// Copyright (c) 2009-2010 Satoshi Nakamoto // Copyright (c) 2009-2022 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 #include #include #include #include #include #include #include #include #include #include #include #include #include class AddrMan; class BanMan; class CChainParams; class CNode; class CScheduler; 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 constexpr std::chrono::minutes TIMEOUT_INTERVAL{20}; /** Run the feeler connection loop once every 2 minutes. **/ static constexpr auto FEELER_INTERVAL = 2min; /** Run the extra block-relay-only connection loop once every 5 minutes. **/ static constexpr auto EXTRA_BLOCK_RELAY_ONLY_PEER_INTERVAL = 5min; /** 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; /** 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 std::string DEFAULT_MAX_UPLOAD_TARGET{"0M"}; /** Default for blocks only*/ static const bool DEFAULT_BLOCKSONLY = false; /** -peertimeout default */ static const int64_t DEFAULT_PEER_CONNECT_TIMEOUT = 60; /** Number of file descriptors required for message capture **/ static const int NUM_FDS_MESSAGE_CAPTURE = 1; static constexpr bool DEFAULT_FORCEDNSSEED{false}; static constexpr bool DEFAULT_DNSSEED{true}; static constexpr bool DEFAULT_FIXEDSEEDS{true}; static const size_t DEFAULT_MAXRECEIVEBUFFER = 5 * 1000; static const size_t DEFAULT_MAXSENDBUFFER = 1 * 1000; static constexpr bool DEFAULT_V2_TRANSPORT{false}; typedef int64_t NodeId; struct AddedNodeParams { std::string m_added_node; bool m_use_v2transport; }; struct AddedNodeInfo { AddedNodeParams m_params; CService resolvedAddress; bool fConnected; bool fInbound; }; class CNodeStats; class CClientUIInterface; struct CSerializedNetMsg { CSerializedNetMsg() = default; CSerializedNetMsg(CSerializedNetMsg&&) = default; CSerializedNetMsg& operator=(CSerializedNetMsg&&) = default; // No implicit copying, only moves. CSerializedNetMsg(const CSerializedNetMsg& msg) = delete; CSerializedNetMsg& operator=(const CSerializedNetMsg&) = delete; CSerializedNetMsg Copy() const { CSerializedNetMsg copy; copy.data = data; copy.m_type = m_type; return copy; } std::vector data; std::string m_type; /** Compute total memory usage of this object (own memory + any dynamic memory). */ size_t GetMemoryUsage() const noexcept; }; /** * Look up IP addresses from all interfaces on the machine and add them to the * list of local addresses to self-advertise. * The loopback interface is skipped and only the first address from each * interface is used. */ void Discover(); uint16_t GetListenPort(); enum { LOCAL_NONE, // unknown LOCAL_IF, // address a local interface listens on LOCAL_BIND, // address explicit bound to LOCAL_MAPPED, // address reported by UPnP or NAT-PMP LOCAL_MANUAL, // address explicitly specified (-externalip=) LOCAL_MAX }; /** Returns a local address that we should advertise to this peer. */ std::optional GetLocalAddrForPeer(CNode& node); 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); CService GetLocalAddress(const CNode& peer); extern bool fDiscover; extern bool fListen; /** Subversion as sent to the P2P network in `version` messages */ extern std::string strSubVersion; struct LocalServiceInfo { int nScore; uint16_t nPort; }; extern GlobalMutex g_maplocalhost_mutex; extern std::map mapLocalHost GUARDED_BY(g_maplocalhost_mutex); extern const std::string NET_MESSAGE_TYPE_OTHER; using mapMsgTypeSize = std::map; class CNodeStats { public: NodeId nodeid; std::chrono::seconds m_last_send; std::chrono::seconds m_last_recv; std::chrono::seconds m_last_tx_time; std::chrono::seconds m_last_block_time; std::chrono::seconds m_connected; int64_t nTimeOffset; std::string m_addr_name; int nVersion; std::string cleanSubVer; bool fInbound; // We requested high bandwidth connection to peer bool m_bip152_highbandwidth_to; // Peer requested high bandwidth connection bool m_bip152_highbandwidth_from; int m_starting_height; uint64_t nSendBytes; mapMsgTypeSize mapSendBytesPerMsgType; uint64_t nRecvBytes; mapMsgTypeSize mapRecvBytesPerMsgType; NetPermissionFlags m_permission_flags; std::chrono::microseconds m_last_ping_time; std::chrono::microseconds m_min_ping_time; // 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; // Network the peer connected through Network m_network; uint32_t m_mapped_as; ConnectionType m_conn_type; /** Transport protocol type. */ TransportProtocolType m_transport_type; /** BIP324 session id string in hex, if any. */ std::string m_session_id; }; /** Transport protocol agnostic message container. * Ideally it should only contain receive time, payload, * type 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_type; CNetMessage(CDataStream&& recv_in) : m_recv(std::move(recv_in)) {} // Only one CNetMessage object will exist for the same message on either // the receive or processing queue. For performance reasons we therefore // delete the copy constructor and assignment operator to avoid the // possibility of copying CNetMessage objects. CNetMessage(CNetMessage&&) = default; CNetMessage(const CNetMessage&) = delete; CNetMessage& operator=(CNetMessage&&) = default; CNetMessage& operator=(const CNetMessage&) = delete; void SetVersion(int nVersionIn) { m_recv.SetVersion(nVersionIn); } }; /** The Transport converts one connection's sent messages to wire bytes, and received bytes back. */ class Transport { public: virtual ~Transport() {} struct Info { TransportProtocolType transport_type; std::optional session_id; }; /** Retrieve information about this transport. */ virtual Info GetInfo() const noexcept = 0; // 1. Receiver side functions, for decoding bytes received on the wire into transport protocol // agnostic CNetMessage (message type & payload) objects. /** Returns true if the current message is complete (so GetReceivedMessage can be called). */ virtual bool ReceivedMessageComplete() const = 0; /** Feed wire bytes to the transport. * * @return false if some bytes were invalid, in which case the transport can't be used anymore. * * Consumed bytes are chopped off