#!/usr/sbin/nft -f

# Start with clean NAT table
flush table nat

{% if helper_functions == 'remove' %}
{# NAT if going to be disabled - remove rules and targets from nftables #}
delete rule ip raw PREROUTING handle {{ pre_ct_ignore }}
delete rule ip raw PREROUTING handle {{ pre_ct_conntrack }}
delete rule ip raw OUTPUT handle {{ out_ct_ignore }}
delete rule ip raw OUTPUT handle {{ out_ct_conntrack }}

delete chain ip raw NAT_CONNTRACK

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

add rule ip raw PREROUTING position {{ pre_ct_ignore }} counter jump VYATTA_CT_HELPER
add rule ip raw PREROUTING position {{ pre_ct_conntrack }} counter jump NAT_CONNTRACK
add rule ip raw OUTPUT position {{ out_ct_ignore }} counter jump VYATTA_CT_HELPER
add rule ip raw OUTPUT position {{ out_ct_conntrack }} counter jump NAT_CONNTRACK
{% endif %}

{% for r in destination if not r.disabled -%}
{%   set chain     = "PREROUTING" %}
{%   set dst_addr  = "ip daddr " + r.dest_address if r.dest_address %}
{%   set dst_port  = "dport { " + r.dest_port +" }" if r.dest_port %}
{%   set trns_addr = "dnat to " + r.translation_address %}
{%   set trns_port = ":" + r.translation_port if r.translation_port %}
{%   set comment   = "DST-NAT-" + r.number %}
{%   set iface     = r.interface_in %}

{%   if r.log %}
{%     if r.exclude %}
{%       set log = "[" + comment + "-EXCL]" %}
{%     elif r.translation_address == 'masquerade' %}
{%       set log = "[" + comment + "-MASQ]" %}
{%     else %}
{%       set log = "[" + comment + "]" %}
{%     endif %}
{%   endif %}

{%   if r.exclude %}
{#     rule has been marked as "exclude" thus we simply return here #}
{%     set trns_addr = "return" %}
{%     set trns_port = "" %}
{%   endif %}

{%   if r.protocol == 'tcp_udp' %}
{#     Special handling for protocol tcp_udp which is represented as two individual rules #}
{%     set comment = comment + " tcp_udp" %}
{%     if log %}

{%       set tcp_dst_port = "tcp " + dst_port if dst_port else "ip protocol tcp" %}
{%       set udp_dst_port = "udp " + dst_port if dst_port else "ip protocol udp" %}

add rule ip nat {{ chain }} iifname "{{ iface }}" {{ tcp_dst_port }} {{ dst_addr }} counter log prefix "{{ log }}" comment "{{ comment }}"
{%     endif %}
add rule ip nat {{ chain }} iifname "{{ iface }}" {{ tcp_dst_port }} {{ dst_addr }} counter {{ trns_addr }}{{ trns_port }} comment "{{ comment }}"
{%     if log %}
add rule ip nat {{ chain }} iifname "{{ iface }}" {{ udp_dst_port }} {{ dst_addr }} counter log prefix "{{ log }}" comment "{{ comment }}"
{%     endif %}
add rule ip nat {{ chain }} iifname "{{ iface }}" {{ udp_dst_port }} {{ dst_addr }} counter {{ trns_addr }}{{ trns_port }} comment "{{ comment }}"

{%   else %}
{%       set proto_dst_port = dst_port if dst_port else "ip protocol " + r.protocol %}
{%     if log %}
add rule ip nat {{ chain }} iifname "{{ iface }}" {{ proto_dst_port }} {{ dst_addr }} counter log prefix "{{ log }}" comment "{{ comment }}"
{%     endif %}
add rule ip nat {{ chain }} iifname "{{ iface }}" {{ proto_dst_port }} {{ dst_addr }} counter {{ trns_addr }}{{ trns_port }} comment "{{ comment }}"
{%   endif %}
{% endfor %}


{% for r in source if not r.disabled -%}
{%   set chain     = "POSTROUTING" %}
{%   set dst_addr  = "ip daddr " + r.dest_address if r.dest_address %}
{%   set dst_port  = "dport { " + r.dest_port +" }" if r.dest_port %}
{%   set trns_addr = "snat to " + r.translation_address %}
{%   set trns_port = ":" + r.translation_port if r.translation_port %}
{%   set comment   = "SRC-NAT-" + r.number %}
{%   set iface     = r.interface_out %}

{%   if r.log %}
{%     if r.exclude %}
{%       set log = "[" + comment + "-EXCL]" %}
{%     elif r.translation_address == 'masquerade' %}
{%       set log = "[" + comment + "-MASQ]" %}
{%     else %}
{%       set log = "[" + comment + "]" %}
{%     endif %}
{%   endif %}

{%   if r.exclude %}
{#     rule has been marked as "exclude" thus we simply return here #}
{%     set trns_addr = "return" %}
{%     set trns_port = "" %}
{%   endif %}

{%   if r.protocol == 'tcp_udp' %}
{#     Special handling for protocol tcp_udp which is represented as two individual rules #}
{%     set comment = comment + " tcp_udp" %}
{%     if log %}

{%       set tcp_dst_port = "tcp " + dst_port if dst_port else "ip protocol tcp" %}
{%       set udp_dst_port = "udp " + dst_port if dst_port else "ip protocol udp" %}

add rule ip nat {{ chain }} oifname "{{ iface }}" {{ tcp_dst_port }} {{ dst_addr }} counter log prefix "{{ log }}" comment "{{ comment }}"
{%     endif %}
add rule ip nat {{ chain }} oifname "{{ iface }}" {{ tcp_dst_port }} {{ dst_addr }} counter {{ trns_addr }}{{ trns_port }} comment "{{ comment }}"
{%     if log %}
add rule ip nat {{ chain }} oifname "{{ iface }}" {{ udp_dst_port }} {{ dst_addr }} counter log prefix "{{ log }}" comment "{{ comment }}"
{%     endif %}
add rule ip nat {{ chain }} oifname "{{ iface }}" {{ udp_dst_port }} {{ dst_addr }} counter {{ trns_addr }}{{ trns_port }} comment "{{ comment }}"

{%   else %}
{%       set proto_dst_port = dst_port if dst_port else "ip protocol " + r.protocol %}
{%     if log %}
add rule ip nat {{ chain }} oifname "{{ iface }}" {{ proto_dst_port }} {{ dst_addr }} counter log prefix "{{ log }}" comment "{{ comment }}"
{%     endif %}
add rule ip nat {{ chain }} oifname "{{ iface }}" {{ proto_dst_port }} {{ dst_addr }} counter {{ trns_addr }}{{ trns_port }} comment "{{ comment }}"
{%   endif %}
{% endfor %}