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_dir.h"
  25 #include "xfs_dir2.h"
  26 #include "xfs_bmap_btree.h"
  27 #include "xfs_alloc_btree.h"
  28 #include "xfs_ialloc_btree.h"
  29 #include "xfs_dir_sf.h"
  30 #include "xfs_dir2_sf.h"
  31 #include "xfs_attr_sf.h"
  32 #include "xfs_dinode.h"
  33 #include "xfs_inode.h"
  34 #include "xfs_btree.h"
  35 #include "xfs_acl.h"
  36 #include "xfs_mac.h"
  37 #include "xfs_attr.h"
  38
  39 #include <linux/capability.h>
  40 #include <linux/posix_acl_xattr.h>
  41
  42 STATIC int      xfs_acl_setmode(vnode_t *, xfs_acl_t *, int *);
  43 STATIC void     xfs_acl_filter_mode(mode_t, xfs_acl_t *);
  44 STATIC void     xfs_acl_get_endian(xfs_acl_t *);
  45 STATIC int      xfs_acl_access(uid_t, gid_t, xfs_acl_t *, mode_t, cred_t *);
  46 STATIC int      xfs_acl_invalid(xfs_acl_t *);
  47 STATIC void     xfs_acl_sync_mode(mode_t, xfs_acl_t *);
  48 STATIC void     xfs_acl_get_attr(vnode_t *, xfs_acl_t *, int, int, int *);
  49 STATIC void     xfs_acl_set_attr(vnode_t *, xfs_acl_t *, int, int *);
  50 STATIC int      xfs_acl_allow_set(vnode_t *, int);
  51
  52 kmem_zone_t *xfs_acl_zone;
  53
  54
  55 /*
  56  * Test for existence of access ACL attribute as efficiently as possible.
  57  */
  58 int
  59 xfs_acl_vhasacl_access(
  60         vnode_t         *vp)
  61 {
  62         int             error;
  63
  64         xfs_acl_get_attr(vp, NULL, _ACL_TYPE_ACCESS, ATTR_KERNOVAL, &error);
  65         return (error == 0);
  66 }
  67
  68 /*
  69  * Test for existence of default ACL attribute as efficiently as possible.
  70  */
  71 int
  72 xfs_acl_vhasacl_default(
  73         vnode_t         *vp)
  74 {
  75         int             error;
  76
  77         if (!VN_ISDIR(vp))
  78                 return 0;
  79         xfs_acl_get_attr(vp, NULL, _ACL_TYPE_DEFAULT, ATTR_KERNOVAL, &error);
  80         return (error == 0);
  81 }
  82
  83 /*
  84  * Convert from extended attribute representation to in-memory for XFS.
  85  */
  86 STATIC int
  87 posix_acl_xattr_to_xfs(
  88         posix_acl_xattr_header  *src,
  89         size_t                  size,
  90         xfs_acl_t               *dest)
  91 {
  92         posix_acl_xattr_entry   *src_entry;
  93         xfs_acl_entry_t         *dest_entry;
  94         int                     n;
  95
  96         if (!src || !dest)
  97                 return EINVAL;
  98
  99         if (size < sizeof(posix_acl_xattr_header))
 100                 return EINVAL;
 101
 102         if (src->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
 103                 return EOPNOTSUPP;
 104
 105         memset(dest, 0, sizeof(xfs_acl_t));
 106         dest->acl_cnt = posix_acl_xattr_count(size);
 107         if (dest->acl_cnt < 0 || dest->acl_cnt > XFS_ACL_MAX_ENTRIES)
 108                 return EINVAL;
 109
 110         /*
 111          * acl_set_file(3) may request that we set default ACLs with
 112          * zero length -- defend (gracefully) against that here.
