Fix invariant violation if we get a message without piggyback ack while expecting an ack. (#23282)
* Fix invariant violation if we get a message without piggyback ack while expecting an ack.
Such messages are not allowed per spec, so we should just ignore them.
Fixes https://github.com/project-chip/connectedhomeip/issues/22854
* Fix tests.
* Address review comment.
diff --git a/src/app/tests/TestCommandInteraction.cpp b/src/app/tests/TestCommandInteraction.cpp
index fde62b5..2ad2bc7 100644
--- a/src/app/tests/TestCommandInteraction.cpp
+++ b/src/app/tests/TestCommandInteraction.cpp
@@ -714,6 +714,40 @@
exchange->Close();
}
+/**
+ * Helper macro we can use to pretend we got a reply from the server in cases
+ * when the reply was actually dropped due to us not wanting the client's state
+ * machine to advance.
+ *
+ * When this macro is used, the client has sent a message and is waiting for an
+ * ack+response, and the server has sent a response that got dropped and is
+ * waiting for an ack (and maybe a response).
+ *
+ * What this macro then needs to do is:
+ *
+ * 1. Pretend that the client got an ack (and clear out the corresponding ack
+ * state).
+ * 2. Pretend that the client got a message from the server, with the id of the
+ * message that was dropped, which requires an ack, so the client will send
+ * that ack in its next message.
+ *
+ * This is a macro so we get useful line numbers on assertion failures
+ */
+#define PretendWeGotReplyFromServer(aSuite, aContext, aClientExchange) \
+ { \
+ Messaging::ReliableMessageMgr * localRm = (aContext).GetExchangeManager().GetReliableMessageMgr(); \
+ Messaging::ExchangeContext * localExchange = aClientExchange; \
+ NL_TEST_ASSERT(aSuite, localRm->TestGetCountRetransTable() == 2); \
+ \
+ localRm->ClearRetransTable(localExchange); \
+ NL_TEST_ASSERT(aSuite, localRm->TestGetCountRetransTable() == 1); \
+ \
+ localRm->EnumerateRetransTable([localExchange](auto * entry) { \
+ localExchange->SetPendingPeerAckMessageCounter(entry->retainedBuf.GetMessageCounter()); \
+ return Loop::Break; \
+ }); \
+ }
+
// Command Sender sends invoke request, command handler drops invoke response, then test injects status response message with
// busy to client, client sends out a status response with invalid action.
void TestCommandInteraction::TestCommandInvalidMessage1(nlTestSuite * apSuite, void * apContext)
@@ -757,8 +791,11 @@
Test::MessageCapturer messageLog(ctx);
messageLog.mCaptureStandaloneAcks = false;
- Messaging::ReliableMessageMgr * rm = ctx.GetExchangeManager().GetReliableMessageMgr();
- rm->ClearRetransTable(commandSender.mExchangeCtx.Get());
+ // Since we are dropping packets, things are not getting acked. Set up our
+ // MRP state to look like what it would have looked like if the packet had
+ // not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, commandSender.mExchangeCtx.Get());
+
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 0;
ctx.GetLoopback().mNumMessagesToAllowBeforeDropping = 0;
@@ -823,9 +860,13 @@
payloadHeader.SetExchangeID(0);
payloadHeader.SetMessageType(chip::Protocols::InteractionModel::MsgType::ReportData);
Test::MessageCapturer messageLog(ctx);
- messageLog.mCaptureStandaloneAcks = false;
- Messaging::ReliableMessageMgr * rm = ctx.GetExchangeManager().GetReliableMessageMgr();
- rm->ClearRetransTable(commandSender.mExchangeCtx.Get());
+ messageLog.mCaptureStandaloneAcks = false;
+
+ // Since we are dropping packets, things are not getting acked. Set up our
+ // MRP state to look like what it would have looked like if the packet had
+ // not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, commandSender.mExchangeCtx.Get());
+
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 0;
ctx.GetLoopback().mNumMessagesToAllowBeforeDropping = 0;
@@ -892,8 +933,11 @@
Test::MessageCapturer messageLog(ctx);
messageLog.mCaptureStandaloneAcks = false;
- Messaging::ReliableMessageMgr * rm = ctx.GetExchangeManager().GetReliableMessageMgr();
- rm->ClearRetransTable(commandSender.mExchangeCtx.Get());
+ // Since we are dropping packets, things are not getting acked. Set up our
+ // MRP state to look like what it would have looked like if the packet had
+ // not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, commandSender.mExchangeCtx.Get());
+
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 0;
ctx.GetLoopback().mNumMessagesToAllowBeforeDropping = 0;
@@ -960,8 +1004,11 @@
Test::MessageCapturer messageLog(ctx);
messageLog.mCaptureStandaloneAcks = false;
- Messaging::ReliableMessageMgr * rm = ctx.GetExchangeManager().GetReliableMessageMgr();
- rm->ClearRetransTable(commandSender.mExchangeCtx.Get());
+ // Since we are dropping packets, things are not getting acked. Set up our
+ // MRP state to look like what it would have looked like if the packet had
+ // not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, commandSender.mExchangeCtx.Get());
+
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 0;
ctx.GetLoopback().mNumMessagesToAllowBeforeDropping = 0;
diff --git a/src/app/tests/TestReadInteraction.cpp b/src/app/tests/TestReadInteraction.cpp
index fc9e379..9a27ba7 100644
--- a/src/app/tests/TestReadInteraction.cpp
+++ b/src/app/tests/TestReadInteraction.cpp
@@ -2926,6 +2926,40 @@
} // anonymous namespace
+/**
+ * Helper macro we can use to pretend we got a reply from the server in cases
+ * when the reply was actually dropped due to us not wanting the client's state
+ * machine to advance.
