send tunnel endpoint data to transport session to gateway directly

libi2pd/TransitTunnel.cpp

@@ -133,6 +133,30 @@ namespace tunnel
 		m_Endpoint.HandleDecryptedTunnelDataMsg (newMsg);
 	}
 
+	void TransitTunnelEndpoint::FlushTunnelDataMsgs ()
+	{
+		m_Endpoint.FlushI2NPMsgs ();
+	}	
+
+	std::string TransitTunnelEndpoint::GetNextPeerName () const
+	{ 
+		auto hash = m_Endpoint.GetCurrentHash ();
+		if (hash)
+		{	
+			const auto& sender = m_Endpoint.GetSender ();
+			if (sender)
+			{
+				auto transport = sender->GetCurrentTransport ();
+				if (transport)
+					return i2p::data::GetIdentHashAbbreviation (*hash) + "-" + 
+						i2p::data::RouterInfo::GetTransportName (transport->GetTransportType ());
+				else
+					return i2p::data::GetIdentHashAbbreviation (*hash);
+			}	
+		}
+		return "";
+	}	
+		
 	std::shared_ptr<TransitTunnel> CreateTransitTunnel (uint32_t receiveTunnelID,
 		const i2p::data::IdentHash& nextIdent, uint32_t nextTunnelID,
 		const i2p::crypto::AESKey& layerKey, const i2p::crypto::AESKey& ivKey,

libi2pd/TransitTunnel.h

@@ -103,8 +103,9 @@ namespace tunnel
 			void Cleanup () override { m_Endpoint.Cleanup (); }
 		
 			void HandleTunnelDataMsg (std::shared_ptr<i2p::I2NPMessage>&& tunnelMsg) override;
+			void FlushTunnelDataMsgs () override;
 			size_t GetNumTransmittedBytes () const override { return m_Endpoint.GetNumReceivedBytes (); }
-			std::string GetNextPeerName () const override { return ""; }
+			std::string GetNextPeerName () const override;
 			
 		private:
 

libi2pd/TunnelBase.cpp

@@ -64,7 +64,8 @@ namespace tunnel
 	void TunnelTransportSender::Reset ()
 	{
 		m_CurrentTransport.reset ();
-		m_PendingTransport = std::future<std::shared_ptr<i2p::transport::TransportSession> >();
+		if (m_PendingTransport.valid ())
+			m_PendingTransport = std::future<std::shared_ptr<i2p::transport::TransportSession> >();
 	}	
 }
 }

libi2pd/TunnelEndpoint.cpp

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2023, The PurpleI2P Project
+* Copyright (c) 2013-2024, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -21,10 +21,7 @@ namespace i2p
 {
 namespace tunnel
 {
-	TunnelEndpoint::~TunnelEndpoint ()
-	{
-	}
-
+	
 	void TunnelEndpoint::HandleDecryptedTunnelDataMsg (std::shared_ptr<I2NPMessage> msg)
 	{
 		m_NumReceivedBytes += TUNNEL_DATA_MSG_SIZE;
@@ -331,13 +328,13 @@ namespace tunnel
 			break;
 			case eDeliveryTypeTunnel:
 				if (!m_IsInbound) // outbound transit tunnel
-					i2p::transport::transports.SendMessage (msg.hash, i2p::CreateTunnelGatewayMsg (msg.tunnelID, msg.data));
+					SendMessageTo (msg.hash, i2p::CreateTunnelGatewayMsg (msg.tunnelID, msg.data));
 				else
 					LogPrint (eLogError, "TunnelMessage: Delivery type 'tunnel' arrived from an inbound tunnel, dropped");
 			break;
 			case eDeliveryTypeRouter:
 				if (!m_IsInbound) // outbound transit tunnel
-					i2p::transport::transports.SendMessage (msg.hash, msg.data);
+					i2p::transport::transports.SendMessage (msg.hash, msg.data); // send right away, because most likely it's single message
 				else // we shouldn't send this message. possible leakage
 					LogPrint (eLogError, "TunnelMessage: Delivery type 'router' arrived from an inbound tunnel, dropped");
 			break;
@@ -366,5 +363,36 @@ namespace tunnel
 				++it;
 		}
 	}
+
+	void TunnelEndpoint::SendMessageTo (const i2p::data::IdentHash& to, std::shared_ptr<i2p::I2NPMessage> msg)
+	{	
+		if (msg)
+		{	
+			if (!m_Sender && m_I2NPMsgs.empty ()) // first message
+				m_CurrentHash = to;
+			else if (m_CurrentHash != to) // new target router
+			{
+				FlushI2NPMsgs (); //  flush message to previous
+				if (m_Sender) m_Sender->Reset (); // reset sender
+				m_CurrentHash = to; // set new target router
+			}	// otherwise add msg to the list for current target router
+			m_I2NPMsgs.push_back (msg);
+			i2p::transport::transports.SendMessage (to, msg);
+		}	
+	}
+	
+	void TunnelEndpoint::FlushI2NPMsgs ()
+	{
+		if (!m_I2NPMsgs.empty ())
+		{
+			if (!m_Sender) m_Sender = std::make_unique<TunnelTransportSender>();
+			m_Sender->SendMessagesTo (m_CurrentHash, m_I2NPMsgs); // send and clear
+		}	
+	}	
+
+	const i2p::data::IdentHash * TunnelEndpoint::GetCurrentHash () const
+	{
+		return (m_Sender || !m_I2NPMsgs.empty ()) ? &m_CurrentHash : nullptr;
+	}	
 }
 }

