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, unsigned entry_index)
 353 {
 354         unsigned 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 meets, must_append;
 372         unsigned i;
 373         struct acl_entry *entry, *copy, *previous,
 374             *a1, *a2, *a3, *a4, *a5, *a6;
 375         mode_t amode;
 376         const int READ = 04;
 377         const int WRITE = 02;
 378         const int EXEC = 01;
 379
 380         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
 381             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 382
 383         /*
 384          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 385          *
 386          * 3.16.6.3. Applying a Mode to an Existing ACL
 387          */
 388
 389         /*
 390          * 1. For each ACE:
 391          */
 392         for (i = 0; i < aclp->acl_cnt; i++) {
 393                 entry = &(aclp->acl_entry[i]);
 394
 395                 /*
 396                  * 1.1. If the type is neither ALLOW or DENY - skip.
 397                  */
 398                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 399                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 400                         continue;
 401
 402                 /*
 403                  * 1.2. If ACL_ENTRY_INHERIT_ONLY is set - skip.
 404                  */
 405                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
 406                         continue;
 407
 408                 /*
 409                  * 1.3. If ACL_ENTRY_FILE_INHERIT or ACL_ENTRY_DIRECTORY_INHERIT
 410                  *      are set:
 411                  */
 412                 if (entry->ae_flags &
 413                     (ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT)) {
 414                         /*
 415                          * 1.3.1. A copy of the current ACE is made, and placed
 416                          *        in the ACL immediately following the current
 417                          *        ACE.
 418                          */
 419                         copy = _acl_duplicate_entry(aclp, i);
 420
 421                         /*
 422                          * 1.3.2. In the first ACE, the flag
 423                          *        ACL_ENTRY_INHERIT_ONLY is set.
 424                          */
 425                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 426
 427                         /*
 428                          * 1.3.3. In the second ACE, the following flags
 429                          *        are cleared:
 430                          *        ACL_ENTRY_FILE_INHERIT,
 431                          *        ACL_ENTRY_DIRECTORY_INHERIT,
 432                          *        ACL_ENTRY_NO_PROPAGATE_INHERIT.
 433                          */
 434                         copy->ae_flags &= ~(ACL_ENTRY_FILE_INHERIT |
 435                             ACL_ENTRY_DIRECTORY_INHERIT |
 436                             ACL_ENTRY_NO_PROPAGATE_INHERIT);
 437
 438                         /*
 439                          * The algorithm continues on with the second ACE.
 440                          */
 441                         i++;
 442                         entry = copy;
 443                 }
 444
 445                 /*
 446                  * 1.4. If it's owner@, group@ or everyone@ entry, clear
 447                  *      ACL_READ_DATA, ACL_WRITE_DATA, ACL_APPEND_DATA
 448                  *      and ACL_EXECUTE.  Continue to the next entry.
 449                  */
 450                 if (entry->ae_tag == ACL_USER_OBJ ||
 451                     entry->ae_tag == ACL_GROUP_OBJ ||
 452                     entry->ae_tag == ACL_EVERYONE) {
 453                         entry->ae_perm &= ~(ACL_READ_DATA | ACL_WRITE_DATA |
 454                             ACL_APPEND_DATA | ACL_EXECUTE);
 455                         continue;
 456                 }
 457
 458                 /*
 459                  * 1.5. Otherwise, if the "who" field did not match one
 460                  *      of OWNER@, GROUP@, EVERYONE@:
 461                  *
 462                  * 1.5.1. If the type is ALLOW, check the preceding ACE.
 463                  *        If it does not meet all of the following criteria:
 464                  */
 465                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW)
 466                         continue;
 467
 468                 meets = 0;
 469                 if (i > 0) {
 470                         meets = 1;
 471                         previous = &(aclp->acl_entry[i - 1]);
 472
 473                         /*
 474                          * 1.5.1.1. The type field is DENY,
 475                          */
 476                         if (previous->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 477                                 meets = 0;
 478
 479                         /*
 480                          * 1.5.1.2. The "who" field is the same as the current
 481                          *          ACE,
 482                          *
 483                          * 1.5.1.3. The flag bit ACE4_IDENTIFIER_GROUP
 484                          *          is the same as it is in the current ACE,
 485                          *          and no other flag bits are set,
 486                          */
 487                         if (previous->ae_id != entry->ae_id ||
 488                             previous->ae_tag != entry->ae_tag)
 489                                 meets = 0;
 490
 491                         if (previous->ae_flags)
 492                                 meets = 0;
 493
 494                         /*
 495                          * 1.5.1.4. The mask bits are a subset of the mask bits
 496                          *          of the current ACE, and are also subset of
 497                          *          the following: ACL_READ_DATA,
 498                          *          ACL_WRITE_DATA, ACL_APPEND_DATA, ACL_EXECUTE
 499                          */
 500                         if (previous->ae_perm & ~(entry->ae_perm))
 501                                 meets = 0;
 502
 503                         if (previous->ae_perm & ~(ACL_READ_DATA |
 504                             ACL_WRITE_DATA | ACL_APPEND_DATA | ACL_EXECUTE))
 505                                 meets = 0;
 506                 }
 507
 508                 if (!meets) {
 509                         /*
 510                          * Then the ACE of type DENY, with a who equal
 511                          * to the current ACE, flag bits equal to
 512                          * (<current ACE flags> & <ACE_IDENTIFIER_GROUP>)
 513                          * and no mask bits, is prepended.
