i2pd/core/tunnel/Tunnel.h

#ifndef TUNNEL_H__
#define TUNNEL_H__

#include <inttypes.h>
#include <map>
#include <list>
#include <vector>
#include <string>
#include <thread>
#include <mutex>
#include <memory>
#include "util/Queue.h"
#include "TunnelConfig.h"
#include "TunnelPool.h"
#include "TransitTunnel.h"
#include "TunnelEndpoint.h"
#include "TunnelGateway.h"
#include "TunnelBase.h"
#include "I2NPProtocol.h"

namespace i2p
{
namespace tunnel
{   
    const int TUNNEL_EXPIRATION_TIMEOUT = 660; // 11 minutes    
    const int TUNNEL_EXPIRATION_THRESHOLD = 60; // 1 minute 
    const int TUNNEL_RECREATION_THRESHOLD = 90; // 1.5 minutes  
    const int TUNNEL_CREATION_TIMEOUT = 30; // 30 seconds
    const int STANDARD_NUM_RECORDS = 5; // in VariableTunnelBuild message

    enum TunnelState
    {
        eTunnelStatePending,
        eTunnelStateBuildReplyReceived,
        eTunnelStateBuildFailed,
        eTunnelStateEstablished,
        eTunnelStateTestFailed,
        eTunnelStateFailed,
        eTunnelStateExpiring
    };  
    
    class OutboundTunnel;
    class InboundTunnel;
    class Tunnel: public TunnelBase
    {
        public:

            Tunnel (std::shared_ptr<const TunnelConfig> config);
            ~Tunnel ();

            void Build (uint32_t replyMsgID, std::shared_ptr<OutboundTunnel> outboundTunnel = nullptr);
            
            std::shared_ptr<const TunnelConfig> GetTunnelConfig () const { return m_Config; }
            TunnelState GetState () const { return m_State; };
            void SetState (TunnelState state)  { m_State = state; };
            bool IsEstablished () const { return m_State == eTunnelStateEstablished; };
            bool IsFailed () const { return m_State == eTunnelStateFailed; };
            bool IsRecreated () const { return m_IsRecreated; };
            void SetIsRecreated () { m_IsRecreated = true; };

            std::shared_ptr<TunnelPool> GetTunnelPool () const { return m_Pool; };
            void SetTunnelPool (std::shared_ptr<TunnelPool> pool) { m_Pool = pool; };           
            
            bool HandleTunnelBuildResponse (uint8_t * msg, size_t len);
            
            // implements TunnelBase
            void SendTunnelDataMsg (std::shared_ptr<i2p::I2NPMessage> msg);
            void EncryptTunnelMsg (std::shared_ptr<const I2NPMessage> in, std::shared_ptr<I2NPMessage> out); 
            uint32_t GetNextTunnelID () const { return m_Config->GetFirstHop ()->tunnelID; };
            const i2p::data::IdentHash& GetNextIdentHash () const { return m_Config->GetFirstHop ()->router->GetIdentHash (); };
            
        private:

            std::shared_ptr<const TunnelConfig> m_Config;
            std::shared_ptr<TunnelPool> m_Pool; // pool, tunnel belongs to, or null
            TunnelState m_State;
            bool m_IsRecreated;
    };  

    class OutboundTunnel: public Tunnel 
    {
        public:

            OutboundTunnel (std::shared_ptr<const TunnelConfig> config): Tunnel (config), m_Gateway (this) {};

            void SendTunnelDataMsg (const uint8_t * gwHash, uint32_t gwTunnel, std::shared_ptr<i2p::I2NPMessage> msg);
            void SendTunnelDataMsg (const std::vector<TunnelMessageBlock>& msgs); // multiple messages
            std::shared_ptr<const i2p::data::RouterInfo> GetEndpointRouter () const 
                { return GetTunnelConfig ()->GetLastHop ()->router; }; 
            size_t GetNumSentBytes () const { return m_Gateway.GetNumSentBytes (); };

            // implements TunnelBase
            void HandleTunnelDataMsg (std::shared_ptr<const i2p::I2NPMessage> tunnelMsg);
            uint32_t GetTunnelID () const { return GetNextTunnelID (); };
            
        private:

            std::mutex m_SendMutex;
            TunnelGateway m_Gateway; 
    };
    
    class InboundTunnel: public Tunnel, public std::enable_shared_from_this<InboundTunnel>
    {
        public:

            InboundTunnel (std::shared_ptr<const TunnelConfig> config): Tunnel (config), m_Endpoint (true) {};
            void HandleTunnelDataMsg (std::shared_ptr<const I2NPMessage> msg);
            size_t GetNumReceivedBytes () const { return m_Endpoint.GetNumReceivedBytes (); };

            // implements TunnelBase
            uint32_t GetTunnelID () const { return GetTunnelConfig ()->GetLastHop ()->nextTunnelID; };
        private:

