handle PeerTest msg 1

libi2pd/SSU2.cpp

@@ -245,6 +245,31 @@ namespace transport
 		return nullptr;
 	}	
 
+	std::shared_ptr<SSU2Session> SSU2Server::GetRandomSession (i2p::data::RouterInfo::CompatibleTransports remoteTransports) const
+	{
+		if (m_Sessions.empty ()) return nullptr;
+		uint16_t ind;
+		RAND_bytes ((uint8_t *)&ind, sizeof (ind));
+		ind %= m_Sessions.size ();
+		auto it = m_Sessions.begin ();
+		std::advance (it, ind);
+		while (it != m_Sessions.end ())
+		{
+			if (it->second->GetRemoteTransports () & remoteTransports)
+				return it->second;
+			it++;
+		}
+		// not found, try from begining
+		it = m_Sessions.begin ();
+		while (it != m_Sessions.end () && ind)
+		{
+			if (it->second->GetRemoteTransports () & remoteTransports)
+				return it->second;
+			it++; ind--;
+		}	
+		return nullptr;
+	}	
+		
 	void SSU2Server::AddRelay (uint32_t tag, std::shared_ptr<SSU2Session> relay)
 	{
 		m_Relays.emplace (tag, relay);

libi2pd/SSU2.h

@@ -54,6 +54,7 @@ namespace transport
 			void AddSessionByRouterHash (std::shared_ptr<SSU2Session> session);
 			void AddPendingOutgoingSession (std::shared_ptr<SSU2Session> session);
 			std::shared_ptr<SSU2Session> FindSession (const i2p::data::IdentHash& ident) const;
+			std::shared_ptr<SSU2Session> GetRandomSession (i2p::data::RouterInfo::CompatibleTransports remoteTransports) const;
 		
 			void AddRelay (uint32_t tag, std::shared_ptr<SSU2Session> relay);
 			void RemoveRelay (uint32_t tag);

