socket.cpp

linux下的终端管理工具源码

    #else

    if (EGET() == EOPNOTSUPP)
    {
      result = 0;
    }

    #endif
  }

  if (result < 0)
  {
    #ifdef PANIC
    *logofs << "Socket: PANIC! Failed to set TCP_NODELAY flag on "
            << "FD#" << fd << " to " << value << ". Error is "
            << EGET() << " '" << ESTR() << "'.\n" << logofs_flush;
    #endif

    cerr << "Error" << ": Failed to set TCP_NODELAY flag on "
         << "FD#" << fd << " to " << value << ". Error is "
         << EGET() << " '" << ESTR() << "'.\n";
  }
  #ifdef TEST
  else if (result == 0)
  {
    #ifdef TEST
    *logofs << "Socket: Option TCP_NODELAY not supported "
            << "on FD#" << fd << ".\n" << logofs_flush;
    #endif
  }
  else
  {
    *logofs << "Socket: Set TCP_NODELAY flag on FD#"
            << fd << " to " << value << ".\n"
            << logofs_flush;
  }
  #endif

  return result;
}

int SetKeepAlive(int fd)
{
  int flag = 1;

  if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &flag, sizeof(flag)) < 0)
  {
    #ifdef PANIC
    *logofs << "Socket: PANIC! Failed to set SO_KEEPALIVE flag on "
            << "FD#" << fd << ". Error is " << EGET() << " '"
            << ESTR() << "'.\n" << logofs_flush;
    #endif

    cerr << "Error" << ": Failed to set SO_KEEPALIVE flag on "
         << "FD#" << fd << ". Error is " << EGET() << " '"
         << ESTR() << "'.\n";

    return -1;
  }
  #ifdef TEST
  else
  {
    *logofs << "Socket: Set SO_KEEPALIVE flag on FD#"
            << fd << ".\n" << logofs_flush;
  }
  #endif

  return 1;
}

int SetLowDelay(int fd)
{
  if (_kernelStep < 0)
  {
    GetKernelStep();
  }

  switch (_kernelStep)
  {
    case 3:
    case 2:
    case 1:
    {
      int flag = IPTOS_LOWDELAY;

      if (setsockopt(fd, SOL_IP, IP_TOS, &flag, sizeof(flag)) < 0)
      {
        if (EGET() == EOPNOTSUPP)
        {
          #ifdef TEST
          *logofs << "Socket: Option IPTOS_LOWDELAY not supported "
                  << "on FD#" << fd << ".\n" << logofs_flush;
          #endif
        }
        else
        {
          #ifdef PANIC
          *logofs << "Socket: PANIC! Failed to set IPTOS_LOWDELAY flag on "
                  << "FD#" << fd << ". Error is " << EGET() << " '" << ESTR()
                  << "'.\n" << logofs_flush;
          #endif

          cerr << "Error" << ": Failed to set IPTOS_LOWDELAY flag on "
               << "FD#" << fd << ". Error is " << EGET() << " '" << ESTR()
               << "'.\n";
        }

        return -1;
      }
      #ifdef TEST
      else
      {
        *logofs << "Socket: Set IPTOS_LOWDELAY flag on FD#"
                << fd << ".\n" << logofs_flush;
      }
      #endif

      return 1;
    }
    default:
    {
      #ifdef TEST
      *logofs << "Socket: Option IPTOS_LOWDELAY not "
              << "supported on FD#" << fd << ".\n"
              << logofs_flush;
      #endif

      return 0;
    }
  }
}

int SetCloseOnExec(int fd)
{
  if (fcntl(fd, F_SETFD, 1) != 0)
  {
    #ifdef TEST
    *logofs << "NXClient: PANIC! Cannot set close-on-exec "
            << "on FD#" << fd << ". Error is " << EGET()
            << " '" << ESTR() << "'.\n" << logofs_flush;
    #endif

    cerr << "Error" << ": Cannot set close-on-exec on FD#"
         << fd << ". Error is " << EGET() << " '" << ESTR()
         << "'.\n";

    return -1;
  }

  return 1;
}

int GetBytesReadable(int fd)
{
  long readable = 0;

