USER_OBJ: 503 if (user++) 504 goto acl_invalid; 505 break; 506 case ACL_GROUP_OBJ: 507 if (group++) 508 goto acl_invalid; 509 break; 510 case ACL_OTHER: 511 if (other++) 512 goto acl_invalid; 513 break; 514 case ACL_USER: 515 case ACL_GROUP: 516 for (j = i + 1; j < aclp->acl_cnt; j++) { 517 e = &aclp->acl_entry[j]; 518 if (e->ae_id == entry->ae_id && 519 e->ae_tag == entry->ae_tag) 520 goto acl_invalid; 521 } 522 mask_required++; 523 break; 524 case ACL_MASK: 525 if (mask++) 526 goto acl_invalid; 527 break; 528 default: 529 goto acl_invalid; 530 } 531 } 532 if (!user || !group || !other || (mask_required && !mask)) 533 goto acl_invalid; 534 else 535 return 0; 536 acl_invalid: 537 return EINVAL; 538 } 539 540 /* 541 * Do ACL endian conversion. 542 */ 543 STATIC void 544 xfs_acl_get_endian( 545 xfs_acl_t *aclp) 546 { 547 xfs_acl_entry_t *ace, *end; 548 549 INT_SET(aclp->acl_cnt, ARCH_CONVERT, aclp->acl_cnt); 550 end = &aclp->acl_entry[0]+aclp->acl_cnt; 551 for (ace = &aclp->acl_entry[0]; ace < end; ace++) { 552 INT_SET(ace->ae_tag, ARCH_CONVERT, ace->ae_tag); 553 INT_SET(ace->ae_id, ARCH_CONVERT, ace->ae_id); 554 INT_SET(ace->ae_perm, ARCH_CONVERT, ace->ae_perm); 555 } 556 } 557 558 /* 559 * Get the ACL from the EA and do endian conversion. 560 */ 561 STATIC void 562 xfs_acl_get_attr( 563 struct inode *vp, 564 xfs_acl_t *aclp, 565 int kind, 566 int flags, 567 int *error) 568 { 569 int len = sizeof(xfs_acl_t); 570 571 ASSERT((flags & ATTR_KERNOVAL) ? (aclp == NULL) : 1); 572 flags |= ATTR_ROOT; 573 *error = xfs_attr_get(XFS_I(vp), 574 kind == _ACL_TYPE_ACCESS ? 575 SGI_ACL_FILE : SGI_ACL_DEFAULT, 576 (char *)aclp, &len, flags); 577 if (*error || (flags & ATTR_KERNOVAL)) 578 return; 579 xfs_acl_get_endian(aclp); 580 } 581 582 /* 583 * Set the EA with the ACL and do endian conversion. 584 */ 585 STATIC void 586 xfs_acl_set_attr( 587 struct inode *vp, 588 xfs_acl_t *aclp, 589 int kind, 590 int *error) 591 { 592 xfs_acl_entry_t *ace, *newace, *end; 593 xfs_acl_t *newacl; 594 int len; 595 596 if (!(_ACL_ALLOC(newacl))) { 597 *error = ENOMEM; 598 return; 599 } 600 601 len = sizeof(xfs_acl_t) - 602 (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt)); 603 end = &aclp->acl_entry[0]+aclp->acl_cnt; 604 for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0]; 605 ace < end; 606 ace++, newace++) { 607 INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag); 608 INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id); 609 INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm); 610 } 611 INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt); 612 *error = xfs_attr_set(XFS_I(vp), 613 kind == _ACL_TYPE_ACCESS ? 614 SGI_ACL_FILE: SGI_ACL_DEFAULT, 615 (char *)newacl, len, ATTR_ROOT); 616 _ACL_FREE(newacl); 617 } 618 619 int 620 xfs_acl_vtoacl( 621 struct inode *vp, 622 xfs_acl_t *access_acl, 623 xfs_acl_t *default_acl) 624 { 625 int error = 0; 626 627 if (access_acl) { 628 /* 629 * Get the Access ACL and the mode. If either cannot 630 * be obtained for some reason, invalidate the access ACL. 631 */ 632 xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error); 633 if (error) 634 access_acl->acl_cnt = XFS_ACL_NOT_PRESENT; 635 else /* We have a good ACL and the file mode, synchronize. */ 636 xfs_acl_sync_mode(XFS_I(vp)->i_d.di_mode, access_acl); 637 } 638 639 if (default_acl) { 640 xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error); 641 if (error) 642 default_acl->acl_cnt = XFS_ACL_NOT_PRESENT; 643 } 644 return error; 645 } 646 647 /* 648 * This function retrieves the parent directory's acl, processes it 649 * and lets the child inherit the acl(s) that it should. 