The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_acl_nfs4.c

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    1 /*-
    2  * Copyright (c) 2008-2010 Edward Tomasz NapieraƂa <trasz@FreeBSD.org>
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   24  * SUCH DAMAGE.
   25  */
   26 
   27 /*
   28  * ACL support routines specific to NFSv4 access control lists.  These are
   29  * utility routines for code common across file systems implementing NFSv4
   30  * ACLs.
   31  */
   32 
   33 #ifdef _KERNEL
   34 #include <sys/cdefs.h>
   35 __FBSDID("$FreeBSD: stable/10/sys/kern/subr_acl_nfs4.c 290893 2015-11-15 23:54:34Z ngie $");
   36 
   37 #include <sys/param.h>
   38 #include <sys/kernel.h>
   39 #include <sys/module.h>
   40 #include <sys/systm.h>
   41 #include <sys/mount.h>
   42 #include <sys/priv.h>
   43 #include <sys/vnode.h>
   44 #include <sys/errno.h>
   45 #include <sys/stat.h>
   46 #include <sys/sysctl.h>
   47 #include <sys/acl.h>
   48 #else
   49 #include <errno.h>
   50 #include <assert.h>
   51 #include <sys/acl.h>
   52 #include <sys/stat.h>
   53 #define KASSERT(a, b) assert(a)
   54 #define CTASSERT(a)
   55 
   56 #endif /* !_KERNEL */
   57 
   58 #ifdef _KERNEL
   59 
   60 static void     acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode);
   61 
   62 static int      acl_nfs4_old_semantics = 0;
   63 
   64 SYSCTL_INT(_vfs, OID_AUTO, acl_nfs4_old_semantics, CTLFLAG_RW,
   65     &acl_nfs4_old_semantics, 0, "Use pre-PSARC/2010/029 NFSv4 ACL semantics");
   66 
   67 static struct {
   68         accmode_t accmode;
   69         int mask;
   70 } accmode2mask[] = {{VREAD, ACL_READ_DATA},
   71                     {VWRITE, ACL_WRITE_DATA},
   72                     {VAPPEND, ACL_APPEND_DATA},
   73                     {VEXEC, ACL_EXECUTE},
   74                     {VREAD_NAMED_ATTRS, ACL_READ_NAMED_ATTRS},
   75                     {VWRITE_NAMED_ATTRS, ACL_WRITE_NAMED_ATTRS},
   76                     {VDELETE_CHILD, ACL_DELETE_CHILD},
   77                     {VREAD_ATTRIBUTES, ACL_READ_ATTRIBUTES},
   78                     {VWRITE_ATTRIBUTES, ACL_WRITE_ATTRIBUTES},
   79                     {VDELETE, ACL_DELETE},
   80                     {VREAD_ACL, ACL_READ_ACL},
   81                     {VWRITE_ACL, ACL_WRITE_ACL},
   82                     {VWRITE_OWNER, ACL_WRITE_OWNER},
   83                     {VSYNCHRONIZE, ACL_SYNCHRONIZE},
   84                     {0, 0}};
   85 
   86 static int
   87 _access_mask_from_accmode(accmode_t accmode)
   88 {
   89         int access_mask = 0, i;
   90 
   91         for (i = 0; accmode2mask[i].accmode != 0; i++) {
   92                 if (accmode & accmode2mask[i].accmode)
   93                         access_mask |= accmode2mask[i].mask;
   94         }
   95 
   96         /*
   97          * VAPPEND is just a modifier for VWRITE; if the caller asked
   98          * for 'VAPPEND | VWRITE', we want to check for ACL_APPEND_DATA only.
   99          */
  100         if (access_mask & ACL_APPEND_DATA)
  101                 access_mask &= ~ACL_WRITE_DATA;
  102 
  103         return (access_mask);
  104 }
  105 
  106 /*
  107  * Return 0, iff access is allowed, 1 otherwise.
  108  */
  109 static int
  110 _acl_denies(const struct acl *aclp, int access_mask, struct ucred *cred,
  111     int file_uid, int file_gid, int *denied_explicitly)
  112 {
  113         int i;
  114         const struct acl_entry *entry;
  115 
  116         if (denied_explicitly != NULL)
  117                 *denied_explicitly = 0;
  118 
  119         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
  120             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
  121 
  122         for (i = 0; i < aclp->acl_cnt; i++) {
  123                 entry = &(aclp->acl_entry[i]);
  124 
  125                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
  126                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
  127                         continue;
  128                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
  129                         continue;
  130                 switch (entry->ae_tag) {
  131                 case ACL_USER_OBJ:
  132                         if (file_uid != cred->cr_uid)
  133                                 continue;
  134                         break;
  135                 case ACL_USER:
  136                         if (entry->ae_id != cred->cr_uid)
  137                                 continue;
  138                         break;
  139                 case ACL_GROUP_OBJ:
  140                         if (!groupmember(file_gid, cred))
  141                                 continue;
  142                         break;
  143                 case ACL_GROUP:
  144                         if (!groupmember(entry->ae_id, cred))
  145                                 continue;
  146                         break;
  147                 default:
  148                         KASSERT(entry->ae_tag == ACL_EVERYONE,
  149                             ("entry->ae_tag == ACL_EVERYONE"));
  150                 }
  151 
  152                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_DENY) {
  153                         if (entry->ae_perm & access_mask) {
  154                                 if (denied_explicitly != NULL)
  155                                         *denied_explicitly = 1;
  156                                 return (1);
  157                         }
  158                 }
  159 
  160                 access_mask &= ~(entry->ae_perm);
  161                 if (access_mask == 0)
  162                         return (0);
  163         }
  164 
  165         if (access_mask == 0)
  166                 return (0);
  167 
  168         return (1);
  169 }
  170 
  171 int
  172 vaccess_acl_nfs4(enum vtype type, uid_t file_uid, gid_t file_gid,
  173     struct acl *aclp, accmode_t accmode, struct ucred *cred, int *privused)
  174 {
  175         accmode_t priv_granted = 0;
  176         int denied, explicitly_denied, access_mask, is_directory,
  177             must_be_owner = 0;
  178         mode_t file_mode = 0;
  179 
  180         KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND |
  181             VEXPLICIT_DENY | VREAD_NAMED_ATTRS | VWRITE_NAMED_ATTRS |
  182             VDELETE_CHILD | VREAD_ATTRIBUTES | VWRITE_ATTRIBUTES | VDELETE |
  183             VREAD_ACL | VWRITE_ACL | VWRITE_OWNER | VSYNCHRONIZE)) == 0,
  184             ("invalid bit in accmode"));
  185         KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
  186                 ("VAPPEND without VWRITE"));
  187 
  188         if (privused != NULL)
  189                 *privused = 0;
  190 
  191         if (accmode & VADMIN)
  192                 must_be_owner = 1;
  193 
  194         /*
  195          * Ignore VSYNCHRONIZE permission.
