text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2012 The Bitcoin developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "netbase.h"
  #include "util.h"
  #include "sync.h"
  #include "hash.h"
  
  #ifndef WIN32
  #include <sys/fcntl.h>
  #endif
  
  #include <boost/algorithm/string/case_conv.hpp> // for to_lower()
  #include <boost/algorithm/string/predicate.hpp> // for startswith() and endswith()
  
  using namespace std;
  
  // Settings
  static proxyType proxyInfo[NET_MAX];
  static CService nameProxy;
  static CCriticalSection cs_proxyInfos;
  int nConnectTimeout = 5000;
  bool fNameLookup = false;
  
  static const unsigned char pchIPv4[12] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff };
  
  enum Network ParseNetwork(std::string net) {
      boost::to_lower(net);
      if (net == "ipv4") return NET_IPV4;
      if (net == "ipv6") return NET_IPV6;
      if (net == "tor")  return NET_TOR;
      if (net == "i2p")  return NET_I2P;
      return NET_UNROUTABLE;
  }
  
  void SplitHostPort(std::string in, int &portOut, std::string &hostOut) {
      size_t colon = in.find_last_of(':');
      // if a : is found, and it either follows a [...], or no other : is in the string, treat it as port separator
      bool fHaveColon = colon != in.npos;
      bool fBracketed = fHaveColon && (in[0]=='[' && in[colon-1]==']'); // if there is a colon, and in[0]=='[', colon is not 0, so in[colon-1] is safe
      bool fMultiColon = fHaveColon && (in.find_last_of(':',colon-1) != in.npos);
      if (fHaveColon && (colon==0 || fBracketed || !fMultiColon)) {
          char *endp = NULL;
          int n = strtol(in.c_str() + colon + 1, &endp, 10);
          if (endp && *endp == 0 && n >= 0) {
              in = in.substr(0, colon);
              if (n > 0 && n < 0x10000)
                  portOut = n;
          }
      }
      if (in.size()>0 && in[0] == '[' && in[in.size()-1] == ']')
          hostOut = in.substr(1, in.size()-2);
      else
          hostOut = in;
  }
  
  bool static LookupIntern(const char *pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup)
  {
      vIP.clear();
  
      {
          CNetAddr addr;
          if (addr.SetSpecial(std::string(pszName))) {
              vIP.push_back(addr);
              return true;
          }
      }
  
      struct addrinfo aiHint;
      memset(&aiHint, 0, sizeof(struct addrinfo));
  
      aiHint.ai_socktype = SOCK_STREAM;
      aiHint.ai_protocol = IPPROTO_TCP;
  #ifdef WIN32
      aiHint.ai_family = AF_UNSPEC;
      aiHint.ai_flags = fAllowLookup ? 0 : AI_NUMERICHOST;
  #else
      aiHint.ai_family = AF_UNSPEC;
      aiHint.ai_flags = fAllowLookup ? AI_ADDRCONFIG : AI_NUMERICHOST;
  #endif
      struct addrinfo *aiRes = NULL;
      int nErr = getaddrinfo(pszName, NULL, &aiHint, &aiRes);
      if (nErr)
          return false;
  
      struct addrinfo *aiTrav = aiRes;
      while (aiTrav != NULL && (nMaxSolutions == 0 || vIP.size() < nMaxSolutions))
      {
          if (aiTrav->ai_family == AF_INET)
          {
              assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in));
              vIP.push_back(CNetAddr(((struct sockaddr_in*)(aiTrav->ai_addr))->sin_addr));
          }
  
          if (aiTrav->ai_family == AF_INET6)
          {
              assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in6));
              vIP.push_back(CNetAddr(((struct sockaddr_in6*)(aiTrav->ai_addr))->sin6_addr));
          }
  
          aiTrav = aiTrav->ai_next;
      }
  
      freeaddrinfo(aiRes);
  
      return (vIP.size() > 0);
  }
  
  bool LookupHost(const char *pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup)
  {
      std::string str(pszName);
      std::string strHost = str;
      if (str.empty())
          return false;
      if (boost::algorithm::starts_with(str, "[") && boost::algorithm::ends_with(str, "]"))
      {
          strHost = str.substr(1, str.size() - 2);
      }
  
      return LookupIntern(strHost.c_str(), vIP, nMaxSolutions, fAllowLookup);
  }
  
  bool Lookup(const char *pszName, std::vector<CService>& vAddr, int portDefault, bool fAllowLookup, unsigned int nMaxSolutions)
  {
      if (pszName[0] == 0)
          return false;
      int port = portDefault;
      std::string hostname = "";
      SplitHostPort(std::string(pszName), port, hostname);
  
