fs/xfs/xfs_acl.c

   1 /*
   2  * Copyright (c) 2001-2002 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32 #include "xfs.h"
  33 #include "xfs_fs.h"
  34 #include "xfs_types.h"
  35 #include "xfs_bit.h"
  36 #include "xfs_inum.h"
  37 #include "xfs_ag.h"
  38 #include "xfs_dir.h"
  39 #include "xfs_dir2.h"
  40 #include "xfs_bmap_btree.h"
  41 #include "xfs_alloc_btree.h"
  42 #include "xfs_ialloc_btree.h"
  43 #include "xfs_dir_sf.h"
  44 #include "xfs_dir2_sf.h"
  45 #include "xfs_attr_sf.h"
  46 #include "xfs_dinode.h"
  47 #include "xfs_inode.h"
  48 #include "xfs_btree.h"
  49 #include "xfs_acl.h"
  50 #include "xfs_mac.h"
  51 #include "xfs_attr.h"
  52
  53 #include <linux/posix_acl_xattr.h>
  54
  55 STATIC int      xfs_acl_setmode(vnode_t *, xfs_acl_t *, int *);
  56 STATIC void     xfs_acl_filter_mode(mode_t, xfs_acl_t *);
  57 STATIC void     xfs_acl_get_endian(xfs_acl_t *);
  58 STATIC int      xfs_acl_access(uid_t, gid_t, xfs_acl_t *, mode_t, cred_t *);
  59 STATIC int      xfs_acl_invalid(xfs_acl_t *);
  60 STATIC void     xfs_acl_sync_mode(mode_t, xfs_acl_t *);
  61 STATIC void     xfs_acl_get_attr(vnode_t *, xfs_acl_t *, int, int, int *);
  62 STATIC void     xfs_acl_set_attr(vnode_t *, xfs_acl_t *, int, int *);
  63 STATIC int      xfs_acl_allow_set(vnode_t *, int);
  64
  65 kmem_zone_t *xfs_acl_zone;
  66
  67
  68 /*
  69  * Test for existence of access ACL attribute as efficiently as possible.
  70  */
  71 int
  72 xfs_acl_vhasacl_access(
  73         vnode_t         *vp)
  74 {
  75         int             error;
  76
  77         xfs_acl_get_attr(vp, NULL, _ACL_TYPE_ACCESS, ATTR_KERNOVAL, &error);
  78         return (error == 0);
  79 }
  80
  81 /*
  82  * Test for existence of default ACL attribute as efficiently as possible.
  83  */
  84 int
  85 xfs_acl_vhasacl_default(
  86         vnode_t         *vp)
  87 {
  88         int             error;
  89
  90         if (!VN_ISDIR(vp))
  91                 return 0;
  92         xfs_acl_get_attr(vp, NULL, _ACL_TYPE_DEFAULT, ATTR_KERNOVAL, &error);
  93         return (error == 0);
  94 }
  95
  96 /*
  97  * Convert from extended attribute representation to in-memory for XFS.
  98  */
  99 STATIC int
 100 posix_acl_xattr_to_xfs(
 101         posix_acl_xattr_header  *src,
 102         size_t                  size,
 103         xfs_acl_t               *dest)
 104 {
 105         posix_acl_xattr_entry   *src_entry;
 106         xfs_acl_entry_t         *dest_entry;
 107         int                     n;
 108
 109         if (!src || !dest)
 110                 return EINVAL;
 111
 112         if (size < sizeof(posix_acl_xattr_header))
 113                 return EINVAL;
 114
 115         if (src->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
 116                 return EOPNOTSUPP;
 117
 118         memset(dest, 0, sizeof(xfs_acl_t));
 119         dest->acl_cnt = posix_acl_xattr_count(size);
 120         if (dest->acl_cnt < 0 || dest->acl_cnt > XFS_ACL_MAX_ENTRIES)
 121                 return EINVAL;
 122
 123         /*
 124          * acl_set_file(3) may request that we set default ACLs with
 125          * zero length -- defend (gracefully) against that here.
