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README.md

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cfnetwork

Description

The module exclusively configures system network interfaces, related sysctl items and system firewall. The module is designed to be used with Hiera-like data providers.

Concept

Each network interface has a unique name. This identifier is used in firewall port definition to specify the interface to apply the rule.

There are predefined interface names:

  • 'local' - assign rule to loopback interface
  • 'any' - assign rule to all interfaces, unless src or dst is specified. See below.

Each firewall rule name has format of "interface:service". Optionally, additional tag can be specified like "interface:service:tag". Such format allows resource to be defined multiple times with no name clash and no need for explicit virtual resource processing.

!!! ALL CONNECTIONS ARE BLOCKED BY DEFAULT, EVEN LOCAL !!!

The module is designed without actual firewall implementation to serve as abstract API for plug&play firewall rules definition. For example:

  • this module automatically enables DNS clients and services, if '$local' or '$serve' is configured
  • cfauth module automatically enables incoming SSH connections on configured ports from admin hosts
  • cfsystem module automatically defines rules for NTP, APT repositories, APT cache, puppet, etc.
  • [cfdb] module allows outgoing database connections for particular users.

Examples:

    class { 'cfnetwork':
      main => {
        device  => 'eth0',
        address => [
            '128.0.0.2/24',
            '128.0.0.3/24',
            '128.0.0.4/24',
        ],
        gateway => '128.0.0.1',
      },
      dns => ['8.8.8.8', '8.8.4.4'],
      is_router => true,
    }
    cfnetwork::iface { 'dmz1':
        device  => 'eth2',
        address => '128.0.1.2/24',
        # no gateway
    }
    cfnetwork::iface { 'dmz2':
        device  => 'eth3',
        address => '128.0.2.2/24',
        # no gateway
    }
    cfnetwork::describe_service { myservice':
        server => ['tcp/123', 'udp/234']
    }
    cfnetwork::describe_service { myhttp':
        server => ['tcp/80', 'tcp/443']
    }
    # allow incoming for myservice on auto-detected dmz1 and dmz2 ifaces
    # note: still, please consider using explicit ifaces
    cfnetwork::service_port { 'any:myservice':
        src => [
            '128.0.1.0/24',
            '128.0.2.0/24',
            'ipset:myclients',
        ]
    }
    # allow client request on main interface
    cfnetwork::client_port { 'main:myhttp:tag1': }
    # duplicate, no worry
    cfnetwork::client_port { 'main:myhttp:tag2': }
    # allow client request on dmz2
    cfnetwork::client_port { 'dmz2:myhttp': }
    # Allow clients from dmz1 to dmz2
    cfnetwork::router_port { 'dmz1/dmz2:myhttp': }
    # DNAT external to dmz2
    cfnetwork::dnat_port { 'main/dmz2:myhttp':
        to_dst => 'dmz2server',
    }
    cfnetwork::ipset { 'myclients':
        addr => [
            '128.0.3.0/24',
        ]
    }
    cfnetwork::ipset { 'otherset':
        addr => [
            '128.0.4.0/24',
            'ipset:myclients',
        ]
    }

The same using Hiera:

    # someconfig.yaml
    classes:
        - cfnetwork
    cfnetwork::main:
        device: eth0
        address:
            - '128.0.0.2/24'
            - '128.0.0.3/24'
            - '128.0.0.4/24'
        gateway: '128.0.0.1'
    cfnetwork::dns:
        - '8.8.8.8'
        - '8.8.4.4'
    cfnetwork::is_router: true
    cfnetwork::ifaces:
        dmz1:
            device: eth1
            address: '128.0.1.1/24'
        dmz2:
            device: eth2
            address: '128.0.2.1/24'
    cfnetwork::describe_services:
        myservice:
            server:
                - 'tcp/123'
                - 'udp/234'
        myhttp: { server: [ 'tcp/80', 'tcp/443' ] }
    cfnetwork::service_ports:
        'any:myservice':
            src:
                - '128.0.1.0/24'
                - '128.0.2.0/24'
                - 'ipset:myclients'
    cfnetwork::client_ports:
        'main:myhttp:tag1': {}
        'main:myhttp:tag2': {}
        'dmz2:myhttp': {}
    cfnetwork::router_ports
        'dmz1/dmz2:myhttp': {}
    cfnetwork::dnat_ports:
        'main/dmz2:myhttp': {}
    cfnetwork::ipsets:
        myclients:
            addr:
                - '128.0.3.0/24'
        otherset:
            addr:
                - '128.0.4.0/24'
                - 'ipset:myclients'

'any' interface matching rules

If client port has 'src' property set then rule is applied only to matching interfaces. If server port has 'dst' property set then rule is applied only to matching interfaces.

