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zfs_acl.c

/*
 * 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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/systm.h>
#include <sys/sysmacros.h>
#include <sys/resource.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/kmem.h>
#include <sys/cmn_err.h>
#include <sys/errno.h>
#include <sys/unistd.h>
#include <sys/sdt.h>
#include <sys/fs/zfs.h>
#include <sys/policy.h>
#include <sys/zfs_znode.h>
#include <sys/zfs_fuid.h>
#include <sys/zfs_acl.h>
#include <sys/zfs_dir.h>
#include <sys/zfs_vfsops.h>
#include <sys/dmu.h>
#include <sys/dnode.h>
#include <sys/zap.h>
#include <acl/acl_common.h>

#define     ALLOW ACE_ACCESS_ALLOWED_ACE_TYPE
#define     DENY  ACE_ACCESS_DENIED_ACE_TYPE
#define     MAX_ACE_TYPE      ACE_SYSTEM_ALARM_CALLBACK_OBJECT_ACE_TYPE
#define     MIN_ACE_TYPE      ALLOW

#define     OWNING_GROUP            (ACE_GROUP|ACE_IDENTIFIER_GROUP)
#define     EVERYONE_ALLOW_MASK (ACE_READ_ACL|ACE_READ_ATTRIBUTES | \
    ACE_READ_NAMED_ATTRS|ACE_SYNCHRONIZE)
#define     EVERYONE_DENY_MASK (ACE_WRITE_ACL|ACE_WRITE_OWNER | \
    ACE_WRITE_ATTRIBUTES|ACE_WRITE_NAMED_ATTRS)
#define     OWNER_ALLOW_MASK (ACE_WRITE_ACL | ACE_WRITE_OWNER | \
    ACE_WRITE_ATTRIBUTES|ACE_WRITE_NAMED_ATTRS)
#define     WRITE_MASK_DATA (ACE_WRITE_DATA|ACE_APPEND_DATA|ACE_WRITE_NAMED_ATTRS)

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

#define     WRITE_MASK (WRITE_MASK_DATA|ACE_WRITE_ATTRIBUTES|ACE_WRITE_ACL|\
    ACE_WRITE_OWNER|ACE_DELETE|ACE_DELETE_CHILD)

#define     OGE_CLEAR   (ACE_READ_DATA|ACE_LIST_DIRECTORY|ACE_WRITE_DATA| \
    ACE_ADD_FILE|ACE_APPEND_DATA|ACE_ADD_SUBDIRECTORY|ACE_EXECUTE)

#define     OKAY_MASK_BITS (ACE_READ_DATA|ACE_LIST_DIRECTORY|ACE_WRITE_DATA| \
    ACE_ADD_FILE|ACE_APPEND_DATA|ACE_ADD_SUBDIRECTORY|ACE_EXECUTE)

#define     ALL_INHERIT (ACE_FILE_INHERIT_ACE|ACE_DIRECTORY_INHERIT_ACE | \
    ACE_NO_PROPAGATE_INHERIT_ACE|ACE_INHERIT_ONLY_ACE|ACE_INHERITED_ACE)

#define     RESTRICTED_CLEAR  (ACE_WRITE_ACL|ACE_WRITE_OWNER)

#define     V4_ACL_WIDE_FLAGS (ZFS_ACL_AUTO_INHERIT|ZFS_ACL_DEFAULTED|\
    ZFS_ACL_PROTECTED)

#define     ZFS_ACL_WIDE_FLAGS (V4_ACL_WIDE_FLAGS|ZFS_ACL_TRIVIAL|ZFS_INHERIT_ACE|\
    ZFS_ACL_OBJ_ACE)

static uint16_t
zfs_ace_v0_get_type(void *acep)
{
      return (((zfs_oldace_t *)acep)->z_type);
}

static uint16_t
zfs_ace_v0_get_flags(void *acep)
{
      return (((zfs_oldace_t *)acep)->z_flags);
}

static uint32_t
zfs_ace_v0_get_mask(void *acep)
{
      return (((zfs_oldace_t *)acep)->z_access_mask);
}

static uint64_t
zfs_ace_v0_get_who(void *acep)
{
      return (((zfs_oldace_t *)acep)->z_fuid);
}

static void
zfs_ace_v0_set_type(void *acep, uint16_t type)
{
      ((zfs_oldace_t *)acep)->z_type = type;
}

static void
zfs_ace_v0_set_flags(void *acep, uint16_t flags)
{
      ((zfs_oldace_t *)acep)->z_flags = flags;
}

static void
zfs_ace_v0_set_mask(void *acep, uint32_t mask)
{
      ((zfs_oldace_t *)acep)->z_access_mask = mask;
}

static void
zfs_ace_v0_set_who(void *acep, uint64_t who)
{
      ((zfs_oldace_t *)acep)->z_fuid = who;
}

/*ARGSUSED*/
static size_t
zfs_ace_v0_size(void *acep)
{
      return (sizeof (zfs_oldace_t));
}

static size_t
zfs_ace_v0_abstract_size(void)
{
      return (sizeof (zfs_oldace_t));
}

static int
zfs_ace_v0_mask_off(void)
{
      return (offsetof(zfs_oldace_t, z_access_mask));
}

/*ARGSUSED*/
static int
zfs_ace_v0_data(void *acep, void **datap)
{
      *datap = NULL;
      return (0);
}

static acl_ops_t zfs_acl_v0_ops = {
      zfs_ace_v0_get_mask,
      zfs_ace_v0_set_mask,
      zfs_ace_v0_get_flags,
      zfs_ace_v0_set_flags,
      zfs_ace_v0_get_type,
      zfs_ace_v0_set_type,
      zfs_ace_v0_get_who,
      zfs_ace_v0_set_who,
      zfs_ace_v0_size,
      zfs_ace_v0_abstract_size,
      zfs_ace_v0_mask_off,
      zfs_ace_v0_data
};

static uint16_t
zfs_ace_fuid_get_type(void *acep)
{
      return (((zfs_ace_hdr_t *)acep)->z_type);
}

static uint16_t
zfs_ace_fuid_get_flags(void *acep)
{
      return (((zfs_ace_hdr_t *)acep)->z_flags);
}

static uint32_t
zfs_ace_fuid_get_mask(void *acep)
{
      return (((zfs_ace_hdr_t *)acep)->z_access_mask);
}

static uint64_t
zfs_ace_fuid_get_who(void *args)
{
      uint16_t entry_type;
      zfs_ace_t *acep = args;

      entry_type = acep->z_hdr.z_flags & ACE_TYPE_FLAGS;

      if (entry_type == ACE_OWNER || entry_type == OWNING_GROUP ||
          entry_type == ACE_EVERYONE)
            return (-1);
      return (((zfs_ace_t *)acep)->z_fuid);
}

static void
zfs_ace_fuid_set_type(void *acep, uint16_t type)
{
      ((zfs_ace_hdr_t *)acep)->z_type = type;
}

static void
zfs_ace_fuid_set_flags(void *acep, uint16_t flags)
{
      ((zfs_ace_hdr_t *)acep)->z_flags = flags;
}

static void
zfs_ace_fuid_set_mask(void *acep, uint32_t mask)
{
      ((zfs_ace_hdr_t *)acep)->z_access_mask = mask;
}

static void
zfs_ace_fuid_set_who(void *arg, uint64_t who)
{
      zfs_ace_t *acep = arg;

      uint16_t entry_type = acep->z_hdr.z_flags & ACE_TYPE_FLAGS;

      if (entry_type == ACE_OWNER || entry_type == OWNING_GROUP ||
          entry_type == ACE_EVERYONE)
            return;
      acep->z_fuid = who;
}

static size_t
zfs_ace_fuid_size(void *acep)
{
      zfs_ace_hdr_t *zacep = acep;
      uint16_t entry_type;

      switch (zacep->z_type) {
      case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
      case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
      case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
      case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
            return (sizeof (zfs_object_ace_t));
      case ALLOW:
      case DENY:
            entry_type =
                (((zfs_ace_hdr_t *)acep)->z_flags & ACE_TYPE_FLAGS);
            if (entry_type == ACE_OWNER ||
                entry_type == OWNING_GROUP ||
                entry_type == ACE_EVERYONE)
                  return (sizeof (zfs_ace_hdr_t));
            /*FALLTHROUGH*/
      default:
            return (sizeof (zfs_ace_t));
      }
}

static size_t
zfs_ace_fuid_abstract_size(void)
{
      return (sizeof (zfs_ace_hdr_t));
}

static int
zfs_ace_fuid_mask_off(void)
{
      return (offsetof(zfs_ace_hdr_t, z_access_mask));
}

static int
zfs_ace_fuid_data(void *acep, void **datap)
{
      zfs_ace_t *zacep = acep;
      zfs_object_ace_t *zobjp;

      switch (zacep->z_hdr.z_type) {
      case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
      case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
      case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
      case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
            zobjp = acep;
            *datap = (caddr_t)zobjp + sizeof (zfs_ace_t);
            return (sizeof (zfs_object_ace_t) - sizeof (zfs_ace_t));
      default:
            *datap = NULL;
            return (0);
      }
}

static acl_ops_t zfs_acl_fuid_ops = {
      zfs_ace_fuid_get_mask,
      zfs_ace_fuid_set_mask,
      zfs_ace_fuid_get_flags,
      zfs_ace_fuid_set_flags,
      zfs_ace_fuid_get_type,
      zfs_ace_fuid_set_type,
      zfs_ace_fuid_get_who,
      zfs_ace_fuid_set_who,
      zfs_ace_fuid_size,
      zfs_ace_fuid_abstract_size,
      zfs_ace_fuid_mask_off,
      zfs_ace_fuid_data
};

static int
zfs_acl_version(int version)
{
      if (version < ZPL_VERSION_FUID)
            return (ZFS_ACL_VERSION_INITIAL);
      else
            return (ZFS_ACL_VERSION_FUID);
}

static int
zfs_acl_version_zp(znode_t *zp)
{
      return (zfs_acl_version(zp->z_zfsvfs->z_version));
}

static zfs_acl_t *
zfs_acl_alloc(int vers)
{
      zfs_acl_t *aclp;

      aclp = kmem_zalloc(sizeof (zfs_acl_t), KM_SLEEP);
      list_create(&aclp->z_acl, sizeof (zfs_acl_node_t),
          offsetof(zfs_acl_node_t, z_next));
      aclp->z_version = vers;
      if (vers == ZFS_ACL_VERSION_FUID)
            aclp->z_ops = zfs_acl_fuid_ops;
      else
            aclp->z_ops = zfs_acl_v0_ops;
      return (aclp);
}

static zfs_acl_node_t *
zfs_acl_node_alloc(size_t bytes)
{
      zfs_acl_node_t *aclnode;

      aclnode = kmem_zalloc(sizeof (zfs_acl_node_t), KM_SLEEP);
      if (bytes) {
            aclnode->z_acldata = kmem_alloc(bytes, KM_SLEEP);
            aclnode->z_allocdata = aclnode->z_acldata;
            aclnode->z_allocsize = bytes;
            aclnode->z_size = bytes;
      }

      return (aclnode);
}

static void
zfs_acl_node_free(zfs_acl_node_t *aclnode)
{
      if (aclnode->z_allocsize)
            kmem_free(aclnode->z_allocdata, aclnode->z_allocsize);
      kmem_free(aclnode, sizeof (zfs_acl_node_t));
}

static void
zfs_acl_release_nodes(zfs_acl_t *aclp)
{
      zfs_acl_node_t *aclnode;

      while (aclnode = list_head(&aclp->z_acl)) {
            list_remove(&aclp->z_acl, aclnode);
            zfs_acl_node_free(aclnode);
      }
      aclp->z_acl_count = 0;
      aclp->z_acl_bytes = 0;
}

void
zfs_acl_free(zfs_acl_t *aclp)
{
      zfs_acl_release_nodes(aclp);
      list_destroy(&aclp->z_acl);
      kmem_free(aclp, sizeof (zfs_acl_t));
}

static boolean_t
zfs_acl_valid_ace_type(uint_t type, uint_t flags)
{
      uint16_t entry_type;

      switch (type) {
      case ALLOW:
      case DENY:
      case ACE_SYSTEM_AUDIT_ACE_TYPE:
      case ACE_SYSTEM_ALARM_ACE_TYPE:
            entry_type = flags & ACE_TYPE_FLAGS;
            return (entry_type == ACE_OWNER ||
                entry_type == OWNING_GROUP ||
                entry_type == ACE_EVERYONE || entry_type == 0 ||
                entry_type == ACE_IDENTIFIER_GROUP);
      default:
            if (type >= MIN_ACE_TYPE && type <= MAX_ACE_TYPE)
                  return (B_TRUE);
      }
      return (B_FALSE);
}

static boolean_t
zfs_ace_valid(vtype_t obj_type, zfs_acl_t *aclp, uint16_t type, uint16_t iflags)
{
      /*
       * first check type of entry
       */

      if (!zfs_acl_valid_ace_type(type, iflags))
            return (B_FALSE);

      switch (type) {
      case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
      case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
      case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
      case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
            if (aclp->z_version < ZFS_ACL_VERSION_FUID)
                  return (B_FALSE);
            aclp->z_hints |= ZFS_ACL_OBJ_ACE;
      }

