Anonymize bt addresses in listAudioPorts (07971a32) · Commits · e / os / android_frameworks_av

media/audioaidlconversion/AidlConversionCppNdk.cpp

+32 −4

Original line number	Diff line number	Diff line
		@@ -1055,6 +1055,14 @@ AudioDeviceAddress::Tag suggestDeviceAddressTag(const AudioDeviceDescription& de
		return OK;
		}

		namespace {
		// Use '01' for LSB bits 0 and 1 as Bluetooth MAC addresses are never multicast
		// and universaly administered
		constexpr std::array<uint8_t, 4> BTANON_PREFIX {0xFD, 0xFF, 0xFF, 0xFF};
		// Keep sync with ServiceUtilities.cpp mustAnonymizeBluetoothAddress
		constexpr const char * BTANON_PREFIX_STR = "XX:XX:XX:XX:";
		}

		::android::status_t aidl2legacy_AudioDevice_audio_device(
		const AudioDevice& aidl,
		audio_devices_t* legacyType, std::string* legacyAddress) {
		@@ -1069,8 +1077,16 @@ AudioDeviceAddress::Tag suggestDeviceAddressTag(const AudioDeviceDescription& de
		case Tag::mac: {
		const std::vector<uint8_t>& mac = aidl.address.get<AudioDeviceAddress::mac>();
		if (mac.size() != 6) return BAD_VALUE;
		snprintf(addressBuffer, AUDIO_DEVICE_MAX_ADDRESS_LEN, "%02X:%02X:%02X:%02X:%02X:%02X",
		if (std::equal(BTANON_PREFIX.begin(), BTANON_PREFIX.end(), mac.begin())) {
		// special case for anonymized mac address:
		// change anonymized bytes back from FD:FF:FF:FF: to XX:XX:XX:XX:
		snprintf(addressBuffer, AUDIO_DEVICE_MAX_ADDRESS_LEN,
		"%s%02X:%02X", BTANON_PREFIX_STR, mac[4], mac[5]);
		} else {
		snprintf(addressBuffer, AUDIO_DEVICE_MAX_ADDRESS_LEN,
		"%02X:%02X:%02X:%02X:%02X:%02X",
		mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
		}
		} break;
		case Tag::ipv4: {
		const std::vector<uint8_t>& ipv4 = aidl.address.get<AudioDeviceAddress::ipv4>();
		@@ -1132,8 +1148,20 @@ legacy2aidl_audio_device_AudioDevice(
		switch (suggestDeviceAddressTag(aidl.type)) {
		case Tag::mac: {
		std::vector<uint8_t> mac(6);
		int status = sscanf(legacyAddress.c_str(), "%hhX:%hhX:%hhX:%hhX:%hhX:%hhX",
		int status;
		// special case for anonymized mac address:
		// change anonymized bytes so that they can be scanned as HEX bytes
		if (legacyAddress.starts_with(BTANON_PREFIX_STR)) {
		std::copy(BTANON_PREFIX.begin(), BTANON_PREFIX.end(), mac.begin());
		LOG_ALWAYS_FATAL_IF(legacyAddress.length() <= strlen(BTANON_PREFIX_STR));
		status = sscanf(legacyAddress.c_str() + strlen(BTANON_PREFIX_STR),
		"%hhX:%hhX",
		&mac[4], &mac[5]);
		status += 4;
		} else {
		status = sscanf(legacyAddress.c_str(), "%hhX:%hhX:%hhX:%hhX:%hhX:%hhX",
		&mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5]);
		}
		if (status != mac.size()) {
		ALOGE("%s: malformed MAC address: \"%s\"", __func__, legacyAddress.c_str());
		return unexpected(BAD_VALUE);

media/libaudioclient/tests/audio_aidl_legacy_conversion_tests.cpp

+19 −0

Original line number	Diff line number	Diff line
		@@ -483,8 +483,27 @@ INSTANTIATE_TEST_SUITE_P(
		AudioDeviceAddress::make<AudioDeviceAddress::Tag::alsa>(
		std::vector<int32_t>{1, 2}))));

