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, int *privused)
 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 (privused != NULL)
 191                 *privused = 0;
 192
 193         if (accmode & VADMIN)
 194                 must_be_owner = 1;
 195
 196         /*
 197          * Ignore VSYNCHRONIZE permission.
 198          */
 199         accmode &= ~VSYNCHRONIZE;
 200
 201         access_mask = _access_mask_from_accmode(accmode);
 202
 203         if (type == VDIR)
 204                 is_directory = 1;
 205         else
 206                 is_directory = 0;
 207
 208         /*
 209          * File owner is always allowed to read and write the ACL
 210          * and basic attributes.  This is to prevent a situation
 211          * where user would change ACL in a way that prevents him
 212          * from undoing the change.
 213          */
 214         if (file_uid == cred->cr_uid)
 215                 access_mask &= ~(ACL_READ_ACL | ACL_WRITE_ACL |
 216                     ACL_READ_ATTRIBUTES | ACL_WRITE_ATTRIBUTES);
 217
 218         /*
 219          * Ignore append permission for regular files; use write
 220          * permission instead.
 221          */
 222         if (!is_directory && (access_mask & ACL_APPEND_DATA)) {
 223                 access_mask &= ~ACL_APPEND_DATA;
 224                 access_mask |= ACL_WRITE_DATA;
 225         }
 226
 227         denied = _acl_denies(aclp, access_mask, cred, file_uid, file_gid,
 228             &explicitly_denied);
 229
 230         if (must_be_owner) {
 231                 if (file_uid != cred->cr_uid)
 232                         denied = EPERM;
 233         }
 234
 235         /*
 236          * For VEXEC, ensure that at least one execute bit is set for
 237          * non-directories. We have to check the mode here to stay
 238          * consistent with execve(2). See the test in
 239          * exec_check_permissions().
 240          */
 241         acl_nfs4_sync_mode_from_acl(&file_mode, aclp);
 242         if (!denied && !is_directory && (accmode & VEXEC) &&
 243             (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)
 244                 denied = EACCES;
 245
 246         if (!denied)
 247                 return (0);
 248
 249         /*
 250          * Access failed.  Iff it was not denied explicitly and
 251          * VEXPLICIT_DENY flag was specified, allow access.
 252          */
 253         if ((accmode & VEXPLICIT_DENY) && explicitly_denied == 0)
 254                 return (0);
 255
 256         accmode &= ~VEXPLICIT_DENY;
 257
 258         /*
 259          * No match.  Try to use privileges, if there are any.
 260          */
 261         if (is_directory) {
 262                 if ((accmode & VEXEC) && !priv_check_cred(cred,
 263                     PRIV_VFS_LOOKUP, 0))
 264                         priv_granted |= VEXEC;
 265         } else {
 266                 /*
 267                  * Ensure that at least one execute bit is on. Otherwise,
 268                  * a privileged user will always succeed, and we don't want
 269                  * this to happen unless the file really is executable.
 270                  */
 271                 if ((accmode & VEXEC) && (file_mode &
 272                     (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
 273                     !priv_check_cred(cred, PRIV_VFS_EXEC, 0))
 274                         priv_granted |= VEXEC;
 275         }
 276
 277         if ((accmode & VREAD) && !priv_check_cred(cred, PRIV_VFS_READ, 0))
 278                 priv_granted |= VREAD;
 279
 280         if ((accmode & (VWRITE | VAPPEND | VDELETE_CHILD)) &&
 281             !priv_check_cred(cred, PRIV_VFS_WRITE, 0))
 282                 priv_granted |= (VWRITE | VAPPEND | VDELETE_CHILD);
 283
 284         if ((accmode & VADMIN_PERMS) &&
 285             !priv_check_cred(cred, PRIV_VFS_ADMIN, 0))
 286                 priv_granted |= VADMIN_PERMS;
 287
 288         if ((accmode & VSTAT_PERMS) &&
 289             !priv_check_cred(cred, PRIV_VFS_STAT, 0))
 290                 priv_granted |= VSTAT_PERMS;
 291
 292         if ((accmode & priv_granted) == accmode) {
 293                 if (privused != NULL)
 294                         *privused = 1;
 295
 296                 return (0);
 297         }
 298
 299         if (accmode & (VADMIN_PERMS | VDELETE_CHILD | VDELETE))
 300                 denied = EPERM;
 301         else
 302                 denied = EACCES;
 303
 304         return (denied);
 305 }
 306 #endif /* _KERNEL */
 307
 308 static int
 309 _acl_entry_matches(struct acl_entry *entry, acl_tag_t tag, acl_perm_t perm,
 310     acl_entry_type_t entry_type)
 311 {
 312         if (entry->ae_tag != tag)
 313                 return (0);
 314
 315         if (entry->ae_id != ACL_UNDEFINED_ID)
 316                 return (0);
 317
 318         if (entry->ae_perm != perm)
 319                 return (0);
 320
 321         if (entry->ae_entry_type != entry_type)
 322                 return (0);
 323
 324         if (entry->ae_flags != 0)
 325                 return (0);
 326
 327         return (1);
 328 }
 329
 330 static struct acl_entry *
 331 _acl_append(struct acl *aclp, acl_tag_t tag, acl_perm_t perm,
 332     acl_entry_type_t entry_type)
 333 {
 334         struct acl_entry *entry;
 335
 336         KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 337             ("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 338
 339         entry = &(aclp->acl_entry[aclp->acl_cnt]);
 340         aclp->acl_cnt++;
 341
 342         entry->ae_tag = tag;
 343         entry->ae_id = ACL_UNDEFINED_ID;
 344         entry->ae_perm = perm;
 345         entry->ae_entry_type = entry_type;
 346         entry->ae_flags = 0;
 347
 348         return (entry);
 349 }
 350
 351 static struct acl_entry *
 352 _acl_duplicate_entry(struct acl *aclp, int entry_index)
 353 {
 354         int i;
 355
 356         KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 357             ("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 358
 359         for (i = aclp->acl_cnt; i > entry_index; i--)
 360                 aclp->acl_entry[i] = aclp->acl_entry[i - 1];
 361
 362         aclp->acl_cnt++;
 363
 364         return (&(aclp->acl_entry[entry_index + 1]));
 365 }
 366
 367 static void
 368 acl_nfs4_sync_acl_from_mode_draft(struct acl *aclp, mode_t mode,
 369     int file_owner_id)
 370 {
 371         int i, meets, must_append;
 372         struct acl_entry *entry, *copy, *previous,
 373             *a1, *a2, *a3, *a4, *a5, *a6;
 374         mode_t amode;
 375         const int READ = 04;
 376         const int WRITE = 02;
 377         const int EXEC = 01;
 378
 379         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
 380             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 381
 382         /*
 383          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 384          *
 385          * 3.16.6.3. Applying a Mode to an Existing ACL
 386          */
 387
 388         /*
 389          * 1. For each ACE:
 390          */
 391         for (i = 0; i < aclp->acl_cnt; i++) {
 392                 entry = &(aclp->acl_entry[i]);
 393
 394                 /*
 395                  * 1.1. If the type is neither ALLOW or DENY - skip.