650 */ 651 int 652 xfs_acl_inherit( 653 struct inode *vp, 654 mode_t mode, 655 xfs_acl_t *pdaclp) 656 { 657 xfs_acl_t *cacl; 658 int error = 0; 659 int basicperms = 0; 660 661 /* 662 * If the parent does not have a default ACL, or it's an 663 * invalid ACL, we're done. 664 */ 665 if (!vp) 666 return 0; 667 if (!pdaclp || xfs_acl_invalid(pdaclp)) 668 return 0; 669 670 /* 671 * Copy the default ACL of the containing directory to 672 * the access ACL of the new file and use the mode that 673 * was passed in to set up the correct initial values for 674 * the u::,g::[m::], and o:: entries. This is what makes 675 * umask() "work" with ACL's. 676 */ 677 678 if (!(_ACL_ALLOC(cacl))) 679 return ENOMEM; 680 681 memcpy(cacl, pdaclp, sizeof(xfs_acl_t)); 682 xfs_acl_filter_mode(mode, cacl); 683 error = xfs_acl_setmode(vp, cacl, &basicperms); 684 if (error) 685 goto out_error; 686 687 /* 688 * Set the Default and Access ACL on the file. The mode is already 689 * set on the file, so we don't need to worry about that. 690 * 691 * If the new file is a directory, its default ACL is a copy of 692 * the containing directory's default ACL. 693 */ 694 if (S_ISDIR(vp->i_mode)) 695 xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error); 696 if (!error && !basicperms) 697 xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error); 698 out_error: 699 _ACL_FREE(cacl); 700 return error; 701 } 702 703 /* 704 * Set up the correct mode on the file based on the supplied ACL. This 705 * makes sure that the mode on the file reflects the state of the 706 * u::,g::[m::], and o:: entries in the ACL. Since the mode is where 707 * the ACL is going to get the permissions for these entries, we must 708 * synchronize the mode whenever we set the ACL on a file. 709 */ 710 STATIC int 711 xfs_acl_setmode( 712 struct inode *vp, 713 xfs_acl_t *acl, 714 int *basicperms) 715 { 716 struct iattr iattr; 717 xfs_acl_entry_t *ap; 718 xfs_acl_entry_t *gap = NULL; 719 int i, nomask = 1; 720 721 *basicperms = 1; 722 723 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) 724 return 0; 725 726 /* 727 * Copy the u::, g::, o::, and m:: bits from the ACL into the 728 * mode. The m:: bits take precedence over the g:: bits. 729 */ 730 iattr.ia_valid = ATTR_MODE; 731 iattr.ia_mode = XFS_I(vp)->i_d.di_mode; 732 iattr.ia_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO); 733 ap = acl->acl_entry; 734 for (i = 0; i < acl->acl_cnt; ++i) { 735 switch (ap->ae_tag) { 736 case ACL_USER_OBJ: 737 iattr.ia_mode |= ap->ae_perm << 6; 738 break; 739 case ACL_GROUP_OBJ: 740 gap = ap; 741 break; 742 case ACL_MASK: /* more than just standard modes */ 743 nomask = 0; 744 iattr.ia_mode |= ap->ae_perm << 3; 745 *basicperms = 0; 746 break; 747 case ACL_OTHER: 748 iattr.ia_mode |= ap->ae_perm; 749 break; 750 default: /* more than just standard modes */ 751 *basicperms = 0; 752 break; 753 } 754 ap++; 755 } 756 757 /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */ 758 if (gap && nomask) 759 iattr.ia_mode |= gap->ae_perm << 3; 760 761 return xfs_setattr(XFS_I(vp), &iattr, 0, sys_cred); 762 } 763 764 /* 765 * The permissions for the special ACL entries (u::, g::[m::], o::) are 766 * actually stored in the file mode (if there is both a group and a mask, 767 * the group is stored in the ACL entry and the mask is stored on the file). 