Changes to CommandSender and CommandHandler for supporting commands (p…

…roject-chip#33889)

with large payloads.

src/app/CommandHandlerExchangeInterface.h

@@ -102,6 +102,18 @@ class CommandHandlerExchangeInterface
  * Called by CommandHandler to relay this information to the requester.
  */
  virtual void ResponseDropped() = 0;
+
+ /**
+ * @brief Gets the maximum size of a packet buffer to encode a Command
+ * Response message. This size depends on the underlying session used
+ * by the exchange.
+ *
+ * The size returned here is the size not including the prepended headers.
+ *
+ * Called by CommandHandler when allocating buffer for encoding the Command
+ * response.
+ */
+ virtual size_t GetCommandResponseMaxBufferSize() = 0;
 };
 
 } // namespace app

src/app/CommandHandlerImpl.cpp

@@ -67,7 +67,9 @@ CHIP_ERROR CommandHandlerImpl::AllocateBuffer()
  {
  mCommandMessageWriter.Reset();
 
- System::PacketBufferHandle commandPacket = System::PacketBufferHandle::New(chip::app::kMaxSecureSduLengthBytes);
+ const size_t commandBufferMaxSize = mpResponder->GetCommandResponseMaxBufferSize();
+ auto commandPacket = System::PacketBufferHandle::New(commandBufferMaxSize);
+
  VerifyOrReturnError(!commandPacket.IsNull(), CHIP_ERROR_NO_MEMORY);
 
  mCommandMessageWriter.Init(std::move(commandPacket));

src/app/CommandResponseSender.cpp

@@ -226,6 +226,22 @@ void CommandResponseSender::OnInvokeCommandRequest(Messaging::ExchangeContext *
  }
 }
 
+size_t CommandResponseSender::GetCommandResponseMaxBufferSize()
+{
+ if (!mExchangeCtx || !mExchangeCtx->HasSessionHandle())
+ {
+ ChipLogError(DataManagement, "Session not available. Unable to infer session-specific buffer capacities.");
+ return kMaxSecureSduLengthBytes;
+ }
+
+ if (mExchangeCtx->GetSessionHandle()->AllowsLargePayload())
+ {
+ return kMaxLargeSecureSduLengthBytes;
+ }
+
+ return kMaxSecureSduLengthBytes;
+}
+
 #if CHIP_WITH_NLFAULTINJECTION
 
 void CommandResponseSender::TestOnlyInvokeCommandRequestWithFaultsInjected(Messaging::ExchangeContext * ec,

src/app/CommandResponseSender.h

@@ -124,6 +124,8 @@ class CommandResponseSender : public Messaging::ExchangeDelegate,
 
  void ResponseDropped() override { mReportResponseDropped = true; }
 
+ size_t GetCommandResponseMaxBufferSize() override;
+
  /*
  * Main entrypoint for this class to handle an invoke request.
  *

src/app/CommandSender.cpp

@@ -55,18 +55,19 @@ CHIP_ERROR GetRef(ParserT aParser, Optional<uint16_t> & aRef, bool commandRefReq
 } // namespace
 
 CommandSender::CommandSender(Callback * apCallback, Messaging::ExchangeManager * apExchangeMgr, bool aIsTimedRequest,
- bool aSuppressResponse) :
+ bool aSuppressResponse, bool aAllowLargePayload) :
  mExchangeCtx(*this),
- mCallbackHandle(apCallback), mpExchangeMgr(apExchangeMgr), mSuppressResponse(aSuppressResponse), mTimedRequest(aIsTimedRequest)
+ mCallbackHandle(apCallback), mpExchangeMgr(apExchangeMgr), mSuppressResponse(aSuppressResponse), mTimedRequest(aIsTimedRequest),
+ mAllowLargePayload(aAllowLargePayload)
 {
  assertChipStackLockedByCurrentThread();
 }
 
 CommandSender::CommandSender(ExtendableCallback * apExtendableCallback, Messaging::ExchangeManager * apExchangeMgr,
- bool aIsTimedRequest, bool aSuppressResponse) :
+ bool aIsTimedRequest, bool aSuppressResponse, bool aAllowLargePayload) :
  mExchangeCtx(*this),
  mCallbackHandle(apExtendableCallback), mpExchangeMgr(apExchangeMgr), mSuppressResponse(aSuppressResponse),
- mTimedRequest(aIsTimedRequest), mUseExtendableCallback(true)
+ mTimedRequest(aIsTimedRequest), mUseExtendableCallback(true), mAllowLargePayload(aAllowLargePayload)
 {
  assertChipStackLockedByCurrentThread();
 #if CHIP_CONFIG_COMMAND_SENDER_BUILTIN_SUPPORT_FOR_BATCHED_COMMANDS
@@ -85,7 +86,15 @@ CHIP_ERROR CommandSender::AllocateBuffer()
  {
  mCommandMessageWriter.Reset();
 