            TunnelEndpoint m_Endpoint; 
    };  

    
    class Tunnels
    {   
        public:

            Tunnels ();
            ~Tunnels ();
            void Start ();
            void Stop ();       
            
            std::shared_ptr<InboundTunnel> GetInboundTunnel (uint32_t tunnelID);
            std::shared_ptr<InboundTunnel> GetPendingInboundTunnel (uint32_t replyMsgID);   
            std::shared_ptr<OutboundTunnel> GetPendingOutboundTunnel (uint32_t replyMsgID);         
            std::shared_ptr<InboundTunnel> GetNextInboundTunnel ();
            std::shared_ptr<OutboundTunnel> GetNextOutboundTunnel ();
            std::shared_ptr<TunnelPool> GetExploratoryPool () const { return m_ExploratoryPool; };
            TransitTunnel * GetTransitTunnel (uint32_t tunnelID);
            int GetTransitTunnelsExpirationTimeout ();
            void AddTransitTunnel (TransitTunnel * tunnel);
            void AddOutboundTunnel (std::shared_ptr<OutboundTunnel> newTunnel);
            void AddInboundTunnel (std::shared_ptr<InboundTunnel> newTunnel);
            void PostTunnelData (std::shared_ptr<I2NPMessage> msg);
            void PostTunnelData (const std::vector<std::shared_ptr<I2NPMessage> >& msgs);
            template<class TTunnel>
            std::shared_ptr<TTunnel> CreateTunnel (std::shared_ptr<TunnelConfig> config, std::shared_ptr<OutboundTunnel> outboundTunnel = nullptr);
            void AddPendingTunnel (uint32_t replyMsgID, std::shared_ptr<InboundTunnel> tunnel);
            void AddPendingTunnel (uint32_t replyMsgID, std::shared_ptr<OutboundTunnel> tunnel);
            std::shared_ptr<TunnelPool> CreateTunnelPool (i2p::garlic::GarlicDestination * localDestination, int numInboundHops, int numOuboundHops, int numInboundTunnels, int numOutboundTunnels);
            void DeleteTunnelPool (std::shared_ptr<TunnelPool> pool);
            void StopTunnelPool (std::shared_ptr<TunnelPool> pool);
            
        private:
        
            template<class TTunnel>
            std::shared_ptr<TTunnel> GetPendingTunnel (uint32_t replyMsgID, const std::map<uint32_t, std::shared_ptr<TTunnel> >& pendingTunnels);           

            void HandleTunnelGatewayMsg (TunnelBase * tunnel, std::shared_ptr<I2NPMessage> msg);

            void Run ();    
            void ManageTunnels ();
            void ManageOutboundTunnels ();
            void ManageInboundTunnels ();
            void ManageTransitTunnels ();
            void ManagePendingTunnels ();
            template<class PendingTunnels>
            void ManagePendingTunnels (PendingTunnels& pendingTunnels);
            void ManageTunnelPools ();
            
            void CreateZeroHopsInboundTunnel ();
            
        private:

            bool m_IsRunning;
            std::thread * m_Thread; 
            std::map<uint32_t, std::shared_ptr<InboundTunnel> > m_PendingInboundTunnels; // by replyMsgID
            std::map<uint32_t, std::shared_ptr<OutboundTunnel> > m_PendingOutboundTunnels; // by replyMsgID
            std::map<uint32_t, std::shared_ptr<InboundTunnel> > m_InboundTunnels;
            std::list<std::shared_ptr<OutboundTunnel> > m_OutboundTunnels;
            std::mutex m_TransitTunnelsMutex;
            std::map<uint32_t, TransitTunnel *> m_TransitTunnels;
            std::mutex m_PoolsMutex;
            std::list<std::shared_ptr<TunnelPool>> m_Pools;
            std::shared_ptr<TunnelPool> m_ExploratoryPool;
            i2p::util::Queue<std::shared_ptr<I2NPMessage> > m_Queue;

            // some stats
            int m_NumSuccesiveTunnelCreations, m_NumFailedTunnelCreations;

        public:

            // for HTTP only
            const decltype(m_OutboundTunnels)& GetOutboundTunnels () const { return m_OutboundTunnels; };
            const decltype(m_InboundTunnels)& GetInboundTunnels () const { return m_InboundTunnels; };
            const decltype(m_TransitTunnels)& GetTransitTunnels () const { return m_TransitTunnels; };
            int GetQueueSize () { return m_Queue.GetSize (); };
            int GetTunnelCreationSuccessRate () const // in percents
            { 
                int totalNum = m_NumSuccesiveTunnelCreations + m_NumFailedTunnelCreations;
                return totalNum ? m_NumSuccesiveTunnelCreations*100/totalNum : 0;
            }       
    };  

    extern Tunnels tunnels;
}   
}

#endif