+ *
+ * When this macro is used, the client has sent a message and is waiting for an
+ * ack+response, and the server has sent a response that got dropped and is
+ * waiting for an ack (and maybe a response).
+ *
+ * What this macro then needs to do is:
+ *
+ * 1. Pretend that the client got an ack (and clear out the corresponding ack
+ * state).
+ * 2. Pretend that the client got a message from the server, with the id of the
+ * message that was dropped, which requires an ack, so the client will send
+ * that ack in its next message.
+ *
+ * This is a macro so we get useful line numbers on assertion failures
+ */
+#define PretendWeGotReplyFromServer(aSuite, aContext, aClientExchange) \
+ { \
+ Messaging::ReliableMessageMgr * localRm = (aContext).GetExchangeManager().GetReliableMessageMgr(); \
+ Messaging::ExchangeContext * localExchange = aClientExchange; \
+ NL_TEST_ASSERT(aSuite, localRm->TestGetCountRetransTable() == 2); \
+ \
+ localRm->ClearRetransTable(localExchange); \
+ NL_TEST_ASSERT(aSuite, localRm->TestGetCountRetransTable() == 1); \
+ \
+ localRm->EnumerateRetransTable([localExchange](auto * entry) { \
+ localExchange->SetPendingPeerAckMessageCounter(entry->retainedBuf.GetMessageCounter()); \
+ return Loop::Break; \
+ }); \
+ }
+
// Read Client sends the read request, Read Handler drops the response, then test injects unknown status reponse message for Read
// Client.
void TestReadInteraction::TestReadClientReceiveInvalidMessage(nlTestSuite * apSuite, void * apContext)
@@ -2957,8 +2991,7 @@
readPrepareParams.mAttributePathParamsListSize = 2;
{
- app::ReadClient readClient(chip::app::InteractionModelEngine::GetInstance(), &ctx.GetExchangeManager(), delegate,
- chip::app::ReadClient::InteractionType::Read);
+ app::ReadClient readClient(engine, &ctx.GetExchangeManager(), delegate, chip::app::ReadClient::InteractionType::Read);
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 1;
@@ -2968,6 +3001,9 @@
NL_TEST_ASSERT(apSuite, err == CHIP_NO_ERROR);
ctx.DrainAndServiceIO();
+ NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mSentMessageCount == 2);
+ NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mDroppedMessageCount == 1);
+
System::PacketBufferHandle msgBuf = System::PacketBufferHandle::New(kMaxSecureSduLengthBytes);
NL_TEST_ASSERT(apSuite, !msgBuf.IsNull());
System::PacketBufferTLVWriter writer;
@@ -2983,9 +3019,11 @@
Test::MessageCapturer messageLog(ctx);
messageLog.mCaptureStandaloneAcks = false;
- rm->ClearRetransTable(readClient.mExchange.Get());
- NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mSentMessageCount == 2);
- NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mDroppedMessageCount == 1);
+ // Since we are dropping packets, things are not getting acked. Set up
+ // our MRP state to look like what it would have looked like if the
+ // packet had not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, readClient.mExchange.Get());
+
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 0;
ctx.GetLoopback().mNumMessagesToAllowBeforeDropping = 0;
@@ -3065,13 +3103,16 @@
payloadHeader.SetExchangeID(0);
payloadHeader.SetMessageType(chip::Protocols::InteractionModel::MsgType::StatusResponse);
- rm->ClearRetransTable(readClient.mExchange.Get());
+ // Since we are dropping packets, things are not getting acked. Set up
+ // our MRP state to look like what it would have looked like if the
+ // packet had not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, readClient.mExchange.Get());
+
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mSentMessageCount == 2);
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mDroppedMessageCount == 1);
-
NL_TEST_ASSERT(apSuite, engine->GetNumActiveReadHandlers() == 1);
