fix #846. ability to limit transit bandwidth

daemon/Daemon.cpp

@@ -189,6 +189,9 @@ namespace i2p
 				i2p::context.SetBandwidth (i2p::data::CAPS_FLAG_LOW_BANDWIDTH2);
 			}	
 
+			int shareRatio; i2p::config::GetOption("share", shareRatio);
+			i2p::context.SetShareRatio (shareRatio);
+
 			std::string family; i2p::config::GetOption("family", family);
 			i2p::context.SetFamily (family);
 			if (family.length () > 0)

libi2pd/Config.cpp

@@ -54,6 +54,7 @@ namespace config {
       ("notransit", value<bool>()->zero_tokens()->default_value(false), "Router will not accept transit tunnels at startup")
       ("floodfill", value<bool>()->zero_tokens()->default_value(false), "Router will be floodfill")
       ("bandwidth", value<std::string>()->default_value(""), "Bandwidth limit: integer in KBps or letters: L (32), O (256), P (2048), X (>9000)")
+	  ("share",	value<int>()->default_value(100), "Limit of transit traffic from max bandwidth in percents. (default: 100")
       ("ntcp", value<bool>()->zero_tokens()->default_value(true), "Enable NTCP transport")
       ("ssu", value<bool>()->zero_tokens()->default_value(true), "Enable SSU transport")
 #ifdef _WIN32

libi2pd/I2NPProtocol.cpp

@@ -332,7 +332,8 @@ namespace i2p
 				// replace record to reply			
 				if (i2p::context.AcceptsTunnels () && 
 					i2p::tunnel::tunnels.GetTransitTunnels ().size () <= g_MaxNumTransitTunnels &&
-					!i2p::transport::transports.IsBandwidthExceeded ())
+					!i2p::transport::transports.IsBandwidthExceeded () &&
+					!i2p::transport::transports.IsTransitBandwidthExceeded ())
 				{	
 					auto transitTunnel = i2p::tunnel::CreateTransitTunnel (
 							bufbe32toh (clearText + BUILD_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET), 

libi2pd/RouterContext.cpp

@@ -17,8 +17,8 @@ namespace i2p
 
 	RouterContext::RouterContext ():
 		m_LastUpdateTime (0), m_AcceptsTunnels (true), m_IsFloodfill (false), 
-		m_StartupTime (0), m_Status (eRouterStatusOK), m_Error (eRouterErrorNone),
-		m_NetID (I2PD_NET_ID)
+		m_StartupTime (0), m_ShareRatio (100), m_Status (eRouterStatusOK), 
+		m_Error (eRouterErrorNone), m_NetID (I2PD_NET_ID)
 	{
 	}
 
@@ -246,6 +246,13 @@ namespace i2p
 		else                   { SetBandwidth('K'); }
 	}
 
+	void RouterContext::SetShareRatio (int percents)
+	{
+		if (percents < 0) percents = 0;
+		if (percents > 100) percents = 100;
+		m_ShareRatio = percents;
+	}
+
 	bool RouterContext::IsUnreachable () const
 	{
 		return m_RouterInfo.GetCaps () & i2p::data::RouterInfo::eUnreachable;

libi2pd/RouterContext.h

@@ -54,6 +54,7 @@ namespace i2p
 			uint32_t GetStartupTime () const { return m_StartupTime; };
 			uint64_t GetLastUpdateTime () const { return m_LastUpdateTime; };
 			uint64_t GetBandwidthLimit () const { return m_BandwidthLimit; };
+			uint64_t GetTransitBandwidthLimit () const { return (m_BandwidthLimit*m_ShareRatio)/100LL; };
 			RouterStatus GetStatus () const { return m_Status; };
 			void SetStatus (RouterStatus status);
 			RouterError GetError () const { return m_Error; };
@@ -74,6 +75,7 @@ namespace i2p
 			std::string GetFamily () const;
 			void SetBandwidth (int limit); /* in kilobytes */
 			void SetBandwidth (char L); /* by letter */
+			void SetShareRatio (int percents); // 0 - 100
 			bool AcceptsTunnels () const { return m_AcceptsTunnels; };
 			void SetAcceptsTunnels (bool acceptsTunnels) { m_AcceptsTunnels = acceptsTunnels; };
 			bool SupportsV6 () const { return m_RouterInfo.IsV6 (); };
@@ -116,7 +118,8 @@ namespace i2p
 			uint64_t m_LastUpdateTime;
 			bool m_AcceptsTunnels, m_IsFloodfill;
 			uint64_t m_StartupTime; // in seconds since epoch
-			uint32_t m_BandwidthLimit; // allowed bandwidth
+			uint64_t m_BandwidthLimit; // allowed bandwidth
+			int m_ShareRatio;
 			RouterStatus m_Status;
 			RouterError m_Error;
 			int m_NetID;

libi2pd/Transports.cpp

@@ -261,6 +261,12 @@ namespace transport
 		return bw > limit;
 	}
 
+	bool Transports::IsTransitBandwidthExceeded () const
+	{
+		auto limit = i2p::context.GetTransitBandwidthLimit() * 1024; // convert to bytes
+		return m_TransitBandwidth > limit;
+	}	
+
 	void Transports::SendMessage (const i2p::data::IdentHash& ident, std::shared_ptr<i2p::I2NPMessage> msg)
 	{
 		SendMessages (ident, std::vector<std::shared_ptr<i2p::I2NPMessage> > {msg });															

libi2pd/Transports.h

@@ -106,6 +106,7 @@ namespace transport
 			uint32_t GetOutBandwidth () const { return m_OutBandwidth; };
 			uint32_t GetTransitBandwidth () const { return m_TransitBandwidth; };
 			bool IsBandwidthExceeded () const;
+			bool IsTransitBandwidthExceeded () const;
 			size_t GetNumPeers () const { return m_Peers.size (); };
 			std::shared_ptr<const i2p::data::RouterInfo> GetRandomPeer () const;