Re: Exposing bssid information

[James Prestwood <prestwoj@gmail.com>]

Hi,

On 2/19/25 12:42 PM, James Hanley wrote:
> Thanks - this is really helpful for direction. I was going to
> initially brute force load all the attributes into a new interface,
> but it seems the preferred course from your suggestion is to gather
> the ESSID information and query each node individually for the BSSID
> information and populate that method with the associated details?

Properties, but yes. All the information you seek should already be 
within the scan_bss structure. So you'd really just need to add getters 
for each extra piece of info you want (RSSI, SNR, etc). The address is 
already there [1] so you should be able to add more getters following 
that as an example.

[1] 
https://git.kernel.org/pub/scm/network/wireless/iwd.git/tree/src/network.c#n2184


> One point that I'm stumbling on in testing the pristine codebase is
> accessing the ExtendedServiceSet property:
> test-wifi/test# dbus-send --system --type=method_call --print-reply
> --dest=net.connman.iwd /net/connman/iwd/0/2/53-elided-53_psk
> net.connman.iwd.Network.ExtendedServiceSet
> Error org.freedesktop.DBus.Error.NotFound: No matching method found
>
> When I query for the available interfaces and methods, I am able to see:
> test-wifi/test# dbus-send --system --type=method_call --print-reply
> --dest=net.connman.iwd /net/connman/iwd/0/2/53-elided-53_psk
> org.freedesktop.DBus.Introspectable.Introspect
> method return time=1739996534.609643 sender=:1.1090 ->
> destination=:1.1474 serial=2631 reply_serial=2
>     string "<!DOCTYPE node PUBLIC "-//freedesktop//DTD D-BUS Object
> Introspection 1.0//EN"
> "http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd">
> <node>
>          <interface name="org.freedesktop.DBus.Introspectable">
>                  <method name="Introspect">
>                          <arg name="xml" type="s" direction="out"/>
>                  </method>
>          </interface>
>          <interface name="net.connman.iwd.Network">
>                  <method name="Connect">
>                  </method>
>                  <property name="Name" type="s" access="read"/>
>                  <property name="Connected" type="b" access="read"/>
>                  <property name="Device" type="o" access="read"/>
>                  <property name="Type" type="s" access="read"/>
>                  <property name="KnownNetwork" type="o" access="read"/>
>                  <property name="ExtendedServiceSet" type="ao" access="read"/>
>          </interface>
>          <interface name="org.freedesktop.DBus.Properties">
>                  <method name="Get">
>                          <arg name="interface_name" type="s" direction="in"/>
>                          <arg name="property_name" type="s" direction="in"/>
>                          <arg name="value" type="v" direction="out"/>
>                  </method>
>                  <method name="Set">
>                          <arg name="interface_name" type="s" direction="in"/>
>                          <arg name="property_name" type="s" direction="in"/>
>                          <arg name="value" type="v" direction="in"/>
>                  </method>
>                  <method name="GetAll">
>                          <arg name="interface_name" type="s" direction="in"/>
>                          <arg name="props" type="a{sv}" direction="out"/>
>                  </method>
>                  <signal name="PropertiesChanged">
>                          <arg name="interface_name" type="s"/>
>                          <arg name="changed_properties" type="a{sv}"/>
>                          <arg name="invalidated_properties" type="as"/>
>                  </signal>
>          </interface>
>          <node name="d8-elided-95"/>
>          <node name="d8-elided-55"/>
>          <node name="d8-elided-15"/>
>          <node name="d8-elided-95"/>
>          <node name="d8-elided-55"/>
>          <node name="d8-elided-95"/>
> </node>
> "
>
> Is there something I'm missing in attempting to access this detail
> from dbus-send?  Ultimately this is only for testing, but I do plan on
> using the DBusConnection c-api and getting it right with dbus-send
> will help me in defining the code flow.
>
> -Jim
>
> On Sat, Feb 15, 2025 at 3:29 PM James Prestwood <prestwoj@gmail.com> wrote:
>> Hi Jim,
>>
>> On 2/15/25 12:10 PM, James Hanley wrote:
>>> Hi,
>>> I’m looking to access (and/or expose) via dbus scanned information on
>>> bssid. Specifically, information as follows:
>>>
>>> {
>>>     "wifiAccessPoints": [
>>>    {
>>>     "macAddress": "f0:d5:bf:fd:12:ae",
>>>     "signalStrength": -43,
>>>     "signalToNoiseRatio": 0,
>>>     "channel": 11,
>>>     "age": 0
>>> },
>>> {
>>>     "macAddress": "3c:37:86:5d:75:d4",
>>>     "signalStrength": -35,
>>>     "signalToNoiseRatio": 0
>>> },
>>> {
>>>     "macAddress": "30:86:2d:c4:29:d0",
>>>     "signalStrength": -35,
>>>     "signalToNoiseRatio": 0
>>> }
>>>    ]
>>> }
>>>
>>> This would be for geolocation services such as skyhook or google
>>> https://developers.google.com/maps/documentation/geolocation/requests-geolocation
>>> to allow a device to estimate its location. It seems that what is
>>> exposed is ESSID information with the strongest AP, or does is this
>>> information already exposed in iwd and which module/interface should
>>> be used? If not exposed, which model would be the most appropriate to
>>> add this to - scan, station, or another - and what interface for dbus
>>> should the method be exposed through?
>> Take a look at the ExtendedServiceSet property [1] on the network
>> objects. This contains a list of BasicServiceSet object [2] paths. At
>> the moment the BasicServiceSet objects only contain the BSSID as this
>> was all I really needed for the affinity functionality, but I'm not
>> opposed to additional info being added such as signal strength/channel
>> etc. If you need any pointers for this let me know, but it should be
>> relatively straight forward to add extra properties in the interface
>> setup [3].
>>
>> iwctl also supports showing the BSS object paths/properties via:
>>
>> "station wlan0 get-bsses"
>>
>> [1]
>> https://git.kernel.org/pub/scm/network/wireless/iwd.git/tree/doc/network-api.txt#n54
>> [2]
>> https://git.kernel.org/pub/scm/network/wireless/iwd.git/tree/doc/basic-service-set.txt
>> [3]
>> https://git.kernel.org/pub/scm/network/wireless/iwd.git/tree/src/network.c#n2196
>>> -Jim
>>>