service: Add advertising support to LowEnergyClient (869fa4d4) · Commits · e / os / android_packages_modules_Bluetooth

system/service/advertise_data.cpp

+5 −0

Original line number	Diff line number	Diff line
		@@ -57,6 +57,11 @@ bool AdvertiseData::IsValid() const {
		return false;
		}

		// A field length of 0 would be invalid as it should at least contain the
		// EIR field type.
		if (field_len < 1)
		return false;

		uint8_t type = data_[i + 1];

		// Clients are not allowed to set the following EIR fields as these are

system/service/low_energy_client.cpp

+426 −2

Original line number	Diff line number	Diff line
		@@ -18,23 +18,440 @@

		#include <base/logging.h>

		#include "stack/include/bt_types.h"
		#include "stack/include/hcidefs.h"

		using std::lock_guard;
		using std::mutex;

		namespace bluetooth {

		namespace {

		BLEStatus GetBLEStatus(int status) {
		if (status == BT_STATUS_FAIL)
		return BLE_STATUS_FAILURE;

		return static_cast<BLEStatus>(status);
		}

		// TODO(armansito): BTIF currently expects each advertising field in a
		// specific format passed directly in arguments. We should fix BTIF to accept
		// the advertising data directly instead.
		struct HALAdvertiseData {
		std::vector<uint8_t> manufacturer_data;
		std::vector<uint8_t> service_data;
		std::vector<uint8_t> service_uuid;
		};

		bool ProcessAdvertiseData(const AdvertiseData& adv,
		HALAdvertiseData* out_data) {
		CHECK(out_data);
		CHECK(out_data->manufacturer_data.empty());
		CHECK(out_data->service_data.empty());
		CHECK(out_data->service_uuid.empty());

		const auto& data = adv.data();
		size_t len = data.size();
		for (size_t i = 0, field_len = 0; i < len; i += (field_len + 1)) {
		// The length byte is the first byte in the adv. "TLV" format.
		field_len = data[i];

		// The type byte is the next byte in the adv. "TLV" format.
		uint8_t type = data[i + 1];
		size_t uuid_len = 0;

		switch (type) {
		case HCI_EIR_MANUFACTURER_SPECIFIC_TYPE: {
		// TODO(armansito): BTIF doesn't allow setting more than one
		// manufacturer-specific data entry. This is something we should fix. For
		// now, fail if more than one entry was set.
		if (!out_data->manufacturer_data.empty()) {
		VLOG(1) << "More than one Manufacturer Specific Data entry not allowed";
		return false;
		}

		// The value bytes start at the next byte in the "TLV" format.
		const uint8_t* mnf_data = data.data() + i + 2;
		out_data->manufacturer_data.insert(
		out_data->manufacturer_data.begin(),
		mnf_data, mnf_data + field_len - 1);
		break;
		}
		// TODO(armansito): Support other fields.
		default:
		VLOG(1) << "Unrecognized EIR field: " << type;
		return false;
		}
		}

		return true;
		}

		// The Bluetooth Core Specification defines time interval (e.g. Page Scan
		// Interval, Advertising Interval, etc) units as 0.625 milliseconds (or 1
		// Baseband slot). The HAL advertising functions expect the interval in this
		// unit. This function maps an AdvertiseSettings::Mode value to the
		// corresponding time unit.
		int GetAdvertisingIntervalUnit(AdvertiseSettings::Mode mode) {
		int ms;

		switch (mode) {
		case AdvertiseSettings::MODE_BALANCED:
		ms = kAdvertisingIntervalMediumMs;
		break;
		case AdvertiseSettings::MODE_LOW_LATENCY:
		ms = kAdvertisingIntervalLowMs;
		break;
		case AdvertiseSettings::MODE_LOW_POWER:
		// Fall through
		default:
		ms = kAdvertisingIntervalHighMs;
		break;
		}

