src/messaging/ExchangeContext.cpp - third_party/github/project-chip/connectedhomeip - Git at Google

 /*
  *
  *    Copyright (c) 2020 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.
  */

 /**
  *    @file
  *      This file implements the ExchangeContext class.
  *
  */
 #ifndef __STDC_FORMAT_MACROS
 #define __STDC_FORMAT_MACROS
 #endif

 #ifndef __STDC_LIMIT_MACROS
 #define __STDC_LIMIT_MACROS
 #endif

 #include <inttypes.h>
 #include <stdint.h>
 #include <stdlib.h>

 #include <core/CHIPCore.h>
 #include <core/CHIPEncoding.h>
 #include <messaging/ExchangeContext.h>
 #include <messaging/ExchangeMgr.h>
 #include <protocols/Protocols.h>
 #include <support/logging/CHIPLogging.h>
 #include <system/SystemTimer.h>

 using namespace chip::Encoding;
 using namespace chip::Inet;
 using namespace chip::System;

 namespace chip {

 static void DefaultOnMessageReceived(ExchangeContext * ec, const PacketHeader & packetHeader, uint32_t protocolId, uint8_t msgType,
                                      PacketBufferHandle payload)
 {
     ChipLogError(ExchangeManager, "Dropping unexpected message %08" PRIX32 ":%d %04" PRIX16 " MsgId:%08" PRIX32, protocolId,
                  msgType, ec->GetExchangeId(), packetHeader.GetMessageId());
 }

 bool ExchangeContext::IsInitiator() const
 {
     return mFlags.Has(ExFlagValues::kFlagInitiator);
 }

 bool ExchangeContext::IsResponseExpected() const
 {
     return mFlags.Has(ExFlagValues::kFlagResponseExpected);
 }

 void ExchangeContext::SetResponseExpected(bool inResponseExpected)
 {
     mFlags.Set(ExFlagValues::kFlagResponseExpected, inResponseExpected);
 }

 CHIP_ERROR ExchangeContext::SendMessage(uint16_t protocolId, uint8_t msgType, PacketBuffer * msgBuf, uint16_t sendFlags,
                                         void * msgCtxt)
 {
     CHIP_ERROR err = CHIP_NO_ERROR;
     PayloadHeader payloadHeader;

     // Don't let method get called on a freed object.
     VerifyOrDie(mExchangeMgr != nullptr && GetReferenceCount() > 0);

     // we hold the exchange context here in case the entity that
     // originally generated it tries to close it as a result of
     // an error arising below. at the end, we have to close it.
     Retain();

     // Set the exchange ID for this header.
     payloadHeader.SetExchangeID(mExchangeId);

     // Set the protocol ID for this header.
     payloadHeader.SetProtocolID(protocolId);

     // Set the message type for this header.
     payloadHeader.SetMessageType(msgType);

     // If a response message is expected...
     if ((sendFlags & kSendFlag_ExpectResponse) != 0)
     {
         // Only one 'response expected' message can be outstanding at a time.
         VerifyOrExit(!IsResponseExpected(), err = CHIP_ERROR_INCORRECT_STATE);

         SetResponseExpected(true);

         // Arm the response timer if a timeout has been specified.
         if (mResponseTimeout > 0)
         {
             err = StartResponseTimer();
             SuccessOrExit(err);
         }
     }

     payloadHeader.SetInitiator(IsInitiator());

     err    = mExchangeMgr->GetSessionMgr()->SendMessage(payloadHeader, mPeerNodeId, msgBuf);
     msgBuf = nullptr;
     SuccessOrExit(err);

 exit:
     if (err != CHIP_NO_ERROR && IsResponseExpected())
     {
         CancelResponseTimer();
         SetResponseExpected(false);
     }
     if (msgBuf != nullptr && (sendFlags & kSendFlag_RetainBuffer) == 0)
     {
         PacketBuffer::Free(msgBuf);
     }

     // Release the reference to the exchange context acquired above. Under normal circumstances
     // this will merely decrement the reference count, without actually freeing the exchange context.
     // However if one of the function calls in this method resulted in a callback to the protocol,
     // the protocol may have released its reference, resulting in the exchange context actually
     // being freed here.
     Release();

     return err;
 }

 void ExchangeContext::DoClose(bool clearRetransTable)
 {
     // Clear protocol callbacks
     if (mDelegate != nullptr)
     {
         mDelegate->OnExchangeClosing(this);
     }
     mDelegate = nullptr;

