LXR linux/fs/ext2/xattr

   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 <linux/module.h>
   9#include <linux/string.h>
  10#include <linux/capability.h>
  11#include <linux/fs.h>
  12#include <linux/ext2_fs.h>
  13#include "xattr.h"
  14
  15#define XATTR_TRUSTED_PREFIX "trusted."
  16
  17static size_t
  18ext2_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
  19                        const char *name, size_t name_len)
  20{
  21        const int prefix_len = sizeof(XATTR_TRUSTED_PREFIX)-1;
  22        const size_t total_len = prefix_len + name_len + 1;
  23
  24        if (!capable(CAP_SYS_ADMIN))
  25                return 0;
  26
  27        if (list && total_len <= list_size) {
  28                memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
  29                memcpy(list+prefix_len, name, name_len);
  30                list[prefix_len + name_len] = '\0';
  31        }
  32        return total_len;
  33}
  34
  35static int
  36ext2_xattr_trusted_get(struct inode *inode, const char *name,
  37                       void *buffer, size_t size)
  38{
  39        if (strcmp(name, "") == 0)
  40                return -EINVAL;
  41        return ext2_xattr_get(inode, EXT2_XATTR_INDEX_TRUSTED, name,
  42                              buffer, size);
  43}
  44
  45static int
  46ext2_xattr_trusted_set(struct inode *inode, const char *name,
  47                       const void *value, size_t size, int flags)
  48{
  49        if (strcmp(name, "") == 0)
  50                return -EINVAL;
  51        return ext2_xattr_set(inode, EXT2_XATTR_INDEX_TRUSTED, name,
  52                              value, size, flags);
  53}
  54
  55struct xattr_handler ext2_xattr_trusted_handler = {
  56        .prefix = XATTR_TRUSTED_PREFIX,
  57        .list   = ext2_xattr_trusted_list,
  58        .get    = ext2_xattr_trusted_get,
  59        .set    = ext2_xattr_trusted_set,
  60};
  61