the front of msg_bytes. */ virtual bool ReceivedBytes(Span& msg_bytes) = 0; /** Retrieve a completed message from transport. * * This can only be called when ReceivedMessageComplete() is true. * * If reject_message=true is returned the message itself is invalid, but (other than false * returned by ReceivedBytes) the transport is not in an inconsistent state. */ virtual CNetMessage GetReceivedMessage(std::chrono::microseconds time, bool& reject_message) = 0; // 2. Sending side functions, for converting messages into bytes to be sent over the wire. /** Set the next message to send. * * If no message can currently be set (perhaps because the previous one is not yet done being * sent), returns false, and msg will be unmodified. Otherwise msg is enqueued (and * possibly moved-from) and true is returned. */ virtual bool SetMessageToSend(CSerializedNetMsg& msg) noexcept = 0; /** Return type for GetBytesToSend, consisting of: * - Span to_send: span of bytes to be sent over the wire (possibly empty). * - bool more: whether there will be more bytes to be sent after the ones in to_send are * all sent (as signaled by MarkBytesSent()). * - const std::string& m_type: message type on behalf of which this is being sent * ("" for bytes that are not on behalf of any message). */ using BytesToSend = std::tuple< Span /*to_send*/, bool /*more*/, const std::string& /*m_type*/ >; /** Get bytes to send on the wire, if any, along with other information about it. * * As a const function, it does not modify the transport's observable state, and is thus safe * to be called multiple times. * * @param[in] have_next_message If true, the "more" return value reports whether more will * be sendable after a SetMessageToSend call. It is set by the caller when they know * they have another message ready to send, and only care about what happens * after that. The have_next_message argument only affects this "more" return value * and nothing else. * * Effectively, there are three possible outcomes about whether there are more bytes * to send: * - Yes: the transport itself has more bytes to send later. For example, for * V1Transport this happens during the sending of the header of a * message, when there is a non-empty payload that follows. * - No: the transport itself has no more bytes to send, but will have bytes to * send if handed a message through SetMessageToSend. In V1Transport this * happens when sending the payload of a message. * - Blocked: the transport itself has no more bytes to send, and is also incapable * of sending anything more at all now, if it were handed another * message to send. This occurs in V2Transport before the handshake is * complete, as the encryption ciphers are not set up for sending * messages before that point. * * The boolean 'more' is true for Yes, false for Blocked, and have_next_message * controls what is returned for No. * * @return a BytesToSend object. The to_send member returned acts as a stream which is only * ever appended to. This means that with the exception of MarkBytesSent (which pops * bytes off the front of later to_sends), operations on the transport can only append * to what is being returned. Also note that m_type and to_send refer to data that is * internal to the transport, and calling any non-const function on this object may * invalidate them. */ virtual BytesToSend GetBytesToSend(bool have_next_message) const noexcept = 0; /** Report how many bytes returned by the last GetBytesToSend() have been sent. * * bytes_sent cannot exceed to_send.size() of the last GetBytesToSend() result. * * If bytes_sent=0, this call has no effect. */ virtual void MarkBytesSent(size_t bytes_sent) noexcept = 0; /** Return the memory usage of this transport attributable to buffered data to send. */ virtual size_t GetSendMemoryUsage() const noexcept = 0; // 3. Miscellaneous functions. /** Whether upon disconnections, a reconnect with V1 is warranted. */ virtual bool ShouldReconnectV1() const noexcept = 0; }; class V1Transport final : public Transport { private: const MessageStartChars m_magic_bytes; const NodeId m_node_id; // Only for logging mutable Mutex m_recv_mutex; //!< Lock for receive state mutable CHash256 hasher GUARDED_BY(m_recv_mutex); mutable uint256 data_hash GUARDED_BY(m_recv_mutex); bool in_data GUARDED_BY(m_recv_mutex); // parsing header (false) or data (true) CDataStream hdrbuf GUARDED_BY(m_recv_mutex); // partially received header CMessageHeader hdr GUARDED_BY(m_recv_mutex); // complete header CDataStream vRecv GUARDED_BY(m_recv_mutex); // received message data unsigned int nHdrPos GUARDED_BY(m_recv_mutex); unsigned int nDataPos GUARDED_BY(m_recv_mutex); const uint256& GetMessageHash() const EXCLUSIVE_LOCKS_REQUIRED(m_recv_mutex); int readHeader(Span msg_bytes) EXCLUSIVE_LOCKS_REQUIRED(m_recv_mutex); int readData(Span msg_bytes) EXCLUSIVE_LOCKS_REQUIRED(m_recv_mutex); void Reset() EXCLUSIVE_LOCKS_REQUIRED(m_recv_mutex) { AssertLockHeld(m_recv_mutex); vRecv.clear(); hdrbuf.clear(); hdrbuf.resize(24); in_data = false; nHdrPos = 0; nDataPos = 0; data_hash.SetNull(); hasher.Reset(); } bool CompleteInternal() const noexcept EXCLUSIVE_LOCKS_REQUIRED(m_recv_mutex) { AssertLockHeld(m_recv_mutex); if (!in_data) return false; return hdr.nMessageSize == nDataPos; } /** Lock for sending state. */ mutable Mutex m_send_mutex; /** The header of the message currently being sent. */ std::vector m_header_to_send GUARDED_BY(m_send_mutex); /** The data of the message currently being sent. */ CSerializedNetMsg m_message_to_send GUARDED_BY(m_send_mutex); /** Whether we're currently sending header bytes or message bytes. */ bool m_sending_header GUARDED_BY(m_send_mutex) {false}; /** How many bytes have been sent so far (from m_header_to_send, or from m_message_to_send.data). */ size_t m_bytes_sent GUARDED_BY(m_send_mutex) {0}; public: V1Transport(const NodeId node_id, int nTypeIn, int nVersionIn) noexcept; bool ReceivedMessageComplete() const override EXCLUSIVE_LOCKS_REQUIRED(!m_recv_mutex) { AssertLockNotHeld(m_recv_mutex); return