		// Convert milliseconds Bluetooth units.
		return (ms * 1000) / 625;
		}

		struct AdvertiseParams {
		int min_interval;
		int max_interval;
		int event_type;
		int tx_power_level;
		int timeout_s;
		};

		void GetAdvertiseParams(const AdvertiseSettings& settings, bool has_scan_rsp,
		AdvertiseParams* out_params) {
		CHECK(out_params);

		out_params->min_interval = GetAdvertisingIntervalUnit(settings.mode());
		out_params->max_interval =
		out_params->min_interval + kAdvertisingIntervalDeltaUnit;

		if (settings.connectable())
		out_params->event_type = kAdvertisingEventTypeConnectable;
		else if (has_scan_rsp)
		out_params->event_type = kAdvertisingEventTypeScannable;
		else
		out_params->event_type = kAdvertisingEventTypeNonConnectable;

		out_params->tx_power_level = settings.tx_power_level();
		out_params->timeout_s = settings.timeout().InSeconds();
		}

		} // namespace

		// LowEnergyClient implementation
		// ========================================================

		LowEnergyClient::LowEnergyClient(const UUID& uuid, int client_if)
		: app_identifier_(uuid),
		client_if_(client_if) {
		client_if_(client_if),
		adv_data_needs_update_(false),
		scan_rsp_needs_update_(false),
		is_setting_adv_data_(false),
		adv_started_(false),
		adv_start_callback_(nullptr),
		adv_stop_callback_(nullptr) {
		}

		LowEnergyClient::~LowEnergyClient() {
		// Automatically unregister the client.
		VLOG(1) << "LowEnergyClient unregistering client: " << client_if_;

		// Unregister as observer so we no longer receive any callbacks.
		hal::BluetoothGattInterface::Get()->RemoveClientObserver(this);

		// Stop advertising and ignore the result.
		hal::BluetoothGattInterface::Get()->
		GetClientHALInterface()->multi_adv_disable(client_if_);
		hal::BluetoothGattInterface::Get()->
		GetClientHALInterface()->unregister_client(client_if_);
		}

		bool LowEnergyClient::StartAdvertising(const AdvertiseSettings& settings,
		const AdvertiseData& advertise_data,
		const AdvertiseData& scan_response,
		const StatusCallback& callback) {
		VLOG(2) << __func__;
		lock_guard<mutex> lock(adv_fields_lock_);

		if (IsAdvertisingStarted()) {
		LOG(WARNING) << "Already advertising";
		return false;
		}

		if (IsStartingAdvertising()) {
		LOG(WARNING) << "StartAdvertising already pending";
		return false;
		}

		if (!advertise_data.IsValid()) {
		LOG(ERROR) << "Invalid advertising data";
		return false;
		}

		if (!scan_response.IsValid()) {
		LOG(ERROR) << "Invalid scan response data";
		return false;
		}

		CHECK(!adv_data_needs_update_.load());
		CHECK(!scan_rsp_needs_update_.load());

		adv_data_ = advertise_data;
		scan_response_ = scan_response;
		settings_ = settings;

		AdvertiseParams params;
		GetAdvertiseParams(settings, !scan_response_.data().empty(), &params);

		bt_status_t status = hal::BluetoothGattInterface::Get()->
		GetClientHALInterface()->multi_adv_enable(
		client_if_,
		params.min_interval,
		params.max_interval,
		params.event_type,
		kAdvertisingChannelAll,
		params.tx_power_level,
		params.timeout_s);
		if (status != BT_STATUS_SUCCESS) {
		LOG(ERROR) << "Failed to initiate call to enable multi-advertising";
		return false;
		}

		// Always update advertising data.
		adv_data_needs_update_ = true;

		// Update scan response only if it has data, since otherwise we just won't
		// send ADV_SCAN_IND.
		if (!scan_response_.data().empty())
		scan_rsp_needs_update_ = true;

		// OK to set this at the end since we're still holding \|adv_fields_lock_\|.
		adv_start_callback_.reset(new StatusCallback(callback));

		return true;
		}

		bool LowEnergyClient::StopAdvertising(const StatusCallback& callback) {
		VLOG(2) << __func__;
		lock_guard<mutex> lock(adv_fields_lock_);

		if (!IsAdvertisingStarted()) {
		LOG(ERROR) << "Not advertising";
		return false;
		}

		if (IsStoppingAdvertising()) {
		LOG(ERROR) << "StopAdvertising already pending";
		return false;
		}

