check for transport protocols compatibility between routers

NetDb.cpp

@@ -427,7 +427,7 @@ namespace data
 		auto inbound = i2p::tunnel::tunnels.GetNextInboundTunnel ();
 		if (outbound && inbound)
 		{
-			auto floodfill = GetRandomNTCPRouter (true);
+			auto floodfill = GetRandomRouter (outbound->GetEndpointRouter (), true);
 			if (floodfill)
 			{
 				LogPrint ("Exploring new routers ...");
@@ -495,19 +495,29 @@ namespace data
 		return last;
 	}	
 
-	const RouterInfo * NetDb::GetRandomRouter () const
+	const RouterInfo * NetDb::GetRandomRouter (const RouterInfo * compatibleWith, bool floodfillOnly) const
 	{
 		CryptoPP::RandomNumberGenerator& rnd = i2p::context.GetRandomNumberGenerator ();
-		uint32_t ind = rnd.GenerateWord32 (0, m_RouterInfos.size () - 1), i = 0;
-		RouterInfo * last = nullptr;	
+		uint32_t ind = rnd.GenerateWord32 (0, m_RouterInfos.size () - 1);	
+		for (int j = 0; j < 2; j++)
+		{	
+			uint32_t i = 0;
 			for (auto it: m_RouterInfos)
 			{	
-			if (!it.second->IsUnreachable ())
-				last = it.second;
-			if (i >= ind) break;
-			else i++;
+				if (i >= ind)
+				{	
+					if (!it.second->IsUnreachable () && 
+					 (!compatibleWith || it.second->IsCompatible (*compatibleWith)) &&
+					 (!floodfillOnly || it.second->IsFloodfill ()))
+						return it.second;
 				}	
-		return last;
+				else 
+					i++;
+			}
+			// we couldn't find anything, try second pass
+			ind = 0;
+		}	
+		return nullptr; // seem we have too few routers
 	}	
 
 	void NetDb::PostI2NPMsg (I2NPMessage * msg)

NetDb.h

@@ -68,7 +68,7 @@ namespace data
 			void HandleDatabaseSearchReplyMsg (I2NPMessage * msg);
 			
 			const RouterInfo * GetRandomNTCPRouter (bool floodfillOnly = false) const;
-			const RouterInfo * GetRandomRouter () const;
+			const RouterInfo * GetRandomRouter (const RouterInfo * compatibleWith = nullptr, bool floodfillOnly = false) const;
 
 			void PostI2NPMsg (I2NPMessage * msg);
 			

RouterInfo.cpp

@@ -13,19 +13,18 @@
 #include "RouterContext.h"
 
 
-
 namespace i2p
 {
 namespace data
 {		
 	RouterInfo::RouterInfo (const char * filename):
-		m_IsUpdated (false), m_IsUnreachable (false)
+		m_IsUpdated (false), m_IsUnreachable (false), m_SupportedTransports (0)
 	{
 		ReadFromFile (filename);
 	}	
 
 	RouterInfo::RouterInfo (const uint8_t * buf, int len):
-		m_IsUpdated (true)
+		m_IsUpdated (true), m_IsUnreachable (false), m_SupportedTransports (0)
 	{
 		memcpy (m_Buffer, buf, len);
 		m_BufferLen = len;
@@ -112,6 +111,14 @@ namespace data
 						LogPrint ("Unexpected address ", value);
 						SetUnreachable (true);
 					}	
+					else
+					{
+						// add supported protocol
+						if (address.host.is_v4 ())
+							m_SupportedTransports |= (address.transportStyle == eTransportNTCP) ? eNTCPV4 : eSSUV4;	
+						else
+							m_SupportedTransports |= (address.transportStyle == eTransportNTCP) ? eNTCPV6 : eSSUV6;
+ 					}	
 				}	
 				else if (!strcmp (key, "port"))
 					address.port = boost::lexical_cast<int>(value);
@@ -275,15 +282,10 @@ namespace data
 
 	bool RouterInfo::IsNTCP (bool v4only) const
 	{
-		for (auto& address : m_Addresses)
-		{
-			if (address.transportStyle == eTransportNTCP)
-			{	
-				if (!v4only || address.host.is_v4 ())
-					return true;
-			}	
-		}		
-		return false;
+		if (v4only)
+			return m_SupportedTransports & eNTCPV4;
+		else
+			return m_SupportedTransports & (eNTCPV4 | eNTCPV6);
 	}		
 		