A matching interface is one of:

  • 'address' and 'extra_addresses' of interface subnets matches 'dst'
  • otherwise default interface is used, which is 'gateway' property defined

Public interface notes

  • All not routable private networks will be dropped for incoming and outgoing packets
  • Automatic SNAT to address enabled for all valid destinations with unroutable source address
  • Default policy is DROP. For private interfaces default policy is REJECT

ipset notes

  • Main name pattern: [a-z][a-z0-9_]
  • Referred as "ipset:<main_name' (e.g. ipset:admins)
  • Allowed in any src/dst/to_dst of port types
  • Allowed in addr of other ipsets
  • Additional entries can be defined with partial definition:
    • Partial name pattern: <main_name>:[a-z][a-z0-9_]
    • It's not allowed to refer to partial names
    • Note: type attribute must match the main definition

Dependency on configured firewall

Please depend on Anchor['cfnetwork:firewall'], if you need new firewal configuration before some processing.

Technical Support

Setup

Up to date installation instructions are available in Puppet Forge: https://forge.puppet.com/codingfuture/cfnetwork

Please use librarian-puppet or cfpuppetserver module to deal with dependencies.

There is a known r10k issue RK-3 which prevents automatic dependencies of dependencies installation.

Examples

Please check codingufuture/puppet-test for example of a complete infrastructure configuration and Vagrant provisioning.

Implicitly created resources

cfnetwork::ipsets:
    blacklist:
        type: net
        dynamic: true
    whitelist:
        type: net
        dynamic: true
    localnet:
        type: net
        addr:
            - 10.0.0.0/8
            - 172.16.0.0/12
            - 192.168.0.0/16
            - 'fd00::/8'
cfnetwork::describe_services:
    'dns':
        server: [ 'tcp/53', 'udp/53' ]
        client: 'any'
    'http':
        server: [ 'tcp/80' ]
        client: 'any'
    'https':
        server: [ 'tcp/443' ]
        client: 'any'
    'cfhttp':
        server: [ 'tcp/80', 'tcp/443' ]
        client: 'any'
    'alltcp':
        server: 'tcp/1:65535'
        client: 'any'
        comment: "Use to open all TCP ports (e.g. for local)"
    'alludp':
        server: 'udp/1:65535'
        client: 'any'
        comment: "Use to open all UDP ports (e.g. for local)"
    'allports':
        server: [ 'udp/1:65535', 'tcp/1:65535']
        client: 'any'
        comment: "Use to open all TCP and UDP ports (e.g. for local)"
cfnetwork::service_ports:
    'local:dns': {}
        comment: 'only in $serve or $local mode'
    "${cfnetwork::service_face}:dns":
        comment: 'only in $serve mode'
cfnetwork::client_ports:
    'any:dns:dnsmasq':
        user: 'dnsmasq'
        comment: 'only in $serve or $local mode'
    'any:dns:cfnetwork':
        dst: $cfnetwork::dns
        comment: 'unless in $serve or $local mode'
    'any:dns:cfnetwork':
        comment: 'only if no DNS servers are configured'
    '{iface}:dhcp:cfnetwork':
        comment: "for IPv4 ifaces with method=dhcp"
    '{iface}:dhcpv6:cfnetwork':
        comment: "for IPv6 ifaces with method=dhcp"
cfnetwork::router_ports:
    # for each cfnetwork::dnat_port
anchor:
    'cfnetwork:firewall'

Classes and resources types

cfnetwork class

  • main Main network interface configuration, see cfnetwork::iface for details. Can be defined separately.
  • dns DNS server list. Can be defined directly with one of cfnetwork::iface. Special values: - '$local' - Setup own DNS cache - '$serve' - Same as '$recure', but also serve clients on $service_face
  • 'ifaces' Create cfnetwork::iface resources, if set
  • 'describe_services' Create cfnetwork::describe_services resources, if set
  • 'service_ports' Create cfnetwork::service_port resources, if set
  • 'client_ports' Create cfnetwork::client_port resources, if set
  • 'dnat_ports' Create cfnetwork::dnat_port resources, if set
  • 'router_ports' Create cfnetwork::router_port resources, if set
  • 'is_router' = false If true, enables packet forwarding and other related sysctl
  • 'optimize_10gbe' = false If true, optimizes network stack for 10+ Gbit network
  • 'firewall_provider' = 'auto' Module name, implementing fireall provider. Its value is a soft dependency. 'cffirehol' is used by default for Linux
  • 'export_resources' = true If true, resources are exported to PuppetDB as well
  • service_face = 'any' - the interface to listen for client of configured services
  • hosts = undef - arbitrary definition of custom /etc/hosts entries based on host type
  • hosts_locality = 'localtion' - either 'location' or 'pool' for static hosts selection
  • prefer_ipv4 = true - prefer IPv4 address resolution over IPv6
  • dnnsec = on - control systemd-resolved DNSSEC option

