diff options
Diffstat (limited to 'src')
| -rwxr-xr-x | src/conf_mode/policy-route-interface.py | 120 | ||||
| -rwxr-xr-x | src/conf_mode/policy-route.py | 154 |
2 files changed, 274 insertions, 0 deletions
diff --git a/src/conf_mode/policy-route-interface.py b/src/conf_mode/policy-route-interface.py new file mode 100755 index 000000000..e81135a74 --- /dev/null +++ b/src/conf_mode/policy-route-interface.py @@ -0,0 +1,120 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2021 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 <http://www.gnu.org/licenses/>. + +import os +import re + +from sys import argv +from sys import exit + +from vyos.config import Config +from vyos.ifconfig import Section +from vyos.template import render +from vyos.util import cmd +from vyos import ConfigError +from vyos import airbag +airbag.enable() + +def get_config(config=None): + if config: + conf = config + else: + conf = Config() + + ifname = argv[1] + ifpath = Section.get_config_path(ifname) + if_policy_path = f'interfaces {ifpath} policy' + + if_policy = conf.get_config_dict(if_policy_path, key_mangling=('-', '_'), get_first_key=True, + no_tag_node_value_mangle=True) + + if_policy['ifname'] = ifname + if_policy['policy'] = conf.get_config_dict(['policy'], key_mangling=('-', '_'), get_first_key=True, + no_tag_node_value_mangle=True) + + return if_policy + +def verify(if_policy): + # bail out early - looks like removal from running config + if not if_policy: + return None + + for route in ['route', 'ipv6_route']: + if route in if_policy: + if route not in if_policy['policy']: + raise ConfigError('Policy route not configured') + + route_name = if_policy[route] + + if route_name not in if_policy['policy'][route]: + raise ConfigError(f'Invalid policy route name "{name}"') + + return None + +def generate(if_policy): + return None + +def cleanup_rule(table, chain, ifname, new_name=None): + results = cmd(f'nft -a list chain {table} {chain}').split("\n") + retval = None + for line in results: + if f'oifname "{ifname}"' in line: + if new_name and f'jump {new_name}' in line: + # new_name is used to clear rules for any previously referenced chains + # returns true when rule exists and doesn't need to be created + retval = True + continue + + handle_search = re.search('handle (\d+)', line) + if handle_search: + cmd(f'nft delete rule {table} {chain} handle {handle_search[1]}') + return retval + +def apply(if_policy): + ifname = if_policy['ifname'] + + route_chain = 'VYOS_PBR_PREROUTING' + ipv6_route_chain = 'VYOS_PBR6_PREROUTING' + + if 'route' in if_policy: + name = 'VYOS_PBR_' + if_policy['route'] + rule_exists = cleanup_rule('ip mangle', route_chain, ifname, name) + + if not rule_exists: + cmd(f'nft insert rule ip mangle {route_chain} iifname {ifname} counter jump {name}') + else: + cleanup_rule('ip mangle', route_chain, ifname) + + if 'ipv6_route' in if_policy: + name = 'VYOS_PBR6_' + if_policy['ipv6_route'] + rule_exists = cleanup_rule('ip6 mangle', ipv6_route_chain, ifname, name) + + if not rule_exists: + cmd(f'nft insert rule ip6 mangle {ipv6_route_chain} iifname {ifname} counter jump {name}') + else: + cleanup_rule('ip6 mangle', ipv6_route_chain, ifname) + + return None + +if __name__ == '__main__': + try: + c = get_config() + verify(c) + generate(c) + apply(c) + except ConfigError as e: + print(e) + exit(1) diff --git a/src/conf_mode/policy-route.py b/src/conf_mode/policy-route.py new file mode 100755 index 000000000..d098be68d --- /dev/null +++ b/src/conf_mode/policy-route.py @@ -0,0 +1,154 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2021 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 <http://www.gnu.org/licenses/>. + +import os + +from json import loads +from sys import exit + +from vyos.config import Config +from vyos.template import render +from