iwlibs.py

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# -*- coding: latin1 -*-
# Python WiFi -- a library to access wireless card properties via Python
# Copyright (C) 2004 - 2008 Róman Joost
# Copyright (C) 2008 - 2009 Sean Robinson
#
# Contributions from:
#   Mike Auty <m.auty@softhome.net> (Iwscanresult, Iwscan)
#
#    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, write to the Free Software
#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
#    USA

import struct
import array
import math
import errno
import fcntl
import os
import socket
import time
import re

import flags
from types import StringType, IntType, TupleType


KILO = 10**3
MEGA = 10**6
GIGA = 10**9


def getNICnames():
    """ Extract network device names from /proc/net/dev.

        Returns list of device names.  Returns empty list if no network
        devices are present.

        >>> getNICnames()
        ['lo', 'eth0']

    """
    device = re.compile('[a-z]{2,}[0-9]*:')
    ifnames = []

    fp = open('/proc/net/dev', 'r')
    for line in fp:
        try:
            # append matching pattern, without the trailing colon
            ifnames.append(device.search(line).group()[:-1])
        except AttributeError:
            pass
    return ifnames

def getWNICnames():
    """ Extract wireless device names from /proc/net/wireless.

        Returns empty list if no devices are present.

        >>> getWNICnames()
        ['eth1', 'wifi0']

    """
    device = re.compile('[a-z]{2,}[0-9]*:')
    ifnames = []

    fp = open('/proc/net/wireless', 'r')
    for line in fp:
        try:
            # append matching pattern, without the trailing colon
            ifnames.append(device.search(line).group()[:-1])
        except AttributeError:
            pass
    # if we couldn't lookup the devices, try to ask the kernel
    if ifnames == []:
        ifnames = getConfiguredWNICnames()

    return ifnames

def getConfiguredWNICnames():
    """ Get the *configured* ifnames by a systemcall.

       >>> getConfiguredWNICnames()
       []

    """
    iwstruct = Iwstruct()
    ifnames = []
    buff = array.array('c', '\0'*1024)
    caddr_t, length = buff.buffer_nfo()
    datastr = iwstruct.pack('iP', length, caddr_t)
    result = iwstruct._fcntl(flags.SIOCGIFCONF, datastr)
    # get the interface names out of the buffer
    for i in range(0, 1024, 32):
        ifname = buff.tostring()[i:i+32]
        ifname = struct.unpack('32s', ifname)[0]
        ifname = ifname.split('\0', 1)[0]
        if ifname:
            # verify if ifnames are really wifi devices
            wifi = Wireless(ifname)
            try:
                result = wifi.getAPaddr()
            except IOError, (errno, strerror):
                # don't stop on an individual error
                pass
            if result[0] == 0:
                ifnames.append(ifname)
    return ifnames

def makedict(**kwargs):
    return kwargs

def hex2int(hexstring):
    """ Convert hex string to integer. """
    return int(hexstring, 16)


class Wireless(object):
    """ Provides high-level access to wireless interfaces.

        This class uses WirelessInfo for most access.

    """

    def __init__(self, ifname):
        self.sockfd = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        self.ifname = ifname
        self.iwstruct = Iwstruct()
        self.wireless_info = WirelessInfo(self.ifname)

    def getAPaddr(self):
        """ Returns the access point MAC address.

            >>> from iwlibs import Wireless, getNICnames
            >>> ifnames = getNICnames()
            >>> ifnames
            ['eth1', 'wifi0']
            >>> wifi = Wireless(ifnames[0])
            >>> wifi.getAPaddr()
            '00:0D:88:8E:4E:93'

            Test with non-wifi card:
            >>> wifi = Wireless('eth0')
            >>> wifi.getAPaddr()
            (95, 'Operation not supported')

            Test with non-existant card:
            >>> wifi = Wireless('eth2')
            >>> wifi.getAPaddr()
            (19, 'No such device')

        """
        return self.wireless_info.getAPaddr()

    def setAPaddr(self, addr):
        """ Sets the access point MAC address.

            translated from iwconfig.c

        """
        addr = addr.upper()
        if (addr == "AUTO" or addr == "ANY"):
            mac_addr = "\xFF"*flags.ETH_ALEN
        elif addr == "OFF":
            mac_addr = '\x00'*flags.ETH_ALEN
        else:
            if ":" not in addr: return (errno.ENOSYS, os.strerror(errno.ENOSYS))
            mac_addr = "%c%c%c%c%c%c" % tuple(map(hex2int, addr.split(':')))

        iwreq = self.iwstruct.pack("H14s", 1, mac_addr)
        status, result = self.iwstruct.iw_set_ext(self.ifname,
                                               flags.SIOCSIWAP,
                                               iwreq)

    def _formatBitrate(self, raw_bitrate):
        """ Returns formatted bitrate.

            'raw_bitrate' -- long -- The unformatted bitrate as a long integer.

        """
        if raw_bitrate >= GIGA:
            return "%g Gb/s" % (float(raw_bitrate)/GIGA)
        if raw_bitrate >= MEGA:
            return "%g Mb/s" % (float(raw_bitrate)/MEGA)
        if raw_bitrate >= KILO:
            return "%g kb/s" % (float(raw_bitrate)/KILO)

    def getBitrate(self):
        """ Returns the device's currently set bit rate in Mbit.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getBitrate()
            '11 Mb/s'

        """
        iwparam = self.wireless_info.getBitrate()
        return self._formatBitrate(iwparam.value)

    def getBitrates(self):
        """ Returns the number of bitrates available for the device.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> num, rates = wifi.getBitrates()
            >>> num == len(rates)
            True

        """
        num_bitrates, bitrates = self.wireless_info.getBitrates()
        cooked_rates = []
        for rate in bitrates:
            cooked_rates.append(self._formatBitrate(rate))
        return (num_bitrates, cooked_rates)

    def _formatFrequency(self, raw_frequency):
        """ Returns formatted frequency.