cfnetwork::iface type

  • device = $title - system interface device name, e.g. 'eth0'
  • method = 'static' - address setup method ('static' of 'dhcp'). Please avoid DHCP as possible. Note: it is allowed to specify 'net/prefix' address as firewall hint for private interfaces
  • address - list of IPv4 and IPv6 addresses with /netprefix
    • (string)
    • (array)
  • routes - additional routes, if any
    • (string) - maps to network in hash below
    • (hash)
      • network - network address to route
      • via - gateway to use, if any
      • metric - metric to set, if any
  • gateway - default gateway to setup. Only one iface must have one.
    • (string) either IPv4 or IPv6 address
    • (array) one IPv4 and one IPv6 address
  • dns_servers - DNS servers to use. Only one iface should have one.
  • domain - DNS search domain, auto-detect by default
  • Bridge setup:
    • bridge_ports - Indicates a bridge device. List of participating ports.
    • bridge_stp - enabled STP, if set
    • bridge_fd - forwarding delay
  • Bonding setup:
    • bond_slaves - slave device list
    • bond_primary - primary slave
    • bond_mode - bonding mode, see modinfo bonding
    • bond_miimon = MII monitoring interval, see modinfo bonding
  • preup list of arbitrary commands to execute before bringing the interface up (not recommended, prefer up)
  • up list of arbitrary commands to execute after interface is up
  • down list of arbitrary commands to execute before interface goes down
  • postdown list of arbitrary commands to execute after interface gets down
  • ipv6 = false control IPv6 support on the interface
    • false - disable IPv6
    • true - enable IPv6
    • 'auto' - enable IPv6, if explicitly configured
    • 'only' - enable IPv6 and disable IPv4
  • force_public - firewall-specific. Force mark the interface as public, even if it has address from private range, what is useful in cloud environments with suboptimal NAT.
  • debian_template = 'cfnetwork/debian_iface.epp' - supply own template for non-standard interface setup
  • custom_args - provide custom arguments to custom $debian_template

cfnetwork::ipset type

Define ipset item.

  • Title:
    • Main name: [a-z][a-z0-9_]* (e.g. "blacklist")
    • Partial additions to the main list: <main_name>:[a-z][a-z0-9_]* (e.g. "blacklist:attackers", "blacklist:spam")
  • $addr - mixes list of IPv4 & IPv6 addresses and other ipsets in form ipset:<main_name>
  • $type = 'net' - either ip or net. See man ipset
  • $dynamic = false - notify firewall that additional addresses can be added dynamically (e.g. dynamic list of attackers)
  • $comment = undef - arbitrary comment

cfnetwork::describe_service type

Describe service to use in firewall rules.

  • Title: <service>
  • server - list of server-side ports in format "protocol/port", example: 'tcp/80', 'udp/53'
  • client = 'default' - list of client-side ports, 'default' - firewall-specific (all ports or 1024-65535)

cfnetwork::client_port type

Define allowed outgoing connection for on .

  • Title: <iface>:<service>[:<tag>]
  • src - list of allowed source addresses, if any
  • dst - list of allowed destination addresses, if any
  • user - list of allowed system user names
  • group - list of allowed system group names
  • comment - arbitrary comment

cfnetwork::service_port type

Define allowed incoming connection for on .

  • Title: <iface>:<service>[:<tag>]
  • src - list of allowed source addresses, if any
  • dst - list of allowed destination addresses, if any
  • comment - arbitrary comment

cfnetwork::router_port type

Define allowed routing connection from to for .

  • Title: <iface>/<outface>:<service>[:<tag>]
  • src - list of allowed source addresses, if any
  • dst - list of allowed destination addresses, if any
  • comment - arbitrary comment

cfnetwork::dnat_port type

Destination Network Address Translation to for . Note: implicit cfnetwork::route_port is defined - no need to define one manually.

