src/messaging/tests/MessagingContext.h - third_party/github/project-chip/connectedhomeip - Git at Google

 /*
  *
  *    Copyright (c) 2021 Project CHIP Authors
  *
  *    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.
  */
 #pragma once

 #include <credentials/PersistentStorageOpCertStore.h>
 #include <crypto/DefaultSessionKeystore.h>
 #include <crypto/PersistentStorageOperationalKeystore.h>
 #include <lib/core/CASEAuthTag.h>
 #include <lib/support/TestPersistentStorageDelegate.h>
 #include <messaging/ExchangeContext.h>
 #include <messaging/ExchangeMgr.h>
 #include <protocols/secure_channel/MessageCounterManager.h>
 #include <protocols/secure_channel/PASESession.h>
 #include <system/SystemClock.h>
 #include <transport/SessionManager.h>
 #include <transport/TransportMgr.h>
 #include <transport/tests/LoopbackTransportManager.h>
 #include <transport/tests/UDPTransportManager.h>

 #include <nlunit-test.h>

 #include <vector>

 namespace chip {
 namespace Test {

 /**
  * @brief
  *  Test contexts that use Platform::Memory and might call Free() on destruction can inherit from this class and call its Init().
  *  Platform::MemoryShutdown() will then be called after the subclasses' destructor.
  */
 class PlatformMemoryUser
 {
 public:
     PlatformMemoryUser() : mInitialized(false) {}
     ~PlatformMemoryUser()
     {
         if (mInitialized)
         {
             chip::Platform::MemoryShutdown();
         }
     }
     CHIP_ERROR Init()
     {
         CHIP_ERROR status = CHIP_NO_ERROR;
         if (!mInitialized)
         {
             status       = chip::Platform::MemoryInit();
             mInitialized = (status == CHIP_NO_ERROR);
         }
         return status;
     }

 private:
     bool mInitialized;
 };

 /**
  * @brief The context of test cases for messaging layer. It will initialize network layer and system layer, and create
  *        two secure sessions, connected with each other. Exchanges can be created for each secure session.
  */
 class MessagingContext : public PlatformMemoryUser
 {
 public:
     enum MRPMode
     {
         kDefault = 1, // This adopts the default MRP values for idle/active as per the spec.
                       //      i.e IDLE = 500ms, ACTIVE = 300ms

         kResponsive = 2, // This adopts values that are better suited for loopback tests that
                          // don't actually go over a network interface, and are tuned much lower
                          // to permit more responsive tests.
                          //      i.e IDLE = 10ms, ACTIVE = 10ms
     };

     //
     // See above for a description of the values used.
     //
     static constexpr System::Clock::Timeout kResponsiveIdleRetransTimeout   = System::Clock::Milliseconds32(10);
     static constexpr System::Clock::Timeout kResponsiveActiveRetransTimeout = System::Clock::Milliseconds32(10);

     MessagingContext() :
         mInitialized(false), mAliceAddress(Transport::PeerAddress::UDP(GetAddress(), CHIP_PORT + 1)),
         mBobAddress(Transport::PeerAddress::UDP(GetAddress(), CHIP_PORT))
     {}
     ~MessagingContext() { VerifyOrDie(mInitialized == false); }

     // Whether Alice and Bob are initialized, must be called before Init
     void ConfigInitializeNodes(bool initializeNodes) { mInitializeNodes = initializeNodes; }

     /// Initialize the underlying layers and test suite pointer
     CHIP_ERROR Init(TransportMgrBase * transport, IOContext * io);

     // Shutdown all layers, finalize operations
     void Shutdown();

     // Initialize from an existing messaging context.  Useful if we want to
     // share some state (like the transport).
     CHIP_ERROR InitFromExisting(const MessagingContext & existing);