            'raw_frequency' -- long -- The unformatted frequency as a long
                integer.

        """
        raw_frequency = float(raw_frequency)
        if raw_frequency >= GIGA:
            return "%0.3f GHz" % (raw_frequency/GIGA)
        if raw_frequency >= MEGA:
            return "%0.3f MHZ" % (raw_frequency/MEGA)
        if raw_frequency >= KILO:
            return "%0.3f kHz" % (raw_frequency/KILO)
        # This is probably a channel number
        raw_frequency = int(raw_frequency)
        try:
            return self.getChannelInfo()[1][raw_frequency-1]
        except IndexError:
            # probably auto (i.e. -1 (a.k.a. 255))
            pass
        return raw_frequency

    def getChannelInfo(self):
        """ Returns the number of channels and available frequencies for
           the device.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> num, rates = wifi.getChannelInfo()
            >>> num == len(rates)
            True

        """
        iwrange = Iwrange(self.ifname)
        frequencies = []
        for freq in iwrange.frequencies:
            frequencies.append(self._formatFrequency(freq))
        return (iwrange.num_channels, frequencies)

    def getEssid(self):
        """ Returns the current ESSID information.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getEssid()
            'romanofski'

        """
        return self.wireless_info.getEssid()

    def setEssid(self, essid):
        """ Sets the ESSID.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getEssid()
            'romanofski'
            >>> wifi.setEssid('Joost')
            >>> wifi.getEssid()
            'Joost'

        """
        if len(essid) > flags.IW_ESSID_MAX_SIZE:
            raise OverflowError(errno.EOVERFLOW, os.strerror(errno.EOVERFLOW))
        iwpoint = Iwpoint(essid, 1)
        status, result = self.iwstruct.iw_set_ext(self.ifname,
                                             flags.SIOCSIWESSID,
                                             data=iwpoint.packed_data)

    def getEncryption(self):
        """ Get the association mode, which is probably a string of '*',
            'open', 'private', 'off'.

            As a normal user, you will get an 'Operation not permitted'
            error:

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getEncryption()
            (1, 'Operation not permitted')

        """
        # use an IW_ENCODING_TOKEN_MAX-cell array of NULLs
        #   as space for ioctl to write encryption info
        iwpoint = Iwpoint('\x00'*flags.IW_ENCODING_TOKEN_MAX)
        status, result = self.iwstruct.iw_get_ext(self.ifname,
                                             flags.SIOCGIWENCODE,
                                             data=iwpoint.packed_data)
        iwpoint.update(result)

        if iwpoint.flags & flags.IW_ENCODE_NOKEY > 0:
            return '**'*iwpoint.length
        elif iwpoint.flags & flags.IW_ENCODE_OPEN > 0:
            return 'open'
        elif iwpoint.flags & flags.IW_ENCODE_RESTRICTED > 0:
            return 'restricted'
        elif iwpoint.flags & flags.IW_ENCODE_DISABLED > 0:
            return 'off'

    def setEncryption(self, mode):
        """ Set the association mode.

            As a normal user, you will get an 'Operation not permitted'
            error:

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.setEncryption()
            (1, 'Operation not permitted')

        """
        if type(mode) == IntType:
            mode = mode
        else:
            mode = mode.upper()
        numeric_mode = self.getEncryption(symbolic=False)
        # turn off all associate modes, but do not touch other flag bits
        numeric_mode = numeric_mode & ~flags.IW_ENCODE_OPEN \
                        & ~flags.IW_ENCODE_RESTRICTED \
                        & ~flags.IW_ENCODE_DISABLED
        if (mode == 'OPEN') or (mode == flags.IW_ENCODE_OPEN):
            numeric_mode = numeric_mode | flags.IW_ENCODE_OPEN
        elif (mode == 'RESTRICTED') or (mode == flags.IW_ENCODE_RESTRICTED):
            numeric_mode = numeric_mode | flags.IW_ENCODE_RESTRICTED
        elif (mode == 'OFF') or (mode == flags.IW_ENCODE_DISABLED):
            numeric_mode = numeric_mode | flags.IW_ENCODE_DISABLED
        iwpoint = Iwpoint('\x00'*flags.IW_ENCODING_TOKEN_MAX, numeric_mode)
        status, result = self.iwstruct.iw_get_ext(self.ifname,
                                             flags.SIOCSIWENCODE,
                                             data=iwpoint.packed_data)

    def getKey(self, key=0, formatted=True):
        """ Get an encryption key.

            key 0 is current key, otherwise, retrieve specific key (1-4)

            As a normal user, you will get an 'Operation not permitted'
            error:

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getKey()
            ABCD-9512-34

        """
        iwpoint = self.wireless_info.getKey(key)

        # build a list of each char in key
        raw_key = map(ord, iwpoint.buff.tolist())[:iwpoint.length]
        if sum(raw_key) == 0:
            return "off"
        if not formatted:
            return raw_key

        # format key in standard form
        key = "%.2X" % raw_key[0]
        for i in range(1, iwpoint.length):
            if ( i & 0x1 ) == 0:
                    key = key + '-'
            key = key + "%.2X" % raw_key[i]
        return key

    def setKey(self, key, index=0):
        """ Set an encryption key.

            As a normal user, you will get an 'Operation not permitted'
            error:

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.setKey()

        """
        if index not in range(1, flags.IW_ENCODE_INDEX):
            raise IndexError

        if key:
            cooked_key = ''
            for i in range(0, len(key), 2):
                cooked_key = cooked_key + chr(hex2int(key[i:i+2]))
        else:
            raw_key = self.getKey(index, False)
            cooked_key = map(chr, raw_key)

        iwpoint = Iwpoint(cooked_key,
                    index + flags.IW_ENCODE_ENABLED)
        status, result = self.iwstruct.iw_get_ext(self.ifname,
                                             flags.SIOCSIWENCODE,
                                             data=iwpoint.packed_data)

    def getKeys(self):
        """ Get all encryption keys.