 396                  */
 397                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 398                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 399                         continue;
 400
 401                 /*
 402                  * 1.2. If ACL_ENTRY_INHERIT_ONLY is set - skip.
 403                  */
 404                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
 405                         continue;
 406
 407                 /*
 408                  * 1.3. If ACL_ENTRY_FILE_INHERIT or ACL_ENTRY_DIRECTORY_INHERIT
 409                  *      are set:
 410                  */
 411                 if (entry->ae_flags &
 412                     (ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT)) {
 413                         /*
 414                          * 1.3.1. A copy of the current ACE is made, and placed
 415                          *        in the ACL immediately following the current
 416                          *        ACE.
 417                          */
 418                         copy = _acl_duplicate_entry(aclp, i);
 419
 420                         /*
 421                          * 1.3.2. In the first ACE, the flag
 422                          *        ACL_ENTRY_INHERIT_ONLY is set.
 423                          */
 424                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 425
 426                         /*
 427                          * 1.3.3. In the second ACE, the following flags
 428                          *        are cleared:
 429                          *        ACL_ENTRY_FILE_INHERIT,
 430                          *        ACL_ENTRY_DIRECTORY_INHERIT,
 431                          *        ACL_ENTRY_NO_PROPAGATE_INHERIT.
 432                          */
 433                         copy->ae_flags &= ~(ACL_ENTRY_FILE_INHERIT |
 434                             ACL_ENTRY_DIRECTORY_INHERIT |
 435                             ACL_ENTRY_NO_PROPAGATE_INHERIT);
 436
 437                         /*
 438                          * The algorithm continues on with the second ACE.
 439                          */
 440                         i++;
 441                         entry = copy;
 442                 }
 443
 444                 /*
 445                  * 1.4. If it's owner@, group@ or everyone@ entry, clear
 446                  *      ACL_READ_DATA, ACL_WRITE_DATA, ACL_APPEND_DATA
 447                  *      and ACL_EXECUTE.  Continue to the next entry.
 448                  */
 449                 if (entry->ae_tag == ACL_USER_OBJ ||
 450                     entry->ae_tag == ACL_GROUP_OBJ ||
 451                     entry->ae_tag == ACL_EVERYONE) {
 452                         entry->ae_perm &= ~(ACL_READ_DATA | ACL_WRITE_DATA |
 453                             ACL_APPEND_DATA | ACL_EXECUTE);
 454                         continue;
 455                 }
 456
 457                 /*
 458                  * 1.5. Otherwise, if the "who" field did not match one
 459                  *      of OWNER@, GROUP@, EVERYONE@:
 460                  *
 461                  * 1.5.1. If the type is ALLOW, check the preceding ACE.
 462                  *        If it does not meet all of the following criteria:
 463                  */
 464                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW)
 465                         continue;
 466
 467                 meets = 0;
 468                 if (i > 0) {
 469                         meets = 1;
 470                         previous = &(aclp->acl_entry[i - 1]);
 471
 472                         /*
 473                          * 1.5.1.1. The type field is DENY,
 474                          */
 475                         if (previous->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 476                                 meets = 0;
 477
 478                         /*
 479                          * 1.5.1.2. The "who" field is the same as the current
 480                          *          ACE,
 481                          *
 482                          * 1.5.1.3. The flag bit ACE4_IDENTIFIER_GROUP
 483                          *          is the same as it is in the current ACE,
 484                          *          and no other flag bits are set,
 485                          */
 486                         if (previous->ae_id != entry->ae_id ||
 487                             previous->ae_tag != entry->ae_tag)
 488                                 meets = 0;
 489
 490                         if (previous->ae_flags)
 491                                 meets = 0;
 492
 493                         /*
 494                          * 1.5.1.4. The mask bits are a subset of the mask bits
 495                          *          of the current ACE, and are also subset of
 496                          *          the following: ACL_READ_DATA,
 497                          *          ACL_WRITE_DATA, ACL_APPEND_DATA, ACL_EXECUTE
 498                          */
 499                         if (previous->ae_perm & ~(entry->ae_perm))
 500                                 meets = 0;
 501
 502                         if (previous->ae_perm & ~(ACL_READ_DATA |
 503                             ACL_WRITE_DATA | ACL_APPEND_DATA | ACL_EXECUTE))
 504                                 meets = 0;
 505                 }
 506
 507                 if (!meets) {
 508                         /*
 509                          * Then the ACE of type DENY, with a who equal
 510                          * to the current ACE, flag bits equal to
 511                          * (<current ACE flags> & <ACE_IDENTIFIER_GROUP>)
 512                          * and no mask bits, is prepended.