		TEST(AnonymizedBluetoothAddressRoundTripTest, Legacy2Aidl2Legacy) {
		const std::vector<uint8_t> sAnonymizedAidlAddress {0xFD, 0xFF, 0xFF, 0xFF, 0xAB, 0xCD};
		const std::string sAnonymizedLegacyAddress = std::string("XX:XX:XX:XX:AB:CD");
		auto device = legacy2aidl_audio_device_AudioDevice(AUDIO_DEVICE_OUT_BLUETOOTH_A2DP,
		sAnonymizedLegacyAddress);
		ASSERT_TRUE(device.ok());
		ASSERT_EQ(AudioDeviceAddress::Tag::mac, device.value().address.getTag());
		ASSERT_EQ(sAnonymizedAidlAddress, device.value().address.get<AudioDeviceAddress::mac>());

		audio_devices_t legacyType;
		std::string legacyAddress;
		status_t status =
		aidl2legacy_AudioDevice_audio_device(device.value(), &legacyType, &legacyAddress);
		ASSERT_EQ(OK, status);
		EXPECT_EQ(legacyType, AUDIO_DEVICE_OUT_BLUETOOTH_A2DP);
		EXPECT_EQ(sAnonymizedLegacyAddress, legacyAddress);
		}

		class AudioFormatDescriptionRoundTripTest : public testing::TestWithParam<AudioFormatDescription> {
		};

		TEST_P(AudioFormatDescriptionRoundTripTest, Aidl2Legacy2Aidl) {
		const auto initial = GetParam();
		auto conv = aidl2legacy_AudioFormatDescription_audio_format_t(initial);

media/utils/ServiceUtilities.cpp

+104 −1

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@
		#define LOG_TAG "ServiceUtilities"

		#include <audio_utils/clock.h>
		#include <android-base/properties.h>
		#include <binder/AppOpsManager.h>
		#include <binder/IPCThreadState.h>
		#include <binder/IServiceManager.h>
		@@ -28,9 +29,11 @@
		#include <media/AidlConversionUtil.h>
		#include <android/content/AttributionSourceState.h>

		#include <iterator>
		#include <algorithm>
		#include <iterator>
		#include <mutex>
		#include <pwd.h>
		#include <thread>

		/* When performing permission checks we do not use permission cache for
		* runtime permissions (protection level dangerous) as they may change at
		@@ -396,6 +399,106 @@ status_t checkIMemory(const sp<IMemory>& iMemory)
		return NO_ERROR;
		}

		// TODO(b/285588444), clean this up on main, but soak it for backporting purposes for now
		namespace {
		class BluetoothPermissionCache {
		static constexpr auto SYSPROP_NAME = "cache_key.system_server.package_info";
		const String16 BLUETOOTH_PERM {"android.permission.BLUETOOTH_CONNECT"};
		mutable std::mutex mLock;
		// Cached property conditionally defined, since only avail on bionic. On host, don't inval cache
		#if defined(__BIONIC__)
		// Unlocked, but only accessed from mListenerThread
		base::CachedProperty mCachedProperty;
		#endif
		// This thread is designed to never join/terminate, so no signal is fine
		const std::thread mListenerThread;
		GUARDED_BY(mLock)
		std::string mPropValue;
		GUARDED_BY(mLock)
		std::unordered_map<uid_t, bool> mCache;
		PermissionController mPc{};
		public:
		BluetoothPermissionCache()
		#if defined(__BIONIC__)
		: mCachedProperty{SYSPROP_NAME},
		mListenerThread([this]() mutable {
		while (true) {
		std::string newVal = mCachedProperty.WaitForChange() ?: "";
		std::lock_guard l{mLock};
		if (newVal != mPropValue) {
		ALOGV("Bluetooth permission update");
		mPropValue = newVal;
		mCache.clear();
		}
		}
		})
		#endif
		{}

		bool checkPermission(uid_t uid, pid_t pid) {
		std::lock_guard l{mLock};
		auto it = mCache.find(uid);
		if (it == mCache.end()) {
		it = mCache.insert({uid, mPc.checkPermission(BLUETOOTH_PERM, uid, pid)}).first;
		}
		return it->second;
		}
		};

