[EasyUnlock] Update BluetoothLowEnergyConnectionFinder to look for EIDs.

components/proximity_auth/ble/bluetooth_low_energy_connection_finder.cc

-// Copyright 2015 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/proximity_auth/ble/bluetooth_low_energy_connection_finder.h"
-
-#include <memory>
-#include <string>
-#include <utility>
-
-#include "base/bind.h"
-#include "base/bind_helpers.h"
-#include "base/location.h"
-#include "base/logging.h"
-#include "base/memory/ptr_util.h"
-#include "base/strings/utf_string_conversions.h"
-#include "base/threading/thread_task_runner_handle.h"
-#include "components/cryptauth/bluetooth_throttler.h"
-#include "components/cryptauth/connection.h"
-#include "components/proximity_auth/ble/bluetooth_low_energy_connection.h"
-#include "components/proximity_auth/ble/bluetooth_low_energy_device_whitelist.h"
-#include "components/proximity_auth/logging/logging.h"
-#include "device/bluetooth/bluetooth_adapter_factory.h"
-#include "device/bluetooth/bluetooth_common.h"
-#include "device/bluetooth/bluetooth_device.h"
-#include "device/bluetooth/bluetooth_discovery_session.h"
-#include "device/bluetooth/bluetooth_uuid.h"
-
-using device::BluetoothAdapter;
-using device::BluetoothDevice;
-using device::BluetoothGattConnection;
-using device::BluetoothDiscoveryFilter;
-
-namespace proximity_auth {
-namespace {
-const int kMinDiscoveryRSSI = -90;
-}  // namespace
-
-BluetoothLowEnergyConnectionFinder::BluetoothLowEnergyConnectionFinder(
-    const cryptauth::RemoteDevice remote_device,
-    const std::string& remote_service_uuid,
-    FinderStrategy finder_strategy,
-    const BluetoothLowEnergyDeviceWhitelist* device_whitelist,
-    cryptauth::BluetoothThrottler* bluetooth_throttler,
-    int max_number_of_tries)
-    : remote_device_(remote_device),
-      remote_service_uuid_(device::BluetoothUUID(remote_service_uuid)),
-      finder_strategy_(finder_strategy),
-      device_whitelist_(device_whitelist),
-      bluetooth_throttler_(bluetooth_throttler),
-      max_number_of_tries_(max_number_of_tries),
-      weak_ptr_factory_(this) {
-  DCHECK(finder_strategy_ == FIND_ANY_DEVICE ||
-         !remote_device.bluetooth_address.empty());
-}
-
-BluetoothLowEnergyConnectionFinder::~BluetoothLowEnergyConnectionFinder() {
-  if (discovery_session_) {
-    StopDiscoverySession();
-  }
-
-  if (connection_) {
-    connection_->RemoveObserver(this);
-    connection_.reset();
-  }
-
-  if (adapter_) {
-    adapter_->RemoveObserver(this);
-    adapter_ = NULL;
-  }
-}
-
-void BluetoothLowEnergyConnectionFinder::Find(
-    const cryptauth::ConnectionFinder::ConnectionCallback&
-        connection_callback) {
-  if (!device::BluetoothAdapterFactory::IsBluetoothSupported()) {
-    PA_LOG(WARNING) << "Bluetooth is unsupported on this platform. Aborting.";
-    return;
-  }
-  PA_LOG(INFO) << "Finding connection";
-
-  connection_callback_ = connection_callback;
-
-  device::BluetoothAdapterFactory::GetAdapter(
-      base::Bind(&BluetoothLowEnergyConnectionFinder::OnAdapterInitialized,
-                 weak_ptr_factory_.GetWeakPtr()));
-}
-
-// It's not necessary to observe |AdapterPresentChanged| too. When |adapter_| is
-// present, but not powered, it's not possible to scan for new devices.
-void BluetoothLowEnergyConnectionFinder::AdapterPoweredChanged(
-    BluetoothAdapter* adapter,
-    bool powered) {
-  DCHECK_EQ(adapter_.get(), adapter);
-  PA_LOG(INFO) << "Adapter powered: " << powered;
-
-  // Important: do not rely on |adapter->IsDiscoverying()| to verify if there is
-  // an active discovery session. We need to create our own with an specific
-  // filter.
-  if (powered && (!discovery_session_ || !discovery_session_->IsActive()))
-    StartDiscoverySession();
-}
-
-void BluetoothLowEnergyConnectionFinder::DeviceAdded(BluetoothAdapter* adapter,
-                                                     BluetoothDevice* device) {
-  DCHECK_EQ(adapter_.get(), adapter);
-  DCHECK(device);
-
-  // Note: Only consider |device| when it was actually added/updated during a
-  // scanning, otherwise the device is stale and the GATT connection will fail.
