common/acl/acl_common.c

	acl_common.c revision 1eb4e906ec75b9bde421954ace46ef137b0fc9eb
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/errno.h>
#include <sys/avl.h>
#if defined(_KERNEL) || defined(_FAKE_KERNEL)
#include <sys/debug.h>
#include <sys/kmem.h>
#include <sys/systm.h>
#include <sys/sysmacros.h>
#include <acl/acl_common.h>
#else
#include <errno.h>
#include <stdlib.h>
#include <stddef.h>
#include <strings.h>
#include <unistd.h>
#include <assert.h>
#include <grp.h>
#include <pwd.h>
#include <acl_common.h>
#define ASSERT  assert
#endif

#define ACE_POSIX_SUPPORTED_BITS (ACE_READ_DATA | \
    ACE_WRITE_DATA | ACE_APPEND_DATA | ACE_EXECUTE | \
    ACE_READ_ATTRIBUTES | ACE_READ_ACL | ACE_WRITE_ACL)


#define ACL_SYNCHRONIZE_SET_DENY        0x0000001
#define ACL_SYNCHRONIZE_SET_ALLOW       0x0000002
#define ACL_SYNCHRONIZE_ERR_DENY        0x0000004
#define ACL_SYNCHRONIZE_ERR_ALLOW       0x0000008

#define ACL_WRITE_OWNER_SET_DENY        0x0000010
#define ACL_WRITE_OWNER_SET_ALLOW       0x0000020
#define ACL_WRITE_OWNER_ERR_DENY        0x0000040
#define ACL_WRITE_OWNER_ERR_ALLOW       0x0000080

#define ACL_DELETE_SET_DENY         0x0000100
#define ACL_DELETE_SET_ALLOW            0x0000200
#define ACL_DELETE_ERR_DENY         0x0000400
#define ACL_DELETE_ERR_ALLOW            0x0000800

#define ACL_WRITE_ATTRS_OWNER_SET_DENY      0x0001000
#define ACL_WRITE_ATTRS_OWNER_SET_ALLOW     0x0002000
#define ACL_WRITE_ATTRS_OWNER_ERR_DENY      0x0004000
#define ACL_WRITE_ATTRS_OWNER_ERR_ALLOW     0x0008000

#define ACL_WRITE_ATTRS_WRITER_SET_DENY     0x0010000
#define ACL_WRITE_ATTRS_WRITER_SET_ALLOW    0x0020000
#define ACL_WRITE_ATTRS_WRITER_ERR_DENY     0x0040000
#define ACL_WRITE_ATTRS_WRITER_ERR_ALLOW    0x0080000

#define ACL_WRITE_NAMED_WRITER_SET_DENY     0x0100000
#define ACL_WRITE_NAMED_WRITER_SET_ALLOW    0x0200000
#define ACL_WRITE_NAMED_WRITER_ERR_DENY     0x0400000
#define ACL_WRITE_NAMED_WRITER_ERR_ALLOW    0x0800000

#define ACL_READ_NAMED_READER_SET_DENY      0x1000000
#define ACL_READ_NAMED_READER_SET_ALLOW     0x2000000
#define ACL_READ_NAMED_READER_ERR_DENY      0x4000000
#define ACL_READ_NAMED_READER_ERR_ALLOW     0x8000000


#define ACE_VALID_MASK_BITS (\
    ACE_READ_DATA | \
    ACE_LIST_DIRECTORY | \
    ACE_WRITE_DATA | \
    ACE_ADD_FILE | \
    ACE_APPEND_DATA | \
    ACE_ADD_SUBDIRECTORY | \
    ACE_READ_NAMED_ATTRS | \
    ACE_WRITE_NAMED_ATTRS | \
    ACE_EXECUTE | \
    ACE_DELETE_CHILD | \
    ACE_READ_ATTRIBUTES | \
    ACE_WRITE_ATTRIBUTES | \
    ACE_DELETE | \
    ACE_READ_ACL | \
    ACE_WRITE_ACL | \
    ACE_WRITE_OWNER | \
    ACE_SYNCHRONIZE)

#define ACE_MASK_UNDEFINED          0x80000000

#define ACE_VALID_FLAG_BITS (ACE_FILE_INHERIT_ACE | \
    ACE_DIRECTORY_INHERIT_ACE | \
    ACE_NO_PROPAGATE_INHERIT_ACE | ACE_INHERIT_ONLY_ACE | \
    ACE_SUCCESSFUL_ACCESS_ACE_FLAG | ACE_FAILED_ACCESS_ACE_FLAG | \
    ACE_IDENTIFIER_GROUP | ACE_OWNER | ACE_GROUP | ACE_EVERYONE)

/*
 * ACL conversion helpers
 */

typedef enum {
    ace_unused,
    ace_user_obj,
    ace_user,
    ace_group, /* includes GROUP and GROUP_OBJ */
    ace_other_obj
} ace_to_aent_state_t;

typedef struct acevals {
    uid_t key;
    avl_node_t avl;
    uint32_t mask;
    uint32_t allowed;
    uint32_t denied;
    int aent_type;
} acevals_t;

typedef struct ace_list {
    acevals_t user_obj;
    avl_tree_t user;
    int numusers;
    acevals_t group_obj;
    avl_tree_t group;
    int numgroups;
    acevals_t other_obj;
    uint32_t acl_mask;
    int hasmask;
    int dfacl_flag;
    ace_to_aent_state_t state;
    int seen; /* bitmask of all aclent_t a_type values seen */
} ace_list_t;

/*
 * Generic shellsort, from K&R (1st ed, p 58.), somewhat modified.
 * v = Ptr to array/vector of objs
 * n = # objs in the array
 * s = size of each obj (must be multiples of a word size)
 * f = ptr to function to compare two objs
 *  returns (-1 = less than, 0 = equal, 1 = greater than
 */
void
ksort(caddr_t v, int n, int s, int (*f)())
{
    int g, i, j, ii;
    unsigned int *p1, *p2;
    unsigned int tmp;

    /* No work to do */
    if (v == NULL || n <= 1)
        return;

    /* Sanity check on arguments */
    ASSERT(((uintptr_t)v & 0x3) == 0 && (s & 0x3) == 0);
    ASSERT(s > 0);
    for (g = n / 2; g > 0; g /= 2) {
        for (i = g; i < n; i++) {
            for (j = i - g; j >= 0 &&
                (*f)(v + j * s, v + (j + g) * s) == 1;
                j -= g) {
                p1 = (void *)(v + j * s);
                p2 = (void *)(v + (j + g) * s);
                for (ii = 0; ii < s / 4; ii++) {
                    tmp = *p1;
                    *p1++ = *p2;
                    *p2++ = tmp;
                }
            }
        }
    }
}

/*
 * Compare two acls, all fields.  Returns:
 * -1 (less than)
 *  0 (equal)
 * +1 (greater than)
 */
int
cmp2acls(void *a, void *b)
{
    aclent_t *x = (aclent_t *)a;
    aclent_t *y = (aclent_t *)b;

    /* Compare types */
    if (x->a_type < y->a_type)
        return (-1);
    if (x->a_type > y->a_type)
        return (1);
    /* Equal types; compare id's */
    if (x->a_id < y->a_id)
        return (-1);
    if (x->a_id > y->a_id)
        return (1);
    /* Equal ids; compare perms */
    if (x->a_perm < y->a_perm)
        return (-1);
    if (x->a_perm > y->a_perm)
        return (1);
    /* Totally equal */
    return (0);
}

