fs/xfs/xfs_acl.c

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