path: root/source3/smbd/posix_acls.c

#define OLD_NTDOMAIN 1
/*
   Unix SMB/Netbios implementation.
   Version 1.9.
   SMB NT Security Descriptor / Unix permission conversion.
   Copyright (C) Jeremy Allison 1994-2000

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

enum ace_owner {UID_ACE, GID_ACE, WORLD_ACE};

typedef union posix_id {
		uid_t uid;
		gid_t gid;
		int world;
} posix_id;

typedef struct canon_ace {
	struct canon_ace *next, *prev;
	SMB_ACL_TAG_T type;
	mode_t perms; /* Only use S_I(R|W|X)USR mode bits here. */
	DOM_SID sid;
	enum ace_owner owner_type;
	posix_id unix_ug; 
} canon_ace;

static void free_canon_ace_list( canon_ace *list_head );

/****************************************************************************
 Function to create owner and group SIDs from a SMB_STRUCT_STAT.
****************************************************************************/

static void create_file_sids(SMB_STRUCT_STAT *psbuf, DOM_SID *powner_sid, DOM_SID *pgroup_sid)
{
	uid_to_sid( powner_sid, psbuf->st_uid );
	gid_to_sid( pgroup_sid, psbuf->st_gid );
}

/****************************************************************************
 Print out a canon ace.
****************************************************************************/

static void print_canon_ace(canon_ace *ace, int num)
{
	fstring str;

	dbgtext( "canon_ace index %d.", num );
    dbgtext( "SID = %s ", sid_to_string( str, &ace->sid));
	if (ace->owner_type == UID_ACE) {
		struct passwd *pass = sys_getpwuid(ace->unix_ug.uid);
		dbgtext( "uid %u (%s) ", (unsigned int)ace->unix_ug.uid, pass ? pass->pw_name : "UNKNOWN");
	} else if (ace->owner_type == GID_ACE) {
		struct group *grp = getgrgid(ace->unix_ug.gid);
		dbgtext( "gid %u (%s) ", (unsigned int)ace->unix_ug.gid, grp ? grp->gr_name : "UNKNOWN");
	} else
		dbgtext( "other ");
	switch (ace->type) {
		case SMB_ACL_USER:
			dbgtext( "SMB_ACL_USER ");
			break;
		case SMB_ACL_USER_OBJ:
			dbgtext( "SMB_ACL_USER_OBJ ");
			break;
		case SMB_ACL_GROUP:
			dbgtext( "SMB_ACL_GROUP ");
			break;
		case SMB_ACL_GROUP_OBJ:
			dbgtext( "SMB_ACL_GROUP_OBJ ");
			break;
		case SMB_ACL_OTHER:
			dbgtext( "SMB_ACL_OTHER ");
			break;
	}
	dbgtext( "perms ");
	dbgtext( "%c", ace->perms & S_IRUSR ? 'r' : '-');
	dbgtext( "%c", ace->perms & S_IWUSR ? 'w' : '-');
	dbgtext( "%c\n", ace->perms & S_IXUSR ? 'x' : '-');
}

/****************************************************************************
 Map canon_ace perms to permission bits NT.
****************************************************************************/

static SEC_ACCESS map_canon_ace_perms(int *pacl_type, DOM_SID *powner_sid, canon_ace *ace)
{
	SEC_ACCESS sa;
	uint32 nt_mask = 0;

	*pacl_type = SEC_ACE_TYPE_ACCESS_ALLOWED;

	if((ace->perms & (S_IRUSR|S_IWUSR|S_IXUSR)) == (S_IRUSR|S_IWUSR|S_IXUSR)) {
			nt_mask = UNIX_ACCESS_RWX;
	} else if((ace->perms & (S_IRUSR|S_IWUSR|S_IXUSR)) == 0) {
		/*
		 * Here we differentiate between the owner and any other user.
		 */
		if (sid_equal(powner_sid, &ace->sid)) {
			nt_mask = UNIX_ACCESS_NONE;
		} else {
			/* Not owner, no access. */
			nt_mask = 0;
		}
	} else {
		nt_mask |= ((ace->perms & S_IRUSR) ? UNIX_ACCESS_R : 0 );
		nt_mask |= ((ace->perms & S_IWUSR) ? UNIX_ACCESS_W : 0 );
		nt_mask |= ((ace->perms & S_IXUSR) ? UNIX_ACCESS_X : 0 );
	}

	DEBUG(10,("map_canon_ace_perms: Mapped (UNIX) %x to (NT) %x\n",
			(unsigned int)ace->perms, (unsigned int)nt_mask ));

	init_sec_access(&sa,nt_mask);
	return sa;
}

/****************************************************************************
 Map NT perms to a UNIX mode_t.
****************************************************************************/

#define FILE_SPECIFIC_READ_BITS (FILE_READ_DATA|FILE_READ_EA|FILE_READ_ATTRIBUTES)
#define FILE_SPECIFIC_WRITE_BITS (FILE_WRITE_DATA|FILE_APPEND_DATA|FILE_WRITE_EA|FILE_WRITE_ATTRIBUTES)
#define FILE_SPECIFIC_EXECUTE_BITS (FILE_EXECUTE)

static mode_t map_nt_perms( SEC_ACCESS sec_access, int type)
{
	mode_t mode = 0;