 113          */
 114         if (!dest->acl_cnt)
 115                 return 0;
 116
 117         src_entry = (posix_acl_xattr_entry *)((char *)src + sizeof(*src));
 118         dest_entry = &dest->acl_entry[0];
 119
 120         for (n = 0; n < dest->acl_cnt; n++, src_entry++, dest_entry++) {
 121                 dest_entry->ae_perm = le16_to_cpu(src_entry->e_perm);
 122                 if (_ACL_PERM_INVALID(dest_entry->ae_perm))
 123                         return EINVAL;
 124                 dest_entry->ae_tag  = le16_to_cpu(src_entry->e_tag);
 125                 switch(dest_entry->ae_tag) {
 126                 case ACL_USER:
 127                 case ACL_GROUP:
 128                         dest_entry->ae_id = le32_to_cpu(src_entry->e_id);
 129                         break;
 130                 case ACL_USER_OBJ:
 131                 case ACL_GROUP_OBJ:
 132                 case ACL_MASK:
 133                 case ACL_OTHER:
 134                         dest_entry->ae_id = ACL_UNDEFINED_ID;
 135                         break;
 136                 default:
 137                         return EINVAL;
 138                 }
 139         }
 140         if (xfs_acl_invalid(dest))
 141                 return EINVAL;
 142
 143         return 0;
 144 }
 145
 146 /*
 147  * Comparison function called from xfs_sort().
 148  * Primary key is ae_tag, secondary key is ae_id.
 149  */
 150 STATIC int
 151 xfs_acl_entry_compare(
 152         const void      *va,
 153         const void      *vb)
 154 {
 155         xfs_acl_entry_t *a = (xfs_acl_entry_t *)va,
 156                         *b = (xfs_acl_entry_t *)vb;
 157
 158         if (a->ae_tag == b->ae_tag)
 159                 return (a->ae_id - b->ae_id);
 160         return (a->ae_tag - b->ae_tag);
 161 }
 162
 163 /*
 164  * Convert from in-memory XFS to extended attribute representation.
 165  */
 166 STATIC int
 167 posix_acl_xfs_to_xattr(
 168         xfs_acl_t               *src,
 169         posix_acl_xattr_header  *dest,
 170         size_t                  size)
 171 {
 172         int                     n;
 173         size_t                  new_size = posix_acl_xattr_size(src->acl_cnt);
 174         posix_acl_xattr_entry   *dest_entry;
 175         xfs_acl_entry_t         *src_entry;
 176
 177         if (size < new_size)
 178                 return -ERANGE;
 179
 180         /* Need to sort src XFS ACL by <ae_tag,ae_id> */
 181         xfs_sort(src->acl_entry, src->acl_cnt, sizeof(src->acl_entry[0]),
 182                  xfs_acl_entry_compare);
 183
 184         dest->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
 185         dest_entry = &dest->a_entries[0];
 186         src_entry = &src->acl_entry[0];
 187         for (n = 0; n < src->acl_cnt; n++, dest_entry++, src_entry++) {
 188                 dest_entry->e_perm = cpu_to_le16(src_entry->ae_perm);
 189                 if (_ACL_PERM_INVALID(src_entry->ae_perm))
 190                         return -EINVAL;
 191                 dest_entry->e_tag  = cpu_to_le16(src_entry->ae_tag);
 192                 switch (src_entry->ae_tag) {
 193                 case ACL_USER:
 194                 case ACL_GROUP:
 195                         dest_entry->e_id = cpu_to_le32(src_entry->ae_id);
 196                                 break;
 197                 case ACL_USER_OBJ:
 198                 case ACL_GROUP_OBJ:
 199                 case ACL_MASK:
 200                 case ACL_OTHER:
 201                         dest_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
 202                         break;
 203                 default:
 204                         return -EINVAL;
 205                 }
 206         }
 207         return new_size;
 208 }
 209
 210 int
 211 xfs_acl_vget(
 212         vnode_t         *vp,
 213         void            *acl,
