• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1# Copyright (c) 2013 The Chromium Authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5import collections
6import copy
7import logging
8import re
9import time
10
11from autotest_lib.client.common_lib import error
12from autotest_lib.client.common_lib import utils
13from autotest_lib.client.common_lib.cros.network import iw_event_logger
14
15# These must mirror the values in 'iw list' output.
16CHAN_FLAG_DISABLED = 'disabled'
17CHAN_FLAG_NO_IR = 'no IR'
18CHAN_FLAG_PASSIVE_SCAN = 'passive scan'
19CHAN_FLAG_RADAR_DETECT = 'radar detection'
20DEV_MODE_AP = 'AP'
21DEV_MODE_IBSS = 'IBSS'
22DEV_MODE_MONITOR = 'monitor'
23
24HT20 = 'HT20'
25HT40_ABOVE = 'HT40+'
26HT40_BELOW = 'HT40-'
27
28SECURITY_OPEN = 'open'
29SECURITY_WEP = 'wep'
30SECURITY_WPA = 'wpa'
31SECURITY_WPA2 = 'wpa2'
32# Mixed mode security is WPA2/WPA
33SECURITY_MIXED = 'mixed'
34
35# Table of lookups between the output of item 'secondary channel offset:' from
36# iw <device> scan to constants.
37
38HT_TABLE = {'no secondary': HT20,
39            'above': HT40_ABOVE,
40            'below': HT40_BELOW}
41
42IwBand = collections.namedtuple(
43    'Band', ['num', 'frequencies', 'frequency_flags', 'mcs_indices'])
44IwBss = collections.namedtuple('IwBss', ['bss', 'frequency', 'ssid', 'security',
45                                         'ht', 'signal'])
46IwNetDev = collections.namedtuple('IwNetDev', ['phy', 'if_name', 'if_type'])
47IwTimedScan = collections.namedtuple('IwTimedScan', ['time', 'bss_list'])
48
49# The fields for IwPhy are as follows:
50#   name: string name of the phy, such as "phy0"
51#   bands: list of IwBand objects.
52#   modes: List of strings containing interface modes supported, such as "AP".
53#   commands: List of strings containing nl80211 commands supported, such as
54#          "authenticate".
55#   features: List of strings containing nl80211 features supported, such as
56#          "T-DLS".
57#   max_scan_ssids: Maximum number of SSIDs which can be scanned at once.
58IwPhy = collections.namedtuple(
59    'Phy', ['name', 'bands', 'modes', 'commands', 'features',
60            'max_scan_ssids', 'avail_tx_antennas', 'avail_rx_antennas',
61            'supports_setting_antenna_mask', 'support_vht'])
62
63DEFAULT_COMMAND_IW = 'iw'
64
65# Redirect stderr to stdout on Cros since adb commands cannot distinguish them
66# on Brillo.
67IW_TIME_COMMAND_FORMAT = '(time -p %s) 2>&1'
68IW_TIME_COMMAND_OUTPUT_START = 'real'
69
70IW_LINK_KEY_BEACON_INTERVAL = 'beacon int'
71IW_LINK_KEY_DTIM_PERIOD = 'dtim period'
72IW_LINK_KEY_FREQUENCY = 'freq'
73IW_LOCAL_EVENT_LOG_FILE = './debug/iw_event_%d.log'
74
75
76class IwRunner(object):
77    """Defines an interface to the 'iw' command."""
78
79
80    def __init__(self, remote_host=None, command_iw=DEFAULT_COMMAND_IW):
81        self._run = utils.run
82        self._host = remote_host
83        if remote_host:
84            self._run = remote_host.run
85        self._command_iw = command_iw
86        self._log_id = 0
87
88
89    def _parse_scan_results(self, output):
90        """Parse the output of the 'scan' and 'scan dump' commands.
