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_mac.h" 35 #include "xfs_attr.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 = bhv_vop_getattr(vp, &va, 0, sys_cred); 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 = bhv_vop_attr_remove(vp, kind == _ACL_TYPE_DEFAULT? 270 SGI_ACL_DEFAULT: SGI_ACL_FILE, 271 ATTR_ROOT, sys_cred); 272 if (error == ENOATTR) 273 error = 0; /* 'scool */ 274 } 275 VN_RELE(vp); 276 return -error; 277 } 278 279 int 280 xfs_acl_vset( 281 bhv_vnode_t *vp, 282 void *acl, 283 size_t size, 284 int kind) 285 { 286 posix_acl_xattr_header *ext_acl = acl; 287 xfs_acl_t *xfs_acl; 288 int error; 289 int basicperms = 0; /* more than std unix perms? */ 290 291 if (!acl) 292 return -EINVAL; 293 294 if (!(_ACL_ALLOC(xfs_acl))) 295 return -ENOMEM; 296 297 error = posix_acl_xattr_to_xfs(ext_acl, size, xfs_acl); 298 if (error) { 299 _ACL_FREE(xfs_acl); 300 return -error; 301 } 302 if (!xfs_acl->acl_cnt) { 303 _ACL_FREE(xfs_acl); 304 return 0; 305 } 306 307 VN_HOLD(vp); 308 error = xfs_acl_allow_set(vp, kind); 309 if (error) 310 goto out; 311 312 /* Incoming ACL exists, set file mode based on its value */ 313 if (kind == _ACL_TYPE_ACCESS) 314 xfs_acl_setmode(vp, xfs_acl, &basicperms); 315 316 /* 317 * If we have more than std unix permissions, set up the actual attr. 318 * Otherwise, delete any existing attr. This prevents us from 319 * having actual attrs for permissions that can be stored in the 320 * standard permission bits. 321 */ 322 if (!basicperms) { 323 xfs_acl_set_attr(vp, xfs_acl, kind, &error); 324 } else { 325 xfs_acl_vremove(vp, _ACL_TYPE_ACCESS); 326 } 327 328 out: 329 VN_RELE(vp); 330 _ACL_FREE(xfs_acl); 331 return -error; 332 } 333 334 int 335 xfs_acl_iaccess( 336 xfs_inode_t *ip, 337 mode_t mode, 338 cred_t *cr) 339 { 340 xfs_acl_t *acl; 341 int rval; 342 343 if (!(_ACL_ALLOC(acl))) 344 return -1; 345 346 /* If the file has no ACL return -1. */ 347 rval = sizeof(xfs_acl_t); 348 if (xfs_attr_fetch(ip, SGI_ACL_FILE, SGI_ACL_FILE_SIZE, 349 (char *)acl, &rval, ATTR_ROOT | ATTR_KERNACCESS, cr)) { 350 _ACL_FREE(acl); 351 return -1; 352 } 353 xfs_acl_get_endian(acl); 354 355 /* If the file has an empty ACL return -1. */ 356 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) { 357 _ACL_FREE(acl); 358 return -1; 359 } 360 361 /* Synchronize ACL with mode bits */ 362 xfs_acl_sync_mode(ip->i_d.di_mode, acl); 363 364 rval = xfs_acl_access(ip->i_d.di_uid, ip->i_d.di_gid, acl, mode, cr); 365 _ACL_FREE(acl); 366 return rval; 367 } 368 369 STATIC int 370 xfs_acl_allow_set( 371 bhv_vnode_t *vp, 372 int kind) 373 { 374 bhv_vattr_t va; 375 int error; 376 377 if (vp->v_inode.i_flags & (S_IMMUTABLE|S_APPEND)) 378 return EPERM; 379 if (kind == _ACL_TYPE_DEFAULT && !VN_ISDIR(vp)) 380 return ENOTDIR; 381 if (vp->v_vfsp->vfs_flag & VFS_RDONLY) 382 return EROFS; 383 va.va_mask = XFS_AT_UID; 384 error = bhv_vop_getattr(vp, &va, 0, NULL); 385 if (error) 386 return error; 387 if (va.va_uid != current->fsuid && !capable(CAP_FOWNER)) 388 return EPERM; 389 return error; 390 } 391 392 /* 393 * The access control process to determine the access permission: 394 * if uid == file owner id, use the file owner bits. 395 * if gid == file owner group id, use the file group bits. 396 * scan ACL for a matching user or group, and use matched entry 397 * permission. Use total permissions of all matching group entries, 398 * until all acl entries are exhausted. The final permission produced 399 * by matching acl entry or entries needs to be & with group permission. 