WITH_LOCK(m_recv_mutex, return CompleteInternal()); } Info GetInfo() const noexcept override; bool ReceivedBytes(Span& msg_bytes) override EXCLUSIVE_LOCKS_REQUIRED(!m_recv_mutex) { AssertLockNotHeld(m_recv_mutex); LOCK(m_recv_mutex); int ret = in_data ? readData(msg_bytes) : readHeader(msg_bytes); if (ret < 0) { Reset(); } else { msg_bytes = msg_bytes.subspan(ret); } return ret >= 0; } CNetMessage GetReceivedMessage(std::chrono::microseconds time, bool& reject_message) override EXCLUSIVE_LOCKS_REQUIRED(!m_recv_mutex); bool SetMessageToSend(CSerializedNetMsg& msg) noexcept override EXCLUSIVE_LOCKS_REQUIRED(!m_send_mutex); BytesToSend GetBytesToSend(bool have_next_message) const noexcept override EXCLUSIVE_LOCKS_REQUIRED(!m_send_mutex); void MarkBytesSent(size_t bytes_sent) noexcept override EXCLUSIVE_LOCKS_REQUIRED(!m_send_mutex); size_t GetSendMemoryUsage() const noexcept override EXCLUSIVE_LOCKS_REQUIRED(!m_send_mutex); bool ShouldReconnectV1() const noexcept override { return false; } }; class V2Transport final : public Transport { private: /** Contents of the version packet to send. BIP324 stipulates that senders should leave this * empty, and receivers should ignore it. Future extensions can change what is sent as long as * an empty version packet contents is interpreted as no extensions supported. */ static constexpr std::array VERSION_CONTENTS = {}; /** The length of the V1 prefix to match bytes initially received by responders with to * determine if their peer is speaking V1 or V2. */ static constexpr size_t V1_PREFIX_LEN = 16; // The sender side and receiver side of V2Transport are state machines that are transitioned // through, based on what has been received. The receive state corresponds to the contents of, // and bytes received to, the receive buffer. The send state controls what can be appended to // the send buffer and what can be sent from it. /** State type that defines the current contents of the receive buffer and/or how the next * received bytes added to it will be interpreted. * * Diagram: * * start(responder) * | * | start(initiator) /---------\ * | | | | * v v v | * KEY_MAYBE_V1 -> KEY -> GARB_GARBTERM -> VERSION -> APP -> APP_READY * | * \-------> V1 */ enum class RecvState : uint8_t { /** (Responder only) either v2 public key or v1 header. * * This is the initial state for responders, before data has been received to distinguish * v1 from v2 connections. When that happens, the state becomes either KEY (for v2) or V1 * (for v1). */ KEY_MAYBE_V1, /** Public key. * * This is the initial state for initiators, during which the other side's public key is * received. When that information arrives, the ciphers get initialized and the state * becomes GARB_GARBTERM. */ KEY, /** Garbage and garbage terminator. * * Whenever a byte is received, the last 16 bytes are compared with the expected garbage * terminator. When that happens, the state becomes VERSION. If no matching terminator is * received in 4111 bytes (4095 for the maximum garbage length, and 16 bytes for the * terminator), the connection aborts. */ GARB_GARBTERM, /** Version packet. * * A packet is received, and decrypted/verified. If that fails, the connection aborts. The * first received packet in this state (whether it's a decoy or not) is expected to * authenticate the garbage received during the GARB_GARBTERM state as associated * authenticated data (AAD). The first non-decoy packet in this state is interpreted as * version negotiation (currently, that means ignoring the contents, but it can be used for * negotiating future extensions), and afterwards the state becomes APP. */ VERSION, /** Application packet. * * A packet is received, and decrypted/verified. If that succeeds, the state becomes * APP_READY and the decrypted contents is kept in m_recv_decode_buffer until it is * retrieved as a message by GetMessage(). */ APP, /** Nothing (an application packet is available for GetMessage()). * * Nothing can be received in this state. When the message is retrieved by GetMessage, * the state becomes APP again. */ APP_READY, /** Nothing (this transport is using v1 fallback). * * All receive operations are redirected to m_v1_fallback. */ V1, }; /** State type that controls the sender side. * * Diagram: * * start(responder) * | * | start(initiator) * | | * v v * MAYBE_V1 -> AWAITING_KEY -> READY * | * \-----> V1 */ enum class SendState : uint8_t { /** (Responder only) Not sending until v1 or v2 is detected. * * This is the initial state for responders. The send buffer is empty. * When the receiver determines whether this * is a V1 or V2 connection, the sender state becomes AWAITING_KEY (for v2) or V1 (for v1). */ MAYBE_V1, /** Waiting for the other side's public key. * * This is the initial state for initiators. The public key and garbage is sent out. When * the receiver receives the other side's public key and transitions to GARB_GARBTERM, the * sender state becomes READY. */ AWAITING_KEY, /** Normal sending state. * * In this state, the ciphers are initialized, so packets can be sent. When this state is * entered, the garbage terminator and version packet are appended to the send buffer (in * addition to the key and garbage which may still be there). In this state a message can be * provided if the send buffer is empty. */ READY, /** This transport is using v1 fallback. * * All send operations are redirected to m_v1_fallback. */ V1, }; /** Cipher state. */ BIP324Cipher m_cipher; /** Whether we are the initiator side. */ const bool m_initiating; /** NodeId (for debug logging). */ const NodeId m_nodeid; /** Encapsulate a V1Transport to fall back to. */ V1Transport m_v1_fallback; /** Lock for receiver-side fields. */ mutable Mutex m_recv_mutex ACQUIRED_BEFORE(m_send_mutex); /** In {VERSION, APP}, the decrypted packet length, if m_recv_buffer.size() >= * BIP324Cipher::LENGTH_LEN. Unspecified otherwise. */ uint32_t m_recv_len GUARDED_BY(m_recv_mutex) {0}; /** Receive buffer; meaning is determined by m_recv_state. */ std::vector m_recv_buffer GUARDED_BY(m_recv_mutex); /** AAD expected in next received packet (currently used only for garbage). */ std::vector m_recv_aad GUARDED_BY(m_recv_mutex); /** Buffer to put decrypted contents in, for converting to CNetMessage. */ std::vector m_recv_decode_buffer GUARDED_BY(m_recv_mutex); /** Deserialization type. */ const int m_recv_type; /** Deserialization version number. */ const int m_recv_version; /** Current receiver state. */ RecvState m_recv_state GUARDED_BY(m_recv_mutex); /** Lock for sending-side fields. If both sending and receiving fields are accessed, * m_recv_mutex must be acquired before m_send_mutex. */ mutable Mutex m_send_mutex ACQUIRED_AFTER(m_recv_mutex); /** The send buffer; meaning is determined by m_send_state. */ std::vector m_send_buffer GUARDED_BY(m_send_mutex); /** How many bytes from the send buffer have been sent so far. */ uint32_t m_send_pos GUARDED_BY(m_send_mutex) {0}; /** The garbage sent, or to be sent (MAYBE_V1 and AWAITING_KEY state only). */ std::vector m_send_garbage GUARDED_BY(m_send_mutex); /** Type of the message being sent. */ std::string m_send_type GUARDED_BY(m_send_mutex); /** Current sender state. */ SendState m_send_state GUARDED_BY(m_send_mutex); /** Whether we've sent at least 24 bytes (which would trigger disconnect for V1 peers). */ bool m_sent_v1_header_worth GUARDED_BY(m_send_mutex) {false}; /** Change the receive state. */ void SetReceiveState(RecvState recv_state) noexcept EXCLUSIVE_LOCKS_REQUIRED(m_recv_mutex); /** Change the send state. */ void SetSendState(SendState send_state) noexcept EXCLUSIVE_LOCKS_REQUIRED(m_send_mutex); /** Given a packet's contents, find the message type (if valid), and strip it from contents. */ static std::optional GetMessageType(Span& contents) noexcept; /** Determine how many received bytes can be processed in one go (not allowed in V1 state). */ size_t GetMaxBytesToProcess() noexcept EXCLUSIVE_LOCKS_REQUIRED(m_recv_mutex); /** Put our public key + garbage in the send buffer. */ void StartSendingHandshake() noexcept EXCLUSIVE_LOCKS_REQUIRED(m_send_mutex); /** Process bytes in m_recv_buffer, while in KEY_MAYBE_V1 state. */ void ProcessReceivedMaybeV1Bytes() noexcept EXCLUSIVE_LOCKS_REQUIRED(m_recv_mutex, !m_send_mutex); /** Process bytes in m_recv_buffer, while in KEY state. */ bool ProcessReceivedKeyBytes() noexcept EXCLUSIVE_LOCKS_REQUIRED(m_recv_mutex, !m_send_mutex); /** Process bytes in m_recv_buffer, while in GARB_GARBTERM state. */ bool ProcessReceivedGarbageBytes() noexcept EXCLUSIVE_LOCKS_REQUIRED(m_recv_mutex); /** Process bytes in m_recv_buffer, while in VERSION/APP state. */ bool ProcessReceivedPacketBytes() noexcept EXCLUSIVE_LOCKS_REQUIRED(m_recv_mutex); public: static constexpr uint32_t MAX_GARBAGE_LEN = 4095; /** Construct a V2 transport with securely generated random keys. * * @param[in] nodeid the node's NodeId (only for debug log output). * @param[in] initiating whether we are the initiator side. * @param[in] type_in the serialization type of returned CNetMessages. * @param[in] version_in the serialization version of returned CNetMessages. */ V2Transport(NodeId nodeid, bool initiating, int type_in, int version_in) noexcept; /** Construct a V2 transport with specified keys and garbage (test use only). */ V2Transport(NodeId nodeid, bool initiating, int type_in, int version_in, const CKey& key, Span ent32, std::vector garbage) noexcept; // Receive side functions. bool ReceivedMessageComplete() const noexcept override EXCLUSIVE_LOCKS_REQUIRED(!m_recv_mutex); bool ReceivedBytes(Span& msg_bytes) noexcept override EXCLUSIVE_LOCKS_REQUIRED(!m_recv_mutex, !m_send_mutex); CNetMessage GetReceivedMessage(std::chrono::microseconds time, bool& reject_message) noexcept override EXCLUSIVE_LOCKS_REQUIRED(!m_recv_mutex); // Send side functions. bool SetMessageToSend(CSerializedNetMsg& msg) noexcept override EXCLUSIVE_LOCKS_REQUIRED(!m_send_mutex); BytesToSend GetBytesToSend(bool have_next_message) const noexcept override EXCLUSIVE_LOCKS_REQUIRED(!m_send_mutex); void MarkBytesSent(size_t bytes_sent) noexcept override EXCLUSIVE_LOCKS_REQUIRED(!m_send_mutex); size_t GetSendMemoryUsage() const noexcept override EXCLUSIVE_LOCKS_REQUIRED(!m_send_mutex); // Miscellaneous functions. bool ShouldReconnectV1() const noexcept override EXCLUSIVE_LOCKS_REQUIRED(!m_recv_mutex, !m_send_mutex); Info GetInfo() const noexcept override EXCLUSIVE_LOCKS_REQUIRED(!m_recv_mutex); }; struct CNodeOptions { NetPermissionFlags permission_flags = NetPermissionFlags::None; std::unique_ptr i2p_sam_session = nullptr; bool prefer_evict = false; size_t recv_flood_size{DEFAULT_MAXRECEIVEBUFFER * 1000}; bool use_v2transport = false; }; /** Information about a peer */ class CNode { public: /** Transport serializer/deserializer. The receive side functions are only called under cs_vRecv, while * the sending side functions are only called under cs_vSend. */ const std::unique_ptr m_transport; const NetPermissionFlags m_permission_flags; /** * Socket used for communication with the node. * May not own a Sock object (after `CloseSocketDisconnect()` or during tests). * `shared_ptr` (instead of `unique_ptr`) is used to avoid premature close of * the underlying file descriptor by one thread while another thread is * poll(2)-ing it for activity. * @see https://github.com/bitcoin/bitcoin/issues/21744 for details. */ std::shared_ptr m_sock GUARDED_BY(m_sock_mutex); /** Sum of GetMemoryUsage of all vSendMsg entries. */ size_t m_send_memusage GUARDED_BY(cs_vSend){0}; /** Total number of bytes sent on the wire to this peer. */ uint64_t nSendBytes GUARDED_BY(cs_vSend){0}; /** Messages still to be fed to m_transport->SetMessageToSend. */ std::deque vSendMsg GUARDED_BY(cs_vSend); Mutex cs_vSend; Mutex m_sock_mutex; Mutex cs_vRecv; uint64_t nRecvBytes GUARDED_BY(cs_vRecv){0}; std::atomic m_last_send{0s}; std::atomic m_last_recv{0s}; //! Unix epoch time at peer connection const std::chrono::seconds m_connected; std::atomic nTimeOffset{0}; // Address