diff options
Diffstat (limited to 'src/conf_mode/system_flow-accounting.py')
| -rwxr-xr-x | src/conf_mode/system_flow-accounting.py | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/src/conf_mode/system_flow-accounting.py b/src/conf_mode/system_flow-accounting.py new file mode 100755 index 000000000..f29fc94fb --- /dev/null +++ b/src/conf_mode/system_flow-accounting.py @@ -0,0 +1,320 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2018-2023 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.base import Warning +from vyos.config import Config +from vyos.config import config_dict_merge +from vyos.configverify import verify_vrf +from vyos.ifconfig import Section +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_CT_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']: + if interface not in Section.interfaces(): + # Changed from error to warning to allow adding dynamic interfaces + # and interface templates + Warning(f'Interface "{interface}" is not presented in the system') + + # 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) |