TODO: lib/whatweb/scan: refactor IP range parsing

[bcoles]

      # TODO: refactor this
      ip_range = url_list.map do |x|
        range = nil
        # Parse IP ranges
        if x =~ %r{^[0-9\.\-\/]+$} && x !~ %r{^[\d\.]+$}
          begin
            # CIDR notation
            if x =~ %r{\d+\.\d+\.\d+\.\d+/\d+$}
              range = IPAddr.new(x).to_range.map(&:to_s)
            # x.x.x.x-x
            elsif x =~ %r{^(\d+\.\d+\.\d+\.\d+)-(\d+)$}
              start_ip = IPAddr.new(Regexp.last_match(1), Socket::AF_INET)
              end_ip   = IPAddr.new("#{start_ip.to_s.split('.')[0..2].join('.')}.#{Regexp.last_match(2)}", Socket::AF_INET)
              range = (start_ip..end_ip).map(&:to_s)
            # x.x.x.x-x.x.x.x
            elsif x =~ %r{^(\d+\.\d+\.\d+\.\d+)-(\d+\.\d+\.\d+\.\d+)$}
              start_ip = IPAddr.new(Regexp.last_match(1), Socket::AF_INET)
              end_ip   = IPAddr.new(Regexp.last_match(2), Socket::AF_INET)
              range = (start_ip..end_ip).map(&:to_s)
            end
          rescue => e
            # Something went horribly wrong parsing the target IP range
            raise "Error parsing target IP range: #{e}"
          end
        end
        range
      end.compact.flatten