91
92        Here is an example of what a single network would look like for
93        the input parameter.  Some fields have been removed in this example:
94          BSS 00:11:22:33:44:55(on wlan0)
95          freq: 2447
96          beacon interval: 100 TUs
97          signal: -46.00 dBm
98          Information elements from Probe Response frame:
99          SSID: my_open_network
100          Extended supported rates: 24.0 36.0 48.0 54.0
101          HT capabilities:
102          Capabilities: 0x0c
103          HT20
104          HT operation:
105          * primary channel: 8
106          * secondary channel offset: no secondary
107          * STA channel width: 20 MHz
108          RSN: * Version: 1
109          * Group cipher: CCMP
110          * Pairwise ciphers: CCMP
111          * Authentication suites: PSK
112          * Capabilities: 1-PTKSA-RC 1-GTKSA-RC (0x0000)
113
114        @param output: string command output.
115
116        @returns a list of IwBss namedtuples; None if the scan fails
117
118        """
119        bss = None
120        frequency = None
121        ssid = None
122        ht = None
123        signal = None
124        security = None
125        supported_securities = []
126        bss_list = []
127        for line in output.splitlines():
128            line = line.strip()
129            bss_match = re.match('BSS ([0-9a-f:]+)', line)
130            if bss_match:
131                if bss != None:
132                    security = self.determine_security(supported_securities)
133                    iwbss = IwBss(bss, frequency, ssid, security, ht, signal)
134                    bss_list.append(iwbss)
135                    bss = frequency = ssid = security = ht = None
136                    supported_securities = []
137                bss = bss_match.group(1)
138            if line.startswith('freq:'):
139                frequency = int(line.split()[1])
140            if line.startswith('signal:'):
141                signal = float(line.split()[1])
142            if line.startswith('SSID: '):
143                _, ssid = line.split(': ', 1)
144            if line.startswith('* secondary channel offset'):
145                ht = HT_TABLE[line.split(':')[1].strip()]
146            if line.startswith('WPA'):
147               supported_securities.append(SECURITY_WPA)
148            if line.startswith('RSN'):
149               supported_securities.append(SECURITY_WPA2)
150        security = self.determine_security(supported_securities)
151        bss_list.append(IwBss(bss, frequency, ssid, security, ht, signal))
152        return bss_list
153
154
155    def _parse_scan_time(self, output):
156        """
157        Parse the scan time in seconds from the output of the 'time -p "scan"'
158        command.
159
160        'time -p' Command output format is below:
161        real     0.01
162        user     0.01
163        sys      0.00
164
165        @param output: string command output.
166
167        @returns float time in seconds.
168
169        """
170        output_lines = output.splitlines()
171        for line_num, line in enumerate(output_lines):
172            line = line.strip()
173            if (line.startswith(IW_TIME_COMMAND_OUTPUT_START) and
174                output_lines[line_num + 1].startswith('user') and
175                output_lines[line_num + 2].startswith('sys')):
176                return float(line.split()[1])
177        raise error.TestFail('Could not parse scan time.')
178
179
180    def add_interface(self, phy, interface, interface_type):
181        """
182        Add an interface to a WiFi PHY.
183
184        @param phy: string name of PHY to add an interface to.
185        @param interface: string name of interface to add.
186        @param interface_type: string type of interface to add (e.g. 'monitor').
187
188        """
189        self._run('%s phy %s interface add %s type %s' %
190                  (self._command_iw, phy, interface, interface_type))
191
192
193    def disconnect_station(self, interface):
194        """
195        Disconnect a STA from a network.
196
197        @param interface: string name of interface to disconnect.
198
199        """
200        self._run('%s dev %s disconnect' % (self._command_iw, interface))
201
202
203    def get_current_bssid(self, interface_name):
204        """Get the BSSID that |interface_name| is associated with.
205
206        @param interface_name: string name of interface (e.g. 'wlan0').
207        @return string bssid of our current association, or None.
208
209        """
210        result = self._run('%s dev %s link' %
211                           (self._command_iw, interface_name),
212                           ignore_status=True)
213        if result.exit_status:
214            # See comment in get_link_value.