 514                          */
 515                         previous = entry;
 516                         entry = _acl_duplicate_entry(aclp, i);
 517
 518                         /* Adjust counter, as we've just added an entry. */
 519                         i++;
 520
 521                         previous->ae_tag = entry->ae_tag;
 522                         previous->ae_id = entry->ae_id;
 523                         previous->ae_flags = entry->ae_flags;
 524                         previous->ae_perm = 0;
 525                         previous->ae_entry_type = ACL_ENTRY_TYPE_DENY;
 526                 }
 527
 528                 /*
 529                  * 1.5.2. The following modifications are made to the prepended
 530                  *        ACE.  The intent is to mask the following ACE
 531                  *        to disallow ACL_READ_DATA, ACL_WRITE_DATA,
 532                  *        ACL_APPEND_DATA, or ACL_EXECUTE, based upon the group
 533                  *        permissions of the new mode.  As a special case,
 534                  *        if the ACE matches the current owner of the file,
 535                  *        the owner bits are used, rather than the group bits.
 536                  *        This is reflected in the algorithm below.
 537                  */
 538                 amode = mode >> 3;
 539
 540                 /*
 541                  * If ACE4_IDENTIFIER_GROUP is not set, and the "who" field
 542                  * in ACE matches the owner of the file, we shift amode three
 543                  * more bits, in order to have the owner permission bits
 544                  * placed in the three low order bits of amode.
 545                  */
 546                 if (entry->ae_tag == ACL_USER && entry->ae_id == file_owner_id)
 547                         amode = amode >> 3;
 548
 549                 if (entry->ae_perm & ACL_READ_DATA) {
 550                         if (amode & READ)
 551                                 previous->ae_perm &= ~ACL_READ_DATA;
 552                         else
 553                                 previous->ae_perm |= ACL_READ_DATA;
 554                 }
 555
 556                 if (entry->ae_perm & ACL_WRITE_DATA) {
 557                         if (amode & WRITE)
 558                                 previous->ae_perm &= ~ACL_WRITE_DATA;
 559                         else
 560                                 previous->ae_perm |= ACL_WRITE_DATA;
 561                 }
 562
 563                 if (entry->ae_perm & ACL_APPEND_DATA) {
 564                         if (amode & WRITE)
 565                                 previous->ae_perm &= ~ACL_APPEND_DATA;
 566                         else
 567                                 previous->ae_perm |= ACL_APPEND_DATA;
 568                 }
 569
 570                 if (entry->ae_perm & ACL_EXECUTE) {
 571                         if (amode & EXEC)
 572                                 previous->ae_perm &= ~ACL_EXECUTE;
 573                         else
 574                                 previous->ae_perm |= ACL_EXECUTE;
 575                 }
 576
 577                 /*
 578                  * 1.5.3. If ACE4_IDENTIFIER_GROUP is set in the flags
 579                  *        of the ALLOW ace:
 580                  *
 581                  * XXX: This point is not there in the Falkner's draft.
 582                  */
 583                 if (entry->ae_tag == ACL_GROUP &&
 584                     entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) {
 585                         mode_t extramode, ownermode;
 586                         extramode = (mode >> 3) & 07;
 587                         ownermode = mode >> 6;
 588                         extramode &= ~ownermode;
 589
 590                         if (extramode) {
 591                                 if (extramode & READ) {
 592                                         entry->ae_perm &= ~ACL_READ_DATA;
 593                                         previous->ae_perm &= ~ACL_READ_DATA;
 594                                 }
 595
 596                                 if (extramode & WRITE) {
 597                                         entry->ae_perm &=
 598                                             ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
 599                                         previous->ae_perm &=
 600                                             ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
 601                                 }
 602
 603                                 if (extramode & EXEC) {
 604                                         entry->ae_perm &= ~ACL_EXECUTE;
 605                                         previous->ae_perm &= ~ACL_EXECUTE;
 606                                 }
 607                         }
 608                 }
 609         }
 610
 611         /*
 612          * 2. If there at least six ACEs, the final six ACEs are examined.
 613          *    If they are not equal to what we want, append six ACEs.