     // Cancel the response timer.
     CancelResponseTimer();
 }

 /**
  *  Gracefully close an exchange context. This call decrements the
  *  reference count and releases the exchange when the reference
  *  count goes to zero.
  *
  */
 void ExchangeContext::Close()
 {
     VerifyOrDie(mExchangeMgr != nullptr && GetReferenceCount() > 0);

 #if defined(CHIP_EXCHANGE_CONTEXT_DETAIL_LOGGING)
     ChipLogProgress(ExchangeManager, "ec id: %d [%04" PRIX16 "], %s", (this - mExchangeMgr->ContextPool + 1), mExchangeId,
                     __func__);
 #endif

     DoClose(false);
     Release();
 }
 /**
  *  Abort the Exchange context immediately and release all
  *  references to it.
  *
  */
 void ExchangeContext::Abort()
 {
     VerifyOrDie(mExchangeMgr != nullptr && GetReferenceCount() > 0);

 #if defined(CHIP_EXCHANGE_CONTEXT_DETAIL_LOGGING)
     ChipLogProgress(ExchangeManager, "ec id: %d [%04" PRIX16 "], %s", (this - mExchangeMgr->ContextPool + 1), mExchangeId,
                     __func__);
 #endif

     DoClose(true);
     Release();
 }

 void ExchangeContext::Reset()
 {
     *this = ExchangeContext();
 }

 ExchangeContext * ExchangeContext::Alloc(ExchangeManager * em, uint16_t ExchangeId, uint64_t PeerNodeId, bool Initiator,
                                          ExchangeDelegate * delegate)
 {
     VerifyOrDie(delegate != nullptr);
     VerifyOrDie(mExchangeMgr == nullptr && GetReferenceCount() == 0);

     Reset();
     Retain();
     mExchangeMgr = em;
     em->IncrementContextsInUse();
     mExchangeId = ExchangeId;
     mPeerNodeId = PeerNodeId;
     mFlags.Set(ExFlagValues::kFlagInitiator, Initiator);
     mDelegate = delegate;

 #if defined(CHIP_EXCHANGE_CONTEXT_DETAIL_LOGGING)
     ChipLogProgress(ExchangeManager, "ec++ id: %d, inUse: %d, addr: 0x%x", (this - em->ContextPool + 1), em->GetContextsInUse(),
                     this);
 #endif
     SYSTEM_STATS_INCREMENT(chip::System::Stats::kExchangeMgr_NumContexts);

     return this;
 }

 void ExchangeContext::Free()
 {
     VerifyOrDie(mExchangeMgr != nullptr && GetReferenceCount() == 0);

     // Ideally, in this scenario, the retransmit table should
     // be clear of any outstanding messages for this context and
     // the boolean parameter passed to DoClose() should not matter.
     ExchangeManager * em = mExchangeMgr;

     DoClose(false);
     mExchangeMgr = nullptr;

     em->DecrementContextsInUse();

 #if defined(CHIP_EXCHANGE_CONTEXT_DETAIL_LOGGING)
     ChipLogProgress(ExchangeManager, "ec-- id: %d [%04" PRIX16 "], inUse: %d, addr: 0x%x", (this - em->ContextPool + 1),
                     mExchangeId, em->GetContextsInUse(), this);
 #endif
     SYSTEM_STATS_DECREMENT(chip::System::Stats::kExchangeMgr_NumContexts);
 }

 bool ExchangeContext::MatchExchange(const PacketHeader & packetHeader, const PayloadHeader & payloadHeader)
 {
     // A given message is part of a particular exchange if...
     return

         // The exchange identifier of the message matches the exchange identifier of the context.
         (mExchangeId == payloadHeader.GetExchangeID())

         // AND The message was received from the peer node associated with the exchange, or the peer node identifier is 'any'.
         && ((mPeerNodeId == kAnyNodeId) || (mPeerNodeId == packetHeader.GetSourceNodeId().Value()))

         // AND The message was sent by an initiator and the exchange context is a responder (IsInitiator==false)
         //    OR The message was sent by a responder and the exchange context is an initiator (IsInitiator==true) (for the broadcast
         //    case, the initiator is ill defined)

