bind tunnel gateway to transport session

libi2pd/Transports.cpp

@@ -447,28 +447,29 @@ namespace transport
 		return std::max (bwCongestionLevel, tbwCongestionLevel);
 	}
 
-	void Transports::SendMessage (const i2p::data::IdentHash& ident, std::shared_ptr<i2p::I2NPMessage> msg)
+	std::future<std::shared_ptr<TransportSession> > Transports::SendMessage (const i2p::data::IdentHash& ident, std::shared_ptr<i2p::I2NPMessage> msg)
 	{
 		if (m_IsOnline)
-			SendMessages (ident, { msg });
+			return SendMessages (ident, { msg });
+		return {}; // invalid future
 	}
 
-	void Transports::SendMessages (const i2p::data::IdentHash& ident, std::list<std::shared_ptr<i2p::I2NPMessage> >& msgs)
+	std::future<std::shared_ptr<TransportSession> > Transports::SendMessages (const i2p::data::IdentHash& ident, std::list<std::shared_ptr<i2p::I2NPMessage> >& msgs)
 	{
 		std::list<std::shared_ptr<i2p::I2NPMessage> > msgs1;
 		msgs.swap (msgs1);
-		SendMessages (ident, std::move (msgs1));
+		return SendMessages (ident, std::move (msgs1));
 	}
 
-	void Transports::SendMessages (const i2p::data::IdentHash& ident, std::list<std::shared_ptr<i2p::I2NPMessage> >&& msgs)
+	std::future<std::shared_ptr<TransportSession> > Transports::SendMessages (const i2p::data::IdentHash& ident, std::list<std::shared_ptr<i2p::I2NPMessage> >&& msgs)
 	{
-		boost::asio::post (*m_Service, [this, ident, msgs = std::move(msgs)] () mutable
+		return boost::asio::post (*m_Service, boost::asio::use_future ([this, ident, msgs = std::move(msgs)] () mutable
 			{
-				PostMessages (ident, msgs);
-			});	
+				return PostMessages (ident, msgs);
+			}));	
 	}	
 	
-	void Transports::PostMessages (const i2p::data::IdentHash& ident, std::list<std::shared_ptr<i2p::I2NPMessage> >& msgs)
+	std::shared_ptr<TransportSession> Transports::PostMessages (const i2p::data::IdentHash& ident, std::list<std::shared_ptr<i2p::I2NPMessage> >& msgs)
 	{
 		if (ident == i2p::context.GetRouterInfo ().GetIdentHash ())
 		{
@@ -476,9 +477,9 @@ namespace transport
 			for (auto& it: msgs)
 				m_LoopbackHandler.PutNextMessage (std::move (it));
 			m_LoopbackHandler.Flush ();
-			return;
+			return nullptr;
 		}
-		if(RoutesRestricted() && !IsRestrictedPeer(ident)) return;
+		if(RoutesRestricted() && !IsRestrictedPeer(ident)) return nullptr;
 		std::shared_ptr<Peer> peer;
 		{
 			std::lock_guard<std::mutex> l(m_PeersMutex);
@@ -489,13 +490,13 @@ namespace transport
 		if (!peer)
 		{
 			// check if not banned
-			if (i2p::data::IsRouterBanned (ident)) return; // don't create peer to unreachable router
+			if (i2p::data::IsRouterBanned (ident)) return nullptr; // don't create peer to unreachable router
 			// try to connect
 			bool connected = false;
 			try
 			{
 				auto r = netdb.FindRouter (ident);
-				if (r && (r->IsUnreachable () || !r->IsReachableFrom (i2p::context.GetRouterInfo ()))) return; // router found but non-reachable
+				if (r && (r->IsUnreachable () || !r->IsReachableFrom (i2p::context.GetRouterInfo ()))) return nullptr; // router found but non-reachable
 
 				peer = std::make_shared<Peer>(r, i2p::util::GetSecondsSinceEpoch ());
 				{	
@@ -509,12 +510,16 @@ namespace transport
 			{
 				LogPrint (eLogError, "Transports: PostMessages exception:", ex.what ());
 			}
-			if (!connected) return;
+			if (!connected) return nullptr;
 		}
 		
-		if (!peer) return;
+		if (!peer) return nullptr;
 		if (peer->IsConnected ())
-			peer->sessions.front ()->SendI2NPMessages (msgs);
+		{	
+			auto session = peer->sessions.front (); 
+			if (session) session->SendI2NPMessages (msgs);
+			return session;
+		}	
 		else
 		{
 			auto sz = peer->delayedMessages.size (); 	
@@ -527,7 +532,7 @@ namespace transport
 						LogPrint (eLogWarning, "Transports: Router ", ident.ToBase64 (), " is banned. Peer dropped");
 						std::lock_guard<std::mutex> l(m_PeersMutex);
 						m_Peers.erase (ident);
-						return;
+						return nullptr;
 					}	
 				}	
 				if (sz > MAX_NUM_DELAYED_MESSAGES/2)
@@ -549,6 +554,7 @@ namespace transport
 				m_Peers.erase (ident);
 			}
 		}
+		return nullptr;
 	}
 
 	bool Transports::ConnectToPeer (const i2p::data::IdentHash& ident, std::shared_ptr<Peer> peer)

libi2pd/Transports.h

@@ -11,6 +11,7 @@
 
 #include <thread>
 #include <mutex>
+#include <future>
 #include <condition_variable>
 #include <functional>
 #include <unordered_map>
@@ -143,9 +144,9 @@ namespace transport
 			std::shared_ptr<i2p::crypto::X25519Keys> GetNextX25519KeysPair ();
 			void ReuseX25519KeysPair (std::shared_ptr<i2p::crypto::X25519Keys> pair);
 
