sys/kern/subr_acl_nfs4.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2008-2010 Edward Tomasz Napierała <trasz@FreeBSD.org>
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  */
  27
  28 /*
  29  * ACL support routines specific to NFSv4 access control lists.  These are
  30  * utility routines for code common across file systems implementing NFSv4
  31  * ACLs.
  32  */
  33
  34 #ifdef _KERNEL
  35 #include <sys/cdefs.h>
  36 __FBSDID("$FreeBSD$");
  37
  38 #include <sys/param.h>
  39 #include <sys/kernel.h>
  40 #include <sys/module.h>
  41 #include <sys/systm.h>
  42 #include <sys/mount.h>
  43 #include <sys/priv.h>
  44 #include <sys/vnode.h>
  45 #include <sys/errno.h>
  46 #include <sys/stat.h>
  47 #include <sys/sysctl.h>
  48 #include <sys/acl.h>
  49 #else
  50 #include <errno.h>
  51 #include <assert.h>
  52 #include <sys/acl.h>
  53 #include <sys/stat.h>
  54 #define KASSERT(a, b) assert(a)
  55 #define CTASSERT(a)
  56
  57 #endif /* !_KERNEL */
  58
  59 #ifdef _KERNEL
  60
  61 static void     acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode);
  62
  63 static int      acl_nfs4_old_semantics = 0;
  64
  65 SYSCTL_INT(_vfs, OID_AUTO, acl_nfs4_old_semantics, CTLFLAG_RW,
  66     &acl_nfs4_old_semantics, 0, "Use pre-PSARC/2010/029 NFSv4 ACL semantics");
  67
  68 static struct {
  69         accmode_t accmode;
  70         int mask;
  71 } accmode2mask[] = {{VREAD, ACL_READ_DATA},
  72                     {VWRITE, ACL_WRITE_DATA},
  73                     {VAPPEND, ACL_APPEND_DATA},
  74                     {VEXEC, ACL_EXECUTE},
  75                     {VREAD_NAMED_ATTRS, ACL_READ_NAMED_ATTRS},
  76                     {VWRITE_NAMED_ATTRS, ACL_WRITE_NAMED_ATTRS},
  77                     {VDELETE_CHILD, ACL_DELETE_CHILD},
  78                     {VREAD_ATTRIBUTES, ACL_READ_ATTRIBUTES},
  79                     {VWRITE_ATTRIBUTES, ACL_WRITE_ATTRIBUTES},
  80                     {VDELETE, ACL_DELETE},
  81                     {VREAD_ACL, ACL_READ_ACL},
  82                     {VWRITE_ACL, ACL_WRITE_ACL},
  83                     {VWRITE_OWNER, ACL_WRITE_OWNER},
  84                     {VSYNCHRONIZE, ACL_SYNCHRONIZE},
  85                     {0, 0}};
  86
  87 static int
  88 _access_mask_from_accmode(accmode_t accmode)
  89 {
  90         int access_mask = 0, i;
  91
  92         for (i = 0; accmode2mask[i].accmode != 0; i++) {
  93                 if (accmode & accmode2mask[i].accmode)
  94                         access_mask |= accmode2mask[i].mask;
  95         }
  96
  97         /*
  98          * VAPPEND is just a modifier for VWRITE; if the caller asked
  99          * for 'VAPPEND | VWRITE', we want to check for ACL_APPEND_DATA only.
 100          */
 101         if (access_mask & ACL_APPEND_DATA)
 102                 access_mask &= ~ACL_WRITE_DATA;
 103
 104         return (access_mask);
 105 }
 106
 107 /*
 108  * Return 0, iff access is allowed, 1 otherwise.
 109  */
 110 static int
 111 _acl_denies(const struct acl *aclp, int access_mask, struct ucred *cred,
 112     int file_uid, int file_gid, int *denied_explicitly)
 113 {
 114         int i;
 115         const struct acl_entry *entry;
 116
 117         if (denied_explicitly != NULL)
 118                 *denied_explicitly = 0;
 119
 120         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
 121             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 122
 123         for (i = 0; i < aclp->acl_cnt; i++) {
 124                 entry = &(aclp->acl_entry[i]);
 125
 126                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 127                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 128                         continue;
 129                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
 130                         continue;
 131                 switch (entry->ae_tag) {
 132                 case ACL_USER_OBJ:
 133                         if (file_uid != cred->cr_uid)
 134                                 continue;
 135                         break;
 136                 case ACL_USER:
 137                         if (entry->ae_id != cred->cr_uid)
 138                                 continue;
 139                         break;
 140                 case ACL_GROUP_OBJ:
 141                         if (!groupmember(file_gid, cred))
 142                                 continue;
 143                         break;
 144                 case ACL_GROUP:
 145                         if (!groupmember(entry->ae_id, cred))
 146                                 continue;
 147                         break;
 148                 default:
 149                         KASSERT(entry->ae_tag == ACL_EVERYONE,
 150                             ("entry->ae_tag == ACL_EVERYONE"));
 151                 }
 152
 153                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_DENY) {
 154                         if (entry->ae_perm & access_mask) {
 155                                 if (denied_explicitly != NULL)
 156                                         *denied_explicitly = 1;
 157                                 return (1);
 158                         }
 159                 }
 160
 161                 access_mask &= ~(entry->ae_perm);
 162                 if (access_mask == 0)
 163                         return (0);
 164         }
 165
 166         if (access_mask == 0)
 167                 return (0);
 168
 169         return (1);
 170 }
 171
 172 int
 173 vaccess_acl_nfs4(enum vtype type, uid_t file_uid, gid_t file_gid,
 174     struct acl *aclp, accmode_t accmode, struct ucred *cred)
 175 {
 176         accmode_t priv_granted = 0;
 177         int denied, explicitly_denied, access_mask, is_directory,
 178             must_be_owner = 0;
 179         mode_t file_mode = 0;
 180
 181         KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND |
 182             VEXPLICIT_DENY | VREAD_NAMED_ATTRS | VWRITE_NAMED_ATTRS |
 183             VDELETE_CHILD | VREAD_ATTRIBUTES | VWRITE_ATTRIBUTES | VDELETE |
 184             VREAD_ACL | VWRITE_ACL | VWRITE_OWNER | VSYNCHRONIZE)) == 0,
 185             ("invalid bit in accmode"));
 186         KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
 187                 ("VAPPEND without VWRITE"));
 188
 189         if (accmode & VADMIN)
 190                 must_be_owner = 1;
 191
 192         /*
 193          * Ignore VSYNCHRONIZE permission.
