text: // Copyright (c) 2010 Satoshi Nakamoto
  // Copyright (c) 2017-2019 The SXL Developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #ifndef COIN_NETBASE_H
  #define COIN_NETBASE_H
  
  #if defined(HAVE_CONFIG_H)
  #include "config/coin-config.h"
  #endif
  
  #include "commons/serialize.h"
  #include "commons/compat/compat.h"
  
  #include <stdint.h>
  #include <string>
  #include <vector>
  
  enum Network {
      NET_UNROUTABLE,
      NET_IPV4,
      NET_IPV6,
      NET_TOR,
  
      NET_MAX,
  };
  
  extern bool fNameLookup;
  
  /** IP address (IPv6, or IPv4 using mapped IPv6 range (::FFFF:0:0/96)) */
  class CNetAddr {
  protected:
      unsigned char ip[16];  // in network byte order
  
  public:
      CNetAddr();
      CNetAddr(const struct in_addr& ipv4Addr);
      explicit CNetAddr(const char* pszIp, bool fAllowLookup = false);
      explicit CNetAddr(const std::string& strIp, bool fAllowLookup = false);
      void Init();
      void SetIP(const CNetAddr& ip);
      bool SetSpecial(const std::string& strName);  // for Tor addresses
      bool IsIPv4() const;                          // IPv4 mapped address (::FFFF:0:0/96, 0.0.0.0/0)
      bool IsIPv6() const;                          // IPv6 address (not mapped IPv4, not Tor)
      bool IsRFC1918() const;                       // IPv4 private networks (10.0.0.0/8, 192.168.0.0/16, 172.16.0.0/12)
      bool IsRFC3849() const;                       // IPv6 documentation address (2001:0DB8::/32)
      bool IsRFC3927() const;                       // IPv4 autoconfig (169.254.0.0/16)
      bool IsRFC3964() const;                       // IPv6 6to4 tunnelling (2002::/16)
      bool IsRFC4193() const;                       // IPv6 unique local (FC00::/7)
      bool IsRFC4380() const;                       // IPv6 Teredo tunnelling (2001::/32)
      bool IsRFC4843() const;                       // IPv6 ORCHID (2001:10::/28)
      bool IsRFC4862() const;                       // IPv6 autoconfig (FE80::/64)
      bool IsRFC6052() const;                       // IPv6 well-known prefix (64:FF9B::/96)
      bool IsRFC6145() const;                       // IPv6 IPv4-translated address (::FFFF:0:0:0/96)
      bool IsTor() const;
      bool IsLocal() const;
      bool IsRoutable() const;
      bool IsValid() const;
      bool IsMulticast() const;
      enum Network GetNetwork() const;
      std::string ToString() const;
      std::string ToStringIP() const;
      unsigned int GetByte(int n) const;
      uint64_t GetHash() const;
      bool GetInAddr(struct in_addr* pipv4Addr) const;
      std::vector<unsigned char> GetGroup() const;
      int GetReachabilityFrom(const CNetAddr* paddrPartner = nullptr) const;
      void Print() const;
  
      CNetAddr(const struct in6_addr& pipv6Addr);
      bool GetIn6Addr(struct in6_addr* pipv6Addr) const;
  
      friend bool operator==(const CNetAddr& a, const CNetAddr& b);
      friend bool operator!=(const CNetAddr& a, const CNetAddr& b);
      friend bool operator<(const CNetAddr& a, const CNetAddr& b);
  
      IMPLEMENT_SERIALIZE(READWRITE(FLATDATA(ip));)
  
      friend class CSubNet;
  };
  
  class CSubNet {
  protected:
      /// Network (base) address
      CNetAddr network;
      /// Netmask, in network byte order
      uint8_t netmask[16];
      /// Is this value valid? (only used to signal parse errors)
      bool valid;
  
  public:
      CSubNet();
      CSubNet(const CNetAddr& addr, int32_t mask);
      CSubNet(const CNetAddr& addr, const CNetAddr& mask);
  
