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  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 /*
  30  * ACL support routines specific to NFSv4 access control lists.  These are
  31  * utility routines for code common across file systems implementing NFSv4
  32  * ACLs.
  33  */
  34
  35 #ifdef _KERNEL
  36 #include <sys/cdefs.h>
  37 __FBSDID("$FreeBSD$");
  38
  39 #include <sys/param.h>
  40 #include <sys/kernel.h>
  41 #include <sys/module.h>
  42 #include <sys/systm.h>
  43 #include <sys/mount.h>
  44 #include <sys/priv.h>
  45 #include <sys/vnode.h>
  46 #include <sys/errno.h>
  47 #include <sys/stat.h>
  48 #include <sys/sysctl.h>
  49 #include <sys/acl.h>
  50 #else
  51 #include <errno.h>
  52 #include <assert.h>
  53 #include <sys/acl.h>
  54 #include <sys/stat.h>
  55 #define KASSERT(a, b) assert(a)
  56 #define CTASSERT(a)
  57
  58 #endif /* !_KERNEL */
  59
  60 #ifdef _KERNEL
  61
  62 static void     acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode);
  63
  64 static int      acl_nfs4_old_semantics = 0;
  65
  66 SYSCTL_INT(_vfs, OID_AUTO, acl_nfs4_old_semantics, CTLFLAG_RW,
  67     &acl_nfs4_old_semantics, 0, "Use pre-PSARC/2010/029 NFSv4 ACL semantics");
  68
  69 static struct {
  70         accmode_t accmode;
  71         int mask;
  72 } accmode2mask[] = {{VREAD, ACL_READ_DATA},
  73                     {VWRITE, ACL_WRITE_DATA},
  74                     {VAPPEND, ACL_APPEND_DATA},
  75                     {VEXEC, ACL_EXECUTE},
  76                     {VREAD_NAMED_ATTRS, ACL_READ_NAMED_ATTRS},
  77                     {VWRITE_NAMED_ATTRS, ACL_WRITE_NAMED_ATTRS},
  78                     {VDELETE_CHILD, ACL_DELETE_CHILD},
  79                     {VREAD_ATTRIBUTES, ACL_READ_ATTRIBUTES},
  80                     {VWRITE_ATTRIBUTES, ACL_WRITE_ATTRIBUTES},
  81                     {VDELETE, ACL_DELETE},
  82                     {VREAD_ACL, ACL_READ_ACL},
  83                     {VWRITE_ACL, ACL_WRITE_ACL},
  84                     {VWRITE_OWNER, ACL_WRITE_OWNER},
  85                     {VSYNCHRONIZE, ACL_SYNCHRONIZE},
  86                     {0, 0}};
  87
  88 static int
  89 _access_mask_from_accmode(accmode_t accmode)
  90 {
  91         int access_mask = 0, i;
  92
  93         for (i = 0; accmode2mask[i].accmode != 0; i++) {
  94                 if (accmode & accmode2mask[i].accmode)
  95                         access_mask |= accmode2mask[i].mask;
  96         }
  97
  98         /*
  99          * VAPPEND is just a modifier for VWRITE; if the caller asked
 100          * for 'VAPPEND | VWRITE', we want to check for ACL_APPEND_DATA only.
 101          */
 102         if (access_mask & ACL_APPEND_DATA)
 103                 access_mask &= ~ACL_WRITE_DATA;
 104
 105         return (access_mask);
 106 }
 107
 108 /*
 109  * Return 0, iff access is allowed, 1 otherwise.
 110  */
 111 static int
 112 _acl_denies(const struct acl *aclp, int access_mask, struct ucred *cred,
 113     int file_uid, int file_gid, int *denied_explicitly)
 114 {
 115         int i;
 116         const struct acl_entry *entry;
 117
 118         if (denied_explicitly != NULL)
 119                 *denied_explicitly = 0;
 120
 121         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
 122             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 123
 124         for (i = 0; i < aclp->acl_cnt; i++) {
 125                 entry = &(aclp->acl_entry[i]);
 126
 127                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 128                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 129                         continue;
 130                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
 131                         continue;
 132                 switch (entry->ae_tag) {
 133                 case ACL_USER_OBJ:
 134                         if (file_uid != cred->cr_uid)
 135                                 continue;
 136                         break;
 137                 case ACL_USER:
 138                         if (entry->ae_id != cred->cr_uid)
 139                                 continue;
 140                         break;
 141                 case ACL_GROUP_OBJ:
 142                         if (!groupmember(file_gid, cred))
 143                                 continue;
 144                         break;
 145                 case ACL_GROUP:
 146                         if (!groupmember(entry->ae_id, cred))
 147                                 continue;
 148                         break;
 149                 default:
 150                         KASSERT(entry->ae_tag == ACL_EVERYONE,
 151                             ("entry->ae_tag == ACL_EVERYONE"));
 152                 }
 153
 154                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_DENY) {
 155                         if (entry->ae_perm & access_mask) {
 156                                 if (denied_explicitly != NULL)
 157                                         *denied_explicitly = 1;
 158                                 return (1);
 159                         }
 160                 }
 161
 162                 access_mask &= ~(entry->ae_perm);
 163                 if (access_mask == 0)
 164                         return (0);
 165         }
 166
 167         if (access_mask == 0)
 168                 return (0);
 169
 170         return (1);
 171 }
 172
 173 int
 174 vaccess_acl_nfs4(enum vtype type, uid_t file_uid, gid_t file_gid,
 175     struct acl *aclp, accmode_t accmode, struct ucred *cred)
 176 {
 177         accmode_t priv_granted = 0;
 178         int denied, explicitly_denied, access_mask, is_directory,
 179             must_be_owner = 0;
 180         mode_t file_mode = 0;
 181
 182         KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND |
 183             VEXPLICIT_DENY | VREAD_NAMED_ATTRS | VWRITE_NAMED_ATTRS |
 184             VDELETE_CHILD | VREAD_ATTRIBUTES | VWRITE_ATTRIBUTES | VDELETE |
 185             VREAD_ACL | VWRITE_ACL | VWRITE_OWNER | VSYNCHRONIZE)) == 0,
 186             ("invalid bit in accmode"));
 187         KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
 188                 ("VAPPEND without VWRITE"));
 189
 190         if (accmode & VADMIN)
 191                 must_be_owner = 1;
 192
 193         /*
 194          * Ignore VSYNCHRONIZE permission.
