change datagram routing path if nothing comes back in 10 seconds

libi2pd/Datagram.cpp

@@ -315,6 +315,13 @@ namespace datagram
 		}	
 		
 		auto path = m_RoutingSession->GetSharedRoutingPath();
+		if (path && m_RoutingSession->IsRatchets () &&
+		    m_LastUse > m_RoutingSession->GetLastActivityTimestamp ()*1000 + DATAGRAM_SESSION_PATH_TIMEOUT)
+		{	
+			m_RoutingSession->SetSharedRoutingPath (nullptr);
+			path = nullptr;
+		}
+				
 		if (path) 
 		{
 			if (path->outboundTunnel && !path->outboundTunnel->IsEstablished ())

libi2pd/ECIESX25519AEADRatchetSession.cpp

@@ -770,7 +770,7 @@ namespace garlic
 			if (m_NextSendRatchet->newKey) payloadLen += 32;
 		}
 		uint8_t paddingSize = 0;
-		if (payloadLen)
+		if (payloadLen || ts > m_LastSentTimestamp + ECIESX25519_SEND_INACTIVITY_TIMEOUT)
 		{
 			int delta = (int)ECIESX25519_OPTIMAL_PAYLOAD_SIZE - (int)payloadLen;
 			if (delta < 0 || delta > 3) // don't create padding if we are close to optimal size
@@ -791,83 +791,87 @@ namespace garlic
 			}
 		}
 		std::vector<uint8_t> v(payloadLen);
-		size_t offset = 0;
+		if (payloadLen)
-		// DateTime
+		{	
-		if (first)
+			m_LastSentTimestamp = ts;
-		{
+			size_t offset = 0;
-			v[offset] = eECIESx25519BlkDateTime; offset++;
+			// DateTime
-			htobe16buf (v.data () + offset, 4); offset += 2;
+			if (first)
-			htobe32buf (v.data () + offset, ts/1000); offset += 4; // in seconds
-		}
-		// LeaseSet
-		if (leaseSet)
-		{
-			offset += CreateLeaseSetClove (leaseSet, ts, v.data () + offset, payloadLen - offset);
-			if (!first)
 			{
-				// ack request
+				v[offset] = eECIESx25519BlkDateTime; offset++;
-				v[offset] = eECIESx25519BlkAckRequest; offset++;
+				htobe16buf (v.data () + offset, 4); offset += 2;
-				htobe16buf (v.data () + offset, 1); offset += 2;
+				htobe32buf (v.data () + offset, ts/1000); offset += 4; // in seconds
-				v[offset] = 0; offset++; // flags
 			}
-		}
+			// LeaseSet
-		// msg
+			if (leaseSet)
-		if (msg && m_Destination)
-			offset += CreateGarlicClove (msg, v.data () + offset, payloadLen - offset, true);
-		// ack
-		if (m_AckRequests.size () > 0)
-		{
-			v[offset] = eECIESx25519BlkAck; offset++;
-			htobe16buf (v.data () + offset, m_AckRequests.size () * 4); offset += 2;
-			for (auto& it: m_AckRequests)
 			{
-				htobe16buf (v.data () + offset, it.first); offset += 2;
+				offset += CreateLeaseSetClove (leaseSet, ts, v.data () + offset, payloadLen - offset);
-				htobe16buf (v.data () + offset, it.second); offset += 2;
+				if (!first)
+				{
+					// ack request
+					v[offset] = eECIESx25519BlkAckRequest; offset++;
+					htobe16buf (v.data () + offset, 1); offset += 2;
+					v[offset] = 0; offset++; // flags
+				}
 			}
-			m_AckRequests.clear ();
+			// msg
-		}
+			if (msg && m_Destination)
-		// next keys
+				offset += CreateGarlicClove (msg, v.data () + offset, payloadLen - offset, true);
-		if (m_SendReverseKey)
+			// ack
-		{
+			if (m_AckRequests.size () > 0)
-			v[offset] = eECIESx25519BlkNextKey; offset++;
-			htobe16buf (v.data () + offset, m_NextReceiveRatchet->newKey ? 35 : 3); offset += 2;
-			v[offset] = ECIESX25519_NEXT_KEY_REVERSE_KEY_FLAG;
-			int keyID = m_NextReceiveRatchet->keyID - 1;
-			if (m_NextReceiveRatchet->newKey)
 			{
