i2pd/transport/Transports.h

#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 <cryptopp/osrng.h>
#include <boost/asio.hpp>
#include "TransportSession.h"
#include "NTCPSession.h"
#include "SSU.h"
#include "RouterInfo.h"
#include "I2NPProtocol.h"
#include "Identity.h"

#ifdef USE_UPNP
#include "UPnP.h"
#endif

namespace i2p
{
namespace transport
{
    class DHKeysPairSupplier
    {
        public:

            DHKeysPairSupplier (int size);
            ~DHKeysPairSupplier ();
            void Start ();
            void Stop ();
            DHKeysPair * Acquire ();
            void Return (DHKeysPair * pair);

        private:

            void Run ();
            void CreateDHKeysPairs (int num);

        private:

            const int m_QueueSize;
            std::queue<DHKeysPair *> m_Queue;

            bool m_IsRunning;
            std::thread * m_Thread; 
            std::condition_variable m_Acquired;
            std::mutex m_AcquiredMutex;
            CryptoPP::AutoSeededRandomPool m_Rnd;
    };

    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 uint32_t LOW_BANDWIDTH_LIMIT = 32*1024; // 32KBs
    class Transports
    {
        public:

            Transports ();
            ~Transports ();

            void Start ();
            void Stop ();
            
            boost::asio::io_service& GetService () { return m_Service; };
            i2p::transport::DHKeysPair * GetNextDHKeysPair ();  
            void ReuseDHKeysPair (DHKeysPair * 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 CloseSession (std::shared_ptr<const i2p::data::RouterInfo> router);

            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; };       
            uint32_t GetInBandwidth () const { return m_InBandwidth; }; // bytes per second
            uint32_t GetOutBandwidth () const { return m_OutBandwidth; }; // bytes per second
            bool IsBandwidthExceeded () const;
            size_t GetNumPeers () const { return m_Peers.size (); };
            std::shared_ptr<const i2p::data::RouterInfo> GetRandomPeer () const;

        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, const i2p::data::IdentHash& ident);
            void PostMessages (i2p::data::IdentHash ident, std::vector<std::shared_ptr<i2p::I2NPMessage> > msgs);
            void PostCloseSession (std::shared_ptr<const i2p::data::RouterInfo> router);
            bool ConnectToPeer (const i2p::data::IdentHash& ident, Peer& peer);
            void HandlePeerCleanupTimer (const boost::system::error_code& ecode);           

            void NTCPResolve (const std::string& addr, const i2p::data::IdentHash& ident);
            void HandleNTCPResolve (const boost::system::error_code& ecode, boost::asio::ip::tcp::resolver::iterator it,
                i2p::data::IdentHash ident, std::shared_ptr<boost::asio::ip::tcp::resolver> resolver);

            void UpdateBandwidth ();
            void DetectExternalIP ();
            
        private:

            bool m_IsRunning;
            std::thread * m_Thread; 
            boost::asio::io_service m_Service;
            boost::asio::io_service::work m_Work;
            boost::asio::deadline_timer m_PeerCleanupTimer;

            NTCPServer * m_NTCPServer;
            SSUServer * m_SSUServer;
            std::map<i2p::data::IdentHash, Peer> m_Peers;
            
            DHKeysPairSupplier m_DHKeysPairSupplier;

            std::atomic<uint64_t> m_TotalSentBytes, m_TotalReceivedBytes;
            uint32_t m_InBandwidth, m_OutBandwidth;
            uint64_t m_LastInBandwidthUpdateBytes, m_LastOutBandwidthUpdateBytes;   
            uint64_t m_LastBandwidthUpdateTime;     

#ifdef USE_UPNP
            UPnP m_UPnP;
#endif

        public:

            // for HTTP only
            const NTCPServer * GetNTCPServer () const { return m_NTCPServer; };
            const SSUServer * GetSSUServer () const { return m_SSUServer; };
            const decltype(m_Peers)& GetPeers () const { return m_Peers; };
    };  

    extern Transports transports;
}   
}

#endif