  196          */
  197         accmode &= ~VSYNCHRONIZE;
  198 
  199         access_mask = _access_mask_from_accmode(accmode);
  200 
  201         if (type == VDIR)
  202                 is_directory = 1;
  203         else
  204                 is_directory = 0;
  205 
  206         /*
  207          * File owner is always allowed to read and write the ACL
  208          * and basic attributes.  This is to prevent a situation
  209          * where user would change ACL in a way that prevents him
  210          * from undoing the change.
  211          */
  212         if (file_uid == cred->cr_uid)
  213                 access_mask &= ~(ACL_READ_ACL | ACL_WRITE_ACL |
  214                     ACL_READ_ATTRIBUTES | ACL_WRITE_ATTRIBUTES);
  215 
  216         /*
  217          * Ignore append permission for regular files; use write
  218          * permission instead.
  219          */
  220         if (!is_directory && (access_mask & ACL_APPEND_DATA)) {
  221                 access_mask &= ~ACL_APPEND_DATA;
  222                 access_mask |= ACL_WRITE_DATA;
  223         }
  224 
  225         denied = _acl_denies(aclp, access_mask, cred, file_uid, file_gid,
  226             &explicitly_denied);
  227 
  228         if (must_be_owner) {
  229                 if (file_uid != cred->cr_uid)
  230                         denied = EPERM;
  231         }
  232 
  233         /*
  234          * For VEXEC, ensure that at least one execute bit is set for
  235          * non-directories. We have to check the mode here to stay
  236          * consistent with execve(2). See the test in
  237          * exec_check_permissions().
  238          */
  239         acl_nfs4_sync_mode_from_acl(&file_mode, aclp);
  240         if (!denied && !is_directory && (accmode & VEXEC) &&
  241             (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)
  242                 denied = EACCES;
  243 
  244         if (!denied)
  245                 return (0);
  246 
  247         /*
  248          * Access failed.  Iff it was not denied explicitly and
  249          * VEXPLICIT_DENY flag was specified, allow access.
  250          */
  251         if ((accmode & VEXPLICIT_DENY) && explicitly_denied == 0)
  252                 return (0);
  253 
  254         accmode &= ~VEXPLICIT_DENY;
  255 
  256         /*
  257          * No match.  Try to use privileges, if there are any.
  258          */
  259         if (is_directory) {
  260                 if ((accmode & VEXEC) && !priv_check_cred(cred,
  261                     PRIV_VFS_LOOKUP, 0))
  262                         priv_granted |= VEXEC;
  263         } else {
  264                 /*
  265                  * Ensure that at least one execute bit is on. Otherwise,
  266                  * a privileged user will always succeed, and we don't want
  267                  * this to happen unless the file really is executable.
  268                  */
  269                 if ((accmode & VEXEC) && (file_mode &
  270                     (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
  271                     !priv_check_cred(cred, PRIV_VFS_EXEC, 0))
  272                         priv_granted |= VEXEC;
  273         }
  274 
  275         if ((accmode & VREAD) && !priv_check_cred(cred, PRIV_VFS_READ, 0))
  276                 priv_granted |= VREAD;
  277 
  278         if ((accmode & (VWRITE | VAPPEND | VDELETE_CHILD)) &&
  279             !priv_check_cred(cred, PRIV_VFS_WRITE, 0))
  280                 priv_granted |= (VWRITE | VAPPEND | VDELETE_CHILD);
  281 
  282         if ((accmode & VADMIN_PERMS) &&
  283             !priv_check_cred(cred, PRIV_VFS_ADMIN, 0))
  284                 priv_granted |= VADMIN_PERMS;
  285 
  286         if ((accmode & VSTAT_PERMS) &&
  287             !priv_check_cred(cred, PRIV_VFS_STAT, 0))
  288                 priv_granted |= VSTAT_PERMS;
  289 
  290         if ((accmode & priv_granted) == accmode) {
  291                 if (privused != NULL)
  292                         *privused = 1;
  293 
  294                 return (0);
  295         }
  296 
  297         if (accmode & (VADMIN_PERMS | VDELETE_CHILD | VDELETE))
  298                 denied = EPERM;
  299         else
  300                 denied = EACCES;
  301 
  302         return (denied);
  303 }
  304 #endif /* _KERNEL */
  305 
  306 static int
  307 _acl_entry_matches(struct acl_entry *entry, acl_tag_t tag, acl_perm_t perm,
  308     acl_entry_type_t entry_type)
  309 {
  310         if (entry->ae_tag != tag)
  311                 return (0);
  312 
  313         if (entry->ae_id != ACL_UNDEFINED_ID)
  314                 return (0);
  315 
  316         if (entry->ae_perm != perm)
  317                 return (0);
  318 
  319         if (entry->ae_entry_type != entry_type)
  320                 return (0);
  321 
  322         if (entry->ae_flags != 0)
  323                 return (0);
  324 
  325         return (1);
  326 }
  327 
  328 static struct acl_entry *
  329 _acl_append(struct acl *aclp, acl_tag_t tag, acl_perm_t perm,
  330     acl_entry_type_t entry_type)
  331 {
  332         struct acl_entry *entry;
  333 
  334         KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
  335             ("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
  336 
  337         entry = &(aclp->acl_entry[aclp->acl_cnt]);
  338         aclp->acl_cnt++;
  339 
  340         entry->ae_tag = tag;
  341         entry->ae_id = ACL_UNDEFINED_ID;
  342         entry->ae_perm = perm;
  343         entry->ae_entry_type = entry_type;
  344         entry->ae_flags = 0;
  345 
  346         return (entry);
  347 }
  348 
  349 static struct acl_entry *
  350 _acl_duplicate_entry(struct acl *aclp, int entry_index)
  351 {
  352         int i;
  353 
  354         KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
  355             ("aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
  356 
  357         for (i = aclp->acl_cnt; i > entry_index; i--)
  358                 aclp->acl_entry[i] = aclp->acl_entry[i - 1];
  359 
  360         aclp->acl_cnt++;
  361 
  362         return (&(aclp->acl_entry[entry_index + 1]));
  363 }
  364 
  365 static void
  366 acl_nfs4_sync_acl_from_mode_draft(struct acl *aclp, mode_t mode,
  367     int file_owner_id)
  368 {
  369         int i, meets, must_append;
  370         struct acl_entry *entry, *copy, *previous,
  371             *a1, *a2, *a3, *a4, *a5, *a6;
  372         mode_t amode;
  373         const int READ = 04;
  374         const int WRITE = 02;
  375         const int EXEC = 01;
  376 
  377         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
  378             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
  379 
  380         /*
  381          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
  382          *
  383          * 3.16.6.3. Applying a Mode to an Existing ACL
  384          */
  385 
  386         /*
  387          * 1. For each ACE:
  388          */
  389         for (i = 0; i < aclp->acl_cnt; i++) {
  390                 entry = &(aclp->acl_entry[i]);
  391 
  392                 /*
  393                  * 1.1. If the type is neither ALLOW or DENY - skip.