 614          */
 615         must_append = 0;
 616         if (aclp->acl_cnt < 6) {
 617                 must_append = 1;
 618         } else {
 619                 a6 = &(aclp->acl_entry[aclp->acl_cnt - 1]);
 620                 a5 = &(aclp->acl_entry[aclp->acl_cnt - 2]);
 621                 a4 = &(aclp->acl_entry[aclp->acl_cnt - 3]);
 622                 a3 = &(aclp->acl_entry[aclp->acl_cnt - 4]);
 623                 a2 = &(aclp->acl_entry[aclp->acl_cnt - 5]);
 624                 a1 = &(aclp->acl_entry[aclp->acl_cnt - 6]);
 625
 626                 if (!_acl_entry_matches(a1, ACL_USER_OBJ, 0,
 627                     ACL_ENTRY_TYPE_DENY))
 628                         must_append = 1;
 629                 if (!_acl_entry_matches(a2, ACL_USER_OBJ, ACL_WRITE_ACL |
 630                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 631                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW))
 632                         must_append = 1;
 633                 if (!_acl_entry_matches(a3, ACL_GROUP_OBJ, 0,
 634                     ACL_ENTRY_TYPE_DENY))
 635                         must_append = 1;
 636                 if (!_acl_entry_matches(a4, ACL_GROUP_OBJ, 0,
 637                     ACL_ENTRY_TYPE_ALLOW))
 638                         must_append = 1;
 639                 if (!_acl_entry_matches(a5, ACL_EVERYONE, ACL_WRITE_ACL |
 640                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 641                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY))
 642                         must_append = 1;
 643                 if (!_acl_entry_matches(a6, ACL_EVERYONE, ACL_READ_ACL |
 644                     ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
 645                     ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW))
 646                         must_append = 1;
 647         }
 648
 649         if (must_append) {
 650                 KASSERT(aclp->acl_cnt + 6 <= ACL_MAX_ENTRIES,
 651                     ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 652
 653                 a1 = _acl_append(aclp, ACL_USER_OBJ, 0, ACL_ENTRY_TYPE_DENY);
 654                 a2 = _acl_append(aclp, ACL_USER_OBJ, ACL_WRITE_ACL |
 655                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 656                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW);
 657                 a3 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_DENY);
 658                 a4 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_ALLOW);
 659                 a5 = _acl_append(aclp, ACL_EVERYONE, ACL_WRITE_ACL |
 660                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 661                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY);
 662                 a6 = _acl_append(aclp, ACL_EVERYONE, ACL_READ_ACL |
 663                     ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
 664                     ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW);
 665
 666                 KASSERT(a1 != NULL && a2 != NULL && a3 != NULL && a4 != NULL &&
 667                     a5 != NULL && a6 != NULL, ("couldn't append to ACL."));
 668         }
 669
 670         /*
 671          * 3. The final six ACEs are adjusted according to the incoming mode.
 672          */
 673         if (mode & S_IRUSR)
 674                 a2->ae_perm |= ACL_READ_DATA;
 675         else
 676                 a1->ae_perm |= ACL_READ_DATA;
 677         if (mode & S_IWUSR)
 678                 a2->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 679         else
 680                 a1->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 681         if (mode & S_IXUSR)
 682                 a2->ae_perm |= ACL_EXECUTE;
 683         else
 684                 a1->ae_perm |= ACL_EXECUTE;
 685
 686         if (mode & S_IRGRP)
 687                 a4->ae_perm |= ACL_READ_DATA;
 688         else
 689                 a3->ae_perm |= ACL_READ_DATA;
 690         if (mode & S_IWGRP)
 691                 a4->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 692         else
 693                 a3->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 694         if (mode & S_IXGRP)
 695                 a4->ae_perm |= ACL_EXECUTE;
 696         else
 697                 a3->ae_perm |= ACL_EXECUTE;
 698
 699         if (mode & S_IROTH)
 700                 a6->ae_perm |= ACL_READ_DATA;
 701         else
 702                 a5->ae_perm |= ACL_READ_DATA;
 703         if (mode & S_IWOTH)
 704                 a6->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 705         else
 706                 a5->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 707         if (mode & S_IXOTH)
 708                 a6->ae_perm |= ACL_EXECUTE;
 709         else
 710                 a5->ae_perm |= ACL_EXECUTE;
 711 }
 712
 713 #ifdef _KERNEL
 714 void
 715 acl_nfs4_sync_acl_from_mode(struct acl *aclp, mode_t mode,
 716     int file_owner_id)
 717 {
 718
 719         if (acl_nfs4_old_semantics)
 720                 acl_nfs4_sync_acl_from_mode_draft(aclp, mode, file_owner_id);
 721         else
 722                 acl_nfs4_trivial_from_mode(aclp, mode);
 723 }
 724 #endif /* _KERNEL */
 725
 726 void
 727 acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp)
 728 {
 729         int i;
 730         mode_t old_mode = *_mode, mode = 0, seen = 0;
 731         const struct acl_entry *entry;
 732
 733         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
 734             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 735
 736         /*
 737          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 738          *
 739          * 3.16.6.1. Recomputing mode upon SETATTR of ACL
 740          */
 741
 742         for (i = 0; i < aclp->acl_cnt; i++) {
 743                 entry = &(aclp->acl_entry[i]);
 744
 745                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 746                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 747                         continue;
 748
 749                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
 750                         continue;
 751
 752                 if (entry->ae_tag == ACL_USER_OBJ) {
 753                         if ((entry->ae_perm & ACL_READ_DATA) &&
 754                             ((seen & S_IRUSR) == 0)) {
 755                                 seen |= S_IRUSR;
 756                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 757                                         mode |= S_IRUSR;