/*ARGSUSED*/
static void *
cacl_realloc(void *ptr, size_t size, size_t new_size)
{
#if defined(_KERNEL) || defined(_FAKE_KERNEL)
    void *tmp;

    tmp = kmem_alloc(new_size, KM_SLEEP);
    (void) memcpy(tmp, ptr, (size < new_size) ? size : new_size);
    kmem_free(ptr, size);
    return (tmp);
#else
    return (realloc(ptr, new_size));
#endif
}

static int
cacl_malloc(void **ptr, size_t size)
{
#if defined(_KERNEL) || defined(_FAKE_KERNEL)
    *ptr = kmem_zalloc(size, KM_SLEEP);
    return (0);
#else
    *ptr = calloc(1, size);
    if (*ptr == NULL)
        return (errno);

    return (0);
#endif
}

/*ARGSUSED*/
static void
cacl_free(void *ptr, size_t size)
{
#if defined(_KERNEL) || defined(_FAKE_KERNEL)
    kmem_free(ptr, size);
#else
    free(ptr);
#endif
}

acl_t *
acl_alloc(enum acl_type type)
{
    acl_t *aclp;

    if (cacl_malloc((void **)&aclp, sizeof (acl_t)) != 0)
        return (NULL);

    aclp->acl_aclp = NULL;
    aclp->acl_cnt = 0;

    switch (type) {
    case ACE_T:
        aclp->acl_type = ACE_T;
        aclp->acl_entry_size = sizeof (ace_t);
        break;
    case ACLENT_T:
        aclp->acl_type = ACLENT_T;
        aclp->acl_entry_size = sizeof (aclent_t);
        break;
    default:
        acl_free(aclp);
        aclp = NULL;
    }
    return (aclp);
}

/*
 * Free acl_t structure
 */
void
acl_free(acl_t *aclp)
{
    int acl_size;

    if (aclp == NULL)
        return;

    if (aclp->acl_aclp) {
        acl_size = aclp->acl_cnt * aclp->acl_entry_size;
        cacl_free(aclp->acl_aclp, acl_size);
    }

    cacl_free(aclp, sizeof (acl_t));
}

static uint32_t
access_mask_set(int haswriteperm, int hasreadperm, int isowner, int isallow)
{
    uint32_t access_mask = 0;
    int acl_produce;
    int synchronize_set = 0, write_owner_set = 0;
    int delete_set = 0, write_attrs_set = 0;
    int read_named_set = 0, write_named_set = 0;

    acl_produce = (ACL_SYNCHRONIZE_SET_ALLOW |
        ACL_WRITE_ATTRS_OWNER_SET_ALLOW |
        ACL_WRITE_ATTRS_WRITER_SET_DENY);

    if (isallow) {
        synchronize_set = ACL_SYNCHRONIZE_SET_ALLOW;
        write_owner_set = ACL_WRITE_OWNER_SET_ALLOW;
        delete_set = ACL_DELETE_SET_ALLOW;
        if (hasreadperm)
            read_named_set = ACL_READ_NAMED_READER_SET_ALLOW;
        if (haswriteperm)
            write_named_set = ACL_WRITE_NAMED_WRITER_SET_ALLOW;
        if (isowner)
            write_attrs_set = ACL_WRITE_ATTRS_OWNER_SET_ALLOW;
        else if (haswriteperm)
            write_attrs_set = ACL_WRITE_ATTRS_WRITER_SET_ALLOW;
    } else {

        synchronize_set = ACL_SYNCHRONIZE_SET_DENY;
        write_owner_set = ACL_WRITE_OWNER_SET_DENY;
        delete_set = ACL_DELETE_SET_DENY;
        if (hasreadperm)
            read_named_set = ACL_READ_NAMED_READER_SET_DENY;
        if (haswriteperm)
            write_named_set = ACL_WRITE_NAMED_WRITER_SET_DENY;
        if (isowner)
            write_attrs_set = ACL_WRITE_ATTRS_OWNER_SET_DENY;
        else if (haswriteperm)
            write_attrs_set = ACL_WRITE_ATTRS_WRITER_SET_DENY;
        else
            /*
             * If the entity is not the owner and does not
             * have write permissions ACE_WRITE_ATTRIBUTES will
             * always go in the DENY ACE.
             */
            access_mask |= ACE_WRITE_ATTRIBUTES;
    }

    if (acl_produce & synchronize_set)
        access_mask |= ACE_SYNCHRONIZE;
    if (acl_produce & write_owner_set)
        access_mask |= ACE_WRITE_OWNER;
    if (acl_produce & delete_set)
        access_mask |= ACE_DELETE;
    if (acl_produce & write_attrs_set)
        access_mask |= ACE_WRITE_ATTRIBUTES;
    if (acl_produce & read_named_set)
        access_mask |= ACE_READ_NAMED_ATTRS;
    if (acl_produce & write_named_set)
        access_mask |= ACE_WRITE_NAMED_ATTRS;

    return (access_mask);
}

/*
 * Given an mode_t, convert it into an access_mask as used
 * by nfsace, assuming aclent_t -> nfsace semantics.
 */
static uint32_t
mode_to_ace_access(mode_t mode, boolean_t isdir, int isowner, int isallow)
{
    uint32_t access = 0;
    int haswriteperm = 0;
    int hasreadperm = 0;

    if (isallow) {
        haswriteperm = (mode & S_IWOTH);
        hasreadperm = (mode & S_IROTH);
    } else {
        haswriteperm = !(mode & S_IWOTH);
        hasreadperm = !(mode & S_IROTH);
    }

    /*
     * The following call takes care of correctly setting the following
     * mask bits in the access_mask:
     * ACE_SYNCHRONIZE, ACE_WRITE_OWNER, ACE_DELETE,
     * ACE_WRITE_ATTRIBUTES, ACE_WRITE_NAMED_ATTRS, ACE_READ_NAMED_ATTRS
     */
    access = access_mask_set(haswriteperm, hasreadperm, isowner, isallow);

    if (isallow) {
        access |= ACE_READ_ACL | ACE_READ_ATTRIBUTES;
        if (isowner)
            access |= ACE_WRITE_ACL;
    } else {
        if (! isowner)
            access |= ACE_WRITE_ACL;
    }

    /* read */
    if (mode & S_IROTH) {
        access |= ACE_READ_DATA;
    }
    /* write */
    if (mode & S_IWOTH) {
        access |= ACE_WRITE_DATA |
            ACE_APPEND_DATA;
        if (isdir)
            access |= ACE_DELETE_CHILD;
    }
    /* exec */
    if (mode & S_IXOTH) {
        access |= ACE_EXECUTE;
    }

    return (access);
}

/*
 * Given an nfsace (presumably an ALLOW entry), make a
 * corresponding DENY entry at the address given.
 */
static void
ace_make_deny(ace_t *allow, ace_t *deny, int isdir, int isowner)
{
    (void) memcpy(deny, allow, sizeof (ace_t));

    deny->a_who = allow->a_who;

    deny->a_type = ACE_ACCESS_DENIED_ACE_TYPE;
    deny->a_access_mask ^= ACE_POSIX_SUPPORTED_BITS;
    if (isdir)
        deny->a_access_mask ^= ACE_DELETE_CHILD;

    deny->a_access_mask &= ~(ACE_SYNCHRONIZE | ACE_WRITE_OWNER |
        ACE_DELETE | ACE_WRITE_ATTRIBUTES | ACE_READ_NAMED_ATTRS |
        ACE_WRITE_NAMED_ATTRS);
    deny->a_access_mask |= access_mask_set((allow->a_access_mask &
        ACE_WRITE_DATA), (allow->a_access_mask & ACE_READ_DATA), isowner,
        B_FALSE);
}
/*
 * Make an initial pass over an array of aclent_t's.  Gather
 * information such as an ACL_MASK (if any), number of users,
 * number of groups, and whether the array needs to be sorted.
 */
static int
ln_aent_preprocess(aclent_t *aclent, int n,
    int *hasmask, mode_t *mask,
    int *numuser, int *numgroup, int *needsort)
{
    int error = 0;
    int i;
    int curtype = 0;