 513                          */
 514                         previous = entry;
 515                         entry = _acl_duplicate_entry(aclp, i);
 516
 517                         /* Adjust counter, as we've just added an entry. */
 518                         i++;
 519
 520                         previous->ae_tag = entry->ae_tag;
 521                         previous->ae_id = entry->ae_id;
 522                         previous->ae_flags = entry->ae_flags;
 523                         previous->ae_perm = 0;
 524                         previous->ae_entry_type = ACL_ENTRY_TYPE_DENY;
 525                 }
 526
 527                 /*
 528                  * 1.5.2. The following modifications are made to the prepended
 529                  *        ACE.  The intent is to mask the following ACE
 530                  *        to disallow ACL_READ_DATA, ACL_WRITE_DATA,
 531                  *        ACL_APPEND_DATA, or ACL_EXECUTE, based upon the group
 532                  *        permissions of the new mode.  As a special case,
 533                  *        if the ACE matches the current owner of the file,
 534                  *        the owner bits are used, rather than the group bits.
 535                  *        This is reflected in the algorithm below.
 536                  */
 537                 amode = mode >> 3;
 538
 539                 /*
 540                  * If ACE4_IDENTIFIER_GROUP is not set, and the "who" field
 541                  * in ACE matches the owner of the file, we shift amode three
 542                  * more bits, in order to have the owner permission bits
 543                  * placed in the three low order bits of amode.
 544                  */
 545                 if (entry->ae_tag == ACL_USER && entry->ae_id == file_owner_id)
 546                         amode = amode >> 3;
 547
 548                 if (entry->ae_perm & ACL_READ_DATA) {
 549                         if (amode & READ)
 550                                 previous->ae_perm &= ~ACL_READ_DATA;
 551                         else
 552                                 previous->ae_perm |= ACL_READ_DATA;
 553                 }
 554
 555                 if (entry->ae_perm & ACL_WRITE_DATA) {
 556                         if (amode & WRITE)
 557                                 previous->ae_perm &= ~ACL_WRITE_DATA;
 558                         else
 559                                 previous->ae_perm |= ACL_WRITE_DATA;
 560                 }
 561
 562                 if (entry->ae_perm & ACL_APPEND_DATA) {
 563                         if (amode & WRITE)
 564                                 previous->ae_perm &= ~ACL_APPEND_DATA;
 565                         else
 566                                 previous->ae_perm |= ACL_APPEND_DATA;
 567                 }
 568
 569                 if (entry->ae_perm & ACL_EXECUTE) {
 570                         if (amode & EXEC)
 571                                 previous->ae_perm &= ~ACL_EXECUTE;
 572                         else
 573                                 previous->ae_perm |= ACL_EXECUTE;
 574                 }
 575
 576                 /*
 577                  * 1.5.3. If ACE4_IDENTIFIER_GROUP is set in the flags
 578                  *        of the ALLOW ace:
 579                  *
 580                  * XXX: This point is not there in the Falkner's draft.
 581                  */
 582                 if (entry->ae_tag == ACL_GROUP &&
 583                     entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) {
 584                         mode_t extramode, ownermode;
 585                         extramode = (mode >> 3) & 07;
 586                         ownermode = mode >> 6;
 587                         extramode &= ~ownermode;
 588
 589                         if (extramode) {
 590                                 if (extramode & READ) {
 591                                         entry->ae_perm &= ~ACL_READ_DATA;
 592                                         previous->ae_perm &= ~ACL_READ_DATA;
 593                                 }
 594
 595                                 if (extramode & WRITE) {
 596                                         entry->ae_perm &=
 597                                             ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
 598                                         previous->ae_perm &=
 599                                             ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
 600                                 }
 601
 602                                 if (extramode & EXEC) {
 603                                         entry->ae_perm &= ~ACL_EXECUTE;
 604                                         previous->ae_perm &= ~ACL_EXECUTE;
 605                                 }
 606                         }
 607                 }
 608         }
 609
 610         /*
 611          * 2. If there at least six ACEs, the final six ACEs are examined.
 612          *    If they are not equal to what we want, append six ACEs.
 613          */
 614         must_append = 0;
 615         if (aclp->acl_cnt < 6) {
 616                 must_append = 1;
 617         } else {
 618                 a6 = &(aclp->acl_entry[aclp->acl_cnt - 1]);
 619                 a5 = &(aclp->acl_entry[aclp->acl_cnt - 2]);
 620                 a4 = &(aclp->acl_entry[aclp->acl_cnt - 3]);
 621                 a3 = &(aclp->acl_entry[aclp->acl_cnt - 4]);
 622                 a2 = &(aclp->acl_entry[aclp->acl_cnt - 5]);
 623                 a1 = &(aclp->acl_entry[aclp->acl_cnt - 6]);
 624
 625                 if (!_acl_entry_matches(a1, ACL_USER_OBJ, 0,
 626                     ACL_ENTRY_TYPE_DENY))
 627                         must_append = 1;
 628                 if (!_acl_entry_matches(a2, ACL_USER_OBJ, ACL_WRITE_ACL |
 629                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 630                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW))
 631                         must_append = 1;
 632                 if (!_acl_entry_matches(a3, ACL_GROUP_OBJ, 0,
 633                     ACL_ENTRY_TYPE_DENY))
 634                         must_append = 1;
 635                 if (!_acl_entry_matches(a4, ACL_GROUP_OBJ, 0,
 636                     ACL_ENTRY_TYPE_ALLOW))
 637                         must_append = 1;
 638                 if (!_acl_entry_matches(a5, ACL_EVERYONE, ACL_WRITE_ACL |
 639                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 640                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY))
 641                         must_append = 1;
 642                 if (!_acl_entry_matches(a6, ACL_EVERYONE, ACL_READ_ACL |
 643                     ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
 644                     ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW))
 645                         must_append = 1;
 646         }
 647
 648         if (must_append) {
 649                 KASSERT(aclp->acl_cnt + 6 <= ACL_MAX_ENTRIES,
 650                     ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 651
 652                 a1 = _acl_append(aclp, ACL_USER_OBJ, 0, ACL_ENTRY_TYPE_DENY);
 653                 a2 = _acl_append(aclp, ACL_USER_OBJ, ACL_WRITE_ACL |
 654                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 655                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW);
 656                 a3 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_DENY);
 657                 a4 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_ALLOW);
 658                 a5 = _acl_append(aclp, ACL_EVERYONE, ACL_WRITE_ACL |
 659                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 660                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY);
 661                 a6 = _acl_append(aclp, ACL_EVERYONE, ACL_READ_ACL |
 662                     ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
 663                     ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW);
 664
 665                 KASSERT(a1 != NULL && a2 != NULL && a3 != NULL && a4 != NULL &&
 666                     a5 != NULL && a6 != NULL, ("couldn't append to ACL."));
 667         }
 668
 669         /*
 670          * 3. The final six ACEs are adjusted according to the incoming mode.
