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(const struct xattr_handler *handler,
  13                         struct dentry *dentry, char *list, size_t list_size,
  14                         const char *name, size_t name_len)
  15 {
  16         const int prefix_len = XATTR_TRUSTED_PREFIX_LEN;
  17         const size_t total_len = prefix_len + name_len + 1;
  18
  19         if (!capable(CAP_SYS_ADMIN))
  20                 return 0;
  21
  22         if (list && total_len <= list_size) {
  23                 memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
  24                 memcpy(list+prefix_len, name, name_len);
  25                 list[prefix_len + name_len] = '\0';
  26         }
  27         return total_len;
  28 }
  29
  30 static int
  31 ext2_xattr_trusted_get(const struct xattr_handler *handler,
  32                        struct dentry *dentry, const char *name,
  33                        void *buffer, size_t size)
  34 {
  35         if (strcmp(name, "") == 0)
  36                 return -EINVAL;
  37         return ext2_xattr_get(d_inode(dentry), EXT2_XATTR_INDEX_TRUSTED, name,
  38                               buffer, size);
  39 }
  40
  41 static int
  42 ext2_xattr_trusted_set(const struct xattr_handler *handler,
  43                        struct dentry *dentry, const char *name,
  44                        const void *value, size_t size, int flags)
  45 {
  46         if (strcmp(name, "") == 0)
  47                 return -EINVAL;
  48         return ext2_xattr_set(d_inode(dentry), EXT2_XATTR_INDEX_TRUSTED, name,
  49                               value, size, flags);
  50 }
  51
  52 const struct xattr_handler ext2_xattr_trusted_handler = {
  53         .prefix = XATTR_TRUSTED_PREFIX,
  54         .list   = ext2_xattr_trusted_list,
  55         .get    = ext2_xattr_trusted_get,
  56         .set    = ext2_xattr_trusted_set,
  57 };