 126          */
 127         if (!dest->acl_cnt)
 128                 return 0;
 129
 130         src_entry = (posix_acl_xattr_entry *)((char *)src + sizeof(*src));
 131         dest_entry = &dest->acl_entry[0];
 132
 133         for (n = 0; n < dest->acl_cnt; n++, src_entry++, dest_entry++) {
 134                 dest_entry->ae_perm = le16_to_cpu(src_entry->e_perm);
 135                 if (_ACL_PERM_INVALID(dest_entry->ae_perm))
 136                         return EINVAL;
 137                 dest_entry->ae_tag  = le16_to_cpu(src_entry->e_tag);
 138                 switch(dest_entry->ae_tag) {
 139                 case ACL_USER:
 140                 case ACL_GROUP:
 141                         dest_entry->ae_id = le32_to_cpu(src_entry->e_id);
 142                         break;
 143                 case ACL_USER_OBJ:
 144                 case ACL_GROUP_OBJ:
 145                 case ACL_MASK:
 146                 case ACL_OTHER:
 147                         dest_entry->ae_id = ACL_UNDEFINED_ID;
 148                         break;
 149                 default:
 150                         return EINVAL;
 151                 }
 152         }
 153         if (xfs_acl_invalid(dest))
 154                 return EINVAL;
 155
 156         return 0;
 157 }
 158
 159 /*
 160  * Comparison function called from xfs_sort().
 161  * Primary key is ae_tag, secondary key is ae_id.
 162  */
 163 STATIC int
 164 xfs_acl_entry_compare(
 165         const void      *va,
 166         const void      *vb)
 167 {
 168         xfs_acl_entry_t *a = (xfs_acl_entry_t *)va,
 169                         *b = (xfs_acl_entry_t *)vb;
 170
 171         if (a->ae_tag == b->ae_tag)
 172                 return (a->ae_id - b->ae_id);
 173         return (a->ae_tag - b->ae_tag);
 174 }
 175
 176 /*
 177  * Convert from in-memory XFS to extended attribute representation.
 178  */
 179 STATIC int
 180 posix_acl_xfs_to_xattr(
 181         xfs_acl_t               *src,
 182         posix_acl_xattr_header  *dest,
 183         size_t                  size)
 184 {
 185         int                     n;
 186         size_t                  new_size = posix_acl_xattr_size(src->acl_cnt);
 187         posix_acl_xattr_entry   *dest_entry;
 188         xfs_acl_entry_t         *src_entry;
 189
 190         if (size < new_size)
 191                 return -ERANGE;
 192
 193         /* Need to sort src XFS ACL by <ae_tag,ae_id> */
 194         xfs_sort(src->acl_entry, src->acl_cnt, sizeof(src->acl_entry[0]),
 195                  xfs_acl_entry_compare);
 196
 197         dest->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
 198         dest_entry = &dest->a_entries[0];
 199         src_entry = &src->acl_entry[0];
 200         for (n = 0; n < src->acl_cnt; n++, dest_entry++, src_entry++) {
 201                 dest_entry->e_perm = cpu_to_le16(src_entry->ae_perm);
 202                 if (_ACL_PERM_INVALID(src_entry->ae_perm))
 203                         return -EINVAL;
 204                 dest_entry->e_tag  = cpu_to_le16(src_entry->ae_tag);
 205                 switch (src_entry->ae_tag) {
 206                 case ACL_USER:
 207                 case ACL_GROUP:
 208                         dest_entry->e_id = cpu_to_le32(src_entry->ae_id);
 209                                 break;
 210                 case ACL_USER_OBJ:
 211                 case ACL_GROUP_OBJ:
 212                 case ACL_MASK:
 213                 case ACL_OTHER:
 214                         dest_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
 215                         break;
 216                 default:
 217                         return -EINVAL;
 218                 }
 219         }
 220         return new_size;
 221 }
 222
 223 int
 224 xfs_acl_vget(
 225         vnode_t         *vp,
 226         void            *acl,