400 * if not owner, owning group, or matching entry in ACL, use file 401 * other bits. 402 */ 403 STATIC int 404 xfs_acl_capability_check( 405 mode_t mode, 406 cred_t *cr) 407 { 408 if ((mode & ACL_READ) && !capable_cred(cr, CAP_DAC_READ_SEARCH)) 409 return EACCES; 410 if ((mode & ACL_WRITE) && !capable_cred(cr, CAP_DAC_OVERRIDE)) 411 return EACCES; 412 if ((mode & ACL_EXECUTE) && !capable_cred(cr, CAP_DAC_OVERRIDE)) 413 return EACCES; 414 415 return 0; 416 } 417 418 /* 419 * Note: cr is only used here for the capability check if the ACL test fails. 420 * It is not used to find out the credentials uid or groups etc, as was 421 * done in IRIX. It is assumed that the uid and groups for the current 422 * thread are taken from "current" instead of the cr parameter. 423 */ 424 STATIC int 425 xfs_acl_access( 426 uid_t fuid, 427 gid_t fgid, 428 xfs_acl_t *fap, 429 mode_t md, 430 cred_t *cr) 431 { 432 xfs_acl_entry_t matched; 433 int i, allows; 434 int maskallows = -1; /* true, but not 1, either */ 435 int seen_userobj = 0; 436 437 matched.ae_tag = 0; /* Invalid type */ 438 matched.ae_perm = 0; 439 md >>= 6; /* Normalize the bits for comparison */ 440 441 for (i = 0; i < fap->acl_cnt; i++) { 442 /* 443 * Break out if we've got a user_obj entry or 444 * a user entry and the mask (and have processed USER_OBJ) 445 */ 446 if (matched.ae_tag == ACL_USER_OBJ) 447 break; 448 if (matched.ae_tag == ACL_USER) { 449 if (maskallows != -1 && seen_userobj) 450 break; 451 if (fap->acl_entry[i].ae_tag != ACL_MASK && 452 fap->acl_entry[i].ae_tag != ACL_USER_OBJ) 453 continue; 454 } 455 /* True if this entry allows the requested access */ 456 allows = ((fap->acl_entry[i].ae_perm & md) == md); 457 458 switch (fap->acl_entry[i].ae_tag) { 459 case ACL_USER_OBJ: 460 seen_userobj = 1; 461 if (fuid != current->fsuid) 462 continue; 463 matched.ae_tag = ACL_USER_OBJ; 464 matched.ae_perm = allows; 465 break; 466 case ACL_USER: 467 if (fap->acl_entry[i].ae_id != current->fsuid) 468 continue; 469 matched.ae_tag = ACL_USER; 470 matched.ae_perm = allows; 471 break; 472 case ACL_GROUP_OBJ: 473 if ((matched.ae_tag == ACL_GROUP_OBJ || 474 matched.ae_tag == ACL_GROUP) && !allows) 475 continue; 476 if (!in_group_p(fgid)) 477 continue; 478 matched.ae_tag = ACL_GROUP_OBJ; 479 matched.ae_perm = allows; 480 break; 481 case ACL_GROUP: 482 if ((matched.ae_tag == ACL_GROUP_OBJ || 483 matched.ae_tag == ACL_GROUP) && !allows) 484 continue; 485 if (!in_group_p(fap->acl_entry[i].ae_id)) 486 continue; 487 matched.ae_tag = ACL_GROUP; 488 matched.ae_perm = allows; 489 break; 490 case ACL_MASK: 491 maskallows = allows; 492 break; 493 case ACL_OTHER: 494 if (matched.ae_tag != 0) 495 continue; 496 matched.ae_tag = ACL_OTHER; 497 matched.ae_perm = allows; 498 break; 499 } 500 } 501 /* 502 * First possibility is that no matched entry allows access. 503 * The capability to override DAC may exist, so check for it. 504 */ 505 switch (matched.ae_tag) { 506 case ACL_OTHER: 507 case ACL_USER_OBJ: 508 if (matched.ae_perm) 509 return 0; 510 break; 511 case ACL_USER: 512 case ACL_GROUP_OBJ: 513 case ACL_GROUP: 514 if (maskallows && matched.ae_perm) 515 return 0; 516 break; 517 case 0: 518 break; 519 } 520 521 return xfs_acl_capability_check(md, cr); 522 } 523 524 /* 525 * ACL validity checker. 526 * This acl validation routine checks each ACL entry read in makes sense. 