path: root/REFERENCE.md

# Reference

<!-- DO NOT EDIT: This document was generated by Puppet Strings -->

## Table of Contents

### Classes

#### Public Classes

* [`ferm`](#ferm): This class manages ferm installation and rule generation on modern linux systems

#### Private Classes

* `ferm::config`: This class handles the configuration file. Avoid modifying private classes.
* `ferm::install`: This class handles the configuration file. Avoid modifying private classes.
* `ferm::service`: This class handles the configuration file. Avoid modifying private classes.

### Defined types

* [`ferm::chain`](#fermchain): This defined resource manages ferm/iptables chains
* [`ferm::ipset`](#fermipset): a defined resource that can match for ipsets at the top of a chain. This is a per-chain resource. You cannot mix IPv4 and IPv6 sets.
* [`ferm::rule`](#fermrule): This defined resource manages a single rule in a specific chain

### Data types

* [`Ferm::Actions`](#fermactions): a list of allowed actions for a rule
* [`Ferm::Policies`](#fermpolicies): a list of allowed policies for a chain
* [`Ferm::Port`](#fermport): ferm port-spec
* [`Ferm::Protocols`](#fermprotocols): a list of allowed protocolls to match
* [`Ferm::Tables`](#fermtables): a list of available tables

## Classes

### `ferm`

This class manages ferm installation and rule generation on modern linux systems

#### Examples

##### deploy ferm without any configured rules, but also don't start the service or modify existing config files

```puppet
include ferm
```

##### deploy ferm and start it, on nodes with only ipv6 enabled

```puppet
class{'ferm':
  manage_service  => true,
  ip_versions     => ['ip6'],
}
```

##### deploy ferm and don't touch chains from other software, like fail2ban and docker

```puppet
class{'ferm':
  manage_service            => true,
  preserve_chains_in_tables => {
    'filter' => [
      'f2b-sshd',
      'DOCKER',
      'DOCKER-ISOLATION-STAGE-1',
      'DOCKER-ISOLATION-STAGE-2',
      'DOCKER-USER',
      'FORWARD',
    ],
    'nat' => [
      'DOCKER',
    ],
  },
}
```

#### Parameters

The following parameters are available in the `ferm` class.

##### `manage_service`

Data type: `Boolean`

Disable/Enable the management of the ferm daemon

Default value: ``false``

##### `manage_configfile`

Data type: `Boolean`

Disable/Enable the management of the ferm default config

Default value: ``false``

##### `configfile`

Data type: `Stdlib::Absolutepath`

Path to the config file

##### `configdirectory`

Data type: `Stdlib::Absolutepath`

Path to the directory where the module stores ferm configuration files

##### `forward_disable_conntrack`

Data type: `Boolean`

Enable/Disable the generation of conntrack rules for the FORWARD chain

Default value: ``true``

##### `output_disable_conntrack`

Data type: `Boolean`

Enable/Disable the generation of conntrack rules for the OUTPUT chain

Default value: ``true``

##### `input_disable_conntrack`

Data type: `Boolean`

Enable/Disable the generation of conntrack rules for the INPUT chain

Default value: ``false``

##### `forward_policy`

Data type: `Ferm::Policies`

Default policy for the FORWARD chain

Default value: `'DROP'`

##### `output_policy`

Data type: `Ferm::Policies`

Default policy for the OUTPUT chain

Default value: `'ACCEPT'`

##### `input_policy`

Data type: `Ferm::Policies`

Default policy for the INPUT chain

Default value: `'DROP'`

##### `input_drop_invalid_packets_with_conntrack`

Data type: `Boolean`

Enable/Disable the `mod conntrack ctstate INVALID DROP` statement. Only works if `$disable_conntrack` is `false`. You can set this to false if your policy is DROP. This only effects the INPUT chain.

Default value: ``false``

##### `rules`

Data type: `Hash`

A hash that holds all data for ferm::rule

Default value: `{}`

##### `chains`

Data type: `Hash`

A hash that holds all data for ferm::chain

Default value: `{}`

##### `forward_log_dropped_packets`

Data type: `Boolean`

Enable/Disable logging in the FORWARD chain of packets to the kernel log, if no explicit chain matched

Default value: ``false``

##### `output_log_dropped_packets`

Data type: `Boolean`

Enable/Disable logging in the OUTPUT chain of packets to the kernel log, if no explicit chain matched

Default value: ``false``

##### `input_log_dropped_packets`

Data type: `Boolean`

Enable/Disable logging in the INPUT chain of packets to the kernel log, if no explicit chain matched

Default value: ``false``

##### `ip_versions`

Data type: `Array[Enum['ip','ip6']]`

Set list of versions of ip we want ot use.

