sys/kern/subr_acl_nfs4.c

   1 /*-
   2  * Copyright (c) 2008-2009 Edward Tomasz Napierała <trasz@FreeBSD.org>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 /*
  28  * ACL support routines specific to NFSv4 access control lists.  These are
  29  * utility routines for code common across file systems implementing NFSv4
  30  * ACLs.
  31  */
  32
  33 #ifdef _KERNEL
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/mount.h>
  40 #include <sys/priv.h>
  41 #include <sys/vnode.h>
  42 #include <sys/errno.h>
  43 #include <sys/stat.h>
  44 #include <sys/acl.h>
  45 #else
  46 #include <errno.h>
  47 #include <assert.h>
  48 #include <sys/acl.h>
  49 #include <sys/stat.h>
  50 #define KASSERT(a, b) assert(a)
  51 #define CTASSERT(a)
  52 #endif /* _KERNEL */
  53
  54 #ifdef _KERNEL
  55
  56 static struct {
  57         accmode_t accmode;
  58         int mask;
  59 } accmode2mask[] = {{VREAD, ACL_READ_DATA},
  60                     {VWRITE, ACL_WRITE_DATA},
  61                     {VAPPEND, ACL_APPEND_DATA},
  62                     {VEXEC, ACL_EXECUTE},
  63                     {VREAD_NAMED_ATTRS, ACL_READ_NAMED_ATTRS},
  64                     {VWRITE_NAMED_ATTRS, ACL_WRITE_NAMED_ATTRS},
  65                     {VDELETE_CHILD, ACL_DELETE_CHILD},
  66                     {VREAD_ATTRIBUTES, ACL_READ_ATTRIBUTES},
  67                     {VWRITE_ATTRIBUTES, ACL_WRITE_ATTRIBUTES},
  68                     {VDELETE, ACL_DELETE},
  69                     {VREAD_ACL, ACL_READ_ACL},
  70                     {VWRITE_ACL, ACL_WRITE_ACL},
  71                     {VWRITE_OWNER, ACL_WRITE_OWNER},
  72                     {VSYNCHRONIZE, ACL_SYNCHRONIZE},
  73                     {0, 0}};
  74
  75 static int
  76 _access_mask_from_accmode(accmode_t accmode)
  77 {
  78         int access_mask = 0, i;
  79
  80         for (i = 0; accmode2mask[i].accmode != 0; i++) {
  81                 if (accmode & accmode2mask[i].accmode)
  82                         access_mask |= accmode2mask[i].mask;
  83         }
  84
  85         /*
  86          * VAPPEND is just a modifier for VWRITE; if the caller asked
  87          * for 'VAPPEND | VWRITE', we want to check for ACL_APPEND_DATA only.
  88          */
  89         if (access_mask & ACL_APPEND_DATA)
  90                 access_mask &= ~ACL_WRITE_DATA;
  91
  92         return (access_mask);
  93 }
  94
  95 /*
  96  * Return 0, iff access is allowed, 1 otherwise.
  97  */
  98 static int
  99 _acl_denies(const struct acl *aclp, int access_mask, struct ucred *cred,
 100     int file_uid, int file_gid, int *denied_explicitly)
 101 {
 102         int i;
 103         const struct acl_entry *entry;
 104
 105         if (denied_explicitly != NULL)
 106                 *denied_explicitly = 0;
 107
 108         KASSERT(aclp->acl_cnt > 0, ("aclp->acl_cnt > 0"));
 109         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
 110             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 111
 112         for (i = 0; i < aclp->acl_cnt; i++) {
 113                 entry = &(aclp->acl_entry[i]);
 114
 115                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 116                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 117                         continue;
 118                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
 119                         continue;
 120                 switch (entry->ae_tag) {
 121                 case ACL_USER_OBJ:
 122                         if (file_uid != cred->cr_uid)
 123                                 continue;
 124                         break;
 125                 case ACL_USER:
 126                         if (entry->ae_id != cred->cr_uid)
 127                                 continue;
 128                         break;
 129                 case ACL_GROUP_OBJ:
 130                         if (!groupmember(file_gid, cred))
 131                                 continue;
 132                         break;
 133                 case ACL_GROUP:
 134                         if (!groupmember(entry->ae_id, cred))
 135                                 continue;
 136                         break;
 137                 default:
 138                         KASSERT(entry->ae_tag == ACL_EVERYONE,
 139                             ("entry->ae_tag == ACL_EVERYONE"));
 140                 }
 141
 142                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_DENY) {
 143                         if (entry->ae_perm & access_mask) {
 144                                 if (denied_explicitly != NULL)
 145                                         *denied_explicitly = 1;
 146                                 return (1);
 147                         }
 148                 }
 149
 150                 access_mask &= ~(entry->ae_perm);
 151                 if (access_mask == 0)
 152                         return (0);
 153         }
 154
 155         return (1);
 156 }
 157
 158 int
 159 vaccess_acl_nfs4(enum vtype type, uid_t file_uid, gid_t file_gid,
 160     struct acl *aclp, accmode_t accmode, struct ucred *cred, int *privused)
 161 {
 162         accmode_t priv_granted = 0;
 163         int denied, explicitly_denied, access_mask, is_directory,
 164             must_be_owner = 0;
 165
 166         if (privused != NULL)
 167                 *privused = 0;
 168
 169         if (accmode & VADMIN)
 170                 must_be_owner = 1;
 171
 172         /*
 173          * Ignore VSYNCHRONIZE permission.