     // The shutdown method to use if using InitFromExisting.  Must pass in the
     // same existing context as was passed to InitFromExisting.
     void ShutdownAndRestoreExisting(MessagingContext & existing);

     static Inet::IPAddress GetAddress()
     {
         Inet::IPAddress addr;
         Inet::IPAddress::FromString("::1", addr);
         return addr;
     }

     static const uint16_t kBobKeyId     = 1;
     static const uint16_t kAliceKeyId   = 2;
     static const uint16_t kCharlieKeyId = 3;
     static const uint16_t kDavidKeyId   = 4;
     GroupId GetFriendsGroupId() const { return mFriendsGroupId; }

     SessionManager & GetSecureSessionManager() { return mSessionManager; }
     Messaging::ExchangeManager & GetExchangeManager() { return mExchangeManager; }
     secure_channel::MessageCounterManager & GetMessageCounterManager() { return mMessageCounterManager; }
     FabricTable & GetFabricTable() { return mFabricTable; }
     Crypto::DefaultSessionKeystore & GetSessionKeystore() { return mSessionKeystore; }

     FabricIndex GetAliceFabricIndex() { return mAliceFabricIndex; }
     FabricIndex GetBobFabricIndex() { return mBobFabricIndex; }
     const FabricInfo * GetAliceFabric() { return mFabricTable.FindFabricWithIndex(mAliceFabricIndex); }
     const FabricInfo * GetBobFabric() { return mFabricTable.FindFabricWithIndex(mBobFabricIndex); }

     CHIP_ERROR CreateSessionBobToAlice(); // Creates PASE session
     CHIP_ERROR CreateCASESessionBobToAlice();
     CHIP_ERROR CreateCASESessionBobToAlice(const CATValues & cats);
     CHIP_ERROR CreateSessionAliceToBob(); // Creates PASE session
     CHIP_ERROR CreateCASESessionAliceToBob();
     CHIP_ERROR CreateCASESessionAliceToBob(const CATValues & cats);
     CHIP_ERROR CreateSessionBobToFriends(); // Creates PASE session
     CHIP_ERROR CreatePASESessionCharlieToDavid();
     CHIP_ERROR CreatePASESessionDavidToCharlie();

     void ExpireSessionBobToAlice();
     void ExpireSessionAliceToBob();
     void ExpireSessionBobToFriends();

     void SetMRPMode(MRPMode mode);

     SessionHandle GetSessionBobToAlice();
     SessionHandle GetSessionAliceToBob();
     SessionHandle GetSessionCharlieToDavid();
     SessionHandle GetSessionDavidToCharlie();
     SessionHandle GetSessionBobToFriends();

     CHIP_ERROR CreateAliceFabric();
     CHIP_ERROR CreateBobFabric();

     const Transport::PeerAddress & GetAliceAddress() { return mAliceAddress; }
     const Transport::PeerAddress & GetBobAddress() { return mBobAddress; }

     Messaging::ExchangeContext * NewUnauthenticatedExchangeToAlice(Messaging::ExchangeDelegate * delegate);
     Messaging::ExchangeContext * NewUnauthenticatedExchangeToBob(Messaging::ExchangeDelegate * delegate);

     Messaging::ExchangeContext * NewExchangeToAlice(Messaging::ExchangeDelegate * delegate, bool isInitiator = true);
     Messaging::ExchangeContext * NewExchangeToBob(Messaging::ExchangeDelegate * delegate, bool isInitiator = true);

     System::Layer & GetSystemLayer() { return mIOContext->GetSystemLayer(); }

 private:
     bool mInitializeNodes = true;
     bool mInitialized;
     FabricTable mFabricTable;

     SessionManager mSessionManager;
     Messaging::ExchangeManager mExchangeManager;
     secure_channel::MessageCounterManager mMessageCounterManager;
     IOContext * mIOContext;
     TransportMgrBase * mTransport;                // Only needed for InitFromExisting.
     chip::TestPersistentStorageDelegate mStorage; // for SessionManagerInit
     chip::PersistentStorageOperationalKeystore mOpKeyStore;
     chip::Credentials::PersistentStorageOpCertStore mOpCertStore;
     chip::Crypto::DefaultSessionKeystore mSessionKeystore;

