libs/binder/tests/binderStabilityTest.cpp - android_frameworks_native - Gitiles

 /*
  * Copyright (C) 2019 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 <android/binder_libbinder.h>
 #include <android/binder_manager.h>
 #include <android/binder_stability.h>
 #include <binder/Binder.h>
 #include <binder/IBinder.h>
 #include <binder/IPCThreadState.h>
 #include <binder/IServiceManager.h>
 #include <binder/Parcel.h>
 #include <binder/Stability.h>
 #include <gtest/gtest.h>

 #include <sys/prctl.h>

 #include "aidl/BnBinderStabilityTest.h"
 #include "BnBinderStabilityTest.h"

 using namespace android;
 using namespace ndk;
 using android::binder::Status;
 using android::internal::Stability; // for testing only!

 const String16 kSystemStabilityServer = String16("binder_stability_test_service_system");

 // This is handwritten so that we can test different stability levels w/o having the AIDL
 // compiler assign them. Hand-writing binder interfaces is considered a bad practice
 // sanity reasons. YOU SHOULD DEFINE AN AIDL INTERFACE INSTEAD!
 class BadStableBinder : public BBinder {
 public:
     static constexpr uint32_t USER_TRANSACTION = IBinder::FIRST_CALL_TRANSACTION;
     static String16 kDescriptor;

     bool gotUserTransaction = false;

     static status_t doUserTransaction(const sp<IBinder>& binder) {
         Parcel data, reply;
         data.writeInterfaceToken(kDescriptor);
         return binder->transact(USER_TRANSACTION, data, &reply, 0/*flags*/);
     }

     status_t onTransact(uint32_t code,
             const Parcel& data, Parcel* reply, uint32_t flags) override {
         if (code == USER_TRANSACTION) {
             // not interested in this kind of stability. Make sure
             // we have a test failure
             LOG_ALWAYS_FATAL_IF(!data.enforceInterface(kDescriptor));

             gotUserTransaction = true;

             ALOGE("binder stability: Got user transaction");
             return OK;
         }
         return BBinder::onTransact(code, data, reply, flags);
     }

     static sp<BadStableBinder> undef() {
         sp<BadStableBinder> iface = new BadStableBinder();
         return iface;
     }

     static sp<BadStableBinder> system() {
         sp<BadStableBinder> iface = new BadStableBinder();
         Stability::markCompilationUnit(iface.get()); // <- for test only
         return iface;
     }

     static sp<BadStableBinder> vintf() {
         sp<BadStableBinder> iface = new BadStableBinder();
         Stability::markVintf(iface.get()); // <- for test only
         return iface;
     }

     static sp<BadStableBinder> vendor() {
         sp<BadStableBinder> iface = new BadStableBinder();
         Stability::markVndk(iface.get()); // <- for test only
         return iface;
     }
 };
 String16 BadStableBinder::kDescriptor = String16("BadStableBinder.test");

 // NO! NO! NO! Do not even think of doing something like this!
 // This is for testing! If a class like this was actually used in production,
 // it would ruin everything!
 class MyBinderStabilityTest : public BnBinderStabilityTest {
 public:
     Status sendBinder(const sp<IBinder>& /*binder*/) override {
         return Status::ok();
     }
     Status sendAndCallBinder(const sp<IBinder>& binder) override {
         ALOGI("Debug log stability: %s", Stability::debugToString(binder).c_str());
         return Status::fromExceptionCode(BadStableBinder::doUserTransaction(binder));
     }
     Status returnNoStabilityBinder(sp<IBinder>* _aidl_return) override {
         *_aidl_return = BadStableBinder::undef();
         return Status::ok();
     }
     Status returnLocalStabilityBinder(sp<IBinder>* _aidl_return) override {
         *_aidl_return = BadStableBinder::system();
         return Status::ok();
     }
     Status returnVintfStabilityBinder(sp<IBinder>* _aidl_return) override {
         *_aidl_return = BadStableBinder::vintf();
         return Status::ok();
     }
     Status returnVendorStabilityBinder(sp<IBinder>* _aidl_return) override {
         *_aidl_return = BadStableBinder::vendor();
         return Status::ok();
     }
 };