215            return None
216
217        # We're looking for a line like:
218        #   Connected to 04:f0:21:03:7d:bb (on wlan0)
219        match = re.search(
220                'Connected to ([0-9a-fA-F:]{17}) \\(on %s\\)' % interface_name,
221                result.stdout)
222        if match is None:
223            return None
224        return match.group(1)
225
226
227    def get_interface(self, interface_name):
228        """Get full information about an interface given an interface name.
229
230        @param interface_name: string name of interface (e.g. 'wlan0').
231        @return IwNetDev tuple.
232
233        """
234        matching_interfaces = [iw_if for iw_if in self.list_interfaces()
235                                     if iw_if.if_name == interface_name]
236        if len(matching_interfaces) != 1:
237            raise error.TestFail('Could not find interface named %s' %
238                                 interface_name)
239
240        return matching_interfaces[0]
241
242
243    def get_link_value(self, interface, iw_link_key):
244        """Get the value of a link property for |interface|.
245
246        This command parses fields of iw link:
247
248        #> iw dev wlan0 link
249        Connected to 74:e5:43:10:4f:c0 (on wlan0)
250              SSID: PMKSACaching_4m9p5_ch1
251              freq: 5220
252              RX: 5370 bytes (37 packets)
253              TX: 3604 bytes (15 packets)
254              signal: -59 dBm
255              tx bitrate: 13.0 MBit/s MCS 1
256
257              bss flags:      short-slot-time
258              dtim period:    5
259              beacon int:     100
260
261        @param iw_link_key: string one of IW_LINK_KEY_* defined above.
262        @param interface: string desired value of iw link property.
263
264        """
265        result = self._run('%s dev %s link' % (self._command_iw, interface),
266                           ignore_status=True)
267        if result.exit_status:
268            # When roaming, there is a period of time for mac80211 based drivers
269            # when the driver is 'associated' with an SSID but not a particular
270            # BSS.  This causes iw to return an error code (-2) when attempting
271            # to retrieve information specific to the BSS.  This does not happen
272            # in mwifiex drivers.
273            return None
274
275        find_re = re.compile('\s*%s:\s*(.*\S)\s*$' % iw_link_key)
276        find_results = filter(bool,
277                              map(find_re.match, result.stdout.splitlines()))
278        if not find_results:
279            return None
280
281        actual_value = find_results[0].group(1)
282        logging.info('Found iw link key %s with value %s.',
283                     iw_link_key, actual_value)
284        return actual_value
285
286
287    def ibss_join(self, interface, ssid, frequency):
288        """
289        Join a WiFi interface to an IBSS.
290
291        @param interface: string name of interface to join to the IBSS.
292        @param ssid: string SSID of IBSS to join.
293        @param frequency: int frequency of IBSS in Mhz.
294
295        """
296        self._run('%s dev %s ibss join %s %d' %
297                  (self._command_iw, interface, ssid, frequency))
298
299
300    def ibss_leave(self, interface):
301        """
302        Leave an IBSS.
303
304        @param interface: string name of interface to remove from the IBSS.
305
306        """
307        self._run('%s dev %s ibss leave' % (self._command_iw, interface))
308
309
310    def list_interfaces(self, desired_if_type=None):
311        """List WiFi related interfaces on this system.
312
313        @param desired_if_type: string type of interface to filter
314                our returned list of interfaces for (e.g. 'managed').
315
316        @return list of IwNetDev tuples.
317
318        """
319
320        # Parse output in the following format:
321        #
322        #   $ adb shell iw dev
323        #   phy#0
324        #     Unnamed/non-netdev interface
325        #       wdev 0x2
326        #       addr aa:bb:cc:dd:ee:ff
327        #       type P2P-device
328        #     Interface wlan0
329        #       ifindex 4
330        #       wdev 0x1
331        #       addr aa:bb:cc:dd:ee:ff
332        #       ssid Whatever
333        #       type managed
334
335        output = self._run('%s dev' % self._command_iw).stdout
336        interfaces = []
337        phy = None
338        if_name = None
339        if_type = None
340        for line in output.splitlines():
341            m = re.match('phy#([0-9]+)', line)
342            if m:
343                phy = 'phy%d' % int(m.group(1))
344                if_name = None
345                if_type = None
346                continue
347            if not phy:
348                continue
349            m = re.match('[\s]*Interface (.*)', line)
350            if m:
351                if_name = m.group(1)
352                continue
353            if not if_name:
354                continue
355            # Common values for type are 'managed', 'monitor', and 'IBSS'.