 214         size_t          size,
 215         int             kind)
 216 {
 217         int                     error;
 218         xfs_acl_t               *xfs_acl = NULL;
 219         posix_acl_xattr_header  *ext_acl = acl;
 220         int                     flags = 0;
 221
 222         VN_HOLD(vp);
 223         if(size) {
 224                 if (!(_ACL_ALLOC(xfs_acl))) {
 225                         error = ENOMEM;
 226                         goto out;
 227                 }
 228                 memset(xfs_acl, 0, sizeof(xfs_acl_t));
 229         } else
 230                 flags = ATTR_KERNOVAL;
 231
 232         xfs_acl_get_attr(vp, xfs_acl, kind, flags, &error);
 233         if (error)
 234                 goto out;
 235
 236         if (!size) {
 237                 error = -posix_acl_xattr_size(XFS_ACL_MAX_ENTRIES);
 238         } else {
 239                 if (xfs_acl_invalid(xfs_acl)) {
 240                         error = EINVAL;
 241                         goto out;
 242                 }
 243                 if (kind == _ACL_TYPE_ACCESS) {
 244                         vattr_t va;
 245
 246                         va.va_mask = XFS_AT_MODE;
 247                         VOP_GETATTR(vp, &va, 0, sys_cred, error);
 248                         if (error)
 249                                 goto out;
 250                         xfs_acl_sync_mode(va.va_mode, xfs_acl);
 251                 }
 252                 error = -posix_acl_xfs_to_xattr(xfs_acl, ext_acl, size);
 253         }
 254 out:
 255         VN_RELE(vp);
 256         if(xfs_acl)
 257                 _ACL_FREE(xfs_acl);
 258         return -error;
 259 }
 260
 261 int
 262 xfs_acl_vremove(
 263         vnode_t         *vp,
 264         int             kind)
 265 {
 266         int             error;
 267
 268         VN_HOLD(vp);
 269         error = xfs_acl_allow_set(vp, kind);
 270         if (!error) {
 271                 VOP_ATTR_REMOVE(vp, kind == _ACL_TYPE_DEFAULT?
 272                                 SGI_ACL_DEFAULT: SGI_ACL_FILE,
 273                                 ATTR_ROOT, sys_cred, error);
 274                 if (error == ENOATTR)
 275                         error = 0;      /* 'scool */
 276         }
 277         VN_RELE(vp);
 278         return -error;
 279 }
 280
 281 int
 282 xfs_acl_vset(
 283         vnode_t                 *vp,
 284         void                    *acl,
 285         size_t                  size,
 286         int                     kind)
 287 {
 288         posix_acl_xattr_header  *ext_acl = acl;
 289         xfs_acl_t               *xfs_acl;
 290         int                     error;
 291         int                     basicperms = 0; /* more than std unix perms? */
 292
 293         if (!acl)
 294                 return -EINVAL;
 295
 296         if (!(_ACL_ALLOC(xfs_acl)))
 297                 return -ENOMEM;
 298
 299         error = posix_acl_xattr_to_xfs(ext_acl, size, xfs_acl);
 300         if (error) {
 301                 _ACL_FREE(xfs_acl);
 302                 return -error;
 303         }
 304         if (!xfs_acl->acl_cnt) {
 305                 _ACL_FREE(xfs_acl);
 306                 return 0;
 307         }
 308
 309         VN_HOLD(vp);
 310         error = xfs_acl_allow_set(vp, kind);
 311         if (error)
 312                 goto out;
 313
 314         /* Incoming ACL exists, set file mode based on its value */
 315         if (kind == _ACL_TYPE_ACCESS)
 316                 xfs_acl_setmode(vp, xfs_acl, &basicperms);
 317
 318         /*
 319          * If we have more than std unix permissions, set up the actual attr.
 320          * Otherwise, delete any existing attr.  This prevents us from
 321          * having actual attrs for permissions that can be stored in the
 322          * standard permission bits.