 TEST(BinderStability, OnlyVintfStabilityBinderNeedsVintfDeclaration) {
     EXPECT_FALSE(Stability::requiresVintfDeclaration(nullptr));
     EXPECT_FALSE(Stability::requiresVintfDeclaration(BadStableBinder::undef()));
     EXPECT_FALSE(Stability::requiresVintfDeclaration(BadStableBinder::system()));
     EXPECT_FALSE(Stability::requiresVintfDeclaration(BadStableBinder::vendor()));

     EXPECT_TRUE(Stability::requiresVintfDeclaration(BadStableBinder::vintf()));
 }

 TEST(BinderStability, ForceDowngradeToLocalStability) {
     sp<IBinder> someBinder = BadStableBinder::vintf();

     EXPECT_TRUE(Stability::requiresVintfDeclaration(someBinder));

     // silly to do this after already using the binder, but it's for the test
     Stability::forceDowngradeToLocalStability(someBinder);

     EXPECT_FALSE(Stability::requiresVintfDeclaration(someBinder));
 }

 TEST(BinderStability, NdkForceDowngradeToLocalStability) {
     sp<IBinder> someBinder = BadStableBinder::vintf();

     EXPECT_TRUE(Stability::requiresVintfDeclaration(someBinder));

     // silly to do this after already using the binder, but it's for the test
     AIBinder_forceDowngradeToLocalStability(AIBinder_fromPlatformBinder(someBinder));

     EXPECT_FALSE(Stability::requiresVintfDeclaration(someBinder));
 }

 TEST(BinderStability, ForceDowngradeToVendorStability) {
     sp<IBinder> serverBinder = android::defaultServiceManager()->getService(kSystemStabilityServer);
     auto server = interface_cast<IBinderStabilityTest>(serverBinder);

     ASSERT_NE(nullptr, server.get());
     ASSERT_NE(nullptr, IInterface::asBinder(server)->remoteBinder());

     {
         sp<BadStableBinder> binder = BadStableBinder::vintf();

         EXPECT_TRUE(Stability::requiresVintfDeclaration(binder));
         EXPECT_TRUE(server->sendAndCallBinder(binder).isOk());
         EXPECT_TRUE(binder->gotUserTransaction);
     }
     {
         sp<BadStableBinder> binder = BadStableBinder::vintf();

         // This method should never be called directly. This is done only for the test.
         Stability::forceDowngradeToVendorStability(binder);

         // Binder downgraded to vendor stability, cannot be called from system context
         EXPECT_FALSE(Stability::requiresVintfDeclaration(binder));
         EXPECT_EQ(BAD_TYPE, server->sendAndCallBinder(binder).exceptionCode());
         EXPECT_FALSE(binder->gotUserTransaction);
     }
 }

 TEST(BinderStability, VintfStabilityServerMustBeDeclaredInManifest) {
     sp<IBinder> vintfServer = BadStableBinder::vintf();

     for (const char* instance8 : {
         ".", "/", "/.", "a.d.IFoo", "foo", "a.d.IFoo/foo"
     }) {
         String16 instance (instance8);

         EXPECT_EQ(Status::EX_ILLEGAL_ARGUMENT,
             android::defaultServiceManager()->addService(String16("."), vintfServer)) << instance8;
         EXPECT_FALSE(android::defaultServiceManager()->isDeclared(instance)) << instance8;
         EXPECT_EQ(std::nullopt, android::defaultServiceManager()->updatableViaApex(instance))
                 << instance8;
     }
 }

 TEST(BinderStability, ConnectionInfoRequiresManifestEntries) {
     sp<IServiceManager> sm = android::defaultServiceManager();
     sp<IBinder> systemBinder = BadStableBinder::system();
     EXPECT_EQ(OK, sm->addService(String16("no.connection.foo"), systemBinder));
     std::optional<android::IServiceManager::ConnectionInfo> connectionInfo;
     connectionInfo = sm->getConnectionInfo(String16("no.connection.foo"));
     EXPECT_EQ(connectionInfo, std::nullopt);
 }
 TEST(BinderStability, CantCallVendorBinderInSystemContext) {
     sp<IBinder> serverBinder = android::defaultServiceManager()->getService(kSystemStabilityServer);
     auto server = interface_cast<IBinderStabilityTest>(serverBinder);