      /*
       * next check inheritance level flags
       */

      if (obj_type == VDIR &&
          (iflags & (ACE_FILE_INHERIT_ACE|ACE_DIRECTORY_INHERIT_ACE)))
            aclp->z_hints |= ZFS_INHERIT_ACE;

      if (iflags & (ACE_INHERIT_ONLY_ACE|ACE_NO_PROPAGATE_INHERIT_ACE)) {
            if ((iflags & (ACE_FILE_INHERIT_ACE|
                ACE_DIRECTORY_INHERIT_ACE)) == 0) {
                  return (B_FALSE);
            }
      }

      return (B_TRUE);
}

static void *
zfs_acl_next_ace(zfs_acl_t *aclp, void *start, uint64_t *who,
    uint32_t *access_mask, uint16_t *iflags, uint16_t *type)
{
      zfs_acl_node_t *aclnode;

      if (start == NULL) {
            aclnode = list_head(&aclp->z_acl);
            if (aclnode == NULL)
                  return (NULL);

            aclp->z_next_ace = aclnode->z_acldata;
            aclp->z_curr_node = aclnode;
            aclnode->z_ace_idx = 0;
      }

      aclnode = aclp->z_curr_node;

      if (aclnode == NULL)
            return (NULL);

      if (aclnode->z_ace_idx >= aclnode->z_ace_count) {
            aclnode = list_next(&aclp->z_acl, aclnode);
            if (aclnode == NULL)
                  return (NULL);
            else {
                  aclp->z_curr_node = aclnode;
                  aclnode->z_ace_idx = 0;
                  aclp->z_next_ace = aclnode->z_acldata;
            }
      }

      if (aclnode->z_ace_idx < aclnode->z_ace_count) {
            void *acep = aclp->z_next_ace;
            size_t ace_size;

            /*
             * Make sure we don't overstep our bounds
             */
            ace_size = aclp->z_ops.ace_size(acep);

            if (((caddr_t)acep + ace_size) >
                ((caddr_t)aclnode->z_acldata + aclnode->z_size)) {
                  return (NULL);
            }

            *iflags = aclp->z_ops.ace_flags_get(acep);
            *type = aclp->z_ops.ace_type_get(acep);
            *access_mask = aclp->z_ops.ace_mask_get(acep);
            *who = aclp->z_ops.ace_who_get(acep);
            aclp->z_next_ace = (caddr_t)aclp->z_next_ace + ace_size;
            aclnode->z_ace_idx++;
            return ((void *)acep);
      }
      return (NULL);
}

/*ARGSUSED*/
static uint64_t
zfs_ace_walk(void *datap, uint64_t cookie, int aclcnt,
    uint16_t *flags, uint16_t *type, uint32_t *mask)
{
      zfs_acl_t *aclp = datap;
      zfs_ace_hdr_t *acep = (zfs_ace_hdr_t *)(uintptr_t)cookie;
      uint64_t who;

      acep = zfs_acl_next_ace(aclp, acep, &who, mask,
          flags, type);
      return ((uint64_t)(uintptr_t)acep);
}

static zfs_acl_node_t *
zfs_acl_curr_node(zfs_acl_t *aclp)
{
      ASSERT(aclp->z_curr_node);
      return (aclp->z_curr_node);
}

/*
 * Copy ACE to internal ZFS format.
 * While processing the ACL each ACE will be validated for correctness.
 * ACE FUIDs will be created later.
 */
int
zfs_copy_ace_2_fuid(vtype_t obj_type, zfs_acl_t *aclp, void *datap,
    zfs_ace_t *z_acl, int aclcnt, size_t *size)
{
      int i;
      uint16_t entry_type;
      zfs_ace_t *aceptr = z_acl;
      ace_t *acep = datap;
      zfs_object_ace_t *zobjacep;
      ace_object_t *aceobjp;

      for (i = 0; i != aclcnt; i++) {
            aceptr->z_hdr.z_access_mask = acep->a_access_mask;
            aceptr->z_hdr.z_flags = acep->a_flags;
            aceptr->z_hdr.z_type = acep->a_type;
            entry_type = aceptr->z_hdr.z_flags & ACE_TYPE_FLAGS;
            if (entry_type != ACE_OWNER && entry_type != OWNING_GROUP &&
                entry_type != ACE_EVERYONE) {
                  if (!aclp->z_has_fuids)
                        aclp->z_has_fuids = IS_EPHEMERAL(acep->a_who);
                  aceptr->z_fuid = (uint64_t)acep->a_who;
            }

            /*
             * Make sure ACE is valid
             */
            if (zfs_ace_valid(obj_type, aclp, aceptr->z_hdr.z_type,
                aceptr->z_hdr.z_flags) != B_TRUE)
                  return (EINVAL);

            switch (acep->a_type) {
            case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
            case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
            case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
            case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
                  zobjacep = (zfs_object_ace_t *)aceptr;
                  aceobjp = (ace_object_t *)acep;

                  bcopy(aceobjp->a_obj_type, zobjacep->z_object_type,
                      sizeof (aceobjp->a_obj_type));
                  bcopy(aceobjp->a_inherit_obj_type,
                      zobjacep->z_inherit_type,
                      sizeof (aceobjp->a_inherit_obj_type));
                  acep = (ace_t *)((caddr_t)acep + sizeof (ace_object_t));
                  break;
            default:
                  acep = (ace_t *)((caddr_t)acep + sizeof (ace_t));
            }

            aceptr = (zfs_ace_t *)((caddr_t)aceptr +
                aclp->z_ops.ace_size(aceptr));
      }

      *size = (caddr_t)aceptr - (caddr_t)z_acl;

      return (0);
}

/*
 * Copy ZFS ACEs to fixed size ace_t layout
 */
static void
zfs_copy_fuid_2_ace(zfsvfs_t *zfsvfs, zfs_acl_t *aclp, cred_t *cr,
    void *datap, int filter)
{
      uint64_t who;
      uint32_t access_mask;
      uint16_t iflags, type;
      zfs_ace_hdr_t *zacep = NULL;
      ace_t *acep = datap;
      ace_object_t *objacep;
      zfs_object_ace_t *zobjacep;
      size_t ace_size;
      uint16_t entry_type;

      while (zacep = zfs_acl_next_ace(aclp, zacep,
          &who, &access_mask, &iflags, &type)) {

            switch (type) {
            case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
            case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
            case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
            case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
                  if (filter) {
                        continue;
                  }
                  zobjacep = (zfs_object_ace_t *)zacep;
                  objacep = (ace_object_t *)acep;
                  bcopy(zobjacep->z_object_type,
                      objacep->a_obj_type,
                      sizeof (zobjacep->z_object_type));
                  bcopy(zobjacep->z_inherit_type,
                      objacep->a_inherit_obj_type,
                      sizeof (zobjacep->z_inherit_type));
                  ace_size = sizeof (ace_object_t);
                  break;
            default:
                  ace_size = sizeof (ace_t);
                  break;
            }

            entry_type = (iflags & ACE_TYPE_FLAGS);
            if ((entry_type != ACE_OWNER &&
                entry_type != OWNING_GROUP &&
                entry_type != ACE_EVERYONE)) {
                  acep->a_who = zfs_fuid_map_id(zfsvfs, who,
                      cr, (entry_type & ACE_IDENTIFIER_GROUP) ?
                      ZFS_ACE_GROUP : ZFS_ACE_USER);
            } else {
                  acep->a_who = (uid_t)(int64_t)who;
            }
            acep->a_access_mask = access_mask;
            acep->a_flags = iflags;
            acep->a_type = type;
            acep = (ace_t *)((caddr_t)acep + ace_size);
      }
}

static int
zfs_copy_ace_2_oldace(vtype_t obj_type, zfs_acl_t *aclp, ace_t *acep,
    zfs_oldace_t *z_acl, int aclcnt, size_t *size)
{
      int i;
      zfs_oldace_t *aceptr = z_acl;

      for (i = 0; i != aclcnt; i++, aceptr++) {
            aceptr->z_access_mask = acep[i].a_access_mask;
            aceptr->z_type = acep[i].a_type;
            aceptr->z_flags = acep[i].a_flags;
            aceptr->z_fuid = acep[i].a_who;
            /*
             * Make sure ACE is valid
             */
            if (zfs_ace_valid(obj_type, aclp, aceptr->z_type,
                aceptr->z_flags) != B_TRUE)
                  return (EINVAL);
      }
      *size = (caddr_t)aceptr - (caddr_t)z_acl;
      return (0);
}

/*
 * convert old ACL format to new
 */
void
zfs_acl_xform(znode_t *zp, zfs_acl_t *aclp)
{
      zfs_oldace_t *oldaclp;
      int i;
      uint16_t type, iflags;
      uint32_t access_mask;
      uint64_t who;
      void *cookie = NULL;
      zfs_acl_node_t *newaclnode;

      ASSERT(aclp->z_version == ZFS_ACL_VERSION_INITIAL);
      /*
       * First create the ACE in a contiguous piece of memory
       * for zfs_copy_ace_2_fuid().
       *
       * We only convert an ACL once, so this won't happen
       * everytime.
       */
      oldaclp = kmem_alloc(sizeof (zfs_oldace_t) * aclp->z_acl_count,
          KM_SLEEP);
      i = 0;
      while (cookie = zfs_acl_next_ace(aclp, cookie, &who,
          &access_mask, &iflags, &type)) {
            oldaclp[i].z_flags = iflags;
            oldaclp[i].z_type = type;
            oldaclp[i].z_fuid = who;
            oldaclp[i++].z_access_mask = access_mask;
      }

      newaclnode = zfs_acl_node_alloc(aclp->z_acl_count *
          sizeof (zfs_object_ace_t));
      aclp->z_ops = zfs_acl_fuid_ops;
      VERIFY(zfs_copy_ace_2_fuid(ZTOV(zp)->v_type, aclp, oldaclp,
          newaclnode->z_acldata, aclp->z_acl_count,
          &newaclnode->z_size) == 0);
      newaclnode->z_ace_count = aclp->z_acl_count;
      aclp->z_version = ZFS_ACL_VERSION;
      kmem_free(oldaclp, aclp->z_acl_count * sizeof (zfs_oldace_t));

