#!/usr/bin/env python3 # # Copyright (C) 2018-2024 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 exit from ipaddress import ip_address from vyos.config import Config from vyos.config import config_dict_merge from vyos.configverify import verify_vrf from vyos.configverify import verify_interface_exists from vyos.template import render from vyos.utils.process import call from vyos.utils.process import cmd from vyos.utils.process import run from vyos.utils.network import is_addr_assigned from vyos import ConfigError from vyos import airbag airbag.enable() uacctd_conf_path = '/run/pmacct/uacctd.conf' systemd_service = 'uacctd.service' systemd_override = f'/run/systemd/system/{systemd_service}.d/override.conf' nftables_nflog_table = 'raw' nftables_nflog_chain = 'VYOS_PREROUTING_HOOK' egress_nftables_nflog_table = 'inet mangle' egress_nftables_nflog_chain = 'FORWARD' # get nftables rule dict for chain in table def _nftables_get_nflog(chain, table): # define list with rules rules = [] # prepare regex for parsing rules rule_pattern = '[io]ifname "(?P<interface>[\w\.\*\-]+)".*handle (?P<handle>[\d]+)' rule_re = re.compile(rule_pattern) # run nftables, save output and split it by lines nftables_command = f'nft -a list chain {table} {chain}' tmp = cmd(nftables_command, message='Failed to get flows list') # parse each line and add information to list for current_rule in tmp.splitlines(): if 'FLOW_ACCOUNTING_RULE' not in current_rule: continue current_rule_parsed = rule_re.search(current_rule) if current_rule_parsed: groups = current_rule_parsed.groupdict() rules.append({ 'interface': groups["interface"], 'table': table, 'handle': groups["handle"] }) # return list with rules return rules def _nftables_config(configured_ifaces, direction, length=None): # define list of nftables commands to modify settings nftable_commands = [] nftables_chain = nftables_nflog_chain nftables_table = nftables_nflog_table if direction == "egress": nftables_chain = egress_nftables_nflog_chain nftables_table = egress_nftables_nflog_table # prepare extended list with configured interfaces configured_ifaces_extended = [] for iface in configured_ifaces: configured_ifaces_extended.append({ 'iface': iface }) # get currently configured interfaces with nftables rules active_nflog_rules = _nftables_get_nflog(nftables_chain, nftables_table) # compare current active list with configured one and delete excessive interfaces, add missed active_nflog_ifaces = [] for rule in active_nflog_rules: interface = rule['interface'] if interface not in configured_ifaces: table = rule['table'] handle = rule['handle'] nftable_commands.append(f'nft delete rule {table} {nftables_chain} handle {handle}') else: active_nflog_ifaces.append({ 'iface': interface, }) # do not create new rules for already configured interfaces for iface in active_nflog_ifaces: if iface in active_nflog_ifaces and iface in configured_ifaces_extended: configured_ifaces_extended.remove(iface) # create missed rules for iface_extended in configured_ifaces_extended: iface = iface_extended['iface'] iface_prefix = "o" if direction == "egress" else "i" rule_definition = f'{iface_prefix}ifname "{iface}" counter log group 2 snaplen {length} queue-threshold 100 comment "FLOW_ACCOUNTING_RULE"' nftable_commands.append(f'nft insert rule {nftables_table} {nftables_chain} {rule_definition}') # Also add IPv6 ingres logging if nftables_table == nftables_nflog_table: nftable_commands.append(f'nft insert rule ip6 {nftables_table} {nftables_chain} {rule_definition}') # change nftables for command in nftable_commands: cmd(command, raising=ConfigError) def _nftables_trigger_setup(operation: str) -> None: """Add a dummy rule to unlock the main pmacct loop with a packet-trigger Args: operation (str): 'add' or 'delete' a trigger """ # check if a chain exists table_exists = False if run('nft -snj list table ip pmacct') == 0: table_exists = True if operation == 'delete' and table_exists: nft_cmd: str = 'nft delete table ip pmacct' cmd(nft_cmd, raising=ConfigError) if operation == 'add' and not table_exists: nft_cmds: list[str] = [ 'nft add table ip pmacct', 'nft add chain ip pmacct pmacct_out { type filter hook output priority raw - 50 \\; policy accept \\; }', 'nft add rule ip pmacct pmacct_out oif lo ip daddr 127.0.254.0 counter log group 2 snaplen 1 queue-threshold 0 comment NFLOG_TRIGGER' ] for nft_cmd in nft_cmds: cmd(nft_cmd, raising=ConfigError) def get_config(config=None): if config: conf = config else: conf = Config() base = ['system', 'flow-accounting'] if not conf.exists(base): return None flow_accounting = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True) # We have gathered the dict representation of the CLI, but there are # default values which we need to conditionally update into the # dictionary retrieved. default_values = conf.get_config_defaults(**flow_accounting.kwargs, recursive=True) # delete individual flow type defaults - should only be added if user # sets this feature for flow_type in ['sflow', 'netflow']: if flow_type not in flow_accounting and flow_type in default_values: del default_values[flow_type] flow_accounting = config_dict_merge(default_values, flow_accounting) return flow_accounting def verify(flow_config): if not flow_config: return None # check if at least one collector is enabled if 'sflow' not