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Diffstat (limited to 'python')
| -rw-r--r-- | python/vyos/utils/wwan.py | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/python/vyos/utils/wwan.py b/python/vyos/utils/wwan.py new file mode 100644 index 000000000..fd8cd4f2e --- /dev/null +++ b/python/vyos/utils/wwan.py @@ -0,0 +1,124 @@ +# Copyright (C) VyOS Inc. +# +# 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/>. + +"""ModemManager helpers shared between the WWAN conf_mode script and +vyos-netlinkd. + +Both dial the very same modem with the very same parameters - conf_mode when +the CLI config is applied, vyos-netlinkd when a session has to be re- +established after it was lost. Keeping the option string and the mmcli +invocations in one place means a re-dial can never drift from what conf_mode +would have done. +""" + +from time import sleep + +from vyos.utils.dict import dict_search +from vyos.utils.process import call +from vyos.utils.process import cmdl +from vyos.utils.process import DEVNULL +from vyos.utils.process import is_systemd_service_active + +service_name = 'ModemManager.service' + +# Bounded wait for a modem to appear after ModemManager has been started. The +# service being up is not enough - the modem is only dialable once it has been +# probed and exported on the bus, which takes a moment longer. +modem_wait_timeout = 25 +modem_wait_poll = 0.250 + +def modem_index(ifname: str) -> str: + """ Return the ModemManager modem index backing an interface, wwan0 -> 0 """ + if not ifname.startswith('wwan'): + raise ValueError(f'Specified interface "{ifname}" is not a WWAN interface') + return ifname[len('wwan'):] + +def start_modem_manager() -> None: + """ ModemManager is required to dial WWAN connections - a single instance + serves all modems. Start it if it is not running yet and wait until a modem + has been detected, so a dial that follows does not race the probing. """ + if is_systemd_service_active(service_name): + return None + + cmdl(['systemctl', 'start', service_name]) + + counter = int(modem_wait_timeout / modem_wait_poll) + while counter > 0: + counter -= 1 + try: + tmp = cmdl(['mmcli', '-L']) + except OSError: + # ModemManager is up but not yet answering on the bus - keep + # polling, this is expected for the first moments after start. + tmp = '' + if tmp and tmp != 'No modems were found': + break + sleep(modem_wait_poll) + + return None + +def connect_options(config: dict) -> str: + """ Build the mmcli --simple-connect option string for a WWAN interface. + + config is an interface configuration dict as returned by + get_interface_dict() in conf_mode or op_mode_config_dict() in an op-mode + context - both are key-mangled the same way, so both are accepted here. + """ + ip_type = 'ipv4' + slaac = dict_search('ipv6.address.autoconf', config) != None + if 'address' in config: + if 'dhcp' in config['address'] and ('dhcpv6' in config['address'] or slaac): + ip_type = 'ipv4v6' + elif 'dhcpv6' in config['address'] or slaac: + ip_type = 'ipv6' + elif 'dhcp' in config['address']: + ip_type = 'ipv4' + + options = f'ip-type={ip_type},apn=' + config['apn'] + if 'authentication' in config: + options += ',user={username},password={password}'.format(**config['authentication']) + + return options + +def modem_disconnect(ifname: str) -> None: + """ Disconnect every bearer of the modem backing ifname. The number of + bearers a modem can hold is limited, so we always disconnect before we + dial again. """ + call(f'mmcli --modem {modem_index(ifname)} --simple-disconnect') + +def modem_connect(ifname: str, options: str) -> bool: + """ Dial the modem backing ifname, returns True if the modem connected """ + modem = modem_index(ifname) + + # Some networks only ever admit a single combined IPv4+IPv6 PDN context per + # APN and reject a standalone IPv6 "Start Network" request outright (QMI + # CallEndReason ip-version-mismatch) once an IPv4 session already exists for + # that APN. ModemManager's --simple-connect with ip-type=ipv4v6 opens two + # separate WDS sessions (one per family) rather than negotiating both + # together, which is what a normal handset attach does and why this is + # invisible on most other devices. + # + # Pre-negotiating the attach-time PDN type upfront avoids the rejection; the + # resulting bearer only sets up what the *next* --simple-connect is allowed + # to request and can't be connected directly, so a failure here isn't fatal + # - unsupported modems simply proceed to --simple-connect exactly as before. + if options.partition('ip-type=')[2].partition(',')[0] in ('ipv6', 'ipv4v6'): + # best effort by definition, so do not report the rejection a modem + # without attach configuration support answers with on every dial + call(f'mmcli --modem {modem} --3gpp-set-initial-eps-bearer-settings="{options}"', + stdout=DEVNULL, stderr=DEVNULL) + + command = f'mmcli --modem {modem} --simple-connect="{options}"' + return call(command, stdout=DEVNULL) == 0 |