text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2015 The Bitcoin developers
  // Copyright (c) 2015-2020 The PIVX developers
  // Copyright (c) 2021 The T-Notes developers
  // Distributed under the MIT/X11 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 "addrdb.h"
  #include "addrman.h"
  #include "bloom.h"
  #include "compat.h"
  #include "fs.h"
  #include "hash.h"
  #include "limitedmap.h"
  #include "netaddress.h"
  #include "protocol.h"
  #include "random.h"
  #include "streams.h"
  #include "sync.h"
  #include "uint256.h"
  #include "utilstrencodings.h"
  #include "threadinterrupt.h"
  
  #include <atomic>
  #include <deque>
  #include <stdint.h>
  #include <thread>
  #include <memory>
  #include <condition_variable>
  
  #ifndef WIN32
  #include <arpa/inet.h>
  #endif
  
  #include <boost/signals2/signal.hpp>
  
  class CAddrMan;
  class CBlockIndex;
  class CScheduler;
  class CNode;
  
  /** Time between pings automatically sent out for latency probing and keepalive (in seconds). */
  static const int PING_INTERVAL = 2 * 60;
  /** 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 entries in an 'inv' protocol message */
  static const unsigned int MAX_INV_SZ = 50000;
  /** The maximum number of entries in a locator */
  static const unsigned int MAX_LOCATOR_SZ = 101;
  /** The maximum number of new addresses to accumulate before announcing. */
  static const unsigned int MAX_ADDR_TO_SEND = 1000;
  /** Maximum length of incoming protocol messages (no message over 2 MiB is currently acceptable). */
  static const unsigned int MAX_PROTOCOL_MESSAGE_LENGTH = 2 * 1024 * 1024;
  /** Maximum length of strSubVer in `version` message */
  static const unsigned int MAX_SUBVERSION_LENGTH = 256;
  /** Maximum number of outgoing nodes */
  static const int MAX_OUTBOUND_CONNECTIONS = 16;
  /** -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 entries in mapAskFor */
  static const size_t MAPASKFOR_MAX_SZ = MAX_INV_SZ;
  /** The maximum number of peer connections to maintain. */
  static const unsigned int DEFAULT_MAX_PEER_CONNECTIONS = 125;
  /** Disconnected peers are added to setOffsetDisconnectedPeers only if node has less than ENOUGH_CONNECTIONS */
  #define ENOUGH_CONNECTIONS 2
  /** Maximum number of peers added to setOffsetDisconnectedPeers before triggering a warning */
  #define MAX_TIMEOFFSET_DISCONNECTIONS 16
  
  static const ServiceFlags REQUIRED_SERVICES = NODE_NETWORK;
  
  static const bool DEFAULT_FORCEDNSSEED = false;
  static const size_t DEFAULT_MAXRECEIVEBUFFER = 5 * 1000;
  static const size_t DEFAULT_MAXSENDBUFFER    = 1 * 1000;
  
  // NOTE: When adjusting this, update rpcnet:setban's help ("24h")
  static const unsigned int DEFAULT_MISBEHAVING_BANTIME = 60 * 60 * 24;  // Default 24-hour ban
  
  typedef int NodeId;
  
  struct AddedNodeInfo
  {
      std::string strAddedNode;
      CService resolvedAddress;
      bool fConnected;
      bool fInbound;
  
      AddedNodeInfo(const std::string& _strAddedNode, const CService& _resolvedAddress, bool _fConnected, bool _fInbound):
          strAddedNode(_strAddedNode),
          resolvedAddress(_resolvedAddress),
          fConnected(_fConnected),
          fInbound(_fInbound)
      {}
  };
  
  class CTransaction;
  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<unsigned char> data;
      std::string command;
  };
  