-				v[offset] |= ECIESX25519_NEXT_KEY_KEY_PRESENT_FLAG;
+				v[offset] = eECIESx25519BlkAck; offset++;
-				keyID++;
+				htobe16buf (v.data () + offset, m_AckRequests.size () * 4); offset += 2;
+				for (auto& it: m_AckRequests)
+				{
+					htobe16buf (v.data () + offset, it.first); offset += 2;
+					htobe16buf (v.data () + offset, it.second); offset += 2;
+				}
+				m_AckRequests.clear ();
 			}
-			offset++; // flag
+			// next keys
-			htobe16buf (v.data () + offset, keyID); offset += 2; // keyid
+			if (m_SendReverseKey)
-			if (m_NextReceiveRatchet->newKey)
 			{
-				memcpy (v.data () + offset, m_NextReceiveRatchet->key->GetPublicKey (), 32);
+				v[offset] = eECIESx25519BlkNextKey; offset++;
-				offset += 32; // public key
+				htobe16buf (v.data () + offset, m_NextReceiveRatchet->newKey ? 35 : 3); offset += 2;
+				v[offset] = ECIESX25519_NEXT_KEY_REVERSE_KEY_FLAG;
+				int keyID = m_NextReceiveRatchet->keyID - 1;
+				if (m_NextReceiveRatchet->newKey)
+				{
+					v[offset] |= ECIESX25519_NEXT_KEY_KEY_PRESENT_FLAG;
+					keyID++;
+				}
+				offset++; // flag
+				htobe16buf (v.data () + offset, keyID); offset += 2; // keyid
+				if (m_NextReceiveRatchet->newKey)
+				{
+					memcpy (v.data () + offset, m_NextReceiveRatchet->key->GetPublicKey (), 32);
+					offset += 32; // public key
+				}
+				m_SendReverseKey = false;
 			}
-			m_SendReverseKey = false;
+			if (m_SendForwardKey)
-		}
-		if (m_SendForwardKey)
-		{
-			v[offset] = eECIESx25519BlkNextKey; offset++;
-			htobe16buf (v.data () + offset, m_NextSendRatchet->newKey ? 35 : 3); offset += 2;
-			v[offset] = m_NextSendRatchet->newKey ? ECIESX25519_NEXT_KEY_KEY_PRESENT_FLAG : ECIESX25519_NEXT_KEY_REQUEST_REVERSE_KEY_FLAG;
-			if (!m_NextSendRatchet->keyID) v[offset] |= ECIESX25519_NEXT_KEY_REQUEST_REVERSE_KEY_FLAG; // for first key only
-			offset++; // flag
-			htobe16buf (v.data () + offset, m_NextSendRatchet->keyID); offset += 2; // keyid
-			if (m_NextSendRatchet->newKey)
 			{
-				memcpy (v.data () + offset, m_NextSendRatchet->key->GetPublicKey (), 32);
+				v[offset] = eECIESx25519BlkNextKey; offset++;
-				offset += 32; // public key
+				htobe16buf (v.data () + offset, m_NextSendRatchet->newKey ? 35 : 3); offset += 2;
+				v[offset] = m_NextSendRatchet->newKey ? ECIESX25519_NEXT_KEY_KEY_PRESENT_FLAG : ECIESX25519_NEXT_KEY_REQUEST_REVERSE_KEY_FLAG;
+				if (!m_NextSendRatchet->keyID) v[offset] |= ECIESX25519_NEXT_KEY_REQUEST_REVERSE_KEY_FLAG; // for first key only
+				offset++; // flag
+				htobe16buf (v.data () + offset, m_NextSendRatchet->keyID); offset += 2; // keyid
+				if (m_NextSendRatchet->newKey)
+				{
+					memcpy (v.data () + offset, m_NextSendRatchet->key->GetPublicKey (), 32);
+					offset += 32; // public key
+				}
 			}
-		}
+			// padding
-		// padding
+			if (paddingSize)
-		if (paddingSize)
+			{
-		{
+				v[offset] = eECIESx25519BlkPadding; offset++;
-			v[offset] = eECIESx25519BlkPadding; offset++;
+				htobe16buf (v.data () + offset, paddingSize); offset += 2;
-			htobe16buf (v.data () + offset, paddingSize); offset += 2;
+				memset (v.data () + offset, 0, paddingSize); offset += paddingSize;
-			memset (v.data () + offset, 0, paddingSize); offset += paddingSize;
+			}
-		}
+		}	
 		return v;
 	}
 