 671          */
 672         if (mode & S_IRUSR)
 673                 a2->ae_perm |= ACL_READ_DATA;
 674         else
 675                 a1->ae_perm |= ACL_READ_DATA;
 676         if (mode & S_IWUSR)
 677                 a2->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 678         else
 679                 a1->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 680         if (mode & S_IXUSR)
 681                 a2->ae_perm |= ACL_EXECUTE;
 682         else
 683                 a1->ae_perm |= ACL_EXECUTE;
 684
 685         if (mode & S_IRGRP)
 686                 a4->ae_perm |= ACL_READ_DATA;
 687         else
 688                 a3->ae_perm |= ACL_READ_DATA;
 689         if (mode & S_IWGRP)
 690                 a4->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 691         else
 692                 a3->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 693         if (mode & S_IXGRP)
 694                 a4->ae_perm |= ACL_EXECUTE;
 695         else
 696                 a3->ae_perm |= ACL_EXECUTE;
 697
 698         if (mode & S_IROTH)
 699                 a6->ae_perm |= ACL_READ_DATA;
 700         else
 701                 a5->ae_perm |= ACL_READ_DATA;
 702         if (mode & S_IWOTH)
 703                 a6->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 704         else
 705                 a5->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 706         if (mode & S_IXOTH)
 707                 a6->ae_perm |= ACL_EXECUTE;
 708         else
 709                 a5->ae_perm |= ACL_EXECUTE;
 710 }
 711
 712 #ifdef _KERNEL
 713 void
 714 acl_nfs4_sync_acl_from_mode(struct acl *aclp, mode_t mode,
 715     int file_owner_id)
 716 {
 717
 718         if (acl_nfs4_old_semantics)
 719                 acl_nfs4_sync_acl_from_mode_draft(aclp, mode, file_owner_id);
 720         else
 721                 acl_nfs4_trivial_from_mode(aclp, mode);
 722 }
 723 #endif /* _KERNEL */
 724
 725 void
 726 acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp)
 727 {
 728         int i;
 729         mode_t old_mode = *_mode, mode = 0, seen = 0;
 730         const struct acl_entry *entry;
 731
 732         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
 733             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 734
 735         /*
 736          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 737          *
 738          * 3.16.6.1. Recomputing mode upon SETATTR of ACL
 739          */
 740
 741         for (i = 0; i < aclp->acl_cnt; i++) {
 742                 entry = &(aclp->acl_entry[i]);
 743
 744                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 745                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 746                         continue;
 747
 748                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
 749                         continue;
 750
 751                 if (entry->ae_tag == ACL_USER_OBJ) {
 752                         if ((entry->ae_perm & ACL_READ_DATA) &&
 753                             ((seen & S_IRUSR) == 0)) {
 754                                 seen |= S_IRUSR;
 755                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 756                                         mode |= S_IRUSR;
 757                         }
 758                         if ((entry->ae_perm & ACL_WRITE_DATA) &&
 759                              ((seen & S_IWUSR) == 0)) {
 760                                 seen |= S_IWUSR;
 761                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 762                                         mode |= S_IWUSR;
 763                         }
 764                         if ((entry->ae_perm & ACL_EXECUTE) &&
 765                             ((seen & S_IXUSR) == 0)) {
 766                                 seen |= S_IXUSR;
 767                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 768                                         mode |= S_IXUSR;
 769                         }
 770                 } else if (entry->ae_tag == ACL_GROUP_OBJ) {
 771                         if ((entry->ae_perm & ACL_READ_DATA) &&
 772                             ((seen & S_IRGRP) == 0)) {
 773                                 seen |= S_IRGRP;
 774                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 775                                         mode |= S_IRGRP;
 776                         }
 777                         if ((entry->ae_perm & ACL_WRITE_DATA) &&
 778                             ((seen & S_IWGRP) == 0)) {
 779                                 seen |= S_IWGRP;
 780                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 781                                         mode |= S_IWGRP;
 782                         }
 783                         if ((entry->ae_perm & ACL_EXECUTE) &&
 784                             ((seen & S_IXGRP) == 0)) {
 785                                 seen |= S_IXGRP;
 786                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 787                                         mode |= S_IXGRP;
 788                         }
 789                 } else if (entry->ae_tag == ACL_EVERYONE) {
 790                         if (entry->ae_perm & ACL_READ_DATA) {
 791                                 if ((seen & S_IRUSR) == 0) {
 792                                         seen |= S_IRUSR;
 793                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 794                                                 mode |= S_IRUSR;
 795                                 }
 796                                 if ((seen & S_IRGRP) == 0) {
 797                                         seen |= S_IRGRP;
 798                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 799                                                 mode |= S_IRGRP;
 800                                 }
 801                                 if ((seen & S_IROTH) == 0) {
 802                                         seen |= S_IROTH;
 803                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 804                                                 mode |= S_IROTH;
 805                                 }
 806                         }
 807                         if (entry->ae_perm & ACL_WRITE_DATA) {
 808                                 if ((seen & S_IWUSR) == 0) {
 809                                         seen |= S_IWUSR;
 810                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 811                                                 mode |= S_IWUSR;
 812                                 }
 813                                 if ((seen & S_IWGRP) == 0) {
 814                                         seen |= S_IWGRP;
 815                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 816                                                 mode |= S_IWGRP;
 817                                 }