     ASSERT_NE(nullptr, server.get());
     ASSERT_NE(nullptr, IInterface::asBinder(server)->remoteBinder());

     EXPECT_TRUE(server->sendBinder(BadStableBinder::undef()).isOk());
     EXPECT_TRUE(server->sendBinder(BadStableBinder::system()).isOk());
     EXPECT_TRUE(server->sendBinder(BadStableBinder::vintf()).isOk());
     EXPECT_TRUE(server->sendBinder(BadStableBinder::vendor()).isOk());

     {
         sp<BadStableBinder> binder = BadStableBinder::undef();
         EXPECT_TRUE(server->sendAndCallBinder(binder).isOk());
         EXPECT_TRUE(binder->gotUserTransaction);
     }
     {
         sp<BadStableBinder> binder = BadStableBinder::system();
         EXPECT_TRUE(server->sendAndCallBinder(binder).isOk());
         EXPECT_TRUE(binder->gotUserTransaction);
     }
     {
         sp<BadStableBinder> binder = BadStableBinder::vintf();
         EXPECT_TRUE(server->sendAndCallBinder(binder).isOk());
         EXPECT_TRUE(binder->gotUserTransaction);
     }
     {
         // !!! user-defined transaction may not be stable for remote server !!!
         // !!! so, it does not work !!!
         sp<BadStableBinder> binder = BadStableBinder::vendor();
         EXPECT_EQ(BAD_TYPE, server->sendAndCallBinder(binder).exceptionCode());
         EXPECT_FALSE(binder->gotUserTransaction);
     }

     sp<IBinder> out;
     EXPECT_TRUE(server->returnNoStabilityBinder(&out).isOk());
     ASSERT_NE(nullptr, out.get());
     EXPECT_EQ(OK, out->pingBinder());
     EXPECT_EQ(OK, BadStableBinder::doUserTransaction(out));

     EXPECT_TRUE(server->returnLocalStabilityBinder(&out).isOk());
     ASSERT_NE(nullptr, out.get());
     EXPECT_EQ(OK, out->pingBinder());
     EXPECT_EQ(OK, BadStableBinder::doUserTransaction(out));

     EXPECT_TRUE(server->returnVintfStabilityBinder(&out).isOk());
     ASSERT_NE(nullptr, out.get());
     EXPECT_EQ(OK, out->pingBinder());
     EXPECT_EQ(OK, BadStableBinder::doUserTransaction(out));

     EXPECT_TRUE(server->returnVendorStabilityBinder(&out).isOk());
     ASSERT_NE(nullptr, out.get());

     // !!! libbinder-defined transaction works !!!
     EXPECT_EQ(OK, out->pingBinder());

     // !!! user-defined transaction may not be stable !!!
     // !!! so, it does not work !!!
     EXPECT_EQ(BAD_TYPE, BadStableBinder::doUserTransaction(out));
 }

 // This is handwritten so that we can test different stability levels w/o having the AIDL
 // compiler assign them. Hand-writing binder interfaces is considered a bad practice
 // sanity reasons. YOU SHOULD DEFINE AN AIDL INTERFACE INSTEAD!

 struct NdkBinderStable_DataClass {
     bool gotUserTransaction = false;
 };
 void* NdkBadStableBinder_Class_onCreate(void* args) {
     LOG_ALWAYS_FATAL_IF(args != nullptr, "Takes no args");
     return static_cast<void*>(new NdkBinderStable_DataClass);
 }
 void NdkBadStableBinder_Class_onDestroy(void* userData) {
     delete static_cast<NdkBinderStable_DataClass*>(userData);
 }
 NdkBinderStable_DataClass* NdkBadStableBinder_getUserData(AIBinder* binder) {
     LOG_ALWAYS_FATAL_IF(binder == nullptr);
     void* userData = AIBinder_getUserData(binder);
     LOG_ALWAYS_FATAL_IF(userData == nullptr, "null data - binder is remote?");

