From 682bfd2c869acbf9f7c6dc681e28ca703c290d7f Mon Sep 17 00:00:00 2001 From: Christian Poessinger Date: Fri, 15 May 2020 21:43:39 +0200 Subject: nat: T2198: restructure DNAT template Make the entire template more maintainable --- data/templates/firewall/nftables-nat.tmpl | 146 +++++++++++++++++++----------- 1 file changed, 91 insertions(+), 55 deletions(-) (limited to 'data/templates/firewall') 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 %} + -- cgit v1.2.3