 195          */
 196         accmode &= ~VSYNCHRONIZE;
 197
 198         access_mask = _access_mask_from_accmode(accmode);
 199
 200         if (type == VDIR)
 201                 is_directory = 1;
 202         else
 203                 is_directory = 0;
 204
 205         /*
 206          * File owner is always allowed to read and write the ACL
 207          * and basic attributes.  This is to prevent a situation
 208          * where user would change ACL in a way that prevents him
 209          * from undoing the change.
 210          */
 211         if (file_uid == cred->cr_uid)
 212                 access_mask &= ~(ACL_READ_ACL | ACL_WRITE_ACL |
 213                     ACL_READ_ATTRIBUTES | ACL_WRITE_ATTRIBUTES);
 214
 215         /*
 216          * Ignore append permission for regular files; use write
 217          * permission instead.
 218          */
 219         if (!is_directory && (access_mask & ACL_APPEND_DATA)) {
 220                 access_mask &= ~ACL_APPEND_DATA;
 221                 access_mask |= ACL_WRITE_DATA;
 222         }
 223
 224         denied = _acl_denies(aclp, access_mask, cred, file_uid, file_gid,
 225             &explicitly_denied);
 226
 227         if (must_be_owner) {
 228                 if (file_uid != cred->cr_uid)
 229                         denied = EPERM;
 230         }
 231
 232         /*
 233          * For VEXEC, ensure that at least one execute bit is set for
 234          * non-directories. We have to check the mode here to stay
 235          * consistent with execve(2). See the test in
 236          * exec_check_permissions().
 237          */
 238         acl_nfs4_sync_mode_from_acl(&file_mode, aclp);
 239         if (!denied && !is_directory && (accmode & VEXEC) &&
 240             (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)
 241                 denied = EACCES;
 242
 243         if (!denied)
 244                 return (0);
 245
 246         /*
 247          * Access failed.  Iff it was not denied explicitly and
 248          * VEXPLICIT_DENY flag was specified, allow access.
 249          */
 250         if ((accmode & VEXPLICIT_DENY) && explicitly_denied == 0)
 251                 return (0);
 252
 253         accmode &= ~VEXPLICIT_DENY;
 254
 255         /*
 256          * No match.  Try to use privileges, if there are any.
 257          */
 258         if (is_directory) {
 259                 if ((accmode & VEXEC) && !priv_check_cred(cred, PRIV_VFS_LOOKUP))
 260                         priv_granted |= VEXEC;
 261         } else {
 262                 /*
 263                  * Ensure that at least one execute bit is on. Otherwise,
 264                  * a privileged user will always succeed, and we don't want
 265                  * this to happen unless the file really is executable.
 266                  */
 267                 if ((accmode & VEXEC) && (file_mode &
 268                     (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
 269                     !priv_check_cred(cred, PRIV_VFS_EXEC))
 270                         priv_granted |= VEXEC;
 271         }
 272
 273         if ((accmode & VREAD) && !priv_check_cred(cred, PRIV_VFS_READ))
 274                 priv_granted |= VREAD;
 275
 276         if ((accmode & (VWRITE | VAPPEND | VDELETE_CHILD)) &&
 277             !priv_check_cred(cred, PRIV_VFS_WRITE))
 278                 priv_granted |= (VWRITE | VAPPEND | VDELETE_CHILD);
 279
 280         if ((accmode & VADMIN_PERMS) &&
 281             !priv_check_cred(cred, PRIV_VFS_ADMIN))
 282                 priv_granted |= VADMIN_PERMS;
 283
 284         if ((accmode & VSTAT_PERMS) &&
 285             !priv_check_cred(cred, PRIV_VFS_STAT))
 286                 priv_granted |= VSTAT_PERMS;
 287
 288         if ((accmode & priv_granted) == accmode) {
 289                 return (0);
 290         }
 291
 292         if (accmode & (VADMIN_PERMS | VDELETE_CHILD | VDELETE))
 293                 denied = EPERM;
 294         else
 295                 denied = EACCES;
 296
 297         return (denied);
 298 }
 299 #endif /* _KERNEL */
 300
 301 static int
 302 _acl_entry_matches(struct acl_entry *entry, acl_tag_t tag, acl_perm_t perm,
 303     acl_entry_type_t entry_type)
 304 {
 305         if (entry->ae_tag != tag)
 306                 return (0);
 307
 308         if (entry->ae_id != ACL_UNDEFINED_ID)
 309                 return (0);
 310
 311         if (entry->ae_perm != perm)
 312                 return (0);
 313
 314         if (entry->ae_entry_type != entry_type)
 315                 return (0);
 316
 317         if (entry->ae_flags != 0)
 318                 return (0);
 319
 320         return (1);
 321 }
 322
 323 static struct acl_entry *
 324 _acl_append(struct acl *aclp, acl_tag_t tag, acl_perm_t perm,
 325     acl_entry_type_t entry_type)
 326 {
 327         struct acl_entry *entry;
 328
 329         KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 330             ("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 331
 332         entry = &(aclp->acl_entry[aclp->acl_cnt]);
 333         aclp->acl_cnt++;
 334
 335         entry->ae_tag = tag;
 336         entry->ae_id = ACL_UNDEFINED_ID;
 337         entry->ae_perm = perm;
 338         entry->ae_entry_type = entry_type;
 339         entry->ae_flags = 0;
 340
 341         return (entry);
 342 }
 343
 344 static struct acl_entry *
 345 _acl_duplicate_entry(struct acl *aclp, unsigned entry_index)
 346 {
 347         unsigned i;
 348
 349         KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 350             ("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 351
 352         for (i = aclp->acl_cnt; i > entry_index; i--)
 353                 aclp->acl_entry[i] = aclp->acl_entry[i - 1];
 354
 355         aclp->acl_cnt++;
 356
 357         return (&(aclp->acl_entry[entry_index + 1]));
 358 }
 359
 360 static void
 361 acl_nfs4_sync_acl_from_mode_draft(struct acl *aclp, mode_t mode,
 362     int file_owner_id)
 363 {
 364         int meets, must_append;
 365         unsigned i;
 366         struct acl_entry *entry, *copy, *previous,
 367             *a1, *a2, *a3, *a4, *a5, *a6;
 368         mode_t amode;
 369         const int READ = 04;
 370         const int WRITE = 02;
 371         const int EXEC = 01;
 372
 373         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
 374             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 375
 376         /*
 377          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 378          *
 379          * 3.16.6.3. Applying a Mode to an Existing ACL
 380          */
 381
 382         /*
 383          * 1. For each ACE:
 384          */
 385         for (i = 0; i < aclp->acl_cnt; i++) {
 386                 entry = &(aclp->acl_entry[i]);
 387
 388                 /*
 389                  * 1.1. If the type is neither ALLOW or DENY - skip.
