From bafa91b945ac77e2e1d000e356ca819bd5f87460 Mon Sep 17 00:00:00 2001 From: Christian Poessinger Date: Mon, 8 Jun 2020 22:45:04 +0200 Subject: console: T2529: migrate from ttyUSB device to new device in /dev/serial/by-bus During testing it was discovered that there is a well known problem (we had for ethernet interfaces) also in the serial port world. They will be enumerated and mapped to /dev/ttyUSBxxx differently from boot to boot. This is especially painful on my development APU4 board which also has a Sierra Wireless MC7710 LTE module installed. The serial port will toggle between ttyUSB2 and ttyUSB5 depending on the amount of serial port extenders attached (FT4232H). The shipped udev rule (/usr/lib/udev/rules.d/60-serial.rules) partly solves this by enumerating the devices into /dev/serial/by-id folder with their name and serial number - it's a very good idea but I've found that not all of the FT4232H dongles have a serial number programmed - this leads to the situation that when you plug in two cables with both having serial number 0 - only one device symlink will appear - the previous one is always overwritten by the latter one. Derive /usr/lib/udev/rules.d/60-serial.rules and create a /dev/serial/by-bus directory and group devices by attached USB root port. --- src/conf_mode/system_console.py | 59 ++++++++++++++++------------------- src/migration-scripts/system/16-to-17 | 20 ++++++++++++ 2 files changed, 47 insertions(+), 32 deletions(-) (limited to 'src') diff --git a/src/conf_mode/system_console.py b/src/conf_mode/system_console.py index d1d9b7c70..a3e450a36 100755 --- a/src/conf_mode/system_console.py +++ b/src/conf_mode/system_console.py @@ -18,40 +18,46 @@ import os from vyos.config import Config from vyos.util import call +from vyos.template import render from vyos import ConfigError, airbag airbag.enable() -serial_getty_file = '/lib/systemd/system/serial-getty@.service' - def get_config(): conf = Config() base = ['system', 'console'] - if not conf.exists(base): - return None - # retrieve configuration at once console = conf.get_config_dict(base) - # set default values - if 'device' in console.keys(): - for device in console['device'].keys(): - # no speed setting has been configured - use default value - if not 'speed' in console['device'][device].keys(): - tmp = { 'speed': '' } - if device.startswith('hvc'): - tmp['speed'] = 38400 - else: - tmp['speed'] = 115200 + # bail out early if no serial console is configured + if 'device' not in console.keys(): + return console - console['device'][device].update(tmp) + # convert CLI values to system values + for device in console['device'].keys(): + # no speed setting has been configured - use default value + if not 'speed' in console['device'][device].keys(): + tmp = { 'speed': '' } + if device.startswith('hvc'): + tmp['speed'] = 38400 + else: + tmp['speed'] = 115200 + + console['device'][device].update(tmp) + + if device.startswith('usb'): + # It is much easiert to work with the native ttyUSBn name when using + # getty, but that name may change across reboots - depending on the + # amount of connected devices. We will resolve the fixed device name + # to its dynamic device file - and create a new dict entry for it. + # + # updating the dict must come as last step in the loop! + tmp = os.path.basename(os.readlink('/dev/serial/by-bus/usb0b1p1.0')) + console['device'][tmp] = console['device'].pop(device) return console def verify(console): - if not os.path.isfile(serial_getty_file): - raise ConfigError(f'Could not open: {serial_getty_file}') - return None def generate(console): @@ -63,20 +69,9 @@ def generate(console): call(f'systemctl stop {basename}') os.unlink(os.path.join(root, basename)) - # bail out early if serial device is not configured - if not console or 'device' not in console.keys(): - return None - for device in console['device'].keys(): - serial_getty_device_file = f'{base_dir}/serial-getty@{device}.service' - serial_getty_wants_file = f'{base_dir}/getty.target.wants/serial-getty@{device}.service' - - with open(serial_getty_file, 'r') as f: - tmp = f.read() - tmp = tmp.replace('115200,38400,9600', str(console['device'][device]['speed'])) - - with open(serial_getty_device_file, 'w') as f: - f.write(tmp) + config_file = base_dir + f'/serial-getty@{device}.service' + render(config_file, 'getty/serial-getty.service.tmpl', console['device'][device]) # Reload systemd manager configuration call('systemctl daemon-reload') diff --git a/src/migration-scripts/system/16-to-17 b/src/migration-scripts/system/16-to-17 index ca3b10f49..981149d1b 100755 --- a/src/migration-scripts/system/16-to-17 +++ b/src/migration-scripts/system/16-to-17 @@ -47,6 +47,26 @@ else: if config.exists(dev_path + ['modem']): config.delete(dev_path + ['modem']) + # Only continue on USB based serial consoles + if not 'ttyUSB' in device: + continue + + # A serial console has been configured but it does no longer + # exist on the system - cleanup + if not os.path.exists(f'/dev/{device}'): + config.delete(dev_path) + continue + + # migrate from ttyUSB device to new device in /dev/serial/by-bus + for root, dirs, files in os.walk('/dev/serial/by-bus'): + for usb_device in files: + device_file = os.path.realpath(os.path.join(root, usb_device)) + # migrate to new USB device names (T2529) + if os.path.basename(device_file) == device: + config.copy(dev_path, base + ['device', usb_device]) + # Delete old USB node from config + config.delete(dev_path) + try: with open(file_name, 'w') as f: f.write(config.to_string()) -- cgit v1.2.3