#!/usr/bin/env python #-*- coding: utf-8 -*- # # This script checks with ifconfig which WLAN channel is used by the current system and reports # whether other SSIDs use the same channel or whether there are channel range overlaps # by other channels used by other SSIDs # # You will get better scan results if you invoke the script as root. No change on the system will be done # shell commands executed: # 1) iwlist scan # 2) iwconfig # # Invoke script with any parameter to get the following sample result if there is a WLAN adapter available. # --------------------------------------------------------------------------------------------------------- # WLAN channel analysis for SSID 'MyESSID' using channel 6 on wlan0 # # Channels | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | SSIDs # 1 *01**---------> Channel1 # 2 <----*01**---------> OverlapChannel2 # 4 <---------*01**---------> BorderChannel4 # 5 <---------*01**---------> InbetweenChannel5 # 6 <---------*02**---------> * MyESSID, SameChannel6 # 9 <---------*01**---------> OverlapChannel9 # 13 <---------*01** Channel13 # # SSIDs with identical channel : 1 SameChannel6 # SSIDs with overlapping channels : 4 BorderChannel4, InbetweenChannel5, OverlapChannel2, OverlapChannel9 # Sum of detected SSIDs : 8 # Minimal overlapped channels : 11,12 # # *** Switch your access point channel from 6 to an optimal channel 12 # ---------------------------------------------------------------------------------------------------- # # 05/03/12 framp at linux-tips-and-tricks dot de # 03/30/15 Enhanced rating logic # # Credits: Thx for beta tests executed by members of minthouse.forumieren.com # import subprocess import re import sys import os from optparse import OptionParser mySelf=os.path.basename(sys.argv[0]) version='0.4' myVersion=mySelf+" V" + version debug=False class wlanScanner(): def executeCommand(self,command): rc=None result=None try: proc = subprocess.Popen(command, stdout=subprocess.PIPE,shell=True) result = proc.communicate()[0] rc = proc.returncode except OSError, e: print "===> Error occured in command %s" % (command) raise e return (rc,result) def printOverlap(self,usageCount, scanChannel,suffix=""): print " %2d " % (scanChannel), for channel in range(1,14): if channel == scanChannel: sys.stdout.write ("*%.2d**" % (usageCount)) elif channel == max(scanChannel-2,1): sys.stdout.write ("<----") elif channel == min(scanChannel+2,13): sys.stdout.write ("---->") elif channel >= max(scanChannel-2,1) and channel <= min(scanChannel+2,13): sys.stdout.write ("-----") else: sys.stdout.write (" ") print " %s" % (suffix) def findCommand(self,command): pathes=['/sbin','/usr/bin','/usr/sbin','/bin'] for path in pathes: (rc,result)=self.executeCommand('find ' + path + ' -name ' + command + ' | head -n 1') if rc != 0: print "*** Error: Unable to execute " + command sys.exit(1) if result: return result.rstrip() return None def run(self,essid=None,testData=None): accessPoints=[] channelUsage=[0]*14 if testData: scanEssid=testData['scanEssid'] scanDevice=testData['scanDevice'] scanChannel=testData['scanChannel'] myDevs=[[scanDevice,scanEssid]] accessPoints=testData['accessPoints'] channelUsage=testData['channelUsage'] else: myDevs=[] command=self.findCommand('iwconfig') (rc,result)=self.executeCommand(command + ' 2>/dev/null') if rc > 0: sys.exit(1) result=result.split('\n') devFound=None for line in result: match=re.search('^(\S+).*IEEE',line,re.IGNORECASE) if match: devFound=match.group(1) if essid: myDev=match.group(1) myEssid=essid myDevs.append((myDev,myEssid)) break match=re.search('^(\S+).