      std::vector<CNetAddr> vIP;
      bool fRet = LookupIntern(hostname.c_str(), vIP, nMaxSolutions, fAllowLookup);
      if (!fRet)
          return false;
      vAddr.resize(vIP.size());
      for (unsigned int i = 0; i < vIP.size(); i++)
          vAddr[i] = CService(vIP[i], port);
      return true;
  }
  
  bool Lookup(const char *pszName, CService& addr, int portDefault, bool fAllowLookup)
  {
      std::vector<CService> vService;
      bool fRet = Lookup(pszName, vService, portDefault, fAllowLookup, 1);
      if (!fRet)
          return false;
      addr = vService[0];
      return true;
  }
  
  bool LookupNumeric(const char *pszName, CService& addr, int portDefault)
  {
      return Lookup(pszName, addr, portDefault, false);
  }
  
  bool static Socks5(string strDest, int port, SOCKET& hSocket)
  {
      LogPrintf("SOCKS5 connecting %s\n", strDest);
      if (strDest.size() > 255)
      {
          closesocket(hSocket);
          return error("Hostname too long");
      }
      char pszSocks5Init[] = "\5\1\0";
      char *pszSocks5 = pszSocks5Init;
      ssize_t nSize = sizeof(pszSocks5Init) - 1;
  
      ssize_t ret = send(hSocket, pszSocks5, nSize, 0);
      if (ret != nSize)
      {
          closesocket(hSocket);
          return error("Error sending to proxy");
      }
      char pchRet1[2];
      if (recv(hSocket, pchRet1, 2, 0) != 2)
      {
          closesocket(hSocket);
          return error("Error reading proxy response");
      }
      if (pchRet1[0] != 0x05 || pchRet1[1] != 0x00)
      {
          closesocket(hSocket);
          return error("Proxy failed to initialize");
      }
      string strSocks5("\5\1");
      strSocks5 += '\000'; strSocks5 += '\003';
      strSocks5 += static_cast<char>(std::min((int)strDest.size(), 255));
      strSocks5 += strDest;
      strSocks5 += static_cast<char>((port >> 8) & 0xFF);
      strSocks5 += static_cast<char>((port >> 0) & 0xFF);
      ret = send(hSocket, strSocks5.data(), strSocks5.size(), 0);
      if (ret != (ssize_t)strSocks5.size())
      {
          closesocket(hSocket);
          return error("Error sending to proxy");
      }
      char pchRet2[4];
      if (recv(hSocket, pchRet2, 4, 0) != 4)
      {
          closesocket(hSocket);
          return error("Error reading proxy response");
      }
      if (pchRet2[0] != 0x05)
      {
          closesocket(hSocket);
          return error("Proxy failed to accept request");
      }
      if (pchRet2[1] != 0x00)
      {
          closesocket(hSocket);
          switch (pchRet2[1])
          {
              case 0x01: return error("Proxy error: general failure");
              case 0x02: return error("Proxy error: connection not allowed");
              case 0x03: return error("Proxy error: network unreachable");
              case 0x04: return error("Proxy error: host unreachable");
              case 0x05: return error("Proxy error: connection refused");
              case 0x06: return error("Proxy error: TTL expired");
              case 0x07: return error("Proxy error: protocol error");
              case 0x08: return error("Proxy error: address type not supported");
              default:   return error("Proxy error: unknown");
          }
      }
      if (pchRet2[2] != 0x00)
      {
          closesocket(hSocket);
          return error("Error: malformed proxy response");
      }
      char pchRet3[256];
      switch (pchRet2[3])
      {
          case 0x01: ret = recv(hSocket, pchRet3, 4, 0) != 4; break;
          case 0x04: ret = recv(hSocket, pchRet3, 16, 0) != 16; break;
          case 0x03:
          {
              ret = recv(hSocket, pchRet3, 1, 0) != 1;
              if (ret) {
                  closesocket(hSocket);
                  return error("Error reading from proxy");
              }
              int nRecv = pchRet3[0];
              ret = recv(hSocket, pchRet3, nRecv, 0) != nRecv;
              break;
          }
          default: closesocket(hSocket); return error("Error: malformed proxy response");
      }
      if (ret)
      {
          closesocket(hSocket);
          return error("Error reading from proxy");
      }
      if (recv(hSocket, pchRet3, 2, 0) != 2)
      {
          closesocket(hSocket);
          return error("Error reading from proxy");
      }
      LogPrintf("SOCKS5 connected %s\n", strDest);
      return true;
  }
  
  bool static ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int nTimeout)
  {
      hSocketRet = INVALID_SOCKET;
  
      struct sockaddr_storage sockaddr;
      socklen_t len = sizeof(sockaddr);
      if (!addrConnect.GetSockAddr((struct sockaddr*)&sockaddr, &len)) {
          LogPrintf("Cannot connect to %s: unsupported network\n", addrConnect.ToString());
          return false;
      }
  
