don't create SSU session for HolePunch

libi2pd/SSU.cpp

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2020, The PurpleI2P Project
+* Copyright (c) 2013-2021, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -385,7 +385,7 @@ namespace transport
 					auto it = sessions->find (packet->from);
 					if (it != sessions->end ())
 						session = it->second;
-					if (!session)
+					if (!session && packet->len > 0)
 					{
 						session = std::make_shared<SSUSession> (*this, packet->from);
 						session->WaitForConnect ();

libi2pd/SSUSession.cpp

@@ -418,6 +418,7 @@ namespace transport
 		else
 			FillHeaderAndEncrypt (PAYLOAD_TYPE_RELAY_REQUEST, buf, 96, introducer.iKey, iv, introducer.iKey);
 		m_Server.Send (buf, 96, m_RemoteEndpoint);
+		LogPrint (eLogDebug, "SSU: relay request sent");
 	}
 
 	void SSUSession::SendSessionCreated (const uint8_t * x, bool sendRelayTag)
@@ -682,6 +683,7 @@ namespace transport
 				LogPrint (eLogInfo, "SSU: RelayReponse connecting to endpoint ", remoteEndpoint);
 				if (i2p::context.GetRouterInfo ().UsesIntroducer ()) // if we are unreachable
 					m_Server.Send (buf, 0, remoteEndpoint); // send HolePunch
+				// we assume that HolePunch has been sent by this time and our SessionRequest will go through
 				m_Server.CreateDirectSession (it->second, remoteEndpoint, false);
 			}
 			// delete request