      /*
       * Release all previous ACL nodes
       */

      zfs_acl_release_nodes(aclp);

      list_insert_head(&aclp->z_acl, newaclnode);

      aclp->z_acl_bytes = newaclnode->z_size;
      aclp->z_acl_count = newaclnode->z_ace_count;

}

/*
 * Convert unix access mask to v4 access mask
 */
static uint32_t
zfs_unix_to_v4(uint32_t access_mask)
{
      uint32_t new_mask = 0;

      if (access_mask & S_IXOTH)
            new_mask |= ACE_EXECUTE;
      if (access_mask & S_IWOTH)
            new_mask |= ACE_WRITE_DATA;
      if (access_mask & S_IROTH)
            new_mask |= ACE_READ_DATA;
      return (new_mask);
}

static void
zfs_set_ace(zfs_acl_t *aclp, void *acep, uint32_t access_mask,
    uint16_t access_type, uint64_t fuid, uint16_t entry_type)
{
      uint16_t type = entry_type & ACE_TYPE_FLAGS;

      aclp->z_ops.ace_mask_set(acep, access_mask);
      aclp->z_ops.ace_type_set(acep, access_type);
      aclp->z_ops.ace_flags_set(acep, entry_type);
      if ((type != ACE_OWNER && type != OWNING_GROUP &&
          type != ACE_EVERYONE))
            aclp->z_ops.ace_who_set(acep, fuid);
}

/*
 * Determine mode of file based on ACL.
 * Also, create FUIDs for any User/Group ACEs
 */
static uint64_t
zfs_mode_fuid_compute(znode_t *zp, zfs_acl_t *aclp, cred_t *cr,
    zfs_fuid_info_t **fuidp, dmu_tx_t *tx)
{
      int         entry_type;
      mode_t            mode;
      mode_t            seen = 0;
      zfs_ace_hdr_t     *acep = NULL;
      uint64_t    who;
      uint16_t    iflags, type;
      uint32_t    access_mask;

      mode = (zp->z_phys->zp_mode & (S_IFMT | S_ISUID | S_ISGID | S_ISVTX));

      while (acep = zfs_acl_next_ace(aclp, acep, &who,
          &access_mask, &iflags, &type)) {

            if (!zfs_acl_valid_ace_type(type, iflags))
                  continue;

            entry_type = (iflags & ACE_TYPE_FLAGS);

            /*
             * Skip over owner@, group@ or everyone@ inherit only ACEs
             */
            if ((iflags & ACE_INHERIT_ONLY_ACE) &&
                (entry_type == ACE_OWNER || entry_type == ACE_EVERYONE ||
                entry_type == OWNING_GROUP))
                  continue;

            if (entry_type == ACE_OWNER) {
                  if ((access_mask & ACE_READ_DATA) &&
                      (!(seen & S_IRUSR))) {
                        seen |= S_IRUSR;
                        if (type == ALLOW) {
                              mode |= S_IRUSR;
                        }
                  }
                  if ((access_mask & ACE_WRITE_DATA) &&
                      (!(seen & S_IWUSR))) {
                        seen |= S_IWUSR;
                        if (type == ALLOW) {
                              mode |= S_IWUSR;
                        }
                  }
                  if ((access_mask & ACE_EXECUTE) &&
                      (!(seen & S_IXUSR))) {
                        seen |= S_IXUSR;
                        if (type == ALLOW) {
                              mode |= S_IXUSR;
                        }
                  }
            } else if (entry_type == OWNING_GROUP) {
                  if ((access_mask & ACE_READ_DATA) &&
                      (!(seen & S_IRGRP))) {
                        seen |= S_IRGRP;
                        if (type == ALLOW) {
                              mode |= S_IRGRP;
                        }
                  }
                  if ((access_mask & ACE_WRITE_DATA) &&
                      (!(seen & S_IWGRP))) {
                        seen |= S_IWGRP;
                        if (type == ALLOW) {
                              mode |= S_IWGRP;
                        }
                  }
                  if ((access_mask & ACE_EXECUTE) &&
                      (!(seen & S_IXGRP))) {
                        seen |= S_IXGRP;
                        if (type == ALLOW) {
                              mode |= S_IXGRP;
                        }
                  }
            } else if (entry_type == ACE_EVERYONE) {
                  if ((access_mask & ACE_READ_DATA)) {
                        if (!(seen & S_IRUSR)) {
                              seen |= S_IRUSR;
                              if (type == ALLOW) {
                                    mode |= S_IRUSR;
                              }
                        }
                        if (!(seen & S_IRGRP)) {
                              seen |= S_IRGRP;
                              if (type == ALLOW) {
                                    mode |= S_IRGRP;
                              }
                        }
                        if (!(seen & S_IROTH)) {
                              seen |= S_IROTH;
                              if (type == ALLOW) {
                                    mode |= S_IROTH;
                              }
                        }
                  }
                  if ((access_mask & ACE_WRITE_DATA)) {
                        if (!(seen & S_IWUSR)) {
                              seen |= S_IWUSR;
                              if (type == ALLOW) {
                                    mode |= S_IWUSR;
                              }
                        }
                        if (!(seen & S_IWGRP)) {
                              seen |= S_IWGRP;
                              if (type == ALLOW) {
                                    mode |= S_IWGRP;
                              }
                        }
                        if (!(seen & S_IWOTH)) {
                              seen |= S_IWOTH;
                              if (type == ALLOW) {
                                    mode |= S_IWOTH;
                              }
                        }
                  }
                  if ((access_mask & ACE_EXECUTE)) {
                        if (!(seen & S_IXUSR)) {
                              seen |= S_IXUSR;
                              if (type == ALLOW) {
                                    mode |= S_IXUSR;
                              }
                        }
                        if (!(seen & S_IXGRP)) {
                              seen |= S_IXGRP;
                              if (type == ALLOW) {
                                    mode |= S_IXGRP;
                              }
                        }
                        if (!(seen & S_IXOTH)) {
                              seen |= S_IXOTH;
                              if (type == ALLOW) {
                                    mode |= S_IXOTH;
                              }
                        }
                  }
            }
            /*
             * Now handle FUID create for user/group ACEs
             */
            if (entry_type == 0 || entry_type == ACE_IDENTIFIER_GROUP) {
                  aclp->z_ops.ace_who_set(acep,
                      zfs_fuid_create(zp->z_zfsvfs, who, cr,
                      (entry_type == 0) ? ZFS_ACE_USER : ZFS_ACE_GROUP,
                      tx, fuidp));
            }
      }
      return (mode);
}

static zfs_acl_t *
zfs_acl_node_read_internal(znode_t *zp, boolean_t will_modify)
{
      zfs_acl_t   *aclp;
      zfs_acl_node_t    *aclnode;

      aclp = zfs_acl_alloc(zp->z_phys->zp_acl.z_acl_version);

      /*
       * Version 0 to 1 znode_acl_phys has the size/count fields swapped.
       * Version 0 didn't have a size field, only a count.
       */
      if (zp->z_phys->zp_acl.z_acl_version == ZFS_ACL_VERSION_INITIAL) {
            aclp->z_acl_count = zp->z_phys->zp_acl.z_acl_size;
            aclp->z_acl_bytes = ZFS_ACL_SIZE(aclp->z_acl_count);
      } else {
            aclp->z_acl_count = zp->z_phys->zp_acl.z_acl_count;
            aclp->z_acl_bytes = zp->z_phys->zp_acl.z_acl_size;
      }

      aclnode = zfs_acl_node_alloc(will_modify ? aclp->z_acl_bytes : 0);
      aclnode->z_ace_count = aclp->z_acl_count;
      if (will_modify) {
            bcopy(zp->z_phys->zp_acl.z_ace_data, aclnode->z_acldata,
                aclp->z_acl_bytes);
      } else {
            aclnode->z_size = aclp->z_acl_bytes;
            aclnode->z_acldata = &zp->z_phys->zp_acl.z_ace_data[0];
      }

      list_insert_head(&aclp->z_acl, aclnode);

      return (aclp);
}

/*
 * Read an external acl object.
 */
static int
zfs_acl_node_read(znode_t *zp, zfs_acl_t **aclpp, boolean_t will_modify)
{
      uint64_t extacl = zp->z_phys->zp_acl.z_acl_extern_obj;
      zfs_acl_t   *aclp;
      size_t            aclsize;
      size_t            acl_count;
      zfs_acl_node_t    *aclnode;
      int error;

      ASSERT(MUTEX_HELD(&zp->z_acl_lock));

      if (zp->z_phys->zp_acl.z_acl_extern_obj == 0) {
            *aclpp = zfs_acl_node_read_internal(zp, will_modify);
            return (0);
      }

      aclp = zfs_acl_alloc(zp->z_phys->zp_acl.z_acl_version);
      if (zp->z_phys->zp_acl.z_acl_version == ZFS_ACL_VERSION_INITIAL) {
            zfs_acl_phys_v0_t *zacl0 =
                (zfs_acl_phys_v0_t *)&zp->z_phys->zp_acl;

            aclsize = ZFS_ACL_SIZE(zacl0->z_acl_count);
            acl_count = zacl0->z_acl_count;
      } else {
            aclsize = zp->z_phys->zp_acl.z_acl_size;
            acl_count = zp->z_phys->zp_acl.z_acl_count;
            if (aclsize == 0)
                  aclsize = acl_count * sizeof (zfs_ace_t);
      }
      aclnode = zfs_acl_node_alloc(aclsize);
      list_insert_head(&aclp->z_acl, aclnode);
      error = dmu_read(zp->z_zfsvfs->z_os, extacl, 0,
          aclsize, aclnode->z_acldata);
      aclnode->z_ace_count = acl_count;
      aclp->z_acl_count = acl_count;
      aclp->z_acl_bytes = aclsize;

      if (error != 0) {
            zfs_acl_free(aclp);
            /* convert checksum errors into IO errors */
            if (error == ECKSUM)
                  error = EIO;
            return (error);
      }

      *aclpp = aclp;
      return (0);
}

/*
 * common code for setting ACLs.
 *
 * This function is called from zfs_mode_update, zfs_perm_init, and zfs_setacl.
 * zfs_setacl passes a non-NULL inherit pointer (ihp) to indicate that it's
 * already checked the acl and knows whether to inherit.
 */
int
zfs_aclset_common(znode_t *zp, zfs_acl_t *aclp, cred_t *cr,
    zfs_fuid_info_t **fuidp, dmu_tx_t *tx)
{
      int         error;
      znode_phys_t      *zphys = zp->z_phys;
      zfs_acl_phys_t    *zacl = &zphys->zp_acl;
      zfsvfs_t    *zfsvfs = zp->z_zfsvfs;
      uint64_t    aoid = zphys->zp_acl.z_acl_extern_obj;
      uint64_t    off = 0;
      dmu_object_type_t otype;
      zfs_acl_node_t    *aclnode;

      ASSERT(MUTEX_HELD(&zp->z_lock));
      ASSERT(MUTEX_HELD(&zp->z_acl_lock));

      dmu_buf_will_dirty(zp->z_dbuf, tx);

      zphys->zp_mode = zfs_mode_fuid_compute(zp, aclp, cr, fuidp, tx);