 194          */
 195         accmode &= ~VSYNCHRONIZE;
 196
 197         access_mask = _access_mask_from_accmode(accmode);
 198
 199         if (type == VDIR)
 200                 is_directory = 1;
 201         else
 202                 is_directory = 0;
 203
 204         /*
 205          * File owner is always allowed to read and write the ACL
 206          * and basic attributes.  This is to prevent a situation
 207          * where user would change ACL in a way that prevents him
 208          * from undoing the change.
 209          */
 210         if (file_uid == cred->cr_uid)
 211                 access_mask &= ~(ACL_READ_ACL | ACL_WRITE_ACL |
 212                     ACL_READ_ATTRIBUTES | ACL_WRITE_ATTRIBUTES);
 213
 214         /*
 215          * Ignore append permission for regular files; use write
 216          * permission instead.
 217          */
 218         if (!is_directory && (access_mask & ACL_APPEND_DATA)) {
 219                 access_mask &= ~ACL_APPEND_DATA;
 220                 access_mask |= ACL_WRITE_DATA;
 221         }
 222
 223         denied = _acl_denies(aclp, access_mask, cred, file_uid, file_gid,
 224             &explicitly_denied);
 225
 226         if (must_be_owner) {
 227                 if (file_uid != cred->cr_uid)
 228                         denied = EPERM;
 229         }
 230
 231         /*
 232          * For VEXEC, ensure that at least one execute bit is set for
 233          * non-directories. We have to check the mode here to stay
 234          * consistent with execve(2). See the test in
 235          * exec_check_permissions().
 236          */
 237         acl_nfs4_sync_mode_from_acl(&file_mode, aclp);
 238         if (!denied && !is_directory && (accmode & VEXEC) &&
 239             (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)
 240                 denied = EACCES;
 241
 242         if (!denied)
 243                 return (0);
 244
 245         /*
 246          * Access failed.  Iff it was not denied explicitly and
 247          * VEXPLICIT_DENY flag was specified, allow access.
 248          */
 249         if ((accmode & VEXPLICIT_DENY) && explicitly_denied == 0)
 250                 return (0);
 251
 252         accmode &= ~VEXPLICIT_DENY;
 253
 254         /*
 255          * No match.  Try to use privileges, if there are any.
 256          */
 257         if (is_directory) {
 258                 if ((accmode & VEXEC) && !priv_check_cred(cred, PRIV_VFS_LOOKUP))
 259                         priv_granted |= VEXEC;
 260         } else {
 261                 /*
 262                  * Ensure that at least one execute bit is on. Otherwise,
 263                  * a privileged user will always succeed, and we don't want
 264                  * this to happen unless the file really is executable.
 265                  */
 266                 if ((accmode & VEXEC) && (file_mode &
 267                     (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
 268                     !priv_check_cred(cred, PRIV_VFS_EXEC))
 269                         priv_granted |= VEXEC;
 270         }
 271
 272         if ((accmode & VREAD) && !priv_check_cred(cred, PRIV_VFS_READ))
 273                 priv_granted |= VREAD;
 274
 275         if ((accmode & (VWRITE | VAPPEND | VDELETE_CHILD)) &&
 276             !priv_check_cred(cred, PRIV_VFS_WRITE))
 277                 priv_granted |= (VWRITE | VAPPEND | VDELETE_CHILD);
 278
 279         if ((accmode & VADMIN_PERMS) &&
 280             !priv_check_cred(cred, PRIV_VFS_ADMIN))
 281                 priv_granted |= VADMIN_PERMS;
 282
 283         if ((accmode & VSTAT_PERMS) &&
 284             !priv_check_cred(cred, PRIV_VFS_STAT))
 285                 priv_granted |= VSTAT_PERMS;
 286
 287         if ((accmode & priv_granted) == accmode) {
 288                 return (0);
 289         }
 290
 291         if (accmode & (VADMIN_PERMS | VDELETE_CHILD | VDELETE))
 292                 denied = EPERM;
 293         else
 294                 denied = EACCES;
 295
 296         return (denied);
 297 }
 298 #endif /* _KERNEL */
 299
 300 static int
 301 _acl_entry_matches(struct acl_entry *entry, acl_tag_t tag, acl_perm_t perm,
 302     acl_entry_type_t entry_type)
 303 {
 304         if (entry->ae_tag != tag)
 305                 return (0);
 306
 307         if (entry->ae_id != ACL_UNDEFINED_ID)
 308                 return (0);
 309
 310         if (entry->ae_perm != perm)
 311                 return (0);
 312
 313         if (entry->ae_entry_type != entry_type)
 314                 return (0);
 315
 316         if (entry->ae_flags != 0)
 317                 return (0);
 318
 319         return (1);
 320 }
 321
 322 static struct acl_entry *
 323 _acl_append(struct acl *aclp, acl_tag_t tag, acl_perm_t perm,
 324     acl_entry_type_t entry_type)
 325 {
 326         struct acl_entry *entry;
 327
 328         KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 329             ("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 330
 331         entry = &(aclp->acl_entry[aclp->acl_cnt]);
 332         aclp->acl_cnt++;
 333
 334         entry->ae_tag = tag;
 335         entry->ae_id = ACL_UNDEFINED_ID;
 336         entry->ae_perm = perm;
 337         entry->ae_entry_type = entry_type;
 338         entry->ae_flags = 0;
 339
 340         return (entry);
 341 }
 342
 343 static struct acl_entry *
 344 _acl_duplicate_entry(struct acl *aclp, unsigned entry_index)
 345 {
 346         unsigned i;
 347
 348         KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 349             ("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 350
 351         for (i = aclp->acl_cnt; i > entry_index; i--)
 352                 aclp->acl_entry[i] = aclp->acl_entry[i - 1];
 353
 354         aclp->acl_cnt++;
 355
 356         return (&(aclp->acl_entry[entry_index + 1]));
 357 }
 358
 359 static void
 360 acl_nfs4_sync_acl_from_mode_draft(struct acl *aclp, mode_t mode,
 361     int file_owner_id)
 362 {
 363         int meets, must_append;
 364         unsigned i;
 365         struct acl_entry *entry, *copy, *previous,
 366             *a1, *a2, *a3, *a4, *a5, *a6;
 367         mode_t amode;
 368         const int READ = 04;
 369         const int WRITE = 02;
 370         const int EXEC = 01;
 371
 372         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
 373             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 374
 375         /*
 376          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 377          *
 378          * 3.16.6.3. Applying a Mode to an Existing ACL
 379          */
 380
 381         /*
 382          * 1. For each ACE:
 383          */
 384         for (i = 0; i < aclp->acl_cnt; i++) {
 385                 entry = &(aclp->acl_entry[i]);
 386
 387                 /*
 388                  * 1.1. If the type is neither ALLOW or DENY - skip.