 323          */
 324         if (!basicperms) {
 325                 xfs_acl_set_attr(vp, xfs_acl, kind, &error);
 326         } else {
 327                 xfs_acl_vremove(vp, _ACL_TYPE_ACCESS);
 328         }
 329
 330 out:
 331         VN_RELE(vp);
 332         _ACL_FREE(xfs_acl);
 333         return -error;
 334 }
 335
 336 int
 337 xfs_acl_iaccess(
 338         xfs_inode_t     *ip,
 339         mode_t          mode,
 340         cred_t          *cr)
 341 {
 342         xfs_acl_t       *acl;
 343         int             rval;
 344
 345         if (!(_ACL_ALLOC(acl)))
 346                 return -1;
 347
 348         /* If the file has no ACL return -1. */
 349         rval = sizeof(xfs_acl_t);
 350         if (xfs_attr_fetch(ip, SGI_ACL_FILE, SGI_ACL_FILE_SIZE,
 351                         (char *)acl, &rval, ATTR_ROOT | ATTR_KERNACCESS, cr)) {
 352                 _ACL_FREE(acl);
 353                 return -1;
 354         }
 355         xfs_acl_get_endian(acl);
 356
 357         /* If the file has an empty ACL return -1. */
 358         if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) {
 359                 _ACL_FREE(acl);
 360                 return -1;
 361         }
 362
 363         /* Synchronize ACL with mode bits */
 364         xfs_acl_sync_mode(ip->i_d.di_mode, acl);
 365
 366         rval = xfs_acl_access(ip->i_d.di_uid, ip->i_d.di_gid, acl, mode, cr);
 367         _ACL_FREE(acl);
 368         return rval;
 369 }
 370
 371 STATIC int
 372 xfs_acl_allow_set(
 373         vnode_t         *vp,
 374         int             kind)
 375 {
 376         vattr_t         va;
 377         int             error;
 378
 379         if (vp->v_inode.i_flags & (S_IMMUTABLE|S_APPEND))
 380                 return EPERM;
 381         if (kind == _ACL_TYPE_DEFAULT && !VN_ISDIR(vp))
 382                 return ENOTDIR;
 383         if (vp->v_vfsp->vfs_flag & VFS_RDONLY)
 384                 return EROFS;
 385         va.va_mask = XFS_AT_UID;
 386         VOP_GETATTR(vp, &va, 0, NULL, error);
 387         if (error)
 388                 return error;
 389         if (va.va_uid != current->fsuid && !capable(CAP_FOWNER))
 390                 return EPERM;
 391         return error;
 392 }
 393
 394 /*
 395  * The access control process to determine the access permission:
 396  *      if uid == file owner id, use the file owner bits.
 397  *      if gid == file owner group id, use the file group bits.
 398  *      scan ACL for a matching user or group, and use matched entry
 399  *      permission. Use total permissions of all matching group entries,
 400  *      until all acl entries are exhausted. The final permission produced
 401  *      by matching acl entry or entries needs to be & with group permission.
 402  *      if not owner, owning group, or matching entry in ACL, use file
 403  *      other bits.
 404  */
 405 STATIC int
 406 xfs_acl_capability_check(
 407         mode_t          mode,
 408         cred_t          *cr)
 409 {
 410         if ((mode & ACL_READ) && !capable_cred(cr, CAP_DAC_READ_SEARCH))
 411                 return EACCES;
 412         if ((mode & ACL_WRITE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
 413                 return EACCES;
 414         if ((mode & ACL_EXECUTE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
 415                 return EACCES;
 416
 417         return 0;
 418 }
 419
 420 /*
 421  * Note: cr is only used here for the capability check if the ACL test fails.
 422  *       It is not used to find out the credentials uid or groups etc, as was
 423  *       done in IRIX. It is assumed that the uid and groups for the current
 424  *       thread are taken from "current" instead of the cr parameter.
 425  */
 426 STATIC int
 427 xfs_acl_access(
 428         uid_t           fuid,
 429         gid_t           fgid,
 430         xfs_acl_t       *fap,
 431         mode_t          md,
 432         cred_t          *cr)
 433 {
 434         xfs_acl_entry_t matched;
 435         int             i, allows;
 436         int             maskallows = -1;        /* true, but not 1, either */
 437         int             seen_userobj = 0;
 438
 439         matched.ae_tag = 0;     /* Invalid type */
 440         matched.ae_perm = 0;
 441         md >>= 6;       /* Normalize the bits for comparison */
 442
 443         for (i = 0; i < fap->acl_cnt; i++) {
 444                 /*
 445                  * Break out if we've got a user_obj entry or
 446                  * a user entry and the mask (and have processed USER_OBJ)
 447                  */
 448                 if (matched.ae_tag == ACL_USER_OBJ)
 449                         break;
 450                 if (matched.ae_tag == ACL_USER) {
 451                         if (maskallows != -1 && seen_userobj)
 452                                 break;
 453                         if (fap->acl_entry[i].ae_tag != ACL_MASK &&
 454                             fap->acl_entry[i].ae_tag != ACL_USER_OBJ)
 455                                 continue;
 456                 }
 457                 /* True if this entry allows the requested access */
 458                 allows = ((fap->acl_entry[i].ae_perm & md) == md);