      /*
       * Decide which opbject type to use.  If we are forced to
       * use old ACL format than transform ACL into zfs_oldace_t
       * layout.
       */
      if (!zfsvfs->z_use_fuids) {
            otype = DMU_OT_OLDACL;
      } else {
            if ((aclp->z_version == ZFS_ACL_VERSION_INITIAL) &&
                (zfsvfs->z_version >= ZPL_VERSION_FUID))
                  zfs_acl_xform(zp, aclp);
            ASSERT(aclp->z_version >= ZFS_ACL_VERSION_FUID);
            otype = DMU_OT_ACL;
      }

      if (aclp->z_acl_bytes > ZFS_ACE_SPACE) {
            /*
             * If ACL was previously external and we are now
             * converting to new ACL format then release old
             * ACL object and create a new one.
             */
            if (aoid && aclp->z_version != zacl->z_acl_version) {
                  error = dmu_object_free(zfsvfs->z_os,
                      zp->z_phys->zp_acl.z_acl_extern_obj, tx);
                  if (error)
                        return (error);
                  aoid = 0;
            }
            if (aoid == 0) {
                  aoid = dmu_object_alloc(zfsvfs->z_os,
                      otype, aclp->z_acl_bytes,
                      otype == DMU_OT_ACL ? DMU_OT_SYSACL : DMU_OT_NONE,
                      otype == DMU_OT_ACL ? DN_MAX_BONUSLEN : 0, tx);
            } else {
                  (void) dmu_object_set_blocksize(zfsvfs->z_os, aoid,
                      aclp->z_acl_bytes, 0, tx);
            }
            zphys->zp_acl.z_acl_extern_obj = aoid;
            for (aclnode = list_head(&aclp->z_acl); aclnode;
                aclnode = list_next(&aclp->z_acl, aclnode)) {
                  if (aclnode->z_ace_count == 0)
                        continue;
                  dmu_write(zfsvfs->z_os, aoid, off,
                      aclnode->z_size, aclnode->z_acldata, tx);
                  off += aclnode->z_size;
            }
      } else {
            void *start = zacl->z_ace_data;
            /*
             * Migrating back embedded?
             */
            if (zphys->zp_acl.z_acl_extern_obj) {
                  error = dmu_object_free(zfsvfs->z_os,
                      zp->z_phys->zp_acl.z_acl_extern_obj, tx);
                  if (error)
                        return (error);
                  zphys->zp_acl.z_acl_extern_obj = 0;
            }

            for (aclnode = list_head(&aclp->z_acl); aclnode;
                aclnode = list_next(&aclp->z_acl, aclnode)) {
                  if (aclnode->z_ace_count == 0)
                        continue;
                  bcopy(aclnode->z_acldata, start, aclnode->z_size);
                  start = (caddr_t)start + aclnode->z_size;
            }
      }

      /*
       * If Old version then swap count/bytes to match old
       * layout of znode_acl_phys_t.
       */
      if (aclp->z_version == ZFS_ACL_VERSION_INITIAL) {
            zphys->zp_acl.z_acl_size = aclp->z_acl_count;
            zphys->zp_acl.z_acl_count = aclp->z_acl_bytes;
      } else {
            zphys->zp_acl.z_acl_size = aclp->z_acl_bytes;
            zphys->zp_acl.z_acl_count = aclp->z_acl_count;
      }

      zphys->zp_acl.z_acl_version = aclp->z_version;

      /*
       * Replace ACL wide bits, but first clear them.
       */
      zp->z_phys->zp_flags &= ~ZFS_ACL_WIDE_FLAGS;

      zp->z_phys->zp_flags |= aclp->z_hints;

      if (ace_trivial_common(aclp, 0, zfs_ace_walk) == 0)
            zp->z_phys->zp_flags |= ZFS_ACL_TRIVIAL;

      zfs_time_stamper_locked(zp, STATE_CHANGED, tx);
      return (0);
}

/*
 * Update access mask for prepended ACE
 *
 * This applies the "groupmask" value for aclmode property.
 */
static void
zfs_acl_prepend_fixup(zfs_acl_t *aclp, void  *acep, void  *origacep,
    mode_t mode, uint64_t owner)
{
      int   rmask, wmask, xmask;
      int   user_ace;
      uint16_t aceflags;
      uint32_t origmask, acepmask;
      uint64_t fuid;

      aceflags = aclp->z_ops.ace_flags_get(acep);
      fuid = aclp->z_ops.ace_who_get(acep);
      origmask = aclp->z_ops.ace_mask_get(origacep);
      acepmask = aclp->z_ops.ace_mask_get(acep);

      user_ace = (!(aceflags &
          (ACE_OWNER|ACE_GROUP|ACE_IDENTIFIER_GROUP)));

      if (user_ace && (fuid == owner)) {
            rmask = S_IRUSR;
            wmask = S_IWUSR;
            xmask = S_IXUSR;
      } else {
            rmask = S_IRGRP;
            wmask = S_IWGRP;
            xmask = S_IXGRP;
      }

      if (origmask & ACE_READ_DATA) {
            if (mode & rmask) {
                  acepmask &= ~ACE_READ_DATA;
            } else {
                  acepmask |= ACE_READ_DATA;
            }
      }

      if (origmask & ACE_WRITE_DATA) {
            if (mode & wmask) {
                  acepmask &= ~ACE_WRITE_DATA;
            } else {
                  acepmask |= ACE_WRITE_DATA;
            }
      }

      if (origmask & ACE_APPEND_DATA) {
            if (mode & wmask) {
                  acepmask &= ~ACE_APPEND_DATA;
            } else {
                  acepmask |= ACE_APPEND_DATA;
            }
      }

      if (origmask & ACE_EXECUTE) {
            if (mode & xmask) {
                  acepmask &= ~ACE_EXECUTE;
            } else {
                  acepmask |= ACE_EXECUTE;
            }
      }
      aclp->z_ops.ace_mask_set(acep, acepmask);
}

/*
 * Apply mode to canonical six ACEs.
 */
static void
zfs_acl_fixup_canonical_six(zfs_acl_t *aclp, mode_t mode)
{
      zfs_acl_node_t *aclnode = list_tail(&aclp->z_acl);
      void  *acep;
      int   maskoff = aclp->z_ops.ace_mask_off();
      size_t abstract_size = aclp->z_ops.ace_abstract_size();

      ASSERT(aclnode != NULL);

      acep = (void *)((caddr_t)aclnode->z_acldata +
          aclnode->z_size - (abstract_size * 6));

      /*
       * Fixup final ACEs to match the mode
       */

      adjust_ace_pair_common(acep, maskoff, abstract_size,
          (mode & 0700) >> 6);      /* owner@ */

      acep = (caddr_t)acep + (abstract_size * 2);

      adjust_ace_pair_common(acep, maskoff, abstract_size,
          (mode & 0070) >> 3);      /* group@ */

      acep = (caddr_t)acep + (abstract_size * 2);
      adjust_ace_pair_common(acep, maskoff,
          abstract_size, mode);     /* everyone@ */
}


static int
zfs_acl_ace_match(zfs_acl_t *aclp, void *acep, int allow_deny,
    int entry_type, int accessmask)
{
      uint32_t mask = aclp->z_ops.ace_mask_get(acep);
      uint16_t type = aclp->z_ops.ace_type_get(acep);
      uint16_t flags = aclp->z_ops.ace_flags_get(acep);

      return (mask == accessmask && type == allow_deny &&
          ((flags & ACE_TYPE_FLAGS) == entry_type));
}

/*
 * Can prepended ACE be reused?
 */
static int
zfs_reuse_deny(zfs_acl_t *aclp, void *acep, void *prevacep)
{
      int okay_masks;
      uint16_t prevtype;
      uint16_t prevflags;
      uint16_t flags;
      uint32_t mask, prevmask;

      if (prevacep == NULL)
            return (B_FALSE);

      prevtype = aclp->z_ops.ace_type_get(prevacep);
      prevflags = aclp->z_ops.ace_flags_get(prevacep);
      flags = aclp->z_ops.ace_flags_get(acep);
      mask = aclp->z_ops.ace_mask_get(acep);
      prevmask = aclp->z_ops.ace_mask_get(prevacep);

      if (prevtype != DENY)
            return (B_FALSE);

      if (prevflags != (flags & ACE_IDENTIFIER_GROUP))
            return (B_FALSE);

      okay_masks = (mask & OKAY_MASK_BITS);

      if (prevmask & ~okay_masks)
            return (B_FALSE);

      return (B_TRUE);
}


/*
 * Insert new ACL node into chain of zfs_acl_node_t's
 *
 * This will result in two possible results.
 * 1. If the ACL is currently just a single zfs_acl_node and
 *    we are prepending the entry then current acl node will have
 *    a new node inserted above it.
 *
 * 2. If we are inserting in the middle of current acl node then
 *    the current node will be split in two and new node will be inserted
 *    in between the two split nodes.
 */
static zfs_acl_node_t *
zfs_acl_ace_insert(zfs_acl_t *aclp, void  *acep)
{
      zfs_acl_node_t    *newnode;
      zfs_acl_node_t    *trailernode = NULL;
      zfs_acl_node_t    *currnode = zfs_acl_curr_node(aclp);
      int         curr_idx = aclp->z_curr_node->z_ace_idx;
      int         trailer_count;
      size_t            oldsize;

      newnode = zfs_acl_node_alloc(aclp->z_ops.ace_size(acep));
      newnode->z_ace_count = 1;

      oldsize = currnode->z_size;

      if (curr_idx != 1) {
            trailernode = zfs_acl_node_alloc(0);
            trailernode->z_acldata = acep;

            trailer_count = currnode->z_ace_count - curr_idx + 1;
            currnode->z_ace_count = curr_idx - 1;
            currnode->z_size = (caddr_t)acep - (caddr_t)currnode->z_acldata;
            trailernode->z_size = oldsize - currnode->z_size;
            trailernode->z_ace_count = trailer_count;
      }

      aclp->z_acl_count += 1;
      aclp->z_acl_bytes += aclp->z_ops.ace_size(acep);

      if (curr_idx == 1)
            list_insert_before(&aclp->z_acl, currnode, newnode);
      else
            list_insert_after(&aclp->z_acl, currnode, newnode);
      if (trailernode) {
            list_insert_after(&aclp->z_acl, newnode, trailernode);
            aclp->z_curr_node = trailernode;
            trailernode->z_ace_idx = 1;
      }

      return (newnode);
}

/*
 * Prepend deny ACE
 */
static void *
zfs_acl_prepend_deny(znode_t *zp, zfs_acl_t *aclp, void *acep,
    mode_t mode)
{
      zfs_acl_node_t *aclnode;
      void  *newacep;
      uint64_t fuid;
      uint16_t flags;

      aclnode = zfs_acl_ace_insert(aclp, acep);
      newacep = aclnode->z_acldata;
      fuid = aclp->z_ops.ace_who_get(acep);
      flags = aclp->z_ops.ace_flags_get(acep);
      zfs_set_ace(aclp, newacep, 0, DENY, fuid, (flags & ACE_TYPE_FLAGS));
      zfs_acl_prepend_fixup(aclp, newacep, acep, mode, zp->z_phys->zp_uid);

      return (newacep);
}

/*
 * Split an inherited ACE into inherit_only ACE
 * and original ACE with inheritance flags stripped off.
 */
static void
zfs_acl_split_ace(zfs_acl_t *aclp, zfs_ace_hdr_t *acep)
{
      zfs_acl_node_t *aclnode;
      zfs_acl_node_t *currnode;
      void  *newacep;
      uint16_t type, flags;
      uint32_t mask;
      uint64_t fuid;

      type = aclp->z_ops.ace_type_get(acep);
      flags = aclp->z_ops.ace_flags_get(acep);
      mask = aclp->z_ops.ace_mask_get(acep);
      fuid = aclp->z_ops.ace_who_get(acep);

      aclnode = zfs_acl_ace_insert(aclp, acep);
      newacep = aclnode->z_acldata;

      aclp->z_ops.ace_type_set(newacep, type);
      aclp->z_ops.ace_flags_set(newacep, flags | ACE_INHERIT_ONLY_ACE);
      aclp->z_ops.ace_mask_set(newacep, mask);
      aclp->z_ops.ace_type_set(newacep, type);
      aclp->z_ops.ace_who_set(newacep, fuid);
      aclp->z_next_ace = acep;
      flags &= ~ALL_INHERIT;
      aclp->z_ops.ace_flags_set(acep, flags);
      currnode = zfs_acl_curr_node(aclp);
      ASSERT(currnode->z_ace_idx >= 1);
      currnode->z_ace_idx -= 1;
}

