Send an unused TCPacket periodically from tcd to urfd as a simple keepalive solution

reflector/TCPacketDef.h

@@ -17,7 +17,7 @@
 
 #include <cstdint>
 
-enum class ECodecType : std::uint8_t { none = 0, dstar = 1, dmr = 2, c2_1600 = 3, c2_3200 = 4, p25 = 5, usrp = 6 };
+enum class ECodecType : std::uint8_t { none = 0, dstar = 1, dmr = 2, c2_1600 = 3, c2_3200 = 4, p25 = 5, usrp = 6, ping = 0xff };
 
 using STCPacket = struct tcpacket_tag {
 	uint32_t sequence;

reflector/TCSocket.cpp

@@ -116,12 +116,19 @@ bool CTCServer::AnyAreClosed() const
 
 bool CTCSocket::Send(const STCPacket *packet)
 {
-	const auto pos = m_Modules.find(packet->module);
+	auto pos = m_Modules.find(packet->module);
 	if (pos == std::string::npos)
+	{
+		if(packet->codec_in == ECodecType::ping)
+		{
+			pos = 0; // There is at least one transcoding module, use it to send the ping
+		}
+		else
 		{
 			std::cerr << "Can't Send() this packet to unconfigured module '" << packet->module << "'" << std::endl;
 			return true;
 		}
+	}
 	unsigned count = 0;
 	auto data = (const unsigned char *)packet;
 	do {
@@ -214,6 +221,10 @@ bool CTCServer::Receive(char module, STCPacket *packet, int ms)
 
 	if (rv)
 		Close(pfds->fd);
+		
+	if(packet->codec_in == ECodecType::ping)
+		return false; 
+	else 
 		return !rv;
 }
 
@@ -434,8 +445,12 @@ bool CTCClient::Connect(char module)
 	return false;
 }
 
-void CTCClient::ReConnect()
+void CTCClient::ReConnect() // and sometimes ping
 {
+	static std::chrono::system_clock::time_point start = std::chrono::system_clock::now();
+	auto now = std::chrono::system_clock::now();
+	std::chrono::duration<double> secs = now - start;
+	
 	for (char m : m_Modules)
 	{
 		if (0 > GetFD(m))
@@ -447,6 +462,14 @@ void CTCClient::ReConnect()
 			}
 		}
 	}
+	
+	if(secs.count() > 5.0)
+	{
+		STCPacket ping;
+		ping.codec_in = ECodecType::ping;
+		Send(&ping);
+		start = now;
+	}
 }
 
 void CTCClient::Receive(std::queue<std::unique_ptr<STCPacket>> &queue, int ms)