vyos.util import cmd +from vyos.util import dict_search_args +from vyos.util import run +from vyos import ConfigError +from vyos import airbag +airbag.enable() + +mark_offset = 0x7FFFFFFF +nftables_conf = '/run/nftables_policy.conf' + +def get_config(config=None): + if config: + conf = config + else: + conf = Config() + base = ['policy'] + + if not conf.exists(base + ['route']) and not conf.exists(base + ['ipv6-route']): + return None + + policy = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True, + no_tag_node_value_mangle=True) + + return policy + +def verify(policy): + # bail out early - looks like removal from running config + if not policy: + return None + + for route in ['route', 'ipv6_route']: + if route in policy: + for name, pol_conf in policy[route].items(): + if 'rule' in pol_conf: + for rule_id, rule_conf in pol_conf.items(): + icmp = 'icmp' if route == 'route' else 'icmpv6' + if icmp in rule_conf: + icmp_defined = False + if 'type_name' in rule_conf[icmp]: + icmp_defined = True + if 'code' in rule_conf[icmp] or 'type' in rule_conf[icmp]: + raise ConfigError(f'{name} rule {rule_id}: Cannot use ICMP type/code with ICMP type-name') + if 'code' in rule_conf[icmp]: + icmp_defined = True + if 'type' not in rule_conf[icmp]: + raise ConfigError(f'{name} rule {rule_id}: ICMP code can only be defined if ICMP type is defined') + if 'type' in rule_conf[icmp]: + icmp_defined = True + + if icmp_defined and 'protocol' not in rule_conf or rule_conf['protocol'] != icmp: + raise ConfigError(f'{name} rule {rule_id}: ICMP type/code or type-name can only be defined if protocol is ICMP') + if 'set' in rule_conf: + if 'tcp_mss' in rule_conf['set']: + tcp_flags = dict_search_args(rule_conf, 'tcp', 'flags') + if not tcp_flags or 'SYN' not in tcp_flags.split(","): + raise ConfigError(f'{name} rule {rule_id}: TCP SYN flag must be set to modify TCP-MSS') + if 'tcp' in rule_conf: + if 'flags' in rule_conf['tcp']: + if 'protocol' not in rule_conf or rule_conf['protocol'] != 'tcp': + raise ConfigError(f'{name} rule {rule_id}: TCP flags can only be set if protocol is set to TCP') + + + return None + +def generate(policy): + if not policy: + if os.path.exists(nftables_conf): + os.unlink(nftables_conf) + return None + + if not os.path.exists(nftables_conf): + policy['first_install'] = True + + render(nftables_conf, 'firewall/nftables-policy.tmpl', policy) + return None + +def apply_table_marks(policy): + for route in ['route', 'ipv6_route']: + if route in policy: + for name, pol_conf in policy[route].items(): + if 'rule' in pol_conf: + for rule_id, rule_conf in pol_conf['rule'].items(): + set_table = dict_search_args(rule_conf, 'set', 'table') + if set_table: + if set_table == 'main': + set_table = '254' + table_mark = mark_offset - int(set_table) + cmd(f'ip rule add fwmark {table_mark} table {set_table}') + +def cleanup_table_marks(): + json_rules = cmd('ip -j -N rule list') + rules = loads(json_rules) + for rule in rules: + if 'fwmark' not in rule or 'table' not in rule: + continue + fwmark = rule['fwmark'] + table = int(rule['table']) + if fwmark[:2] == '0x': + fwmark = int(fwmark, 16) + if (int(fwmark) == (mark_offset - table)): + cmd(f'ip rule del fwmark {fwmark} table {table}') + +def apply(policy): + if not policy or 'first_install' not in policy: + run(f'nft flush table ip mangle') + run(f'nft flush table ip6 mangle') + + if not policy: + cleanup_table_marks() + return None + + install_result = run(f'nft -f {nftables_conf}') + if install_result == 1: + raise ConfigError('Failed to apply policy based routing') + + if 'first_install' not in policy: + cleanup_table_marks() + + apply_table_marks(policy) + + return None + +if __name__ == '__main__': + try: + c = get_config() + verify(c) + generate(c) + apply(c) + except ConfigError as e: + print(e) + exit(1) |