 818                                 if ((seen & S_IWOTH) == 0) {
 819                                         seen |= S_IWOTH;
 820                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 821                                                 mode |= S_IWOTH;
 822                                 }
 823                         }
 824                         if (entry->ae_perm & ACL_EXECUTE) {
 825                                 if ((seen & S_IXUSR) == 0) {
 826                                         seen |= S_IXUSR;
 827                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 828                                                 mode |= S_IXUSR;
 829                                 }
 830                                 if ((seen & S_IXGRP) == 0) {
 831                                         seen |= S_IXGRP;
 832                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 833                                                 mode |= S_IXGRP;
 834                                 }
 835                                 if ((seen & S_IXOTH) == 0) {
 836                                         seen |= S_IXOTH;
 837                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 838                                                 mode |= S_IXOTH;
 839                                 }
 840                         }
 841                 }
 842         }
 843
 844         *_mode = mode | (old_mode & ACL_PRESERVE_MASK);
 845 }
 846
 847 #ifdef _KERNEL
 848 /*
 849  * Calculate inherited ACL in a manner compatible with NFSv4 Minor Version 1,
 850  * draft-ietf-nfsv4-minorversion1-03.txt.
 851  */
 852 static void
 853 acl_nfs4_compute_inherited_acl_draft(const struct acl *parent_aclp,
 854     struct acl *child_aclp, mode_t mode, int file_owner_id,
 855     int is_directory)
 856 {
 857         int i, flags;
 858         const struct acl_entry *parent_entry;
 859         struct acl_entry *entry, *copy;
 860
 861         KASSERT(child_aclp->acl_cnt == 0, ("child_aclp->acl_cnt == 0"));
 862         KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
 863             ("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 864
 865         /*
 866          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 867          *
 868          * 3.16.6.2. Applying the mode given to CREATE or OPEN
 869          *           to an inherited ACL
 870          */
 871
 872         /*
 873          * 1. Form an ACL that is the concatenation of all inheritable ACEs.
 874          */
 875         for (i = 0; i < parent_aclp->acl_cnt; i++) {
 876                 parent_entry = &(parent_aclp->acl_entry[i]);
 877                 flags = parent_entry->ae_flags;
 878
 879                 /*
 880                  * Entry is not inheritable at all.
 881                  */
 882                 if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
 883                     ACL_ENTRY_FILE_INHERIT)) == 0)
 884                         continue;
 885
 886                 /*
 887                  * We're creating a file, but entry is not inheritable
 888                  * by files.
 889                  */
 890                 if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
 891                         continue;
 892
 893                 /*
 894                  * Entry is inheritable only by files, but has NO_PROPAGATE
 895                  * flag set, and we're creating a directory, so it wouldn't
 896                  * propagate to any file in that directory anyway.
 897                  */
 898                 if (is_directory &&
 899                     (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
 900                     (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
 901                         continue;
 902
 903                 KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 904                     ("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 905                 child_aclp->acl_entry[child_aclp->acl_cnt] = *parent_entry;
 906                 child_aclp->acl_cnt++;
 907         }
 908
 909         /*
 910          * 2. For each entry in the new ACL, adjust its flags, possibly
 911          *    creating two entries in place of one.
 912          */
 913         for (i = 0; i < child_aclp->acl_cnt; i++) {
 914                 entry = &(child_aclp->acl_entry[i]);
 915
 916                 /*
 917                  * This is not in the specification, but SunOS
 918                  * apparently does that.
 919                  */
 920                 if (((entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT) ||
 921                     !is_directory) &&
 922                     entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 923                         entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
 924
 925                 /*
 926                  * 2.A. If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if the object
 927                  *      being created is not a directory, then clear the
 928                  *      following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
 929                  *      ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
 930                  *      ACL_ENTRY_INHERIT_ONLY.
 931                  */
 932                 if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
 933                     !is_directory) {
 934                         entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
 935                         ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
 936                         ACL_ENTRY_INHERIT_ONLY);
 937
 938                         /*
 939                          * Continue on to the next ACE.
 940                          */
 941                         continue;
 942                 }
 943
 944                 /*
 945                  * 2.B. If the object is a directory and ACL_ENTRY_FILE_INHERIT
 946                  *      is set, but ACL_ENTRY_NO_PROPAGATE_INHERIT is not set, ensure
 947                  *      that ACL_ENTRY_INHERIT_ONLY is set.  Continue to the
 948                  *      next ACE.  Otherwise...
 949                  */
 950                 /*
 951                  * XXX: Read it again and make sure what does the "otherwise"
 952                  *      apply to.
 953                  */
 954                 if (is_directory &&
 955                     (entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
 956                     ((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
 957                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 958                         continue;
 959                 }
 960
 961                 /*
 962                  * 2.C. If the type of the ACE is neither ALLOW nor deny,
 963                  *      then continue.