 389                  */
 390                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 391                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 392                         continue;
 393
 394                 /*
 395                  * 1.2. If ACL_ENTRY_INHERIT_ONLY is set - skip.
 396                  */
 397                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
 398                         continue;
 399
 400                 /*
 401                  * 1.3. If ACL_ENTRY_FILE_INHERIT or ACL_ENTRY_DIRECTORY_INHERIT
 402                  *      are set:
 403                  */
 404                 if (entry->ae_flags &
 405                     (ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT)) {
 406                         /*
 407                          * 1.3.1. A copy of the current ACE is made, and placed
 408                          *        in the ACL immediately following the current
 409                          *        ACE.
 410                          */
 411                         copy = _acl_duplicate_entry(aclp, i);
 412
 413                         /*
 414                          * 1.3.2. In the first ACE, the flag
 415                          *        ACL_ENTRY_INHERIT_ONLY is set.
 416                          */
 417                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 418
 419                         /*
 420                          * 1.3.3. In the second ACE, the following flags
 421                          *        are cleared:
 422                          *        ACL_ENTRY_FILE_INHERIT,
 423                          *        ACL_ENTRY_DIRECTORY_INHERIT,
 424                          *        ACL_ENTRY_NO_PROPAGATE_INHERIT.
 425                          */
 426                         copy->ae_flags &= ~(ACL_ENTRY_FILE_INHERIT |
 427                             ACL_ENTRY_DIRECTORY_INHERIT |
 428                             ACL_ENTRY_NO_PROPAGATE_INHERIT);
 429
 430                         /*
 431                          * The algorithm continues on with the second ACE.
 432                          */
 433                         i++;
 434                         entry = copy;
 435                 }
 436
 437                 /*
 438                  * 1.4. If it's owner@, group@ or everyone@ entry, clear
 439                  *      ACL_READ_DATA, ACL_WRITE_DATA, ACL_APPEND_DATA
 440                  *      and ACL_EXECUTE.  Continue to the next entry.
 441                  */
 442                 if (entry->ae_tag == ACL_USER_OBJ ||
 443                     entry->ae_tag == ACL_GROUP_OBJ ||
 444                     entry->ae_tag == ACL_EVERYONE) {
 445                         entry->ae_perm &= ~(ACL_READ_DATA | ACL_WRITE_DATA |
 446                             ACL_APPEND_DATA | ACL_EXECUTE);
 447                         continue;
 448                 }
 449
 450                 /*
 451                  * 1.5. Otherwise, if the "who" field did not match one
 452                  *      of OWNER@, GROUP@, EVERYONE@:
 453                  *
 454                  * 1.5.1. If the type is ALLOW, check the preceding ACE.
 455                  *        If it does not meet all of the following criteria:
 456                  */
 457                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW)
 458                         continue;
 459
 460                 meets = 0;
 461                 if (i > 0) {
 462                         meets = 1;
 463                         previous = &(aclp->acl_entry[i - 1]);
 464
 465                         /*
 466                          * 1.5.1.1. The type field is DENY,
 467                          */
 468                         if (previous->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 469                                 meets = 0;
 470
 471                         /*
 472                          * 1.5.1.2. The "who" field is the same as the current
 473                          *          ACE,
 474                          *
 475                          * 1.5.1.3. The flag bit ACE4_IDENTIFIER_GROUP
 476                          *          is the same as it is in the current ACE,
 477                          *          and no other flag bits are set,
 478                          */
 479                         if (previous->ae_id != entry->ae_id ||
 480                             previous->ae_tag != entry->ae_tag)
 481                                 meets = 0;
 482
 483                         if (previous->ae_flags)
 484                                 meets = 0;
 485
 486                         /*
 487                          * 1.5.1.4. The mask bits are a subset of the mask bits
 488                          *          of the current ACE, and are also subset of
 489                          *          the following: ACL_READ_DATA,
 490                          *          ACL_WRITE_DATA, ACL_APPEND_DATA, ACL_EXECUTE
 491                          */
 492                         if (previous->ae_perm & ~(entry->ae_perm))
 493                                 meets = 0;
 494
 495                         if (previous->ae_perm & ~(ACL_READ_DATA |
 496                             ACL_WRITE_DATA | ACL_APPEND_DATA | ACL_EXECUTE))
 497                                 meets = 0;
 498                 }
 499
 500                 if (!meets) {
 501                         /*
 502                          * Then the ACE of type DENY, with a who equal
 503                          * to the current ACE, flag bits equal to
 504                          * (<current ACE flags> & <ACE_IDENTIFIER_GROUP>)
 505                          * and no mask bits, is prepended.
 506                          */
 507                         previous = entry;
 508                         entry = _acl_duplicate_entry(aclp, i);
 509
 510                         /* Adjust counter, as we've just added an entry. */
 511                         i++;
 512
 513                         previous->ae_tag = entry->ae_tag;
 514                         previous->ae_id = entry->ae_id;
 515                         previous->ae_flags = entry->ae_flags;
 516                         previous->ae_perm = 0;
 517                         previous->ae_entry_type = ACL_ENTRY_TYPE_DENY;
 518                 }
 519
 520                 /*
 521                  * 1.5.2. The following modifications are made to the prepended
 522                  *        ACE.  The intent is to mask the following ACE
 523                  *        to disallow ACL_READ_DATA, ACL_WRITE_DATA,
 524                  *        ACL_APPEND_DATA, or ACL_EXECUTE, based upon the group
 525                  *        permissions of the new mode.  As a special case,
 526                  *        if the ACE matches the current owner of the file,
 527                  *        the owner bits are used, rather than the group bits.
 528                  *        This is reflected in the algorithm below.
 529                  */
 530                 amode = mode >> 3;
 531
 532                 /*
 533                  * If ACE4_IDENTIFIER_GROUP is not set, and the "who" field
 534                  * in ACE matches the owner of the file, we shift amode three
 535                  * more bits, in order to have the owner permission bits
 536                  * placed in the three low order bits of amode.