527 */ 528 STATIC int 529 xfs_acl_invalid( 530 xfs_acl_t *aclp) 531 { 532 xfs_acl_entry_t *entry, *e; 533 int user = 0, group = 0, other = 0, mask = 0; 534 int mask_required = 0; 535 int i, j; 536 537 if (!aclp) 538 goto acl_invalid; 539 540 if (aclp->acl_cnt > XFS_ACL_MAX_ENTRIES) 541 goto acl_invalid; 542 543 for (i = 0; i < aclp->acl_cnt; i++) { 544 entry = &aclp->acl_entry[i]; 545 switch (entry->ae_tag) { 546 case ACL_USER_OBJ: 547 if (user++) 548 goto acl_invalid; 549 break; 550 case ACL_GROUP_OBJ: 551 if (group++) 552 goto acl_invalid; 553 break; 554 case ACL_OTHER: 555 if (other++) 556 goto acl_invalid; 557 break; 558 case ACL_USER: 559 case ACL_GROUP: 560 for (j = i + 1; j < aclp->acl_cnt; j++) { 561 e = &aclp->acl_entry[j]; 562 if (e->ae_id == entry->ae_id && 563 e->ae_tag == entry->ae_tag) 564 goto acl_invalid; 565 } 566 mask_required++; 567 break; 568 case ACL_MASK: 569 if (mask++) 570 goto acl_invalid; 571 break; 572 default: 573 goto acl_invalid; 574 } 575 } 576 if (!user || !group || !other || (mask_required && !mask)) 577 goto acl_invalid; 578 else 579 return 0; 580 acl_invalid: 581 return EINVAL; 582 } 583 584 /* 585 * Do ACL endian conversion. 586 */ 587 STATIC void 588 xfs_acl_get_endian( 589 xfs_acl_t *aclp) 590 { 591 xfs_acl_entry_t *ace, *end; 592 593 INT_SET(aclp->acl_cnt, ARCH_CONVERT, aclp->acl_cnt); 594 end = &aclp->acl_entry[0]+aclp->acl_cnt; 595 for (ace = &aclp->acl_entry[0]; ace < end; ace++) { 596 INT_SET(ace->ae_tag, ARCH_CONVERT, ace->ae_tag); 597 INT_SET(ace->ae_id, ARCH_CONVERT, ace->ae_id); 598 INT_SET(ace->ae_perm, ARCH_CONVERT, ace->ae_perm); 599 } 600 } 601 602 /* 603 * Get the ACL from the EA and do endian conversion. 604 */ 605 STATIC void 606 xfs_acl_get_attr( 607 bhv_vnode_t *vp, 608 xfs_acl_t *aclp, 609 int kind, 610 int flags, 611 int *error) 612 { 613 int len = sizeof(xfs_acl_t); 614 615 ASSERT((flags & ATTR_KERNOVAL) ? (aclp == NULL) : 1); 616 flags |= ATTR_ROOT; 617 *error = bhv_vop_attr_get(vp, kind == _ACL_TYPE_ACCESS ? 618 SGI_ACL_FILE : SGI_ACL_DEFAULT, 619 (char *)aclp, &len, flags, sys_cred); 620 if (*error || (flags & ATTR_KERNOVAL)) 621 return; 622 xfs_acl_get_endian(aclp); 623 } 624 625 /* 626 * Set the EA with the ACL and do endian conversion. 627 */ 628 STATIC void 629 xfs_acl_set_attr( 630 bhv_vnode_t *vp, 631 xfs_acl_t *aclp, 632 int kind, 633 int *error) 634 { 635 xfs_acl_entry_t *ace, *newace, *end; 636 xfs_acl_t *newacl; 637 int len; 638 639 if (!(_ACL_ALLOC(newacl))) { 640 *error = ENOMEM; 641 return; 642 } 643 644 len = sizeof(xfs_acl_t) - 645 (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt)); 646 end = &aclp->acl_entry[0]+aclp->acl_cnt; 647 for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0]; 648 ace < end; 649 ace++, newace++) { 650 INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag); 651 INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id); 652 INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm); 653 } 654 INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt); 655 *error = bhv_vop_attr_set(vp, kind == _ACL_TYPE_ACCESS ? 656 SGI_ACL_FILE: SGI_ACL_DEFAULT, 657 (char *)newacl, len, ATTR_ROOT, sys_cred); 658 _ACL_FREE(newacl); 659 } 660 661 int 662 xfs_acl_vtoacl( 663 bhv_vnode_t *vp, 664 xfs_acl_t *access_acl, 665 xfs_acl_t *default_acl) 666 { 667 bhv_vattr_t va; 668 int error = 0; 669 670 if (access_acl) { 671 /* 672 * Get the Access ACL and the mode. If either cannot 673 * be obtained for some reason, invalidate the access ACL. 674 */ 675 xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error); 676 if (!error) { 677 /* Got the ACL, need the mode... */ 678 va.va_mask = XFS_AT_MODE; 679 error = bhv_vop_getattr(vp, &va, 0, sys_cred); 680 } 681 682 if (error) 683 access_acl->acl_cnt = XFS_ACL_NOT_PRESENT; 684 else /* We have a good ACL and the file mode, synchronize. */ 685 xfs_acl_sync_mode(va.va_mode, access_acl); 686 } 687 688 if (default_acl) { 689 xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error); 690 if (error) 691 default_acl->acl_cnt = XFS_ACL_NOT_PRESENT; 692 } 693 return error; 694 } 695 696 /* 697 * This function retrieves the parent directory's acl, processes it 698 * and lets the child inherit the acl(s) that it should. 