 459
 460                 switch (fap->acl_entry[i].ae_tag) {
 461                 case ACL_USER_OBJ:
 462                         seen_userobj = 1;
 463                         if (fuid != current->fsuid)
 464                                 continue;
 465                         matched.ae_tag = ACL_USER_OBJ;
 466                         matched.ae_perm = allows;
 467                         break;
 468                 case ACL_USER:
 469                         if (fap->acl_entry[i].ae_id != current->fsuid)
 470                                 continue;
 471                         matched.ae_tag = ACL_USER;
 472                         matched.ae_perm = allows;
 473                         break;
 474                 case ACL_GROUP_OBJ:
 475                         if ((matched.ae_tag == ACL_GROUP_OBJ ||
 476                             matched.ae_tag == ACL_GROUP) && !allows)
 477                                 continue;
 478                         if (!in_group_p(fgid))
 479                                 continue;
 480                         matched.ae_tag = ACL_GROUP_OBJ;
 481                         matched.ae_perm = allows;
 482                         break;
 483                 case ACL_GROUP:
 484                         if ((matched.ae_tag == ACL_GROUP_OBJ ||
 485                             matched.ae_tag == ACL_GROUP) && !allows)
 486                                 continue;
 487                         if (!in_group_p(fap->acl_entry[i].ae_id))
 488                                 continue;
 489                         matched.ae_tag = ACL_GROUP;
 490                         matched.ae_perm = allows;
 491                         break;
 492                 case ACL_MASK:
 493                         maskallows = allows;
 494                         break;
 495                 case ACL_OTHER:
 496                         if (matched.ae_tag != 0)
 497                                 continue;
 498                         matched.ae_tag = ACL_OTHER;
 499                         matched.ae_perm = allows;
 500                         break;
 501                 }
 502         }
 503         /*
 504          * First possibility is that no matched entry allows access.
 505          * The capability to override DAC may exist, so check for it.
 506          */
 507         switch (matched.ae_tag) {
 508         case ACL_OTHER:
 509         case ACL_USER_OBJ:
 510                 if (matched.ae_perm)
 511                         return 0;
 512                 break;
 513         case ACL_USER:
 514         case ACL_GROUP_OBJ:
 515         case ACL_GROUP:
 516                 if (maskallows && matched.ae_perm)
 517                         return 0;
 518                 break;
 519         case 0:
 520                 break;
 521         }
 522
 523         return xfs_acl_capability_check(md, cr);
 524 }
 525
 526 /*
 527  * ACL validity checker.
 528  *   This acl validation routine checks each ACL entry read in makes sense.
 529  */
 530 STATIC int
 531 xfs_acl_invalid(
 532         xfs_acl_t       *aclp)
 533 {
 534         xfs_acl_entry_t *entry, *e;
 535         int             user = 0, group = 0, other = 0, mask = 0;
 536         int             mask_required = 0;
 537         int             i, j;
 538
 539         if (!aclp)
 540                 goto acl_invalid;
 541
 542         if (aclp->acl_cnt > XFS_ACL_MAX_ENTRIES)
 543                 goto acl_invalid;
 544
 545         for (i = 0; i < aclp->acl_cnt; i++) {
 546                 entry = &aclp->acl_entry[i];
 547                 switch (entry->ae_tag) {
 548                 case ACL_USER_OBJ:
 549                         if (user++)
 550                                 goto acl_invalid;
 551                         break;
 552                 case ACL_GROUP_OBJ:
 553                         if (group++)
 554                                 goto acl_invalid;
 555                         break;
 556                 case ACL_OTHER:
 557                         if (other++)
 558                                 goto acl_invalid;
 559                         break;
 560                 case ACL_USER:
 561                 case ACL_GROUP:
 562                         for (j = i + 1; j < aclp->acl_cnt; j++) {
 563                                 e = &aclp->acl_entry[j];
 564                                 if (e->ae_id == entry->ae_id &&
 565                                     e->ae_tag == entry->ae_tag)
 566                                         goto acl_invalid;
 567                         }
 568                         mask_required++;
 569                         break;
 570                 case ACL_MASK:
 571                         if (mask++)
 572                                 goto acl_invalid;
 573                         break;
 574                 default:
 575                         goto acl_invalid;
 576                 }
 577         }
 578         if (!user || !group || !other || (mask_required && !mask))
 579                 goto acl_invalid;
 580         else
 581                 return 0;
 582 acl_invalid:
 583         return EINVAL;
 584 }
 585
 586 /*
 587  * Do ACL endian conversion.