		CHECK(!adv_start_callback_);

		bt_status_t status = hal::BluetoothGattInterface::Get()->
		GetClientHALInterface()->multi_adv_disable(client_if_);
		if (status != BT_STATUS_SUCCESS) {
		LOG(ERROR) << "Failed to initiate call to disable multi-advertising";
		return false;
		}

		// OK to set this at the end since we're still holding \|adv_fields_lock_\|.
		adv_stop_callback_.reset(new StatusCallback(callback));

		return true;
		}

		bool LowEnergyClient::IsAdvertisingStarted() const {
		return adv_started_.load();
		}

		bool LowEnergyClient::IsStartingAdvertising() const {
		return !IsAdvertisingStarted() && adv_start_callback_;
		}

		bool LowEnergyClient::IsStoppingAdvertising() const {
		return IsAdvertisingStarted() && adv_stop_callback_;
		}

		void LowEnergyClient::MultiAdvEnableCallback(
		hal::BluetoothGattInterface* gatt_iface,
		int client_if, int status) {
		if (client_if != client_if_)
		return;

		lock_guard<mutex> lock(adv_fields_lock_);

		VLOG(1) << __func__ << "client_if: " << client_if << " status: " << status;

		CHECK(adv_start_callback_);
		CHECK(!adv_stop_callback_);

		// Terminate operation in case of error.
		if (status != BT_STATUS_SUCCESS) {
		LOG(ERROR) << "Failed to enable multi-advertising";
		InvokeAndClearStartCallback(GetBLEStatus(status));
		return;
		}

		// Now handle deferred tasks.
		HandleDeferredAdvertiseData(gatt_iface);
		}

		void LowEnergyClient::MultiAdvDataCallback(
		hal::BluetoothGattInterface* gatt_iface,
		int client_if, int status) {
		if (client_if != client_if_)
		return;

		lock_guard<mutex> lock(adv_fields_lock_);

		VLOG(1) << __func__ << "client_if: " << client_if << " status: " << status;

		is_setting_adv_data_ = false;

		// Terminate operation in case of error.
		if (status != BT_STATUS_SUCCESS) {
		LOG(ERROR) << "Failed to set advertising data";
		InvokeAndClearStartCallback(GetBLEStatus(status));
		return;
		}

		// Now handle deferred tasks.
		HandleDeferredAdvertiseData(gatt_iface);
		}

		void LowEnergyClient::MultiAdvDisableCallback(
		hal::BluetoothGattInterface* /* gatt_iface */,
		int client_if, int status) {
		if (client_if != client_if_)
		return;

		lock_guard<mutex> lock(adv_fields_lock_);

		VLOG(1) << __func__ << "client_if: " << client_if << " status: " << status;

		CHECK(!adv_start_callback_);
		CHECK(adv_stop_callback_);

		if (status == BT_STATUS_SUCCESS) {
		VLOG(1) << "Multi-advertising stopped for client_if: " << client_if;
		adv_started_ = false;
		} else {
		LOG(ERROR) << "Failed to stop multi-advertising";
		}

		InvokeAndClearStopCallback(GetBLEStatus(status));
		}

		bt_status_t LowEnergyClient::SetAdvertiseData(
		hal::BluetoothGattInterface* gatt_iface,
		const AdvertiseData& data,
		bool set_scan_rsp) {
		VLOG(2) << __func__;

		HALAdvertiseData hal_data;

		// TODO(armansito): The stack should check that the length is valid when other
		// fields inserted by the stack (e.g. flags, device name, tx-power) are taken
		// into account. At the moment we are skipping this check; this means that if
		// the given data is too long then the stack will truncate it.
		if (!ProcessAdvertiseData(data, &hal_data)) {
		VLOG(1) << "Malformed advertise data given";
		return BT_STATUS_FAIL;
		}

		if (is_setting_adv_data_.load()) {
		VLOG(1) << "Setting advertising data already in progress.";
		return BT_STATUS_FAIL;
		}

