include/linux/posix_acl_xattr.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3   File: linux/posix_acl_xattr.h
   4
   5   Extended attribute system call representation of Access Control Lists.
   6
   7   Copyright (C) 2000 by Andreas Gruenbacher <a.gruenbacher@computer.org>
   8   Copyright (C) 2002 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com>
   9  */
  10 #ifndef _POSIX_ACL_XATTR_H
  11 #define _POSIX_ACL_XATTR_H
  12
  13 #include <uapi/linux/xattr.h>
  14 #include <uapi/linux/posix_acl_xattr.h>
  15 #include <linux/posix_acl.h>
  16
  17 static inline size_t
  18 posix_acl_xattr_size(int count)
  19 {
  20         return (sizeof(struct posix_acl_xattr_header) +
  21                 (count * sizeof(struct posix_acl_xattr_entry)));
  22 }
  23
  24 static inline int
  25 posix_acl_xattr_count(size_t size)
  26 {
  27         if (size < sizeof(struct posix_acl_xattr_header))
  28                 return -1;
  29         size -= sizeof(struct posix_acl_xattr_header);
  30         if (size % sizeof(struct posix_acl_xattr_entry))
  31                 return -1;
  32         return size / sizeof(struct posix_acl_xattr_entry);
  33 }
  34
  35 #ifdef CONFIG_FS_POSIX_ACL
  36 void posix_acl_fix_xattr_from_user(struct user_namespace *mnt_userns,
  37                                    void *value, size_t size);
  38 void posix_acl_fix_xattr_to_user(struct user_namespace *mnt_userns,
  39                                  void *value, size_t size);
  40 #else
  41 static inline void posix_acl_fix_xattr_from_user(struct user_namespace *mnt_userns,
  42                                                  void *value, size_t size)
  43 {
  44 }
  45 static inline void posix_acl_fix_xattr_to_user(struct user_namespace *mnt_userns,
  46                                                void *value, size_t size)
  47 {
  48 }
  49 #endif
  50
  51 struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns,
  52                                        const void *value, size_t size);
  53 int posix_acl_to_xattr(struct user_namespace *user_ns,
  54                        const struct posix_acl *acl, void *buffer, size_t size);
  55
  56 extern const struct xattr_handler posix_acl_access_xattr_handler;
  57 extern const struct xattr_handler posix_acl_default_xattr_handler;
  58
  59 #endif  /* _POSIX_ACL_XATTR_H */