Re: [PATCH] mac80211: Set CAN_REPLACE_PTK0 for SW crypto only drivers

[Johannes Berg <johannes@sipsolutions.net>]

On Wed, 2019-04-24 at 19:32 +0200, Alexander Wetzel wrote:
> Mac80211 SW crypto handles replacing PTK keys correctly.
> 
> Don't trigger needless warnings or workarounds when the driver can only
> use the known good SW crypto provided by mac80211.
> 
> Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
> ---
>  net/mac80211/main.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/net/mac80211/main.c b/net/mac80211/main.c
> index e56650a9838e..2b608044ae23 100644
> --- a/net/mac80211/main.c
> +++ b/net/mac80211/main.c
> @@ -1060,6 +1060,13 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
>  		wiphy_ext_feature_set(local->hw.wiphy,
>  				      NL80211_EXT_FEATURE_EXT_KEY_ID);
>  
> +	/* Mac80211 and therefore all cards only using SW crypto are able to
> +	 * handle PTK rekeys correctly
> +	 */
> +	if (!local->ops->set_key)
> +		wiphy_ext_feature_set(local->hw.wiphy,
> +				      NL80211_EXT_FEATURE_CAN_REPLACE_PTK0);

Now I wonder - shouldn't the same A-MPDU issue apply here? After all, if
you replace the PTK 0 surely you shouldn't use different ones for the
same frame in an A-MPDU?

johannes