    *hasmask = 0;
    *mask = 07;
    *needsort = 0;
    *numuser = 0;
    *numgroup = 0;

    for (i = 0; i < n; i++) {
        if (aclent[i].a_type < curtype)
            *needsort = 1;
        else if (aclent[i].a_type > curtype)
            curtype = aclent[i].a_type;
        if (aclent[i].a_type & USER)
            (*numuser)++;
        if (aclent[i].a_type & (GROUP | GROUP_OBJ))
            (*numgroup)++;
        if (aclent[i].a_type & CLASS_OBJ) {
            if (*hasmask) {
                error = EINVAL;
                goto out;
            } else {
                *hasmask = 1;
                *mask = aclent[i].a_perm;
            }
        }
    }

    if ((! *hasmask) && (*numuser + *numgroup > 1)) {
        error = EINVAL;
        goto out;
    }

out:
    return (error);
}

/*
 * Convert an array of aclent_t into an array of nfsace entries,
 * following POSIX draft -> nfsv4 conversion semantics as outlined in
 * the IETF draft.
 */
static int
ln_aent_to_ace(aclent_t *aclent, int n, ace_t **acepp, int *rescount, int isdir)
{
    int error = 0;
    mode_t mask;
    int numuser, numgroup, needsort;
    int resultsize = 0;
    int i, groupi = 0, skip;
    ace_t *acep, *result = NULL;
    int hasmask;

    error = ln_aent_preprocess(aclent, n, &hasmask, &mask,
        &numuser, &numgroup, &needsort);
    if (error != 0)
        goto out;

    /* allow + deny for each aclent */
    resultsize = n * 2;
    if (hasmask) {
        /*
         * stick extra deny on the group_obj and on each
         * user|group for the mask (the group_obj was added
         * into the count for numgroup)
         */
        resultsize += numuser + numgroup;
        /* ... and don't count the mask itself */
        resultsize -= 2;
    }

    /* sort the source if necessary */
    if (needsort)
        ksort((caddr_t)aclent, n, sizeof (aclent_t), cmp2acls);

    if (cacl_malloc((void **)&result, resultsize * sizeof (ace_t)) != 0)
        goto out;

    acep = result;

    for (i = 0; i < n; i++) {
        /*
         * don't process CLASS_OBJ (mask); mask was grabbed in
         * ln_aent_preprocess()
         */
        if (aclent[i].a_type & CLASS_OBJ)
            continue;

        /* If we need an ACL_MASK emulator, prepend it now */
        if ((hasmask) &&
            (aclent[i].a_type & (USER | GROUP | GROUP_OBJ))) {
            acep->a_type = ACE_ACCESS_DENIED_ACE_TYPE;
            acep->a_flags = 0;
            if (aclent[i].a_type & GROUP_OBJ) {
                acep->a_who = (uid_t)-1;
                acep->a_flags |=
                    (ACE_IDENTIFIER_GROUP|ACE_GROUP);
            } else if (aclent[i].a_type & USER) {
                acep->a_who = aclent[i].a_id;
            } else {
                acep->a_who = aclent[i].a_id;
                acep->a_flags |= ACE_IDENTIFIER_GROUP;
            }
            if (aclent[i].a_type & ACL_DEFAULT) {
                acep->a_flags |= ACE_INHERIT_ONLY_ACE |
                    ACE_FILE_INHERIT_ACE |
                    ACE_DIRECTORY_INHERIT_ACE;
            }
            /*
             * Set the access mask for the prepended deny
             * ace.  To do this, we invert the mask (found
             * in ln_aent_preprocess()) then convert it to an
             * DENY ace access_mask.
             */
            acep->a_access_mask = mode_to_ace_access((mask ^ 07),
                isdir, 0, 0);
            acep += 1;
        }

        /* handle a_perm -> access_mask */
        acep->a_access_mask = mode_to_ace_access(aclent[i].a_perm,
            isdir, aclent[i].a_type & USER_OBJ, 1);

        /* emulate a default aclent */
        if (aclent[i].a_type & ACL_DEFAULT) {
            acep->a_flags |= ACE_INHERIT_ONLY_ACE |
                ACE_FILE_INHERIT_ACE |
                ACE_DIRECTORY_INHERIT_ACE;
        }

        /*
         * handle a_perm and a_id
         *
         * this must be done last, since it involves the
         * corresponding deny aces, which are handled
         * differently for each different a_type.
         */
        if (aclent[i].a_type & USER_OBJ) {
            acep->a_who = (uid_t)-1;
            acep->a_flags |= ACE_OWNER;
            ace_make_deny(acep, acep + 1, isdir, B_TRUE);
            acep += 2;
        } else if (aclent[i].a_type & USER) {
            acep->a_who = aclent[i].a_id;
            ace_make_deny(acep, acep + 1, isdir, B_FALSE);
            acep += 2;
        } else if (aclent[i].a_type & (GROUP_OBJ | GROUP)) {
            if (aclent[i].a_type & GROUP_OBJ) {
                acep->a_who = (uid_t)-1;
                acep->a_flags |= ACE_GROUP;
            } else {
                acep->a_who = aclent[i].a_id;
            }
            acep->a_flags |= ACE_IDENTIFIER_GROUP;
            /*
             * Set the corresponding deny for the group ace.
             *
             * The deny aces go after all of the groups, unlike
             * everything else, where they immediately follow
             * the allow ace.
             *
             * We calculate "skip", the number of slots to
             * skip ahead for the deny ace, here.
             *
             * The pattern is:
             * MD1 A1 MD2 A2 MD3 A3 D1 D2 D3
             * thus, skip is
             * (2 * numgroup) - 1 - groupi
             * (2 * numgroup) to account for MD + A
             * - 1 to account for the fact that we're on the
             * access (A), not the mask (MD)
             * - groupi to account for the fact that we have
             * passed up groupi number of MD's.
             */
            skip = (2 * numgroup) - 1 - groupi;
            ace_make_deny(acep, acep + skip, isdir, B_FALSE);
            /*
             * If we just did the last group, skip acep past
             * all of the denies; else, just move ahead one.
             */
            if (++groupi >= numgroup)
                acep += numgroup + 1;
            else
                acep += 1;
        } else if (aclent[i].a_type & OTHER_OBJ) {
            acep->a_who = (uid_t)-1;
            acep->a_flags |= ACE_EVERYONE;
            ace_make_deny(acep, acep + 1, isdir, B_FALSE);
            acep += 2;
        } else {
            error = EINVAL;
            goto out;
        }
    }

