nat: T2198: restructure DNAT template

Make the entire template more maintainable

1 files changed, 91 insertions, 55 deletions

diff --git a/data/templates/firewall/nftables-nat.tmpl b/data/templates/firewall/nftables-nat.tmpl
index 161ef27fb..01dcec19f 100644
--- a/data/templates/firewall/nftables-nat.tmpl
+++ b/data/templates/firewall/nftables-nat.tmpl
@@ -1,55 +1,91 @@
-#!/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 r.protocol == 'tcp_udp' %}

-  {# Special handling for protocol tcp_udp which is represented as two individual rules #}

-  add rule ip nat PREROUTING iifname "{{ r.interface_in }}" tcp dport { {{ r.dest_port }} } counter dnat to {{ r.translation_address }}{{ ":" + r.translation_port if r.translation_port }} comment "DST-NAT-{{ r.number }} tcp_udp"

-  add rule ip nat PREROUTING iifname "{{ r.interface_in }}" udp dport { {{ r.dest_port }} } counter dnat to {{ r.translation_address }}{{ ":" + r.translation_port if r.translation_port }} comment "DST-NAT-{{ r.number }} tcp_udp"

-{%   else %}

-  add rule ip nat PREROUTING iifname "{{ r.interface_in }}" {{ r.protocol }} dport { {{ r.dest_port }} } counter dnat to {{ r.translation_address }}{{ ":" + r.translation_port if r.translation_port }} comment "DST-NAT-{{ r.number }}"

-{%   endif %}

-{% endfor %}

-

-

-{% for r in source -%}

-{%   if r.log %}

-{%     if r.exclude %}

-{%       set value = 'EXCL' %}

-{%     elif r.translation_address == 'masquerade' %}

-{%       set value = 'MASQ' %}

-{%     endif %}

-  add rule ip nat POSTROUTING oifname "{{ r.interface_out }}" ip saddr {{ r.source_address }} counter log prefix "[NAT-SRC-{{ r.number }}-{{ value }}]" comment "SRC-NAT-{{ r.number }}"

-{%   endif %}

-

-{%   if r.exclude %}

-{%     set value = 'return' %}

-{%   elif r.translation_address == 'masquerade' %}

-{%     set value = 'masquerade' %}

-{%   else %}

-{%     set value = 'snat to ' + r.translation_address %}

-{%   endif %}

-  add rule ip nat POSTROUTING oifname "{{ r.interface_out }}" ip saddr {{ r.source_address }} counter {{ value }} comment "SRC-NAT-{{ r.number }}"

-{% endfor %}

+#!/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 -%}
+{%   set chain     = "PREROUTING" %}
+{%   set dst_addr  = "ip daddr " + r.dest_address if r.dest_address %}
+{%   set dst_port  = "dport { " + r.dest_port +" }" %}
+{%   set trns_addr = r.translation_address %}
+{%   set trns_port = ":" + r.translation_port if r.translation_port %}
+{%   set trns      = "dnat to " + trns_addr + trns_port if trns_port %}
+{%   set comment   = "DST-NAT-" + r.number %}
+{%   set iface     = "iifname " + 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      = "return" %}
+{%   endif %}
+
+
+{%   if r.protocol == 'tcp_udp' %}
+{#     Special handling for protocol tcp_udp which is represented as two individual rules #}
+{%     if log %}
+add rule ip nat {{ chain }} {{ iface }} tcp {{ dst_port }} counter log prefix "{{ log }}" comment "{{ comment }} tcp_udp"
+{%     endif %}
+add rule ip nat {{ chain }} {{ iface }} tcp {{ dst_port }} counter {{ trns }} comment {{ comment }}
+{%     if log %}
+add rule ip nat {{ chain }} {{ iface }} udp {{ dst_port }} counter log prefix "{{ log }}" comment "{{ comment }} tcp_udp"
+{%     endif %}
+add rule ip nat {{ chain }} {{ iface }} udp {{ dst_port }} counter {{ trns }} comment {{ comment }}
+{%   else %}
+
+{%     if log %}
+add rule ip nat {{ chain }} {{ iface }} {{ r.protocol }} counter log prefix "{{ log }}" comment {{ comment }}
+{%     endif %}
+add rule ip nat {{ chain }} {{ iface }} {{ dst_addr }} {{ r.protocol }} {{ dst_port }} counter {{ trns }} comment {{ comment }}
+{%   endif %}
+{% endfor %}
+
+
+{% for r in source -%}
+{%   if r.log %}
+{%     if r.exclude %}
+{%       set value = 'EXCL' %}
+{%     elif r.translation_address == 'masquerade' %}
+{%       set value = 'MASQ' %}
+{%     endif %}
+  add rule ip nat POSTROUTING oifname "{{ r.interface_out }}" ip saddr {{ r.source_address }} counter log prefix "[NAT-SRC-{{ r.number }}-{{ value }}]" comment "SRC-NAT-{{ r.number }}"
+{%   endif %}
+
+{%   if r.exclude %}
+{%     set value = 'return' %}
+{%   elif r.translation_address == 'masquerade' %}
+{%     set value = 'masquerade' %}
+{%   else %}
+{%     set value = 'snat to ' + r.translation_address %}
+{%   endif %}
+  add rule ip nat POSTROUTING oifname "{{ r.interface_out }}" ip saddr {{ r.source_address }} counter {{ value }} comment "SRC-NAT-{{ r.number }}"
+{% endfor %}
+