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 #include "xfs_vnodeops.h"
  36
  37 #include <linux/capability.h>
  38 #include <linux/posix_acl_xattr.h>
  39
  40 STATIC int      xfs_acl_setmode(bhv_vnode_t *, xfs_acl_t *, int *);
  41 STATIC void     xfs_acl_filter_mode(mode_t, xfs_acl_t *);
  42 STATIC void     xfs_acl_get_endian(xfs_acl_t *);
  43 STATIC int      xfs_acl_access(uid_t, gid_t, xfs_acl_t *, mode_t, cred_t *);
  44 STATIC int      xfs_acl_invalid(xfs_acl_t *);
  45 STATIC void     xfs_acl_sync_mode(mode_t, xfs_acl_t *);
  46 STATIC void     xfs_acl_get_attr(bhv_vnode_t *, xfs_acl_t *, int, int, int *);
  47 STATIC void     xfs_acl_set_attr(bhv_vnode_t *, xfs_acl_t *, int, int *);
  48 STATIC int      xfs_acl_allow_set(bhv_vnode_t *, int);
  49
  50 kmem_zone_t *xfs_acl_zone;
  51
  52
  53 /*
  54  * Test for existence of access ACL attribute as efficiently as possible.
  55  */
  56 int
  57 xfs_acl_vhasacl_access(
  58         bhv_vnode_t     *vp)
  59 {
  60         int             error;
  61
  62         xfs_acl_get_attr(vp, NULL, _ACL_TYPE_ACCESS, ATTR_KERNOVAL, &error);
  63         return (error == 0);
  64 }
  65
  66 /*
  67  * Test for existence of default ACL attribute as efficiently as possible.
  68  */
  69 int
  70 xfs_acl_vhasacl_default(
  71         bhv_vnode_t     *vp)
  72 {
  73         int             error;
  74
  75         if (!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 = xfs_getattr(xfs_vtoi(vp), &va, 0);
 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 = xfs_attr_remove(xfs_vtoi(vp),
 270                                                 kind == _ACL_TYPE_DEFAULT?
 271                                                 SGI_ACL_DEFAULT: SGI_ACL_FILE,
 272                                                 ATTR_ROOT);
 273                 if (error == ENOATTR)
 274                         error = 0;      /* 'scool */
 275         }
 276         VN_RELE(vp);
 277         return -error;
 278 }
 279
 280 int
 281 xfs_acl_vset(
 282         bhv_vnode_t             *vp,
 283         void                    *acl,
 284         size_t                  size,
 285         int                     kind)
 286 {
 287         posix_acl_xattr_header  *ext_acl = acl;
 288         xfs_acl_t               *xfs_acl;
 289         int                     error;
 290         int                     basicperms = 0; /* more than std unix perms? */
 291
 292         if (!acl)
 293                 return -EINVAL;
 294
 295         if (!(_ACL_ALLOC(xfs_acl)))
 296                 return -ENOMEM;
 297
 298         error = posix_acl_xattr_to_xfs(ext_acl, size, xfs_acl);
 299         if (error) {
 300                 _ACL_FREE(xfs_acl);
 301                 return -error;
 302         }
 303         if (!xfs_acl->acl_cnt) {
 304                 _ACL_FREE(xfs_acl);
 305                 return 0;
 306         }
 307
 308         VN_HOLD(vp);
 309         error = xfs_acl_allow_set(vp, kind);
 310         if (error)
 311                 goto out;
 312
 313         /* Incoming ACL exists, set file mode based on its value */
 314         if (kind == _ACL_TYPE_ACCESS)
 315                 xfs_acl_setmode(vp, xfs_acl, &basicperms);
 316
 317         /*
 318          * If we have more than std unix permissions, set up the actual attr.
 319          * Otherwise, delete any existing attr.  This prevents us from
 320          * having actual attrs for permissions that can be stored in the
 321          * standard permission bits.