libi2pd/SSU2Session.cpp

@@ -22,9 +22,10 @@ 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_DestConnID (0), m_SourceConnID (0),
+		m_Server (server), m_Address (addr), m_RemoteTransports (0),
-		m_State (eSSU2SessionStateUnknown), m_SendPacketNum (0), m_ReceivePacketNum (0),
+		m_DestConnID (0), m_SourceConnID (0), m_State (eSSU2SessionStateUnknown),
-		m_IsDataReceived (false), m_WindowSize (SSU2_MAX_WINDOW_SIZE), m_RelayTag (0)
+		m_SendPacketNum (0), m_ReceivePacketNum (0), m_IsDataReceived (false), 
+		m_WindowSize (SSU2_MAX_WINDOW_SIZE), m_RelayTag (0)
 	{
 		m_NoiseState.reset (new i2p::crypto::NoiseSymmetricState);
 		if (in_RemoteRouter && m_Address)
@@ -32,6 +33,7 @@ namespace transport
 			// outgoing
 			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);
 			RAND_bytes ((uint8_t *)&m_DestConnID, 8);
 			RAND_bytes ((uint8_t *)&m_SourceConnID, 8);
 		}
@@ -612,6 +614,7 @@ namespace transport
 			LogPrint (eLogError, "SSU2: No SSU2 address with static key found in SessionConfirmed");
 			return false;
 		}
+		m_RemoteTransports = ri->GetCompatibleTransports (false);
 		i2p::data::netdb.PostI2NPMsg (CreateI2NPMessage (eI2NPDummyMsg, ri->GetBuffer (), ri->GetBufferLen ())); // TODO: should insert ri
 		// handle other blocks
 		HandlePayload (decryptedPayload.data () + riSize + 3, decryptedPayload.size () - riSize - 3);
@@ -1333,12 +1336,37 @@ namespace transport
 		{
 			case 1: // Bob from Alice
 			{	
-				// TODO: find Charlie	
+				auto session = m_Server.GetRandomSession ((buf[12] == 6) ? i2p::data::RouterInfo::eSSU2V4 : i2p::data::RouterInfo::eSSU2V6);
+				if (session) // session with Charlie
+				{
+					session->m_PeerTests.emplace (nonce, std::make_pair (shared_from_this (), i2p::util::GetSecondsSinceEpoch ()));
+					uint8_t payload[SSU2_MAX_PAYLOAD_SIZE];
+					// Alice's RouterInfo
+					auto r = i2p::data::netdb.FindRouter (GetRemoteIdentity ()->GetIdentHash ());
+					size_t payloadSize = r ? CreateRouterInfoBlock (payload, SSU2_MAX_PAYLOAD_SIZE - len - 32, r) : 0;
+					if (!payloadSize && r)
+						session->SendFragmentedMessage (CreateDatabaseStoreMsg (r));
+					if (payloadSize + len + 48 > SSU2_MAX_PAYLOAD_SIZE)
+					{
+						// doesn't fit one message, send RouterInfo in separate message
+						session->SendData (payload, payloadSize);
+						payloadSize = 0;
+					}	
+					// PeerTest to Charlie
+					payloadSize += CreatePeerTestBlock (payload, SSU2_MAX_PAYLOAD_SIZE - payloadSize, 2, 
+						eSSU2PeerTestCodeAccept, GetRemoteIdentity ()->GetIdentHash (), buf + 3, len - 3);
+					payloadSize += CreatePaddingBlock (payload + payloadSize, SSU2_MAX_PAYLOAD_SIZE - payloadSize);
+					session->SendData (payload, payloadSize);
+				}
+				else
+				{
+					// Charlie not found, send error back to Alice
 					uint8_t payload[SSU2_MAX_PAYLOAD_SIZE], zeroHash[32] = {0};
 					size_t payloadSize = CreatePeerTestBlock (payload, SSU2_MAX_PAYLOAD_SIZE, 4, 
 						eSSU2PeerTestCodeBobNoCharlieAvailable, zeroHash, buf + 3, len - 3);
 					payloadSize += CreatePaddingBlock (payload + payloadSize, SSU2_MAX_PAYLOAD_SIZE - payloadSize);
 					SendData (payload, payloadSize);
+				}	
 				break;
 			}
 			case 2: // Charlie from Bob
@@ -1401,7 +1429,19 @@ namespace transport
 				if (it != m_PeerTests.end () && it->second.first)
 				{
 					uint8_t payload[SSU2_MAX_PAYLOAD_SIZE];
-					size_t payloadSize = CreatePeerTestBlock (payload, SSU2_MAX_PAYLOAD_SIZE, 4, 
+					// Charlie's RouterInfo
+					auto r = i2p::data::netdb.FindRouter (GetRemoteIdentity ()->GetIdentHash ());
+					size_t payloadSize = r ? CreateRouterInfoBlock (payload, SSU2_MAX_PAYLOAD_SIZE - len - 32, r) : 0;
+					if (!payloadSize && r)
+						it->second.first->SendFragmentedMessage (CreateDatabaseStoreMsg (r));
+					if (payloadSize + len + 16 > SSU2_MAX_PAYLOAD_SIZE)
+					{
+						// doesn't fit one message, send RouterInfo in separate message
+						it->second.first->SendData (payload, payloadSize);
+						payloadSize = 0;
+					}
+					// PeerTest to Alice
+					payloadSize = CreatePeerTestBlock (payload, SSU2_MAX_PAYLOAD_SIZE, 4, 
 						(SSU2PeerTestCode)buf[1], GetRemoteIdentity ()->GetIdentHash (), buf + 3, len - 3);
 					if (payloadSize < SSU2_MAX_PAYLOAD_SIZE)
 						payloadSize += CreatePaddingBlock (payload + payloadSize, SSU2_MAX_PAYLOAD_SIZE - payloadSize);

libi2pd/SSU2Session.h

@@ -160,6 +160,7 @@ 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; };
 			void SetOnEstablished (OnEstablished e) { m_OnEstablished = e; };
 
 			void Connect ();
@@ -244,6 +245,7 @@ namespace transport
 			std::unique_ptr<SessionConfirmedFragment> m_SessionConfirmedFragment1; // for Bob if applicable
 			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
 			uint64_t m_DestConnID, m_SourceConnID;
 			SSU2SessionState m_State;
 			uint8_t m_KeyDataSend[64], m_KeyDataReceive[64];