/*
 * Are ACES started at index i, the canonical six ACES?
 */
static int
zfs_have_canonical_six(zfs_acl_t *aclp)
{
      void *acep;
      zfs_acl_node_t *aclnode = list_tail(&aclp->z_acl);
      int         i = 0;
      size_t abstract_size = aclp->z_ops.ace_abstract_size();

      ASSERT(aclnode != NULL);

      if (aclnode->z_ace_count < 6)
            return (0);

      acep = (void *)((caddr_t)aclnode->z_acldata +
          aclnode->z_size - (aclp->z_ops.ace_abstract_size() * 6));

      if ((zfs_acl_ace_match(aclp, (caddr_t)acep + (abstract_size * i++),
          DENY, ACE_OWNER, 0) &&
          zfs_acl_ace_match(aclp, (caddr_t)acep + (abstract_size * i++),
          ALLOW, ACE_OWNER, OWNER_ALLOW_MASK) &&
          zfs_acl_ace_match(aclp, (caddr_t)acep + (abstract_size * i++), DENY,
          OWNING_GROUP, 0) && zfs_acl_ace_match(aclp, (caddr_t)acep +
          (abstract_size * i++),
          ALLOW, OWNING_GROUP, 0) &&
          zfs_acl_ace_match(aclp, (caddr_t)acep + (abstract_size * i++),
          DENY, ACE_EVERYONE, EVERYONE_DENY_MASK) &&
          zfs_acl_ace_match(aclp, (caddr_t)acep + (abstract_size * i++),
          ALLOW, ACE_EVERYONE, EVERYONE_ALLOW_MASK))) {
            return (1);
      } else {
            return (0);
      }
}


/*
 * Apply step 1g, to group entries
 *
 * Need to deal with corner case where group may have
 * greater permissions than owner.  If so then limit
 * group permissions, based on what extra permissions
 * group has.
 */
static void
zfs_fixup_group_entries(zfs_acl_t *aclp, void *acep, void *prevacep,
    mode_t mode)
{
      uint32_t prevmask = aclp->z_ops.ace_mask_get(prevacep);
      uint32_t mask = aclp->z_ops.ace_mask_get(acep);
      uint16_t prevflags = aclp->z_ops.ace_flags_get(prevacep);
      mode_t extramode = (mode >> 3) & 07;
      mode_t ownermode = (mode >> 6);

      if (prevflags & ACE_IDENTIFIER_GROUP) {

            extramode &= ~ownermode;

            if (extramode) {
                  if (extramode & S_IROTH) {
                        prevmask &= ~ACE_READ_DATA;
                        mask &= ~ACE_READ_DATA;
                  }
                  if (extramode & S_IWOTH) {
                        prevmask &= ~(ACE_WRITE_DATA|ACE_APPEND_DATA);
                        mask &= ~(ACE_WRITE_DATA|ACE_APPEND_DATA);
                  }
                  if (extramode & S_IXOTH) {
                        prevmask  &= ~ACE_EXECUTE;
                        mask &= ~ACE_EXECUTE;
                  }
            }
      }
      aclp->z_ops.ace_mask_set(acep, mask);
      aclp->z_ops.ace_mask_set(prevacep, prevmask);
}

/*
 * Apply the chmod algorithm as described
 * in PSARC/2002/240
 */
static void
zfs_acl_chmod(znode_t *zp, uint64_t mode, zfs_acl_t *aclp)
{
      zfsvfs_t    *zfsvfs = zp->z_zfsvfs;
      void        *acep = NULL, *prevacep = NULL;
      uint64_t    who;
      int         i;
      int         entry_type;
      int         reuse_deny;
      int         need_canonical_six = 1;
      uint16_t    iflags, type;
      uint32_t    access_mask;

      ASSERT(MUTEX_HELD(&zp->z_acl_lock));
      ASSERT(MUTEX_HELD(&zp->z_lock));

      aclp->z_hints = (zp->z_phys->zp_flags & V4_ACL_WIDE_FLAGS);

      /*
       * If discard then just discard all ACL nodes which
       * represent the ACEs.
       *
       * New owner@/group@/everone@ ACEs will be added
       * later.
       */
      if (zfsvfs->z_acl_mode == ZFS_ACL_DISCARD)
            zfs_acl_release_nodes(aclp);

      while (acep = zfs_acl_next_ace(aclp, acep, &who, &access_mask,
          &iflags, &type)) {

            entry_type = (iflags & ACE_TYPE_FLAGS);
            iflags = (iflags & ALL_INHERIT);

            if ((type != ALLOW && type != DENY) ||
                (iflags & ACE_INHERIT_ONLY_ACE)) {
                  if (iflags)
                        aclp->z_hints |= ZFS_INHERIT_ACE;
                  switch (type) {
                  case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
                  case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
                  case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
                  case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
                        aclp->z_hints |= ZFS_ACL_OBJ_ACE;
                        break;
                  }
                  goto nextace;
            }

            /*
             * Need to split ace into two?
             */
            if ((iflags & (ACE_FILE_INHERIT_ACE|
                ACE_DIRECTORY_INHERIT_ACE)) &&
                (!(iflags & ACE_INHERIT_ONLY_ACE))) {
                  zfs_acl_split_ace(aclp, acep);
                  aclp->z_hints |= ZFS_INHERIT_ACE;
                  goto nextace;
            }

            if (entry_type == ACE_OWNER || entry_type == ACE_EVERYONE ||
                (entry_type == OWNING_GROUP)) {
                  access_mask &= ~OGE_CLEAR;
                  aclp->z_ops.ace_mask_set(acep, access_mask);
                  goto nextace;
            } else {
                  reuse_deny = B_TRUE;
                  if (type == ALLOW) {

                        /*
                         * Check preceding ACE if any, to see
                         * if we need to prepend a DENY ACE.
                         * This is only applicable when the acl_mode
                         * property == groupmask.
                         */
                        if (zfsvfs->z_acl_mode == ZFS_ACL_GROUPMASK) {

                              reuse_deny = zfs_reuse_deny(aclp, acep,
                                  prevacep);

                              if (!reuse_deny) {
                                    prevacep =
                                        zfs_acl_prepend_deny(zp,
                                        aclp, acep, mode);
                              } else {
                                    zfs_acl_prepend_fixup(
                                        aclp, prevacep,
                                        acep, mode,
                                        zp->z_phys->zp_uid);
                              }
                              zfs_fixup_group_entries(aclp, acep,
                                  prevacep, mode);

                        }
                  }
            }
nextace:
            prevacep = acep;
      }

      /*
       * Check out last six aces, if we have six.
       */

      if (aclp->z_acl_count >= 6) {
            if (zfs_have_canonical_six(aclp)) {
                  need_canonical_six = 0;
            }
      }

      if (need_canonical_six) {
            size_t abstract_size = aclp->z_ops.ace_abstract_size();
            void *zacep;
            zfs_acl_node_t *aclnode =
                zfs_acl_node_alloc(abstract_size * 6);

            aclnode->z_size = abstract_size * 6;
            aclnode->z_ace_count = 6;
            aclp->z_acl_bytes += aclnode->z_size;
            list_insert_tail(&aclp->z_acl, aclnode);

            zacep = aclnode->z_acldata;

            i = 0;
            zfs_set_ace(aclp, (caddr_t)zacep + (abstract_size * i++),
                0, DENY, -1, ACE_OWNER);
            zfs_set_ace(aclp, (caddr_t)zacep + (abstract_size * i++),
                OWNER_ALLOW_MASK, ALLOW, -1, ACE_OWNER);
            zfs_set_ace(aclp, (caddr_t)zacep + (abstract_size * i++), 0,
                DENY, -1, OWNING_GROUP);
            zfs_set_ace(aclp, (caddr_t)zacep + (abstract_size * i++), 0,
                ALLOW, -1, OWNING_GROUP);
            zfs_set_ace(aclp, (caddr_t)zacep + (abstract_size * i++),
                EVERYONE_DENY_MASK, DENY, -1, ACE_EVERYONE);
            zfs_set_ace(aclp, (caddr_t)zacep + (abstract_size * i++),
                EVERYONE_ALLOW_MASK, ALLOW, -1, ACE_EVERYONE);
            aclp->z_acl_count += 6;
      }

      zfs_acl_fixup_canonical_six(aclp, mode);
}

int
zfs_acl_chmod_setattr(znode_t *zp, zfs_acl_t **aclp, uint64_t mode)
{
      int error;

      mutex_enter(&zp->z_lock);
      mutex_enter(&zp->z_acl_lock);
      *aclp = NULL;
      error = zfs_acl_node_read(zp, aclp, B_TRUE);
      if (error == 0)
            zfs_acl_chmod(zp, mode, *aclp);
      mutex_exit(&zp->z_acl_lock);
      mutex_exit(&zp->z_lock);
      return (error);
}

/*
 * strip off write_owner and write_acl
 */
static void
zfs_restricted_update(zfsvfs_t *zfsvfs, zfs_acl_t *aclp, void *acep)
{
      uint32_t mask = aclp->z_ops.ace_mask_get(acep);

      if ((zfsvfs->z_acl_inherit == ZFS_ACL_RESTRICTED) &&
          (aclp->z_ops.ace_type_get(acep) == ALLOW)) {
            mask &= ~RESTRICTED_CLEAR;
            aclp->z_ops.ace_mask_set(acep, mask);
      }
}

/*
 * Should ACE be inherited?
 */
static int
zfs_ace_can_use(znode_t *zp, uint16_t acep_flags)
{
      int vtype = ZTOV(zp)->v_type;
      int   iflags = (acep_flags & 0xf);

      if ((vtype == VDIR) && (iflags & ACE_DIRECTORY_INHERIT_ACE))
            return (1);
      else if (iflags & ACE_FILE_INHERIT_ACE)
            return (!((vtype == VDIR) &&
                (iflags & ACE_NO_PROPAGATE_INHERIT_ACE)));
      return (0);
}

/*
 * inherit inheritable ACEs from parent
 */
static zfs_acl_t *
zfs_acl_inherit(znode_t *zp, zfs_acl_t *paclp, uint64_t mode,
    boolean_t *need_chmod)
{
      zfsvfs_t    *zfsvfs = zp->z_zfsvfs;
      void        *pacep;
      void        *acep, *acep2;
      zfs_acl_node_t  *aclnode, *aclnode2;
      zfs_acl_t   *aclp = NULL;
      uint64_t    who;
      uint32_t    access_mask;
      uint16_t    iflags, newflags, type;
      size_t            ace_size;
      void        *data1, *data2;
      size_t            data1sz, data2sz;
      boolean_t   vdir = ZTOV(zp)->v_type == VDIR;
      boolean_t   vreg = ZTOV(zp)->v_type == VREG;
      boolean_t   passthrough, passthrough_x, noallow;

      passthrough_x =
          zfsvfs->z_acl_inherit == ZFS_ACL_PASSTHROUGH_X;
      passthrough = passthrough_x ||
          zfsvfs->z_acl_inherit == ZFS_ACL_PASSTHROUGH;
      noallow =
          zfsvfs->z_acl_inherit == ZFS_ACL_NOALLOW;

      *need_chmod = B_TRUE;
      pacep = NULL;
      aclp = zfs_acl_alloc(paclp->z_version);
      if (zfsvfs->z_acl_inherit == ZFS_ACL_DISCARD)
            return (aclp);
      while (pacep = zfs_acl_next_ace(paclp, pacep, &who,
          &access_mask, &iflags, &type)) {

