text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2012 The Bitcoin developers
  // Copyright (c) 2011-2012 Litecoin Developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "irc.h"
  #include "net.h"
  #include "strlcpy.h"
  #include "base58.h"
  
  using namespace std;
  using namespace boost;
  
  int nGotIRCAddresses = 0;
  
  void ThreadIRCSeed2(void* parg);
  
  
  
  
  #pragma pack(push, 1)
  struct ircaddr
  {
      struct in_addr ip;
      short port;
  };
  #pragma pack(pop)
  
  string EncodeAddress(const CService& addr)
  {
      struct ircaddr tmp;
      if (addr.GetInAddr(&tmp.ip))
      {
          tmp.port = htons(addr.GetPort());
  
          vector<unsigned char> vch(UBEGIN(tmp), UEND(tmp));
          return string("u") + EncodeBase58Check(vch);
      }
      return "";
  }
  
  bool DecodeAddress(string str, CService& addr)
  {
      vector<unsigned char> vch;
      if (!DecodeBase58Check(str.substr(1), vch))
          return false;
  
      struct ircaddr tmp;
      if (vch.size() != sizeof(tmp))
          return false;
      memcpy(&tmp, &vch[0], sizeof(tmp));
  
      addr = CService(tmp.ip, ntohs(tmp.port));
      return true;
  }
  
  
  
  
  
  
  static bool Send(SOCKET hSocket, const char* pszSend)
  {
      if (strstr(pszSend, "PONG") != pszSend)
          printf("IRC SENDING: %s\n", pszSend);
      const char* psz = pszSend;
      const char* pszEnd = psz + strlen(psz);
      while (psz < pszEnd)
      {
          int ret = send(hSocket, psz, pszEnd - psz, MSG_NOSIGNAL);
          if (ret < 0)
              return false;
          psz += ret;
      }
      return true;
  }
  
  bool RecvLineIRC(SOCKET hSocket, string& strLine)
  {
      loop
      {
          bool fRet = RecvLine(hSocket, strLine);
          if (fRet)
          {
              if (fShutdown)
                  return false;
              vector<string> vWords;
              ParseString(strLine, ' ', vWords);
              if (vWords.size() >= 1 && vWords[0] == "PING")
              {
                  strLine[1] = 'O';
                  strLine += '\r';
                  Send(hSocket, strLine.c_str());
                  continue;
              }
          }
          return fRet;
      }
  }
  
  int RecvUntil(SOCKET hSocket, const char* psz1, const char* psz2=NULL, const char* psz3=NULL, const char* psz4=NULL)
  {
      loop
      {
          string strLine;
          strLine.reserve(10000);
          if (!RecvLineIRC(hSocket, strLine))
              return 0;
          printf("IRC %s\n", strLine.c_str());
          if (psz1 && strLine.find(psz1) != string::npos)
              return 1;
          if (psz2 && strLine.find(psz2) != string::npos)
              return 2;
          if (psz3 && strLine.find(psz3) != string::npos)
              return 3;
          if (psz4 && strLine.find(psz4) != string::npos)
              return 4;
      }
  }
  
  bool Wait(int nSeconds)
  {
      if (fShutdown)
          return false;
      printf("IRC waiting %d seconds to reconnect\n", nSeconds);
      for (int i = 0; i < nSeconds; i++)
      {
          if (fShutdown)
              return false;
          Sleep(1000);
      }
      return true;
  }
  
  bool RecvCodeLine(SOCKET hSocket, const char* psz1, string& strRet)
  {
      strRet.clear();
      loop
      {
          string strLine;
          if (!RecvLineIRC(hSocket, strLine))
              return false;
  
          vector<string> vWords;
          ParseString(strLine, ' ', vWords);
          if (vWords.size() < 2)
              continue;
  
          if (vWords[1] == psz1)
          {
              printf("IRC %s\n", strLine.c_str());
              strRet = strLine;
              return true;
          }
      }
  }
  
  bool GetIPFromIRC(SOCKET hSocket, string strMyName, CNetAddr& ipRet)
  {
      Send(hSocket, strprintf("USERHOST %s\r", strMyName.c_str()).c_str());
  
      string strLine;
      if (!RecvCodeLine(hSocket, "302", strLine))
          return false;
  
      vector<string> vWords;
      ParseString(strLine, ' ', vWords);
      if (vWords.size() < 4)
          return false;
  
      string str = vWords[3];
      if (str.rfind("@") == string::npos)
          return false;
      string strHost = str.substr(str.rfind("@")+1);
  
      // Hybrid IRC used by lfnet always returns IP when you userhost yourself,
      // but in case another IRC is ever used this should work.
      printf("GetIPFromIRC() got userhost %s\n", strHost.c_str());
      CNetAddr addr(strHost, true);
      if (!addr.IsValid())
          return false;
      ipRet = addr;
  
      return true;
  }
  
  
  
  void ThreadIRCSeed(void* parg)
  {
      IMPLEMENT_RANDOMIZE_STACK(ThreadIRCSeed(parg));
  
      // Make this thread recognisable as the IRC seeding thread
      RenameThread("bitcoin-ircseed");
  
      try
      {
          ThreadIRCSeed2(parg);
      }
      catch (std::exception& e) {
          PrintExceptionContinue(&e, "ThreadIRCSeed()");
      } catch (...) {
          PrintExceptionContinue(NULL, "ThreadIRCSeed()");
      }
      printf("ThreadIRCSeed exited\n");
  }
  
  void ThreadIRCSeed2(void* parg)
  {
      /* Dont advertise on IRC if we don't allow incoming connections */
      if (mapArgs.count("-connect") || fNoListen)
          return;
  
      if (!GetBoolArg("-irc", false))
          return;
  
      printf("ThreadIRCSeed started\n");
      int nErrorWait = 10;
      int nRetryWait = 10;
  
      while (!fShutdown)
      {
          CService addrConnect("92.243.23.21", 6667); // irc.lfnet.org
  
