check if connection to peer exists already

NTCPSession.cpp

@@ -316,6 +316,11 @@ namespace transport
 			uint8_t * buf = m_ReceiveBuffer;
 			uint16_t size = bufbe16toh (buf);
 			m_RemoteIdentity.FromBuffer (buf + 2, size);
+			if (m_Server.FindNTCPSession (m_RemoteIdentity.GetIdentHash ()))
+			{
+				LogPrint (eLogError, "NTCP session already exists");
+				Terminate ();
+			}	
 			size_t expectedSize = size + 2/*size*/ + 4/*timestamp*/ + m_RemoteIdentity.GetSignatureLen ();
 			size_t paddingLen = expectedSize & 0x0F;
 			if (paddingLen) paddingLen = (16 - paddingLen);	

Transports.cpp

@@ -428,7 +428,7 @@ namespace transport
 		{  
 			auto ident = session->GetRemoteIdentity ().GetIdentHash ();
 			auto it = m_Peers.find (ident);
-			if (it != m_Peers.end () && it->second.session == session)
+			if (it != m_Peers.end () && (!it->second.session || it->second.session == session))
 			{
 				if (it->second.delayedMessages.size () > 0)
 					ConnectToPeer (ident, it->second);