      SOCKET hSocket = socket(((struct sockaddr*)&sockaddr)->sa_family, SOCK_STREAM, IPPROTO_TCP);
      if (hSocket == INVALID_SOCKET)
          return false;
  
      int set = 1;
  #ifdef SO_NOSIGPIPE
      // Different way of disabling SIGPIPE on BSD
      setsockopt(hSocket, SOL_SOCKET, SO_NOSIGPIPE, (void*)&set, sizeof(int));
  #endif
  
       //Disable Nagle's algorithm
  #ifdef WIN32
      setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (const char*)&set, sizeof(int));
  #else
      setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (void*)&set, sizeof(int));
  #endif
  
  #ifdef WIN32
      u_long fNonblock = 1;
      if (ioctlsocket(hSocket, FIONBIO, &fNonblock) == SOCKET_ERROR)
  #else
      int fFlags = fcntl(hSocket, F_GETFL, 0);
      if (fcntl(hSocket, F_SETFL, fFlags | O_NONBLOCK) == -1)
  #endif
      {
          closesocket(hSocket);
          return false;
      }
  
      if (connect(hSocket, (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR)
      {
          int nErr = WSAGetLastError();
          // WSAEINVAL is here because some legacy version of winsock uses it
          if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL)
          {
              struct timeval timeout;
              timeout.tv_sec  = nTimeout / 1000;
              timeout.tv_usec = (nTimeout % 1000) * 1000;
  
              fd_set fdset;
              FD_ZERO(&fdset);
              FD_SET(hSocket, &fdset);
              int nRet = select(hSocket + 1, NULL, &fdset, NULL, &timeout);
              if (nRet == 0)
              {
                  LogPrint("net", "connection to %s timeout\n", addrConnect.ToString());
                  closesocket(hSocket);
                  return false;
              }
              if (nRet == SOCKET_ERROR)
              {
                  LogPrintf("select() for %s failed: %i\n", addrConnect.ToString(), WSAGetLastError());
                  closesocket(hSocket);
                  return false;
              }
              socklen_t nRetSize = sizeof(nRet);
  #ifdef WIN32
              if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, (char*)(&nRet), &nRetSize) == SOCKET_ERROR)
  #else
              if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, &nRet, &nRetSize) == SOCKET_ERROR)
  #endif
              {
                  LogPrintf("getsockopt() for %s failed: %i\n", addrConnect.ToString(), WSAGetLastError());
                  closesocket(hSocket);
                  return false;
              }
              if (nRet != 0)
              {
                  LogPrintf("connect() to %s failed after select(): %s\n", addrConnect.ToString(), strerror(nRet));
                  closesocket(hSocket);
                  return false;
              }
          }
  #ifdef WIN32
          else if (WSAGetLastError() != WSAEISCONN)
  #else
          else
  #endif
          {
              LogPrintf("connect() to %s failed: %i\n", addrConnect.ToString(), WSAGetLastError());
              closesocket(hSocket);
              return false;
          }
      }
  
      // this isn't even strictly necessary
      // CNode::ConnectNode immediately turns the socket back to non-blocking
      // but we'll turn it back to blocking just in case
  #ifdef WIN32
      fNonblock = 0;
      if (ioctlsocket(hSocket, FIONBIO, &fNonblock) == SOCKET_ERROR)
  #else
      fFlags = fcntl(hSocket, F_GETFL, 0);
      if (fcntl(hSocket, F_SETFL, fFlags & !O_NONBLOCK) == SOCKET_ERROR)
  #endif
      {
          closesocket(hSocket);
          return false;
      }
  
      hSocketRet = hSocket;
      return true;
  }
  
  bool SetProxy(enum Network net, CService addrProxy) {
      assert(net >= 0 && net < NET_MAX);
      if (!addrProxy.IsValid())
          return false;
      LOCK(cs_proxyInfos);
      proxyInfo[net] = addrProxy;
      return true;
  }
  
  bool GetProxy(enum Network net, proxyType &proxyInfoOut) {
      assert(net >= 0 && net < NET_MAX);
      LOCK(cs_proxyInfos);
      if (!proxyInfo[net].IsValid())
          return false;
      proxyInfoOut = proxyInfo[net];
      return true;
  }
  
  bool SetNameProxy(CService addrProxy) {
      if (!addrProxy.IsValid())
          return false;
      LOCK(cs_proxyInfos);
      nameProxy = addrProxy;
      return true;
  }
  
