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 (!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 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 xfs_acl_sync_mode(xfs_vtoi(vp)->i_d.di_mode, xfs_acl); 243 error = -posix_acl_xfs_to_xattr(xfs_acl, ext_acl, size); 244 } 245 out: 246 VN_RELE(vp); 247 if(xfs_acl) 248 _ACL_FREE(xfs_acl); 249 return -error; 250 } 251 252 int 253 xfs_acl_vremove( 254 bhv_vnode_t *vp, 255 int kind) 256 { 257 int error; 258 259 VN_HOLD(vp); 260 error = xfs_acl_allow_set(vp, kind); 261 if (!error) { 262 error = xfs_attr_remove(xfs_vtoi(vp), 263 kind == _ACL_TYPE_DEFAULT? 264 SGI_ACL_DEFAULT: SGI_ACL_FILE, 265 ATTR_ROOT); 266 if (error == ENOATTR) 267 error = 0; /* 'scool */ 268 } 269 VN_RELE(vp); 270 return -error; 271 } 272 273 int 274 xfs_acl_vset( 275 bhv_vnode_t *vp, 276 void *acl, 277 size_t size, 278 int kind) 279 { 280 posix_acl_xattr_header *ext_acl = acl; 281 xfs_acl_t *xfs_acl; 282 int error; 283 int basicperms = 0; /* more than std unix perms? */ 284 285 if (!acl) 286 return -EINVAL; 287 288 if (!(_ACL_ALLOC(xfs_acl))) 289 return -ENOMEM; 290 291 error = posix_acl_xattr_to_xfs(ext_acl, size, xfs_acl); 292 if (error) { 293 _ACL_FREE(xfs_acl); 294 return -error; 295 } 296 if (!xfs_acl->acl_cnt) { 297 _ACL_FREE(xfs_acl); 298 return 0; 299 } 300 301 VN_HOLD(vp); 302 error = xfs_acl_allow_set(vp, kind); 303 304 /* Incoming ACL exists, set file mode based on its value */ 305 if (!error && kind == _ACL_TYPE_ACCESS) 306 error = xfs_acl_setmode(vp, xfs_acl, &basicperms); 307 308 if (error) 309 goto out; 310 311 /* 312 * If we have more than std unix permissions, set up the actual attr. 313 * Otherwise, delete any existing attr. This prevents us from 314 * having actual attrs for permissions that can be stored in the 315 * standard permission bits. 316 */ 317 if (!basicperms) { 318 xfs_acl_set_attr(vp, xfs_acl, kind, &error); 319 } else { 320 error = -xfs_acl_vremove(vp, _ACL_TYPE_ACCESS); 321 } 322 323 out: 324 VN_RELE(vp); 325 _ACL_FREE(xfs_acl); 326 return -error; 327 } 328 329 int 330 xfs_acl_iaccess( 331 xfs_inode_t *ip, 332 mode_t mode, 333 cred_t *cr) 334 { 335 xfs_acl_t *acl; 336 int rval; 337 struct xfs_name acl_name = {SGI_ACL_FILE, SGI_ACL_FILE_SIZE}; 338 339 if (!(_ACL_ALLOC(acl))) 340 return -1; 341 342 /* If the file has no ACL return -1. */ 343 rval = sizeof(xfs_acl_t); 344 if (xfs_attr_fetch(ip, &acl_name, (char *)acl, &rval, 345 ATTR_ROOT | ATTR_KERNACCESS)) { 346 _ACL_FREE(acl); 347 return -1; 348 } 349 xfs_acl_get_endian(acl); 350 351 /* If the file has an empty ACL return -1. */ 352 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) { 353 _ACL_FREE(acl); 354 return -1; 355 } 356 357 /* Synchronize ACL with mode bits */ 358 xfs_acl_sync_mode(ip->i_d.di_mode, acl); 359 360 rval = xfs_acl_access(ip->i_d.di_uid, ip->i_d.di_gid, acl, mode, cr); 361 _ACL_FREE(acl); 362 return rval; 363 } 364 365 STATIC int 366 xfs_acl_allow_set( 367 bhv_vnode_t *vp, 368 int kind) 369 { 370 if (vp->i_flags & (S_IMMUTABLE|S_APPEND)) 371 return EPERM; 372 if (kind == _ACL_TYPE_DEFAULT && !S_ISDIR(vp->i_mode)) 373 return ENOTDIR; 374 if (vp->i_sb->s_flags & MS_RDONLY) 375 return EROFS; 376 if (xfs_vtoi(vp)->i_d.di_uid != current->fsuid && !capable(CAP_FOWNER)) 377 return EPERM; 378 return 0; 379 } 380 381 /* 382 * Note: cr is only used here for the capability check if the ACL test fails. 