mac80211: add extended channel switching capability if the driver supports CSA

The Extended Channel Switching capability bit in the extended
capabilities element must be set if the driver supports CSA on
non-beaconing interfaces.

Since this capability needs to be set during driver registration, the
extended_capabiliities global variable needs to be moved to the local
structure so that it can be modified.
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/linux/ieee80211.h

@@ -1998,6 +1998,11 @@ enum ieee80211_tdls_actioncode {
 	WLAN_TDLS_DISCOVERY_REQUEST = 10,
 };
 
+/* Extended Channel Switching capability to be set in the 1st byte of
+ * the @WLAN_EID_EXT_CAPABILITY information element
+ */
+#define WLAN_EXT_CAPA1_EXT_CHANNEL_SWITCHING	BIT(2)
+
 /* Interworking capabilities are set in 7th bit of 4th byte of the
  * @WLAN_EID_EXT_CAPABILITY information element
  */

net/mac80211/ieee80211_i.h

@@ -1307,6 +1307,9 @@ struct ieee80211_local {
 	/* virtual monitor interface */
 	struct ieee80211_sub_if_data __rcu *monitor_sdata;
 	struct cfg80211_chan_def monitor_chandef;
+
+	/* extended capabilities provided by mac80211 */
+	u8 ext_capa[8];
 };
 
 static inline struct ieee80211_sub_if_data *

net/mac80211/main.c

@@ -478,11 +478,6 @@ static const struct ieee80211_vht_cap mac80211_vht_capa_mod_mask = {
 	},
 };
 
-static const u8 extended_capabilities[] = {
-	0, 0, 0, 0, 0, 0, 0,
-	WLAN_EXT_CAPA8_OPMODE_NOTIF,
-};
-
 struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 					const struct ieee80211_ops *ops)
 {
@@ -539,10 +534,6 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 			WIPHY_FLAG_REPORTS_OBSS |
 			WIPHY_FLAG_OFFCHAN_TX;
 
-	wiphy->extended_capabilities = extended_capabilities;
-	wiphy->extended_capabilities_mask = extended_capabilities;
-	wiphy->extended_capabilities_len = ARRAY_SIZE(extended_capabilities);
-
 	if (ops->remain_on_channel)
 		wiphy->flags |= WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL;
 
@@ -591,6 +582,13 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 	wiphy->ht_capa_mod_mask = &mac80211_ht_capa_mod_mask;
 	wiphy->vht_capa_mod_mask = &mac80211_vht_capa_mod_mask;
 
+	local->ext_capa[7] = WLAN_EXT_CAPA8_OPMODE_NOTIF;
+
+	wiphy->extended_capabilities = local->ext_capa;
+	wiphy->extended_capabilities_mask = local->ext_capa;
+	wiphy->extended_capabilities_len =
+		ARRAY_SIZE(local->ext_capa);
+
 	INIT_LIST_HEAD(&local->interfaces);
 
 	__hw_addr_init(&local->mc_list);
@@ -958,6 +956,10 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 	if (local->hw.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS)
 		local->hw.wiphy->flags |= WIPHY_FLAG_TDLS_EXTERNAL_SETUP;
 
+	/* mac80211 supports eCSA, if the driver supports STA CSA at all */
+	if (local->hw.flags & IEEE80211_HW_CHANCTX_STA_CSA)
+		local->ext_capa[0] |= WLAN_EXT_CAPA1_EXT_CHANNEL_SWITCHING;
+
 	local->hw.wiphy->max_num_csa_counters = IEEE80211_MAX_CSA_COUNTERS_NUM;
 
 	result = wiphy_register(local->hw.wiphy);