  bool GetNameProxy(CService &nameProxyOut) {
      LOCK(cs_proxyInfos);
      if(!nameProxy.IsValid())
          return false;
      nameProxyOut = nameProxy;
      return true;
  }
  
  bool HaveNameProxy() {
      LOCK(cs_proxyInfos);
      return nameProxy.IsValid();
  }
  
  bool IsProxy(const CNetAddr &addr) {
      LOCK(cs_proxyInfos);
      for (int i = 0; i < NET_MAX; i++) {
          if (addr == (CNetAddr)proxyInfo[i])
              return true;
      }
      return false;
  }
  
  bool ConnectSocket(const CService &addrDest, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed)
  {
      proxyType proxy;
      if (outProxyConnectionFailed)
          *outProxyConnectionFailed = false;
      // no proxy needed (none set for target network)
      if (!GetProxy(addrDest.GetNetwork(), proxy))
          return ConnectSocketDirectly(addrDest, hSocketRet, nTimeout);
  
      SOCKET hSocket = INVALID_SOCKET;
  
      // first connect to proxy server
      if (!ConnectSocketDirectly(proxy, hSocket, nTimeout)) {
          if (outProxyConnectionFailed)
              *outProxyConnectionFailed = true;
          return false;
      }
      // do socks negotiation
      if (!Socks5(addrDest.ToStringIP(), addrDest.GetPort(), hSocket))
          return false;
  
      hSocketRet = hSocket;
      return true;
  }
  
  bool ConnectSocketByName(CService &addr, SOCKET& hSocketRet, const char *pszDest, int portDefault, int nTimeout, bool *outProxyConnectionFailed)
  {
      string strDest;
      int port = portDefault;
  
      if (outProxyConnectionFailed)
          *outProxyConnectionFailed = false;
  
      SplitHostPort(string(pszDest), port, strDest);
  
      SOCKET hSocket = INVALID_SOCKET;
  
      CService nameProxy;
      GetNameProxy(nameProxy);
  
      CService addrResolved(CNetAddr(strDest, fNameLookup && !HaveNameProxy()), port);
      if (addrResolved.IsValid()) {
          addr = addrResolved;
          return ConnectSocket(addr, hSocketRet, nTimeout);
      }
  
      addr = CService("0.0.0.0:0");
  
      if (!HaveNameProxy())
          return false;
      // first connect to name proxy server
      if (!ConnectSocketDirectly(nameProxy, hSocket, nTimeout)) {
          if (outProxyConnectionFailed)
              *outProxyConnectionFailed = true;
          return false;
      }
      // do socks negotiation
      if (!Socks5(strDest, (unsigned short)port, hSocket))
          return false;
  
      hSocketRet = hSocket;
      return true;
  }
  
  void CNetAddr::Init()
  {
      memset(ip, 0, sizeof(ip));
  }
  
  void CNetAddr::SetIP(const CNetAddr& ipIn)
  {
      memcpy(ip, ipIn.ip, sizeof(ip));
  }
  
  static const unsigned char pchOnionCat[] = {0xFD,0x87,0xD8,0x7E,0xEB,0x43};
  static const unsigned char pchGarliCat[] = {0xFD,0x60,0xDB,0x4D,0xDD,0xB5};
  
  bool CNetAddr::SetSpecial(const std::string &strName)
  {
      if (strName.size()>6 && strName.substr(strName.size() - 6, 6) == ".onion") {
          std::vector<unsigned char> vchAddr = DecodeBase32(strName.substr(0, strName.size() - 6).c_str());
          if (vchAddr.size() != 16-sizeof(pchOnionCat))
              return false;
          memcpy(ip, pchOnionCat, sizeof(pchOnionCat));
          for (unsigned int i=0; i<16-sizeof(pchOnionCat); i++)
              ip[i + sizeof(pchOnionCat)] = vchAddr[i];
          return true;
      }
      if (strName.size()>11 && strName.substr(strName.size() - 11, 11) == ".oc.b32.i2p") {
          std::vector<unsigned char> vchAddr = DecodeBase32(strName.substr(0, strName.size() - 11).c_str());
          if (vchAddr.size() != 16-sizeof(pchGarliCat))
              return false;
          memcpy(ip, pchOnionCat, sizeof(pchGarliCat));
          for (unsigned int i=0; i<16-sizeof(pchGarliCat); i++)
              ip[i + sizeof(pchGarliCat)] = vchAddr[i];
          return true;
      }
      return false;
  }
  
  CNetAddr::CNetAddr()
  {
      Init();
  }
  
  CNetAddr::CNetAddr(const struct in_addr& ipv4Addr)
  {
      memcpy(ip,    pchIPv4, 12);
      memcpy(ip+12, &ipv4Addr, 4);
  }
  
