blob: eb7b0d7e8fdea6b5d674f931e90a0959be5f6dcc [file] [log] [blame]
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "components/metrics/machine_id_provider.h"
#include <windows.h>
#include <stdint.h>
#include <winioctl.h>
#include "base/base_paths.h"
#include "base/files/file_path.h"
#include "base/path_service.h"
#include "base/threading/scoped_blocking_call.h"
#include "base/win/scoped_handle.h"
namespace metrics {
// static
bool MachineIdProvider::HasId() {
return true;
// On windows, the machine id is based on the serial number of the drive Chrome
// is running from.
// static
std::string MachineIdProvider::GetMachineId() {
base::ScopedBlockingCall scoped_blocking_call(base::BlockingType::MAY_BLOCK);
// Use the program's path to get the drive used for the machine id. This means
// that whenever the underlying drive changes, it's considered a new machine.
// This is fine as we do not support migrating Chrome installs to new drives.
base::FilePath executable_path;
if (!base::PathService::Get(base::FILE_EXE, &executable_path)) {
return std::string();
std::vector<base::FilePath::StringType> path_components;
if (path_components.empty()) {
return std::string();
base::FilePath::StringType drive_name = L"\\\\.\\" + path_components[0];
base::win::ScopedHandle drive_handle(
CreateFile(drive_name.c_str(), 0, FILE_SHARE_READ | FILE_SHARE_WRITE,
nullptr, OPEN_EXISTING, 0, nullptr));
query.PropertyId = StorageDeviceProperty;
query.QueryType = PropertyStandardQuery;
// Perform an initial query to get the number of bytes being returned.
DWORD bytes_returned;
BOOL status = DeviceIoControl(
drive_handle.Get(), IOCTL_STORAGE_QUERY_PROPERTY, &query,
sizeof(STORAGE_PROPERTY_QUERY), &header,
sizeof(STORAGE_DESCRIPTOR_HEADER), &bytes_returned, nullptr);
if (!status)
return std::string();
// Query for the actual serial number.
std::vector<int8_t> output_buf(header.Size);
status =
DeviceIoControl(drive_handle.Get(), IOCTL_STORAGE_QUERY_PROPERTY, &query,
sizeof(STORAGE_PROPERTY_QUERY), &output_buf[0],
output_buf.size(), &bytes_returned, nullptr);
if (!status)
return std::string();
const STORAGE_DEVICE_DESCRIPTOR* device_descriptor =
// The serial number is stored in the |output_buf| as a null-terminated
// string starting at the specified offset.
const DWORD offset = device_descriptor->SerialNumberOffset;
if (offset >= output_buf.size())
return std::string();
// Make sure that the null-terminator exists.
const std::vector<int8_t>::iterator serial_number_begin =
output_buf.begin() + offset;
const std::vector<int8_t>::iterator null_location =
std::find(serial_number_begin, output_buf.end(), '\0');
if (null_location == output_buf.end())
return std::string();
const char* serial_number =
reinterpret_cast<const char*>(&output_buf[offset]);
return std::string(serial_number);
} // namespace metrics