[PATCH V2 0/9] nl80211: add support for PTK/GTK handshake offload

[Arend Van Spriel]

On 18-5-2017 12:40, Johannes Berg wrote:
> On Thu, 2017-05-18 at 12:29 +0200, Arend Van Spriel wrote:
>> On 18-5-2017 11:22, Johannes Berg wrote:
>>> On Thu, 2017-05-18 at 10:18 +0200, Arend Van Spriel wrote:
>>>>
>>>>> We should therefore probably set the expectation that wpa_s -
>>>>> if
>>>>> it's new enough - always uses the offloaded functionality and
>>>>> always sets the WANT_1X. Then this is even better with such
>>>>> drivers, since they can immediately reject the connect()
>>>>> command if
>>>>> want_1x isn't set.
>>
>> Getting back at this. With "always" you mean for every connect()
>> regardless whether it is using 1X or PSK?
> 
> No, I just meant it would never use the non-offloaded functionality for
> 1X, as long as wpa_s was new enough to support it.
> 
> The same consideration kinda applies to (non-)offloaded 4-way-HS for
> PSK though I guess, with some drivers (devices) not able to not offload
> it.

Thanks for clarifying that. And indeed it applies to both cases.

>> You mean adding a nl80211 command in which user-space can indicate
>> what features it supports? Do you want to use the same feature bits
>> on both sides to easily determine the combined feature set?
>> ext_feature does not really have much overlapping so not sure if it
>> adds value.
> 
> No, I meant that we have NL80211_EXT_FEATURE_4WAY_HANDSHAKE_STA_1X
> today, but then we might need also
> NL80211_EXT_FEATURE_HOST_4WAY_HANDSHAKE_STA_1X.
> 
> Come to think of it though, I guess the fact that the NEW_KEY command
> isn't support would already indicate that.

True. However, we touched this topic a while ago in generic context, ie.
preference for ext_features over supported_commands. Right now
wpa_supplicant does not check NEW_KEY support so we can go either way.

I have cleaned up the wpa_supplicant patches for the offloads, but
waited with submitting them until the kernel side got applied. So
depending on what is decided here I can rework it.

Regards,
Arend