	switch(type) {
	case S_IRUSR:
		if(sec_access.mask & GENERIC_ALL_ACCESS)
			mode = S_IRUSR|S_IWUSR|S_IXUSR;
		else {
			mode |= (sec_access.mask & (GENERIC_READ_ACCESS|FILE_SPECIFIC_READ_BITS)) ? S_IRUSR : 0;
			mode |= (sec_access.mask & (GENERIC_WRITE_ACCESS|FILE_SPECIFIC_WRITE_BITS)) ? S_IWUSR : 0;
			mode |= (sec_access.mask & (GENERIC_EXECUTE_ACCESS|FILE_SPECIFIC_EXECUTE_BITS)) ? S_IXUSR : 0;
		}
		break;
	case S_IRGRP:
		if(sec_access.mask & GENERIC_ALL_ACCESS)
			mode = S_IRGRP|S_IWGRP|S_IXGRP;
		else {
			mode |= (sec_access.mask & (GENERIC_READ_ACCESS|FILE_SPECIFIC_READ_BITS)) ? S_IRGRP : 0;
			mode |= (sec_access.mask & (GENERIC_WRITE_ACCESS|FILE_SPECIFIC_WRITE_BITS)) ? S_IWGRP : 0;
			mode |= (sec_access.mask & (GENERIC_EXECUTE_ACCESS|FILE_SPECIFIC_EXECUTE_BITS)) ? S_IXGRP : 0;
		}
		break;
	case S_IROTH:
		if(sec_access.mask & GENERIC_ALL_ACCESS)
			mode = S_IROTH|S_IWOTH|S_IXOTH;
		else {
			mode |= (sec_access.mask & (GENERIC_READ_ACCESS|FILE_SPECIFIC_READ_BITS)) ? S_IROTH : 0;
			mode |= (sec_access.mask & (GENERIC_WRITE_ACCESS|FILE_SPECIFIC_WRITE_BITS)) ? S_IWOTH : 0;
			mode |= (sec_access.mask & (GENERIC_EXECUTE_ACCESS|FILE_SPECIFIC_EXECUTE_BITS)) ? S_IXOTH : 0;
		}
		break;
	}

	return mode;
}

/****************************************************************************
 Unpack a SEC_DESC into a UNIX owner and group.
****************************************************************************/

static BOOL unpack_nt_owners(SMB_STRUCT_STAT *psbuf, uid_t *puser, gid_t *pgrp, uint32 security_info_sent, SEC_DESC *psd)
{
	DOM_SID owner_sid;
	DOM_SID grp_sid;
	enum SID_NAME_USE sid_type;

	*puser = (uid_t)-1;
	*pgrp = (gid_t)-1;

	if(security_info_sent == 0) {
		DEBUG(0,("unpack_nt_owners: no security info sent !\n"));
		return False;
	}

	/*
	 * Validate the owner and group SID's.
	 */

	memset(&owner_sid, '\0', sizeof(owner_sid));
	memset(&grp_sid, '\0', sizeof(grp_sid));

	DEBUG(5,("unpack_nt_owners: validating owner_sids.\n"));

	/*
	 * Don't immediately fail if the owner sid cannot be validated.
	 * This may be a group chown only set.
	 */

	if (security_info_sent & OWNER_SECURITY_INFORMATION) {
		sid_copy(&owner_sid, psd->owner_sid);
		if (!sid_to_uid( &owner_sid, puser, &sid_type))
			DEBUG(3,("unpack_nt_owners: unable to validate owner sid.\n"));
 	}

	/*
	 * Don't immediately fail if the group sid cannot be validated.
	 * This may be an owner chown only set.
	 */

	if (security_info_sent & GROUP_SECURITY_INFORMATION) {
		sid_copy(&grp_sid, psd->grp_sid);
		if (!sid_to_gid( &grp_sid, pgrp, &sid_type))
			DEBUG(3,("unpack_nt_owners: unable to validate group sid.\n"));
	}

	return True;
}

/****************************************************************************
 Merge aces with a common user.
****************************************************************************/

static BOOL merge_aces( canon_ace *list_head, canon_ace *p_ace)
{
	canon_ace *curr_ace;

	for (curr_ace = list_head; curr_ace; curr_ace = curr_ace->next) {
		if (curr_ace == p_ace)
			continue;

		if (curr_ace->type == p_ace->type && sid_equal(&curr_ace->sid, &p_ace->sid)) {
			if( DEBUGLVL( 10 )) {
				dbgtext("Merging ACE's\n");
				print_canon_ace( p_ace, 0);
				print_canon_ace( curr_ace, 0);
			}
			p_ace->perms |= curr_ace->perms;
			DLIST_REMOVE(list_head, curr_ace);
			free(curr_ace);
			return True;
		}
	}

	return False;
}

/****************************************************************************
 Unpack a SEC_DESC into two canonical ace lists. We don't depend on this
 succeeding.
****************************************************************************/

static BOOL unpack_canon_ace(files_struct *fsp, 
							DOM_SID *pfile_owner_sid,
							DOM_SID *pfile_grp_sid,
							canon_ace **ppfile_ace, canon_ace **ppdir_ace,
							uint32 security_info_sent, SEC_DESC *psd)
{
	extern DOM_SID global_sid_World;
	SEC_ACL *dacl = psd->dacl;
	BOOL all_aces_are_inherit_only = (fsp->is_directory ? True : False);
	canon_ace *file_ace = NULL;
	canon_ace *dir_ace = NULL;
	canon_ace *current_ace = NULL;
	enum SID_NAME_USE sid_type;
	int i;

	*ppfile_ace = NULL;
	*ppdir_ace = NULL;

	if(security_info_sent == 0) {
		DEBUG(0,("unpack_canon_ace: no security info sent !\n"));
		return False;
	}

	/*
	 * If no DACL then this is a chown only security descriptor.
	 */

	if(!(security_info_sent & DACL_SECURITY_INFORMATION) || !dacl)
		return True;

	/*
	 * Now go through the DACL and create the canon_ace lists.
	 */

	for(i = 0; i < dacl->num_aces; i++) {
		SEC_ACE *psa = &dacl->ace[i];

		if((psa->type != SEC_ACE_TYPE_ACCESS_ALLOWED) && (psa->type != SEC_ACE_TYPE_ACCESS_DENIED)) {
			DEBUG(3,("unpack_canon_ace: unable to set anything but an ALLOW or DENY ACE.\n"));
			return False;
		}

		/*
		 * The security mask may be UNIX_ACCESS_NONE which should map into
		 * no permissions (we overload the WRITE_OWNER bit for this) or it
		 * should be one of the ALL/EXECUTE/READ/WRITE bits. Arrange for this
		 * to be so. Any other bits override the UNIX_ACCESS_NONE bit.
		 */

		psa->info.mask &= (GENERIC_ALL_ACCESS|GENERIC_EXECUTE_ACCESS|GENERIC_WRITE_ACCESS|
							GENERIC_READ_ACCESS|UNIX_ACCESS_NONE|FILE_ALL_ATTRIBUTES);

		if(psa->info.mask != UNIX_ACCESS_NONE)
			psa->info.mask &= ~UNIX_ACCESS_NONE;