 758                         }
 759                         if ((entry->ae_perm & ACL_WRITE_DATA) &&
 760                              ((seen & S_IWUSR) == 0)) {
 761                                 seen |= S_IWUSR;
 762                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 763                                         mode |= S_IWUSR;
 764                         }
 765                         if ((entry->ae_perm & ACL_EXECUTE) &&
 766                             ((seen & S_IXUSR) == 0)) {
 767                                 seen |= S_IXUSR;
 768                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 769                                         mode |= S_IXUSR;
 770                         }
 771                 } else if (entry->ae_tag == ACL_GROUP_OBJ) {
 772                         if ((entry->ae_perm & ACL_READ_DATA) &&
 773                             ((seen & S_IRGRP) == 0)) {
 774                                 seen |= S_IRGRP;
 775                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 776                                         mode |= S_IRGRP;
 777                         }
 778                         if ((entry->ae_perm & ACL_WRITE_DATA) &&
 779                             ((seen & S_IWGRP) == 0)) {
 780                                 seen |= S_IWGRP;
 781                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 782                                         mode |= S_IWGRP;
 783                         }
 784                         if ((entry->ae_perm & ACL_EXECUTE) &&
 785                             ((seen & S_IXGRP) == 0)) {
 786                                 seen |= S_IXGRP;
 787                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 788                                         mode |= S_IXGRP;
 789                         }
 790                 } else if (entry->ae_tag == ACL_EVERYONE) {
 791                         if (entry->ae_perm & ACL_READ_DATA) {
 792                                 if ((seen & S_IRUSR) == 0) {
 793                                         seen |= S_IRUSR;
 794                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 795                                                 mode |= S_IRUSR;
 796                                 }
 797                                 if ((seen & S_IRGRP) == 0) {
 798                                         seen |= S_IRGRP;
 799                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 800                                                 mode |= S_IRGRP;
 801                                 }
 802                                 if ((seen & S_IROTH) == 0) {
 803                                         seen |= S_IROTH;
 804                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 805                                                 mode |= S_IROTH;
 806                                 }
 807                         }
 808                         if (entry->ae_perm & ACL_WRITE_DATA) {
 809                                 if ((seen & S_IWUSR) == 0) {
 810                                         seen |= S_IWUSR;
 811                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 812                                                 mode |= S_IWUSR;
 813                                 }
 814                                 if ((seen & S_IWGRP) == 0) {
 815                                         seen |= S_IWGRP;
 816                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 817                                                 mode |= S_IWGRP;
 818                                 }
 819                                 if ((seen & S_IWOTH) == 0) {
 820                                         seen |= S_IWOTH;
 821                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 822                                                 mode |= S_IWOTH;
 823                                 }
 824                         }
 825                         if (entry->ae_perm & ACL_EXECUTE) {
 826                                 if ((seen & S_IXUSR) == 0) {
 827                                         seen |= S_IXUSR;
 828                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 829                                                 mode |= S_IXUSR;
 830                                 }
 831                                 if ((seen & S_IXGRP) == 0) {
 832                                         seen |= S_IXGRP;
 833                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 834                                                 mode |= S_IXGRP;
 835                                 }
 836                                 if ((seen & S_IXOTH) == 0) {
 837                                         seen |= S_IXOTH;
 838                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 839                                                 mode |= S_IXOTH;
 840                                 }
 841                         }
 842                 }
 843         }
 844
 845         *_mode = mode | (old_mode & ACL_PRESERVE_MASK);
 846 }
 847
 848 #ifdef _KERNEL
 849 /*
 850  * Calculate inherited ACL in a manner compatible with NFSv4 Minor Version 1,
 851  * draft-ietf-nfsv4-minorversion1-03.txt.
 852  */
 853 static void
 854 acl_nfs4_compute_inherited_acl_draft(const struct acl *parent_aclp,
 855     struct acl *child_aclp, mode_t mode, int file_owner_id,
 856     int is_directory)
 857 {
 858         int i, flags;
 859         const struct acl_entry *parent_entry;
 860         struct acl_entry *entry, *copy;
 861
 862         KASSERT(child_aclp->acl_cnt == 0, ("child_aclp->acl_cnt == 0"));
 863         KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
 864             ("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 865
 866         /*
 867          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
 868          *
 869          * 3.16.6.2. Applying the mode given to CREATE or OPEN
 870          *           to an inherited ACL
 871          */
 872
 873         /*
 874          * 1. Form an ACL that is the concatenation of all inheritable ACEs.
 875          */
 876         for (i = 0; i < parent_aclp->acl_cnt; i++) {
 877                 parent_entry = &(parent_aclp->acl_entry[i]);
 878                 flags = parent_entry->ae_flags;
 879
 880                 /*
 881                  * Entry is not inheritable at all.