 964                  */
 965                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 966                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 967                         continue;
 968
 969                 /*
 970                  * 2.D. Copy the original ACE into a second, adjacent ACE.
 971                  */
 972                 copy = _acl_duplicate_entry(child_aclp, i);
 973
 974                 /*
 975                  * 2.E. On the first ACE, ensure that ACL_ENTRY_INHERIT_ONLY
 976                  *      is set.
 977                  */
 978                 entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 979
 980                 /*
 981                  * 2.F. On the second ACE, clear the following flags:
 982                  *      ACL_ENTRY_NO_PROPAGATE_INHERIT, ACL_ENTRY_FILE_INHERIT,
 983                  *      ACL_ENTRY_DIRECTORY_INHERIT, ACL_ENTRY_INHERIT_ONLY.
 984                  */
 985                 copy->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
 986                     ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
 987                     ACL_ENTRY_INHERIT_ONLY);
 988
 989                 /*
 990                  * 2.G. On the second ACE, if the type is ALLOW,
 991                  *      an implementation MAY clear the following
 992                  *      mask bits: ACL_WRITE_ACL, ACL_WRITE_OWNER.
 993                  */
 994                 if (copy->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 995                         copy->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
 996
 997                 /*
 998                  * Increment the counter to skip the copied entry.
 999                  */
1000                 i++;
1001         }
1002
1003         /*
1004          * 3. To ensure that the mode is honored, apply the algorithm describe
1005          *    in Section 2.16.6.3, using the mode that is to be used for file
1006          *    creation.
1007          */
1008         acl_nfs4_sync_acl_from_mode(child_aclp, mode, file_owner_id);
1009 }
1010 #endif /* _KERNEL */
1011
1012 /*
1013  * Populate the ACL with entries inherited from parent_aclp.
1014  */
1015 static void
1016 acl_nfs4_inherit_entries(const struct acl *parent_aclp,
1017     struct acl *child_aclp, mode_t mode, int file_owner_id,
1018     int is_directory)
1019 {
1020         int i, flags, tag;
1021         const struct acl_entry *parent_entry;
1022         struct acl_entry *entry;
1023
1024         KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
1025             ("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
1026
1027         for (i = 0; i < parent_aclp->acl_cnt; i++) {
1028                 parent_entry = &(parent_aclp->acl_entry[i]);
1029                 flags = parent_entry->ae_flags;
1030                 tag = parent_entry->ae_tag;
1031
1032                 /*
1033                  * Don't inherit owner@, group@, or everyone@ entries.
1034                  */
1035                 if (tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ ||
1036                     tag == ACL_EVERYONE)
1037                         continue;
1038
1039                 /*
1040                  * Entry is not inheritable at all.
1041                  */
1042                 if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
1043                     ACL_ENTRY_FILE_INHERIT)) == 0)
1044                         continue;
1045
1046                 /*
1047                  * We're creating a file, but entry is not inheritable
1048                  * by files.
1049                  */
1050                 if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
1051                         continue;
1052
1053                 /*
1054                  * Entry is inheritable only by files, but has NO_PROPAGATE
1055                  * flag set, and we're creating a directory, so it wouldn't
1056                  * propagate to any file in that directory anyway.
1057                  */
1058                 if (is_directory &&
1059                     (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
1060                     (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
1061                         continue;
1062
1063                 /*
1064                  * Entry qualifies for being inherited.
1065                  */
1066                 KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
1067                     ("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
1068                 entry = &(child_aclp->acl_entry[child_aclp->acl_cnt]);
1069                 *entry = *parent_entry;
1070                 child_aclp->acl_cnt++;
1071
1072                 entry->ae_flags &= ~ACL_ENTRY_INHERIT_ONLY;
1073                 entry->ae_flags |= ACL_ENTRY_INHERITED;
1074
1075                 /*
1076                  * If the type of the ACE is neither ALLOW nor DENY,
1077                  * then leave it as it is and proceed to the next one.
1078                  */
1079                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
1080                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
1081                         continue;
1082
1083                 /*
1084                  * If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if
1085                  * the object being created is not a directory, then clear
1086                  * the following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
1087                  * ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
1088                  * ACL_ENTRY_INHERIT_ONLY.
1089                  */
1090                 if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
1091                     !is_directory) {
1092                         entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
1093                         ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
1094                         ACL_ENTRY_INHERIT_ONLY);
1095                 }
1096
1097                 /*
1098                  * If the object is a directory and ACL_ENTRY_FILE_INHERIT
1099                  * is set, but ACL_ENTRY_DIRECTORY_INHERIT is not set, ensure
1100                  * that ACL_ENTRY_INHERIT_ONLY is set.
1101                  */
1102                 if (is_directory &&
1103                     (entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
1104                     ((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
1105                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
1106                 }
1107
1108                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW &&
1109                     (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY) == 0) {
1110                         /*
1111                          * Some permissions must never be inherited.
1112                          */
1113                         entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER |
1114                             ACL_WRITE_NAMED_ATTRS | ACL_WRITE_ATTRIBUTES);
1115
1116                         /*
1117                          * Others must be masked according to the file mode.
1118                          */
1119                         if ((mode & S_IRGRP) == 0)
1120                                 entry->ae_perm &= ~ACL_READ_DATA;
1121                         if ((mode & S_IWGRP) == 0)
1122                                 entry->ae_perm &=
1123                                     ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
1124                         if ((mode & S_IXGRP) == 0)
1125                                 entry->ae_perm &= ~ACL_EXECUTE;
1126                 }
1127         }
1128 }
1129
1130 /*
1131  * Calculate inherited ACL in a manner compatible with PSARC/2010/029.
1132  * It's also being used to calculate a trivial ACL, by inheriting from
1133  * a NULL ACL.