 322          */
 323         if (!basicperms) {
 324                 xfs_acl_set_attr(vp, xfs_acl, kind, &error);
 325         } else {
 326                 xfs_acl_vremove(vp, _ACL_TYPE_ACCESS);
 327         }
 328
 329 out:
 330         VN_RELE(vp);
 331         _ACL_FREE(xfs_acl);
 332         return -error;
 333 }
 334
 335 int
 336 xfs_acl_iaccess(
 337         xfs_inode_t     *ip,
 338         mode_t          mode,
 339         cred_t          *cr)
 340 {
 341         xfs_acl_t       *acl;
 342         int             rval;
 343
 344         if (!(_ACL_ALLOC(acl)))
 345                 return -1;
 346
 347         /* If the file has no ACL return -1. */
 348         rval = sizeof(xfs_acl_t);
 349         if (xfs_attr_fetch(ip, SGI_ACL_FILE, SGI_ACL_FILE_SIZE,
 350                         (char *)acl, &rval, ATTR_ROOT | ATTR_KERNACCESS, cr)) {
 351                 _ACL_FREE(acl);
 352                 return -1;
 353         }
 354         xfs_acl_get_endian(acl);
 355
 356         /* If the file has an empty ACL return -1. */
 357         if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) {
 358                 _ACL_FREE(acl);
 359                 return -1;
 360         }
 361
 362         /* Synchronize ACL with mode bits */
 363         xfs_acl_sync_mode(ip->i_d.di_mode, acl);
 364
 365         rval = xfs_acl_access(ip->i_d.di_uid, ip->i_d.di_gid, acl, mode, cr);
 366         _ACL_FREE(acl);
 367         return rval;
 368 }
 369
 370 STATIC int
 371 xfs_acl_allow_set(
 372         bhv_vnode_t     *vp,
 373         int             kind)
 374 {
 375         xfs_inode_t     *ip = xfs_vtoi(vp);
 376         bhv_vattr_t     va;
 377         int             error;
 378
 379         if (vp->i_flags & (S_IMMUTABLE|S_APPEND))
 380                 return EPERM;
 381         if (kind == _ACL_TYPE_DEFAULT && !VN_ISDIR(vp))
 382                 return ENOTDIR;
 383         if (vp->i_sb->s_flags & MS_RDONLY)
 384                 return EROFS;
 385         va.va_mask = XFS_AT_UID;
 386         error = xfs_getattr(ip, &va, 0);
 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         bhv_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         *error = xfs_attr_get(xfs_vtoi(vp),
 620                                         kind == _ACL_TYPE_ACCESS ?
 621                                         SGI_ACL_FILE : SGI_ACL_DEFAULT,
 622                                         (char *)aclp, &len, flags, sys_cred);
 623         if (*error || (flags & ATTR_KERNOVAL))
 624                 return;
 625         xfs_acl_get_endian(aclp);
 626 }
 627
 628 /*
 629  * Set the EA with the ACL and do endian conversion.
 630  */
 631 STATIC void
 632 xfs_acl_set_attr(
 633         bhv_vnode_t     *vp,
 634         xfs_acl_t       *aclp,
 635         int             kind,
 636         int             *error)
 637 {
 638         xfs_acl_entry_t *ace, *newace, *end;
 639         xfs_acl_t       *newacl;
 640         int             len;
 641
 642         if (!(_ACL_ALLOC(newacl))) {
 643                 *error = ENOMEM;
 644                 return;
 645         }
 646
 647         len = sizeof(xfs_acl_t) -
 648               (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt));
 649         end = &aclp->acl_entry[0]+aclp->acl_cnt;
 650         for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0];
 651              ace < end;
 652              ace++, newace++) {
 653                 INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag);
 654                 INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id);
 655                 INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm);
 656         }
 657         INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
 658         *error = xfs_attr_set(xfs_vtoi(vp),
 659                                 kind == _ACL_TYPE_ACCESS ?
 660                                 SGI_ACL_FILE: SGI_ACL_DEFAULT,
 661                                 (char *)newacl, len, ATTR_ROOT);
 662         _ACL_FREE(newacl);
 663 }
 664
 665 int
 666 xfs_acl_vtoacl(
 667         bhv_vnode_t     *vp,
 668         xfs_acl_t       *access_acl,
 669         xfs_acl_t       *default_acl)
 670 {
 671         bhv_vattr_t     va;
 672         int             error = 0;
 673
 674         if (access_acl) {
 675                 /*
 676                  * Get the Access ACL and the mode.  If either cannot
 677                  * be obtained for some reason, invalidate the access ACL.
 678                  */
 679                 xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error);
 680                 if (!error) {
 681                         /* Got the ACL, need the mode... */
 682                         va.va_mask = XFS_AT_MODE;
 683                         error = xfs_getattr(xfs_vtoi(vp), &va, 0);
 684                 }
 685
 686                 if (error)
 687                         access_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
 688                 else /* We have a good ACL and the file mode, synchronize. */
 689                         xfs_acl_sync_mode(va.va_mode, access_acl);
 690         }
 691
 692         if (default_acl) {
 693                 xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error);
 694                 if (error)
 695                         default_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
 696         }
 697         return error;
 698 }
 699
 700 /*
 701  * This function retrieves the parent directory's acl, processes it
 702  * and lets the child inherit the acl(s) that it should.