     FabricIndex mAliceFabricIndex = kUndefinedFabricIndex;
     FabricIndex mBobFabricIndex   = kUndefinedFabricIndex;
     GroupId mFriendsGroupId       = 0x0101;
     Transport::PeerAddress mAliceAddress;
     Transport::PeerAddress mBobAddress;
     Transport::PeerAddress mCharlieAddress;
     Transport::PeerAddress mDavidAddress;
     SessionHolder mSessionAliceToBob;
     SessionHolder mSessionBobToAlice;
     SessionHolder mSessionCharlieToDavid;
     SessionHolder mSessionDavidToCharlie;
     Optional<Transport::OutgoingGroupSession> mSessionBobToFriends;
 };

 // LoopbackMessagingContext enriches MessagingContext with an async loopback transport
 class LoopbackMessagingContext : public LoopbackTransportManager, public MessagingContext
 {
 public:
     virtual ~LoopbackMessagingContext() {}

     // Performs shared setup for all tests in the test suite
     virtual CHIP_ERROR SetUpTestSuite()
     {
         CHIP_ERROR err = CHIP_NO_ERROR;
         VerifyOrExit((err = chip::Platform::MemoryInit()) == CHIP_NO_ERROR,
                      ChipLogError(AppServer, "Init CHIP memory failed: %" CHIP_ERROR_FORMAT, err.Format()));
         VerifyOrExit((err = LoopbackTransportManager::Init()) == CHIP_NO_ERROR,
                      ChipLogError(AppServer, "Init LoopbackTransportManager failed: %" CHIP_ERROR_FORMAT, err.Format()));
     exit:
         return err;
     }

     // Performs shared teardown for all tests in the test suite
     virtual void TearDownTestSuite()
     {
         LoopbackTransportManager::Shutdown();
         chip::Platform::MemoryShutdown();
     }

     // Performs setup for each individual test in the test suite
     virtual CHIP_ERROR SetUp()
     {
         CHIP_ERROR err = CHIP_NO_ERROR;
         VerifyOrExit((err = MessagingContext::Init(&GetTransportMgr(), &GetIOContext())) == CHIP_NO_ERROR,
                      ChipLogError(AppServer, "Init MessagingContext failed: %" CHIP_ERROR_FORMAT, err.Format()));
     exit:
         return err;
     }

     // Performs teardown for each individual test in the test suite
     virtual void TearDown() { MessagingContext::Shutdown(); }

     // Helpers that can be used directly by the nlTestSuite

     static int nlTestSetUpTestSuite(void * context)
     {
         auto err = static_cast<LoopbackMessagingContext *>(context)->SetUpTestSuite();
         return err == CHIP_NO_ERROR ? SUCCESS : FAILURE;
     }

     static int nlTestTearDownTestSuite(void * context)
     {
         static_cast<LoopbackMessagingContext *>(context)->TearDownTestSuite();
         return SUCCESS;
     }

     static int nlTestSetUp(void * context)
     {
         auto err = static_cast<LoopbackMessagingContext *>(context)->SetUp();
         return err == CHIP_NO_ERROR ? SUCCESS : FAILURE;
     }

     static int nlTestTearDown(void * context)
     {
         static_cast<LoopbackMessagingContext *>(context)->TearDown();
         return SUCCESS;
     }

     using LoopbackTransportManager::GetSystemLayer;
 };

 // UDPMessagingContext enriches MessagingContext with an UDP transport
 class UDPMessagingContext : public UDPTransportManager, public MessagingContext
 {
 public:
     virtual ~UDPMessagingContext() {}