Default value: `['ip','ip6']`

##### `preserve_chains_in_tables`

Data type: `Hash[String[1],Array[String[1]]]`

Hash with table:chains[] to use ferm @preserve for (since ferm v2.4)
Example: {'nat' => ['PREROUTING', 'POSTROUTING']}

Default value: `{}`

##### `install_method`

Data type: `Enum['package','vcsrepo']`

method used to install ferm

Default value: `'package'`

##### `vcsrepo`

Data type: `Stdlib::HTTPSUrl`

git repository where ferm sources are hosted

Default value: `'https://github.com/MaxKellermann/ferm.git'`

##### `vcstag`

Data type: `String[1]`

git tag used when install_method is vcsrepo

Default value: `'v2.5.1'`

## Defined types

### `ferm::chain`

This defined resource manages ferm/iptables chains

#### Examples

##### create a custom chain, e.g. for all incoming SSH connections

```puppet
ferm::chain{'check-ssh':
  chain               => 'SSH',
  disable_conntrack   => true,
  log_dropped_packets => true,
}
```

#### Parameters

The following parameters are available in the `ferm::chain` defined type.

##### `disable_conntrack`

Data type: `Boolean`

Disable/Enable usage of conntrack. By default, we enable conntrack only for the filter INPUT chain

Default value: ``true``

##### `drop_invalid_packets_with_conntrack`

Data type: `Boolean`

Enable/Disable the `mod conntrack ctstate INVALID DROP` statement. Only works if `$disable_conntrack` is `false` in this chain. You can set this to false if your policy is DROP.

Default value: ``false``

##### `log_dropped_packets`

Data type: `Boolean`

Enable/Disable logging of packets to the kernel log, if no explicit chain matched

Default value: ``false``

##### `policy`

Data type: `Optional[Ferm::Policies]`

Set the default policy for CHAIN (works only for builtin chains)
Allowed values: (ACCEPT|DROP) (see Ferm::Policies type)

Default value: ``undef``

##### `chain`

Data type: `String[1]`

Name of the chain that should be managed
Allowed values: String[1]

Default value: `$name`

##### `table`

Data type: `Ferm::Tables`

Select the target table (filter/raw/mangle/nat)
Allowed values: (filter|raw|mangle|nat) (see Ferm::Tables type)

Default value: `'filter'`

##### `ip_versions`

Data type: `Array[Enum['ip', 'ip6']]`

Set list of versions of ip we want ot use.

Default value: `$ferm::ip_versions`

##### `content`

Data type: `Optional[String[1]]`

custom string that will be written into th chain file

Default value: ``undef``

### `ferm::ipset`

a defined resource that can match for ipsets at the top of a chain. This is a per-chain resource. You cannot mix IPv4 and IPv6 sets.

* **See also**
  * http://ferm.foo-projects.org/download/2.1/ferm.html#set

#### Examples

##### Create an iptables rule that allows traffic that matches the ipset `internet`

```puppet
ferm::ipset { 'CONSUL':
  sets => {
    'internet' => 'ACCEPT'
  },
}
```

##### create two matches for IPv6, both at the end of the `INPUT` chain. Explicitly mention the `filter` table.

```puppet
ferm::ipset { 'INPUT':
  prepend_to_chain => false,
  table            => 'filter',
  ip_version       => 'ip6',
  sets             => {
    'testset01'      => 'ACCEPT',
    'anothertestset' => 'DROP'
  },
}
```

#### Parameters

The following parameters are available in the `ferm::ipset` defined type.

##### `sets`

Data type: `Hash[String[1], Ferm::Actions]`

A hash with multiple sets. For each hash you can provide an action like `DROP` or `ACCEPT`.

##### `chain`

Data type: `String[1]`

name of the chain we want to apply those rules to. The name of the defined resource will be used as default value for this.

Default value: `$name`

##### `table`

Data type: `Ferm::Tables`

name of the table where we want to apply  this. Defaults to `filter` because that's the most common usecase.

Default value: `'filter'`

##### `ip_version`

Data type: `Enum['ip','ip6']`

sadly, ip sets are version specific. You cannot mix IPv4 and IPv6 addresses. Because of this you need to provide the version.

Default value: `'ip'`

##### `prepend_to_chain`

Data type: `Boolean`

By default, ipset rules are added to the top of the chain. Set this to false to append them to the end instead.