    *acepp = result;
    *rescount = resultsize;

out:
    if (error != 0) {
        if ((result != NULL) && (resultsize > 0)) {
            cacl_free(result, resultsize * sizeof (ace_t));
        }
    }

    return (error);
}

static int
convert_aent_to_ace(aclent_t *aclentp, int aclcnt, boolean_t isdir,
    ace_t **retacep, int *retacecnt)
{
    ace_t *acep;
    ace_t *dfacep;
    int acecnt = 0;
    int dfacecnt = 0;
    int dfaclstart = 0;
    int dfaclcnt = 0;
    aclent_t *aclp;
    int i;
    int error;
    int acesz, dfacesz;

    ksort((caddr_t)aclentp, aclcnt, sizeof (aclent_t), cmp2acls);

    for (i = 0, aclp = aclentp; i < aclcnt; aclp++, i++) {
        if (aclp->a_type & ACL_DEFAULT)
            break;
    }

    if (i < aclcnt) {
        dfaclstart = i;
        dfaclcnt = aclcnt - i;
    }

    if (dfaclcnt && !isdir) {
        return (EINVAL);
    }

    error = ln_aent_to_ace(aclentp, i,  &acep, &acecnt, isdir);
    if (error)
        return (error);

    if (dfaclcnt) {
        error = ln_aent_to_ace(&aclentp[dfaclstart], dfaclcnt,
            &dfacep, &dfacecnt, isdir);
        if (error) {
            if (acep) {
                cacl_free(acep, acecnt * sizeof (ace_t));
            }
            return (error);
        }
    }

    if (dfacecnt != 0) {
        acesz = sizeof (ace_t) * acecnt;
        dfacesz = sizeof (ace_t) * dfacecnt;
        acep = cacl_realloc(acep, acesz, acesz + dfacesz);
        if (acep == NULL)
            return (ENOMEM);
        if (dfaclcnt) {
            (void) memcpy(acep + acecnt, dfacep, dfacesz);
        }
    }
    if (dfaclcnt)
        cacl_free(dfacep, dfacecnt * sizeof (ace_t));

    *retacecnt = acecnt + dfacecnt;
    *retacep = acep;
    return (0);
}

static int
ace_mask_to_mode(uint32_t  mask, o_mode_t *modep, boolean_t isdir)
{
    int error = 0;
    o_mode_t mode = 0;
    uint32_t bits, wantbits;

    /* read */
    if (mask & ACE_READ_DATA)
        mode |= S_IROTH;

    /* write */
    wantbits = (ACE_WRITE_DATA | ACE_APPEND_DATA);
    if (isdir)
        wantbits |= ACE_DELETE_CHILD;
    bits = mask & wantbits;
    if (bits != 0) {
        if (bits != wantbits) {
            error = ENOTSUP;
            goto out;
        }
        mode |= S_IWOTH;
    }

    /* exec */
    if (mask & ACE_EXECUTE) {
        mode |= S_IXOTH;
    }

    *modep = mode;

out:
    return (error);
}

static void
acevals_init(acevals_t *vals, uid_t key)
{
    bzero(vals, sizeof (*vals));
    vals->allowed = ACE_MASK_UNDEFINED;
    vals->denied = ACE_MASK_UNDEFINED;
    vals->mask = ACE_MASK_UNDEFINED;
    vals->key = key;
}

static void
ace_list_init(ace_list_t *al, int dfacl_flag)
{
    acevals_init(&al->user_obj, NULL);
    acevals_init(&al->group_obj, NULL);
    acevals_init(&al->other_obj, NULL);
    al->numusers = 0;
    al->numgroups = 0;
    al->acl_mask = 0;
    al->hasmask = 0;
    al->state = ace_unused;
    al->seen = 0;
    al->dfacl_flag = dfacl_flag;
}

/*
 * Find or create an acevals holder for a given id and avl tree.
 *
 * Note that only one thread will ever touch these avl trees, so
 * there is no need for locking.
 */
static acevals_t *
acevals_find(ace_t *ace, avl_tree_t *avl, int *num)
{
    acevals_t key, *rc;
    avl_index_t where;

    key.key = ace->a_who;
    rc = avl_find(avl, &key, &where);
    if (rc != NULL)
        return (rc);

    /* this memory is freed by ln_ace_to_aent()->ace_list_free() */
    if (cacl_malloc((void **)&rc, sizeof (acevals_t)) != 0)
        return (NULL);

    acevals_init(rc, ace->a_who);
    avl_insert(avl, rc, where);
    (*num)++;

    return (rc);
}

static int
access_mask_check(ace_t *acep, int mask_bit, int isowner)
{
    int set_deny, err_deny;
    int set_allow, err_allow;
    int acl_consume;
    int haswriteperm, hasreadperm;

    if (acep->a_type == ACE_ACCESS_DENIED_ACE_TYPE) {
        haswriteperm = (acep->a_access_mask & ACE_WRITE_DATA) ? 0 : 1;
        hasreadperm = (acep->a_access_mask & ACE_READ_DATA) ? 0 : 1;
    } else {
        haswriteperm = (acep->a_access_mask & ACE_WRITE_DATA) ? 1 : 0;
        hasreadperm = (acep->a_access_mask & ACE_READ_DATA) ? 1 : 0;
    }

    acl_consume = (ACL_SYNCHRONIZE_ERR_DENY |
        ACL_DELETE_ERR_DENY |
        ACL_WRITE_OWNER_ERR_DENY |
        ACL_WRITE_OWNER_ERR_ALLOW |
        ACL_WRITE_ATTRS_OWNER_SET_ALLOW |
        ACL_WRITE_ATTRS_OWNER_ERR_DENY |
        ACL_WRITE_ATTRS_WRITER_SET_DENY |
        ACL_WRITE_ATTRS_WRITER_ERR_ALLOW |
        ACL_WRITE_NAMED_WRITER_ERR_DENY |
        ACL_READ_NAMED_READER_ERR_DENY);

    if (mask_bit == ACE_SYNCHRONIZE) {
        set_deny = ACL_SYNCHRONIZE_SET_DENY;
        err_deny =  ACL_SYNCHRONIZE_ERR_DENY;
        set_allow = ACL_SYNCHRONIZE_SET_ALLOW;
        err_allow = ACL_SYNCHRONIZE_ERR_ALLOW;
    } else if (mask_bit == ACE_WRITE_OWNER) {
        set_deny = ACL_WRITE_OWNER_SET_DENY;
        err_deny =  ACL_WRITE_OWNER_ERR_DENY;
        set_allow = ACL_WRITE_OWNER_SET_ALLOW;
        err_allow = ACL_WRITE_OWNER_ERR_ALLOW;
    } else if (mask_bit == ACE_DELETE) {
        set_deny = ACL_DELETE_SET_DENY;
        err_deny =  ACL_DELETE_ERR_DENY;
        set_allow = ACL_DELETE_SET_ALLOW;
        err_allow = ACL_DELETE_ERR_ALLOW;
    } else if (mask_bit == ACE_WRITE_ATTRIBUTES) {
        if (isowner) {
            set_deny = ACL_WRITE_ATTRS_OWNER_SET_DENY;
            err_deny =  ACL_WRITE_ATTRS_OWNER_ERR_DENY;
            set_allow = ACL_WRITE_ATTRS_OWNER_SET_ALLOW;
            err_allow = ACL_WRITE_ATTRS_OWNER_ERR_ALLOW;
        } else if (haswriteperm) {
            set_deny = ACL_WRITE_ATTRS_WRITER_SET_DENY;
            err_deny =  ACL_WRITE_ATTRS_WRITER_ERR_DENY;
            set_allow = ACL_WRITE_ATTRS_WRITER_SET_ALLOW;
            err_allow = ACL_WRITE_ATTRS_WRITER_ERR_ALLOW;
        } else {
            if ((acep->a_access_mask & mask_bit) &&
                (acep->a_type & ACE_ACCESS_ALLOWED_ACE_TYPE)) {
                return (ENOTSUP);
            }
            return (0);
        }
    } else if (mask_bit == ACE_READ_NAMED_ATTRS) {
        if (!hasreadperm)
            return (0);