-  // For instance, when |adapter_| change status from unpowered to powered,
-  // |DeviceAdded| is called for each paired |device|.
-  if (adapter_->IsPowered() && discovery_session_ &&
-      discovery_session_->IsActive())
-    HandleDeviceUpdated(device);
-}
-
-void BluetoothLowEnergyConnectionFinder::DeviceChanged(
-    BluetoothAdapter* adapter,
-    BluetoothDevice* device) {
-  DCHECK_EQ(adapter_.get(), adapter);
-  DCHECK(device);
-
-  // Note: Only consider |device| when it was actually added/updated during a
-  // scanning, otherwise the device is stale and the GATT connection will fail.
-  // For instance, when |adapter_| change status from unpowered to powered,
-  // |DeviceAdded| is called for each paired |device|.
-  if (adapter_->IsPowered() && discovery_session_ &&
-      discovery_session_->IsActive())
-    HandleDeviceUpdated(device);
-}
-
-void BluetoothLowEnergyConnectionFinder::HandleDeviceUpdated(
-    BluetoothDevice* device) {
-  // Ensuring only one call to |CreateConnection()| is made. A new |connection_|
-  // can be created only when the previous one disconnects, triggering a call to
-  // |OnConnectionStatusChanged|.
-  if (connection_)
-    return;
-
-  if (IsRightDevice(device)) {
-    PA_LOG(INFO) << "Connecting to device " << device->GetAddress()
-                 << " with service (" << HasService(device)
-                 << ") and is paired (" << device->IsPaired();
-
-    connection_ = CreateConnection(device->GetAddress());
-    connection_->AddObserver(this);
-    connection_->Connect();
-
-    StopDiscoverySession();
-  }
-}
-
-bool BluetoothLowEnergyConnectionFinder::IsRightDevice(
-    BluetoothDevice* device) {
-  if (!device)
-    return false;
-
-  // TODO(sacomoto): Remove it when ProximityAuthBleSystem is not needed
-  // anymore.
-  if (device_whitelist_)
-    return device->IsPaired() &&
-           (HasService(device) ||
-            device_whitelist_->HasDeviceWithAddress(device->GetAddress()));
-
-  // The device should be paired when looking for BLE devices by bluetooth
-  // address.
-  if (finder_strategy_ == FIND_PAIRED_DEVICE)
-    return device->IsPaired() &&
-           device->GetAddress() == remote_device_.bluetooth_address;
-  return HasService(device);
-}
-
-bool BluetoothLowEnergyConnectionFinder::HasService(
-    BluetoothDevice* remote_device) {
-  if (!remote_device) {
-    return false;
-  }
-
-  BluetoothDevice::UUIDSet uuids = remote_device->GetUUIDs();
-
-  PA_LOG(INFO) << "Device " << remote_device->GetAddress() << " has "
-               << uuids.size() << " services.";
-  return base::ContainsKey(uuids, remote_service_uuid_);
-}
-
-void BluetoothLowEnergyConnectionFinder::OnAdapterInitialized(
-    scoped_refptr<BluetoothAdapter> adapter) {
-  PA_LOG(INFO) << "Adapter ready";
-
-  adapter_ = adapter;
-  adapter_->AddObserver(this);
-
-  // This is important for debugging. To eliminate the case where the device was
-  // removed (forgotten) by the user, or BlueZ didn't load the device correctly.
-  if (finder_strategy_ == FIND_PAIRED_DEVICE) {
-    PA_LOG(INFO) << "Looking for paired device: "
-                 << remote_device_.bluetooth_address;
-    for (const auto* device : adapter_->GetDevices()) {
-      if (device->IsPaired())
-        PA_LOG(INFO) << device->GetAddress() << " is paired";
-    }
-  }
-
-  // Note: It's possible to connect to the paired directly, so when using
-  // FIND_PAIRED_DEVICE strategy this is not necessary. However, the discovery
-  // doesn't add a lot of latency, and the makes the code path for both
-  // strategies more similar.
-  StartDiscoverySession();
-}
-
-void BluetoothLowEnergyConnectionFinder::OnDiscoverySessionStarted(
-    std::unique_ptr<device::BluetoothDiscoverySession> discovery_session) {
-  PA_LOG(INFO) << "Discovery session started";
-  discovery_session_ = std::move(discovery_session);
-}
-
-void BluetoothLowEnergyConnectionFinder::OnStartDiscoverySessionError() {
-  PA_LOG(WARNING) << "Error starting discovery session";
-}
-
-void BluetoothLowEnergyConnectionFinder::StartDiscoverySession() {
-  DCHECK(adapter_);
-  if (discovery_session_ && discovery_session_->IsActive()) {
-    PA_LOG(INFO) << "Discovery session already active";
-    return;
-  }
-
-  // Discover only low energy (LE) devices with strong enough signal.