     // Performs shared setup for all tests in the test suite
     virtual CHIP_ERROR SetUpTestSuite()
     {
         CHIP_ERROR err = CHIP_NO_ERROR;
         VerifyOrExit((err = chip::Platform::MemoryInit()) == CHIP_NO_ERROR,
                      ChipLogError(AppServer, "Init CHIP memory failed: %" CHIP_ERROR_FORMAT, err.Format()));
         VerifyOrExit((err = UDPTransportManager::Init()) == CHIP_NO_ERROR,
                      ChipLogError(AppServer, "Init UDPTransportManager failed: %" CHIP_ERROR_FORMAT, err.Format()));
     exit:
         return err;
     }

     // Performs shared teardown for all tests in the test suite
     virtual void TearDownTestSuite()
     {
         UDPTransportManager::Shutdown();
         chip::Platform::MemoryShutdown();
     }

     // Performs setup for each individual test in the test suite
     virtual CHIP_ERROR SetUp()
     {
         CHIP_ERROR err = CHIP_NO_ERROR;
         VerifyOrExit((err = MessagingContext::Init(&GetTransportMgr(), &GetIOContext())) == CHIP_NO_ERROR,
                      ChipLogError(AppServer, "Init MessagingContext failed: %" CHIP_ERROR_FORMAT, err.Format()));
     exit:
         return err;
     }

     // Performs teardown for each individual test in the test suite
     virtual void TearDown() { MessagingContext::Shutdown(); }

     // Helpers that can be used directly by the nlTestSuite

     static int nlTestSetUpTestSuite(void * context)
     {
         auto err = static_cast<UDPMessagingContext *>(context)->SetUpTestSuite();
         return err == CHIP_NO_ERROR ? SUCCESS : FAILURE;
     }

     static int nlTestTearDownTestSuite(void * context)
     {
         static_cast<UDPMessagingContext *>(context)->TearDownTestSuite();
         return SUCCESS;
     }

     static int nlTestSetUp(void * context)
     {
         auto err = static_cast<UDPMessagingContext *>(context)->SetUp();
         return err == CHIP_NO_ERROR ? SUCCESS : FAILURE;
     }

     static int nlTestTearDown(void * context)
     {
         static_cast<UDPMessagingContext *>(context)->TearDown();
         return SUCCESS;
     }

     using UDPTransportManager::GetSystemLayer;
 };

 // Class that can be used to capture decrypted message traffic in tests using
 // MessagingContext.
 class MessageCapturer : public SessionMessageDelegate
 {
 public:
     MessageCapturer(MessagingContext & aContext) :
         mSessionManager(aContext.GetSecureSessionManager()), mOriginalDelegate(aContext.GetExchangeManager())
     {
         // Interpose ourselves into the message flow.
         mSessionManager.SetMessageDelegate(this);
     }

     ~MessageCapturer()
     {
         // Restore the normal message flow.
         mSessionManager.SetMessageDelegate(&mOriginalDelegate);
     }

     struct Message
     {
         PacketHeader mPacketHeader;
         PayloadHeader mPayloadHeader;
         DuplicateMessage mIsDuplicate;
         System::PacketBufferHandle mPayload;
     };

     size_t MessageCount() const { return mCapturedMessages.size(); }

     template <typename MessageType, typename = std::enable_if_t<std::is_enum<MessageType>::value>>
     bool IsMessageType(size_t index, MessageType type)
     {
         return mCapturedMessages[index].mPayloadHeader.HasMessageType(type);
     }

     System::PacketBufferHandle & MessagePayload(size_t index) { return mCapturedMessages[index].mPayload; }

     bool mCaptureStandaloneAcks = true;

 private:
     // SessionMessageDelegate implementation.
     void OnMessageReceived(const PacketHeader & packetHeader, const PayloadHeader & payloadHeader, const SessionHandle & session,
                            DuplicateMessage isDuplicate, System::PacketBufferHandle && msgBuf) override;

     SessionManager & mSessionManager;
     SessionMessageDelegate & mOriginalDelegate;
     std::vector<Message> mCapturedMessages;
 };