            Returns a list of tuples.

            As a normal user, you will get a 'Operation not permitted'
            error:

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getKeys()
            [(1, '1234-5678-91'), (2, None), (3, 'ABCD-EFAB-CD'), (4, None)]

        """
        iwrange = Iwrange(self.ifname);
        keys = []
        if iwrange.max_encoding_tokens > 0:
            for i in range(1, iwrange.max_encoding_tokens+1):
                keys.append((i, self.getKey(i)))
        return keys

    def getFragmentation(self):
        """ Returns the fragmentation threshold.

            It depends on what the driver says. If you have fragmentation
            threshold turned on, you'll get an int. If it's turned off
            you'll get a string: 'off'.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getFragmentation()
            'off'

        """
        iwparam = self.wireless_info.getFragmentation()
        if iwparam.disabled:
            return "off"
        return iwparam.value

    def getFrequency(self):
        """ Returns currently set frequency of the card.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getFrequency()
            '2.417 GHz'

        """
        iwfreq = self.wireless_info.getFrequency()
        return self._formatFrequency(iwfreq.getFrequency())

    def setFrequency(self, freq):
        """ Sets the frequency on the card.

           translated from iwconfig.c

        """
        iwstruct = Iwstruct()
        if freq == "auto":
            iwreq = iwstruct.pack("ihBB", -1, 0, 0, flags.IW_FREQ_AUTO)
        else:
            if freq == "fixed":
                freq = self.getFrequency()
            freq_pattern = re.compile("([\d\.]+)(\w)", re.I|re.M|re.S)
            freq_match = freq_pattern.search(freq)
            freq_num, unit = freq_match.groups()
            if unit == "G": freq_num = float(freq_num) * GIGA
            if unit == "M": freq_num = float(freq_num) * MEGA
            if unit == "k": freq_num = float(freq_num) * KILO
            e = math.floor(math.log10(freq_num))
            if e > 8:
                m = int(math.floor(freq_num / math.pow(10, e - 6))) * 100
                e = e - 8
            else:
                m = int(math.floor(freq_num))
                e = 0
            iwreq = iwstruct.pack("ihBB", m, e, 0, flags.IW_FREQ_FIXED)
        status, result = iwstruct.iw_set_ext(self.ifname,
                                               flags.SIOCSIWFREQ,
                                               iwreq)

    def getMode(self):
        """ Returns currently set operation mode.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getMode()
            'Managed'

        """
        return flags.modes[self.wireless_info.getMode()]

    def setMode(self, mode):
        """ Sets the operation mode.

        """
        try:
            this_modes = [x.lower() for x in flags.modes]
            mode = mode.lower()
            wifimode = this_modes.index(mode)
        except ValueError:
            raise ValueError("Invalid operation mode!")

        datastr = self.iwstruct.pack('I', wifimode)
        status, result = self.iwstruct.iw_set_ext(self.ifname,
                                             flags.SIOCSIWMODE,
                                             data=datastr)

    def getWirelessName(self):
        """ Returns the wireless name.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getWirelessName()
            'IEEE 802.11-DS'

        """
        return self.wireless_info.getWirelessName()

    def getPowermanagement(self):
        """ Returns the power management settings.

            #>>> from iwlibs import Wireless
            #>>> wifi = Wireless('eth1')
            #>>> wifi.getPowermanagement()
            #'off'

        """
        iwrange = Iwrange(self.ifname)
        iwparam = self.wireless_info.getPower()
        return (iwrange.pm_capa,
                (iwrange.pmp_flags, iwrange.min_pmp, iwrange.max_pmp),
                (iwrange.pmt_flags, iwrange.min_pmt, iwrange.max_pmt),
                (iwrange.pms_flags, iwrange.min_pms, iwrange.max_pms),
                iwparam)

    def getQualityMax(self):
        """ Returns an Iwquality object with maximum quality information.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> mq = wifi.getQualityMax()
            >>> print "quality:", mq.quality, "signal:", mq.siglevel, "noise:", mq.nlevel
            quality: 38 signal: 13 noise: 0

        """
        iwrange = Iwrange(self.ifname)
        if iwrange.errorflag:
            return (iwrange.errorflag, iwrange.error)
        return iwrange.max_qual

    def getQualityAvg(self):
        """ Returns an Iwquality object with average quality information.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> aq = wifi.getQualityAvg()
            >>> print "quality:", aq.quality, "signal:", aq.siglevel, "noise:", aq.nlevel
            quality: 38 signal: 13 noise: 0

        """
        iwrange = Iwrange(self.ifname)
        if iwrange.errorflag:
            return (iwrange.errorflag, iwrange.error)
        return iwrange.avg_qual

    def getRetrylimit(self):
        """ Returns the retry/lifetime limit.

            man iwconfig:
                "Most cards have MAC retransmissions, and some allow to set
                the behaviour of the retry mechanism."

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getRetrylimit()
            16

        """
        iwparam = self.wireless_info.getRetry()
        return iwparam.value

    def getRTS(self):
        """ Returns the RTS threshold, likely to be int, 'auto',
            'fixed', 'off'

            man iwconfig:
                "RTS/CTS adds a handshake before each packet transmission to
                make sure that the channel is clear. This adds overhead, but
                increases performance in case of hidden nodes or a large
                number of active nodes. This parameter sets the size of the
                smallest packet for which the node sends RTS; a value equal
                to the maximum packet size disable the mechanism."