 227         size_t          size,
 228         int             kind)
 229 {
 230         int                     error;
 231         xfs_acl_t               *xfs_acl = NULL;
 232         posix_acl_xattr_header  *ext_acl = acl;
 233         int                     flags = 0;
 234
 235         VN_HOLD(vp);
 236         if(size) {
 237                 if (!(_ACL_ALLOC(xfs_acl))) {
 238                         error = ENOMEM;
 239                         goto out;
 240                 }
 241                 memset(xfs_acl, 0, sizeof(xfs_acl_t));
 242         } else
 243                 flags = ATTR_KERNOVAL;
 244
 245         xfs_acl_get_attr(vp, xfs_acl, kind, flags, &error);
 246         if (error)
 247                 goto out;
 248
 249         if (!size) {
 250                 error = -posix_acl_xattr_size(XFS_ACL_MAX_ENTRIES);
 251         } else {
 252                 if (xfs_acl_invalid(xfs_acl)) {
 253                         error = EINVAL;
 254                         goto out;
 255                 }
 256                 if (kind == _ACL_TYPE_ACCESS) {
 257                         vattr_t va;
 258
 259                         va.va_mask = XFS_AT_MODE;
 260                         VOP_GETATTR(vp, &va, 0, sys_cred, error);
 261                         if (error)
 262                                 goto out;
 263                         xfs_acl_sync_mode(va.va_mode, xfs_acl);
 264                 }
 265                 error = -posix_acl_xfs_to_xattr(xfs_acl, ext_acl, size);
 266         }
 267 out:
 268         VN_RELE(vp);
 269         if(xfs_acl)
 270                 _ACL_FREE(xfs_acl);
 271         return -error;
 272 }
 273
 274 int
 275 xfs_acl_vremove(
 276         vnode_t         *vp,
 277         int             kind)
 278 {
 279         int             error;
 280
 281         VN_HOLD(vp);
 282         error = xfs_acl_allow_set(vp, kind);
 283         if (!error) {
 284                 VOP_ATTR_REMOVE(vp, kind == _ACL_TYPE_DEFAULT?
 285                                 SGI_ACL_DEFAULT: SGI_ACL_FILE,
 286                                 ATTR_ROOT, sys_cred, error);
 287                 if (error == ENOATTR)
 288                         error = 0;      /* 'scool */
 289         }
 290         VN_RELE(vp);
 291         return -error;
 292 }
 293
 294 int
 295 xfs_acl_vset(
 296         vnode_t                 *vp,
 297         void                    *acl,
 298         size_t                  size,
 299         int                     kind)
 300 {
 301         posix_acl_xattr_header  *ext_acl = acl;
 302         xfs_acl_t               *xfs_acl;
 303         int                     error;
 304         int                     basicperms = 0; /* more than std unix perms? */
 305
 306         if (!acl)
 307                 return -EINVAL;
 308
 309         if (!(_ACL_ALLOC(xfs_acl)))
 310                 return -ENOMEM;
 311
 312         error = posix_acl_xattr_to_xfs(ext_acl, size, xfs_acl);
 313         if (error) {
 314                 _ACL_FREE(xfs_acl);
 315                 return -error;
 316         }
 317         if (!xfs_acl->acl_cnt) {
 318                 _ACL_FREE(xfs_acl);
 319                 return 0;
 320         }
 321
 322         VN_HOLD(vp);
 323         error = xfs_acl_allow_set(vp, kind);
 324         if (error)
 325                 goto out;
 326
 327         /* Incoming ACL exists, set file mode based on its value */
 328         if (kind == _ACL_TYPE_ACCESS)
 329                 xfs_acl_setmode(vp, xfs_acl, &basicperms);
 330
 331         /*
 332          * If we have more than std unix permissions, set up the actual attr.
 333          * Otherwise, delete any existing attr.  This prevents us from
 334          * having actual attrs for permissions that can be stored in the
 335          * standard permission bits.