 } // namespace Test
 } // namespace chip
	/*
	*
	* Copyright (c) 2021 Project CHIP Authors
	*
	* 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.
	*/
	#pragma once

	#include <credentials/PersistentStorageOpCertStore.h>
	#include <crypto/DefaultSessionKeystore.h>
	#include <crypto/PersistentStorageOperationalKeystore.h>
	#include <lib/core/CASEAuthTag.h>
	#include <lib/support/TestPersistentStorageDelegate.h>
	#include <messaging/ExchangeContext.h>
	#include <messaging/ExchangeMgr.h>
	#include <protocols/secure_channel/MessageCounterManager.h>
	#include <protocols/secure_channel/PASESession.h>
	#include <system/SystemClock.h>
	#include <transport/SessionManager.h>
	#include <transport/TransportMgr.h>
	#include <transport/tests/LoopbackTransportManager.h>
	#include <transport/tests/UDPTransportManager.h>

	#include <nlunit-test.h>

	#include <vector>

	namespace chip {
	namespace Test {

	/**
	* @brief
	* Test contexts that use Platform::Memory and might call Free() on destruction can inherit from this class and call its Init().
	* Platform::MemoryShutdown() will then be called after the subclasses' destructor.
	*/
	class PlatformMemoryUser
	{
	public:
	PlatformMemoryUser() : mInitialized(false) {}
	~PlatformMemoryUser()
	{
	if (mInitialized)
	{
	chip::Platform::MemoryShutdown();
	}
	}
	CHIP_ERROR Init()
	{
	CHIP_ERROR status = CHIP_NO_ERROR;
	if (!mInitialized)
	{
	status = chip::Platform::MemoryInit();
	mInitialized = (status == CHIP_NO_ERROR);
	}
	return status;
	}

	private:
	bool mInitialized;
	};

	/**
	* @brief The context of test cases for messaging layer. It will initialize network layer and system layer, and create
	* two secure sessions, connected with each other. Exchanges can be created for each secure session.
	*/
	class MessagingContext : public PlatformMemoryUser
	{
	public:
	enum MRPMode
	{
	kDefault = 1, // This adopts the default MRP values for idle/active as per the spec.
	// i.e IDLE = 500ms, ACTIVE = 300ms

	kResponsive = 2, // This adopts values that are better suited for loopback tests that
	// don't actually go over a network interface, and are tuned much lower
	// to permit more responsive tests.
	// i.e IDLE = 10ms, ACTIVE = 10ms
	};

	//
	// See above for a description of the values used.
	//
	static constexpr System::Clock::Timeout kResponsiveIdleRetransTimeout = System::Clock::Milliseconds32(10);
	static constexpr System::Clock::Timeout kResponsiveActiveRetransTimeout = System::Clock::Milliseconds32(10);

	MessagingContext() :
	mInitialized(false), mAliceAddress(Transport::PeerAddress::UDP(GetAddress(), CHIP_PORT + 1)),
	mBobAddress(Transport::PeerAddress::UDP(GetAddress(), CHIP_PORT))
	{}
	~MessagingContext() { VerifyOrDie(mInitialized == false); }

	// Whether Alice and Bob are initialized, must be called before Init
	void ConfigInitializeNodes(bool initializeNodes) { mInitializeNodes = initializeNodes; }

	/// Initialize the underlying layers and test suite pointer
	CHIP_ERROR Init(TransportMgrBase * transport, IOContext * io);

	// Shutdown all layers, finalize operations
	void Shutdown();

	// Initialize from an existing messaging context. Useful if we want to
	// share some state (like the transport).
	CHIP_ERROR InitFromExisting(const MessagingContext & existing);

