class Geocoder::IpAddress

def loopback?
  valid? and (self == "0.0.0.0" or self.match(/\A127\./))
end

def valid?
  !!self.match(/\A(::ffff:)?(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\z/)
end