		/*
		 * Create a cannon_ace entry representing this NT DACL ACE.
		 */

		if ((current_ace = (canon_ace *)malloc(sizeof(canon_ace))) == NULL) {
			free_canon_ace_list(file_ace);
			free_canon_ace_list(dir_ace);
			DEBUG(0,("unpack_canon_ace: malloc fail.\n"));
			return False;
		}

		ZERO_STRUCTP(current_ace);

		sid_copy(&current_ace->sid, &psa->sid);

		/*
		 * Try and work out if the SID is a user or group
		 * as we need to flag these differently for POSIX.
		 */

		if( sid_equal(&current_ace->sid, &global_sid_World)) {
			current_ace->owner_type = WORLD_ACE;
			current_ace->unix_ug.world = -1;
		} else if (sid_to_uid( &current_ace->sid, &current_ace->unix_ug.uid, &sid_type)) {
			current_ace->owner_type = UID_ACE;
		} else if (sid_to_gid( &current_ace->sid, &current_ace->unix_ug.gid, &sid_type)) {
			current_ace->owner_type = GID_ACE;
		} else {
			fstring str;

			free_canon_ace_list(file_ace);
			free_canon_ace_list(dir_ace);
			free(current_ace);
			DEBUG(0,("unpack_canon_ace: unable to map SID %s to uid or gid.\n",
				sid_to_string(str, &current_ace->sid) ));
			return False;
		}

		/*
		 * Map the given NT permissions into a UNIX mode_t containing only
		 * S_I(R|W|X)USR bits.
		 */

		if(psa->type == SEC_ACE_TYPE_ACCESS_ALLOWED)
			current_ace->perms |= map_nt_perms( psa->info, S_IRUSR);
		else
			current_ace->perms = 0;

		/*
		 * Now note what kind of a POSIX ACL this should map to.
		 */

		if(sid_equal(&current_ace->sid, pfile_owner_sid)) {
			/* Note we should apply the default mode/mask here.... FIXME ! JRA */
			current_ace->type = SMB_ACL_USER_OBJ;
		} else if( sid_equal(&current_ace->sid, pfile_grp_sid)) {
			/* Note we should apply the default mode/mask here.... FIXME ! JRA */
			current_ace->type = SMB_ACL_GROUP_OBJ;
		} else if( sid_equal(&current_ace->sid, &global_sid_World)) {
			/* Note we should apply the default mode/mask here.... FIXME ! JRA */
			current_ace->type = SMB_ACL_OTHER;
		} else {
			/*
			 * Could be a SMB_ACL_USER or SMB_ACL_GROUP. Check by
			 * looking at owner_type.
			 */

			current_ace->type = (current_ace->owner_type == UID_ACE) ? SMB_ACL_USER : SMB_ACL_GROUP;
		}

		if (fsp->is_directory && (psa->flags & SEC_ACE_FLAG_INHERIT_ONLY)) {
			/*
			 * We can only add to the default POSIX ACE list if the ACE is
			 * designed to be inherited by both files and directories.
			 */
			if ((psa->flags & (SEC_ACE_FLAG_OBJECT_INHERIT|SEC_ACE_FLAG_CONTAINER_INHERIT)) ==
				(SEC_ACE_FLAG_OBJECT_INHERIT|SEC_ACE_FLAG_CONTAINER_INHERIT)) {
				DLIST_ADD(dir_ace, current_ace);
			} else {
				DEBUG(0,("unpack_canon_ace: unable to use a non-generic default ACE.\n"));
				free(current_ace);
			}
		} else {
			DLIST_ADD(file_ace, current_ace);
			all_aces_are_inherit_only = False;
		}
	}

	if (fsp->is_directory && all_aces_are_inherit_only) {
		/*
		 * Windows 2000 is doing one of these weird 'inherit acl'
		 * traverses to conserve NTFS ACL resources. Just pretend
		 * there was no DACL sent. JRA.
		 */

		DEBUG(10,("unpack_canon_ace: Win2k inherit acl traverse. Ignoring DACL.\n"));
		free_sec_acl(&psd->dacl);
	}

	/*
	 * Now go through the canon_ace lists and merge entries
	 * belonging to identical users.
	 */

  again_file:

	for (current_ace = file_ace; current_ace; current_ace = current_ace->next ) {
		if (merge_aces( file_ace, current_ace))
			goto again_file;
	}

  again_dir:

	for (current_ace = dir_ace; current_ace; current_ace = current_ace->next ) {
		if (merge_aces( dir_ace, current_ace))
			goto again_dir;
	}

	*ppfile_ace = file_ace;
	*ppdir_ace = dir_ace;
	return True;
}

/****************************************************************************
 Unpack a SEC_DESC into a set of standard POSIX permissions.
****************************************************************************/

static BOOL unpack_posix_permissions(files_struct *fsp, SMB_STRUCT_STAT *psbuf, mode_t *pmode,
								uint32 security_info_sent, SEC_DESC *psd, BOOL posix_acls)
{
  extern DOM_SID global_sid_World;
  connection_struct *conn = fsp->conn;
  DOM_SID file_owner_sid;
  DOM_SID file_grp_sid;
  SEC_ACL *dacl = psd->dacl;
  BOOL all_aces_are_inherit_only = (fsp->is_directory ? True : False);
  int i;

  *pmode = 0;

  if(security_info_sent == 0) {
    DEBUG(0,("unpack_posix_permissions: no security info sent !\n"));
    return False;
  }

  /*
   * Windows 2000 sends the owner and group SIDs as the logged in
   * user, not the connected user. But it still sends the file
   * owner SIDs on an ACL set. So we need to check for the file
   * owner and group SIDs as well as the owner SIDs. JRA.
   */
 
  create_file_sids(psbuf, &file_owner_sid, &file_grp_sid);

  /*
   * If no DACL then this is a chown only security descriptor.
   */

  if(!(security_info_sent & DACL_SECURITY_INFORMATION) || !dacl) {
    *pmode = 0;
    return True;
  }

