From e4ea410b7587b0018055962c295ab491133f458c Mon Sep 17 00:00:00 2001 From: Christian Poessinger Date: Sat, 28 Nov 2020 21:10:10 +0100 Subject: nat: T3092: migrate to get_config_dict() The NAT system consists out of nested tag nodes which makes manual parsing very hard. This is a perfect candidate for migrating this to get_config_dict() as there is already a smoketest in place. In addition this should make it easier to add features like static nat/hairpin. --- src/conf_mode/nat.py | 233 ++++++++++++++++----------------------------------- 1 file changed, 73 insertions(+), 160 deletions(-) (limited to 'src') diff --git a/src/conf_mode/nat.py b/src/conf_mode/nat.py index b467f3d74..f5c023b81 100755 --- a/src/conf_mode/nat.py +++ b/src/conf_mode/nat.py @@ -18,18 +18,19 @@ import jmespath import json import os -from copy import deepcopy from distutils.version import LooseVersion from platform import release as kernel_version 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 call from vyos.util import cmd from vyos.util import check_kmod +from vyos.util import dict_search from vyos.validate import is_addr_assigned +from vyos.xml import defaults from vyos import ConfigError from vyos import airbag @@ -40,17 +41,6 @@ if LooseVersion(kernel_version()) > LooseVersion('5.1'): else: k_mod = ['nft_nat', 'nft_chain_nat_ipv4'] -default_config_data = { - 'deleted': False, - 'destination': [], - 'helper_functions': None, - 'pre_ct_helper': '', - 'pre_ct_conntrack': '', - 'out_ct_helper': '', - 'out_ct_conntrack': '', - 'source': [] -} - iptables_nat_config = '/tmp/vyos-nat-rules.nft' def get_handler(json, chain, target): @@ -66,114 +56,43 @@ def get_handler(json, chain, target): return None -def verify_rule(rule, err_msg): +def verify_rule(config, err_msg): """ Common verify steps used for both source and destination NAT """ - if rule['translation_port'] or rule['dest_port'] or rule['source_port']: - if rule['protocol'] not in ['tcp', 'udp', 'tcp_udp']: - proto = rule['protocol'] - raise ConfigError(f'{err_msg} ports can only be specified when protocol is "tcp", "udp" or "tcp_udp" (currently "{proto}")') - if '/' in rule['translation_address']: + if (dict_search('translation.port', config) != None or + dict_search('destination.port', config) != None or + dict_search('source.port', config)): + + if config['protocol'] not in ['tcp', 'udp', 'tcp_udp']: + raise ConfigError(f'{err_msg}\n' \ + 'ports can only be specified when protocol is '\ + 'either tcp, udp or tcp_udp!') + + if '/' in (dict_search('translation.address', config) or []): raise ConfigError(f'{err_msg}\n' \ 'Cannot use ports with an IPv4net type translation address as it\n' \ 'statically maps a whole network of addresses onto another\n' \ 'network of addresses') - -def parse_configuration(conf, source_dest): - """ Common wrapper to read in both NAT source and destination CLI """ - ruleset = [] - base_level = ['nat', source_dest] - conf.set_level(base_level) - for number in conf.list_nodes(['rule']): - rule = { - 'description': '', - 'dest_address': '', - 'dest_port': '', - 'disabled': False, - 'exclude': False, - 'interface_in': '', - 'interface_out': '', - 'log': False, - 'protocol': 'all', - 'number': number, - 'source_address': '', - 'source_prefix': '', - 'source_port': '', - 'translation_address': '', - 'translation_prefix': '', - 'translation_port': '' - } - conf.set_level(base_level + ['rule', number]) - - if conf.exists(['description']): - rule['description'] = conf.return_value(['description']) - - if conf.exists(['destination', 'address']): - tmp = conf.return_value(['destination', 'address']) - if tmp.startswith('!'): - tmp = tmp.replace('!', '!=') - rule['dest_address'] = tmp - - if conf.exists(['destination', 'port']): - tmp = conf.return_value(['destination', 'port']) - if tmp.startswith('!'): - tmp = tmp.replace('!', '!=') - rule['dest_port'] = tmp - - if conf.exists(['disable']): - rule['disabled'] = True - - if conf.exists(['exclude']): - rule['exclude'] = True - - if conf.exists(['inbound-interface']): - rule['interface_in'] = conf.return_value(['inbound-interface']) - - if conf.exists(['outbound-interface']): - rule['interface_out'] = conf.return_value(['outbound-interface']) - - if conf.exists(['log']): - rule['log'] = True - - if conf.exists(['protocol']): - rule['protocol'] = conf.return_value(['protocol']) - - if conf.exists(['source', 'address']): - tmp = conf.return_value(['source', 'address']) - if tmp.startswith('!'): - tmp = tmp.replace('!', '!=') - rule['source_address'] = tmp - - if conf.exists(['source', 'prefix']): - rule['source_prefix'] = conf.return_value(['source', 'prefix']) - - if conf.exists(['source', 'port']): - tmp = conf.return_value(['source', 'port']) - if tmp.startswith('!'): - tmp = tmp.replace('!', '!