            /*
             * don't inherit bogus ACEs
             */
            if (!zfs_acl_valid_ace_type(type, iflags))
                  continue;

            if (noallow && type == ALLOW)
                  continue;

            ace_size = aclp->z_ops.ace_size(pacep);

            if (!zfs_ace_can_use(zp, iflags))
                  continue;

            /*
             * If owner@, group@, or everyone@ inheritable
             * then zfs_acl_chmod() isn't needed.
             */
            if (passthrough &&
                ((iflags & (ACE_OWNER|ACE_EVERYONE)) ||
                ((iflags & OWNING_GROUP) ==
                OWNING_GROUP)) && (vreg || (vdir && (iflags &
                ACE_DIRECTORY_INHERIT_ACE)))) {
                  *need_chmod = B_FALSE;

                  if (!vdir && passthrough_x &&
                      ((mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)) {
                        access_mask &= ~ACE_EXECUTE;
                  }
            }

            aclnode = zfs_acl_node_alloc(ace_size);
            list_insert_tail(&aclp->z_acl, aclnode);
            acep = aclnode->z_acldata;

            zfs_set_ace(aclp, acep, access_mask, type,
                who, iflags|ACE_INHERITED_ACE);

            /*
             * Copy special opaque data if any
             */
            if ((data1sz = paclp->z_ops.ace_data(pacep, &data1)) != 0) {
                  VERIFY((data2sz = aclp->z_ops.ace_data(acep,
                      &data2)) == data1sz);
                  bcopy(data1, data2, data2sz);
            }
            aclp->z_acl_count++;
            aclnode->z_ace_count++;
            aclp->z_acl_bytes += aclnode->z_size;
            newflags = aclp->z_ops.ace_flags_get(acep);

            if (vdir)
                  aclp->z_hints |= ZFS_INHERIT_ACE;

            if ((iflags & ACE_NO_PROPAGATE_INHERIT_ACE) || !vdir) {
                  newflags &= ~ALL_INHERIT;
                  aclp->z_ops.ace_flags_set(acep,
                      newflags|ACE_INHERITED_ACE);
                  zfs_restricted_update(zfsvfs, aclp, acep);
                  continue;
            }

            ASSERT(vdir);

            newflags = aclp->z_ops.ace_flags_get(acep);
            if ((iflags & (ACE_FILE_INHERIT_ACE |
                ACE_DIRECTORY_INHERIT_ACE)) !=
                ACE_FILE_INHERIT_ACE) {
                  aclnode2 = zfs_acl_node_alloc(ace_size);
                  list_insert_tail(&aclp->z_acl, aclnode2);
                  acep2 = aclnode2->z_acldata;
                  zfs_set_ace(aclp, acep2,
                      access_mask, type, who,
                      iflags|ACE_INHERITED_ACE);
                  newflags |= ACE_INHERIT_ONLY_ACE;
                  aclp->z_ops.ace_flags_set(acep, newflags);
                  newflags &= ~ALL_INHERIT;
                  aclp->z_ops.ace_flags_set(acep2,
                      newflags|ACE_INHERITED_ACE);

                  /*
                   * Copy special opaque data if any
                   */
                  if ((data1sz = aclp->z_ops.ace_data(acep,
                      &data1)) != 0) {
                        VERIFY((data2sz =
                            aclp->z_ops.ace_data(acep2,
                            &data2)) == data1sz);
                        bcopy(data1, data2, data1sz);
                  }
                  aclp->z_acl_count++;
                  aclnode2->z_ace_count++;
                  aclp->z_acl_bytes += aclnode->z_size;
                  zfs_restricted_update(zfsvfs, aclp, acep2);
            } else {
                  newflags |= ACE_INHERIT_ONLY_ACE;
                  aclp->z_ops.ace_flags_set(acep,
                      newflags|ACE_INHERITED_ACE);
            }
      }
      return (aclp);
}

/*
 * Create file system object initial permissions
 * including inheritable ACEs.
 */
void
zfs_perm_init(znode_t *zp, znode_t *parent, int flag,
    vattr_t *vap, dmu_tx_t *tx, cred_t *cr,
    zfs_acl_t *setaclp, zfs_fuid_info_t **fuidp)
{
      uint64_t    mode, fuid, fgid;
      int         error;
      zfsvfs_t    *zfsvfs = zp->z_zfsvfs;
      zfs_acl_t   *aclp = NULL;
      zfs_acl_t   *paclp;
      xvattr_t    *xvap = (xvattr_t *)vap;
      gid_t       gid;
      boolean_t   need_chmod = B_TRUE;

      if (setaclp)
            aclp = setaclp;

      mode = MAKEIMODE(vap->va_type, vap->va_mode);

      /*
       * Determine uid and gid.
       */
      if ((flag & (IS_ROOT_NODE | IS_REPLAY)) ||
          ((flag & IS_XATTR) && (vap->va_type == VDIR))) {
            fuid = zfs_fuid_create(zfsvfs, vap->va_uid, cr,
                ZFS_OWNER, tx, fuidp);
            fgid = zfs_fuid_create(zfsvfs, vap->va_gid, cr,
                ZFS_GROUP, tx, fuidp);
            gid = vap->va_gid;
      } else {
            fuid = zfs_fuid_create_cred(zfsvfs, ZFS_OWNER, tx, cr, fuidp);
            fgid = 0;
            if (vap->va_mask & AT_GID)  {
                  fgid = zfs_fuid_create(zfsvfs, vap->va_gid, cr,
                      ZFS_GROUP, tx, fuidp);
                  gid = vap->va_gid;
                  if (fgid != parent->z_phys->zp_gid &&
                      !groupmember(vap->va_gid, cr) &&
                      secpolicy_vnode_create_gid(cr) != 0)
                        fgid = 0;
            }
            if (fgid == 0) {
                  if (parent->z_phys->zp_mode & S_ISGID) {
                        fgid = parent->z_phys->zp_gid;
                        gid = zfs_fuid_map_id(zfsvfs, fgid,
                            cr, ZFS_GROUP);
                  } else {
                        fgid = zfs_fuid_create_cred(zfsvfs,
                            ZFS_GROUP, tx, cr, fuidp);
#ifdef __FreeBSD__
                        gid = fgid = parent->z_phys->zp_gid;
#else
                        gid = crgetgid(cr);
#endif
                  }
            }
      }

      /*
       * If we're creating a directory, and the parent directory has the
       * set-GID bit set, set in on the new directory.
       * Otherwise, if the user is neither privileged nor a member of the
       * file's new group, clear the file's set-GID bit.
       */

      if ((parent->z_phys->zp_mode & S_ISGID) && (vap->va_type == VDIR)) {
            mode |= S_ISGID;
      } else {
            if ((mode & S_ISGID) &&
                secpolicy_vnode_setids_setgids(ZTOV(zp), cr, gid) != 0)
                  mode &= ~S_ISGID;
      }

      zp->z_phys->zp_uid = fuid;
      zp->z_phys->zp_gid = fgid;
      zp->z_phys->zp_mode = mode;

      if (aclp == NULL) {
            mutex_enter(&parent->z_lock);
            if ((ZTOV(parent)->v_type == VDIR &&
                (parent->z_phys->zp_flags & ZFS_INHERIT_ACE)) &&
                !(zp->z_phys->zp_flags & ZFS_XATTR)) {
                  mutex_enter(&parent->z_acl_lock);
                  VERIFY(0 == zfs_acl_node_read(parent, &paclp, B_FALSE));
                  mutex_exit(&parent->z_acl_lock);
                  aclp = zfs_acl_inherit(zp, paclp, mode, &need_chmod);
                  zfs_acl_free(paclp);
            } else {
                  aclp = zfs_acl_alloc(zfs_acl_version_zp(zp));
            }
            mutex_exit(&parent->z_lock);
            mutex_enter(&zp->z_lock);
            mutex_enter(&zp->z_acl_lock);
            if (need_chmod)
                  zfs_acl_chmod(zp, mode, aclp);
      } else {
            mutex_enter(&zp->z_lock);
            mutex_enter(&zp->z_acl_lock);
      }

      /* Force auto_inherit on all new directory objects */
      if (vap->va_type == VDIR)
            aclp->z_hints |= ZFS_ACL_AUTO_INHERIT;

      error = zfs_aclset_common(zp, aclp, cr, fuidp, tx);

      /* Set optional attributes if any */
      if (vap->va_mask & AT_XVATTR)
            zfs_xvattr_set(zp, xvap);

      mutex_exit(&zp->z_lock);
      mutex_exit(&zp->z_acl_lock);
      ASSERT3U(error, ==, 0);

      if (aclp != setaclp)
            zfs_acl_free(aclp);
}

/*
 * Retrieve a files ACL
 */
int
zfs_getacl(znode_t *zp, vsecattr_t *vsecp, boolean_t skipaclchk, cred_t *cr)
{
      zfs_acl_t   *aclp;
      ulong_t           mask;
      int         error;
      int         count = 0;
      int         largeace = 0;

      mask = vsecp->vsa_mask & (VSA_ACE | VSA_ACECNT |
          VSA_ACE_ACLFLAGS | VSA_ACE_ALLTYPES);

      if (error = zfs_zaccess(zp, ACE_READ_ACL, 0, skipaclchk, cr))
            return (error);

      if (mask == 0)
            return (ENOSYS);

      mutex_enter(&zp->z_acl_lock);

      error = zfs_acl_node_read(zp, &aclp, B_FALSE);
      if (error != 0) {
            mutex_exit(&zp->z_acl_lock);
            return (error);
      }

      /*
       * Scan ACL to determine number of ACEs
       */
      if ((zp->z_phys->zp_flags & ZFS_ACL_OBJ_ACE) &&
          !(mask & VSA_ACE_ALLTYPES)) {
            void *zacep = NULL;
            uint64_t who;
            uint32_t access_mask;
            uint16_t type, iflags;

            while (zacep = zfs_acl_next_ace(aclp, zacep,
                &who, &access_mask, &iflags, &type)) {
                  switch (type) {
                  case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
                  case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
                  case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
                  case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
                        largeace++;
                        continue;
                  default:
                        count++;
                  }
            }
            vsecp->vsa_aclcnt = count;
      } else
            count = aclp->z_acl_count;

      if (mask & VSA_ACECNT) {
            vsecp->vsa_aclcnt = count;
      }

      if (mask & VSA_ACE) {
            size_t aclsz;

            zfs_acl_node_t *aclnode = list_head(&aclp->z_acl);

            aclsz = count * sizeof (ace_t) +
                sizeof (ace_object_t) * largeace;

            vsecp->vsa_aclentp = kmem_alloc(aclsz, KM_SLEEP);
            vsecp->vsa_aclentsz = aclsz;

            if (aclp->z_version == ZFS_ACL_VERSION_FUID)
                  zfs_copy_fuid_2_ace(zp->z_zfsvfs, aclp, cr,
                      vsecp->vsa_aclentp, !(mask & VSA_ACE_ALLTYPES));
            else {
                  bcopy(aclnode->z_acldata, vsecp->vsa_aclentp,
                      count * sizeof (ace_t));
            }
      }
      if (mask & VSA_ACE_ACLFLAGS) {
            vsecp->vsa_aclflags = 0;
            if (zp->z_phys->zp_flags & ZFS_ACL_DEFAULTED)
                  vsecp->vsa_aclflags |= ACL_DEFAULTED;
            if (zp->z_phys->zp_flags & ZFS_ACL_PROTECTED)
                  vsecp->vsa_aclflags |= ACL_PROTECTED;
            if (zp->z_phys->zp_flags & ZFS_ACL_AUTO_INHERIT)
                  vsecp->vsa_aclflags |= ACL_AUTO_INHERIT;
      }

