LXR linux/include/linux/posix_acl

   1/*
   2  File: linux/posix_acl_xattr.h
   3
   4  Extended attribute system call representation of Access Control Lists.
   5
   6  Copyright (C) 2000 by Andreas Gruenbacher <a.gruenbacher@computer.org>
   7  Copyright (C) 2002 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com>
   8 */
   9#ifndef _POSIX_ACL_XATTR_H
  10#define _POSIX_ACL_XATTR_H
  11
  12#include <linux/posix_acl.h>
  13
  14/* Extended attribute names */
  15#define POSIX_ACL_XATTR_ACCESS  "system.posix_acl_access"
  16#define POSIX_ACL_XATTR_DEFAULT "system.posix_acl_default"
  17
  18/* Supported ACL a_version fields */
  19#define POSIX_ACL_XATTR_VERSION 0x0002
  20
  21
  22/* An undefined entry e_id value */
  23#define ACL_UNDEFINED_ID        (-1)
  24
  25typedef struct {
  26        __le16                  e_tag;
  27        __le16                  e_perm;
  28        __le32                  e_id;
  29} posix_acl_xattr_entry;
  30
  31typedef struct {
  32        __le32                  a_version;
  33        posix_acl_xattr_entry   a_entries[0];
  34} posix_acl_xattr_header;
  35
  36
  37static inline size_t
  38posix_acl_xattr_size(int count)
  39{
  40        return (sizeof(posix_acl_xattr_header) +
  41                (count * sizeof(posix_acl_xattr_entry)));
  42}
  43
  44static inline int
  45posix_acl_xattr_count(size_t size)
  46{
  47        if (size < sizeof(posix_acl_xattr_header))
  48                return -1;
  49        size -= sizeof(posix_acl_xattr_header);
  50        if (size % sizeof(posix_acl_xattr_entry))
  51                return -1;
  52        return size / sizeof(posix_acl_xattr_entry);
  53}
  54
  55struct posix_acl *posix_acl_from_xattr(const void *value, size_t size);
  56int posix_acl_to_xattr(const struct posix_acl *acl, void *buffer, size_t size);
  57
  58#endif  /* _POSIX_ACL_XATTR_H */
  59