-  std::unique_ptr<BluetoothDiscoveryFilter> filter(
-      new BluetoothDiscoveryFilter(device::BLUETOOTH_TRANSPORT_LE));
-  filter->SetRSSI(kMinDiscoveryRSSI);
-
-  adapter_->StartDiscoverySessionWithFilter(
-      std::move(filter),
-      base::Bind(&BluetoothLowEnergyConnectionFinder::OnDiscoverySessionStarted,
-                 weak_ptr_factory_.GetWeakPtr()),
-      base::Bind(
-          &BluetoothLowEnergyConnectionFinder::OnStartDiscoverySessionError,
-          weak_ptr_factory_.GetWeakPtr()));
-}
-
-void BluetoothLowEnergyConnectionFinder::StopDiscoverySession() {
-  PA_LOG(INFO) << "Stopping discovery session";
-  // Destroying the discovery session also stops it.
-  discovery_session_.reset();
-}
-
-std::unique_ptr<cryptauth::Connection>
-BluetoothLowEnergyConnectionFinder::CreateConnection(
-    const std::string& device_address) {
-  DCHECK(remote_device_.bluetooth_address.empty() ||
-         remote_device_.bluetooth_address == device_address);
-  remote_device_.bluetooth_address = device_address;
-  return base::MakeUnique<BluetoothLowEnergyConnection>(
-      remote_device_, adapter_, remote_service_uuid_, bluetooth_throttler_,
-      max_number_of_tries_);
-}
-
-void BluetoothLowEnergyConnectionFinder::OnConnectionStatusChanged(
-    cryptauth::Connection* connection,
-    cryptauth::Connection::Status old_status,
-    cryptauth::Connection::Status new_status) {
-  DCHECK_EQ(connection, connection_.get());
-  PA_LOG(INFO) << "OnConnectionStatusChanged: " << old_status << " -> "
-               << new_status;
-
-  if (!connection_callback_.is_null() && connection_->IsConnected()) {
-    adapter_->RemoveObserver(this);
-    connection_->RemoveObserver(this);
-
-    // If we invoke the callback now, the callback function may install its own
-    // observer to |connection_|. Because we are in the ConnectionObserver
-    // callstack, this new observer will receive this connection event.
-    // Therefore, we need to invoke the callback or restart discovery
-    // asynchronously.
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE,
-        base::Bind(&BluetoothLowEnergyConnectionFinder::InvokeCallbackAsync,
-                   weak_ptr_factory_.GetWeakPtr()));
-  } else if (old_status == cryptauth::Connection::IN_PROGRESS) {
-    PA_LOG(WARNING) << "Connection failed. Retrying.";
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE,
-        base::Bind(
-            &BluetoothLowEnergyConnectionFinder::RestartDiscoverySessionAsync,
-            weak_ptr_factory_.GetWeakPtr()));
-  }
-}
-
-void BluetoothLowEnergyConnectionFinder::RestartDiscoverySessionAsync() {
-  PA_LOG(INFO) << "Restarting discovery session.";
-  connection_.reset();
-  if (!discovery_session_ || !discovery_session_->IsActive())
-    StartDiscoverySession();
-}
-
-BluetoothDevice* BluetoothLowEnergyConnectionFinder::GetDevice(
-    const std::string& device_address) {
-  // It's not possible to simply use
-  // |adapter_->GetDevice(GetRemoteDeviceAddress())| to find the device with MAC
-  // address |GetRemoteDeviceAddress()|. For paired devices,
-  // BluetoothAdapter::GetDevice(XXX) searches for the temporary MAC address
-  // XXX, whereas |remote_device_.bluetooth_address| is the real MAC address.
-  // This is a bug in the way device::BluetoothAdapter is storing the devices
-  // (see crbug.com/497841).
-  std::vector<BluetoothDevice*> devices = adapter_->GetDevices();
-  for (auto* device : devices) {
-    if (device->GetAddress() == device_address)
-      return device;
-  }
-  return nullptr;
-}
-
-void BluetoothLowEnergyConnectionFinder::InvokeCallbackAsync() {
-  connection_callback_.Run(std::move(connection_));
-}
-
-}  // namespace proximity_auth