         && (payloadHeader.IsInitiator() != IsInitiator());
 }

 CHIP_ERROR ExchangeContext::StartResponseTimer()
 {
     System::Layer * lSystemLayer = mExchangeMgr->GetSessionMgr()->SystemLayer();
     if (lSystemLayer == nullptr)
     {
         // this is an assertion error, which shall never happen
         return CHIP_ERROR_INTERNAL;
     }

     return lSystemLayer->StartTimer(mResponseTimeout, HandleResponseTimeout, this);
 }

 void ExchangeContext::CancelResponseTimer()
 {
     System::Layer * lSystemLayer = mExchangeMgr->GetSessionMgr()->SystemLayer();
     if (lSystemLayer == nullptr)
     {
         // this is an assertion error, which shall never happen
         return;
     }

     lSystemLayer->CancelTimer(HandleResponseTimeout, this);
 }

 void ExchangeContext::HandleResponseTimeout(System::Layer * aSystemLayer, void * aAppState, System::Error aError)
 {
     ExchangeContext * ec = reinterpret_cast<ExchangeContext *>(aAppState);

     if (ec == nullptr)
         return;

     // NOTE: we don't set mResponseExpected to false here because the response could still arrive. If the user
     // wants to never receive the response, they must close the exchange context.

     ExchangeDelegate * delegate = ec->GetDelegate();

     // Call the user's timeout handler.
     if (delegate != nullptr)
         delegate->OnResponseTimeout(ec);
 }

 CHIP_ERROR ExchangeContext::HandleMessage(const PacketHeader & packetHeader, const PayloadHeader & payloadHeader,
                                           PacketBufferHandle msgBuf)
 {
     CHIP_ERROR err      = CHIP_NO_ERROR;
     uint16_t protocolId = 0;
     uint8_t messageType = 0;

     // We hold a reference to the ExchangeContext here to
     // guard against Close() calls(decrementing the reference
     // count) by the protocol before the CHIP Exchange
     // layer has completed its work on the ExchangeContext.
     Retain();

     protocolId  = payloadHeader.GetProtocolID();
     messageType = payloadHeader.GetMessageType();

     // Since we got the response, cancel the response timer.
     CancelResponseTimer();

     // If the context was expecting a response to a previously sent message, this message
     // is implicitly that response.
     SetResponseExpected(false);

     if (mDelegate != nullptr)
     {
         mDelegate->OnMessageReceived(this, packetHeader, protocolId, messageType, std::move(msgBuf));
     }
     else
     {
         DefaultOnMessageReceived(this, packetHeader, protocolId, messageType, std::move(msgBuf));
     }

     // Release the reference to the ExchangeContext that was held at the beginning of this function.
     // This call should also do the needful of closing the ExchangeContext if the protocol has
     // already made a prior call to Close().
     Release();

     return err;
 }

 } // namespace chip
	/*
	*
	* Copyright (c) 2020 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.
	*/

	/**
	* @file
	* This file implements the ExchangeContext class.
	*
	*/
	#ifndef __STDC_FORMAT_MACROS
	#define __STDC_FORMAT_MACROS
	#endif

	#ifndef __STDC_LIMIT_MACROS
	#define __STDC_LIMIT_MACROS
	#endif

	#include <inttypes.h>
	#include <stdint.h>
	#include <stdlib.h>

	#include <core/CHIPCore.h>
	#include <core/CHIPEncoding.h>
	#include <messaging/ExchangeContext.h>
	#include <messaging/ExchangeMgr.h>
	#include <protocols/Protocols.h>
	#include <support/logging/CHIPLogging.h>
	#include <system/SystemTimer.h>

	using namespace chip::Encoding;
	using namespace chip::Inet;
	using namespace chip::System;

	namespace chip {

	static void DefaultOnMessageReceived(ExchangeContext * ec, const PacketHeader & packetHeader, uint32_t protocolId, uint8_t msgType,
	PacketBufferHandle payload)
	{
	ChipLogError(ExchangeManager, "Dropping unexpected message %08" PRIX32 ":%d %04" PRIX16 " MsgId:%08" PRIX32, protocolId,
	msgType, ec->GetExchangeId(), packetHeader.GetMessageId());
	}

	bool ExchangeContext::IsInitiator() const
	{
	return mFlags.Has(ExFlagValues::kFlagInitiator);
	}

	bool ExchangeContext::IsResponseExpected() const
	{
	return mFlags.Has(ExFlagValues::kFlagResponseExpected);
	}

	void ExchangeContext::SetResponseExpected(bool inResponseExpected)
	{
	mFlags.Set(ExFlagValues::kFlagResponseExpected, inResponseExpected);
	}

	CHIP_ERROR ExchangeContext::SendMessage(uint16_t protocolId, uint8_t msgType, PacketBuffer * msgBuf, uint16_t sendFlags,
	void * msgCtxt)
	{
	CHIP_ERROR err = CHIP_NO_ERROR;
	PayloadHeader payloadHeader;