  /*
   * Now go through the DACL and ensure that
   * any owner/group sids match.
   */

  for(i = 0; i < dacl->num_aces; i++) {
    DOM_SID ace_sid;
    SEC_ACE *psa = &dacl->ace[i];

    if((psa->type != SEC_ACE_TYPE_ACCESS_ALLOWED) &&
       (psa->type != SEC_ACE_TYPE_ACCESS_DENIED)) {
      DEBUG(3,("unpack_posix_permissions: unable to set anything but an ALLOW or DENY ACE.\n"));
      return False;
    }

    /*
     * Ignore or remove bits we don't care about on a directory ACE.
     */

    if(fsp->is_directory) {
      if(psa->flags & SEC_ACE_FLAG_INHERIT_ONLY) {
        DEBUG(3,("unpack_posix_permissions: ignoring inherit only ACE.\n"));
        continue;
      }

      /*
       * At least one of the ACE entries wasn't inherit only.
       * Flag this so we know the returned mode is valid.
       */

      all_aces_are_inherit_only = False;
    }

    /*
     * Windows 2000 sets these flags even on *file* ACE's. This is wrong
     * but we can ignore them for now. Revisit this when we go to POSIX
     * ACLs on directories.
     */

    psa->flags &= ~(SEC_ACE_FLAG_OBJECT_INHERIT|SEC_ACE_FLAG_CONTAINER_INHERIT);

    if(psa->flags != 0) {
      DEBUG(1,("unpack_posix_permissions: unable to set ACE flags (%x).\n", 
            (unsigned int)psa->flags));
      return False;
    }

    /*
     * The security mask may be UNIX_ACCESS_NONE which should map into
     * no permissions (we overload the WRITE_OWNER bit for this) or it
     * should be one of the ALL/EXECUTE/READ/WRITE bits. Arrange for this
     * to be so. Any other bits override the UNIX_ACCESS_NONE bit.
     */

    psa->info.mask &= (GENERIC_ALL_ACCESS|GENERIC_EXECUTE_ACCESS|GENERIC_WRITE_ACCESS|
                     GENERIC_READ_ACCESS|UNIX_ACCESS_NONE|FILE_ALL_ATTRIBUTES);

    if(psa->info.mask != UNIX_ACCESS_NONE)
      psa->info.mask &= ~UNIX_ACCESS_NONE;

    sid_copy(&ace_sid, &psa->sid);

    if(sid_equal(&ace_sid, &file_owner_sid)) {
      /*
       * Map the desired permissions into owner perms.
       */

      if(psa->type == SEC_ACE_TYPE_ACCESS_ALLOWED)
        *pmode |= map_nt_perms( psa->info, S_IRUSR);
      else
        *pmode &= ~(map_nt_perms( psa->info, S_IRUSR));

      
    } else if( sid_equal(&ace_sid, &file_grp_sid)) {
      /*
       * Map the desired permissions into group perms.
       */

      if(psa->type == SEC_ACE_TYPE_ACCESS_ALLOWED)
        *pmode |= map_nt_perms( psa->info, S_IRGRP);
      else
        *pmode &= ~(map_nt_perms( psa->info, S_IRGRP));

    } else if( sid_equal(&ace_sid, &global_sid_World)) {
      /*
       * Map the desired permissions into other perms.
       */

      if(psa->type == SEC_ACE_TYPE_ACCESS_ALLOWED)
        *pmode |= map_nt_perms( psa->info, S_IROTH);
      else
        *pmode &= ~(map_nt_perms( psa->info, S_IROTH));

    } else {
      /*
       * Only bother printing the level zero error if we didn't get any
       * POSIX ACLS.
       */
      if (!posix_acls)
        DEBUG(0,("unpack_posix_permissions: unknown SID used in ACL.\n"));
      return False;
    }
  }

  if (fsp->is_directory && all_aces_are_inherit_only) {
    /*
     * Windows 2000 is doing one of these weird 'inherit acl'
     * traverses to conserve NTFS ACL resources. Just pretend
     * there was no DACL sent. JRA.
     */

    DEBUG(10,("unpack_posix_permissions: Win2k inherit acl traverse. Ignoring DACL.\n"));
    free_sec_acl(&psd->dacl);
  }

  /*
   * Check to see if we need to change anything.
   * Enforce limits on modified bits *only*. Don't enforce masks
   * on bits not changed by the user.
   */

  if(fsp->is_directory) {

    *pmode &= (lp_dir_security_mask(SNUM(conn)) | psbuf->st_mode);
    *pmode |= (lp_force_dir_security_mode(SNUM(conn)) & ( *pmode ^ psbuf->st_mode ));

  } else {

    *pmode &= (lp_security_mask(SNUM(conn)) | psbuf->st_mode); 
    *pmode |= (lp_force_security_mode(SNUM(conn)) & ( *pmode ^ psbuf->st_mode ));

  }

  /*
   * Preserve special bits.
   */

  *pmode |= (psbuf->st_mode & ~0777);

  return True;
}

/****************************************************************************
 Map POSIX ACL perms to canon_ace permissions (a mode_t containing only S_(R|W|X)USR bits).
****************************************************************************/

static mode_t convert_permset_to_mode_t(SMB_ACL_PERMSET_T permset)
{
	mode_t ret = 0;

	ret |= (sys_acl_get_perm(permset, SMB_ACL_READ) ? S_IRUSR : 0);
	ret |= (sys_acl_get_perm(permset, SMB_ACL_WRITE) ? S_IWUSR : 0);
	ret |= (sys_acl_get_perm(permset, SMB_ACL_EXECUTE) ? S_IXUSR : 0);

	return ret;
}

/****************************************************************************
 Map generic UNIX permissions to canon_ace permissions (a mode_t containing only S_(R|W|X)USR bits).
****************************************************************************/

static mode_t unix_perms_to_acl_perms(mode_t mode, int r_mask, int w_mask, int x_mask)
{
	mode_t ret = 0;

	if (mode & r_mask)
		ret |= S_IRUSR;
	if (mode & w_mask)
		ret |= S_IWUSR;
	if (mode & x_mask)
		ret |= S_IXUSR;

	return ret;
}

/****************************************************************************
 Map canon_ace permissions (a mode_t containing only S_(R|W|X)USR bits) to
 an SMB_ACL_PERMSET_T.
****************************************************************************/

static int map_acl_perms_to_permset(mode_t mode, SMB_ACL_PERMSET_T *p_permset)
{
	if (sys_acl_clear_perms(*p_permset) ==  -1)
		return -1;
	if (mode & S_IRUSR) {
		if (sys_acl_add_perm(*p_permset, SMB_ACL_READ) == -1)
			return -1;
	}
	if (mode & S_IWUSR) {
		if (sys_acl_add_perm(*p_permset, SMB_ACL_WRITE) == -1)
			return -1;
	}
	if (mode & S_IXUSR) {
		if (sys_acl_add_perm(*p_permset, SMB_ACL_EXECUTE) == -1)
			return -1;
	}
	return 0;
}

