// Copyright (c) 2009-2010 Satoshi Nakamoto // Copyright (c) 2009-2020 The Bitcoin Core developers // Distributed under the MIT software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. #ifndef BITCOIN_NET_H #define BITCOIN_NET_H #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef WIN32 #include #endif class CScheduler; class CNode; class BanMan; struct bilingual_str; /** Default for -whitelistrelay. */ static const bool DEFAULT_WHITELISTRELAY = true; /** Default for -whitelistforcerelay. */ static const bool DEFAULT_WHITELISTFORCERELAY = false; /** Time after which to disconnect, after waiting for a ping response (or inactivity). */ static const int TIMEOUT_INTERVAL = 20 * 60; /** Run the feeler connection loop once every 2 minutes or 120 seconds. **/ static const int FEELER_INTERVAL = 120; /** The maximum number of addresses from our addrman to return in response to a getaddr message. */ static constexpr size_t MAX_ADDR_TO_SEND = 1000; /** Maximum length of incoming protocol messages (no message over 4 MB is currently acceptable). */ static const unsigned int MAX_PROTOCOL_MESSAGE_LENGTH = 4 * 1000 * 1000; /** Maximum length of the user agent string in `version` message */ static const unsigned int MAX_SUBVERSION_LENGTH = 256; /** Maximum number of automatic outgoing nodes over which we'll relay everything (blocks, tx, addrs, etc) */ static const int MAX_OUTBOUND_FULL_RELAY_CONNECTIONS = 8; /** Maximum number of addnode outgoing nodes */ static const int MAX_ADDNODE_CONNECTIONS = 8; /** Maximum number of block-relay-only outgoing connections */ static const int MAX_BLOCK_RELAY_ONLY_CONNECTIONS = 2; /** Maximum number of feeler connections */ static const int MAX_FEELER_CONNECTIONS = 1; /** -listen default */ static const bool DEFAULT_LISTEN = true; /** -upnp default */ #ifdef USE_UPNP static const bool DEFAULT_UPNP = USE_UPNP; #else static const bool DEFAULT_UPNP = false; #endif /** The maximum number of peer connections to maintain. */ static const unsigned int DEFAULT_MAX_PEER_CONNECTIONS = 125; /** The default for -maxuploadtarget. 0 = Unlimited */ static const uint64_t DEFAULT_MAX_UPLOAD_TARGET = 0; /** The default timeframe for -maxuploadtarget. 1 day. */ static const uint64_t MAX_UPLOAD_TIMEFRAME = 60 * 60 * 24; /** Default for blocks only*/ static const bool DEFAULT_BLOCKSONLY = false; /** -peertimeout default */ static const int64_t DEFAULT_PEER_CONNECT_TIMEOUT = 60; static const bool DEFAULT_FORCEDNSSEED = false; static const size_t DEFAULT_MAXRECEIVEBUFFER = 5 * 1000; static const size_t DEFAULT_MAXSENDBUFFER = 1 * 1000; typedef int64_t NodeId; struct AddedNodeInfo { std::string strAddedNode; CService resolvedAddress; bool fConnected; bool fInbound; }; class CNodeStats; class CClientUIInterface; struct CSerializedNetMsg { CSerializedNetMsg() = default; CSerializedNetMsg(CSerializedNetMsg&&) = default; CSerializedNetMsg& operator=(CSerializedNetMsg&&) = default; // No copying, only moves. CSerializedNetMsg(const CSerializedNetMsg& msg) = delete; CSerializedNetMsg& operator=(const CSerializedNetMsg&) = delete; std::vector data; std::string m_type; }; /** Different types of connections to a peer. This enum encapsulates the * information we have available at the time of opening or accepting the * connection. Aside from INBOUND, all types are initiated by us. * * If adding or removing types, please update CONNECTION_TYPE_DOC in * src/rpc/net.cpp. */ enum class ConnectionType { /** * Inbound connections are those initiated by a peer. This is the only * property we know at the time of connection, until P2P messages are * exchanged. */ INBOUND, /** * These are the default connections that we use to connect with the * network. There is no restriction on what is relayed- by default we relay * blocks, addresses & transactions. We automatically attempt to open * MAX_OUTBOUND_FULL_RELAY_CONNECTIONS using addresses from our AddrMan. */ OUTBOUND_FULL_RELAY, /** * We open manual connections to addresses that users explicitly inputted * via the addnode RPC, or the -connect command line argument. Even if a * manual connection is misbehaving, we do not automatically disconnect or * add it to our discouragement filter. */ MANUAL, /** * Feeler connections are short-lived connections made to check that a node * is alive. They can be useful for: * - test-before-evict: if one of the peers is considered for eviction from * our AddrMan because another peer is mapped to the same slot in the tried table, * evict only if this longer-known peer is offline. * - move node addresses from New to Tried table, so that we have more * connectable addresses in our AddrMan. * Note that in the literature ("Eclipse Attacks on Bitcoin’s Peer-to-Peer Network") * only