  
  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;
          ServiceFlags nRelevantServices = NODE_NONE;
          int nMaxConnections = 0;
          int nMaxOutbound = 0;
          int nMaxFeeler = 0;
          int nBestHeight = 0;
          CClientUIInterface* uiInterface = nullptr;
          unsigned int nSendBufferMaxSize = 0;
          unsigned int nReceiveFloodSize = 0;
      };
      CConnman(uint64_t seed0, uint64_t seed1);
      ~CConnman();
      bool Start(CScheduler& scheduler, std::string& strNodeError, Options options);
      void Stop();
      void Interrupt();
      bool BindListenPort(const CService &bindAddr, std::string& strError, bool fWhitelisted = false);
      bool OpenNetworkConnection(const CAddress& addrConnect, bool fCountFailure, CSemaphoreGrant* grantOutbound = NULL, const char* strDest = NULL, bool fOneShot = false, bool fFeeler = false);
      bool CheckIncomingNonce(uint64_t nonce);
  
      bool ForNode(NodeId id, std::function<bool(CNode* pnode)> func);
  
      void PushMessage(CNode* pnode, CSerializedNetMsg&& msg);
  
      template<typename Callable>
      bool ForEachNodeContinueIf(Callable&& func)
      {
          LOCK(cs_vNodes);
          for (auto&& node : vNodes)
              if (NodeFullyConnected(node)) {
                  if (!func(node))
                      return false;
              }
          return true;
      };
  
      template<typename Callable>
      void ForEachNode(Callable&& func)
      {
          LOCK(cs_vNodes);
          for (auto&& node : vNodes) {
              if (NodeFullyConnected(node))
                  func(node);
          }
      };
  
      template<typename Callable>
      void ForEachNode(Callable&& func) const
      {
          LOCK(cs_vNodes);
          for (auto&& node : vNodes) {
              if (NodeFullyConnected(node))
                  func(node);
          }
      };
  
      template<typename Callable, typename CallableAfter>
      void ForEachNodeThen(Callable&& pre, CallableAfter&& post)
      {
          LOCK(cs_vNodes);
          for (auto&& node : vNodes) {
              if (NodeFullyConnected(node))
                  pre(node);
          }
          post();
      };
  
      template<typename Callable, typename CallableAfter>
      void ForEachNodeThen(Callable&& pre, CallableAfter&& post) const
      {
          LOCK(cs_vNodes);
          for (auto&& node : vNodes) {
              if (NodeFullyConnected(node))
                  pre(node);
          }
          post();
      };
  
      void RelayInv(CInv& inv);
      bool IsNodeConnected(const CAddress& addr);
      // Retrieves a connected peer (if connection success). Used only to check peer address availability for now.
      CNode* ConnectNode(CAddress addrConnect);
  
      // Addrman functions
      size_t GetAddressCount() const;
      void SetServices(const CService &addr, ServiceFlags nServices);
      void MarkAddressGood(const CAddress& addr);
      void AddNewAddress(const CAddress& addr, const CAddress& addrFrom, int64_t nTimePenalty = 0);
      void AddNewAddresses(const std::vector<CAddress>& vAddr, const CAddress& addrFrom, int64_t nTimePenalty = 0);
      std::vector<CAddress> GetAddresses();
      void AddressCurrentlyConnected(const CService& addr);
  
      // Denial-of-service detection/prevention
      // The idea is to detect peers that are behaving
      // badly and disconnect/ban them, but do it in a
      // one-coding-mistake-won't-shatter-the-entire-network
      // way.
      // IMPORTANT:  There should be nothing I can give a
      // node that it will forward on that will make that
      // node's peers drop it. If there is, an attacker
      // can isolate a node and/or try to split the network.
      // Dropping a node for sending stuff that is invalid
      // now but might be valid in a later version is also
      // dangerous, because it can cause a network split
      // between nodes running old code and nodes running
      // new code.
      void Ban(const CNetAddr& netAddr, const BanReason& reason, int64_t bantimeoffset = 0, bool sinceUnixEpoch = false);
      void Ban(const CSubNet& subNet, const BanReason& reason, int64_t bantimeoffset = 0, bool sinceUnixEpoch = false);
      void ClearBanned(); // needed for unit testing
      bool IsBanned(CNetAddr ip);
      bool IsBanned(CSubNet subnet);
      bool Unban(const CNetAddr &ip);
      bool Unban(const CSubNet &ip);
      void GetBanned(banmap_t &banmap);
      void SetBanned(const banmap_t &banmap);
  
      void AddOneShot(const std::string& strDest);
  
      bool AddNode(const std::string& node);
      bool RemoveAddedNode(const std::string& node);
      std::vector<AddedNodeInfo> GetAddedNodeInfo();
  
      size_t GetNodeCount(NumConnections num);
      void GetNodeStats(std::vector<CNodeStats>& vstats);
      bool DisconnectNode(const std::string& node);
      bool DisconnectNode(NodeId id);
  
      unsigned int GetSendBufferSize() const;
  
      void AddWhitelistedRange(const CSubNet& subnet);
  