 882                  */
 883                 if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
 884                     ACL_ENTRY_FILE_INHERIT)) == 0)
 885                         continue;
 886
 887                 /*
 888                  * We're creating a file, but entry is not inheritable
 889                  * by files.
 890                  */
 891                 if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
 892                         continue;
 893
 894                 /*
 895                  * Entry is inheritable only by files, but has NO_PROPAGATE
 896                  * flag set, and we're creating a directory, so it wouldn't
 897                  * propagate to any file in that directory anyway.
 898                  */
 899                 if (is_directory &&
 900                     (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
 901                     (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
 902                         continue;
 903
 904                 KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 905                     ("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 906                 child_aclp->acl_entry[child_aclp->acl_cnt] = *parent_entry;
 907                 child_aclp->acl_cnt++;
 908         }
 909
 910         /*
 911          * 2. For each entry in the new ACL, adjust its flags, possibly
 912          *    creating two entries in place of one.
 913          */
 914         for (i = 0; i < child_aclp->acl_cnt; i++) {
 915                 entry = &(child_aclp->acl_entry[i]);
 916
 917                 /*
 918                  * This is not in the specification, but SunOS
 919                  * apparently does that.
 920                  */
 921                 if (((entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT) ||
 922                     !is_directory) &&
 923                     entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 924                         entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
 925
 926                 /*
 927                  * 2.A. If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if the object
 928                  *      being created is not a directory, then clear the
 929                  *      following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
 930                  *      ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
 931                  *      ACL_ENTRY_INHERIT_ONLY.
 932                  */
 933                 if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
 934                     !is_directory) {
 935                         entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
 936                         ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
 937                         ACL_ENTRY_INHERIT_ONLY);
 938
 939                         /*
 940                          * Continue on to the next ACE.
 941                          */
 942                         continue;
 943                 }
 944
 945                 /*
 946                  * 2.B. If the object is a directory and ACL_ENTRY_FILE_INHERIT
 947                  *      is set, but ACL_ENTRY_NO_PROPAGATE_INHERIT is not set, ensure
 948                  *      that ACL_ENTRY_INHERIT_ONLY is set.  Continue to the
 949                  *      next ACE.  Otherwise...
 950                  */
 951                 /*
 952                  * XXX: Read it again and make sure what does the "otherwise"
 953                  *      apply to.
 954                  */
 955                 if (is_directory &&
 956                     (entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
 957                     ((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
 958                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 959                         continue;
 960                 }
 961
 962                 /*
 963                  * 2.C. If the type of the ACE is neither ALLOW nor deny,
 964                  *      then continue.
 965                  */
 966                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 967                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 968                         continue;
 969
 970                 /*
 971                  * 2.D. Copy the original ACE into a second, adjacent ACE.
 972                  */
 973                 copy = _acl_duplicate_entry(child_aclp, i);
 974
 975                 /*
 976                  * 2.E. On the first ACE, ensure that ACL_ENTRY_INHERIT_ONLY
 977                  *      is set.
 978                  */
 979                 entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 980
 981                 /*
 982                  * 2.F. On the second ACE, clear the following flags:
 983                  *      ACL_ENTRY_NO_PROPAGATE_INHERIT, ACL_ENTRY_FILE_INHERIT,
 984                  *      ACL_ENTRY_DIRECTORY_INHERIT, ACL_ENTRY_INHERIT_ONLY.
 985                  */
 986                 copy->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
 987                     ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
 988                     ACL_ENTRY_INHERIT_ONLY);
 989
 990                 /*
 991                  * 2.G. On the second ACE, if the type is ALLOW,
 992                  *      an implementation MAY clear the following
 993                  *      mask bits: ACL_WRITE_ACL, ACL_WRITE_OWNER.
 994                  */
 995                 if (copy->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
 996                         copy->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
 997
 998                 /*
 999                  * Increment the counter to skip the copied entry.
1000                  */
1001                 i++;
1002         }
1003
1004         /*
1005          * 3. To ensure that the mode is honored, apply the algorithm describe
1006          *    in Section 2.16.6.3, using the mode that is to be used for file
1007          *    creation.
1008          */
1009         acl_nfs4_sync_acl_from_mode(child_aclp, mode, file_owner_id);
1010 }
1011 #endif /* _KERNEL */
1012
1013 /*
1014  * Populate the ACL with entries inherited from parent_aclp.
1015  */
1016 static void
1017 acl_nfs4_inherit_entries(const struct acl *parent_aclp,
1018     struct acl *child_aclp, mode_t mode, int file_owner_id,
1019     int is_directory)
1020 {
1021         int i, flags, tag;
1022         const struct acl_entry *parent_entry;
1023         struct acl_entry *entry;
1024
1025         KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
1026             ("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
1027
1028         for (i = 0; i < parent_aclp->acl_cnt; i++) {
1029                 parent_entry = &(parent_aclp->acl_entry[i]);
1030                 flags = parent_entry->ae_flags;
1031                 tag = parent_entry->ae_tag;
1032
1033                 /*
1034                  * Don't inherit owner@, group@, or everyone@ entries.
