[deliverable/linux.git] / net / mac80211 / offchannel.c

/*
 * 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;
	}

	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);
}
Commit	Line	Data
b203ffc3 JM	1	/*
	2	* Off-channel operation helpers
	3	*
	4	* Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
	5	* Copyright 2004, Instant802 Networks, Inc.
	6	* Copyright 2005, Devicescape Software, Inc.
	7	* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
	8	* Copyright 2007, Michael Wu <flamingice@sourmilk.net>
	9	* Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
	10	*
	11	* This program is free software; you can redistribute it and/or modify
	12	* it under the terms of the GNU General Public License version 2 as
	13	* published by the Free Software Foundation.
	14	*/
bc3b2d7f	15	#include <linux/export.h>
b203ffc3 JM	16	#include <net/mac80211.h>
b203ffc3 JM	17	#include "ieee80211_i.h"
21f83589	18	#include "driver-trace.h"
b203ffc3 JM	19
b203ffc3 JM	20	/*
b23b025f BG	21	* Tell our hardware to disable PS.
	22	* Optionally inform AP that we will go to sleep so that it will buffer
	23	* the frames while we are doing off-channel work. This is optional
	24	* because we may be doing work on-operating channel, and want our
	25	* hardware unconditionally awake, but still let the AP send us normal frames.
b203ffc3	26	*/
b23b025f BG	27	static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata,
b23b025f BG	28	bool tell_ap)
b203ffc3 JM	29	{
b203ffc3 JM	30	struct ieee80211_local *local = sdata->local;
4730d597	31	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
b203ffc3 JM	32
	33	local->offchannel_ps_enabled = false;
	34
	35	/* FIXME: what to do when local->pspolling is true? */
	36
	37	del_timer_sync(&local->dynamic_ps_timer);
3bc3c0d7	38	del_timer_sync(&ifmgd->bcn_mon_timer);
4730d597 LR	39	del_timer_sync(&ifmgd->conn_mon_timer);
4730d597 LR	40
b203ffc3 JM	41	cancel_work_sync(&local->dynamic_ps_enable_work);
	42
	43	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
	44	local->offchannel_ps_enabled = true;
	45	local->hw.conf.flags &= ~IEEE80211_CONF_PS;
	46	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
	47	}
	48
b23b025f BG	49	if (tell_ap && (!local->offchannel_ps_enabled \|\|
b23b025f BG	50	!(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)))
b203ffc3 JM	51	/*
	52	* If power save was enabled, no need to send a nullfunc
	53	* frame because AP knows that we are sleeping. But if the
	54	* hardware is creating the nullfunc frame for power save
	55	* status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
	56	* enabled) and power save was enabled, the firmware just
	57	* sent a null frame with power save disabled. So we need
	58	* to send a new nullfunc frame to inform the AP that we
	59	* are again sleeping.
	60	*/
	61	ieee80211_send_nullfunc(local, sdata, 1);
	62	}
	63
	64	/* inform AP that we are awake again, unless power save is enabled */
	65	static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
	66	{
	67	struct ieee80211_local *local = sdata->local;
	68
	69	if (!local->ps_sdata)
	70	ieee80211_send_nullfunc(local, sdata, 0);
	71	else if (local->offchannel_ps_enabled) {
	72	/*
	73	* In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
	74	* will send a nullfunc frame with the powersave bit set
	75	* even though the AP already knows that we are sleeping.
	76	* This could be avoided by sending a null frame with power
	77	* save bit disabled before enabling the power save, but
	78	* this doesn't gain anything.
	79	*
	80	* When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
	81	* to send a nullfunc frame because AP already knows that
	82	* we are sleeping, let's just enable power save mode in
	83	* hardware.
	84	*/
b23b025f BG	85	/* TODO: Only set hardware if CONF_PS changed?
	86	* TODO: Should we set offchannel_ps_enabled to false?
	87	*/
b203ffc3 JM	88	local->hw.conf.flags \|= IEEE80211_CONF_PS;
	89	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
	90	} else if (local->hw.conf.dynamic_ps_timeout > 0) {
	91	/*
	92	* If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
	93	* had been running before leaving the operating channel,
	94	* restart the timer now and send a nullfunc frame to inform
	95	* the AP that we are awake.
	96	*/
	97	ieee80211_send_nullfunc(local, sdata, 0);
	98	mod_timer(&local->dynamic_ps_timer, jiffies +
	99	msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
	100	}
4730d597	101
3bc3c0d7	102	ieee80211_sta_reset_beacon_monitor(sdata);
4730d597	103	ieee80211_sta_reset_conn_monitor(sdata);
b203ffc3 JM	104	}
b203ffc3 JM	105
b23b025f BG	106	void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
b23b025f BG	107	bool offchannel_ps_enable)
b203ffc3 JM	108	{
	109	struct ieee80211_sub_if_data *sdata;
	110
b23b025f BG	111	/*
	112	* notify the AP about us leaving the channel and stop all
	113	* STA interfaces.
