//
|
// Copyright 2016 The Android Open Source Project
|
//
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
// you may not use this file except in compliance with the License.
|
// You may obtain a copy of the License at:
|
//
|
// http://www.apache.org/licenses/LICENSE-2.0
|
//
|
// Unless required by applicable law or agreed to in writing, software
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
// See the License for the specific language governing permissions and
|
// limitations under the License.
|
//
|
|
#include "service/low_energy_scanner.h"
|
|
#include "service/adapter.h"
|
#include "service/logging_helpers.h"
|
#include "stack/include/bt_types.h"
|
#include "stack/include/hcidefs.h"
|
|
#include <base/bind.h>
|
#include <base/callback.h>
|
#include <base/logging.h>
|
|
using std::lock_guard;
|
using std::mutex;
|
|
namespace bluetooth {
|
|
namespace {
|
|
// 31 + 31 for advertising data and scan response. This is the maximum length
|
// TODO(armansito): Fix the HAL to return a concatenated blob that contains the
|
// true length of each field and also provide a length parameter so that we
|
// can support advertising length extensions in the future.
|
const size_t kScanRecordLength = 62;
|
|
// Returns the length of the given scan record array. We have to calculate this
|
// based on the maximum possible data length and the TLV data. See TODO above
|
// |kScanRecordLength|.
|
size_t GetScanRecordLength(std::vector<uint8_t> bytes) {
|
for (size_t i = 0, field_len = 0; i < kScanRecordLength;
|
i += (field_len + 1)) {
|
field_len = bytes[i];
|
|
// Assert here that the data returned from the stack is correctly formatted
|
// in TLV form and that the length of the current field won't exceed the
|
// total data length.
|
CHECK(i + field_len < kScanRecordLength);
|
|
// If the field length is zero and we haven't reached the maximum length,
|
// then we have found the length, as the stack will pad the data with zeros
|
// accordingly.
|
if (field_len == 0) return i;
|
}
|
|
// We have reached the end.
|
return kScanRecordLength;
|
}
|
|
} // namespace
|
|
// LowEnergyScanner implementation
|
// ========================================================
|
|
LowEnergyScanner::LowEnergyScanner(Adapter& adapter, const Uuid& uuid,
|
int scanner_id)
|
: adapter_(adapter),
|
app_identifier_(uuid),
|
scanner_id_(scanner_id),
|
scan_started_(false),
|
delegate_(nullptr) {}
|
|
LowEnergyScanner::~LowEnergyScanner() {
|
// Automatically unregister the scanner.
|
VLOG(1) << "LowEnergyScanner unregistering scanner: " << scanner_id_;
|
|
// Unregister as observer so we no longer receive any callbacks.
|
hal::BluetoothGattInterface::Get()->RemoveScannerObserver(this);
|
|
hal::BluetoothGattInterface::Get()->GetScannerHALInterface()->Unregister(
|
scanner_id_);
|
|
// Stop any scans started by this client.
|
if (scan_started_.load()) StopScan();
|
}
|
|
void LowEnergyScanner::SetDelegate(Delegate* delegate) {
|
lock_guard<mutex> lock(delegate_mutex_);
|
delegate_ = delegate;
|
}
|
|
bool LowEnergyScanner::StartScan(const ScanSettings& settings,
|
const std::vector<ScanFilter>& filters) {
|
VLOG(2) << __func__;
|
|
// Cannot start a scan if the adapter is not enabled.
|
if (!adapter_.IsEnabled()) {
|
LOG(ERROR) << "Cannot scan while Bluetooth is disabled";
|
return false;
|
}
|
|
// TODO(jpawlowski): Push settings and filtering logic below the HAL.
|
bt_status_t status =
|
hal::BluetoothGattInterface::Get()->StartScan(scanner_id_);
|
if (status != BT_STATUS_SUCCESS) {
|
LOG(ERROR) << "Failed to initiate scanning for client: " << scanner_id_;
|
return false;
|
}
|
|
scan_started_ = true;
|
return true;
|
}
|
|
bool LowEnergyScanner::StopScan() {
|
VLOG(2) << __func__;
|
|
// TODO(armansito): We don't support batch scanning yet so call
|
// StopRegularScanForClient directly. In the future we will need to
|
// conditionally call a batch scan API here.