1035                  */
1036                 if (tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ ||
1037                     tag == ACL_EVERYONE)
1038                         continue;
1039
1040                 /*
1041                  * Entry is not inheritable at all.
1042                  */
1043                 if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
1044                     ACL_ENTRY_FILE_INHERIT)) == 0)
1045                         continue;
1046
1047                 /*
1048                  * We're creating a file, but entry is not inheritable
1049                  * by files.
1050                  */
1051                 if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
1052                         continue;
1053
1054                 /*
1055                  * Entry is inheritable only by files, but has NO_PROPAGATE
1056                  * flag set, and we're creating a directory, so it wouldn't
1057                  * propagate to any file in that directory anyway.
1058                  */
1059                 if (is_directory &&
1060                     (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
1061                     (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
1062                         continue;
1063
1064                 /*
1065                  * Entry qualifies for being inherited.
1066                  */
1067                 KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
1068                     ("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
1069                 entry = &(child_aclp->acl_entry[child_aclp->acl_cnt]);
1070                 *entry = *parent_entry;
1071                 child_aclp->acl_cnt++;
1072
1073                 entry->ae_flags &= ~ACL_ENTRY_INHERIT_ONLY;
1074                 entry->ae_flags |= ACL_ENTRY_INHERITED;
1075
1076                 /*
1077                  * If the type of the ACE is neither ALLOW nor DENY,
1078                  * then leave it as it is and proceed to the next one.
1079                  */
1080                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
1081                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
1082                         continue;
1083
1084                 /*
1085                  * If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if
1086                  * the object being created is not a directory, then clear
1087                  * the following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
1088                  * ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
1089                  * ACL_ENTRY_INHERIT_ONLY.
1090                  */
1091                 if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
1092                     !is_directory) {
1093                         entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
1094                         ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
1095                         ACL_ENTRY_INHERIT_ONLY);
1096                 }
1097
1098                 /*
1099                  * If the object is a directory and ACL_ENTRY_FILE_INHERIT
1100                  * is set, but ACL_ENTRY_DIRECTORY_INHERIT is not set, ensure
1101                  * that ACL_ENTRY_INHERIT_ONLY is set.
1102                  */
1103                 if (is_directory &&
1104                     (entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
1105                     ((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
1106                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
1107                 }
1108
1109                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW &&
1110                     (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY) == 0) {
1111                         /*
1112                          * Some permissions must never be inherited.
1113                          */
1114                         entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER |
1115                             ACL_WRITE_NAMED_ATTRS | ACL_WRITE_ATTRIBUTES);
1116
1117                         /*
1118                          * Others must be masked according to the file mode.
1119                          */
1120                         if ((mode & S_IRGRP) == 0)
1121                                 entry->ae_perm &= ~ACL_READ_DATA;
1122                         if ((mode & S_IWGRP) == 0)
1123                                 entry->ae_perm &=
1124                                     ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
1125                         if ((mode & S_IXGRP) == 0)
1126                                 entry->ae_perm &= ~ACL_EXECUTE;
1127                 }
1128         }
1129 }
1130
1131 /*
1132  * Calculate inherited ACL in a manner compatible with PSARC/2010/029.
1133  * It's also being used to calculate a trivial ACL, by inheriting from
1134  * a NULL ACL.
1135  */
1136 static void
1137 acl_nfs4_compute_inherited_acl_psarc(const struct acl *parent_aclp,
1138     struct acl *aclp, mode_t mode, int file_owner_id, int is_directory)
1139 {
1140         acl_perm_t user_allow_first = 0, user_deny = 0, group_deny = 0;
1141         acl_perm_t user_allow, group_allow, everyone_allow;
1142
1143         KASSERT(aclp->acl_cnt == 0, ("aclp->acl_cnt == 0"));
1144
1145         user_allow = group_allow = everyone_allow = ACL_READ_ACL |