 336          */
 337         if (!basicperms) {
 338                 xfs_acl_set_attr(vp, xfs_acl, kind, &error);
 339         } else {
 340                 xfs_acl_vremove(vp, _ACL_TYPE_ACCESS);
 341         }
 342
 343 out:
 344         VN_RELE(vp);
 345         _ACL_FREE(xfs_acl);
 346         return -error;
 347 }
 348
 349 int
 350 xfs_acl_iaccess(
 351         xfs_inode_t     *ip,
 352         mode_t          mode,
 353         cred_t          *cr)
 354 {
 355         xfs_acl_t       *acl;
 356         int             rval;
 357
 358         if (!(_ACL_ALLOC(acl)))
 359                 return -1;
 360
 361         /* If the file has no ACL return -1. */
 362         rval = sizeof(xfs_acl_t);
 363         if (xfs_attr_fetch(ip, SGI_ACL_FILE, SGI_ACL_FILE_SIZE,
 364                         (char *)acl, &rval, ATTR_ROOT | ATTR_KERNACCESS, cr)) {
 365                 _ACL_FREE(acl);
 366                 return -1;
 367         }
 368         xfs_acl_get_endian(acl);
 369
 370         /* If the file has an empty ACL return -1. */
 371         if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) {
 372                 _ACL_FREE(acl);
 373                 return -1;
 374         }
 375
 376         /* Synchronize ACL with mode bits */
 377         xfs_acl_sync_mode(ip->i_d.di_mode, acl);
 378
 379         rval = xfs_acl_access(ip->i_d.di_uid, ip->i_d.di_gid, acl, mode, cr);
 380         _ACL_FREE(acl);
 381         return rval;
 382 }
 383
 384 STATIC int
 385 xfs_acl_allow_set(
 386         vnode_t         *vp,
 387         int             kind)
 388 {
 389         vattr_t         va;
 390         int             error;
 391
 392         if (vp->v_inode.i_flags & (S_IMMUTABLE|S_APPEND))
 393                 return EPERM;
 394         if (kind == _ACL_TYPE_DEFAULT && !VN_ISDIR(vp))
 395                 return ENOTDIR;
 396         if (vp->v_vfsp->vfs_flag & VFS_RDONLY)
 397                 return EROFS;
 398         va.va_mask = XFS_AT_UID;
 399         VOP_GETATTR(vp, &va, 0, NULL, error);
 400         if (error)
 401                 return error;
 402         if (va.va_uid != current->fsuid && !capable(CAP_FOWNER))
 403                 return EPERM;
 404         return error;
 405 }
 406
 407 /*
 408  * The access control process to determine the access permission:
 409  *      if uid == file owner id, use the file owner bits.
 410  *      if gid == file owner group id, use the file group bits.
 411  *      scan ACL for a maching user or group, and use matched entry
 412  *      permission. Use total permissions of all matching group entries,
 413  *      until all acl entries are exhausted. The final permission produced
 414  *      by matching acl entry or entries needs to be & with group permission.
 415  *      if not owner, owning group, or matching entry in ACL, use file
 416  *      other bits.
 417  */
 418 STATIC int
 419 xfs_acl_capability_check(
 420         mode_t          mode,
 421         cred_t          *cr)
 422 {
 423         if ((mode & ACL_READ) && !capable_cred(cr, CAP_DAC_READ_SEARCH))
 424                 return EACCES;
 425         if ((mode & ACL_WRITE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
 426                 return EACCES;
 427         if ((mode & ACL_EXECUTE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
 428                 return EACCES;
 429
 430         return 0;
 431 }
 432
 433 /*
 434  * Note: cr is only used here for the capability check if the ACL test fails.
 435  *       It is not used to find out the credentials uid or groups etc, as was
 436  *       done in IRIX. It is assumed that the uid and groups for the current
 437  *       thread are taken from "current" instead of the cr parameter.