356            m = re.match('[\s]*type ([a-zA-Z]+)', line)
357            if m:
358                if_type = m.group(1)
359                interfaces.append(IwNetDev(phy=phy, if_name=if_name,
360                                           if_type=if_type))
361                # One phy may have many interfaces, so don't reset it.
362                if_name = None
363
364        if desired_if_type:
365            interfaces = [interface for interface in interfaces
366                          if interface.if_type == desired_if_type]
367        return interfaces
368
369
370    def list_phys(self):
371        """
372        List WiFi PHYs on the given host.
373
374        @return list of IwPhy tuples.
375
376        """
377        output = self._run('%s list' % self._command_iw).stdout
378
379        pending_phy_name = None
380        current_band = None
381        current_section = None
382        all_phys = []
383
384        def add_pending_phy():
385            """Add the pending phy into |all_phys|."""
386            bands = tuple(IwBand(band.num,
387                                 tuple(band.frequencies),
388                                 dict(band.frequency_flags),
389                                 tuple(band.mcs_indices))
390                          for band in pending_phy_bands)
391            new_phy = IwPhy(pending_phy_name,
392                            bands,
393                            tuple(pending_phy_modes),
394                            tuple(pending_phy_commands),
395                            tuple(pending_phy_features),
396                            pending_phy_max_scan_ssids,
397                            pending_phy_tx_antennas,
398                            pending_phy_rx_antennas,
399                            pending_phy_tx_antennas and pending_phy_rx_antennas,
400                            pending_phy_support_vht)
401            all_phys.append(new_phy)
402
403        for line in output.splitlines():
404            match_phy = re.search('Wiphy (.*)', line)
405            if match_phy:
406                if pending_phy_name:
407                    add_pending_phy()
408                pending_phy_name = match_phy.group(1)
409                pending_phy_bands = []
410                pending_phy_modes = []
411                pending_phy_commands = []
412                pending_phy_features = []
413                pending_phy_max_scan_ssids = None
414                pending_phy_tx_antennas = 0
415                pending_phy_rx_antennas = 0
416                pending_phy_support_vht = False
417                continue
418
419            match_section = re.match('\s*(\w.*):\s*$', line)
420            if match_section:
421                current_section = match_section.group(1)
422                match_band = re.match('Band (\d+)', current_section)
423                if match_band:
424                    current_band = IwBand(num=int(match_band.group(1)),
425                                          frequencies=[],
426                                          frequency_flags={},
427                                          mcs_indices=[])
428                    pending_phy_bands.append(current_band)
429                continue
430
431            # Check for max_scan_ssids. This isn't a section, but it
432            # also isn't within a section.
433            match_max_scan_ssids = re.match('\s*max # scan SSIDs: (\d+)',
434                                            line)
435            if match_max_scan_ssids and pending_phy_name:
436                pending_phy_max_scan_ssids = int(
437                    match_max_scan_ssids.group(1))
438                continue
439
440            if (current_section == 'Supported interface modes' and
441                pending_phy_name):
442                mode_match = re.search('\* (\w+)', line)
443                if mode_match:
444                    pending_phy_modes.append(mode_match.group(1))
445                    continue
446
447            if current_section == 'Supported commands' and pending_phy_name:
448                command_match = re.search('\* (\w+)', line)
449                if command_match:
450                    pending_phy_commands.append(command_match.group(1))
451                    continue
452
453            if (current_section is not None and
454                current_section.startswith('VHT Capabilities') and
455                pending_phy_name):
456                pending_phy_support_vht = True
457                continue
458
459            match_avail_antennas = re.match('\s*Available Antennas: TX (\S+)'
460                                            ' RX (\S+)', line)
461            if match_avail_antennas and pending_phy_name:
462                pending_phy_tx_antennas = int(
463                        match_avail_antennas.group(1), 16)
464                pending_phy_rx_antennas = int(
465                        match_avail_antennas.group(2), 16)
466                continue
467
468            match_device_support = re.match('\s*Device supports (.*)\.', line)
469            if match_device_support and pending_phy_name:
470                pending_phy_features.append(match_device_support.group(1))
471                continue
472
473            if not all([current_band, pending_phy_name,
474                        line.startswith('\t')]):
475                continue
476
477            # E.g.