1134  */
1135 static void
1136 acl_nfs4_compute_inherited_acl_psarc(const struct acl *parent_aclp,
1137     struct acl *aclp, mode_t mode, int file_owner_id, int is_directory)
1138 {
1139         acl_perm_t user_allow_first = 0, user_deny = 0, group_deny = 0;
1140         acl_perm_t user_allow, group_allow, everyone_allow;
1141
1142         KASSERT(aclp->acl_cnt == 0, ("aclp->acl_cnt == 0"));
1143
1144         user_allow = group_allow = everyone_allow = ACL_READ_ACL |
1145             ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS | ACL_SYNCHRONIZE;
1146         user_allow |= ACL_WRITE_ACL | ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
1147             ACL_WRITE_NAMED_ATTRS;
1148
1149         if (mode & S_IRUSR)
1150                 user_allow |= ACL_READ_DATA;
1151         if (mode & S_IWUSR)
1152                 user_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1153         if (mode & S_IXUSR)
1154                 user_allow |= ACL_EXECUTE;
1155
1156         if (mode & S_IRGRP)
1157                 group_allow |= ACL_READ_DATA;
1158         if (mode & S_IWGRP)
1159                 group_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1160         if (mode & S_IXGRP)
1161                 group_allow |= ACL_EXECUTE;
1162
1163         if (mode & S_IROTH)
1164                 everyone_allow |= ACL_READ_DATA;
1165         if (mode & S_IWOTH)
1166                 everyone_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1167         if (mode & S_IXOTH)
1168                 everyone_allow |= ACL_EXECUTE;
1169
1170         user_deny = ((group_allow | everyone_allow) & ~user_allow);
1171         group_deny = everyone_allow & ~group_allow;
1172         user_allow_first = group_deny & ~user_deny;
1173
1174         if (user_allow_first != 0)
1175                 _acl_append(aclp, ACL_USER_OBJ, user_allow_first,
1176                     ACL_ENTRY_TYPE_ALLOW);
1177         if (user_deny != 0)
1178                 _acl_append(aclp, ACL_USER_OBJ, user_deny,
1179                     ACL_ENTRY_TYPE_DENY);
1180         if (group_deny != 0)
1181                 _acl_append(aclp, ACL_GROUP_OBJ, group_deny,
1182                     ACL_ENTRY_TYPE_DENY);
1183
1184         if (parent_aclp != NULL)
1185                 acl_nfs4_inherit_entries(parent_aclp, aclp, mode,
1186                     file_owner_id, is_directory);
1187
1188         _acl_append(aclp, ACL_USER_OBJ, user_allow, ACL_ENTRY_TYPE_ALLOW);
1189         _acl_append(aclp, ACL_GROUP_OBJ, group_allow, ACL_ENTRY_TYPE_ALLOW);
1190         _acl_append(aclp, ACL_EVERYONE, everyone_allow, ACL_ENTRY_TYPE_ALLOW);
1191 }
1192
1193 #ifdef _KERNEL
1194 void
1195 acl_nfs4_compute_inherited_acl(const struct acl *parent_aclp,
1196     struct acl *child_aclp, mode_t mode, int file_owner_id,
1197     int is_directory)
1198 {
1199
1200         if (acl_nfs4_old_semantics)
1201                 acl_nfs4_compute_inherited_acl_draft(parent_aclp, child_aclp,
1202                     mode, file_owner_id, is_directory);
1203         else
1204                 acl_nfs4_compute_inherited_acl_psarc(parent_aclp, child_aclp,
1205                     mode, file_owner_id, is_directory);
1206 }
1207 #endif /* _KERNEL */
1208
1209 /*
1210  * Calculate trivial ACL in a manner compatible with PSARC/2010/029.
1211  * Note that this results in an ACL different from (but semantically
1212  * equal to) the "canonical six" trivial ACL computed using algorithm
1213  * described in draft-ietf-nfsv4-minorversion1-03.txt, 3.16.6.2.
1214  */
1215 static void
1216 acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode)
1217 {
1218
1219         aclp->acl_cnt = 0;
1220         acl_nfs4_compute_inherited_acl_psarc(NULL, aclp, mode, -1, -1);
1221 }
1222
1223 #ifndef _KERNEL
1224 /*
1225  * This routine is used by libc to implement acl_strip_np(3)
1226  * and acl_is_trivial_np(3).
1227  */
1228 void
1229 acl_nfs4_trivial_from_mode_libc(struct acl *aclp, int mode, int canonical_six)
1230 {
1231
1232         aclp->acl_cnt = 0;
1233         if (canonical_six)
1234                 acl_nfs4_sync_acl_from_mode_draft(aclp, mode, -1);
1235         else
1236                 acl_nfs4_trivial_from_mode(aclp, mode);
1237 }
1238 #endif /* !_KERNEL */
1239
1240 #ifdef _KERNEL
1241 static int
1242 _acls_are_equal(const struct acl *a, const struct acl *b)
1243 {
1244         int i;
1245         const struct acl_entry *entrya, *entryb;
1246
1247         if (a->acl_cnt != b->acl_cnt)
1248                 return (0);
1249
1250         for (i = 0; i < b->acl_cnt; i++) {
1251                 entrya = &(a->acl_entry[i]);
1252                 entryb = &(b->acl_entry[i]);
1253
1254                 if (entrya->ae_tag != entryb->ae_tag ||
1255                     entrya->ae_id != entryb->ae_id ||
1256                     entrya->ae_perm != entryb->ae_perm ||
1257                     entrya->ae_entry_type != entryb->ae_entry_type ||
1258                     entrya->ae_flags != entryb->ae_flags)
1259                         return (0);
1260         }
1261
1262         return (1);
1263 }
1264
1265 /*
1266  * This routine is used to determine whether to remove extended attribute
1267  * that stores ACL contents.
