diff options
Diffstat (limited to 'src/op_mode/dhcp.py')
| -rw-r--r-- | src/op_mode/dhcp.py | 530 |
1 files changed, 530 insertions, 0 deletions
diff --git a/src/op_mode/dhcp.py b/src/op_mode/dhcp.py new file mode 100644 index 0000000..e5455c8 --- /dev/null +++ b/src/op_mode/dhcp.py @@ -0,0 +1,530 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2022-2024 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 sys +import typing + +from datetime import datetime +from glob import glob +from ipaddress import ip_address +from tabulate import tabulate + +import vyos.opmode + +from vyos.base import Warning +from vyos.configquery import ConfigTreeQuery + +from vyos.kea import kea_get_active_config +from vyos.kea import kea_get_leases +from vyos.kea import kea_get_pool_from_subnet_id +from vyos.kea import kea_delete_lease +from vyos.utils.process import is_systemd_service_running +from vyos.utils.process import call + +time_string = "%a %b %d %H:%M:%S %Z %Y" + +config = ConfigTreeQuery() +lease_valid_states = ['all', 'active', 'free', 'expired', 'released', 'abandoned', 'reset', 'backup'] +sort_valid_inet = ['end', 'mac', 'hostname', 'ip', 'pool', 'remaining', 'start', 'state'] +sort_valid_inet6 = ['end', 'duid', 'ip', 'last_communication', 'pool', 'remaining', 'state', 'type'] +mapping_sort_valid = ['mac', 'ip', 'pool', 'duid'] + +ArgFamily = typing.Literal['inet', 'inet6'] +ArgState = typing.Literal['all', 'active', 'free', 'expired', 'released', 'abandoned', 'reset', 'backup'] +ArgOrigin = typing.Literal['local', 'remote'] + +def _utc_to_local(utc_dt): + return datetime.fromtimestamp((datetime.fromtimestamp(utc_dt) - datetime(1970, 1, 1)).total_seconds()) + + +def _format_hex_string(in_str): + out_str = "" + # if input is divisible by 2, add : every 2 chars + if len(in_str) > 0 and len(in_str) % 2 == 0: + out_str = ':'.join(a+b for a,b in zip(in_str[::2], in_str[1::2])) + else: + out_str = in_str + + return out_str + + +def _find_list_of_dict_index(lst, key='ip', value='') -> int: + """ + Find the index entry of list of dict matching the dict value + Exampe: + % lst = [{'ip': '192.0.2.1'}, {'ip': '192.0.2.2'}] + % _find_list_of_dict_index(lst, key='ip', value='192.0.2.2') + % 1 + """ + idx = next((index for (index, d) in enumerate(lst) if d[key] == value), None) + return idx + + +def _get_raw_server_leases(family='inet', pool=None, sorted=None, state=[], origin=None) -> list: + """ + Get DHCP server leases + :return list + """ + inet_suffix = '6' if family == 'inet6' else '4' + try: + leases = kea_get_leases(inet_suffix) + except: + raise vyos.opmode.DataUnavailable('Cannot fetch DHCP server lease information') + + if pool is None: + pool = _get_dhcp_pools(family=family) + else: + pool = [pool] + + try: + active_config = kea_get_active_config(inet_suffix) + except: + raise vyos.opmode.DataUnavailable('Cannot fetch DHCP server configuration') + + data = [] + for lease in leases: + lifetime = lease['valid-lft'] + expiry = (lease['cltt'] + lifetime) + + lease['start_timestamp'] = datetime.utcfromtimestamp(expiry - lifetime) + lease['expire_timestamp'] = datetime.utcfromtimestamp(expiry) if expiry else None + + data_lease = {} + data_lease['ip'] = lease['ip-address'] + lease_state_long = {0: 'active', 1: 'rejected', 2: 'expired'} + data_lease['state'] = lease_state_long[lease['state']] + data_lease['pool'] = kea_get_pool_from_subnet_id(active_config, inet_suffix, lease['subnet-id']) if active_config else '-' + data_lease['end'] = lease['expire_timestamp'].timestamp() if lease['expire_timestamp'] else None + data_lease['origin'] = 'local' # TODO: Determine remote in HA + + if family == 'inet': + data_lease['mac'] = lease['hw-address'] + data_lease['start'] = lease['start_timestamp'].timestamp() + data_lease['hostname'] = lease['hostname'] + + if family == 'inet6': + data_lease['last_communication'] = lease['start_timestamp'].timestamp() + data_lease['duid'] = _format_hex_string(lease['duid']) + data_lease['type'] = lease['type'] + + if lease['type'] == 'IA_PD': + prefix_len = lease['prefix-len'] + data_lease['ip'] += f'/{prefix_len}' + + data_lease['remaining'] = '-' + + if lease['valid-lft'] > 0: + data_lease['remaining'] = lease['expire_timestamp'] - datetime.utcnow() + + if data_lease['remaining'].days >= 0: + # substraction gives us a timedelta object which can't be formatted with strftime + # so we use str(), split gets rid of the microseconds + data_lease['remaining'] = str(data_lease["remaining"]).split('.')[0] + + # Do not add old leases + if data_lease['remaining'] != '' and data_lease['pool'] in pool and data_lease['state'] != 'free': + if not state or state == 'all' or data_lease['state'] in state: + data.append(data_lease) + + # deduplicate + checked = [] + for entry in data: + addr = entry.get('ip') + if addr not in checked: + checked.append(addr) + else: + idx = _find_list_of_dict_index(data, key='ip', value=addr) + data.pop(idx) + + if sorted: + if sorted == 'ip': + data.sort(key = lambda x:ip_address(x['ip'])) + else: + data.sort(key = lambda x:x[sorted]) + return data + + +def _get_formatted_server_leases(raw_data, family='inet'): + data_entries = [] + if family == 'inet': + for lease in raw_data: + ipaddr = lease.get('ip') + hw_addr = lease.get('mac') + state = lease.get('state') + start = lease.get('start') + start = _utc_to_local(start).strftime('%Y/%m/%d %H:%M:%S') + end = lease.get('end') + end = _utc_to_local(end).strftime('%Y/%m/%d %H:%M:%S') if end else '-' + remain = lease.get('remaining') + pool = lease.get('pool') + hostname = lease.get('hostname') + origin = lease.get('origin') + data_entries.append([ipaddr, hw_addr, state, start, end, remain, pool, hostname, origin]) + + headers = ['IP Address', 'MAC address', 'State', 'Lease start', 'Lease expiration', 'Remaining', 'Pool', + 'Hostname', 'Origin'] + + if family == 'inet6': + for lease in raw_data: + ipaddr = lease.get('ip') + state = lease.get('state') + start = lease.get('last_communication') + start = _utc_to_local(start).strftime('%Y/%m/%d %H:%M:%S') + end = lease.get('end') + end = _utc_to_local(end).strftime('%Y/%m/%d %H:%M:%S') + remain = lease.get('remaining') + lease_type = lease.get('type') + pool = lease.get('pool') + host_identifier = lease.get('duid') + data_entries.append([ipaddr, state, start, end, remain, lease_type, pool, host_identifier]) + + headers = ['IPv6 address', 'State', 'Last communication', 'Lease expiration', 'Remaining', 'Type', 'Pool', + 'DUID'] + + output = tabulate(data_entries, headers, numalign='left') + return output + + +def _get_dhcp_pools(family='inet') -> list: + v = 'v6' if family == 'inet6' else '' + pools = config.list_nodes(f'service dhcp{v}-server shared-network-name') + return pools + + +def _get_pool_size(pool, family='inet'): + v = 'v6' if family == 'inet6' else '' + base = f'service dhcp{v}-server shared-network-name {pool}' + size = 0 + subnets = config.list_nodes(f'{base} subnet') + for subnet in subnets: + ranges = config.list_nodes(f'{base} subnet {subnet} range') + for range in ranges: + if family == 'inet6': + start = config.value(f'{base} subnet {subnet} range {range} start') + stop = config.value(f'{base} subnet {subnet} range {range} stop') + else: + start = config.value(f'{base} subnet {subnet} range {range} start') + stop = config.value(f'{base} subnet {subnet} range {range} stop') + # Add +1 because both range boundaries are inclusive + size += int(ip_address(stop)) - int(ip_address(start)) + 1 + return size + + +def _get_raw_pool_statistics(family='inet', pool=None): + if pool is None: + pool = _get_dhcp_pools(family=family) + else: + pool = [pool] + + v = 'v6' if family == 'inet6' else '' + stats = [] + for p in pool: + subnet = config.list_nodes(f'service dhcp{v}-server shared-network-name {p} subnet') + size = _get_pool_size(family=family, pool=p) + leases = len(_get_raw_server_leases(family=family, pool=p)) + use_percentage = round(leases / size * 100) if size != 0 else 0 + pool_stats = {'pool': p, 'size': size, 'leases': leases, + 'available': (size - leases), 'use_percentage': use_percentage, 'subnet': subnet} + stats.append(pool_stats) + return stats + + +def _get_formatted_pool_statistics(pool_data, family='inet'): + data_entries = [] + for entry in pool_data: + pool = entry.get('pool') + size = entry.get('size') + leases = entry.get('leases') + available = entry.get('available') + use_percentage = entry.get('use_percentage') + use_percentage = f'{use_percentage}%' + data_entries.append([pool, size, leases, available, use_percentage]) + + headers = ['Pool', 'Size','Leases', 'Available', 'Usage'] + output = tabulate(data_entries, headers, numalign='left') + return output + +def _get_raw_server_static_mappings(family='inet', pool=None, sorted=None): + if pool is None: + pool = _get_dhcp_pools(family=family) + else: + pool = [pool] + + v = 'v6' if family == 'inet6' else '' + mappings = [] + for p in pool: + pool_config = config.get_config_dict(['service', f'dhcp{v}-server', 'shared-network-name', p], + get_first_key=True) + if 'subnet' in pool_config: + for subnet, subnet_config in pool_config['subnet'].items(): + if 'static-mapping' in subnet_config: + for name, mapping_config in subnet_config['static-mapping'].items(): + mapping = {'pool': p, 'subnet': subnet, 'name': name} + mapping.update(mapping_config) + mappings.append(mapping) + + if sorted: + if sorted == 'ip': + data.sort(key = lambda x:ip_address(x['ip-address'])) + else: + data.sort(key = lambda x:x[sorted]) + return mappings + +def _get_formatted_server_static_mappings(raw_data, family='inet'): + data_entries = [] + for entry in raw_data: + pool = entry.get('pool') + subnet = entry.get('subnet') + name = entry.get('name') + ip_addr = entry.get('ip-address', 'N/A') + mac_addr = entry.get('mac', 'N/A') + duid = entry.get('duid', 'N/A') + description = entry.get('description', 'N/A') + data_entries.append([pool, subnet, name, ip_addr, mac_addr, duid, description]) + + headers = ['Pool', 'Subnet', 'Name', 'IP Address', 'MAC Address', 'DUID', 'Description'] + output = tabulate(data_entries, headers, numalign='left') + return output + +def _verify(func): + """Decorator checks if DHCP(v6) config exists""" + from functools import wraps + + @wraps(func) + def _wrapper(*args, **kwargs): + config = ConfigTreeQuery() + family = kwargs.get('family') + v = 'v6' if family == 'inet6' else '' + unconf_message = f'DHCP{v} server is not configured' + # Check if config does not exist + if not config.exists(f'service dhcp{v}-server'): + raise vyos.opmode.UnconfiguredSubsystem(unconf_message) + return func(*args, **kwargs) + return _wrapper + +def _verify_client(func): + """Decorator checks if interface is configured as DHCP client""" + from functools import wraps + from vyos.ifconfig import Section + + @wraps(func) + def _wrapper(*args, **kwargs): + config = ConfigTreeQuery() + family = kwargs.get('family') + v = 'v6' if family == 'inet6' else '' + interface = kwargs.get('interface') + interface_path = Section.get_config_path(interface) + unconf_message = f'DHCP{v} client not configured on interface {interface}!' + + # Check if config does not exist + if not config.exists(f'interfaces {interface_path} address dhcp{v}'): + raise vyos.opmode.UnconfiguredObject(unconf_message) + return func(*args, **kwargs) + return _wrapper + +@_verify +def show_pool_statistics(raw: bool, family: ArgFamily, pool: typing.Optional[str]): + pool_data = _get_raw_pool_statistics(family=family, pool=pool) + if raw: + return pool_data + else: + return _get_formatted_pool_statistics(pool_data, family=family) + + +@_verify +def show_server_leases(raw: bool, family: ArgFamily, pool: typing.Optional[str], + sorted: typing.Optional[str], state: typing.Optional[ArgState], + origin: typing.Optional[ArgOrigin] ): + # if dhcp server is down, inactive leases may still be shown as active, so warn the user. + v = '6' if family == 'inet6' else '4' + if not is_systemd_service_running(f'kea-dhcp{v}-server.service'): + Warning('DHCP server is configured but not started. Data may be stale.') + + v = 'v6' if family == 'inet6' else '' + if pool and pool not in _get_dhcp_pools(family=family): + raise vyos.opmode.IncorrectValue(f'DHCP{v} pool "{pool}" does not exist!') + + if state and state not in lease_valid_states: + raise vyos.opmode.IncorrectValue(f'DHCP{v} state "{state}" is invalid!') + + sort_valid = sort_valid_inet6 if family == 'inet6' else sort_valid_inet + if sorted and sorted not in sort_valid: + raise vyos.opmode.IncorrectValue(f'DHCP{v} sort "{sorted}" is invalid!') + + lease_data = _get_raw_server_leases(family=family, pool=pool, sorted=sorted, state=state, origin=origin) + if raw: + return lease_data + else: + return _get_formatted_server_leases(lease_data, family=family) + +@_verify +def show_server_static_mappings(raw: bool, family: ArgFamily, pool: typing.Optional[str], + sorted: typing.Optional[str]): + v = 'v6' if family == 'inet6' else '' + if pool and pool not in _get_dhcp_pools(family=family): + raise vyos.opmode.IncorrectValue(f'DHCP{v} pool "{pool}" does not exist!') + + if sorted and sorted not in mapping_sort_valid: + raise vyos.opmode.IncorrectValue(f'DHCP{v} sort "{sorted}" is invalid!') + + static_mappings = _get_raw_server_static_mappings(family=family, pool=pool, sorted=sorted) + if raw: + return static_mappings + else: + return _get_formatted_server_static_mappings(static_mappings, family=family) + +def _lease_valid(inet, address): + leases = kea_get_leases(inet) + for lease in leases: + if address == lease['ip-address']: + return True + return False + +@_verify +def clear_dhcp_server_lease(family: ArgFamily, address: str): + v = 'v6' if family == 'inet6' else '' + inet = '6' if family == 'inet6' else '4' + + if not _lease_valid(inet, address): + print(f'Lease not found on DHCP{v} server') + return None + + if not kea_delete_lease(inet, address): + print(f'Failed to clear lease for "{address}"') + return None + + print(f'Lease "{address}" has been cleared') + +def _get_raw_client_leases(family='inet', interface=None): + from time import mktime + from datetime import datetime + from vyos.defaults import directories + from vyos.utils.network import get_interface_vrf + + lease_dir = directories['isc_dhclient_dir'] + lease_files = [] + lease_data = [] + + if interface: + tmp = f'{lease_dir}/dhclient_{interface}.lease' + if os.path.exists(tmp): + lease_files.append(tmp) + else: + # All DHCP leases + lease_files = glob(f'{lease_dir}/dhclient_*.lease') + + for lease in lease_files: + tmp = {} + with open(lease, 'r') as f: + for line in f.readlines(): + line = line.rstrip() + if 'last_update' not in tmp: + # ISC dhcp client contains least_update timestamp in human readable + # format this makes less sense for an API and also the expiry + # timestamp is provided in UNIX time. Convert string (e.g. Sun Jul + # 30 18:13:44 CEST 2023) to UNIX time (1690733624) + tmp.update({'last_update' : int(mktime(datetime.strptime(line, time_string).timetuple()))}) + continue + + k, v = line.split('=') + tmp.update({k : v.replace("'", "")}) + + if 'interface' in tmp: + vrf = get_interface_vrf(tmp['interface']) + if vrf: tmp.update({'vrf' : vrf}) + + lease_data.append(tmp) + + return lease_data + +def _get_formatted_client_leases(lease_data, family): + from time import localtime + from time import strftime + + from vyos.utils.network import is_intf_addr_assigned + + data_entries = [] + for lease in lease_data: + if not lease.get('new_ip_address'): + continue + data_entries.append(["Interface", lease['interface']]) + if 'new_ip_address' in lease: + tmp = '[Active]' if is_intf_addr_assigned(lease['interface'], lease['new_ip_address']) else '[Inactive]' + data_entries.append(["IP address", lease['new_ip_address'], tmp]) + if 'new_subnet_mask' in lease: + data_entries.append(["Subnet Mask", lease['new_subnet_mask']]) + if 'new_domain_name' in lease: + data_entries.append(["Domain Name", lease['new_domain_name']]) + if 'new_routers' in lease: + data_entries.append(["Router", lease['new_routers']]) + if 'new_domain_name_servers' in lease: + data_entries.append(["Name Server", lease['new_domain_name_servers']]) + if 'new_dhcp_server_identifier' in lease: + data_entries.append(["DHCP Server", lease['new_dhcp_server_identifier']]) + if 'new_dhcp_lease_time' in lease: + data_entries.append(["DHCP Server", lease['new_dhcp_lease_time']]) + if 'vrf' in lease: + data_entries.append(["VRF", lease['vrf']]) + if 'last_update' in lease: + tmp = strftime(time_string, localtime(int(lease['last_update']))) + data_entries.append(["Last Update", tmp]) + if 'new_expiry' in lease: + tmp = strftime(time_string, localtime(int(lease['new_expiry']))) + data_entries.append(["Expiry", tmp]) + + # Add empty marker + data_entries.append(['']) + + output = tabulate(data_entries, tablefmt='plain') + + return output + +def show_client_leases(raw: bool, family: ArgFamily, interface: typing.Optional[str]): + lease_data = _get_raw_client_leases(family=family, interface=interface) + if raw: + return lease_data + else: + return _get_formatted_client_leases(lease_data, family=family) + +@_verify_client +def renew_client_lease(raw: bool, family: ArgFamily, interface: str): + if not raw: + v = 'v6' if family == 'inet6' else '' + print(f'Restarting DHCP{v} client on interface {interface}...') + if family == 'inet6': + call(f'systemctl restart dhcp6c@{interface}.service') + else: + call(f'systemctl restart dhclient@{interface}.service') + +@_verify_client +def release_client_lease(raw: bool, family: ArgFamily, interface: str): + if not raw: + v = 'v6' if family == 'inet6' else '' + print(f'Release DHCP{v} client on interface {interface}...') + if family == 'inet6': + call(f'systemctl stop dhcp6c@{interface}.service') + else: + call(f'systemctl stop dhclient@{interface}.service') + +if __name__ == '__main__': + try: + res = vyos.opmode.run(sys.modules[__name__]) + if res: + print(res) + except (ValueError, vyos.opmode.Error) as e: + print(e) + sys.exit(1) |