libi2pd/ECIESX25519AEADRatchetSession.h

@@ -27,7 +27,8 @@ namespace garlic
 {
 	const int ECIESX25519_RESTART_TIMEOUT = 120; // number of second since session creation we can restart session after
 	const int ECIESX25519_EXPIRATION_TIMEOUT = 480; // in seconds
-	const int ECIESX25519_INACTIVITY_TIMEOUT = 90; // number of second we receive nothing and should restart if we can
+	const int ECIESX25519_INACTIVITY_TIMEOUT = 90; // number of seconds we receive nothing and should restart if we can
+	const int ECIESX25519_SEND_INACTIVITY_TIMEOUT = 5000; // number of milliseconds we can send empty(pyaload only) packet after 
 	const int ECIESX25519_INCOMING_TAGS_EXPIRATION_TIMEOUT = 600; // in seconds
 	const int ECIESX25519_PREVIOUS_TAGSET_EXPIRATION_TIMEOUT = 180; // 180
 	const int ECIESX25519_TAGSET_MAX_NUM_TAGS = 4096; // number of tags we request new tagset after
@@ -148,6 +149,7 @@ namespace garlic
 			bool IsInactive (uint64_t ts) const { return ts > m_LastActivityTimestamp + ECIESX25519_INACTIVITY_TIMEOUT && CanBeRestarted (ts); }
 			
 			bool IsRatchets () const { return true; };
+			uint64_t GetLastActivityTimestamp () const { return m_LastActivityTimestamp; };
 
 		private:
 
@@ -182,7 +184,8 @@ namespace garlic
 			uint8_t m_NSREncodedKey[32], m_NSRH[32], m_NSRKey[32]; // new session reply, for incoming only
 			std::shared_ptr<i2p::crypto::X25519Keys> m_EphemeralKeys;
 			SessionState m_State = eSessionStateNew;
-			uint64_t m_SessionCreatedTimestamp = 0,  m_LastActivityTimestamp = 0; // incoming
+			uint64_t m_SessionCreatedTimestamp = 0,  m_LastActivityTimestamp = 0, // incoming
+				m_LastSentTimestamp = 0; // in milliseconds
 			std::shared_ptr<RatchetTagSet> m_SendTagset, m_NSRSendTagset;
 			std::unique_ptr<i2p::data::IdentHash> m_Destination;// TODO: might not need it
 			std::list<std::pair<uint16_t, int> > m_AckRequests; // (tagsetid, index)

libi2pd/Garlic.h

@@ -114,6 +114,7 @@ namespace garlic
 			virtual bool CleanupUnconfirmedTags () { return false; }; // for I2CP, override in ElGamalAESSession
 			virtual bool MessageConfirmed (uint32_t msgID);
 			virtual bool IsRatchets () const { return false; };
+			virtual uint64_t GetLastActivityTimestamp () const { return 0; }; // non-zero for rathets only
 
 			void SetLeaseSetUpdated ()
 			{