How can I get the signal strength of nearby wireless LAN networks in Windows using Python?

Question

How can I get the signal strength of neighboring wireless LAN networks in Windows using Python?

I would like to show or plot the values.

Answer 1

If you are on Windows , you probably want to use the WLAN API , which provides the WlanGetAvailableNetworkList () function (see the API docs for use). I don't know any python shells for WLANAPI.DLL , so you may have to wrap it yourself using ctypes . I have a preliminary script that does this (works for me), but can be cruel. You will want to read the documentation to understand the meaning of all the fields:

 from ctypes import * from ctypes.wintypes import * from sys import exit def customresize(array, new_size): return (array._type_*new_size).from_address(addressof(array)) wlanapi = windll.LoadLibrary('wlanapi.dll') ERROR_SUCCESS = 0 class GUID(Structure): _fields_ = [ ('Data1', c_ulong), ('Data2', c_ushort), ('Data3', c_ushort), ('Data4', c_ubyte*8), ] WLAN_INTERFACE_STATE = c_uint (wlan_interface_state_not_ready, wlan_interface_state_connected, wlan_interface_state_ad_hoc_network_formed, wlan_interface_state_disconnecting, wlan_interface_state_disconnected, wlan_interface_state_associating, wlan_interface_state_discovering, wlan_interface_state_authenticating) = map(WLAN_INTERFACE_STATE, xrange(0, 8)) class WLAN_INTERFACE_INFO(Structure): _fields_ = [ ("InterfaceGuid", GUID), ("strInterfaceDescription", c_wchar * 256), ("isState", WLAN_INTERFACE_STATE) ] class WLAN_INTERFACE_INFO_LIST(Structure): _fields_ = [ ("NumberOfItems", DWORD), ("Index", DWORD), ("InterfaceInfo", WLAN_INTERFACE_INFO * 1) ] WLAN_MAX_PHY_TYPE_NUMBER = 0x8 DOT11_SSID_MAX_LENGTH = 32 WLAN_REASON_CODE = DWORD DOT11_BSS_TYPE = c_uint (dot11_BSS_type_infrastructure, dot11_BSS_type_independent, dot11_BSS_type_any) = map(DOT11_BSS_TYPE, xrange(1, 4)) DOT11_PHY_TYPE = c_uint dot11_phy_type_unknown = 0 dot11_phy_type_any = 0 dot11_phy_type_fhss = 1 dot11_phy_type_dsss = 2 dot11_phy_type_irbaseband = 3 dot11_phy_type_ofdm = 4 dot11_phy_type_hrdsss = 5 dot11_phy_type_erp = 6 dot11_phy_type_ht = 7 dot11_phy_type_IHV_start = 0x80000000 dot11_phy_type_IHV_end = 0xffffffff DOT11_AUTH_ALGORITHM = c_uint DOT11_AUTH_ALGO_80211_OPEN = 1 DOT11_AUTH_ALGO_80211_SHARED_KEY = 2 DOT11_AUTH_ALGO_WPA = 3 DOT11_AUTH_ALGO_WPA_PSK = 4 DOT11_AUTH_ALGO_WPA_NONE = 5 DOT11_AUTH_ALGO_RSNA = 6 DOT11_AUTH_ALGO_RSNA_PSK = 7 DOT11_AUTH_ALGO_IHV_START = 0x80000000 DOT11_AUTH_ALGO_IHV_END = 0xffffffff DOT11_CIPHER_ALGORITHM = c_uint DOT11_CIPHER_ALGO_NONE = 0x00 DOT11_CIPHER_ALGO_WEP40 = 0x01 DOT11_CIPHER_ALGO_TKIP = 0x02 DOT11_CIPHER_ALGO_CCMP = 0x04 DOT11_CIPHER_ALGO_WEP104 = 0x05 DOT11_CIPHER_ALGO_WPA_USE_GROUP = 0x100 DOT11_CIPHER_ALGO_RSN_USE_GROUP = 0x100 DOT11_CIPHER_ALGO_WEP = 0x101 DOT11_CIPHER_ALGO_IHV_START = 0x80000000 DOT11_CIPHER_ALGO_IHV_END = 0xffffffff WLAN_AVAILABLE_NETWORK_CONNECTED = 1 WLAN_AVAILABLE_NETWORK_HAS_PROFILE = 2 WLAN_AVAILABLE_NETWORK_INCLUDE_ALL_ADHOC_PROFILES = 0x00000001 WLAN_AVAILABLE_NETWORK_INCLUDE_ALL_MANUAL_HIDDEN_PROFILES = 0x00000002 class DOT11_SSID(Structure): _fields_ = [ ("SSIDLength", c_ulong), ("SSID", c_char * DOT11_SSID_MAX_LENGTH) ] class WLAN_AVAILABLE_NETWORK(Structure): _fields_ = [ ("ProfileName", c_wchar * 256), ("dot11Ssid", DOT11_SSID), ("dot11BssType", DOT11_BSS_TYPE), ("NumberOfBssids", c_ulong), ("NetworkConnectable", c_bool), ("wlanNotConnectableReason", WLAN_REASON_CODE), ("NumberOfPhyTypes", c_ulong), ("dot11PhyTypes", DOT11_PHY_TYPE * WLAN_MAX_PHY_TYPE_NUMBER), ("MorePhyTypes", c_bool), ("wlanSignalQuality", c_ulong), ("SecurityEnabled", c_bool), ("dot11DefaultAuthAlgorithm", DOT11_AUTH_ALGORITHM), ("dot11DefaultCipherAlgorithm", DOT11_CIPHER_ALGORITHM), ("Flags", DWORD), ("Reserved", DWORD) ] class WLAN_AVAILABLE_NETWORK_LIST(Structure): _fields_ = [ ("NumberOfItems", DWORD), ("Index", DWORD), ("Network", WLAN_AVAILABLE_NETWORK * 1) ] WlanOpenHandle = wlanapi.WlanOpenHandle WlanOpenHandle.argtypes = (DWORD, c_void_p, POINTER(DWORD), POINTER(HANDLE)) WlanOpenHandle.restype = DWORD WlanEnumInterfaces = wlanapi.WlanEnumInterfaces WlanEnumInterfaces.argtypes = (HANDLE, c_void_p, POINTER(POINTER(WLAN_INTERFACE_INFO_LIST))) WlanEnumInterfaces.restype = DWORD WlanGetAvailableNetworkList = wlanapi.WlanGetAvailableNetworkList WlanGetAvailableNetworkList.argtypes = (HANDLE, POINTER(GUID), DWORD, c_void_p, POINTER(POINTER(WLAN_AVAILABLE_NETWORK_LIST))) WlanGetAvailableNetworkList.restype = DWORD WlanFreeMemory = wlanapi.WlanFreeMemory WlanFreeMemory.argtypes = [c_void_p] if __name__ == '__main__': NegotiatedVersion = DWORD() ClientHandle = HANDLE() ret = WlanOpenHandle(1, None, byref(NegotiatedVersion), byref(ClientHandle)) if ret != ERROR_SUCCESS: exit(FormatError(ret)) # find all wireless network interfaces pInterfaceList = pointer(WLAN_INTERFACE_INFO_LIST()) ret = WlanEnumInterfaces(ClientHandle, None, byref(pInterfaceList)) if ret != ERROR_SUCCESS: exit(FormatError(ret)) try: ifaces = customresize(pInterfaceList.contents.InterfaceInfo, pInterfaceList.contents.NumberOfItems) # find each available network for each interface for iface in ifaces: print "Interface: %s" % (iface.strInterfaceDescription) pAvailableNetworkList = pointer(WLAN_AVAILABLE_NETWORK_LIST()) ret = WlanGetAvailableNetworkList(ClientHandle, byref(iface.InterfaceGuid), 0, None, byref(pAvailableNetworkList)) if ret != ERROR_SUCCESS: exit(FormatError(ret)) try: avail_net_list = pAvailableNetworkList.contents networks = customresize(avail_net_list.Network, avail_net_list.NumberOfItems) for network in networks: print "SSID: %s, quality: %02d%%" % ( network.dot11Ssid.SSID[:network.dot11Ssid.SSIDLength], network.wlanSignalQuality) finally: WlanFreeMemory(pAvailableNetworkList) finally: WlanFreeMemory(pInterfaceList) 

On Linux , you have several options:

The standard parameters are parsing the output of iwlist -scan . However, if you are currently connected to wlan and are not running as root, it only returns the currently connected wlan.