383 * It is not used to find out the credentials uid or groups etc, as was 384 * done in IRIX. It is assumed that the uid and groups for the current 385 * thread are taken from "current" instead of the cr parameter. 386 */ 387 STATIC int 388 xfs_acl_access( 389 uid_t fuid, 390 gid_t fgid, 391 xfs_acl_t *fap, 392 mode_t md, 393 cred_t *cr) 394 { 395 xfs_acl_entry_t matched; 396 int i, allows; 397 int maskallows = -1; /* true, but not 1, either */ 398 int seen_userobj = 0; 399 400 matched.ae_tag = 0; /* Invalid type */ 401 matched.ae_perm = 0; 402 403 for (i = 0; i < fap->acl_cnt; i++) { 404 /* 405 * Break out if we've got a user_obj entry or 406 * a user entry and the mask (and have processed USER_OBJ) 407 */ 408 if (matched.ae_tag == ACL_USER_OBJ) 409 break; 410 if (matched.ae_tag == ACL_USER) { 411 if (maskallows != -1 && seen_userobj) 412 break; 413 if (fap->acl_entry[i].ae_tag != ACL_MASK && 414 fap->acl_entry[i].ae_tag != ACL_USER_OBJ) 415 continue; 416 } 417 /* True if this entry allows the requested access */ 418 allows = ((fap->acl_entry[i].ae_perm & md) == md); 419 420 switch (fap->acl_entry[i].ae_tag) { 421 case ACL_USER_OBJ: 422 seen_userobj = 1; 423 if (fuid != current->fsuid) 424 continue; 425 matched.ae_tag = ACL_USER_OBJ; 426 matched.ae_perm = allows; 427 break; 428 case ACL_USER: 429 if (fap->acl_entry[i].ae_id != current->fsuid) 430 continue; 431 matched.ae_tag = ACL_USER; 432 matched.ae_perm = allows; 433 break; 434 case ACL_GROUP_OBJ: 435 if ((matched.ae_tag == ACL_GROUP_OBJ || 436 matched.ae_tag == ACL_GROUP) && !allows) 437 continue; 438 if (!in_group_p(fgid)) 439 continue; 440 matched.ae_tag = ACL_GROUP_OBJ; 441 matched.ae_perm = allows; 442 break; 443 case ACL_GROUP: 444 if ((matched.ae_tag == ACL_GROUP_OBJ || 445 matched.ae_tag == ACL_GROUP) && !allows) 446 continue; 447 if (!in_group_p(fap->acl_entry[i].ae_id)) 448 continue; 449 matched.ae_tag = ACL_GROUP; 450 matched.ae_perm = allows; 451 break; 452 case ACL_MASK: 453 maskallows = allows; 454 break; 455 case ACL_OTHER: 456 if (matched.ae_tag != 0) 457 continue; 458 matched.ae_tag = ACL_OTHER; 459 matched.ae_perm = allows; 460 break; 461 } 462 } 463 /* 464 * First possibility is that no matched entry allows access. 465 * The capability to override DAC may exist, so check for it. 466 */ 467 switch (matched.ae_tag) { 468 case ACL_OTHER: 469 case ACL_USER_OBJ: 470 if (matched.ae_perm) 471 return 0; 472 break; 473 case ACL_USER: 474 case ACL_GROUP_OBJ: 475 case ACL_GROUP: 476 if (maskallows && matched.ae_perm) 477 return 0; 478 break; 479 case 0: 480 break; 481 } 482 483 /* EACCES tells generic_permission to check for capability overrides */ 484 return EACCES; 485 } 486 487 /* 488 * ACL validity checker. 489 * This acl validation routine checks each ACL entry read in makes sense. 490 */ 491 STATIC int 492 xfs_acl_invalid( 493 xfs_acl_t *aclp) 494 { 495 xfs_acl_entry_t *entry, *e; 496 int user = 0, group = 0, other = 0, mask = 0; 497 int mask_required = 0; 498 int i, j; 499 500 if (!aclp) 501 goto acl_invalid; 502 503 if (aclp->acl_cnt > XFS_ACL_MAX_ENTRIES) 504 goto acl_invalid; 505 506 for (i = 0; i < aclp->acl_cnt; i++) { 507 entry = &aclp->acl_entry[i]; 508 switch (entry->ae_tag) { 509 case ACL_USER_OBJ: 510 if (user++) 511 goto acl_invalid; 512 break; 513 case ACL_GROUP_OBJ: 514 if (group++) 515 goto acl_invalid; 516 break; 517 case ACL_OTHER: 518 if (other++) 519 goto acl_invalid; 520 break; 521 case ACL_USER: 522 case ACL_GROUP: 523 for (j = i + 1; j < aclp->acl_cnt; j++) { 524 e = &aclp->acl_entry[j]; 525 if (e->ae_id == entry->ae_id && 526 e->ae_tag == entry->ae_tag) 527 goto acl_invalid; 528 } 529 mask_required++; 530 break; 531 case ACL_MASK: 532 if (mask++) 533 goto acl_invalid; 534 break; 535 default: 536 goto acl_invalid; 537 } 538 } 539 if (!user || !group || !other || (mask_required && !mask)) 540 goto acl_invalid; 541 else 542 return 0; 543 acl_invalid: 544 return EINVAL; 545 } 546 547 /* 548 * Do ACL endian conversion. 