  CNetAddr::CNetAddr(const struct in6_addr& ipv6Addr)
  {
      memcpy(ip, &ipv6Addr, 16);
  }
  
  CNetAddr::CNetAddr(const char *pszIp, bool fAllowLookup)
  {
      Init();
      std::vector<CNetAddr> vIP;
      if (LookupHost(pszIp, vIP, 1, fAllowLookup))
          *this = vIP[0];
  }
  
  CNetAddr::CNetAddr(const std::string &strIp, bool fAllowLookup)
  {
      Init();
      std::vector<CNetAddr> vIP;
      if (LookupHost(strIp.c_str(), vIP, 1, fAllowLookup))
          *this = vIP[0];
  }
  
  unsigned int CNetAddr::GetByte(int n) const
  {
      return ip[15-n];
  }
  
  bool CNetAddr::IsIPv4() const
  {
      return (memcmp(ip, pchIPv4, sizeof(pchIPv4)) == 0);
  }
  
  bool CNetAddr::IsIPv6() const
  {
      return (!IsIPv4() && !IsTor() && !IsI2P());
  }
  
  bool CNetAddr::IsRFC1918() const
  {
      return IsIPv4() && (
          GetByte(3) == 10 ||
          (GetByte(3) == 192 && GetByte(2) == 168) ||
          (GetByte(3) == 172 && (GetByte(2) >= 16 && GetByte(2) <= 31)));
  }
  
  bool CNetAddr::IsRFC3927() const
  {
      return IsIPv4() && (GetByte(3) == 169 && GetByte(2) == 254);
  }
  
  bool CNetAddr::IsRFC3849() const
  {
      return GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x0D && GetByte(12) == 0xB8;
  }
  
  bool CNetAddr::IsRFC3964() const
  {
      return (GetByte(15) == 0x20 && GetByte(14) == 0x02);
  }
  
  bool CNetAddr::IsRFC6052() const
  {
      static const unsigned char pchRFC6052[] = {0,0x64,0xFF,0x9B,0,0,0,0,0,0,0,0};
      return (memcmp(ip, pchRFC6052, sizeof(pchRFC6052)) == 0);
  }
  
  bool CNetAddr::IsRFC4380() const
  {
      return (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0 && GetByte(12) == 0);
  }
  
  bool CNetAddr::IsRFC4862() const
  {
      static const unsigned char pchRFC4862[] = {0xFE,0x80,0,0,0,0,0,0};
      return (memcmp(ip, pchRFC4862, sizeof(pchRFC4862)) == 0);
  }
  
  bool CNetAddr::IsRFC4193() const
  {
      return ((GetByte(15) & 0xFE) == 0xFC);
  }
  
  bool CNetAddr::IsRFC6145() const
  {
      static const unsigned char pchRFC6145[] = {0,0,0,0,0,0,0,0,0xFF,0xFF,0,0};
      return (memcmp(ip, pchRFC6145, sizeof(pchRFC6145)) == 0);
  }
  
  bool CNetAddr::IsRFC4843() const
  {
      return (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x00 && (GetByte(12) & 0xF0) == 0x10);
  }
  
  bool CNetAddr::IsTor() const
  {
      return (memcmp(ip, pchOnionCat, sizeof(pchOnionCat)) == 0);
  }
  
  bool CNetAddr::IsI2P() const
  {
      return (memcmp(ip, pchGarliCat, sizeof(pchGarliCat)) == 0);
  }
  
  bool CNetAddr::IsLocal() const
  {
      // IPv4 loopback
     if (IsIPv4() && (GetByte(3) == 127 || GetByte(3) == 0))
         return true;
  
     // IPv6 loopback (::1/128)
     static const unsigned char pchLocal[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
     if (memcmp(ip, pchLocal, 16) == 0)
         return true;
  
     return false;
  }
  
  bool CNetAddr::IsMulticast() const
  {
      return    (IsIPv4() && (GetByte(3) & 0xF0) == 0xE0)
             || (GetByte(15) == 0xFF);
  }
  
  bool CNetAddr::IsValid() const
  {
      // Cleanup 3-byte shifted addresses caused by garbage in size field
      // of addr messages from versions before 0.2.9 checksum.
      // Two consecutive addr messages look like this:
      // header20 vectorlen3 addr26 addr26 addr26 header20 vectorlen3 addr26 addr26 addr26...
      // so if the first length field is garbled, it reads the second batch
      // of addr misaligned by 3 bytes.
      if (memcmp(ip, pchIPv4+3, sizeof(pchIPv4)-3) == 0)
          return false;
  