		// TODO(armansito): The length fields in the BTIF function below are signed
		// integers so a call to std::vector::size might get capped. This is very
		// unlikely anyway but it's safer to stop using signed-integer types for
		// length in APIs, so we should change that.
		bt_status_t status = gatt_iface->GetClientHALInterface()->
		multi_adv_set_inst_data(
		client_if_,
		set_scan_rsp,
		data.include_device_name(),
		data.include_tx_power_level(),
		0, // This is what Bluetooth.apk current hardcodes for "appearance".
		hal_data.manufacturer_data.size(),
		reinterpret_cast<char*>(hal_data.manufacturer_data.data()),
		0, nullptr, 0, nullptr); // TODO(armansito): Support the rest.
		if (status != BT_STATUS_SUCCESS) {
		LOG(ERROR) << "Failed to set instance advertising data.";
		return status;
		}

		if (set_scan_rsp)
		scan_rsp_needs_update_ = false;
		else
		adv_data_needs_update_ = false;

		is_setting_adv_data_ = true;

		return status;
		}

		void LowEnergyClient::HandleDeferredAdvertiseData(
		hal::BluetoothGattInterface* gatt_iface) {
		VLOG(2) << __func__;

		CHECK(!IsAdvertisingStarted());
		CHECK(!IsStoppingAdvertising());
		CHECK(IsStartingAdvertising());
		CHECK(!is_setting_adv_data_.load());

		if (adv_data_needs_update_.load()) {
		bt_status_t status = SetAdvertiseData(gatt_iface, adv_data_, false);
		if (status != BT_STATUS_SUCCESS) {
		LOG(ERROR) << "Failed setting advertisement data";
		InvokeAndClearStartCallback(GetBLEStatus(status));
		}
		return;
		}

		if (scan_rsp_needs_update_.load()) {
		bt_status_t status = SetAdvertiseData(gatt_iface, scan_response_, true);
		if (status != BT_STATUS_SUCCESS) {
		LOG(ERROR) << "Failed setting scan response data";
		InvokeAndClearStartCallback(GetBLEStatus(status));
		}
		return;
		}

		// All pending tasks are complete. Report success.
		adv_started_ = true;
		InvokeAndClearStartCallback(BLE_STATUS_SUCCESS);
		}

		void LowEnergyClient::InvokeAndClearStartCallback(BLEStatus status) {
		adv_data_needs_update_ = false;
		scan_rsp_needs_update_ = false;

		// We allow NULL callbacks.
		if (*adv_start_callback_)
		(*adv_start_callback_)(status);

		adv_start_callback_ = nullptr;
		}

		void LowEnergyClient::InvokeAndClearStopCallback(BLEStatus status) {
		// We allow NULL callbacks.
		if (*adv_stop_callback_)
		(*adv_stop_callback_)(status);

		adv_stop_callback_ = nullptr;
		}

		// LowEnergyClientFactory implementation
		// ========================================================

		LowEnergyClientFactory::LowEnergyClientFactory() {
		hal::BluetoothGattInterface::Get()->AddClientObserver(this);
		}
		@@ -67,7 +484,7 @@ bool LowEnergyClientFactory::RegisterClient(const UUID& uuid,
		}

		void LowEnergyClientFactory::RegisterClientCallback(
		hal::BluetoothGattInterface* /* gatt_iface */,
		hal::BluetoothGattInterface* gatt_iface,
		int status, int client_if,
		const bt_uuid_t& app_uuid) {
		UUID uuid(app_uuid);
		@@ -86,6 +503,13 @@ void LowEnergyClientFactory::RegisterClientCallback(
		BLEStatus result = BLE_STATUS_FAILURE;
		if (status == BT_STATUS_SUCCESS) {
		client.reset(new LowEnergyClient(uuid, client_if));

		// Use the unsafe variant to register this as an observer, since
		// LowEnergyClient instances only get created by LowEnergyClientCallback
		// from inside this GATT client observer event, which would otherwise cause
		// a deadlock.
		gatt_iface->AddClientObserverUnsafe(client.get());

		result = BLE_STATUS_SUCCESS;
		}

system/service/low_energy_client.h

+75 −1

Original line number	Diff line number	Diff line
		@@ -23,6 +23,8 @@
		#include <base/macros.h>

		#include "hal/bluetooth_gatt_interface.h"
		#include "service/advertise_data.h"
		#include "service/advertise_settings.h"
		#include "service/low_energy_constants.h"
		#include "service/uuid.h"