 703  */
 704 int
 705 xfs_acl_inherit(
 706         bhv_vnode_t     *vp,
 707         mode_t          mode,
 708         xfs_acl_t       *pdaclp)
 709 {
 710         xfs_acl_t       *cacl;
 711         int             error = 0;
 712         int             basicperms = 0;
 713
 714         /*
 715          * If the parent does not have a default ACL, or it's an
 716          * invalid ACL, we're done.
 717          */
 718         if (!vp)
 719                 return 0;
 720         if (!pdaclp || xfs_acl_invalid(pdaclp))
 721                 return 0;
 722
 723         /*
 724          * Copy the default ACL of the containing directory to
 725          * the access ACL of the new file and use the mode that
 726          * was passed in to set up the correct initial values for
 727          * the u::,g::[m::], and o:: entries.  This is what makes
 728          * umask() "work" with ACL's.
 729          */
 730
 731         if (!(_ACL_ALLOC(cacl)))
 732                 return ENOMEM;
 733
 734         memcpy(cacl, pdaclp, sizeof(xfs_acl_t));
 735         xfs_acl_filter_mode(mode, cacl);
 736         xfs_acl_setmode(vp, cacl, &basicperms);
 737
 738         /*
 739          * Set the Default and Access ACL on the file.  The mode is already
 740          * set on the file, so we don't need to worry about that.
 741          *
 742          * If the new file is a directory, its default ACL is a copy of
 743          * the containing directory's default ACL.
 744          */
 745         if (VN_ISDIR(vp))
 746                 xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error);
 747         if (!error && !basicperms)
 748                 xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error);
 749         _ACL_FREE(cacl);
 750         return error;
 751 }
 752
 753 /*
 754  * Set up the correct mode on the file based on the supplied ACL.  This
 755  * makes sure that the mode on the file reflects the state of the
 756  * u::,g::[m::], and o:: entries in the ACL.  Since the mode is where
 757  * the ACL is going to get the permissions for these entries, we must
 758  * synchronize the mode whenever we set the ACL on a file.
 759  */
 760 STATIC int
 761 xfs_acl_setmode(
 762         bhv_vnode_t     *vp,
 763         xfs_acl_t       *acl,
 764         int             *basicperms)
 765 {
 766         bhv_vattr_t     va;
 767         xfs_acl_entry_t *ap;
 768         xfs_acl_entry_t *gap = NULL;
 769         int             i, error, nomask = 1;
 770
 771         *basicperms = 1;
 772
 773         if (acl->acl_cnt == XFS_ACL_NOT_PRESENT)
 774                 return 0;
 775
 776         /*
 777          * Copy the u::, g::, o::, and m:: bits from the ACL into the
 778          * mode.  The m:: bits take precedence over the g:: bits.
 779          */
 780         va.va_mask = XFS_AT_MODE;
 781         error = xfs_getattr(xfs_vtoi(vp), &va, 0);
 782         if (error)
 783                 return error;
 784
 785         va.va_mask = XFS_AT_MODE;
 786         va.va_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO);
 787         ap = acl->acl_entry;
 788         for (i = 0; i < acl->acl_cnt; ++i) {
 789                 switch (ap->ae_tag) {
 790                 case ACL_USER_OBJ:
 791                         va.va_mode |= ap->ae_perm << 6;
 792                         break;
 793                 case ACL_GROUP_OBJ:
 794                         gap = ap;
 795                         break;
 796                 case ACL_MASK:  /* more than just standard modes */
 797                         nomask = 0;
 798                         va.va_mode |= ap->ae_perm << 3;
 799                         *basicperms = 0;
 800                         break;
 801                 case ACL_OTHER:
 802                         va.va_mode |= ap->ae_perm;
 803                         break;
 804                 default:        /* more than just standard modes */
 805                         *basicperms = 0;
 806                         break;
 807                 }
 808                 ap++;
 809         }
 810
 811         /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */
 812         if (gap && nomask)
 813                 va.va_mode |= gap->ae_perm << 3;
 814
 815         return xfs_setattr(xfs_vtoi(vp), &va, 0, sys_cred);
 816 }
 817
 818 /*
 819  * The permissions for the special ACL entries (u::, g::[m::], o::) are
 820  * actually stored in the file mode (if there is both a group and a mask,
 821  * the group is stored in the ACL entry and the mask is stored on the file).