 537                  */
 538                 if (entry->ae_tag == ACL_USER && entry->ae_id == file_owner_id)
 539                         amode = amode >> 3;
 540
 541                 if (entry->ae_perm & ACL_READ_DATA) {
 542                         if (amode & READ)
 543                                 previous->ae_perm &= ~ACL_READ_DATA;
 544                         else
 545                                 previous->ae_perm |= ACL_READ_DATA;
 546                 }
 547
 548                 if (entry->ae_perm & ACL_WRITE_DATA) {
 549                         if (amode & WRITE)
 550                                 previous->ae_perm &= ~ACL_WRITE_DATA;
 551                         else
 552                                 previous->ae_perm |= ACL_WRITE_DATA;
 553                 }
 554
 555                 if (entry->ae_perm & ACL_APPEND_DATA) {
 556                         if (amode & WRITE)
 557                                 previous->ae_perm &= ~ACL_APPEND_DATA;
 558                         else
 559                                 previous->ae_perm |= ACL_APPEND_DATA;
 560                 }
 561
 562                 if (entry->ae_perm & ACL_EXECUTE) {
 563                         if (amode & EXEC)
 564                                 previous->ae_perm &= ~ACL_EXECUTE;
 565                         else
 566                                 previous->ae_perm |= ACL_EXECUTE;
 567                 }
 568
 569                 /*
 570                  * 1.5.3. If ACE4_IDENTIFIER_GROUP is set in the flags
 571                  *        of the ALLOW ace:
 572                  *
 573                  * XXX: This point is not there in the Falkner's draft.
 574                  */
 575                 if (entry->ae_tag == ACL_GROUP &&
 576                     entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) {
 577                         mode_t extramode, ownermode;
 578                         extramode = (mode >> 3) & 07;
 579                         ownermode = mode >> 6;
 580                         extramode &= ~ownermode;
 581
 582                         if (extramode) {
 583                                 if (extramode & READ) {
 584                                         entry->ae_perm &= ~ACL_READ_DATA;
 585                                         previous->ae_perm &= ~ACL_READ_DATA;
 586                                 }
 587
 588                                 if (extramode & WRITE) {
 589                                         entry->ae_perm &=
 590                                             ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
 591                                         previous->ae_perm &=
 592                                             ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
 593                                 }
 594
 595                                 if (extramode & EXEC) {
 596                                         entry->ae_perm &= ~ACL_EXECUTE;
 597                                         previous->ae_perm &= ~ACL_EXECUTE;
 598                                 }
 599                         }
 600                 }
 601         }
 602
 603         /*
 604          * 2. If there at least six ACEs, the final six ACEs are examined.
 605          *    If they are not equal to what we want, append six ACEs.
 606          */
 607         must_append = 0;
 608         if (aclp->acl_cnt < 6) {
 609                 must_append = 1;
 610         } else {
 611                 a6 = &(aclp->acl_entry[aclp->acl_cnt - 1]);
 612                 a5 = &(aclp->acl_entry[aclp->acl_cnt - 2]);
 613                 a4 = &(aclp->acl_entry[aclp->acl_cnt - 3]);
 614                 a3 = &(aclp->acl_entry[aclp->acl_cnt - 4]);
 615                 a2 = &(aclp->acl_entry[aclp->acl_cnt - 5]);
 616                 a1 = &(aclp->acl_entry[aclp->acl_cnt - 6]);
 617
 618                 if (!_acl_entry_matches(a1, ACL_USER_OBJ, 0,
 619                     ACL_ENTRY_TYPE_DENY))
 620                         must_append = 1;
 621                 if (!_acl_entry_matches(a2, ACL_USER_OBJ, ACL_WRITE_ACL |
 622                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 623                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW))
 624                         must_append = 1;
 625                 if (!_acl_entry_matches(a3, ACL_GROUP_OBJ, 0,
 626                     ACL_ENTRY_TYPE_DENY))
 627                         must_append = 1;
 628                 if (!_acl_entry_matches(a4, ACL_GROUP_OBJ, 0,
 629                     ACL_ENTRY_TYPE_ALLOW))
 630                         must_append = 1;
 631                 if (!_acl_entry_matches(a5, ACL_EVERYONE, ACL_WRITE_ACL |
 632                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 633                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY))
 634                         must_append = 1;
 635                 if (!_acl_entry_matches(a6, ACL_EVERYONE, ACL_READ_ACL |
 636                     ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
 637                     ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW))
 638                         must_append = 1;
 639         }
 640
 641         if (must_append) {
 642                 KASSERT(aclp->acl_cnt + 6 <= ACL_MAX_ENTRIES,
 643                     ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 644
 645                 a1 = _acl_append(aclp, ACL_USER_OBJ, 0, ACL_ENTRY_TYPE_DENY);
 646                 a2 = _acl_append(aclp, ACL_USER_OBJ, ACL_WRITE_ACL |
 647                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 648                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW);
 649                 a3 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_DENY);
 650                 a4 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_ALLOW);
 651                 a5 = _acl_append(aclp, ACL_EVERYONE, ACL_WRITE_ACL |
 652                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 653                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY);
 654                 a6 = _acl_append(aclp, ACL_EVERYONE, ACL_READ_ACL |
 655                     ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
 656                     ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW);
 657
 658                 KASSERT(a1 != NULL && a2 != NULL && a3 != NULL && a4 != NULL &&
 659                     a5 != NULL && a6 != NULL, ("couldn't append to ACL."));
 660         }
 661
 662         /*
 663          * 3. The final six ACEs are adjusted according to the incoming mode.
