mac80211: add TDLS channel-switch Rx flow

When receiving a TDLS channel switch request or response, parse the frame
and call a new tdls_recv_channel_switch op in the low level driver with
the parsed data.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -1826,6 +1826,31 @@ struct ieee80211_scan_request {
 	struct cfg80211_scan_request req;
 };
 
+/**
+ * struct ieee80211_tdls_ch_sw_params - TDLS channel switch parameters
+ *
+ * @sta: peer this TDLS channel-switch request/response came from
+ * @chandef: channel referenced in a TDLS channel-switch request
+ * @action_code: see &enum ieee80211_tdls_actioncode
+ * @status: channel-switch response status
+ * @timestamp: time at which the frame was received
+ * @switch_time: switch-timing parameter received in the frame
+ * @switch_timeout: switch-timing parameter received in the frame
+ * @tmpl_skb: TDLS switch-channel response template
+ * @ch_sw_tm_ie: offset of the channel-switch timing IE inside @tmpl_skb
+ */
+struct ieee80211_tdls_ch_sw_params {
+	struct ieee80211_sta *sta;
+	struct cfg80211_chan_def *chandef;
+	u8 action_code;
+	u32 status;
+	u32 timestamp;
+	u16 switch_time;
+	u16 switch_timeout;
+	struct sk_buff *tmpl_skb;
+	u32 ch_sw_tm_ie;
+};
+
 /**
  * wiphy_to_ieee80211_hw - return a mac80211 driver hw struct from a wiphy
  *
@@ -2925,6 +2950,13 @@ enum ieee80211_reconfig_type {
  *	optionally copy the skb for further re-use.
  * @tdls_cancel_channel_switch: Stop channel-switching with a TDLS peer. Both
  *	peers must be on the base channel when the call completes.
+ * @tdls_recv_channel_switch: a TDLS channel-switch related frame (request or
+ *	response) has been received from a remote peer. The driver gets
+ *	parameters parsed from the incoming frame and may use them to continue
+ *	an ongoing channel-switch operation. In addition, a channel-switch
+ *	response template is provided, together with the location of the
+ *	switch-timing IE within the template. The skb can only be used within
+ *	the function call.
  */
 struct ieee80211_ops {
 	void (*tx)(struct ieee80211_hw *hw,
@@ -3141,10 +3173,13 @@ struct ieee80211_ops {
 				   struct ieee80211_vif *vif,
 				   struct ieee80211_sta *sta, u8 oper_class,
 				   struct cfg80211_chan_def *chandef,
-				   struct sk_buff *skb, u32 ch_sw_tm_ie);
+				   struct sk_buff *tmpl_skb, u32 ch_sw_tm_ie);
 	void (*tdls_cancel_channel_switch)(struct ieee80211_hw *hw,
 					   struct ieee80211_vif *vif,
 					   struct ieee80211_sta *sta);
+	void (*tdls_recv_channel_switch)(struct ieee80211_hw *hw,
+					 struct ieee80211_vif *vif,
+					 struct ieee80211_tdls_ch_sw_params *params);
 };
 
 /**

net/mac80211/driver-ops.h

@@ -1337,4 +1337,16 @@ drv_tdls_cancel_channel_switch(struct ieee80211_local *local,
 	trace_drv_return_void(local);
 }
 
+static inline void
+drv_tdls_recv_channel_switch(struct ieee80211_local *local,
+			     struct ieee80211_sub_if_data *sdata,
+			     struct ieee80211_tdls_ch_sw_params *params)
+{
+	trace_drv_tdls_recv_channel_switch(local, sdata, params);
+	if (local->ops->tdls_recv_channel_switch)
+		local->ops->tdls_recv_channel_switch(&local->hw, &sdata->vif,
+						     params);
+	trace_drv_return_void(local);
+}
+
 #endif /* __MAC80211_DRIVER_OPS */

net/mac80211/ieee80211_i.h

@@ -993,6 +993,7 @@ enum sdata_queue_type {
 	IEEE80211_SDATA_QUEUE_AGG_STOP		= 2,
 	IEEE80211_SDATA_QUEUE_RX_AGG_START	= 3,
 	IEEE80211_SDATA_QUEUE_RX_AGG_STOP	= 4,
+	IEEE80211_SDATA_QUEUE_TDLS_CHSW		= 5,
 };
 
 enum {
@@ -2013,6 +2014,8 @@ int ieee80211_tdls_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 void ieee80211_tdls_cancel_channel_switch(struct wiphy *wiphy,
 					  struct net_device *dev,
 					  const u8 *addr);
+void ieee80211_process_tdls_channel_switch(struct ieee80211_sub_if_data *sdata,
+					   struct sk_buff *skb);
 
 extern const struct ethtool_ops ieee80211_ethtool_ops;
 

net/mac80211/iface.c

@@ -1202,6 +1202,8 @@ static void ieee80211_iface_work(struct work_struct *work)
 							WLAN_BACK_RECIPIENT, 0,
 							false);
 			mutex_unlock(&local->sta_mtx);
+		} else if (skb->pkt_type == IEEE80211_SDATA_QUEUE_TDLS_CHSW) {
+			ieee80211_process_tdls_channel_switch(sdata, skb);
 		} else if (ieee80211_is_action(mgmt->frame_control) &&
 			   mgmt->u.action.category == WLAN_CATEGORY_BACK) {
 			int len = skb->len;

net/mac80211/main.c

@@ -766,7 +766,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 
 	if ((hw->wiphy->features & NL80211_FEATURE_TDLS_CHANNEL_SWITCH) &&
 	    (!local->ops->tdls_channel_switch ||
-	     !local->ops->tdls_cancel_channel_switch))
+	     !local->ops->tdls_cancel_channel_switch ||
+	     !local->ops->tdls_recv_channel_switch))
 		return -EOPNOTSUPP;
 
 #ifdef CONFIG_PM

net/mac80211/rx.c

@@ -2333,6 +2333,27 @@ ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
 	if (!ieee80211_frame_allowed(rx, fc))
 		return RX_DROP_MONITOR;
 
+	/* directly handle TDLS channel switch requests/responses */
+	if (unlikely(((struct ethhdr *)rx->skb->data)->h_proto ==
+						cpu_to_be16(ETH_P_TDLS))) {
+		struct ieee80211_tdls_data *tf = (void *)rx->skb->data;
+
+		if (pskb_may_pull(rx->skb,
+				  offsetof(struct ieee80211_tdls_data, u)) &&
+		    tf->payload_type == WLAN_TDLS_SNAP_RFTYPE &&
+		    tf->category == WLAN_CATEGORY_TDLS &&
+		    (tf->action_code == WLAN_TDLS_CHANNEL_SWITCH_REQUEST ||
+		     tf->action_code == WLAN_TDLS_CHANNEL_SWITCH_RESPONSE)) {
+			rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TDLS_CHSW;
+			skb_queue_tail(&sdata->skb_queue, rx->skb);
+			ieee80211_queue_work(&rx->local->hw, &sdata->work);
+			if (rx->sta)
+				rx->sta->rx_packets++;
+
+			return RX_QUEUED;
+		}
+	}
+
 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
 	    unlikely(port_control) && sdata->bss) {
 		sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,