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Diffstat (limited to 'python/vyos/utils/serial.py')
| -rw-r--r-- | python/vyos/utils/serial.py | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/python/vyos/utils/serial.py b/python/vyos/utils/serial.py new file mode 100644 index 000000000..7a662bf96 --- /dev/null +++ b/python/vyos/utils/serial.py @@ -0,0 +1,117 @@ +# Copyright 2024 VyOS maintainers and contributors <maintainers@vyos.io> +# +# This library is free software; you can redistribute it and/or +# modify it under the terms of the GNU Lesser General Public +# License as published by the Free Software Foundation; either +# version 2.1 of the License, or (at your option) any later version. +# +# This library 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 +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public +# License along with this library. If not, see <http://www.gnu.org/licenses/>. + +import os, re, json +from typing import List + +from vyos.base import Warning +from vyos.utils.io import ask_yes_no +from vyos.utils.process import cmd + +GLOB_GETTY_UNITS = 'serial-getty@*.service' +RE_GETTY_DEVICES = re.compile(r'.+@(.+).service$') + +SD_UNIT_PATH = '/run/systemd/system' +UTMP_PATH = '/run/utmp' + +def get_serial_units(include_devices=[]): + # Since we cannot depend on the current config for decommissioned ports, + # we just grab everything that systemd knows about. + tmp = cmd(f'systemctl list-units {GLOB_GETTY_UNITS} --all --output json --no-pager') + getty_units = json.loads(tmp) + for sdunit in getty_units: + m = RE_GETTY_DEVICES.search(sdunit['unit']) + if m is None: + Warning(f'Serial console unit name "{sdunit["unit"]}" is malformed and cannot be checked for activity!') + continue + + getty_device = m.group(1) + if include_devices and getty_device not in include_devices: + continue + + sdunit['device'] = getty_device + + return getty_units + +def get_authenticated_ports(units): + connected = [] + ports = [ x['device'] for x in units if 'device' in x ] + # + # utmpdump just gives us an easily parseable dump of currently logged-in sessions, for eg: + # $ utmpdump /run/utmp + # Utmp dump of /run/utmp + # [2] [00000] [~~ ] [reboot ] [~ ] [6.6.31-amd64-vyos ] [0.0.0.0 ] [2024-06-18T13:56:53,958484+00:00] + # [1] [00051] [~~ ] [runlevel] [~ ] [6.6.31-amd64-vyos ] [0.0.0.0 ] [2024-06-18T13:57:01,790808+00:00] + # [6] [03178] [tty1] [LOGIN ] [tty1 ] [ ] [0.0.0.0 ] [2024-06-18T13:57:31,015392+00:00] + # [7] [37151] [ts/0] [vyos ] [pts/0 ] [10.9.8.7 ] [10.9.8.7 ] [2024-07-04T13:42:08,760892+00:00] + # [8] [24812] [ts/1] [ ] [pts/1 ] [10.9.8.7 ] [10.9.8.7 ] [2024-06-20T18:10:07,309365+00:00] + # + # We can safely skip blank or LOGIN sessions with valid device names. + # + for line in cmd(f'utmpdump {UTMP_PATH}').splitlines(): + row = line.split('] [') + user_name = row[3].strip() + user_term = row[4].strip() + if user_name and user_name != 'LOGIN' and user_term in ports: + connected.append(user_term) + + return connected + +def restart_login_consoles(prompt_user=False, quiet=True, devices: List[str]=[]): + # restart_login_consoles() is called from both conf- and op-mode scripts, including + # the warning messages and user prompts common to both. + # + # The default case, called with no arguments, is a simple serial-getty restart & + # cleanup wrapper with no output or prompts that can be used from anywhere. + # + # quiet and prompt_user args have been split from an original "no_prompt", in + # order to support the completely silent default use case. "no_prompt" would + # only suppress the user interactive prompt. + # + # quiet intentionally does not suppress a vyos.base.Warning() for malformed + # device names in _get_serial_units(). + # + cmd('systemctl daemon-reload') + + units = get_serial_units(devices) + connected = get_authenticated_ports(units) + + if connected: + if not quiet: + print('There are user sessions connected via serial console that will be terminated\n' \ + 'when serial console settings are changed.\n') # extra newline is deliberate. + if not prompt_user: + # This flag is used by conf_mode/system_console.py to reset things, if there's + # a problem, the user should issue a manual restart for serial-getty. + print('Please ensure all settings are committed and saved before issuing a\n' \ + '"restart serial console" command to apply new configuration.') + if not prompt_user: + return False + if not ask_yes_no('Any uncommitted changes from these sessions will be lost and in-progress actions\n' \ + 'may be left in an inconsistent state. Continue?'): + return False + + for unit in units: + if 'device' not in unit: + continue # malformed or filtered. + unit_name = unit['unit'] + unit_device = unit['device'] + if os.path.exists(os.path.join(SD_UNIT_PATH, unit_name)): + cmd(f'systemctl restart {unit_name}') + else: + # Deleted stubs don't need to be restarted, just shut them down. + cmd(f'systemctl stop {unit_name}') + + return True |