fs/ext2/xattr_trusted.c

   1 /*
   2  * linux/fs/ext2/xattr_trusted.c
   3  * Handler for trusted extended attributes.
   4  *
   5  * Copyright (C) 2003 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
   6  */
   7
   8 #include "ext2.h"
   9 #include "xattr.h"
  10
  11 static size_t
  12 ext2_xattr_trusted_list(struct dentry *dentry, char *list, size_t list_size,
  13                 const char *name, size_t name_len, int type)
  14 {
  15         const int prefix_len = XATTR_TRUSTED_PREFIX_LEN;
  16         const size_t total_len = prefix_len + name_len + 1;
  17
  18         if (!capable(CAP_SYS_ADMIN))
  19                 return 0;
  20
  21         if (list && total_len <= list_size) {
  22                 memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
  23                 memcpy(list+prefix_len, name, name_len);
  24                 list[prefix_len + name_len] = '\0';
  25         }
  26         return total_len;
  27 }
  28
  29 static int
  30 ext2_xattr_trusted_get(struct dentry *dentry, const char *name,
  31                 void *buffer, size_t size, int type)
  32 {
  33         if (strcmp(name, "") == 0)
  34                 return -EINVAL;
  35         return ext2_xattr_get(d_inode(dentry), EXT2_XATTR_INDEX_TRUSTED, name,
  36                               buffer, size);
  37 }
  38
  39 static int
  40 ext2_xattr_trusted_set(struct dentry *dentry, const char *name,
  41                 const void *value, size_t size, int flags, int type)
  42 {
  43         if (strcmp(name, "") == 0)
  44                 return -EINVAL;
  45         return ext2_xattr_set(d_inode(dentry), EXT2_XATTR_INDEX_TRUSTED, name,
  46                               value, size, flags);
  47 }
  48
  49 const struct xattr_handler ext2_xattr_trusted_handler = {
  50         .prefix = XATTR_TRUSTED_PREFIX,
  51         .list   = ext2_xattr_trusted_list,
  52         .get    = ext2_xattr_trusted_get,
  53         .set    = ext2_xattr_trusted_set,
  54 };