/****************************************************************************
 Count a linked list of canonical ACE entries.
****************************************************************************/

static size_t count_canon_ace_list( canon_ace *list_head )
{
	size_t count = 0;
	canon_ace *ace;

	for (ace = list_head; ace; ace = ace->next)
		count++;

	return count;
}

/****************************************************************************
 Free a linked list of canonical ACE entries.
****************************************************************************/

static void free_canon_ace_list( canon_ace *list_head )
{
	while (list_head) {
		canon_ace *old_head = list_head;
		DLIST_REMOVE(list_head, list_head);
		free(old_head);
	}
}

/******************************************************************************
 Fall back to the generic 3 element UNIX permissions.
********************************************************************************/

static canon_ace *unix_canonicalise_acl(files_struct *fsp, SMB_STRUCT_STAT *psbuf,
										DOM_SID *powner, DOM_SID *pgroup)
{
	extern DOM_SID global_sid_World;
	canon_ace *list_head = NULL;
	canon_ace *owner_ace = NULL;
	canon_ace *group_ace = NULL;
	canon_ace *other_ace = NULL;

	/*
	 * Create 3 linked list entries.
	 */

	if ((owner_ace = (canon_ace *)malloc(sizeof(canon_ace))) == NULL)
		goto fail;

	if ((group_ace = (canon_ace *)malloc(sizeof(canon_ace))) == NULL)
		goto fail;

	if ((other_ace = (canon_ace *)malloc(sizeof(canon_ace))) == NULL)
		goto fail;

	ZERO_STRUCTP(owner_ace);
	ZERO_STRUCTP(group_ace);
	ZERO_STRUCTP(other_ace);

	owner_ace->type = SMB_ACL_USER_OBJ;
	owner_ace->sid = *powner;
	owner_ace->unix_ug.uid = psbuf->st_uid;
	owner_ace->owner_type = UID_ACE;

	group_ace->type = SMB_ACL_GROUP_OBJ;
	group_ace->sid = *pgroup;
	owner_ace->unix_ug.gid = psbuf->st_gid;
	owner_ace->owner_type = GID_ACE;

	other_ace->type = SMB_ACL_OTHER;
	other_ace->sid = global_sid_World;
	owner_ace->unix_ug.world = -1;
	owner_ace->owner_type = WORLD_ACE;

	if (!fsp->is_directory) {
		owner_ace->perms = unix_perms_to_acl_perms(psbuf->st_mode, S_IRUSR, S_IWUSR, S_IXUSR);
		group_ace->perms = unix_perms_to_acl_perms(psbuf->st_mode, S_IRGRP, S_IWGRP, S_IXGRP);
		other_ace->perms = unix_perms_to_acl_perms(psbuf->st_mode, S_IROTH, S_IWOTH, S_IXOTH);
	} else {
		mode_t mode = unix_mode( fsp->conn, FILE_ATTRIBUTE_ARCHIVE, fsp->fsp_name);

		owner_ace->perms = unix_perms_to_acl_perms(mode, S_IRUSR, S_IWUSR, S_IXUSR);
		group_ace->perms = unix_perms_to_acl_perms(mode, S_IRGRP, S_IWGRP, S_IXGRP);
		other_ace->perms = unix_perms_to_acl_perms(mode, S_IROTH, S_IWOTH, S_IXOTH);
	}

	DLIST_ADD(list_head, other_ace);
	DLIST_ADD(list_head, group_ace);
	DLIST_ADD(list_head, owner_ace);

	return list_head;

  fail:

	safe_free(owner_ace);
	safe_free(group_ace);
	safe_free(other_ace);

	return NULL;
}

/****************************************************************************
 Create a linked list of canonical ACE entries. This is sorted so that DENY
 entries are at the front of the list, as NT requires.
****************************************************************************/

static canon_ace *canonicalise_acl( SMB_ACL_T posix_acl, SMB_STRUCT_STAT *psbuf)
{
	extern DOM_SID global_sid_World;
	mode_t acl_mask = (S_IRUSR|S_IWUSR|S_IXUSR);
	canon_ace *list_head = NULL;
	canon_ace *ace = NULL;
	canon_ace *next_ace = NULL;
	int entry_id = SMB_ACL_FIRST_ENTRY;
	SMB_ACL_ENTRY_T entry;

	while ( sys_acl_get_entry(posix_acl, entry_id, &entry) == 1) {
		SMB_ACL_TAG_T tagtype;
		SMB_ACL_PERMSET_T permset;
		DOM_SID sid;
		posix_id unix_ug;
		enum ace_owner owner_type;

		/* get_next... */
		if (entry_id == SMB_ACL_FIRST_ENTRY)
			entry_id = SMB_ACL_NEXT_ENTRY;

		/* Is this a MASK entry ? */
		if (sys_acl_get_tag_type(entry, &tagtype) == -1)
			continue;

		if (sys_acl_get_permset(entry, &permset) == -1)
			continue;

