LXR linux/fs/ext4/xattr

   1/*
   2 * linux/fs/ext4/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 <linux/module.h>
   9#include <linux/string.h>
  10#include <linux/capability.h>
  11#include <linux/fs.h>
  12#include "ext4_jbd2.h"
  13#include "ext4.h"
  14#include "xattr.h"
  15
  16static size_t
  17ext4_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
  18                        const char *name, size_t name_len)
  19{
  20        const size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN;
  21        const size_t total_len = prefix_len + name_len + 1;
  22
  23        if (!capable(CAP_SYS_ADMIN))
  24                return 0;
  25
  26        if (list && total_len <= list_size) {
  27                memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
  28                memcpy(list+prefix_len, name, name_len);
  29                list[prefix_len + name_len] = '\0';
  30        }
  31        return total_len;
  32}
  33
  34static int
  35ext4_xattr_trusted_get(struct inode *inode, const char *name,
  36                       void *buffer, size_t size)
  37{
  38        if (strcmp(name, "") == 0)
  39                return -EINVAL;
  40        return ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED, name,
  41                              buffer, size);
  42}
  43
  44static int
  45ext4_xattr_trusted_set(struct inode *inode, const char *name,
  46                       const void *value, size_t size, int flags)
  47{
  48        if (strcmp(name, "") == 0)
  49                return -EINVAL;
  50        return ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED, name,
  51                              value, size, flags);
  52}
  53
  54struct xattr_handler ext4_xattr_trusted_handler = {
  55        .prefix = XATTR_TRUSTED_PREFIX,
  56        .list   = ext4_xattr_trusted_list,
  57        .get    = ext4_xattr_trusted_get,
  58        .set    = ext4_xattr_trusted_set,
  59};
  60