	// Don't let method get called on a freed object.
	VerifyOrDie(mExchangeMgr != nullptr && GetReferenceCount() > 0);

	// we hold the exchange context here in case the entity that
	// originally generated it tries to close it as a result of
	// an error arising below. at the end, we have to close it.
	Retain();

	// Set the exchange ID for this header.
	payloadHeader.SetExchangeID(mExchangeId);

	// Set the protocol ID for this header.
	payloadHeader.SetProtocolID(protocolId);

	// Set the message type for this header.
	payloadHeader.SetMessageType(msgType);

	// If a response message is expected...
	if ((sendFlags & kSendFlag_ExpectResponse) != 0)
	{
	// Only one 'response expected' message can be outstanding at a time.
	VerifyOrExit(!IsResponseExpected(), err = CHIP_ERROR_INCORRECT_STATE);

	SetResponseExpected(true);

	// Arm the response timer if a timeout has been specified.
	if (mResponseTimeout > 0)
	{
	err = StartResponseTimer();
	SuccessOrExit(err);
	}
	}

	payloadHeader.SetInitiator(IsInitiator());

	err = mExchangeMgr->GetSessionMgr()->SendMessage(payloadHeader, mPeerNodeId, msgBuf);
	msgBuf = nullptr;
	SuccessOrExit(err);

	exit:
	if (err != CHIP_NO_ERROR && IsResponseExpected())
	{
	CancelResponseTimer();
	SetResponseExpected(false);
	}
	if (msgBuf != nullptr && (sendFlags & kSendFlag_RetainBuffer) == 0)
	{
	PacketBuffer::Free(msgBuf);
	}

	// Release the reference to the exchange context acquired above. Under normal circumstances
	// this will merely decrement the reference count, without actually freeing the exchange context.
	// However if one of the function calls in this method resulted in a callback to the protocol,
	// the protocol may have released its reference, resulting in the exchange context actually
	// being freed here.
	Release();

	return err;
	}

	void ExchangeContext::DoClose(bool clearRetransTable)
	{
	// Clear protocol callbacks
	if (mDelegate != nullptr)
	{
	mDelegate->OnExchangeClosing(this);
	}
	mDelegate = nullptr;

	// Cancel the response timer.
	CancelResponseTimer();
	}

	/**
	* Gracefully close an exchange context. This call decrements the
	* reference count and releases the exchange when the reference
	* count goes to zero.
	*
	*/
	void ExchangeContext::Close()
	{
	VerifyOrDie(mExchangeMgr != nullptr && GetReferenceCount() > 0);

	#if defined(CHIP_EXCHANGE_CONTEXT_DETAIL_LOGGING)
	ChipLogProgress(ExchangeManager, "ec id: %d [%04" PRIX16 "], %s", (this - mExchangeMgr->ContextPool + 1), mExchangeId,
	__func__);
	#endif

	DoClose(false);
	Release();
	}
	/**
	* Abort the Exchange context immediately and release all
	* references to it.
	*
	*/
	void ExchangeContext::Abort()
	{
	VerifyOrDie(mExchangeMgr != nullptr && GetReferenceCount() > 0);

	#if defined(CHIP_EXCHANGE_CONTEXT_DETAIL_LOGGING)
	ChipLogProgress(ExchangeManager, "ec id: %d [%04" PRIX16 "], %s", (this - mExchangeMgr->ContextPool + 1), mExchangeId,
	__func__);
	#endif

	DoClose(true);
	Release();
	}

	void ExchangeContext::Reset()
	{
	*this = ExchangeContext();
	}

	ExchangeContext * ExchangeContext::Alloc(ExchangeManager * em, uint16_t ExchangeId, uint64_t PeerNodeId, bool Initiator,
	ExchangeDelegate * delegate)
	{
	VerifyOrDie(delegate != nullptr);
	VerifyOrDie(mExchangeMgr == nullptr && GetReferenceCount() == 0);

	Reset();
	Retain();
	mExchangeMgr = em;
	em->IncrementContextsInUse();
	mExchangeId = ExchangeId;
	mPeerNodeId = PeerNodeId;
	mFlags.Set(ExFlagValues::kFlagInitiator, Initiator);
	mDelegate = delegate;

	#if defined(CHIP_EXCHANGE_CONTEXT_DETAIL_LOGGING)
	ChipLogProgress(ExchangeManager, "ec++ id: %d, inUse: %d, addr: 0x%x", (this - em->ContextPool + 1), em->GetContextsInUse(),
	this);
	#endif
	SYSTEM_STATS_INCREMENT(chip::System::Stats::kExchangeMgr_NumContexts);

	return this;
	}

	void ExchangeContext::Free()
	{
	VerifyOrDie(mExchangeMgr != nullptr && GetReferenceCount() == 0);