 390                  */
 391                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 392                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 393                         continue;
 394
 395                 /*
 396                  * 1.2. If ACL_ENTRY_INHERIT_ONLY is set - skip.
 397                  */
 398                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
 399                         continue;
 400
 401                 /*
 402                  * 1.3. If ACL_ENTRY_FILE_INHERIT or ACL_ENTRY_DIRECTORY_INHERIT
 403                  *      are set:
 404                  */
 405                 if (entry->ae_flags &
 406                     (ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT)) {
 407                         /*
 408                          * 1.3.1. A copy of the current ACE is made, and placed
 409                          *        in the ACL immediately following the current
 410                          *        ACE.
 411                          */
 412                         copy = _acl_duplicate_entry(aclp, i);
 413
 414                         /*
 415                          * 1.3.2. In the first ACE, the flag
 416                          *        ACL_ENTRY_INHERIT_ONLY is set.
 417                          */
 418                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 419
 420                         /*
 421                          * 1.3.3. In the second ACE, the following flags
 422                          *        are cleared:
 423                          *        ACL_ENTRY_FILE_INHERIT,
 424                          *        ACL_ENTRY_DIRECTORY_INHERIT,
 425                          *        ACL_ENTRY_NO_PROPAGATE_INHERIT.
 426                          */
 427                         copy->ae_flags &= ~(ACL_ENTRY_FILE_INHERIT |
 428                             ACL_ENTRY_DIRECTORY_INHERIT |
 429                             ACL_ENTRY_NO_PROPAGATE_INHERIT);
 430
 431                         /*
 432                          * The algorithm continues on with the second ACE.
 433                          */
 434                         i++;
 435                         entry = copy;
 436                 }
 437
 438                 /*
 439                  * 1.4. If it's owner@, group@ or everyone@ entry, clear
 440                  *      ACL_READ_DATA, ACL_WRITE_DATA, ACL_APPEND_DATA
 441                  *      and ACL_EXECUTE.  Continue to the next entry.
 442                  */
 443                 if (entry->ae_tag == ACL_USER_OBJ ||
 444                     entry->ae_tag == ACL_GROUP_OBJ ||
 445                     entry->ae_tag == ACL_EVERYONE) {
 446                         entry->ae_perm &= ~(ACL_READ_DATA | ACL_WRITE_DATA |
 447                             ACL_APPEND_DATA | ACL_EXECUTE);
 448                         continue;
 449                 }
 450
 451                 /*
 452                  * 1.5. Otherwise, if the "who" field did not match one
 453                  *      of OWNER@, GROUP@, EVERYONE@:
 454                  *
 455                  * 1.5.1. If the type is ALLOW, check the preceding ACE.
 456                  *        If it does not meet all of the following criteria:
 457                  */
 458                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW)
 459                         continue;
 460
 461                 meets = 0;
 462                 if (i > 0) {
 463                         meets = 1;
 464                         previous = &(aclp->acl_entry[i - 1]);
 465
 466                         /*
 467                          * 1.5.1.1. The type field is DENY,
 468                          */
 469                         if (previous->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 470                                 meets = 0;
 471
 472                         /*
 473                          * 1.5.1.2. The "who" field is the same as the current
 474                          *          ACE,
 475                          *
 476                          * 1.5.1.3. The flag bit ACE4_IDENTIFIER_GROUP
 477                          *          is the same as it is in the current ACE,
 478                          *          and no other flag bits are set,
 479                          */
 480                         if (previous->ae_id != entry->ae_id ||
 481                             previous->ae_tag != entry->ae_tag)
 482                                 meets = 0;
 483
 484                         if (previous->ae_flags)
 485                                 meets = 0;
 486
 487                         /*
 488                          * 1.5.1.4. The mask bits are a subset of the mask bits
 489                          *          of the current ACE, and are also subset of
 490                          *          the following: ACL_READ_DATA,
 491                          *          ACL_WRITE_DATA, ACL_APPEND_DATA, ACL_EXECUTE
 492                          */
 493                         if (previous->ae_perm & ~(entry->ae_perm))
 494                                 meets = 0;
 495
 496                         if (previous->ae_perm & ~(ACL_READ_DATA |
 497                             ACL_WRITE_DATA | ACL_APPEND_DATA | ACL_EXECUTE))
 498                                 meets = 0;
 499                 }
 500
 501                 if (!meets) {
 502                         /*
 503                          * Then the ACE of type DENY, with a who equal
 504                          * to the current ACE, flag bits equal to
 505                          * (<current ACE flags> & <ACE_IDENTIFIER_GROUP>)
 506                          * and no mask bits, is prepended.
 507                          */
 508                         previous = entry;
 509                         entry = _acl_duplicate_entry(aclp, i);
 510
 511                         /* Adjust counter, as we've just added an entry. */
 512                         i++;
 513
 514                         previous->ae_tag = entry->ae_tag;
 515                         previous->ae_id = entry->ae_id;
 516                         previous->ae_flags = entry->ae_flags;
 517                         previous->ae_perm = 0;
 518                         previous->ae_entry_type = ACL_ENTRY_TYPE_DENY;
 519                 }
 520
 521                 /*
 522                  * 1.5.2. The following modifications are made to the prepended
 523                  *        ACE.  The intent is to mask the following ACE
 524                  *        to disallow ACL_READ_DATA, ACL_WRITE_DATA,
 525                  *        ACL_APPEND_DATA, or ACL_EXECUTE, based upon the group
 526                  *        permissions of the new mode.  As a special case,
 527                  *        if the ACE matches the current owner of the file,
 528                  *        the owner bits are used, rather than the group bits.
 529                  *        This is reflected in the algorithm below.
 530                  */
 531                 amode = mode >> 3;
 532
 533                 /*
 534                  * If ACE4_IDENTIFIER_GROUP is not set, and the "who" field
 535                  * in ACE matches the owner of the file, we shift amode three
 536                  * more bits, in order to have the owner permission bits
 537                  * placed in the three low order bits of amode.