1146             ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS | ACL_SYNCHRONIZE;
1147         user_allow |= ACL_WRITE_ACL | ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
1148             ACL_WRITE_NAMED_ATTRS;
1149
1150         if (mode & S_IRUSR)
1151                 user_allow |= ACL_READ_DATA;
1152         if (mode & S_IWUSR)
1153                 user_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1154         if (mode & S_IXUSR)
1155                 user_allow |= ACL_EXECUTE;
1156
1157         if (mode & S_IRGRP)
1158                 group_allow |= ACL_READ_DATA;
1159         if (mode & S_IWGRP)
1160                 group_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1161         if (mode & S_IXGRP)
1162                 group_allow |= ACL_EXECUTE;
1163
1164         if (mode & S_IROTH)
1165                 everyone_allow |= ACL_READ_DATA;
1166         if (mode & S_IWOTH)
1167                 everyone_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
1168         if (mode & S_IXOTH)
1169                 everyone_allow |= ACL_EXECUTE;
1170
1171         user_deny = ((group_allow | everyone_allow) & ~user_allow);
1172         group_deny = everyone_allow & ~group_allow;
1173         user_allow_first = group_deny & ~user_deny;
1174
1175         if (user_allow_first != 0)
1176                 _acl_append(aclp, ACL_USER_OBJ, user_allow_first,
1177                     ACL_ENTRY_TYPE_ALLOW);
1178         if (user_deny != 0)
1179                 _acl_append(aclp, ACL_USER_OBJ, user_deny,
1180                     ACL_ENTRY_TYPE_DENY);
1181         if (group_deny != 0)
1182                 _acl_append(aclp, ACL_GROUP_OBJ, group_deny,
1183                     ACL_ENTRY_TYPE_DENY);
1184
1185         if (parent_aclp != NULL)
1186                 acl_nfs4_inherit_entries(parent_aclp, aclp, mode,
1187                     file_owner_id, is_directory);
1188
1189         _acl_append(aclp, ACL_USER_OBJ, user_allow, ACL_ENTRY_TYPE_ALLOW);
1190         _acl_append(aclp, ACL_GROUP_OBJ, group_allow, ACL_ENTRY_TYPE_ALLOW);
1191         _acl_append(aclp, ACL_EVERYONE, everyone_allow, ACL_ENTRY_TYPE_ALLOW);
1192 }
1193
1194 #ifdef _KERNEL
1195 void
1196 acl_nfs4_compute_inherited_acl(const struct acl *parent_aclp,
1197     struct acl *child_aclp, mode_t mode, int file_owner_id,
1198     int is_directory)
1199 {
1200
1201         if (acl_nfs4_old_semantics)
1202                 acl_nfs4_compute_inherited_acl_draft(parent_aclp, child_aclp,
1203                     mode, file_owner_id, is_directory);
1204         else
1205                 acl_nfs4_compute_inherited_acl_psarc(parent_aclp, child_aclp,
1206                     mode, file_owner_id, is_directory);
1207 }
1208 #endif /* _KERNEL */
1209
1210 /*
1211  * Calculate trivial ACL in a manner compatible with PSARC/2010/029.
1212  * Note that this results in an ACL different from (but semantically
1213  * equal to) the "canonical six" trivial ACL computed using algorithm
1214  * described in draft-ietf-nfsv4-minorversion1-03.txt, 3.16.6.2.
1215  */
1216 static void
1217 acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode)
1218 {
1219
1220         aclp->acl_cnt = 0;
1221         acl_nfs4_compute_inherited_acl_psarc(NULL, aclp, mode, -1, -1);
1222 }
1223
1224 #ifndef _KERNEL
1225 /*
1226  * This routine is used by libc to implement acl_strip_np(3)
1227  * and acl_is_trivial_np(3).
1228  */
1229 void
1230 acl_nfs4_trivial_from_mode_libc(struct acl *aclp, int mode, int canonical_six)
1231 {
1232
1233         aclp->acl_cnt = 0;
1234         if (canonical_six)
1235                 acl_nfs4_sync_acl_from_mode_draft(aclp, mode, -1);
1236         else
1237                 acl_nfs4_trivial_from_mode(aclp, mode);
1238 }
1239 #endif /* !_KERNEL */
1240
1241 #ifdef _KERNEL
1242 static int
1243 _acls_are_equal(const struct acl *a, const struct acl *b)
1244 {
1245         int i;
1246         const struct acl_entry *entrya, *entryb;
1247
1248         if (a->acl_cnt != b->acl_cnt)
1249                 return (0);
1250
1251         for (i = 0; i < b->acl_cnt; i++) {
1252                 entrya = &(a->acl_entry[i]);
1253                 entryb = &(b->acl_entry[i]);
1254
1255                 if (entrya->ae_tag != entryb->ae_tag ||
1256                     entrya->ae_id != entryb->ae_id ||
1257                     entrya->ae_perm != entryb->ae_perm ||
1258                     entrya->ae_entry_type != entryb->ae_entry_type ||
1259                     entrya->ae_flags != entryb->ae_flags)
1260                         return (0);
1261         }
1262
1263         return (1);
1264 }
1265
1266 /*
1267  * This routine is used to determine whether to remove extended attribute
1268  * that stores ACL contents.
1269  */
1270 int
1271 acl_nfs4_is_trivial(const struct acl *aclp, int file_owner_id)
1272 {
1273         int trivial;
1274         mode_t tmpmode = 0;
1275         struct acl *tmpaclp;
1276
1277         if (aclp->acl_cnt > 6)
1278                 return (0);
1279
1280         /*
1281          * Compute the mode from the ACL, then compute new ACL from that mode.
1282          * If the ACLs are identical, then the ACL is trivial.
1283          *
1284          * XXX: I guess there is a faster way to do this.  However, even
1285          *      this slow implementation significantly speeds things up
1286          *      for files that don't have non-trivial ACLs - it's critical
1287          *      for performance to not use EA when they are not needed.
