From b047855b80754d78cab4d3161ad0e97c21f479bc Mon Sep 17 00:00:00 2001 From: jack9603301 Date: Mon, 30 Nov 2020 20:03:00 +0800 Subject: nptv6: T2518: Initial support for nat66 (NPT) --- src/conf_mode/nat66.py | 221 +++++++++++++++++++++++++++++++++++++ src/migration-scripts/nat66/0-to-1 | 76 +++++++++++++ src/systemd/ndppd.service | 15 +++ 3 files changed, 312 insertions(+) create mode 100755 src/conf_mode/nat66.py create mode 100755 src/migration-scripts/nat66/0-to-1 create mode 100644 src/systemd/ndppd.service (limited to 'src') diff --git a/src/conf_mode/nat66.py b/src/conf_mode/nat66.py new file mode 100755 index 000000000..fdfffe335 --- /dev/null +++ b/src/conf_mode/nat66.py @@ -0,0 +1,221 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2020 VyOS maintainers and contributors +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License version 2 or later as +# published by the Free Software Foundation. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +import jmespath +import json +import os + +from sys import exit +from netifaces import interfaces + +from vyos.config import Config +from vyos.configdict import dict_merge +from vyos.template import render +from vyos.util import cmd +from vyos.util import check_kmod +from vyos.util import dict_search +from vyos.template import is_ipv6 +from vyos.xml import defaults +from vyos import ConfigError +import platform +from vyos import airbag +airbag.enable() + +k_mod = ['nft_nat', 'nft_chain_nat'] + +iptables_nat_config = '/tmp/vyos-nat66-rules.nft' +ndppd_config = '/run/ndppd/ndppd.conf' + +def get_handler(json, chain, target): + """ Get nftable rule handler number of given chain/target combination. + Handler is required when adding NAT66/Conntrack helper targets """ + for x in json: + if x['chain'] != chain: + continue + if x['target'] != target: + continue + return x['handle'] + + return None + +def get_config(config=None): + if config: + conf = config + else: + conf = Config() + + base = ['nat66'] + nat = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True) + + # T2665: we must add the tagNode defaults individually until this is + # moved to the base class + for direction in ['source', 'destination']: + if direction in nat: + default_values = defaults(base + [direction, 'rule']) + for rule in nat[direction]['rule']: + nat[direction]['rule'][rule] = dict_merge(default_values, + nat[direction]['rule'][rule]) + + # read in current nftable (once) for further processing + tmp = cmd('nft -j list table ip6 raw') + nftable_json = json.loads(tmp) + + # condense the full JSON table into a list with only relevand informations + pattern = 'nftables[?rule].rule[?expr[].jump].{chain: chain, handle: handle, target: expr[].jump.target | [0]}' + condensed_json = jmespath.search(pattern, nftable_json) + + if not conf.exists(base): + nat['helper_functions'] = 'remove' + + nat['pre_ct_conntrack'] = get_handler(condensed_json, 'PREROUTING', 'NAT_CONNTRACK') + nat['out_ct_conntrack'] = get_handler(condensed_json, 'OUTPUT','NAT_CONNTRACK') + + nat['deleted'] = '' + + return nat + + # check if NAT66 connection tracking helpers need to be set up - this has to + # be done only once + if not get_handler(condensed_json, 'PREROUTING', 'NAT_CONNTRACK'): + nat['helper_functions'] = 'add' + + # Retrieve current table handler positions + nat['pre_ct_conntrack'] = get_handler(condensed_json, 'PREROUTING', 'VYATTA_CT_PREROUTING_HOOK') + nat['out_ct_conntrack'] = get_handler(condensed_json, 'OUTPUT','VYATTA_CT_OUTPUT_HOOK') + else: + nat['helper_functions'] = 'has' + + return nat + +def verify(nat): + if not nat or 'deleted' in nat: + # no need to verify the CLI as NAT66 is going to be deactivated + return None + + if 'helper_functions' in nat and nat['helper_functions'] != 'has': + if not (nat['pre_ct_conntrack'] or nat['out_ct_conntrack']): + raise Exception('could not determine nftable ruleset handlers') + + if dict_search('source.rule', nat): + for rule, config in dict_search('source.rule', nat).items(): + err_msg = f'Source NAT66 configuration error in rule {rule}:' + if 'outbound_interface' not in config: + raise ConfigError(f'{err_msg}\n' \ + 'outbound-interface not specified') + else: + if config['outbound_interface'] not in 'any' and config['outbound_interface'] not in interfaces(): + print(f'WARNING: rule "{rule}" interface "{config["outbound_interface"]}" does not exist on this system') + + + prefix = dict_search('translation.prefix', config) + if prefix != None: + if not is_ipv6(prefix): + raise ConfigError(f'Warning: IPv6 prefix {prefix} is not a valid address prefix') + + prefix = dict_search('source.prefix', config) + if prefix != None: + if not is_ipv6(prefix): + raise ConfigError(f'{err_msg} source-prefix not specified') + + + if dict_search('destination.rule', nat): + for rule, config in dict_search('destination.rule', nat).items(): + err_msg = f'Destination NAT66 configuration error in rule {rule}:' + + if 'inbound_interface' not in config: + raise ConfigError(f'{err_msg}\n' \ + 'inbound-interface not specified') + else: + if config['inbound_interface'] not in 'any' and config['inbound_interface'] not in interfaces(): + print(f'WARNING: rule "{rule}" interface "{config["inbound_interface"]}" does not exist on this system') + + return