 174          */
 175         accmode &= ~VSYNCHRONIZE;
 176
 177         access_mask = _access_mask_from_accmode(accmode);
 178
 179         if (type == VDIR)
 180                 is_directory = 1;
 181         else
 182                 is_directory = 0;
 183
 184         /*
 185          * File owner is always allowed to read and write the ACL
 186          * and basic attributes.  This is to prevent a situation
 187          * where user would change ACL in a way that prevents him
 188          * from undoing the change.
 189          */
 190         if (file_uid == cred->cr_uid)
 191                 access_mask &= ~(ACL_READ_ACL | ACL_WRITE_ACL |
 192                     ACL_READ_ATTRIBUTES | ACL_WRITE_ATTRIBUTES);
 193
 194         /*
 195          * Ignore append permission for regular files; use write
 196          * permission instead.
 197          */
 198         if (!is_directory && (access_mask & ACL_APPEND_DATA)) {
 199                 access_mask &= ~ACL_APPEND_DATA;
 200                 access_mask |= ACL_WRITE_DATA;
 201         }
 202
 203         denied = _acl_denies(aclp, access_mask, cred, file_uid, file_gid,
 204             &explicitly_denied);
 205
 206         if (must_be_owner) {
 207                 if (file_uid != cred->cr_uid)
 208                         denied = EPERM;
 209         }
 210
 211         if (!denied)
 212                 return (0);
 213
 214         /*
 215          * Access failed.  Iff it was not denied explicitly and
 216          * VEXPLICIT_DENY flag was specified, allow access.
 217          */
 218         if ((accmode & VEXPLICIT_DENY) && explicitly_denied == 0)
 219                 return (0);
 220
 221         accmode &= ~VEXPLICIT_DENY;
 222
 223         /*
 224          * No match.  Try to use privileges, if there are any.
 225          */
 226         if (is_directory) {
 227                 if ((accmode & VEXEC) && !priv_check_cred(cred,
 228                     PRIV_VFS_LOOKUP, 0))
 229                         priv_granted |= VEXEC;
 230         } else {
 231                 if ((accmode & VEXEC) && !priv_check_cred(cred,
 232                     PRIV_VFS_EXEC, 0))
 233                         priv_granted |= VEXEC;
 234         }
 235
 236         if ((accmode & VREAD) && !priv_check_cred(cred, PRIV_VFS_READ, 0))
 237                 priv_granted |= VREAD;
 238
 239         if ((accmode & (VWRITE | VAPPEND | VDELETE_CHILD)) &&
 240             !priv_check_cred(cred, PRIV_VFS_WRITE, 0))
 241                 priv_granted |= (VWRITE | VAPPEND | VDELETE_CHILD);
 242
 243         if ((accmode & VADMIN_PERMS) &&
 244             !priv_check_cred(cred, PRIV_VFS_ADMIN, 0))
 245                 priv_granted |= VADMIN_PERMS;
 246
 247         if ((accmode & VSTAT_PERMS) &&
 248             !priv_check_cred(cred, PRIV_VFS_STAT, 0))
 249                 priv_granted |= VSTAT_PERMS;
 250
 251         if ((accmode & priv_granted) == accmode) {
 252                 if (privused != NULL)
 253                         *privused = 1;
 254
 255                 return (0);
 256         }
 257
 258         if (accmode & (VADMIN_PERMS | VDELETE_CHILD | VDELETE))
 259                 denied = EPERM;
 260         else
 261                 denied = EACCES;
 262
 263         return (denied);
 264 }
 265 #endif /* _KERNEL */
 266
 267 static int
 268 _acl_entry_matches(struct acl_entry *entry, acl_tag_t tag, acl_perm_t perm,
 269     acl_entry_type_t entry_type)
 270 {
 271         if (entry->ae_tag != tag)
 272                 return (0);
 273
 274         if (entry->ae_id != ACL_UNDEFINED_ID)
 275                 return (0);
 276
 277         if (entry->ae_perm != perm)
 278                 return (0);
 279
 280         if (entry->ae_entry_type != entry_type)
 281                 return (0);
 282
 283         if (entry->ae_flags != 0)
 284                 return (0);
 285
 286         return (1);
 287 }
 288
 289 static struct acl_entry *
 290 _acl_append(struct acl *aclp, acl_tag_t tag, acl_perm_t perm,
 291     acl_entry_type_t entry_type)
 292 {
 293         struct acl_entry *entry;
 294
 295         KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 296             ("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 297
 298         entry = &(aclp->acl_entry[aclp->acl_cnt]);
 299         aclp->acl_cnt++;
 300
 301         entry->ae_tag = tag;
 302         entry->ae_id = ACL_UNDEFINED_ID;
 303         entry->ae_perm = perm;
 304         entry->ae_entry_type = entry_type;
 305         entry->ae_flags = 0;
 306
 307         return (entry);
 308 }
 309
 310 static struct acl_entry *
 311 _acl_duplicate_entry(struct acl *aclp, int entry_index)
 312 {
 313         int i;
 314
 315         KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 316             ("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 317
 318         for (i = aclp->acl_cnt; i > entry_index; i--)
 319                 aclp->acl_entry[i] = aclp->acl_entry[i - 1];
 320
 321         aclp->acl_cnt++;
 322
 323         return (&(aclp->acl_entry[entry_index + 1]));
 324 }
 325
 326 /*
 327  * Calculate trivial ACL in a manner compatible with PSARC/2010/029.
