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# Copyright (c) 2013 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import collections
import logging
import re
import time
from autotest_lib.client.common_lib import error
from autotest_lib.client.common_lib import utils
from import iw_event_logger
HT20 = 'HT20'
HT40_ABOVE = 'HT40+'
HT40_BELOW = 'HT40-'
SECURITY_WPA2 = 'wpa2'
# MIxed mode security is WPA2/WPA
# Table of lookups between the output of item 'secondary channel offset:' from
# iw <device> scan to constants.
HT_TABLE = {'no secondary': HT20,
'above': HT40_ABOVE,
'below': HT40_BELOW}
IwBand = collections.namedtuple('Band', ['num', 'frequencies', 'mcs_indices'])
IwBss = collections.namedtuple('IwBss', ['bss', 'frequency', 'ssid', 'security',
IwNetDev = collections.namedtuple('IwNetDev', ['phy', 'if_name', 'if_type'])
IwTimedScan = collections.namedtuple('IwTimedScan', ['time', 'bss_list'])
# The fields for IwPhy are as follows:
# name: string name of the phy, such as "phy0"
# bands: list of IwBand objects.
# modes: List of strings containing interface modes supported, such as "AP".
# commands: List of strings containing nl80211 commands supported, such as
# "authenticate".
# features: List of strings containing nl80211 features supported, such as
# "T-DLS".
# max_scan_ssids: Maximum number of SSIDs which can be scanned at once.
IwPhy = collections.namedtuple(
'Phy', ['name', 'bands', 'modes', 'commands', 'features',
'max_scan_ssids', 'avail_tx_antennas', 'avail_rx_antennas',
'supports_setting_antenna_mask', 'support_vht'])
# Time command to get elapsed time. Full path is used to avoid using the
# built-in 'time' command from the bash shell
IW_TIME_COMMAND = '/usr/local/bin/time -f "%e"'
IW_LINK_KEY_DTIM_PERIOD = 'dtim period'
IW_LOCAL_EVENT_LOG_FILE = './debug/iw_event_%d.log'
class IwRunner(object):
"""Defines an interface to the 'iw' command."""
def __init__(self, remote_host=None, command_iw=DEFAULT_COMMAND_IW):
self._run =
self._host = remote_host
if remote_host:
self._run =
self._command_iw = command_iw
self._log_id = 0
def _parse_scan_results(self, output):
"""Parse the output of the 'scan' and 'scan dump' commands.
@param output: string command output.
@returns a list of IwBss namedtuples; None if the scan fails
bss = None
frequency = None
ssid = None
ht = None
security = None
supported_securities = []
bss_list = []
for line in output.splitlines():
line = line.strip()
bss_match = re.match('BSS ([0-9a-f:]+)', line)
if bss_match:
if bss != None:
security = self.determine_security(supported_securities)
iwbss = IwBss(bss, frequency, ssid, security, ht)
bss = frequency = ssid = security = ht = None
supported_securities = []
bss =
if line.startswith('freq:'):
frequency = int(line.split()[1])
if line.startswith('SSID: '):
_, ssid = line.split(': ', 1)
if line.startswith('* secondary channel offset'):
ht = HT_TABLE[line.split(':')[1].strip()]
if line.startswith('WPA'):
if line.startswith('RSN'):
security = self.determine_security(supported_securities)
bss_list.append(IwBss(bss, frequency, ssid, security, ht))
return bss_list
def add_interface(self, phy, interface, interface_type):
Add an interface to a WiFi PHY.
@param phy: string name of PHY to add an interface to.
@param interface: string name of interface to add.
@param interface_type: string type of interface to add (e.g. 'monitor').
self._run('%s phy %s interface add %s type %s' %
(self._command_iw, phy, interface, interface_type))
def disconnect_station(self, interface):
Disconnect a STA from a network.
@param interface: string name of interface to disconnect.
self._run('%s dev %s disconnect' % (self._command_iw, interface))
def get_current_bssid(self, interface_name):
"""Get the BSSID that |interface_name| is associated with.
@param interface_name: string name of interface (e.g. 'wlan0').
@return string bssid of our current association, or None.
result = self._run('%s dev %s link' %
(self._command_iw, interface_name),
if result.exit_status:
# See comment in get_link_value.
return None
# We're looking for a line like:
# Connected to 04:f0:21:03:7d:bb (on wlan0)
match =
'Connected to ([0-9a-fA-F:]{17}) \\(on %s\\)' % interface_name,
if match is None:
return None
def get_interface(self, interface_name):
"""Get full information about an interface given an interface name.
@param interface_name: string name of interface (e.g. 'wlan0').
@return IwNetDev tuple.
matching_interfaces = [iw_if for iw_if in self.list_interfaces()
if iw_if.if_name == interface_name]
if len(matching_interfaces) != 1:
raise error.TestFail('Could not find interface named %s' %
return matching_interfaces[0]
def get_link_value(self, interface, iw_link_key):
"""Get the value of a link property for |interface|.
This command parses fields of iw link:
#> iw dev wlan0 link
Connected to 74:e5:43:10:4f:c0 (on wlan0)
SSID: PMKSACaching_4m9p5_ch1
freq: 5220
RX: 5370 bytes (37 packets)
TX: 3604 bytes (15 packets)
signal: -59 dBm
tx bitrate: 13.0 MBit/s MCS 1
bss flags: short-slot-time
dtim period: 5
beacon int: 100
@param iw_link_key: string one of IW_LINK_KEY_* defined above.
@param interface: string desired value of iw link property.
result = self._run('%s dev %s link' % (self._command_iw, interface),
if result.exit_status:
# When roaming, there is a period of time for mac80211 based drivers
# when the driver is 'associated' with an SSID but not a particular
# BSS. This causes iw to return an error code (-2) when attempting
# to retrieve information specific to the BSS. This does not happen
# in mwifiex drivers.
return None
find_re = re.compile('\s*%s:\s*(.*\S)\s*$' % iw_link_key)
find_results = filter(bool,
map(find_re.match, result.stdout.splitlines()))
if not find_results:
return None
actual_value = find_results[0].group(1)'Found iw link key %s with value %s.',
iw_link_key, actual_value)
return actual_value
def ibss_join(self, interface, ssid, frequency):
Join a WiFi interface to an IBSS.
@param interface: string name of interface to join to the IBSS.
@param ssid: string SSID of IBSS to join.
@param frequency: int frequency of IBSS in Mhz.
self._run('%s dev %s ibss join %s %d' %
(self._command_iw, interface, ssid, frequency))
def ibss_leave(self, interface):
Leave an IBSS.
@param interface: string name of interface to remove from the IBSS.
self._run('%s dev %s ibss leave' % (self._command_iw, interface))
def list_interfaces(self, desired_if_type=None):
"""List WiFi related interfaces on this system.
@param desired_if_type: string type of interface to filter
our returned list of interfaces for (e.g. 'managed').
@return list of IwNetDev tuples.
output = self._run('%s dev' % self._command_iw).stdout
interfaces = []
phy = None
if_name = None
if_type = None
for line in output.splitlines():
m = re.match('phy#([0-9]+)', line)
if m:
phy = 'phy%d' % int(
m = re.match('[\s]*Interface (.*)', line)
if m:
if_name =
# Common values for type are 'managed', 'monitor', and 'IBSS'.
m = re.match('[\s]*type ([a-zA-Z]+)', line)
if m:
if_type =
if phy and if_name and if_type:
interfaces.append(IwNetDev(phy=phy, if_name=if_name,
# One phy may have many interfaces, so don't reset it.
if_name = if_type = None
if desired_if_type:
interfaces = [interface for interface in interfaces
if interface.if_type == desired_if_type]
return interfaces
def list_phys(self):
List WiFi PHYs on the given host.
@return list of IwPhy tuples.
output = self._run('%s list' % self._command_iw).stdout
pending_phy_name = None
current_band = None
current_section = None
all_phys = []
def add_pending_phy():
"""Add the pending phy into |all_phys|."""
bands = tuple(IwBand(band.num,
for band in pending_phy_bands)
new_phy = IwPhy(pending_phy_name,
pending_phy_tx_antennas and pending_phy_rx_antennas,
for line in output.splitlines():
match_phy ='Wiphy (.*)', line)
if match_phy:
if pending_phy_name:
pending_phy_name =
pending_phy_bands = []
pending_phy_modes = []
pending_phy_commands = []
pending_phy_features = []
pending_phy_max_scan_ssids = None
pending_phy_tx_antennas = 0
pending_phy_rx_antennas = 0
pending_phy_support_vht = False
match_section = re.match('\s*(\w.*):\s*$', line)
if match_section:
current_section =
match_band = re.match('Band (\d+)', current_section)
if match_band:
current_band = IwBand(num=int(,
# Check for max_scan_ssids. This isn't a section, but it
# also isn't within a section.
match_max_scan_ssids = re.match('\s*max # scan SSIDs: (\d+)',
if match_max_scan_ssids and pending_phy_name:
pending_phy_max_scan_ssids = int(
if (current_section == 'Supported interface modes' and
mode_match ='\* (\w+)', line)
if mode_match:
if current_section == 'Supported commands' and pending_phy_name:
command_match ='\* (\w+)', line)
if command_match:
if (current_section is not None and
current_section.startswith('VHT Capabilities') and
pending_phy_support_vht = True
match_avail_antennas = re.match('\s*Available Antennas: TX (\S+)'
' RX (\S+)', line)
if match_avail_antennas and pending_phy_name:
pending_phy_tx_antennas = int(, 16)
pending_phy_rx_antennas = int(, 16)
match_device_support = re.match('\s*Device supports (.*)\.', line)
if match_device_support and pending_phy_name:
if not all([current_band, pending_phy_name,
mhz_match ='(\d+) MHz', line)
if mhz_match:
# re_mcs needs to match something like:
# HT TX/RX MCS rate indexes supported: 0-15, 32
if'HT TX/RX MCS rate indexes supported: ', line):
rate_string = line.split(':')[1].strip()
for piece in rate_string.split(','):
if piece.find('-') > 0:
# Must be a range like ' 0-15'
begin, end = piece.split('-')
for index in range(int(begin), int(end) + 1):
# Must be a single rate like '32 '
if pending_phy_name:
return all_phys
def remove_interface(self, interface, ignore_status=False):
Remove a WiFi interface from a PHY.
@param interface: string name of interface (e.g. mon0)
@param ignore_status: boolean True iff we should ignore failures
to remove the interface.
self._run('%s dev %s del' % (self._command_iw, interface),
def determine_security(self, supported_securities):
"""Determines security from the given list of supported securities.
@param supported_securities: list of supported securities from scan
if not supported_securities:
security = SECURITY_OPEN
elif len(supported_securities) == 1:
security = supported_securities[0]
return security
def scan(self, interface, frequencies=(), ssids=()):
"""Performs a scan.
@param interface: the interface to run the iw command against
@param frequencies: list of int frequencies in Mhz to scan.
@param ssids: list of string SSIDs to send probe requests for.
@returns a list of IwBss namedtuples; None if the scan fails
scan_result = self.timed_scan(interface, frequencies, ssids)
if scan_result is None:
return None
return scan_result.bss_list
def timed_scan(self, interface, frequencies=(), ssids=()):
"""Performs a timed scan.
@param interface: the interface to run the iw command against
@param frequencies: list of int frequencies in Mhz to scan.
@param ssids: list of string SSIDs to send probe requests for.
@returns a IwTimedScan namedtuple; None if the scan fails
freq_param = ''
if frequencies:
freq_param = ' freq %s' % ' '.join(map(str, frequencies))
ssid_param = ''
if ssids:
ssid_param = ' ssid "%s"' % '" "'.join(ssids)
command = '%s %s dev %s scan%s%s' % (IW_TIME_COMMAND,
self._command_iw, interface, freq_param, ssid_param)
scan = self._run(command, ignore_status=True)
if scan.exit_status != 0:
# The device was busy
logging.debug('scan exit_status: %d', scan.exit_status)
return None
if not scan.stdout:
logging.debug('Empty scan result')
bss_list = []
bss_list = self._parse_scan_results(scan.stdout)
scan_time = float(scan.stderr)
return IwTimedScan(scan_time, bss_list)
def scan_dump(self, interface):
"""Dump the contents of the scan cache.
