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 <linux/ext4_jbd2.h>
  13#include <linux/ext4_fs.h>
  14#include "xattr.h"
  15
  16#define XATTR_TRUSTED_PREFIX "trusted."
  17
  18static size_t
  19ext4_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
  20                        const char *name, size_t name_len)
  21{
  22        const size_t prefix_len = sizeof(XATTR_TRUSTED_PREFIX)-1;
  23        const size_t total_len = prefix_len + name_len + 1;
  24
  25        if (!capable(CAP_SYS_ADMIN))
  26                return 0;
  27
  28        if (list && total_len <= list_size) {
  29                memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
  30                memcpy(list+prefix_len, name, name_len);
  31                list[prefix_len + name_len] = '\0';
  32        }
  33        return total_len;
  34}
  35
  36static int
  37ext4_xattr_trusted_get(struct inode *inode, const char *name,
  38                       void *buffer, size_t size)
  39{
  40        if (strcmp(name, "") == 0)
  41                return -EINVAL;
  42        return ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED, name,
  43                              buffer, size);
  44}
  45
  46static int
  47ext4_xattr_trusted_set(struct inode *inode, const char *name,
  48                       const void *value, size_t size, int flags)
  49{
  50        if (strcmp(name, "") == 0)
  51                return -EINVAL;
  52        return ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED, name,
  53                              value, size, flags);
  54}
  55
  56struct xattr_handler ext4_xattr_trusted_handler = {
  57        .prefix = XATTR_TRUSTED_PREFIX,
  58        .list   = ext4_xattr_trusted_list,
  59        .get    = ext4_xattr_trusted_get,
  60        .set    = ext4_xattr_trusted_set,
  61};
  62