     return static_cast<NdkBinderStable_DataClass*>(userData);
 }
 binder_status_t NdkBadStableBinder_Class_onTransact(
     AIBinder* binder, transaction_code_t code, const AParcel* /*in*/, AParcel* /*out*/) {

     if (code == BadStableBinder::USER_TRANSACTION) {
         ALOGE("ndk binder stability: Got user transaction");
         NdkBadStableBinder_getUserData(binder)->gotUserTransaction = true;
         return STATUS_OK;
     }

     return STATUS_UNKNOWN_TRANSACTION;
 }

 static AIBinder_Class* kNdkBadStableBinder =
     AIBinder_Class_define(String8(BadStableBinder::kDescriptor).c_str(),
                           NdkBadStableBinder_Class_onCreate,
                           NdkBadStableBinder_Class_onDestroy,
                           NdkBadStableBinder_Class_onTransact);

 // for testing only to get around __ANDROID_VNDK__ guard.
 extern "C" void AIBinder_markVendorStability(AIBinder* binder); // <- BAD DO NOT COPY

 TEST(BinderStability, NdkCantCallVendorBinderInSystemContext) {
     SpAIBinder binder = SpAIBinder(AServiceManager_getService(
         String8(kSystemStabilityServer).c_str()));

     std::shared_ptr<aidl::IBinderStabilityTest> remoteServer =
         aidl::IBinderStabilityTest::fromBinder(binder);

     ASSERT_NE(nullptr, remoteServer.get());

     SpAIBinder comp = SpAIBinder(AIBinder_new(kNdkBadStableBinder, nullptr /*args*/));
     EXPECT_TRUE(remoteServer->sendBinder(comp).isOk());
     EXPECT_TRUE(remoteServer->sendAndCallBinder(comp).isOk());
     EXPECT_TRUE(NdkBadStableBinder_getUserData(comp.get())->gotUserTransaction);

     SpAIBinder vendor = SpAIBinder(AIBinder_new(kNdkBadStableBinder, nullptr /*args*/));
     AIBinder_markVendorStability(vendor.get());
     EXPECT_TRUE(remoteServer->sendBinder(vendor).isOk());
     EXPECT_FALSE(remoteServer->sendAndCallBinder(vendor).isOk());
     EXPECT_FALSE(NdkBadStableBinder_getUserData(vendor.get())->gotUserTransaction);
 }

 class MarksStabilityInConstructor : public BBinder {
 public:
     static bool gDestructed;

     MarksStabilityInConstructor() {
         Stability::markCompilationUnit(this);
     }
     ~MarksStabilityInConstructor() {
         gDestructed = true;
     }
 };
 bool MarksStabilityInConstructor::gDestructed = false;

 TEST(BinderStability, MarkingObjectNoDestructTest) {
     ASSERT_FALSE(MarksStabilityInConstructor::gDestructed);

     // best practice is to put this directly in an sp, but for this test, we
     // want to explicitly check what happens before that happens
     MarksStabilityInConstructor* binder = new MarksStabilityInConstructor();
     ASSERT_FALSE(MarksStabilityInConstructor::gDestructed);

     sp<MarksStabilityInConstructor> binderSp = binder;
     ASSERT_FALSE(MarksStabilityInConstructor::gDestructed);

     binderSp = nullptr;
     ASSERT_TRUE(MarksStabilityInConstructor::gDestructed);
 }

 TEST(BinderStability, RemarkDies) {
     ASSERT_DEATH({
         sp<IBinder> binder = new BBinder();
         Stability::markCompilationUnit(binder.get()); // <-- only called for tests
         Stability::markVndk(binder.get()); // <-- only called for tests
     }, "Should only mark known object.");
 }

 int main(int argc, char** argv) {
     ::testing::InitGoogleTest(&argc, argv);

     if (fork() == 0) {
         // child process
         prctl(PR_SET_PDEATHSIG, SIGHUP);

         sp<IBinder> server = new MyBinderStabilityTest;
         android::defaultServiceManager()->addService(kSystemStabilityServer, server);

         IPCThreadState::self()->joinThreadPool(true);
         exit(1);  // should not reach
     }