If you need more than this, the best way is to request the Wireless Manager daemon. In modern linux files, this is usually NetworkManager , although wicd is becoming more and more popular. Both of these managers can be requested via dbus . If you cannot control what clients have on their systems, you may need to support both of these options or at least one option and backup for iwlist .

Answer 2

If you do not want to deal with the Windows API, you can use the method shown here with a slight modification.

You can use this command:

 netsh wlan show networks mode=Bssid 

using this code

 import subprocess results = subprocess.check_output(["netsh", "wlan", "show", "network", "mode=Bssid"]) 

This will give you additional “Signal” information in percent. It can be converted to RSSI using this method .

Answer 3

Well, you can call the system command to get this information (Linux = iwlist), analyze the result and display it.

Answer 4

@fmark I just wanted to say THANKS so much for this awesome post. In my work, I try to get RSSI from a connected access point in Windows, and you deserve a lot of thanks for the fact that I finally did it. I am currently listing all access points, but I am working on a modification of it. I wanted to offer a recommendation regarding your code. I am not very experienced with C or the Python CTypes module, but I think I could find a possible error. I really don't know what the difference is, but I noticed:

You define the transfers as follows:

 DOT11_BSS_TYPE = c_uint (dot11_BSS_type_infrastructure, dot11_BSS_type_independent, dot11_BSS_type_any) = map(DOT11_BSS_TYPE, xrange(1, 4)) 

But sometimes you define something like this:

 DOT11_PHY_TYPE = c_uint dot11_phy_type_unknown = 0 dot11_phy_type_any = 0 dot11_phy_type_fhss = 1 dot11_phy_type_dsss = 2 dot11_phy_type_irbaseband = 3 dot11_phy_type_ofdm = 4 dot11_phy_type_hrdsss = 5 dot11_phy_type_erp = 6 dot11_phy_type_ht = 7 dot11_phy_type_IHV_start = 0x80000000 dot11_phy_type_IHV_end = 0xffffffff 

I think the second snipp should be modeled as the first, but I could be wrong. Here is my idea:

 DOT11_PHY_TYPE = c_uint (dot11_phy_type_unknown, dot11_phy_type_any, dot11_phy_type_fhss, dot11_phy_type_dsss, dot11_phy_type_irbaseband, dot11_phy_type_ofdm, dot11_phy_type_hrdsss, dot11_phy_type_erp, dot11_phy_type_ht, dot11_phy_type_IHV_start, dot11_phy_type_IHV_end) = map(DOT11_PHY_TYPE, [0,0,1,2,3,4, 5,6,7,0x80000000, 0xffffffff]) 

Thus, these values ​​will be correctly displayed in DOT11_PHY_TYPE. Maybe I'm completely wrong, but for future people like me, I just wanted everything to stumble on to be right :) Thanks again @fmark.

Answer 5

So, I was based on @fmarks code (which was safer for me to live), and you have to add the WlanScan function , otherwise RSSI values ​​will not be updated .

Here is my extended code!

All props for @fmarks!