 328  * Note that this results in an ACL different from (but semantically
 329  * equal to) the "canonical six" trivial ACL computed using algorithm
 330  * described in draft-ietf-nfsv4-minorversion1-03.txt, 3.16.6.2.
 331  */
 332 void
 333 acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode)
 334 {
 335         acl_perm_t user_allow_first = 0, user_deny = 0, group_deny = 0;
 336         acl_perm_t user_allow, group_allow, everyone_allow;
 337
 338         KASSERT(aclp->acl_cnt == 0, ("aclp->acl_cnt == 0"));
 339
 340         user_allow = group_allow = everyone_allow = ACL_READ_ACL |
 341             ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS | ACL_SYNCHRONIZE;
 342         user_allow |= ACL_WRITE_ACL | ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 343             ACL_WRITE_NAMED_ATTRS;
 344
 345         if (mode & S_IRUSR)
 346                 user_allow |= ACL_READ_DATA;
 347         if (mode & S_IWUSR)
 348                 user_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 349         if (mode & S_IXUSR)
 350                 user_allow |= ACL_EXECUTE;
 351
 352         if (mode & S_IRGRP)
 353                 group_allow |= ACL_READ_DATA;
 354         if (mode & S_IWGRP)
 355                 group_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 356         if (mode & S_IXGRP)
 357                 group_allow |= ACL_EXECUTE;
 358
 359         if (mode & S_IROTH)
 360                 everyone_allow |= ACL_READ_DATA;
 361         if (mode & S_IWOTH)
 362                 everyone_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 363         if (mode & S_IXOTH)
 364                 everyone_allow |= ACL_EXECUTE;
 365
 366         user_deny = ((group_allow | everyone_allow) & ~user_allow);
 367         group_deny = everyone_allow & ~group_allow;
 368         user_allow_first = group_deny & ~user_deny;
 369
 370         if (user_allow_first != 0)
 371                 _acl_append(aclp, ACL_USER_OBJ, user_allow_first, ACL_ENTRY_TYPE_ALLOW);
 372         if (user_deny != 0)
 373                 _acl_append(aclp, ACL_USER_OBJ, user_deny, ACL_ENTRY_TYPE_DENY);
 374         if (group_deny != 0)
 375                 _acl_append(aclp, ACL_GROUP_OBJ, group_deny, ACL_ENTRY_TYPE_DENY);
 376         _acl_append(aclp, ACL_USER_OBJ, user_allow, ACL_ENTRY_TYPE_ALLOW);
 377         _acl_append(aclp, ACL_GROUP_OBJ, group_allow, ACL_ENTRY_TYPE_ALLOW);
 378         _acl_append(aclp, ACL_EVERYONE, everyone_allow, ACL_ENTRY_TYPE_ALLOW);
 379 }
 380
 381 void
 382 acl_nfs4_sync_acl_from_mode(struct acl *aclp, mode_t mode, int file_owner_id)
 383 {
 384         int i, meets, must_append;
 385         struct acl_entry *entry, *copy, *previous,
 386             *a1, *a2, *a3, *a4, *a5, *a6;
 387         mode_t amode;
 388         const int READ = 04;
 389         const int WRITE = 02;
 390         const int EXEC = 01;
 391
 392         KASSERT(aclp->acl_cnt >= 0, ("aclp->acl_cnt >= 0"));
 393         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
 394             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 395
 396         /*
 397          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 398          *
 399          * 3.16.6.3. Applying a Mode to an Existing ACL
 400          */
 401
 402         /*
 403          * 1. For each ACE:
 404          */
 405         for (i = 0; i < aclp->acl_cnt; i++) {
 406                 entry = &(aclp->acl_entry[i]);
 407
 408                 /*
 409                  * 1.1. If the type is neither ALLOW or DENY - skip.
 410                  */
 411                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 412                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 413                         continue;
 414
 415                 /*
 416                  * 1.2. If ACL_ENTRY_INHERIT_ONLY is set - skip.
 417                  */
 418                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
 419                         continue;
 420
 421                 /*
 422                  * 1.3. If ACL_ENTRY_FILE_INHERIT or ACL_ENTRY_DIRECTORY_INHERIT
 423                  *      are set:
 424                  */
 425                 if (entry->ae_flags &
 426                     (ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT)) {
 427                         /*
 428                          * 1.3.1. A copy of the current ACE is made, and placed
 429                          *        in the ACL immediately following the current
 430                          *        ACE.
 431                          */
 432                         copy = _acl_duplicate_entry(aclp, i);
 433
 434                         /*
 435                          * 1.3.2. In the first ACE, the flag
 436                          *        ACL_ENTRY_INHERIT_ONLY is set.
 437                          */
 438                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 439
 440                         /*
 441                          * 1.3.3. In the second ACE, the following flags
 442                          *        are cleared:
 443                          *        ACL_ENTRY_FILE_INHERIT,
 444                          *        ACL_ENTRY_DIRECTORY_INHERIT,
 445                          *        ACL_ENTRY_NO_PROPAGATE_INHERIT.