     // This is not racey. Just giving these services some time to register before we call
     // getService which sleeps for much longer...
     usleep(10000);

     return RUN_ALL_TESTS();
 }
	/*
	* Copyright (C) 2019 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 <android/binder_libbinder.h>
	#include <android/binder_manager.h>
	#include <android/binder_stability.h>
	#include <binder/Binder.h>
	#include <binder/IBinder.h>
	#include <binder/IPCThreadState.h>
	#include <binder/IServiceManager.h>
	#include <binder/Parcel.h>
	#include <binder/Stability.h>
	#include <gtest/gtest.h>

	#include <sys/prctl.h>

	#include "aidl/BnBinderStabilityTest.h"
	#include "BnBinderStabilityTest.h"

	using namespace android;
	using namespace ndk;
	using android::binder::Status;
	using android::internal::Stability; // for testing only!

	const String16 kSystemStabilityServer = String16("binder_stability_test_service_system");

	// This is handwritten so that we can test different stability levels w/o having the AIDL
	// compiler assign them. Hand-writing binder interfaces is considered a bad practice
	// sanity reasons. YOU SHOULD DEFINE AN AIDL INTERFACE INSTEAD!
	class BadStableBinder : public BBinder {
	public:
	static constexpr uint32_t USER_TRANSACTION = IBinder::FIRST_CALL_TRANSACTION;
	static String16 kDescriptor;

	bool gotUserTransaction = false;

	static status_t doUserTransaction(const sp<IBinder>& binder) {
	Parcel data, reply;
	data.writeInterfaceToken(kDescriptor);
	return binder->transact(USER_TRANSACTION, data, &reply, 0/flags/);
	}

	status_t onTransact(uint32_t code,
	const Parcel& data, Parcel* reply, uint32_t flags) override {
	if (code == USER_TRANSACTION) {
	// not interested in this kind of stability. Make sure
	// we have a test failure
	LOG_ALWAYS_FATAL_IF(!data.enforceInterface(kDescriptor));

	gotUserTransaction = true;

	ALOGE("binder stability: Got user transaction");
	return OK;
	}
	return BBinder::onTransact(code, data, reply, flags);
	}

	static sp<BadStableBinder> undef() {
	sp<BadStableBinder> iface = new BadStableBinder();
	return iface;
	}

	static sp<BadStableBinder> system() {
	sp<BadStableBinder> iface = new BadStableBinder();
	Stability::markCompilationUnit(iface.get()); // <- for test only
	return iface;
	}

	static sp<BadStableBinder> vintf() {
	sp<BadStableBinder> iface = new BadStableBinder();
	Stability::markVintf(iface.get()); // <- for test only
	return iface;
	}

	static sp<BadStableBinder> vendor() {
	sp<BadStableBinder> iface = new BadStableBinder();
	Stability::markVndk(iface.get()); // <- for test only
	return iface;
	}
	};
	String16 BadStableBinder::kDescriptor = String16("BadStableBinder.test");

	// NO! NO! NO! Do not even think of doing something like this!
	// This is for testing! If a class like this was actually used in production,
	// it would ruin everything!
	class MyBinderStabilityTest : public BnBinderStabilityTest {
	public:
	Status sendBinder(const sp<IBinder>& /binder/) override {
	return Status::ok();
	}
	Status sendAndCallBinder(const sp<IBinder>& binder) override {
	ALOGI("Debug log stability: %s", Stability::debugToString(binder).c_str());
	return Status::fromExceptionCode(BadStableBinder::doUserTransaction(binder));
	}
	Status returnNoStabilityBinder(sp<IBinder>* _aidl_return) override {
	*_aidl_return = BadStableBinder::undef();
	return Status::ok();
	}
	Status returnLocalStabilityBinder(sp<IBinder>* _aidl_return) override {
	*_aidl_return = BadStableBinder::system();
	return Status::ok();
	}
	Status returnVintfStabilityBinder(sp<IBinder>* _aidl_return) override {
	*_aidl_return = BadStableBinder::vintf();
	return Status::ok();
	}
	Status returnVendorStabilityBinder(sp<IBinder>* _aidl_return) override {
	*_aidl_return = BadStableBinder::vendor();
	return Status::ok();
	}
	};