 664          */
 665         if (mode & S_IRUSR)
 666                 a2->ae_perm |= ACL_READ_DATA;
 667         else
 668                 a1->ae_perm |= ACL_READ_DATA;
 669         if (mode & S_IWUSR)
 670                 a2->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 671         else
 672                 a1->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 673         if (mode & S_IXUSR)
 674                 a2->ae_perm |= ACL_EXECUTE;
 675         else
 676                 a1->ae_perm |= ACL_EXECUTE;
 677
 678         if (mode & S_IRGRP)
 679                 a4->ae_perm |= ACL_READ_DATA;
 680         else
 681                 a3->ae_perm |= ACL_READ_DATA;
 682         if (mode & S_IWGRP)
 683                 a4->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 684         else
 685                 a3->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 686         if (mode & S_IXGRP)
 687                 a4->ae_perm |= ACL_EXECUTE;
 688         else
 689                 a3->ae_perm |= ACL_EXECUTE;
 690
 691         if (mode & S_IROTH)
 692                 a6->ae_perm |= ACL_READ_DATA;
 693         else
 694                 a5->ae_perm |= ACL_READ_DATA;
 695         if (mode & S_IWOTH)
 696                 a6->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 697         else
 698                 a5->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 699         if (mode & S_IXOTH)
 700                 a6->ae_perm |= ACL_EXECUTE;
 701         else
 702                 a5->ae_perm |= ACL_EXECUTE;
 703 }
 704
 705 #ifdef _KERNEL
 706 void
 707 acl_nfs4_sync_acl_from_mode(struct acl *aclp, mode_t mode,
 708     int file_owner_id)
 709 {
 710
 711         if (acl_nfs4_old_semantics)
 712                 acl_nfs4_sync_acl_from_mode_draft(aclp, mode, file_owner_id);
 713         else
 714                 acl_nfs4_trivial_from_mode(aclp, mode);
 715 }
 716 #endif /* _KERNEL */
 717
 718 void
 719 acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp)
 720 {
 721         int i;
 722         mode_t old_mode = *_mode, mode = 0, seen = 0;
 723         const struct acl_entry *entry;
 724
 725         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
 726             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 727
 728         /*
 729          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 730          *
 731          * 3.16.6.1. Recomputing mode upon SETATTR of ACL
 732          */
 733
 734         for (i = 0; i < aclp->acl_cnt; i++) {
 735                 entry = &(aclp->acl_entry[i]);
 736
 737                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 738                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 739                         continue;
 740
 741                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
 742                         continue;
 743
 744                 if (entry->ae_tag == ACL_USER_OBJ) {
 745                         if ((entry->ae_perm & ACL_READ_DATA) &&
 746                             ((seen & S_IRUSR) == 0)) {
 747                                 seen |= S_IRUSR;
 748                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 749                                         mode |= S_IRUSR;
 750                         }
 751                         if ((entry->ae_perm & ACL_WRITE_DATA) &&
 752                              ((seen & S_IWUSR) == 0)) {
 753                                 seen |= S_IWUSR;
 754                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 755                                         mode |= S_IWUSR;
 756                         }
 757                         if ((entry->ae_perm & ACL_EXECUTE) &&
 758                             ((seen & S_IXUSR) == 0)) {
 759                                 seen |= S_IXUSR;
 760                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 761                                         mode |= S_IXUSR;
 762                         }
 763                 } else if (entry->ae_tag == ACL_GROUP_OBJ) {
 764                         if ((entry->ae_perm & ACL_READ_DATA) &&
 765                             ((seen & S_IRGRP) == 0)) {
 766                                 seen |= S_IRGRP;
 767                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 768                                         mode |= S_IRGRP;
 769                         }
 770                         if ((entry->ae_perm & ACL_WRITE_DATA) &&
 771                             ((seen & S_IWGRP) == 0)) {
 772                                 seen |= S_IWGRP;
 773                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 774                                         mode |= S_IWGRP;
 775                         }
 776                         if ((entry->ae_perm & ACL_EXECUTE) &&
 777                             ((seen & S_IXGRP) == 0)) {
 778                                 seen |= S_IXGRP;
 779                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 780                                         mode |= S_IXGRP;
 781                         }
 782                 } else if (entry->ae_tag == ACL_EVERYONE) {
 783                         if (entry->ae_perm & ACL_READ_DATA) {
 784                                 if ((seen & S_IRUSR) == 0) {
 785                                         seen |= S_IRUSR;
 786                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 787                                                 mode |= S_IRUSR;
 788                                 }
 789                                 if ((seen & S_IRGRP) == 0) {
 790                                         seen |= S_IRGRP;
 791                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 792                                                 mode |= S_IRGRP;
 793                                 }
 794                                 if ((seen & S_IROTH) == 0) {
 795                                         seen |= S_IROTH;
 796                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 797                                                 mode |= S_IROTH;
 798                                 }
 799                         }
 800                         if (entry->ae_perm & ACL_WRITE_DATA) {
 801                                 if ((seen & S_IWUSR) == 0) {
 802                                         seen |= S_IWUSR;
 803                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 804                                                 mode |= S_IWUSR;
 805                                 }
 806                                 if ((seen & S_IWGRP) == 0) {
 807                                         seen |= S_IWGRP;
 808                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 809                                                 mode |= S_IWGRP;
 810                                 }
 811                                 if ((seen & S_IWOTH) == 0) {
 812                                         seen |= S_IWOTH;
 813                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 814                                                 mode |= S_IWOTH;
 815                                 }
 816                         }
 817                         if (entry->ae_perm & ACL_EXECUTE) {
 818                                 if ((seen & S_IXUSR) == 0) {
 819                                         seen |= S_IXUSR;
 820                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 821                                                 mode |= S_IXUSR;
 822                                 }
 823                                 if ((seen & S_IXGRP) == 0) {
 824                                         seen |= S_IXGRP;
 825                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 826                                                 mode |= S_IXGRP;
 827                                 }
 828                                 if ((seen & S_IXOTH) == 0) {
 829                                         seen |= S_IXOTH;
 830                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 831                                                 mode |= S_IXOTH;
 832                                 }
 833                         }
 834                 }
 835         }
 836
 837         *_mode = mode | (old_mode & ACL_PRESERVE_MASK);
 838 }
 839
 840 #ifdef _KERNEL
 841 /*
 842  * Calculate inherited ACL in a manner compatible with NFSv4 Minor Version 1,
 843  * draft-ietf-nfsv4-minorversion1-03.txt.
 844  */
 845 static void
 846 acl_nfs4_compute_inherited_acl_draft(const struct acl *parent_aclp,
 847     struct acl *child_aclp, mode_t mode, int file_owner_id,
 848     int is_directory)
 849 {
 850         int i, flags;
 851         const struct acl_entry *parent_entry;
 852         struct acl_entry *entry, *copy;
 853
 854         KASSERT(child_aclp->acl_cnt == 0, ("child_aclp->acl_cnt == 0"));
 855         KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
 856             ("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 857
 858         /*
 859          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 860          *
 861          * 3.16.6.2. Applying the mode given to CREATE or OPEN
 862          *           to an inherited ACL
 863          */
 864
 865         /*
 866          * 1. Form an ACL that is the concatenation of all inheritable ACEs.
 867          */
 868         for (i = 0; i < parent_aclp->acl_cnt; i++) {
 869                 parent_entry = &(parent_aclp->acl_entry[i]);
 870                 flags = parent_entry->ae_flags;
 871
 872                 /*
 873                  * Entry is not inheritable at all.
 874                  */
 875                 if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
 876                     ACL_ENTRY_FILE_INHERIT)) == 0)
 877                         continue;
 878
 879                 /*
 880                  * We're creating a file, but entry is not inheritable
 881                  * by files.
