don't send termination again if termination received block received

libi2pd/SSU2.cpp

@@ -496,9 +496,10 @@ namespace transport
 				break;
 				case eSSU2SessionStateClosing:
 					m_LastSession->ProcessData (buf, len, senderEndpoint); // we might receive termintaion block
-					if (m_LastSession && m_LastSession->GetState () != eSSU2SessionStateTerminated)
+					if (m_LastSession && m_LastSession->GetState () == eSSU2SessionStateClosing)
 						m_LastSession->RequestTermination (eSSU2TerminationReasonIdleTimeout); // send termination again
 				break;
+				case eSSU2SessionStateClosingConfirmed:	
 				case eSSU2SessionStateTerminated:
 					m_LastSession = nullptr;
 				break;

libi2pd/SSU2Session.cpp

@@ -1462,12 +1462,19 @@ namespace transport
 					m_IsDataReceived = true;
 				break;
 				case eSSU2BlkTermination:
-					LogPrint (eLogDebug, "SSU2: Termination reason=", (int)buf[11]);
+				{	
-					if (IsEstablished () && buf[11] != eSSU2TerminationReasonTerminationReceived)
+					uint8_t rsn = buf[11]; // reason		
+					LogPrint (eLogDebug, "SSU2: Termination reason=", (int)rsn);
+					if (IsEstablished () && rsn != eSSU2TerminationReasonTerminationReceived)
 						RequestTermination (eSSU2TerminationReasonTerminationReceived);
-					else
+					else if (m_State != eSSU2SessionStateTerminated)	
+					{
+						if (m_State == eSSU2SessionStateClosing && rsn == eSSU2TerminationReasonTerminationReceived)	
+							m_State = eSSU2SessionStateClosingConfirmed;
 						Done ();
-				break;
+					}		
+					break;
+				}		
 				case eSSU2BlkRelayRequest:
 					LogPrint (eLogDebug, "SSU2: RelayRequest");
 					HandleRelayRequest (buf + offset, size);

libi2pd/SSU2Session.h

@@ -100,6 +100,7 @@ namespace transport
 		eSSU2SessionStateSessionConfirmedSent,
 		eSSU2SessionStateEstablished,
 		eSSU2SessionStateClosing,
+		eSSU2SessionStateClosingConfirmed,
 		eSSU2SessionStateTerminated,
 		eSSU2SessionStateFailed,
 		eSSU2SessionStateIntroduced,