478            # * 2412 MHz [1] (20.0 dBm)
479            # * 2467 MHz [12] (20.0 dBm) (passive scan)
480            # * 2472 MHz [13] (disabled)
481            # * 5260 MHz [52] (19.0 dBm) (no IR, radar detection)
482            match_chan_info = re.search(
483                r'(?P<frequency>\d+) MHz'
484                r' (?P<chan_num>\[\d+\])'
485                r'(?: \((?P<tx_power_limit>[0-9.]+ dBm)\))?'
486                r'(?: \((?P<flags>[a-zA-Z, ]+)\))?', line)
487            if match_chan_info:
488                frequency = int(match_chan_info.group('frequency'))
489                current_band.frequencies.append(frequency)
490                flags_string = match_chan_info.group('flags')
491                if flags_string:
492                    current_band.frequency_flags[frequency] = frozenset(
493                        flags_string.split(','))
494                else:
495                    # Populate the dict with an empty set, to make
496                    # things uniform for client code.
497                    current_band.frequency_flags[frequency] = frozenset()
498                continue
499
500            # re_mcs needs to match something like:
501            # HT TX/RX MCS rate indexes supported: 0-15, 32
502            if re.search('HT TX/RX MCS rate indexes supported: ', line):
503                rate_string = line.split(':')[1].strip()
504                for piece in rate_string.split(','):
505                    if piece.find('-') > 0:
506                        # Must be a range like '  0-15'
507                        begin, end = piece.split('-')
508                        for index in range(int(begin), int(end) + 1):
509                            current_band.mcs_indices.append(index)
510                    else:
511                        # Must be a single rate like '32   '
512                        current_band.mcs_indices.append(int(piece))
513        if pending_phy_name:
514            add_pending_phy()
515        return all_phys
516
517
518    def remove_interface(self, interface, ignore_status=False):
519        """
520        Remove a WiFi interface from a PHY.
521
522        @param interface: string name of interface (e.g. mon0)
523        @param ignore_status: boolean True iff we should ignore failures
524                to remove the interface.
525
526        """
527        self._run('%s dev %s del' % (self._command_iw, interface),
528                  ignore_status=ignore_status)
529
530
531    def determine_security(self, supported_securities):
532        """Determines security from the given list of supported securities.
533
534        @param supported_securities: list of supported securities from scan
535
536        """
537        if not supported_securities:
538            security = SECURITY_OPEN
539        elif len(supported_securities) == 1:
540            security = supported_securities[0]
541        else:
542            security = SECURITY_MIXED
543        return security
544
545
546    def scan(self, interface, frequencies=(), ssids=()):
547        """Performs a scan.
548
549        @param interface: the interface to run the iw command against
550        @param frequencies: list of int frequencies in Mhz to scan.
551        @param ssids: list of string SSIDs to send probe requests for.
552
553        @returns a list of IwBss namedtuples; None if the scan fails
554
555        """
556        scan_result = self.timed_scan(interface, frequencies, ssids)
557        if scan_result is None:
558            return None
559        return scan_result.bss_list
560
561
562    def timed_scan(self, interface, frequencies=(), ssids=()):
563        """Performs a timed scan.
