limit SSU outgoing windows

SSUData.cpp

@@ -425,6 +425,7 @@ namespace transport
 		if (ecode != boost::asio::error::operation_aborted)
 		{
 			uint32_t ts = i2p::util::GetSecondsSinceEpoch ();
+			int numResent = 0;
 			for (auto it = m_SentMessages.begin (); it != m_SentMessages.end ();)
 			{
 				if (ts >= it->second->nextResendTime)
@@ -437,6 +438,7 @@ namespace transport
 								try
 								{	
 									m_Session.Send (f->buf, f->len); // resend
+									numResent++;
 								}
 								catch (boost::system::system_error& ec)
 								{
@@ -457,7 +459,13 @@ namespace transport
 				else
 					it++;
 			}
-			ScheduleResend ();	
+			if (numResent < MAX_OUTGOING_WINDOW_SIZE)
+				ScheduleResend ();
+			else
+			{
+				LogPrint (eLogError, "SSU: resend window exceeds max size. Session terminated");
+				m_Session.Close ();
+			}	
 		}	
 	}	
 

SSUData.h

@@ -29,6 +29,7 @@ namespace transport
 	const int DECAY_INTERVAL = 20; // in seconds
 	const int INCOMPLETE_MESSAGES_CLEANUP_TIMEOUT = 30; // in seconds
 	const unsigned int MAX_NUM_RECEIVED_MESSAGES = 1000; // how many msgID we store for duplicates check
+	const int MAX_OUTGOING_WINDOW_SIZE = 200; // how many unacked message we can store
 	// data flags
 	const uint8_t DATA_FLAG_EXTENDED_DATA_INCLUDED = 0x02;
 	const uint8_t DATA_FLAG_WANT_REPLY = 0x04;