 446                          */
 447                         copy->ae_flags &= ~(ACL_ENTRY_FILE_INHERIT |
 448                             ACL_ENTRY_DIRECTORY_INHERIT |
 449                             ACL_ENTRY_NO_PROPAGATE_INHERIT);
 450
 451                         /*
 452                          * The algorithm continues on with the second ACE.
 453                          */
 454                         i++;
 455                         entry = copy;
 456                 }
 457
 458                 /*
 459                  * 1.4. If it's owner@, group@ or everyone@ entry, clear
 460                  *      ACL_READ_DATA, ACL_WRITE_DATA, ACL_APPEND_DATA
 461                  *      and ACL_EXECUTE.  Continue to the next entry.
 462                  */
 463                 if (entry->ae_tag == ACL_USER_OBJ ||
 464                     entry->ae_tag == ACL_GROUP_OBJ ||
 465                     entry->ae_tag == ACL_EVERYONE) {
 466                         entry->ae_perm &= ~(ACL_READ_DATA | ACL_WRITE_DATA |
 467                             ACL_APPEND_DATA | ACL_EXECUTE);
 468                         continue;
 469                 }
 470
 471                 /*
 472                  * 1.5. Otherwise, if the "who" field did not match one
 473                  *      of OWNER@, GROUP@, EVERYONE@:
 474                  *
 475                  * 1.5.1. If the type is ALLOW, check the preceding ACE.
 476                  *        If it does not meet all of the following criteria:
 477                  */
 478                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW)
 479                         continue;
 480
 481                 meets = 0;
 482                 if (i > 0) {
 483                         meets = 1;
 484                         previous = &(aclp->acl_entry[i - 1]);
 485
 486                         /*
 487                          * 1.5.1.1. The type field is DENY,
 488                          */
 489                         if (previous->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 490                                 meets = 0;
 491
 492                         /*
 493                          * 1.5.1.2. The "who" field is the same as the current
 494                          *          ACE,
 495                          *
 496                          * 1.5.1.3. The flag bit ACE4_IDENTIFIER_GROUP
 497                          *          is the same as it is in the current ACE,
 498                          *          and no other flag bits are set,
 499                          */
 500                         if (previous->ae_id != entry->ae_id ||
 501                             previous->ae_tag != entry->ae_tag)
 502                                 meets = 0;
 503
 504                         if (previous->ae_flags)
 505                                 meets = 0;
 506
 507                         /*
 508                          * 1.5.1.4. The mask bits are a subset of the mask bits
 509                          *          of the current ACE, and are also subset of
 510                          *          the following: ACL_READ_DATA,
 511                          *          ACL_WRITE_DATA, ACL_APPEND_DATA, ACL_EXECUTE
 512                          */
 513                         if (previous->ae_perm & ~(entry->ae_perm))
 514                                 meets = 0;
 515
 516                         if (previous->ae_perm & ~(ACL_READ_DATA |
 517                             ACL_WRITE_DATA | ACL_APPEND_DATA | ACL_EXECUTE))
 518                                 meets = 0;
 519                 }
 520
 521                 if (!meets) {
 522                         /*
 523                          * Then the ACE of type DENY, with a who equal
 524                          * to the current ACE, flag bits equal to
 525                          * (<current ACE flags> & <ACE_IDENTIFIER_GROUP>)
 526                          * and no mask bits, is prepended.
 527                          */
 528                         previous = entry;
 529                         entry = _acl_duplicate_entry(aclp, i);
 530
 531                         /* Adjust counter, as we've just added an entry. */
 532                         i++;
 533
 534                         previous->ae_tag = entry->ae_tag;
 535                         previous->ae_id = entry->ae_id;
 536                         previous->ae_flags = entry->ae_flags;
 537                         previous->ae_perm = 0;
 538                         previous->ae_entry_type = ACL_ENTRY_TYPE_DENY;
 539                 }
 540
 541                 /*
 542                  * 1.5.2. The following modifications are made to the prepended
 543                  *        ACE.  The intent is to mask the following ACE
 544                  *        to disallow ACL_READ_DATA, ACL_WRITE_DATA,
 545                  *        ACL_APPEND_DATA, or ACL_EXECUTE, based upon the group
 546                  *        permissions of the new mode.  As a special case,
 547                  *        if the ACE matches the current owner of the file,
 548                  *        the owner bits are used, rather than the group bits.
 549                  *        This is reflected in the algorithm below.
 550                  */
 551                 amode = mode >> 3;
 552
 553                 /*
 554                  * If ACE4_IDENTIFIER_GROUP is not set, and the "who" field
 555                  * in ACE matches the owner of the file, we shift amode three
 556                  * more bits, in order to have the owner permission bits
 557                  * placed in the three low order bits of amode.