 882                  */
 883                 if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
 884                         continue;
 885
 886                 /*
 887                  * Entry is inheritable only by files, but has NO_PROPAGATE
 888                  * flag set, and we're creating a directory, so it wouldn't
 889                  * propagate to any file in that directory anyway.
 890                  */
 891                 if (is_directory &&
 892                     (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
 893                     (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
 894                         continue;
 895
 896                 KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 897                     ("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 898                 child_aclp->acl_entry[child_aclp->acl_cnt] = *parent_entry;
 899                 child_aclp->acl_cnt++;
 900         }
 901
 902         /*
 903          * 2. For each entry in the new ACL, adjust its flags, possibly
 904          *    creating two entries in place of one.
 905          */
 906         for (i = 0; i < child_aclp->acl_cnt; i++) {
 907                 entry = &(child_aclp->acl_entry[i]);
 908
 909                 /*
 910                  * This is not in the specification, but SunOS
 911                  * apparently does that.
 912                  */
 913                 if (((entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT) ||
 914                     !is_directory) &&
 915                     entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 916                         entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
 917
 918                 /*
 919                  * 2.A. If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if the object
 920                  *      being created is not a directory, then clear the
 921                  *      following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
 922                  *      ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
 923                  *      ACL_ENTRY_INHERIT_ONLY.
 924                  */
 925                 if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
 926                     !is_directory) {
 927                         entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
 928                         ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
 929                         ACL_ENTRY_INHERIT_ONLY);
 930
 931                         /*
 932                          * Continue on to the next ACE.
 933                          */
 934                         continue;
 935                 }
 936
 937                 /*
 938                  * 2.B. If the object is a directory and ACL_ENTRY_FILE_INHERIT
 939                  *      is set, but ACL_ENTRY_NO_PROPAGATE_INHERIT is not set, ensure
 940                  *      that ACL_ENTRY_INHERIT_ONLY is set.  Continue to the
 941                  *      next ACE.  Otherwise...
 942                  */
 943                 /*
 944                  * XXX: Read it again and make sure what does the "otherwise"
 945                  *      apply to.
 946                  */
 947                 if (is_directory &&
 948                     (entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
 949                     ((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
 950                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 951                         continue;
 952                 }
 953
 954                 /*
 955                  * 2.C. If the type of the ACE is neither ALLOW nor deny,
 956                  *      then continue.
 957                  */
 958                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 959                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 960                         continue;
 961
 962                 /*
 963                  * 2.D. Copy the original ACE into a second, adjacent ACE.
 964                  */
 965                 copy = _acl_duplicate_entry(child_aclp, i);
 966
 967                 /*
 968                  * 2.E. On the first ACE, ensure that ACL_ENTRY_INHERIT_ONLY
 969                  *      is set.
 970                  */
 971                 entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 972
 973                 /*
 974                  * 2.F. On the second ACE, clear the following flags:
 975                  *      ACL_ENTRY_NO_PROPAGATE_INHERIT, ACL_ENTRY_FILE_INHERIT,
 976                  *      ACL_ENTRY_DIRECTORY_INHERIT, ACL_ENTRY_INHERIT_ONLY.
 977                  */
 978                 copy->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
 979                     ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
 980                     ACL_ENTRY_INHERIT_ONLY);
 981
 982                 /*
 983                  * 2.G. On the second ACE, if the type is ALLOW,
 984                  *      an implementation MAY clear the following
 985                  *      mask bits: ACL_WRITE_ACL, ACL_WRITE_OWNER.
 986                  */
 987                 if (copy->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 988                         copy->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
 989
 990                 /*
 991                  * Increment the counter to skip the copied entry.
 992                  */
 993                 i++;
 994         }
 995
 996         /*
 997          * 3. To ensure that the mode is honored, apply the algorithm describe
 998          *    in Section 2.16.6.3, using the mode that is to be used for file
 999          *    creation.
1000          */
1001         acl_nfs4_sync_acl_from_mode(child_aclp, mode, file_owner_id);
1002 }
1003 #endif /* _KERNEL */
1004
1005 /*
1006  * Populate the ACL with entries inherited from parent_aclp.
1007  */
1008 static void
1009 acl_nfs4_inherit_entries(const struct acl *parent_aclp,
1010     struct acl *child_aclp, mode_t mode, int file_owner_id,
1011     int is_directory)
1012 {
1013         int i, flags, tag;
1014         const struct acl_entry *parent_entry;
1015         struct acl_entry *entry;
1016
1017         KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
1018             ("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
1019
1020         for (i = 0; i < parent_aclp->acl_cnt; i++) {
1021                 parent_entry = &(parent_aclp->acl_entry[i]);
1022                 flags = parent_entry->ae_flags;
1023                 tag = parent_entry->ae_tag;
1024
1025                 /*
1026                  * Don't inherit owner@, group@, or everyone@ entries.
1027                  */
1028                 if (tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ ||
1029                     tag == ACL_EVERYONE)
1030                         continue;
1031
1032                 /*
1033                  * Entry is not inheritable at all.
1034                  */
1035                 if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
1036                     ACL_ENTRY_FILE_INHERIT)) == 0)
1037                         continue;
1038
1039                 /*
1040                  * We're creating a file, but entry is not inheritable
1041                  * by files.
1042                  */
1043                 if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
1044                         continue;
1045
1046                 /*
1047                  * Entry is inheritable only by files, but has NO_PROPAGATE
1048                  * flag set, and we're creating a directory, so it wouldn't
1049                  * propagate to any file in that directory anyway.
1050                  */
1051                 if (is_directory &&
1052                     (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
1053                     (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
1054                         continue;
1055
1056                 /*
1057                  * Entry qualifies for being inherited.
1058                  */
1059                 KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
1060                     ("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
1061                 entry = &(child_aclp->acl_entry[child_aclp->acl_cnt]);
1062                 *entry = *parent_entry;
1063                 child_aclp->acl_cnt++;
1064
1065                 entry->ae_flags &= ~ACL_ENTRY_INHERIT_ONLY;
1066                 entry->ae_flags |= ACL_ENTRY_INHERITED;
1067
1068                 /*
1069                  * If the type of the ACE is neither ALLOW nor DENY,
1070                  * then leave it as it is and proceed to the next one.
1071                  */
1072                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
1073                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
1074                         continue;
1075
1076                 /*
1077                  * If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if
1078                  * the object being created is not a directory, then clear
1079                  * the following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
1080                  * ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
1081                  * ACL_ENTRY_INHERIT_ONLY.