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getRTS()
            'off'

        """
        iwparam = self.wireless_info.getRTS()
        if iwparam.disabled:
            return "off"
        return iwparam.value

    def getSensitivity(self):
        """ Returns sensitivity information.

            man iwconfig:
                "This is the lowest signal level for which the hardware
                attempt packet reception, signals weaker than this are
                ignored. This is used to avoid receiving background noise,
                so you should set it according to the average noise
                level. Positive values are assumed to be the raw value used
                by the hardware or a percentage, negative values are
                assumed to be dBm."

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getSensitivity()
            'off'

        """
        iwparam = self.wireless_info.getSensitivity()
        return iwparam.value

    def getTXPower(self):
        """ Returns the transmit power in dBm.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getTXPower()
            '17 dBm'

        """
        def mw2dbm(self, mwatt):
            """ Converts mW to dBm (float). """
            if mwatt == 0:
                return 0
            return math.ceil(10.0 * math.log10(mwatt))

        iwparam = self.wireless_info.getTXPower()
        return "%i dBm" % iwparam.value

    def getStatistics(self):
        """ Returns statistics information which can also be found in
            /proc/net/wireless.

        """
        iwstats = Iwstats(self.ifname)
        if iwstats.errorflag > 0:
            return (iwstats.errorflag, iwstats.error)
        return [iwstats.status, iwstats.qual, iwstats.discard,
            iwstats.missed_beacon]

    def scan(self):
        """ Returns Iwscanresult objects, after a successful scan. """
        return Iwscan(self.ifname)

    def commit(self):
        """ Commit pending changes. """
        status, result = self.iwstruct.iw_set_ext(self.ifname,
                                                  flags.SIOCSIWCOMMIT)
        return (status, result)


class WirelessConfig(object):
    """ Low level access to wireless information on a device.  This class
        contains only those things absolutely needed to configure a card.

        WirelessConfig implements the wireless_config struct in iwlib.h.
        It will probably never be called directly, but instead be used via
        WirelessInfo.

    """

    def __init__(self, ifname):
        self.sockfd = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        self.ifname = ifname
        self.iwstruct = Iwstruct()
        #self.nwid = Iwparam
        self.freq_flags = 0
        self.essid_on = 0

    def getWirelessName(self):
        """ Returns the wireless name.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getWirelessName()
            'IEEE 802.11-DS'

        """
        status, result = self.iwstruct.iw_get_ext(self.ifname,
                                             flags.SIOCGIWNAME)
        return result.tostring().strip('\x00')

    def getEncryption(self):
        """ Returns the encryption status.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getEncryption()
            'off'

        """
        # use an IW_ENCODING_TOKEN_MAX-cell array of NULLs
        #   as space for ioctl to write encryption info
        iwpoint = Iwpoint('\x00'*flags.IW_ENCODING_TOKEN_MAX)
        status, result = self.iwstruct.iw_get_ext(self.ifname,
                                             flags.SIOCGIWENCODE,
                                             data=iwpoint.packed_data)
        iwpoint.update(result)

        return iwpoint

    def getFrequency(self):
        """ Returns currently set frequency of the card.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getFrequency()
            '2.417 GHz'

        """
        status, result = self.iwstruct.iw_get_ext(self.ifname,
                                                  flags.SIOCGIWFREQ)
        return Iwfreq(result)

    def getKey(self, key=0):
        """ Get an encryption key.

            key 0 is current key, otherwise, retrieve specific key (1-4)

            As a normal user, you will get an 'Operation not permitted'
            error:

            >>> from iwlibs import Wireless
            >>> wifi_conf = WirelessConfig('eth1')
            >>> isinstance(wifi_conf.getKey(), Iwpoint)
            True

        """
        # use an IW_ENCODING_TOKEN_MAX-cell array of NULLs
        #   as space for ioctl to write encryption info
        iwpoint = Iwpoint('\x00'*flags.IW_ENCODING_TOKEN_MAX, key)
        status, result = self.iwstruct.iw_get_ext(self.ifname,
                                             flags.SIOCGIWENCODE,
                                             data=iwpoint.packed_data)
        iwpoint.update(result)
        return iwpoint

    def getEssid(self):
        """ Returns the current ESSID information.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getEssid()
            'romanofski'

        """
        # use an IW_ESSID_MAX_SIZE-cell array of NULLs
        #   as space for ioctl to write ESSID
        iwpoint = Iwpoint('\x00'*flags.IW_ESSID_MAX_SIZE)
        status, result = self.iwstruct.iw_get_ext(self.ifname,
                                             flags.SIOCGIWESSID,
                                             data=iwpoint.packed_data)
        raw_essid = iwpoint.buff.tostring()
        return raw_essid.strip('\x00')

    def getMode(self):
        """ Returns currently set operation mode.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getMode()
            'Managed'

        """
        status, result = self.iwstruct.iw_get_ext(self.ifname,
                                             flags.SIOCGIWMODE)
        return self.iwstruct.unpack('I', result[:4])[0]


class WirelessInfo(WirelessConfig):
    """ Low level access to wireless extensions on a device.  This class
        is the exhaustive list of information for a card.

        WirelessInfo implements the wireless_info struct in iwlib.h.
        This class should be used by those needing lower-level access
        than Wireless provides.

    """

    def __init__(self, ifname):
        self.sockfd = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        self.ifname = ifname
        self.iwstruct = Iwstruct()

        self.nickname = ""
        # Stats
        self.stats = Iwstats
        self.range = Iwrange
        # Auth params for WPA/802.1x/802.11i
        self.auth_key_mgmt = 0
        self.has_auth_key_mgmt = 0
        self.auth_cipher_pairwise = 0
        self.has_auth_cipher_pairwise = 0
        self.auth_cipher_group = 0
        self.has_auth_cipher_group = 0
        WirelessConfig.__init__(self, ifname)

    def getSensitivity(self):
        """ Returns sensitivity information.

            man iwconfig:
                "This is the lowest signal level for which the hardware
                attempt packet reception, signals weaker than this are
                ignored. This is used to avoid receiving background noise,
                so you should set it according to the average noise
                level. Positive values are assumed to be the raw value used
                by the hardware or a percentage, negative values are
                assumed to be dBm."