NL_TEST_ASSERT(apSuite, engine->ActiveHandlerAt(0) != nullptr);
- rm->ClearRetransTable(engine->ActiveHandlerAt(0)->mExchangeCtx.Get());
+
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 0;
ctx.GetLoopback().mNumMessagesToAllowBeforeDropping = 0;
@@ -3155,13 +3196,16 @@
payloadHeader.SetExchangeID(0);
payloadHeader.SetMessageType(chip::Protocols::InteractionModel::MsgType::StatusResponse);
- rm->ClearRetransTable(readClient.mExchange.Get());
+ // Since we are dropping packets, things are not getting acked. Set up
+ // our MRP state to look like what it would have looked like if the
+ // packet had not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, readClient.mExchange.Get());
+
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mSentMessageCount == 2);
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mDroppedMessageCount == 1);
-
NL_TEST_ASSERT(apSuite, engine->GetNumActiveReadHandlers() == 1);
NL_TEST_ASSERT(apSuite, engine->ActiveHandlerAt(0) != nullptr);
- rm->ClearRetransTable(engine->ActiveHandlerAt(0)->mExchangeCtx.Get());
+
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 0;
ctx.GetLoopback().mNumMessagesToAllowBeforeDropping = 0;
@@ -3243,12 +3287,15 @@
payloadHeader.SetExchangeID(0);
payloadHeader.SetMessageType(chip::Protocols::InteractionModel::MsgType::ReportData);
- rm->ClearRetransTable(readClient.mExchange.Get());
+ // Since we are dropping packets, things are not getting acked. Set up
+ // our MRP state to look like what it would have looked like if the
+ // packet had not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, readClient.mExchange.Get());
+
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mSentMessageCount == 2);
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mDroppedMessageCount == 1);
NL_TEST_ASSERT(apSuite, engine->GetNumActiveReadHandlers() == 1);
NL_TEST_ASSERT(apSuite, engine->ActiveHandlerAt(0) != nullptr);
- rm->ClearRetransTable(engine->ActiveHandlerAt(0)->mExchangeCtx.Get());
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 0;
@@ -3407,12 +3454,15 @@
payloadHeader.SetExchangeID(0);
payloadHeader.SetMessageType(chip::Protocols::InteractionModel::MsgType::SubscribeResponse);
- rm->ClearRetransTable(readClient.mExchange.Get());
+ // Since we are dropping packets, things are not getting acked. Set up
+ // our MRP state to look like what it would have looked like if the
+ // packet had not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, readClient.mExchange.Get());
+
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mSentMessageCount == 4);
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mDroppedMessageCount == 1);
NL_TEST_ASSERT(apSuite, engine->GetNumActiveReadHandlers() == 1);
NL_TEST_ASSERT(apSuite, engine->ActiveHandlerAt(0) != nullptr);
- rm->ClearRetransTable(engine->ActiveHandlerAt(0)->mExchangeCtx.Get());
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 0;
@@ -3574,7 +3624,11 @@
NL_TEST_ASSERT(apSuite, writer.Finalize(&msgBuf) == CHIP_NO_ERROR);
- rm->ClearRetransTable(readClient.mExchange.Get());
+ // Since we are dropping packets, things are not getting acked. Set up
+ // our MRP state to look like what it would have looked like if the
+ // packet had not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, readClient.mExchange.Get());
+
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mSentMessageCount == 4);
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mDroppedMessageCount == 1);
NL_TEST_ASSERT(apSuite, engine->GetNumActiveReadHandlers() == 1);
@@ -3780,17 +3834,21 @@
NL_TEST_ASSERT(apSuite, err == CHIP_NO_ERROR);
ctx.DrainAndServiceIO();
+ // Since we are dropping packets, things are not getting acked. Set up
