Re: [PATCH 0/7] nl80211: rx path for control port frames (enabled only for wpa_supplicant)

On 2/23/20 5:29 PM, Jouni Malinen wrote:
> On Mon, Jan 13, 2020 at 03:58:31PM +0100, Markus Theil wrote:
>> This patch series adds rx control port support over nl80211. Control port
>> over nl80211 delivers all EAPOL and PREAUTH frames to userspace. This conflicts
>> with the current hostapd handling of pre-auth frames. Therefore, this feature
>> gets disabled for hostapd. Furthermore a pending kernel patch is necessary to
>> forward pre-auth frames from userspace (otherwise handled by Linux bridge code).
> Can you please clarify why the special control port would be used for
> RSN preauthentication frames? Those frame are supposed to be normal Data
> frames than can be sent out only when fully associated. Why would they
> need any special processing? And is it clear that that special
> processing would not result in incorrect behavior somewhere? It should
> be noted that these frame are _not_ supposed to be going over the EAPOL
> controlled port as defined in IEEE 802.1X (only EAPOL frames should).
>
This is just how I found the current Linux kernel to be build, when I started to integrate its
control port over nl80211. It allows to set a ethertype, which should be received over the controlled port,
which I set to EAPOL. Additionally and uncoditionally, it forwards all PRE-AUTH frames over the very same
control port (cannot be configured). Therefore I had to do it that way, in order to use the current kernels
implementation.