use existing SSU session if available

SSU.cpp

@@ -796,6 +796,18 @@ namespace ssu
 			LogPrint ("SSU receive error: ", ecode.message ());
 	}
 
+	SSUSession * SSUServer::FindSession (const i2p::data::RouterInfo * router)
+	{
+		if (!router) return nullptr;
+		auto address = router->GetSSUAddress ();
+		if (!address) return nullptr;
+		auto it = m_Sessions.find (boost::asio::ip::udp::endpoint (address->host, address->port));
+		if (it != m_Sessions.end ())
+			return it->second;
+		else
+			return nullptr;
+	}	
+		
 	SSUSession * SSUServer::GetSession (const i2p::data::RouterInfo * router)
 	{
 		SSUSession * session = nullptr;

SSU.h

@@ -126,6 +126,7 @@ namespace ssu
 			void Start ();
 			void Stop ();
 			SSUSession * GetSession (const i2p::data::RouterInfo * router);
+			SSUSession * FindSession (const i2p::data::RouterInfo * router);
 			void DeleteSession (SSUSession * session);
 			void DeleteAllSessions ();			
 

Transports.cpp

@@ -156,34 +156,36 @@ namespace i2p
 	void Transports::PostMessage (const i2p::data::IdentHash& ident, i2p::I2NPMessage * msg)
 	{
 		auto session = FindNTCPSession (ident);
-		if (!session)
+		if (session)
+			session->SendI2NPMessage (msg);
+		else
 		{
 			RouterInfo * r = netdb.FindRouter (ident);
 			if (r)
 			{	
+				auto ssuSession = m_SSUServer ? m_SSUServer->FindSession (r) : nullptr;
+				if (ssuSession)
+					ssuSession->SendI2NPMessage (msg);
+				else
+				{	
+					// existing session not found. create new 
+					// try NTCP first
 					auto address = r->GetNTCPAddress ();
 					if (address)
 					{	
-					session = new i2p::ntcp::NTCPClient (m_Service, address->host, address->port, *r);
-					AddNTCPSession (session);
+						auto s = new i2p::ntcp::NTCPClient (m_Service, address->host, address->port, *r);
+						AddNTCPSession (s);
+						s->SendI2NPMessage (msg);
 					}	
 					else
 					{	
-					// SSU always have lower prioprity than NTCP
-					// TODO: it shouldn't
-					LogPrint ("No NTCP addresses available. Trying SSU");
-					address = r->GetSSUAddress ();
-					if (address && m_SSUServer)
-					{
-						auto s = m_SSUServer->GetSession (r);
+						// then SSU					
+						auto s = m_SSUServer ? m_SSUServer->GetSession (r) : nullptr;
 						if (s)
-						{
 							s->SendI2NPMessage (msg);
-							return;
-						}
-					}
 						else
-						LogPrint ("No SSU addresses available");
+							LogPrint ("No NTCP and SSU addresses available");
+					}
 				}	
 			}
 			else
@@ -192,10 +194,6 @@ namespace i2p
 				i2p::data::netdb.RequestDestination (ident);
 			}	
 		}	
-		if (session)
-			session->SendI2NPMessage (msg);
-		else
-			LogPrint ("Session not found"); 
 	}	
 
 	void Transports::DetectExternalIP ()