/* * Copyright (c) 2022-2024, 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 SSU2_H__ #define SSU2_H__ #include <unordered_map> #include <unordered_set> #include <vector> #include <list> #include <array> #include <mutex> #include <random> #include "util.h" #include "SSU2Session.h" #include "SSU2OutOfSession.h" #include "Socks5.h" namespace i2p { namespace transport { const int SSU2_TERMINATION_CHECK_TIMEOUT = 23; // in seconds const int SSU2_TERMINATION_CHECK_TIMEOUT_VARIANCE = 5; // in seconds const int SSU2_CLEANUP_INTERVAL = 72; // in seconds const int SSU2_RESEND_CHECK_TIMEOUT = 40; // in milliseconds const int SSU2_RESEND_CHECK_TIMEOUT_VARIANCE = 10; // in milliseconds const int SSU2_RESEND_CHECK_MORE_TIMEOUT = 4; // in milliseconds const int SSU2_RESEND_CHECK_MORE_TIMEOUT_VARIANCE = 9; // in milliseconds const size_t SSU2_MAX_RESEND_PACKETS = 128; // packets to resend at the time const uint64_t SSU2_SOCKET_MIN_BUFFER_SIZE = 128 * 1024; const uint64_t SSU2_SOCKET_MAX_BUFFER_SIZE = 4 * 1024 * 1024; const size_t SSU2_MAX_NUM_INTRODUCERS = 3; const size_t SSU2_MIN_RECEIVED_PACKET_SIZE = 40; // 16 byte short header + 8 byte minimum payload + 16 byte MAC const size_t SSU2_MAX_RECEIVED_QUEUE_SIZE = 2500; // in packets const int SSU2_TO_INTRODUCER_SESSION_DURATION = 3600; // 1 hour const int SSU2_TO_INTRODUCER_SESSION_EXPIRATION = 4800; // 80 minutes const int SSU2_KEEP_ALIVE_INTERVAL = 15; // in seconds const int SSU2_KEEP_ALIVE_INTERVAL_VARIANCE = 4; // in seconds const int SSU2_PROXY_CONNECT_RETRY_TIMEOUT = 30; // in seconds const int SSU2_MIN_HOLE_PUNCH_EXPIRATION = 30; // in seconds const int SSU2_MAX_HOLE_PUNCH_EXPIRATION = 160; // in seconds const size_t SSU2_MAX_NUM_PACKETS_PER_BATCH = 64; class SSU2Server: private i2p::util::RunnableServiceWithWork { struct Packet { uint8_t buf[SSU2_MAX_PACKET_SIZE]; size_t len; boost::asio::ip::udp::endpoint from; }; class ReceiveService: public i2p::util::RunnableService { public: ReceiveService (const std::string& name): RunnableService (name) {}; auto& GetService () { return GetIOService (); }; void Start () { StartIOService (); }; void Stop () { StopIOService (); }; }; public: SSU2Server (); ~SSU2Server () {}; void Start (); void Stop (); auto& GetService () { return GetIOService (); }; void SetLocalAddress (const boost::asio::ip::address& localAddress); bool SetProxy (const std::string& address, uint16_t port); bool UsesProxy () const { return m_IsThroughProxy; }; bool IsSupported (const boost::asio::ip::address& addr) const; uint16_t GetPort (bool v4) const; bool IsConnectedRecently (const boost::asio::ip::udp::endpoint& ep, bool max = true); void AddConnectedRecently (const boost::asio::ip::udp::endpoint& ep, uint64_t ts); std::mt19937& GetRng () { return m_Rng; } bool AEADChaCha20Poly1305Encrypt (const uint8_t * msg, size_t msgLen, const uint8_t * ad, size_t adLen, const uint8_t * key, const uint8_t * nonce, uint8_t * buf, size_t len); bool AEADChaCha20Poly1305Decrypt (const uint8_t * msg, size_t msgLen, const uint8_t * ad, size_t adLen, const uint8_t * key, const uint8_t * nonce, uint8_t * buf, size_t len); bool IsMaxNumIntroducers (bool v4) const { return (v4 ? m_Introducers.size () : m_IntroducersV6.size ()) >= SSU2_MAX_NUM_INTRODUCERS; } bool IsSyncClockFromPeers () const { return m_IsSyncClockFromPeers; }; void AdjustTimeOffset (int64_t offset, std::shared_ptr<const i2p::data::IdentityEx> from); bool AddSession (std::shared_ptr<SSU2Session> session); void RemoveSession (uint64_t connID); void RequestRemoveSession (uint64_t connID); void AddSessionByRouterHash (std::shared_ptr<SSU2Session> session); bool AddPendingOutgoingSession (std::shared_ptr<SSU2Session> session); void RemovePendingOutgoingSession (const boost::asio::ip::udp::endpoint& ep); std::shared_ptr<SSU2Session> FindSession (const i2p::data::IdentHash& ident); std::shared_ptr<SSU2Session> FindPendingOutgoingSession (const boost::asio::ip::udp::endpoint& ep) const; std::shared_ptr<SSU2Session> GetRandomPeerTestSession (i2p::data::RouterInfo::CompatibleTransports remoteTransports, const i2p::data::IdentHash& excluded); void AddRelay (uint32_t tag, std::shared_ptr<SSU2Session> relay); void RemoveRelay (uint32_t tag); std::shared_ptr<SSU2Session> FindRelaySession (uint32_t tag); bool AddPeerTest (uint32_t nonce, std::shared_ptr<SSU2Session> aliceSession, uint64_t ts); std::shared_ptr<SSU2Session> GetPeerTest (uint32_t nonce); bool AddRequestedPeerTest (uint32_t nonce, std::shared_ptr<SSU2PeerTestSession> session, uint64_t ts); std::shared_ptr<SSU2PeerTestSession> GetRequestedPeerTest (uint32_t nonce); void Send (const uint8_t * header, size_t headerLen, const uint8_t * payload, size_t payloadLen, const boost::asio::ip::udp::endpoint& to); void Send (const uint8_t * header, size_t headerLen, const uint8_t * headerX, size_t headerXLen, const uint8_t * payload, size_t payloadLen, const boost::asio::ip::udp::endpoint& to); bool CreateSession (std::shared_ptr<const i2p::data::RouterInfo> router, std::shared_ptr<const i2p::data::RouterInfo::Address> address, bool peerTest = false); bool StartPeerTest (std::shared_ptr<const i2p::data::RouterInfo> router, bool v4); void UpdateOutgoingToken (const boost::asio::ip::udp::endpoint& ep, uint64_t token, uint32_t exp); uint64_t FindOutgoingToken (const boost::asio::ip::udp::endpoint& ep); uint64_t GetIncomingToken (const boost::asio::ip::udp::endpoint& ep); std::pair<uint64_t, uint32_t> NewIncomingToken (const boost::asio::ip::udp::endpoint& ep); void RescheduleIntroducersUpdateTimer (); void RescheduleIntroducersUpdateTimerV6 (); i2p::util::MemoryPool<SSU2SentPacket>& GetSentPacketsPool () { return m_SentPacketsPool; }; i2p::util::MemoryPool<SSU2IncompleteMessage>& GetIncompleteMessagesPool () { return m_IncompleteMessagesPool; }; i2p::util::MemoryPool<SSU2IncompleteMessage::Fragment>& GetFragmentsPool () { return m_FragmentsPool; }; private: boost::asio::ip::udp::socket& OpenSocket (const boost::asio::ip::udp::endpoint& localEndpoint); void Receive (boost::asio::ip::udp::socket& socket); void HandleReceivedFrom (const boost::system::error_code& ecode, size_t bytes_transferred, Packet * packet, boost::asio::ip::udp::socket& socket); void HandleReceivedPackets (std::list<Packet *>&& packets); void ProcessNextPacket (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint); void InsertToReceivedPacketsQueue (Packet * packet); void InsertToReceivedPacketsQueue (std::list<Packet *>& packets); void HandleReceivedPacketsQueue (); void ScheduleTermination (); void HandleTerminationTimer (const boost::system::error_code& ecode); void ScheduleCleanup (); void HandleCleanupTimer (const boost::system::error_code& ecode); void ScheduleResend (bool more); void HandleResendTimer (const boost::system::error_code& ecode); bool CheckPendingOutgoingSession (const boost::asio::ip::udp::endpoint& ep, bool peerTest); void ConnectThroughIntroducer (std::shared_ptr<SSU2Session> session); std::vector<std::shared_ptr<SSU2Session> > FindIntroducers (int maxNumIntroducers, bool v4, const std::unordered_set<i2p::data::IdentHash>& excluded); void UpdateIntroducers (bool v4); void ScheduleIntroducersUpdateTimer (); void HandleIntroducersUpdateTimer (const boost::system::error_code& ecode, bool v4); void ScheduleIntroducersUpdateTimerV6 (); void SendThroughProxy (const uint8_t * header, size_t headerLen, const uint8_t * headerX, size_t headerXLen, const uint8_t * payload, size_t payloadLen, const boost::asio::ip::udp::endpoint& to); void ProcessNextPacketFromProxy (uint8_t * buf, size_t len); void ConnectToProxy (); void ReconnectToProxy (); void HandshakeWithProxy (); void ReadHandshakeWithProxyReply (); void SendUDPAssociateRequest (); void ReadUDPAssociateReply (); void ReadUDPAssociateSocket (); // handle if closed by peer private: ReceiveService m_ReceiveService; boost::asio::ip::udp::socket m_SocketV4, m_SocketV6; boost::asio::ip::address m_AddressV4, m_AddressV6; std::unordered_map<uint64_t, std::shared_ptr<SSU2Session> > m_Sessions; std::unordered_map<i2p::data::IdentHash, std::weak_ptr<SSU2Session> > m_SessionsByRouterHash; mutable std::mutex m_SessionsByRouterHashMutex; std::map<boost::asio::ip::udp::endpoint, std::shared_ptr<SSU2Session> > m_PendingOutgoingSessions; mutable std::mutex m_PendingOutgoingSessionsMutex; std::map<boost::asio::ip::udp::endpoint, std::pair<uint64_t, uint32_t> > m_IncomingTokens, m_OutgoingTokens; // remote endpoint -> (token, expires in seconds) std::unordered_map<uint32_t, std::weak_ptr<SSU2Session> > m_Relays; // we are introducer, relay tag -> session std::unordered_map<uint32_t, std::pair <std::weak_ptr<SSU2Session>, uint64_t > > m_PeerTests; // nonce->(Alice, timestamp). We are Bob std::list<std::pair<i2p::data::IdentHash, uint32_t> > m_Introducers, m_IntroducersV6; // introducers we are connected to i2p::util::MemoryPoolMt<Packet> m_PacketsPool; i2p::util::MemoryPool<SSU2SentPacket> m_SentPacketsPool; i2p::util::MemoryPool<SSU2IncompleteMessage> m_IncompleteMessagesPool; i2p::util::MemoryPool<SSU2IncompleteMessage::Fragment> m_FragmentsPool; boost::asio::deadline_timer m_TerminationTimer, m_CleanupTimer, m_ResendTimer, m_IntroducersUpdateTimer, m_IntroducersUpdateTimerV6; std::shared_ptr<SSU2Session> m_LastSession; bool m_IsPublished; // if we maintain introducers bool m_IsSyncClockFromPeers; int64_t m_PendingTimeOffset; // during peer test std::shared_ptr<const i2p::data::IdentityEx> m_PendingTimeOffsetFrom; std::mt19937 m_Rng; std::map<boost::asio::ip::udp::endpoint, uint64_t> m_ConnectedRecently; // endpoint -> last activity time in seconds mutable std::mutex m_ConnectedRecentlyMutex; std::unordered_map<uint32_t, std::pair <std::weak_ptr<SSU2PeerTestSession>, uint64_t > > m_RequestedPeerTests; // nonce->(Alice, timestamp) std::list<Packet *> m_ReceivedPacketsQueue; mutable std::mutex m_ReceivedPacketsQueueMutex; i2p::crypto::AEADChaCha20Poly1305Encryptor m_Encryptor; i2p::crypto::AEADChaCha20Poly1305Decryptor m_Decryptor; // proxy bool m_IsThroughProxy; uint8_t m_UDPRequestHeader[SOCKS5_UDP_IPV6_REQUEST_HEADER_SIZE]; std::unique_ptr<boost::asio::ip::tcp::endpoint> m_ProxyEndpoint; std::unique_ptr<boost::asio::ip::tcp::socket> m_UDPAssociateSocket; std::unique_ptr<boost::asio::ip::udp::endpoint> m_ProxyRelayEndpoint; std::unique_ptr<boost::asio::deadline_timer> m_ProxyConnectRetryTimer; public: // for HTTP/I2PControl const decltype(m_Sessions)& GetSSU2Sessions () const { return m_Sessions; }; }; } } #endif