the latter feature is referred to as "feeler connections", * although in our codebase feeler connections encompass test-before-evict as well. * We make these connections approximately every FEELER_INTERVAL: * first we resolve previously found collisions if they exist (test-before-evict), * otherwise connect to a node from the new table. */ FEELER, /** * We use block-relay-only connections to help prevent against partition * attacks. By not relaying transactions or addresses, these connections * are harder to detect by a third party, thus helping obfuscate the * network topology. We automatically attempt to open * MAX_BLOCK_RELAY_ONLY_ANCHORS using addresses from our anchors.dat. Then * addresses from our AddrMan if MAX_BLOCK_RELAY_ONLY_CONNECTIONS * isn't reached yet. */ BLOCK_RELAY, /** * AddrFetch connections are short lived connections used to solicit * addresses from peers. These are initiated to addresses submitted via the * -seednode command line argument, or under certain conditions when the * AddrMan is empty. */ ADDR_FETCH, }; class NetEventsInterface; class CConnman { public: enum NumConnections { CONNECTIONS_NONE = 0, CONNECTIONS_IN = (1U << 0), CONNECTIONS_OUT = (1U << 1), CONNECTIONS_ALL = (CONNECTIONS_IN | CONNECTIONS_OUT), }; struct Options { ServiceFlags nLocalServices = NODE_NONE; int nMaxConnections = 0; int m_max_outbound_full_relay = 0; int m_max_outbound_block_relay = 0; int nMaxAddnode = 0; int nMaxFeeler = 0; int nBestHeight = 0; CClientUIInterface* uiInterface = nullptr; NetEventsInterface* m_msgproc = nullptr; BanMan* m_banman = nullptr; unsigned int nSendBufferMaxSize = 0; unsigned int nReceiveFloodSize = 0; uint64_t nMaxOutboundTimeframe = 0; uint64_t nMaxOutboundLimit = 0; int64_t m_peer_connect_timeout = DEFAULT_PEER_CONNECT_TIMEOUT; std::vector vSeedNodes; std::vector vWhitelistedRange; std::vector vWhiteBinds; std::vector vBinds; std::vector onion_binds; bool m_use_addrman_outgoing = true; std::vector m_specified_outgoing; std::vector m_added_nodes; std::vector m_asmap; }; void Init(const Options& connOptions) { nLocalServices = connOptions.nLocalServices; nMaxConnections = connOptions.nMaxConnections; m_max_outbound_full_relay = std::min(connOptions.m_max_outbound_full_relay, connOptions.nMaxConnections); m_max_outbound_block_relay = connOptions.m_max_outbound_block_relay; m_use_addrman_outgoing = connOptions.m_use_addrman_outgoing; nMaxAddnode = connOptions.nMaxAddnode; nMaxFeeler = connOptions.nMaxFeeler; m_max_outbound = m_max_outbound_full_relay + m_max_outbound_block_relay + nMaxFeeler; nBestHeight = connOptions.nBestHeight; clientInterface = connOptions.uiInterface; m_banman = connOptions.m_banman; m_msgproc = connOptions.m_msgproc; nSendBufferMaxSize = connOptions.nSendBufferMaxSize; nReceiveFloodSize = connOptions.nReceiveFloodSize; m_peer_connect_timeout = connOptions.m_peer_connect_timeout; { LOCK(cs_totalBytesSent); nMaxOutboundTimeframe = connOptions.nMaxOutboundTimeframe; nMaxOutboundLimit = connOptions.nMaxOutboundLimit; } vWhitelistedRange = connOptions.vWhitelistedRange; { LOCK(cs_vAddedNodes); vAddedNodes = connOptions.m_added_nodes; } m_onion_binds = connOptions.onion_binds; } CConnman(uint64_t seed0, uint64_t seed1, bool network_active = true); ~CConnman(); bool Start(CScheduler& scheduler, const Options& options); void StopThreads(); void StopNodes(); void Stop() { StopThreads(); StopNodes(); }; void Interrupt(); bool GetNetworkActive() const { return fNetworkActive; }; bool GetUseAddrmanOutgoing() const { return m_use_addrman_outgoing; }; void SetNetworkActive(bool active); void OpenNetworkConnection(const CAddress& addrConnect, bool fCountFailure, CSemaphoreGrant* grantOutbound, const char* strDest, ConnectionType conn_type); bool CheckIncomingNonce(uint64_t nonce); bool ForNode(NodeId id, std::function func); void PushMessage(CNode* pnode, CSerializedNetMsg&& msg); using NodeFn = std::function; void ForEachNode(const NodeFn& func) { LOCK(cs_vNodes); for (auto&& node : vNodes) { if (NodeFullyConnected(node)) func(node); } }; void ForEachNode(const NodeFn& func) const { LOCK(cs_vNodes); for (auto&& node : vNodes) { if (NodeFullyConnected(node)) func(node); } }; template void ForEachNodeThen(Callable&& pre, CallableAfter&& post) { LOCK(cs_vNodes); for (auto&& node : vNodes) { if (NodeFullyConnected(node)) pre(node); } post(); }; template void ForEachNodeThen(Callable&& pre, CallableAfter&& post) const { LOCK(cs_vNodes); for (auto&& node : vNodes) { if (NodeFullyConnected(node)) pre(node); } post(); }; // Addrman functions void SetServices(const CService &addr, ServiceFlags nServices); void MarkAddressGood(const CAddress& addr); bool AddNewAddresses(const std::vector& vAddr, const