  //
  // A failure is sometimes what we want,
  // for example at session shutdown.
  //

  if (ioctl(fd, FIONREAD, (void *) &readable) < 0)
  {
    #ifdef TEST
    *logofs << "Socket: PANIC! Failed to get bytes readable "
            << "from FD#" << fd << ". Error is " << EGET()
            << " '" << ESTR() << "'.\n" << logofs_flush;
    #endif

    return -1;
  }

  #ifdef TEST
  *logofs << "Socket: Returning " << readable
          << " bytes readable on FD#" << fd
          << ".\n" << logofs_flush;
  #endif

  return (int) readable;
}

int GetBytesWritable(int fd)
{
  if (_kernelStep < 0)
  {
    GetKernelStep();
  }

  long writable;

  switch (_kernelStep)
  {
    case 3:
    {
      //
      // TODO: Should query the real size
      // of the TCP write buffer.
      //

      writable = 16384 - GetBytesQueued(fd);

      if (writable < 0)
      {
        writable = 0;
      }

      break;
    }
    case 2:
    {
      if (ioctl(fd, TIOCOUTQ, (void *) &writable) < 0)
      {
        #ifdef PANIC
        *logofs << "Socket: PANIC! Failed to get bytes writable "
                << "on FD#" << fd << ". Error is " << EGET()
                << " '" << ESTR() << "'.\n" << logofs_flush;
        #endif

        cerr << "Error" << ": Failed to get bytes writable "
             << "on FD#" << fd << ". Error is " << EGET()
             << " '" << ESTR() << "'.\n";

        return -1;
      }

      break;
    }
    default:
    {
      #ifdef TEST
      *logofs << "Socket: Option TIOCOUTQ not supported "
              << "on FD#" << fd << ",\n" << logofs_flush;
      #endif

      //
      // TODO: Should query the real size
      // of the TCP write buffer.
      //

      writable = 16384;

      break;
    }
  }

  #ifdef TEST
  *logofs << "Socket: Returning " << writable
          << " bytes writable on FD#" << fd
          << ".\n" << logofs_flush;
  #endif

  return (int) writable;
}

int GetBytesQueued(int fd)
{
  //
  // The TIOCOUTQ ioctl is not implemented on Cygwin
  // and returns the space available on Linux Kernels
  // 2.0 and 2.2 (like current MIPS for PS/2). This
  // function is used to detect proxy congestion, so
  // it is only critical at X client side.
  //

  if (_kernelStep < 0)
  {
    GetKernelStep();
  }

  long queued;

  switch (_kernelStep)
  {
    case 3:
    {
      if (ioctl(fd, TIOCOUTQ, (void *) &queued) < 0)
      {
        #ifdef PANIC
        *logofs << "Socket: PANIC! Failed to get bytes queued "
                << "on FD#" << fd << ". Error is " << EGET()
                << " '" << ESTR() << "'.\n" << logofs_flush;
        #endif

        cerr << "Error" << ": Failed to get bytes queued "
             << "on FD#" << fd << ". Error is " << EGET()
             << " '" << ESTR() << "'.\n";

        return -1;
      }

      break;
    }
    case 2:
    {
      //
      // TODO: Should query the real size
      // of the TCP write buffer.
      //

      queued = 16384 - GetBytesWritable(fd);

      if (queued < 0)
      {
        queued = 0;
      }

      break;
    }
    default:
    {
      #ifdef TEST
      *logofs << "Socket: Option TIOCOUTQ not supported "
              << "on FD#" << fd << ",\n" << logofs_flush;
      #endif

      queued = 0;

      break;
    }
  }

  #ifdef TEST
  *logofs << "Socket: Returning " << queued
          << " bytes queued on FD#" << fd
          << ".\n" << logofs_flush;
  #endif

  return (int) queued;
}

int GetHostAddress(const char *name)
{
  hostent *host = gethostbyname(name);

  if (host == NULL)
  {
    //
    // On some Unices gethostbyname() doesn't
    // accept IP addresses, so try inet_addr.
    //

    in_addr_t address = inet_addr(name);

    if (address == INADDR_NONE)
    {
      #ifdef PANIC
      *logofs << "Socket: PANIC! Failed to resolve address of '"
              << name << "'.\n" << logofs_flush;
      #endif

      cerr << "Error" << ": Failed to resolve address of '"
           << name << "'.\n";

      return 0;
    }

    return (int) address;
  }
  else
  {
    return (*((int *) host -> h_addr_list[0]));
  }
}