get_labels

# File lib/resolv.rb, line 1412
        def get_labels(limit=nil)
          limit = @index if !limit || @index < limit
          d = []
          while true
            case @data[@index].ord
            when 0
              @index += 1
              return d
            when 192..255
              idx = self.get_unpack('n')[0] & 0x3fff
              if limit <= idx
                raise DecodeError.new("non-backward name pointer")
              end
              save_index = @index
              @index = idx
              d += self.get_labels(limit)
              @index = save_index
              return d
            else
              d << self.get_label
            end
          end
          return d
        end