CAddress& addrFrom, int64_t nTimePenalty = 0); std::vector GetAddresses(size_t max_addresses, size_t max_pct); /** * Cache is used to minimize topology leaks, so it should * be used for all non-trusted calls, for example, p2p. * A non-malicious call (from RPC or a peer with addr permission) should * call the function without a parameter to avoid using the cache. */ std::vector GetAddresses(CNode& requestor, size_t max_addresses, size_t max_pct); // This allows temporarily exceeding m_max_outbound_full_relay, with the goal of finding // a peer that is better than all our current peers. void SetTryNewOutboundPeer(bool flag); bool GetTryNewOutboundPeer(); // Return the number of outbound peers we have in excess of our target (eg, // if we previously called SetTryNewOutboundPeer(true), and have since set // to false, we may have extra peers that we wish to disconnect). This may // return a value less than (num_outbound_connections - num_outbound_slots) // in cases where some outbound connections are not yet fully connected, or // not yet fully disconnected. int GetExtraOutboundCount(); bool AddNode(const std::string& node); bool RemoveAddedNode(const std::string& node); std::vector GetAddedNodeInfo(); /** * Attempts to open a connection. Currently only used from tests. * * @param[in] address Address of node to try connecting to * @param[in] conn_type ConnectionType::OUTBOUND, ConnectionType::BLOCK_RELAY, * ConnectionType::ADDR_FETCH or ConnectionType::FEELER * @return bool Returns false if there are no available * slots for this connection: * - conn_type not a supported ConnectionType * - Max total outbound connection capacity filled * - Max connection capacity for type is filled */ bool AddConnection(const std::string& address, ConnectionType conn_type); size_t GetNodeCount(NumConnections num); void GetNodeStats(std::vector& vstats); bool DisconnectNode(const std::string& node); bool DisconnectNode(const CSubNet& subnet); bool DisconnectNode(const CNetAddr& addr); bool DisconnectNode(NodeId id); //! Used to convey which local services we are offering peers during node //! connection. //! //! The data returned by this is used in CNode construction, //! which is used to advertise which services we are offering //! that peer during `net_processing.cpp:PushNodeVersion()`. ServiceFlags GetLocalServices() const; //!set the max outbound target in bytes void SetMaxOutboundTarget(uint64_t limit); uint64_t GetMaxOutboundTarget(); //!set the timeframe for the max outbound target void SetMaxOutboundTimeframe(uint64_t timeframe); uint64_t GetMaxOutboundTimeframe(); //! check if the outbound target is reached //! if param historicalBlockServingLimit is set true, the function will //! response true if the limit for serving historical blocks has been reached bool OutboundTargetReached(bool historicalBlockServingLimit); //! response the bytes left in the current max outbound cycle //! in case of no limit, it will always response 0 uint64_t GetOutboundTargetBytesLeft(); //! response the time in second left in the current max outbound cycle //! in case of no limit, it will always response 0 uint64_t GetMaxOutboundTimeLeftInCycle(); uint64_t GetTotalBytesRecv(); uint64_t GetTotalBytesSent(); void SetBestHeight(int height); int GetBestHeight() const; /** Get a unique deterministic randomizer. */ CSipHasher GetDeterministicRandomizer(uint64_t id) const; unsigned int GetReceiveFloodSize() const; void WakeMessageHandler(); /** Attempts to obfuscate tx time through exponentially distributed emitting. Works assuming that a single interval is used. Variable intervals will result in privacy decrease. */ int64_t PoissonNextSendInbound(int64_t now, int average_interval_seconds); void SetAsmap(std::vector asmap) { addrman.m_asmap = std::move(asmap); } private: struct ListenSocket { public: SOCKET socket; inline void AddSocketPermissionFlags(NetPermissionFlags& flags) const { NetPermissions::AddFlag(flags, m_permissions); } ListenSocket(SOCKET socket_, NetPermissionFlags permissions_) : socket(socket_), m_permissions(permissions_) {} private: NetPermissionFlags m_permissions; }; bool BindListenPort(const CService& bindAddr, bilingual_str& strError, NetPermissionFlags permissions); bool Bind(const CService& addr, unsigned int flags, NetPermissionFlags permissions); bool InitBinds( const std::vector& binds, const std::vector& whiteBinds, const std::vector& onion_binds); void ThreadOpenAddedConnections(); void AddAddrFetch(const std::string& strDest); void ProcessAddrFetch(); void ThreadOpenConnections(std::vector connect); void ThreadMessageHandler(); void AcceptConnection(const ListenSocket& hListenSocket); void DisconnectNodes(); void NotifyNumConnectionsChanged(); void InactivityCheck(CNode *pnode); bool GenerateSelectSet(std::set &recv_set, std::set &send_set, std::set &error_set); void SocketEvents(std::set &recv_set, std::set &send_set, std::set &error_set); void SocketHandler(); void ThreadSocketHandler(); void ThreadDNSAddressSeed(); uint64_t CalculateKeyedNetGroup(const CAddress& ad) const; CNode* FindNode(const CNetAddr& ip); CNode* FindNode(const CSubNet& subNet); CNode* FindNode(const std::string& addrName); CNode* FindNode(const CService& addr); /** * Determine whether we're already connected to a given address, in order to * avoid initiating duplicate connections. */ bool AlreadyConnectedToAddress(const CAddress& addr); bool AttemptToEvictConnection(); CNode* ConnectNode(CAddress addrConnect, const char *pszDest, bool fCountFailure, ConnectionType conn_type); void AddWhitelistPermissionFlags(NetPermissionFlags& flags, const CNetAddr &addr) const; void DeleteNode(CNode* pnode); NodeId GetNewNodeId(); size_t SocketSendData(CNode *pnode) const; void DumpAddresses(); // Network stats void RecordBytesRecv(uint64_t bytes); void RecordBytesSent(uint64_t bytes); /** * Return vector of current BLOCK_RELAY peers. */ std::vector GetCurrentBlockRelayOnlyConns() const; // Whether the node should be passed out in ForEach* callbacks static bool NodeFullyConnected(const CNode* pnode); // Network usage totals RecursiveMutex cs_totalBytesRecv; RecursiveMutex cs_totalBytesSent; uint64_t nTotalBytesRecv GUARDED_BY(cs_totalBytesRecv) {0}; uint64_t nTotalBytesSent GUARDED_BY(cs_totalBytesSent) {0}; // outbound limit & stats uint64_t nMaxOutboundTotalBytesSentInCycle GUARDED_BY(cs_totalBytesSent); uint64_t nMaxOutboundCycleStartTime GUARDED_BY(cs_totalBytesSent); uint64_t nMaxOutboundLimit GUARDED_BY(cs_totalBytesSent); uint64_t nMaxOutboundTimeframe GUARDED_BY(cs_totalBytesSent); // P2P timeout in seconds int64_t m_peer_connect_timeout; // Whitelisted ranges. Any node connecting from these is automatically // whitelisted (as well as those connecting to whitelisted binds). std::vector vWhitelistedRange; unsigned int nSendBufferMaxSize{0}; unsigned int nReceiveFloodSize{0}; std::vector vhListenSocket; std::atomic fNetworkActive{true}; bool fAddressesInitialized{false}; CAddrMan addrman; std::deque m_addr_fetches GUARDED_BY(m_addr_fetches_mutex); RecursiveMutex m_addr_fetches_mutex; std::vector vAddedNodes GUARDED_BY(cs_vAddedNodes); RecursiveMutex cs_vAddedNodes; std::vector vNodes GUARDED_BY(cs_vNodes); std::list vNodesDisconnected; mutable RecursiveMutex cs_vNodes; std::atomic nLastNodeId{0}; unsigned int nPrevNodeCount{0}; /** * Cache responses to addr requests to minimize privacy leak. * Attack example: scraping addrs in real-time may allow an attacker * to infer new connections of the victim by detecting new records * with fresh timestamps (per self-announcement). */ struct CachedAddrResponse { std::vector m_addrs_response_cache; std::chrono::microseconds m_cache_entry_expiration{0}; }; /** * Addr responses stored in different caches * per (network, local socket) prevent cross-network node identification. * If a node for example is multi-homed under Tor and IPv6, * a single cache (or no cache at all) would let an attacker * to easily detect that it is the same node by comparing responses. * Indexing by local socket prevents leakage when a node has multiple * listening addresses on the same network. * * The used memory equals to 1000 CAddress records (or around 40 bytes) per * distinct Network (up to 5) we have/had an inbound peer from, * resulting in at most ~196 KB. Every separate local socket may * add up to ~196 KB extra. */ std::map m_addr_response_caches; /** * Services this instance offers. * * This data is replicated in each CNode instance we create during peer * connection (in ConnectNode()) under a member also called * nLocalServices. * * This data is not marked const, but after being set it should not * change. See the note in CNode::nLocalServices documentation. * * \sa CNode::nLocalServices */ ServiceFlags nLocalServices; std::unique_ptr semOutbound; std::unique_ptr semAddnode; int nMaxConnections; // How many full-relay (tx, block, addr) outbound peers we want int m_max_outbound_full_relay; // How many block-relay only outbound peers we want // We do not relay tx or addr messages with these peers int m_max_outbound_block_relay; int nMaxAddnode; int nMaxFeeler; int m_max_outbound; bool m_use_addrman_outgoing; std::atomic nBestHeight; CClientUIInterface* clientInterface; NetEventsInterface* m_msgproc; /** Pointer to this node's banman. May be nullptr - check existence before dereferencing. */ BanMan* m_banman; /** * Addresses that were saved during the previous clean shutdown. We'll * attempt to make block-relay-only