 438  */
 439 STATIC int
 440 xfs_acl_access(
 441         uid_t           fuid,
 442         gid_t           fgid,
 443         xfs_acl_t       *fap,
 444         mode_t          md,
 445         cred_t          *cr)
 446 {
 447         xfs_acl_entry_t matched;
 448         int             i, allows;
 449         int             maskallows = -1;        /* true, but not 1, either */
 450         int             seen_userobj = 0;
 451
 452         matched.ae_tag = 0;     /* Invalid type */
 453         md >>= 6;       /* Normalize the bits for comparison */
 454
 455         for (i = 0; i < fap->acl_cnt; i++) {
 456                 /*
 457                  * Break out if we've got a user_obj entry or
 458                  * a user entry and the mask (and have processed USER_OBJ)
 459                  */
 460                 if (matched.ae_tag == ACL_USER_OBJ)
 461                         break;
 462                 if (matched.ae_tag == ACL_USER) {
 463                         if (maskallows != -1 && seen_userobj)
 464                                 break;
 465                         if (fap->acl_entry[i].ae_tag != ACL_MASK &&
 466                             fap->acl_entry[i].ae_tag != ACL_USER_OBJ)
 467                                 continue;
 468                 }
 469                 /* True if this entry allows the requested access */
 470                 allows = ((fap->acl_entry[i].ae_perm & md) == md);
 471
 472                 switch (fap->acl_entry[i].ae_tag) {
 473                 case ACL_USER_OBJ:
 474                         seen_userobj = 1;
 475                         if (fuid != current->fsuid)
 476                                 continue;
 477                         matched.ae_tag = ACL_USER_OBJ;
 478                         matched.ae_perm = allows;
 479                         break;
 480                 case ACL_USER:
 481                         if (fap->acl_entry[i].ae_id != current->fsuid)
 482                                 continue;
 483                         matched.ae_tag = ACL_USER;
 484                         matched.ae_perm = allows;
 485                         break;
 486                 case ACL_GROUP_OBJ:
 487                         if ((matched.ae_tag == ACL_GROUP_OBJ ||
 488                             matched.ae_tag == ACL_GROUP) && !allows)
 489                                 continue;
 490                         if (!in_group_p(fgid))
 491                                 continue;
 492                         matched.ae_tag = ACL_GROUP_OBJ;
 493                         matched.ae_perm = allows;
 494                         break;
 495                 case ACL_GROUP:
 496                         if ((matched.ae_tag == ACL_GROUP_OBJ ||
 497                             matched.ae_tag == ACL_GROUP) && !allows)
 498                                 continue;
 499                         if (!in_group_p(fap->acl_entry[i].ae_id))
 500                                 continue;
 501                         matched.ae_tag = ACL_GROUP;
 502                         matched.ae_perm = allows;
 503                         break;
 504                 case ACL_MASK:
 505                         maskallows = allows;
 506                         break;
 507                 case ACL_OTHER:
 508                         if (matched.ae_tag != 0)
 509                                 continue;
 510                         matched.ae_tag = ACL_OTHER;
 511                         matched.ae_perm = allows;
 512                         break;
 513                 }
 514         }
 515         /*
 516          * First possibility is that no matched entry allows access.
 517          * The capability to override DAC may exist, so check for it.
 518          */
 519         switch (matched.ae_tag) {
 520         case ACL_OTHER:
 521         case ACL_USER_OBJ:
 522                 if (matched.ae_perm)
 523                         return 0;
 524                 break;
 525         case ACL_USER:
 526         case ACL_GROUP_OBJ:
 527         case ACL_GROUP:
 528                 if (maskallows && matched.ae_perm)
 529                         return 0;
 530                 break;
 531         case 0:
 532                 break;
 533         }
 534
 535         return xfs_acl_capability_check(md, cr);
 536 }
 537
 538 /*
 539  * ACL validity checker.
 540  *   This acl validation routine checks each ACL entry read in makes sense.
 541  */
 542 STATIC int
 543 xfs_acl_invalid(
 544         xfs_acl_t       *aclp)
 545 {
 546         xfs_acl_entry_t *entry, *e;
 547         int             user = 0, group = 0, other = 0, mask = 0;
 548         int             mask_required = 0;
 549         int             i, j;
 550
 551         if (!aclp)
 552                 goto acl_invalid;
 553
 554         if (aclp->acl_cnt > XFS_ACL_MAX_ENTRIES)
 555                 goto acl_invalid;
 556
 557         for (i = 0; i < aclp->acl_cnt; i++) {
 558                 entry = &aclp->acl_entry[i];
 559                 switch (entry->ae_tag) {
 560                 case ACL_USER_OBJ:
 561                         if (user++)
 562                                 goto acl_invalid;
 563                         break;
 564                 case ACL_GROUP_OBJ:
 565                         if (group++)
 566                                 goto acl_invalid;
 567                         break;
 568                 case ACL_OTHER:
 569                         if (other++)
 570                                 goto acl_invalid;
 571                         break;
 572                 case ACL_USER:
 573                 case ACL_GROUP:
 574                         for (j = i + 1; j < aclp->acl_cnt; j++) {
 575                                 e = &aclp->acl_entry[j];
 576                                 if (e->ae_id == entry->ae_id &&
 577                                     e->ae_tag == entry->ae_tag)
 578                                         goto acl_invalid;
 579                         }
 580                         mask_required++;
 581                         break;
 582                 case ACL_MASK:
 583                         if (mask++)
 584                                 goto acl_invalid;
 585                         break;
 586                 default:
 587                         goto acl_invalid;
 588                 }
 589         }
 590         if (!user || !group || !other || (mask_required && !mask))
 591                 goto acl_invalid;
 592         else
 593                 return 0;
 594 acl_invalid:
 595         return EINVAL;
 596 }
 597
 598 /*
 599  * Do ACL endian conversion.