        set_deny = ACL_READ_NAMED_READER_SET_DENY;
        err_deny = ACL_READ_NAMED_READER_ERR_DENY;
        set_allow = ACL_READ_NAMED_READER_SET_ALLOW;
        err_allow = ACL_READ_NAMED_READER_ERR_ALLOW;
    } else if (mask_bit == ACE_WRITE_NAMED_ATTRS) {
        if (!haswriteperm)
            return (0);

        set_deny = ACL_WRITE_NAMED_WRITER_SET_DENY;
        err_deny = ACL_WRITE_NAMED_WRITER_ERR_DENY;
        set_allow = ACL_WRITE_NAMED_WRITER_SET_ALLOW;
        err_allow = ACL_WRITE_NAMED_WRITER_ERR_ALLOW;
    } else {
        return (EINVAL);
    }

    if (acep->a_type == ACE_ACCESS_DENIED_ACE_TYPE) {
        if (acl_consume & set_deny) {
            if (!(acep->a_access_mask & mask_bit)) {
                return (ENOTSUP);
            }
        } else if (acl_consume & err_deny) {
            if (acep->a_access_mask & mask_bit) {
                return (ENOTSUP);
            }
        }
    } else {
        /* ACE_ACCESS_ALLOWED_ACE_TYPE */
        if (acl_consume & set_allow) {
            if (!(acep->a_access_mask & mask_bit)) {
                return (ENOTSUP);
            }
        } else if (acl_consume & err_allow) {
            if (acep->a_access_mask & mask_bit) {
                return (ENOTSUP);
            }
        }
    }
    return (0);
}

static int
ace_to_aent_legal(ace_t *acep)
{
    int error = 0;
    int isowner;

    /* only ALLOW or DENY */
    if ((acep->a_type != ACE_ACCESS_ALLOWED_ACE_TYPE) &&
        (acep->a_type != ACE_ACCESS_DENIED_ACE_TYPE)) {
        error = ENOTSUP;
        goto out;
    }

    /* check for invalid flags */
    if (acep->a_flags & ~(ACE_VALID_FLAG_BITS)) {
        error = EINVAL;
        goto out;
    }

    /* some flags are illegal */
    if (acep->a_flags & (ACE_SUCCESSFUL_ACCESS_ACE_FLAG |
        ACE_FAILED_ACCESS_ACE_FLAG |
        ACE_NO_PROPAGATE_INHERIT_ACE)) {
        error = ENOTSUP;
        goto out;
    }

    /* check for invalid masks */
    if (acep->a_access_mask & ~(ACE_VALID_MASK_BITS)) {
        error = EINVAL;
        goto out;
    }

    if ((acep->a_flags & ACE_OWNER)) {
        isowner = 1;
    } else {
        isowner = 0;
    }

    error = access_mask_check(acep, ACE_SYNCHRONIZE, isowner);
    if (error)
        goto out;

    error = access_mask_check(acep, ACE_WRITE_OWNER, isowner);
    if (error)
        goto out;

    error = access_mask_check(acep, ACE_DELETE, isowner);
    if (error)
        goto out;

    error = access_mask_check(acep, ACE_WRITE_ATTRIBUTES, isowner);
    if (error)
        goto out;

    error = access_mask_check(acep, ACE_READ_NAMED_ATTRS, isowner);
    if (error)
        goto out;

    error = access_mask_check(acep, ACE_WRITE_NAMED_ATTRS, isowner);
    if (error)
        goto out;

    /* more detailed checking of masks */
    if (acep->a_type == ACE_ACCESS_ALLOWED_ACE_TYPE) {
        if (! (acep->a_access_mask & ACE_READ_ATTRIBUTES)) {
            error = ENOTSUP;
            goto out;
        }
        if ((acep->a_access_mask & ACE_WRITE_DATA) &&
            (! (acep->a_access_mask & ACE_APPEND_DATA))) {
            error = ENOTSUP;
            goto out;
        }
        if ((! (acep->a_access_mask & ACE_WRITE_DATA)) &&
            (acep->a_access_mask & ACE_APPEND_DATA)) {
            error = ENOTSUP;
            goto out;
        }
    }

    /* ACL enforcement */
    if ((acep->a_access_mask & ACE_READ_ACL) &&
        (acep->a_type != ACE_ACCESS_ALLOWED_ACE_TYPE)) {
        error = ENOTSUP;
        goto out;
    }
    if (acep->a_access_mask & ACE_WRITE_ACL) {
        if ((acep->a_type == ACE_ACCESS_DENIED_ACE_TYPE) &&
            (isowner)) {
            error = ENOTSUP;
            goto out;
        }
        if ((acep->a_type == ACE_ACCESS_ALLOWED_ACE_TYPE) &&
            (! isowner)) {
            error = ENOTSUP;
            goto out;
        }
    }

out:
    return (error);
}

static int
ace_allow_to_mode(uint32_t mask, o_mode_t *modep, boolean_t isdir)
{
    /* ACE_READ_ACL and ACE_READ_ATTRIBUTES must both be set */
    if ((mask & (ACE_READ_ACL | ACE_READ_ATTRIBUTES)) !=
        (ACE_READ_ACL | ACE_READ_ATTRIBUTES)) {
        return (ENOTSUP);
    }

    return (ace_mask_to_mode(mask, modep, isdir));
}

static int
acevals_to_aent(acevals_t *vals, aclent_t *dest, ace_list_t *list,
    uid_t owner, gid_t group, boolean_t isdir)
{
    int error;
    uint32_t  flips = ACE_POSIX_SUPPORTED_BITS;

    if (isdir)
        flips |= ACE_DELETE_CHILD;
    if (vals->allowed != (vals->denied ^ flips)) {
        error = ENOTSUP;
        goto out;
    }
    if ((list->hasmask) && (list->acl_mask != vals->mask) &&
        (vals->aent_type & (USER | GROUP | GROUP_OBJ))) {
        error = ENOTSUP;
        goto out;
    }
    error = ace_allow_to_mode(vals->allowed, &dest->a_perm, isdir);
    if (error != 0)
        goto out;
    dest->a_type = vals->aent_type;
    if (dest->a_type & (USER | GROUP)) {
        dest->a_id = vals->key;
    } else if (dest->a_type & USER_OBJ) {
        dest->a_id = owner;
    } else if (dest->a_type & GROUP_OBJ) {
        dest->a_id = group;
    } else if (dest->a_type & OTHER_OBJ) {
        dest->a_id = 0;
    } else {
        error = EINVAL;
        goto out;
    }

out:
    return (error);
}


static int
ace_list_to_aent(ace_list_t *list, aclent_t **aclentp, int *aclcnt,
    uid_t owner, gid_t group, boolean_t isdir)
{
    int error = 0;
    aclent_t *aent, *result = NULL;
    acevals_t *vals;
    int resultcount;

    if ((list->seen & (USER_OBJ | GROUP_OBJ | OTHER_OBJ)) !=
        (USER_OBJ | GROUP_OBJ | OTHER_OBJ)) {
        error = ENOTSUP;
        goto out;
    }
    if ((! list->hasmask) && (list->numusers + list->numgroups > 0)) {
        error = ENOTSUP;
        goto out;
    }

    resultcount = 3 + list->numusers + list->numgroups;
    /*
     * This must be the same condition as below, when we add the CLASS_OBJ
     * (aka ACL mask)
     */
    if ((list->hasmask) || (! list->dfacl_flag))
        resultcount += 1;

    if (cacl_malloc((void **)&result,
        resultcount * sizeof (aclent_t)) != 0) {
        error = ENOMEM;
        goto out;
    }
    aent = result;

