ffho-salt-public/nftables/nftables.conf.tmpl

#!/usr/sbin/nft -f
#
# /etc/nftables.conf - FFHO packet filter configuration
#
{%- set node_config = salt['pillar.get']('nodes:' ~ grains['id']) %}
{%- set nf_cc = node_config.get ('nftables', {}) %}
{%- set roles = node_config.get ('roles', []) %}
{%- set services = node_config.get ('services', []) %}

{%- set fw_policy = salt['pillar.get']('firewall:policy', {}) %}
{%- set acls = salt['pillar.get']('firewall:acls') %}
{%- set admin_access = salt['pillar.get']('firewall:admin_access') %}
{%- set ssh = salt['pillar.get']("firewall:ssh") %}

{%- set icinga2_queriers = salt['pillar.get']('monitoring:icinga2:queriers', []) %}
{%- set nms_list = salt['pillar.get']('globals:snmp:nms_list', []) %}

{%- set forward = salt['ffho_netfilter.generate_forward_policy'](fw_policy, roles, nf_cc) %}
{%- set nat_policy = salt['ffho_netfilter.generate_nat_policy'](roles, nf_cc) %}
{%- set urpf = salt['ffho_netfilter.generate_urpf_policy'](node_config['ifaces']) %}
{%- set allow_dhcp = salt['ffho_netfilter.allow_dhcp'](fw_policy, roles) %}

flush ruleset

table ip filter {
	set ibgp-peers {
		type ipv4_addr
		elements = {
			10.132.255.1,	# cr01.in.ffho.net
			10.132.255.2,	# cr02.in.ffho.net
			10.132.255.3,	# cr03.in.ffho.net
		}
	}

	chain input {
		type filter hook input priority 0; policy drop;
		iifname "lo" counter accept
		ip protocol icmp counter jump icmp_chain
		udp dport 0 counter drop
		tcp dport 7 counter drop comment "Ignore echo protocol queries"
		udp dport 4789 jump vxlan
		ct state invalid counter drop
		counter jump admin_access
		counter jump monitoring
		tcp dport 22 counter jump ssh
{%- if 'router' in roles %}
		ip daddr { 224.0.0.5, 224.0.0.6 } meta l4proto ospf accept
		tcp dport 179 counter jump bgp
{%- endif %}
		ct state related,established counter accept
		counter jump services
		limit rate 1/second burst 3 packets counter log prefix "nf input: "
		limit rate 1/second burst 3 packets counter reject with icmp type admin-prohibited
		counter drop
	}

	chain forward {
		type filter hook forward priority 0; policy {{ forward['policy'] }}; # {{ forward['policy_reason'] }}
{#- custom rules #}
{%- for rule in forward['rules'].get ('4', []) %}
		{{ rule }}
{%- endfor %}

{#- uRPF #}
{%- for iface_cfg in urpf  %}
  {%- if loop.first %}
		# uRPF
  {%- endif %}
  {%- for pfx in iface_cfg[4] %}
		iif {{ iface_cfg['iface'] }} ip saddr {{ pfx }} accept
  {%- endfor %}
		iif {{ iface_cfg['iface'] }} counter drop
{%- endfor %}

{%- if forward['policy'] == 'drop' %}
		limit rate 1/second burst 3 packets counter log prefix "nf forward: "
		limit rate 1/second burst 3 packets counter reject with icmp type admin-prohibited
{%- endif %}
	}

	chain icmp_chain {
		icmp type { echo-request, destination-unreachable, time-exceeded } counter accept
	}

	chain admin_access {
{%- for pfx in admin_access[4].keys()|sort %}
  {%- set comment = admin_access[4][pfx] %}
		ip saddr {{ pfx }} counter accept comment "{{ comment }}"
{%- endfor %}
	}

{%- if 'router' in roles %}
	chain bgp {
		ip saddr @ibgp-peers counter accept comment "iBGP peers"
		# TODO: Add external BGP peers, if any
	}
{%- endif %}

	chain monitoring {
{%- for ip in icinga2_queriers if not ":" in ip %}
		ip saddr {{ ip }} counter accept comment "Icinga2"
{%- endfor %}
{%- for ip in nms_list if not ":" in ip %}
		ip saddr {{ ip }} udp dport 161 counter accept comment "NMS"
{%- endfor %}
	}

	chain ssh {
{%- for pfx in ssh[4].keys()|sort %}
  {%- set comment = ssh[4][pfx] %}
		ip saddr {{ pfx }} counter accept comment "{{ comment }}"
{%- endfor %}
	}

	chain services {
{%- if allow_dhcp %}
		udp dport 67 counter accept comment "DHCP"
{%- endif %}

