Close TCP connection when received message size is too large.

When the framing length value of a received message is larger
than what the local node can process, abort the connection
with the peer.
The peer was already aware of the max length this node was
willing to receive during its TCP advertisement.

Fixes project-chip#33307.

Author: pidarped

src/transport/raw/TCP.cpp

@@ -331,7 +331,10 @@ CHIP_ERROR TCPBase::ProcessReceivedBuffer(Inet::TCPEndPoint * endPoint, const Pe
         uint32_t messageSize = LittleEndian::Get32(messageSizeBuf);
         if (messageSize >= kMaxTCPMessageSize)
         {
-            // This message is too long for upper layers.
+            // Message is too big for this node to process. Disconnect with peer.
+            ChipLogError(Inet, "Received TCP message of length %" PRIu32 " exceeds limit.", messageSize);
+            CloseConnectionInternal(state, CHIP_ERROR_MESSAGE_TOO_LONG, SuppressCallback::No);
+
             return CHIP_ERROR_MESSAGE_TOO_LONG;
         }
         // The subtraction will not underflow because we successfully read kPacketSizeBytes.

src/transport/raw/tests/TestTCP.cpp

@@ -682,7 +682,9 @@ TEST_F(TestTCP, CheckProcessReceivedBuffer)
     EXPECT_EQ(err, CHIP_ERROR_MESSAGE_TOO_LONG);
     EXPECT_EQ(gMockTransportMgrDelegate.mReceiveHandlerCallCount, 0);
 
-    gMockTransportMgrDelegate.DisconnectTest(tcp, addr);
+    // The receipt of a message exceeding the allowed size should have
+    // closed the connection.
+    EXPECT_EQ(TestAccess::GetEndpoint(state), nullptr);
 }
 
 } // namespace