Wireless config file design proposal for multi-radio wiphy

[Felix Fietkau]

Hi Harshitha,

On 26.09.24 07:14, Harshitha Prem wrote:
> Hi Team,
> 
> The MLO interface requires support for multi-radio wiphy and we would
> like to propose the following design for the wireless configuration file
> to accommodate multi-radio wiphy. For the multi-radio wireless
> configuration, we could use Wi-Fi devices named as radio0_band0,
> radio0_band1, etc. This naming convention would be helpful for hardware
> that includes a combination of one multi-radio capable wiphy
> (radio0_band0, radio0_band1) and one non-multi-radio wiphy (radio1).
> 
> Sample multi-radio wireless configuration file:
> 
> config wifi-device  radio0
>           option type     mac80211
>           option channel  11
>           option hwmode   11g
>           option htmode   HT20
>           # REMOVE THIS LINE TO ENABLE WIFI:
>           option disabled 1
> config wifi-iface
>           option device   radio0
>           option network  lan
>           option mode     ap
>           option ssid     OpenWrt
>           option encryption  none
> config wifi-device  radio1_band0
>           option type     mac80211
>           option channel  36
>           option hwmode   11a
>           option htmode   VHT80
>           # REMOVE THIS LINE TO ENABLE WIFI:
>           option disabled 1
>           option country US
> config wifi-iface
>           option device   radio1_band0
>           option network  lan
>           option mode     ap
>           option ssid     OpenWrt
>           option encryption  none
> config wifi-device  radio1_band1
>           option type     mac80211
>           option channel  49
>           option hwmode   11a
>           option band     3
>           option htmode   HE80
>           # REMOVE THIS LINE TO ENABLE WIFI:
>           option disabled 1
> config wifi-iface
>           option device   radio1_band1
>           option network  lan
>           option mode     ap
>           option ssid     OpenWrt
>           option encryption  sae
>           option sae_pwe  1
>           option key      0123456789
> 
> To configure a IEEE802.11be Multi-link Interface (MLD VAP), we could use
> options such as mld in each wifi-iface section which are part of MLD and
> introduce a new wireless configuration section, wifi-mld. This allows us
> to couple multiple links together under a single interface and any ML
> specific configurations could be updated under this section.
> 
> Please find the sample ML interface configuration below:

I have a different plan for supporting MLD already. In my staging tree, 
I've been working on user space code for using the multi-radio wiphy 
support that I added to cfg80211/mac80211.
The idea is to still have multiple wifi-device sections (like on your 
proposal), but with an option radio <idx> matching the wiphy radio index.
The code will use my work-in-progress code for setting allowed radios 
for each vif.

The next step (which I have not implemented yet) is to turn the device 
option for a wifi-iface into a list, so that the same SSID can be 
brought up on multiple radios without duplicating the section.
That should be supported for both MLD and non-MLD configurations, adding 
an extra option to enable MLD for the SSID.

I want to retain the ability to bring individual wifi devices up and 
down via the wifi command and make the hostapd ucode script responsible 
for adding/removing MLD links accordingly.

I can go into more detail once I've made more progress with the code.
The next step for me is to rework the vif-allowed-radios code based on 
feedback from Johannes and to complete the single-wiphy support for 
legacy mode. After that I will move on to MLD.

- Felix