1082                  */
1083                 if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
1084                     !is_directory) {
1085                         entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
1086                         ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
1087                         ACL_ENTRY_INHERIT_ONLY);
1088                 }
1089
1090                 /*
1091                  * If the object is a directory and ACL_ENTRY_FILE_INHERIT
1092                  * is set, but ACL_ENTRY_DIRECTORY_INHERIT is not set, ensure
1093                  * that ACL_ENTRY_INHERIT_ONLY is set.
1094                  */
1095                 if (is_directory &&
1096                     (entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
1097                     ((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
1098                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
1099                 }
1100
1101                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW &&
1102                     (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY) == 0) {
1103                         /*
1104                          * Some permissions must never be inherited.
1105                          */
1106                         entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER |
1107                             ACL_WRITE_NAMED_ATTRS | ACL_WRITE_ATTRIBUTES);
1108
1109                         /*
1110                          * Others must be masked according to the file mode.
1111                          */
1112                         if ((mode & S_IRGRP) == 0)
1113                                 entry->ae_perm &= ~ACL_READ_DATA;
1114                         if ((mode & S_IWGRP) == 0)
1115                                 entry->ae_perm &=
1116                                     ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
1117                         if ((mode & S_IXGRP) == 0)
1118                                 entry->ae_perm &= ~ACL_EXECUTE;
1119                 }
1120         }
1121 }
1122
1123 /*
1124  * Calculate inherited ACL in a manner compatible with PSARC/2010/029.
1125  * It's also being used to calculate a trivial ACL, by inheriting from
1126  * a NULL ACL.
1127  */
1128 static void
1129 acl_nfs4_compute_inherited_acl_psarc(const struct acl *parent_aclp,
1130     struct acl *aclp, mode_t mode, int file_owner_id, int is_directory)
1131 {
1132         acl_perm_t user_allow_first = 0, user_deny = 0, group_deny = 0;
1133         acl_perm_t user_allow, group_allow, everyone_allow;
1134
1135         KASSERT(aclp->acl_cnt == 0, ("aclp->acl_cnt == 0"));
1136
1137         user_allow = group_allow = everyone_allow = ACL_READ_ACL |
1138             ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS | ACL_SYNCHRONIZE;
1139         user_allow |= ACL_WRITE_ACL | ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
1140             ACL_WRITE_NAMED_ATTRS;
1141
1142         if (mode & S_IRUSR)
1143                 user_allow |= ACL_READ_DATA;
1144         if (mode & S_IWUSR)
1145                 user_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1146         if (mode & S_IXUSR)
1147                 user_allow |= ACL_EXECUTE;
1148
1149         if (mode & S_IRGRP)
1150                 group_allow |= ACL_READ_DATA;
1151         if (mode & S_IWGRP)
1152                 group_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1153         if (mode & S_IXGRP)
1154                 group_allow |= ACL_EXECUTE;
1155
1156         if (mode & S_IROTH)
1157                 everyone_allow |= ACL_READ_DATA;
1158         if (mode & S_IWOTH)
1159                 everyone_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1160         if (mode & S_IXOTH)
1161                 everyone_allow |= ACL_EXECUTE;
1162
1163         user_deny = ((group_allow | everyone_allow) & ~user_allow);
1164         group_deny = everyone_allow & ~group_allow;
1165         user_allow_first = group_deny & ~user_deny;
1166
1167         if (user_allow_first != 0)
1168                 _acl_append(aclp, ACL_USER_OBJ, user_allow_first,
1169                     ACL_ENTRY_TYPE_ALLOW);
1170         if (user_deny != 0)
1171                 _acl_append(aclp, ACL_USER_OBJ, user_deny,
1172                     ACL_ENTRY_TYPE_DENY);
1173         if (group_deny != 0)
1174                 _acl_append(aclp, ACL_GROUP_OBJ, group_deny,
1175                     ACL_ENTRY_TYPE_DENY);
1176
1177         if (parent_aclp != NULL)
1178                 acl_nfs4_inherit_entries(parent_aclp, aclp, mode,
1179                     file_owner_id, is_directory);
1180
1181         _acl_append(aclp, ACL_USER_OBJ, user_allow, ACL_ENTRY_TYPE_ALLOW);
1182         _acl_append(aclp, ACL_GROUP_OBJ, group_allow, ACL_ENTRY_TYPE_ALLOW);
1183         _acl_append(aclp, ACL_EVERYONE, everyone_allow, ACL_ENTRY_TYPE_ALLOW);
1184 }
1185
1186 #ifdef _KERNEL
1187 void
1188 acl_nfs4_compute_inherited_acl(const struct acl *parent_aclp,
1189     struct acl *child_aclp, mode_t mode, int file_owner_id,
1190     int is_directory)
1191 {
1192
1193         if (acl_nfs4_old_semantics)
1194                 acl_nfs4_compute_inherited_acl_draft(parent_aclp, child_aclp,
1195                     mode, file_owner_id, is_directory);
1196         else
1197                 acl_nfs4_compute_inherited_acl_psarc(parent_aclp, child_aclp,
1198                     mode, file_owner_id, is_directory);
1199 }
1200 #endif /* _KERNEL */
1201
1202 /*
1203  * Calculate trivial ACL in a manner compatible with PSARC/2010/029.
1204  * Note that this results in an ACL different from (but semantically
1205  * equal to) the "canonical six" trivial ACL computed using algorithm
1206  * described in draft-ietf-nfsv4-minorversion1-03.txt, 3.16.6.2.
1207  */
1208 static void
1209 acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode)
1210 {
1211
1212         aclp->acl_cnt = 0;
1213         acl_nfs4_compute_inherited_acl_psarc(NULL, aclp, mode, -1, -1);
1214 }
1215
1216 #ifndef _KERNEL
1217 /*
1218  * This routine is used by libc to implement acl_strip_np(3)
1219  * and acl_is_trivial_np(3).