	TEST(BinderStability, OnlyVintfStabilityBinderNeedsVintfDeclaration) {
	EXPECT_FALSE(Stability::requiresVintfDeclaration(nullptr));
	EXPECT_FALSE(Stability::requiresVintfDeclaration(BadStableBinder::undef()));
	EXPECT_FALSE(Stability::requiresVintfDeclaration(BadStableBinder::system()));
	EXPECT_FALSE(Stability::requiresVintfDeclaration(BadStableBinder::vendor()));

	EXPECT_TRUE(Stability::requiresVintfDeclaration(BadStableBinder::vintf()));
	}

	TEST(BinderStability, ForceDowngradeToLocalStability) {
	sp<IBinder> someBinder = BadStableBinder::vintf();

	EXPECT_TRUE(Stability::requiresVintfDeclaration(someBinder));

	// silly to do this after already using the binder, but it's for the test
	Stability::forceDowngradeToLocalStability(someBinder);

	EXPECT_FALSE(Stability::requiresVintfDeclaration(someBinder));
	}

	TEST(BinderStability, NdkForceDowngradeToLocalStability) {
	sp<IBinder> someBinder = BadStableBinder::vintf();

	EXPECT_TRUE(Stability::requiresVintfDeclaration(someBinder));

	// silly to do this after already using the binder, but it's for the test
	AIBinder_forceDowngradeToLocalStability(AIBinder_fromPlatformBinder(someBinder));

	EXPECT_FALSE(Stability::requiresVintfDeclaration(someBinder));
	}

	TEST(BinderStability, ForceDowngradeToVendorStability) {
	sp<IBinder> serverBinder = android::defaultServiceManager()->getService(kSystemStabilityServer);
	auto server = interface_cast<IBinderStabilityTest>(serverBinder);

	ASSERT_NE(nullptr, server.get());
	ASSERT_NE(nullptr, IInterface::asBinder(server)->remoteBinder());

	{
	sp<BadStableBinder> binder = BadStableBinder::vintf();

	EXPECT_TRUE(Stability::requiresVintfDeclaration(binder));
	EXPECT_TRUE(server->sendAndCallBinder(binder).isOk());
	EXPECT_TRUE(binder->gotUserTransaction);
	}
	{
	sp<BadStableBinder> binder = BadStableBinder::vintf();

	// This method should never be called directly. This is done only for the test.
	Stability::forceDowngradeToVendorStability(binder);

	// Binder downgraded to vendor stability, cannot be called from system context
	EXPECT_FALSE(Stability::requiresVintfDeclaration(binder));
	EXPECT_EQ(BAD_TYPE, server->sendAndCallBinder(binder).exceptionCode());
	EXPECT_FALSE(binder->gotUserTransaction);
	}
	}

	TEST(BinderStability, VintfStabilityServerMustBeDeclaredInManifest) {
	sp<IBinder> vintfServer = BadStableBinder::vintf();

	for (const char* instance8 : {
	".", "/", "/.", "a.d.IFoo", "foo", "a.d.IFoo/foo"
	}) {
	String16 instance (instance8);

	EXPECT_EQ(Status::EX_ILLEGAL_ARGUMENT,
	android::defaultServiceManager()->addService(String16("."), vintfServer)) << instance8;
	EXPECT_FALSE(android::defaultServiceManager()->isDeclared(instance)) << instance8;
	EXPECT_EQ(std::nullopt, android::defaultServiceManager()->updatableViaApex(instance))
	<< instance8;
	}
	}

	TEST(BinderStability, ConnectionInfoRequiresManifestEntries) {
	sp<IServiceManager> sm = android::defaultServiceManager();
	sp<IBinder> systemBinder = BadStableBinder::system();
	EXPECT_EQ(OK, sm->addService(String16("no.connection.foo"), systemBinder));
	std::optional<android::IServiceManager::ConnectionInfo> connectionInfo;
	connectionInfo = sm->getConnectionInfo(String16("no.connection.foo"));
	EXPECT_EQ(connectionInfo, std::nullopt);
	}
	TEST(BinderStability, CantCallVendorBinderInSystemContext) {
	sp<IBinder> serverBinder = android::defaultServiceManager()->getService(kSystemStabilityServer);
	auto server = interface_cast<IBinderStabilityTest>(serverBinder);