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getSensitivity()
            'off'

        """
        return Iwparam(self.ifname, flags.SIOCGIWSENS)

    def getAPaddr(self):
        """ Returns the access point MAC address.

            >>> from iwlibs import Wireless, getNICnames
            >>> ifnames = getNICnames()
            >>> ifnames
            ['eth1', 'wifi0']
            >>> wifi = Wireless(ifnames[0])
            >>> wifi.getAPaddr()
            '00:0D:88:8E:4E:93'

            Test with non-wifi card:
            >>> wifi = Wireless('eth0')
            >>> wifi.getAPaddr()
            (95, 'Operation not supported')

            Test with non-existant card:
            >>> wifi = Wireless('eth2')
            >>> wifi.getAPaddr()
            (19, 'No such device')

        """
        buff, datastr = self.iwstruct.pack_wrq(32)
        status, result = self.iwstruct.iw_get_ext(self.ifname,
                                                  flags.SIOCGIWAP,
                                                  data=datastr)
        # Extracts MAC address from packed data and returns it as a str.
        mac_addr = struct.unpack('xxBBBBBB', result[:8])
        return "%02X:%02X:%02X:%02X:%02X:%02X" % mac_addr

    def getBitrate(self):
        """ Returns the device's currently set bit rate.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getBitrate()
            '11 Mb/s'

        """
        return Iwparam(self.ifname, flags.SIOCGIWRATE)

    def getBitrates(self):
        """ Returns the device's number and list of available bit rates.

            The bit rates in the list are long integer type.

        """
        iwrange = Iwrange(self.ifname)
        return (iwrange.num_bitrates, iwrange.bitrates)

    def getRTS(self):
        """ Returns the RTS threshold.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getRTS()
            'off'

        """
        return Iwparam(self.ifname, flags.SIOCGIWRTS)

    def getFragmentation(self):
        """ Returns the fragmentation threshold.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getFragmentation()
            'off'

        """
        return Iwparam(self.ifname, flags.SIOCGIWFRAG)

    def getPower(self):
        """ Returns the power management settings.

            #>>> from iwlibs import Wireless
            #>>> wifi = Wireless('eth1')
            #>>> wifi.getPowermanagement()
            #'off'

        """
        return Iwparam(self.ifname, flags.SIOCGIWPOWER)

    def getTXPower(self):
        """ Returns the transmit power in dBm.

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getTXPower()
            '17 dBm'

        """
        return Iwparam(self.ifname, flags.SIOCGIWTXPOW)

    def getRetry(self):
        """ Returns the retry/lifetime limit.

            man iwconfig:
                "Most cards have MAC retransmissions, and some allow to set
                the behaviour of the retry mechanism."

            >>> from iwlibs import Wireless
            >>> wifi = Wireless('eth1')
            >>> wifi.getRetrylimit()
            16

        """
        return Iwparam(self.ifname, flags.SIOCGIWRETRY)


class Iwstruct(object):
    """ The basic class to handle iwstruct data. """

    def __init__(self):
        self.idx = 0
        self.sockfd = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

    def parse_data(self, fmt, data):
        """ Unpacks raw C data. """
        size = struct.calcsize(fmt)
        idx = self.idx

        datastr = data[idx:idx + size]
        self.idx = idx+size
        value = struct.unpack(fmt, datastr)

        # take care of a tuple like (int, )
        if len(value) == 1:
            return value[0]
        else:
            return value

    def pack(self, fmt, *args):
        """ Calls struct.pack and returns the result. """
        return struct.pack(fmt, *args)

    def pack_wrq(self, buffsize):
        """ Packs wireless request data for sending it to the kernel. """
        # Prepare a buffer
        # We need the address of our buffer and the size for it. The
        # ioctl itself looks for the pointer to the address in our
        # memory and the size of it.
        # Don't change the order how the structure is packed!!!
        buff = array.array('c', '\0'*buffsize)
        caddr_t, length = buff.buffer_info()
        datastr = struct.pack('Pi', caddr_t, length)
        return buff, datastr

    def pack_test(self, string, buffsize):
        """ Packs wireless request data for sending it to the kernel. """
        buffsize = buffsize - len(string)
        buff = array.array('c', string+'\0'*buffsize)
        caddr_t, length = buff.buffer_info()
        s = struct.pack('PHH', caddr_t, length, 1)
        return buff, s

    def unpack(self, fmt, packed_data):
        """ Unpacks data with given format. """
        return struct.unpack(fmt, packed_data)

    def _fcntl(self, request, args):
        return fcntl.ioctl(self.sockfd.fileno(), request, args)

    def iw_get_ext(self, ifname, request, data=None):
        """ Read information from ifname. """
        buff = flags.IFNAMSIZE-len(ifname)
        ifreq = array.array('c', ifname + '\0'*buff)
        # put some additional data behind the interface name
        if data is not None:
            ifreq.extend(data)
        else:
            buff = 32 # - flags.IFNAMSIZE
            ifreq.extend('\0'*buff)

        result = self._fcntl(request, ifreq)
        return (result, ifreq[flags.IFNAMSIZE:])

    def iw_set_ext(self, ifname, operation, data=None):
        """ Set options on ifname. """
        return self.iw_get_ext(ifname, operation, data)

    #def getMAC(self, packed_data):
        #""" Extracts MAC address from packed data and returns it as a str. """
        #mac_addr = struct.unpack('xxBBBBBB', packed_data[:8])
        #return "%02X:%02X:%02X:%02X:%02X:%02X" % mac_addr


class Iwparam(object):
    """ Class to hold iwparam data. """

    def __init__(self, ifname, ioctl):
        # (i) value, (b) fixed, (b) disabled, (H) flags
        self.fmt = "ibbH"
        self.ifname = ifname
        self.ioctl = ioctl
        self.value = 0
        self.fixed = 0
        self.disabled = 0
        self.flags = 0
        self.update()

    def update(self):
        """ Updates Iwstruct object by a system call to the kernel
           and updates internal attributes.

