algo/roles/vpn/templates/rules.v4.j2

*mangle
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
{% if max_mss is defined %}
-A FORWARD -s {{ vpn_network }} -p tcp -m tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss {{ max_mss }}
{% endif %}
COMMIT
*nat
:PREROUTING ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
-A POSTROUTING -s {{ vpn_network }} -m policy --pol none --dir out -j MASQUERADE
COMMIT
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -i lo -j ACCEPT
-A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p esp -j ACCEPT
-A INPUT -p ah -j ACCEPT
# rate limit ICMP traffic per source
-A INPUT -p icmp --icmp-type echo-request -m hashlimit --hashlimit-upto 5/s --hashlimit-mode srcip --hashlimit-srcmask 32 --hashlimit-name icmp-echo-drop -j DROP
-A INPUT -p udp -m multiport --dports 500,4500 -j ACCEPT
-A INPUT -p tcp --dport 22 -m conntrack --ctstate NEW -j ACCEPT
-A INPUT -p ipencap -m policy --dir in --pol ipsec --proto esp -j ACCEPT
# TODO:
# The IP of the resolver should be bound to a DUMMY interface.
# DUMMY interfaces are the proper way to install IPs without assigning them any
# particular virtual (tun,tap,...) or physical (ethernet) interface.
-A INPUT -d {{ local_service_ip }} -p udp --dport 53 -j ACCEPT
-A INPUT -d {{ local_service_ip }} -p tcp -m multiport --dport 8080,8118 -j ACCEPT
{% if BetweenClients_DROP is defined and BetweenClients_DROP == "Y" %}
-A FORWARD -s {{ vpn_network }} -d {{ vpn_network }} -j DROP
{% endif %}
-A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -p tcp --dport 445 -j DROP
-A FORWARD -p udp -m multiport --ports 137,138 -j DROP
-A FORWARD -p tcp -m multiport --ports 137,139 -j DROP
-A FORWARD -m conntrack --ctstate NEW -s {{ vpn_network }} -m policy --pol ipsec --dir in -j ACCEPT
COMMIT