      mutex_exit(&zp->z_acl_lock);

      zfs_acl_free(aclp);

      return (0);
}

int
zfs_vsec_2_aclp(zfsvfs_t *zfsvfs, vtype_t obj_type,
    vsecattr_t *vsecp, zfs_acl_t **zaclp)
{
      zfs_acl_t *aclp;
      zfs_acl_node_t *aclnode;
      int aclcnt = vsecp->vsa_aclcnt;
      int error;

      if (vsecp->vsa_aclcnt > MAX_ACL_ENTRIES || vsecp->vsa_aclcnt <= 0)
            return (EINVAL);

      aclp = zfs_acl_alloc(zfs_acl_version(zfsvfs->z_version));

      aclp->z_hints = 0;
      aclnode = zfs_acl_node_alloc(aclcnt * sizeof (zfs_object_ace_t));
      if (aclp->z_version == ZFS_ACL_VERSION_INITIAL) {
            if ((error = zfs_copy_ace_2_oldace(obj_type, aclp,
                (ace_t *)vsecp->vsa_aclentp, aclnode->z_acldata,
                aclcnt, &aclnode->z_size)) != 0) {
                  zfs_acl_free(aclp);
                  zfs_acl_node_free(aclnode);
                  return (error);
            }
      } else {
            if ((error = zfs_copy_ace_2_fuid(obj_type, aclp,
                vsecp->vsa_aclentp, aclnode->z_acldata, aclcnt,
                &aclnode->z_size)) != 0) {
                  zfs_acl_free(aclp);
                  zfs_acl_node_free(aclnode);
                  return (error);
            }
      }
      aclp->z_acl_bytes = aclnode->z_size;
      aclnode->z_ace_count = aclcnt;
      aclp->z_acl_count = aclcnt;
      list_insert_head(&aclp->z_acl, aclnode);

      /*
       * If flags are being set then add them to z_hints
       */
      if (vsecp->vsa_mask & VSA_ACE_ACLFLAGS) {
            if (vsecp->vsa_aclflags & ACL_PROTECTED)
                  aclp->z_hints |= ZFS_ACL_PROTECTED;
            if (vsecp->vsa_aclflags & ACL_DEFAULTED)
                  aclp->z_hints |= ZFS_ACL_DEFAULTED;
            if (vsecp->vsa_aclflags & ACL_AUTO_INHERIT)
                  aclp->z_hints |= ZFS_ACL_AUTO_INHERIT;
      }

      *zaclp = aclp;

      return (0);
}

/*
 * Set a files ACL
 */
int
zfs_setacl(znode_t *zp, vsecattr_t *vsecp, boolean_t skipaclchk, cred_t *cr)
{
      zfsvfs_t    *zfsvfs = zp->z_zfsvfs;
      zilog_t           *zilog = zfsvfs->z_log;
      ulong_t           mask = vsecp->vsa_mask & (VSA_ACE | VSA_ACECNT);
      dmu_tx_t    *tx;
      int         error;
      zfs_acl_t   *aclp;
      zfs_fuid_info_t   *fuidp = NULL;

      if (mask == 0)
            return (ENOSYS);

      if (zp->z_phys->zp_flags & ZFS_IMMUTABLE)
            return (EPERM);

      if (error = zfs_zaccess(zp, ACE_WRITE_ACL, 0, skipaclchk, cr))
            return (error);

      error = zfs_vsec_2_aclp(zfsvfs, ZTOV(zp)->v_type, vsecp, &aclp);
      if (error)
            return (error);

      /*
       * If ACL wide flags aren't being set then preserve any
       * existing flags.
       */
      if (!(vsecp->vsa_mask & VSA_ACE_ACLFLAGS)) {
            aclp->z_hints |= (zp->z_phys->zp_flags & V4_ACL_WIDE_FLAGS);
      }
top:
      if (error = zfs_zaccess(zp, ACE_WRITE_ACL, 0, skipaclchk, cr)) {
            zfs_acl_free(aclp);
            return (error);
      }

      mutex_enter(&zp->z_lock);
      mutex_enter(&zp->z_acl_lock);

      tx = dmu_tx_create(zfsvfs->z_os);
      dmu_tx_hold_bonus(tx, zp->z_id);

      if (zp->z_phys->zp_acl.z_acl_extern_obj) {
            /* Are we upgrading ACL? */
            if (zfsvfs->z_version <= ZPL_VERSION_FUID &&
                zp->z_phys->zp_acl.z_acl_version ==
                ZFS_ACL_VERSION_INITIAL) {
                  dmu_tx_hold_free(tx,
                      zp->z_phys->zp_acl.z_acl_extern_obj,
                      0, DMU_OBJECT_END);
                  dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
                      0, aclp->z_acl_bytes);
            } else {
                  dmu_tx_hold_write(tx,
                      zp->z_phys->zp_acl.z_acl_extern_obj,
                      0, aclp->z_acl_bytes);
            }
      } else if (aclp->z_acl_bytes > ZFS_ACE_SPACE) {
            dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, aclp->z_acl_bytes);
      }
      if (aclp->z_has_fuids) {
            if (zfsvfs->z_fuid_obj == 0) {
                  dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
                  dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
                      FUID_SIZE_ESTIMATE(zfsvfs));
                  dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, FALSE, NULL);
            } else {
                  dmu_tx_hold_bonus(tx, zfsvfs->z_fuid_obj);
                  dmu_tx_hold_write(tx, zfsvfs->z_fuid_obj, 0,
                      FUID_SIZE_ESTIMATE(zfsvfs));
            }
      }

      error = dmu_tx_assign(tx, zfsvfs->z_assign);
      if (error) {
            mutex_exit(&zp->z_acl_lock);
            mutex_exit(&zp->z_lock);

            if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) {
                  dmu_tx_wait(tx);
                  dmu_tx_abort(tx);
                  goto top;
            }
            dmu_tx_abort(tx);
            zfs_acl_free(aclp);
            return (error);
      }

      error = zfs_aclset_common(zp, aclp, cr, &fuidp, tx);
      ASSERT(error == 0);

      zfs_log_acl(zilog, tx, zp, vsecp, fuidp);

      if (fuidp)
            zfs_fuid_info_free(fuidp);
      zfs_acl_free(aclp);
      dmu_tx_commit(tx);
done:
      mutex_exit(&zp->z_acl_lock);
      mutex_exit(&zp->z_lock);

      return (error);
}

/*
 * working_mode returns the permissions that were not granted
 */
static int
zfs_zaccess_common(znode_t *zp, uint32_t v4_mode, uint32_t *working_mode,
    boolean_t *check_privs, boolean_t skipaclchk, cred_t *cr)
{
      zfs_acl_t   *aclp;
      zfsvfs_t    *zfsvfs = zp->z_zfsvfs;
      int         error;
      uid_t       uid = crgetuid(cr);
      uint64_t    who;
      uint16_t    type, iflags;
      uint16_t    entry_type;
      uint32_t    access_mask;
      uint32_t    deny_mask = 0;
      zfs_ace_hdr_t     *acep = NULL;
      boolean_t   checkit;
      uid_t       fowner;
      uid_t       gowner;

      /*
       * Short circuit empty requests
       */
      if (v4_mode == 0)
            return (0);

      *check_privs = B_TRUE;

      if (zfsvfs->z_assign >= TXG_INITIAL) {          /* ZIL replay */
            *working_mode = 0;
            return (0);
      }

      *working_mode = v4_mode;

      if ((v4_mode & WRITE_MASK) &&
          (zp->z_zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) &&
          (!IS_DEVVP(ZTOV(zp)))) {
            *check_privs = B_FALSE;
            return (EROFS);
      }

      /*
       * Only check for READONLY on non-directories.
       */
      if ((v4_mode & WRITE_MASK_DATA) &&
          (((ZTOV(zp)->v_type != VDIR) &&
          (zp->z_phys->zp_flags & (ZFS_READONLY | ZFS_IMMUTABLE))) ||
          (ZTOV(zp)->v_type == VDIR &&
          (zp->z_phys->zp_flags & ZFS_IMMUTABLE)))) {
            *check_privs = B_FALSE;
            return (EPERM);
      }

#ifdef sun
      if ((v4_mode & (ACE_DELETE | ACE_DELETE_CHILD)) &&
          (zp->z_phys->zp_flags & ZFS_NOUNLINK)) {
            *check_privs = B_FALSE;
            return (EPERM);
      }
#else
      /*
       * In FreeBSD we allow to modify directory's content is ZFS_NOUNLINK
       * (sunlnk) is set. We just don't allow directory removal, which is
       * handled in zfs_zaccess_delete().
       */
      if ((v4_mode & ACE_DELETE) &&
          (zp->z_phys->zp_flags & ZFS_NOUNLINK)) {
            *check_privs = B_FALSE;
            return (EPERM);
      }
#endif

      if (((v4_mode & (ACE_READ_DATA|ACE_EXECUTE)) &&
          (zp->z_phys->zp_flags & ZFS_AV_QUARANTINED))) {
            *check_privs = B_FALSE;
            return (EACCES);
      }

      /*
       * The caller requested that the ACL check be skipped.  This
       * would only happen if the caller checked VOP_ACCESS() with a
       * 32 bit ACE mask and already had the appropriate permissions.
       */
      if (skipaclchk) {
            *working_mode = 0;
            return (0);
      }

      zfs_fuid_map_ids(zp, cr, &fowner, &gowner);

      mutex_enter(&zp->z_acl_lock);

      error = zfs_acl_node_read(zp, &aclp, B_FALSE);
      if (error != 0) {
            mutex_exit(&zp->z_acl_lock);
            return (error);
      }

      while (acep = zfs_acl_next_ace(aclp, acep, &who, &access_mask,
          &iflags, &type)) {

            if (!zfs_acl_valid_ace_type(type, iflags))
                  continue;

            if (ZTOV(zp)->v_type == VDIR && (iflags & ACE_INHERIT_ONLY_ACE))
                  continue;

            entry_type = (iflags & ACE_TYPE_FLAGS);

            checkit = B_FALSE;

            switch (entry_type) {
            case ACE_OWNER:
                  if (uid == fowner)
                        checkit = B_TRUE;
                  break;
            case OWNING_GROUP:
                  who = gowner;
                  /*FALLTHROUGH*/
            case ACE_IDENTIFIER_GROUP:
                  checkit = zfs_groupmember(zfsvfs, who, cr);
                  break;
            case ACE_EVERYONE:
                  checkit = B_TRUE;
                  break;

            /* USER Entry */
            default:
                  if (entry_type == 0) {
                        uid_t newid;

                        newid = zfs_fuid_map_id(zfsvfs, who, cr,
                            ZFS_ACE_USER);
                        if (newid != IDMAP_WK_CREATOR_OWNER_UID &&
                            uid == newid)
                              checkit = B_TRUE;
                        break;
                  } else {
                        zfs_acl_free(aclp);
                        mutex_exit(&zp->z_acl_lock);
                        return (EIO);
                  }
            }

            if (checkit) {
                  uint32_t mask_matched = (access_mask & *working_mode);

                  if (mask_matched) {
                        if (type == DENY)
                              deny_mask |= mask_matched;

                        *working_mode &= ~mask_matched;
                  }
            }

            /* Are we done? */
            if (*working_mode == 0)
                  break;
      }

      mutex_exit(&zp->z_acl_lock);
      zfs_acl_free(aclp);

      /* Put the found 'denies' back on the working mode */
      if (deny_mask) {
            *working_mode |= deny_mask;
            return (EACCES);
      } else if (*working_mode) {
            return (-1);
      }

      return (0);
}

static int
zfs_zaccess_append(znode_t *zp, uint32_t *working_mode, boolean_t *check_privs,
    cred_t *cr)
{
      if (*working_mode != ACE_WRITE_DATA)
            return (EACCES);

      return (zfs_zaccess_common(zp, ACE_APPEND_DATA, working_mode,
          check_privs, B_FALSE, cr));
}

