#!/usr/sbin/nft -f

{% macro nptv6_rule(rule,config, chain) %}

{%     set src_prefix  = "ip6 saddr " + config.source.prefix if config.source is defined and config.source.prefix is defined and config.source.prefix is not none  %}
{%     set dest_address  = "ip6 daddr " + config.destination.address if config.destination is defined and config.destination.address is defined and config.destination.address is not none %}

{%   if chain == "PREROUTING" %}
{%     set interface = " iifname \"" + config.inbound_interface + "\"" if config.inbound_interface is defined and config.inbound_interface != 'any' else '' %}
{%     if config.translation.address | is_ip_network %}
{#       support 1:1 network translation #}
{%       set dnat_type = "dnat prefix to " %}
{%     else   %}
{%       set dnat_type = "dnat to " %}
{%     endif %}
{%     set trns_address = dnat_type + config.translation.address if config.translation is defined and config.translation.address is defined and config.translation.address is not none  %}
{%   elif chain == "POSTROUTING" %}
{%     set interface = " oifname \"" + config.outbound_interface + "\"" if config.outbound_interface is defined and config.outbound_interface != 'any' else '' %}
{%     set trns_prefix = "snat prefix to " + config.translation.prefix if config.translation is defined and config.translation.prefix is defined and config.translation.prefix is not none %}
{%   endif %}
{%   set comment   = "NPT-NAT-" + rule %}
{%   if rule.log %}
{%     set base_log = "[NPT-DST-" + rule %}
{%     set log = base_log + "]" %}
{%   endif %}
{%   set output = "add rule ip6 nat " + chain + interface %}
{#   Count packets #}
{%     set output = output + " counter" %}

{#   Special handling of log option, we must repeat the entire rule before the #}
{#   NAT translation options are added, this is essential                      #}
{%   if log %}
{%     set log_output = output + " log prefix \"" + log + "\" comment \"" + comment + "\"" %}
{%   endif %}

{%   if src_prefix %}
{%     set output = output + " " + src_prefix %}
{%   endif %}


{%   if dest_address %}
{%     set output = output + " " + dest_address %}
{%   endif %}

{%   if trns_prefix %}
{%     set output = output + " " + trns_prefix %}
{%   endif %}

{%   if trns_address %}
{%     set output = output + " " + trns_address %}
{%   endif %}


{%   if comment %}
{%     set output = output + " comment \"" + comment + "\"" %}
{%   endif %}

{{ log_output if log_output }}
{{ output }}
{% endmacro %}

# Start with clean NAT table
flush table ip6 nat

{% if helper_functions == 'remove' %}
{# NAT if going to be disabled - remove rules and targets from nftables #}



{%   set base_command = "delete rule ip6 raw" %}

{{base_command}} PREROUTING handle {{ pre_ct_conntrack }}
{{base_command}} OUTPUT handle {{ out_ct_conntrack }}

delete chain ip6 raw NAT_CONNTRACK

{% elif helper_functions == 'add' %}
{# NAT if enabled - add targets to nftables #}
add chain ip6 raw NAT_CONNTRACK
add rule ip6 raw NAT_CONNTRACK counter accept

{%   set base_command = "add rule ip6 raw" %}


{{ base_command }} PREROUTING position {{ pre_ct_conntrack }} counter jump NAT_CONNTRACK
{{ base_command }} OUTPUT     position {{ out_ct_conntrack }} counter jump NAT_CONNTRACK

{% endif %}

#
# Destination NAT66 rules build up here
#
{% if destination is defined and destination.rule is defined and destination.rule is not none %}
{%   for rule, config in destination.rule.items() if config.disable is not defined %}
{{ nptv6_rule(rule, config, 'PREROUTING') }}
{%   endfor %}
{% endif %}

#
# Source NAT66 rules build up here
#
{% if source is defined and source.rule is defined and source.rule is not none %}
{%   for rule, config in source.rule.items() if config.disable is not defined %}
{{ nptv6_rule(rule, config, 'POSTROUTING') }}
{%   endfor %}
{% endif %}