connections to them. */ std::vector m_anchors; /** SipHasher seeds for deterministic randomness */ const uint64_t nSeed0, nSeed1; /** flag for waking the message processor. */ bool fMsgProcWake GUARDED_BY(mutexMsgProc); std::condition_variable condMsgProc; Mutex mutexMsgProc; std::atomic flagInterruptMsgProc{false}; CThreadInterrupt interruptNet; std::thread threadDNSAddressSeed; std::thread threadSocketHandler; std::thread threadOpenAddedConnections; std::thread threadOpenConnections; std::thread threadMessageHandler; /** flag for deciding to connect to an extra outbound peer, * in excess of m_max_outbound_full_relay * This takes the place of a feeler connection */ std::atomic_bool m_try_another_outbound_peer; std::atomic m_next_send_inv_to_incoming{0}; /** * A vector of -bind=
:=onion arguments each of which is * an address and port that are designated for incoming Tor connections. */ std::vector m_onion_binds; friend struct CConnmanTest; friend struct ConnmanTestMsg; }; void Discover(); void StartMapPort(); void InterruptMapPort(); void StopMapPort(); uint16_t GetListenPort(); /** * Interface for message handling */ class NetEventsInterface { public: virtual bool ProcessMessages(CNode* pnode, std::atomic& interrupt) = 0; virtual bool SendMessages(CNode* pnode) = 0; virtual void InitializeNode(CNode* pnode) = 0; virtual void FinalizeNode(const CNode& node, bool& update_connection_time) = 0; protected: /** * Protected destructor so that instances can only be deleted by derived classes. * If that restriction is no longer desired, this should be made public and virtual. */ ~NetEventsInterface() = default; }; enum { LOCAL_NONE, // unknown LOCAL_IF, // address a local interface listens on LOCAL_BIND, // address explicit bound to LOCAL_UPNP, // address reported by UPnP LOCAL_MANUAL, // address explicitly specified (-externalip=) LOCAL_MAX }; bool IsPeerAddrLocalGood(CNode *pnode); void AdvertiseLocal(CNode *pnode); /** * Mark a network as reachable or unreachable (no automatic connects to it) * @note Networks are reachable by default */ void SetReachable(enum Network net, bool reachable); /** @returns true if the network is reachable, false otherwise */ bool IsReachable(enum Network net); /** @returns true if the address is in a reachable network, false otherwise */ bool IsReachable(const CNetAddr& addr); bool AddLocal(const CService& addr, int nScore = LOCAL_NONE); bool AddLocal(const CNetAddr& addr, int nScore = LOCAL_NONE); void RemoveLocal(const CService& addr); bool SeenLocal(const CService& addr); bool IsLocal(const CService& addr); bool GetLocal(CService &addr, const CNetAddr *paddrPeer = nullptr); CAddress GetLocalAddress(const CNetAddr *paddrPeer, ServiceFlags nLocalServices); extern bool fDiscover; extern bool fListen; extern bool g_relay_txes; /** Subversion as sent to the P2P network in `version` messages */ extern std::string strSubVersion; struct LocalServiceInfo { int nScore; int nPort; }; extern RecursiveMutex cs_mapLocalHost; extern std::map mapLocalHost GUARDED_BY(cs_mapLocalHost); extern const std::string NET_MESSAGE_COMMAND_OTHER; typedef std::map mapMsgCmdSize; //command, total bytes class CNodeStats { public: NodeId nodeid; ServiceFlags nServices; bool fRelayTxes; int64_t nLastSend; int64_t nLastRecv; int64_t nLastTXTime; int64_t nLastBlockTime; int64_t nTimeConnected; int64_t nTimeOffset; std::string addrName; int nVersion; std::string cleanSubVer; bool fInbound; bool m_manual_connection; int nStartingHeight; uint64_t nSendBytes; mapMsgCmdSize mapSendBytesPerMsgCmd; uint64_t nRecvBytes; mapMsgCmdSize mapRecvBytesPerMsgCmd; NetPermissionFlags m_permissionFlags; bool m_legacyWhitelisted; int64_t m_ping_usec; int64_t m_ping_wait_usec; int64_t m_min_ping_usec; CAmount minFeeFilter; // Our address, as reported by the peer std::string addrLocal; // Address of this peer CAddress addr; // Bind address of our side of the connection CAddress addrBind; // Name of the network the peer connected through std::string m_network; uint32_t m_mapped_as; std::string m_conn_type_string; }; /** Transport protocol agnostic message container. * Ideally it should only contain receive time, payload, * command and size. */ class CNetMessage { public: CDataStream m_recv; //!< received message data std::chrono::microseconds m_time{0}; //!< time of message receipt uint32_t m_message_size{0}; //!< size of the payload uint32_t m_raw_message_size{0}; //!