pick peer test session only if Charlie's address supports peer testing

libi2pd/SSU2.cpp

@@ -494,7 +494,7 @@ namespace transport
 		m_PendingOutgoingSessions.erase (ep);
 	}
 
-	std::shared_ptr<SSU2Session> SSU2Server::GetRandomSession (
+	std::shared_ptr<SSU2Session> SSU2Server::GetRandomPeerTestSession (
 		i2p::data::RouterInfo::CompatibleTransports remoteTransports, const i2p::data::IdentHash& excluded) const
 	{
 		if (m_Sessions.empty ()) return nullptr;
@@ -505,7 +505,7 @@ namespace transport
 		std::advance (it, ind);
 		while (it != m_Sessions.end ())
 		{
-			if ((it->second->GetRemoteTransports () & remoteTransports) &&
+			if ((it->second->GetRemotePeerTestTransports () & remoteTransports) &&
 			    it->second->GetRemoteIdentity ()->GetIdentHash () != excluded)
 				return it->second;
 			it++;
@@ -514,7 +514,7 @@ namespace transport
 		it = m_Sessions.begin ();
 		while (it != m_Sessions.end () && ind)
 		{
-			if ((it->second->GetRemoteTransports () & remoteTransports) &&
+			if ((it->second->GetRemotePeerTestTransports () & remoteTransports) &&
 			    it->second->GetRemoteIdentity ()->GetIdentHash () != excluded)
 				return it->second;
 			it++; ind--;

libi2pd/SSU2.h

@@ -77,7 +77,7 @@ namespace transport
 			void RemovePendingOutgoingSession (const boost::asio::ip::udp::endpoint& ep);
 			std::shared_ptr<SSU2Session> FindSession (const i2p::data::IdentHash& ident) const;
 			std::shared_ptr<SSU2Session> FindPendingOutgoingSession (const boost::asio::ip::udp::endpoint& ep) const;
-			std::shared_ptr<SSU2Session> GetRandomSession (i2p::data::RouterInfo::CompatibleTransports remoteTransports,
+			std::shared_ptr<SSU2Session> GetRandomPeerTestSession (i2p::data::RouterInfo::CompatibleTransports remoteTransports,
 				const i2p::data::IdentHash& excluded) const;
 
 			void AddRelay (uint32_t tag, std::shared_ptr<SSU2Session> relay);

libi2pd/SSU2Session.cpp

@@ -81,7 +81,7 @@ namespace transport
 	SSU2Session::SSU2Session (SSU2Server& server, std::shared_ptr<const i2p::data::RouterInfo> in_RemoteRouter,
 		std::shared_ptr<const i2p::data::RouterInfo::Address> addr):
 		TransportSession (in_RemoteRouter, SSU2_CONNECT_TIMEOUT),
-		m_Server (server), m_Address (addr), m_RemoteTransports (0),
+		m_Server (server), m_Address (addr), m_RemoteTransports (0), m_RemotePeerTestTransports (0),
 		m_DestConnID (0), m_SourceConnID (0), m_State (eSSU2SessionStateUnknown),
 		m_SendPacketNum (0), m_ReceivePacketNum (0), m_LastDatetimeSentPacketNum (0),
 		m_IsDataReceived (false), m_WindowSize (SSU2_MIN_WINDOW_SIZE),
@@ -96,6 +96,8 @@ namespace transport
 			InitNoiseXKState1 (*m_NoiseState, m_Address->s);
 			m_RemoteEndpoint = boost::asio::ip::udp::endpoint (m_Address->host, m_Address->port);
 			m_RemoteTransports = in_RemoteRouter->GetCompatibleTransports (false);
+			if (in_RemoteRouter->IsSSU2PeerTesting (true)) m_RemotePeerTestTransports |= i2p::data::RouterInfo::eSSU2V4;
+			if (in_RemoteRouter->IsSSU2PeerTesting (false)) m_RemotePeerTestTransports |= i2p::data::RouterInfo::eSSU2V6;
 			RAND_bytes ((uint8_t *)&m_DestConnID, 8);
 			RAND_bytes ((uint8_t *)&m_SourceConnID, 8);
 		}
@@ -1110,6 +1112,10 @@ namespace transport
 		AdjustMaxPayloadSize ();
 		m_Server.AddSessionByRouterHash (shared_from_this ()); // we know remote router now
 		m_RemoteTransports = ri->GetCompatibleTransports (false);
+		m_RemotePeerTestTransports = 0;
+		if (ri->IsSSU2PeerTesting (true)) m_RemotePeerTestTransports |= i2p::data::RouterInfo::eSSU2V4;
+		if (ri->IsSSU2PeerTesting (false)) m_RemotePeerTestTransports |= i2p::data::RouterInfo::eSSU2V6;
+
 		// handle other blocks
 		HandlePayload (decryptedPayload.data () + riSize + 3, decryptedPayload.size () - riSize - 3);
 		Established ();
@@ -2109,7 +2115,7 @@ namespace transport
 		{
 			case 1: // Bob from Alice
 			{
-				auto session = m_Server.GetRandomSession ((buf[12] == 6) ? i2p::data::RouterInfo::eSSU2V4 : i2p::data::RouterInfo::eSSU2V6,
+				auto session = m_Server.GetRandomPeerTestSession ((buf[12] == 6) ? i2p::data::RouterInfo::eSSU2V4 : i2p::data::RouterInfo::eSSU2V6,
 					GetRemoteIdentity ()->GetIdentHash ());
 				if (session) // session with Charlie
 				{

libi2pd/SSU2Session.h

@@ -238,6 +238,7 @@ namespace transport
 			void SetRemoteEndpoint (const boost::asio::ip::udp::endpoint& ep) { m_RemoteEndpoint = ep; };
 			const boost::asio::ip::udp::endpoint& GetRemoteEndpoint () const { return m_RemoteEndpoint; };
 			i2p::data::RouterInfo::CompatibleTransports GetRemoteTransports () const { return m_RemoteTransports; };
+			i2p::data::RouterInfo::CompatibleTransports GetRemotePeerTestTransports () const { return m_RemotePeerTestTransports; };
 			std::shared_ptr<const i2p::data::RouterInfo::Address> GetAddress () const { return m_Address; };
 			void SetOnEstablished (OnEstablished e) { m_OnEstablished = e; };
 			OnEstablished GetOnEstablished () const { return m_OnEstablished; };
@@ -343,7 +344,7 @@ namespace transport
 			std::unique_ptr<HandshakePacket> m_SentHandshakePacket; // SessionRequest, SessionCreated or SessionConfirmed
 			std::shared_ptr<const i2p::data::RouterInfo::Address> m_Address;
 			boost::asio::ip::udp::endpoint m_RemoteEndpoint;
-			i2p::data::RouterInfo::CompatibleTransports m_RemoteTransports; // for peer tests
+			i2p::data::RouterInfo::CompatibleTransports m_RemoteTransports, m_RemotePeerTestTransports; 
 			uint64_t m_DestConnID, m_SourceConnID;
 			SSU2SessionState m_State;
 			uint8_t m_KeyDataSend[64], m_KeyDataReceive[64];