# File lib/net/ssh/proxy/socks4.rb, line 52
        def open( host, port )
          sock = TCPSocket.new( @proxy_host, @proxy_port )

          ip_addr = IPAddr.new( Resolv.getaddress( host ) )
          
          packet = [ SOCKS_VERSION, SOCKS_CMD_CONNECT,
                     port.to_i, ip_addr.to_i,
                     proxy_user, 0 ].pack( "CCnNA*C" )
          sock.send packet, 0

          version, status, port, ip = sock.recv( 8 ).unpack( "CCnN" )
          if status != SOCKS_GRANTED
            sock.close
            raise ConnectError, "error connecting to proxy (#{status})"
          end

          return sock
        end