549 */ 550 STATIC void 551 xfs_acl_get_endian( 552 xfs_acl_t *aclp) 553 { 554 xfs_acl_entry_t *ace, *end; 555 556 INT_SET(aclp->acl_cnt, ARCH_CONVERT, aclp->acl_cnt); 557 end = &aclp->acl_entry[0]+aclp->acl_cnt; 558 for (ace = &aclp->acl_entry[0]; ace < end; ace++) { 559 INT_SET(ace->ae_tag, ARCH_CONVERT, ace->ae_tag); 560 INT_SET(ace->ae_id, ARCH_CONVERT, ace->ae_id); 561 INT_SET(ace->ae_perm, ARCH_CONVERT, ace->ae_perm); 562 } 563 } 564 565 /* 566 * Get the ACL from the EA and do endian conversion. 567 */ 568 STATIC void 569 xfs_acl_get_attr( 570 bhv_vnode_t *vp, 571 xfs_acl_t *aclp, 572 int kind, 573 int flags, 574 int *error) 575 { 576 int len = sizeof(xfs_acl_t); 577 578 ASSERT((flags & ATTR_KERNOVAL) ? (aclp == NULL) : 1); 579 flags |= ATTR_ROOT; 580 *error = xfs_attr_get(xfs_vtoi(vp), 581 kind == _ACL_TYPE_ACCESS ? 582 SGI_ACL_FILE : SGI_ACL_DEFAULT, 583 (char *)aclp, &len, flags); 584 if (*error || (flags & ATTR_KERNOVAL)) 585 return; 586 xfs_acl_get_endian(aclp); 587 } 588 589 /* 590 * Set the EA with the ACL and do endian conversion. 591 */ 592 STATIC void 593 xfs_acl_set_attr( 594 bhv_vnode_t *vp, 595 xfs_acl_t *aclp, 596 int kind, 597 int *error) 598 { 599 xfs_acl_entry_t *ace, *newace, *end; 600 xfs_acl_t *newacl; 601 int len; 602 603 if (!(_ACL_ALLOC(newacl))) { 604 *error = ENOMEM; 605 return; 606 } 607 608 len = sizeof(xfs_acl_t) - 609 (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt)); 610 end = &aclp->acl_entry[0]+aclp->acl_cnt; 611 for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0]; 612 ace < end; 613 ace++, newace++) { 614 INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag); 615 INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id); 616 INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm); 617 } 618 INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt); 619 *error = xfs_attr_set(xfs_vtoi(vp), 620 kind == _ACL_TYPE_ACCESS ? 621 SGI_ACL_FILE: SGI_ACL_DEFAULT, 622 (char *)newacl, len, ATTR_ROOT); 623 _ACL_FREE(newacl); 624 } 625 626 int 627 xfs_acl_vtoacl( 628 bhv_vnode_t *vp, 629 xfs_acl_t *access_acl, 630 xfs_acl_t *default_acl) 631 { 632 int error = 0; 633 634 if (access_acl) { 635 /* 636 * Get the Access ACL and the mode. If either cannot 637 * be obtained for some reason, invalidate the access ACL. 638 */ 639 xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error); 640 if (error) 641 access_acl->acl_cnt = XFS_ACL_NOT_PRESENT; 642 else /* We have a good ACL and the file mode, synchronize. */ 643 xfs_acl_sync_mode(xfs_vtoi(vp)->i_d.di_mode, access_acl); 644 } 645 646 if (default_acl) { 647 xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error); 648 if (error) 649 default_acl->acl_cnt = XFS_ACL_NOT_PRESENT; 650 } 651 return error; 652 } 653 654 /* 655 * This function retrieves the parent directory's acl, processes it 656 * and lets the child inherit the acl(s) that it should. 