diff options
Diffstat (limited to 'src/op_mode/dhcp.py')
| -rwxr-xr-x | src/op_mode/dhcp.py | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/src/op_mode/dhcp.py b/src/op_mode/dhcp.py new file mode 100755 index 000000000..b9e6e7bc9 --- /dev/null +++ b/src/op_mode/dhcp.py @@ -0,0 +1,291 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2022 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 sys +import typing + +from datetime import datetime +from ipaddress import ip_address +from isc_dhcp_leases import IscDhcpLeases +from tabulate import tabulate + +import vyos.opmode + +from vyos.base import Warning +from vyos.configquery import ConfigTreeQuery + +from vyos.util import cmd +from vyos.util import dict_search +from vyos.util import is_systemd_service_running + +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', 'iaid_duid', 'ip', 'last_communication', 'pool', 'remaining', 'state', 'type'] + +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=[]) -> list: + """ + Get DHCP server leases + :return list + """ + lease_file = '/config/dhcpdv6.leases' if family == 'inet6' else '/config/dhcpd.leases' + data = [] + leases = IscDhcpLeases(lease_file).get() + + if pool is None: + pool = _get_dhcp_pools(family=family) + else: + pool = [pool] + + for lease in leases: + data_lease = {} + data_lease['ip'] = lease.ip + data_lease['state'] = lease.binding_state + data_lease['pool'] = lease.sets.get('shared-networkname', '') + data_lease['end'] = lease.end.timestamp() + + if family == 'inet': + data_lease['mac'] = lease.ethernet + data_lease['start'] = lease.start.timestamp() + data_lease['hostname'] = lease.hostname + + if family == 'inet6': + data_lease['last_communication'] = lease.last_communication.timestamp() + data_lease['iaid_duid'] = _format_hex_string(lease.host_identifier_string) + lease_types_long = {'na': 'non-temporary', 'ta': 'temporary', 'pd': 'prefix delegation'} + data_lease['type'] = lease_types_long[lease.type] + + data_lease['remaining'] = lease.end - 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] + else: + data_lease['remaining'] = '' + + # Do not add old leases + if data_lease['remaining'] != '' and data_lease['pool'] in pool: + if not state 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') + remain = lease.get('remaining') + pool = lease.get('pool') + hostname = lease.get('hostname') + data_entries.append([ipaddr, hw_addr, state, start, end, remain, pool, hostname]) + + headers = ['IP Address', 'MAC address', 'State', 'Lease start', 'Lease expiration', 'Remaining', 'Pool', + 'Hostname'] + + 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('iaid_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', + 'IAID_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: + if family == 'inet6': + ranges = config.list_nodes(f'{base} subnet {subnet} address-range start') + else: + ranges = config.list_nodes(f'{base} subnet {subnet} range') + for range in ranges: + if family == 'inet6': + start = config.list_nodes(f'{base} subnet {subnet} address-range start')[0] + stop = config.value(f'{base} subnet {subnet} address-range start {start} 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 _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 + + +@_verify +def show_pool_statistics(raw: bool, family: str, 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: str, pool: typing.Optional[str], + sorted: typing.Optional[str], state: typing.Optional[str]): + # if dhcp server is down, inactive leases may still be shown as active, so warn the user. + if not is_systemd_service_running('isc-dhcp-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) + if raw: + return lease_data + else: + return _get_formatted_server_leases(lease_data, family=family) + + +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) |