      ServiceFlags GetLocalServices() const;
  
      uint64_t GetTotalBytesRecv();
      uint64_t GetTotalBytesSent();
  
      void SetBestHeight(int height);
      int GetBestHeight() const;
  
      /** Get a unique deterministic randomizer. */
      CSipHasher GetDeterministicRandomizer(uint64_t id);
  
      unsigned int GetReceiveFloodSize() const;
  private:
      struct ListenSocket {
          SOCKET socket;
          bool whitelisted;
  
          ListenSocket(SOCKET socket_, bool whitelisted_) : socket(socket_), whitelisted(whitelisted_) {}
      };
  
      void ThreadOpenAddedConnections();
      void ProcessOneShot();
      void ThreadOpenConnections();
      void ThreadMessageHandler();
      void AcceptConnection(const ListenSocket& hListenSocket);
      void ThreadSocketHandler();
      void ThreadDNSAddressSeed();
  
      void WakeMessageHandler();
  
      uint64_t CalculateKeyedNetGroup(const CAddress& ad);
  
      CNode* FindNode(const CNetAddr& ip);
      CNode* FindNode(const CSubNet& subNet);
      CNode* FindNode(const std::string& addrName);
      CNode* FindNode(const CService& addr);
  
      bool AttemptToEvictConnection(bool fPreferNewConnection);
      CNode* ConnectNode(CAddress addrConnect, const char* pszDest, bool fCountFailure);
      bool IsWhitelistedRange(const CNetAddr &addr);
  
      void DeleteNode(CNode* pnode);
  
      NodeId GetNewNodeId();
  
      size_t SocketSendData(CNode *pnode);
      //!check is the banlist has unwritten changes
      bool BannedSetIsDirty();
      //!set the "dirty" flag for the banlist
      void SetBannedSetDirty(bool dirty=true);
      //!clean unused entries (if bantime has expired)
      void SweepBanned();
      void DumpAddresses();
      void DumpData();
      void DumpBanlist();
  
      // Network stats
      void RecordBytesRecv(uint64_t bytes);
      void RecordBytesSent(uint64_t bytes);
  
      // 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{0};
      uint64_t nTotalBytesSent{0};
  
      // Whitelisted ranges. Any node connecting from these is automatically
      // whitelisted (as well as those connecting to whitelisted binds).
      std::vector<CSubNet> vWhitelistedRange;
      RecursiveMutex cs_vWhitelistedRange;
  
      unsigned int nSendBufferMaxSize{0};
      unsigned int nReceiveFloodSize{0};
  
      std::vector<ListenSocket> vhListenSocket;
      banmap_t setBanned;
      RecursiveMutex cs_setBanned;
      bool setBannedIsDirty{false};
      bool fAddressesInitialized{false};
      CAddrMan addrman;
      std::deque<std::string> vOneShots;
      RecursiveMutex cs_vOneShots;
      std::vector<std::string> vAddedNodes;
      RecursiveMutex cs_vAddedNodes;
      std::vector<CNode*> vNodes;
      std::list<CNode*> vNodesDisconnected;
      mutable RecursiveMutex cs_vNodes;
      std::atomic<NodeId> nLastNodeId;
  
      /** Services this instance offers */
      ServiceFlags nLocalServices{NODE_NONE};
  
      /** Services this instance cares about */
      ServiceFlags nRelevantServices{NODE_NONE};
  
      CSemaphore *semOutbound{nullptr};
      int nMaxConnections{0};
      int nMaxOutbound{0};
      int nMaxFeeler{0};
      std::atomic<int> nBestHeight;
      CClientUIInterface* clientInterface{nullptr};
  
      /** SipHasher seeds for deterministic randomness */
      const uint64_t nSeed0{0}, nSeed1{0};
  
      /** flag for waking the message processor. */
      bool fMsgProcWake{false};
  
      std::condition_variable condMsgProc;
      std::mutex mutexMsgProc;
      std::atomic<bool> flagInterruptMsgProc;
  