of this peer const CAddress addr; // Bind address of our side of the connection const CAddress addrBind; const std::string m_addr_name; /** The pszDest argument provided to ConnectNode(). Only used for reconnections. */ const std::string m_dest; //! Whether this peer is an inbound onion, i.e. connected via our Tor onion service. const bool m_inbound_onion; std::atomic nVersion{0}; Mutex m_subver_mutex; /** * 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(m_subver_mutex){}; const bool m_prefer_evict{false}; // This peer is preferred for eviction. bool HasPermission(NetPermissionFlags permission) const { return NetPermissions::HasFlag(m_permission_flags, permission); } /** fSuccessfullyConnected is set to true on receiving VERACK from the peer. */ 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}; CSemaphoreGrant grantOutbound; std::atomic nRefCount{0}; const uint64_t nKeyedNetGroup; std::atomic_bool fPauseRecv{false}; std::atomic_bool fPauseSend{false}; const ConnectionType m_conn_type; /** Move all messages from the received queue to the processing queue. */ void MarkReceivedMsgsForProcessing() EXCLUSIVE_LOCKS_REQUIRED(!m_msg_process_queue_mutex); /** Poll the next message from the processing queue of this connection. * * Returns std::nullopt if the processing queue is empty, or a pair * consisting of the message and a bool that indicates if the processing * queue has more entries. */ std::optional> PollMessage() EXCLUSIVE_LOCKS_REQUIRED(!m_msg_process_queue_mutex); /** Account for the total size of a sent message in the per msg type connection stats. */ void AccountForSentBytes(const std::string& msg_type, size_t sent_bytes) EXCLUSIVE_LOCKS_REQUIRED(cs_vSend) { mapSendBytesPerMsgType[msg_type] += sent_bytes; } 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 IsManualOrFullOutboundConn() const { switch (m_conn_type) { case ConnectionType::INBOUND: case ConnectionType::FEELER: case ConnectionType::BLOCK_RELAY: case ConnectionType::ADDR_FETCH: return false; case ConnectionType::OUTBOUND_FULL_RELAY: case ConnectionType::MANUAL: return true; } // no default case, so the compiler can warn about missing cases assert(false); } 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; } 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; /** Whether this peer connected through a privacy network. */ [[nodiscard]] bool IsConnectedThroughPrivacyNet() const; // We selected peer as (compact blocks) high-bandwidth peer (BIP152) std::atomic m_bip152_highbandwidth_to{false}; // Peer selected us as (compact blocks) high-bandwidth peer (BIP152) std::atomic m_bip152_highbandwidth_from{false}; /** Whether this peer provides all services that we want. Used for eviction decisions */ std::atomic_bool m_has_all_wanted_services{false}; /** Whether we should relay transactions to this peer. This only changes * from false to true. It will never change back to false. */ std::atomic_bool m_relays_txs{false}; /** Whether this peer has loaded a bloom filter. Used only in inbound * eviction logic. */ std::atomic_bool m_bloom_filter_loaded{false}; /** 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 m_last_block_time{0s}; /** 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 m_last_tx_time{0s}; /** Last measured round-trip time. Used only for RPC/GUI stats/debugging.*/ std::atomic m_last_ping_time{0us}; /** Lowest measured round-trip time. Used as an inbound peer eviction * criterium in CConnman::AttemptToEvictConnection. */ std::atomic m_min_ping_time{std::chrono::microseconds::max()}; CNode(NodeId id, std::shared_ptr sock, const CAddress& addrIn, uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn, const CAddress& addrBindIn, const std::string& addrNameIn, ConnectionType conn_type_in, bool inbound_onion, CNodeOptions&& node_opts = {}); CNode(const CNode&) = delete; CNode& operator=(const CNode&) = delete; NodeId GetId() const { return id; } uint64_t GetLocalNonce() const { return nLocalHostNonce; } int GetRefCount() const { assert(nRefCount >= 0); return nRefCount; } /** * Receive bytes from the buffer and deserialize them into messages. * * @param[in] msg_bytes The raw data * @param[out] complete Set True if at least one message has been * deserialized and is ready to be processed * @return True if the peer should stay connected, * False if the peer should be disconnected from. */ bool ReceiveMsgBytes(Span msg_bytes, bool& complete) EXCLUSIVE_LOCKS_REQUIRED(!cs_vRecv); void SetCommonVersion(int greatest_common_version) { Assume(m_greatest_common_version == INIT_PROTO_VERSION); m_greatest_common_version = greatest_common_version; } int GetCommonVersion() const { return m_greatest_common_version; } CService GetAddrLocal() const EXCLUSIVE_LOCKS_REQUIRED(!m_addr_local_mutex); //! May not be called more than once void SetAddrLocal(const CService& addrLocalIn) EXCLUSIVE_LOCKS_REQUIRED(!m_addr_local_mutex); CNode* AddRef() { nRefCount++; return this; } void Release() { nRefCount--; } void CloseSocketDisconnect() EXCLUSIVE_LOCKS_REQUIRED(!m_sock_mutex); void CopyStats(CNodeStats& stats) EXCLUSIVE_LOCKS_REQUIRED(!m_subver_mutex, !m_addr_local_mutex, !cs_vSend, !cs_vRecv); std::string ConnectionTypeAsString() const { return ::ConnectionTypeAsString(m_conn_type); } /** A ping-pong round trip has completed successfully. Update latest and minimum ping times. */ void PongReceived(std::chrono::microseconds ping_time) { m_last_ping_time = ping_time; m_min_ping_time = std::min(m_min_ping_time.load(), ping_time); } private: const NodeId id; const uint64_t nLocalHostNonce; std::atomic m_greatest_common_version{INIT_PROTO_VERSION}; const size_t m_recv_flood_size; std::list vRecvMsg; // Used only by SocketHandler thread Mutex m_msg_process_queue_mutex; std::list m_msg_process_queue GUARDED_BY(m_msg_process_queue_mutex); size_t m_msg_process_queue_size GUARDED_BY(m_msg_process_queue_mutex){0}; // Our address, as reported by the peer CService addrLocal GUARDED_BY(m_addr_local_mutex); mutable Mutex