FIAIF is an Intelligent Firewall.

fiaif <start|stop|restart|force-reload|status|panic|tc-start|tc-stop|tc-status>

Fiaif deploys a packet-filtering firewall by reading configuration files and setting up IP packet filtering rules using iptables. The firewall is "zone" based, meaning that each network interface is associated with a defined piece of the "IP universe" on the other side of that interface from the host. A zone is defined in a text file (the zone configuration file) listing rules for the handling of IP traffic into, out of, and through the associated interface. The rules spell out which connections to accept, which to reject, which to ignore, and which to forward through the firewall. It is also possible to setup source and destination NAT for altering the source and/or destination addresses of packets as they pass through. All non-accepted packets are logged to the system log.

It should be noted that any packet related to an already accepted connection is allowed though the firewall.

start

This will save the current state of netfilter, and apply the new firewall as described in the configuration files.

stop

Restores the state saved when FIAIF was started.

restart

Same as stop,start

force-reload

This option is the same as start, although it does not use any previously saved rules, and can be used even if fiaif has already been started.

start-tc

Start/restart only traffic shaping. Useful if you are playing arround with that part of the fiaf subsystem.

panic

Shut off all IP traffic - don't accept any packets from anywhere for any reason. This can be used, for example, if uninvited guests are discovered on the system to quickly close the firewall and start analyzing log files.

status

Lists all rules in the firewall.

test

Instead of deploying the firewall, all rules are written to the file specified in the "TEST_FILE" parameter in the global configuration file. This command also runs a sanity check on the networking configuration. Any problems or warnings arising from this check are printed to STDERR. Refer to http://www.linuxhq.com/kernel/v2.4/doc/networking/ip-sysctl.txt.html for details on settings tested. When deployed, FIAIF can automatically fix the warnings and/or errors displayed. Please see fiaif.conf(8) for more information.

tc-start

Start only traffic shaping. This option ignores the "ENABLE_TC" parameter in the global configuration file.

tc-stop

Stops the traffic shaping. This option ignores the "ENABLE_TC" parameter in the global configuration file.

tc-status

Lists packet counters for all traffic classes.

/etc/fiaif/fiaif.conf The global configuration file. See fiaif.conf(8) for further details.

/var/lib/fiaif/fiaif file containing rules generated by fiaif. /var/lib/fiaif/iptables previous netfilter state

/var/lib/fiaif/sysctl previous state of /proc before fiaif was started.

/var/log/messages All illegal packets are logged to this file though syslog(3)

Errors are logged to STDOUT. If any errors is printed, then please recheck your configuration files.

If the NO_CLEANUP variable is set to a non-empty value, then rules are not cleaned up after FIAIF is started. This will speed up FIAIF startup time, but at the cost of having lots of rules and performance may (on small systems with many zones) be affected. On a three zone system FIAIF generated in total 310 rules. After cleaning up the rules, the number of rules was down to 241. A reduction of 22%.

The FIAIF_CONF can be used to specify an anternative global configurationfile, rather than using the default /etc/fiaif/fiaif.conf. This can be used to ease switching between two different firewall configurations.

The test command line option is no guarantee that the firewall will perform as expected, only that the syntax is correct. Only limited semantic checks of rulesis performed.

Report bugs to <fiaif@fiaif.net>.

Anders Fugmann <anders(at)fugmann.net>

fiaif.conf(8), zone.conf(8), iptables(8), syslog(3)