vps/roles/nftables/templates/nftables.conf

#!/usr/sbin/nft -f

flush ruleset

# Forward Syncthing relay traffic from port {{ ports['syncthing_relaysrv'] }} to 22067
table inet nat {
    chain prerouting {
        type nat hook prerouting priority dstnat;
        iif eth0 tcp dport {{ ports['syncthing_relaysrv'] }} redirect to :22067
    }
}

table inet filter {
	chain input {
		type filter hook input priority 0; policy drop;

		iif lo accept
		
		ct state invalid drop
		ct state { established, related } accept
	
		# Allow ICMP
		meta l4proto icmp limit rate 1/second accept
		meta l4proto ipv6-icmp limit rate 1/second accept

		# HTTP/S
		tcp dport { http, https } limit rate 5/second accept

		# SSH
		tcp dport 995 limit rate 15/minute accept

		# Syncthing
		tcp dport { {{ ports['syncthing_tcp'] }}, 22067 } limit rate 5/second accept
		udp dport {{ ports['syncthing_udp'] }} limit rate 5/second accept

		# Coturn
		tcp dport { {{ ports['coturn_listening'] }}, {{ ports['coturn_tls_listening'] }} } limit rate 5/second accept
		udp dport { {{ ports['coturn_listening'] }}, {{ ports['coturn_tls_listening'] }}, {{ ports['coturn_relay_min'] }}-{{ ports['coturn_relay_max'] }} } limit rate 5/second accept

	}

	chain forward {
		type filter hook forward priority 0; policy accept;
	}
	
	chain output {
		type filter hook output priority 0; policy accept;
	}
}