 558                  */
 559                 if (entry->ae_tag == ACL_USER && entry->ae_id == file_owner_id)
 560                         amode = amode >> 3;
 561
 562                 if (entry->ae_perm & ACL_READ_DATA) {
 563                         if (amode & READ)
 564                                 previous->ae_perm &= ~ACL_READ_DATA;
 565                         else
 566                                 previous->ae_perm |= ACL_READ_DATA;
 567                 }
 568
 569                 if (entry->ae_perm & ACL_WRITE_DATA) {
 570                         if (amode & WRITE)
 571                                 previous->ae_perm &= ~ACL_WRITE_DATA;
 572                         else
 573                                 previous->ae_perm |= ACL_WRITE_DATA;
 574                 }
 575
 576                 if (entry->ae_perm & ACL_APPEND_DATA) {
 577                         if (amode & WRITE)
 578                                 previous->ae_perm &= ~ACL_APPEND_DATA;
 579                         else
 580                                 previous->ae_perm |= ACL_APPEND_DATA;
 581                 }
 582
 583                 if (entry->ae_perm & ACL_EXECUTE) {
 584                         if (amode & EXEC)
 585                                 previous->ae_perm &= ~ACL_EXECUTE;
 586                         else
 587                                 previous->ae_perm |= ACL_EXECUTE;
 588                 }
 589
 590                 /*
 591                  * 1.5.3. If ACE4_IDENTIFIER_GROUP is set in the flags
 592                  *        of the ALLOW ace:
 593                  *
 594                  * XXX: This point is not there in the Falkner's draft.
 595                  */
 596                 if (entry->ae_tag == ACL_GROUP &&
 597                     entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) {
 598                         mode_t extramode, ownermode;
 599                         extramode = (mode >> 3) & 07;
 600                         ownermode = mode >> 6;
 601                         extramode &= ~ownermode;
 602
 603                         if (extramode) {
 604                                 if (extramode & READ) {
 605                                         entry->ae_perm &= ~ACL_READ_DATA;
 606                                         previous->ae_perm &= ~ACL_READ_DATA;
 607                                 }
 608
 609                                 if (extramode & WRITE) {
 610                                         entry->ae_perm &=
 611                                             ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
 612                                         previous->ae_perm &=
 613                                             ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
 614                                 }
 615
 616                                 if (extramode & EXEC) {
 617                                         entry->ae_perm &= ~ACL_EXECUTE;
 618                                         previous->ae_perm &= ~ACL_EXECUTE;
 619                                 }
 620                         }
 621                 }
 622         }
 623
 624         /*
 625          * 2. If there at least six ACEs, the final six ACEs are examined.
 626          *    If they are not equal to what we want, append six ACEs.
 627          */
 628         must_append = 0;
 629         if (aclp->acl_cnt < 6) {
 630                 must_append = 1;
 631         } else {
 632                 a6 = &(aclp->acl_entry[aclp->acl_cnt - 1]);
 633                 a5 = &(aclp->acl_entry[aclp->acl_cnt - 2]);
 634                 a4 = &(aclp->acl_entry[aclp->acl_cnt - 3]);
 635                 a3 = &(aclp->acl_entry[aclp->acl_cnt - 4]);
 636                 a2 = &(aclp->acl_entry[aclp->acl_cnt - 5]);
 637                 a1 = &(aclp->acl_entry[aclp->acl_cnt - 6]);
 638
 639                 if (!_acl_entry_matches(a1, ACL_USER_OBJ, 0,
 640                     ACL_ENTRY_TYPE_DENY))
 641                         must_append = 1;
 642                 if (!_acl_entry_matches(a2, ACL_USER_OBJ, ACL_WRITE_ACL |
 643                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 644                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW))
 645                         must_append = 1;
 646                 if (!_acl_entry_matches(a3, ACL_GROUP_OBJ, 0,
 647                     ACL_ENTRY_TYPE_DENY))
 648                         must_append = 1;
 649                 if (!_acl_entry_matches(a4, ACL_GROUP_OBJ, 0,
 650                     ACL_ENTRY_TYPE_ALLOW))
 651                         must_append = 1;
 652                 if (!_acl_entry_matches(a5, ACL_EVERYONE, ACL_WRITE_ACL |
 653                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 654                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY))
 655                         must_append = 1;
 656                 if (!_acl_entry_matches(a6, ACL_EVERYONE, ACL_READ_ACL |
 657                     ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
 658                     ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW))
 659                         must_append = 1;
 660         }
 661
 662         if (must_append) {
 663                 KASSERT(aclp->acl_cnt + 6 <= ACL_MAX_ENTRIES,
 664                     ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 665
 666                 a1 = _acl_append(aclp, ACL_USER_OBJ, 0, ACL_ENTRY_TYPE_DENY);
 667                 a2 = _acl_append(aclp, ACL_USER_OBJ, ACL_WRITE_ACL |
 668                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 669                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW);
 670                 a3 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_DENY);
 671                 a4 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_ALLOW);
 672                 a5 = _acl_append(aclp, ACL_EVERYONE, ACL_WRITE_ACL |
 673                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 674                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY);
 675                 a6 = _acl_append(aclp, ACL_EVERYONE, ACL_READ_ACL |
 676                     ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
 677                     ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW);
 678
 679                 KASSERT(a1 != NULL && a2 != NULL && a3 != NULL && a4 != NULL &&
 680                     a5 != NULL && a6 != NULL, ("couldn't append to ACL."));
 681         }
 682
 683         /*
 684          * 3. The final six ACEs are adjusted according to the incoming mode.