      // unspecified IPv6 address (::/128)
      unsigned char ipNone[16] = {};
      if (memcmp(ip, ipNone, 16) == 0)
          return false;
  
      // documentation IPv6 address
      if (IsRFC3849())
          return false;
  
      if (IsIPv4())
      {
          // INADDR_NONE
          uint32_t ipNone = INADDR_NONE;
          if (memcmp(ip+12, &ipNone, 4) == 0)
              return false;
  
          // 0
          ipNone = 0;
          if (memcmp(ip+12, &ipNone, 4) == 0)
              return false;
      }
  
      return true;
  }
  
  bool CNetAddr::IsRoutable() const
  {
      return IsValid() && !(IsRFC1918() || IsRFC3927() || IsRFC4862() || (IsRFC4193() && !IsTor() && !IsI2P()) || IsRFC4843() || IsLocal());
  }
  
  enum Network CNetAddr::GetNetwork() const
  {
      if (!IsRoutable())
          return NET_UNROUTABLE;
  
      if (IsIPv4())
          return NET_IPV4;
  
      if (IsTor())
          return NET_TOR;
  
      if (IsI2P())
          return NET_I2P;
  
      return NET_IPV6;
  }
  
  std::string CNetAddr::ToStringIP() const
  {
      if (IsTor())
          return EncodeBase32(&ip[6], 10) + ".onion";
      if (IsI2P())
          return EncodeBase32(&ip[6], 10) + ".oc.b32.i2p";
      CService serv(*this, 0);
      struct sockaddr_storage sockaddr;
      socklen_t socklen = sizeof(sockaddr);
      if (serv.GetSockAddr((struct sockaddr*)&sockaddr, &socklen)) {
          char name[1025] = "";
          if (!getnameinfo((const struct sockaddr*)&sockaddr, socklen, name, sizeof(name), NULL, 0, NI_NUMERICHOST))
              return std::string(name);
      }
      if (IsIPv4())
          return strprintf("%u.%u.%u.%u", GetByte(3), GetByte(2), GetByte(1), GetByte(0));
      else
          return strprintf("%x:%x:%x:%x:%x:%x:%x:%x",
                           GetByte(15) << 8 | GetByte(14), GetByte(13) << 8 | GetByte(12),
                           GetByte(11) << 8 | GetByte(10), GetByte(9) << 8 | GetByte(8),
                           GetByte(7) << 8 | GetByte(6), GetByte(5) << 8 | GetByte(4),
                           GetByte(3) << 8 | GetByte(2), GetByte(1) << 8 | GetByte(0));
  }
  
  std::string CNetAddr::ToString() const
  {
      return ToStringIP();
  }
  
  bool operator==(const CNetAddr& a, const CNetAddr& b)
  {
      return (memcmp(a.ip, b.ip, 16) == 0);
  }
  
  bool operator!=(const CNetAddr& a, const CNetAddr& b)
  {
      return (memcmp(a.ip, b.ip, 16) != 0);
  }
  
  bool operator<(const CNetAddr& a, const CNetAddr& b)
  {
      return (memcmp(a.ip, b.ip, 16) < 0);
  }
  
  bool CNetAddr::GetInAddr(struct in_addr* pipv4Addr) const
  {
      if (!IsIPv4())
          return false;
      memcpy(pipv4Addr, ip+12, 4);
      return true;
  }
  
  bool CNetAddr::GetIn6Addr(struct in6_addr* pipv6Addr) const
  {
      memcpy(pipv6Addr, ip, 16);
      return true;
  }
  
  // get canonical identifier of an address' group
  // no two connections will be attempted to addresses with the same group
  std::vector<unsigned char> CNetAddr::GetGroup() const
  {
      std::vector<unsigned char> vchRet;
      int nClass = NET_IPV6;
      int nStartByte = 0;
      int nBits = 16;
  
      // all local addresses belong to the same group
      if (IsLocal())
      {
          nClass = 255;
          nBits = 0;
      }
  
