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_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 }