  394                  */
  395                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
  396                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
  397                         continue;
  398 
  399                 /*
  400                  * 1.2. If ACL_ENTRY_INHERIT_ONLY is set - skip.
  401                  */
  402                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
  403                         continue;
  404 
  405                 /*
  406                  * 1.3. If ACL_ENTRY_FILE_INHERIT or ACL_ENTRY_DIRECTORY_INHERIT
  407                  *      are set:
  408                  */
  409                 if (entry->ae_flags &
  410                     (ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT)) {
  411                         /*
  412                          * 1.3.1. A copy of the current ACE is made, and placed
  413                          *        in the ACL immediately following the current
  414                          *        ACE.
  415                          */
  416                         copy = _acl_duplicate_entry(aclp, i);
  417 
  418                         /*
  419                          * 1.3.2. In the first ACE, the flag
  420                          *        ACL_ENTRY_INHERIT_ONLY is set.
  421                          */
  422                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
  423 
  424                         /*
  425                          * 1.3.3. In the second ACE, the following flags
  426                          *        are cleared:
  427                          *        ACL_ENTRY_FILE_INHERIT,
  428                          *        ACL_ENTRY_DIRECTORY_INHERIT,
  429                          *        ACL_ENTRY_NO_PROPAGATE_INHERIT.
  430                          */
  431                         copy->ae_flags &= ~(ACL_ENTRY_FILE_INHERIT |
  432                             ACL_ENTRY_DIRECTORY_INHERIT |
  433                             ACL_ENTRY_NO_PROPAGATE_INHERIT);
  434 
  435                         /*
  436                          * The algorithm continues on with the second ACE.
  437                          */
  438                         i++;
  439                         entry = copy;
  440                 }
  441 
  442                 /*
  443                  * 1.4. If it's owner@, group@ or everyone@ entry, clear
  444                  *      ACL_READ_DATA, ACL_WRITE_DATA, ACL_APPEND_DATA
  445                  *      and ACL_EXECUTE.  Continue to the next entry.
  446                  */
  447                 if (entry->ae_tag == ACL_USER_OBJ ||
  448                     entry->ae_tag == ACL_GROUP_OBJ ||
  449                     entry->ae_tag == ACL_EVERYONE) {
  450                         entry->ae_perm &= ~(ACL_READ_DATA | ACL_WRITE_DATA |
  451                             ACL_APPEND_DATA | ACL_EXECUTE);
  452                         continue;
  453                 }
  454 
  455                 /*
  456                  * 1.5. Otherwise, if the "who" field did not match one
  457                  *      of OWNER@, GROUP@, EVERYONE@:
  458                  *
  459                  * 1.5.1. If the type is ALLOW, check the preceding ACE.
  460                  *        If it does not meet all of the following criteria:
  461                  */
  462                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW)
  463                         continue;
  464 
  465                 meets = 0;
  466                 if (i > 0) {
  467                         meets = 1;
  468                         previous = &(aclp->acl_entry[i - 1]);
  469 
  470                         /*
  471                          * 1.5.1.1. The type field is DENY,
  472                          */
  473                         if (previous->ae_entry_type != ACL_ENTRY_TYPE_DENY)
  474                                 meets = 0;
  475 
  476                         /*
  477                          * 1.5.1.2. The "who" field is the same as the current
  478                          *          ACE,
  479                          *
  480                          * 1.5.1.3. The flag bit ACE4_IDENTIFIER_GROUP
  481                          *          is the same as it is in the current ACE,
  482                          *          and no other flag bits are set,
  483                          */
  484                         if (previous->ae_id != entry->ae_id ||
  485                             previous->ae_tag != entry->ae_tag)
  486                                 meets = 0;
  487 
  488                         if (previous->ae_flags)
  489                                 meets = 0;
  490 
  491                         /*
  492                          * 1.5.1.4. The mask bits are a subset of the mask bits
  493                          *          of the current ACE, and are also subset of
  494                          *          the following: ACL_READ_DATA,
  495                          *          ACL_WRITE_DATA, ACL_APPEND_DATA, ACL_EXECUTE
  496                          */
  497                         if (previous->ae_perm & ~(entry->ae_perm))
  498                                 meets = 0;
  499 
  500                         if (previous->ae_perm & ~(ACL_READ_DATA |
  501                             ACL_WRITE_DATA | ACL_APPEND_DATA | ACL_EXECUTE))
  502                                 meets = 0;
  503                 }
  504 
  505                 if (!meets) {
  506                         /*
  507                          * Then the ACE of type DENY, with a who equal
  508                          * to the current ACE, flag bits equal to
  509                          * (<current ACE flags> & <ACE_IDENTIFIER_GROUP>)
  510                          * and no mask bits, is prepended.
  511                          */
  512                         previous = entry;
  513                         entry = _acl_duplicate_entry(aclp, i);
  514 
  515                         /* Adjust counter, as we've just added an entry. */
  516                         i++;
  517 
  518                         previous->ae_tag = entry->ae_tag;
  519                         previous->ae_id = entry->ae_id;
  520                         previous->ae_flags = entry->ae_flags;
  521                         previous->ae_perm = 0;
  522                         previous->ae_entry_type = ACL_ENTRY_TYPE_DENY;
  523                 }
  524 
  525                 /*
  526                  * 1.5.2. The following modifications are made to the prepended
  527                  *        ACE.  The intent is to mask the following ACE
  528                  *        to disallow ACL_READ_DATA, ACL_WRITE_DATA,
  529                  *        ACL_APPEND_DATA, or ACL_EXECUTE, based upon the group
  530                  *        permissions of the new mode.  As a special case,
  531                  *        if the ACE matches the current owner of the file,
  532                  *        the owner bits are used, rather than the group bits.
  533                  *        This is reflected in the algorithm below.
  534                  */
  535                 amode = mode >> 3;
  536 
  537                 /*
  538                  * If ACE4_IDENTIFIER_GROUP is not set, and the "who" field
  539                  * in ACE matches the owner of the file, we shift amode three
  540                  * more bits, in order to have the owner permission bits
  541                  * placed in the three low order bits of amode.
