path: root/fs/xfs/xfs_acl.c

/*
 * Copyright (c) 2001-2002,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * 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.
 *
 * This program is distributed in the hope that it would 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 the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_inum.h"
#include "xfs_ag.h"
#include "xfs_dir.h"
#include "xfs_dir2.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_acl.h"
#include "xfs_mac.h"
#include "xfs_attr.h"

#include <linux/posix_acl_xattr.h>

STATIC int	xfs_acl_setmode(vnode_t *, xfs_acl_t *, int *);
STATIC void     xfs_acl_filter_mode(mode_t, xfs_acl_t *);
STATIC void	xfs_acl_get_endian(xfs_acl_t *);
STATIC int	xfs_acl_access(uid_t, gid_t, xfs_acl_t *, mode_t, cred_t *);
STATIC int	xfs_acl_invalid(xfs_acl_t *);
STATIC void	xfs_acl_sync_mode(mode_t, xfs_acl_t *);
STATIC void	xfs_acl_get_attr(vnode_t *, xfs_acl_t *, int, int, int *);
STATIC void	xfs_acl_set_attr(vnode_t *, xfs_acl_t *, int, int *);
STATIC int	xfs_acl_allow_set(vnode_t *, int);

kmem_zone_t *xfs_acl_zone;


/*
 * Test for existence of access ACL attribute as efficiently as possible.
 */
int
xfs_acl_vhasacl_access(
	vnode_t		*vp)
{
	int		error;

	xfs_acl_get_attr(vp, NULL, _ACL_TYPE_ACCESS, ATTR_KERNOVAL, &error);
	return (error == 0);
}

/*
 * Test for existence of default ACL attribute as efficiently as possible.
 */
int
xfs_acl_vhasacl_default(
	vnode_t		*vp)
{
	int		error;

	if (!VN_ISDIR(vp))
		return 0;
	xfs_acl_get_attr(vp, NULL, _ACL_TYPE_DEFAULT, ATTR_KERNOVAL, &error);
	return (error == 0);
}

/*
 * Convert from extended attribute representation to in-memory for XFS.
 */
STATIC int
posix_acl_xattr_to_xfs(
	posix_acl_xattr_header	*src,
	size_t			size,
	xfs_acl_t		*dest)
{
	posix_acl_xattr_entry	*src_entry;
	xfs_acl_entry_t		*dest_entry;
	int			n;

	if (!src || !dest)
		return EINVAL;

	if (size < sizeof(posix_acl_xattr_header))
		return EINVAL;

	if (src->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
		return EOPNOTSUPP;

	memset(dest, 0, sizeof(xfs_acl_t));
	dest->acl_cnt = posix_acl_xattr_count(size);
	if (dest->acl_cnt < 0 || dest->acl_cnt > XFS_ACL_MAX_ENTRIES)
		return EINVAL;

	/*
	 * acl_set_file(3) may request that we set default ACLs with
	 * zero length -- defend (gracefully) against that here.
	 */
	if (!dest->acl_cnt)
		return 0;

	src_entry = (posix_acl_xattr_entry *)((char *)src + sizeof(*src));
	dest_entry = &dest->acl_entry[0];

	for (n = 0; n < dest->acl_cnt; n++, src_entry++, dest_entry++) {
		dest_entry->ae_perm = le16_to_cpu(src_entry->e_perm);
		if (_ACL_PERM_INVALID(dest_entry->ae_perm))
			return EINVAL;
		dest_entry->ae_tag  = le16_to_cpu(src_entry->e_tag);
		switch(dest_entry->ae_tag) {
		case ACL_USER:
		case ACL_GROUP:
			dest_entry->ae_id = le32_to_cpu(src_entry->e_id);
			break;
		case ACL_USER_OBJ:
		case ACL_GROUP_OBJ:
		case ACL_MASK:
		case ACL_OTHER:
			dest_entry->ae_id = ACL_UNDEFINED_ID;
			break;
		default:
			return EINVAL;
		}
	}
	if (xfs_acl_invalid(dest))
		return EINVAL;

	return 0;
}

/*
 * Comparison function called from xfs_sort().
 * Primary key is ae_tag, secondary key is ae_id.
 */
STATIC int
xfs_acl_entry_compare(
	const void	*va,
	const void	*vb)
{
	xfs_acl_entry_t	*a = (xfs_acl_entry_t *)va,
			*b = (xfs_acl_entry_t *)vb;

	if (a->ae_tag == b->ae_tag)
		return (a->ae_id - b->ae_id);
	return (a->ae_tag - b->ae_tag);
}

/*
 * Convert from in-memory XFS to extended attribute representation.
 */
STATIC int
posix_acl_xfs_to_xattr(
	xfs_acl_t		*src,
	posix_acl_xattr_header	*dest,
	size_t			size)
{
	int			n;
	size_t			new_size = posix_acl_xattr_size(src->acl_cnt);
	posix_acl_xattr_entry	*dest_entry;
	xfs_acl_entry_t		*src_entry;

	if (size < new_size)
		return -ERANGE;

	/* Need to sort src XFS ACL by <ae_tag,ae_id> */
	xfs_sort(src->acl_entry, src->acl_cnt, sizeof