update introducers. cleanup unreachable routers

libi2pd/NetDb.cpp

@@ -106,7 +106,7 @@ namespace data
 	{
 		i2p::util::SetThreadName("NetDB");
 
-		uint64_t lastSave = 0, lastExploratory = 0, lastManageRequest = 0, lastDestinationCleanup = 0;
+		uint64_t lastManage = 0, lastExploratory = 0, lastManageRequest = 0, lastDestinationCleanup = 0;
 		uint64_t lastProfilesCleanup = i2p::util::GetSecondsSinceEpoch ();
 		int16_t profilesCleanupVariance = 0;
 
@@ -155,14 +155,14 @@ namespace data
 					lastManageRequest = ts;
 				}
 
-				if (ts - lastSave >= 60 || ts + 60 < lastSave) // save routers, manage leasesets and validate subscriptions every minute
+				if (ts - lastManage >= 60 || ts + 60 < lastManage) // manage routers and leasesets every minute
 				{
-					if (lastSave)
+					if (lastManage)
 					{
-						SaveUpdated ();
+						ManageRouterInfos ();
 						ManageLeaseSets ();
 					}
-					lastSave = ts;
+					lastManage = ts;
 				}
 
 				if (ts - lastDestinationCleanup >= i2p::garlic::INCOMING_TAGS_EXPIRATION_TIMEOUT ||
@@ -631,13 +631,8 @@ namespace data
 			if (!it.second->IsUnreachable ())
 			{	
 				// find & mark expired routers
-				if (!it.second->IsReachable () && (it.second->GetCompatibleTransports (true) & RouterInfo::eSSU2V4))
+				if (it.second->GetCompatibleTransports (true)) // non reachable by any transport
-				// non-reachable router, but reachable by ipv4  SSU2 means introducers
-				{
-					if (ts > it.second->GetTimestamp () + NETDB_INTRODUCEE_EXPIRATION_TIMEOUT*1000LL)
-					// RouterInfo expires after 1 hour if uses introducer
 					it.second->SetUnreachable (true);
-				}
 				else if (checkForExpiration && ts > it.second->GetTimestamp () + expirationTimeout)
 					it.second->SetUnreachable (true);
 				else if (ts + NETDB_EXPIRATION_TIMEOUT_THRESHOLD*1000LL < it.second->GetTimestamp ())
@@ -1348,6 +1343,17 @@ namespace data
 		return r;
 	}
 
+	void NetDb::ManageRouterInfos ()
+	{
+		auto ts = i2p::util::GetSecondsSinceEpoch ();
+		{
+			std::unique_lock<std::mutex> l(m_RouterInfosMutex);
+			for (auto& it: m_RouterInfos)
+				it.second->UpdateIntroducers (ts);
+		}	
+		SaveUpdated ();
+	}	
+	
 	void NetDb::ManageLeaseSets ()
 	{
 		auto ts = i2p::util::GetMillisecondsSinceEpoch ();

libi2pd/NetDb.hpp

@@ -40,7 +40,6 @@ namespace data
 	const int NETDB_MIN_FLOODFILLS = 5;
 	const int NETDB_MIN_TUNNEL_CREATION_SUCCESS_RATE = 8; // in percents
 	const int NETDB_FLOODFILL_EXPIRATION_TIMEOUT = 60 * 60; // 1 hour, in seconds
-	const int NETDB_INTRODUCEE_EXPIRATION_TIMEOUT = 65 * 60;
 	const int NETDB_MIN_EXPIRATION_TIMEOUT = 90 * 60; // 1.5 hours
 	const int NETDB_MAX_EXPIRATION_TIMEOUT = 27 * 60 * 60; // 27 hours
 	const int NETDB_MAX_OFFLINE_EXPIRATION_TIMEOUT = 180; // in days
@@ -139,6 +138,7 @@ namespace data
 			void Run (); // exploratory thread
 			void Explore (int numDestinations);
 			void Flood (const IdentHash& ident, std::shared_ptr<I2NPMessage> floodMsg);
+			void ManageRouterInfos ();
 			void ManageLeaseSets ();
 			void ManageRequests ();
 

libi2pd/RouterInfo.cpp

@@ -400,18 +400,9 @@ namespace data
 				{
 					// exclude invalid introducers
 					uint32_t ts = i2p::util::GetSecondsSinceEpoch ();
-					int numValid = 0;
+					UpdateIntroducers (address, ts);
-					for (auto& it: address->ssu->introducers)
+					if (!address->ssu->introducers.empty ()) // still has something
-					{
-						if (it.iTag && ts < it.iExp)
-							numValid++;
-						else
-							it.iTag = 0;
-					}
-					if (numValid)
 						m_ReachableTransports |= supportedTransports;
-					else
-						address->ssu->introducers.resize (0);
 				}
 			}
 			if (supportedTransports)
@@ -576,6 +567,21 @@ namespace data
 		return caps;
 	}
 
+	void RouterInfo::UpdateIntroducers (std::shared_ptr<Address> address, uint64_t ts)
+	{
+		if (!address || !address->ssu) return;
+		int numValid = 0;
+		for (auto& it: address->ssu->introducers)
+		{
+			if (it.iTag && ts < it.iExp)
+				numValid++;
+			else
+				it.iTag = 0;
+		}
+		if (!numValid)
+			address->ssu->introducers.resize (0);
+	}	
+		
 	bool RouterInfo::IsNewer (const uint8_t * buf, size_t len) const
 	{
 		if (!m_RouterIdentity) return false;
@@ -1036,6 +1042,31 @@ namespace data
 		}
 	}
 