564
565        @param interface: the interface to run the iw command against
566        @param frequencies: list of int frequencies in Mhz to scan.
567        @param ssids: list of string SSIDs to send probe requests for.
568
569        @returns a IwTimedScan namedtuple; None if the scan fails
570
571        """
572        freq_param = ''
573        if frequencies:
574            freq_param = ' freq %s' % ' '.join(map(str, frequencies))
575        ssid_param = ''
576        if ssids:
577           ssid_param = ' ssid "%s"' % '" "'.join(ssids)
578
579        iw_command = '%s dev %s scan%s%s' % (self._command_iw,
580                interface, freq_param, ssid_param)
581        command = IW_TIME_COMMAND_FORMAT % iw_command
582        scan = self._run(command, ignore_status=True)
583        if scan.exit_status != 0:
584            # The device was busy
585            logging.debug('scan exit_status: %d', scan.exit_status)
586            return None
587        if not scan.stdout:
588            raise error.TestFail('Missing scan parse time')
589
590        if scan.stdout.startswith(IW_TIME_COMMAND_OUTPUT_START):
591            logging.debug('Empty scan result')
592            bss_list = []
593        else:
594            bss_list = self._parse_scan_results(scan.stdout)
595        scan_time = self._parse_scan_time(scan.stdout)
596        return IwTimedScan(scan_time, bss_list)
597
598
599    def scan_dump(self, interface):
600        """Dump the contents of the scan cache.
601
602        Note that this does not trigger a scan.  Instead, it returns
603        the kernel's idea of what BSS's are currently visible.
604
605        @param interface: the interface to run the iw command against
606
607        @returns a list of IwBss namedtuples; None if the scan fails
608
609        """
610        result = self._run('%s dev %s scan dump' % (self._command_iw,
611                                                    interface))
612        return self._parse_scan_results(result.stdout)
613
614
615    def set_tx_power(self, interface, power):
616        """
617        Set the transmission power for an interface.
618
619        @param interface: string name of interface to set Tx power on.
620        @param power: string power parameter. (e.g. 'auto').
621
622        """
623        self._run('%s dev %s set txpower %s' %
624                  (self._command_iw, interface, power))
625
626
627    def set_freq(self, interface, freq):
628        """
629        Set the frequency for an interface.
630
631        @param interface: string name of interface to set frequency on.
632        @param freq: int frequency
633
634        """
635        self._run('%s dev %s set freq %d' %
636                  (self._command_iw, interface, freq))
637
638
639    def set_regulatory_domain(self, domain_string):
640        """
641        Set the regulatory domain of the current machine.  Note that
642        the regulatory change happens asynchronously to the exit of
643        this function.
644
645        @param domain_string: string regulatory domain name (e.g. 'US').
646
647        """
648        self._run('%s reg set %s' % (self._command_iw, domain_string))
649
650
651    def get_regulatory_domain(self):
652        """
653        Get the regulatory domain of the current machine.
654
655        @returns a string containing the 2-letter regulatory domain name
656            (e.g. 'US').
657
658        """
659        output = self._run('%s reg get' % self._command_iw).stdout
660        m = re.match('^country (..):', output)
661        if not m:
662            return None
663        return m.group(1)
664
665
666    def wait_for_scan_result(self, interface, bsses=(), ssids=(),
667                             timeout_seconds=30, wait_for_all=False):
668        """Returns a list of IWBSS objects for given list of bsses or ssids.
669
670        This method will scan for a given timeout and return all of the networks
671        that have a matching ssid or bss.  If wait_for_all is true and all
672        networks are not found within the given timeout an empty list will
673        be returned.
674
675        @param interface: which interface to run iw against
676        @param bsses: a list of BSS strings
677        @param ssids: a list of ssid strings
678        @param timeout_seconds: the amount of time to wait in seconds
679        @param wait_for_all: True to wait for all listed bsses or ssids; False
680                             to return if any of the networks were found
681
682        @returns a list of IwBss collections that contain the given bss or ssid;
683            if the scan is empty or returns an error code None is returned.