699 */ 700 int 701 xfs_acl_inherit( 702 bhv_vnode_t *vp, 703 bhv_vattr_t *vap, 704 xfs_acl_t *pdaclp) 705 { 706 xfs_acl_t *cacl; 707 int error = 0; 708 int basicperms = 0; 709 710 /* 711 * If the parent does not have a default ACL, or it's an 712 * invalid ACL, we're done. 713 */ 714 if (!vp) 715 return 0; 716 if (!pdaclp || xfs_acl_invalid(pdaclp)) 717 return 0; 718 719 /* 720 * Copy the default ACL of the containing directory to 721 * the access ACL of the new file and use the mode that 722 * was passed in to set up the correct initial values for 723 * the u::,g::[m::], and o:: entries. This is what makes 724 * umask() "work" with ACL's. 725 */ 726 727 if (!(_ACL_ALLOC(cacl))) 728 return ENOMEM; 729 730 memcpy(cacl, pdaclp, sizeof(xfs_acl_t)); 731 xfs_acl_filter_mode(vap->va_mode, cacl); 732 xfs_acl_setmode(vp, cacl, &basicperms); 733 734 /* 735 * Set the Default and Access ACL on the file. The mode is already 736 * set on the file, so we don't need to worry about that. 737 * 738 * If the new file is a directory, its default ACL is a copy of 739 * the containing directory's default ACL. 740 */ 741 if (VN_ISDIR(vp)) 742 xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error); 743 if (!error && !basicperms) 744 xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error); 745 _ACL_FREE(cacl); 746 return error; 747 } 748 749 /* 750 * Set up the correct mode on the file based on the supplied ACL. This 751 * makes sure that the mode on the file reflects the state of the 752 * u::,g::[m::], and o:: entries in the ACL. Since the mode is where 753 * the ACL is going to get the permissions for these entries, we must 754 * synchronize the mode whenever we set the ACL on a file. 755 */ 756 STATIC int 757 xfs_acl_setmode( 758 bhv_vnode_t *vp, 759 xfs_acl_t *acl, 760 int *basicperms) 761 { 762 bhv_vattr_t va; 763 xfs_acl_entry_t *ap; 764 xfs_acl_entry_t *gap = NULL; 765 int i, error, nomask = 1; 766 767 *basicperms = 1; 768 769 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) 770 return 0; 771 772 /* 773 * Copy the u::, g::, o::, and m:: bits from the ACL into the 774 * mode. The m:: bits take precedence over the g:: bits. 775 */ 776 va.va_mask = XFS_AT_MODE; 777 error = bhv_vop_getattr(vp, &va, 0, sys_cred); 778 if (error) 779 return error; 780 781 va.va_mask = XFS_AT_MODE; 782 va.va_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO); 783 ap = acl->acl_entry; 784 for (i = 0; i < acl->acl_cnt; ++i) { 785 switch (ap->ae_tag) { 786 case ACL_USER_OBJ: 787 va.va_mode |= ap->ae_perm << 6; 788 break; 789 case ACL_GROUP_OBJ: 790 gap = ap; 791 break; 792 case ACL_MASK: /* more than just standard modes */ 793 nomask = 0; 794 va.va_mode |= ap->ae_perm << 3; 795 *basicperms = 0; 796 break; 797 case ACL_OTHER: 798 va.va_mode |= ap->ae_perm; 799 break; 800 default: /* more than just standard modes */ 801 *basicperms = 0; 802 break; 803 } 804 ap++; 805 } 806 807 /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */ 808 if (gap && nomask) 809 va.va_mode |= gap->ae_perm << 3; 810 811 return bhv_vop_setattr(vp, &va, 0, sys_cred); 812 } 813 814 /* 815 * The permissions for the special ACL entries (u::, g::[m::], o::) are 816 * actually stored in the file mode (if there is both a group and a mask, 817 * the group is stored in the ACL entry and the mask is stored on the file). 