in flow_config and 'netflow' not in flow_config and 'disable_imt' in flow_config: raise ConfigError('You need to configure at least sFlow or NetFlow, ' \ 'or not set "disable-imt" for flow-accounting!') # Check if at least one interface is configured if 'interface' not in flow_config: raise ConfigError('Flow accounting requires at least one interface to ' \ 'be configured!') # check that all configured interfaces exists in the system for interface in flow_config['interface']: verify_interface_exists(interface, warning_only=True) # check sFlow configuration if 'sflow' in flow_config: # check if at least one sFlow collector is configured if 'server' not in flow_config['sflow']: raise ConfigError('You need to configure at least one sFlow server!') # check that all sFlow collectors use the same IP protocol version sflow_collector_ipver = None for server in flow_config['sflow']['server']: if sflow_collector_ipver: if sflow_collector_ipver != ip_address(server).version: raise ConfigError("All sFlow servers must use the same IP protocol") else: sflow_collector_ipver = ip_address(server).version # check if vrf is defined for Sflow verify_vrf(flow_config) sflow_vrf = None if 'vrf' in flow_config: sflow_vrf = flow_config['vrf'] # check agent-id for sFlow: we should avoid mixing IPv4 agent-id with IPv6 collectors and vice-versa for server in flow_config['sflow']['server']: if 'agent_address' in flow_config['sflow']: if ip_address(server).version != ip_address(flow_config['sflow']['agent_address']).version: raise ConfigError('IPv4 and IPv6 addresses can not be mixed in "sflow agent-address" and "sflow '\ 'server". You need to set the same IP version for both "agent-address" and '\ 'all sFlow servers') if 'agent_address' in flow_config['sflow']: tmp = flow_config['sflow']['agent_address'] if not is_addr_assigned(tmp, sflow_vrf): raise ConfigError(f'Configured "sflow agent-address {tmp}" does not exist in the system!') # Check if configured sflow source-address exist in the system if 'source_address' in flow_config['sflow']: if not is_addr_assigned(flow_config['sflow']['source_address'], sflow_vrf): tmp = flow_config['sflow']['source_address'] raise ConfigError(f'Configured "sflow source-address {tmp}" does not exist on the system!') # check NetFlow configuration if 'netflow' in flow_config: # check if vrf is defined for netflow netflow_vrf = None if 'vrf' in flow_config: netflow_vrf = flow_config['vrf'] # check if at least one NetFlow collector is configured if NetFlow configuration is presented if 'server' not in flow_config['netflow']: raise ConfigError('You need to configure at least one NetFlow server!') # Check if configured netflow source-address exist in the system if 'source_address' in flow_config['netflow']: if not is_addr_assigned(flow_config['netflow']['source_address'], netflow_vrf): tmp = flow_config['netflow']['source_address'] raise ConfigError(f'Configured "netflow source-address {tmp}" does not exist on the system!') # Check if engine-id compatible with selected protocol version if 'engine_id' in flow_config['netflow']: v5_filter = '^(\d|[1-9]\d|1\d{2}|2[0-4]\d|25[0-5]):(\d|[1-9]\d|1\d{2}|2[0-4]\d|25[0-5])$' v9v10_filter = '^(\d|[1-9]\d{1,8}|[1-3]\d{9}|4[01]\d{8}|42[0-8]\d{7}|429[0-3]\d{6}|4294[0-8]\d{5}|42949[0-5]\d{4}|429496[0-6]\d{3}|4294967[01]\d{2}|42949672[0-8]\d|429496729[0-5])$' engine_id = flow_config['netflow']['engine_id'] version = flow_config['netflow']['version'] if flow_config['netflow']['version'] == '5': regex_filter = re.compile(v5_filter) if not regex_filter.search(engine_id): raise ConfigError(f'You cannot use NetFlow engine-id "{engine_id}" '\ f'together with NetFlow protocol version "{version}"!') else: regex_filter = re.compile(v9v10_filter) if not regex_filter.search(flow_config['netflow']['engine_id']): raise ConfigError(f'Can not use NetFlow engine-id "{engine_id}" together '\ f'with NetFlow protocol version "{version}"!') # return True if all checks were passed return True def generate(flow_config): if not flow_config: return None render(uacctd_conf_path, 'pmacct/uacctd.conf.j2', flow_config) render(systemd_override, 'pmacct/override.conf.j2', flow_config) # Reload systemd manager configuration call('systemctl daemon-reload') def apply(flow_config): # Check if flow-accounting was removed and define command if not flow_config: _nftables_config([], 'ingress') _nftables_config([], 'egress') # Stop flow-accounting daemon and remove configuration file call(f'systemctl stop {systemd_service}') if os.path.exists(uacctd_conf_path): os.unlink(uacctd_conf_path) # must be done after systemctl _nftables_trigger_setup('delete') return # Start/reload flow-accounting daemon call(f'systemctl restart {systemd_service}') # configure nftables rules for defined interfaces if 'interface' in flow_config: _nftables_config(flow_config['interface'], 'ingress', flow_config['packet_length']) # configure egress the same way if configured otherwise remove it if 'enable_egress' in flow_config: _nftables_config(flow_config['interface'], 'egress', flow_config['packet_length']) else: _nftables_config([], 'egress') # add a trigger for signal processing _nftables_trigger_setup('add') if __name__ == '__main__': try: config = get_config() verify(config) generate(config) apply(config) except ConfigError as e: print(e) exit(1)