684
685        """
686        start_time = time.time()
687        scan_failure_attempts = 0
688        logging.info('Performing a scan with a max timeout of %d seconds.',
689                     timeout_seconds)
690        remaining_bsses = copy.copy(bsses)
691        remaining_ssids = copy.copy(ssids)
692        while time.time() - start_time < timeout_seconds:
693            scan_results = self.scan(interface)
694            if scan_results is None or len(scan_results) == 0:
695                scan_failure_attempts += 1
696                # Allow in-progress scan to complete
697                time.sleep(5)
698                # If the in-progress scan takes more than 30 seconds to
699                # complete it will most likely never complete; abort.
700                # See crbug.com/309148.
701                if scan_failure_attempts > 5:
702                    logging.error('Scan failed to run, see debug log for '
703                                  'error code.')
704                    return None
705                continue
706            scan_failure_attempts = 0
707            matching_iwbsses = set()
708            for iwbss in scan_results:
709              if iwbss.bss in bsses and len(remaining_bsses) > 0:
710                    remaining_bsses.remove(iwbss.bss)
711                    matching_iwbsses.add(iwbss)
712              if iwbss.ssid in ssids and len(remaining_ssids) > 0:
713                    remaining_ssids.remove(iwbss.ssid)
714                    matching_iwbsses.add(iwbss)
715            if wait_for_all:
716                if len(remaining_bsses) == 0 and len(remaining_ssids) == 0:
717                    return list(matching_iwbsses)
718            else:
719                if len(matching_iwbsses) > 0:
720                    return list(matching_iwbsses)
721
722
723        if scan_failure_attempts > 0:
724            return None
725        # The SSID wasn't found, but the device is fine.
726        return list()
727
728
729    def wait_for_link(self, interface, timeout_seconds=10):
730        """Waits until a link completes on |interface|.
731
732        @param interface: which interface to run iw against.
733        @param timeout_seconds: the amount of time to wait in seconds.
734
735        @returns True if link was established before the timeout.
736
737        """
738        start_time = time.time()
739        while time.time() - start_time < timeout_seconds:
740            link_results = self._run('%s dev %s link' %
741                                     (self._command_iw, interface))
742            if 'Not connected' not in link_results.stdout:
743                return True
744            time.sleep(1)
745        return False
746
747
748    def set_antenna_bitmap(self, phy, tx_bitmap, rx_bitmap):
749        """Set antenna chain mask on given phy (radio).
750
751        This function will set the antennas allowed to use for TX and
752        RX on the |phy| based on the |tx_bitmap| and |rx_bitmap|.
753        This command is only allowed when the interfaces on the phy are down.
754
755        @param phy: phy name
756        @param tx_bitmap: bitmap of allowed antennas to use for TX
757        @param rx_bitmap: bitmap of allowed antennas to use for RX
758
759        """
760        command = '%s phy %s set antenna %d %d' % (self._command_iw, phy,
761                                                   tx_bitmap, rx_bitmap)
762        self._run(command)
763
764
765    def get_event_logger(self):
766        """Create and return a IwEventLogger object.
767
768        @returns a IwEventLogger object.
769
770        """
771        local_file = IW_LOCAL_EVENT_LOG_FILE % (self._log_id)
772        self._log_id += 1
773        return iw_event_logger.IwEventLogger(self._host, self._command_iw,
774                                             local_file)
775
776
777    def vht_supported(self):
778        """Returns True if VHT is supported; False otherwise."""
779        result = self._run('%s list' % self._command_iw).stdout
780        if 'VHT Capabilities' in result:
781            return True
782        return False
783
784
785    def frequency_supported(self, frequency):
786        """Returns True if the given frequency is supported; False otherwise.
787
788        @param frequency: int Wifi frequency to check if it is supported by
789                          DUT.
790        """
791        phys = self.list_phys()
792        for phy in phys:
793            for band in phy.bands:
794                if frequency in band.frequencies:
795                    return True
796        return False
797