        """
        iwstruct = Iwstruct()
        status, result = iwstruct.iw_get_ext(self.ifname, self.ioctl)
        self._parse(result)

    def _parse(self, data):
        """ Unpacks iwparam data. """
        iwstruct = Iwstruct()
        self.value, self.fixed, self.disabled, self.flags = \
            iwstruct.parse_data(self.fmt, data)

class Iwfreq(object):
    """ Class to hold iwfreq data. """

    def __init__(self, data=None):
        # (i) mantissa, (h) exponent, (b) list index, (b) flags
        self.fmt = "ihbb"
        self.m = 0
        self.e = 0
        self.index = 0
        self.flags = 0
        if data:
            if isinstance(data, TupleType):
                self.m, self.e, self.index, self.flags = data
            else:
                self.parse(data)

    def parse(self, data):
        """ Unpacks iw_freq. """
        size = struct.calcsize(self.fmt)
        self.m, self.e, self.index, self.flags = struct.unpack(self.fmt, data[:size])

    def getFrequency(self):
        """ Returns frequency or channel, depending on the driver. """
        if self.e == 0:
            return self.m
        else:
            return self.m*10**self.e

    def setFrequency(self, value):
        """ Sets mantissa and exponent from given frequency (or channel). """
        if value % GIGA == 0:
            self.e = 9
        if value % MEGA == 0:
            self.e = 6
        if value % KILO == 0:
            self.e = 3
        else:
            self.e = 0
        self.m = value / 10**self.e


class Iwstats(object):
    """ Class to hold iwstat data. """

    def __init__(self, ifname):
        # (2B) status, 4B iw_quality, 6i iw_discarded
        self.fmt = "2B4B6i"
        self.status = 0
        self.qual = Iwquality()
        self.discard = {}
        self.missed_beacon = 0
        self.ifname = ifname
        self.errorflag = 0
        self.error = ""
        self.update()

    def update(self):
        """ Updates Iwstats object by a system call to the kernel
            and updates internal attributes.

        """
        iwstruct = Iwstruct()
        buff, s = iwstruct.pack_wrq(32)
        i, result = iwstruct.iw_get_ext(self.ifname,
                                        flags.SIOCGIWSTATS,
                                        data=s)
        if i > 0:
            self.error = result
            self.errorflag = i
        self._parse(buff.tostring())

    def _parse(self, data):
        """ Unpacks iwstruct data. """
        iwstruct = Iwstruct()
        iwqual = Iwquality()
        iwstats_data = iwstruct.parse_data(self.fmt, data)

        self.status = iwstats_data[0:2]
        self.qual.quality, self.qual.siglevel, self.qual.nlevel, \
            self.qual.updated = iwstats_data[2:6]
        # Conversion below works for ralink. Many other cases aren't handled properly by this code. We should be checking flags to do this properly.
        self.qual.siglevel -= 256
        self.qual.nlevel -= 256
        nwid, code, frag, retries, iwflags = iwstats_data[6:11]
        self.missed_beacon = iwstats_data[11:12][0]
        self.discard = makedict(nwid=nwid, code=code,
            fragment=frag, retries=retries, misc=iwflags)


class Iwquality(object):
    """ Class to hold iwquality data. """

    def __init__(self):
        self.quality = 0
        self.siglevel = 0
        self.nlevel = 0
        self.updated = 0
        self.fmt = "4B"

    def parse(self, data):
        """ Unpacks iwquality data. """
        iwstruct = Iwstruct()
        qual, siglevel, nlevel, iwflags = iwstruct.parse_data(self.fmt, data)

        # compute signal and noise level
        self.siglevel = siglevel
        self.nlevel = nlevel

        # asign the other values
        self.quality = qual
        self.updated = iwflags

    def setValues(self, vallist):
        """ Assigns values given by a list to our attributes. """
        attributes = ["quality", "siglevel", "nlevel", "updated"]
        assert len(vallist) == 4

        for i in range(len(vallist)):
            setattr(self, attributes[i], vallist[i])

    def getSignallevel(self):
        """ Returns signal level. """
        return self.siglevel

    def setSignallevel(self, siglevel):
        """ Sets signal level. """
        self.siglevel = siglevel
    signallevel = property(getSignallevel, setSignallevel)

    def getNoiselevel(self):
        """ Returns noise level. """
        return self.nlevel

    def setNoiselevel(self, val):
        # currently not implemented
        # XXX
        self.nlevel = val
    noiselevel = property(getNoiselevel, setNoiselevel)


class Iwpoint(object):
    """ Class to hold iw_point data. """

    def __init__(self, data=None, flags=0):
        if data is None:
            raise ValueError, "data must be passed to Iwpoint"
        # P pointer to data, H length, H flags
        self.fmt = 'PHH'
        self.flags = flags
        self.buff = array.array('c', data)
        self.caddr_t, self.length = self.buff.buffer_info()
        self.packed_data = struct.pack(self.fmt, self.caddr_t,
                                       self.length, self.flags)

    def update(self, packed_data):
        """ Updates the object attributes. """
        self.packed_data = packed_data
        self.caddr_t, self.length, self.flags = struct.unpack(self.fmt,
                                                              self.packed_data)


class Iwrange(object):
    """ Holds iwrange struct. """

    def __init__(self, ifname):
        self.fmt = "IIIHB6Ii4B4BB" + flags.IW_MAX_BITRATES*"i" + \
                   "2i2i2i2i3H" + flags.IW_MAX_ENCODING_SIZES*"H" + \
                   "2BBHB" + flags.IW_MAX_TXPOWER*"i" + \
                   "2B3H2i2iHB" + flags.IW_MAX_FREQUENCIES*"ihBB" + \
                   "IiiHiI"

        self.ifname = ifname
        self.errorflag = 0
        self.error = ""