*ESSID[^"]*"([^"]*)"',line,re.IGNORECASE) if match: myDev=match.group(1) myEssid=match.group(2) myDevs.append((myDev,myEssid)) continue if not myDevs: if devFound: print "*** Error: WLAN device %s not connected to an accesspoint. Use option -e" % (devFound) else: print "*** Error: No WLAN device found" sys.exit(1) (scanDevice,scanEssid)=myDevs[0] if len(myDevs) > 1: print "*** Warning: More than one WLAN device found. Using %s for channel scans" % (scanDevice) command=self.findCommand('iwlist') (rc,result)=self.executeCommand(command + ' ' + scanDevice + ' scan') if rc > 0: sys.exit(1) result=result.split('\n') essid=None channel=None scanChannel=None for line in result: match=re.search('ESSID[^"]*"([^"]*)"',line,re.IGNORECASE) if match: essid=match.group(1) else: match=re.search('Channel[^\d]*(\d+)',line,re.IGNORECASE) if match: channel=int(match.group(1)) if essid and channel: accessPoints.append((essid,channel)) channelUsage[channel]+=1 if essid == scanEssid: scanChannel=channel (essid,channel)=(None,None) if not scanChannel: print "*** Error: Unable to get channel used by %s" % (scanEssid) sys.exit(1) print "\nWLAN channel analysis for SSID '%s' using channel %d on %s" % (scanEssid, scanChannel, scanDevice) print print "Channels | ", for channel in range(1,14): sys.stdout.write ("%.2d | " % (channel)) print "SSIDs" overlappedChannelsSSID=[] identicalChannelsSSID=[] channelSSID=[ [] for i in xrange(0,14)] for (ssid,channel) in accessPoints: channelSSID[channel].append(ssid) if abs(channel - scanChannel) <= 4 and ssid != scanEssid: if channel != scanChannel: overlappedChannelsSSID.append(ssid) else: identicalChannelsSSID.append(ssid) identicalChannel=len(identicalChannelsSSID) identicalList = ', '.join(identicalChannelsSSID) if identicalChannel > 0 else "" overlappedChannels=len(overlappedChannelsSSID) overlappedList = ', '.join(overlappedChannelsSSID) if overlappedChannels > 0 else "" accessPoints=sorted(accessPoints, key=lambda ap: ap[1]) processedChannels=[False]*14 for (ssid,channel) in accessPoints: if not processedChannels[channel]: suffix="" if channelSSID[channel]: if ssid == scanEssid: suffix="* " suffix+=', '.join(channelSSID[channel]) self.printOverlap(channelUsage[channel],channel,suffix) processedChannels[channel] = True print print "SSIDs with identical channel : %d %s" % (identicalChannel, identicalList) print "SSIDs with overlapping channels : %d %s" % (overlappedChannels, overlappedList) sumDetectedAPs=len(accessPoints) print "Sum of detected SSIDs : %d" % (sumDetectedAPs) channelWeight=[0.55,0.72,1,0.72,0.55] channelUsage=[0]*14 for (ssid,channel) in accessPoints: if ssid != scanEssid: actualWeight=0 if channel>=3 else 3-channel for c in xrange(max(1,channel-2),min(14,channel+3)): channelUsage[c]+=channelWeight[actualWeight] actualWeight+=1 if debug: print "ChannelUsage: ", ["%.2f" % c for c in channelUsage[1:] ] minimum=min(channelUsage[1:]) minimumChannels=[ c for c in xrange(1,14) if channelUsage[c] == minimum ] minimumChannelWeight=[0]*14 for channel in minimumChannels: for c in xrange(max(1,channel-2),min(14,channel+3)): minimumChannelWeight[channel]+=channelUsage[c] if debug: print "MinimumWeight: ", ["%.2f" % w for w in minimumChannelWeight[1:]] minimum = min([ minimumChannelWeight[c] for c in minimumChannels ]) minimumChannelWeights=[ [c,minimumChannelWeight[c]] for c in minimumChannels ] minimumChannels=[ str(e[0]) for e in minimumChannelWeights if e[1] == minimum] print if len(minimumChannels) > 1: optimalChannels=','.join(minimumChannels[:-1])+' or ' + minimumChannels[-1] else: optimalChannels=minimumChannels[0:] if not str(scanChannel) in minimumChannels: print "*** Switch your access point channel from %s to optimal channel%s %s" % (scanChannel,['','s'] [len(optimalChannels)>1],''.join(optimalChannels)) else: if len(optimalChannels) == 1: print "*** Your access point channel %s is optimal" % (scanChannel) else: print "*** Your access point channel %s is optimal but can also be changed to channel%s %s" % (scanChannel, ['','s'] [len(optimalChannels)>1], ''.join(optimalChannels)) if testData: result={} result['identicalChannel']=identicalChannel result['identicalList']=identicalList result['overlappedChannels']=overlappedChannels result['overlappedList']=overlappedList result['sumDetectedAPs']=sumDetectedAPs result['channelUsage']=channelUsage result['minimumChannels']=minimumChannels return result import unittest class TestFunctions(unittest.TestCase): def setUp(self): self.scanner = wlanScanner # @unittest.skip("Works") def test_no1(self): testData={} scanChannel=6 scanEssid='MyESSID1' testData['scanEssid']=scanEssid testData['scanDevice']='wlan0' testData['scanChannel']=scanChannel accessPoints=[] channelUsage=[0]*14 accessPoints.append((scanEssid,scanChannel)) testData['accessPoints']=accessPoints