path: root/src/conf_mode/interfaces-wireless.py

#!/usr/bin/env python3
#
# Copyright (C) 2019-2020 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

from sys import exit
from re import findall
from copy import deepcopy
from netaddr import EUI, mac_unix_expanded

from vyos.config import Config
from vyos.configdict import get_interface_dict
from vyos.configdict import dict_merge
from vyos.configverify import verify_address
from vyos.configverify import verify_bridge_delete
from vyos.configverify import verify_dhcpv6
from vyos.configverify import verify_source_interface
from vyos.configverify import verify_vlan_config
from vyos.configverify import verify_vrf
from vyos.ifconfig import WiFiIf
from vyos.template import render
from vyos.util import call
from vyos import ConfigError
from vyos import airbag
airbag.enable()

# XXX: wpa_supplicant works on the source interface
wpa_suppl_conf = '/run/wpa_supplicant/{ifname}.conf'
hostapd_conf = '/run/hostapd/{ifname}.conf'

def find_other_stations(conf, base, ifname):
    """
    Only one wireless interface per phy can be in station mode -
    find all interfaces attached to a phy which run in station mode
    """
    old_level = conf.get_level()
    conf.set_level(base)
    dict = {}
    for phy in os.listdir('/sys/class/ieee80211'):
        list = []
        for interface in conf.list_nodes([]):
            if interface == ifname:
                continue
            # the following node is mandatory
            if conf.exists([interface, 'physical-device', phy]):
                tmp = conf.return_value([interface, 'type'])
                if tmp == 'station':
                    list.append(interface)
        if list:
            dict.update({phy: list})
    conf.set_level(old_level)
    return dict

def get_config(config=None):
    """
    Retrive CLI config as dictionary. Dictionary can never be empty, as at least the
    interface name will be added or a deleted flag
    """
    if config:
        conf = config
    else:
        conf = Config()
    base = ['interfaces', 'wireless']
    wifi = get_interface_dict(conf, base)

    if 'security' in wifi and 'wpa' in wifi['security']:
        wpa_cipher = wifi['security']['wpa'].get('cipher')
        wpa_mode = wifi['security']['wpa'].get('mode')
        if not wpa_cipher:
            tmp = None
            if wpa_mode == 'wpa':
                tmp = {'security': {'wpa': {'cipher' : ['TKIP', 'CCMP']}}}
            elif wpa_mode == 'wpa2':
                tmp = {'security': {'wpa': {'cipher' : ['CCMP']}}}
            elif wpa_mode == 'both':
                tmp = {'security': {'wpa': {'cipher' : ['CCMP', 'TKIP']}}}

            if tmp: wifi = dict_merge(tmp, wifi)

    # retrieve configured regulatory domain
    conf.set_level(['system'])
    if conf.exists(['wifi-regulatory-domain']):
        wifi['country_code'] = conf.return_value(['wifi-regulatory-domain'])

    # Only one wireless interface per phy can be in station mode
    tmp = find_other_stations(conf, base, wifi['ifname'])
    if tmp: wifi['station_interfaces'] = tmp

    return wifi

def verify(wifi):
    if 'deleted' in wifi:
        verify_bridge_delete(wifi)
        return None

    if 'physical_device' not in wifi:
        raise ConfigError('You must specify a physical-device "phy"')

    if 'type' not in wifi:
        raise ConfigError('You must specify a WiFi mode')

    if 'ssid' not in wifi and wifi['type'] != 'monitor':
        raise ConfigError('SSID must be configured')

    if wifi['type'] == 'access-point':
        if 'country_code' not in wifi:
            raise ConfigError('Wireless regulatory domain is mandatory,\n' \
                              'use "set system wifi-regulatory-domain" for configuration.')

        if 'channel' not in wifi:
            raise ConfigError('Wireless channel must be configured!')

    if 'security' in wifi:
        if {'wep', 'wpa'} <= set(wifi.get('security', {})):
            raise ConfigError('Must either use WEP or WPA security!')

        if 'wep' in wifi['security']:
            if 'key' in wifi['security']['wep'] and len(wifi['security']['wep']) > 4:
                raise ConfigError('No more then 4 WEP keys configurable')
            elif 'key' not in wifi['security']['wep']:
                raise ConfigError('Security WEP configured - missing WEP keys!')