|
bt_status_t status =
|
hal::BluetoothGattInterface::Get()->StopScan(scanner_id_);
|
if (status != BT_STATUS_SUCCESS) {
|
LOG(ERROR) << "Failed to stop scan for client: " << scanner_id_;
|
return false;
|
}
|
|
scan_started_ = false;
|
return true;
|
}
|
|
const Uuid& LowEnergyScanner::GetAppIdentifier() const {
|
return app_identifier_;
|
}
|
|
int LowEnergyScanner::GetInstanceId() const { return scanner_id_; }
|
|
void LowEnergyScanner::ScanResultCallback(
|
hal::BluetoothGattInterface* gatt_iface, const RawAddress& bda, int rssi,
|
std::vector<uint8_t> adv_data) {
|
// Ignore scan results if this client didn't start a scan.
|
if (!scan_started_.load()) return;
|
|
lock_guard<mutex> lock(delegate_mutex_);
|
if (!delegate_) return;
|
|
// TODO(armansito): Apply software filters here.
|
|
size_t record_len = GetScanRecordLength(adv_data);
|
std::vector<uint8_t> scan_record(adv_data.begin(),
|
adv_data.begin() + record_len);
|
|
ScanResult result(BtAddrString(&bda), scan_record, rssi);
|
|
delegate_->OnScanResult(this, result);
|
}
|
|
// LowEnergyScannerFactory implementation
|
// ========================================================
|
|
LowEnergyScannerFactory::LowEnergyScannerFactory(Adapter& adapter)
|
: adapter_(adapter) {
|
hal::BluetoothGattInterface::Get()->AddScannerObserver(this);
|
}
|
|
LowEnergyScannerFactory::~LowEnergyScannerFactory() {
|
hal::BluetoothGattInterface::Get()->RemoveScannerObserver(this);
|
}
|
|
bool LowEnergyScannerFactory::RegisterInstance(
|
const Uuid& uuid, const RegisterCallback& callback) {
|
VLOG(1) << __func__ << " - Uuid: " << uuid.ToString();
|
lock_guard<mutex> lock(pending_calls_lock_);
|
|
if (pending_calls_.find(uuid) != pending_calls_.end()) {
|
LOG(ERROR) << "Low-Energy scanner with given Uuid already registered - "
|
<< "Uuid: " << uuid.ToString();
|
return false;
|
}
|
|
BleScannerInterface* hal_iface =
|
hal::BluetoothGattInterface::Get()->GetScannerHALInterface();
|
|
hal_iface->RegisterScanner(
|
base::Bind(&LowEnergyScannerFactory::RegisterScannerCallback,
|
base::Unretained(this), callback, uuid));
|
|
pending_calls_.insert(uuid);
|
|
return true;
|
}
|
|
void LowEnergyScannerFactory::RegisterScannerCallback(
|
const RegisterCallback& callback, const Uuid& app_uuid, uint8_t scanner_id,
|
uint8_t status) {
|
Uuid uuid(app_uuid);
|
|
VLOG(1) << __func__ << " - Uuid: " << uuid.ToString();
|
lock_guard<mutex> lock(pending_calls_lock_);
|
|
auto iter = pending_calls_.find(uuid);
|
if (iter == pending_calls_.end()) {
|
VLOG(1) << "Ignoring callback for unknown app_id: " << uuid.ToString();
|
return;
|
}
|
|
// No need to construct a scanner if the call wasn't successful.
|
std::unique_ptr<LowEnergyScanner> scanner;
|
BLEStatus result = BLE_STATUS_FAILURE;
|
if (status == BT_STATUS_SUCCESS) {
|
scanner.reset(new LowEnergyScanner(adapter_, uuid, scanner_id));
|
|
hal::BluetoothGattInterface::Get()->AddScannerObserver(scanner.get());
|
|
result = BLE_STATUS_SUCCESS;
|
}
|
|
// Notify the result via the result callback.
|
callback(result, app_uuid, std::move(scanner));
|
|
pending_calls_.erase(iter);
|
}
|
|
} // namespace bluetooth
|
