grammar IPTables

  rule exp

    target s action s src:ip s 'to' s dst:ip s proto:proto+ state:state? {

        def eval

            ds = Hash.new

            ds['target'] = target.text_value.to_s

            ds['action'] = action.text_value.to_s

            ds['src_ip'] = src.text_value.to_s

            ds['dst_ip'] = dst.text_value.to_s

            ds['proto'] = proto.text_value.to_s.strip

            ds['state'] = state.text_value.to_s if defined?(state)

            ds

        end

    }

  end

  rule s

    ' '*

  end

  rule action

    "allow" / "deny" / "reject" / "log"

  end

  rule target

    "forward" / "input" / "output"

  end

  rule ip

    ip_address ':' port / ip_address

  end

  rule ip_address

    octet '.' octet '.' octet '.' octet  '/'? octet?

  end

  rule port

    [0-9]+

  end

  rule octet

    [0-9]+

  end

  rule proto

    ( "tcp" / "udp" / "icmp" / "all" ) s?

  end

  rule state

    "state"

  end

end