- System::PacketBufferHandle commandPacket = System::PacketBufferHandle::New(chip::app::kMaxSecureSduLengthBytes);
+ System::PacketBufferHandle commandPacket;
+ if (mAllowLargePayload)
+ {
+ commandPacket = System::PacketBufferHandle::New(kMaxLargeSecureSduLengthBytes);
+ }
+ else
+ {
+ commandPacket = System::PacketBufferHandle::New(kMaxSecureSduLengthBytes);
+ }
  VerifyOrReturnError(!commandPacket.IsNull(), CHIP_ERROR_NO_MEMORY);
 
  mCommandMessageWriter.Init(std::move(commandPacket));
@@ -139,6 +148,12 @@ CHIP_ERROR CommandSender::TestOnlyCommandSenderTimedRequestFlagWithNoTimedInvoke
 
 CHIP_ERROR CommandSender::SendCommandRequest(const SessionHandle & session, Optional<System::Clock::Timeout> timeout)
 {
+ // If the command is expected to be large, ensure that the underlying
+ // session supports it.
+ if (mAllowLargePayload)
+ {
+ VerifyOrReturnError(session->AllowsLargePayload(), CHIP_ERROR_INCORRECT_STATE);
+ }
 
  if (mTimedRequest != mTimedInvokeTimeoutMs.HasValue())
  {

src/app/CommandSender.h

@@ -308,18 +308,19 @@ class CommandSender final : public Messaging::ExchangeDelegate
  * If callbacks are passed the only one that will be called in a group sesttings is the onDone
  */
  CommandSender(Callback * apCallback, Messaging::ExchangeManager * apExchangeMgr, bool aIsTimedRequest = false,
- bool aSuppressResponse = false);
+ bool aSuppressResponse = false, bool aAllowLargePayload = false);
  CommandSender(std::nullptr_t, Messaging::ExchangeManager * apExchangeMgr, bool aIsTimedRequest = false,
- bool aSuppressResponse = false) :
- CommandSender(static_cast<Callback *>(nullptr), apExchangeMgr, aIsTimedRequest, aSuppressResponse)
+ bool aSuppressResponse = false, bool aAllowLargePayload = false) :
+ CommandSender(static_cast<Callback *>(nullptr), apExchangeMgr, aIsTimedRequest, aSuppressResponse, aAllowLargePayload)
  {}
  CommandSender(ExtendableCallback * apCallback, Messaging::ExchangeManager * apExchangeMgr, bool aIsTimedRequest = false,
- bool aSuppressResponse = false);
+ bool aSuppressResponse = false, bool aAllowLargePayload = false);
  // TODO(#32138): After there is a macro that is always defined for all unit tests, the constructor with
  // TestOnlyMarker should only be compiled if that macro is defined.
  CommandSender(TestOnlyMarker aTestMarker, ExtendableCallback * apCallback, Messaging::ExchangeManager * apExchangeMgr,
- PendingResponseTracker * apPendingResponseTracker, bool aIsTimedRequest = false, bool aSuppressResponse = false) :
- CommandSender(apCallback, apExchangeMgr, aIsTimedRequest, aSuppressResponse)
+ PendingResponseTracker * apPendingResponseTracker, bool aIsTimedRequest = false, bool aSuppressResponse = false,
+ bool aAllowLargePayload = false) :
+ CommandSender(apCallback, apExchangeMgr, aIsTimedRequest, aSuppressResponse, aAllowLargePayload)
  {
  mpPendingResponseTracker = apPendingResponseTracker;
  }
@@ -636,6 +637,7 @@ class CommandSender final : public Messaging::ExchangeDelegate
  bool mBufferAllocated = false;
  bool mBatchCommandsEnabled = false;
  bool mUseExtendableCallback = false;
+ bool mAllowLargePayload = false;
 };
 
 } // namespace app

src/app/tests/TestCommandInteraction.cpp

@@ -330,6 +330,8 @@ class MockCommandResponder : public CommandHandlerExchangeInterface
  void AddInvokeResponseToSend(System::PacketBufferHandle && aPacket) override { mChunks.AddToEnd(std::move(aPacket)); }
  void ResponseDropped() override { mResponseDropped = true; }
 
+ size_t GetCommandResponseMaxBufferSize() override { return kMaxSecureSduLengthBytes; }
+
  System::PacketBufferHandle mChunks;
  bool mResponseDropped = false;
 };