    /* USER_OBJ */
    if (!(list->user_obj.aent_type & USER_OBJ)) {
        error = EINVAL;
        goto out;
    }

    error = acevals_to_aent(&list->user_obj, aent, list, owner, group,
        isdir);

    if (error != 0)
        goto out;
    ++aent;
    /* USER */
    vals = NULL;
    for (vals = avl_first(&list->user); vals != NULL;
        vals = AVL_NEXT(&list->user, vals)) {
        if (!(vals->aent_type & USER)) {
            error = EINVAL;
            goto out;
        }
        error = acevals_to_aent(vals, aent, list, owner, group,
            isdir);
        if (error != 0)
            goto out;
        ++aent;
    }
    /* GROUP_OBJ */
    if (!(list->group_obj.aent_type & GROUP_OBJ)) {
        error = EINVAL;
        goto out;
    }
    error = acevals_to_aent(&list->group_obj, aent, list, owner, group,
        isdir);
    if (error != 0)
        goto out;
    ++aent;
    /* GROUP */
    vals = NULL;
    for (vals = avl_first(&list->group); vals != NULL;
        vals = AVL_NEXT(&list->group, vals)) {
        if (!(vals->aent_type & GROUP)) {
            error = EINVAL;
            goto out;
        }
        error = acevals_to_aent(vals, aent, list, owner, group,
            isdir);
        if (error != 0)
            goto out;
        ++aent;
    }
    /*
     * CLASS_OBJ (aka ACL_MASK)
     *
     * An ACL_MASK is not fabricated if the ACL is a default ACL.
     * This is to follow UFS's behavior.
     */
    if ((list->hasmask) || (! list->dfacl_flag)) {
        if (list->hasmask) {
            uint32_t flips = ACE_POSIX_SUPPORTED_BITS;
            if (isdir)
                flips |= ACE_DELETE_CHILD;
            error = ace_mask_to_mode(list->acl_mask ^ flips,
                &aent->a_perm, isdir);
            if (error != 0)
                goto out;
        } else {
            /* fabricate the ACL_MASK from the group permissions */
            error = ace_mask_to_mode(list->group_obj.allowed,
                &aent->a_perm, isdir);
            if (error != 0)
                goto out;
        }
        aent->a_id = 0;
        aent->a_type = CLASS_OBJ | list->dfacl_flag;
        ++aent;
    }
    /* OTHER_OBJ */
    if (!(list->other_obj.aent_type & OTHER_OBJ)) {
        error = EINVAL;
        goto out;
    }
    error = acevals_to_aent(&list->other_obj, aent, list, owner, group,
        isdir);
    if (error != 0)
        goto out;
    ++aent;

    *aclentp = result;
    *aclcnt = resultcount;

out:
    if (error != 0) {
        if (result != NULL)
            cacl_free(result, resultcount * sizeof (aclent_t));
    }

    return (error);
}


/*
 * free all data associated with an ace_list
 */
static void
ace_list_free(ace_list_t *al)
{
    acevals_t *node;
    void *cookie;

    if (al == NULL)
        return;

    cookie = NULL;
    while ((node = avl_destroy_nodes(&al->user, &cookie)) != NULL)
        cacl_free(node, sizeof (acevals_t));
    cookie = NULL;
    while ((node = avl_destroy_nodes(&al->group, &cookie)) != NULL)
        cacl_free(node, sizeof (acevals_t));

    avl_destroy(&al->user);
    avl_destroy(&al->group);

    /* free the container itself */
    cacl_free(al, sizeof (ace_list_t));
}

static int
acevals_compare(const void *va, const void *vb)
{
    const acevals_t *a = va, *b = vb;

    if (a->key == b->key)
        return (0);

    if (a->key > b->key)
        return (1);

    else
        return (-1);
}

/*
 * Convert a list of ace_t entries to equivalent regular and default
 * aclent_t lists.  Return error (ENOTSUP) when conversion is not possible.
 */
static int
ln_ace_to_aent(ace_t *ace, int n, uid_t owner, gid_t group,
    aclent_t **aclentp, int *aclcnt, aclent_t **dfaclentp, int *dfaclcnt,
    boolean_t isdir)
{
    int error = 0;
    ace_t *acep;
    uint32_t bits;
    int i;
    ace_list_t *normacl = NULL, *dfacl = NULL, *acl;
    acevals_t *vals;

    *aclentp = NULL;
    *aclcnt = 0;
    *dfaclentp = NULL;
    *dfaclcnt = 0;

    /* we need at least user_obj, group_obj, and other_obj */
    if (n < 6) {
        error = ENOTSUP;
        goto out;
    }
    if (ace == NULL) {
        error = EINVAL;
        goto out;
    }

    error = cacl_malloc((void **)&normacl, sizeof (ace_list_t));
    if (error != 0)
        goto out;

    avl_create(&normacl->user, acevals_compare, sizeof (acevals_t),
        offsetof(acevals_t, avl));
    avl_create(&normacl->group, acevals_compare, sizeof (acevals_t),
        offsetof(acevals_t, avl));

    ace_list_init(normacl, 0);

    error = cacl_malloc((void **)&dfacl, sizeof (ace_list_t));
    if (error != 0)
        goto out;

    avl_create(&dfacl->user, acevals_compare, sizeof (acevals_t),
        offsetof(acevals_t, avl));
    avl_create(&dfacl->group, acevals_compare, sizeof (acevals_t),
        offsetof(acevals_t, avl));
    ace_list_init(dfacl, ACL_DEFAULT);

    /* process every ace_t... */
    for (i = 0; i < n; i++) {
        acep = &ace[i];

        /* rule out certain cases quickly */
        error = ace_to_aent_legal(acep);
        if (error != 0)
            goto out;

        /*
         * Turn off these bits in order to not have to worry about
         * them when doing the checks for compliments.
         */
        acep->a_access_mask &= ~(ACE_WRITE_OWNER | ACE_DELETE |
            ACE_SYNCHRONIZE | ACE_WRITE_ATTRIBUTES |
            ACE_READ_NAMED_ATTRS | ACE_WRITE_NAMED_ATTRS);