      CThreadInterrupt interruptNet;
  
      std::thread threadDNSAddressSeed;
      std::thread threadSocketHandler;
      std::thread threadOpenAddedConnections;
      std::thread threadOpenConnections;
      std::thread threadMessageHandler;
  };
  extern std::unique_ptr<CConnman> g_connman;
  void Discover();
  void StartMapPort();
  void InterruptMapPort();
  void StopMapPort();
  unsigned short GetListenPort();
  bool BindListenPort(const CService& bindAddr, std::string& strError, bool fWhitelisted = false);
  void CheckOffsetDisconnectedPeers(const CNetAddr& ip);
  
  struct CombinerAll {
      typedef bool result_type;
  
      template <typename I>
      bool operator()(I first, I last) const
      {
          while (first != last) {
              if (!(*first)) return false;
              ++first;
          }
          return true;
      }
  };
  
  // Signals for message handling
  struct CNodeSignals
  {
      boost::signals2::signal<bool (CNode*, CConnman&, std::atomic<bool>&), CombinerAll> ProcessMessages;
      boost::signals2::signal<bool (CNode*, CConnman&, std::atomic<bool>&), CombinerAll> SendMessages;
      boost::signals2::signal<void (CNode*, CConnman&)> InitializeNode;
      boost::signals2::signal<void (NodeId, bool&)> FinalizeNode;
  };
  
  
  CNodeSignals& GetNodeSignals();
  
  
  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);
  void SetLimited(enum Network net, bool fLimited = true);
  bool IsLimited(enum Network net);
  bool IsLimited(const CNetAddr& addr);
  bool AddLocal(const CService& addr, int nScore = LOCAL_NONE);
  bool AddLocal(const CNetAddr& addr, int nScore = LOCAL_NONE);
  bool RemoveLocal(const CService& addr);
  bool SeenLocal(const CService& addr);
  bool IsLocal(const CService& addr);
  bool GetLocal(CService& addr, const CNetAddr* paddrPeer = NULL);
  bool IsReachable(enum Network net);
  bool IsReachable(const CNetAddr& addr);
  CAddress GetLocalAddress(const CNetAddr* paddrPeer, ServiceFlags nLocalServices);
  
  bool validateMasternodeIP(const std::string& addrStr);          // valid, reachable and routable address
  
  
  extern bool fDiscover;
  extern bool fListen;
  
  extern limitedmap<CInv, int64_t> mapAlreadyAskedFor;
  
  /** 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<CNetAddr, LocalServiceInfo> mapLocalHost;
  typedef std::map<std::string, uint64_t> mapMsgCmdSize; //command, total bytes
  
  class CNodeStats
  {
  public:
      NodeId nodeid;
      ServiceFlags nServices;
      int64_t nLastSend;
      int64_t nLastRecv;
      int64_t nTimeConnected;
      int64_t nTimeOffset;
      std::string addrName;
      int nVersion;
      std::string cleanSubVer;
      bool fInbound;
      int nStartingHeight;
      uint64_t nSendBytes;
      mapMsgCmdSize mapSendBytesPerMsgCmd;
      uint64_t nRecvBytes;
      mapMsgCmdSize mapRecvBytesPerMsgCmd;
      bool fWhitelisted;
      double dPingTime;
      double dPingWait;
      std::string addrLocal;
  };
  
  
  class CNetMessage
  {
  public:
      bool in_data; // parsing header (false) or data (true)
  
      CDataStream hdrbuf; // partially received header
      CMessageHeader hdr; // complete header
      unsigned int nHdrPos;
  
      CDataStream vRecv; // received message data
      unsigned int nDataPos;
  
      int64_t nTime; // time (in microseconds) of message receipt.
  
      CNetMessage(const CMessageHeader::MessageStartChars& pchMessageStartIn, int nTypeIn, int nVersionIn) : hdrbuf(nTypeIn, nVersionIn), hdr(pchMessageStartIn), vRecv(nTypeIn, nVersionIn) {
          hdrbuf.resize(24);
          in_data = false;
          nHdrPos = 0;
          nDataPos = 0;
          nTime = 0;
      }
  
      bool complete() const
      {
          if (!in_data)
              return false;
          return (hdr.nMessageSize == nDataPos);
      }
  
      void SetVersion(int nVersionIn)
      {
          hdrbuf.SetVersion(nVersionIn);
          vRecv.SetVersion(nVersionIn);
      }
  
      int readHeader(const char* pch, unsigned int nBytes);
      int readData(const char* pch, unsigned int nBytes);
  };
  