/*
 * Determine whether Access should be granted/denied, invoking least
 * priv subsytem when a deny is determined.
 */
int
zfs_zaccess(znode_t *zp, int mode, int flags, boolean_t skipaclchk, cred_t *cr)
{
      uint32_t    working_mode;
      int         error;
      int         is_attr;
      zfsvfs_t    *zfsvfs = zp->z_zfsvfs;
      boolean_t   check_privs;
      znode_t           *xzp;
      znode_t     *check_zp = zp;

      is_attr = ((zp->z_phys->zp_flags & ZFS_XATTR) &&
          (ZTOV(zp)->v_type == VDIR));

#ifdef __FreeBSD__
      /*
       * In FreeBSD, we don't care about permissions of individual ADS.
       * Note that not checking them is not just an optimization - without
       * this shortcut, EA operations may bogusly fail with EACCES.
       */
      if (zp->z_phys->zp_flags & ZFS_XATTR)
            return (0);
#else
      /*
       * If attribute then validate against base file
       */
      if (is_attr) {
            if ((error = zfs_zget(zp->z_zfsvfs,
                zp->z_phys->zp_parent, &xzp)) != 0)   {
                  return (error);
            }

            check_zp = xzp;

            /*
             * fixup mode to map to xattr perms
             */

            if (mode & (ACE_WRITE_DATA|ACE_APPEND_DATA)) {
                  mode &= ~(ACE_WRITE_DATA|ACE_APPEND_DATA);
                  mode |= ACE_WRITE_NAMED_ATTRS;
            }

            if (mode & (ACE_READ_DATA|ACE_EXECUTE)) {
                  mode &= ~(ACE_READ_DATA|ACE_EXECUTE);
                  mode |= ACE_READ_NAMED_ATTRS;
            }
      }
#endif

      if ((error = zfs_zaccess_common(check_zp, mode, &working_mode,
          &check_privs, skipaclchk, cr)) == 0) {
            if (is_attr)
                  VN_RELE(ZTOV(xzp));
            return (0);
      }

      if (error && !check_privs) {
            if (is_attr)
                  VN_RELE(ZTOV(xzp));
            return (error);
      }

      if (error && (flags & V_APPEND)) {
            error = zfs_zaccess_append(zp, &working_mode, &check_privs, cr);
      }

      if (error && check_privs) {
            uid_t       owner;
            mode_t            checkmode = 0;

            owner = zfs_fuid_map_id(zfsvfs, check_zp->z_phys->zp_uid, cr,
                ZFS_OWNER);

            /*
             * First check for implicit owner permission on
             * read_acl/read_attributes
             */

            error = 0;
            ASSERT(working_mode != 0);

            if ((working_mode & (ACE_READ_ACL|ACE_READ_ATTRIBUTES) &&
                owner == crgetuid(cr)))
                  working_mode &= ~(ACE_READ_ACL|ACE_READ_ATTRIBUTES);

            if (working_mode & (ACE_READ_DATA|ACE_READ_NAMED_ATTRS|
                ACE_READ_ACL|ACE_READ_ATTRIBUTES|ACE_SYNCHRONIZE))
                  checkmode |= VREAD;
            if (working_mode & (ACE_WRITE_DATA|ACE_WRITE_NAMED_ATTRS|
                ACE_APPEND_DATA|ACE_WRITE_ATTRIBUTES|ACE_SYNCHRONIZE))
                  checkmode |= VWRITE;
            if (working_mode & ACE_EXECUTE)
                  checkmode |= VEXEC;

            if (checkmode)
                  error = secpolicy_vnode_access(cr, ZTOV(check_zp),
                      owner, checkmode);

            if (error == 0 && (working_mode & ACE_WRITE_OWNER))
                  error = secpolicy_vnode_chown(ZTOV(check_zp), cr, B_TRUE);
            if (error == 0 && (working_mode & ACE_WRITE_ACL))
                  error = secpolicy_vnode_setdac(ZTOV(check_zp), cr, owner);

            if (error == 0 && (working_mode &
                (ACE_DELETE|ACE_DELETE_CHILD)))
                  error = secpolicy_vnode_remove(ZTOV(check_zp), cr);

            if (error == 0 && (working_mode & ACE_SYNCHRONIZE)) {
                  error = secpolicy_vnode_chown(ZTOV(check_zp), cr, B_FALSE);
            }
            if (error == 0) {
                  /*
                   * See if any bits other than those already checked
                   * for are still present.  If so then return EACCES
                   */
                  if (working_mode & ~(ZFS_CHECKED_MASKS)) {
                        error = EACCES;
                  }
            }
      }

      if (is_attr)
            VN_RELE(ZTOV(xzp));

      return (error);
}

/*
 * Translate traditional unix VREAD/VWRITE/VEXEC mode into
 * native ACL format and call zfs_zaccess()
 */
int
zfs_zaccess_rwx(znode_t *zp, mode_t mode, int flags, cred_t *cr)
{
      return (zfs_zaccess(zp, zfs_unix_to_v4(mode >> 6), flags, B_FALSE, cr));
}

/*
 * Access function for secpolicy_vnode_setattr
 */
int
zfs_zaccess_unix(znode_t *zp, mode_t mode, cred_t *cr)
{
      int v4_mode = zfs_unix_to_v4(mode >> 6);

      return (zfs_zaccess(zp, v4_mode, 0, B_FALSE, cr));
}

static int
zfs_delete_final_check(znode_t *zp, znode_t *dzp,
    mode_t missing_perms, cred_t *cr)
{
      int error;
      uid_t downer;
      zfsvfs_t *zfsvfs = zp->z_zfsvfs;

      downer = zfs_fuid_map_id(zfsvfs, dzp->z_phys->zp_uid, cr, ZFS_OWNER);

      error = secpolicy_vnode_access(cr, ZTOV(dzp), downer, missing_perms);

      if (error == 0)
            error = zfs_sticky_remove_access(dzp, zp, cr);

      return (error);
}

/*
 * Determine whether Access should be granted/deny, without
 * consulting least priv subsystem.
 *
 *
 * The following chart is the recommended NFSv4 enforcement for
 * ability to delete an object.
 *
 *      -------------------------------------------------------
 *      |   Parent Dir  |           Target Object Permissions |
 *      |  permissions  |                                     |
 *      -------------------------------------------------------
 *      |               | ACL Allows | ACL Denies| Delete     |
 *      |               |  Delete    |  Delete   | unspecified|
 *      -------------------------------------------------------
 *      |  ACL Allows   | Permit     | Permit    | Permit     |
 *      |  DELETE_CHILD |                                     |
 *      -------------------------------------------------------
 *      |  ACL Denies   | Permit     | Deny      | Deny       |
 *      |  DELETE_CHILD |            |           |            |
 *      -------------------------------------------------------
 *      | ACL specifies |            |           |            |
 *      | only allow    | Permit     | Permit    | Permit     |
 *      | write and     |            |           |            |
 *      | execute       |            |           |            |
 *      -------------------------------------------------------
 *      | ACL denies    |            |           |            |
 *      | write and     | Permit     | Deny      | Deny       |
 *      | execute       |            |           |            |
 *      -------------------------------------------------------
 *         ^
 *         |
 *         No search privilege, can't even look up file?
 *
 */
int
zfs_zaccess_delete(znode_t *dzp, znode_t *zp, cred_t *cr)
{
      uint32_t dzp_working_mode = 0;
      uint32_t zp_working_mode = 0;
      int dzp_error, zp_error;
      mode_t missing_perms;
      boolean_t dzpcheck_privs = B_TRUE;
      boolean_t zpcheck_privs = B_TRUE;

      /*
       * We want specific DELETE permissions to
       * take precedence over WRITE/EXECUTE.  We don't
       * want an ACL such as this to mess us up.
       * user:joe:write_data:deny,user:joe:delete:allow
       *
       * However, deny permissions may ultimately be overridden
       * by secpolicy_vnode_access().
       *
       * We will ask for all of the necessary permissions and then
       * look at the working modes from the directory and target object
       * to determine what was found.
       */

      if (zp->z_phys->zp_flags & (ZFS_IMMUTABLE | ZFS_NOUNLINK))
            return (EPERM);

      /*
       * First row
       * If the directory permissions allow the delete, we are done.
       */
      if ((dzp_error = zfs_zaccess_common(dzp, ACE_DELETE_CHILD,
          &dzp_working_mode, &dzpcheck_privs, B_FALSE, cr)) == 0)
            return (0);

      /*
       * If target object has delete permission then we are done
       */
      if ((zp_error = zfs_zaccess_common(zp, ACE_DELETE, &zp_working_mode,
          &zpcheck_privs, B_FALSE, cr)) == 0)
            return (0);

      ASSERT(dzp_error && zp_error);

      if (!dzpcheck_privs)
            return (dzp_error);
      if (!zpcheck_privs)
            return (zp_error);

      /*
       * Second row
       *
       * If directory returns EACCES then delete_child was denied
       * due to deny delete_child.  In this case send the request through
       * secpolicy_vnode_remove().  We don't use zfs_delete_final_check()
       * since that *could* allow the delete based on write/execute permission
       * and we want delete permissions to override write/execute.
       */

      if (dzp_error == EACCES)
            return (secpolicy_vnode_remove(ZTOV(dzp), cr)); /* XXXPJD: s/dzp/zp/ ? */

      /*
       * Third Row
       * only need to see if we have write/execute on directory.
       */

      if ((dzp_error = zfs_zaccess_common(dzp, ACE_EXECUTE|ACE_WRITE_DATA,
          &dzp_working_mode, &dzpcheck_privs, B_FALSE, cr)) == 0)
            return (zfs_sticky_remove_access(dzp, zp, cr));

      if (!dzpcheck_privs)
            return (dzp_error);

      /*
       * Fourth row
       */

      missing_perms = (dzp_working_mode & ACE_WRITE_DATA) ? VWRITE : 0;
      missing_perms |= (dzp_working_mode & ACE_EXECUTE) ? VEXEC : 0;

      ASSERT(missing_perms);

      return (zfs_delete_final_check(zp, dzp, missing_perms, cr));

}

int
zfs_zaccess_rename(znode_t *sdzp, znode_t *szp, znode_t *tdzp,
    znode_t *tzp, cred_t *cr)
{
      int add_perm;
      int error;

      if (szp->z_phys->zp_flags & ZFS_AV_QUARANTINED)
            return (EACCES);

      add_perm = (ZTOV(szp)->v_type == VDIR) ?
          ACE_ADD_SUBDIRECTORY : ACE_ADD_FILE;

      /*
       * Rename permissions are combination of delete permission +
       * add file/subdir permission.
       *
       * BSD operating systems also require write permission
       * on the directory being moved from one parent directory
       * to another.
       */
      if (ZTOV(szp)->v_type == VDIR && ZTOV(sdzp) != ZTOV(tdzp)) {
            if (error = zfs_zaccess(szp, ACE_WRITE_DATA, 0, B_FALSE, cr))
                  return (error);
      }

      /*
       * first make sure we do the delete portion.
       *
       * If that succeeds then check for add_file/add_subdir permissions
       */

      if (error = zfs_zaccess_delete(sdzp, szp, cr))
            return (error);

      /*
       * If we have a tzp, see if we can delete it?
       */
      if (tzp) {
            if (error = zfs_zaccess_delete(tdzp, tzp, cr))
                  return (error);
      }

      /*
       * Now check for add permissions
       */
      error = zfs_zaccess(tdzp, add_perm, 0, B_FALSE, cr);

      return (error);
}

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