#!/usr/sbin/nft -f

{% macro nat_rule(rule, config, chain) %}
{% set comment  = '' %}
{% set base_log = '' %}

{% if chain is vyos_defined('PREROUTING') %}
{%     set comment   = 'STATIC-NAT-' ~ rule %}
{%     set base_log  = '[NAT-DST-' ~ rule %}
{%     set interface = ' iifname "' ~ config.inbound_interface ~ '"' if config.inbound_interface is vyos_defined and config.inbound_interface is not vyos_defined('any') else '' %}
{%     if config.translation.address is vyos_defined %}
{#         support 1:1 network translation #}
{%         if config.translation.address | is_ip_network %}
{%             set trns_addr = 'dnat ip prefix to ip daddr map { ' ~ config.destination.address ~ ' : ' ~ config.translation.address ~ ' }' %}
{#             we can now clear out the dst_addr part as it's already covered in aboves map #}
{%         else %}
{%             set dst_addr  = 'ip daddr ' ~ config.destination.address if config.destination.address is vyos_defined %}
{%             set trns_addr = 'dnat to ' ~ config.translation.address %}
{%         endif %}
{%     endif %}
{% elif chain is vyos_defined('POSTROUTING') %}
{%     set comment   = 'STATIC-NAT-' ~ rule %}
{%     set base_log  = '[NAT-SRC-' ~ rule %}
{%     set interface = ' oifname "' ~ config.inbound_interface ~ '"' if config.inbound_interface is vyos_defined and config.inbound_interface is not vyos_defined('any') else '' %}
{%     if config.translation.address is vyos_defined %}
{#         support 1:1 network translation #}
{%         if config.translation.address | is_ip_network %}
{%             set trns_addr = 'snat ip prefix to ip saddr map { ' ~ config.translation.address ~ ' : ' ~ config.destination.address ~ ' }' %}
{#             we can now clear out the src_addr part as it's already covered in aboves map #}
{%         else %}
{%             set src_addr  = 'ip saddr ' ~ config.translation.address if config.translation.address is vyos_defined %}
{%             set trns_addr = 'snat to ' ~ config.destination.address %}
{%         endif %}
{%     endif %}
{% endif %}

{% if config.exclude is vyos_defined %}
{#     rule has been marked as 'exclude' thus we simply return here #}
{%     set trns_addr = 'return' %}
{%     set trns_port = '' %}
{% endif %}

{% if config.translation.options is vyos_defined %}
{%     if config.translation.options.address_mapping is vyos_defined('persistent') %}
{%         set trns_opts_addr  = 'persistent' %}
{%     endif %}
{%     if config.translation.options.port_mapping is vyos_defined('random') %}
{%         set trns_opts_port  = 'random' %}
{%     elif config.translation.options.port_mapping is vyos_defined('fully-random') %}
{%         set trns_opts_port  = 'fully-random' %}
{%     endif %}
{% endif %}

{% if trns_opts_addr is vyos_defined and trns_opts_port is vyos_defined %}
{%     set trns_opts  = trns_opts_addr ~ ',' ~ trns_opts_port %}
{% elif trns_opts_addr is vyos_defined %}
{%     set trns_opts  = trns_opts_addr %}
{% elif trns_opts_port is vyos_defined %}
{%     set trns_opts  = trns_opts_port %}
{% endif %}

{% set output = 'add rule ip vyos_static_nat ' ~ chain ~ interface %}

{% if dst_addr is vyos_defined %}
{%     set output = output ~ ' ' ~ dst_addr %}
{% endif %}
{% if src_addr is vyos_defined %}
{%     set output = output ~ ' ' ~ src_addr %}
{% endif %}

{# 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 is vyos_defined %}
{%     set log_output = output ~ ' log prefix "' ~ log ~ '" comment "' ~ comment ~ '"' %}
{% endif %}
{% if trns_addr is vyos_defined %}
{%     set output = output ~ ' ' ~ trns_addr %}
{% endif %}

{% if trns_opts is vyos_defined %}
{%     set output = output ~ ' ' ~ trns_opts %}
{% endif %}
{% if comment is vyos_defined %}
{%     set output = output ~ ' comment "' ~ comment ~ '"' %}
{% endif %}
{{ log_output if log_output is vyos_defined }}
{{ output }}
{% endmacro %}

# Start with clean STATIC NAT chains
flush chain ip vyos_static_nat PREROUTING
flush chain ip vyos_static_nat POSTROUTING

{# NAT if enabled - add targets to nftables #}

#
# Destination NAT rules build up here
#
add rule ip vyos_static_nat PREROUTING counter jump VYOS_PRE_DNAT_HOOK
{% if static.rule is vyos_defined %}
{%     for rule, config in static.rule.items() if config.disable is not vyos_defined %}
{{ nat_rule(rule, config, 'PREROUTING') }}
{%     endfor %}
{% endif %}
#
# Source NAT rules build up here
#
add rule ip vyos_static_nat POSTROUTING counter jump VYOS_PRE_SNAT_HOOK
{% if static.rule is vyos_defined %}
{%     for rule, config in static.rule.items() if config.disable is not vyos_defined %}
{{ nat_rule(rule, config, 'POSTROUTING') }}
{%     endfor %}
{% endif %}