		// Don't call this from locks, since it potentially calls up to system server!
		// Check for non-app UIDs above this method!
		bool checkBluetoothPermission(const AttributionSourceState& attr) {
		[[clang::no_destroy]] static BluetoothPermissionCache impl{};
		return impl.checkPermission(attr.uid, attr.pid);
		}
		} // anonymous

		/**
		* Determines if the MAC address in Bluetooth device descriptors returned by APIs of
		* a native audio service (audio flinger, audio policy) must be anonymized.
		* MAC addresses returned to system server or apps with BLUETOOTH_CONNECT permission
		* are not anonymized.
		*
		* @param attributionSource The attribution source of the calling app.
		* @param caller string identifying the caller for logging.
		* @return true if the MAC addresses must be anonymized, false otherwise.
		*/
		bool mustAnonymizeBluetoothAddress(
		const AttributionSourceState& attributionSource, const String16&) {
		uid_t uid = VALUE_OR_FATAL(aidl2legacy_int32_t_uid_t(attributionSource.uid));
		bool res;
		switch(multiuser_get_app_id(uid)) {
		case AID_ROOT:
		case AID_SYSTEM:
		case AID_RADIO:
		case AID_BLUETOOTH:
		case AID_MEDIA:
		case AID_AUDIOSERVER:
		// Don't anonymize for privileged clients
		res = false;
		break;
		default:
		res = !checkBluetoothPermission(attributionSource);
		break;
		}
		ALOGV("%s uid: %d, result: %d", __func__, uid, res);
		return res;
		}

		/**
		* Modifies the passed MAC address string in place for consumption by unprivileged clients.
		* the string is assumed to have a valid MAC address format.
		* the anonymization must be kept in sync with toAnonymizedAddress() in BluetoothUtils.java
		*
		* @param address input/output the char string contining the MAC address to anonymize.
		*/
		void anonymizeBluetoothAddress(char *address) {
		if (address == nullptr \|\| strlen(address) != strlen("AA:BB:CC:DD:EE:FF")) {
		return;
		}
		memcpy(address, "XX:XX:XX:XX", strlen("XX:XX:XX:XX"));
		}

		sp<content::pm::IPackageManagerNative> MediaPackageManager::retrievePackageManager() {
		const sp<IServiceManager> sm = defaultServiceManager();
		if (sm == nullptr) {

media/utils/include/mediautils/ServiceUtilities.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -114,6 +114,10 @@ bool modifyPhoneStateAllowed(const AttributionSourceState& attributionSource);
		bool bypassInterruptionPolicyAllowed(const AttributionSourceState& attributionSource);
		bool callAudioInterceptionAllowed(const AttributionSourceState& attributionSource);
		void purgePermissionCache();
		bool mustAnonymizeBluetoothAddress(
		const AttributionSourceState& attributionSource, const String16& caller);
		void anonymizeBluetoothAddress(char *address);

		int32_t getOpForSource(audio_source_t source);

		AttributionSourceState getCallingAttributionSource();

services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp

+75 −19

Original line number	Diff line number	Diff line
		@@ -1687,6 +1687,19 @@ Status AudioPolicyService::isDirectOutputSupported(
		return Status::ok();
		}

		template <typename Port>
		void anonymizePortBluetoothAddress(Port& port) {
		if (port.type != AUDIO_PORT_TYPE_DEVICE) {
		return;
		}
		if (!(audio_is_a2dp_device(port.ext.device.type)
		\|\| audio_is_ble_device(port.ext.device.type)
		\|\| audio_is_bluetooth_sco_device(port.ext.device.type)
		\|\| audio_is_hearing_aid_out_device(port.ext.device.type))) {
		return;
		}
		anonymizeBluetoothAddress(port.ext.device.address);
		}