      // all unroutable addresses belong to the same group
      if (!IsRoutable())
      {
          nClass = NET_UNROUTABLE;
          nBits = 0;
      }
      // for IPv4 addresses, '1' + the 16 higher-order bits of the IP
      // includes mapped IPv4, SIIT translated IPv4, and the well-known prefix
      else if (IsIPv4() || IsRFC6145() || IsRFC6052())
      {
          nClass = NET_IPV4;
          nStartByte = 12;
      }
      // for 6to4 tunnelled addresses, use the encapsulated IPv4 address
      else if (IsRFC3964())
      {
          nClass = NET_IPV4;
          nStartByte = 2;
      }
      // for Teredo-tunnelled IPv6 addresses, use the encapsulated IPv4 address
      else if (IsRFC4380())
      {
          vchRet.push_back(NET_IPV4);
          vchRet.push_back(GetByte(3) ^ 0xFF);
          vchRet.push_back(GetByte(2) ^ 0xFF);
          return vchRet;
      }
      else if (IsTor())
      {
          nClass = NET_TOR;
          nStartByte = 6;
          nBits = 4;
      }
      else if (IsI2P())
      {
          nClass = NET_I2P;
          nStartByte = 6;
          nBits = 4;
      }
      // for he.net, use /36 groups
      else if (GetByte(15) == 0x20 && GetByte(14) == 0x11 && GetByte(13) == 0x04 && GetByte(12) == 0x70)
          nBits = 36;
      // for the rest of the IPv6 network, use /32 groups
      else
          nBits = 32;
  
      vchRet.push_back(nClass);
      while (nBits >= 8)
      {
          vchRet.push_back(GetByte(15 - nStartByte));
          nStartByte++;
          nBits -= 8;
      }
      if (nBits > 0)
          vchRet.push_back(GetByte(15 - nStartByte) | ((1 << nBits) - 1));
  
      return vchRet;
  }
  
  uint64_t CNetAddr::GetHash() const
  {
      uint256 hash = Hash(&ip[0], &ip[16]);
      uint64_t nRet;
      memcpy(&nRet, &hash, sizeof(nRet));
      return nRet;
  }
  
  // private extensions to enum Network, only returned by GetExtNetwork,
  // and only used in GetReachabilityFrom
  static const int NET_UNKNOWN = NET_MAX + 0;
  static const int NET_TEREDO  = NET_MAX + 1;
  int static GetExtNetwork(const CNetAddr *addr)
  {
      if (addr == NULL)
          return NET_UNKNOWN;
      if (addr->IsRFC4380())
          return NET_TEREDO;
      return addr->GetNetwork();
  }
  
  /** Calculates a metric for how reachable (*this) is from a given partner */
  int CNetAddr::GetReachabilityFrom(const CNetAddr *paddrPartner) const
  {
      enum Reachability {
          REACH_UNREACHABLE,
          REACH_DEFAULT,
          REACH_TEREDO,
          REACH_IPV6_WEAK,
          REACH_IPV4,
          REACH_IPV6_STRONG,
          REACH_PRIVATE
      };
  
      if (!IsRoutable())
          return REACH_UNREACHABLE;
  
      int ourNet = GetExtNetwork(this);
      int theirNet = GetExtNetwork(paddrPartner);
      bool fTunnel = IsRFC3964() || IsRFC6052() || IsRFC6145();
  
      switch(theirNet) {
      case NET_IPV4:
          switch(ourNet) {
          default:       return REACH_DEFAULT;
          case NET_IPV4: return REACH_IPV4;
          }
      case NET_IPV6:
          switch(ourNet) {
          default:         return REACH_DEFAULT;
          case NET_TEREDO: return REACH_TEREDO;
          case NET_IPV4:   return REACH_IPV4;
          case NET_IPV6:   return fTunnel ? REACH_IPV6_WEAK : REACH_IPV6_STRONG; // only prefer giving our IPv6 address if it's not tunnelled
          }
      case NET_TOR:
          switch(ourNet) {
          default:         return REACH_DEFAULT;
          case NET_IPV4:   return REACH_IPV4; // Tor users can connect to IPv4 as well
          case NET_TOR:    return REACH_PRIVATE;
          }
      case NET_I2P:
          switch(ourNet) {
          default:         return REACH_DEFAULT;
          case NET_I2P:    return REACH_PRIVATE;
          }
      case NET_TEREDO:
          switch(ourNet) {
          default:          return REACH_DEFAULT;
          case NET_TEREDO:  return REACH_TEREDO;
          case NET_IPV6:    return REACH_IPV6_WEAK;
          case NET_IPV4:    return REACH_IPV4;
          }
      case NET_UNKNOWN:
      case NET_UNROUTABLE:
      default:
          switch(ourNet) {
          default:          return REACH_DEFAULT;
          case NET_TEREDO:  return REACH_TEREDO;
          case NET_IPV6:    return REACH_IPV6_WEAK;
          case NET_IPV4:    return REACH_IPV4;
          case NET_I2P:     return REACH_PRIVATE; // assume connections from unroutable addresses are
          case NET_TOR:     return REACH_PRIVATE; // either from Tor/I2P, or don't care about our address
          }
      }
  }
  
  void CService::Init()
  {
      port = 0;
  }
  
  CService::CService()
  {
      Init();
  }
  
  CService::CService(const CNetAddr& cip, unsigned short portIn) : CNetAddr(cip), port(portIn)
  {
  }
  