	ASSERT_NE(nullptr, server.get());
	ASSERT_NE(nullptr, IInterface::asBinder(server)->remoteBinder());

	EXPECT_TRUE(server->sendBinder(BadStableBinder::undef()).isOk());
	EXPECT_TRUE(server->sendBinder(BadStableBinder::system()).isOk());
	EXPECT_TRUE(server->sendBinder(BadStableBinder::vintf()).isOk());
	EXPECT_TRUE(server->sendBinder(BadStableBinder::vendor()).isOk());

	{
	sp<BadStableBinder> binder = BadStableBinder::undef();
	EXPECT_TRUE(server->sendAndCallBinder(binder).isOk());
	EXPECT_TRUE(binder->gotUserTransaction);
	}
	{
	sp<BadStableBinder> binder = BadStableBinder::system();
	EXPECT_TRUE(server->sendAndCallBinder(binder).isOk());
	EXPECT_TRUE(binder->gotUserTransaction);
	}
	{
	sp<BadStableBinder> binder = BadStableBinder::vintf();
	EXPECT_TRUE(server->sendAndCallBinder(binder).isOk());
	EXPECT_TRUE(binder->gotUserTransaction);
	}
	{
	// !!! user-defined transaction may not be stable for remote server !!!
	// !!! so, it does not work !!!
	sp<BadStableBinder> binder = BadStableBinder::vendor();
	EXPECT_EQ(BAD_TYPE, server->sendAndCallBinder(binder).exceptionCode());
	EXPECT_FALSE(binder->gotUserTransaction);
	}

	sp<IBinder> out;
	EXPECT_TRUE(server->returnNoStabilityBinder(&out).isOk());
	ASSERT_NE(nullptr, out.get());
	EXPECT_EQ(OK, out->pingBinder());
	EXPECT_EQ(OK, BadStableBinder::doUserTransaction(out));

	EXPECT_TRUE(server->returnLocalStabilityBinder(&out).isOk());
	ASSERT_NE(nullptr, out.get());
	EXPECT_EQ(OK, out->pingBinder());
	EXPECT_EQ(OK, BadStableBinder::doUserTransaction(out));

	EXPECT_TRUE(server->returnVintfStabilityBinder(&out).isOk());
	ASSERT_NE(nullptr, out.get());
	EXPECT_EQ(OK, out->pingBinder());
	EXPECT_EQ(OK, BadStableBinder::doUserTransaction(out));

	EXPECT_TRUE(server->returnVendorStabilityBinder(&out).isOk());
	ASSERT_NE(nullptr, out.get());

	// !!! libbinder-defined transaction works !!!
	EXPECT_EQ(OK, out->pingBinder());

	// !!! user-defined transaction may not be stable !!!
	// !!! so, it does not work !!!
	EXPECT_EQ(BAD_TYPE, BadStableBinder::doUserTransaction(out));
	}

	// This is handwritten so that we can test different stability levels w/o having the AIDL
	// compiler assign them. Hand-writing binder interfaces is considered a bad practice
	// sanity reasons. YOU SHOULD DEFINE AN AIDL INTERFACE INSTEAD!

	struct NdkBinderStable_DataClass {
	bool gotUserTransaction = false;
	};
	void* NdkBadStableBinder_Class_onCreate(void* args) {
	LOG_ALWAYS_FATAL_IF(args != nullptr, "Takes no args");
	return static_cast<void*>(new NdkBinderStable_DataClass);
	}
	void NdkBadStableBinder_Class_onDestroy(void* userData) {
	delete static_cast<NdkBinderStable_DataClass*>(userData);
	}
	NdkBinderStable_DataClass* NdkBadStableBinder_getUserData(AIBinder* binder) {
	LOG_ALWAYS_FATAL_IF(binder == nullptr);
	void* userData = AIBinder_getUserData(binder);
	LOG_ALWAYS_FATAL_IF(userData == nullptr, "null data - binder is remote?");

