select router with ipv4 for endpoint

libi2pd/NetDb.cpp

@@ -59,7 +59,7 @@ namespace data
 		{
 			Reseed ();
 		}
-		else if (!GetRandomRouter (i2p::context.GetSharedRouterInfo (), false))
+		else if (!GetRandomRouter (i2p::context.GetSharedRouterInfo (), false, false))
 			Reseed (); // we don't have a router we can connect to. Trying to reseed
 
 		auto it = m_RouterInfos.find (i2p::context.GetIdentHash ());
@@ -1199,15 +1199,17 @@ namespace data
 			});
 	}
 
-	std::shared_ptr<const RouterInfo> NetDb::GetRandomRouter (std::shared_ptr<const RouterInfo> compatibleWith, bool reverse) const
+	std::shared_ptr<const RouterInfo> NetDb::GetRandomRouter (std::shared_ptr<const RouterInfo> compatibleWith,
+		bool reverse, bool endpoint) const
 	{
 		return GetRandomRouter (
-			[compatibleWith, reverse](std::shared_ptr<const RouterInfo> router)->bool
+			[compatibleWith, reverse, endpoint](std::shared_ptr<const RouterInfo> router)->bool
 			{
 				return !router->IsHidden () && router != compatibleWith &&
 					(reverse ? compatibleWith->IsReachableFrom (*router) :
 						router->IsReachableFrom (*compatibleWith)) &&
-					router->IsECIES () && !router->IsHighCongestion (false);
+					router->IsECIES () && !router->IsHighCongestion (false) &&
+					(!endpoint || (router->IsV4 () && (!reverse || router->IsPublished (true)))); // endpoint must be ipv4 and published if inbound(reverse)
 			});
 	}
 
@@ -1231,17 +1233,20 @@ namespace data
 			});
 	}
 
-	std::shared_ptr<const RouterInfo> NetDb::GetHighBandwidthRandomRouter (std::shared_ptr<const RouterInfo> compatibleWith, bool reverse) const
+	std::shared_ptr<const RouterInfo> NetDb::GetHighBandwidthRandomRouter (std::shared_ptr<const RouterInfo> compatibleWith, 
+		bool reverse, bool endpoint) const
 	{
 		return GetRandomRouter (
-			[compatibleWith, reverse](std::shared_ptr<const RouterInfo> router)->bool
+			[compatibleWith, reverse, endpoint](std::shared_ptr<const RouterInfo> router)->bool
 			{
 				return !router->IsHidden () && router != compatibleWith &&
 					(reverse ? compatibleWith->IsReachableFrom (*router) :
 						router->IsReachableFrom (*compatibleWith)) &&
 					(router->GetCaps () & RouterInfo::eHighBandwidth) &&
 					router->GetVersion () >= NETDB_MIN_HIGHBANDWIDTH_VERSION &&
-					router->IsECIES () && !router->IsHighCongestion (true);
+					router->IsECIES () && !router->IsHighCongestion (true) &&
+					(!endpoint || (router->IsV4 () && (!reverse || router->IsPublished (true)))); // endpoint must be ipv4 and published if inbound(reverse)
+
 			});
 	}
 

libi2pd/NetDb.hpp

@@ -84,8 +84,8 @@ namespace data
 			void HandleNTCP2RouterInfoMsg (std::shared_ptr<const I2NPMessage> m);
 
 			std::shared_ptr<const RouterInfo> GetRandomRouter () const;
-			std::shared_ptr<const RouterInfo> GetRandomRouter (std::shared_ptr<const RouterInfo> compatibleWith, bool reverse) const;
-			std::shared_ptr<const RouterInfo> GetHighBandwidthRandomRouter (std::shared_ptr<const RouterInfo> compatibleWith, bool reverse) const;
+			std::shared_ptr<const RouterInfo> GetRandomRouter (std::shared_ptr<const RouterInfo> compatibleWith, bool reverse, bool endpoint) const;
+			std::shared_ptr<const RouterInfo> GetHighBandwidthRandomRouter (std::shared_ptr<const RouterInfo> compatibleWith, bool reverse, bool endpoint) const;
 			std::shared_ptr<const RouterInfo> GetRandomSSU2PeerTestRouter (bool v4, const std::set<IdentHash>& excluded) const;
 			std::shared_ptr<const RouterInfo> GetRandomSSU2Introducer (bool v4, const std::set<IdentHash>& excluded) const;
 			std::shared_ptr<const RouterInfo> GetClosestFloodfill (const IdentHash& destination, const std::set<IdentHash>& excluded) const;

libi2pd/Tunnel.cpp

@@ -709,7 +709,7 @@ namespace tunnel
 			auto inboundTunnel = GetNextInboundTunnel ();
 			auto router = i2p::transport::transports.RoutesRestricted() ?
 				i2p::transport::transports.GetRestrictedPeer() :
-				i2p::data::netdb.GetRandomRouter (i2p::context.GetSharedRouterInfo (), false); // reachable by us
+				i2p::data::netdb.GetRandomRouter (i2p::context.GetSharedRouterInfo (), false, true); // reachable by us
 			if (!inboundTunnel || !router) return;
 			LogPrint (eLogDebug, "Tunnel: Creating one hop outbound tunnel");
 			CreateTunnel<OutboundTunnel> (
@@ -781,7 +781,7 @@ namespace tunnel
 			auto router = i2p::transport::transports.RoutesRestricted() ?
 				i2p::transport::transports.GetRestrictedPeer() :
 				// should be reachable by us because we send build request directly
-				i2p::data::netdb.GetRandomRouter (i2p::context.GetSharedRouterInfo (), false);
+				i2p::data::netdb.GetRandomRouter (i2p::context.GetSharedRouterInfo (), false, true);
 			if (!router) {
 				LogPrint (eLogWarning, "Tunnel: Can't find any router, skip creating tunnel");
 				return;

libi2pd/TunnelPool.cpp

@@ -470,13 +470,14 @@ namespace tunnel
 		return i2p::tunnel::tunnels.GetExploratoryPool () == shared_from_this ();
 	}
 