		/* Decide which SID to use based on the ACL type. */
		switch(tagtype) {
			case SMB_ACL_USER_OBJ:
				/* Get the SID from the owner. */
				uid_to_sid( &sid, psbuf->st_uid );
				unix_ug.uid = psbuf->st_uid;
				owner_type = UID_ACE;
				break;
			case SMB_ACL_USER:
				{
					uid_t *puid = (uid_t *)sys_acl_get_qualifier(entry);
					if (puid == NULL) {
						DEBUG(0,("canonicalise_acl: Failed to get uid.\n"));
						continue;
					}
					uid_to_sid( &sid, *puid);
					unix_ug.uid = *puid;
					owner_type = UID_ACE;
					break;
				}
			case SMB_ACL_GROUP_OBJ:
				/* Get the SID from the owning group. */
				gid_to_sid( &sid, psbuf->st_gid );
				unix_ug.gid = psbuf->st_gid;
				owner_type = GID_ACE;
				break;
			case SMB_ACL_GROUP:
				{
					gid_t *pgid = (gid_t *)sys_acl_get_qualifier(entry);
					if (pgid == NULL) {
						DEBUG(0,("canonicalise_acl: Failed to get gid.\n"));
						continue;
					}
					gid_to_sid( &sid, *pgid);
					unix_ug.gid = *pgid;
					owner_type = GID_ACE;
					break;
				}
			case SMB_ACL_MASK:
				acl_mask = convert_permset_to_mode_t(permset);
				continue; /* Don't count the mask as an entry. */
			case SMB_ACL_OTHER:
				/* Use the Everyone SID */
				sid = global_sid_World;
				unix_ug.world = -1;
				owner_type = WORLD_ACE;
				break;
			default:
				DEBUG(0,("canonicalise_acl: Unknown tagtype %u\n", (unsigned int)tagtype));
				continue;
		}

		/*
		 * Add this entry to the list.
		 */

		if ((ace = (canon_ace *)malloc(sizeof(canon_ace))) == NULL)
			goto fail;

		ZERO_STRUCTP(ace);
		ace->type = tagtype;
		ace->perms = convert_permset_to_mode_t(permset);
		ace->sid = sid;
		ace->unix_ug = unix_ug;
		ace->owner_type = owner_type;

		DLIST_ADD(list_head, ace);
	}

	/*
	 * Now go through the list, masking the permissions with the
	 * acl_mask. If the permissions are 0 it should be listed
	 * first.
	 */

	for ( ace = list_head; ace; ace = next_ace) {
		next_ace = ace->next;

		/* Masks are only applied to entries other than USER_OBJ and OTHER. */
		if (ace->type != SMB_ACL_OTHER && ace->type != SMB_ACL_USER_OBJ)
			ace->perms &= acl_mask;

		if (ace->perms == 0)
			DLIST_PROMOTE(list_head, ace);
	}

	if( DEBUGLVL( 10 ) ) {
		char *acl_text = sys_acl_to_text( posix_acl, NULL);

		dbgtext("canonicalize_acl: processed acl %s\n", acl_text == NULL ? "NULL" : acl_text );
		if (acl_text)
			sys_acl_free_text(acl_text);
	}

	return list_head;

  fail:

	free_canon_ace_list(list_head);
	return NULL;
}

/****************************************************************************
 Attempt to apply an ACL to a file or directory.
****************************************************************************/

static BOOL set_canon_ace_list(files_struct *fsp, canon_ace *the_ace, BOOL default_ace)
{
	BOOL ret = False;
	SMB_ACL_T the_acl = sys_acl_init((int)count_canon_ace_list(the_ace) + 1);
	canon_ace *p_ace;
	int i;
	SMB_ACL_ENTRY_T mask_entry;
	SMB_ACL_PERMSET_T mask_permset;
	SMB_ACL_TYPE_T the_acl_type = (default_ace ? SMB_ACL_TYPE_DEFAULT : SMB_ACL_TYPE_ACCESS);

	if (the_acl == NULL) {
#if !defined(HAVE_NO_ACLS)
		/*
		 * Only print this error message if we have some kind of ACL
		 * support that's not working. Otherwise we would always get this.
		 */
		DEBUG(0,("set_canon_ace_list: Unable to init %s ACL. (%s)\n",
			default_ace ? "default" : "file", strerror(errno) ));
#endif
		return False;
	}

	for (i = 0, p_ace = the_ace; p_ace; p_ace = p_ace->next, i++ ) {
		SMB_ACL_ENTRY_T the_entry;
		SMB_ACL_PERMSET_T the_permset;

		/*
		 * Get the entry for this ACE.
		 */

		if (sys_acl_create_entry( &the_acl, &the_entry) == -1) {
			DEBUG(0,("set_canon_ace_list: Failed to create entry %d. (%s)\n",
				i, strerror(errno) ));
			goto done;
		}

		/*
		 * Initialise the entry from the canon_ace.
		 */

		/*
		 * First tell the entry what type of ACE this is.
		 */

		if (sys_acl_set_tag_type(the_entry, p_ace->type) == -1) {
			DEBUG(0,("set_canon_ace_list: Failed to set tag type on entry %d. (%s)\n",
				i, strerror(errno) ));
			goto done;
		}

		/*
		 * Only set the qualifier (user or group id) if the entry is a user
		 * or group id ACE.
		 */

		if ((p_ace->type == SMB_ACL_USER) || (p_ace->type == SMB_ACL_GROUP)) {
			if (sys_acl_set_qualifier(the_entry,(void *)&p_ace->unix_ug.uid) == -1) {
				DEBUG(0,("set_canon_ace_list: Failed to set qualifier on entry %d. (%s)\n",
					i, strerror(errno) ));
				goto done;
			}
		}

		/*
		 * Convert the mode_t perms in the canon_ace to a POSIX permset.
		 */

		if (sys_acl_get_permset(the_entry, &the_permset) == -1) {
			DEBUG(0,("set_canon_ace_list: Failed to get permset on entry %d. (%s)\n",
				i, strerror(errno) ));
			goto done;
		}

		if (map_acl_perms_to_permset(p_ace->perms, &the_permset) == -1) {
			DEBUG(0,("set_canon_ace_list: Failed to create permset for mode (%u) on entry %d. (%s)\n",
				p_ace->perms, i, strerror(errno) ));
			goto done;
		}

