address resolver for NTCP address

RouterInfo.h

@@ -69,6 +69,7 @@ namespace data
 			{
 				TransportStyle transportStyle;
 				boost::asio::ip::address host;
+				char * addressString;
 				int port, mtu;
 				uint64_t date;
 				uint8_t cost;
@@ -76,6 +77,9 @@ namespace data
 				Tag<32> key; // intro key for SSU
 				std::vector<Introducer> introducers;
 
+				Address (): addressString (nullptr) {};
+				~Address () { if (addressString) delete[] addressString; };
+
 				bool IsCompatible (const boost::asio::ip::address& other) const 
 				{
 					return (host.is_v4 () && other.is_v4 ()) ||

Transports.cpp

@@ -219,11 +219,26 @@ namespace transport
 			{
 				peer.numAttempts++;
 				auto address = peer.router->GetNTCPAddress (!context.SupportsV6 ());
-				if (address && !peer.router->UsesIntroducer () && !peer.router->IsUnreachable ())
+				if (address)
 				{
-					auto s = std::make_shared<NTCPSession> (*m_NTCPServer, peer.router);
-					m_NTCPServer->Connect (address->host, address->port, s);
-					return true;
+					if (!address->host.is_unspecified ()) // we have address now
+					{
+						if (!peer.router->UsesIntroducer () && !peer.router->IsUnreachable ())
+						{	
+							auto s = std::make_shared<NTCPSession> (*m_NTCPServer, peer.router);
+							m_NTCPServer->Connect (address->host, address->port, s);
+							return true;
+						}
+					}
+					else // we don't have address
+					{
+						if (address->addressString) // trying to resolve
+						{
+							LogPrint (eLogInfo, "Resolving ", address->addressString);
+							NTCPResolve (address->addressString, ident);
+							return true;
+						}
+					}
 				}	
 			}
 			else  if (peer.numAttempts == 1)// SSU
@@ -272,6 +287,39 @@ namespace transport
 		}	
 	}	
 
+	void Transports::NTCPResolve (const char * addr, const i2p::data::IdentHash& ident)
+	{
+		auto resolver = std::make_shared<boost::asio::ip::tcp::resolver>(m_Service);
+		resolver->async_resolve (boost::asio::ip::tcp::resolver::query (addr), 
+			std::bind (&Transports::HandleNTCPResolve, this, 
+				std::placeholders::_1, std::placeholders::_2, ident, resolver));
+	}
+
+	void Transports::HandleNTCPResolve (const boost::system::error_code& ecode, boost::asio::ip::tcp::resolver::iterator it, 
+		const i2p::data::IdentHash& ident, std::shared_ptr<boost::asio::ip::tcp::resolver> resolver)
+	{
+		auto it1 = m_Peers.find (ident);
+		if (it1 != m_Peers.end () && it1->second.router)
+		{
+			auto& peer = it1->second;
+			if (!ecode)
+			{
+				auto address = (*it).endpoint ().address ();
+				LogPrint (eLogInfo, (*it).host_name (), " has been resolved to ", address);
+				auto addr = peer.router->GetNTCPAddress ();
+				if (addr)
+				{
+					auto s = std::make_shared<NTCPSession> (*m_NTCPServer, peer.router);
+					m_NTCPServer->Connect (address, addr->port, s);
+					return;
+				}	
+			}
+		}
+
+		LogPrint (eLogError, "Unable to resolve NTCP address: ", ecode.message ());
+		m_Peers.erase (it1);
+	}
+
 	void Transports::CloseSession (std::shared_ptr<const i2p::data::RouterInfo> router)
 	{
 		if (!router) return;

Transports.h

@@ -94,6 +94,10 @@ namespace transport
 			void PostCloseSession (std::shared_ptr<const i2p::data::RouterInfo> router);
 			bool ConnectToPeer (const i2p::data::IdentHash& ident, Peer& peer);
 			
+			void NTCPResolve (const char * addr, const i2p::data::IdentHash& ident);
+			void HandleNTCPResolve (const boost::system::error_code& ecode, boost::asio::ip::tcp::resolver::iterator it,
+ 				const i2p::data::IdentHash& ident, std::shared_ptr<boost::asio::ip::tcp::resolver> resolver);
+
 			void DetectExternalIP ();
 			
 		private: