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

#!/usr/bin/env python3
#
# Copyright (C) 2019 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 jinja2 import FileSystemLoader, Environment

from netifaces import interfaces
from netaddr import EUI, mac_unix_expanded

from vyos.config import Config
from vyos.configdict import list_diff, vlan_to_dict
from vyos.defaults import directories as vyos_data_dir
from vyos.ifconfig import WiFiIf
from vyos.ifconfig_vlan import apply_vlan_config, verify_vlan_config
from vyos.util import process_running, chmod_755, chown, run, is_bridge_member
from vyos import ConfigError

user = 'root'
group = 'vyattacfg'

default_config_data = {
    'address': [],
    'address_remove': [],
    'cap_ht' : False,
    'cap_ht_40mhz_incapable' : False,
    'cap_ht_powersave' : False,
    'cap_ht_chan_set_width' : '',
    'cap_ht_delayed_block_ack' : False,
    'cap_ht_dsss_cck_40' : False,
    'cap_ht_greenfield' : False,
    'cap_ht_ldpc' : False,
    'cap_ht_lsig_protection' : False,
    'cap_ht_max_amsdu' : '',
    'cap_ht_short_gi' :  [],
    'cap_ht_smps' : '',
    'cap_ht_stbc_rx' : '',
    'cap_ht_stbc_tx' : False,
    'cap_req_ht' : False,
    'cap_req_vht' : False,
    'cap_vht' : False,
    'cap_vht_antenna_cnt' : '',
    'cap_vht_antenna_fixed' : False,
    'cap_vht_beamform' : '',
    'cap_vht_center_freq_1' : '',
    'cap_vht_center_freq_2' : '',
    'cap_vht_chan_set_width' : '',
    'cap_vht_ldpc' : False,
    'cap_vht_link_adaptation' : '',
    'cap_vht_max_mpdu_exp' : '',
    'cap_vht_max_mpdu' : '',
    'cap_vht_short_gi' : [],
    'cap_vht_stbc_rx' : '',
    'cap_vht_stbc_tx' : False,
    'cap_vht_tx_powersave' : False,
    'cap_vht_vht_cf' : False,
    'channel': '',
    'country_code': '',
    'description': '',
    'deleted': False,
    'dhcp_client_id': '',
    'dhcp_hostname': '',
    'dhcp_vendor_class_id': '',
    'dhcpv6_prm_only': False,
    'dhcpv6_temporary': False,
    'disable': False,
    'disable_broadcast_ssid' : False,
    'disable_link_detect' : 1,
    'expunge_failing_stations' : False,
    'hw_id' : '',
    'intf': '',
    'isolate_stations' : False,
    'ip_disable_arp_filter': 1,
    'ip_enable_arp_accept': 0,
    'ip_enable_arp_announce': 0,
    'ip_enable_arp_ignore': 0,
    'ipv6_autoconf': 0,
    'ipv6_eui64_prefix': '',
    'ipv6_forwarding': 1,
    'ipv6_dup_addr_detect': 1,
    'mac' : '',
    'max_stations' : '',
    'mgmt_frame_protection' : 'disabled',
    'mode' : 'g',
    'phy' : '',
    'reduce_transmit_power' : '',
    'sec_wep' : False,
    'sec_wep_key' : [],
    'sec_wpa' : False,
    'sec_wpa_cipher' : [],
    'sec_wpa_mode' : 'both',
    'sec_wpa_passphrase' : '',
    'sec_wpa_radius' : [],
    'ssid' : '',
    'op_mode' : 'monitor',
    'vif': [],
    'vif_remove': [],
    'vrf': ''
}

def get_conf_file(conf_type, intf):
    cfg_dir = '/var/run/' + conf_type

    # create directory on demand
    if not os.path.exists(cfg_dir):
        os.mkdir(cfg_dir)
        chmod_755(cfg_dir)
        chown(cfg_dir, user, group)

    cfg_file = cfg_dir + r'/{}.cfg'.format(intf)
    return cfg_file

def get_pid(conf_type, intf):
    cfg_dir = '/var/run/' + conf_type

    # create directory on demand
    if not os.path.exists(cfg_dir):
        os.mkdir(cfg_dir)
        chmod_755(cfg_dir)
        chown(cfg_dir, user, group)

    cfg_file = cfg_dir + r'/{}.pid'.format(intf)
    return cfg_file


def get_wpa_suppl_config_name(intf):
    cfg_dir = '/var/run/wpa_supplicant'

    # create directory on demand
    if not os.path.exists(cfg_dir):
        os.mkdir(cfg_dir)
        chmod_755(cfg_dir)
        chown(cfg_dir, user, group)

    cfg_file = cfg_dir + r'/{}.cfg'.format(intf)
    return cfg_file


def get_config():
    wifi = deepcopy(default_config_data)
    conf = Config()

    # determine tagNode instance
    if 'VYOS_TAGNODE_VALUE' not in os.environ:
        raise ConfigError('Interface (VYOS_TAGNODE_VALUE) not specified')

    wifi['intf'] = os.environ['VYOS_TAGNODE_VALUE']

    # check if wireless interface has been removed
    cfg_base = 'interfaces wireless ' + wifi['intf']
    if not conf.exists(cfg_base):
        wifi['deleted'] = True
        # we can not bail out early as wireless interface can not be removed
        # Kernel will complain with: RTNETLINK answers: Operation not supported.
        # Thus we need to remove individual settings
        return wifi

    # set new configuration level
    conf.set_level(cfg_base)

    # retrieve configured interface addresses
    if conf.exists('address'):
        wifi['address'] = conf.return_values('address')

    # get interface addresses (currently effective) - to determine which
    # address is no longer valid and needs to be removed
    eff_addr = conf.return_effective_values('address')
    wifi['address_remove'] = list_diff(eff_addr, wifi['address'])

    # 40MHz intolerance, use 20MHz only
    if conf.exists('capabilities ht 40mhz-incapable'):
        wifi['cap_ht'] = True
        wifi['cap_ht_40mhz_incapable'] = True

    # WMM-PS Unscheduled Automatic Power Save Delivery [U-APSD]
    if conf.exists('capabilities ht auto-powersave'):
        wifi['cap_ht'] = True
        wifi['cap_ht_powersave'] = True

    # Supported channel set width
    if conf.exists('capabilities ht channel-set-width'):
        wifi['cap_ht'] = True
        wifi['cap_ht_chan_set_width'] = conf.return_values('capabilities ht channel-set-width')

    # HT-delayed Block Ack
    if conf.exists('capabilities ht delayed-block-ack'):
        wifi['cap_ht'] = True
        wifi['cap_ht_delayed_block_ack'] = True

    # DSSS/CCK Mode in 40 MHz
    if conf.exists('capabilities ht dsss-cck-40'):
        wifi['cap_ht'] = True
        wifi['cap_ht_dsss_cck_40'] = True

    # HT-greenfield capability
    if conf.exists('capabilities ht greenfield'):
        wifi['cap_ht'] = True
        wifi['cap_ht_greenfield'] = True

    # LDPC coding capability
    if conf.exists('capabilities ht ldpc'):
        wifi['cap_ht'] = True
        wifi['cap_ht_ldpc'] = True

    # L-SIG TXOP protection capability
    if conf.exists('capabilities ht lsig-protection'):
        wifi['cap_ht'] = True
        wifi['cap_ht_lsig_protection'] = True

    # Set Maximum A-MSDU length
    if conf.exists('capabilities ht max-amsdu'):
        wifi['cap_ht'] = True
        wifi['cap_ht_max_amsdu'] = conf.return_value('capabilities ht max-amsdu')

    # Short GI capabilities
    if conf.exists('capabilities ht short-gi'):
        wifi['cap_ht'] = True
        wifi['cap_ht_short_gi'] = conf.return_values('capabilities ht short-gi')

    # Spatial Multiplexing Power Save (SMPS) settings
    if conf.exists('capabilities ht smps'):
        wifi['cap_ht'] = True
        wifi['cap_ht_smps'] = conf.return_value('capabilities ht smps')

    # Support for receiving PPDU using STBC (Space Time Block Coding)
    if conf.exists('capabilities ht stbc rx'):
        wifi['cap_ht'] = True
        wifi['cap_ht_stbc_rx'] = conf.return_value('capabilities ht stbc rx')

    # Support for sending PPDU using STBC (Space Time Block Coding)
    if conf.exists('capabilities ht stbc tx'):
        wifi['cap_ht'] = True
        wifi['cap_ht_stbc_tx'] = True

    # Require stations to support HT PHY (reject association if they do not)
    if conf.exists('capabilities require-ht'):
        wifi['cap_req_ht'] = True

    # Require stations to support VHT PHY (reject association if they do not)
    if conf.exists('capabilities require-vht'):
        wifi['cap_req_vht'] = True

    # Number of antennas on this card
    if conf.exists('capabilities vht antenna-count'):
        wifi['cap_vht'] = True
        wifi['cap_vht_antenna_cnt'] = conf.return_value('capabilities vht antenna-count')

    # set if antenna pattern does not change during the lifetime of an association
    if conf.exists('capabilities vht antenna-pattern-fixed'):
        wifi['cap_vht'] = True
        wifi['cap_vht_antenna_fixed'] = True

    # Beamforming capabilities
    if conf.exists('capabilities vht beamform'):
        wifi['cap_vht'] = True
        wifi['cap_vht_beamform'] = conf.return_values('capabilities vht beamform')

    # VHT operating channel center frequency - center freq 1 (for use with 80, 80+80 and 160 modes)
    if conf.exists('capabilities vht center-channel-freq freq-1'):
        wifi['cap_vht'] = True
        wifi['cap_vht_center_freq_1'] = conf.return_value('capabilities vht center-channel-freq freq-1')

    # VHT operating channel center frequency - center freq 2 (for use with the 80+80 mode)
    if conf.exists('capabilities vht center-channel-freq freq-2'):
        wifi['cap_vht'] = True
        wifi['cap_vht_center_freq_2'] = conf.return_value('capabilities vht center-channel-freq freq-2')

    # VHT operating Channel width
    if conf.exists('capabilities vht channel-set-width'):
        wifi['cap_vht'] = True
        wifi['cap_vht_chan_set_width'] = conf.return_value('capabilities vht channel-set-width')

    # LDPC coding capability
    if conf.exists('capabilities vht ldpc'):
        wifi['cap_vht'] = True
        wifi['cap_vht_ldpc'] = True

    # VHT link adaptation capabilities
    if conf.exists('capabilities vht link-adaptation'):
        wifi['cap_vht'] = True
        wifi['cap_vht_link_adaptation'] = conf.return_value('capabilities vht link-adaptation')

    # Set the maximum length of A-MPDU pre-EOF padding that the station can receive
    if conf.exists('capabilities vht max-mpdu-exp'):
        wifi['cap_vht'] = True
        wifi['cap_vht_max_mpdu_exp'] = conf.return_value('capabilities vht max-mpdu-exp')

    # Increase Maximum MPDU length
    if conf.exists('capabilities vht max-mpdu'):
        wifi['cap_vht'] = True
        wifi['cap_vht_max_mpdu'] = conf.return_value('capabilities vht max-mpdu')

    # Increase Maximum MPDU length
    if conf.exists('capabilities vht short-gi'):
        wifi['cap_vht'] = True
        wifi['cap_vht_short_gi'] = conf.return_values('capabilities vht short-gi')

    # Support for receiving PPDU using STBC (Space Time Block Coding)
    if conf.exists('capabilities vht stbc rx'):
        wifi['cap_vht'] = True
        wifi['cap_vht_stbc_rx'] = conf.return_value('capabilities vht stbc rx')

    # Support for the transmission of at least 2x1 STBC (Space Time Block Coding)
    if conf.exists('capabilities vht stbc tx'):
        wifi['cap_vht'] = True
        wifi['cap_vht_stbc_tx'] = True

    # Support for VHT TXOP Power Save Mode
    if conf.exists('capabilities vht tx-powersave'):
        wifi['cap_vht'] = True
        wifi['cap_vht_tx_powersave'] = True

    # STA supports receiving a VHT variant HT Control field
    if conf.exists('capabilities vht vht-cf'):
        wifi['cap_vht'] = True
        wifi['cap_vht_vht_cf'] = True

    # Wireless radio channel
    if conf.exists('channel'):
        wifi['channel'] = conf.return_value('channel')

    # retrieve interface description
    if conf.exists('description'):
        wifi['description'] = conf.return_value('description')

    # get DHCP client identifier
    if conf.exists('dhcp-options client-id'):
        wifi['dhcp_client_id'] = conf.return_value('dhcp-options client-id')

    # DHCP client host name (overrides the system host name)
    if conf.exists('dhcp-options host-name'):
        wifi['dhcp_hostname'] = conf.return_value('dhcp-options host-name')

    # DHCP client vendor identifier
    if conf.exists('dhcp-options vendor-class-id'):
        wifi['dhcp_vendor_class_id'] = conf.return_value('dhcp-options vendor-class-id')

    # DHCPv6 only acquire config parameters, no address
    if conf.exists('dhcpv6-options parameters-only'):
        wifi['dhcpv6_prm_only'] = conf.return_value('dhcpv6-options parameters-only')

    # DHCPv6 temporary IPv6 address
    if conf.exists('dhcpv6-options temporary'):
        wifi['dhcpv6_temporary'] = conf.return_value('dhcpv6-options temporary')

    # Disable broadcast of SSID from access-point
    if conf.exists('disable-broadcast-ssid'):
        wifi['disable_broadcast_ssid'] = True

    # ignore link state changes on this interface
    if conf.exists('disable-link-detect'):
        wifi['disable_link_detect'] = 2

    # Disassociate stations based on excessive transmission failures
    if conf.exists('expunge-failing-stations'):
        wifi['expunge_failing_stations'] = True

    # retrieve real hardware address
    if conf.exists('hw-id'):
        wifi['hw_id'] = conf.return_value('hw-id')

    # Isolate stations on the AP so they cannot see each other
    if conf.exists('isolate-stations'):
        wifi['isolate_stations'] = True

    # ARP filter configuration
    if conf.exists('ip disable-arp-filter'):
        wifi['ip_disable_arp_filter'] = 0

    # ARP enable accept
    if conf.exists('ip enable-arp-accept'):
        wifi['ip_enable_arp_accept'] = 1

    # ARP enable announce
    if conf.exists('ip enable-arp-announce'):
        wifi['ip_enable_arp_announce'] = 1

    # Enable acquisition of IPv6 address using stateless autoconfig (SLAAC)
    if conf.exists('ipv6 address autoconf'):
        wifi['ipv6_autoconf'] = 1

    # Get prefix for IPv6 addressing based on MAC address (EUI-64)
    if conf.exists('ipv6 address eui64'):
        wifi['ipv6_eui64_prefix'] = conf.return_value('ipv6 address eui64')

    # ARP enable ignore
    if conf.exists('ip enable-arp-ignore'):
        wifi['ip_enable_arp_ignore'] = 1

    # Disable IPv6 forwarding on this interface
    if conf.exists('ipv6 disable-forwarding'):
        wifi['ipv6_forwarding'] = 0

    # IPv6 Duplicate Address Detection (DAD) tries
    if conf.exists('ipv6 dup-addr-detect-transmits'):
        wifi['ipv6_dup_addr_detect'] = int(conf.return_value('ipv6 dup-addr-detect-transmits'))

    # Wireless physical device
    if conf.exists('physical-device'):
        wifi['phy'] = conf.return_value('physical-device')

    # Media Access Control (MAC) address
    if conf.exists('mac'):
        wifi['mac'] = conf.return_value('mac')

    # Maximum number of wireless radio stations
    if conf.exists('max-stations'):
        wifi['max_stations'] = conf.return_value('max-stations')

    # Management Frame Protection (MFP) according to IEEE 802.11w
    if conf.exists('mgmt-frame-protection'):
        wifi['mgmt_frame_protection'] = conf.return_value('mgmt-frame-protection')

    # Wireless radio mode
    if conf.exists('mode'):
        wifi['mode'] = conf.return_value('mode')

    # retrieve VRF instance
    if conf.exists('vrf'):
        wifi['vrf'] = conf.return_value('vrf')

    # Transmission power reduction in dBm
    if conf.exists('reduce-transmit-power'):
        wifi['reduce_transmit_power'] = conf.return_value('reduce-transmit-power')

    # WEP enabled?
    if conf.exists('security wep'):
        wifi['sec_wep'] = True

    # WEP encryption key(s)
    if conf.exists('security wep key'):
        wifi['sec_wep_key'] = conf.return_values('security wep key')

    # WPA enabled?
    if conf.exists('security wpa'):
        wifi['sec_wpa'] = True

    # WPA Cipher suite
    if conf.exists('security wpa cipher'):
        wifi['sec_wpa_cipher'] = conf.return_values('security wpa cipher')

    # WPA mode
    if conf.exists('security wpa mode'):
        wifi['sec_wpa_mode'] = conf.return_value('security wpa mode')

    # WPA default ciphers depend on WPA mode
    if not wifi['sec_wpa_cipher']:
        if wifi['sec_wpa_mode'] == 'wpa':
            wifi['sec_wpa_cipher'].append('TKIP')
            wifi['sec_wpa_cipher'].append('CCMP')

        elif wifi['sec_wpa_mode'] == 'wpa2':
            wifi['sec_wpa_cipher'].append('CCMP')

        elif wifi['sec_wpa_mode'] == 'both':
            wifi['sec_wpa_cipher'].append('CCMP')
            wifi['sec_wpa_cipher'].append('TKIP')

    # WPA personal shared pass phrase
    if conf.exists('security wpa passphrase'):
        wifi['sec_wpa_passphrase'] = conf.return_value('security wpa passphrase')

    # WPA RADIUS source address
    if conf.exists('security wpa radius source-address'):
        wifi['sec_wpa_radius_source'] = conf.return_value('security wpa radius source-address')

    # WPA RADIUS server
    for server in conf.list_nodes('security wpa radius server'):
        # set new configuration level
        conf.set_level(cfg_base + ' security wpa radius server ' + server)
        radius = {
            'server' : server,
            'acc_port' : '',
            'disabled': False,
            'port' : 1812,
            'key' : ''
        }

        # RADIUS server port
        if conf.exists('port'):
            radius['port'] = int(conf.return_value('port'))

        # receive RADIUS accounting info
        if conf.exists('accounting'):
            radius['acc_port'] = radius['port'] + 1

        # Check if RADIUS server was temporary disabled
        if conf.exists(['disable']):
            radius['disabled'] = True

        # RADIUS server shared-secret
        if conf.exists('key'):
            radius['key'] = conf.return_value('key')

        # append RADIUS server to list of servers
        wifi['sec_wpa_radius'].append(radius)

    # re-set configuration level to parse new nodes
    conf.set_level(cfg_base)

    # Wireless access-point service set identifier (SSID)
    if conf.exists('ssid'):
        wifi['ssid'] = conf.return_value('ssid')

    # Wireless device type for this interface
    if conf.exists('type'):
        tmp = conf.return_value('type')
        if tmp == 'access-point':
            tmp = 'ap'

        wifi['op_mode'] = tmp

    # re-set configuration level to parse new nodes
    conf.set_level(cfg_base)
    # Determine vif interfaces (currently effective) - to determine which
    # vif interface is no longer present and needs to be removed
    eff_intf = conf.list_effective_nodes('vif')
    act_intf = conf.list_nodes('vif')
    wifi['vif_remove'] = list_diff(eff_intf, act_intf)

    if conf.exists('vif'):
        for vif in conf.list_nodes('vif'):
            # set config level to vif interface
            conf.set_level(cfg_base + ' vif ' + vif)
            wifi['vif'].append(vlan_to_dict(conf))

    # disable interface
    if conf.exists('disable'):
        wifi['disable'] = True

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

    return wifi


def verify(wifi):
    if wifi['deleted']:
        interface = wifi['intf']
        is_member, bridge = is_bridge_member(interface)
        if is_member:
            # can not use a f'' formatted-string here as bridge would not get
            # expanded in the print statement
            raise ConfigError('Can not delete interface "{0}" as it ' \
                              'is a member of bridge "{1}"!'.format(interface, bridge))
        return None


    if wifi['op_mode'] != 'monitor' and not wifi['ssid']:
        raise ConfigError('SSID must be set for {}'.format(wifi['intf']))

    if not wifi['phy']:
        raise ConfigError('You must specify physical-device')

    if not wifi['mode']:
        raise ConfigError('You must specify a WiFi mode')

    if wifi['op_mode'] == 'ap':
        c = Config()
        if not c.exists('system wifi-regulatory-domain'):
            raise ConfigError('Wireless regulatory domain is mandatory,\n' \
                              'use "set system wifi-regulatory-domain".')

        if not wifi['channel']:
            raise ConfigError('Channel must be set for {}'.format(wifi['intf']))

    if len(wifi['sec_wep_key']) > 4:
        raise ConfigError('No more then 4 WEP keys configurable')

    if wifi['cap_vht'] and not wifi['cap_ht']:
        raise ConfigError('Specify HT flags if you want to use VHT!')

    if wifi['cap_vht_beamform'] and wifi['cap_vht_antenna_cnt'] == 1:
        raise ConfigError('Cannot use beam forming with just one antenna!')

    if wifi['cap_vht_beamform'] == 'single-user-beamformer' and wifi['cap_vht_antenna_cnt'] < 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 wifi['sec_wep'] and (len(wifi['sec_wep_key']) == 0):
        raise ConfigError('Missing WEP keys')

    if wifi['sec_wpa'] and not (wifi['sec_wpa_passphrase'] or wifi['sec_wpa_radius']):
        raise ConfigError('Misssing WPA key or RADIUS server')

    for radius in wifi['sec_wpa_radius']:
        if not radius['key']:
            raise ConfigError('Misssing RADIUS shared secret key for server: {}'.format(radius['server']))

    vrf_name = wifi['vrf']
    if vrf_name and vrf_name not in interfaces():
        raise ConfigError(f'VRF "{vrf_name}" does not exist')

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

    conf = Config()
    # Only one wireless interface per phy can be in station mode
    base = ['interfaces', 'wireless']
    for phy in os.listdir('/sys/class/ieee80211'):
        stations = []
        for wlan in conf.list_nodes(base):
            # the following node is mandatory
            if conf.exists(base + [wlan, 'physical-device', phy]):
                tmp = conf.return_value(base + [wlan, 'type'])
                if tmp == 'station':
                    stations.append(wlan)

        if len(stations) > 1:
            raise ConfigError('Only one station per wireless physical interface possible!')

    return None

def generate(wifi):
    # Prepare Jinja2 template loader from files
    tmpl_path = os.path.join(vyos_data_dir["data"], "templates", "wifi")
    fs_loader = FileSystemLoader(tmpl_path)
    env = Environment(loader=fs_loader)

    # always stop hostapd service first before reconfiguring it
    pidfile = get_pid('hostapd', wifi['intf'])
    if process_running(pidfile):
        command = 'start-stop-daemon'
        command += ' --stop '
        command += ' --quiet'
        command += ' --oknodo'
        command += ' --pidfile ' + pidfile
        run(command)

    # always stop wpa_supplicant service first before reconfiguring it
    pidfile = get_pid('wpa_supplicant', wifi['intf'])
    if process_running(pidfile):
        command = 'start-stop-daemon'
        command += ' --stop '
        command += ' --quiet'
        command += ' --oknodo'
        command += ' --pidfile ' + pidfile
        run(command)

    # Delete config files if interface is removed
    if wifi['deleted']:
        if os.path.isfile(get_conf_file('hostapd', wifi['intf'])):
            os.unlink(get_conf_file('hostapd', wifi['intf']))

        if os.path.isfile(get_conf_file('wpa_supplicant', wifi['intf'])):
            os.unlink(get_conf_file('wpa_supplicant', wifi['intf']))

        return None

    if not wifi['mac']:
        # http://wiki.stocksy.co.uk/wiki/Multiple_SSIDs_with_hostapd
        # generate locally administered MAC address from used phy interface
        with open('/sys/class/ieee80211/{}/addresses'.format(wifi['phy']), '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+', wifi['intf'])[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['op_mode'] == 'ap':
        tmpl = env.get_template('hostapd.conf.tmpl')
        config_text = tmpl.render(wifi)
        with open(get_conf_file('hostapd', wifi['intf']), 'w') as f:
            f.write(config_text)

    elif wifi['op_mode'] == 'station':
        tmpl = env.get_template('wpa_supplicant.conf.tmpl')
        config_text = tmpl.render(wifi)
        with open(get_conf_file('wpa_supplicant', wifi['intf']), 'w') as f:
            f.write(config_text)

    return None

def apply(wifi):
    if wifi['deleted']:
        w = WiFiIf(wifi['intf'])
        # delete interface
        w.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['phy']

        # Finally create the new interface
        w = WiFiIf(wifi['intf'], **conf)

        # assign/remove VRF
        w.set_vrf(wifi['vrf'])

        # update interface description used e.g. within SNMP
        w.set_alias(wifi['description'])

        if wifi['dhcp_client_id']:
            w.dhcp.v4.options['client_id'] = wifi['dhcp_client_id']

        if wifi['dhcp_hostname']:
            w.dhcp.v4.options['hostname'] = wifi['dhcp_hostname']

        if wifi['dhcp_vendor_class_id']:
            w.dhcp.v4.options['vendor_class_id'] = wifi['dhcp_vendor_class_id']

        if wifi['dhcpv6_prm_only']:
            w.dhcp.v6.options['dhcpv6_prm_only'] = True

        if wifi['dhcpv6_temporary']:
            w.dhcp.v6.options['dhcpv6_temporary'] = True

        # ignore link state changes
        w.set_link_detect(wifi['disable_link_detect'])

        # Change interface MAC address - re-set to real hardware address (hw-id)
        # if custom mac is removed
        if wifi['mac']:
            w.set_mac(wifi['mac'])
        elif wifi['hw_id']:
            w.set_mac(wifi['hw_id'])

        # configure ARP filter configuration
        w.set_arp_filter(wifi['ip_disable_arp_filter'])
        # configure ARP accept
        w.set_arp_accept(wifi['ip_enable_arp_accept'])
        # configure ARP announce
        w.set_arp_announce(wifi['ip_enable_arp_announce'])
        # configure ARP ignore
        w.set_arp_ignore(wifi['ip_enable_arp_ignore'])
        # IPv6 address autoconfiguration
        w.set_ipv6_autoconf(wifi['ipv6_autoconf'])
        # IPv6 EUI-based address
        w.set_ipv6_eui64_address(wifi['ipv6_eui64_prefix'])
        # IPv6 forwarding
        w.set_ipv6_forwarding(wifi['ipv6_forwarding'])
        # IPv6 Duplicate Address Detection (DAD) tries
        w.set_ipv6_dad_messages(wifi['ipv6_dup_addr_detect'])

        # Configure interface address(es)
        # - not longer required addresses get removed first
        # - newly addresses will be added second
        for addr in wifi['address_remove']:
            w.del_addr(addr)
        for addr in wifi['address']:
            w.add_addr(addr)

        # remove no longer required VLAN interfaces (vif)
        for vif in wifi['vif_remove']:
            w.del_vlan(vif)

        # create VLAN interfaces (vif)
        for vif in wifi['vif']:
            # QoS priority mapping can only be set during interface creation
            # so we delete the interface first if required.
            if vif['egress_qos_changed'] or vif['ingress_qos_changed']:
                try:
                    # on system bootup the above condition is true but the interface
                    # does not exists, which throws an exception, but that's legal
                    w.del_vlan(vif['id'])
                except:
                    pass

            vlan = w.add_vlan(vif['id'])
            apply_vlan_config(vlan, vif)

        # Enable/Disable interface - interface is always placed in
        # administrative down state in WiFiIf class
        if not wifi['disable']:
            w.set_admin_state('up')

            # Physical interface is now configured. Proceed by starting hostapd or
            # wpa_supplicant daemon. When type is monitor we can just skip this.
            if wifi['op_mode'] == 'ap':
                command = 'start-stop-daemon'
                command += ' --start '
                command += ' --quiet'
                command += ' --oknodo'
                command += ' --pidfile ' + get_pid('hostapd', wifi['intf'])
                command += ' --exec /usr/sbin/hostapd'
                # now pass arguments to hostapd binary
                command += ' -- '
                command += ' -B'
                command += ' -P ' + get_pid('hostapd', wifi['intf'])
                command += ' ' + get_conf_file('hostapd', wifi['intf'])

                # execute assembled command
                run(command)

            elif wifi['op_mode'] == 'station':
                command = 'start-stop-daemon'
                command += ' --start '
                command += ' --quiet'
                command += ' --oknodo'
                command += ' --pidfile ' + get_pid('hostapd', wifi['intf'])
                command += ' --exec /sbin/wpa_supplicant'
                # now pass arguments to hostapd binary
                command += ' -- '
                command += ' -s -B -D nl80211'
                command += ' -P ' + get_pid('wpa_supplicant', wifi['intf'])
                command += ' -i ' + wifi['intf']
                command += ' -c ' + \
                    get_conf_file('wpa_supplicant', wifi['intf'])

                # execute assembled command
                run(command)

    return None

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