        /* see if this should be a regular or default acl */
        bits = acep->a_flags &
            (ACE_INHERIT_ONLY_ACE |
            ACE_FILE_INHERIT_ACE |
            ACE_DIRECTORY_INHERIT_ACE);
        if (bits != 0) {
            /* all or nothing on these inherit bits */
            if (bits != (ACE_INHERIT_ONLY_ACE |
                ACE_FILE_INHERIT_ACE |
                ACE_DIRECTORY_INHERIT_ACE)) {
                error = ENOTSUP;
                goto out;
            }
            acl = dfacl;
        } else {
            acl = normacl;
        }

        if ((acep->a_flags & ACE_OWNER)) {
            if (acl->state > ace_user_obj) {
                error = ENOTSUP;
                goto out;
            }
            acl->state = ace_user_obj;
            acl->seen |= USER_OBJ;
            vals = &acl->user_obj;
            vals->aent_type = USER_OBJ | acl->dfacl_flag;
        } else if ((acep->a_flags & ACE_EVERYONE)) {
            acl->state = ace_other_obj;
            acl->seen |= OTHER_OBJ;
            vals = &acl->other_obj;
            vals->aent_type = OTHER_OBJ | acl->dfacl_flag;
        } else if (acep->a_flags & ACE_IDENTIFIER_GROUP) {
            if (acl->state > ace_group) {
                error = ENOTSUP;
                goto out;
            }
            if ((acep->a_flags & ACE_GROUP)) {
                acl->seen |= GROUP_OBJ;
                vals = &acl->group_obj;
                vals->aent_type = GROUP_OBJ | acl->dfacl_flag;
            } else {
                acl->seen |= GROUP;
                vals = acevals_find(acep, &acl->group,
                    &acl->numgroups);
                if (vals == NULL) {
                    error = ENOMEM;
                    goto out;
                }
                vals->aent_type = GROUP | acl->dfacl_flag;
            }
            acl->state = ace_group;
        } else {
            if (acl->state > ace_user) {
                error = ENOTSUP;
                goto out;
            }
            acl->state = ace_user;
            acl->seen |= USER;
            vals = acevals_find(acep, &acl->user,
                &acl->numusers);
            if (vals == NULL) {
                error = ENOMEM;
                goto out;
            }
            vals->aent_type = USER | acl->dfacl_flag;
        }

        if (!(acl->state > ace_unused)) {
            error = EINVAL;
            goto out;
        }

        if (acep->a_type == ACE_ACCESS_ALLOWED_ACE_TYPE) {
            /* no more than one allowed per aclent_t */
            if (vals->allowed != ACE_MASK_UNDEFINED) {
                error = ENOTSUP;
                goto out;
            }
            vals->allowed = acep->a_access_mask;
        } else {
            /*
             * it's a DENY; if there was a previous DENY, it
             * must have been an ACL_MASK.
             */
            if (vals->denied != ACE_MASK_UNDEFINED) {
                /* ACL_MASK is for USER and GROUP only */
                if ((acl->state != ace_user) &&
                    (acl->state != ace_group)) {
                    error = ENOTSUP;
                    goto out;
                }

                if (! acl->hasmask) {
                    acl->hasmask = 1;
                    acl->acl_mask = vals->denied;
                /* check for mismatched ACL_MASK emulations */
                } else if (acl->acl_mask != vals->denied) {
                    error = ENOTSUP;
                    goto out;
                }
                vals->mask = vals->denied;
            }
            vals->denied = acep->a_access_mask;
        }
    }

    /* done collating; produce the aclent_t lists */
    if (normacl->state != ace_unused) {
        error = ace_list_to_aent(normacl, aclentp, aclcnt,
            owner, group, isdir);
        if (error != 0) {
            goto out;
        }
    }
    if (dfacl->state != ace_unused) {
        error = ace_list_to_aent(dfacl, dfaclentp, dfaclcnt,
            owner, group, isdir);
        if (error != 0) {
            goto out;
        }
    }

out:
    if (normacl != NULL)
        ace_list_free(normacl);
    if (dfacl != NULL)
        ace_list_free(dfacl);

    return (error);
}

static int
convert_ace_to_aent(ace_t *acebufp, int acecnt, boolean_t isdir,
    uid_t owner, gid_t group, aclent_t **retaclentp, int *retaclcnt)
{
    int error = 0;
    aclent_t *aclentp, *dfaclentp;
    int aclcnt, dfaclcnt;
    int aclsz, dfaclsz = 0;

    error = ln_ace_to_aent(acebufp, acecnt, owner, group,
        &aclentp, &aclcnt, &dfaclentp, &dfaclcnt, isdir);

    if (error)
        return (error);


    if (dfaclcnt != 0) {
        /*
         * Slap aclentp and dfaclentp into a single array.
         */
        aclsz = sizeof (aclent_t) * aclcnt;
        dfaclsz = sizeof (aclent_t) * dfaclcnt;
        aclentp = cacl_realloc(aclentp, aclsz, aclsz + dfaclsz);
        if (aclentp != NULL) {
            (void) memcpy(aclentp + aclcnt, dfaclentp, dfaclsz);
        } else {
            error = ENOMEM;
        }
    }

    if (aclentp) {
        *retaclentp = aclentp;
        *retaclcnt = aclcnt + dfaclcnt;
    }

    if (dfaclentp)
        cacl_free(dfaclentp, dfaclsz);

    return (error);
}


int
acl_translate(acl_t *aclp, int target_flavor, boolean_t isdir, uid_t owner,
    gid_t group)
{
    int aclcnt;
    void *acldata;
    int error;

    /*
     * See if we need to translate
     */
    if ((target_flavor == _ACL_ACE_ENABLED && aclp->acl_type == ACE_T) ||
        (target_flavor == _ACL_ACLENT_ENABLED &&
        aclp->acl_type == ACLENT_T))
        return (0);

    if (target_flavor == -1) {
        error = EINVAL;
        goto out;
    }

    if (target_flavor ==  _ACL_ACE_ENABLED &&
        aclp->acl_type == ACLENT_T) {
        error = convert_aent_to_ace(aclp->acl_aclp,
            aclp->acl_cnt, isdir, (ace_t **)&acldata, &aclcnt);
        if (error)
            goto out;

    } else if (target_flavor == _ACL_ACLENT_ENABLED &&
        aclp->acl_type == ACE_T) {
        error = convert_ace_to_aent(aclp->acl_aclp, aclp->acl_cnt,
            isdir, owner, group, (aclent_t **)&acldata, &aclcnt);
        if (error)
            goto out;
    } else {
        error = ENOTSUP;
        goto out;
    }

    /*
     * replace old acl with newly translated acl
     */
    cacl_free(aclp->acl_aclp, aclp->acl_cnt * aclp->acl_entry_size);
    aclp->acl_aclp = acldata;
    aclp->acl_cnt = aclcnt;
    if (target_flavor == _ACL_ACE_ENABLED) {
        aclp->acl_type = ACE_T;
        aclp->acl_entry_size = sizeof (ace_t);
    } else {
        aclp->acl_type = ACLENT_T;
        aclp->acl_entry_size = sizeof (aclent_t);
    }
    return (0);

out:

#if defined(_KERNEL) || defined(_FAKE_KERNEL)
    return (error);
#else
    errno = error;
    return (-1);
#endif
}