None + +def nat66_conf_to_ndp_proxy_conf(nat): + ndpproxy = { + 'interface': {} + } + if not nat or 'deleted' in nat: + # no need to verify the CLI as NAT66 is going to be deactivated + return None + # Detect and convert the default configuration of the configured interface + source_rule = dict_search('source.rule', nat) + if source_rule: + for rule,config in source_rule.items(): + interface_ndp = { + 'router': 'yes', + 'timeout': 500, + 'ttl': 30000, + 'prefix': {} + } + if config['outbound_interface'] not in ndpproxy['interface']: + ndpproxy['interface'].update({config['outbound_interface']: interface_ndp}) + for rule,config in source_rule.items(): + if config['outbound_interface'] in ndpproxy['interface']: + prefix = dict_search('translation.prefix', config) + if prefix: + nat66_prefix = config['translation']['prefix'] + if nat66_prefix not in ndpproxy['interface'][config['outbound_interface']]['prefix']: + ndpproxy['interface'][config['outbound_interface']]['prefix'].update({nat66_prefix: {'mode':'auto'}}) + + # Detect and convert the default configuration of the configured interface + destination_rule = dict_search('destination.rule', nat) + if destination_rule: + for rule,config in destination_rule.items(): + interface_ndp = { + 'router': 'yes', + 'timeout': 500, + 'ttl': 30000, + 'prefix': {} + } + if config['inbound_interface'] not in ndpproxy['interface']: + ndpproxy['interface'].update({config['inbound_interface']: interface_ndp}) + for rule,config in destination_rule.items(): + if rule['interface'] in ndpproxy['interface']: + prefix = dict_search('destination.address', config) + if prefix: + nat66_address = config['destination']['address'] + if nat66_prefix not in ndpproxy['interface'][config['inbound_interface']]['prefix']: + ndpproxy['interface'][config['inbound_interface']]['prefix'].update({nat66_prefix: {'mode':'auto'}}) + + return ndpproxy + +def generate(nat,ndp_proxy): + render(iptables_nat_config, 'firewall/nftables-nat66.tmpl', nat, permission=0o755) + if ndp_proxy == None: + return None + render(ndppd_config, 'proxy-ndp/ndppd.conf.tmpl', ndp_proxy, permission=0o755) + return None + +def apply(nat): + cmd(f'{iptables_nat_config}') + cmd('systemctl restart ndppd') + if os.path.isfile(iptables_nat_config): + os.unlink(iptables_nat_config) + + return None + +if __name__ == '__main__': + try: + check_kmod(k_mod) + c = get_config() + verify(c) + ndp_proxy = nat66_conf_to_ndp_proxy_conf(c) + generate(c,ndp_proxy) + apply(c) + except ConfigError as e: + print(e) + exit(1) diff --git a/src/migration-scripts/nat66/0-to-1 b/src/migration-scripts/nat66/0-to-1 new file mode 100755 index 000000000..2bc22061d --- /dev/null +++ b/src/migration-scripts/nat66/0-to-1 @@ -0,0 +1,76 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2020 VyOS maintainers and contributors +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License version 2 or later as +# published by the Free Software Foundation. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +from sys import argv,exit +from vyos.configtree import ConfigTree + +if (len(argv) < 1): + print("Must specify file name!") + exit(1) + +file_name = argv[1] + +with open(file_name, 'r') as f: + config_file = f.read() + +config = ConfigTree(config_file) + +def merge_npt(config,base,rule): + merge_base = ['nat66','source','rule',rule] + # Configure migration functions + if config.exists(base + ['description']): + tmp = config.return_value(base + ['description']) + config.set(merge_base + ['description'],value=tmp) + + if config.exists(base + ['disable']): + tmp = config.return_value(base + ['disable']) + config.set(merge_base + ['disable'],value=tmp) + + if config.exists(base + ['outbound-interface']): + tmp = config.return_value(base + ['outbound-interface']) + config.set(merge_base + ['outbound-interface'],value=tmp) + + if config.exists(base + ['source','prefix']): + tmp = config.return_value(base + ['source','prefix']) + config.set(merge_base + ['source','prefix'],value=tmp) + + if config.exists(base + ['translation','prefix']): + tmp = config.return_value(base + ['translation','prefix']) + config.set(merge_base + ['translation','prefix'],value=tmp) + + +if not config.exists(['nat']): + # Nothing to do + exit(0) +else: + if not config.exists(['nat', 'nptv6']): + exit(0) + + for rule in config.list_nodes(['nat', 'nptv6', 'rule']): + base = ['nat', 'nptv6', 'rule', rule] + # Merge 'nat nptv6' to 'nat66 source' + merge_npt(config,base,rule) + + # Delete the original NPT configuration + config.delete(['nat','nptv6']); + + try: + with open(file_name, 'w') as f: + f.write(config.to_string()) + except OSError as e: + print("Failed to save the modified config: {}".format(e)) + exit(1) + diff --git a/src/systemd/ndppd.service b/src/systemd/ndppd.service new file mode 100644 index 000000000..566172fb0 --- /dev/null +++ b/src/systemd/ndppd.service @@ -0,0 +1,15 @@ +[Unit] +Description=NDP Proxy Daemon +After=network.target vyos-router.service +ConditionPathExists=/run/ndppd/ndppd.conf +StartLimitIntervalSec=0 + +[Service] +ExecStart=/usr/sbin/ndppd -d -p /var/run/ndppd/ndppd.pid -c /var/run/ndppd/ndppd.conf +Type=forking +PIDFile=/var/run/ndppd/ndppd.pid +Restart=on-failure +RestartSec=20 + +[Install] +WantedBy=multi-user.target -- cgit v1.2.3