+	void RouterInfo::UpdateIntroducers (uint64_t ts)
+	{
+		if (ts*1000 < m_Timestamp + INTRODUCER_UPDATE_INTERVAL) return;
+		if (m_ReachableTransports & eSSU2V4)
+		{
+			auto addr = (*GetAddresses ())[eSSU2V4Idx];
+			if (addr && addr->UsesIntroducer ())
+			{
+				UpdateIntroducers (addr, ts);
+				if (!addr->UsesIntroducer ()) // no more valid introducers
+					m_ReachableTransports &= ~eSSU2V4;
+			}	
+		}	
+		if (m_ReachableTransports & eSSU2V6)
+		{
+			auto addr = (*GetAddresses ())[eSSU2V6Idx];
+			if (addr && addr->UsesIntroducer ())
+			{
+				UpdateIntroducers (addr, ts);
+				if (!addr->UsesIntroducer ()) // no more valid introducers
+					m_ReachableTransports &= ~eSSU2V6;
+			}	
+		}	
+	}	
+		
 	void RouterInfo::UpdateBuffer (const uint8_t * buf, size_t len)
 	{
 		if (!m_Buffer)

libi2pd/RouterInfo.h

@@ -61,6 +61,7 @@ namespace data
 
 	const size_t MAX_RI_BUFFER_SIZE = 3072; // if RouterInfo exceeds 3K we consider it as malformed, might extend later
 	const int HIGH_CONGESTION_INTERVAL = 15*60; // in seconds, 15 minutes
+	const int INTRODUCER_UPDATE_INTERVAL = 20*60*1000; // in milliseconds, 20 minutes
 		
 	class RouterInfo: public RoutingDestination
 	{
@@ -221,8 +222,8 @@ namespace data
 			void RemoveSSU2Address (bool v4);
 			void SetUnreachableAddressesTransportCaps (uint8_t transports); // bitmask of AddressCaps
 			void UpdateSupportedTransports ();
+			void UpdateIntroducers (uint64_t ts); // ts in seconds
 			bool IsFloodfill () const { return m_Caps & Caps::eFloodfill; };
-			bool IsReachable () const { return m_Caps & Caps::eReachable; };
 			bool IsECIES () const { return m_RouterIdentity->GetCryptoKeyType () == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD; };
 			bool IsNTCP2 (bool v4only = true) const;
 			bool IsNTCP2V6 () const { return m_SupportedTransports & eNTCP2V6; };
@@ -302,6 +303,7 @@ namespace data
 			size_t ReadString (char* str, size_t len, std::istream& s) const;
 			void ExtractCaps (const char * value);
 			uint8_t ExtractAddressCaps (const char * value) const;
+			void UpdateIntroducers (std::shared_ptr<Address> address, uint64_t ts); 
 			template<typename Filter>
 			std::shared_ptr<const Address> GetAddress (Filter filter) const;
 			virtual std::shared_ptr<Buffer> NewBuffer () const;
@@ -315,7 +317,7 @@ namespace data
 			std::shared_ptr<const IdentityEx> m_RouterIdentity;
 			std::shared_ptr<Buffer> m_Buffer;
 			size_t m_BufferLen;
-			uint64_t m_Timestamp;
+			uint64_t m_Timestamp; // in milliseconds
 			boost::shared_ptr<Addresses> m_Addresses; // TODO: use std::shared_ptr and std::atomic_store for gcc >= 4.9
 			bool m_IsUpdated, m_IsUnreachable;
 			CompatibleTransports m_SupportedTransports, m_ReachableTransports;

libi2pd/TunnelPool.cpp

@@ -498,7 +498,8 @@ namespace tunnel
 		{
 			auto r = i2p::transport::transports.GetRandomPeer (!IsExploratory ());
 			if (r && r->IsECIES () && !r->GetProfile ()->IsBad () &&
-				(numHops > 1 || (r->IsV4 () && (!inbound || r->IsReachable ())))) // first inbound must be reachable
+				(numHops > 1 || (r->IsV4 () && (!inbound || 
+				 r->IsReachableBy (i2p::data::RouterInfo::eNTCP2V4 | i2p::data::RouterInfo::eSSU2V4))))) // first inbound must be reachable
 			{
 				prevHop = r;
 				path.Add (r);
@@ -520,8 +521,8 @@ namespace tunnel
 				LogPrint (eLogError, "Tunnels: Can't select next hop for ", prevHop->GetIdentHashBase64 ());
 				return false;
 			}
-			if ((i == numHops - 1) && (!hop->IsV4 () || // doesn't support ipv4
+			if ((i == numHops - 1) && (!hop->IsV4 () || (inbound &&  // doesn't support ipv4
-				(inbound && !hop->IsReachable ()))) // IBGW is not reachable
+				!hop->IsReachableBy (i2p::data::RouterInfo::eNTCP2V4 | i2p::data::RouterInfo::eSSU2V4)))) // IBGW is not reachable
 			{
 				auto hop1 = nextHop (prevHop, true);
 				if (hop1) hop = hop1;