m_addr_local_mutex; mapMsgTypeSize mapSendBytesPerMsgType GUARDED_BY(cs_vSend); mapMsgTypeSize mapRecvBytesPerMsgType GUARDED_BY(cs_vRecv); /** * If an I2P session is created per connection (for outbound transient I2P * connections) then it is stored here so that it can be destroyed when the * socket is closed. I2P sessions involve a data/transport socket (in `m_sock`) * and a control socket (in `m_i2p_sam_session`). For transient sessions, once * the data socket is closed, the control socket is not going to be used anymore * and is just taking up resources. So better close it as soon as `m_sock` is * closed. * Otherwise this unique_ptr is empty. */ std::unique_ptr m_i2p_sam_session GUARDED_BY(m_sock_mutex); }; /** * Interface for message handling */ class NetEventsInterface { public: /** Mutex for anything that is only accessed via the msg processing thread */ static Mutex g_msgproc_mutex; /** Initialize a peer (setup state, queue any initial messages) */ virtual void InitializeNode(CNode& node, ServiceFlags our_services) = 0; /** Handle removal of a peer (clear state) */ virtual void FinalizeNode(const CNode& node) = 0; /** * Process protocol messages received from a given node * * @param[in] pnode The node which we have received messages from. * @param[in] interrupt Interrupt condition for processing threads * @return True if there is more work to be done */ virtual bool ProcessMessages(CNode* pnode, std::atomic& interrupt) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex) = 0; /** * Send queued protocol messages to a given node. * * @param[in] pnode The node which we are sending messages to. * @return True if there is more work to be done */ virtual bool SendMessages(CNode* pnode) EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex) = 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; }; class CConnman { public: struct Options { ServiceFlags nLocalServices = NODE_NONE; int m_max_automatic_connections = 0; CClientUIInterface* uiInterface = nullptr; NetEventsInterface* m_msgproc = nullptr; BanMan* m_banman = nullptr; unsigned int nSendBufferMaxSize = 0; unsigned int nReceiveFloodSize = 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; /// True if the user did not specify -bind= or -whitebind= and thus /// we should bind on `0.0.0.0` (IPv4) and `::` (IPv6). bool bind_on_any; bool m_use_addrman_outgoing = true; std::vector m_specified_outgoing; std::vector m_added_nodes; bool m_i2p_accept_incoming; }; void Init(const Options& connOptions) EXCLUSIVE_LOCKS_REQUIRED(!m_added_nodes_mutex, !m_total_bytes_sent_mutex) { AssertLockNotHeld(m_total_bytes_sent_mutex); nLocalServices = connOptions.nLocalServices; m_max_automatic_connections = connOptions.m_max_automatic_connections; m_max_outbound_full_relay = std::min(MAX_OUTBOUND_FULL_RELAY_CONNECTIONS, m_max_automatic_connections); m_max_outbound_block_relay = std::min(MAX_BLOCK_RELAY_ONLY_CONNECTIONS, m_max_automatic_connections - m_max_outbound_full_relay); m_max_automatic_outbound = m_max_outbound_full_relay + m_max_outbound_block_relay + m_max_feeler; m_max_inbound = std::max(0, m_max_automatic_connections - m_max_automatic_outbound); m_use_addrman_outgoing = connOptions.m_use_addrman_outgoing; m_client_interface = connOptions.uiInterface; m_banman = connOptions.m_banman; m_msgproc = connOptions.m_msgproc; nSendBufferMaxSize = connOptions.nSendBufferMaxSize; nReceiveFloodSize = connOptions.nReceiveFloodSize; m_peer_connect_timeout = std::chrono::seconds{connOptions.m_peer_connect_timeout}; { LOCK(m_total_bytes_sent_mutex); nMaxOutboundLimit = connOptions.nMaxOutboundLimit; } vWhitelistedRange = connOptions.vWhitelistedRange; { LOCK(m_added_nodes_mutex); for (const std::string& added_node : connOptions.m_added_nodes) { // -addnode cli arg does not currently have a way to signal BIP324 support m_added_node_params.push_back({added_node, false}); } } m_onion_binds = connOptions.onion_binds; } CConnman(uint64_t seed0, uint64_t seed1, AddrMan& addrman, const NetGroupManager& netgroupman, const CChainParams& params, bool network_active = true); ~CConnman(); bool Start(CScheduler& scheduler, const Options& options) EXCLUSIVE_LOCKS_REQUIRED(!m_total_bytes_sent_mutex, !m_added_nodes_mutex, !m_addr_fetches_mutex, !mutexMsgProc); void StopThreads(); void StopNodes(); void Stop() { StopThreads(); StopNodes(); }; void Interrupt() EXCLUSIVE_LOCKS_REQUIRED(!mutexMsgProc); 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&& grant_outbound, const char* strDest, ConnectionType conn_type, bool use_v2transport) EXCLUSIVE_LOCKS_REQUIRED(!m_unused_i2p_sessions_mutex); bool CheckIncomingNonce(uint64_t nonce); // alias for thread safety annotations only, not defined RecursiveMutex& GetNodesMutex() const LOCK_RETURNED(m_nodes_mutex); bool ForNode(NodeId id, std::function func); void PushMessage(CNode* pnode, CSerializedNetMsg&& msg) EXCLUSIVE_LOCKS_REQUIRED(!m_total_bytes_sent_mutex); using NodeFn = std::function; void ForEachNode(const NodeFn& func) { LOCK(m_nodes_mutex); for (auto&& node : m_nodes) { if (NodeFullyConnected(node)) func(node); } }; void ForEachNode(const NodeFn& func) const { LOCK(m_nodes_mutex); for (auto&& node : m_nodes) { if (NodeFullyConnected(node)) func(node); } }; // Addrman functions /** * Return all or many randomly selected addresses, optionally by network. * * @param[in] max_addresses Maximum number of addresses to return (0 = all). * @param[in] max_pct Maximum percentage of addresses to return (0 = all). * @param[in] network Select only addresses of this network (nullopt = all). */ std::vector GetAddresses(size_t max_addresses, size_t max_pct, std::optional network) const; /** * 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() const; void StartExtraBlockRelayPeers(); // 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 GetExtraFullOutboundCount() const; // Count the number of block-relay-only peers we have over our limit. int GetExtraBlockRelayCount() const; bool AddNode(const AddedNodeParams& add) EXCLUSIVE_LOCKS_REQUIRED(!m_added_nodes_mutex); bool RemoveAddedNode(const std::string& node) EXCLUSIVE_LOCKS_REQUIRED(!m_added_nodes_mutex); std::vector GetAddedNodeInfo(bool include_connected) const EXCLUSIVE_LOCKS_REQUIRED(!m_added_nodes_mutex); /** * 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) EXCLUSIVE_LOCKS_REQUIRED(!m_unused_i2p_sessions_mutex); size_t GetNodeCount(ConnectionDirection) const; uint32_t GetMappedAS(const CNetAddr& addr) const; void GetNodeStats(std::vector& vstats) const; 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; uint64_t GetMaxOutboundTarget() const EXCLUSIVE_LOCKS_REQUIRED(!m_total_bytes_sent_mutex); std::chrono::seconds GetMaxOutboundTimeframe() const; //! 