Default value: ``true``

### `ferm::rule`

This defined resource manages a single rule in a specific chain

#### Examples

##### Jump to the 'SSH' chain for all incoming SSH traffic (see chain.pp examples on how to create the chain)

```puppet
ferm::rule{'incoming-ssh':
  chain  => 'INPUT',
  action => 'SSH',
  proto  => 'tcp',
  dport  => 22,
}
```

##### Create a rule in the 'SSH' chain to allow connections from localhost

```puppet
ferm::rule{'allow-ssh-localhost':
  chain  => 'SSH',
  action => 'ACCEPT',
  proto  => 'tcp',
  dport  => 22,
  saddr  => '127.0.0.1',
}
```

##### Confuse people that do a traceroute/mtr/ping to your system

```puppet
ferm::rule{'drop-icmp-time-exceeded':
  chain         => 'OUTPUT',
  policy        => 'DROP',
  proto         => 'icmp',
  proto_options => 'icmp-type time-exceeded',
}
```

##### allow multiple protocols

```puppet
ferm::rule{'allow_consul':
  chain  => 'INPUT',
  policy => 'ACCEPT',
  proto  => ['udp', 'tcp'],
  dport  => 8301,
}
```

#### Parameters

The following parameters are available in the `ferm::rule` defined type.

##### `chain`

Data type: `String[1]`

Configure the chain where we want to add the rule

##### `proto`

Data type: `Ferm::Protocols`

Which protocol do we want to match, typically UDP or TCP

##### `comment`

Data type: `String`

A comment that will be added to the ferm config and to ip{,6}tables

Default value: `$name`

##### `action`

Data type: `Optional[Ferm::Actions]`

Configure what we want to do with the packet (drop/accept/reject, can also be a target chain name)
Default value: undef
Allowed values: (RETURN|ACCEPT|DROP|REJECT|NOTRACK|LOG|MARK|DNAT|SNAT|MASQUERADE|REDIRECT|String[1])

Default value: ``undef``

##### `policy`

Data type: `Optional[Ferm::Policies]`

Configure what we want to do with the packet (drop/accept/reject, can also be a target chain name) [DEPRECATED]
Default value: undef
Allowed values: (RETURN|ACCEPT|DROP|REJECT|NOTRACK|LOG|MARK|DNAT|SNAT|MASQUERADE|REDIRECT|String[1])

Default value: ``undef``

##### `dport`

Data type: `Optional[Ferm::Port]`

The destination port, can be a single port number as integer or an Array of integers (which will then use the multiport matcher)

Default value: ``undef``

##### `sport`

Data type: `Optional[Ferm::Port]`

The source port, can be a single port number as integer or an Array of integers (which will then use the multiport matcher)

Default value: ``undef``

##### `saddr`

Data type: `Optional[Variant[Array, String[1]]]`

The source address we want to match

Default value: ``undef``

##### `daddr`

Data type: `Optional[Variant[Array, String[1]]]`

The destination address we want to match

Default value: ``undef``

##### `proto_options`

Data type: `Optional[String[1]]`

Optional parameters that will be passed to the protocol (for example to match specific ICMP types)

Default value: ``undef``

##### `interface`

Data type: `Optional[String[1]]`

an Optional interface where this rule should be applied

Default value: ``undef``

##### `ensure`

Data type: `Enum['absent','present']`

Set the rule to present or absent

Default value: `'present'`

##### `table`

Data type: `Ferm::Tables`

Select the target table (filter/raw/mangle/nat)
Default value: filter
Allowed values: (filter|raw|mangle|nat) (see Ferm::Tables type)

Default value: `'filter'`

## Data types

### `Ferm::Actions`

As you can also *jump* to other chains, each chain-name is also a valid action/target

Alias of `Variant[Enum['RETURN', 'ACCEPT', 'DROP', 'REJECT', 'NOTRACK', 'LOG', 'MARK', 'DNAT', 'SNAT', 'MASQUERADE', 'REDIRECT'], String[1]]`

### `Ferm::Policies`

a list of allowed policies for a chain

Alias of `Enum['ACCEPT', 'DROP']`

### `Ferm::Port`

allowed variants:
-----------------
+ single Integer port
+ Array of Integers (creates a multiport matcher)
+ ferm range port-spec (pair of colon-separated integer, assumes 0 if first is omitted)

Alias of `Variant[Stdlib::Port, Array[Stdlib::Port], Pattern['^\d*:\d+$']]`

### `Ferm::Protocols`

a list of allowed protocolls to match

Alias of `Variant[Enum['icmp', 'tcp', 'udp', 'udplite', 'icmpv6', 'esp', 'ah', 'sctp', 'mh', 'all'], Array[Enum['icmp', 'tcp', 'udp', 'udplite', 'icmpv6', 'esp', 'ah', 'sctp', 'mh', 'all']]]`

### `Ferm::Tables`

a list of available tables

Alias of `Enum['raw', 'mangle', 'nat', 'filter']`