  542                  */
  543                 if (entry->ae_tag == ACL_USER && entry->ae_id == file_owner_id)
  544                         amode = amode >> 3;
  545 
  546                 if (entry->ae_perm & ACL_READ_DATA) {
  547                         if (amode & READ)
  548                                 previous->ae_perm &= ~ACL_READ_DATA;
  549                         else
  550                                 previous->ae_perm |= ACL_READ_DATA;
  551                 }
  552 
  553                 if (entry->ae_perm & ACL_WRITE_DATA) {
  554                         if (amode & WRITE)
  555                                 previous->ae_perm &= ~ACL_WRITE_DATA;
  556                         else
  557                                 previous->ae_perm |= ACL_WRITE_DATA;
  558                 }
  559 
  560                 if (entry->ae_perm & ACL_APPEND_DATA) {
  561                         if (amode & WRITE)
  562                                 previous->ae_perm &= ~ACL_APPEND_DATA;
  563                         else
  564                                 previous->ae_perm |= ACL_APPEND_DATA;
  565                 }
  566 
  567                 if (entry->ae_perm & ACL_EXECUTE) {
  568                         if (amode & EXEC)
  569                                 previous->ae_perm &= ~ACL_EXECUTE;
  570                         else
  571                                 previous->ae_perm |= ACL_EXECUTE;
  572                 }
  573 
  574                 /*
  575                  * 1.5.3. If ACE4_IDENTIFIER_GROUP is set in the flags
  576                  *        of the ALLOW ace:
  577                  *
  578                  * XXX: This point is not there in the Falkner's draft.
  579                  */
  580                 if (entry->ae_tag == ACL_GROUP &&
  581                     entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) {
  582                         mode_t extramode, ownermode;
  583                         extramode = (mode >> 3) & 07;
  584                         ownermode = mode >> 6;
  585                         extramode &= ~ownermode;
  586 
  587                         if (extramode) {
  588                                 if (extramode & READ) {
  589                                         entry->ae_perm &= ~ACL_READ_DATA;
  590                                         previous->ae_perm &= ~ACL_READ_DATA;
  591                                 }
  592 
  593                                 if (extramode & WRITE) {
  594                                         entry->ae_perm &=
  595                                             ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
  596                                         previous->ae_perm &=
  597                                             ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
  598                                 }
  599 
  600                                 if (extramode & EXEC) {
  601                                         entry->ae_perm &= ~ACL_EXECUTE;
  602                                         previous->ae_perm &= ~ACL_EXECUTE;
  603                                 }
  604                         }
  605                 }
  606         }
  607 
  608         /*
  609          * 2. If there at least six ACEs, the final six ACEs are examined.
  610          *    If they are not equal to what we want, append six ACEs.
  611          */
  612         must_append = 0;
  613         if (aclp->acl_cnt < 6) {
  614                 must_append = 1;
  615         } else {
  616                 a6 = &(aclp->acl_entry[aclp->acl_cnt - 1]);
  617                 a5 = &(aclp->acl_entry[aclp->acl_cnt - 2]);
  618                 a4 = &(aclp->acl_entry[aclp->acl_cnt - 3]);
  619                 a3 = &(aclp->acl_entry[aclp->acl_cnt - 4]);
  620                 a2 = &(aclp->acl_entry[aclp->acl_cnt - 5]);
  621                 a1 = &(aclp->acl_entry[aclp->acl_cnt - 6]);
  622 
  623                 if (!_acl_entry_matches(a1, ACL_USER_OBJ, 0,
  624                     ACL_ENTRY_TYPE_DENY))
  625                         must_append = 1;
  626                 if (!_acl_entry_matches(a2, ACL_USER_OBJ, ACL_WRITE_ACL |
  627                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
  628                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW))
  629                         must_append = 1;
  630                 if (!_acl_entry_matches(a3, ACL_GROUP_OBJ, 0,
  631                     ACL_ENTRY_TYPE_DENY))
  632                         must_append = 1;
  633                 if (!_acl_entry_matches(a4, ACL_GROUP_OBJ, 0,
  634                     ACL_ENTRY_TYPE_ALLOW))
  635                         must_append = 1;
  636                 if (!_acl_entry_matches(a5, ACL_EVERYONE, ACL_WRITE_ACL |
  637                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
  638                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY))
  639                         must_append = 1;
  640                 if (!_acl_entry_matches(a6, ACL_EVERYONE, ACL_READ_ACL |
  641                     ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
  642                     ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW))
  643                         must_append = 1;
  644         }
  645 
  646         if (must_append) {
  647                 KASSERT(aclp->acl_cnt + 6 <= ACL_MAX_ENTRIES,
  648                     ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
  649 
  650                 a1 = _acl_append(aclp, ACL_USER_OBJ, 0, ACL_ENTRY_TYPE_DENY);
  651                 a2 = _acl_append(aclp, ACL_USER_OBJ, ACL_WRITE_ACL |
  652                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
  653                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_ALLOW);
  654                 a3 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_DENY);
  655                 a4 = _acl_append(aclp, ACL_GROUP_OBJ, 0, ACL_ENTRY_TYPE_ALLOW);
  656                 a5 = _acl_append(aclp, ACL_EVERYONE, ACL_WRITE_ACL |
  657                     ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
  658                     ACL_WRITE_NAMED_ATTRS, ACL_ENTRY_TYPE_DENY);
  659                 a6 = _acl_append(aclp, ACL_EVERYONE, ACL_READ_ACL |
  660                     ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS |
  661                     ACL_SYNCHRONIZE, ACL_ENTRY_TYPE_ALLOW);
  662 
  663                 KASSERT(a1 != NULL && a2 != NULL && a3 != NULL && a4 != NULL &&
  664                     a5 != NULL && a6 != NULL, ("couldn't append to ACL."));
  665         }
  666 
  667         /*
  668          * 3. The final six ACEs are adjusted according to the incoming mode.