1268  */
1269 int
1270 acl_nfs4_is_trivial(const struct acl *aclp, int file_owner_id)
1271 {
1272         int trivial;
1273         mode_t tmpmode = 0;
1274         struct acl *tmpaclp;
1275
1276         if (aclp->acl_cnt > 6)
1277                 return (0);
1278
1279         /*
1280          * Compute the mode from the ACL, then compute new ACL from that mode.
1281          * If the ACLs are identical, then the ACL is trivial.
1282          *
1283          * XXX: I guess there is a faster way to do this.  However, even
1284          *      this slow implementation significantly speeds things up
1285          *      for files that don't have non-trivial ACLs - it's critical
1286          *      for performance to not use EA when they are not needed.
1287          *
1288          * First try the PSARC/2010/029 semantics.
1289          */
1290         tmpaclp = acl_alloc(M_WAITOK | M_ZERO);
1291         acl_nfs4_sync_mode_from_acl(&tmpmode, aclp);
1292         acl_nfs4_trivial_from_mode(tmpaclp, tmpmode);
1293         trivial = _acls_are_equal(aclp, tmpaclp);
1294         if (trivial) {
1295                 acl_free(tmpaclp);
1296                 return (trivial);
1297         }
1298
1299         /*
1300          * Check if it's a draft-ietf-nfsv4-minorversion1-03.txt trivial ACL.
1301          */
1302         tmpaclp->acl_cnt = 0;
1303         acl_nfs4_sync_acl_from_mode_draft(tmpaclp, tmpmode, file_owner_id);
1304         trivial = _acls_are_equal(aclp, tmpaclp);
1305         acl_free(tmpaclp);
1306
1307         return (trivial);
1308 }
1309 #endif /* _KERNEL */
1310
1311 int
1312 acl_nfs4_check(const struct acl *aclp, int is_directory)
1313 {
1314         int i;
1315         const struct acl_entry *entry;
1316
1317         /*
1318          * The spec doesn't seem to say anything about ACL validity.
1319          * It seems there is not much to do here.  There is even no need
1320          * to count "owner@" or "everyone@" (ACL_USER_OBJ and ACL_EVERYONE)
1321          * entries, as there can be several of them and that's perfectly
1322          * valid.  There can be none of them too.  Really.
1323          */
1324
1325         if (aclp->acl_cnt > ACL_MAX_ENTRIES || aclp->acl_cnt <= 0)
1326                 return (EINVAL);
1327
1328         for (i = 0; i < aclp->acl_cnt; i++) {
1329                 entry = &(aclp->acl_entry[i]);
1330
1331                 switch (entry->ae_tag) {
1332                 case ACL_USER_OBJ:
1333                 case ACL_GROUP_OBJ:
1334                 case ACL_EVERYONE:
1335                         if (entry->ae_id != ACL_UNDEFINED_ID)
1336                                 return (EINVAL);
1337                         break;
1338
1339                 case ACL_USER:
1340                 case ACL_GROUP:
1341                         if (entry->ae_id == ACL_UNDEFINED_ID)
1342                                 return (EINVAL);
1343                         break;
1344
1345                 default:
1346                         return (EINVAL);
1347                 }
1348
1349                 if ((entry->ae_perm | ACL_NFS4_PERM_BITS) != ACL_NFS4_PERM_BITS)
1350                         return (EINVAL);
1351
1352                 /*
1353                  * Disallow ACL_ENTRY_TYPE_AUDIT and ACL_ENTRY_TYPE_ALARM for now.
1354                  */
1355                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
1356                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
1357                         return (EINVAL);
1358
1359                 if ((entry->ae_flags | ACL_FLAGS_BITS) != ACL_FLAGS_BITS)
1360                         return (EINVAL);
1361
1362                 /* Disallow unimplemented flags. */
1363                 if (entry->ae_flags & (ACL_ENTRY_SUCCESSFUL_ACCESS |
1364                     ACL_ENTRY_FAILED_ACCESS))
1365                         return (EINVAL);
1366
1367                 /* Disallow flags not allowed for ordinary files. */
1368                 if (!is_directory) {
1369                         if (entry->ae_flags & (ACL_ENTRY_FILE_INHERIT |
1370                             ACL_ENTRY_DIRECTORY_INHERIT |
1371                             ACL_ENTRY_NO_PROPAGATE_INHERIT | ACL_ENTRY_INHERIT_ONLY))
1372                                 return (EINVAL);
1373                 }
1374         }
1375
1376         return (0);
1377 }
1378
1379 #ifdef  _KERNEL
1380 static int
1381 acl_nfs4_modload(module_t module, int what, void *arg)
1382 {
1383         int ret;
1384
1385         ret = 0;
1386
1387         switch (what) {
1388         case MOD_LOAD:
1389         case MOD_SHUTDOWN:
1390                 break;
1391
1392         case MOD_QUIESCE:
1393                 /* XXX TODO */
1394                 ret = 0;
1395                 break;
1396
1397         case MOD_UNLOAD:
1398                 /* XXX TODO */
1399                 ret = 0;
1400                 break;
1401         default:
1402                 ret = EINVAL;
1403                 break;
1404         }
1405
1406         return (ret);
1407 }
1408
1409 static moduledata_t acl_nfs4_mod = {
1410         "acl_nfs4",
1411         acl_nfs4_modload,
1412         NULL
1413 };
1414
1415 /*
1416  * XXX TODO: which subsystem, order?
1417  */
1418 DECLARE_MODULE(acl_nfs4, acl_nfs4_mod, SI_SUB_VFS, SI_ORDER_FIRST);
1419 MODULE_VERSION(acl_nfs4, 1);
1420 #endif  /* _KERNEL */