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) const EXCLUSIVE_LOCKS_REQUIRED(!m_total_bytes_sent_mutex); //! response the bytes left in the current max outbound cycle //! in case of no limit, it will always response 0 uint64_t GetOutboundTargetBytesLeft() const EXCLUSIVE_LOCKS_REQUIRED(!m_total_bytes_sent_mutex); std::chrono::seconds GetMaxOutboundTimeLeftInCycle() const EXCLUSIVE_LOCKS_REQUIRED(!m_total_bytes_sent_mutex); uint64_t GetTotalBytesRecv() const; uint64_t GetTotalBytesSent() const EXCLUSIVE_LOCKS_REQUIRED(!m_total_bytes_sent_mutex); /** Get a unique deterministic randomizer. */ CSipHasher GetDeterministicRandomizer(uint64_t id) const; void WakeMessageHandler() EXCLUSIVE_LOCKS_REQUIRED(!mutexMsgProc); /** Return true if we should disconnect the peer for failing an inactivity check. */ bool ShouldRunInactivityChecks(const CNode& node, std::chrono::seconds now) const; bool MultipleManualOrFullOutboundConns(Network net) const EXCLUSIVE_LOCKS_REQUIRED(m_nodes_mutex); private: struct ListenSocket { public: std::shared_ptr sock; inline void AddSocketPermissionFlags(NetPermissionFlags& flags) const { NetPermissions::AddFlag(flags, m_permissions); } ListenSocket(std::shared_ptr sock_, NetPermissionFlags permissions_) : sock{sock_}, m_permissions{permissions_} { } private: NetPermissionFlags m_permissions; }; //! returns the time left in the current max outbound cycle //! in case of no limit, it will always return 0 std::chrono::seconds GetMaxOutboundTimeLeftInCycle_() const EXCLUSIVE_LOCKS_REQUIRED(m_total_bytes_sent_mutex); bool BindListenPort(const CService& bindAddr, bilingual_str& strError, NetPermissionFlags permissions); bool Bind(const CService& addr, unsigned int flags, NetPermissionFlags permissions); bool InitBinds(const Options& options); void ThreadOpenAddedConnections() EXCLUSIVE_LOCKS_REQUIRED(!m_added_nodes_mutex, !m_unused_i2p_sessions_mutex, !m_reconnections_mutex); void AddAddrFetch(const std::string& strDest) EXCLUSIVE_LOCKS_REQUIRED(!m_addr_fetches_mutex); void ProcessAddrFetch() EXCLUSIVE_LOCKS_REQUIRED(!m_addr_fetches_mutex, !m_unused_i2p_sessions_mutex); void ThreadOpenConnections(std::vector connect) EXCLUSIVE_LOCKS_REQUIRED(!m_addr_fetches_mutex, !m_added_nodes_mutex, !m_nodes_mutex, !m_unused_i2p_sessions_mutex, !m_reconnections_mutex); void ThreadMessageHandler() EXCLUSIVE_LOCKS_REQUIRED(!mutexMsgProc); void ThreadI2PAcceptIncoming(); void AcceptConnection(const ListenSocket& hListenSocket); /** * Create a `CNode` object from a socket that has just been accepted and add the node to * the `m_nodes` member. * @param[in] sock Connected socket to communicate with the peer. * @param[in] permission_flags The peer's permissions. * @param[in] addr_bind The address and port at our side of the connection. * @param[in] addr The address and port at the peer's side of the connection. */ void CreateNodeFromAcceptedSocket(std::unique_ptr&& sock, NetPermissionFlags permission_flags, const CAddress& addr_bind, const CAddress& addr); void DisconnectNodes() EXCLUSIVE_LOCKS_REQUIRED(!m_reconnections_mutex, !m_nodes_mutex); void NotifyNumConnectionsChanged(); /** Return true if the peer is inactive and should be disconnected. */ bool InactivityCheck(const CNode& node) const; /** * Generate a collection of sockets to check for IO readiness. * @param[in] nodes Select from these nodes' sockets. * @return sockets to check for readiness */ Sock::EventsPerSock GenerateWaitSockets(Span nodes); /** * Check connected and listening sockets for IO readiness and process them accordingly. */ void SocketHandler() EXCLUSIVE_LOCKS_REQUIRED(!m_total_bytes_sent_mutex, !mutexMsgProc); /** * Do the read/write for connected sockets that are ready for IO. * @param[in] nodes Nodes to process. The socket of each node is checked against `what`. * @param[in] events_per_sock Sockets that are ready for IO. */ void SocketHandlerConnected(const std::vector& nodes, const Sock::EventsPerSock& events_per_sock) EXCLUSIVE_LOCKS_REQUIRED(!m_total_bytes_sent_mutex, !mutexMsgProc); /** * Accept incoming connections, one from each read-ready listening socket. * @param[in] events_per_sock Sockets that are ready for IO. */ void SocketHandlerListening(const Sock::EventsPerSock& events_per_sock); void ThreadSocketHandler() EXCLUSIVE_LOCKS_REQUIRED(!m_total_bytes_sent_mutex, !mutexMsgProc, !m_nodes_mutex, !m_reconnections_mutex); void ThreadDNSAddressSeed() EXCLUSIVE_LOCKS_REQUIRED(!m_addr_fetches_mutex, !m_nodes_mutex); uint64_t CalculateKeyedNetGroup(const CAddress& ad) const; CNode* FindNode(const CNetAddr& ip); 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, bool use_v2transport) EXCLUSIVE_LOCKS_REQUIRED(!m_unused_i2p_sessions_mutex); void AddWhitelistPermissionFlags(NetPermissionFlags& flags, const CNetAddr &addr) const; void DeleteNode(CNode* pnode); NodeId GetNewNodeId(); /** (Try to) send data from node's vSendMsg. Returns (bytes_sent, data_left). */ std::pair SocketSendData(CNode& node) const EXCLUSIVE_LOCKS_REQUIRED(node.cs_vSend); void DumpAddresses(); // Network stats void RecordBytesRecv(uint64_t bytes); void RecordBytesSent(uint64_t bytes) EXCLUSIVE_LOCKS_REQUIRED(!m_total_bytes_sent_mutex); /** Return reachable networks for which we have no addresses in addrman and therefore may require loading fixed seeds. */ std::unordered_set