-			void SendMessage (const i2p::data::IdentHash& ident, std::shared_ptr<i2p::I2NPMessage> msg);
-			void SendMessages (const i2p::data::IdentHash& ident, std::list<std::shared_ptr<i2p::I2NPMessage> >& msgs);
-			void SendMessages (const i2p::data::IdentHash& ident, std::list<std::shared_ptr<i2p::I2NPMessage> >&& msgs);
+			std::future<std::shared_ptr<TransportSession> > SendMessage (const i2p::data::IdentHash& ident, std::shared_ptr<i2p::I2NPMessage> msg);
+			std::future<std::shared_ptr<TransportSession> > SendMessages (const i2p::data::IdentHash& ident, std::list<std::shared_ptr<i2p::I2NPMessage> >& msgs);
+			std::future<std::shared_ptr<TransportSession> > SendMessages (const i2p::data::IdentHash& ident, std::list<std::shared_ptr<i2p::I2NPMessage> >&& msgs);
 
 			void PeerConnected (std::shared_ptr<TransportSession> session);
 			void PeerDisconnected (std::shared_ptr<TransportSession> session);
@@ -189,7 +190,7 @@ namespace transport
 			void Run ();
 			void RequestComplete (std::shared_ptr<const i2p::data::RouterInfo> r, const i2p::data::IdentHash& ident);
 			void HandleRequestComplete (std::shared_ptr<const i2p::data::RouterInfo> r, i2p::data::IdentHash ident);
-			void PostMessages (const i2p::data::IdentHash& ident, std::list<std::shared_ptr<i2p::I2NPMessage> >& msgs);
+			std::shared_ptr<TransportSession> PostMessages (const i2p::data::IdentHash& ident, std::list<std::shared_ptr<i2p::I2NPMessage> >& msgs);
 			bool ConnectToPeer (const i2p::data::IdentHash& ident, std::shared_ptr<Peer> peer);
 			void SetPriority (std::shared_ptr<Peer> peer) const;
 			void HandlePeerCleanupTimer (const boost::system::error_code& ecode);

libi2pd/TunnelGateway.cpp

@@ -220,6 +220,7 @@ namespace tunnel
 
 	void TunnelGateway::SendBuffer ()
 	{
+		// create list or tunnel messages
 		m_Buffer.CompleteCurrentTunnelDataMessage ();
 		std::list<std::shared_ptr<I2NPMessage> > newTunnelMsgs;
 		const auto& tunnelDataMsgs = m_Buffer.GetTunnelDataMsgs ();
@@ -234,7 +235,36 @@ namespace tunnel
 			m_NumSentBytes += TUNNEL_DATA_MSG_SIZE;
 		}
 		m_Buffer.ClearTunnelDataMsgs ();
-		i2p::transport::transports.SendMessages (m_Tunnel->GetNextIdentHash (), std::move (newTunnelMsgs));
+
+		// send 
+		if (m_CurrentTransport && !m_CurrentTransport->IsEstablished ()) // check if session became invalid since last call
+			m_CurrentTransport = nullptr;
+		if (!m_CurrentTransport)
+		{
+			// try to obtain transport from peding reequest or send thought transport is not complete
+			if (m_PendingTransport.valid ()) // pending request?
+			{
+				if (m_PendingTransport.wait_for(std::chrono::seconds(0)) == std::future_status::ready) 
+				{	
+					// pending request complete
+					m_CurrentTransport = m_PendingTransport.get (); // take tarnsports used in pending request
+					if (m_CurrentTransport && !m_CurrentTransport->IsEstablished ()) 
+						m_CurrentTransport = nullptr;
+				}	
+				else // still pending
+				{	
+					// send through transports, but don't update pedning transport
+					i2p::transport::transports.SendMessages (m_Tunnel->GetNextIdentHash (), std::move (newTunnelMsgs));
+					return;
+				}	
+			}
+		}
+		if (m_CurrentTransport) // session is good
+			// send to session directly
+			m_CurrentTransport->SendI2NPMessages (newTunnelMsgs);
+		else // no session yet
+			// send through transports
+			m_PendingTransport = i2p::transport::transports.SendMessages (m_Tunnel->GetNextIdentHash (), std::move (newTunnelMsgs));
 	}
 }
 }

libi2pd/TunnelGateway.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
 *
@@ -12,7 +12,9 @@
 #include <inttypes.h>
 #include <vector>
 #include <memory>
+#include <future>
 #include "I2NPProtocol.h"
+#include "TransportSession.h"
 #include "TunnelBase.h"
 
 namespace i2p
@@ -57,6 +59,8 @@ namespace tunnel
 			TunnelBase * m_Tunnel;
 			TunnelGatewayBuffer m_Buffer;
 			size_t m_NumSentBytes;
+			std::shared_ptr<i2p::transport::TransportSession> m_CurrentTransport;
+			std::future<std::shared_ptr<i2p::transport::TransportSession> > m_PendingTransport;
 	};
 }
 }