      // constructor for single ip subnet (<ipv4>/32 or <ipv6>/128)
      explicit CSubNet(const CNetAddr& addr);
  
      bool Match(const CNetAddr& addr) const;
  
      std::string ToString() const;
      bool IsValid() const;
  
      friend bool operator==(const CSubNet& a, const CSubNet& b);
      friend bool operator!=(const CSubNet& a, const CSubNet& b) { return !(a == b); }
      friend bool operator<(const CSubNet& a, const CSubNet& b);
  
      IMPLEMENT_SERIALIZE(READWRITE(network); READWRITE(FLATDATA(netmask)); READWRITE(valid);)
  };
  
  /** A combination of a network address (CNetAddr) and a (TCP) port */
  class CService : public CNetAddr {
  protected:
      unsigned short port;  // host order
  
  public:
      CService();
      CService(const CNetAddr& ip, unsigned short port);
      CService(const struct in_addr& ipv4Addr, unsigned short port);
      CService(const struct sockaddr_in& addr);
      explicit CService(const char* pszIpPort, int portDefault, bool fAllowLookup = false);
      explicit CService(const char* pszIpPort, bool fAllowLookup = false);
      explicit CService(const std::string& strIpPort, int portDefault, bool fAllowLookup = false);
      explicit CService(const std::string& strIpPort, bool fAllowLookup = false);
      void Init();
      void SetPort(unsigned short portIn);
      unsigned short GetPort() const;
      bool GetSockAddr(struct sockaddr* paddr, socklen_t* addrlen) const;
      bool SetSockAddr(const struct sockaddr* paddr);
      friend bool operator==(const CService& a, const CService& b);
      friend bool operator!=(const CService& a, const CService& b);
      friend bool operator<(const CService& a, const CService& b);
      std::vector<unsigned char> GetKey() const;
      std::string ToString() const;
      std::string ToStringPort() const;
      std::string ToStringIPPort() const;
      void Print() const;
  
      CService(const struct in6_addr& ipv6Addr, unsigned short port);
      CService(const struct sockaddr_in6& addr);
  
      IMPLEMENT_SERIALIZE(
          CService* pService = const_cast<CService*>(this);
          READWRITE(FLATDATA(ip));
          unsigned short portNumber = htons(port);
          READWRITE(portNumber);
          if (fRead)
              pService->port = ntohs(portNumber);
      )
  };
  
  typedef std::pair<CService, int> ProxyType;
  extern int GetConnectTime();
  enum Network ParseNetwork(std::string net);
  void SplitHostPort(std::string in, int& portOut, std::string& hostOut);
  bool SetProxy(enum Network net, CService addrProxy, int nSocksVersion = 5);
  bool GetProxy(enum Network net, ProxyType& proxyInfoOut);
  bool IsProxy(const CNetAddr& addr);
  bool SetNameProxy(CService addrProxy, int nSocksVersion = 5);
  bool HaveNameProxy();
  bool LookupHost(const char* pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions = 0,
                  bool fAllowLookup = true);
  bool LookupHost(const char* pszName, CNetAddr& addr, bool fAllowLookup);
  bool LookupHostNumeric(const char* pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions = 0);
  bool Lookup(const char* pszName, CService& addr, int portDefault = 0, bool fAllowLookup = true);
  bool Lookup(const char* pszName, std::vector<CService>& vAddr, int portDefault = 0, bool fAllowLookup = true,
              unsigned int nMaxSolutions = 0);
  bool LookupNumeric(const char* pszName, CService& addr, int portDefault = 0);
  bool LookupSubNet(const char* pszName, CSubNet& subnet);
  bool ConnectSocket(const CService& addr, SOCKET& hSocketRet, int nTimeout = GetConnectTime());
  bool ConnectSocketByName(CService& addr, SOCKET& hSocketRet, const char* pszDest, int portDefault = 0,
                           int nTimeout = GetConnectTime());
  /** Return readable error string for a network error code */
  std::string NetworkErrorString(int err);
  
  #endif
  