 685          */
 686         if (mode & S_IRUSR)
 687                 a2->ae_perm |= ACL_READ_DATA;
 688         else
 689                 a1->ae_perm |= ACL_READ_DATA;
 690         if (mode & S_IWUSR)
 691                 a2->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 692         else
 693                 a1->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 694         if (mode & S_IXUSR)
 695                 a2->ae_perm |= ACL_EXECUTE;
 696         else
 697                 a1->ae_perm |= ACL_EXECUTE;
 698
 699         if (mode & S_IRGRP)
 700                 a4->ae_perm |= ACL_READ_DATA;
 701         else
 702                 a3->ae_perm |= ACL_READ_DATA;
 703         if (mode & S_IWGRP)
 704                 a4->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 705         else
 706                 a3->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 707         if (mode & S_IXGRP)
 708                 a4->ae_perm |= ACL_EXECUTE;
 709         else
 710                 a3->ae_perm |= ACL_EXECUTE;
 711
 712         if (mode & S_IROTH)
 713                 a6->ae_perm |= ACL_READ_DATA;
 714         else
 715                 a5->ae_perm |= ACL_READ_DATA;
 716         if (mode & S_IWOTH)
 717                 a6->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 718         else
 719                 a5->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 720         if (mode & S_IXOTH)
 721                 a6->ae_perm |= ACL_EXECUTE;
 722         else
 723                 a5->ae_perm |= ACL_EXECUTE;
 724 }
 725
 726 void
 727 acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp)
 728 {
 729         int i;
 730         mode_t old_mode = *_mode, mode = 0, seen = 0;
 731         const struct acl_entry *entry;
 732
 733         KASSERT(aclp->acl_cnt > 0, ("aclp->acl_cnt > 0"));
 734         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
 735             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 736
 737         /*
 738          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 739          *
 740          * 3.16.6.1. Recomputing mode upon SETATTR of ACL
 741          */
 742
 743         for (i = 0; i < aclp->acl_cnt; i++) {
 744                 entry = &(aclp->acl_entry[i]);
 745
 746                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 747                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 748                         continue;
 749
 750                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
 751                         continue;
 752
 753                 if (entry->ae_tag == ACL_USER_OBJ) {
 754                         if ((entry->ae_perm & ACL_READ_DATA) &&
 755                             ((seen & S_IRUSR) == 0)) {
 756                                 seen |= S_IRUSR;
 757                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 758                                         mode |= S_IRUSR;
 759                         }
 760                         if ((entry->ae_perm & ACL_WRITE_DATA) &&
 761                              ((seen & S_IWUSR) == 0)) {
 762                                 seen |= S_IWUSR;
 763                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 764                                         mode |= S_IWUSR;
 765                         }
 766                         if ((entry->ae_perm & ACL_EXECUTE) &&
 767                             ((seen & S_IXUSR) == 0)) {
 768                                 seen |= S_IXUSR;
 769                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 770                                         mode |= S_IXUSR;
 771                         }
 772                 } else if (entry->ae_tag == ACL_GROUP_OBJ) {
 773                         if ((entry->ae_perm & ACL_READ_DATA) &&
 774                             ((seen & S_IRGRP) == 0)) {
 775                                 seen |= S_IRGRP;
 776                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 777                                         mode |= S_IRGRP;
 778                         }
 779                         if ((entry->ae_perm & ACL_WRITE_DATA) &&
 780                             ((seen & S_IWGRP) == 0)) {
 781                                 seen |= S_IWGRP;
 782                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 783                                         mode |= S_IWGRP;
 784                         }
 785                         if ((entry->ae_perm & ACL_EXECUTE) &&
 786                             ((seen & S_IXGRP) == 0)) {
 787                                 seen |= S_IXGRP;
 788                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 789                                         mode |= S_IXGRP;
 790                         }
 791                 } else if (entry->ae_tag == ACL_EVERYONE) {
 792                         if (entry->ae_perm & ACL_READ_DATA) {
 793                                 if ((seen & S_IRUSR) == 0) {
 794                                         seen |= S_IRUSR;
 795                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 796                                                 mode |= S_IRUSR;
 797                                 }
 798                                 if ((seen & S_IRGRP) == 0) {
 799                                         seen |= S_IRGRP;
 800                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 801                                                 mode |= S_IRGRP;
 802                                 }
 803                                 if ((seen & S_IROTH) == 0) {
 804                                         seen |= S_IROTH;
 805                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 806                                                 mode |= S_IROTH;
 807                                 }
 808                         }
 809                         if (entry->ae_perm & ACL_WRITE_DATA) {
 810                                 if ((seen & S_IWUSR) == 0) {
 811                                         seen |= S_IWUSR;
 812                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 813                                                 mode |= S_IWUSR;
 814                                 }
 815                                 if ((seen & S_IWGRP) == 0) {
 816                                         seen |= S_IWGRP;
 817                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 818                                                 mode |= S_IWGRP;
 819                                 }
 820                                 if ((seen & S_IWOTH) == 0) {
 821                                         seen |= S_IWOTH;
 822                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 823                                                 mode |= S_IWOTH;
 824                                 }
 825                         }
 826                         if (entry->ae_perm & ACL_EXECUTE) {
 827                                 if ((seen & S_IXUSR) == 0) {
 828                                         seen |= S_IXUSR;
 829                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 830                                                 mode |= S_IXUSR;
 831                                 }
 832                                 if ((seen & S_IXGRP) == 0) {
 833                                         seen |= S_IXGRP;
 834                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 835                                                 mode |= S_IXGRP;
 836                                 }
 837                                 if ((seen & S_IXOTH) == 0) {
 838                                         seen |= S_IXOTH;
 839                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 840                                                 mode |= S_IXOTH;
 841                                 }
 842                         }
 843                 }
 844         }
 845
 846         *_mode = mode | (old_mode & ACL_PRESERVE_MASK);
 847 }
 848
 849 void
 850 acl_nfs4_compute_inherited_acl(const struct acl *parent_aclp,
 851     struct acl *child_aclp, mode_t mode, int file_owner_id,
 852     int is_directory)
 853 {
 854         int i, flags;
 855         const struct acl_entry *parent_entry;
 856         struct acl_entry *entry, *copy;
 857
 858         KASSERT(child_aclp->acl_cnt == 0, ("child_aclp->acl_cnt == 0"));
 859         KASSERT(parent_aclp->acl_cnt > 0, ("parent_aclp->acl_cnt > 0"));
 860         KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
 861             ("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 862
 863         /*
 864          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 865          *
 866          * 3.16.6.2. Applying the mode given to CREATE or OPEN
 867          *           to an inherited ACL
 868          */
 869
 870         /*
 871          * 1. Form an ACL that is the concatenation of all inheritable ACEs.