  
  /** Information about a peer */
  class CNode
  {
      friend class CConnman;
  public:
      // socket
      std::atomic<ServiceFlags> nServices;
      ServiceFlags nServicesExpected;
      SOCKET hSocket;
      size_t nSendSize;   // total size of all vSendMsg entries
      size_t nSendOffset; // offset inside the first vSendMsg already sent
      uint64_t nSendBytes;
      std::deque<std::vector<unsigned char>> vSendMsg;
      RecursiveMutex cs_vSend;
      RecursiveMutex cs_hSocket;
      RecursiveMutex cs_vRecv;
  
      RecursiveMutex cs_vProcessMsg;
      std::list<CNetMessage> vProcessMsg;
      size_t nProcessQueueSize;
  
      RecursiveMutex cs_sendProcessing;
  
      std::deque<CInv> vRecvGetData;
      uint64_t nRecvBytes;
      std::atomic<int> nRecvVersion;
  
      std::atomic<int64_t> nLastSend;
      std::atomic<int64_t> nLastRecv;
      const int64_t nTimeConnected;
      std::atomic<int64_t> nTimeOffset;
      const CAddress addr;
      std::atomic<int> nVersion;
      // strSubVer is whatever byte array we read from the wire. However, this field is intended
      // to be printed out, displayed to humans in various forms and so on. So we sanitize it and
      // store the sanitized version in cleanSubVer. The original should be used when dealing with
      // the network or wire types and the cleaned string used when displayed or logged.
      std::string strSubVer, cleanSubVer;
      RecursiveMutex cs_SubVer; // used for both cleanSubVer and strSubVer
      bool fWhitelisted; // This peer can bypass DoS banning.
      bool fFeeler;      // If true this node is being used as a short lived feeler.
      bool fOneShot;
      bool fClient;
      const bool fInbound;
      bool fNetworkNode;
      std::atomic_bool fSuccessfullyConnected;
      std::atomic_bool fDisconnect;
      // 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 their version message that we should not relay tx invs
      //    until they have initialized their bloom filter.
      bool fRelayTxes; //protected by cs_filter
      CSemaphoreGrant grantOutbound;
      RecursiveMutex cs_filter;
      CBloomFilter* pfilter;
      std::atomic<int> nRefCount;
      const NodeId id;
  
      const uint64_t nKeyedNetGroup;
      std::atomic_bool fPauseRecv;
      std::atomic_bool fPauseSend;
  protected:
      mapMsgCmdSize mapSendBytesPerMsgCmd;
      mapMsgCmdSize mapRecvBytesPerMsgCmd;
  
      std::vector<std::string> vecRequestsFulfilled; //keep track of what client has asked for
  
  public:
      uint256 hashContinue;
      std::atomic<int> nStartingHeight;
  
      // flood relay
      std::vector<CAddress> vAddrToSend;
      CRollingBloomFilter addrKnown;
      bool fGetAddr;
      std::set<uint256> setKnown;
      int64_t nNextAddrSend;
      int64_t nNextLocalAddrSend;
  
      // inventory based relay
      CRollingBloomFilter filterInventoryKnown;
      // 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<uint256> setInventoryTxToSend;
      // 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<uint256> vInventoryBlockToSend;
      // Set of tier two messages ids we still have to announce.
      std::vector<CInv> vInventoryTierTwoToSend;
      RecursiveMutex cs_inventory;
      std::multimap<int64_t, CInv> mapAskFor;
      std::vector<uint256> vBlockRequested;
      int64_t nNextInvSend;
      // Used for BIP35 mempool sending, also protected by cs_inventory
      bool fSendMempool;
  
      // Last time a "MEMPOOL" request was serviced.
      std::atomic<int64_t> timeLastMempoolReq{0};
  
      // Ping time measurement:
      // The pong reply we're expecting, or 0 if no pong expected.
      std::atomic<uint64_t> nPingNonceSent;
      // Time (in usec) the last ping was sent, or 0 if no ping was ever sent.
      std::atomic<int64_t> nPingUsecStart;
      // Last measured round-trip time.
      std::atomic<int64_t> nPingUsecTime;
      // Best measured round-trip time.
      std::atomic<int64_t> nMinPingUsecTime;
      // Whether a ping is requested.
      std::atomic<bool> fPingQueued;
  
      CNode(NodeId id, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress& addrIn, uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn, const std::string& addrNameIn = "", bool fInboundIn = false);
      ~CNode();
  
  private:
      CNode(const CNode&);
      void operator=(const CNode&);
  
  
      const uint64_t nLocalHostNonce;
      // Services offered to this peer
      const ServiceFlags nLocalServices;
      const int nMyStartingHeight;
      int nSendVersion;
      std::list<CNetMessage> vRecvMsg;  // Used only by SocketHandler thread
  
      mutable RecursiveMutex cs_addrName;
      std::string addrName;
  
      CService addrLocal;
      mutable RecursiveMutex cs_addrLocal;
  public:
      NodeId GetId() const
      {
          return id;
      }
  
      uint64_t GetLocalNonce() const {
        return nLocalHostNonce;
      }
  
      int GetMyStartingHeight() const {
        return nMyStartingHeight;
      }
  
      int GetRefCount()
      {
          assert(nRefCount >= 0);
          return nRefCount;
      }
  
      unsigned int GetTotalRecvSize()
      {
          unsigned int total = 0;
          for (const CNetMessage& msg : vRecvMsg)
              total += msg.vRecv.size() + 24;
          return total;
      }
  
      bool ReceiveMsgBytes(const char* pch, unsigned int nBytes, bool& complete);
  
      void SetRecvVersion(int nVersionIn)
      {
          nRecvVersion = nVersionIn;
      }
      int GetRecvVersion()
      {
          return nRecvVersion;
      }
      void SetSendVersion(int nVersionIn);
      int GetSendVersion() const;
  
      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)
      {
          addrKnown.insert(_addr.GetKey());
      }
  
      void PushAddress(const CAddress& _addr, FastRandomContext &insecure_rand)
      {
          // Known checking here is only to save space from duplicates.
          // SendMessages will filter it again for knowns that were added
          // after addresses were pushed.
          if (_addr.IsValid() && !addrKnown.contains(_addr.GetKey())) {
              if (vAddrToSend.size() >= MAX_ADDR_TO_SEND) {
                  vAddrToSend[insecure_rand.randrange(vAddrToSend.size())] = _addr;
              } else {
                  vAddrToSend.push_back(_addr);
              }
          }
      }
  
  
      void AddInventoryKnown(const CInv& inv)
      {
          {
              LOCK(cs_inventory);
              filterInventoryKnown.insert(inv.hash);
          }
      }
  
      void PushInventory(const CInv& inv)
      {
          LOCK(cs_inventory);
          if (inv.type == MSG_TX) {
              if (!filterInventoryKnown.contains(inv.hash)) {
                  setInventoryTxToSend.insert(inv.hash);
              }
          } else if (inv.type == MSG_BLOCK) {
              vInventoryBlockToSend.push_back(inv.hash);
          } else {
              vInventoryTierTwoToSend.emplace_back(inv);
          }
      }
  
      void AskFor(const CInv& inv);
  
      bool HasFulfilledRequest(std::string strRequest)
      {
          for (std::string& type : vecRequestsFulfilled) {
              if (type == strRequest) return true;
          }
          return false;
      }
  
      void ClearFulfilledRequest(std::string strRequest)
      {
          std::vector<std::string>::iterator it = vecRequestsFulfilled.begin();
          while (it != vecRequestsFulfilled.end()) {
              if ((*it) == strRequest) {
                  vecRequestsFulfilled.erase(it);
                  return;
              }
              ++it;
          }
      }
  
      void FulfilledRequest(std::string strRequest)
      {
          if (HasFulfilledRequest(strRequest)) return;
          vecRequestsFulfilled.push_back(strRequest);
      }
  
      bool IsSubscribed(unsigned int nChannel);
      void Subscribe(unsigned int nChannel, unsigned int nHops = 0);
      void CancelSubscribe(unsigned int nChannel);
      void CloseSocketDisconnect();
      bool DisconnectOldProtocol(int nVersionIn, int nVersionRequired, std::string strLastCommand = "");
  
      void copyStats(CNodeStats& stats);
  
      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);
  };
  
  class CExplicitNetCleanup
  {
  public:
      static void callCleanup();
  };
  
  
  
  /** Return a timestamp in the future (in microseconds) for exponentially distributed events. */
  int64_t PoissonNextSend(int64_t nNow, int average_interval_seconds);
  
  #endif // BITCOIN_NET_H
  