Update session handle for Group message (#11390)

* Update session handle for Group message

src/messaging/ExchangeContext.cpp

@@ -275,7 +275,9 @@ ExchangeContext::ExchangeContext(ExchangeManager * em, uint16_t ExchangeId, Sess
     SetDropAckDebug(false);
     SetAckPending(false);
     SetMsgRcvdFromPeer(false);
-    SetAutoRequestAck(true);
+
+    // Do not request Ack for multicast
+    SetAutoRequestAck(!session.IsGroupSession());
 
 #if defined(CHIP_EXCHANGE_CONTEXT_DETAIL_LOGGING)
     ChipLogDetail(ExchangeManager, "ec++ id: " ChipLogFormatExchange, ChipLogValueExchange(this));

src/messaging/ExchangeMgr.cpp

@@ -213,29 +213,34 @@ void ExchangeManager::OnMessageReceived(const PacketHeader & packetHeader, const
         msgFlags.Set(MessageFlagValues::kDuplicateMessage);
     }
 
-    // Search for an existing exchange that the message applies to. If a match is found...
-    bool found = false;
-    mContextPool.ForEachActiveObject([&](auto * ec) {
-        if (ec->MatchExchange(session, packetHeader, payloadHeader))
-        {
-            // Found a matching exchange. Set flag for correct subsequent MRP
-            // retransmission timeout selection.
-            if (!ec->HasRcvdMsgFromPeer())
+    // Skip retrieval of exchange for group message since no exchange is stored
+    // for group msg (optimization)
+    if (!packetHeader.IsGroupSession())
+    {
+        // Search for an existing exchange that the message applies to. If a match is found...
+        bool found = false;
+        mContextPool.ForEachActiveObject([&](auto * ec) {
+            if (ec->MatchExchange(session, packetHeader, payloadHeader))
             {
-                ec->SetMsgRcvdFromPeer(true);
+                // Found a matching exchange. Set flag for correct subsequent MRP
+                // retransmission timeout selection.
+                if (!ec->HasRcvdMsgFromPeer())
+                {
+                    ec->SetMsgRcvdFromPeer(true);
+                }
+
+                // Matched ExchangeContext; send to message handler.
+                ec->HandleMessage(packetHeader.GetMessageCounter(), payloadHeader, source, msgFlags, std::move(msgBuf));
+                found = true;
+                return false;
             }
+            return true;
+        });
 
-            // Matched ExchangeContext; send to message handler.
-            ec->HandleMessage(packetHeader.GetMessageCounter(), payloadHeader, source, msgFlags, std::move(msgBuf));
-            found = true;
-            return false;
+        if (found)
+        {
+            return;
         }
-        return true;
-    });
-
-    if (found)
-    {
-        return;
     }
 
     // If it's not a duplicate message, search for an unsolicited message handler if it is marked as being sent by an initiator.

src/transport/SessionHandle.h

@@ -43,6 +43,11 @@ class SessionHandle
         mPeerSessionId.SetValue(peerSessionId);
     }
 
+    SessionHandle(NodeId peerNodeId, GroupId groupId, FabricIndex fabric) : mPeerNodeId(peerNodeId), mFabric(fabric)
+    {
+        mGroupId.SetValue(groupId);
+    }
+
     bool IsSecure() const { return !mUnauthenticatedSessionHandle.HasValue(); }
 
     bool HasFabricIndex() const { return (mFabric != kUndefinedFabricIndex); }
@@ -68,6 +73,7 @@ class SessionHandle
     }
 
     NodeId GetPeerNodeId() const { return mPeerNodeId; }
+    bool IsGroupSession() const { return mGroupId.HasValue(); }
     const Optional<uint16_t> & GetPeerSessionId() const { return mPeerSessionId; }
     const Optional<uint16_t> & GetLocalSessionId() const { return mLocalSessionId; }
 
@@ -85,6 +91,7 @@ class SessionHandle
     NodeId mPeerNodeId;
     Optional<uint16_t> mLocalSessionId;
     Optional<uint16_t> mPeerSessionId;
+    Optional<GroupId> mGroupId;
     // TODO: Re-evaluate the storing of Fabric ID in SessionHandle
     //       The Fabric ID will not be available for PASE and group sessions. So need
     //       to identify an approach that'll allow looking up the corresponding information for

src/transport/SessionManager.cpp

@@ -459,6 +459,7 @@ void SessionManager::SecureGroupMessageDispatch(const PacketHeader & packetHeade
     CHIP_ERROR err = CHIP_NO_ERROR;
     PayloadHeader payloadHeader;
     SessionManagerDelegate::DuplicateMessage isDuplicate = SessionManagerDelegate::DuplicateMessage::No;
+    FabricIndex fabricIndex = 0; // TODO : remove initialization once GroupDataProvider->Decrypt is implemented
     // Credentials::GroupDataProvider * groups = Credentials::GetGroupDataProvider();
 
     VerifyOrExit(!msg.IsNull(), ChipLogError(Inet, "Secure transport received NULL packet, discarding"));
@@ -471,6 +472,7 @@ void SessionManager::SecureGroupMessageDispatch(const PacketHeader & packetHeade
     }
 
     // Trial decryption with GroupDataProvider. TODO: Implement the GroupDataProvider Class
+    // TODO retrieve also the fabricIndex with the GroupDataProvider.
     // VerifyOrExit(CHIP_NO_ERROR == groups->DecryptMessage(packetHeader, payloadHeader, msg),
     //     ChipLogError(Inet, "Secure transport received group message, but failed to decode it, discarding"));
 
@@ -488,29 +490,24 @@ void SessionManager::SecureGroupMessageDispatch(const PacketHeader & packetHeade
 
     // TODO: Handle Group message counter here spec 4.7.3
     // spec 4.5.1.2 for msg counter
-
-    if (isDuplicate == SessionManagerDelegate::DuplicateMessage::Yes && !payloadHeader.NeedsAck())
+    if (isDuplicate == SessionManagerDelegate::DuplicateMessage::Yes)
     {
         ChipLogDetail(Inet,
                       "Received a duplicate message with MessageCounter:" ChipLogFormatMessageCounter
                       " on exchange " ChipLogFormatExchangeId,
-                      packetHeader.GetMessageCounter(), ChipLogValueExchangeIdFromReceivedHeader(payloadHeader));
-        if (!payloadHeader.NeedsAck())
-        {
-            // If it's a duplicate message, but doesn't require an ack, let's drop it right here to save CPU
-            // cycles on further message processing.
-            ExitNow(err = CHIP_NO_ERROR);
-        }
+                      packetHeader.GetMessageCounter(), ChipLogValueExchangeIdFromSentHeader(payloadHeader));
+
+        // If it's a duplicate message, let's drop it right here to save CPU
+        // cycles on further message processing.
+        ExitNow(err = CHIP_NO_ERROR);
     }
 
     // TODO: Commit Group Message Counter
 
     if (mCB != nullptr)
     {
-        // TODO: Update Session Handle for Group messages.
-        // SessionHandle session(session->GetPeerNodeId(), session->GetLocalSessionId(), session->GetPeerSessionId(),
-        //                       session->GetFabricIndex());
-        // mCB->OnMessageReceived(packetHeader, payloadHeader, session, peerAddress, isDuplicate, std::move(msg));
+        SessionHandle session(packetHeader.GetSourceNodeId().Value(), packetHeader.GetDestinationGroupId().Value(), fabricIndex);
+        mCB->OnMessageReceived(packetHeader, payloadHeader, session, peerAddress, isDuplicate, std::move(msg));
     }
 
 exit: