text: /*
  * Copyright (c) 2013-2020, The PurpleI2P Project
  *
  * This file is part of Purple i2pd project and licensed under BSD3
  *
  * See full license text in LICENSE file at top of project tree
  */
  
  #ifndef TRANSPORTS_H__
  #define TRANSPORTS_H__
  
  #include <thread>
  #include <mutex>
  #include <condition_variable>
  #include <functional>
  #include <map>
  #include <vector>
  #include <queue>
  #include <string>
  #include <memory>
  #include <atomic>
  #include <boost/asio.hpp>
  #include "TransportSession.h"
  #include "NTCPSession.h"
  #include "SSU.h"
  #include "NTCP2.h"
  #include "RouterInfo.h"
  #include "I2NPProtocol.h"
  #include "Identity.h"
  
  namespace i2p
  {
  namespace transport
  {
  	class DHKeysPairSupplier
  	{
  		public:
  
  			DHKeysPairSupplier (int size);
  			~DHKeysPairSupplier ();
  			void Start ();
  			void Stop ();
  			std::shared_ptr<i2p::crypto::DHKeys> Acquire ();
  			void Return (std::shared_ptr<i2p::crypto::DHKeys> pair);
  
  		private:
  
  			void Run ();
  			void CreateDHKeysPairs (int num);
  
  		private:
  
  			const int m_QueueSize;
  			std::queue<std::shared_ptr<i2p::crypto::DHKeys> > m_Queue;
  
  			bool m_IsRunning;
  			std::thread * m_Thread;
  			std::condition_variable m_Acquired;
  			std::mutex m_AcquiredMutex;
  	};
  
  	struct Peer
  	{
  		int numAttempts;
  		std::shared_ptr<const i2p::data::RouterInfo> router;
  		std::list<std::shared_ptr<TransportSession> > sessions;
  		uint64_t creationTime;
  		std::vector<std::shared_ptr<i2p::I2NPMessage> > delayedMessages;
  
  		void Done ()
  		{
  			for (auto& it: sessions)
  				it->Done ();
  		}
  	};
  
  	const size_t SESSION_CREATION_TIMEOUT = 10; // in seconds
  	const int PEER_TEST_INTERVAL = 71; // in minutes
  	const int MAX_NUM_DELAYED_MESSAGES = 50;
  	class Transports
  	{
  		public:
  
  			Transports ();
  			~Transports ();
  
  			void Start (bool enableNTCP=true, bool enableSSU=true);
  			void Stop ();
  
  			bool IsBoundNTCP() const { return m_NTCPServer != nullptr; }
  			bool IsBoundSSU() const { return m_SSUServer != nullptr; }
  			bool IsBoundNTCP2() const { return m_NTCP2Server != nullptr; }
  
  			bool IsOnline() const { return m_IsOnline; };
  			void SetOnline (bool online) { m_IsOnline = online; };
  
  			boost::asio::io_service& GetService () { return *m_Service; };
  			std::shared_ptr<i2p::crypto::DHKeys> GetNextDHKeysPair ();
  			void ReuseDHKeysPair (std::shared_ptr<i2p::crypto::DHKeys> pair);
  
  			void SendMessage (const i2p::data::IdentHash& ident, std::shared_ptr<i2p::I2NPMessage> msg);
  			void SendMessages (const i2p::data::IdentHash& ident, const std::vector<std::shared_ptr<i2p::I2NPMessage> >& msgs);
  
  			void PeerConnected (std::shared_ptr<TransportSession> session);
  			void PeerDisconnected (std::shared_ptr<TransportSession> session);
  			bool IsConnected (const i2p::data::IdentHash& ident) const;
  
  			void UpdateSentBytes (uint64_t numBytes) { m_TotalSentBytes += numBytes; };
  			void UpdateReceivedBytes (uint64_t numBytes) { m_TotalReceivedBytes += numBytes; };
  			uint64_t GetTotalSentBytes () const { return m_TotalSentBytes; };
  			uint64_t GetTotalReceivedBytes () const { return m_TotalReceivedBytes; };
  			uint64_t GetTotalTransitTransmittedBytes () const { return m_TotalTransitTransmittedBytes; }
  			void UpdateTotalTransitTransmittedBytes (uint32_t add) { m_TotalTransitTransmittedBytes += add; };
  			uint32_t GetInBandwidth () const { return m_InBandwidth; };
  			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;
  