 872          */
 873         for (i = 0; i < parent_aclp->acl_cnt; i++) {
 874                 parent_entry = &(parent_aclp->acl_entry[i]);
 875                 flags = parent_entry->ae_flags;
 876
 877                 /*
 878                  * Entry is not inheritable at all.
 879                  */
 880                 if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
 881                     ACL_ENTRY_FILE_INHERIT)) == 0)
 882                         continue;
 883
 884                 /*
 885                  * We're creating a file, but entry is not inheritable
 886                  * by files.
 887                  */
 888                 if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
 889                         continue;
 890
 891                 /*
 892                  * Entry is inheritable only by files, but has NO_PROPAGATE
 893                  * flag set, and we're creating a directory, so it wouldn't
 894                  * propagate to any file in that directory anyway.
 895                  */
 896                 if (is_directory &&
 897                     (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
 898                     (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
 899                         continue;
 900
 901                 KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 902                     ("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 903                 child_aclp->acl_entry[child_aclp->acl_cnt] = *parent_entry;
 904                 child_aclp->acl_cnt++;
 905         }
 906
 907         /*
 908          * 2. For each entry in the new ACL, adjust its flags, possibly
 909          *    creating two entries in place of one.
 910          */
 911         for (i = 0; i < child_aclp->acl_cnt; i++) {
 912                 entry = &(child_aclp->acl_entry[i]);
 913
 914                 /*
 915                  * This is not in the specification, but SunOS
 916                  * apparently does that.
 917                  */
 918                 if (((entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT) ||
 919                     !is_directory) &&
 920                     entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 921                         entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
 922
 923                 /*
 924                  * 2.A. If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if the object
 925                  *      being created is not a directory, then clear the
 926                  *      following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
 927                  *      ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
 928                  *      ACL_ENTRY_INHERIT_ONLY.
 929                  */
 930                 if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
 931                     !is_directory) {
 932                         entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
 933                         ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
 934                         ACL_ENTRY_INHERIT_ONLY);
 935
 936                         /*
 937                          * Continue on to the next ACE.
 938                          */
 939                         continue;
 940                 }
 941
 942                 /*
 943                  * 2.B. If the object is a directory and ACL_ENTRY_FILE_INHERIT
 944                  *      is set, but ACL_ENTRY_NO_PROPAGATE_INHERIT is not set, ensure
 945                  *      that ACL_ENTRY_INHERIT_ONLY is set.  Continue to the
 946                  *      next ACE.  Otherwise...
 947                  */
 948                 /*
 949                  * XXX: Read it again and make sure what does the "otherwise"
 950                  *      apply to.
 951                  */
 952                 if (is_directory &&
 953                     (entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
 954                     ((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
 955                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 956                         continue;
 957                 }
 958
 959                 /*
 960                  * 2.C. If the type of the ACE is neither ALLOW nor deny,
 961                  *      then continue.
 962                  */
 963                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 964                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 965                         continue;
 966
 967                 /*
 968                  * 2.D. Copy the original ACE into a second, adjacent ACE.
 969                  */
 970                 copy = _acl_duplicate_entry(child_aclp, i);
 971
 972                 /*
 973                  * 2.E. On the first ACE, ensure that ACL_ENTRY_INHERIT_ONLY
 974                  *      is set.
 975                  */
 976                 entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 977
 978                 /*
 979                  * 2.F. On the second ACE, clear the following flags:
 980                  *      ACL_ENTRY_NO_PROPAGATE_INHERIT, ACL_ENTRY_FILE_INHERIT,
 981                  *      ACL_ENTRY_DIRECTORY_INHERIT, ACL_ENTRY_INHERIT_ONLY.
 982                  */
 983                 copy->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
 984                     ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
 985                     ACL_ENTRY_INHERIT_ONLY);
 986
 987                 /*
 988                  * 2.G. On the second ACE, if the type is ALLOW,
 989                  *      an implementation MAY clear the following
 990                  *      mask bits: ACL_WRITE_ACL, ACL_WRITE_OWNER.
 991                  */
 992                 if (copy->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 993                         copy->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
 994
 995                 /*
 996                  * Increment the counter to skip the copied entry.