  669          */
  670         if (mode & S_IRUSR)
  671                 a2->ae_perm |= ACL_READ_DATA;
  672         else
  673                 a1->ae_perm |= ACL_READ_DATA;
  674         if (mode & S_IWUSR)
  675                 a2->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
  676         else
  677                 a1->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
  678         if (mode & S_IXUSR)
  679                 a2->ae_perm |= ACL_EXECUTE;
  680         else
  681                 a1->ae_perm |= ACL_EXECUTE;
  682 
  683         if (mode & S_IRGRP)
  684                 a4->ae_perm |= ACL_READ_DATA;
  685         else
  686                 a3->ae_perm |= ACL_READ_DATA;
  687         if (mode & S_IWGRP)
  688                 a4->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
  689         else
  690                 a3->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
  691         if (mode & S_IXGRP)
  692                 a4->ae_perm |= ACL_EXECUTE;
  693         else
  694                 a3->ae_perm |= ACL_EXECUTE;
  695 
  696         if (mode & S_IROTH)
  697                 a6->ae_perm |= ACL_READ_DATA;
  698         else
  699                 a5->ae_perm |= ACL_READ_DATA;
  700         if (mode & S_IWOTH)
  701                 a6->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
  702         else
  703                 a5->ae_perm |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
  704         if (mode & S_IXOTH)
  705                 a6->ae_perm |= ACL_EXECUTE;
  706         else
  707                 a5->ae_perm |= ACL_EXECUTE;
  708 }
  709 
  710 #ifdef _KERNEL
  711 void
  712 acl_nfs4_sync_acl_from_mode(struct acl *aclp, mode_t mode,
  713     int file_owner_id)
  714 {
  715 
  716         if (acl_nfs4_old_semantics)
  717                 acl_nfs4_sync_acl_from_mode_draft(aclp, mode, file_owner_id);
  718         else
  719                 acl_nfs4_trivial_from_mode(aclp, mode);
  720 }
  721 #endif /* _KERNEL */
  722 
  723 void
  724 acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp)
  725 {
  726         int i;
  727         mode_t old_mode = *_mode, mode = 0, seen = 0;
  728         const struct acl_entry *entry;
  729 
  730         KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES,
  731             ("aclp->acl_cnt <= ACL_MAX_ENTRIES"));
  732 
  733         /*
  734          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
  735          *
  736          * 3.16.6.1. Recomputing mode upon SETATTR of ACL
  737          */
  738 
  739         for (i = 0; i < aclp->acl_cnt; i++) {
  740                 entry = &(aclp->acl_entry[i]);
  741 
  742                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
  743                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
  744                         continue;
  745 
  746                 if (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY)
  747                         continue;
  748 
  749                 if (entry->ae_tag == ACL_USER_OBJ) {
  750                         if ((entry->ae_perm & ACL_READ_DATA) &&
  751                             ((seen & S_IRUSR) == 0)) {
  752                                 seen |= S_IRUSR;
  753                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  754                                         mode |= S_IRUSR;
  755                         }
  756                         if ((entry->ae_perm & ACL_WRITE_DATA) &&
  757                              ((seen & S_IWUSR) == 0)) {
  758                                 seen |= S_IWUSR;
  759                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  760                                         mode |= S_IWUSR;
  761                         }
  762                         if ((entry->ae_perm & ACL_EXECUTE) &&
  763                             ((seen & S_IXUSR) == 0)) {
  764                                 seen |= S_IXUSR;
  765                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  766                                         mode |= S_IXUSR;
  767                         }
  768                 } else if (entry->ae_tag == ACL_GROUP_OBJ) {
  769                         if ((entry->ae_perm & ACL_READ_DATA) &&
  770                             ((seen & S_IRGRP) == 0)) {
  771                                 seen |= S_IRGRP;
  772                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  773                                         mode |= S_IRGRP;
  774                         }
  775                         if ((entry->ae_perm & ACL_WRITE_DATA) &&
  776                             ((seen & S_IWGRP) == 0)) {
  777                                 seen |= S_IWGRP;
  778                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  779                                         mode |= S_IWGRP;
  780                         }
  781                         if ((entry->ae_perm & ACL_EXECUTE) &&
  782                             ((seen & S_IXGRP) == 0)) {
  783                                 seen |= S_IXGRP;
  784                                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  785                                         mode |= S_IXGRP;
  786                         }
  787                 } else if (entry->ae_tag == ACL_EVERYONE) {
  788                         if (entry->ae_perm & ACL_READ_DATA) {
  789                                 if ((seen & S_IRUSR) == 0) {
  790                                         seen |= S_IRUSR;
  791                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  792                                                 mode |= S_IRUSR;
  793                                 }
  794                                 if ((seen & S_IRGRP) == 0) {
  795                                         seen |= S_IRGRP;
  796                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  797                                                 mode |= S_IRGRP;
  798                                 }
  799                                 if ((seen & S_IROTH) == 0) {
  800                                         seen |= S_IROTH;
  801                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  802                                                 mode |= S_IROTH;
  803                                 }
  804                         }
  805                         if (entry->ae_perm & ACL_WRITE_DATA) {
  806                                 if ((seen & S_IWUSR) == 0) {
  807                                         seen |= S_IWUSR;
  808                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  809                                                 mode |= S_IWUSR;
  810                                 }
  811                                 if ((seen & S_IWGRP) == 0) {
  812                                         seen |= S_IWGRP;
  813                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  814                                                 mode |= S_IWGRP;
  815                                 }
  816                                 if ((seen & S_IWOTH) == 0) {
  817                                         seen |= S_IWOTH;
  818                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  819                                                 mode |= S_IWOTH;
  820                                 }
  821                         }
  822                         if (entry->ae_perm & ACL_EXECUTE) {
  823                                 if ((seen & S_IXUSR) == 0) {
  824                                         seen |= S_IXUSR;
  825                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  826                                                 mode |= S_IXUSR;
  827                                 }
  828                                 if ((seen & S_IXGRP) == 0) {
  829                                         seen |= S_IXGRP;
  830                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  831                                                 mode |= S_IXGRP;
  832                                 }
  833                                 if ((seen & S_IXOTH) == 0) {
  834                                         seen |= S_IXOTH;
  835                                         if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  836                                                 mode |= S_IXOTH;
  837                                 }
  838                         }
  839                 }
  840         }
  841 
  842         *_mode = mode | (old_mode & ACL_PRESERVE_MASK);
  843 }
  844 
  845 #ifdef _KERNEL
  846 /*
  847  * Calculate inherited ACL in a manner compatible with NFSv4 Minor Version 1,
  848  * draft-ietf-nfsv4-minorversion1-03.txt.
  849  */
  850 static void             
  851 acl_nfs4_compute_inherited_acl_draft(const struct acl *parent_aclp,
  852     struct acl *child_aclp, mode_t mode, int file_owner_id,
  853     int is_directory)
  854 {
  855         int i, flags;
  856         const struct acl_entry *parent_entry;
  857         struct acl_entry *entry, *copy;
  858 
  859         KASSERT(child_aclp->acl_cnt == 0, ("child_aclp->acl_cnt == 0"));
  860         KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
  861             ("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
  862 
  863         /*
  864          * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
  865          *
  866          * 3.16.6.2. Applying the mode given to CREATE or OPEN
  867          *           to an inherited ACL
  868          */
  869 
  870         /*
  871          * 1. Form an ACL that is the concatenation of all inheritable ACEs.
  872          */
  873         for (i = 0; i < parent_aclp->acl_cnt; i++) {
  874                 parent_entry = &(parent_aclp->acl_entry[i]);
  875                 flags = parent_entry->ae_flags;
  876 
  877                 /*
  878                  * Entry is not inheritable at all.
  879                  */
  880                 if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
  881                     ACL_ENTRY_FILE_INHERIT)) == 0)
  882                         continue;
  883 
  884                 /*
  885                  * We're creating a file, but entry is not inheritable
  886                  * by files.
  887                  */
  888                 if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
  889                         continue;
  890 
  891                 /*
  892                  * Entry is inheritable only by files, but has NO_PROPAGATE
  893                  * flag set, and we're creating a directory, so it wouldn't
  894                  * propagate to any file in that directory anyway.
  895                  */
  896                 if (is_directory &&
  897                     (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
  898                     (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
  899                         continue;
  900 
  901                 KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
  902                     ("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
  903                 child_aclp->acl_entry[child_aclp->acl_cnt] = *parent_entry;
  904                 child_aclp->acl_cnt++;
  905         }
  906 
  907         /*
  908          * 2. For each entry in the new ACL, adjust its flags, possibly
  909          *    creating two entries in place of one.