        # informative stuff
        self.throughput = 0

        # nwid (or domain id)
        self.min_nwid = self.max_nwid = 0

        # frequency for backward compatibility
        self.old_num_channels = self.old_num_frequency = self.old_freq = 0

        # signal level threshold
        self.sensitivity = 0

        # link quality
        self.max_qual = Iwquality()
        self.avg_qual = Iwquality()

        # rates
        self.num_bitrates = 0
        self.bitrates = []

        # rts threshold
        self.min_rts = self.max_rts = 0

        # fragmention threshold
        self.min_frag = self.max_frag = 0

        # power managment
        self.min_pmp = self.max_pmp = 0
        self.min_pmt = self.max_pmt = 0
        self.pmp_flags = self.pmt_flags = self.pm_capa = 0

        # encoder stuff
        self.encoding_size = 0
        self.num_encoding_sizes = self.max_encoding_tokens = 0
        self.encoding_login_index = 0

        # transmit power
        self.txpower_capa = self.num_txpower = self.txpower = 0

        # wireless extension version info
        self.we_vers_compiled = self.we_vers_src = 0

        # retry limits and lifetime
        self.retry_capa = self.retry_flags = self.r_time_flags = 0
        self.min_retry = self.max_retry = 0
        self.min_r_time = self.max_r_time = 0

        # frequency
        self.num_channels = self.num_frequency = 0
        self.frequencies = []

        # capabilities and power management
        self.enc_capa = 0
        self.min_pms = self.max_pms = self.pms_flags = 0
        self.modul_capa = 0
        self.bitrate_capa = 0

        self.update()

    def update(self):
        """ Updates Iwrange object by a system call to the kernel
            and updates internal attributes.

        """
        iwstruct = Iwstruct()
        buff, s = iwstruct.pack_wrq(640)
        status, result = iwstruct.iw_get_ext(self.ifname,
                                        flags.SIOCGIWRANGE,
                                        data=s)
        data = buff.tostring()
        self._parse(data)

    def _parse(self, data):
        iwstruct = Iwstruct()
        result = iwstruct.parse_data(self.fmt, data)

        # XXX there is maybe a much more elegant way to do this
        self.throughput, self.min_nwid, self.max_nwid = result[0:3]
        self.old_num_channels, self.old_num_frequency = result[3:5]
        self.old_freq = result[5:11]
        self.sensitivity = result[11]
        self.max_qual.setValues(result[12:16])
        self.avg_qual.setValues(result[16:20])
        self.num_bitrates = result[20]
        raw_bitrates = result[21:21+self.num_bitrates]
        for rate in raw_bitrates:
            if rate is not None:
                self.bitrates.append(rate)

        self.min_rts, self.max_rts = result[53:55]
        self.min_frag, self.max_frag = result[55:57]
        self.min_pmp, self.max_pmp = result[57:59]
        self.min_pmt, self.max_pmt = result[59:61]
        self.pmp_flags, self.pmt_flags, self.pm_capa = result[61:64]
        self.encoding_size = result[64:72]
        self.num_encoding_sizes, self.max_encoding_tokens = result[72:74]
        self.encoding_login_index = result[74]
        self.txpower_capa, self.num_txpower = result[75:77]
        self.txpower = result[77:85]
        self.we_vers_compiled, self.we_vers_src = result[85:87]
        self.retry_capa, self.retry_flags, self.r_time_flags = result[87:90]
        self.min_retry, self.max_retry = result[90:92]
        self.min_r_time, self.max_r_time = result[92:94]
        self.num_channels = result[94]
        self.num_frequency = result[95]

        freq = result[96:224]
        i = self.num_frequency
        for x in range(0, len(freq), 4):
            iwfreq = Iwfreq(freq[x:x+4])
            fq = iwfreq.getFrequency()
            if fq is not None:
                self.frequencies.append(fq)
            i -= 1
            if i <= 0:
                break
        self.enc_capa = result[224]
        self.min_pms = result[225]
        self.max_pms = result[226]
        self.pms_flags = result[227]
        self.modul_capa = result[228]
        self.bitrate_capa = result[229]


class Iwscan(object):
    """ Class to handle AP scanning. """

    def __init__(self, ifname, fullscan=True):
        """ Completes a scan for available access points,
            and returns them in Iwscanresult format.

           fullscan: If False, data is read from a cache of the last scan
                     If True, a scan is conducted, and then the data is read

        """
        self.ifname = ifname
        self.range = Iwrange(ifname)
        self.stream = None
        self.aplist = None
        self.index = -1

        if fullscan:
            # Triggers the scan
            iwstruct = Iwstruct()
            datastr = iwstruct.pack("Pii", 0, 0, 0)
            status, result = iwstruct.iw_set_ext(self.ifname,
                                                flags.SIOCSIWSCAN,
                                                datastr)
            self.getScan()

    def __iter__(self):
        return self

    def __len__(self):
        return len(self.aplist)

    def next(self):
        self.index = self.index + 1
        if self.index > len(self.aplist) - 1:
            raise StopIteration
        return self.aplist[self.index]

    def getScan(self):
        """ Retrieves results, stored from the most recent scan.