	// The shutdown method to use if using InitFromExisting. Must pass in the
	// same existing context as was passed to InitFromExisting.
	void ShutdownAndRestoreExisting(MessagingContext & existing);

	static Inet::IPAddress GetAddress()
	{
	Inet::IPAddress addr;
	Inet::IPAddress::FromString("::1", addr);
	return addr;
	}

	static const uint16_t kBobKeyId = 1;
	static const uint16_t kAliceKeyId = 2;
	static const uint16_t kCharlieKeyId = 3;
	static const uint16_t kDavidKeyId = 4;
	GroupId GetFriendsGroupId() const { return mFriendsGroupId; }

	SessionManager & GetSecureSessionManager() { return mSessionManager; }
	Messaging::ExchangeManager & GetExchangeManager() { return mExchangeManager; }
	secure_channel::MessageCounterManager & GetMessageCounterManager() { return mMessageCounterManager; }
	FabricTable & GetFabricTable() { return mFabricTable; }
	Crypto::DefaultSessionKeystore & GetSessionKeystore() { return mSessionKeystore; }

	FabricIndex GetAliceFabricIndex() { return mAliceFabricIndex; }
	FabricIndex GetBobFabricIndex() { return mBobFabricIndex; }
	const FabricInfo * GetAliceFabric() { return mFabricTable.FindFabricWithIndex(mAliceFabricIndex); }
	const FabricInfo * GetBobFabric() { return mFabricTable.FindFabricWithIndex(mBobFabricIndex); }

	CHIP_ERROR CreateSessionBobToAlice(); // Creates PASE session
	CHIP_ERROR CreateCASESessionBobToAlice();
	CHIP_ERROR CreateCASESessionBobToAlice(const CATValues & cats);
	CHIP_ERROR CreateSessionAliceToBob(); // Creates PASE session
	CHIP_ERROR CreateCASESessionAliceToBob();
	CHIP_ERROR CreateCASESessionAliceToBob(const CATValues & cats);
	CHIP_ERROR CreateSessionBobToFriends(); // Creates PASE session
	CHIP_ERROR CreatePASESessionCharlieToDavid();
	CHIP_ERROR CreatePASESessionDavidToCharlie();

	void ExpireSessionBobToAlice();
	void ExpireSessionAliceToBob();
	void ExpireSessionBobToFriends();

	void SetMRPMode(MRPMode mode);

	SessionHandle GetSessionBobToAlice();
	SessionHandle GetSessionAliceToBob();
	SessionHandle GetSessionCharlieToDavid();
	SessionHandle GetSessionDavidToCharlie();
	SessionHandle GetSessionBobToFriends();

	CHIP_ERROR CreateAliceFabric();
	CHIP_ERROR CreateBobFabric();

	const Transport::PeerAddress & GetAliceAddress() { return mAliceAddress; }
	const Transport::PeerAddress & GetBobAddress() { return mBobAddress; }

	Messaging::ExchangeContext * NewUnauthenticatedExchangeToAlice(Messaging::ExchangeDelegate * delegate);
	Messaging::ExchangeContext * NewUnauthenticatedExchangeToBob(Messaging::ExchangeDelegate * delegate);

	Messaging::ExchangeContext * NewExchangeToAlice(Messaging::ExchangeDelegate * delegate, bool isInitiator = true);
	Messaging::ExchangeContext * NewExchangeToBob(Messaging::ExchangeDelegate * delegate, bool isInitiator = true);

	System::Layer & GetSystemLayer() { return mIOContext->GetSystemLayer(); }

	private:
	bool mInitializeNodes = true;
	bool mInitialized;
	FabricTable mFabricTable;

	SessionManager mSessionManager;
	Messaging::ExchangeManager mExchangeManager;
	secure_channel::MessageCounterManager mMessageCounterManager;
	IOContext * mIOContext;
	TransportMgrBase * mTransport; // Only needed for InitFromExisting.
	chip::TestPersistentStorageDelegate mStorage; // for SessionManagerInit
	chip::PersistentStorageOperationalKeystore mOpKeyStore;
	chip::Credentials::PersistentStorageOpCertStore mOpCertStore;
	chip::Crypto::DefaultSessionKeystore mSessionKeystore;