-	std::shared_ptr<const i2p::data::RouterInfo> TunnelPool::SelectNextHop (std::shared_ptr<const i2p::data::RouterInfo> prevHop, bool reverse) const
+	std::shared_ptr<const i2p::data::RouterInfo> TunnelPool::SelectNextHop (std::shared_ptr<const i2p::data::RouterInfo> prevHop, 
+		bool reverse, bool endpoint) const
 	{
-		auto hop = IsExploratory () ? i2p::data::netdb.GetRandomRouter (prevHop, reverse):
-			i2p::data::netdb.GetHighBandwidthRandomRouter (prevHop, reverse);
+		auto hop = IsExploratory () ? i2p::data::netdb.GetRandomRouter (prevHop, reverse, endpoint):
+			i2p::data::netdb.GetHighBandwidthRandomRouter (prevHop, reverse, endpoint);
 
 		if (!hop || hop->GetProfile ()->IsBad ())
-			hop = i2p::data::netdb.GetRandomRouter (prevHop, reverse);
+			hop = i2p::data::netdb.GetRandomRouter (prevHop, reverse, endpoint);
 		return hop;
 	}
 
@@ -508,7 +509,7 @@ namespace tunnel
 
 		for(int i = start; i < numHops; i++ )
 		{
-			auto hop = nextHop (prevHop, inbound);
+			auto hop = nextHop (prevHop, inbound, i == numHops - 1);
 			if (!hop && !i) // if no suitable peer found for first hop, try already connected
 			{
 				LogPrint (eLogInfo, "Tunnels: Can't select first hop for a tunnel. Trying already connected");
@@ -520,11 +521,6 @@ namespace tunnel
 				LogPrint (eLogError, "Tunnels: Can't select next hop for ", prevHop->GetIdentHashBase64 ());
 				return false;
 			}
-			if ((i == numHops - 1) && (!hop->IsV4 () || (inbound && !hop->IsPublished (true)))) // IBGW is not published ipv4
-			{
-				auto hop1 = nextHop (prevHop, inbound);
-				if (hop1) hop = hop1;
-			}
 			prevHop = hop;
 			path.Add (hop);
 		}
@@ -566,7 +562,8 @@ namespace tunnel
 			if (m_CustomPeerSelector)
 				return m_CustomPeerSelector->SelectPeers(path, numHops, isInbound);
 		}
-		return StandardSelectPeers(path, numHops, isInbound, std::bind(&TunnelPool::SelectNextHop, this, std::placeholders::_1, std::placeholders::_2));
+		return StandardSelectPeers(path, numHops, isInbound, std::bind(&TunnelPool::SelectNextHop, this, 
+			std::placeholders::_1, std::placeholders::_2, std::placeholders::_3));
 	}
 
 	bool TunnelPool::SelectExplicitPeers (Path& path, bool isInbound)

libi2pd/TunnelPool.h

@@ -56,7 +56,7 @@ namespace tunnel
 
 	class TunnelPool: public std::enable_shared_from_this<TunnelPool> // per local destination
 	{
-		typedef std::function<std::shared_ptr<const i2p::data::RouterInfo>(std::shared_ptr<const i2p::data::RouterInfo>, bool)> SelectHopFunc;
+		typedef std::function<std::shared_ptr<const i2p::data::RouterInfo>(std::shared_ptr<const i2p::data::RouterInfo>, bool, bool)> SelectHopFunc;
 		public:
 
 			TunnelPool (int numInboundHops, int numOutboundHops, int numInboundTunnels,
@@ -112,7 +112,7 @@ namespace tunnel
 			std::shared_ptr<OutboundTunnel> GetLowestLatencyOutboundTunnel(std::shared_ptr<OutboundTunnel> exclude = nullptr) const;
 
 			// for overriding tunnel peer selection
-			std::shared_ptr<const i2p::data::RouterInfo> SelectNextHop (std::shared_ptr<const i2p::data::RouterInfo> prevHop, bool reverse) const;
+			std::shared_ptr<const i2p::data::RouterInfo> SelectNextHop (std::shared_ptr<const i2p::data::RouterInfo> prevHop, bool reverse, bool endpoint) const;
 			bool StandardSelectPeers(Path & path, int numHops, bool inbound, SelectHopFunc nextHop);
 
 		private:

libi2pd_client/MatchedDestination.cpp

@@ -73,7 +73,8 @@ namespace client
 	{
 		auto pool = GetTunnelPool();
 		if(!pool || !pool->StandardSelectPeers(path, hops, inbound,
-			std::bind(&i2p::tunnel::TunnelPool::SelectNextHop, pool, std::placeholders::_1, std::placeholders::_2)))
+			std::bind(&i2p::tunnel::TunnelPool::SelectNextHop, pool, std::placeholders::_1, 
+				std::placeholders::_2, std::placeholders::_3)))
 			return false;
 		// more here for outbound tunnels
 		if(!inbound && m_RemoteLeaseSet)