 600  */
 601 STATIC void
 602 xfs_acl_get_endian(
 603         xfs_acl_t       *aclp)
 604 {
 605         xfs_acl_entry_t *ace, *end;
 606
 607         INT_SET(aclp->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
 608         end = &aclp->acl_entry[0]+aclp->acl_cnt;
 609         for (ace = &aclp->acl_entry[0]; ace < end; ace++) {
 610                 INT_SET(ace->ae_tag, ARCH_CONVERT, ace->ae_tag);
 611                 INT_SET(ace->ae_id, ARCH_CONVERT, ace->ae_id);
 612                 INT_SET(ace->ae_perm, ARCH_CONVERT, ace->ae_perm);
 613         }
 614 }
 615
 616 /*
 617  * Get the ACL from the EA and do endian conversion.
 618  */
 619 STATIC void
 620 xfs_acl_get_attr(
 621         vnode_t         *vp,
 622         xfs_acl_t       *aclp,
 623         int             kind,
 624         int             flags,
 625         int             *error)
 626 {
 627         int             len = sizeof(xfs_acl_t);
 628
 629         ASSERT((flags & ATTR_KERNOVAL) ? (aclp == NULL) : 1);
 630         flags |= ATTR_ROOT;
 631         VOP_ATTR_GET(vp,
 632                 kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE : SGI_ACL_DEFAULT,
 633                 (char *)aclp, &len, flags, sys_cred, *error);
 634         if (*error || (flags & ATTR_KERNOVAL))
 635                 return;
 636         xfs_acl_get_endian(aclp);
 637 }
 638
 639 /*
 640  * Set the EA with the ACL and do endian conversion.
 641  */
 642 STATIC void
 643 xfs_acl_set_attr(
 644         vnode_t         *vp,
 645         xfs_acl_t       *aclp,
 646         int             kind,
 647         int             *error)
 648 {
 649         xfs_acl_entry_t *ace, *newace, *end;
 650         xfs_acl_t       *newacl;
 651         int             len;
 652
 653         if (!(_ACL_ALLOC(newacl))) {
 654                 *error = ENOMEM;
 655                 return;
 656         }
 657
 658         len = sizeof(xfs_acl_t) -
 659               (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt));
 660         end = &aclp->acl_entry[0]+aclp->acl_cnt;
 661         for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0];
 662              ace < end;
 663              ace++, newace++) {
 664                 INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag);
 665                 INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id);
 666                 INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm);
 667         }
 668         INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
 669         VOP_ATTR_SET(vp,
 670                 kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE: SGI_ACL_DEFAULT,
 671                 (char *)newacl, len, ATTR_ROOT, sys_cred, *error);
 672         _ACL_FREE(newacl);
 673 }
 674
 675 int
 676 xfs_acl_vtoacl(
 677         vnode_t         *vp,
 678         xfs_acl_t       *access_acl,
 679         xfs_acl_t       *default_acl)
 680 {
 681         vattr_t         va;
 682         int             error = 0;
 683
 684         if (access_acl) {
 685                 /*
 686                  * Get the Access ACL and the mode.  If either cannot
 687                  * be obtained for some reason, invalidate the access ACL.
 688                  */
 689                 xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error);
 690                 if (!error) {
 691                         /* Got the ACL, need the mode... */
 692                         va.va_mask = XFS_AT_MODE;
 693                         VOP_GETATTR(vp, &va, 0, sys_cred, error);
 694                 }
 695
 696                 if (error)
 697                         access_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
 698                 else /* We have a good ACL and the file mode, synchronize. */
 699                         xfs_acl_sync_mode(va.va_mode, access_acl);
 700         }
 701
 702         if (default_acl) {
 703                 xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error);
 704                 if (error)
 705                         default_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
 706         }
 707         return error;
 708 }
 709
 710 /*
 711  * This function retrieves the parent directory's acl, processes it
 712  * and lets the child inherit the acl(s) that it should.