	FabricIndex mAliceFabricIndex = kUndefinedFabricIndex;
	FabricIndex mBobFabricIndex = kUndefinedFabricIndex;
	GroupId mFriendsGroupId = 0x0101;
	Transport::PeerAddress mAliceAddress;
	Transport::PeerAddress mBobAddress;
	Transport::PeerAddress mCharlieAddress;
	Transport::PeerAddress mDavidAddress;
	SessionHolder mSessionAliceToBob;
	SessionHolder mSessionBobToAlice;
	SessionHolder mSessionCharlieToDavid;
	SessionHolder mSessionDavidToCharlie;
	Optional<Transport::OutgoingGroupSession> mSessionBobToFriends;
	};

	// LoopbackMessagingContext enriches MessagingContext with an async loopback transport
	class LoopbackMessagingContext : public LoopbackTransportManager, public MessagingContext
	{
	public:
	virtual ~LoopbackMessagingContext() {}

	// Performs shared setup for all tests in the test suite
	virtual CHIP_ERROR SetUpTestSuite()
	{
	CHIP_ERROR err = CHIP_NO_ERROR;
	VerifyOrExit((err = chip::Platform::MemoryInit()) == CHIP_NO_ERROR,
	ChipLogError(AppServer, "Init CHIP memory failed: %" CHIP_ERROR_FORMAT, err.Format()));
	VerifyOrExit((err = LoopbackTransportManager::Init()) == CHIP_NO_ERROR,
	ChipLogError(AppServer, "Init LoopbackTransportManager failed: %" CHIP_ERROR_FORMAT, err.Format()));
	exit:
	return err;
	}

	// Performs shared teardown for all tests in the test suite
	virtual void TearDownTestSuite()
	{
	LoopbackTransportManager::Shutdown();
	chip::Platform::MemoryShutdown();
	}

	// Performs setup for each individual test in the test suite
	virtual CHIP_ERROR SetUp()
	{
	CHIP_ERROR err = CHIP_NO_ERROR;
	VerifyOrExit((err = MessagingContext::Init(&GetTransportMgr(), &GetIOContext())) == CHIP_NO_ERROR,
	ChipLogError(AppServer, "Init MessagingContext failed: %" CHIP_ERROR_FORMAT, err.Format()));
	exit:
	return err;
	}

	// Performs teardown for each individual test in the test suite
	virtual void TearDown() { MessagingContext::Shutdown(); }

	// Helpers that can be used directly by the nlTestSuite

	static int nlTestSetUpTestSuite(void * context)
	{
	auto err = static_cast<LoopbackMessagingContext *>(context)->SetUpTestSuite();
	return err == CHIP_NO_ERROR ? SUCCESS : FAILURE;
	}

	static int nlTestTearDownTestSuite(void * context)
	{
	static_cast<LoopbackMessagingContext *>(context)->TearDownTestSuite();
	return SUCCESS;
	}

	static int nlTestSetUp(void * context)
	{
	auto err = static_cast<LoopbackMessagingContext *>(context)->SetUp();
	return err == CHIP_NO_ERROR ? SUCCESS : FAILURE;
	}

	static int nlTestTearDown(void * context)
	{
	static_cast<LoopbackMessagingContext *>(context)->TearDown();
	return SUCCESS;
	}

	using LoopbackTransportManager::GetSystemLayer;
	};

	// UDPMessagingContext enriches MessagingContext with an UDP transport
	class UDPMessagingContext : public UDPTransportManager, public MessagingContext
	{
	public:
	virtual ~UDPMessagingContext() {}