 538                  */
 539                 if (entry->ae_tag == ACL_USER && entry->ae_id == file_owner_id)
 540                         amode = amode >> 3;
 541
 542                 if (entry->ae_perm & ACL_READ_DATA) {
 543                         if (amode & READ)
 544                                 previous->ae_perm &= ~ACL_READ_DATA;
 545                         else
 546                                 previous->ae_perm |= ACL_READ_DATA;
 547                 }
 548
 549                 if (entry->ae_perm & ACL_WRITE_DATA) {
 550                         if (amode & WRITE)
 551                                 previous->ae_perm &= ~ACL_WRITE_DATA;
 552                         else
 553                                 previous->ae_perm |= ACL_WRITE_DATA;
 554                 }
 555
 556                 if (entry->ae_perm & ACL_APPEND_DATA) {
 557                         if (amode & WRITE)
 558                                 previous->ae_perm &= ~ACL_APPEND_DATA;
 559                         else
 560                                 previous->ae_perm |= ACL_APPEND_DATA;
 561                 }
 562
 563                 if (entry->ae_perm & ACL_EXECUTE) {
 564                         if (amode & EXEC)
 565                                 previous->ae_perm &= ~ACL_EXECUTE;
 566                         else
 567                                 previous->ae_perm |= ACL_EXECUTE;
 568                 }
 569
 570                 /*
 571                  * 1.5.3. If ACE4_IDENTIFIER_GROUP is set in the flags
 572                  *        of the ALLOW ace:
 573                  *
 574                  * XXX: This point is not there in the Falkner's draft.
 575                  */
 576                 if (entry->ae_tag == ACL_GROUP &&
 577                     entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) {
 578                         mode_t extramode, ownermode;
 579                         extramode = (mode >> 3) & 07;
 580                         ownermode = mode >> 6;
 581                         extramode &= ~ownermode;
 582
 583                         if (extramode) {
 584                                 if (extramode & READ) {
 585                                         entry->ae_perm &= ~ACL_READ_DATA;
 586                                         previous->ae_perm &= ~ACL_READ_DATA;
 587                                 }
 588
 589                                 if (extramode & WRITE) {
 590                                         entry->ae_perm &=
 591                                             ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
 592                                         previous->ae_perm &=
 593                                             ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
 594                                 }
 595
 596                                 if (extramode & EXEC) {
 597                                         entry->ae_perm &= ~ACL_EXECUTE;
 598                                         previous->ae_perm &= ~ACL_EXECUTE;
 599                                 }
 600                         }
 601                 }
 602         }
 603
 604         /*
 605          * 2. If there at least six ACEs, the final six ACEs are examined.
 606          *    If they are not equal to what we want, append six ACEs.
 607          */
 608         must_append = 0;
 609         if (aclp->acl_cnt < 6) {
 610                 must_append = 1;
 611         } else {
 612                 a6 = &(aclp->acl_entry[aclp->acl_cnt - 1]);
 613                 a5 = &(aclp->acl_entry[aclp->acl_cnt - 2]);
 614                 a4 = &(aclp->acl_entry[aclp->acl_cnt - 3]);
 615                 a3 = &(aclp->acl_entry[aclp->acl_cnt - 4]);
 616                 a2 = &(aclp->acl_entry[aclp->acl_cnt - 5]);
 617                 a1 = &(aclp->acl_entry[aclp->acl_cnt - 6]);
 618
 619                 if (!_acl_entry_matches(a1, ACL_USER_OBJ, 0,
 620                     ACL_ENTRY_TYPE_DENY))
 621                         must_append = 1;
 622                 if (!_acl_entry_matches(a2, ACL_USER_OBJ, ACL_WRITE_ACL |
 623                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 624                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW))
 625                         must_append = 1;
 626                 if (!_acl_entry_matches(a3, ACL_GROUP_OBJ, 0,
 627                     ACL_ENTRY_TYPE_DENY))
 628                         must_append = 1;
 629                 if (!_acl_entry_matches(a4, ACL_GROUP_OBJ, 0,
 630                     ACL_ENTRY_TYPE_ALLOW))
 631                         must_append = 1;
 632                 if (!_acl_entry_matches(a5, ACL_EVERYONE, ACL_WRITE_ACL |
 633                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 634                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY))
 635                         must_append = 1;
 636                 if (!_acl_entry_matches(a6, ACL_EVERYONE, ACL_READ_ACL |
 637                     ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
 638                     ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW))
 639                         must_append = 1;
 640         }
 641
 642         if (must_append) {
 643                 KASSERT(aclp->acl_cnt + 6 <= ACL_MAX_ENTRIES,
 644                     ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 645
 646                 a1 = _acl_append(aclp, ACL_USER_OBJ, 0, ACL_ENTRY_TYPE_DENY);
 647                 a2 = _acl_append(aclp, ACL_USER_OBJ, ACL_WRITE_ACL |
 648                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 649                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW);
 650                 a3 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_DENY);
 651                 a4 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_ALLOW);
 652                 a5 = _acl_append(aclp, ACL_EVERYONE, ACL_WRITE_ACL |
 653                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 654                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY);
 655                 a6 = _acl_append(aclp, ACL_EVERYONE, ACL_READ_ACL |
 656                     ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
 657                     ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW);
 658
 659                 KASSERT(a1 != NULL && a2 != NULL && a3 != NULL && a4 != NULL &&
 660                     a5 != NULL && a6 != NULL, ("couldn't append to ACL."));
 661         }
 662
 663         /*
 664          * 3. The final six ACEs are adjusted according to the incoming mode.