  910          */
  911         for (i = 0; i < child_aclp->acl_cnt; i++) {
  912                 entry = &(child_aclp->acl_entry[i]);
  913 
  914                 /*
  915                  * This is not in the specification, but SunOS
  916                  * apparently does that.
  917                  */
  918                 if (((entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT) ||
  919                     !is_directory) &&
  920                     entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  921                         entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
  922 
  923                 /*
  924                  * 2.A. If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if the object
  925                  *      being created is not a directory, then clear the
  926                  *      following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
  927                  *      ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
  928                  *      ACL_ENTRY_INHERIT_ONLY.
  929                  */
  930                 if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
  931                     !is_directory) {
  932                         entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
  933                         ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
  934                         ACL_ENTRY_INHERIT_ONLY);
  935 
  936                         /*
  937                          * Continue on to the next ACE.
  938                          */
  939                         continue;
  940                 }
  941 
  942                 /*
  943                  * 2.B. If the object is a directory and ACL_ENTRY_FILE_INHERIT
  944                  *      is set, but ACL_ENTRY_NO_PROPAGATE_INHERIT is not set, ensure
  945                  *      that ACL_ENTRY_INHERIT_ONLY is set.  Continue to the
  946                  *      next ACE.  Otherwise...
  947                  */
  948                 /*
  949                  * XXX: Read it again and make sure what does the "otherwise"
  950                  *      apply to.
  951                  */
  952                 if (is_directory &&
  953                     (entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
  954                     ((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
  955                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
  956                         continue;
  957                 }
  958 
  959                 /*
  960                  * 2.C. If the type of the ACE is neither ALLOW nor deny,
  961                  *      then continue.
  962                  */
  963                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
  964                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
  965                         continue;
  966 
  967                 /*
  968                  * 2.D. Copy the original ACE into a second, adjacent ACE.
  969                  */
  970                 copy = _acl_duplicate_entry(child_aclp, i);
  971 
  972                 /*
  973                  * 2.E. On the first ACE, ensure that ACL_ENTRY_INHERIT_ONLY
  974                  *      is set.
  975                  */
  976                 entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
  977 
  978                 /*
  979                  * 2.F. On the second ACE, clear the following flags:
  980                  *      ACL_ENTRY_NO_PROPAGATE_INHERIT, ACL_ENTRY_FILE_INHERIT,
  981                  *      ACL_ENTRY_DIRECTORY_INHERIT, ACL_ENTRY_INHERIT_ONLY.
  982                  */
  983                 copy->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
  984                     ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
  985                     ACL_ENTRY_INHERIT_ONLY);
  986 
  987                 /*
  988                  * 2.G. On the second ACE, if the type is ALLOW,
  989                  *      an implementation MAY clear the following
  990                  *      mask bits: ACL_WRITE_ACL, ACL_WRITE_OWNER.
  991                  */
  992                 if (copy->ae_entry_type == ACL_ENTRY_TYPE_ALLOW)
  993                         copy->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER);
  994 
  995                 /*
  996                  * Increment the counter to skip the copied entry.
  997                  */
  998                 i++;
  999         }
 1000 
 1001         /*
 1002          * 3. To ensure that the mode is honored, apply the algorithm describe
 1003          *    in Section 2.16.6.3, using the mode that is to be used for file
 1004          *    creation.
 1005          */
 1006         acl_nfs4_sync_acl_from_mode(child_aclp, mode, file_owner_id);
 1007 }
 1008 #endif /* _KERNEL */
 1009 
 1010 /*
 1011  * Populate the ACL with entries inherited from parent_aclp.
 1012  */
 1013 static void             
 1014 acl_nfs4_inherit_entries(const struct acl *parent_aclp,
 1015     struct acl *child_aclp, mode_t mode, int file_owner_id,
 1016     int is_directory)
 1017 {
 1018         int i, flags, tag;
 1019         const struct acl_entry *parent_entry;
 1020         struct acl_entry *entry;
 1021 
 1022         KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES,
 1023             ("parent_aclp->acl_cnt <= ACL_MAX_ENTRIES"));
 1024 
 1025         for (i = 0; i < parent_aclp->acl_cnt; i++) {
 1026                 parent_entry = &(parent_aclp->acl_entry[i]);
 1027                 flags = parent_entry->ae_flags;
 1028                 tag = parent_entry->ae_tag;
 1029 
 1030                 /*
 1031                  * Don't inherit owner@, group@, or everyone@ entries.
 1032                  */
 1033                 if (tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ ||
 1034                     tag == ACL_EVERYONE)
 1035                         continue;
 1036 
 1037                 /*
 1038                  * Entry is not inheritable at all.
 1039                  */
 1040                 if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT |
 1041                     ACL_ENTRY_FILE_INHERIT)) == 0)
 1042                         continue;
 1043 
 1044                 /*
 1045                  * We're creating a file, but entry is not inheritable
 1046                  * by files.
 1047                  */
 1048                 if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0)
 1049                         continue;
 1050 
 1051                 /*
 1052                  * Entry is inheritable only by files, but has NO_PROPAGATE
 1053                  * flag set, and we're creating a directory, so it wouldn't
 1054                  * propagate to any file in that directory anyway.
 1055                  */
 1056                 if (is_directory &&
 1057                     (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 &&
 1058                     (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT))
 1059                         continue;
 1060 
 1061                 /*
 1062                  * Entry qualifies for being inherited.
 1063                  */
 1064                 KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES,
 1065                     ("child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES"));
 1066                 entry = &(child_aclp->acl_entry[child_aclp->acl_cnt]);
 1067                 *entry = *parent_entry;
 1068                 child_aclp->acl_cnt++;
 1069 
 1070                 entry->ae_flags &= ~ACL_ENTRY_INHERIT_ONLY;
 1071                 entry->ae_flags |= ACL_ENTRY_INHERITED;
 1072 
 1073                 /*
 1074                  * If the type of the ACE is neither ALLOW nor DENY,
 1075                  * then leave it as it is and proceed to the next one.
 1076                  */
 1077                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 1078                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 1079                         continue;
 1080 
 1081                 /*
 1082                  * If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if
 1083                  * the object being created is not a directory, then clear
 1084                  * the following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT,
 1085                  * ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT,
 1086                  * ACL_ENTRY_INHERIT_ONLY.
 1087                  */
 1088                 if (entry->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT ||
 1089                     !is_directory) {
 1090                         entry->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT |
 1091                         ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT |
 1092                         ACL_ENTRY_INHERIT_ONLY);
 1093                 }
 1094 
 1095                 /*
 1096                  * If the object is a directory and ACL_ENTRY_FILE_INHERIT
 1097                  * is set, but ACL_ENTRY_DIRECTORY_INHERIT is not set, ensure
 1098                  * that ACL_ENTRY_INHERIT_ONLY is set.