	// Performs shared setup for all tests in the test suite
	virtual CHIP_ERROR SetUpTestSuite()
	{
	CHIP_ERROR err = CHIP_NO_ERROR;
	VerifyOrExit((err = chip::Platform::MemoryInit()) == CHIP_NO_ERROR,
	ChipLogError(AppServer, "Init CHIP memory failed: %" CHIP_ERROR_FORMAT, err.Format()));
	VerifyOrExit((err = UDPTransportManager::Init()) == CHIP_NO_ERROR,
	ChipLogError(AppServer, "Init UDPTransportManager failed: %" CHIP_ERROR_FORMAT, err.Format()));
	exit:
	return err;
	}

	// Performs shared teardown for all tests in the test suite
	virtual void TearDownTestSuite()
	{
	UDPTransportManager::Shutdown();
	chip::Platform::MemoryShutdown();
	}

	// Performs setup for each individual test in the test suite
	virtual CHIP_ERROR SetUp()
	{
	CHIP_ERROR err = CHIP_NO_ERROR;
	VerifyOrExit((err = MessagingContext::Init(&GetTransportMgr(), &GetIOContext())) == CHIP_NO_ERROR,
	ChipLogError(AppServer, "Init MessagingContext failed: %" CHIP_ERROR_FORMAT, err.Format()));
	exit:
	return err;
	}

	// Performs teardown for each individual test in the test suite
	virtual void TearDown() { MessagingContext::Shutdown(); }

	// Helpers that can be used directly by the nlTestSuite

	static int nlTestSetUpTestSuite(void * context)
	{
	auto err = static_cast<UDPMessagingContext *>(context)->SetUpTestSuite();
	return err == CHIP_NO_ERROR ? SUCCESS : FAILURE;
	}

	static int nlTestTearDownTestSuite(void * context)
	{
	static_cast<UDPMessagingContext *>(context)->TearDownTestSuite();
	return SUCCESS;
	}

	static int nlTestSetUp(void * context)
	{
	auto err = static_cast<UDPMessagingContext *>(context)->SetUp();
	return err == CHIP_NO_ERROR ? SUCCESS : FAILURE;
	}

	static int nlTestTearDown(void * context)
	{
	static_cast<UDPMessagingContext *>(context)->TearDown();
	return SUCCESS;
	}

	using UDPTransportManager::GetSystemLayer;
	};

	// Class that can be used to capture decrypted message traffic in tests using
	// MessagingContext.
	class MessageCapturer : public SessionMessageDelegate
	{
	public:
	MessageCapturer(MessagingContext & aContext) :
	mSessionManager(aContext.GetSecureSessionManager()), mOriginalDelegate(aContext.GetExchangeManager())
	{
	// Interpose ourselves into the message flow.
	mSessionManager.SetMessageDelegate(this);
	}

	~MessageCapturer()
	{
	// Restore the normal message flow.
	mSessionManager.SetMessageDelegate(&mOriginalDelegate);
	}

	struct Message
	{
	PacketHeader mPacketHeader;
	PayloadHeader mPayloadHeader;
	DuplicateMessage mIsDuplicate;
	System::PacketBufferHandle mPayload;
	};

	size_t MessageCount() const { return mCapturedMessages.size(); }

	template <typename MessageType, typename = std::enable_if_t<std::is_enum<MessageType>::value>>
	bool IsMessageType(size_t index, MessageType type)
	{
	return mCapturedMessages[index].mPayloadHeader.HasMessageType(type);
	}

	System::PacketBufferHandle & MessagePayload(size_t index) { return mCapturedMessages[index].mPayload; }

	bool mCaptureStandaloneAcks = true;

	private:
	// SessionMessageDelegate implementation.
	void OnMessageReceived(const PacketHeader & packetHeader, const PayloadHeader & payloadHeader, const SessionHandle & session,
	DuplicateMessage isDuplicate, System::PacketBufferHandle && msgBuf) override;

	SessionManager & mSessionManager;
	SessionMessageDelegate & mOriginalDelegate;
	std::vector<Message> mCapturedMessages;
	};

	} // namespace Test
	} // namespace chip