- separates iptables messages from all other kernel messages.
reads messages from the /var/lib/fwknop/fwknopfifo named pipe and prints any firewall
related log messages to the fwknop data file "/var/log/fwknop/fwdata".
that knopmd is only used in the legacy port knocking mode, and the default
authentication/authorization method used by fwknop is Single Packet Authorization (SPA).
cannot detect port knocking sequences without knopmd running on the machine.
references the fwknop.conf configuration file which by default is
located at /etc/fwknop/fwknop.conf, but a different path can be specified
on the command line.