 	RouterInfo::Address * RouterInfo::GetNTCPAddress (bool v4only)

RouterInfo.h

@@ -17,6 +17,14 @@ namespace data
 	{
 		public:
 
+			enum SupportedTranports
+			{	
+				eNTCPV4 = 0x01,
+				eNTCPV6 = 0x20,
+				eSSUV4 = 0x40,
+				eSSUV6 = 0x80
+			};
+			
 			enum TransportStyle
 			{
 				eTransportUnknown = 0,
@@ -53,6 +61,8 @@ namespace data
 			const char * GetProperty (const char * key) const;
 			bool IsFloodfill () const;
 			bool IsNTCP (bool v4only = true) const;
+			bool IsCompatible (const RouterInfo& other) const { return m_SupportedTransports & other.m_SupportedTransports; };
+			
 			void SetUnreachable (bool unreachable) { m_IsUnreachable = unreachable; }; 
 			bool IsUnreachable () const { return m_IsUnreachable; };
 			
@@ -91,6 +101,7 @@ namespace data
 			std::vector<Address> m_Addresses;
 			std::map<std::string, std::string> m_Properties;
 			bool m_IsUpdated, m_IsUnreachable;
+			uint8_t m_SupportedTransports;
 	};	
 }	
 }

Tunnel.cpp

@@ -397,11 +397,12 @@ namespace tunnel
 			{
 
 				LogPrint ("Creating two hops outbound tunnel...");
+				auto firstHop = i2p::data::netdb.GetRandomNTCPRouter (); // first hop must be NTCP
 				CreateTunnel<OutboundTunnel> (
 				  	new TunnelConfig (std::vector<const i2p::data::RouterInfo *>
 				    	{
-							i2p::data::netdb.GetRandomNTCPRouter (), // first hop must be NTCP
-							i2p::data::netdb.GetRandomRouter ()
+							firstHop,
+							i2p::data::netdb.GetRandomRouter (firstHop)
 						},		
 			     		inboundTunnel->GetTunnelConfig ()));
 			}	
@@ -449,8 +450,8 @@ namespace tunnel
 				CreateTunnel<InboundTunnel> (
 					new TunnelConfig (std::vector<const i2p::data::RouterInfo *>
 						{                
-				            i2p::data::netdb.GetRandomNTCPRouter (), 
-							router != &i2p::context.GetRouterInfo () ? router : i2p::data::netdb.GetRandomNTCPRouter ()
+				            i2p::data::netdb.GetRandomRouter (outboundTunnel->GetEndpointRouter ()), 
+							router != &i2p::context.GetRouterInfo () ? router : i2p::data::netdb.GetRandomNTCPRouter () // last hop must be NTCP
 		                }),                 
 				    outboundTunnel);
 			}	

Tunnel.h

@@ -67,7 +67,8 @@ namespace tunnel
 
 			void SendTunnelDataMsg (const uint8_t * gwHash, uint32_t gwTunnel, i2p::I2NPMessage * msg);
 			void SendTunnelDataMsg (std::vector<TunnelMessageBlock> msgs); // multiple messages
-			
+			const i2p::data::RouterInfo * GetEndpointRouter () const 
+				{ return GetTunnelConfig ()->GetLastHop ()->router; }; 
 			size_t GetNumSentBytes () const { return m_Gateway.GetNumSentBytes (); };
 
 			// implements TunnelBase