 665          */
 666         if (mode & S_IRUSR)
 667                 a2->ae_perm |= ACL_READ_DATA;
 668         else
 669                 a1->ae_perm |= ACL_READ_DATA;
 670         if (mode & S_IWUSR)
 671                 a2->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 672         else
 673                 a1->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 674         if (mode & S_IXUSR)
 675                 a2->ae_perm |= ACL_EXECUTE;
 676         else
 677                 a1->ae_perm |= ACL_EXECUTE;
 678
 679         if (mode & S_IRGRP)
 680                 a4->ae_perm |= ACL_READ_DATA;
 681         else
 682                 a3->ae_perm |= ACL_READ_DATA;
 683         if (mode & S_IWGRP)
 684                 a4->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 685         else
 686                 a3->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 687         if (mode & S_IXGRP)
 688                 a4->ae_perm |= ACL_EXECUTE;
 689         else
 690                 a3->ae_perm |= ACL_EXECUTE;
 691
 692         if (mode & S_IROTH)
 693                 a6->ae_perm |= ACL_READ_DATA;
 694         else
 695                 a5->ae_perm |= ACL_READ_DATA;
 696         if (mode & S_IWOTH)
 697                 a6->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 698         else
 699                 a5->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 700         if (mode & S_IXOTH)
 701                 a6->ae_perm |= ACL_EXECUTE;
 702         else
 703                 a5->ae_perm |= ACL_EXECUTE;
 704 }
 705
 706 #ifdef _KERNEL
 707 void
 708 acl_nfs4_sync_acl_from_mode(struct acl *aclp, mode_t mode,
 709     int file_owner_id)
 710 {
 711
 712         if (acl_nfs4_old_semantics)
 713                 acl_nfs4_sync_acl_from_mode_draft(aclp, mode, file_owner_id);
 714         else
 715                 acl_nfs4_trivial_from_mode(aclp, mode);
 716 }
 717 #endif /* _KERNEL */
 718
 719 void
 720 acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp)
 721 {
 722         int i;
 723         mode_t old_mode = *_mode, mode = 0, seen = 0;
 724         const struct acl_entry *entry;
 725
 726         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
 727             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 728
 729         /*
 730          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 731          *
 732          * 3.16.6.1. Recomputing mode upon SETATTR of ACL
 733          */
 734
 735         for (i = 0; i < aclp->acl_cnt; i++) {
 736                 entry = &(aclp->acl_entry[i]);
 737
 738                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 739                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 740                         continue;
 741
 742                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
 743                         continue;
 744
 745                 if (entry->ae_tag == ACL_USER_OBJ) {
 746                         if ((entry->ae_perm & ACL_READ_DATA) &&
 747                             ((seen & S_IRUSR) == 0)) {
 748                                 seen |= S_IRUSR;
 749                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 750                                         mode |= S_IRUSR;
 751                         }
 752                         if ((entry->ae_perm & ACL_WRITE_DATA) &&
 753                              ((seen & S_IWUSR) == 0)) {
 754                                 seen |= S_IWUSR;
 755                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 756                                         mode |= S_IWUSR;
 757                         }
 758                         if ((entry->ae_perm & ACL_EXECUTE) &&
 759                             ((seen & S_IXUSR) == 0)) {
 760                                 seen |= S_IXUSR;
 761                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 762                                         mode |= S_IXUSR;
 763                         }
 764                 } else if (entry->ae_tag == ACL_GROUP_OBJ) {
 765                         if ((entry->ae_perm & ACL_READ_DATA) &&
 766                             ((seen & S_IRGRP) == 0)) {
 767                                 seen |= S_IRGRP;
 768                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 769                                         mode |= S_IRGRP;
 770                         }
 771                         if ((entry->ae_perm & ACL_WRITE_DATA) &&
 772                             ((seen & S_IWGRP) == 0)) {
 773                                 seen |= S_IWGRP;
 774                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 775                                         mode |= S_IWGRP;
 776                         }
 777                         if ((entry->ae_perm & ACL_EXECUTE) &&
 778                             ((seen & S_IXGRP) == 0)) {
 779                                 seen |= S_IXGRP;
 780                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 781                                         mode |= S_IXGRP;
 782                         }
 783                 } else if (entry->ae_tag == ACL_EVERYONE) {
 784                         if (entry->ae_perm & ACL_READ_DATA) {
 785                                 if ((seen & S_IRUSR) == 0) {
 786                                         seen |= S_IRUSR;
 787                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 788                                                 mode |= S_IRUSR;
 789                                 }
 790                                 if ((seen & S_IRGRP) == 0) {
 791                                         seen |= S_IRGRP;
 792                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 793                                                 mode |= S_IRGRP;
 794                                 }
 795                                 if ((seen & S_IROTH) == 0) {
 796                                         seen |= S_IROTH;
 797                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 798                                                 mode |= S_IROTH;
 799                                 }
 800                         }
 801                         if (entry->ae_perm & ACL_WRITE_DATA) {
 802                                 if ((seen & S_IWUSR) == 0) {
 803                                         seen |= S_IWUSR;
 804                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 805                                                 mode |= S_IWUSR;
 806                                 }
 807                                 if ((seen & S_IWGRP) == 0) {
 808                                         seen |= S_IWGRP;
 809                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 810                                                 mode |= S_IWGRP;
 811                                 }
 812                                 if ((seen & S_IWOTH) == 0) {
 813                                         seen |= S_IWOTH;
 814                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 815                                                 mode |= S_IWOTH;
 816                                 }
 817                         }
 818                         if (entry->ae_perm & ACL_EXECUTE) {
 819                                 if ((seen & S_IXUSR) == 0) {
 820                                         seen |= S_IXUSR;
 821                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 822                                                 mode |= S_IXUSR;
 823                                 }
 824                                 if ((seen & S_IXGRP) == 0) {
 825                                         seen |= S_IXGRP;
 826                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 827                                                 mode |= S_IXGRP;
 828                                 }
 829                                 if ((seen & S_IXOTH) == 0) {
 830                                         seen |= S_IXOTH;
 831                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 832                                                 mode |= S_IXOTH;
 833                                 }
 834                         }
 835                 }
 836         }
 837
 838         *_mode = mode | (old_mode & ACL_PRESERVE_MASK);
 839 }
 840
 841 #ifdef _KERNEL
 842 /*
 843  * Calculate inherited ACL in a manner compatible with NFSv4 Minor Version 1,
 844  * draft-ietf-nfsv4-minorversion1-03.txt.
 845  */
 846 static void
 847 acl_nfs4_compute_inherited_acl_draft(const struct acl *parent_aclp,
 848     struct acl *child_aclp, mode_t mode, int file_owner_id,
 849     int is_directory)
 850 {
 851         int i, flags;
 852         const struct acl_entry *parent_entry;
 853         struct acl_entry *entry, *copy;
 854
 855         KASSERT(child_aclp->acl_cnt == 0, ("child_aclp->acl_cnt == 0"));
 856         KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
 857             ("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 858
 859         /*
 860          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 861          *
 862          * 3.16.6.2. Applying the mode given to CREATE or OPEN
 863          *           to an inherited ACL
 864          */
 865
 866         /*
 867          * 1. Form an ACL that is the concatenation of all inheritable ACEs.
 868          */
 869         for (i = 0; i < parent_aclp->acl_cnt; i++) {
 870                 parent_entry = &(parent_aclp->acl_entry[i]);
 871                 flags = parent_entry->ae_flags;
 872
 873                 /*
 874                  * Entry is not inheritable at all.
 875                  */
 876                 if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
 877                     ACL_ENTRY_FILE_INHERIT)) == 0)
 878                         continue;
 879
 880                 /*
 881                  * We're creating a file, but entry is not inheritable
 882                  * by files.