 1099                  */
 1100                 if (is_directory &&
 1101                     (entry->ae_flags & ACL_ENTRY_FILE_INHERIT) &&
 1102                     ((entry->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) {
 1103                         entry->ae_flags |= ACL_ENTRY_INHERIT_ONLY;
 1104                 }
 1105 
 1106                 if (entry->ae_entry_type == ACL_ENTRY_TYPE_ALLOW &&
 1107                     (entry->ae_flags & ACL_ENTRY_INHERIT_ONLY) == 0) {
 1108                         /*
 1109                          * Some permissions must never be inherited.
 1110                          */
 1111                         entry->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER |
 1112                             ACL_WRITE_NAMED_ATTRS | ACL_WRITE_ATTRIBUTES);
 1113 
 1114                         /*
 1115                          * Others must be masked according to the file mode.
 1116                          */
 1117                         if ((mode & S_IRGRP) == 0)
 1118                                 entry->ae_perm &= ~ACL_READ_DATA;
 1119                         if ((mode & S_IWGRP) == 0)
 1120                                 entry->ae_perm &=
 1121                                     ~(ACL_WRITE_DATA | ACL_APPEND_DATA);
 1122                         if ((mode & S_IXGRP) == 0)
 1123                                 entry->ae_perm &= ~ACL_EXECUTE;
 1124                 }
 1125         }
 1126 }
 1127 
 1128 /*
 1129  * Calculate inherited ACL in a manner compatible with PSARC/2010/029.
 1130  * It's also being used to calculate a trivial ACL, by inheriting from
 1131  * a NULL ACL.
 1132  */
 1133 static void             
 1134 acl_nfs4_compute_inherited_acl_psarc(const struct acl *parent_aclp,
 1135     struct acl *aclp, mode_t mode, int file_owner_id, int is_directory)
 1136 {
 1137         acl_perm_t user_allow_first = 0, user_deny = 0, group_deny = 0;
 1138         acl_perm_t user_allow, group_allow, everyone_allow;
 1139 
 1140         KASSERT(aclp->acl_cnt == 0, ("aclp->acl_cnt == 0"));
 1141 
 1142         user_allow = group_allow = everyone_allow = ACL_READ_ACL |
 1143             ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS | ACL_SYNCHRONIZE;
 1144         user_allow |= ACL_WRITE_ACL | ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES |
 1145             ACL_WRITE_NAMED_ATTRS;
 1146 
 1147         if (mode & S_IRUSR)
 1148                 user_allow |= ACL_READ_DATA;
 1149         if (mode & S_IWUSR)
 1150                 user_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 1151         if (mode & S_IXUSR)
 1152                 user_allow |= ACL_EXECUTE;
 1153 
 1154         if (mode & S_IRGRP)
 1155                 group_allow |= ACL_READ_DATA;
 1156         if (mode & S_IWGRP)
 1157                 group_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 1158         if (mode & S_IXGRP)
 1159                 group_allow |= ACL_EXECUTE;
 1160 
 1161         if (mode & S_IROTH)
 1162                 everyone_allow |= ACL_READ_DATA;
 1163         if (mode & S_IWOTH)
 1164                 everyone_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA);
 1165         if (mode & S_IXOTH)
 1166                 everyone_allow |= ACL_EXECUTE;
 1167 
 1168         user_deny = ((group_allow | everyone_allow) & ~user_allow);
 1169         group_deny = everyone_allow & ~group_allow;
 1170         user_allow_first = group_deny & ~user_deny;
 1171 
 1172         if (user_allow_first != 0)
 1173                 _acl_append(aclp, ACL_USER_OBJ, user_allow_first,
 1174                     ACL_ENTRY_TYPE_ALLOW);
 1175         if (user_deny != 0)
 1176                 _acl_append(aclp, ACL_USER_OBJ, user_deny,
 1177                     ACL_ENTRY_TYPE_DENY);
 1178         if (group_deny != 0)
 1179                 _acl_append(aclp, ACL_GROUP_OBJ, group_deny,
 1180                     ACL_ENTRY_TYPE_DENY);
 1181 
 1182         if (parent_aclp != NULL)
 1183                 acl_nfs4_inherit_entries(parent_aclp, aclp, mode,
 1184                     file_owner_id, is_directory);
 1185 
 1186         _acl_append(aclp, ACL_USER_OBJ, user_allow, ACL_ENTRY_TYPE_ALLOW);
 1187         _acl_append(aclp, ACL_GROUP_OBJ, group_allow, ACL_ENTRY_TYPE_ALLOW);
 1188         _acl_append(aclp, ACL_EVERYONE, everyone_allow, ACL_ENTRY_TYPE_ALLOW);
 1189 }
 1190 
 1191 #ifdef _KERNEL
 1192 void            
 1193 acl_nfs4_compute_inherited_acl(const struct acl *parent_aclp,
 1194     struct acl *child_aclp, mode_t mode, int file_owner_id,
 1195     int is_directory)
 1196 {
 1197 
 1198         if (acl_nfs4_old_semantics)
 1199                 acl_nfs4_compute_inherited_acl_draft(parent_aclp, child_aclp,
 1200                     mode, file_owner_id, is_directory);
 1201         else
 1202                 acl_nfs4_compute_inherited_acl_psarc(parent_aclp, child_aclp,
 1203                     mode, file_owner_id, is_directory);
 1204 }
 1205 #endif /* _KERNEL */
 1206 
 1207 /*
 1208  * Calculate trivial ACL in a manner compatible with PSARC/2010/029.
 1209  * Note that this results in an ACL different from (but semantically
 1210  * equal to) the "canonical six" trivial ACL computed using algorithm
 1211  * described in draft-ietf-nfsv4-minorversion1-03.txt, 3.16.6.2.
 1212  */
 1213 static void
 1214 acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode)
 1215 {
 1216 
 1217         aclp->acl_cnt = 0;
 1218         acl_nfs4_compute_inherited_acl_psarc(NULL, aclp, mode, -1, -1);
 1219 }
 1220 
 1221 #ifndef _KERNEL
 1222 /*
 1223  * This routine is used by libc to implement acl_strip_np(3)
 1224  * and acl_is_trivial_np(3).
 1225  */
 1226 void
 1227 acl_nfs4_trivial_from_mode_libc(struct acl *aclp, int mode, int canonical_six)
 1228 {
 1229 
 1230         aclp->acl_cnt = 0;
 1231         if (canonical_six)
 1232                 acl_nfs4_sync_acl_from_mode_draft(aclp, mode, -1);
 1233         else
 1234                 acl_nfs4_trivial_from_mode(aclp, mode);
 1235 }
 1236 #endif /* !_KERNEL */
 1237 
 1238 #ifdef _KERNEL
 1239 static int
 1240 _acls_are_equal(const struct acl *a, const struct acl *b)
 1241 {
 1242         int i;
 1243         const struct acl_entry *entrya, *entryb;
 1244 
 1245         if (a->acl_cnt != b->acl_cnt)
 1246                 return (0);
 1247 
 1248         for (i = 0; i < b->acl_cnt; i++) {
 1249                 entrya = &(a->acl_entry[i]);
 1250                 entryb = &(b->acl_entry[i]);
 1251 
 1252                 if (entrya->ae_tag != entryb->ae_tag ||
 1253                     entrya->ae_id != entryb->ae_id ||
 1254                     entrya->ae_perm != entryb->ae_perm ||
 1255                     entrya->ae_entry_type != entryb->ae_entry_type ||
 1256                     entrya->ae_flags != entryb->ae_flags)
 1257                         return (0);
 1258         }
 1259 
 1260         return (1);
 1261 }
 1262 
 1263 /*
 1264  * This routine is used to determine whether to remove extended attribute
 1265  * that stores ACL contents.