657 */ 658 int 659 xfs_acl_inherit( 660 bhv_vnode_t *vp, 661 mode_t mode, 662 xfs_acl_t *pdaclp) 663 { 664 xfs_acl_t *cacl; 665 int error = 0; 666 int basicperms = 0; 667 668 /* 669 * If the parent does not have a default ACL, or it's an 670 * invalid ACL, we're done. 671 */ 672 if (!vp) 673 return 0; 674 if (!pdaclp || xfs_acl_invalid(pdaclp)) 675 return 0; 676 677 /* 678 * Copy the default ACL of the containing directory to 679 * the access ACL of the new file and use the mode that 680 * was passed in to set up the correct initial values for 681 * the u::,g::[m::], and o:: entries. This is what makes 682 * umask() "work" with ACL's. 683 */ 684 685 if (!(_ACL_ALLOC(cacl))) 686 return ENOMEM; 687 688 memcpy(cacl, pdaclp, sizeof(xfs_acl_t)); 689 xfs_acl_filter_mode(mode, cacl); 690 error = xfs_acl_setmode(vp, cacl, &basicperms); 691 if (error) 692 goto out_error; 693 694 /* 695 * Set the Default and Access ACL on the file. The mode is already 696 * set on the file, so we don't need to worry about that. 697 * 698 * If the new file is a directory, its default ACL is a copy of 699 * the containing directory's default ACL. 700 */ 701 if (S_ISDIR(vp->i_mode)) 702 xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error); 703 if (!error && !basicperms) 704 xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error); 705 out_error: 706 _ACL_FREE(cacl); 707 return error; 708 } 709 710 /* 711 * Set up the correct mode on the file based on the supplied ACL. This 712 * makes sure that the mode on the file reflects the state of the 713 * u::,g::[m::], and o:: entries in the ACL. Since the mode is where 714 * the ACL is going to get the permissions for these entries, we must 715 * synchronize the mode whenever we set the ACL on a file. 716 */ 717 STATIC int 718 xfs_acl_setmode( 719 bhv_vnode_t *vp, 720 xfs_acl_t *acl, 721 int *basicperms) 722 { 723 bhv_vattr_t va; 724 xfs_acl_entry_t *ap; 725 xfs_acl_entry_t *gap = NULL; 726 int i, nomask = 1; 727 728 *basicperms = 1; 729 730 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) 731 return 0; 732 733 /* 734 * Copy the u::, g::, o::, and m:: bits from the ACL into the 735 * mode. The m:: bits take precedence over the g:: bits. 736 */ 737 va.va_mask = XFS_AT_MODE; 738 va.va_mode = xfs_vtoi(vp)->i_d.di_mode; 739 va.va_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO); 740 ap = acl->acl_entry; 741 for (i = 0; i < acl->acl_cnt; ++i) { 742 switch (ap->ae_tag) { 743 case ACL_USER_OBJ: 744 va.va_mode |= ap->ae_perm << 6; 745 break; 746 case ACL_GROUP_OBJ: 747 gap = ap; 748 break; 749 case ACL_MASK: /* more than just standard modes */ 750 nomask = 0; 751 va.va_mode |= ap->ae_perm << 3; 752 *basicperms = 0; 753 break; 754 case ACL_OTHER: 755 va.va_mode |= ap->ae_perm; 756 break; 757 default: /* more than just standard modes */ 758 *basicperms = 0; 759 break; 760 } 761 ap++; 762 } 763 764 /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */ 765 if (gap && nomask) 766 va.va_mode |= gap->ae_perm << 3; 767 768 return xfs_setattr(xfs_vtoi(vp), &va, 0, sys_cred); 769 } 770 771 /* 772 * The permissions for the special ACL entries (u::, g::[m::], o::) are 773 * actually stored in the file mode (if there is both a group and a mask, 774 * the group is stored in the ACL entry and the mask is stored on the file). 