 883                  */
 884                 if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
 885                         continue;
 886
 887                 /*
 888                  * Entry is inheritable only by files, but has NO_PROPAGATE
 889                  * flag set, and we're creating a directory, so it wouldn't
 890                  * propagate to any file in that directory anyway.
 891                  */
 892                 if (is_directory &&
 893                     (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
 894                     (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
 895                         continue;
 896
 897                 KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 898                     ("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 899                 child_aclp->acl_entry[child_aclp->acl_cnt] = *parent_entry;
 900                 child_aclp->acl_cnt++;
 901         }
 902
 903         /*
 904          * 2. For each entry in the new ACL, adjust its flags, possibly
 905          *    creating two entries in place of one.
 906          */
 907         for (i = 0; i < child_aclp->acl_cnt; i++) {
 908                 entry = &(child_aclp->acl_entry[i]);
 909
 910                 /*
 911                  * This is not in the specification, but SunOS
 912                  * apparently does that.
 913                  */
 914                 if (((entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT) ||
 915                     !is_directory) &&
 916                     entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 917                         entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
 918
 919                 /*
 920                  * 2.A. If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if the object
 921                  *      being created is not a directory, then clear the
 922                  *      following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
 923                  *      ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
 924                  *      ACL_ENTRY_INHERIT_ONLY.
 925                  */
 926                 if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
 927                     !is_directory) {
 928                         entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
 929                         ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
 930                         ACL_ENTRY_INHERIT_ONLY);
 931
 932                         /*
 933                          * Continue on to the next ACE.
 934                          */
 935                         continue;
 936                 }
 937
 938                 /*
 939                  * 2.B. If the object is a directory and ACL_ENTRY_FILE_INHERIT
 940                  *      is set, but ACL_ENTRY_NO_PROPAGATE_INHERIT is not set, ensure
 941                  *      that ACL_ENTRY_INHERIT_ONLY is set.  Continue to the
 942                  *      next ACE.  Otherwise...
 943                  */
 944                 /*
 945                  * XXX: Read it again and make sure what does the "otherwise"
 946                  *      apply to.
 947                  */
 948                 if (is_directory &&
 949                     (entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
 950                     ((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
 951                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 952                         continue;
 953                 }
 954
 955                 /*
 956                  * 2.C. If the type of the ACE is neither ALLOW nor deny,
 957                  *      then continue.
 958                  */
 959                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 960                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 961                         continue;
 962
 963                 /*
 964                  * 2.D. Copy the original ACE into a second, adjacent ACE.
 965                  */
 966                 copy = _acl_duplicate_entry(child_aclp, i);
 967
 968                 /*
 969                  * 2.E. On the first ACE, ensure that ACL_ENTRY_INHERIT_ONLY
 970                  *      is set.
 971                  */
 972                 entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 973
 974                 /*
 975                  * 2.F. On the second ACE, clear the following flags:
 976                  *      ACL_ENTRY_NO_PROPAGATE_INHERIT, ACL_ENTRY_FILE_INHERIT,
 977                  *      ACL_ENTRY_DIRECTORY_INHERIT, ACL_ENTRY_INHERIT_ONLY.
 978                  */
 979                 copy->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
 980                     ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
 981                     ACL_ENTRY_INHERIT_ONLY);
 982
 983                 /*
 984                  * 2.G. On the second ACE, if the type is ALLOW,
 985                  *      an implementation MAY clear the following
 986                  *      mask bits: ACL_WRITE_ACL, ACL_WRITE_OWNER.
 987                  */
 988                 if (copy->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 989                         copy->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
 990
 991                 /*
 992                  * Increment the counter to skip the copied entry.
 993                  */
 994                 i++;
 995         }
 996
 997         /*
 998          * 3. To ensure that the mode is honored, apply the algorithm describe
 999          *    in Section 2.16.6.3, using the mode that is to be used for file
1000          *    creation.
1001          */
1002         acl_nfs4_sync_acl_from_mode(child_aclp, mode, file_owner_id);
1003 }
1004 #endif /* _KERNEL */
1005
1006 /*
1007  * Populate the ACL with entries inherited from parent_aclp.
1008  */
1009 static void
1010 acl_nfs4_inherit_entries(const struct acl *parent_aclp,
1011     struct acl *child_aclp, mode_t mode, int file_owner_id,
1012     int is_directory)
1013 {
1014         int i, flags, tag;
1015         const struct acl_entry *parent_entry;
1016         struct acl_entry *entry;
1017
1018         KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
1019             ("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
1020
1021         for (i = 0; i < parent_aclp->acl_cnt; i++) {
1022                 parent_entry = &(parent_aclp->acl_entry[i]);
1023                 flags = parent_entry->ae_flags;
1024                 tag = parent_entry->ae_tag;
1025
1026                 /*
1027                  * Don't inherit owner@, group@, or everyone@ entries.
1028                  */
1029                 if (tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ ||
1030                     tag == ACL_EVERYONE)
1031                         continue;
1032
1033                 /*
1034                  * Entry is not inheritable at all.
1035                  */
1036                 if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
1037                     ACL_ENTRY_FILE_INHERIT)) == 0)
1038                         continue;
1039
1040                 /*
1041                  * We're creating a file, but entry is not inheritable
1042                  * by files.
1043                  */
1044                 if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
1045                         continue;
1046
1047                 /*
1048                  * Entry is inheritable only by files, but has NO_PROPAGATE
1049                  * flag set, and we're creating a directory, so it wouldn't
1050                  * propagate to any file in that directory anyway.
1051                  */
1052                 if (is_directory &&
1053                     (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
1054                     (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
1055                         continue;
1056
1057                 /*
1058                  * Entry qualifies for being inherited.
1059                  */
1060                 KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
1061                     ("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
1062                 entry = &(child_aclp->acl_entry[child_aclp->acl_cnt]);
1063                 *entry = *parent_entry;
1064                 child_aclp->acl_cnt++;
1065
1066                 entry->ae_flags &= ~ACL_ENTRY_INHERIT_ONLY;
1067                 entry->ae_flags |= ACL_ENTRY_INHERITED;
1068
1069                 /*
1070                  * If the type of the ACE is neither ALLOW nor DENY,
1071                  * then leave it as it is and proceed to the next one.
1072                  */
1073                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
1074                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
1075                         continue;
1076
1077                 /*
1078                  * If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if
1079                  * the object being created is not a directory, then clear
1080                  * the following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
1081                  * ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
1082                  * ACL_ENTRY_INHERIT_ONLY.