1220  */
1221 void
1222 acl_nfs4_trivial_from_mode_libc(struct acl *aclp, int mode, int canonical_six)
1223 {
1224
1225         aclp->acl_cnt = 0;
1226         if (canonical_six)
1227                 acl_nfs4_sync_acl_from_mode_draft(aclp, mode, -1);
1228         else
1229                 acl_nfs4_trivial_from_mode(aclp, mode);
1230 }
1231 #endif /* !_KERNEL */
1232
1233 #ifdef _KERNEL
1234 static int
1235 _acls_are_equal(const struct acl *a, const struct acl *b)
1236 {
1237         int i;
1238         const struct acl_entry *entrya, *entryb;
1239
1240         if (a->acl_cnt != b->acl_cnt)
1241                 return (0);
1242
1243         for (i = 0; i < b->acl_cnt; i++) {
1244                 entrya = &(a->acl_entry[i]);
1245                 entryb = &(b->acl_entry[i]);
1246
1247                 if (entrya->ae_tag != entryb->ae_tag ||
1248                     entrya->ae_id != entryb->ae_id ||
1249                     entrya->ae_perm != entryb->ae_perm ||
1250                     entrya->ae_entry_type != entryb->ae_entry_type ||
1251                     entrya->ae_flags != entryb->ae_flags)
1252                         return (0);
1253         }
1254
1255         return (1);
1256 }
1257
1258 /*
1259  * This routine is used to determine whether to remove extended attribute
1260  * that stores ACL contents.
1261  */
1262 int
1263 acl_nfs4_is_trivial(const struct acl *aclp, int file_owner_id)
1264 {
1265         int trivial;
1266         mode_t tmpmode = 0;
1267         struct acl *tmpaclp;
1268
1269         if (aclp->acl_cnt > 6)
1270                 return (0);
1271
1272         /*
1273          * Compute the mode from the ACL, then compute new ACL from that mode.
1274          * If the ACLs are identical, then the ACL is trivial.
1275          *
1276          * XXX: I guess there is a faster way to do this.  However, even
1277          *      this slow implementation significantly speeds things up
1278          *      for files that don't have non-trivial ACLs - it's critical
1279          *      for performance to not use EA when they are not needed.
1280          *
1281          * First try the PSARC/2010/029 semantics.
1282          */
1283         tmpaclp = acl_alloc(M_WAITOK | M_ZERO);
1284         acl_nfs4_sync_mode_from_acl(&tmpmode, aclp);
1285         acl_nfs4_trivial_from_mode(tmpaclp, tmpmode);
1286         trivial = _acls_are_equal(aclp, tmpaclp);
1287         if (trivial) {
1288                 acl_free(tmpaclp);
1289                 return (trivial);
1290         }
1291
1292         /*
1293          * Check if it's a draft-ietf-nfsv4-minorversion1-03.txt trivial ACL.
1294          */
1295         tmpaclp->acl_cnt = 0;
1296         acl_nfs4_sync_acl_from_mode_draft(tmpaclp, tmpmode, file_owner_id);
1297         trivial = _acls_are_equal(aclp, tmpaclp);
1298         acl_free(tmpaclp);
1299
1300         return (trivial);
1301 }
1302 #endif /* _KERNEL */
1303
1304 int
1305 acl_nfs4_check(const struct acl *aclp, int is_directory)
1306 {
1307         int i;
1308         const struct acl_entry *entry;
1309
1310         /*
1311          * The spec doesn't seem to say anything about ACL validity.
1312          * It seems there is not much to do here.  There is even no need
1313          * to count "owner@" or "everyone@" (ACL_USER_OBJ and ACL_EVERYONE)
1314          * entries, as there can be several of them and that's perfectly
1315          * valid.  There can be none of them too.  Really.
1316          */
1317
1318         if (aclp->acl_cnt > ACL_MAX_ENTRIES || aclp->acl_cnt <= 0)
1319                 return (EINVAL);
1320
1321         for (i = 0; i < aclp->acl_cnt; i++) {
1322                 entry = &(aclp->acl_entry[i]);
1323
1324                 switch (entry->ae_tag) {
1325                 case ACL_USER_OBJ:
1326                 case ACL_GROUP_OBJ:
1327                 case ACL_EVERYONE:
1328                         if (entry->ae_id != ACL_UNDEFINED_ID)
1329                                 return (EINVAL);
1330                         break;
1331
1332                 case ACL_USER:
1333                 case ACL_GROUP:
1334                         if (entry->ae_id == ACL_UNDEFINED_ID)
1335                                 return (EINVAL);
1336                         break;
1337
1338                 default:
1339                         return (EINVAL);
1340                 }
1341
1342                 if ((entry->ae_perm | ACL_NFS4_PERM_BITS) != ACL_NFS4_PERM_BITS)
1343                         return (EINVAL);
1344
1345                 /*
1346                  * Disallow ACL_ENTRY_TYPE_AUDIT and ACL_ENTRY_TYPE_ALARM for now.
1347                  */
1348                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
1349                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
1350                         return (EINVAL);
1351
1352                 if ((entry->ae_flags | ACL_FLAGS_BITS) != ACL_FLAGS_BITS)
1353                         return (EINVAL);
1354
1355                 /* Disallow unimplemented flags. */
1356                 if (entry->ae_flags & (ACL_ENTRY_SUCCESSFUL_ACCESS |
1357                     ACL_ENTRY_FAILED_ACCESS))
1358                         return (EINVAL);
1359
1360                 /* Disallow flags not allowed for ordinary files. */
1361                 if (!is_directory) {
1362                         if (entry->ae_flags & (ACL_ENTRY_FILE_INHERIT |
1363                             ACL_ENTRY_DIRECTORY_INHERIT |
1364                             ACL_ENTRY_NO_PROPAGATE_INHERIT | ACL_ENTRY_INHERIT_ONLY))
1365                                 return (EINVAL);
1366                 }
1367         }
1368
1369         return (0);
1370 }
1371
1372 #ifdef  _KERNEL
1373 static int
1374 acl_nfs4_modload(module_t module, int what, void *arg)
1375 {
1376         int ret;
1377
1378         ret = 0;
1379
1380         switch (what) {
1381         case MOD_LOAD:
1382         case MOD_SHUTDOWN:
1383                 break;
1384
1385         case MOD_QUIESCE:
1386                 /* XXX TODO */
1387                 ret = 0;
1388                 break;
1389
1390         case MOD_UNLOAD:
1391                 /* XXX TODO */
1392                 ret = 0;
1393                 break;
1394         default:
1395                 ret = EINVAL;
1396                 break;
1397         }
1398
1399         return (ret);
1400 }
1401
1402 static moduledata_t acl_nfs4_mod = {
1403         "acl_nfs4",
1404         acl_nfs4_modload,
1405         NULL
1406 };
1407
1408 /*
1409  * XXX TODO: which subsystem, order?
1410  */
1411 DECLARE_MODULE(acl_nfs4, acl_nfs4_mod, SI_SUB_VFS, SI_ORDER_FIRST);
1412 MODULE_VERSION(acl_nfs4, 1);
1413 #endif  /* _KERNEL */