 588  */
 589 STATIC void
 590 xfs_acl_get_endian(
 591         xfs_acl_t       *aclp)
 592 {
 593         xfs_acl_entry_t *ace, *end;
 594
 595         INT_SET(aclp->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
 596         end = &aclp->acl_entry[0]+aclp->acl_cnt;
 597         for (ace = &aclp->acl_entry[0]; ace < end; ace++) {
 598                 INT_SET(ace->ae_tag, ARCH_CONVERT, ace->ae_tag);
 599                 INT_SET(ace->ae_id, ARCH_CONVERT, ace->ae_id);
 600                 INT_SET(ace->ae_perm, ARCH_CONVERT, ace->ae_perm);
 601         }
 602 }
 603
 604 /*
 605  * Get the ACL from the EA and do endian conversion.
 606  */
 607 STATIC void
 608 xfs_acl_get_attr(
 609         vnode_t         *vp,
 610         xfs_acl_t       *aclp,
 611         int             kind,
 612         int             flags,
 613         int             *error)
 614 {
 615         int             len = sizeof(xfs_acl_t);
 616
 617         ASSERT((flags & ATTR_KERNOVAL) ? (aclp == NULL) : 1);
 618         flags |= ATTR_ROOT;
 619         VOP_ATTR_GET(vp,
 620                 kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE : SGI_ACL_DEFAULT,
 621                 (char *)aclp, &len, flags, sys_cred, *error);
 622         if (*error || (flags & ATTR_KERNOVAL))
 623                 return;
 624         xfs_acl_get_endian(aclp);
 625 }
 626
 627 /*
 628  * Set the EA with the ACL and do endian conversion.
 629  */
 630 STATIC void
 631 xfs_acl_set_attr(
 632         vnode_t         *vp,
 633         xfs_acl_t       *aclp,
 634         int             kind,
 635         int             *error)
 636 {
 637         xfs_acl_entry_t *ace, *newace, *end;
 638         xfs_acl_t       *newacl;
 639         int             len;
 640
 641         if (!(_ACL_ALLOC(newacl))) {
 642                 *error = ENOMEM;
 643                 return;
 644         }
 645
 646         len = sizeof(xfs_acl_t) -
 647               (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt));
 648         end = &aclp->acl_entry[0]+aclp->acl_cnt;
 649         for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0];
 650              ace < end;
 651              ace++, newace++) {
 652                 INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag);
 653                 INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id);
 654                 INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm);
 655         }
 656         INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
 657         VOP_ATTR_SET(vp,
 658                 kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE: SGI_ACL_DEFAULT,
 659                 (char *)newacl, len, ATTR_ROOT, sys_cred, *error);
 660         _ACL_FREE(newacl);
 661 }
 662
 663 int
 664 xfs_acl_vtoacl(
 665         vnode_t         *vp,
 666         xfs_acl_t       *access_acl,
 667         xfs_acl_t       *default_acl)
 668 {
 669         vattr_t         va;
 670         int             error = 0;
 671
 672         if (access_acl) {
 673                 /*
 674                  * Get the Access ACL and the mode.  If either cannot
 675                  * be obtained for some reason, invalidate the access ACL.
 676                  */
 677                 xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error);
 678                 if (!error) {
 679                         /* Got the ACL, need the mode... */
 680                         va.va_mask = XFS_AT_MODE;
 681                         VOP_GETATTR(vp, &va, 0, sys_cred, error);
 682                 }
 683
 684                 if (error)
 685                         access_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
 686                 else /* We have a good ACL and the file mode, synchronize. */
 687                         xfs_acl_sync_mode(va.va_mode, access_acl);
 688         }
 689
 690         if (default_acl) {
 691                 xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error);
 692                 if (error)
 693                         default_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
 694         }
 695         return error;
 696 }
 697
 698 /*
 699  * This function retrieves the parent directory's acl, processes it
 700  * and lets the child inherit the acl(s) that it should.
