delete expired incoming tags

Garlic.cpp

@@ -148,7 +148,7 @@ namespace garlic
 	size_t GarlicRoutingSession::CreateAESBlock (uint8_t * buf, const I2NPMessage * msg)
 	{
 		size_t blockSize = 0;
-		bool createNewTags = m_Owner && ((int)m_SessionTags.size () <= m_NumTags/4);
+		bool createNewTags = m_Owner && ((int)m_SessionTags.size () <= m_NumTags/2);
 		UnconfirmedTags * newTags = createNewTags ? GenerateSessionTags () : nullptr;
 		*(uint16_t *)buf = newTags ? htobe16 (newTags->numTags) : 0; // tag count
 		blockSize += 2;
@@ -343,7 +343,29 @@ namespace garlic
 			else
 				LogPrint ("Failed to decrypt garlic");
 		}
-		DeleteI2NPMessage (msg);	
+		DeleteI2NPMessage (msg);
+
+		// cleanup expired tags
+		uint32_t ts = i2p::util::GetSecondsSinceEpoch ();
+		if (ts > m_LastTagsCleanupTime + INCOMING_TAGS_EXPIRATION_TIMEOUT)
+		{
+			if (m_LastTagsCleanupTime)
+			{
+				int numExpiredTags = 0;
+				for (auto it = m_Tags.begin (); it != m_Tags.end ();)
+				{
+					if (ts > it->first.creationTime + INCOMING_TAGS_EXPIRATION_TIMEOUT)
+					{
+						numExpiredTags++;
+						it = m_Tags.erase (it);
+					}	
+					else
+						it++;
+				}
+				LogPrint (numExpiredTags, " tags expired for ", GetIdentHash().ToBase64 ());
+			}	
+			m_LastTagsCleanupTime = ts;
+		}	
 	}	
 
 	void GarlicDestination::HandleAESBlock (uint8_t * buf, size_t len, std::shared_ptr<i2p::crypto::CBCDecryption> decryption,

Garlic.h

@@ -37,7 +37,7 @@ namespace garlic
 	};		
 #pragma pack()	
 
-	const int INCOMING_TAGS_EXPIRATION_TIMEOUT = 900; // 15 minutes			
+	const int INCOMING_TAGS_EXPIRATION_TIMEOUT = 960; // 16 minutes			
 	const int OUTGOING_TAGS_EXPIRATION_TIMEOUT = 720; // 12 minutes
 	
 	struct SessionTag: public i2p::data::Tag<32> 
@@ -102,7 +102,7 @@ namespace garlic
 	{
 		public:
 
-			GarlicDestination () {};
+			GarlicDestination (): m_LastTagsCleanupTime (0) {};
 			~GarlicDestination ();
 
 			GarlicRoutingSession * GetRoutingSession (const i2p::data::RoutingDestination& destination, int numTags);	
@@ -136,7 +136,8 @@ namespace garlic
 			std::mutex m_SessionsMutex;
 			std::map<i2p::data::IdentHash, GarlicRoutingSession *> m_Sessions;
 			// incoming
-			std::map<SessionTag, std::shared_ptr<i2p::crypto::CBCDecryption>> m_Tags;	
+			std::map<SessionTag, std::shared_ptr<i2p::crypto::CBCDecryption>> m_Tags;
+			uint32_t m_LastTagsCleanupTime;
 			// DeliveryStatus
 			std::map<uint32_t, GarlicRoutingSession *> m_CreatedSessions; // msgID -> session
 	};