mac80211: Generalize off-channel operation helpers from scan code

The off-channel operations for going into power save mode (station
mode) or stop beaconing (AP/IBSS) are not limited to scanning. Move
these into a separate file and allow them to be used for other
purposes, too.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 2a2d7f6..365f409 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -227,82 +227,9 @@
 	return true;
 }
 
-/*
- * inform AP that we will go to sleep so that it will buffer the frames
- * while we scan
- */
-static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata)
-{
-	struct ieee80211_local *local = sdata->local;
-
-	local->scan_ps_enabled = false;
-
-	/* FIXME: what to do when local->pspolling is true? */
-
-	del_timer_sync(&local->dynamic_ps_timer);
-	cancel_work_sync(&local->dynamic_ps_enable_work);
-
-	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
-		local->scan_ps_enabled = true;
-		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
-		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
-	}
-
-	if (!(local->scan_ps_enabled) ||
-	    !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
-		/*
-		 * If power save was enabled, no need to send a nullfunc
-		 * frame because AP knows that we are sleeping. But if the
-		 * hardware is creating the nullfunc frame for power save
-		 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
-		 * enabled) and power save was enabled, the firmware just
-		 * sent a null frame with power save disabled. So we need
-		 * to send a new nullfunc frame to inform the AP that we
-		 * are again sleeping.
-		 */
-		ieee80211_send_nullfunc(local, sdata, 1);
-}
-
-/* inform AP that we are awake again, unless power save is enabled */
-static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata)
-{
-	struct ieee80211_local *local = sdata->local;
-
-	if (!local->ps_sdata)
-		ieee80211_send_nullfunc(local, sdata, 0);
-	else if (local->scan_ps_enabled) {
-		/*
-		 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
-		 * will send a nullfunc frame with the powersave bit set
-		 * even though the AP already knows that we are sleeping.
-		 * This could be avoided by sending a null frame with power
-		 * save bit disabled before enabling the power save, but
-		 * this doesn't gain anything.
-		 *
-		 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
-		 * to send a nullfunc frame because AP already knows that
-		 * we are sleeping, let's just enable power save mode in
-		 * hardware.
-		 */
-		local->hw.conf.flags |= IEEE80211_CONF_PS;
-		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
-	} else if (local->hw.conf.dynamic_ps_timeout > 0) {
-		/*
-		 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
-		 * had been running before leaving the operating channel,
-		 * restart the timer now and send a nullfunc frame to inform
-		 * the AP that we are awake.
-		 */
-		ieee80211_send_nullfunc(local, sdata, 0);
-		mod_timer(&local->dynamic_ps_timer, jiffies +
-			  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
-	}
-}
-
 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
-	struct ieee80211_sub_if_data *sdata;
 	bool was_hw_scan;
 
 	mutex_lock(&local->scan_mtx);
@@ -351,28 +278,7 @@
 
 	drv_sw_scan_complete(local);
 
-	mutex_lock(&local->iflist_mtx);
-	list_for_each_entry(sdata, &local->interfaces, list) {
-		if (!ieee80211_sdata_running(sdata))
-			continue;
-
-		/* Tell AP we're back */
-		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
-			if (sdata->u.mgd.associated) {
-				ieee80211_scan_ps_disable(sdata);
-				netif_wake_queue(sdata->dev);
-			}
-		} else
-			netif_wake_queue(sdata->dev);
-
-		/* re-enable beaconing */
-		if (sdata->vif.type == NL80211_IFTYPE_AP ||
-		    sdata->vif.type == NL80211_IFTYPE_ADHOC ||
-		    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
-			ieee80211_bss_info_change_notify(
-				sdata, BSS_CHANGED_BEACON_ENABLED);
-	}
-	mutex_unlock(&local->iflist_mtx);
+	ieee80211_offchannel_return(local, true);
 
  done:
 	ieee80211_recalc_idle(local);
@@ -384,8 +290,6 @@
 
 static int ieee80211_start_sw_scan(struct ieee80211_local *local)
 {
-	struct ieee80211_sub_if_data *sdata;
-
 	/*
 	 * Hardware/driver doesn't support hw_scan, so use software
 	 * scanning instead. First send a nullfunc frame with power save
@@ -401,26 +305,7 @@
 	 */
 	drv_sw_scan_start(local);
 
-	mutex_lock(&local->iflist_mtx);
-	list_for_each_entry(sdata, &local->interfaces, list) {
-		if (!ieee80211_sdata_running(sdata))
-			continue;
-
-		/* disable beaconing */
-		if (sdata->vif.type == NL80211_IFTYPE_AP ||
-		    sdata->vif.type == NL80211_IFTYPE_ADHOC ||
-		    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
-			ieee80211_bss_info_change_notify(
-				sdata, BSS_CHANGED_BEACON_ENABLED);
-
-		/*
-		 * only handle non-STA interfaces here, STA interfaces
-		 * are handled in the scan state machine
-		 */
-		if (sdata->vif.type != NL80211_IFTYPE_STATION)
-			netif_stop_queue(sdata->dev);
-	}
-	mutex_unlock(&local->iflist_mtx);
+	ieee80211_offchannel_stop_beaconing(local);
 
 	local->next_scan_state = SCAN_DECISION;
 	local->scan_channel_idx = 0;
@@ -568,23 +453,7 @@
 static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local,
 						    unsigned long *next_delay)
 {
-	struct ieee80211_sub_if_data *sdata;
-
-	/*
-	 * notify the AP about us leaving the channel and stop all STA interfaces
-	 */
-	mutex_lock(&local->iflist_mtx);
-	list_for_each_entry(sdata, &local->interfaces, list) {
-		if (!ieee80211_sdata_running(sdata))
-			continue;
-
-		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
-			netif_stop_queue(sdata->dev);
-			if (sdata->u.mgd.associated)
-				ieee80211_scan_ps_enable(sdata);
-		}
-	}
-	mutex_unlock(&local->iflist_mtx);
+	ieee80211_offchannel_stop_station(local);
 
 	__set_bit(SCAN_OFF_CHANNEL, &local->scanning);
 
@@ -604,28 +473,15 @@
 static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local,
 						    unsigned long *next_delay)
 {
-	struct ieee80211_sub_if_data *sdata = local->scan_sdata;
-
 	/* switch back to the operating channel */
 	local->scan_channel = NULL;
 	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 
 	/*
-	 * notify the AP about us being back and restart all STA interfaces
+	 * Only re-enable station mode interface now; beaconing will be
+	 * re-enabled once the full scan has been completed.
 	 */
-	mutex_lock(&local->iflist_mtx);
-	list_for_each_entry(sdata, &local->interfaces, list) {
-		if (!ieee80211_sdata_running(sdata))
-			continue;
-
-		/* Tell AP we're back */
-		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
-			if (sdata->u.mgd.associated)
-				ieee80211_scan_ps_disable(sdata);
-			netif_wake_queue(sdata->dev);
-		}
-	}
-	mutex_unlock(&local->iflist_mtx);
+	ieee80211_offchannel_return(local, false);
 
 	__clear_bit(SCAN_OFF_CHANNEL, &local->scanning);