testData['channelUsage']=channelUsage channelUsage[scanChannel]+=1 accessPoints.append(("Channel1",1)) channelUsage[1]+=1 accessPoints.append(("Channel13",13)) channelUsage[13]+=1 accessPoints.append(("SameChannel6",scanChannel)) channelUsage[scanChannel]+=1 accessPoints.append(("BorderChannel4",4)) channelUsage[4]+=1 accessPoints.append(("InbetweenChannel5",5)) channelUsage[5]+=1 accessPoints.append(("OverlapChannel2",2)) channelUsage[2]+=1 accessPoints.append(("OverlapChannel9",9)) channelUsage[9]+=1 result=wlanScanner().run(testData=testData) self.assertEqual(result['identicalChannel'],1,'Wrong number of equal channels') self.assertEqual(result['identicalList'],'SameChannel6','Wrong names of equal channels') self.assertEqual(result['overlappedChannels'],4,'Wrong number of overlapped channels') self.assertEqual(result['overlappedList'],'BorderChannel4, InbetweenChannel5, OverlapChannel2, OverlapChannel9','Wrong names of overlapped channels') self.assertEqual(result['sumDetectedAPs'],8,'Wrong number of APs') self.assertEqual(result['minimumChannels'],['12'],'Wrong minimum channels') # @unittest.skip("Works") def test_no2(self): testData={} scanChannel=6 scanEssid='MyESSID2' testData['scanEssid']=scanEssid testData['scanDevice']='wlan0' testData['scanChannel']=scanChannel accessPoints=[] channelUsage=[0]*14 accessPoints.append((scanEssid,scanChannel)) testData['accessPoints']=accessPoints testData['channelUsage']=channelUsage channelUsage[scanChannel]+=1 accessPoints.append(("Channel1",1)) channelUsage[1]=1 result=wlanScanner().run(testData=testData) self.assertEqual(result['identicalChannel'],0,'Wrong number of equal channels') self.assertEqual(result['identicalList'],'','Wrong names of equal channels') self.assertEqual(result['overlappedChannels'],0,'Wrong number of overlapped channels') self.assertEqual(result['overlappedList'],'','Wrong names of overlapped channels') self.assertEqual(result['sumDetectedAPs'],2,'Wrong number of APs') self.assertEqual(result['minimumChannels'],['6','7','8','9','10','11','12','13'],'Wrong minimum channels') # @unittest.skip("Works") def test_no3(self): testData={} scanChannel=9 scanEssid='MyESSID3' testData['scanEssid']=scanEssid testData['scanDevice']='wlan0' testData['scanChannel']=scanChannel accessPoints=[] channelUsage=[0]*14 accessPoints.append((scanEssid,scanChannel)) testData['accessPoints']=accessPoints testData['channelUsage']=channelUsage channelUsage[scanChannel]+=1 accessPoints.append(('C11',1)) accessPoints.append(('C12',1)) accessPoints.append(('C13',1)) accessPoints.append(('C14',1)) accessPoints.append(('C15',1)) accessPoints.append(('C16',1)) accessPoints.append(('C17',1)) accessPoints.append(('C18',1)) accessPoints.append(('C19',1)) channelUsage[1]=9 accessPoints.append(('C21',2)) channelUsage[2]=1 accessPoints.append(('C41',4)) channelUsage[4]=1 accessPoints.append(('C61',6)) accessPoints.append(('C62',6)) channelUsage[6]=2 accessPoints.append(('C71',7)) channelUsage[7]=1 result=wlanScanner().run(testData=testData) self.assertEqual(result['identicalChannel'],0,'Wrong number of equal channels') self.assertEqual(result['identicalList'],'','Wrong names of equal channels') self.assertEqual(result['overlappedChannels'],3,'Wrong number of overlapped channels') self.assertEqual(result['overlappedList'],'C61, C62, C71','Wrong names of overlapped channels') self.assertEqual(result['sumDetectedAPs'],15,'Wrong number of APs') self.assertEqual(result['minimumChannels'],['12','13'],'Wrong minimum channels') # @unittest.skip("Works") def test_no4(self): testData={} scanChannel=6 scanEssid='MyESSID4' testData['scanEssid']=scanEssid testData['scanDevice']='wlan0' testData['scanChannel']=scanChannel accessPoints=[] channelUsage=[0]*14 accessPoints.append((scanEssid,scanChannel)) testData['accessPoints']=accessPoints testData['channelUsage']=channelUsage channelUsage[scanChannel]+=1 accessPoints.append(("Channel2",1)) channelUsage[2]=1 accessPoints.append(("Channel9",9)) channelUsage[10]=1 result=wlanScanner().run(testData=testData) self.assertEqual(result['identicalChannel'],0,'Wrong number of equal channels') self.assertEqual(result['identicalList'],'','Wrong names of equal