1288          *
1289          * First try the PSARC/2010/029 semantics.
1290          */
1291         tmpaclp = acl_alloc(M_WAITOK | M_ZERO);
1292         acl_nfs4_sync_mode_from_acl(&tmpmode, aclp);
1293         acl_nfs4_trivial_from_mode(tmpaclp, tmpmode);
1294         trivial = _acls_are_equal(aclp, tmpaclp);
1295         if (trivial) {
1296                 acl_free(tmpaclp);
1297                 return (trivial);
1298         }
1299
1300         /*
1301          * Check if it's a draft-ietf-nfsv4-minorversion1-03.txt trivial ACL.
1302          */
1303         tmpaclp->acl_cnt = 0;
1304         acl_nfs4_sync_acl_from_mode_draft(tmpaclp, tmpmode, file_owner_id);
1305         trivial = _acls_are_equal(aclp, tmpaclp);
1306         acl_free(tmpaclp);
1307
1308         return (trivial);
1309 }
1310 #endif /* _KERNEL */
1311
1312 int
1313 acl_nfs4_check(const struct acl *aclp, int is_directory)
1314 {
1315         int i;
1316         const struct acl_entry *entry;
1317
1318         /*
1319          * The spec doesn't seem to say anything about ACL validity.
1320          * It seems there is not much to do here.  There is even no need
1321          * to count "owner@" or "everyone@" (ACL_USER_OBJ and ACL_EVERYONE)
1322          * entries, as there can be several of them and that's perfectly
1323          * valid.  There can be none of them too.  Really.
1324          */
1325
1326         if (aclp->acl_cnt > ACL_MAX_ENTRIES || aclp->acl_cnt <= 0)
1327                 return (EINVAL);
1328
1329         for (i = 0; i < aclp->acl_cnt; i++) {
1330                 entry = &(aclp->acl_entry[i]);
1331
1332                 switch (entry->ae_tag) {
1333                 case ACL_USER_OBJ:
1334                 case ACL_GROUP_OBJ:
1335                 case ACL_EVERYONE:
1336                         if (entry->ae_id != ACL_UNDEFINED_ID)
1337                                 return (EINVAL);
1338                         break;
1339
1340                 case ACL_USER:
1341                 case ACL_GROUP:
1342                         if (entry->ae_id == ACL_UNDEFINED_ID)
1343                                 return (EINVAL);
1344                         break;
1345
1346                 default:
1347                         return (EINVAL);
1348                 }
1349
1350                 if ((entry->ae_perm | ACL_NFS4_PERM_BITS) != ACL_NFS4_PERM_BITS)
1351                         return (EINVAL);
1352
1353                 /*
1354                  * Disallow ACL_ENTRY_TYPE_AUDIT and ACL_ENTRY_TYPE_ALARM for now.
1355                  */
1356                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
1357                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
1358                         return (EINVAL);
1359
1360                 if ((entry->ae_flags | ACL_FLAGS_BITS) != ACL_FLAGS_BITS)
1361                         return (EINVAL);
1362
1363                 /* Disallow unimplemented flags. */
1364                 if (entry->ae_flags & (ACL_ENTRY_SUCCESSFUL_ACCESS |
1365                     ACL_ENTRY_FAILED_ACCESS))
1366                         return (EINVAL);
1367
1368                 /* Disallow flags not allowed for ordinary files. */
1369                 if (!is_directory) {
1370                         if (entry->ae_flags & (ACL_ENTRY_FILE_INHERIT |
1371                             ACL_ENTRY_DIRECTORY_INHERIT |
1372                             ACL_ENTRY_NO_PROPAGATE_INHERIT | ACL_ENTRY_INHERIT_ONLY))
1373                                 return (EINVAL);
1374                 }
1375         }
1376
1377         return (0);
1378 }
1379
1380 #ifdef  _KERNEL
1381 static int
1382 acl_nfs4_modload(module_t module, int what, void *arg)
1383 {
1384         int ret;
1385
1386         ret = 0;
1387
1388         switch (what) {
1389         case MOD_LOAD:
1390         case MOD_SHUTDOWN:
1391                 break;
1392
1393         case MOD_QUIESCE:
1394                 /* XXX TODO */
1395                 ret = 0;
1396                 break;
1397
1398         case MOD_UNLOAD:
1399                 /* XXX TODO */
1400                 ret = 0;
1401                 break;
1402         default:
1403                 ret = EINVAL;
1404                 break;
1405         }
1406
1407         return (ret);
1408 }
1409
1410 static moduledata_t acl_nfs4_mod = {
1411         "acl_nfs4",
1412         acl_nfs4_modload,
1413         NULL
1414 };
1415
1416 /*
1417  * XXX TODO: which subsystem, order?
1418  */
1419 DECLARE_MODULE(acl_nfs4, acl_nfs4_mod, SI_SUB_VFS, SI_ORDER_FIRST);
1420 MODULE_VERSION(acl_nfs4, 1);
1421 #endif  /* _KERNEL */