 822  * This allows the mode to remain automatically in sync with the ACL without
 823  * the need for a call-back to the ACL system at every point where the mode
 824  * could change.  This function takes the permissions from the specified mode
 825  * and places it in the supplied ACL.
 826  *
 827  * This implementation draws its validity from the fact that, when the ACL
 828  * was assigned, the mode was copied from the ACL.
 829  * If the mode did not change, therefore, the mode remains exactly what was
 830  * taken from the special ACL entries at assignment.
 831  * If a subsequent chmod() was done, the POSIX spec says that the change in
 832  * mode must cause an update to the ACL seen at user level and used for
 833  * access checks.  Before and after a mode change, therefore, the file mode
 834  * most accurately reflects what the special ACL entries should permit/deny.
 835  *
 836  * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly,
 837  *         the existing mode bits will override whatever is in the
 838  *         ACL. Similarly, if there is a pre-existing ACL that was
 839  *         never in sync with its mode (owing to a bug in 6.5 and
 840  *         before), it will now magically (or mystically) be
 841  *         synchronized.  This could cause slight astonishment, but
 842  *         it is better than inconsistent permissions.
 843  *
 844  * The supplied ACL is a template that may contain any combination
 845  * of special entries.  These are treated as place holders when we fill
 846  * out the ACL.  This routine does not add or remove special entries, it
 847  * simply unites each special entry with its associated set of permissions.
 848  */
 849 STATIC void
 850 xfs_acl_sync_mode(
 851         mode_t          mode,
 852         xfs_acl_t       *acl)
 853 {
 854         int             i, nomask = 1;
 855         xfs_acl_entry_t *ap;
 856         xfs_acl_entry_t *gap = NULL;
 857
 858         /*
 859          * Set ACL entries. POSIX1003.1eD16 requires that the MASK
 860          * be set instead of the GROUP entry, if there is a MASK.
 861          */
 862         for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
 863                 switch (ap->ae_tag) {
 864                 case ACL_USER_OBJ:
 865                         ap->ae_perm = (mode >> 6) & 0x7;
 866                         break;
 867                 case ACL_GROUP_OBJ:
 868                         gap = ap;
 869                         break;
 870                 case ACL_MASK:
 871                         nomask = 0;
 872                         ap->ae_perm = (mode >> 3) & 0x7;
 873                         break;
 874                 case ACL_OTHER:
 875                         ap->ae_perm = mode & 0x7;
 876                         break;
 877                 default:
 878                         break;
 879                 }
 880         }
 881         /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
 882         if (gap && nomask)
 883                 gap->ae_perm = (mode >> 3) & 0x7;
 884 }
 885
 886 /*
 887  * When inheriting an Access ACL from a directory Default ACL,
 888  * the ACL bits are set to the intersection of the ACL default
 889  * permission bits and the file permission bits in mode. If there
 890  * are no permission bits on the file then we must not give them
 891  * the ACL. This is what what makes umask() work with ACLs.
 892  */
 893 STATIC void
 894 xfs_acl_filter_mode(
 895         mode_t          mode,
 896         xfs_acl_t       *acl)
 897 {
 898         int             i, nomask = 1;
 899         xfs_acl_entry_t *ap;
 900         xfs_acl_entry_t *gap = NULL;
 901
 902         /*
 903          * Set ACL entries. POSIX1003.1eD16 requires that the MASK
 904          * be merged with GROUP entry, if there is a MASK.
 905          */
 906         for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
 907                 switch (ap->ae_tag) {
 908                 case ACL_USER_OBJ:
 909                         ap->ae_perm &= (mode >> 6) & 0x7;
 910                         break;
 911                 case ACL_GROUP_OBJ:
 912                         gap = ap;
 913                         break;
 914                 case ACL_MASK:
 915                         nomask = 0;
 916                         ap->ae_perm &= (mode >> 3) & 0x7;
 917                         break;
 918                 case ACL_OTHER:
 919                         ap->ae_perm &= mode & 0x7;
 920                         break;
 921                 default:
 922                         break;
 923                 }
 924         }
 925         /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
 926         if (gap && nomask)
 927                 gap->ae_perm &= (mode >> 3) & 0x7;
 928 }