  			/** get a trusted first hop for restricted routes */
  			std::shared_ptr<const i2p::data::RouterInfo> GetRestrictedPeer() const;
  			/** do we want to use restricted routes? */
  			bool RoutesRestricted() const;
  			/** restrict routes to use only these router families for first hops */
  			void RestrictRoutesToFamilies(std::set<std::string> families);
  			/** restrict routes to use only these routers for first hops */
  			void RestrictRoutesToRouters(std::set<i2p::data::IdentHash> routers);
  
  			bool IsRestrictedPeer(const i2p::data::IdentHash & ident) const;
  
  			void PeerTest ();
  
  		private:
  
  			void Run ();
  			void RequestComplete (std::shared_ptr<const i2p::data::RouterInfo> r, const i2p::data::IdentHash& ident);
  			void HandleRequestComplete (std::shared_ptr<const i2p::data::RouterInfo> r, i2p::data::IdentHash ident);
  			void PostMessages (i2p::data::IdentHash ident, std::vector<std::shared_ptr<i2p::I2NPMessage> > msgs);
  			bool ConnectToPeer (const i2p::data::IdentHash& ident, Peer& peer);
  			void HandlePeerCleanupTimer (const boost::system::error_code& ecode);
  			void HandlePeerTestTimer (const boost::system::error_code& ecode);
  
  			void UpdateBandwidth ();
  			void DetectExternalIP ();
  
  		private:
  
  			bool m_IsOnline, m_IsRunning, m_IsNAT;
  			std::thread * m_Thread;
  			boost::asio::io_service * m_Service;
  			boost::asio::io_service::work * m_Work;
  			boost::asio::deadline_timer * m_PeerCleanupTimer, * m_PeerTestTimer;
  
  			NTCPServer * m_NTCPServer;
  			SSUServer * m_SSUServer;
  			NTCP2Server * m_NTCP2Server;
  			mutable std::mutex m_PeersMutex;
  			std::map<i2p::data::IdentHash, Peer> m_Peers;
  
  			DHKeysPairSupplier m_DHKeysPairSupplier;
  
  			std::atomic<uint64_t> m_TotalSentBytes, m_TotalReceivedBytes, m_TotalTransitTransmittedBytes;
  			uint32_t m_InBandwidth, m_OutBandwidth, m_TransitBandwidth; // bytes per second
  			uint64_t m_LastInBandwidthUpdateBytes, m_LastOutBandwidthUpdateBytes, m_LastTransitBandwidthUpdateBytes;
  			uint64_t m_LastBandwidthUpdateTime;
  
  			/** which router families to trust for first hops */
  			std::vector<std::string> m_TrustedFamilies;
  			mutable std::mutex m_FamilyMutex;
  
  			/** which routers for first hop to trust */
  			std::vector<i2p::data::IdentHash> m_TrustedRouters;
  			mutable std::mutex m_TrustedRoutersMutex;
  
  			i2p::I2NPMessagesHandler m_LoopbackHandler;
  
  		public:
  
  			// for HTTP only
  			const NTCPServer * GetNTCPServer () const { return m_NTCPServer; };
  			const SSUServer * GetSSUServer () const { return m_SSUServer; };
  			const NTCP2Server * GetNTCP2Server () const { return m_NTCP2Server; };
  			const decltype(m_Peers)& GetPeers () const { return m_Peers; };
  	};
  
  	extern Transports transports;
  }
  }
  
  #endif
  