	// Ideally, in this scenario, the retransmit table should
	// be clear of any outstanding messages for this context and
	// the boolean parameter passed to DoClose() should not matter.
	ExchangeManager * em = mExchangeMgr;

	DoClose(false);
	mExchangeMgr = nullptr;

	em->DecrementContextsInUse();

	#if defined(CHIP_EXCHANGE_CONTEXT_DETAIL_LOGGING)
	ChipLogProgress(ExchangeManager, "ec-- id: %d [%04" PRIX16 "], inUse: %d, addr: 0x%x", (this - em->ContextPool + 1),
	mExchangeId, em->GetContextsInUse(), this);
	#endif
	SYSTEM_STATS_DECREMENT(chip::System::Stats::kExchangeMgr_NumContexts);
	}

	bool ExchangeContext::MatchExchange(const PacketHeader & packetHeader, const PayloadHeader & payloadHeader)
	{
	// A given message is part of a particular exchange if...
	return

	// The exchange identifier of the message matches the exchange identifier of the context.
	(mExchangeId == payloadHeader.GetExchangeID())

	// AND The message was received from the peer node associated with the exchange, or the peer node identifier is 'any'.
	&& ((mPeerNodeId == kAnyNodeId) \|\| (mPeerNodeId == packetHeader.GetSourceNodeId().Value()))

	// AND The message was sent by an initiator and the exchange context is a responder (IsInitiator==false)
	// OR The message was sent by a responder and the exchange context is an initiator (IsInitiator==true) (for the broadcast
	// case, the initiator is ill defined)

	&& (payloadHeader.IsInitiator() != IsInitiator());
	}

	CHIP_ERROR ExchangeContext::StartResponseTimer()
	{
	System::Layer * lSystemLayer = mExchangeMgr->GetSessionMgr()->SystemLayer();
	if (lSystemLayer == nullptr)
	{
	// this is an assertion error, which shall never happen
	return CHIP_ERROR_INTERNAL;
	}

	return lSystemLayer->StartTimer(mResponseTimeout, HandleResponseTimeout, this);
	}

	void ExchangeContext::CancelResponseTimer()
	{
	System::Layer * lSystemLayer = mExchangeMgr->GetSessionMgr()->SystemLayer();
	if (lSystemLayer == nullptr)
	{
	// this is an assertion error, which shall never happen
	return;
	}

	lSystemLayer->CancelTimer(HandleResponseTimeout, this);
	}

	void ExchangeContext::HandleResponseTimeout(System::Layer * aSystemLayer, void * aAppState, System::Error aError)
	{
	ExchangeContext * ec = reinterpret_cast<ExchangeContext *>(aAppState);

	if (ec == nullptr)
	return;

	// NOTE: we don't set mResponseExpected to false here because the response could still arrive. If the user
	// wants to never receive the response, they must close the exchange context.

	ExchangeDelegate * delegate = ec->GetDelegate();

	// Call the user's timeout handler.
	if (delegate != nullptr)
	delegate->OnResponseTimeout(ec);
	}

	CHIP_ERROR ExchangeContext::HandleMessage(const PacketHeader & packetHeader, const PayloadHeader & payloadHeader,
	PacketBufferHandle msgBuf)
	{
	CHIP_ERROR err = CHIP_NO_ERROR;
	uint16_t protocolId = 0;
	uint8_t messageType = 0;

	// We hold a reference to the ExchangeContext here to
	// guard against Close() calls(decrementing the reference
	// count) by the protocol before the CHIP Exchange
	// layer has completed its work on the ExchangeContext.
	Retain();

	protocolId = payloadHeader.GetProtocolID();
	messageType = payloadHeader.GetMessageType();

	// Since we got the response, cancel the response timer.
	CancelResponseTimer();

	// If the context was expecting a response to a previously sent message, this message
	// is implicitly that response.
	SetResponseExpected(false);

	if (mDelegate != nullptr)
	{
	mDelegate->OnMessageReceived(this, packetHeader, protocolId, messageType, std::move(msgBuf));
	}
	else
	{
	DefaultOnMessageReceived(this, packetHeader, protocolId, messageType, std::move(msgBuf));
	}

	// Release the reference to the ExchangeContext that was held at the beginning of this function.
	// This call should also do the needful of closing the ExchangeContext if the protocol has
	// already made a prior call to Close().
	Release();

	return err;
	}

	} // namespace chip