< used wire size of the message (including header/checksum) std::string m_command; CNetMessage(CDataStream&& recv_in) : m_recv(std::move(recv_in)) {} void SetVersion(int nVersionIn) { m_recv.SetVersion(nVersionIn); } }; /** The TransportDeserializer takes care of holding and deserializing the * network receive buffer. It can deserialize the network buffer into a * transport protocol agnostic CNetMessage (command & payload) */ class TransportDeserializer { public: // returns true if the current deserialization is complete virtual bool Complete() const = 0; // set the serialization context version virtual void SetVersion(int version) = 0; // read and deserialize data virtual int Read(const char *data, unsigned int bytes) = 0; // decomposes a message from the context virtual Optional GetMessage(std::chrono::microseconds time, uint32_t& out_err) = 0; virtual ~TransportDeserializer() {} }; class V1TransportDeserializer final : public TransportDeserializer { private: const CChainParams& m_chain_params; const NodeId m_node_id; // Only for logging mutable CHash256 hasher; mutable uint256 data_hash; bool in_data; // parsing header (false) or data (true) CDataStream hdrbuf; // partially received header CMessageHeader hdr; // complete header CDataStream vRecv; // received message data unsigned int nHdrPos; unsigned int nDataPos; const uint256& GetMessageHash() const; int readHeader(const char *pch, unsigned int nBytes); int readData(const char *pch, unsigned int nBytes); void Reset() { vRecv.clear(); hdrbuf.clear(); hdrbuf.resize(24); in_data = false; nHdrPos = 0; nDataPos = 0; data_hash.SetNull(); hasher.Reset(); } public: V1TransportDeserializer(const CChainParams& chain_params, const NodeId node_id, int nTypeIn, int nVersionIn) : m_chain_params(chain_params), m_node_id(node_id), hdrbuf(nTypeIn, nVersionIn), vRecv(nTypeIn, nVersionIn) { Reset(); } bool Complete() const override { if (!in_data) return false; return (hdr.nMessageSize == nDataPos); } void SetVersion(int nVersionIn) override { hdrbuf.SetVersion(nVersionIn); vRecv.SetVersion(nVersionIn); } int Read(const char *pch, unsigned int nBytes) override { int ret = in_data ? readData(pch, nBytes) : readHeader(pch, nBytes); if (ret < 0) Reset(); return ret; } Optional GetMessage(std::chrono::microseconds time, uint32_t& out_err_raw_size) override; }; /** The TransportSerializer prepares messages for the network transport */ class TransportSerializer { public: // prepare message for transport (header construction, error-correction computation, payload encryption, etc.) virtual void prepareForTransport(CSerializedNetMsg& msg, std::vector& header) = 0; virtual ~TransportSerializer() {} }; class V1TransportSerializer : public TransportSerializer { public: void prepareForTransport(CSerializedNetMsg& msg, std::vector& header) override; }; /** Information about a peer */ class CNode { friend class CConnman; friend struct ConnmanTestMsg; public: std::unique_ptr m_deserializer; std::unique_ptr m_serializer; // socket std::atomic nServices{NODE_NONE}; SOCKET hSocket GUARDED_BY(cs_hSocket); size_t nSendSize{0}; // total size of all vSendMsg entries size_t nSendOffset{0}; // offset inside the first vSendMsg already sent uint64_t nSendBytes GUARDED_BY(cs_vSend){0}; std::deque> vSendMsg GUARDED_BY(cs_vSend); RecursiveMutex cs_vSend; RecursiveMutex cs_hSocket; RecursiveMutex cs_vRecv; RecursiveMutex cs_vProcessMsg; std::list vProcessMsg GUARDED_BY(cs_vProcessMsg); size_t nProcessQueueSize{0}; RecursiveMutex cs_sendProcessing; uint64_t nRecvBytes GUARDED_BY(cs_vRecv){0}; std::atomic nLastSend{0}; std::atomic nLastRecv{0}; const int64_t nTimeConnected; std::atomic nTimeOffset{0}; // Address of this peer const CAddress addr; // Bind address of our side of the connection const CAddress addrBind; std::atomic nVersion{0}; RecursiveMutex cs_SubVer; /** * cleanSubVer is a sanitized string of the user agent byte array we read * from the wire. This cleaned string can safely be logged or displayed. */ std::string cleanSubVer GUARDED_BY(cs_SubVer){}; bool m_prefer_evict{false}; // This peer is preferred for eviction. bool HasPermission(NetPermissionFlags permission) const { return NetPermissions::HasFlag(m_permissionFlags, permission); } // This boolean is unusued in actual processing, only present for backward compatibility at RPC/QT level bool m_legacyWhitelisted{false}; bool fClient{false}; // set by version message bool m_limited_node{false}; //after BIP159, set by version message /** * Whether the peer has signaled support for receiving ADDRv2 (BIP155) * messages, implying a preference to receive ADDRv2 instead of ADDR ones. */ std::atomic_bool m_wants_addrv2{false}; std::atomic_bool fSuccessfullyConnected{false}; // Setting fDisconnect to true will cause the node to be disconnected the // next time DisconnectNodes() runs std::atomic_bool fDisconnect{false}; bool fSentAddr{false}; CSemaphoreGrant grantOutbound; std::atomic nRefCount{0}; const uint64_t nKeyedNetGroup; std::atomic_bool fPauseRecv{false}; std::atomic_bool