Line data    Source code

       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             : 
      25             : typedef struct {
      26             :         __le16                  e_tag;
      27             :         __le16                  e_perm;
      28             :         __le32                  e_id;
      29             : } posix_acl_xattr_entry;
      30             : 
      31             : typedef struct {
      32             :         __le32                  a_version;
      33             :         posix_acl_xattr_entry   a_entries[0];
      34             : } posix_acl_xattr_header;
      35             : 
      36             : 
      37             : static inline size_t
      38             : posix_acl_xattr_size(int count)
      39             : {
      40           0 :         return (sizeof(posix_acl_xattr_header) +
      41           0 :                 (count * sizeof(posix_acl_xattr_entry)));
      42             : }
      43             : 
      44             : static inline int
      45             : posix_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             : 
      55             : #ifdef CONFIG_FS_POSIX_ACL
      56             : void posix_acl_fix_xattr_from_user(void *value, size_t size);
      57             : void posix_acl_fix_xattr_to_user(void *value, size_t size);
      58             : #else
      59             : static inline void posix_acl_fix_xattr_from_user(void *value, size_t size)
      60             : {
      61             : }
      62             : static inline void posix_acl_fix_xattr_to_user(void *value, size_t size)
      63             : {
      64             : }
      65             : #endif
      66             : 
      67             : struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns, 
      68             :                                        const void *value, size_t size);
      69             : int posix_acl_to_xattr(struct user_namespace *user_ns,
      70             :                        const struct posix_acl *acl, void *buffer, size_t size);
      71             : 
      72             : extern const struct xattr_handler posix_acl_access_xattr_handler;
      73             : extern const struct xattr_handler posix_acl_default_xattr_handler;
      74             : 
      75             : #endif  /* _POSIX_ACL_XATTR_H */