libi2pd/TunnelEndpoint.h

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2021, The PurpleI2P Project
+* Copyright (c) 2013-2024, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -11,8 +11,10 @@
 
 #include <inttypes.h>
 #include <vector>
+#include <list>
 #include <string>
 #include <unordered_map>
+#include <memory>
 #include "I2NPProtocol.h"
 #include "TunnelBase.h"
 
@@ -20,7 +22,7 @@ namespace i2p
 {
 namespace tunnel
 {
-	class TunnelEndpoint
+	class TunnelEndpoint final
 	{
 		struct TunnelMessageBlockEx: public TunnelMessageBlock
 		{
@@ -39,18 +41,23 @@ namespace tunnel
 		public:
 
 			TunnelEndpoint (bool isInbound): m_IsInbound (isInbound), m_NumReceivedBytes (0), m_CurrentMsgID (0) {};
-			~TunnelEndpoint ();
+			~TunnelEndpoint () = default;
 			size_t GetNumReceivedBytes () const { return m_NumReceivedBytes; };
 			void Cleanup ();
 
 			void HandleDecryptedTunnelDataMsg (std::shared_ptr<I2NPMessage> msg);
+			void FlushI2NPMsgs (); 
 
+			const i2p::data::IdentHash * GetCurrentHash () const; // return null if not avaiable
+			const std::unique_ptr<TunnelTransportSender>& GetSender () const { return m_Sender; };
+		
 		private:
 
 			void HandleFollowOnFragment (uint32_t msgID, bool isLastFragment, uint8_t fragmentNum, const uint8_t * fragment, size_t size);
 			bool ConcatFollowOnFragment (TunnelMessageBlockEx& msg, const uint8_t * fragment, size_t size) const; // true if success
 			void HandleCurrenMessageFollowOnFragment (const uint8_t * fragment, size_t size, bool isLastFragment);
 			void HandleNextMessage (const TunnelMessageBlock& msg);
+			void SendMessageTo (const i2p::data::IdentHash& to, std::shared_ptr<i2p::I2NPMessage> msg);
 
 			void AddOutOfSequenceFragment (uint32_t msgID, uint8_t fragmentNum, bool isLastFragment, const uint8_t * fragment, size_t size);
 			bool ConcatNextOutOfSequenceFragment (uint32_t msgID, TunnelMessageBlockEx& msg); // true if something added
@@ -65,6 +72,10 @@ namespace tunnel
 			size_t m_NumReceivedBytes;
 			TunnelMessageBlockEx m_CurrentMessage;
 			uint32_t m_CurrentMsgID;
+			// I2NP messages to send
+			std::list<std::shared_ptr<i2p::I2NPMessage> > m_I2NPMsgs; // to send
+			i2p::data::IdentHash m_CurrentHash; // send msgs to
+			std::unique_ptr<TunnelTransportSender> m_Sender;
 	};
 }
 }