[PATCH wireless-next v2] wifi: mac80211: Report parent AP BSS parameters for AP_VLAN

[Aaradhana Sahu]

On 9/21/2026 5:21 PM, Johannes Berg wrote:
> On Tue, 2026-09-15 at 10:59 +0530, Aaradhana Sahu wrote:
>> AP_VLAN interfaces do not maintain independent BSS configuration.
>> When station information is reported for a 4-address station, BSS
>> parameters are read from the AP_VLAN interface, causing beacon interval,
>> DTIM period and BSS capability flags to be reported incorrectly.
>>
>> Read the BSS configuration from the parent AP when populating station
>> information for AP_VLAN interfaces. This ensures that beacon interval,
>> DTIM period, CTS protection, short preamble and short slot time reflect
>> the parent AP configuration for both legacy and MLO station dumps.
>>
>> For MLO, the per-link BSS configuration is used so that CTS protection,
>> short preamble and short slot time reflect the configuration of the
>> corresponding parent AP link.
>>
>> Only advertise NL80211_STA_INFO_BSS_PARAM when a valid BSS
>> configuration is available. This avoids reporting zero-valued BSS
>> parameters when corresponding BSS configuration is unavailable.
> 
> So ... I guess I can't disagree with that - but is it worth reporting
> any of these parameters at all? They're entirely under control of
> hostapd, so it already _knows_ - is there a separate tool that really
> needs to get them via the station info?
> 
> I'd be tempted to just _remove_ these on the AP side rather than making
> the code more complex to report them correctly, in particular since
> basically nobody could actually be using them right now since they're
> just broken ...
> 
> johannes

Since all these parameters (beacon interval, DTIM period, CTS protection,
short preamble, and short slot time) are already populated in sta_info and
are visible through the iw station dump command, I only made changes for the
AP_VLAN case, where these values are currently reported incorrectly.

I am not sure whether any third-party userspace application relies on these values
apart from iw. If we remove these parameters from the AP-side station information,
the iw station dump output will also change. Would that be acceptable?