channels') self.assertEqual(result['overlappedChannels'],1,'Wrong number of overlapped channels') self.assertEqual(result['overlappedList'],'Channel9','Wrong names of overlapped channels') self.assertEqual(result['sumDetectedAPs'],3,'Wrong number of APs') self.assertEqual(result['minimumChannels'],['13'],'Wrong minimum channels') # @unittest.skip("Works") def test_no5(self): testData={} scanChannel=6 scanEssid='MyESSID5' testData['scanEssid']=scanEssid testData['scanDevice']='wlan0' testData['scanChannel']=scanChannel accessPoints=[] channelUsage=[0]*14 accessPoints.append((scanEssid,scanChannel)) testData['accessPoints']=accessPoints testData['channelUsage']=channelUsage channelUsage[scanChannel]+=1 accessPoints.append(("Channel2",1)) channelUsage[2]=1 accessPoints.append(("Channel10",10)) channelUsage[10]=1 result=wlanScanner().run(testData=testData) self.assertEqual(result['identicalChannel'],0,'Wrong number of equal channels') self.assertEqual(result['identicalList'],'','Wrong names of equal channels') self.assertEqual(result['overlappedChannels'],1,'Wrong number of overlapped channels') self.assertEqual(result['overlappedList'],'Channel10','Wrong names of overlapped channels') self.assertEqual(result['sumDetectedAPs'],3,'Wrong number of APs') self.assertEqual(result['minimumChannels'],['5','6'],'Wrong minimum channels') # @unittest.skip("Works") def test_no6(self): testData={} scanChannel=6 scanEssid='MyESSID6' testData['scanEssid']=scanEssid testData['scanDevice']='wlan0' testData['scanChannel']=scanChannel accessPoints=[] channelUsage=[0]*14 accessPoints.append((scanEssid,scanChannel)) testData['accessPoints']=accessPoints testData['channelUsage']=channelUsage channelUsage[scanChannel]+=1 accessPoints.append(("Channel2",1)) channelUsage[2]=1 accessPoints.append(("Channel2_1",2)) channelUsage[2]=1 accessPoints.append(("Channel2_2",2)) channelUsage[2]+=1 result=wlanScanner().run(testData=testData) self.assertEqual(result['identicalChannel'],0,'Wrong number of equal channels') self.assertEqual(result['identicalList'],'','Wrong names of equal channels') self.assertEqual(result['overlappedChannels'],2,'Wrong number of overlapped channels') self.assertEqual(result['overlappedList'],'Channel2_1, Channel2_2','Wrong names of overlapped channels') self.assertEqual(result['sumDetectedAPs'],4,'Wrong number of APs') self.assertEqual(result['minimumChannels'],['7','8','9','10','11','12','13'],'Wrong minimum channels') # @unittest.skip("Works") def test_no7(self): testData={} scanChannel=6 scanEssid='MyESSID7' testData['scanEssid']=scanEssid testData['scanDevice']='wlan0' testData['scanChannel']=scanChannel accessPoints=[] channelUsage=[0]*14 accessPoints.append((scanEssid,scanChannel)) testData['accessPoints']=accessPoints testData['channelUsage']=channelUsage channelUsage[scanChannel]+=1 accessPoints.append(("Channel2",1)) channelUsage[2]=1 accessPoints.append(("Channel10_1",10)) channelUsage[10]=1 accessPoints.append(("Channel10_2",10)) channelUsage[10]+=1 result=wlanScanner().run(testData=testData) self.assertEqual(result['identicalChannel'],0,'Wrong number of equal channels') self.assertEqual(result['identicalList'],'','Wrong names of equal channels') self.assertEqual(result['overlappedChannels'],2,'Wrong number of overlapped channels') self.assertEqual(result['overlappedList'],'Channel10_1, Channel10_2','Wrong names of overlapped channels') self.assertEqual(result['sumDetectedAPs'],4,'Wrong number of APs') self.assertEqual(result['minimumChannels'],['5'],'Wrong minimum channels') # # *** MAIN *** # parser = OptionParser(usage="%prog [-h] [-e ESSID] [-t] [-d]", version=myVersion) parser.add_option("-e", "--essid", dest="essid", help="Don't discover ESSID form existing WLAN connection and use essid passed") parser.add_option("-t", "--test", dest="test", action="store_true", help="Execute self test") parser.add_option("-r", "--rating", dest="debug", action="store_true", help="Write details about the channel rating") (options, args) = parser.parse_args() debug=options.debug print myVersion if options.test: suite = unittest.TestLoader().loadTestsFromTestCase(TestFunctions) unittest.TextTestRunner(verbosity=5).run(suite) else: wlanScanner().run(essid=options.essid)