 701  */
 702 int
 703 xfs_acl_inherit(
 704         vnode_t         *vp,
 705         vattr_t         *vap,
 706         xfs_acl_t       *pdaclp)
 707 {
 708         xfs_acl_t       *cacl;
 709         int             error = 0;
 710         int             basicperms = 0;
 711
 712         /*
 713          * If the parent does not have a default ACL, or it's an
 714          * invalid ACL, we're done.
 715          */
 716         if (!vp)
 717                 return 0;
 718         if (!pdaclp || xfs_acl_invalid(pdaclp))
 719                 return 0;
 720
 721         /*
 722          * Copy the default ACL of the containing directory to
 723          * the access ACL of the new file and use the mode that
 724          * was passed in to set up the correct initial values for
 725          * the u::,g::[m::], and o:: entries.  This is what makes
 726          * umask() "work" with ACL's.
 727          */
 728
 729         if (!(_ACL_ALLOC(cacl)))
 730                 return ENOMEM;
 731
 732         memcpy(cacl, pdaclp, sizeof(xfs_acl_t));
 733         xfs_acl_filter_mode(vap->va_mode, cacl);
 734         xfs_acl_setmode(vp, cacl, &basicperms);
 735
 736         /*
 737          * Set the Default and Access ACL on the file.  The mode is already
 738          * set on the file, so we don't need to worry about that.
 739          *
 740          * If the new file is a directory, its default ACL is a copy of
 741          * the containing directory's default ACL.
 742          */
 743         if (VN_ISDIR(vp))
 744                 xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error);
 745         if (!error && !basicperms)
 746                 xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error);
 747         _ACL_FREE(cacl);
 748         return error;
 749 }
 750
 751 /*
 752  * Set up the correct mode on the file based on the supplied ACL.  This
 753  * makes sure that the mode on the file reflects the state of the
 754  * u::,g::[m::], and o:: entries in the ACL.  Since the mode is where
 755  * the ACL is going to get the permissions for these entries, we must
 756  * synchronize the mode whenever we set the ACL on a file.
 757  */
 758 STATIC int
 759 xfs_acl_setmode(
 760         vnode_t         *vp,
 761         xfs_acl_t       *acl,
 762         int             *basicperms)
 763 {
 764         vattr_t         va;
 765         xfs_acl_entry_t *ap;
 766         xfs_acl_entry_t *gap = NULL;
 767         int             i, error, nomask = 1;
 768
 769         *basicperms = 1;
 770
 771         if (acl->acl_cnt == XFS_ACL_NOT_PRESENT)
 772                 return 0;
 773
 774         /*
 775          * Copy the u::, g::, o::, and m:: bits from the ACL into the
 776          * mode.  The m:: bits take precedence over the g:: bits.
 777          */
 778         va.va_mask = XFS_AT_MODE;
 779         VOP_GETATTR(vp, &va, 0, sys_cred, error);
 780         if (error)
 781                 return error;
 782
 783         va.va_mask = XFS_AT_MODE;
 784         va.va_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO);
 785         ap = acl->acl_entry;
 786         for (i = 0; i < acl->acl_cnt; ++i) {
 787                 switch (ap->ae_tag) {
 788                 case ACL_USER_OBJ:
 789                         va.va_mode |= ap->ae_perm << 6;
 790                         break;
 791                 case ACL_GROUP_OBJ:
 792                         gap = ap;
 793                         break;
 794                 case ACL_MASK:  /* more than just standard modes */
 795                         nomask = 0;
 796                         va.va_mode |= ap->ae_perm << 3;
 797                         *basicperms = 0;
 798                         break;
 799                 case ACL_OTHER:
 800                         va.va_mode |= ap->ae_perm;
 801                         break;
 802                 default:        /* more than just standard modes */
 803                         *basicperms = 0;
 804                         break;
 805                 }
 806                 ap++;
 807         }
 808
 809         /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */
 810         if (gap && nomask)
 811                 va.va_mode |= gap->ae_perm << 3;
 812
 813         VOP_SETATTR(vp, &va, 0, sys_cred, error);
 814         return error;
 815 }
 816
 817 /*
 818  * The permissions for the special ACL entries (u::, g::[m::], o::) are
 819  * actually stored in the file mode (if there is both a group and a mask,
 820  * the group is stored in the ACL entry and the mask is stored on the file).