  CService::CService(const struct in_addr& ipv4Addr, unsigned short portIn) : CNetAddr(ipv4Addr), port(portIn)
  {
  }
  
  CService::CService(const struct in6_addr& ipv6Addr, unsigned short portIn) : CNetAddr(ipv6Addr), port(portIn)
  {
  }
  
  CService::CService(const struct sockaddr_in& addr) : CNetAddr(addr.sin_addr), port(ntohs(addr.sin_port))
  {
      assert(addr.sin_family == AF_INET);
  }
  
  CService::CService(const struct sockaddr_in6 &addr) : CNetAddr(addr.sin6_addr), port(ntohs(addr.sin6_port))
  {
     assert(addr.sin6_family == AF_INET6);
  }
  
  bool CService::SetSockAddr(const struct sockaddr *paddr)
  {
      switch (paddr->sa_family) {
      case AF_INET:
          *this = CService(*(const struct sockaddr_in*)paddr);
          return true;
      case AF_INET6:
          *this = CService(*(const struct sockaddr_in6*)paddr);
          return true;
      default:
          return false;
      }
  }
  
  CService::CService(const char *pszIpPort, bool fAllowLookup)
  {
      Init();
      CService ip;
      if (Lookup(pszIpPort, ip, 0, fAllowLookup))
          *this = ip;
  }
  
  CService::CService(const char *pszIpPort, int portDefault, bool fAllowLookup)
  {
      Init();
      CService ip;
      if (Lookup(pszIpPort, ip, portDefault, fAllowLookup))
          *this = ip;
  }
  
  CService::CService(const std::string &strIpPort, bool fAllowLookup)
  {
      Init();
      CService ip;
      if (Lookup(strIpPort.c_str(), ip, 0, fAllowLookup))
          *this = ip;
  }
  
  CService::CService(const std::string &strIpPort, int portDefault, bool fAllowLookup)
  {
      Init();
      CService ip;
      if (Lookup(strIpPort.c_str(), ip, portDefault, fAllowLookup))
          *this = ip;
  }
  
  unsigned short CService::GetPort() const
  {
      return port;
  }
  
  bool operator==(const CService& a, const CService& b)
  {
      return (CNetAddr)a == (CNetAddr)b && a.port == b.port;
  }
  
  bool operator!=(const CService& a, const CService& b)
  {
      return (CNetAddr)a != (CNetAddr)b || a.port != b.port;
  }
  
  bool operator<(const CService& a, const CService& b)
  {
      return (CNetAddr)a < (CNetAddr)b || ((CNetAddr)a == (CNetAddr)b && a.port < b.port);
  }
  
  bool CService::GetSockAddr(struct sockaddr* paddr, socklen_t *addrlen) const
  {
      if (IsIPv4()) {
          if (*addrlen < (socklen_t)sizeof(struct sockaddr_in))
              return false;
          *addrlen = sizeof(struct sockaddr_in);
          struct sockaddr_in *paddrin = (struct sockaddr_in*)paddr;
          memset(paddrin, 0, *addrlen);
          if (!GetInAddr(&paddrin->sin_addr))
              return false;
          paddrin->sin_family = AF_INET;
          paddrin->sin_port = htons(port);
          return true;
      }
      if (IsIPv6()) {
          if (*addrlen < (socklen_t)sizeof(struct sockaddr_in6))
              return false;
          *addrlen = sizeof(struct sockaddr_in6);
          struct sockaddr_in6 *paddrin6 = (struct sockaddr_in6*)paddr;
          memset(paddrin6, 0, *addrlen);
          if (!GetIn6Addr(&paddrin6->sin6_addr))
              return false;
          paddrin6->sin6_family = AF_INET6;
          paddrin6->sin6_port = htons(port);
          return true;
      }
      return false;
  }
  
  std::vector<unsigned char> CService::GetKey() const
  {
       std::vector<unsigned char> vKey;
       vKey.resize(18);
       memcpy(&vKey[0], ip, 16);
       vKey[16] = port / 0x100;
       vKey[17] = port & 0x0FF;
       return vKey;
  }
  
  std::string CService::ToStringPort() const
  {
      return strprintf("%u", port);
  }
  
  std::string CService::ToStringIPPort() const
  {
      if (IsIPv4() || IsTor() || IsI2P()) {
          return ToStringIP() + ":" + ToStringPort();
      } else {
          return "[" + ToStringIP() + "]:" + ToStringPort();
      }
  }
  
  std::string CService::ToString() const
  {
      return ToStringIPPort();
  }
  
  void CService::SetPort(unsigned short portIn)
  {
      port = portIn;
  }
  