include/linux/posix_acl_xattr.h

   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 <uapi/linux/xattr.h>
  13 #include <uapi/linux/posix_acl_xattr.h>
  14 #include <linux/posix_acl.h>
  15
  16 static inline size_t
  17 posix_acl_xattr_size(int count)
  18 {
  19         return (sizeof(struct posix_acl_xattr_header) +
  20                 (count * sizeof(struct posix_acl_xattr_entry)));
  21 }
  22
  23 static inline int
  24 posix_acl_xattr_count(size_t size)
  25 {
  26         if (size < sizeof(struct posix_acl_xattr_header))
  27                 return -1;
  28         size -= sizeof(struct posix_acl_xattr_header);
  29         if (size % sizeof(struct posix_acl_xattr_entry))
  30                 return -1;
  31         return size / sizeof(struct posix_acl_xattr_entry);
  32 }
  33
  34 #ifdef CONFIG_FS_POSIX_ACL
  35 int posix_acl_fix_xattr_userns(struct user_namespace *to,
  36                                struct user_namespace *from,
  37                                void *value, size_t size);
  38 void posix_acl_fix_xattr_from_user(void *value, size_t size);
  39 void posix_acl_fix_xattr_to_user(void *value, size_t size);
  40 #else
  41 static inline int posix_acl_fix_xattr_userns(struct user_namespace *to,
  42                                              struct user_namespace *from,
  43                                              void *value, size_t size)
  44 {
  45         return 0;
  46 }
  47 static inline void posix_acl_fix_xattr_from_user(void *value, size_t size)
  48 {
  49 }
  50 static inline void posix_acl_fix_xattr_to_user(void *value, size_t size)
  51 {
  52 }
  53 #endif
  54
  55 struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns,
  56                                        const void *value, size_t size);
  57 int posix_acl_to_xattr(struct user_namespace *user_ns,
  58                        const struct posix_acl *acl, void *buffer, size_t size);
  59
  60 extern const struct xattr_handler posix_acl_access_xattr_handler;
  61 extern const struct xattr_handler posix_acl_default_xattr_handler;
  62
  63 #endif  /* _POSIX_ACL_XATTR_H */