Note that this does not trigger a scan. Instead, it returns
the kernel's idea of what BSS's are currently visible.
@param interface: the interface to run the iw command against
@returns a list of IwBss namedtuples; None if the scan fails
result = self._run('%s dev %s scan dump' % (self._command_iw,
return self._parse_scan_results(result.stdout)
def set_tx_power(self, interface, power):
Set the transmission power for an interface.
@param interface: string name of interface to set Tx power on.
@param power: string power parameter. (e.g. 'auto').
self._run('%s dev %s set txpower %s' %
(self._command_iw, interface, power))
def set_freq(self, interface, freq):
Set the frequency for an interface.
@param interface: string name of interface to set frequency on.
@param freq: int frequency
self._run('%s dev %s set freq %d' %
(self._command_iw, interface, freq))
def set_regulatory_domain(self, domain_string):
Set the regulatory domain of the current machine. Note that
the regulatory change happens asynchronously to the exit of
this function.
@param domain_string: string regulatory domain name (e.g. 'US').
self._run('%s reg set %s' % (self._command_iw, domain_string))
def get_regulatory_domain(self):
Get the regulatory domain of the current machine.
@returns a string containing the 2-letter regulatory domain name
(e.g. 'US').
output = self._run('%s reg get' % self._command_iw).stdout
m = re.match('^country (..):', output)
if not m:
return None
def wait_for_scan_result(self, interface, bss=None, ssid=None,
"""Returns a IWBSS object for a network with the given bssed or ssid.
@param interface: which interface to run iw against
@param bss: BSS as a string
@param ssid: ssid as a string
@param timeout_seconds: the amount of time to wait in seconds
@returns a list of IwBss collections that contain the given bss or ssid;
if the scan is empty or returns an error code None is returned.
start_time = time.time()
scan_failure_attempts = 0'Performing a scan with a max timeout of %d seconds.',
while time.time() - start_time < timeout_seconds:
scan_results = self.scan(interface)
if scan_results is None or len(scan_results) == 0:
scan_failure_attempts += 1
# Allow in-progress scan to complete
# If the in-progress scan takes more than 30 seconds to
# complete it will most likely never complete; abort.
# See
if scan_failure_attempts > 5:
logging.error('Scan failed to run, see debug log for '
'error code.')
return None
scan_failure_attempts = 0
matching_bsses = list()
for iwbss in scan_results:
if bss is not None and iwbss.bss != bss:
if ssid is not None and iwbss.ssid != ssid:
if len(matching_bsses) > 0:
return matching_bsses
if scan_failure_attempts > 0:
return None
# The SSID wasn't found, but the device is fine.
return list()
def wait_for_link(self, interface, timeout_seconds=10):
"""Waits until a link completes on |interface|.
@param interface: which interface to run iw against.
@param timeout_seconds: the amount of time to wait in seconds.
@returns True if link was established before the timeout.
start_time = time.time()
while time.time() - start_time < timeout_seconds:
link_results = self._run('%s dev %s link' %
(self._command_iw, interface))
if 'Not connected' not in link_results.stdout:
return True
return False
def set_antenna_bitmap(self, phy, tx_bitmap, rx_bitmap):
"""Set antenna chain mask on given phy (radio).
This function will set the antennas allowed to use for TX and
RX on the |phy| based on the |tx_bitmap| and |rx_bitmap|.
This command is only allowed when the interfaces on the phy are down.
@param phy: phy name
@param tx_bitmap: bitmap of allowed antennas to use for TX
@param rx_bitmap: bitmap of allowed antennas to use for RX
command = '%s phy %s set antenna %d %d' % (self._command_iw, phy,
tx_bitmap, rx_bitmap)
def get_event_logger(self):
"""Create and return a IwEventLogger object.
@returns a IwEventLogger object.
local_file = IW_LOCAL_EVENT_LOG_FILE % (self._log_id)
self._log_id += 1
return iw_event_logger.IwEventLogger(self._host, self._command_iw,
def vht_supported(self):
"""Returns True if VHT is supported; False otherwise."""
result = self._run('%s list' % self._command_iw).stdout
if 'VHT Capabilities' in result:
return True
return False