 713  */
 714 int
 715 xfs_acl_inherit(
 716         vnode_t         *vp,
 717         vattr_t         *vap,
 718         xfs_acl_t       *pdaclp)
 719 {
 720         xfs_acl_t       *cacl;
 721         int             error = 0;
 722         int             basicperms = 0;
 723
 724         /*
 725          * If the parent does not have a default ACL, or it's an
 726          * invalid ACL, we're done.
 727          */
 728         if (!vp)
 729                 return 0;
 730         if (!pdaclp || xfs_acl_invalid(pdaclp))
 731                 return 0;
 732
 733         /*
 734          * Copy the default ACL of the containing directory to
 735          * the access ACL of the new file and use the mode that
 736          * was passed in to set up the correct initial values for
 737          * the u::,g::[m::], and o:: entries.  This is what makes
 738          * umask() "work" with ACL's.
 739          */
 740
 741         if (!(_ACL_ALLOC(cacl)))
 742                 return ENOMEM;
 743
 744         memcpy(cacl, pdaclp, sizeof(xfs_acl_t));
 745         xfs_acl_filter_mode(vap->va_mode, cacl);
 746         xfs_acl_setmode(vp, cacl, &basicperms);
 747
 748         /*
 749          * Set the Default and Access ACL on the file.  The mode is already
 750          * set on the file, so we don't need to worry about that.
 751          *
 752          * If the new file is a directory, its default ACL is a copy of
 753          * the containing directory's default ACL.
 754          */
 755         if (VN_ISDIR(vp))
 756                 xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error);
 757         if (!error && !basicperms)
 758                 xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error);
 759         _ACL_FREE(cacl);
 760         return error;
 761 }
 762
 763 /*
 764  * Set up the correct mode on the file based on the supplied ACL.  This
 765  * makes sure that the mode on the file reflects the state of the
 766  * u::,g::[m::], and o:: entries in the ACL.  Since the mode is where
 767  * the ACL is going to get the permissions for these entries, we must
 768  * synchronize the mode whenever we set the ACL on a file.
 769  */
 770 STATIC int
 771 xfs_acl_setmode(
 772         vnode_t         *vp,
 773         xfs_acl_t       *acl,
 774         int             *basicperms)
 775 {
 776         vattr_t         va;
 777         xfs_acl_entry_t *ap;
 778         xfs_acl_entry_t *gap = NULL;
 779         int             i, error, nomask = 1;
 780
 781         *basicperms = 1;
 782
 783         if (acl->acl_cnt == XFS_ACL_NOT_PRESENT)
 784                 return 0;
 785
 786         /*
 787          * Copy the u::, g::, o::, and m:: bits from the ACL into the
 788          * mode.  The m:: bits take precedence over the g:: bits.
 789          */
 790         va.va_mask = XFS_AT_MODE;
 791         VOP_GETATTR(vp, &va, 0, sys_cred, error);
 792         if (error)
 793                 return error;
 794
 795         va.va_mask = XFS_AT_MODE;
 796         va.va_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO);
 797         ap = acl->acl_entry;
 798         for (i = 0; i < acl->acl_cnt; ++i) {
 799                 switch (ap->ae_tag) {
 800                 case ACL_USER_OBJ:
 801                         va.va_mode |= ap->ae_perm << 6;
 802                         break;
 803                 case ACL_GROUP_OBJ:
 804                         gap = ap;
 805                         break;
 806                 case ACL_MASK:  /* more than just standard modes */
 807                         nomask = 0;
 808                         va.va_mode |= ap->ae_perm << 3;
 809                         *basicperms = 0;
 810                         break;
 811                 case ACL_OTHER:
 812                         va.va_mode |= ap->ae_perm;
 813                         break;
 814                 default:        /* more than just standard modes */
 815                         *basicperms = 0;
 816                         break;
 817                 }
 818                 ap++;
 819         }
 820
 821         /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */
 822         if (gap && nomask)
 823                 va.va_mode |= gap->ae_perm << 3;
 824
 825         VOP_SETATTR(vp, &va, 0, sys_cred, error);
 826         return error;
 827 }
 828
 829 /*
 830  * The permissions for the special ACL entries (u::, g::[m::], o::) are
 831  * actually stored in the file mode (if there is both a group and a mask,
 832  * the group is stored in the ACL entry and the mask is stored on the file).