		Status AudioPolicyService::listAudioPorts(media::AudioPortRole roleAidl,
		media::AudioPortType typeAidl, Int* count,
		@@ -1705,14 +1718,27 @@ Status AudioPolicyService::listAudioPorts(media::AudioPortRole roleAidl,
		std::unique_ptr<audio_port_v7[]> ports(new audio_port_v7[num_ports]);
		unsigned int generation;

		const AttributionSourceState attributionSource = getCallingAttributionSource();
		AutoCallerClear acc;
		{
		audio_utils::lock_guard _l(mMutex);
		if (mAudioPolicyManager == NULL) {
		return binderStatusFromStatusT(NO_INIT);
		}
		AutoCallerClear acc;
		// AudioPolicyManager->listAudioPorts makes a deep copy of port structs into ports
		// so it is safe to access after releasing the mutex
		RETURN_IF_BINDER_ERROR(binderStatusFromStatusT(
		mAudioPolicyManager->listAudioPorts(role, type, &num_ports, ports.get(), &generation)));
		mAudioPolicyManager->listAudioPorts(
		role, type, &num_ports, ports.get(), &generation)));
		numPortsReq = std::min(numPortsReq, num_ports);
		}

		if (mustAnonymizeBluetoothAddress(attributionSource, String16(__func__))) {
		for (size_t i = 0; i < numPortsReq; ++i) {
		anonymizePortBluetoothAddress(ports[i]);
		}
		}

		RETURN_IF_BINDER_ERROR(binderStatusFromStatusT(
		convertRange(ports.get(), ports.get() + numPortsReq, std::back_inserter(*portsAidl),
		legacy2aidl_audio_port_v7_AudioPortFw)));
		@@ -1735,12 +1761,24 @@ Status AudioPolicyService::listDeclaredDevicePorts(media::AudioPortRole role,
		Status AudioPolicyService::getAudioPort(int portId,
		media::AudioPortFw* _aidl_return) {
		audio_port_v7 port{ .id = portId };

		const AttributionSourceState attributionSource = getCallingAttributionSource();
		AutoCallerClear acc;

		{
		audio_utils::lock_guard _l(mMutex);
		if (mAudioPolicyManager == NULL) {
		return binderStatusFromStatusT(NO_INIT);
		}
		AutoCallerClear acc;
		// AudioPolicyManager->getAudioPort makes a deep copy of the port struct into port
		// so it is safe to access after releasing the mutex
		RETURN_IF_BINDER_ERROR(binderStatusFromStatusT(mAudioPolicyManager->getAudioPort(&port)));
		}

		if (mustAnonymizeBluetoothAddress(attributionSource, String16(__func__))) {
		anonymizePortBluetoothAddress(port);
		}

		*_aidl_return = VALUE_OR_RETURN_BINDER_STATUS(legacy2aidl_audio_port_v7_AudioPortFw(port));
		return Status::ok();
		}
		@@ -1802,14 +1840,32 @@ Status AudioPolicyService::listAudioPatches(Int* count,
		std::unique_ptr<audio_patch[]> patches(new audio_patch[num_patches]);
		unsigned int generation;

		const AttributionSourceState attributionSource = getCallingAttributionSource();
		AutoCallerClear acc;

		{
		audio_utils::lock_guard _l(mMutex);
		if (mAudioPolicyManager == NULL) {
		return binderStatusFromStatusT(NO_INIT);
		}
		AutoCallerClear acc;
		// AudioPolicyManager->listAudioPatches makes a deep copy of patches structs into patches
		// so it is safe to access after releasing the mutex
		RETURN_IF_BINDER_ERROR(binderStatusFromStatusT(
		mAudioPolicyManager->listAudioPatches(&num_patches, patches.get(), &generation)));
		numPatchesReq = std::min(numPatchesReq, num_patches);
		}

		if (mustAnonymizeBluetoothAddress(attributionSource, String16(__func__))) {
		for (size_t i = 0; i < numPatchesReq; ++i) {
		for (size_t j = 0; j < patches[i].num_sources; ++j) {
		anonymizePortBluetoothAddress(patches[i].sources[j]);
		}
		for (size_t j = 0; j < patches[i].num_sinks; ++j) {
		anonymizePortBluetoothAddress(patches[i].sinks[j]);
		}
		}
		}

		RETURN_IF_BINDER_ERROR(binderStatusFromStatusT(
		convertRange(patches.get(), patches.get() + numPatchesReq,
		std::back_inserter(*patchesAidl), legacy2aidl_audio_patch_AudioPatchFw)));