	return static_cast<NdkBinderStable_DataClass*>(userData);
	}
	binder_status_t NdkBadStableBinder_Class_onTransact(
	AIBinder* binder, transaction_code_t code, const AParcel* /in/, AParcel* /out/) {

	if (code == BadStableBinder::USER_TRANSACTION) {
	ALOGE("ndk binder stability: Got user transaction");
	NdkBadStableBinder_getUserData(binder)->gotUserTransaction = true;
	return STATUS_OK;
	}

	return STATUS_UNKNOWN_TRANSACTION;
	}

	static AIBinder_Class* kNdkBadStableBinder =
	AIBinder_Class_define(String8(BadStableBinder::kDescriptor).c_str(),
	NdkBadStableBinder_Class_onCreate,
	NdkBadStableBinder_Class_onDestroy,
	NdkBadStableBinder_Class_onTransact);

	// for testing only to get around __ANDROID_VNDK__ guard.
	extern "C" void AIBinder_markVendorStability(AIBinder* binder); // <- BAD DO NOT COPY

	TEST(BinderStability, NdkCantCallVendorBinderInSystemContext) {
	SpAIBinder binder = SpAIBinder(AServiceManager_getService(
	String8(kSystemStabilityServer).c_str()));

	std::shared_ptr<aidl::IBinderStabilityTest> remoteServer =
	aidl::IBinderStabilityTest::fromBinder(binder);

	ASSERT_NE(nullptr, remoteServer.get());

	SpAIBinder comp = SpAIBinder(AIBinder_new(kNdkBadStableBinder, nullptr /args/));
	EXPECT_TRUE(remoteServer->sendBinder(comp).isOk());
	EXPECT_TRUE(remoteServer->sendAndCallBinder(comp).isOk());
	EXPECT_TRUE(NdkBadStableBinder_getUserData(comp.get())->gotUserTransaction);

	SpAIBinder vendor = SpAIBinder(AIBinder_new(kNdkBadStableBinder, nullptr /args/));
	AIBinder_markVendorStability(vendor.get());
	EXPECT_TRUE(remoteServer->sendBinder(vendor).isOk());
	EXPECT_FALSE(remoteServer->sendAndCallBinder(vendor).isOk());
	EXPECT_FALSE(NdkBadStableBinder_getUserData(vendor.get())->gotUserTransaction);
	}

	class MarksStabilityInConstructor : public BBinder {
	public:
	static bool gDestructed;

	MarksStabilityInConstructor() {
	Stability::markCompilationUnit(this);
	}
	~MarksStabilityInConstructor() {
	gDestructed = true;
	}
	};
	bool MarksStabilityInConstructor::gDestructed = false;

	TEST(BinderStability, MarkingObjectNoDestructTest) {
	ASSERT_FALSE(MarksStabilityInConstructor::gDestructed);

	// best practice is to put this directly in an sp, but for this test, we
	// want to explicitly check what happens before that happens
	MarksStabilityInConstructor* binder = new MarksStabilityInConstructor();
	ASSERT_FALSE(MarksStabilityInConstructor::gDestructed);

	sp<MarksStabilityInConstructor> binderSp = binder;
	ASSERT_FALSE(MarksStabilityInConstructor::gDestructed);

	binderSp = nullptr;
	ASSERT_TRUE(MarksStabilityInConstructor::gDestructed);
	}

	TEST(BinderStability, RemarkDies) {
	ASSERT_DEATH({
	sp<IBinder> binder = new BBinder();
	Stability::markCompilationUnit(binder.get()); // <-- only called for tests
	Stability::markVndk(binder.get()); // <-- only called for tests
	}, "Should only mark known object.");
	}

	int main(int argc, char** argv) {
	::testing::InitGoogleTest(&argc, argv);

	if (fork() == 0) {
	// child process
	prctl(PR_SET_PDEATHSIG, SIGHUP);

	sp<IBinder> server = new MyBinderStabilityTest;
	android::defaultServiceManager()->addService(kSystemStabilityServer, server);

	IPCThreadState::self()->joinThreadPool(true);
	exit(1); // should not reach
	}

	// This is not racey. Just giving these services some time to register before we call
	// getService which sleeps for much longer...
	usleep(10000);

	return RUN_ALL_TESTS();
	}