 1266  */
 1267 int
 1268 acl_nfs4_is_trivial(const struct acl *aclp, int file_owner_id)
 1269 {
 1270         int trivial;
 1271         mode_t tmpmode = 0;
 1272         struct acl *tmpaclp;
 1273 
 1274         if (aclp->acl_cnt > 6)
 1275                 return (0);
 1276 
 1277         /*
 1278          * Compute the mode from the ACL, then compute new ACL from that mode.
 1279          * If the ACLs are identical, then the ACL is trivial.
 1280          *
 1281          * XXX: I guess there is a faster way to do this.  However, even
 1282          *      this slow implementation significantly speeds things up
 1283          *      for files that don't have non-trivial ACLs - it's critical
 1284          *      for performance to not use EA when they are not needed.
 1285          *
 1286          * First try the PSARC/2010/029 semantics.
 1287          */
 1288         tmpaclp = acl_alloc(M_WAITOK | M_ZERO);
 1289         acl_nfs4_sync_mode_from_acl(&tmpmode, aclp);
 1290         acl_nfs4_trivial_from_mode(tmpaclp, tmpmode);
 1291         trivial = _acls_are_equal(aclp, tmpaclp);
 1292         if (trivial) {
 1293                 acl_free(tmpaclp);
 1294                 return (trivial);
 1295         }
 1296 
 1297         /*
 1298          * Check if it's a draft-ietf-nfsv4-minorversion1-03.txt trivial ACL.
 1299          */
 1300         tmpaclp->acl_cnt = 0;
 1301         acl_nfs4_sync_acl_from_mode_draft(tmpaclp, tmpmode, file_owner_id);
 1302         trivial = _acls_are_equal(aclp, tmpaclp);
 1303         acl_free(tmpaclp);
 1304 
 1305         return (trivial);
 1306 }
 1307 #endif /* _KERNEL */
 1308 
 1309 int
 1310 acl_nfs4_check(const struct acl *aclp, int is_directory)
 1311 {
 1312         int i;
 1313         const struct acl_entry *entry;
 1314 
 1315         /*
 1316          * The spec doesn't seem to say anything about ACL validity.
 1317          * It seems there is not much to do here.  There is even no need
 1318          * to count "owner@" or "everyone@" (ACL_USER_OBJ and ACL_EVERYONE)
 1319          * entries, as there can be several of them and that's perfectly
 1320          * valid.  There can be none of them too.  Really.
 1321          */
 1322 
 1323         if (aclp->acl_cnt > ACL_MAX_ENTRIES || aclp->acl_cnt <= 0)
 1324                 return (EINVAL);
 1325 
 1326         for (i = 0; i < aclp->acl_cnt; i++) {
 1327                 entry = &(aclp->acl_entry[i]);
 1328 
 1329                 switch (entry->ae_tag) {
 1330                 case ACL_USER_OBJ:
 1331                 case ACL_GROUP_OBJ:
 1332                 case ACL_EVERYONE:
 1333                         if (entry->ae_id != ACL_UNDEFINED_ID)
 1334                                 return (EINVAL);
 1335                         break;
 1336 
 1337                 case ACL_USER:
 1338                 case ACL_GROUP:
 1339                         if (entry->ae_id == ACL_UNDEFINED_ID)
 1340                                 return (EINVAL);
 1341                         break;
 1342 
 1343                 default:
 1344                         return (EINVAL);
 1345                 }
 1346 
 1347                 if ((entry->ae_perm | ACL_NFS4_PERM_BITS) != ACL_NFS4_PERM_BITS)
 1348                         return (EINVAL);
 1349 
 1350                 /*
 1351                  * Disallow ACL_ENTRY_TYPE_AUDIT and ACL_ENTRY_TYPE_ALARM for now.
 1352                  */
 1353                 if (entry->ae_entry_type != ACL_ENTRY_TYPE_ALLOW &&
 1354                     entry->ae_entry_type != ACL_ENTRY_TYPE_DENY)
 1355                         return (EINVAL);
 1356 
 1357                 if ((entry->ae_flags | ACL_FLAGS_BITS) != ACL_FLAGS_BITS)
 1358                         return (EINVAL);
 1359 
 1360                 /* Disallow unimplemented flags. */
 1361                 if (entry->ae_flags & (ACL_ENTRY_SUCCESSFUL_ACCESS |
 1362                     ACL_ENTRY_FAILED_ACCESS))
 1363                         return (EINVAL);
 1364 
 1365                 /* Disallow flags not allowed for ordinary files. */
 1366                 if (!is_directory) {
 1367                         if (entry->ae_flags & (ACL_ENTRY_FILE_INHERIT |
 1368                             ACL_ENTRY_DIRECTORY_INHERIT |
 1369                             ACL_ENTRY_NO_PROPAGATE_INHERIT | ACL_ENTRY_INHERIT_ONLY))
 1370                                 return (EINVAL);
 1371                 }
 1372         }
 1373 
 1374         return (0);
 1375 }
 1376 
 1377 #ifdef  _KERNEL
 1378 static int
 1379 acl_nfs4_modload(module_t module, int what, void *arg)
 1380 {
 1381         int ret;
 1382 
 1383         ret = 0;
 1384 
 1385         switch (what) {
 1386         case MOD_LOAD:
 1387         case MOD_SHUTDOWN:
 1388                 break;
 1389 
 1390         case MOD_QUIESCE:
 1391                 /* XXX TODO */
 1392                 ret = 0;
 1393                 break;
 1394 
 1395         case MOD_UNLOAD:
 1396                 /* XXX TODO */
 1397                 ret = 0;
 1398                 break;
 1399         default:
 1400                 ret = EINVAL;
 1401                 break;
 1402         }
 1403 
 1404         return (ret);
 1405 }
 1406 
 1407 static moduledata_t acl_nfs4_mod = {
 1408         "acl_nfs4",
 1409         acl_nfs4_modload,
 1410         NULL
 1411 };
 1412 
 1413 /*
 1414  * XXX TODO: which subsystem, order?
 1415  */
 1416 DECLARE_MODULE(acl_nfs4, acl_nfs4_mod, SI_SUB_VFS, SI_ORDER_FIRST);
 1417 MODULE_VERSION(acl_nfs4, 1);
 1418 #endif  /* _KERNEL */

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