818 * This allows the mode to remain automatically in sync with the ACL without 819 * the need for a call-back to the ACL system at every point where the mode 820 * could change. This function takes the permissions from the specified mode 821 * and places it in the supplied ACL. 822 * 823 * This implementation draws its validity from the fact that, when the ACL 824 * was assigned, the mode was copied from the ACL. 825 * If the mode did not change, therefore, the mode remains exactly what was 826 * taken from the special ACL entries at assignment. 827 * If a subsequent chmod() was done, the POSIX spec says that the change in 828 * mode must cause an update to the ACL seen at user level and used for 829 * access checks. Before and after a mode change, therefore, the file mode 830 * most accurately reflects what the special ACL entries should permit/deny. 831 * 832 * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly, 833 * the existing mode bits will override whatever is in the 834 * ACL. Similarly, if there is a pre-existing ACL that was 835 * never in sync with its mode (owing to a bug in 6.5 and 836 * before), it will now magically (or mystically) be 837 * synchronized. This could cause slight astonishment, but 838 * it is better than inconsistent permissions. 839 * 840 * The supplied ACL is a template that may contain any combination 841 * of special entries. These are treated as place holders when we fill 842 * out the ACL. This routine does not add or remove special entries, it 843 * simply unites each special entry with its associated set of permissions. 844 */ 845 STATIC void 846 xfs_acl_sync_mode( 847 mode_t mode, 848 xfs_acl_t *acl) 849 { 850 int i, nomask = 1; 851 xfs_acl_entry_t *ap; 852 xfs_acl_entry_t *gap = NULL; 853 854 /* 855 * Set ACL entries. POSIX1003.1eD16 requires that the MASK 856 * be set instead of the GROUP entry, if there is a MASK. 857 */ 858 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) { 859 switch (ap->ae_tag) { 860 case ACL_USER_OBJ: 861 ap->ae_perm = (mode >> 6) & 0x7; 862 break; 863 case ACL_GROUP_OBJ: 864 gap = ap; 865 break; 866 case ACL_MASK: 867 nomask = 0; 868 ap->ae_perm = (mode >> 3) & 0x7; 869 break; 870 case ACL_OTHER: 871 ap->ae_perm = mode & 0x7; 872 break; 873 default: 874 break; 875 } 876 } 877 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */ 878 if (gap && nomask) 879 gap->ae_perm = (mode >> 3) & 0x7; 880 } 881 882 /* 883 * When inheriting an Access ACL from a directory Default ACL, 884 * the ACL bits are set to the intersection of the ACL default 885 * permission bits and the file permission bits in mode. If there 886 * are no permission bits on the file then we must not give them 887 * the ACL. This is what what makes umask() work with ACLs. 888 */ 889 STATIC void 890 xfs_acl_filter_mode( 891 mode_t mode, 892 xfs_acl_t *acl) 893 { 894 int i, nomask = 1; 895 xfs_acl_entry_t *ap; 896 xfs_acl_entry_t *gap = NULL; 897 898 /* 899 * Set ACL entries. POSIX1003.1eD16 requires that the MASK 900 * be merged with GROUP entry, if there is a MASK. 901 */ 902 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) { 903 switch (ap->ae_tag) { 904 case ACL_USER_OBJ: 905 ap->ae_perm &= (mode >> 6) & 0x7; 906 break; 907 case ACL_GROUP_OBJ: 908 gap = ap; 909 break; 910 case ACL_MASK: 911 nomask = 0; 912 ap->ae_perm &= (mode >> 3) & 0x7; 913 break; 914 case ACL_OTHER: 915 ap->ae_perm &= mode & 0x7; 916 break; 917 default: 918 break; 919 } 920 } 921 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */ 922 if (gap && nomask) 923 gap->ae_perm &= (mode >> 3) & 0x7; 924 } 925