 833  * This allows the mode to remain automatically in sync with the ACL without
 834  * the need for a call-back to the ACL system at every point where the mode
 835  * could change.  This function takes the permissions from the specified mode
 836  * and places it in the supplied ACL.
 837  *
 838  * This implementation draws its validity from the fact that, when the ACL
 839  * was assigned, the mode was copied from the ACL.
 840  * If the mode did not change, therefore, the mode remains exactly what was
 841  * taken from the special ACL entries at assignment.
 842  * If a subsequent chmod() was done, the POSIX spec says that the change in
 843  * mode must cause an update to the ACL seen at user level and used for
 844  * access checks.  Before and after a mode change, therefore, the file mode
 845  * most accurately reflects what the special ACL entries should permit/deny.
 846  *
 847  * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly,
 848  *         the existing mode bits will override whatever is in the
 849  *         ACL. Similarly, if there is a pre-existing ACL that was
 850  *         never in sync with its mode (owing to a bug in 6.5 and
 851  *         before), it will now magically (or mystically) be
 852  *         synchronized.  This could cause slight astonishment, but
 853  *         it is better than inconsistent permissions.
 854  *
 855  * The supplied ACL is a template that may contain any combination
 856  * of special entries.  These are treated as place holders when we fill
 857  * out the ACL.  This routine does not add or remove special entries, it
 858  * simply unites each special entry with its associated set of permissions.
 859  */
 860 STATIC void
 861 xfs_acl_sync_mode(
 862         mode_t          mode,
 863         xfs_acl_t       *acl)
 864 {
 865         int             i, nomask = 1;
 866         xfs_acl_entry_t *ap;
 867         xfs_acl_entry_t *gap = NULL;
 868
 869         /*
 870          * Set ACL entries. POSIX1003.1eD16 requires that the MASK
 871          * be set instead of the GROUP entry, if there is a MASK.
 872          */
 873         for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
 874                 switch (ap->ae_tag) {
 875                 case ACL_USER_OBJ:
 876                         ap->ae_perm = (mode >> 6) & 0x7;
 877                         break;
 878                 case ACL_GROUP_OBJ:
 879                         gap = ap;
 880                         break;
 881                 case ACL_MASK:
 882                         nomask = 0;
 883                         ap->ae_perm = (mode >> 3) & 0x7;
 884                         break;
 885                 case ACL_OTHER:
 886                         ap->ae_perm = mode & 0x7;
 887                         break;
 888                 default:
 889                         break;
 890                 }
 891         }
 892         /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
 893         if (gap && nomask)
 894                 gap->ae_perm = (mode >> 3) & 0x7;
 895 }
 896
 897 /*
 898  * When inheriting an Access ACL from a directory Default ACL,
 899  * the ACL bits are set to the intersection of the ACL default
 900  * permission bits and the file permission bits in mode. If there
 901  * are no permission bits on the file then we must not give them
 902  * the ACL. This is what what makes umask() work with ACLs.
 903  */
 904 STATIC void
 905 xfs_acl_filter_mode(
 906         mode_t          mode,
 907         xfs_acl_t       *acl)
 908 {
 909         int             i, nomask = 1;
 910         xfs_acl_entry_t *ap;
 911         xfs_acl_entry_t *gap = NULL;
 912
 913         /*
 914          * Set ACL entries. POSIX1003.1eD16 requires that the MASK
 915          * be merged with GROUP entry, if there is a MASK.
 916          */
 917         for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
 918                 switch (ap->ae_tag) {
 919                 case ACL_USER_OBJ:
 920                         ap->ae_perm &= (mode >> 6) & 0x7;
 921                         break;
 922                 case ACL_GROUP_OBJ:
 923                         gap = ap;
 924                         break;
 925                 case ACL_MASK:
 926                         nomask = 0;
 927                         ap->ae_perm &= (mode >> 3) & 0x7;
 928                         break;
 929                 case ACL_OTHER:
 930                         ap->ae_perm &= mode & 0x7;
 931                         break;
 932                 default:
 933                         break;
 934                 }
 935         }
 936         /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
 937         if (gap && nomask)
 938                 gap->ae_perm &= (mode >> 3) & 0x7;
 939 }