ferm

Table of Contents

1. Description
2. Usage - Configuration options and additional functionality
3. Reference - An under-the-hood peek at what the module is doing and how
4. Limitations - OS compatibility, etc.

Description

This puppet module manages ferm and its rules.

Usage

class { 'ferm': }

ferm::rules

To add a rule to the ferm rules.d directory:

  ferm::rule { 'allow_http':
    rules       => ['proto tcp dport 80 ACCEPT'],
    host        => 'test3',
    interface   => 'eth1',
    daddr       => '10.255.1.10',
    table       => 'filter',
    chain       => 'INPUT',
    description => 'Allow protocole http',
    prio        => '00',
    notarule    => false,
}

ferm::hook

To add a hook to the ferm conf.d directory.

ferm::hook { 'conntrack_ftp':
  description  => 'Module nf_conntrack_ftp pour proftpd',
  content_hook => 'modprobe nf_conntrack_ftp'
}

Reference

Class: ferm

The ferm class performs all steps needed to the use of ferm such as package installation and configuration. Specific rules can be added later with ferm::rule or specific classes.

Parameters within ferm:

default_allow_ssh

Allow SSH connections.

cache

Cache the output of ferm --lines in /var/cache/ferm?

fast

Enable fast mode: ferm generates an iptables-save(8) file, and installs it with iptables-restore(8). This is much faster, because ferm calls iptables(8) once for every rule by default.

Defined type: ferm::rule

This creates an entry in the correct chain file for ferm.

host or saddr

Source IPv4/IPv6 address. Can be one or many of them. Multiple addresses are always encapsulated in braces: '(127.0.0.1 2003::)' IPv4 and IPv6 addresses can be mixed. CIDR notation is possible if you want to block networks, otherwise /32 or /128 is assumed by ferm/ip(6)tables

interface

Define the interface name, your outside network card, like eth0, or dialup like ppp1, or whatever device you want to match for passing packets. It is equivalent to the -i switch in iptables(8).

daddr

Same as above, just for the destination IP address.

table [filter|nat|mangle]

Specifies which netfilter table this rule will be inserted to: "filter" (default), "nat" or "mangle".

chain

Specifies the netfilter chain (within the current table) this rule will be inserted to. Common predefined chain names are "INPUT", "OUTPUT", "FORWARD","PREROUTING", "POSTROUTING", depending on the table. If you specify a non-existing chain here, ferm will add the rule to a custom chain with that name.

description

The description of the rule.

prio

Priority of the rule. Default: '00'.

Limitations

ferm can be installed and used on:

• Debian Jessie
• Debian Stretch
• Debian Buster
• Debian Bullseye

Licensing

This puppet module is licensed under the GPL version 3 or later. Redistribution and modification is encouraged.

The GPL version 3 license text can be found in the "LICENSE" file accompanying this puppet module, or at the following URL:

http://www.gnu.org/licenses/gpl-3.0.html