		@@ -31,7 +33,7 @@ namespace bluetooth {
		// A LowEnergyClient represents an application's handle to perform various
		// Bluetooth Low Energy GAP operations. Instances cannot be created directly and
		// should be obtained through the factory.
		class LowEnergyClient {
		class LowEnergyClient : private hal::BluetoothGattInterface::ClientObserver {
		public:
		// The destructor automatically unregisters this client instance from the
		// stack.
		@@ -44,6 +46,31 @@ class LowEnergyClient {
		// what is used internally for BLE transactions.
		int client_if() const { return client_if_; }

		// Callback type used to return the result of asynchronous operations below.
		using StatusCallback = std::function<void(BLEStatus)>;

		// Starts advertising based on the given advertising and scan response
		// data and the provided \|settings\|. Reports the result of the operation in
		// \|callback\|.
		bool StartAdvertising(const AdvertiseSettings& settings,
		const AdvertiseData& advertise_data,
		const AdvertiseData& scan_response,
		const StatusCallback& callback);

		// Stops advertising if it was already started. Reports the result of the
		// operation in \|callback\|.
		bool StopAdvertising(const StatusCallback& callback);

		// Returns true if advertising has been started.
		bool IsAdvertisingStarted() const;

		// Returns the state of pending advertising operations.
		bool IsStartingAdvertising() const;
		bool IsStoppingAdvertising() const;

		// Returns the current advertising settings.
		const AdvertiseSettings& settings() const { return settings_; }

		private:
		friend class LowEnergyClientFactory;

		@@ -51,10 +78,57 @@ class LowEnergyClient {
		// to be obtained from the factory.
		LowEnergyClient(const UUID& uuid, int client_if);

		// BluetoothGattInterface::ClientObserver overrides:
		void MultiAdvEnableCallback(
		hal::BluetoothGattInterface* gatt_iface,
		int client_if, int status) override;
		void MultiAdvDataCallback(
		hal::BluetoothGattInterface* gatt_iface,
		int client_if, int status) override;
		void MultiAdvDisableCallback(
		hal::BluetoothGattInterface* gatt_iface,
		int client_if, int status) override;

		// Helper method called from SetAdvertiseData/SetScanResponse.
		bt_status_t SetAdvertiseData(
		hal::BluetoothGattInterface* gatt_iface,
		const AdvertiseData& data,
		bool set_scan_rsp);

		// Handles deferred advertise/scan-response data updates. We set the data if
		// there's data to be set, otherwise we either defer it if advertisements
		// aren't enabled or do nothing.
		void HandleDeferredAdvertiseData(hal::BluetoothGattInterface* gatt_iface);

		// Calls and clears the pending callbacks.
		void InvokeAndClearStartCallback(BLEStatus status);
		void InvokeAndClearStopCallback(BLEStatus status);

		// See getters above for documentation.
		UUID app_identifier_;
		int client_if_;

		// Protects advertising-related members below.
		std::mutex adv_fields_lock_;

		// The advertising and scan response data fields that will be sent to the
		// controller.
		AdvertiseData adv_data_;
		AdvertiseData scan_response_;
		std::atomic_bool adv_data_needs_update_;
		std::atomic_bool scan_rsp_needs_update_;

		// Latest advertising settings.
		AdvertiseSettings settings_;

		// Whether or not there is a pending call to update advertising or scan
		// response data.
		std::atomic_bool is_setting_adv_data_;

		std::atomic_bool adv_started_;
		std::unique_ptr<StatusCallback> adv_start_callback_;
		std::unique_ptr<StatusCallback> adv_stop_callback_;

		DISALLOW_COPY_AND_ASSIGN(LowEnergyClient);
		};

system/service/test/advertise_data_unittest.cpp

+2 −1

Original line number	Diff line number	Diff line
		@@ -27,9 +27,10 @@ TEST(AdvertiseDataTest, EmptyData) {
		AdvertiseData adv0(data0);
		EXPECT_TRUE(adv0.IsValid());

		// Single empty field not allowed.
		const std::vector<uint8_t> data1{ 0x00 };
		AdvertiseData adv1(data1);
		EXPECT_TRUE(adv1.IsValid());
		EXPECT_FALSE(adv1.IsValid());
		}

		TEST(AdvertiseDataTest, BadTLV) {

system/service/test/low_energy_client_unittest.cpp

+400 −5

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