775 * This allows the mode to remain automatically in sync with the ACL without 776 * the need for a call-back to the ACL system at every point where the mode 777 * could change. This function takes the permissions from the specified mode 778 * and places it in the supplied ACL. 779 * 780 * This implementation draws its validity from the fact that, when the ACL 781 * was assigned, the mode was copied from the ACL. 782 * If the mode did not change, therefore, the mode remains exactly what was 783 * taken from the special ACL entries at assignment. 784 * If a subsequent chmod() was done, the POSIX spec says that the change in 785 * mode must cause an update to the ACL seen at user level and used for 786 * access checks. Before and after a mode change, therefore, the file mode 787 * most accurately reflects what the special ACL entries should permit/deny. 788 * 789 * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly, 790 * the existing mode bits will override whatever is in the 791 * ACL. Similarly, if there is a pre-existing ACL that was 792 * never in sync with its mode (owing to a bug in 6.5 and 793 * before), it will now magically (or mystically) be 794 * synchronized. This could cause slight astonishment, but 795 * it is better than inconsistent permissions. 796 * 797 * The supplied ACL is a template that may contain any combination 798 * of special entries. These are treated as place holders when we fill 799 * out the ACL. This routine does not add or remove special entries, it 800 * simply unites each special entry with its associated set of permissions. 801 */ 802 STATIC void 803 xfs_acl_sync_mode( 804 mode_t mode, 805 xfs_acl_t *acl) 806 { 807 int i, nomask = 1; 808 xfs_acl_entry_t *ap; 809 xfs_acl_entry_t *gap = NULL; 810 811 /* 812 * Set ACL entries. POSIX1003.1eD16 requires that the MASK 813 * be set instead of the GROUP entry, if there is a MASK. 814 */ 815 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) { 816 switch (ap->ae_tag) { 817 case ACL_USER_OBJ: 818 ap->ae_perm = (mode >> 6) & 0x7; 819 break; 820 case ACL_GROUP_OBJ: 821 gap = ap; 822 break; 823 case ACL_MASK: 824 nomask = 0; 825 ap->ae_perm = (mode >> 3) & 0x7; 826 break; 827 case ACL_OTHER: 828 ap->ae_perm = mode & 0x7; 829 break; 830 default: 831 break; 832 } 833 } 834 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */ 835 if (gap && nomask) 836 gap->ae_perm = (mode >> 3) & 0x7; 837 } 838 839 /* 840 * When inheriting an Access ACL from a directory Default ACL, 841 * the ACL bits are set to the intersection of the ACL default 842 * permission bits and the file permission bits in mode. If there 843 * are no permission bits on the file then we must not give them 844 * the ACL. This is what what makes umask() work with ACLs. 845 */ 846 STATIC void 847 xfs_acl_filter_mode( 848 mode_t mode, 849 xfs_acl_t *acl) 850 { 851 int i, nomask = 1; 852 xfs_acl_entry_t *ap; 853 xfs_acl_entry_t *gap = NULL; 854 855 /* 856 * Set ACL entries. POSIX1003.1eD16 requires that the MASK 857 * be merged with GROUP entry, if there is a MASK. 858 */ 859 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) { 860 switch (ap->ae_tag) { 861 case ACL_USER_OBJ: 862 ap->ae_perm &= (mode >> 6) & 0x7; 863 break; 864 case ACL_GROUP_OBJ: 865 gap = ap; 866 break; 867 case ACL_MASK: 868 nomask = 0; 869 ap->ae_perm &= (mode >> 3) & 0x7; 870 break; 871 case ACL_OTHER: 872 ap->ae_perm &= mode & 0x7; 873 break; 874 default: 875 break; 876 } 877 } 878 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */ 879 if (gap && nomask) 880 gap->ae_perm &= (mode >> 3) & 0x7; 881 } 882