renew connected receintly timestamp, add endpoint to the list if hole punch is being sent

libi2pd/SSU2.cpp

@@ -210,12 +210,17 @@ namespace transport
 		return ep.port ();
 	}
 
-	bool SSU2Server::IsConnectedRecently (const boost::asio::ip::udp::endpoint& ep) const
+	bool SSU2Server::IsConnectedRecently (const boost::asio::ip::udp::endpoint& ep)
 	{
 		if (!ep.port () || ep.address ().is_unspecified ()) return false;
 		auto it = m_ConnectedRecently.find (ep);
 		if (it != m_ConnectedRecently.end ())
-			return i2p::util::GetSecondsSinceEpoch () <= it->second + SSU2_HOLE_PUNCH_EXPIRATION;
+		{	
+			if (i2p::util::GetSecondsSinceEpoch () <= it->second + SSU2_HOLE_PUNCH_EXPIRATION)
+				return true;
+			else
+				m_ConnectedRecently.erase (it);
+		}	
 		return false;
 	}	
 
@@ -223,7 +228,9 @@ namespace transport
 	{
 		if (!ep.port () || ep.address ().is_unspecified () || 
 		    i2p::util::GetSecondsSinceEpoch () > ts + SSU2_HOLE_PUNCH_EXPIRATION) return;
-		m_ConnectedRecently.try_emplace (ep, ts);
+		auto [it, added] = m_ConnectedRecently.try_emplace (ep, ts);
+		if (!added && ts > it->second)
+			it->second = ts; // renew timestamp of existing endpoint
 	}	
 		
 	void SSU2Server::AdjustTimeOffset (int64_t offset, std::shared_ptr<const i2p::data::IdentityEx> from)

libi2pd/SSU2.h

@@ -39,7 +39,7 @@ namespace transport
 	const int SSU2_KEEP_ALIVE_INTERVAL = 15; // in seconds
 	const int SSU2_KEEP_ALIVE_INTERVAL_VARIANCE = 4; // in seconds
 	const int SSU2_PROXY_CONNECT_RETRY_TIMEOUT = 30; // in seconds
-	const int SSU2_HOLE_PUNCH_EXPIRATION = 20; // in seconds
+	const int SSU2_HOLE_PUNCH_EXPIRATION = 150; // in seconds
 
 	class SSU2Server: private i2p::util::RunnableServiceWithWork
 	{
@@ -73,7 +73,7 @@ namespace transport
 			bool UsesProxy () const { return m_IsThroughProxy; };
 			bool IsSupported (const boost::asio::ip::address& addr) const;
 			uint16_t GetPort (bool v4) const;
-			bool IsConnectedRecently (const boost::asio::ip::udp::endpoint& ep) const;
+			bool IsConnectedRecently (const boost::asio::ip::udp::endpoint& ep);
 			void AddConnectedRecently (const boost::asio::ip::udp::endpoint& ep, uint64_t ts);
 			std::mt19937& GetRng () { return m_Rng; }
 			bool IsMaxNumIntroducers (bool v4) const { return (v4 ? m_Introducers.size () : m_IntroducersV6.size ()) >= SSU2_MAX_NUM_INTRODUCERS; }

libi2pd/SSU2Session.cpp

@@ -2054,6 +2054,7 @@ namespace transport
 							token = m_Server.GetIncomingToken (ep);
 							isV4 = ep.address ().is_v4 ();
 							SendHolePunch (bufbe32toh (buf + 33), ep, addr->i, token);
+							m_Server.AddConnectedRecently (ep, i2p::util::GetSecondsSinceEpoch ());
 						}
 						else
 						{