Ansible Role: Shorewall

Description

Ansible role which installs and configures Shorewall and Shorewall6.

Installation

ansible-galaxy install arillso.shorewall

Requirements

Ansible version 2.0 or better.

Role Handlers

Name	Description
enable shorewall, enable shorewall6	Enables and starts Shorewall / Shorewall 6
restart shorewall, restart shorewall6	Restarts Shorewall / Shorewall6

Role Variables

Note: The Shorewall (IPv4) variables are prefixed by shorewall_, whereas the Shorewall6 (IPv6) variables are prefixed by shorewall6_.

Variable	Dictionary / Options
shorewall_package_state	"present", "latest", "absent".
shorewall_startup	"1" or "0"
shorewall_conf	this variable uses standard option / value pairs
shorewall_interfaces	zone, interface, options
shorewall_zones	zone, type, options, options_in, options_out
shorewall_policies	source, dest, policy, log_level, burst_limit, conn_limit
shorewall_rules	sections: section, rules: rule. For each rule: action, source, dest, proto, dest_port, source_port, original_dest, rate_limit, user_group, mark, connlimit, time, headers, switch, helper, when
shorewall_masq	interface, source, address, proto, ports, ipsec, mark, user, switch, original_dest
shorewall_tunnels	type, zone, gateway, gateway_zone
shorewall_hosts	zone, hosts, options
shorewall_params	name, value

shorewall_package_state - Shorewall package state

See the Ansible package module information for more details.

It allows you to control whether Shorewall and dependencies should be either installed ("present"), installed / upgraded to their most recent version ("latest") or should be removed ("absent").

shorewall_startup - Shorewall startup behaviour

This updates the /etc/default/shorewall file's startup option to either enable ("1") startup (using the service or systemctl commands) or disable it ("0").

shorewall_conf - Shorewall Configuration

Specify values for global Shorewall options in the /etc/shorewall/shorewall.conf file. See the Shorewall shorewall.conf man page for more details.

Each shorewall.conf option may be written in lower-case, such as ACCEPT_DEFAULT=none can be written as accept_default: "none" in the variables.

Example

shorewall_conf:
  verbosity: '1'
  log_verbosity: '2'
  logfile: '/var/log/messages'
  blacklist: '"NEW,INVALID,UNTRACKED"'
  blacklist_disposition: 'DROP'

shorewall_interfaces - Interfaces

Define the interfaces on the system and optionally associate them with zones in the /etc/shorewall/interfaces file. See the Shorewall interfaces man page for more details.

Example - Interfaces

shorewall_interfaces:
  - {
      zone: net,
      interface: eth0,
      options: 'dhcp,tcpflags,logmartians,nosmurfs,sourceroute=0',
    }

shorewall_zones - Zones

Declare Shorewall zones in the /etc/shorewall/zones file. See the Shorewall zones man page for more details.

Example - Zone

shorewall_zones:
  - { zone: fw, type: firewall }
  - { zone: net, type: ipv4 }

shorewall_policies - Policies

Define high-level policies for connections between zones in the /etc/shorewall/policies. See the Shorewall policy man page for more details.

Example - Policies

shorewall_policies:
  - { source: '$FW', dest: all, policy: ACCEPT }
  - { source: net, dest: all, policy: REJECT }
  - { source: all, dest: all, policy: REJECT, log_level: info }

shorewall_rules - Rules

Specify exceptions to policies, including DNAT and REDIRECT in the /etc/shorewall/rules file. See the Shorewall rules man page for more details.

WARNING: Please be sure to include a rule for SSH on the correct port, to avoid locking Ansible - and yourself - out from the remote host.

Using the when conditional

An option specific to this role variable. and not part of Shorewall, is the when conditional. This allows a rule to be included only if the condition evaluates to True.

Examples

shorewall_rules:
  - section: NEW
    rules:
      - { action: 'Invalid(DROP)', source: net, dest: '$FW', proto: tcp }
      - { action: ACCEPT, source: net, dest: '$FW', proto: tcp, dest_port: ssh }
      - {
          action: ACCEPT,
          source: net,
          dest: '$FW',
          proto: icmp,
          dest_port: echo-request,
        }

Using the when conditional:

has_webserver: True

# And in a task:
#- name: Disable webserver rule
#  set_fact:
#    has_webserver: False

shorewall_rules:
  - section: NEW
    rules:
      - { action: 'Invalid(DROP)', source: net, dest: '$FW', proto: tcp }
      - { action: ACCEPT, source: net, dest: '$FW', proto: tcp, dest_port: ssh }
      - {
          action: 'HTTP(ACCEPT)',
          source: net,
          dest: '$FW',
          when: '{{ has_webserver }}',
        }

shorewall_masq - Masquerade/SNAT

Define Masquerade/SNAT in the /etc/shorewall/masq file. See the Shorewall masq man page for more details.

shorewall_tunnels - Tunnels

Define VPN connections with endpoints on the firewall in the /etc/shorewall/tunnels file. See the Shorewall tunnels man page for more details.

Example - Tunnels

shorewall_tunnels:
  - { type: ipsec, zone: net, gateway: '0.0.0.0/0', gateway_zones: 'vpn1,vpn2' }

shorewall_hosts - Hosts

Define multiple zones accessed through a single interface in the /etc/shorewall/hosts file. See the Shorewall hosts man page for more details.

shorewall_params - Parameters

Assign any shell variables that you need in the /etc/shorewall/params file. See the Shorewall params man page for more details.

Example Playbook

- hosts: all
  roles:
    - arillso.shorewall

Changelog

v1.0.9

• change variable from ansible_ssh_port to shorewall_ssh_default

v1.0.8

• Enable and start service (use: service is set because of ansible/ansible#22303) (thank S. Veyrié)

v1.0.7

• Added support for shorewall SNAT configuration (thank ErmakovDmitriy)

v1.0.6

• Sort shorewall.conf items to ensure idempotence between runs (thank S. Veyrié)

v1.0.5

• rename role name

v1.0.4

• add support for docker
• add tags support

v1.0.3

• Added: The shorewall_rules has an added option when for each rule, which acts similar to Ansible's when statement and allows rules to be conditional.
• Added: role variable shorewall_tunnels for use with VPNs.
• Changed: The generated shorewall_rules will now take into account the ? prefix in sections (i.e. ?ESTABLISHED), which was introduced at Shorewall version 4.6. If the Shorewall version installed is older than 4.6, this prefix will be omitted to avoid errors.

v1.0

• Added: ipset as a package dependency;
• Added: role variable shorewall_conf, allowing each option in the shorewall.conf file to be defined;
• Added: role variable shorewall_package_state to set package state of Shorewall and dependencies;
• Changed: The default for shorewall_interface now detects the default network interface rather than fixed at eth0 (though eth0 is still a fall-back default);
• Removed: role variables: shorewall_verbosity, shorewall_log_verbosity. Use the shorewall_conf role variable to configure these instead.

Author

• Simon Bärlocher
• ErmakovDmitriy
• S. Veyrié
• Michael Green
• Farhad Shahbazi
• Sascha Biberhofer

License

This project is under the MIT License. See the LICENSE file for the full license text.

Copyright

• Copyright (c) 2019 Simon Bärlocher