ansible-playbooks/roles/common/templates/ferm/ferm.conf.j2

{% if ansible_prolog -%}
{% from 'templates/ansible/prolog.j2' import prolog with context %}
{{ prolog() }}
{% endif -%}
#
#  Configuration file for ferm(1).
#

@def $PORTS = ({{ firewall_public | join(' ') }}); # Services running worldwide

table filter {
    chain INPUT {
        policy DROP;

        # connection tracking
        mod state state INVALID DROP;
        mod state state (ESTABLISHED RELATED) ACCEPT;

        # allow local packet
        interface lo ACCEPT;

        # respond to ping
        proto icmp icmp-type echo-request ACCEPT;

        # standard ports we allow from the outside
        proto (udp tcp) dport $PORTS ACCEPT;
{% if firewall_private is defined %}
        # Private networks configuration
{% for fwconf in firewall_private %}
        interface {{ fwconf.interface }}{% if fwconf.networks is defined %} saddr ({{ fwconf.networks | join(' ') }}){% endif %} {
            proto (udp tcp) dport ({{ fwconf.ports | join(' ') }}) ACCEPT;
        }
{% endfor %}
{% endif %}
    }

    chain OUTPUT {
        policy ACCEPT;

        # connection tracking
        #mod state state INVALID DROP;
        mod state state (ESTABLISHED RELATED) ACCEPT;
    }

    chain FORWARD {
        policy DROP;

        # connection tracking
        mod state state INVALID DROP;
        mod state state (ESTABLISHED RELATED) ACCEPT;
    }
}

domain ip6 table filter {
    chain INPUT {
        policy DROP;

        # connection tracking
        mod state state INVALID DROP;
        mod state state (ESTABLISHED RELATED) ACCEPT;

        # allow local packet
        interface lo ACCEPT;

        # allow ICMP (for neighbor solicitation, like ARP for IPv4)
        proto ipv6-icmp ACCEPT;

        # standard ports we allow from the outside
        proto tcp dport $PORTS ACCEPT;
    }

    chain OUTPUT {
        policy ACCEPT;

        # connection tracking
        #mod state state INVALID DROP;
        mod state state (ESTABLISHED RELATED) ACCEPT;
    }

    chain FORWARD {
        policy DROP;

        # connection tracking
        mod state state INVALID DROP;
        mod state state (ESTABLISHED RELATED) ACCEPT;
    }
}