i2pd/libi2pd/Transports.h

/*
* Copyright (c) 2013-2022, 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 <unordered_map>
#include <vector>
#include <queue>
#include <string>
#include <memory>
#include <atomic>
#include <boost/asio.hpp>
#include "TransportSession.h"
#include "SSU.h"
#include "SSU2.h"
#include "NTCP2.h"
#include "RouterInfo.h"
#include "I2NPProtocol.h"
#include "Identity.h"

namespace i2p {
    namespace transport {
        template<typename Keys>
        class EphemeralKeysSupplier {
            // called from this file only, so implementation is in Transports.cpp
        public:

            EphemeralKeysSupplier(int size);

            ~EphemeralKeysSupplier();

            void Start();

            void Stop();

            std::shared_ptr<Keys> Acquire();

            void Return(std::shared_ptr<Keys> pair);

        private:

            void Run();

            void CreateEphemeralKeys(int num);

        private:

            const int m_QueueSize;
            std::queue<std::shared_ptr<Keys> > m_Queue;

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

        typedef EphemeralKeysSupplier<i2p::crypto::X25519Keys> X25519KeysPairSupplier;

        const int PEER_ROUTER_INFO_UPDATE_INTERVAL = 31 * 60; // in seconds
        const int PEER_ROUTER_INFO_UPDATE_INTERVAL_VARIANCE = 7 * 60; // in seconds
        struct Peer {
            int numAttempts;
            std::shared_ptr<const i2p::data::RouterInfo> router;
            std::list<std::shared_ptr<TransportSession> > sessions;
            uint64_t creationTime, nextRouterInfoUpdateTime;
            std::vector<std::shared_ptr<i2p::I2NPMessage> > delayedMessages;

            void Done() {
                for (auto &it: sessions)
                    it->Done();
            }
        };

        const uint64_t SESSION_CREATION_TIMEOUT = 15; // in seconds
        const int PEER_TEST_INTERVAL = 71; // in minutes
        const int MAX_NUM_DELAYED_MESSAGES = 150;

        class Transports {
        public:

            Transports();

            ~Transports();

            void Start(bool enableNTCP2 = true, bool enableSSU = true, bool enableSSU2 = false);

            void Stop();

            bool IsBoundSSU() const { return m_SSUServer != nullptr; }

            bool IsBoundSSU2() const { return m_SSU2Server != nullptr; }

            bool IsBoundNTCP2() const { return m_NTCP2Server != nullptr; }

            bool IsOnline() const { return m_IsOnline; };

            void SetOnline(bool online);

            boost::asio::io_service &GetService() { return *m_Service; };

            std::shared_ptr<i2p::crypto::X25519Keys> GetNextX25519KeysPair();

            void ReuseX25519KeysPair(std::shared_ptr<i2p::crypto::X25519Keys> 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(const 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(bool ipv4 = true, bool ipv6 = true);

            void SetCheckReserved(bool check) { m_CheckReserved = check; };

            bool IsCheckReserved() { return m_CheckReserved; };

        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:

            volatile bool m_IsOnline;
            bool m_IsRunning, m_IsNAT, m_CheckReserved;
            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;

            SSUServer *m_SSUServer;
            SSU2Server *m_SSU2Server;
            NTCP2Server *m_NTCP2Server;
            mutable std::mutex m_PeersMutex;
            std::unordered_map<i2p::data::IdentHash, Peer> m_Peers;

            X25519KeysPairSupplier m_X25519KeysPairSupplier;

            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<i2p::data::FamilyID> 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 SSUServer *GetSSUServer() const { return m_SSUServer; };

            const NTCP2Server *GetNTCP2Server() const { return m_NTCP2Server; };

            const SSU2Server *GetSSU2Server() const { return m_SSU2Server; };
            const decltype(m_Peers)
            &

            GetPeers() const { return m_Peers; };
        };

        extern Transports transports;
    }
}

#endif