cleanup unclaimed out-of-sequence fragments

Tunnel.cpp

@@ -714,6 +714,8 @@ namespace tunnel
 
 						if (ts + TUNNEL_EXPIRATION_THRESHOLD > tunnel->GetCreationTime () + TUNNEL_EXPIRATION_TIMEOUT)
 							tunnel->SetState (eTunnelStateExpiring);
+						else // we don't need to cleanup expiring tunnels
+							tunnel->Cleanup ();
 					}
 					it++;
 				}
@@ -763,7 +765,10 @@ namespace tunnel
 				it = m_TransitTunnels.erase (it);
 			}
 			else 
+			{
+				tunnel->Cleanup ();
 				it++;
+			}
 		}
 	}
 

Tunnel.h

@@ -165,6 +165,10 @@ namespace tunnel
 			virtual size_t GetNumReceivedBytes () const { return m_Endpoint.GetNumReceivedBytes (); };
 			void Print (std::stringstream& s) const;
 			bool IsInbound() const { return true; }
+
+			// override TunnelBase
+			void Cleanup () { m_Endpoint.Cleanup (); };	
+
 		private:
 
 			TunnelEndpoint m_Endpoint; 

TunnelBase.h

@@ -37,6 +37,7 @@ namespace tunnel
 				m_TunnelID (tunnelID), m_NextTunnelID (nextTunnelID), m_NextIdent (nextIdent),
 				m_CreationTime (i2p::util::GetSecondsSinceEpoch ()) {};
 			virtual ~TunnelBase () {};
+			virtual void Cleanup () {};
 			
 			virtual void HandleTunnelDataMsg (std::shared_ptr<const i2p::I2NPMessage> tunnelMsg) = 0;
 			virtual void SendTunnelDataMsg (std::shared_ptr<i2p::I2NPMessage> msg) = 0;

TunnelEndpoint.cpp

@@ -6,6 +6,7 @@
 #include "I2NPProtocol.h"
 #include "Transports.h"
 #include "RouterContext.h"
+#include "Timestamp.h"
 #include "TunnelEndpoint.h"
 
 namespace i2p
@@ -192,7 +193,7 @@ namespace tunnel
 
 	void TunnelEndpoint::AddOutOfSequenceFragment (uint32_t msgID, uint8_t fragmentNum, bool isLastFragment, std::shared_ptr<I2NPMessage> data)
 	{
-		if (!m_OutOfSequenceFragments.insert ({{msgID, fragmentNum}, {fragmentNum, isLastFragment, data}}).second)
+		if (!m_OutOfSequenceFragments.insert ({{msgID, fragmentNum}, {isLastFragment, data, i2p::util::GetMillisecondsSinceEpoch () }}).second)
 			LogPrint (eLogInfo, "TunnelMessage: duplicate out-of-sequence fragment ", fragmentNum, " of message ", msgID);
 	}	
 
@@ -214,29 +215,24 @@ namespace tunnel
 		auto it = m_OutOfSequenceFragments.find ({msgID, msg.nextFragmentNum});
 		if (it != m_OutOfSequenceFragments.end ())
 		{					
-			if (it->second.fragmentNum == msg.nextFragmentNum)
+			LogPrint (eLogDebug, "TunnelMessage: Out-of-sequence fragment ", (int)msg.nextFragmentNum, " of message ", msgID, " found");
+			size_t size = it->second.data->GetLength ();
+			if (msg.data->len + size > msg.data->maxLen)
 			{
-				LogPrint (eLogDebug, "TunnelMessage: Out-of-sequence fragment ", (int)it->second.fragmentNum, " of message ", msgID, " found");
-				size_t size = it->second.data->GetLength ();
-				if (msg.data->len + size > msg.data->maxLen)
-				{
-					LogPrint (eLogWarning, "TunnelMessage: Tunnel endpoint I2NP message size ", msg.data->maxLen, " is not enough");
-					auto newMsg = NewI2NPMessage ();
-					*newMsg = *(msg.data);
-					msg.data = newMsg;
-				}
-				if (msg.data->Concat (it->second.data->GetBuffer (), size) < size) // concatenate out-of-sync fragment
-					LogPrint (eLogError, "TunnelMessage: Tunnel endpoint I2NP buffer overflow ", msg.data->maxLen);
-				if (it->second.isLastFragment)
-					// message complete
-					msg.nextFragmentNum = 0;
-				else
-					msg.nextFragmentNum++;
-				m_OutOfSequenceFragments.erase (it);
-				return true;
+				LogPrint (eLogWarning, "TunnelMessage: Tunnel endpoint I2NP message size ", msg.data->maxLen, " is not enough");
+				auto newMsg = NewI2NPMessage ();
+				*newMsg = *(msg.data);
+				msg.data = newMsg;
 			}
+			if (msg.data->Concat (it->second.data->GetBuffer (), size) < size) // concatenate out-of-sync fragment
+				LogPrint (eLogError, "TunnelMessage: Tunnel endpoint I2NP buffer overflow ", msg.data->maxLen);
+			if (it->second.isLastFragment)
+				// message complete
+				msg.nextFragmentNum = 0;
 			else
-				LogPrint (eLogError, "Tunnel message: next fragment ", (int)it->second.fragmentNum, " of message ", msgID, " mismatch. ", (int)msg.nextFragmentNum, " expected");
+				msg.nextFragmentNum++;
+			m_OutOfSequenceFragments.erase (it);
+			return true;		
 		}	
 		return false;
 	}	
@@ -276,5 +272,18 @@ namespace tunnel
 				LogPrint (eLogError, "TunnelMessage: Unknown delivery type ", (int)msg.deliveryType);
 		};	
 	}
+
+	void TunnelEndpoint::Cleanup ()
+	{
+		auto ts = i2p::util::GetMillisecondsSinceEpoch ();
+		// out-of-sequence fragments
+		for (auto it = m_OutOfSequenceFragments.begin (); it != m_OutOfSequenceFragments.end ();)
+		{
+			if (ts > it->second.receiveTime + i2p::I2NP_MESSAGE_EXPIRATION_TIMEOUT)
+				it = m_OutOfSequenceFragments.erase (it);
+			else
+				++it;
+		}
+	}	
 }		
 }

TunnelEndpoint.h

@@ -20,9 +20,9 @@ namespace tunnel
 
 		struct Fragment
 		{
-			uint8_t fragmentNum;
 			bool isLastFragment;
 			std::shared_ptr<I2NPMessage> data;
+			uint64_t receiveTime; // milliseconds since epoch
 		};	
 		
 		public:
@@ -30,6 +30,7 @@ namespace tunnel
 			TunnelEndpoint (bool isInbound): m_IsInbound (isInbound), m_NumReceivedBytes (0) {};
 			~TunnelEndpoint ();
 			size_t GetNumReceivedBytes () const { return m_NumReceivedBytes; };
+			void Cleanup ();			
 
 			void HandleDecryptedTunnelDataMsg (std::shared_ptr<I2NPMessage> msg);