1 files changed, 282 insertions, 0 deletions

diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
new file mode 100644
index 00000000..935aa4b6
--- /dev/null
+++ b/net/mac80211/offchannel.c
@@ -0,0 +1,282 @@
+/*
+ * Off-channel operation helpers
+ *
+ * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
+ * Copyright 2004, Instant802 Networks, Inc.
+ * Copyright 2005, Devicescape Software, Inc.
+ * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
+ * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
+ * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/export.h>
+#include <net/mac80211.h>
+#include "ieee80211_i.h"
+#include "driver-trace.h"
+
+/*
+ * Tell our hardware to disable PS.
+ * Optionally inform AP that we will go to sleep so that it will buffer
+ * the frames while we are doing off-channel work.  This is optional
+ * because we *may* be doing work on-operating channel, and want our
+ * hardware unconditionally awake, but still let the AP send us normal frames.
+ */
+static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata,
+					   bool tell_ap)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
+
+	local->offchannel_ps_enabled = false;
+
+	/* FIXME: what to do when local->pspolling is true? */
+
+	del_timer_sync(&local->dynamic_ps_timer);
+	del_timer_sync(&ifmgd->bcn_mon_timer);
+	del_timer_sync(&ifmgd->conn_mon_timer);
+
+	cancel_work_sync(&local->dynamic_ps_enable_work);
+
+	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
+		local->offchannel_ps_enabled = true;
+		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
+		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+	}
+
+	if (tell_ap && (!local->offchannel_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_offchannel_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->offchannel_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.
+		 */
+		/* TODO:  Only set hardware if CONF_PS changed?
+		 * TODO:  Should we set offchannel_ps_enabled to false?
+		 */
+		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));
+	}
+
+	ieee80211_sta_reset_beacon_monitor(sdata);
+	ieee80211_sta_reset_conn_monitor(sdata);
+}
+
+void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
+				    bool offchannel_ps_enable)
+{
+	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_MONITOR)
+			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
+
+		/* Check to see if we should 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);
+
+		if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
+			netif_tx_stop_all_queues(sdata->dev);
+			if (offchannel_ps_enable &&
+			    (sdata->vif.type == NL80211_IFTYPE_STATION) &&
+			    sdata->u.mgd.associated)
+				ieee80211_offchannel_ps_enable(sdata, true);
+		}
+	}
+	mutex_unlock(&local->iflist_mtx);
+}
+
+void ieee80211_offchannel_return(struct ieee80211_local *local,
+				 bool offchannel_ps_disable)
+{
+	struct ieee80211_sub_if_data *sdata;
+
+	mutex_lock(&local->iflist_mtx);
+	list_for_each_entry(sdata, &local->interfaces, list) {
+		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
+			clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
+
+		if (!ieee80211_sdata_running(sdata))
+			continue;
+
+		/* Tell AP we're back */
+		if (offchannel_ps_disable &&
+		    sdata->vif.type == NL80211_IFTYPE_STATION) {
+			if (sdata->u.mgd.associated)
+				ieee80211_offchannel_ps_disable(sdata);
+		}
+
+		if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
+			/*
+			 * This may wake up queues even though the driver
+			 * currently has them stopped. This is not very
+			 * likely, since the driver won't have gotten any
+			 * (or hardly any) new packets while we weren't
+			 * on the right channel, and even if it happens
+			 * it will at most lead to queueing up one more
+			 * packet per queue in mac80211 rather than on
+			 * the interface qdisc.
+			 */
+			netif_tx_wake_all_queues(sdata->dev);
+		}
+
+		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);
+}
+
+static void ieee80211_hw_roc_start(struct work_struct *work)
+{
+	struct ieee80211_local *local =
+		container_of(work, struct ieee80211_local, hw_roc_start);
+	struct ieee80211_sub_if_data *sdata;
+
+	mutex_lock(&local->mtx);
+
+	if (!local->hw_roc_channel) {
+		mutex_unlock(&local->mtx);
+		return;
+	}
+
+	if (local->hw_roc_skb) {
+		sdata = IEEE80211_DEV_TO_SUB_IF(local->hw_roc_dev);
+		ieee80211_tx_skb(sdata, local->hw_roc_skb);
+		local->hw_roc_skb = NULL;
+	} else {
+		cfg80211_ready_on_channel(local->hw_roc_dev,
+					  local->hw_roc_cookie,
+					  local->hw_roc_channel,
+					  local->hw_roc_channel_type,
+					  local->hw_roc_duration,
+					  GFP_KERNEL);
+	}
+
+	ieee80211_recalc_idle(local);
+
+	mutex_unlock(&local->mtx);
+}
+
+void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+
+	trace_api_ready_on_channel(local);
+
+	ieee80211_queue_work(hw, &local->hw_roc_start);
+}
+EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
+
+static void ieee80211_hw_roc_done(struct work_struct *work)
+{
+	struct ieee80211_local *local =
+		container_of(work, struct ieee80211_local, hw_roc_done);
+
+	mutex_lock(&local->mtx);
+
+	if (!local->hw_roc_channel) {
+		mutex_unlock(&local->mtx);
+		return;
+	}
+
+	/* was never transmitted */
+	if (local->hw_roc_skb) {
+		u64 cookie;
+
+		cookie = local->hw_roc_cookie ^ 2;
+
+		cfg80211_mgmt_tx_status(local->hw_roc_dev, cookie,
+					local->hw_roc_skb->data,
+					local->hw_roc_skb->len, false,
+					GFP_KERNEL);
+
+		kfree_skb(local->hw_roc_skb);
+		local->hw_roc_skb = NULL;
+		local->hw_roc_skb_for_status = NULL;
+	}
+
+	if (!local->hw_roc_for_tx)
+		cfg80211_remain_on_channel_expired(local->hw_roc_dev,
+						   local->hw_roc_cookie,
+						   local->hw_roc_channel,
+						   local->hw_roc_channel_type,
+						   GFP_KERNEL);
+
+	local->hw_roc_channel = NULL;
+	local->hw_roc_cookie = 0;
+
+	ieee80211_recalc_idle(local);
+
+	mutex_unlock(&local->mtx);
+}
+
+void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+
+	trace_api_remain_on_channel_expired(local);
+
+	ieee80211_queue_work(hw, &local->hw_roc_done);
+}
+EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
+
+void ieee80211_hw_roc_setup(struct ieee80211_local *local)
+{
+	INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
+	INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
+}