GetReachableEmptyNetworks() const; /** * Return vector of current BLOCK_RELAY peers. */ std::vector GetCurrentBlockRelayOnlyConns() const; /** * Search for a "preferred" network, a reachable network to which we * currently don't have any OUTBOUND_FULL_RELAY or MANUAL connections. * There needs to be at least one address in AddrMan for a preferred * network to be picked. * * @param[out] network Preferred network, if found. * * @return bool Whether a preferred network was found. */ bool MaybePickPreferredNetwork(std::optional& network); // Whether the node should be passed out in ForEach* callbacks static bool NodeFullyConnected(const CNode* pnode); uint16_t GetDefaultPort(Network net) const; uint16_t GetDefaultPort(const std::string& addr) const; // Network usage totals mutable Mutex m_total_bytes_sent_mutex; std::atomic nTotalBytesRecv{0}; uint64_t nTotalBytesSent GUARDED_BY(m_total_bytes_sent_mutex) {0}; // outbound limit & stats uint64_t nMaxOutboundTotalBytesSentInCycle GUARDED_BY(m_total_bytes_sent_mutex) {0}; std::chrono::seconds nMaxOutboundCycleStartTime GUARDED_BY(m_total_bytes_sent_mutex) {0}; uint64_t nMaxOutboundLimit GUARDED_BY(m_total_bytes_sent_mutex); // P2P timeout in seconds std::chrono::seconds 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}; AddrMan& addrman; const NetGroupManager& m_netgroupman; std::deque m_addr_fetches GUARDED_BY(m_addr_fetches_mutex); Mutex m_addr_fetches_mutex; // connection string and whether to use v2 p2p std::vector m_added_node_params GUARDED_BY(m_added_nodes_mutex); mutable Mutex m_added_nodes_mutex; std::vector m_nodes GUARDED_BY(m_nodes_mutex); std::list m_nodes_disconnected; mutable RecursiveMutex m_nodes_mutex; std::atomic nLastNodeId{0}; unsigned int nPrevNodeCount{0}; // Stores number of full-tx connections (outbound and manual) per network std::array m_network_conn_counts GUARDED_BY(m_nodes_mutex) = {}; /** * 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 node offers. * * This data is replicated in each Peer instance we create. * * This data is not marked const, but after being set it should not * change. * * \sa Peer::our_services */ ServiceFlags nLocalServices; std::unique_ptr semOutbound; std::unique_ptr semAddnode; /** * Maximum number of automatic connections permitted, excluding manual * connections but including inbounds. May be changed by the user and is * potentially limited by the operating system (number of file descriptors). */ int m_max_automatic_connections; /* * Maximum number of peers by connection type. Might vary from defaults * based on -maxconnections init value. */ // 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 m_max_addnode{MAX_ADDNODE_CONNECTIONS}; int m_max_feeler{MAX_FEELER_CONNECTIONS}; int m_max_automatic_outbound; int m_max_inbound; bool m_use_addrman_outgoing; CClientUIInterface* m_client_interface; 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}; /** * This is signaled when network activity should cease. * A pointer to it is saved in `m_i2p_sam_session`, so make sure that * the lifetime of `interruptNet` is not shorter than * the lifetime of `m_i2p_sam_session`. */ CThreadInterrupt interruptNet; /** * I2P SAM session. * Used to accept incoming and make outgoing I2P connections from a persistent * address. */ std::unique_ptr m_i2p_sam_session; std::thread threadDNSAddressSeed; std::thread threadSocketHandler; std::thread threadOpenAddedConnections; std::thread threadOpenConnections; std::thread threadMessageHandler; std::thread threadI2PAcceptIncoming; /** 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; /** flag for initiating extra block-relay-only peer connections. * this should only be enabled after initial chain sync has occurred, * as these connections are intended to be short-lived and low-bandwidth. */ std::atomic_bool m_start_extra_block_relay_peers{false}; /** * 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; /** * Mutex protecting m_i2p_sam_sessions. */ Mutex m_unused_i2p_sessions_mutex; /** * A pool of created I2P SAM transient sessions that should be used instead * of creating new ones in order to reduce the load on the I2P network. * Creating a session in I2P is not cheap, thus if this is not empty, then * pick an entry from it instead of creating a new session. If connecting to * a host fails, then the created session is put to this pool for reuse. */ std::queue> m_unused_i2p_sessions GUARDED_BY(m_unused_i2p_sessions_mutex); /** * Mutex protecting m_reconnections. */ Mutex m_reconnections_mutex; /** Struct for entries in m_reconnections. */ struct ReconnectionInfo { CAddress addr_connect; CSemaphoreGrant grant; std::string destination; ConnectionType conn_type; bool use_v2transport; }; /** * List of reconnections we have to make. */ std::list m_reconnections GUARDED_BY(m_reconnections_mutex); /** Attempt reconnections, if m_reconnections non-empty. */ void PerformReconnections() EXCLUSIVE_LOCKS_REQUIRED(!m_reconnections_mutex, !m_unused_i2p_sessions_mutex); /** * Cap on the size of `m_unused_i2p_sessions`, to ensure it does not * unexpectedly use too much memory. */ static constexpr size_t MAX_UNUSED_I2P_SESSIONS_SIZE{10}; /** * RAII helper to atomically create a copy of `m_nodes` and add a reference * to each of the nodes. The nodes are released when this object is destroyed. */ class NodesSnapshot { public: explicit NodesSnapshot(const CConnman& connman, bool shuffle) { { LOCK(connman.m_nodes_mutex); m_nodes_copy = connman.m_nodes; for (auto& node : m_nodes_copy) { node->AddRef(); } } if (shuffle) { Shuffle(m_nodes_copy.begin(), m_nodes_copy.end(), FastRandomContext{}); } } ~NodesSnapshot() { for (auto& node : m_nodes_copy) { node->Release(); } } const std::vector& Nodes() const { return m_nodes_copy; } private: std::vector m_nodes_copy; }; const CChainParams& m_params; friend struct ConnmanTestMsg; }; /** Defaults to `CaptureMessageToFile()`, but can be overridden by unit tests. */ extern std::function data, bool is_incoming)> CaptureMessage; #endif // BITCOIN_NET_H