1083                  */
1084                 if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
1085                     !is_directory) {
1086                         entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
1087                         ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
1088                         ACL_ENTRY_INHERIT_ONLY);
1089                 }
1090
1091                 /*
1092                  * If the object is a directory and ACL_ENTRY_FILE_INHERIT
1093                  * is set, but ACL_ENTRY_DIRECTORY_INHERIT is not set, ensure
1094                  * that ACL_ENTRY_INHERIT_ONLY is set.
1095                  */
1096                 if (is_directory &&
1097                     (entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
1098                     ((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
1099                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
1100                 }
1101
1102                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW &&
1103                     (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY) == 0) {
1104                         /*
1105                          * Some permissions must never be inherited.
1106                          */
1107                         entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER |
1108                             ACL_WRITE_NAMED_ATTRS | ACL_WRITE_ATTRIBUTES);
1109
1110                         /*
1111                          * Others must be masked according to the file mode.
1112                          */
1113                         if ((mode & S_IRGRP) == 0)
1114                                 entry->ae_perm &= ~ACL_READ_DATA;
1115                         if ((mode & S_IWGRP) == 0)
1116                                 entry->ae_perm &=
1117                                     ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
1118                         if ((mode & S_IXGRP) == 0)
1119                                 entry->ae_perm &= ~ACL_EXECUTE;
1120                 }
1121         }
1122 }
1123
1124 /*
1125  * Calculate inherited ACL in a manner compatible with PSARC/2010/029.
1126  * It's also being used to calculate a trivial ACL, by inheriting from
1127  * a NULL ACL.
1128  */
1129 static void
1130 acl_nfs4_compute_inherited_acl_psarc(const struct acl *parent_aclp,
1131     struct acl *aclp, mode_t mode, int file_owner_id, int is_directory)
1132 {
1133         acl_perm_t user_allow_first = 0, user_deny = 0, group_deny = 0;
1134         acl_perm_t user_allow, group_allow, everyone_allow;
1135
1136         KASSERT(aclp->acl_cnt == 0, ("aclp->acl_cnt == 0"));
1137
1138         user_allow = group_allow = everyone_allow = ACL_READ_ACL |
1139             ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS | ACL_SYNCHRONIZE;
1140         user_allow |= ACL_WRITE_ACL | ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
1141             ACL_WRITE_NAMED_ATTRS;
1142
1143         if (mode & S_IRUSR)
1144                 user_allow |= ACL_READ_DATA;
1145         if (mode & S_IWUSR)
1146                 user_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1147         if (mode & S_IXUSR)
1148                 user_allow |= ACL_EXECUTE;
1149
1150         if (mode & S_IRGRP)
1151                 group_allow |= ACL_READ_DATA;
1152         if (mode & S_IWGRP)
1153                 group_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1154         if (mode & S_IXGRP)
1155                 group_allow |= ACL_EXECUTE;
1156
1157         if (mode & S_IROTH)
1158                 everyone_allow |= ACL_READ_DATA;
1159         if (mode & S_IWOTH)
1160                 everyone_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1161         if (mode & S_IXOTH)
1162                 everyone_allow |= ACL_EXECUTE;
1163
1164         user_deny = ((group_allow | everyone_allow) & ~user_allow);
1165         group_deny = everyone_allow & ~group_allow;
1166         user_allow_first = group_deny & ~user_deny;
1167
1168         if (user_allow_first != 0)
1169                 _acl_append(aclp, ACL_USER_OBJ, user_allow_first,
1170                     ACL_ENTRY_TYPE_ALLOW);
1171         if (user_deny != 0)
1172                 _acl_append(aclp, ACL_USER_OBJ, user_deny,
1173                     ACL_ENTRY_TYPE_DENY);
1174         if (group_deny != 0)
1175                 _acl_append(aclp, ACL_GROUP_OBJ, group_deny,
1176                     ACL_ENTRY_TYPE_DENY);
1177
1178         if (parent_aclp != NULL)
1179                 acl_nfs4_inherit_entries(parent_aclp, aclp, mode,
1180                     file_owner_id, is_directory);
1181
1182         _acl_append(aclp, ACL_USER_OBJ, user_allow, ACL_ENTRY_TYPE_ALLOW);
1183         _acl_append(aclp, ACL_GROUP_OBJ, group_allow, ACL_ENTRY_TYPE_ALLOW);
1184         _acl_append(aclp, ACL_EVERYONE, everyone_allow, ACL_ENTRY_TYPE_ALLOW);
1185 }
1186
1187 #ifdef _KERNEL
1188 void
1189 acl_nfs4_compute_inherited_acl(const struct acl *parent_aclp,
1190     struct acl *child_aclp, mode_t mode, int file_owner_id,
1191     int is_directory)
1192 {
1193
1194         if (acl_nfs4_old_semantics)
1195                 acl_nfs4_compute_inherited_acl_draft(parent_aclp, child_aclp,
1196                     mode, file_owner_id, is_directory);
1197         else
1198                 acl_nfs4_compute_inherited_acl_psarc(parent_aclp, child_aclp,
1199                     mode, file_owner_id, is_directory);
1200 }
1201 #endif /* _KERNEL */
1202
1203 /*
1204  * Calculate trivial ACL in a manner compatible with PSARC/2010/029.
1205  * Note that this results in an ACL different from (but semantically
1206  * equal to) the "canonical six" trivial ACL computed using algorithm
1207  * described in draft-ietf-nfsv4-minorversion1-03.txt, 3.16.6.2.
1208  */
1209 static void
1210 acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode)
1211 {
1212
1213         aclp->acl_cnt = 0;
1214         acl_nfs4_compute_inherited_acl_psarc(NULL, aclp, mode, -1, -1);
1215 }
1216
1217 #ifndef _KERNEL
1218 /*
1219  * This routine is used by libc to implement acl_strip_np(3)
1220  * and acl_is_trivial_np(3).