=') - rule['source_port'] = tmp - - if conf.exists(['translation', 'address']): - rule['translation_address'] = conf.return_value(['translation', 'address']) - - if conf.exists(['translation', 'prefix']): - rule['translation_prefix'] = conf.return_value(['translation', 'prefix']) - - if conf.exists(['translation', 'port']): - rule['translation_port'] = conf.return_value(['translation', 'port']) - - ruleset.append(rule) - - return ruleset - def get_config(config=None): - nat = deepcopy(default_config_data) if config: conf = config else: conf = Config() + base = ['nat'] + 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 raw') nftable_json = json.loads(tmp) @@ -182,7 +101,7 @@ def get_config(config=None): 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(['nat']): + if not conf.exists(base): nat['helper_functions'] = 'remove' # Retrieve current table handler positions @@ -190,9 +109,7 @@ def get_config(config=None): nat['pre_ct_conntrack'] = get_handler(condensed_json, 'PREROUTING', 'NAT_CONNTRACK') nat['out_ct_ignore'] = get_handler(condensed_json, 'OUTPUT', 'VYATTA_CT_HELPER') nat['out_ct_conntrack'] = get_handler(condensed_json, 'OUTPUT', 'NAT_CONNTRACK') - - nat['deleted'] = True - + nat['deleted'] = '' return nat # check if NAT connection tracking helpers need to be set up - this has to @@ -206,19 +123,10 @@ def get_config(config=None): nat['out_ct_ignore'] = get_handler(condensed_json, 'OUTPUT', 'VYATTA_CT_IGNORE') nat['out_ct_conntrack'] = get_handler(condensed_json, 'OUTPUT', 'VYATTA_CT_OUTPUT_HOOK') - # set config level for parsing in NAT configuration - conf.set_level(['nat']) - - # use a common wrapper function to read in the source / destination - # tree from the config - thus we do not need to replicate almost the - # same code :-) - for tgt in ['source', 'destination', 'nptv6']: - nat[tgt] = parse_configuration(conf, tgt) - return nat def verify(nat): - if nat['deleted']: + if not nat or 'deleted' in nat: # no need to verify the CLI as NAT is going to be deactivated return None @@ -226,44 +134,49 @@ def verify(nat): if not (nat['pre_ct_ignore'] or nat['pre_ct_conntrack'] or nat['out_ct_ignore'] or nat['out_ct_conntrack']): raise Exception('could not determine nftable ruleset handlers') - for rule in nat['source']: - interface = rule['interface_out'] - err_msg = f'Source NAT configuration error in rule "{rule["number"]}":' - - if interface and interface not in 'any' and interface not in interfaces(): - print(f'Warning: rule "{rule["number"]}" interface "{interface}" does not exist on this system') - - if not rule['interface_out']: - raise ConfigError(f'{err_msg} outbound-interface not specified') - - if rule['translation_address']: - addr = rule['translation_address'] - if addr != 'masquerade': - for ip in addr.split('-'): - if not is_addr_assigned(ip): - print(f'Warning: IP address {ip} does not exist on the system!') - - elif not rule['exclude']: - raise ConfigError(f'{err_msg} translation address not specified') - - # common rule verification - verify_rule(rule, err_msg) - - for rule in nat['destination']: - interface = rule['interface_in'] - err_msg = f'Destination NAT configuration error in rule "{rule["number"]}":' - - if interface and interface not in 'any' and interface not in interfaces(): - print(f'Warning: rule "{rule["number"]}" interface "{interface}" does not exist on this system') - - if not rule['interface_in']: - raise ConfigError(f'{err_msg} inbound-interface not specified') - - if not rule['translation_address'] and not rule['exclude']: - raise ConfigError(f'{err_msg} translation address not specified') - - # common rule verification - verify_rule(rule, err_msg) + if dict_search('source.rule', nat): + for rule, config in dict_search('source.rule', nat).items(): + err_msg = f'Source NAT 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') + + + addr = dict_search('translation.address', config) + if addr != None: + if addr != 'masquerade': + for ip in addr.split('-'): + if not is_addr_assigned(ip): + print(f'WARNING: IP address {ip} does not exist on the system!') + elif 'exclude' not in config: + raise ConfigError(f'{err_msg}\n' \ + 'translation address not specified') + + # common rule verification + verify_rule(config, err_msg) + + + if dict_search('destination.rule', nat): + for rule, config in dict_search('destination.rule', nat).items(): + err_msg = f'Destination NAT 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') + + + if dict_search('translation.address', config) == None and 'exclude' not in config: + raise ConfigError(f'{err_msg}\n' \ + 'translation address not specified') + + # common rule verification + verify_rule(config, err_msg) return None -- cgit v1.2.3