        """
        iwstruct = Iwstruct()
        bufflen = flags.IW_SCAN_MAX_DATA

        # Make repeated requests for scan with various recovery schemes
        while (True):
            buff, datastr = iwstruct.pack_wrq(bufflen)
            try:
                status, result = iwstruct.iw_get_ext(self.ifname,
                                                flags.SIOCGIWSCAN,
                                                data=datastr)
            except IOError, (error_number, error_string):
                if error_number == errno.E2BIG:
                    # Keep resizing the buffer until it's
                    #   large enough to hold the scan
                    pbuff, newlen = iwstruct.unpack('Pi', datastr)
                    if bufflen < newlen:
                        # the driver told us how big to make the buffer
                        bufflen = newlen
                    else:
                        # try doubling the buffer size
                        bufflen = bufflen * 2
                elif error_number == errno.EAGAIN:
                    # Permission was NOT denied,
                    #   therefore we must WAIT to get results
                    time.sleep(0.1)
                else:
                    raise
            except:
                raise
            else:
                break

        # unpack the buffer pointer and length
        pbuff, reslen = iwstruct.unpack('Pi', datastr)
        if reslen > 0:
            # Initialize the stream, and turn it into an enumerator
            self.aplist = self._parse(buff.tostring())

    def _parse(self, data):
        """ Parse the event stream, and return a list of Iwscanresult
            objects.

        """
        iwstruct = Iwstruct()
        scanresult = None
        aplist = []

        # Run through the stream until it is too short to contain a command
        while (len(data) >= flags.IW_EV_LCP_PK_LEN):
            # Unpack the header
            length, cmd = iwstruct.unpack('HH',
                              data[:flags.IW_EV_LCP_PK_LEN])
            # If the event length is too short to contain valid data,
            # then break, because we're probably at the end of the cell's data
            if length < flags.IW_EV_LCP_PK_LEN:
                break;
            # Put the events into their respective result data
            if cmd == flags.SIOCGIWAP:
                if scanresult:
                    aplist.append(scanresult)
                scanresult = Iwscanresult(
                        data[flags.IW_EV_LCP_PK_LEN:length],
                        self.range)
            elif scanresult is None:
                raise RuntimeError("Attempting to add an event without AP data.")
            else:
                scanresult.addEvent(cmd,
                        data[flags.IW_EV_LCP_PK_LEN:length])
            # We're finished with the previous event
            data = data[length:]

        # Don't forget the final result
        if scanresult:
            if scanresult.bssid != "00:00:00:00:00:00":
                aplist.append(scanresult)
            else:
                raise RuntimeError, 'Attempting to add an AP without a bssid'
        return aplist


class Iwscanresult(object):
    """ An object to contain all the events associated with a single
        scanned AP.

    """

    def __init__(self, data, iwrange):
        """ Initialize the scan result with the access point data. """
        self.range = iwrange
        self.bssid = "%02X:%02X:%02X:%02X:%02X:%02X" % (
                        struct.unpack('BBBBBB', data[2:8]))
        self.essid = None
        self.mode = None
        self.rate = []
        self.quality = Iwquality()
        self.frequency = None
        self.encode = None
        self.custom = []
        self.protocol = None

    def addEvent(self, cmd, data):
        """ Attempts to add the data from an event to a scanresult.
            Only certain data is accepted, in which case the result is True
            If the event data is invalid, None is returned
            If the data is valid but unused, False is returned

        """
        if ((cmd in range(flags.SIOCIWFIRST,
                          flags.SIOCIWLAST+1)) or
            (cmd in range(flags.IWEVFIRST,
                          flags.IWEVLAST+1))):
            if cmd == flags.SIOCGIWNWID:
                pass
            elif cmd == flags.SIOCGIWFREQ:
                self.frequency = Iwfreq(data)
            elif cmd == flags.SIOCGIWMODE:
                raw_mode = struct.unpack('I', data)[0]
                self.mode = flags.modes[raw_mode]
            elif cmd == flags.SIOCGIWNAME:
                self.protocol = data[:len(data)-2]
            elif cmd == flags.SIOCGIWESSID:
                self.essid = data[4:]
            elif cmd == flags.SIOCGIWENCODE:
                data = struct.unpack("B"*len(data), data)
                self.encode = Iwpoint("")
                self.encode.update(struct.pack('PHH',
                    (int(data[0])<<16)+int(data[1]), data[2]<<8, data[3]<<8))
                if (self.encode.caddr_t is None):
                    self.encode.flags = \
                        self.encode.flags | flags.IW_ENCODE_NOKEY
            elif cmd == flags.SIOCGIWRATE:
                freqsize = struct.calcsize("ihbb")
                rates = []
                while len(data) >= freqsize:
                    m, e, dummy, pad = struct.unpack("ihbb", data[:freqsize])
                    if e == 0:
                        rates.append(m)
                    else:
                        rates.append(m*10**e)
                    data = data[freqsize:]
                self.rate.append(rates)
            elif cmd == flags.SIOCGIWMODUL:
                pass
            elif cmd == flags.IWEVQUAL:
                self.quality.parse(data)
            elif cmd == flags.IWEVGENIE:
                pass
            elif cmd == flags.IWEVCUSTOM:
                self.custom.append(data[1:])
            else:
                raise ValueError("Unknown IW event command received. This " + \
                                 "command cannot be used to add information " + \
                                 "to the WiFi cell's profile.")
        else:
            raise ValueError("Invalid IW event command received.  \
                              This command is not allowed.")

    def display(self):
        print "ESSID:", self.essid
        print "Access point:", self.bssid
        print "Mode:", self.mode
        if len(self.rate) > 0:
            print "Highest Bitrate:", self.rate[len(self.rate)-1]
        print "Quality: Quality ", self.quality.quality,
        print "Signal ", self.quality.getSignallevel(),
        print " Noise ", self.quality.getNoiselevel()
        print "Encryption:", map(lambda x: hex(ord(x)), self.encode)
        # XXX
        # print "Frequency:", self.frequency.getFrequency(), "(Channel", self.frequency.getChannel(self.range), ")"
        for custom in self.custom:
            print "Custom:", custom
        print ""