#!/usr/bin/env python3 # # Copyright (C) 2022 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 sys from sys import exit from tabulate import tabulate from vyos.util import cmd from vyos.util import dict_search import vyos.opmode def _get_json_data(direction): """ Get NAT format JSON """ if direction == 'source': chain = 'POSTROUTING' if direction == 'destination': chain = 'PREROUTING' return cmd(f'sudo nft --json list chain ip nat {chain}') def _get_raw_data_rules(direction): """Get interested rules :returns dict """ data = _get_json_data(direction) data_dict = json.loads(data) rules = [] for rule in data_dict['nftables']: if 'rule' in rule and 'comment' in rule['rule']: rules.append(rule) return rules def _get_formatted_output_rules(data, direction): # Add default values before loop sport, dport, proto = 'any', 'any', 'any' saddr, daddr = '0.0.0.0/0', '0.0.0.0/0' data_entries = [] for rule in data: if 'comment' in rule['rule']: comment = rule.get('rule').get('comment') rule_number = comment.split('-')[-1] rule_number = rule_number.split(' ')[0] if 'expr' in rule['rule']: interface = rule.get('rule').get('expr')[0].get('match').get('right') \ if jmespath.search('rule.expr[*].match.left.meta', rule) else 'any' for index, match in enumerate(jmespath.search('rule.expr[*].match', rule)): if 'payload' in match['left']: if 'prefix' in match['right'] or 'set' in match['right']: # Merge dict src/dst l3_l4 parameters my_dict = {**match['left']['payload'], **match['right']} proto = my_dict.get('protocol').upper() if my_dict['field'] == 'saddr': saddr = f'{my_dict["prefix"]["addr"]}/{my_dict["prefix"]["len"]}' elif my_dict['field'] == 'daddr': daddr = f'{my_dict["prefix"]["addr"]}/{my_dict["prefix"]["len"]}' elif my_dict['field'] == 'sport': # Port range or single port if jmespath.search('set[*].range', my_dict): sport = my_dict['set'][0]['range'] sport = '-'.join(map(str, sport)) else: sport = my_dict.get('set') sport = ','.join(map(str, sport)) elif my_dict['field'] == 'dport': # Port range or single port if jmespath.search('set[*].range', my_dict): dport = my_dict["set"][0]["range"] dport = '-'.join(map(str, dport)) else: dport = my_dict.get('set') dport = ','.join(map(str, dport)) else: if jmespath.search('left.payload.field', match) == 'saddr': saddr = match.get('right') if jmespath.search('left.payload.field', match) == 'daddr': daddr = match.get('right') else: saddr = '0.0.0.0/0' daddr = '0.0.0.0/0' sport = 'any' dport = 'any' proto = 'any' source = f'''{saddr} sport {sport}''' destination = f'''{daddr} dport {dport}''' if jmespath.search('left.payload.field', match) == 'protocol': field_proto = match.get('right').upper() for expr in rule.get('rule').get('expr'): if 'snat' in expr: translation = dict_search('snat.addr', expr) if expr['snat'] and 'port' in expr['snat']: if jmespath.search('snat.port.range', expr): port = dict_search('snat.port.range', expr) port = '-'.join(map(str, port)) else: port = expr['snat']['port'] translation = f'''{translation} port {port}''' elif 'masquerade' in expr: translation = 'masquerade' if expr['masquerade'] and 'port' in expr['masquerade']: if jmespath.search('masquerade.port.range', expr): port = dict_search('masquerade.port.range', expr) port = '-'.join(map(str, port)) else: port = expr['masquerade']['port'] translation = f'''{translation} port {port}''' else: translation = 'exclude' # Overwrite match loop 'proto' if specified filed 'protocol' exist if 'protocol' in jmespath.search('rule.expr[*].match.left.payload.field', rule): proto = jmespath.search('rule.expr[0].match.right', rule).upper() data_entries.append([rule_number, source, destination, proto, interface, translation]) interface_header = 'Out-Int' if direction == 'source' else 'In-Int' headers = ["Rule", "Source", "Destination", "Proto", interface_header, "Translation"] output = tabulate(data_entries, headers, numalign="left") return output def show_rules(raw: bool, direction: str): nat_rules = _get_raw_data_rules(direction) if raw: return nat_rules else: return _get_formatted_output_rules(nat_rules, direction) if __name__ == '__main__': try: res = vyos.opmode.run(sys.modules[__name__]) if res: print(res) except ValueError as e: print(e) sys.exit(1)