 997                  */
 998                 i++;
 999         }
1000
1001         /*
1002          * 3. To ensure that the mode is honored, apply the algorithm describe
1003          *    in Section 2.16.6.3, using the mode that is to be used for file
1004          *    creation.
1005          */
1006         acl_nfs4_sync_acl_from_mode(child_aclp, mode, file_owner_id);
1007 }
1008
1009 #ifdef _KERNEL
1010 static int
1011 _acls_are_equal(const struct acl *a, const struct acl *b)
1012 {
1013         int i;
1014         const struct acl_entry *entrya, *entryb;
1015
1016         if (a->acl_cnt != b->acl_cnt)
1017                 return (0);
1018
1019         for (i = 0; i < b->acl_cnt; i++) {
1020                 entrya = &(a->acl_entry[i]);
1021                 entryb = &(b->acl_entry[i]);
1022
1023                 if (entrya->ae_tag != entryb->ae_tag ||
1024                     entrya->ae_id != entryb->ae_id ||
1025                     entrya->ae_perm != entryb->ae_perm ||
1026                     entrya->ae_entry_type != entryb->ae_entry_type ||
1027                     entrya->ae_flags != entryb->ae_flags)
1028                         return (0);
1029         }
1030
1031         return (1);
1032 }
1033
1034 /*
1035  * This routine is used to determine whether to remove entry_type attribute
1036  * that stores ACL contents.
1037  */
1038 int
1039 acl_nfs4_is_trivial(const struct acl *aclp, int file_owner_id)
1040 {
1041         int trivial;
1042         mode_t tmpmode = 0;
1043         struct acl *tmpaclp;
1044
1045         if (aclp->acl_cnt != 6)
1046                 return (0);
1047
1048         /*
1049          * Compute the mode from the ACL, then compute new ACL from that mode.
1050          * If the ACLs are identical, then the ACL is trivial.
1051          *
1052          * XXX: I guess there is a faster way to do this.  However, even
1053          *      this slow implementation significantly speeds things up
1054          *      for files that don't have any entry_type ACL entries - it's
1055          *      critical for performance to not use EA when they are not
1056          *      needed.
1057          */
1058         tmpaclp = acl_alloc(M_WAITOK | M_ZERO);
1059         acl_nfs4_sync_mode_from_acl(&tmpmode, aclp);
1060         acl_nfs4_sync_acl_from_mode(tmpaclp, tmpmode, file_owner_id);
1061         trivial = _acls_are_equal(aclp, tmpaclp);
1062         acl_free(tmpaclp);
1063
1064         return (trivial);
1065 }
1066 #endif /* _KERNEL */
1067
1068 int
1069 acl_nfs4_check(const struct acl *aclp, int is_directory)
1070 {
1071         int i;
1072         const struct acl_entry *entry;
1073
1074         /*
1075          * The spec doesn't seem to say anything about ACL validity.
1076          * It seems there is not much to do here.  There is even no need
1077          * to count "owner@" or "everyone@" (ACL_USER_OBJ and ACL_EVERYONE)
1078          * entries, as there can be several of them and that's perfectly
1079          * valid.  There can be none of them too.  Really.
1080          */
1081
1082         if (aclp->acl_cnt > ACL_MAX_ENTRIES || aclp->acl_cnt <= 0)
1083                 return (EINVAL);
1084
1085         for (i = 0; i < aclp->acl_cnt; i++) {
1086                 entry = &(aclp->acl_entry[i]);
1087
1088                 switch (entry->ae_tag) {
1089                 case ACL_USER_OBJ:
1090                 case ACL_GROUP_OBJ:
1091                 case ACL_EVERYONE:
1092                         if (entry->ae_id != ACL_UNDEFINED_ID)
1093                                 return (EINVAL);
1094                         break;
1095
1096                 case ACL_USER:
1097                 case ACL_GROUP:
1098                         if (entry->ae_id == ACL_UNDEFINED_ID)
1099                                 return (EINVAL);
1100                         break;
1101
1102                 default:
1103                         return (EINVAL);
1104                 }
1105
1106                 if ((entry->ae_perm | ACL_NFS4_PERM_BITS) != ACL_NFS4_PERM_BITS)
1107                         return (EINVAL);
1108
1109                 /*
1110                  * Disallow ACL_ENTRY_TYPE_AUDIT and ACL_ENTRY_TYPE_ALARM for now.
1111                  */
1112                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
1113                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
1114                         return (EINVAL);
1115
1116                 if ((entry->ae_flags | ACL_FLAGS_BITS) != ACL_FLAGS_BITS)
1117                         return (EINVAL);
1118
1119                 /* Disallow unimplemented flags. */
1120                 if (entry->ae_flags & (ACL_ENTRY_SUCCESSFUL_ACCESS |
1121                     ACL_ENTRY_FAILED_ACCESS))
1122                         return (EINVAL);
1123
1124                 /* Disallow flags not allowed for ordinary files. */
1125                 if (!is_directory) {
1126                         if (entry->ae_flags & (ACL_ENTRY_FILE_INHERIT |
1127                             ACL_ENTRY_DIRECTORY_INHERIT |
1128                             ACL_ENTRY_NO_PROPAGATE_INHERIT | ACL_ENTRY_INHERIT_ONLY))
1129                                 return (EINVAL);
1130                 }
1131         }
1132
1133         return (0);
1134 }