 821  * This allows the mode to remain automatically in sync with the ACL without
 822  * the need for a call-back to the ACL system at every point where the mode
 823  * could change.  This function takes the permissions from the specified mode
 824  * and places it in the supplied ACL.
 825  *
 826  * This implementation draws its validity from the fact that, when the ACL
 827  * was assigned, the mode was copied from the ACL.
 828  * If the mode did not change, therefore, the mode remains exactly what was
 829  * taken from the special ACL entries at assignment.
 830  * If a subsequent chmod() was done, the POSIX spec says that the change in
 831  * mode must cause an update to the ACL seen at user level and used for
 832  * access checks.  Before and after a mode change, therefore, the file mode
 833  * most accurately reflects what the special ACL entries should permit/deny.
 834  *
 835  * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly,
 836  *         the existing mode bits will override whatever is in the
 837  *         ACL. Similarly, if there is a pre-existing ACL that was
 838  *         never in sync with its mode (owing to a bug in 6.5 and
 839  *         before), it will now magically (or mystically) be
 840  *         synchronized.  This could cause slight astonishment, but
 841  *         it is better than inconsistent permissions.
 842  *
 843  * The supplied ACL is a template that may contain any combination
 844  * of special entries.  These are treated as place holders when we fill
 845  * out the ACL.  This routine does not add or remove special entries, it
 846  * simply unites each special entry with its associated set of permissions.
 847  */
 848 STATIC void
 849 xfs_acl_sync_mode(
 850         mode_t          mode,
 851         xfs_acl_t       *acl)
 852 {
 853         int             i, nomask = 1;
 854         xfs_acl_entry_t *ap;
 855         xfs_acl_entry_t *gap = NULL;
 856
 857         /*
 858          * Set ACL entries. POSIX1003.1eD16 requires that the MASK
 859          * be set instead of the GROUP entry, if there is a MASK.
 860          */
 861         for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
 862                 switch (ap->ae_tag) {
 863                 case ACL_USER_OBJ:
 864                         ap->ae_perm = (mode >> 6) & 0x7;
 865                         break;
 866                 case ACL_GROUP_OBJ:
 867                         gap = ap;
 868                         break;
 869                 case ACL_MASK:
 870                         nomask = 0;
 871                         ap->ae_perm = (mode >> 3) & 0x7;
 872                         break;
 873                 case ACL_OTHER:
 874                         ap->ae_perm = mode & 0x7;
 875                         break;
 876                 default:
 877                         break;
 878                 }
 879         }
 880         /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
 881         if (gap && nomask)
 882                 gap->ae_perm = (mode >> 3) & 0x7;
 883 }
 884
 885 /*
 886  * When inheriting an Access ACL from a directory Default ACL,
 887  * the ACL bits are set to the intersection of the ACL default
 888  * permission bits and the file permission bits in mode. If there
 889  * are no permission bits on the file then we must not give them
 890  * the ACL. This is what what makes umask() work with ACLs.
 891  */
 892 STATIC void
 893 xfs_acl_filter_mode(
 894         mode_t          mode,
 895         xfs_acl_t       *acl)
 896 {
 897         int             i, nomask = 1;
 898         xfs_acl_entry_t *ap;
 899         xfs_acl_entry_t *gap = NULL;
 900
 901         /*
 902          * Set ACL entries. POSIX1003.1eD16 requires that the MASK
 903          * be merged with GROUP entry, if there is a MASK.
 904          */
 905         for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
 906                 switch (ap->ae_tag) {
 907                 case ACL_USER_OBJ:
 908                         ap->ae_perm &= (mode >> 6) & 0x7;
 909                         break;
 910                 case ACL_GROUP_OBJ:
 911                         gap = ap;
 912                         break;
 913                 case ACL_MASK:
 914                         nomask = 0;
 915                         ap->ae_perm &= (mode >> 3) & 0x7;
 916                         break;
 917                 case ACL_OTHER:
 918                         ap->ae_perm &= mode & 0x7;
 919                         break;
 920                 default:
 921                         break;
 922                 }
 923         }
 924         /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
 925         if (gap && nomask)
 926                 gap->ae_perm &= (mode >> 3) & 0x7;
 927 }