Hi James,

On 3/3/21 11:47 AM, James Prestwood wrote:
> This checks if offload is an available extended feature and
> compatible with the desired BSS. It is also conditional on
> the [General].PreferOffload setting which, for now, is being
> added as a 'hidden' developer feature (not documented).
> ---
>   src/wiphy.c | 33 +++++++++++++++++++++++++++++++++
>   src/wiphy.h |  1 +
>   2 files changed, 34 insertions(+)
> 
> diff --git a/src/wiphy.c b/src/wiphy.c
> index 3adc5669..2493e8eb 100644
> --- a/src/wiphy.c
> +++ b/src/wiphy.c
> @@ -412,6 +412,39 @@ bool wiphy_can_randomize_mac_addr(struct wiphy *wiphy)
>   	return wiphy_has_feature(wiphy, NL80211_FEATURE_SCAN_RANDOM_MAC_ADDR);
>   }
>   
> +bool wiphy_can_offload(struct wiphy *wiphy, struct scan_bss *bss)

In theory you're only checking the AKM, which is already available through 
hs->akm_suite after we setup the handshake_state...  So you may as well just 
pass that in instead of struct scan_bss.

> +{
> +	struct ie_rsn_info rsn_info;
> +	int r;
> +	bool prefer_offload = false;
> +
> +	if (!wiphy_has_ext_feature(wiphy,
> +				NL80211_EXT_FEATURE_4WAY_HANDSHAKE_STA_PSK))
> +		return false;
> +
> +	if (!l_settings_get_bool(iwd_get_config(), "General", "PreferOffload",
> +				&prefer_offload) || !prefer_offload)
> +		return false;
> +

Can we make this more future proof and turn it into something like:

if (!l_settings_get_bool(...))
	prefer_offload = false;

if (!prefer_offload)
	return false;

> +	memset(&rsn_info, 0, sizeof(rsn_info));
> +	r = scan_bss_get_rsn_info(bss, &rsn_info);
> +
> +	if (r < 0)
> +		return false;
> +
> +	/*
> +	 * For now offload is only allowed on PSK networks.
> +	 */
> +	switch (rsn_info.akm_suites) {
> +	case IE_RSN_AKM_SUITE_PSK:
> +	case IE_RSN_AKM_SUITE_PSK_SHA256:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
> +
>   bool wiphy_rrm_capable(struct wiphy *wiphy)
>   {
>   	if (wiphy_has_feature(wiphy,
> diff --git a/src/wiphy.h b/src/wiphy.h
> index 50c8c936..016e5879 100644
> --- a/src/wiphy.h
> +++ b/src/wiphy.h
> @@ -80,6 +80,7 @@ const struct scan_freq_set *wiphy_get_supported_freqs(
>   						const struct wiphy *wiphy);
>   bool wiphy_can_connect(struct wiphy *wiphy, struct scan_bss *bss);
>   bool wiphy_can_randomize_mac_addr(struct wiphy *wiphy);
> +bool wiphy_can_offload(struct wiphy *wiphy, struct scan_bss *bss);
>   bool wiphy_rrm_capable(struct wiphy *wiphy);
>   bool wiphy_has_feature(struct wiphy *wiphy, uint32_t feature);
>   bool wiphy_has_ext_feature(struct wiphy *wiphy, uint32_t feature);
> 

Regards,
-Denis