{%- for rule in salt['ffho_netfilter.generate_service_rules'](services, acls, 4) %}
		{{ rule }}
{%- endfor %}
	}

	chain vxlan {
{%- for iface in node_config['ifaces'] if node_config['ifaces'][iface].get ('batman_connect_sites') %}
		iif {{ iface }} accept
{%- endfor %}
		counter drop
	}

	chain log-drop {
		limit rate 1/second burst 3 packets counter log prefix "netfilter: "
		counter drop
	}

	chain log-reject {
		limit rate 1/second burst 3 packets counter log prefix "netfilter: "
		limit rate 1/second burst 3 packets counter reject with icmp type admin-prohibited
		counter drop
	}
}

table ip6 filter {
	set ibgp-peers {
		type ipv6_addr
		elements = {
			2a03:2260:2342:ffff::1,	# cr01.in.ffho.net
			2a03:2260:2342:ffff::2,	# cr02.in.ffho.net
			2a03:2260:2342:ffff::3,	# cr03.in.ffho.net
		}
	}

	chain input {
		type filter hook input priority 0; policy drop;
		iifname "lo" counter accept
		ip6 nexthdr icmpv6 counter jump icmp_chain
		tcp dport 7 counter drop comment "Ignore echo protocol queries"
		udp dport 4789 jump vxlan
		ct state invalid counter drop comment "Drop packets that do not make sense."
		counter jump admin_access
		counter jump monitoring
		tcp dport 22 counter jump ssh
{%- if 'router' in roles %}
		ip6 saddr fe80::/64 ip6 daddr { fe80::/10, ff02::5, ff02::6 } meta l4proto ospf accept
		tcp dport 179 counter jump bgp
{%- endif %}
		ct state related,established counter accept comment "Allow established connections."
		counter jump services
		limit rate 1/second burst 3 packets counter log prefix "netfilter: "
		limit rate 1/second burst 3 packets counter reject with icmpv6 type admin-prohibited
		counter drop
	}

	chain forward {
		type filter hook forward priority 0; policy {{ forward['policy'] }}; # {{ forward['policy_reason'] }}
{#- custom rules #}
{%- for rule in forward['rules'].get ('6', []) %}
		{{ rule }}
{%- endfor %}

{#- uRPF #}
{%- for iface_cfg in urpf  %}
  {%- if loop.first %}
		# uRPF
  {%- endif %}
  {%- for pfx in iface_cfg[6] %}
		iif {{ iface_cfg['iface'] }} ip6 saddr {{ pfx }} accept
  {%- endfor %}
		iif {{ iface_cfg['iface'] }} counter drop
{%- endfor %}

{%- if forward['policy'] == 'drop' %}
		limit rate 1/second burst 3 packets counter log prefix "nf forward: "
		limit rate 1/second burst 3 packets counter reject with icmp type admin-prohibited
{%- endif %}
	}

	chain icmp_chain {
		icmpv6 type { destination-unreachable, packet-too-big, time-exceeded, parameter-problem, echo-request, echo-reply } counter accept
		icmpv6 type { nd-router-solicit, nd-router-advert, nd-neighbor-solicit, nd-neighbor-advert, ind-neighbor-solicit, ind-neighbor-advert } ip6 hoplimit 255 counter accept
	}

	chain admin_access {
{%- for pfx in admin_access[6].keys()|sort %}
  {%- set comment = admin_access[6][pfx] %}
		ip6 saddr {{ pfx }} counter accept comment "{{ comment }}"
{%- endfor %}
	}

{%- if 'router' in roles %}
	chain bgp {
		ip6 saddr @ibgp-peers counter accept comment "iBGP peers"
		# TODO: Add external BGP peers, if any
	}
{%- endif %}

	chain monitoring {
{%- for ip in icinga2_queriers if ":" in ip %}
		ip6 saddr {{ ip }} counter accept comment "Icinga2"
{%- endfor %}
{%- for ip in nms_list if ":" in ip %}
		ip6 saddr {{ ip }} udp dport 161 counter accept comment "NMS"
{%- endfor %}
	}

	chain ssh {
{%- for pfx in ssh[6].keys()|sort %}
  {%- set comment = ssh[6][pfx] %}
		ip6 saddr {{ pfx }} counter accept comment "{{ comment }}"
{%- endfor %}
	}

	chain services {
{%- for rule in salt['ffho_netfilter.generate_service_rules'](services, acls, 6) %}
		{{ rule }}
{%- endfor %}
	}

	chain vxlan {
{%- for iface in node_config['ifaces'] if node_config['ifaces'][iface].get ('batman_connect_sites') %}
		iif {{ iface }} accept
{%- endfor %}
		counter drop
	}

	chain log-drop {
		limit rate 1/second burst 3 packets counter log prefix "netfilter: "
		counter drop
	}

	chain log-reject {
		limit rate 1/second burst 3 packets counter log prefix "netfilter: "
		limit rate 1/second burst 3 packets counter reject with icmpv6 type admin-prohibited
		counter drop
	}
}

{#-
 # NAT
 #}
{%- for af in [ 4, 6 ] %}
  {%- if nat_policy[af] %}
    {%- set af_name = "ip" if af == 4 else "ip6" %}
table {{ af_name }} nat {
    {%- for chain in ['output', 'prerouting', 'postrouting'] if chain in nat_policy[af] %}
	chain {{ chain }} {
		type nat hook {{ chain }} priority 0; policy accept;
      {%- for rule in nat_policy[af][chain] %}
		{{ rule }}
      {%- endfor %}
	}
    {%- endfor %}
}
  {%- endif %}
{%- endfor %}