  • Title: <iface>/<outface>:<service>[:<tag>]
  • src - list of allowed source addresses, if any
  • dst - list of allowed destination addresses, if any
  • to_dst - DNAT to specific address(s)
  • to_port - (int) re-assign port, if needed
  • comment - arbitrary comment

cfnetwork::dnsmasq class

Tune automatically installed dnsmasq, if $local or $serve.

  • $upstream = ['8.8.8.8', '8.8.4.4'] - upstream servers, Public Google DNS by default
  • $dnssec = true - if true, enable DNSSEC validation on dnsmasq
  • $memlimit = '8M' - systemd memory limit for dnsmasq service
  • $custom_config = '' - any arbitrary text to include in dnsmasq.conf

cfnetwork::sysctl class

Self-explanatory sysctl settings with their defaults, unless specially noted:

  • $enable_bridge_filter = !$::cfnetwork::is_router Only if false, loads bridge module and disable netfilter calls on bridges. Use routing instead of bridges, if you really need to do filtering or enable it. After enabling, you will need to cleanup sysctl.conf and setup values manually.
  • $rp_filter = 1
  • $netdev_max_backlog = 30000 if $cfnetwork::optimize_10gbe else 2000
  • $tcp_fin_timeout = 3 Note: it can be too aggressive
  • $tcp_keepalive_time = 300
  • $tcp_keepalive_probes = 3
  • $tcp_keepalive_intvl = 15
  • $tcp_max_syn_backlog = 4096
  • $tcp_no_metrics_save = 1
  • $tcp_rfc1337 = 1
  • $tcp_sack = 1
  • $tcp_slow_start_after_idle = 0
  • $tcp_synack_retries = 2
  • $tcp_syncookies = 1
  • $tcp_timestamps = 1
  • $tcp_tw_recycle = 1
  • $tcp_tw_reuse = 1
  • $tcp_window_scaling = 1
  • $file_max = 256 per every 4MB of RAM
  • $somaxconn = 2048 per every 1GB of RAM
  • $ip_local_port_range = '2000 65535'
  • $rmem_max = 212992 Note: it does not apply to TCP
  • $wmem_max = 212992 Note: it does not apply to TCP
  • $rmem_default = $rmem_max
  • $wmem_default = $wmem_max
  • $tcp_rmem_max = 67108864 if $cfnetwork::optimize_10gbe else 16777216
  • $tcp_wmem_max = 67108864 if $cfnetwork::optimize_10gbe else 16777216
  • $tcp_rmem_default = $tcp_rmem_max / 128 Please note, you have to setup manually, if $tcp_rmem_max is set
  • $tcp_wmem_default = $tcp_wmem_max / 128 Please note, you have to setup manually, if $tcp_wmem_max is set
  • $nf_conntrack_max = undef Note: recent kernels do good autoconfig
  • $nf_conntrack_expect_max = undef Note: recent kernels do good autoconfig
  • $nf_conntrack_generic_timeout = 600
  • $nf_conntrack_tcp_timeout_syn_sent = 20 Note: it can be too aggressive
  • $nf_conntrack_tcp_timeout_syn_recv = 10 Note: it can be too aggressive
  • $nf_conntrack_tcp_timeout_established = 1200 Note: it can be too aggressive
  • $nf_conntrack_tcp_timeout_last_ack = 5 Note: it can be too aggressive
  • $nf_conntrack_tcp_timeout_time_wait = 3 Note: it can be too aggressive
  • $nf_conntrack_tcp_loose = 0 Note: you don't want to set 1 with pedantic firewall
  • $nf_conntrack_tcp_be_liberal = 0 Note: you don't want to set 1 with pedantic firewall
  • $nf_conntrack_tcp_max_retrans = 3 Note: it can be too aggressive
  • $nf_conntrack_udp_timeout = 30 Note: it can be too aggressive
  • $nf_conntrack_udp_timeout_stream = 60 Note: it can be too aggressive
  • $nf_conntrack_icmp_timeout = 30

Public API

  • Cfnetwork::Bindaddress - type alias for bind address name
  • Cfnetwork::Ifacename - type alias for interface name
  • Cfnetwork::Port - type alias for network port Integer
  • cfnetwork::bind_address(arg) - get bind address for specified arg, where:
    • 'iface' - first address of Cfnetwork::Iface[iface] resource
    • 'iface:N' - address #N of Cfnetwork::Iface[iface] resource
  • cfnetwork::fw_face(arg) - extract firewall interface name from Cfnetwork::Bindaddress