 __author__ = 'Pedro Gomes' import time from ctypes import * from ctypes.wintypes import * from sys import exit def customresize(array, new_size): return (array._type_*new_size).from_address(addressof(array)) wlanapi = windll.LoadLibrary('wlanapi.dll') ERROR_SUCCESS = 0 class GUID(Structure): _fields_ = [ ('Data1', c_ulong), ('Data2', c_ushort), ('Data3', c_ushort), ('Data4', c_ubyte*8), ] WLAN_INTERFACE_STATE = c_uint (wlan_interface_state_not_ready, wlan_interface_state_connected, wlan_interface_state_ad_hoc_network_formed, wlan_interface_state_disconnecting, wlan_interface_state_disconnected, wlan_interface_state_associating, wlan_interface_state_discovering, wlan_interface_state_authenticating) = map(WLAN_INTERFACE_STATE, xrange(0, 8)) class WLAN_INTERFACE_INFO(Structure): _fields_ = [ ("InterfaceGuid", GUID), ("strInterfaceDescription", c_wchar * 256), ("isState", WLAN_INTERFACE_STATE) ] class WLAN_INTERFACE_INFO_LIST(Structure): _fields_ = [ ("NumberOfItems", DWORD), ("Index", DWORD), ("InterfaceInfo", WLAN_INTERFACE_INFO * 1) ] WLAN_MAX_PHY_TYPE_NUMBER = 0x8 DOT11_SSID_MAX_LENGTH = 32 WLAN_REASON_CODE = DWORD DOT11_BSS_TYPE = c_uint (dot11_BSS_type_infrastructure, dot11_BSS_type_independent, dot11_BSS_type_any) = map(DOT11_BSS_TYPE, xrange(1, 4)) DOT11_PHY_TYPE = c_uint dot11_phy_type_unknown = 0 dot11_phy_type_any = 0 dot11_phy_type_fhss = 1 dot11_phy_type_dsss = 2 dot11_phy_type_irbaseband = 3 dot11_phy_type_ofdm = 4 dot11_phy_type_hrdsss = 5 dot11_phy_type_erp = 6 dot11_phy_type_ht = 7 dot11_phy_type_IHV_start = 0x80000000 dot11_phy_type_IHV_end = 0xffffffff DOT11_AUTH_ALGORITHM = c_uint DOT11_AUTH_ALGO_80211_OPEN = 1 DOT11_AUTH_ALGO_80211_SHARED_KEY = 2 DOT11_AUTH_ALGO_WPA = 3 DOT11_AUTH_ALGO_WPA_PSK = 4 DOT11_AUTH_ALGO_WPA_NONE = 5 DOT11_AUTH_ALGO_RSNA = 6 DOT11_AUTH_ALGO_RSNA_PSK = 7 DOT11_AUTH_ALGO_IHV_START = 0x80000000 DOT11_AUTH_ALGO_IHV_END = 0xffffffff DOT11_CIPHER_ALGORITHM = c_uint DOT11_CIPHER_ALGO_NONE = 0x00 DOT11_CIPHER_ALGO_WEP40 = 0x01 DOT11_CIPHER_ALGO_TKIP = 0x02 DOT11_CIPHER_ALGO_CCMP = 0x04 DOT11_CIPHER_ALGO_WEP104 = 0x05 DOT11_CIPHER_ALGO_WPA_USE_GROUP = 0x100 DOT11_CIPHER_ALGO_RSN_USE_GROUP = 0x100 DOT11_CIPHER_ALGO_WEP = 0x101 DOT11_CIPHER_ALGO_IHV_START = 0x80000000 DOT11_CIPHER_ALGO_IHV_END = 0xffffffff WLAN_AVAILABLE_NETWORK_CONNECTED = 1 WLAN_AVAILABLE_NETWORK_HAS_PROFILE = 2 WLAN_AVAILABLE_NETWORK_INCLUDE_ALL_ADHOC_PROFILES = 0x00000001 WLAN_AVAILABLE_NETWORK_INCLUDE_ALL_MANUAL_HIDDEN_PROFILES = 0x00000002 class DOT11_SSID(Structure): _fields_ = [ ("SSIDLength", c_ulong), ("SSID", c_char * DOT11_SSID_MAX_LENGTH) ] class WLAN_AVAILABLE_NETWORK(Structure): _fields_ = [ ("ProfileName", c_wchar * 256), ("dot11Ssid", DOT11_SSID), ("dot11BssType", DOT11_BSS_TYPE), ("NumberOfBssids", c_ulong), ("NetworkConnectable", c_bool), ("wlanNotConnectableReason", WLAN_REASON_CODE), ("NumberOfPhyTypes", c_ulong), ("dot11PhyTypes", DOT11_PHY_TYPE * WLAN_MAX_PHY_TYPE_NUMBER), ("MorePhyTypes", c_bool), ("wlanSignalQuality", c_ulong), ("SecurityEnabled", c_bool), ("dot11DefaultAuthAlgorithm", DOT11_AUTH_ALGORITHM), ("dot11DefaultCipherAlgorithm", DOT11_CIPHER_ALGORITHM), ("Flags", DWORD), ("Reserved", DWORD) ] class