		/*
		 * ..and apply them to the entry.
		 */

		if (sys_acl_set_permset(the_entry, the_permset) == -1) {
			DEBUG(0,("set_canon_ace_list: Failed to add permset on entry %d. (%s)\n",
				i, strerror(errno) ));
			goto done;
		}

		if( DEBUGLVL( 10 ))
			print_canon_ace( p_ace, i);
	}

	/*
	 * Add in a mask of rwx.
	 */

	if (sys_acl_create_entry( &the_acl, &mask_entry) == -1) {
		DEBUG(0,("set_canon_ace_list: Failed to create mask entry. (%s)\n", strerror(errno) ));
		goto done;
	}

	if (sys_acl_set_tag_type(mask_entry, SMB_ACL_MASK) == -1) {
		DEBUG(0,("set_canon_ace_list: Failed to set tag type on mask entry. (%s)\n",strerror(errno) ));
		goto done;
	}

	if (sys_acl_get_permset(mask_entry, &mask_permset) == -1) {
		DEBUG(0,("set_canon_ace_list: Failed to get mask permset. (%s)\n", strerror(errno) ));
		goto done;
	}

	if (map_acl_perms_to_permset(S_IRUSR|S_IWUSR|S_IXUSR, &mask_permset) == -1) {
		DEBUG(0,("set_canon_ace_list: Failed to create mask permset. (%s)\n", strerror(errno) ));
		goto done;
	}

	if (sys_acl_set_permset(mask_entry, mask_permset) == -1) {
		DEBUG(0,("set_canon_ace_list: Failed to add mask permset. (%s)\n", strerror(errno) ));
		goto done;
	}

	/*
	 * Check if the ACL is valid.
	 */

	if (sys_acl_valid(the_acl) == -1) {
		DEBUG(0,("set_canon_ace_list: ACL is invalid for set (%s).\n", strerror(errno) ));
		goto done;
	}

	/*
	 * Finally apply it to the file or directory.
	 */

	if(default_ace || fsp->is_directory || fsp->fd == -1) {
		if (sys_acl_set_file(fsp->fsp_name, the_acl_type, the_acl) == -1) {
			DEBUG(0,("set_canon_ace_list: sys_acl_set_file failed for file %s (%s).\n",
					fsp->fsp_name, strerror(errno) ));
			goto done;
		}
	} else {
		if (sys_acl_set_fd(fsp->fd, the_acl) == -1) {
			DEBUG(0,("set_canon_ace_list: sys_acl_set_file failed for file %s (%s).\n",
					fsp->fsp_name, strerror(errno) ));
			goto done;
		}
	}

	ret = True;

  done:

	if (the_acl != NULL)
	    sys_acl_free_acl(the_acl);

	return ret;
}

/****************************************************************************
 Reply to query a security descriptor from an fsp. If it succeeds it allocates
 the space for the return elements and returns the size needed to return the
 security descriptor. This should be the only external function needed for
 the UNIX style get ACL.
****************************************************************************/

size_t get_nt_acl(files_struct *fsp, SEC_DESC **ppdesc)
{
	SMB_STRUCT_STAT sbuf;
	SEC_ACE *nt_ace_list;
	DOM_SID owner_sid;
	DOM_SID group_sid;
	size_t sd_size = 0;
	SEC_ACL *psa = NULL;
	size_t num_acls = 0;
	size_t num_dir_acls = 0;
	size_t num_aces = 0;
	SMB_ACL_T posix_acl = NULL;
	SMB_ACL_T dir_acl = NULL;
	canon_ace *file_ace = NULL;
	canon_ace *dir_ace = NULL;
 
	*ppdesc = NULL;

	DEBUG(10,("get_nt_acl: called for file %s\n", fsp->fsp_name ));

	if(fsp->is_directory || fsp->fd == -1) {

		/* Get the stat struct for the owner info. */
		if(vfs_stat(fsp->conn,fsp->fsp_name, &sbuf) != 0) {
			return 0;
		}
		/*
		 * Get the ACL from the path.
		 */

		posix_acl = sys_acl_get_file( dos_to_unix(fsp->fsp_name, False), SMB_ACL_TYPE_ACCESS);

		/*
		 * If it's a directory get the default POSIX ACL.
		 */

		if(fsp->is_directory)
			dir_acl = sys_acl_get_file( dos_to_unix(fsp->fsp_name, False), SMB_ACL_TYPE_DEFAULT);

	} else {

		/* Get the stat struct for the owner info. */
		if(vfs_fstat(fsp,fsp->fd,&sbuf) != 0) {
			return 0;
		}
		/*
		 * Get the ACL from the fd.
		 */
		posix_acl = sys_acl_get_fd(fsp->fd);
	}

	DEBUG(5,("get_nt_acl : file ACL %s, directory ACL %s\n",
			posix_acl ? "present" :  "absent",
			dir_acl ? "present" :  "absent" ));

	/*
	 * Get the owner, group and world SIDs.
	 */

	create_file_sids(&sbuf, &owner_sid, &group_sid);

	/* Create the canon_ace lists. */
	if (posix_acl)
		file_ace = canonicalise_acl( posix_acl, &sbuf);
	else
		file_ace = unix_canonicalise_acl(fsp, &sbuf, &owner_sid, &group_sid);

	num_acls = count_canon_ace_list(file_ace);

	if (fsp->is_directory) { 
		if (dir_ace)
			dir_ace = canonicalise_acl( dir_acl, &sbuf);
		else
			dir_ace = unix_canonicalise_acl(fsp, &sbuf, &owner_sid, &group_sid);

		num_dir_acls = count_canon_ace_list(dir_ace);
	}

	/* Allocate the ace list. */
	if ((nt_ace_list = (SEC_ACE *)malloc((num_acls + num_dir_acls)* sizeof(SEC_ACE))) == NULL) {
		DEBUG(0,("get_nt_acl: Unable to malloc space for nt_ace_list.\n"));
		goto done;
	}

	memset(nt_ace_list, '\0', (num_acls + num_dir_acls) * sizeof(SEC_ACE) );

	/*
	 * Create the NT ACE list from the canonical ace lists.
	 */

	{
		canon_ace *ace;
		int nt_acl_type;
		int i;

		ace = file_ace;

		for (i = 0; i < num_acls; i++, ace = ace->next) {
			SEC_ACCESS acc = map_canon_ace_perms(&nt_acl_type, &owner_sid, ace );
			init_sec_ace(&nt_ace_list[num_aces++], &ace->sid, nt_acl_type, acc, 0);
		}

		ace = dir_ace;

		for (i = 0; i < num_dir_acls; i++, ace = ace->next) {
			SEC_ACCESS acc = map_canon_ace_perms(&nt_acl_type, &owner_sid, ace );
			init_sec_ace(&nt_ace_list[num_aces++], &ace->sid, nt_acl_type, acc, 
					SEC_ACE_FLAG_OBJECT_INHERIT|SEC_ACE_FLAG_CONTAINER_INHERIT|SEC_ACE_FLAG_INHERIT_ONLY);
		}
	}

	if (num_acls) {
		if((psa = make_sec_acl( ACL_REVISION, num_aces, nt_ace_list)) == NULL) {
			DEBUG(0,("get_nt_acl: Unable to malloc space for acl.\n"));
			goto done;
		}
	}