768 * This allows the mode to remain automatically in sync with the ACL without 769 * the need for a call-back to the ACL system at every point where the mode 770 * could change. This function takes the permissions from the specified mode 771 * and places it in the supplied ACL. 772 * 773 * This implementation draws its validity from the fact that, when the ACL 774 * was assigned, the mode was copied from the ACL. 775 * If the mode did not change, therefore, the mode remains exactly what was 776 * taken from the special ACL entries at assignment. 777 * If a subsequent chmod() was done, the POSIX spec says that the change in 778 * mode must cause an update to the ACL seen at user level and used for 779 * access checks. Before and after a mode change, therefore, the file mode 780 * most accurately reflects what the special ACL entries should permit/deny. 781 * 782 * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly, 783 * the existing mode bits will override whatever is in the 784 * ACL. Similarly, if there is a pre-existing ACL that was 785 * never in sync with its mode (owing to a bug in 6.5 and 786 * before), it will now magically (or mystically) be 787 * synchronized. This could cause slight astonishment, but 788 * it is better than inconsistent permissions. 789 * 790 * The supplied ACL is a template that may contain any combination 791 * of special entries. These are treated as place holders when we fill 792 * out the ACL. This routine does not add or remove special entries, it 793 * simply unites each special entry with its associated set of permissions. 794 */ 795 STATIC void 796 xfs_acl_sync_mode( 797 mode_t mode, 798 xfs_acl_t *acl) 799 { 800 int i, nomask = 1; 801 xfs_acl_entry_t *ap; 802 xfs_acl_entry_t *gap = NULL; 803 804 /* 805 * Set ACL entries. POSIX1003.1eD16 requires that the MASK 806 * be set instead of the GROUP entry, if there is a MASK. 807 */ 808 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) { 809 switch (ap->ae_tag) { 810 case ACL_USER_OBJ: 811 ap->ae_perm = (mode >> 6) & 0x7; 812 break; 813 case ACL_GROUP_OBJ: 814 gap = ap; 815 break; 816 case ACL_MASK: 817 nomask = 0; 818 ap->ae_perm = (mode >> 3) & 0x7; 819 break; 820 case ACL_OTHER: 821 ap->ae_perm = mode & 0x7; 822 break; 823 default: 824 break; 825 } 826 } 827 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */ 828 if (gap && nomask) 829 gap->ae_perm = (mode >> 3) & 0x7; 830 } 831 832 /* 833 * When inheriting an Access ACL from a directory Default ACL, 834 * the ACL bits are set to the intersection of the ACL default 835 * permission bits and the file permission bits in mode. If there 836 * are no permission bits on the file then we must not give them 837 * the ACL. This is what what makes umask() work with ACLs. 838 */ 839 STATIC void 840 xfs_acl_filter_mode( 841 mode_t mode, 842 xfs_acl_t *acl) 843 { 844 int i, nomask = 1; 845 xfs_acl_entry_t *ap; 846 xfs_acl_entry_t *gap = NULL; 847 848 /* 849 * Set ACL entries. POSIX1003.1eD16 requires that the MASK 850 * be merged with GROUP entry, if there is a MASK. 851 */ 852 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) { 853 switch (ap->ae_tag) { 854 case ACL_USER_OBJ: 855 ap->ae_perm &= (mode >> 6) & 0x7; 856 break; 857 case ACL_GROUP_OBJ: 858 gap = ap; 859 break; 860 case ACL_MASK: 861 nomask = 0; 862 ap->ae_perm &= (mode >> 3) & 0x7; 863 break; 864 case ACL_OTHER: 865 ap->ae_perm &= mode & 0x7; 866 break; 867 default: 868 break; 869 } 870 } 871 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */ 872 if (gap && nomask) 873 gap->ae_perm &= (mode >> 3) & 0x7; 874 } 875