WLAN_AVAILABLE_NETWORK_LIST(Structure): _fields_ = [ ("NumberOfItems", DWORD), ("Index", DWORD), ("Network", WLAN_AVAILABLE_NETWORK * 1) ] DOT11_MAC_ADDRESS = c_ubyte * 6 DOT11_CIPHER_ALGORITHM = c_uint DOT11_CIPHER_ALGO_NONE = 0x00 DOT11_CIPHER_ALGO_WEP40 = 0x01 DOT11_CIPHER_ALGO_TKIP = 0x02 DOT11_PHY_TYPE = c_uint DOT11_PHY_TYPE_UNKNOWN = 0 DOT11_PHY_TYPE_ANY = 0 DOT11_PHY_TYPE_FHSS = 1 DOT11_PHY_TYPE_DSSS = 2 DOT11_PHY_TYPE_IRBASEBAND = 3 DOT11_PHY_TYPE_OFDM = 4 DOT11_PHY_TYPE_HRDSSS = 5 DOT11_PHY_TYPE_ERP = 6 DOT11_PHY_TYPE_HT = 7 DOT11_PHY_TYPE_IHV_START = 0X80000000 DOT11_PHY_TYPE_IHV_END = 0XFFFFFFFF class WLAN_RATE_SET(Structure): _fields_ = [ ("uRateSetLength", c_ulong), ("usRateSet", c_ushort * 126) ] class WLAN_BSS_ENTRY(Structure): _fields_ = [ ("dot11Ssid",DOT11_SSID), ("uPhyId",c_ulong), ("dot11Bssid", DOT11_MAC_ADDRESS), ("dot11BssType", DOT11_BSS_TYPE), ("dot11BssPhyType", DOT11_PHY_TYPE), ("lRssi", c_long), ("uLinkQuality", c_ulong), ("bInRegDomain", c_bool), ("usBeaconPeriod",c_ushort), ("ullTimestamp", c_ulonglong), ("ullHostTimestamp",c_ulonglong), ("usCapabilityInformation",c_ushort), ("ulChCenterFrequency", c_ulong), ("wlanRateSet",WLAN_RATE_SET), ("ulIeOffset", c_ulong), ("ulIeSize", c_ulong)] class WLAN_BSS_LIST(Structure): _fields_ = [ ("TotalSize", DWORD), ("NumberOfItems", DWORD), ("NetworkBSS", WLAN_BSS_ENTRY * 1) ] class WLAN_AVAILABLE_NETWORK_LIST_BSS(Structure): _fields_ = [ ("TotalSize", DWORD), ("NumberOfItems", DWORD), ("Network", WLAN_BSS_ENTRY * 1) ] WlanOpenHandle = wlanapi.WlanOpenHandle WlanOpenHandle.argtypes = (DWORD, c_void_p, POINTER(DWORD), POINTER(HANDLE)) WlanOpenHandle.restype = DWORD WlanCloseHandle = wlanapi.WlanCloseHandle WlanCloseHandle.argtypes = (HANDLE, c_void_p) WlanCloseHandle.restype = DWORD WlanEnumInterfaces = wlanapi.WlanEnumInterfaces WlanEnumInterfaces.argtypes = (HANDLE, c_void_p, POINTER(POINTER(WLAN_INTERFACE_INFO_LIST))) WlanEnumInterfaces.restype = DWORD WlanGetAvailableNetworkList = wlanapi.WlanGetAvailableNetworkList WlanGetAvailableNetworkList.argtypes = (HANDLE, POINTER(GUID), DWORD, c_void_p, POINTER(POINTER(WLAN_AVAILABLE_NETWORK_LIST))) WlanGetAvailableNetworkList.restype = DWORD WlanGetNetworkBssList = wlanapi.WlanGetNetworkBssList WlanGetNetworkBssList.argtypes = (HANDLE, POINTER(GUID),POINTER(GUID),POINTER(GUID), c_bool, c_void_p, POINTER(POINTER(WLAN_BSS_LIST))) WlanGetNetworkBssList.restype = DWORD WlanFreeMemory = wlanapi.WlanFreeMemory WlanFreeMemory.argtypes = [c_void_p] WlanScan = wlanapi.WlanScan WlanScan.argtypes = (HANDLE, POINTER(GUID),c_void_p,c_void_p, c_void_p) WlanScan.restype = DWORD def get_interface(): NegotiatedVersion = DWORD() ClientHandle = HANDLE() ret = WlanOpenHandle(1, None, byref(NegotiatedVersion), byref(ClientHandle)) if ret != ERROR_SUCCESS: exit(FormatError(ret)) # find all wireless network interfaces pInterfaceList = pointer(WLAN_INTERFACE_INFO_LIST()) ret = WlanEnumInterfaces(ClientHandle, None, byref(pInterfaceList)) if ret != ERROR_SUCCESS: exit(FormatError(ret)) try: ifaces = customresize(pInterfaceList.contents.InterfaceInfo, pInterfaceList.contents.NumberOfItems) # find each available network for each interface for iface in ifaces: #print "Interface: %s" % (iface.strInterfaceDescription) interface = iface.strInterfaceDescription finally: WlanFreeMemory(pInterfaceList) return interface class MAC_BSSID_POWER: """Classe para os valores retirados""" def __init__(self, mac, bssid): self.mac = str(mac) self.bssid = str(bssid) self.valores = [] def addPower(self,power): self.valores.append(int(power)) def getBssid(self): return self.bssid def getPowers(self): return self.valores def getMac(self): return self.mac def get_BSSI(): BSSI_Values={} NegotiatedVersion = DWORD() ClientHandle = HANDLE() ret = WlanOpenHandle(1, None, byref(NegotiatedVersion), byref(ClientHandle)) if ret != ERROR_SUCCESS: exit(FormatError(ret)) # find all wireless network interfaces pInterfaceList = pointer(WLAN_INTERFACE_INFO_LIST()) ret = WlanEnumInterfaces(ClientHandle, None, byref(pInterfaceList)) if ret != ERROR_SUCCESS: exit(FormatError(ret)) try: ifaces = customresize(pInterfaceList.contents.InterfaceInfo, pInterfaceList.contents.NumberOfItems) # find each available network for each interface for iface in ifaces: # print "Interface: %s" % (iface.strInterfaceDescription) pAvailableNetworkList2 = pointer(WLAN_BSS_LIST()) ret2 = WlanGetNetworkBssList(ClientHandle, byref(iface.InterfaceGuid), None, None,True,None, byref(pAvailableNetworkList2)) if ret2 != ERROR_SUCCESS: exit(FormatError(ret2)) try: retScan = WlanScan(ClientHandle,byref(iface.InterfaceGuid),None,None,None) if retScan != ERROR_SUCCESS: exit(FormatError(retScan)) avail_net_list2 = pAvailableNetworkList2.contents networks2 = customresize(avail_net_list2.NetworkBSS, avail_net_list2.NumberOfItems) for network in networks2: SSID = str(network.dot11Ssid.SSID[:network.dot11Ssid.SSIDLength]) BSSID = ':'.join('%02x' % b for b in network.dot11Bssid).upper() signal_strength = str(network.lRssi) # print "SSID: " + SSID + " BSSID: "+ BSSID+ " SS: "+signal_strength BSSI_Values[BSSID] = [SSID,signal_strength] #print "Total "+str(len(networks2)) #print BSSI_Values finally: WlanFreeMemory(pAvailableNetworkList2) WlanCloseHandle(ClientHandle,None) finally: WlanFreeMemory(pInterfaceList) return BSSI_Values def get_BSSI_times_and_total_seconds(times,seconds): BSSI_to_return = {} for i in range(0,seconds*times): time_to_sleep = float(1.0/times) time.sleep(time_to_sleep) got_bssi_temp = get_BSSI() for bssi in got_bssi_temp: if not BSSI_to_return.get(bssi): BSSI_to_return[bssi] = MAC_BSSID_POWER(bssi,got_bssi_temp[bssi][0]) BSSI_to_return[bssi].addPower( got_bssi_temp[bssi][1] ) #BSSI_to_return[bssi] = [got_bssi_temp[bssi][1]] else: BSSI_to_return[bssi].addPower( got_bssi_temp[bssi][1] ) #BSSI_to_return[bssi].append(got_bssi_temp[bssi][1]) print "Medicao "+str(i)+" de "+str(seconds*times) print BSSI_to_return return BSSI_to_return if __name__ == '__main__': #print get_interface() import time test = get_BSSI() for i in range(0,10): time.sleep(0.5) oldTest = test test = get_BSSI() print "Teste: "+str(i) if oldTest == test: print "IGUAL" else: print "DIFERENTE" print test print "End"