+ // our MRP state to look like what it would have looked like if the
+ // packet had not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, readClient.mExchange.Get());
+
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mSentMessageCount == 2);
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mDroppedMessageCount == 1);
-
- ctx.GetLoopback().mSentMessageCount = 0;
- rm->ClearRetransTable(readClient.mExchange.Get());
NL_TEST_ASSERT(apSuite, engine->GetNumActiveReadHandlers() == 1);
NL_TEST_ASSERT(apSuite, engine->ActiveHandlerAt(0) != nullptr);
+
+ ctx.GetLoopback().mSentMessageCount = 0;
+
// Server sends out status report, client should send status report along with Piggybacking ack, but we don't do that
- // Instead, we send out unknown message to server,but server is still waiting for ack, so we need
- // clear out retranstable
- rm->ClearRetransTable(engine->ActiveHandlerAt(0)->mExchangeCtx.Get());
+ // Instead, we send out unknown message to server
+
System::PacketBufferHandle msgBuf;
ReadRequestMessage::Builder request;
System::PacketBufferTLVWriter writer;
@@ -3853,13 +3911,17 @@
NL_TEST_ASSERT(apSuite, err == CHIP_NO_ERROR);
ctx.DrainAndServiceIO();
+ // Since we are dropping packets, things are not getting acked. Set up
+ // our MRP state to look like what it would have looked like if the
+ // packet had not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, readClient.mExchange.Get());
+
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mSentMessageCount == 2);
NL_TEST_ASSERT(apSuite, ctx.GetLoopback().mDroppedMessageCount == 1);
ctx.GetLoopback().mSentMessageCount = 0;
- rm->ClearRetransTable(readClient.mExchange.Get());
+
NL_TEST_ASSERT(apSuite, engine->GetNumActiveReadHandlers() == 1);
NL_TEST_ASSERT(apSuite, engine->ActiveHandlerAt(0) != nullptr);
- rm->ClearRetransTable(engine->ActiveHandlerAt(0)->mExchangeCtx.Get());
System::PacketBufferHandle msgBuf;
StatusResponseMessage::Builder request;
diff --git a/src/app/tests/TestWriteInteraction.cpp b/src/app/tests/TestWriteInteraction.cpp
index 65f6e8b..6437b25 100644
--- a/src/app/tests/TestWriteInteraction.cpp
+++ b/src/app/tests/TestWriteInteraction.cpp
@@ -679,6 +679,40 @@
#endif
+/**
+ * Helper macro we can use to pretend we got a reply from the server in cases
+ * when the reply was actually dropped due to us not wanting the client's state
+ * machine to advance.
+ *
+ * When this macro is used, the client has sent a message and is waiting for an
+ * ack+response, and the server has sent a response that got dropped and is
+ * waiting for an ack (and maybe a response).
+ *
+ * What this macro then needs to do is:
+ *
+ * 1. Pretend that the client got an ack (and clear out the corresponding ack
+ * state).
+ * 2. Pretend that the client got a message from the server, with the id of the
+ * message that was dropped, which requires an ack, so the client will send
+ * that ack in its next message.
+ *
+ * This is a macro so we get useful line numbers on assertion failures
+ */
+#define PretendWeGotReplyFromServer(aSuite, aContext, aClientExchange) \
+ { \
+ Messaging::ReliableMessageMgr * localRm = (aContext).GetExchangeManager().GetReliableMessageMgr(); \
+ Messaging::ExchangeContext * localExchange = aClientExchange; \
+ NL_TEST_ASSERT(aSuite, localRm->TestGetCountRetransTable() == 2); \
+ \
+ localRm->ClearRetransTable(localExchange); \
+ NL_TEST_ASSERT(aSuite, localRm->TestGetCountRetransTable() == 1); \
+ \
+ localRm->EnumerateRetransTable([localExchange](auto * entry) { \
+ localExchange->SetPendingPeerAckMessageCounter(entry->retainedBuf.GetMessageCounter()); \
+ return Loop::Break; \
+ }); \
+ }
+
// Write Client sends a write request, receives an unexpected message type, sends a status response to that.