fPauseSend{false}; bool IsOutboundOrBlockRelayConn() const { switch (m_conn_type) { case ConnectionType::OUTBOUND_FULL_RELAY: case ConnectionType::BLOCK_RELAY: return true; case ConnectionType::INBOUND: case ConnectionType::MANUAL: case ConnectionType::ADDR_FETCH: case ConnectionType::FEELER: return false; } // no default case, so the compiler can warn about missing cases assert(false); } bool IsFullOutboundConn() const { return m_conn_type == ConnectionType::OUTBOUND_FULL_RELAY; } bool IsManualConn() const { return m_conn_type == ConnectionType::MANUAL; } bool IsBlockOnlyConn() const { return m_conn_type == ConnectionType::BLOCK_RELAY; } bool IsFeelerConn() const { return m_conn_type == ConnectionType::FEELER; } bool IsAddrFetchConn() const { return m_conn_type == ConnectionType::ADDR_FETCH; } bool IsInboundConn() const { return m_conn_type == ConnectionType::INBOUND; } /* Whether we send addr messages over this connection */ bool RelayAddrsWithConn() const { return m_conn_type != ConnectionType::BLOCK_RELAY; } bool ExpectServicesFromConn() const { switch (m_conn_type) { case ConnectionType::INBOUND: case ConnectionType::MANUAL: case ConnectionType::FEELER: return false; case ConnectionType::OUTBOUND_FULL_RELAY: case ConnectionType::BLOCK_RELAY: case ConnectionType::ADDR_FETCH: return true; } // no default case, so the compiler can warn about missing cases assert(false); } /** * Get network the peer connected through. * * Returns Network::NET_ONION for *inbound* onion connections, * and CNetAddr::GetNetClass() otherwise. The latter cannot be used directly * because it doesn't detect the former, and it's not the responsibility of * the CNetAddr class to know the actual network a peer is connected through. * * @return network the peer connected through. */ Network ConnectedThroughNetwork() const; protected: mapMsgCmdSize mapSendBytesPerMsgCmd; mapMsgCmdSize mapRecvBytesPerMsgCmd GUARDED_BY(cs_vRecv); public: uint256 hashContinue; std::atomic nStartingHeight{-1}; // flood relay std::vector vAddrToSend; std::unique_ptr m_addr_known{nullptr}; bool fGetAddr{false}; std::chrono::microseconds m_next_addr_send GUARDED_BY(cs_sendProcessing){0}; std::chrono::microseconds m_next_local_addr_send GUARDED_BY(cs_sendProcessing){0}; // List of block ids we still have announce. // There is no final sorting before sending, as they are always sent immediately // and in the order requested. std::vector vInventoryBlockToSend GUARDED_BY(cs_inventory); Mutex cs_inventory; struct TxRelay { mutable RecursiveMutex cs_filter; // We use fRelayTxes for two purposes - // a) it allows us to not relay tx invs before receiving the peer's version message // b) the peer may tell us in its version message that we should not relay tx invs // unless it loads a bloom filter. bool fRelayTxes GUARDED_BY(cs_filter){false}; std::unique_ptr pfilter PT_GUARDED_BY(cs_filter) GUARDED_BY(cs_filter){nullptr}; mutable RecursiveMutex cs_tx_inventory; CRollingBloomFilter filterInventoryKnown GUARDED_BY(cs_tx_inventory){50000, 0.000001}; // Set of transaction ids we still have to announce. // They are sorted by the mempool before relay, so the order is not important. std::set setInventoryTxToSend; // Used for BIP35 mempool sending bool fSendMempool GUARDED_BY(cs_tx_inventory){false}; // Last time a "MEMPOOL" request was serviced. std::atomic m_last_mempool_req{std::chrono::seconds{0}}; std::chrono::microseconds nNextInvSend{0}; RecursiveMutex cs_feeFilter; // Minimum fee rate with which to filter inv's to this node CAmount minFeeFilter GUARDED_BY(cs_feeFilter){0}; CAmount lastSentFeeFilter{0}; int64_t nextSendTimeFeeFilter{0}; }; // m_tx_relay == nullptr if we're not relaying transactions with this peer std::unique_ptr m_tx_relay; // Used for headers announcements - unfiltered blocks to relay std::vector vBlockHashesToAnnounce GUARDED_BY(cs_inventory); /** UNIX epoch time of the last block received from this peer that we had * not yet seen (e.g. not already received from another peer), that passed * preliminary validity checks and was saved to disk, even if we don't * connect the block or it eventually fails connection. Used as an inbound * peer eviction criterium in CConnman::AttemptToEvictConnection. */ std::atomic nLastBlockTime{0}; /** UNIX epoch time of the last transaction received from this peer that we * had not yet seen (e.g. not already received from another peer) and that * was accepted into our mempool. Used as an inbound peer eviction criterium * in CConnman::AttemptToEvictConnection. */ std::atomic nLastTXTime{0}; // Ping time measurement: // The pong reply we're expecting, or 0 if no pong expected. std::atomic nPingNonceSent{0}; /** When the last ping was sent, or 0 if no ping was ever