diff options
Diffstat (limited to 'src/conf_mode/policy-route.py')
| -rwxr-xr-x | src/conf_mode/policy-route.py | 227 |
1 files changed, 167 insertions, 60 deletions
diff --git a/src/conf_mode/policy-route.py b/src/conf_mode/policy-route.py index d098be68d..3d1d7d8c5 100755 --- a/src/conf_mode/policy-route.py +++ b/src/conf_mode/policy-route.py @@ -15,6 +15,7 @@ # along with this program. If not, see <http://www.gnu.org/licenses/>. import os +import re from json import loads from sys import exit @@ -31,6 +32,35 @@ airbag.enable() mark_offset = 0x7FFFFFFF nftables_conf = '/run/nftables_policy.conf' +preserve_chains = [ + 'VYOS_PBR_PREROUTING', + 'VYOS_PBR_POSTROUTING', + 'VYOS_PBR6_PREROUTING', + 'VYOS_PBR6_POSTROUTING' +] + +valid_groups = [ + 'address_group', + 'network_group', + 'port_group' +] + +def get_policy_interfaces(conf): + out = {} + interfaces = conf.get_config_dict(['interfaces'], key_mangling=('-', '_'), get_first_key=True, + no_tag_node_value_mangle=True) + def find_interfaces(iftype_conf, output={}, prefix=''): + for ifname, if_conf in iftype_conf.items(): + if 'policy' in if_conf: + output[prefix + ifname] = if_conf['policy'] + for vif in ['vif', 'vif_s', 'vif_c']: + if vif in if_conf: + output.update(find_interfaces(if_conf[vif], output, f'{prefix}{ifname}.')) + return output + for iftype, iftype_conf in interfaces.items(): + out.update(find_interfaces(iftype_conf)) + return out + def get_config(config=None): if config: conf = config @@ -38,68 +68,149 @@ def get_config(config=None): 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) + policy['firewall_group'] = conf.get_config_dict(['firewall', 'group'], key_mangling=('-', '_'), get_first_key=True, + no_tag_node_value_mangle=True) + policy['interfaces'] = get_policy_interfaces(conf) + return policy -def verify(policy): - # bail out early - looks like removal from running config - if not policy: - return None +def verify_rule(policy, name, rule_conf, ipv6): + icmp = 'icmp' if not ipv6 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: + raise ConfigError(f'{name} rule {rule_id}: TCP SYN flag must be set to modify TCP-MSS') + + tcp_flags = dict_search_args(rule_conf, 'tcp', 'flags') + if tcp_flags: + if dict_search_args(rule_conf, 'protocol') != 'tcp': + raise ConfigError('Protocol must be tcp when specifying tcp flags') + + not_flags = dict_search_args(rule_conf, 'tcp', 'flags', 'not') + if not_flags: + duplicates = [flag for flag in tcp_flags if flag in not_flags] + if duplicates: + raise ConfigError(f'Cannot match a tcp flag as set and not set') + + for side in ['destination', 'source']: + if side in rule_conf: + side_conf = rule_conf[side] + + if 'group' in side_conf: + if {'address_group', 'network_group'} <= set(side_conf['group']): + raise ConfigError('Only one address-group or network-group can be specified') + + for group in valid_groups: + if group in side_conf['group']: + group_name = side_conf['group'][group] + + if group_name.startswith('!'): + group_name = group_name[1:] + + fw_group = f'ipv6_{group}' if ipv6 and group in ['address_group', 'network_group'] else group + error_group = fw_group.replace("_", "-") + group_obj = dict_search_args(policy['firewall_group'], fw_group, group_name) - for route in ['route', 'ipv6_route']: + if group_obj is None: + raise ConfigError(f'Invalid {error_group} "{group_name}" on policy route rule') + + if not group_obj: + print(f'WARNING: {error_group} "{group_name}" has no members') + + if 'port' in side_conf or dict_search_args(side_conf, 'group', 'port_group'): + if 'protocol' not in rule_conf: + raise ConfigError('Protocol must be defined if specifying a port or port-group') + + if rule_conf['protocol'] not in ['tcp', 'udp', 'tcp_udp']: + raise ConfigError('Protocol must be tcp, udp, or tcp_udp when specifying a port or port-group') + +def verify(policy): + for route in ['route', 'route6']: + ipv6 = route == 'route6' 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') + for rule_id, rule_conf in pol_conf['rule'].items(): + verify_rule(policy, name, rule_conf, ipv6) + + for ifname, if_policy in policy['interfaces'].items(): + name = dict_search_args(if_policy, 'route') + ipv6_name = dict_search_args(if_policy, 'route6') + if name and not dict_search_args(policy, 'route', name): + raise ConfigError(f'Policy route "{name}" is still referenced on interface {ifname}') + + if ipv6_name and not dict_search_args(policy, 'route6', ipv6_name): + raise ConfigError(f'Policy route6 "{ipv6_name}" is still referenced on interface {ifname}') return None -def generate(policy): - if not policy: - if os.path.exists(nftables_conf): - os.unlink(nftables_conf) - return None +def cleanup_rule(table, jump_chain): + commands = [] + results = cmd(f'nft -a list table {table}').split("\n") + for line in results: + if f'jump {jump_chain}' in line: + handle_search = re.search('handle (\d+)', line) + if handle_search: + commands.append(f'delete rule {table} {chain} handle {handle_search[1]}') + return commands +def cleanup_commands(policy): + commands = [] + for table in ['ip mangle', 'ip6 mangle']: + json_str = cmd(f'nft -j list table {table}') + obj = loads(json_str) + if 'nftables' not in obj: + continue + for item in obj['nftables']: + if 'chain' in item: + chain = item['chain']['name'] + if not chain.startswith("VYOS_PBR"): + continue + if chain not in preserve_chains: + if table == 'ip mangle' and dict_search_args(policy, 'route', chain.replace("VYOS_PBR_", "", 1)): + commands.append(f'flush chain {table} {chain}') + elif table == 'ip6 mangle' and dict_search_args(policy, 'route6', chain.replace("VYOS_PBR6_", "", 1)): + commands.append(f'flush chain {table} {chain}') + else: + commands += cleanup_rule(table, chain) + commands.append(f'delete chain {table} {chain}') + return commands + +def generate(policy): if not os.path.exists(nftables_conf): policy['first_install'] = True + else: + policy['cleanup_commands'] = cleanup_commands(policy) render(nftables_conf, 'firewall/nftables-policy.tmpl', policy) return None def apply_table_marks(policy): - for route in ['route', 'ipv6_route']: + for route in ['route', 'route6']: if route in policy: + cmd_str = 'ip' if route == 'route' else 'ip -6' + tables = [] for name, pol_conf in policy[route].items(): if 'rule' in pol_conf: for rule_id, rule_conf in pol_conf['rule'].items(): @@ -107,31 +218,27 @@ def apply_table_marks(policy): if set_table: if set_table == 'main': set_table = '254' + if set_table in tables: + continue + tables.append(set_table) table_mark = mark_offset - int(set_table) - cmd(f'ip rule add fwmark {table_mark} table {set_table}') + cmd(f'{cmd_str} rule add pref {set_table} 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}') + for cmd_str in ['ip', 'ip -6']: + json_rules = cmd(f'{cmd_str} -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'{cmd_str} 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') |