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#!/usr/bin/env python3
#
# Copyright VyOS maintainers and contributors <maintainers@vyos.io>
#
# 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 ipaddress import ip_interface
from sys import exit
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.file import read_file
from vyos.utils.network import is_addr_assigned
from vyos import ConfigError
from vyos import airbag
from vyos import ipt_netflow
airbag.enable()
ipt_netflow_conf_path = '/etc/modprobe.d/ipt_NETFLOW.conf'
# Variable to store between generate and apply
# whether module configuration was changed
# and module reload is needed
need_reload = True
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
flow_type = '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 interface is configured
if 'netflow' not in flow_config or 'interface' not in flow_config['netflow']:
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['netflow']['interface']:
verify_interface_exists(flow_config, interface, warning_only=True)
# check if at least one NetFlow collector is configured
if 'server' not in flow_config['netflow']:
raise ConfigError('You need to configure at least one NetFlow server!')
verify_vrf(flow_config)
# check if vrf is defined for netflow
netflow_vrf = None
if 'vrf' in flow_config:
netflow_vrf = flow_config['vrf']
# Check if configured netflow server source-address exist in the system
# Check if configured netflow server source-address matches protocol of server
# Check if configured netflow server source-interface exists
for server, data in flow_config['netflow']['server'].items():
if 'source_address' in data and 'source_interface' in data:
raise ConfigError(
f'Configured "netflow server {server}" cannot have both "source-address" and "source-interface" fields'
)
if 'source_address' in data:
if not is_addr_assigned(data['source_address'], netflow_vrf):
raise ConfigError(
f'Configured "netflow server {server} source-address {data["source_address"]}" does not exist on the system!'
)
if (
ip_interface(server).version
!= ip_interface(data['source_address']).version
):
raise ConfigError(
f'Configured "netflow server {server} source-address {data["source_address"]}" protocol doesn\'t match server protocol'
)
if 'source_interface' in data:
verify_interface_exists(
flow_config, data['source_interface'], warning_only=True
)
# 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'Cannot 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:
if os.path.exists(ipt_netflow_conf_path):
os.unlink(ipt_netflow_conf_path)
return None
prev_config = read_file(ipt_netflow_conf_path, defaultonfailure='')
render(ipt_netflow_conf_path, 'ipt-netflow/ipt_NETFLOW.conf.j2', flow_config)
new_config = read_file(ipt_netflow_conf_path, defaultonfailure='')
global need_reload
need_reload = prev_config != new_config
def apply(flow_config):
# When reloading module we need to first remove
# all iptables usage of ipt_NETFLOW
# When flow_config is disabled everything should be cleaned-up too
if need_reload or not flow_config:
ipt_netflow.stop()
if not flow_config:
if os.path.exists(ipt_netflow_conf_path):
os.unlink(ipt_netflow_conf_path)
return
ingress_interfaces = []
egress_interfaces = []
# configure iptables for defined interfaces
if 'interface' in flow_config['netflow']:
ingress_interfaces = flow_config['netflow']['interface']
# configure egress the same way if configured otherwise remove it
if 'enable_egress' in flow_config:
egress_interfaces = ingress_interfaces
enable_ipv6 = flow_config['netflow']['version'] != '5'
if need_reload:
ipt_netflow.start(ingress_interfaces, egress_interfaces, ipv6=enable_ipv6)
else:
ipt_netflow.set_watched_iptables_interfaces(
ingress_interfaces, egress_interfaces, ipv6=enable_ipv6
)
if __name__ == '__main__':
try:
config = get_config()
verify(config)
generate(config)
apply(config)
except ConfigError as e:
print(e)
exit(1)
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