pdcfw-main.sh

# pdcfw - manages PDC Linux Netfilter/IPtables firewall configuration

# pdcfw-main.sh - pdcfw test main routine
# Author: Ilari Korhonen, KTH Royal Institute of Technology
#
# Copyright (C) 2018 KTH Royal Institute of Technology. All rights reserved.
# See LICENSE file for more information.

#!/bin/bash

function main()
{
    # table: filter (packet filtering, default)
    # rule chains: INPUT, OUTPUT, FORWARD

    # rule chain: INPUT
    # description: incoming, packets destined to this host
    # default policy: ACCEPT
    set_default_policy INPUT ACCEPT

    # allow all from trusted interfaces, established connections, icmp w/ limits
    allow_trusted_interfaces INPUT
    allow_established INPUT
    allow_icmp_with_limits INPUT

    # allow SSH connections
    allow with INPUT proto tcp from any to $(hostname) dport 22 stateful

    # drop the rest
    drop_and_log_all INPUT

    # rule chain: OUTPUT
    # description: outgoing, packets generated on this host
    # default policy: ACCEPT
    set_default_policy OUTPUT ACCEPT

    # rule chain: FORWARD
    # description: routing, packets destined to be routed
    # default policy: ACCEPT
    set_default_policy FORWARD ACCEPT

    # we drop and log all packets (no routing!)
    drop_and_log_all FORWARD
}