fix datagram bugs

Datagram.cpp

@@ -255,9 +255,11 @@ namespace datagram
 			}
 			if(m_CurrentRemoteLease && m_CurrentRemoteLease->ExpiresWithin(DATAGRAM_SESSION_LEASE_HANDOVER_WINDOW)) {
 				// bad lease, switch to next one
+				if(m_RemoteLeaseSet && m_RemoteLeaseSet->IsExpired())
+					m_RemoteLeaseSet = m_LocalDestination->FindLeaseSet(m_RemoteIdent);
 				if(m_RemoteLeaseSet) {
 					auto ls = m_RemoteLeaseSet->GetNonExpiredLeasesExcluding([&](const i2p::data::Lease& l) -> bool {
-							return l.tunnelGateway == m_CurrentRemoteLease->tunnelGateway;
+							return l.tunnelID == m_CurrentRemoteLease->tunnelID;
 					});
 					auto sz = ls.size();
 					if (sz) {
@@ -278,7 +280,7 @@ namespace datagram
 				m_CurrentOutboundTunnel = m_LocalDestination->GetTunnelPool()->GetNextOutboundTunnel(m_CurrentOutboundTunnel);
 			}
 			// switch lease if bad
-			if(m_CurrentRemoteLease == nullptr || m_CurrentRemoteLease->ExpiresWithin(DATAGRAM_SESSION_LEASE_HANDOVER_WINDOW)) {
+			if(m_CurrentRemoteLease && m_CurrentRemoteLease->ExpiresWithin(DATAGRAM_SESSION_LEASE_HANDOVER_WINDOW)) {
 				if(!m_RemoteLeaseSet) {
 					m_RemoteLeaseSet = m_LocalDestination->FindLeaseSet(m_RemoteIdent);
 				}
@@ -299,6 +301,17 @@ namespace datagram
 					LogPrint(eLogWarning, "DatagramSession: no remote lease set found for ", m_RemoteIdent.ToBase32());
 					return nullptr;
 				}
+			} else if (!m_CurrentRemoteLease) {
+				if(!m_RemoteLeaseSet) m_RemoteLeaseSet = m_LocalDestination->FindLeaseSet(m_RemoteIdent);
+				if (m_RemoteLeaseSet)
+				{
+					auto ls = m_RemoteLeaseSet->GetNonExpiredLeases();
+					auto sz = ls.size();
+					if (sz) {
+						auto idx = rand() % sz;
+						m_CurrentRemoteLease = ls[idx];
+					}
+				}
 			}
 			path->outboundTunnel = m_CurrentOutboundTunnel;
 			path->remoteLease = m_CurrentRemoteLease;
@@ -346,7 +359,7 @@ namespace datagram
 
 	void DatagramSession::ScheduleFlushSendQueue()
 	{
-		boost::posix_time::milliseconds dlt(100);
+		boost::posix_time::milliseconds dlt(10);
 		m_SendQueueTimer.expires_from_now(dlt);
 		auto self = shared_from_this();
 		m_SendQueueTimer.async_wait([self](const boost::system::error_code & ec) { if(ec) return; self->FlushSendQueue(); });

Datagram.h

@@ -26,7 +26,7 @@ namespace datagram
 	// milliseconds interval a routing path is used before switching
 	const uint64_t DATAGRAM_SESSION_PATH_SWITCH_INTERVAL = 20 * 60 * 1000;
 	// milliseconds before lease expire should we try switching leases
-	const uint64_t DATAGRAM_SESSION_LEASE_HANDOVER_WINDOW = 10 * 1000;
+	const uint64_t DATAGRAM_SESSION_LEASE_HANDOVER_WINDOW = 30 * 1000;
 	// milliseconds fudge factor for leases handover
 	const uint64_t DATAGRAM_SESSION_LEASE_HANDOVER_FUDGE = 1000;
 	// milliseconds minimum time between path switches

LeaseSet.h

@@ -30,7 +30,8 @@ namespace data
 		bool ExpiresWithin( const uint64_t t, const uint64_t fudge = 1000 ) const {
 			auto expire = i2p::util::GetMillisecondsSinceEpoch ();
 			if(fudge) expire += rand() % fudge;
-			return endDate - expire >= t;
+			if (endDate < expire) return true;
+			return (endDate - expire) < t;
 		}
 	};