          CService addrIRC("irc.lfnet.org", 6667, true);
          if (addrIRC.IsValid())
              addrConnect = addrIRC;
  
          SOCKET hSocket;
          if (!ConnectSocket(addrConnect, hSocket))
          {
              printf("IRC connect failed\n");
              nErrorWait = nErrorWait * 11 / 10;
              if (Wait(nErrorWait += 60))
                  continue;
              else
                  return;
          }
  
          if (!RecvUntil(hSocket, "Found your hostname", "using your IP address instead", "Couldn't look up your hostname", "ignoring hostname"))
          {
              closesocket(hSocket);
              hSocket = INVALID_SOCKET;
              nErrorWait = nErrorWait * 11 / 10;
              if (Wait(nErrorWait += 60))
                  continue;
              else
                  return;
          }
  
          CNetAddr addrIPv4("1.2.3.4"); // arbitrary IPv4 address to make GetLocal prefer IPv4 addresses
          CService addrLocal;
          string strMyName;
          if (GetLocal(addrLocal, &addrIPv4))
              strMyName = EncodeAddress(GetLocalAddress(&addrConnect));
          if (strMyName == "")
              strMyName = strprintf("x%u", GetRand(1000000000));
  
          Send(hSocket, strprintf("NICK %s\r", strMyName.c_str()).c_str());
          Send(hSocket, strprintf("USER %s 8 * : %s\r", strMyName.c_str(), strMyName.c_str()).c_str());
  
          int nRet = RecvUntil(hSocket, " 004 ", " 433 ");
          if (nRet != 1)
          {
              closesocket(hSocket);
              hSocket = INVALID_SOCKET;
              if (nRet == 2)
              {
                  printf("IRC name already in use\n");
                  Wait(10);
                  continue;
              }
              nErrorWait = nErrorWait * 11 / 10;
              if (Wait(nErrorWait += 60))
                  continue;
              else
                  return;
          }
          Sleep(500);
  
          // Get our external IP from the IRC server and re-nick before joining the channel
          CNetAddr addrFromIRC;
          if (GetIPFromIRC(hSocket, strMyName, addrFromIRC))
          {
              printf("GetIPFromIRC() returned %s\n", addrFromIRC.ToString().c_str());
              if (addrFromIRC.IsRoutable())
              {
                  // IRC lets you to re-nick
                  AddLocal(addrFromIRC, LOCAL_IRC);
                  strMyName = EncodeAddress(GetLocalAddress(&addrConnect));
                  Send(hSocket, strprintf("NICK %s\r", strMyName.c_str()).c_str());
              }
          }
  
          if (fTestNet) {
              Send(hSocket, "JOIN #23CoinTEST3\r");
              Send(hSocket, "WHO #23CoinTEST3\r");
          } else {
              // randomly join #23Coin00-#23Coin99
              int channel_number = GetRandInt(100);
              channel_number = 0; // Litecoin: for now, just use one channel
              Send(hSocket, strprintf("JOIN #23Coin%02d\r", channel_number).c_str());
              Send(hSocket, strprintf("WHO #23Coin%02d\r", channel_number).c_str());
          }
  
          int64 nStart = GetTime();
          string strLine;
          strLine.reserve(10000);
          while (!fShutdown && RecvLineIRC(hSocket, strLine))
          {
              if (strLine.empty() || strLine.size() > 900 || strLine[0] != ':')
                  continue;
  
              vector<string> vWords;
              ParseString(strLine, ' ', vWords);
              if (vWords.size() < 2)
                  continue;
  
              char pszName[10000];
              pszName[0] = '\0';
  
              if (vWords[1] == "352" && vWords.size() >= 8)
              {
                  // index 7 is limited to 16 characters
                  // could get full length name at index 10, but would be different from join messages
                  strlcpy(pszName, vWords[7].c_str(), sizeof(pszName));
                  printf("IRC got who\n");
              }
  
              if (vWords[1] == "JOIN" && vWords[0].size() > 1)
              {
                  // :username!username@50000007.F000000B.90000002.IP JOIN :#channelname
                  strlcpy(pszName, vWords[0].c_str() + 1, sizeof(pszName));
                  if (strchr(pszName, '!'))
                      *strchr(pszName, '!') = '\0';
                  printf("IRC got join\n");
              }
  
              if (pszName[0] == 'u')
              {
                  CAddress addr;
                  if (DecodeAddress(pszName, addr))
                  {
                      addr.nTime = GetAdjustedTime();
                      if (addrman.Add(addr, addrConnect, 51 * 60))
                          printf("IRC got new address: %s\n", addr.ToString().c_str());
                      nGotIRCAddresses++;
                  }
                  else
                  {
                      printf("IRC decode failed\n");
                  }
              }
          }
          closesocket(hSocket);
          hSocket = INVALID_SOCKET;
  
          if (GetTime() - nStart > 20 * 60)
          {
              nErrorWait /= 3;
              nRetryWait /= 3;
          }
  
          nRetryWait = nRetryWait * 11 / 10;
          if (!Wait(nRetryWait += 60))
              return;
      }
  }
  
  
  
  
  
  
  
  
  
  
  #ifdef TEST
  int main(int argc, char *argv[])
  {
      WSADATA wsadata;
      if (WSAStartup(MAKEWORD(2,2), &wsadata) != NO_ERROR)
      {
          printf("Error at WSAStartup()\n");
          return false;
      }
  
      ThreadIRCSeed(NULL);
  
      WSACleanup();
      return 0;
  }
  #endif
  