	114	*/
b203ffc3 JM	115	mutex_lock(&local->iflist_mtx);
	116	list_for_each_entry(sdata, &local->interfaces, list) {
	117	if (!ieee80211_sdata_running(sdata))
	118	continue;
	119
b23b025f BG	120	if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
	121	set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
	122
	123	/* Check to see if we should disable beaconing. */
b203ffc3 JM	124	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
	125	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
	126	sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
	127	ieee80211_bss_info_change_notify(
	128	sdata, BSS_CHANGED_BEACON_ENABLED);
	129
b23b025f	130	if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
cfa6cb20	131	netif_tx_stop_all_queues(sdata->dev);
b23b025f BG	132	if (offchannel_ps_enable &&
	133	(sdata->vif.type == NL80211_IFTYPE_STATION) &&
	134	sdata->u.mgd.associated)
	135	ieee80211_offchannel_ps_enable(sdata, true);
5b714c6a	136	}
b203ffc3 JM	137	}
	138	mutex_unlock(&local->iflist_mtx);
	139	}
	140
b203ffc3	141	void ieee80211_offchannel_return(struct ieee80211_local *local,
b23b025f	142	bool offchannel_ps_disable)
b203ffc3 JM	143	{
	144	struct ieee80211_sub_if_data *sdata;
	145
	146	mutex_lock(&local->iflist_mtx);
	147	list_for_each_entry(sdata, &local->interfaces, list) {
f6e8cb72 EP	148	if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
	149	clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
	150
b203ffc3 JM	151	if (!ieee80211_sdata_running(sdata))
	152	continue;
	153
	154	/* Tell AP we're back */
b23b025f BG	155	if (offchannel_ps_disable &&
b23b025f BG	156	sdata->vif.type == NL80211_IFTYPE_STATION) {
b203ffc3 JM	157	if (sdata->u.mgd.associated)
b203ffc3 JM	158	ieee80211_offchannel_ps_disable(sdata);
b203ffc3 JM	159	}
b203ffc3 JM	160
5b714c6a	161	if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
5b714c6a JB	162	/*
	163	* This may wake up queues even though the driver
	164	* currently has them stopped. This is not very
	165	* likely, since the driver won't have gotten any
	166	* (or hardly any) new packets while we weren't
	167	* on the right channel, and even if it happens
	168	* it will at most lead to queueing up one more
	169	* packet per queue in mac80211 rather than on
	170	* the interface qdisc.
	171	*/
93895757	172	netif_tx_wake_all_queues(sdata->dev);
5b714c6a	173	}
93895757	174
e76aadc5 JB	175	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
	176	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
	177	sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
b203ffc3 JM	178	ieee80211_bss_info_change_notify(
	179	sdata, BSS_CHANGED_BEACON_ENABLED);
	180	}
	181	mutex_unlock(&local->iflist_mtx);
	182	}
21f83589 JB	183
	184	static void ieee80211_hw_roc_start(struct work_struct *work)
	185	{
	186	struct ieee80211_local *local =
	187	container_of(work, struct ieee80211_local, hw_roc_start);
90fc4b3a	188	struct ieee80211_sub_if_data *sdata;
21f83589 JB	189
	190	mutex_lock(&local->mtx);
	191
	192	if (!local->hw_roc_channel) {
	193	mutex_unlock(&local->mtx);
	194	return;
	195	}
	196
90fc4b3a JB	197	if (local->hw_roc_skb) {
	198	sdata = IEEE80211_DEV_TO_SUB_IF(local->hw_roc_dev);
	199	ieee80211_tx_skb(sdata, local->hw_roc_skb);
	200	local->hw_roc_skb = NULL;
	201	} else {
	202	cfg80211_ready_on_channel(local->hw_roc_dev,
	203	local->hw_roc_cookie,
	204	local->hw_roc_channel,
	205	local->hw_roc_channel_type,
	206	local->hw_roc_duration,
	207	GFP_KERNEL);
	208	}
	209
fcac4fb0 FF	210	ieee80211_recalc_idle(local);
fcac4fb0 FF	211
21f83589 JB	212	mutex_unlock(&local->mtx);
	213	}
	214
	215	void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
	216	{
	217	struct ieee80211_local *local = hw_to_local(hw);
	218
	219	trace_api_ready_on_channel(local);
	220
	221	ieee80211_queue_work(hw, &local->hw_roc_start);
	222	}
	223	EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
	224
	225	static void ieee80211_hw_roc_done(struct work_struct *work)
	226	{
	227	struct ieee80211_local *local =
	228	container_of(work, struct ieee80211_local, hw_roc_done);
	229
	230	mutex_lock(&local->mtx);
	231
	232	if (!local->hw_roc_channel) {
	233	mutex_unlock(&local->mtx);
	234	return;
	235	}
	236
90fc4b3a JB	237	if (!local->hw_roc_for_tx)
	238	cfg80211_remain_on_channel_expired(local->hw_roc_dev,
	239	local->hw_roc_cookie,
	240	local->hw_roc_channel,
	241	local->hw_roc_channel_type,
	242	GFP_KERNEL);
21f83589 JB	243
	244	local->hw_roc_channel = NULL;
	245	local->hw_roc_cookie = 0;
	246
	247	ieee80211_recalc_idle(local);
	248
	249	mutex_unlock(&local->mtx);
	250	}
	251
	252	void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
	253	{
	254	struct ieee80211_local *local = hw_to_local(hw);
	255
	256	trace_api_remain_on_channel_expired(local);
	257
	258	ieee80211_queue_work(hw, &local->hw_roc_done);
	259	}
	260	EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
	261
	262	void ieee80211_hw_roc_setup(struct ieee80211_local *local)
	263	{
	264	INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
	265	INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
	266	}