sent */ std::atomic m_ping_start{std::chrono::microseconds{0}}; // Last measured round-trip time. std::atomic nPingUsecTime{0}; // Best measured round-trip time. std::atomic nMinPingUsecTime{std::numeric_limits::max()}; // Whether a ping is requested. std::atomic fPingQueued{false}; CNode(NodeId id, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress &addrIn, uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn, const CAddress &addrBindIn, const std::string &addrNameIn, ConnectionType conn_type_in, bool inbound_onion = false); ~CNode(); CNode(const CNode&) = delete; CNode& operator=(const CNode&) = delete; private: const NodeId id; const uint64_t nLocalHostNonce; const ConnectionType m_conn_type; std::atomic m_greatest_common_version{INIT_PROTO_VERSION}; //! Services offered to this peer. //! //! This is supplied by the parent CConnman during peer connection //! (CConnman::ConnectNode()) from its attribute of the same name. //! //! This is const because there is no protocol defined for renegotiating //! services initially offered to a peer. The set of local services we //! offer should not change after initialization. //! //! An interesting example of this is NODE_NETWORK and initial block //! download: a node which starts up from scratch doesn't have any blocks //! to serve, but still advertises NODE_NETWORK because it will eventually //! fulfill this role after IBD completes. P2P code is written in such a //! way that it can gracefully handle peers who don't make good on their //! service advertisements. const ServiceFlags nLocalServices; const int nMyStartingHeight; NetPermissionFlags m_permissionFlags{ PF_NONE }; std::list vRecvMsg; // Used only by SocketHandler thread mutable RecursiveMutex cs_addrName; std::string addrName GUARDED_BY(cs_addrName); // Our address, as reported by the peer CService addrLocal GUARDED_BY(cs_addrLocal); mutable RecursiveMutex cs_addrLocal; //! Whether this peer connected via our Tor onion service. const bool m_inbound_onion{false}; public: NodeId GetId() const { return id; } uint64_t GetLocalNonce() const { return nLocalHostNonce; } int GetMyStartingHeight() const { return nMyStartingHeight; } int GetRefCount() const { assert(nRefCount >= 0); return nRefCount; } bool ReceiveMsgBytes(const char *pch, unsigned int nBytes, bool& complete); void SetCommonVersion(int greatest_common_version) { m_greatest_common_version = greatest_common_version; } int GetCommonVersion() const { return m_greatest_common_version; } CService GetAddrLocal() const; //! May not be called more than once void SetAddrLocal(const CService& addrLocalIn); CNode* AddRef() { nRefCount++; return this; } void Release() { nRefCount--; } void AddAddressKnown(const CAddress& _addr) { assert(m_addr_known); m_addr_known->insert(_addr.GetKey()); } void PushAddress(const CAddress& _addr, FastRandomContext &insecure_rand) { // Whether the peer supports the address in `_addr`. For example, // nodes that do not implement BIP155 cannot receive Tor v3 addresses // because they require ADDRv2 (BIP155) encoding. const bool addr_format_supported = m_wants_addrv2 || _addr.IsAddrV1Compatible(); // Known checking here is only to save space from duplicates. // SendMessages will filter it again for knowns that were added // after addresses were pushed. assert(m_addr_known); if (_addr.IsValid() && !m_addr_known->contains(_addr.GetKey()) && addr_format_supported) { if (vAddrToSend.size() >= MAX_ADDR_TO_SEND) { vAddrToSend[insecure_rand.randrange(vAddrToSend.size())] = _addr; } else { vAddrToSend.push_back(_addr); } } } void AddKnownTx(const uint256& hash) { if (m_tx_relay != nullptr) { LOCK(m_tx_relay->cs_tx_inventory); m_tx_relay->filterInventoryKnown.insert(hash); } } void PushTxInventory(const uint256& hash) { if (m_tx_relay == nullptr) return; LOCK(m_tx_relay->cs_tx_inventory); if (!m_tx_relay->filterInventoryKnown.contains(hash)) { m_tx_relay->setInventoryTxToSend.insert(hash); } } void CloseSocketDisconnect(); void copyStats(CNodeStats &stats, const std::vector &m_asmap); ServiceFlags GetLocalServices() const { return nLocalServices; } std::string GetAddrName() const; //! Sets the addrName only if it was not previously set void MaybeSetAddrName(const std::string& addrNameIn); std::string ConnectionTypeAsString() const; }; /** Return a timestamp in the future (in microseconds) for exponentially distributed events. */ int64_t PoissonNextSend(int64_t now, int average_interval_seconds); /** Wrapper to return mockable type */ inline std::chrono::microseconds PoissonNextSend(std::chrono::microseconds now, std::chrono::seconds average_interval) { return std::chrono::microseconds{PoissonNextSend(now.count(), average_interval.count())}; } #endif // BITCOIN_NET_H