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