        elif 'wpa' in wifi['security']:
            wpa = wifi['security']['wpa']
            if not any(i in ['passphrase', 'radius'] for i in wpa):
                raise ConfigError('Misssing WPA key or RADIUS server')

            if 'radius' in wpa:
                if 'server' in wpa['radius']:
                    for server in wpa['radius']['server']:
                        if 'key' not in wpa['radius']['server'][server]:
                            raise ConfigError(f'Misssing RADIUS shared secret key for server: {server}')

    if 'capabilities' in wifi:
        capabilities = wifi['capabilities']
        if 'vht' in capabilities:
            if 'ht' not in capabilities:
                raise ConfigError('Specify HT flags if you want to use VHT!')

            if {'beamform', 'antenna_count'} <= set(capabilities.get('vht', {})):
                if capabilities['vht']['antenna_count'] == '1':
                    raise ConfigError('Cannot use beam forming with just one antenna!')

                if capabilities['vht']['beamform'] == 'single-user-beamformer':
                    if int(capabilities['vht']['antenna_count']) < 3:
                        # Nasty Gotcha: see https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf lines 692-705
                        raise ConfigError('Single-user beam former requires at least 3 antennas!')

    if 'station_interfaces' in wifi and wifi['type'] == 'station':
        phy = wifi['physical_device']
        if phy in wifi['station_interfaces']:
            if len(wifi['station_interfaces'][phy]) > 0:
                raise ConfigError('Only one station per wireless physical interface possible!')

    verify_address(wifi)
    verify_vrf(wifi)

    # use common function to verify VLAN configuration
    verify_vlan_config(wifi)

    return None

def generate(wifi):
    interface = wifi['ifname']

    # always stop hostapd service first before reconfiguring it
    call(f'systemctl stop hostapd@{interface}.service')
    # always stop wpa_supplicant service first before reconfiguring it
    call(f'systemctl stop wpa_supplicant@{interface}.service')

    # Delete config files if interface is removed
    if 'deleted' in wifi:
        if os.path.isfile(hostapd_conf.format(**wifi)):
            os.unlink(hostapd_conf.format(**wifi))

        if os.path.isfile(wpa_suppl_conf.format(**wifi)):
            os.unlink(wpa_suppl_conf.format(**wifi))

        return None

    if 'mac' not in wifi:
        # http://wiki.stocksy.co.uk/wiki/Multiple_SSIDs_with_hostapd
        # generate locally administered MAC address from used phy interface
        with open('/sys/class/ieee80211/{physical_device}/addresses'.format(**wifi), 'r') as f:
            # some PHYs tend to have multiple interfaces and thus supply multiple MAC
            # addresses - we only need the first one for our calculation
            tmp = f.readline().rstrip()
            tmp = EUI(tmp).value
            # mask last nibble from the MAC address
            tmp &= 0xfffffffffff0
            # set locally administered bit in MAC address
            tmp |= 0x020000000000
            # we now need to add an offset to our MAC address indicating this
            # subinterfaces index
            tmp += int(findall(r'\d+', interface)[0])

            # convert integer to "real" MAC address representation
            mac = EUI(hex(tmp).split('x')[-1])
            # change dialect to use : as delimiter instead of -
            mac.dialect = mac_unix_expanded
            wifi['mac'] = str(mac)

    # render appropriate new config files depending on access-point or station mode
    if wifi['type'] == 'access-point':
        render(hostapd_conf.format(**wifi), 'wifi/hostapd.conf.tmpl', wifi, trim_blocks=True)

    elif wifi['type'] == 'station':
        render(wpa_suppl_conf.format(**wifi), 'wifi/wpa_supplicant.conf.tmpl', wifi, trim_blocks=True)

    return None

def apply(wifi):
    interface = wifi['ifname']
    if 'deleted' in wifi:
        WiFiIf(interface).remove()
    else:
        # WiFi interface needs to be created on-block (e.g. mode or physical
        # interface) instead of passing a ton of arguments, I just use a dict
        # that is managed by vyos.ifconfig
        conf = deepcopy(WiFiIf.get_config())

        # Assign WiFi instance configuration parameters to config dict
        conf['phy'] = wifi['physical_device']

        # Finally create the new interface
        w = WiFiIf(interface, **conf)
        w.update(wifi)

        # Enable/Disable interface - interface is always placed in
        # administrative down state in WiFiIf class
        if 'disable' not in wifi:
            # Physical interface is now configured. Proceed by starting hostapd or
            # wpa_supplicant daemon. When type is monitor we can just skip this.
            if wifi['type'] == 'access-point':
                call(f'systemctl start hostapd@{interface}.service')

            elif wifi['type'] == 'station':
                call(f'systemctl start wpa_supplicant@{interface}.service')

    return None

if __name__ == '__main__':
    try:
        c = get_config()
        verify(c)
        generate(c)
        apply(c)
    except ConfigError as e:
        print(e)
        exit(1)