	*ppdesc = make_standard_sec_desc( &owner_sid, &group_sid, psa, &sd_size);

	if(!*ppdesc) {
		DEBUG(0,("get_nt_acl: Unable to malloc space for security descriptor.\n"));
		sd_size = 0;
	}

  done:

	if (posix_acl)	
		sys_acl_free_acl(posix_acl);
	if (dir_acl)
		sys_acl_free_acl(dir_acl);
	free_canon_ace_list(file_ace);
	free_canon_ace_list(dir_ace);
	if (nt_ace_list)
		free(nt_ace_list);
	if (psa)
		free_sec_acl(&psa);

	return sd_size;
}

/****************************************************************************
 Reply to set a security descriptor on an fsp. security_info_sent is the
 description of the following NT ACL.
 This should be the only external function needed for the UNIX style set ACL.
****************************************************************************/

BOOL set_nt_acl(files_struct *fsp, uint32 security_info_sent, SEC_DESC *psd)
{
	connection_struct *conn = fsp->conn;
	uid_t user = (uid_t)-1;
	gid_t grp = (gid_t)-1;
	mode_t perms = 0;
	SMB_STRUCT_STAT sbuf;  
	DOM_SID file_owner_sid;
	DOM_SID file_grp_sid;
	canon_ace *file_ace_list = NULL;
	canon_ace *dir_ace_list = NULL;
	BOOL posix_perms;
	BOOL acl_perms;

	DEBUG(10,("set_nt_acl: called for file %s\n", fsp->fsp_name ));

	/*
	 * Get the current state of the file.
	 */

	if(fsp->is_directory || fsp->fd == -1) {
		if(vfs_stat(fsp->conn,fsp->fsp_name, &sbuf) != 0)
			return False;
	} else {
		if(vfs_fstat(fsp,fsp->fd,&sbuf) != 0)
			return False;
	}

	/*
	 * Unpack the user/group/world id's.
	 */

	if (!unpack_nt_owners( &sbuf, &user, &grp, security_info_sent, psd))
		return False;

	/*
	 * Do we need to chown ?
	 */

	if((user != (uid_t)-1 || grp != (uid_t)-1) && (sbuf.st_uid != user || sbuf.st_gid != grp)) {

		DEBUG(3,("set_nt_acl: chown %s. uid = %u, gid = %u.\n",
				fsp->fsp_name, (unsigned int)user, (unsigned int)grp ));

		if(vfs_chown( fsp->conn, fsp->fsp_name, user, grp) == -1) {
			DEBUG(3,("set_nt_acl: chown %s, %u, %u failed. Error = %s.\n",
				fsp->fsp_name, (unsigned int)user, (unsigned int)grp, strerror(errno) ));
			return False;
		}

		/*
		 * Recheck the current state of the file, which may have changed.
		 * (suid/sgid bits, for instance)
		 */

		if(fsp->is_directory) {
			if(vfs_stat(fsp->conn, fsp->fsp_name, &sbuf) != 0) {
				return False;
			}
		} else {

			int ret;
    
			if(fsp->fd == -1)
				ret = vfs_stat(fsp->conn, fsp->fsp_name, &sbuf);
			else
				ret = vfs_fstat(fsp,fsp->fd,&sbuf);
  
			if(ret != 0)
				return False;
		}
	}

	create_file_sids(&sbuf, &file_owner_sid, &file_grp_sid);

	acl_perms = unpack_canon_ace( fsp, &file_owner_sid, &file_grp_sid,
									&file_ace_list, &dir_ace_list, security_info_sent, psd);
	posix_perms = unpack_posix_permissions( fsp, &sbuf, &perms, security_info_sent, psd, acl_perms);

	if (!posix_perms && !acl_perms) {
		/*
		 * Neither method of setting permissions can work. Fail here.
		 */

		DEBUG(3,("set_nt_acl: cannot set normal POSIX permissions or POSIX ACL permissions\n"));
		free_canon_ace_list(file_ace_list);
		free_canon_ace_list(dir_ace_list); 
		return False;
	}

	/*
	 * Only change security if we got a DACL.
	 */

	if((security_info_sent & DACL_SECURITY_INFORMATION) && (psd->dacl != NULL)) {

		BOOL acl_set_support = False;

		/*
		 * Try using the POSIX ACL set first. All back to chmod if
		 * we have no ACL support on this filesystem.
		 */

		if (acl_perms && file_ace_list && set_canon_ace_list(fsp, file_ace_list, False))
			acl_set_support = True;

		if (acl_perms && acl_set_support && fsp->is_directory && dir_ace_list)
			set_canon_ace_list(fsp, dir_ace_list, True);

		/*
		 * If we cannot set using POSIX ACLs we fall back to checking if we need to chmod.
		 */

		if(!acl_set_support && (sbuf.st_mode != perms)) {

			free_canon_ace_list(file_ace_list);
			free_canon_ace_list(dir_ace_list); 
			file_ace_list = NULL;
			dir_ace_list = NULL;

			DEBUG(3,("call_nt_transact_set_security_desc: chmod %s. perms = 0%o.\n",
				fsp->fsp_name, (unsigned int)perms ));

			if(conn->vfs_ops.chmod(conn,dos_to_unix(fsp->fsp_name, False), perms) == -1) {
				DEBUG(3,("set_nt_acl: chmod %s, 0%o failed. Error = %s.\n",
						fsp->fsp_name, (unsigned int)perms, strerror(errno) ));
				return False;
			}
		}
	}

	free_canon_ace_list(file_ace_list);
	free_canon_ace_list(dir_ace_list); 

	return True;
}
#undef OLD_NTDOMAIN