1221  */
1222 void
1223 acl_nfs4_trivial_from_mode_libc(struct acl *aclp, int mode, int canonical_six)
1224 {
1225
1226         aclp->acl_cnt = 0;
1227         if (canonical_six)
1228                 acl_nfs4_sync_acl_from_mode_draft(aclp, mode, -1);
1229         else
1230                 acl_nfs4_trivial_from_mode(aclp, mode);
1231 }
1232 #endif /* !_KERNEL */
1233
1234 #ifdef _KERNEL
1235 static int
1236 _acls_are_equal(const struct acl *a, const struct acl *b)
1237 {
1238         int i;
1239         const struct acl_entry *entrya, *entryb;
1240
1241         if (a->acl_cnt != b->acl_cnt)
1242                 return (0);
1243
1244         for (i = 0; i < b->acl_cnt; i++) {
1245                 entrya = &(a->acl_entry[i]);
1246                 entryb = &(b->acl_entry[i]);
1247
1248                 if (entrya->ae_tag != entryb->ae_tag ||
1249                     entrya->ae_id != entryb->ae_id ||
1250                     entrya->ae_perm != entryb->ae_perm ||
1251                     entrya->ae_entry_type != entryb->ae_entry_type ||
1252                     entrya->ae_flags != entryb->ae_flags)
1253                         return (0);
1254         }
1255
1256         return (1);
1257 }
1258
1259 /*
1260  * This routine is used to determine whether to remove extended attribute
1261  * that stores ACL contents.
1262  */
1263 int
1264 acl_nfs4_is_trivial(const struct acl *aclp, int file_owner_id)
1265 {
1266         int trivial;
1267         mode_t tmpmode = 0;
1268         struct acl *tmpaclp;
1269
1270         if (aclp->acl_cnt > 6)
1271                 return (0);
1272
1273         /*
1274          * Compute the mode from the ACL, then compute new ACL from that mode.
1275          * If the ACLs are identical, then the ACL is trivial.
1276          *
1277          * XXX: I guess there is a faster way to do this.  However, even
1278          *      this slow implementation significantly speeds things up
1279          *      for files that don't have non-trivial ACLs - it's critical
1280          *      for performance to not use EA when they are not needed.
1281          *
1282          * First try the PSARC/2010/029 semantics.
1283          */
1284         tmpaclp = acl_alloc(M_WAITOK | M_ZERO);
1285         acl_nfs4_sync_mode_from_acl(&tmpmode, aclp);
1286         acl_nfs4_trivial_from_mode(tmpaclp, tmpmode);
1287         trivial = _acls_are_equal(aclp, tmpaclp);
1288         if (trivial) {
1289                 acl_free(tmpaclp);
1290                 return (trivial);
1291         }
1292
1293         /*
1294          * Check if it's a draft-ietf-nfsv4-minorversion1-03.txt trivial ACL.
1295          */
1296         tmpaclp->acl_cnt = 0;
1297         acl_nfs4_sync_acl_from_mode_draft(tmpaclp, tmpmode, file_owner_id);
1298         trivial = _acls_are_equal(aclp, tmpaclp);
1299         acl_free(tmpaclp);
1300
1301         return (trivial);
1302 }
1303 #endif /* _KERNEL */
1304
1305 int
1306 acl_nfs4_check(const struct acl *aclp, int is_directory)
1307 {
1308         int i;
1309         const struct acl_entry *entry;
1310
1311         /*
1312          * The spec doesn't seem to say anything about ACL validity.
1313          * It seems there is not much to do here.  There is even no need
1314          * to count "owner@" or "everyone@" (ACL_USER_OBJ and ACL_EVERYONE)
1315          * entries, as there can be several of them and that's perfectly
1316          * valid.  There can be none of them too.  Really.
1317          */
1318
1319         if (aclp->acl_cnt > ACL_MAX_ENTRIES || aclp->acl_cnt <= 0)
1320                 return (EINVAL);
1321
1322         for (i = 0; i < aclp->acl_cnt; i++) {
1323                 entry = &(aclp->acl_entry[i]);
1324
1325                 switch (entry->ae_tag) {
1326                 case ACL_USER_OBJ:
1327                 case ACL_GROUP_OBJ:
1328                 case ACL_EVERYONE:
1329                         if (entry->ae_id != ACL_UNDEFINED_ID)
1330                                 return (EINVAL);
1331                         break;
1332
1333                 case ACL_USER:
1334                 case ACL_GROUP:
1335                         if (entry->ae_id == ACL_UNDEFINED_ID)
1336                                 return (EINVAL);
1337                         break;
1338
1339                 default:
1340                         return (EINVAL);
1341                 }
1342
1343                 if ((entry->ae_perm | ACL_NFS4_PERM_BITS) != ACL_NFS4_PERM_BITS)
1344                         return (EINVAL);
1345
1346                 /*
1347                  * Disallow ACL_ENTRY_TYPE_AUDIT and ACL_ENTRY_TYPE_ALARM for now.
1348                  */
1349                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
1350                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
1351                         return (EINVAL);
1352
1353                 if ((entry->ae_flags | ACL_FLAGS_BITS) != ACL_FLAGS_BITS)
1354                         return (EINVAL);
1355
1356                 /* Disallow unimplemented flags. */
1357                 if (entry->ae_flags & (ACL_ENTRY_SUCCESSFUL_ACCESS |
1358                     ACL_ENTRY_FAILED_ACCESS))
1359                         return (EINVAL);
1360
1361                 /* Disallow flags not allowed for ordinary files. */
1362                 if (!is_directory) {
1363                         if (entry->ae_flags & (ACL_ENTRY_FILE_INHERIT |
1364                             ACL_ENTRY_DIRECTORY_INHERIT |
1365                             ACL_ENTRY_NO_PROPAGATE_INHERIT | ACL_ENTRY_INHERIT_ONLY))
1366                                 return (EINVAL);
1367                 }
1368         }
1369
1370         return (0);
1371 }
1372
1373 #ifdef  _KERNEL
1374 static int
1375 acl_nfs4_modload(module_t module, int what, void *arg)
1376 {
1377         int ret;
1378
1379         ret = 0;
1380
1381         switch (what) {
1382         case MOD_LOAD:
1383         case MOD_SHUTDOWN:
1384                 break;
1385
1386         case MOD_QUIESCE:
1387                 /* XXX TODO */
1388                 ret = 0;
1389                 break;
1390
1391         case MOD_UNLOAD:
1392                 /* XXX TODO */
1393                 ret = 0;
1394                 break;
1395         default:
1396                 ret = EINVAL;
1397                 break;
1398         }
1399
1400         return (ret);
1401 }
1402
1403 static moduledata_t acl_nfs4_mod = {
1404         "acl_nfs4",
1405         acl_nfs4_modload,
1406         NULL
1407 };
1408
1409 /*
1410  * XXX TODO: which subsystem, order?
1411  */
1412 DECLARE_MODULE(acl_nfs4, acl_nfs4_mod, SI_SUB_VFS, SI_ORDER_FIRST);
1413 MODULE_VERSION(acl_nfs4, 1);
1414 #endif  /* _KERNEL */