#define SET_ACE(acl, index, who, mask, type, flags) { \
    acl[0][index].a_who = (uint32_t)who; \
    acl[0][index].a_type = type; \
    acl[0][index].a_flags = flags; \
    acl[0][index++].a_access_mask = mask; \
}

void
acl_trivial_access_masks(mode_t mode, boolean_t isdir, trivial_acl_t *masks)
{
    uint32_t read_mask = ACE_READ_DATA;
    uint32_t write_mask = ACE_WRITE_DATA|ACE_APPEND_DATA;
    uint32_t execute_mask = ACE_EXECUTE;

    if (isdir)
        write_mask |= ACE_DELETE_CHILD;

    masks->deny1 = 0;
    if (!(mode & S_IRUSR) && (mode & (S_IRGRP|S_IROTH)))
        masks->deny1 |= read_mask;
    if (!(mode & S_IWUSR) && (mode & (S_IWGRP|S_IWOTH)))
        masks->deny1 |= write_mask;
    if (!(mode & S_IXUSR) && (mode & (S_IXGRP|S_IXOTH)))
        masks->deny1 |= execute_mask;

    masks->deny2 = 0;
    if (!(mode & S_IRGRP) && (mode & S_IROTH))
        masks->deny2 |= read_mask;
    if (!(mode & S_IWGRP) && (mode & S_IWOTH))
        masks->deny2 |= write_mask;
    if (!(mode & S_IXGRP) && (mode & S_IXOTH))
        masks->deny2 |= execute_mask;

    masks->allow0 = 0;
    if ((mode & S_IRUSR) && (!(mode & S_IRGRP) && (mode & S_IROTH)))
        masks->allow0 |= read_mask;
    if ((mode & S_IWUSR) && (!(mode & S_IWGRP) && (mode & S_IWOTH)))
        masks->allow0 |= write_mask;
    if ((mode & S_IXUSR) && (!(mode & S_IXGRP) && (mode & S_IXOTH)))
        masks->allow0 |= execute_mask;

    masks->owner = ACE_WRITE_ATTRIBUTES|ACE_WRITE_OWNER|ACE_WRITE_ACL|
        ACE_WRITE_NAMED_ATTRS|ACE_READ_ACL|ACE_READ_ATTRIBUTES|
        ACE_READ_NAMED_ATTRS|ACE_SYNCHRONIZE;
    if (mode & S_IRUSR)
        masks->owner |= read_mask;
    if (mode & S_IWUSR)
        masks->owner |= write_mask;
    if (mode & S_IXUSR)
        masks->owner |= execute_mask;

    masks->group = ACE_READ_ACL|ACE_READ_ATTRIBUTES|ACE_READ_NAMED_ATTRS|
        ACE_SYNCHRONIZE;
    if (mode & S_IRGRP)
        masks->group |= read_mask;
    if (mode & S_IWGRP)
        masks->group |= write_mask;
    if (mode & S_IXGRP)
        masks->group |= execute_mask;

    masks->everyone = ACE_READ_ACL|ACE_READ_ATTRIBUTES|ACE_READ_NAMED_ATTRS|
        ACE_SYNCHRONIZE;
    if (mode & S_IROTH)
        masks->everyone |= read_mask;
    if (mode & S_IWOTH)
        masks->everyone |= write_mask;
    if (mode & S_IXOTH)
        masks->everyone |= execute_mask;
}

int
acl_trivial_create(mode_t mode, boolean_t isdir, ace_t **acl, int *count)
{
    int         index = 0;
    int     error;
    trivial_acl_t   masks;

    *count = 3;
    acl_trivial_access_masks(mode, isdir, &masks);

    if (masks.allow0)
        (*count)++;
    if (masks.deny1)
        (*count)++;
    if (masks.deny2)
        (*count)++;

    if ((error = cacl_malloc((void **)acl, *count * sizeof (ace_t))) != 0)
        return (error);

    if (masks.allow0) {
        SET_ACE(acl, index, -1, masks.allow0,
            ACE_ACCESS_ALLOWED_ACE_TYPE, ACE_OWNER);
    }
    if (masks.deny1) {
        SET_ACE(acl, index, -1, masks.deny1,
            ACE_ACCESS_DENIED_ACE_TYPE, ACE_OWNER);
    }
    if (masks.deny2) {
        SET_ACE(acl, index, -1, masks.deny2,
            ACE_ACCESS_DENIED_ACE_TYPE, ACE_GROUP|ACE_IDENTIFIER_GROUP);
    }

    SET_ACE(acl, index, -1, masks.owner, ACE_ACCESS_ALLOWED_ACE_TYPE,
        ACE_OWNER);
    SET_ACE(acl, index, -1, masks.group, ACE_ACCESS_ALLOWED_ACE_TYPE,
        ACE_IDENTIFIER_GROUP|ACE_GROUP);
    SET_ACE(acl, index, -1, masks.everyone, ACE_ACCESS_ALLOWED_ACE_TYPE,
        ACE_EVERYONE);

    return (0);
}

/*
 * ace_trivial:
 * determine whether an ace_t acl is trivial
 *
 * Trivialness implies that the acl is composed of only
 * owner, group, everyone entries.  ACL can't
 * have read_acl denied, and write_owner/write_acl/write_attributes
 * can only be owner@ entry.
 */
int
ace_trivial_common(void *acep, int aclcnt,
    uint64_t (*walk)(void *, uint64_t, int aclcnt,
    uint16_t *, uint16_t *, uint32_t *))
{
    uint16_t flags;
    uint32_t mask;
    uint16_t type;
    uint64_t cookie = 0;

    while (cookie = walk(acep, cookie, aclcnt, &flags, &type, &mask)) {
        switch (flags & ACE_TYPE_FLAGS) {
        case ACE_OWNER:
        case ACE_GROUP|ACE_IDENTIFIER_GROUP:
        case ACE_EVERYONE:
            break;
        default:
            return (1);

        }

        if (flags & (ACE_FILE_INHERIT_ACE|
            ACE_DIRECTORY_INHERIT_ACE|ACE_NO_PROPAGATE_INHERIT_ACE|
            ACE_INHERIT_ONLY_ACE))
            return (1);

        /*
         * Special check for some special bits
         *
         * Don't allow anybody to deny reading basic
         * attributes or a files ACL.
         */
        if ((mask & (ACE_READ_ACL|ACE_READ_ATTRIBUTES)) &&
            (type == ACE_ACCESS_DENIED_ACE_TYPE))
            return (1);

        /*
         * Delete permission is never set by default
         */
        if (mask & ACE_DELETE)
            return (1);

        /*
         * Child delete permission should be accompanied by write
         */
        if ((mask & ACE_DELETE_CHILD) && !(mask & ACE_WRITE_DATA))
            return (1);

        /*
         * only allow owner@ to have
         * write_acl/write_owner/write_attributes/write_xattr/
         */
        if (type == ACE_ACCESS_ALLOWED_ACE_TYPE &&
            (!(flags & ACE_OWNER) && (mask &
            (ACE_WRITE_OWNER|ACE_WRITE_ACL| ACE_WRITE_ATTRIBUTES|
            ACE_WRITE_NAMED_ATTRS))))
            return (1);

    }
    return (0);
}

uint64_t
ace_walk(void *datap, uint64_t cookie, int aclcnt, uint16_t *flags,
    uint16_t *type, uint32_t *mask)
{
    ace_t *acep = datap;

    if (cookie >= aclcnt)
        return (0);

    *flags = acep[cookie].a_flags;
    *type = acep[cookie].a_type;
    *mask = acep[cookie++].a_access_mask;

    return (cookie);
}

int
ace_trivial(ace_t *acep, int aclcnt)
{
    return (ace_trivial_common(acep, aclcnt, ace_walk));
}