void TestWriteInteraction::TestWriteInvalidMessage1(nlTestSuite * apSuite, void * apContext)
{
@@ -724,7 +758,11 @@
payloadHeader.SetExchangeID(0);
payloadHeader.SetMessageType(chip::Protocols::InteractionModel::MsgType::ReportData);
- rm->ClearRetransTable(writeClient.mExchangeCtx.Get());
+ // Since we are dropping packets, things are not getting acked. Set up
+ // our MRP state to look like what it would have looked like if the
+ // packet had not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, writeClient.mExchangeCtx.Get());
+
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 0;
ctx.GetLoopback().mNumMessagesToAllowBeforeDropping = 0;
@@ -791,7 +829,11 @@
payloadHeader.SetExchangeID(0);
payloadHeader.SetMessageType(chip::Protocols::InteractionModel::MsgType::WriteResponse);
- rm->ClearRetransTable(writeClient.mExchangeCtx.Get());
+ // Since we are dropping packets, things are not getting acked. Set up
+ // our MRP state to look like what it would have looked like if the
+ // packet had not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, writeClient.mExchangeCtx.Get());
+
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 0;
ctx.GetLoopback().mNumMessagesToAllowBeforeDropping = 0;
@@ -857,7 +899,11 @@
payloadHeader.SetExchangeID(0);
payloadHeader.SetMessageType(chip::Protocols::InteractionModel::MsgType::StatusResponse);
- rm->ClearRetransTable(writeClient.mExchangeCtx.Get());
+ // Since we are dropping packets, things are not getting acked. Set up
+ // our MRP state to look like what it would have looked like if the
+ // packet had not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, writeClient.mExchangeCtx.Get());
+
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 0;
ctx.GetLoopback().mNumMessagesToAllowBeforeDropping = 0;
@@ -925,7 +971,11 @@
payloadHeader.SetExchangeID(0);
payloadHeader.SetMessageType(chip::Protocols::InteractionModel::MsgType::StatusResponse);
- rm->ClearRetransTable(writeClient.mExchangeCtx.Get());
+ // Since we are dropping packets, things are not getting acked. Set up
+ // our MRP state to look like what it would have looked like if the
+ // packet had not gotten dropped.
+ PretendWeGotReplyFromServer(apSuite, ctx, writeClient.mExchangeCtx.Get());
+
ctx.GetLoopback().mSentMessageCount = 0;
ctx.GetLoopback().mNumMessagesToDrop = 0;
ctx.GetLoopback().mNumMessagesToAllowBeforeDropping = 0;
diff --git a/src/messaging/ExchangeContext.cpp b/src/messaging/ExchangeContext.cpp
index 9d3c8ec..080b73b 100644
--- a/src/messaging/ExchangeContext.cpp
+++ b/src/messaging/ExchangeContext.cpp
@@ -573,6 +573,18 @@
return CHIP_NO_ERROR;
}
+ if (IsMessageNotAcked())
+ {
+ // The only way we can get here is a spec violation on the other side:
+ // we sent a message that needs an ack, and the other side responded
+ // with a message that does not contain an ack for the message we sent.
+ // Just drop this message; if we delivered it to our delegate it might
+ // try to send another message-needing-an-ack in response, which would
+ // violate our internal invariants.
+ ChipLogError(ExchangeManager, "Dropping message without piggyback ack when we are waiting for an ack.");
+ return CHIP_ERROR_INCORRECT_STATE;
+ }
+
// Since we got the response, cancel the response timer.
CancelResponseTimer();
diff --git a/src/messaging/ReliableMessageContext.h b/src/messaging/ReliableMessageContext.h
index 886ed5c..57ec456 100644
--- a/src/messaging/ReliableMessageContext.h
+++ b/src/messaging/ReliableMessageContext.h
@@ -36,6 +36,11 @@
#include <transport/raw/MessageHeader.h>
namespace chip {
+namespace app {
+class TestCommandInteraction;
+class TestReadInteraction;
+class TestWriteInteraction;
+} // namespace app
namespace Messaging {
class ChipMessageInfo;
@@ -193,6 +198,9 @@
friend class ReliableMessageMgr;
friend class ExchangeContext;
friend class ExchangeMessageDispatch;
+ friend class ::chip::app::TestCommandInteraction;
+ friend class ::chip::app::TestReadInteraction;
+ friend class ::chip::app::TestWriteInteraction;
System::Clock::Timestamp mNextAckTime; // Next time for triggering Solo Ack
uint32_t mPendingPeerAckMessageCounter;
diff --git a/src/messaging/ReliableMessageMgr.h b/src/messaging/ReliableMessageMgr.h
index c50ca12..e2fc1e2 100644
--- a/src/messaging/ReliableMessageMgr.h
+++ b/src/messaging/ReliableMessageMgr.h
@@ -192,6 +192,15 @@
#if CHIP_CONFIG_TEST
// Functions for testing
int TestGetCountRetransTable();
+
+ // Enumerate the retransmission table. Clearing an entry while enumerating
+ // that entry is allowed. F must take a RetransTableEntry as an argument
+ // and return Loop::Continue or Loop::Break.
+ template <typename F>
+ void EnumerateRetransTable(F && functor)
+ {
+ mRetransTable.ForEachActiveObject(std::forward<F>(functor));
+ }
#endif // CHIP_CONFIG_TEST
private:
