/*
    File: linux/posix_acl_xattr.h
  
    Extended attribute system call representation of Access Control Lists.
  
    Copyright (C) 2000 by Andreas Gruenbacher <a.gruenbacher@computer.org>
    Copyright (C) 2002 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com>
   */
  #ifndef _POSIX_ACL_XATTR_H
  #define _POSIX_ACL_XATTR_H
  
  #include <linux/posix_acl.h>
  
  /* Extended attribute names */
  #define POSIX_ACL_XATTR_ACCESS	"system.posix_acl_access"
  #define POSIX_ACL_XATTR_DEFAULT	"system.posix_acl_default"
  
  /* Supported ACL a_version fields */
  #define POSIX_ACL_XATTR_VERSION	0x0002
  
  
  /* An undefined entry e_id value */
  #define ACL_UNDEFINED_ID	(-1)
  
  typedef struct {

  	__le16			e_tag;
  	__le16			e_perm;
  	__le32			e_id;

  } posix_acl_xattr_entry;
  
  typedef struct {

  	__le32			a_version;

  	posix_acl_xattr_entry	a_entries[0];
  } posix_acl_xattr_header;
  
  
  static inline size_t
  posix_acl_xattr_size(int count)
  {
  	return (sizeof(posix_acl_xattr_header) +
  		(count * sizeof(posix_acl_xattr_entry)));
  }
  
  static inline int
  posix_acl_xattr_count(size_t size)
  {
  	if (size < sizeof(posix_acl_xattr_header))
  		return -1;
  	size -= sizeof(posix_acl_xattr_header);
  	if (size % sizeof(posix_acl_xattr_entry))
  		return -1;
  	return size / sizeof(posix_acl_xattr_entry);
  }

  struct posix_acl *posix_acl_from_xattr(const void *value, size_t size);
  int posix_acl_to_xattr(const struct posix_acl *acl, void *buffer, size_t size);

  #endif	/* _POSIX_ACL_XATTR_H */