Puppet Class: iptables

Defined in:
manifests/init.pp

Summary

Manage iptables with default rule optimization and a failsafe fallback mode

Overview

> It is **highly recommended** that you place this module in “firewalld“ > mode if the underlying system supports it. > > You can do this by setting “iptables::use_firewalld: true“ in Hiera

This class will detect conflicts with the SIMP option “simp_options::firewall“ and, if necessary, cease management of IPTables in the case of a conflict.

In particular, this means that if “simp_options::firewall“ is “false“, but you have included this class, it will refuse to manage IPTables and will instead raise a warning.

If the “simp_options::firewall“ variable is not present, the module will manage IPTables as expected.

Parameters:

  • enable (Variant[Enum['ignore','firewalld'],Boolean]) (defaults to: simplib::lookup('simp_options::firewall', { 'default_value' => true })) —

    Enable IPTables

    • If set to “true“ will enable management of IPTables

    • If set to “false“ will disable IPTables completely

    • If set to “ignore“ will stop managing IPTables

  • use_firewalld (Boolean) (defaults to: true) —

    Explicitly enable management via “simp_firewalld“

    • Systems that do not have “firewalld“ installed will fall back to “iptables“

  • ensure (String) (defaults to: simplib::lookup('simp_options::package_ensure', { 'default_value' => 'installed' })) —

    The state that the “package“ resources should target

    • May take any value acceptable to the native “package“ resource “ensure“ parameter

  • ipv6 (Boolean) (defaults to: true) —

    Also manage IP6Tables

  • class_debug (Boolean) (defaults to: false) —

    Print messages regarding rule comparisons

  • optimize_rules (Boolean) (defaults to: true) —

    Run the inbuilt iptables rule optimizer to collapse the rules down to as small as is reasonably possible without reordering

    • IPSets have been incorporated via the ‘firewalld` module

  • precise_match (Boolean) (defaults to: false) —

    Instead of matching rule counts, perform a more precise match against the running and to-be-applied rules. You may find that minor changes, such as a simple netmask change will not be enforced without enabling this option.

    • NOTE: You MUST use the exact same syntax that will be returned by ‘iptables-save` and `ip6tables-save` if you use this option!

    • For example, you cannot write ‘echo-request` for an ICMP echo match, you must instead use `8`.

  • ignore (Array[String[1]]) (defaults to: []) —

    Regular expressions that you would like to match in order to preserve running rules

    • This modifies the behavior of the “iptables_optimize“ Type.

    • Do not include the beginning and ending “/“ but do include an end or beginning of word marker (“^“ and/or “$“) if appropriate

  • default_rules (Boolean) (defaults to: true) —

    Enable the usual set of default deny rules that you would expect to see on most systems

    • Uses the following expectations of rule ordering (not enforced):

      * 1     -> ``ESTABLISHED`` and ``RELATED`` rules
* 2-5   -> Standard ``ACCEPT`` and ``DENY`` rules
* 6-10  -> ``JUMP`` to other rule sets
* 11-20 -> Pure ``ACCEPT`` rules
* 22-30 -> ``LOG`` and ``REJECT`` rules
  • scanblock (Boolean) (defaults to: false) —

    Enable a technique for setting up port-based triggers that will block anyone connecting to the system for an hour after connection to a forbidden port

  • prevent_localhost_spoofing (Boolean) (defaults to: true) —

    Add rules to “PREROUTING“ that will prevent spoofed packets from “localhost“ addresses from reaching your system

  • ports (Optional[Hash]) (defaults to: undef) —

    A hash with structure as defined below that will open ports based on the structure of the hash. @example An example section of hieradata:

    iptables::ports:
  defaults:
    apply_to: ipv4
  80:
  53:
    proto: udp
  443:
    apply_to: ipv6

Author:



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# File 'manifests/init.pp', line 106

class iptables (
  Variant[Enum['ignore','firewalld'],Boolean] $enable         = simplib::lookup('simp_options::firewall', { 'default_value' => true }),
  Boolean                         $use_firewalld              = true,
  String                          $ensure                     = simplib::lookup('simp_options::package_ensure', { 'default_value' => 'installed' }),
  Boolean                         $ipv6                       = true,
  Boolean                         $class_debug                = false,
  Boolean                         $optimize_rules             = true,
  Boolean                         $precise_match              = false,
  Array[String[1]]                $ignore                     = [],
  Boolean                         $default_rules              = true,
  Boolean                         $scanblock                  = false,
  Boolean                         $prevent_localhost_spoofing = true,
  Optional[Hash]                  $ports                      = undef
) {
  simplib::assert_metadata($module_name)

  if $enable != 'ignore' {
    # This is required in case you want to put firewalld in iptables mode
    contain 'iptables::install'

    if $use_firewalld {
      simplib::assert_optional_dependency($module_name, 'simp/simp_firewalld')

      include 'simp_firewalld'

      if $ports {
        iptables::ports {'firewalld':
          ports => $ports
        }
      }
    } else {
      contain 'iptables::service'

      if $default_rules { contain 'iptables::rules::base' }
      if $scanblock { contain 'iptables::rules::scanblock' }
      if $prevent_localhost_spoofing { contain 'iptables::rules::prevent_localhost_spoofing' }

      contain 'iptables::rules::default_drop'

      Class['iptables::install'] -> Class['iptables::service']

      file { '/etc/sysconfig/iptables':
        owner   => 'root',
        group   => 'root',
        mode    => '0640',
        require => Class['iptables::install']
      }

      # These are required to run if you are managing iptables with the custom
      # types at all.
      iptables_optimize { '/etc/sysconfig/iptables':
        optimize      => $optimize_rules,
        ignore        => $ignore,
        disable       => !$enable,
        precise_match => $precise_match,
        require       => Class['iptables::install']
      }

      if $ipv6 and $facts['ipv6_enabled'] {
        file { '/etc/sysconfig/ip6tables':
          owner   => 'root',
          group   => 'root',
          mode    => '0640',
          require => Class['iptables::install']
        }

        ip6tables_optimize { '/etc/sysconfig/ip6tables':
          optimize      => $optimize_rules,
          ignore        => $ignore,
          disable       => !$enable,
          precise_match => $precise_match,
          require       => Class['iptables::install']
        }
      }

      if $ports {
        iptables::ports {'iptables':
          ports   => $ports,
          require => Class['iptables::install']
        }
      }
    }
  }
}