[net-next-2.6.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 <net/mac80211.h>
#include "ieee80211_i.h"

/*
 * inform AP that we will go to sleep so that it will buffer the frames
 * while we scan
 */
static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
{
	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->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 (!(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.
		 */
		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_conn_monitor(sdata);
}

void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local)
{
	struct ieee80211_sub_if_data *sdata;

	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 ieee80211_offchannel_stop_station(),
		 * e.g., from the background scan state machine.
		 *
		 * In addition, do not stop monitor interface to allow it to be
		 * used from user space controlled off-channel operations.
		 */
		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
		    sdata->vif.type != NL80211_IFTYPE_MONITOR) {
			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
			netif_tx_stop_all_queues(sdata->dev);
		}
	}
	mutex_unlock(&local->iflist_mtx);
}

void ieee80211_offchannel_stop_station(struct ieee80211_local *local)
{
	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) {
			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
			netif_tx_stop_all_queues(sdata->dev);
			if (sdata->u.mgd.associated)
				ieee80211_offchannel_ps_enable(sdata);
		}
	}
	mutex_unlock(&local->iflist_mtx);
}

void ieee80211_offchannel_return(struct ieee80211_local *local,
				 bool enable_beaconing)
{
	struct ieee80211_sub_if_data *sdata;

	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_offchannel_ps_disable(sdata);
		}

		if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
			clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
			/*
			 * 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);
		}

		/* re-enable beaconing */
		if (enable_beaconing &&
		    (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);
}
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	*/
	15	#include <net/mac80211.h>
	16	#include "ieee80211_i.h"
	17
	18	/*
	19	* inform AP that we will go to sleep so that it will buffer the frames
	20	* while we scan
	21	*/
	22	static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
	23	{
	24	struct ieee80211_local *local = sdata->local;
4730d597	25	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
b203ffc3 JM	26
	27	local->offchannel_ps_enabled = false;
	28
	29	/* FIXME: what to do when local->pspolling is true? */
	30
	31	del_timer_sync(&local->dynamic_ps_timer);
4730d597 LR	32	del_timer_sync(&ifmgd->conn_mon_timer);
4730d597 LR	33
b203ffc3 JM	34	cancel_work_sync(&local->dynamic_ps_enable_work);
	35
	36	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
	37	local->offchannel_ps_enabled = true;
	38	local->hw.conf.flags &= ~IEEE80211_CONF_PS;
	39	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
	40	}
	41
	42	if (!(local->offchannel_ps_enabled) \|\|
	43	!(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
	44	/*
	45	* If power save was enabled, no need to send a nullfunc
	46	* frame because AP knows that we are sleeping. But if the
	47	* hardware is creating the nullfunc frame for power save
	48	* status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
	49	* enabled) and power save was enabled, the firmware just
	50	* sent a null frame with power save disabled. So we need
	51	* to send a new nullfunc frame to inform the AP that we
	52	* are again sleeping.
	53	*/
	54	ieee80211_send_nullfunc(local, sdata, 1);
	55	}
	56
	57	/* inform AP that we are awake again, unless power save is enabled */
	58	static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
	59	{
	60	struct ieee80211_local *local = sdata->local;
	61
	62	if (!local->ps_sdata)
	63	ieee80211_send_nullfunc(local, sdata, 0);
	64	else if (local->offchannel_ps_enabled) {
	65	/*
	66	* In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
	67	* will send a nullfunc frame with the powersave bit set
	68	* even though the AP already knows that we are sleeping.
	69	* This could be avoided by sending a null frame with power
	70	* save bit disabled before enabling the power save, but
	71	* this doesn't gain anything.
	72	*
	73	* When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
	74	* to send a nullfunc frame because AP already knows that
	75	* we are sleeping, let's just enable power save mode in
	76	* hardware.
	77	*/
	78	local->hw.conf.flags \|= IEEE80211_CONF_PS;
	79	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
	80	} else if (local->hw.conf.dynamic_ps_timeout > 0) {
	81	/*
	82	* If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
	83	* had been running before leaving the operating channel,
	84	* restart the timer now and send a nullfunc frame to inform
	85	* the AP that we are awake.
	86	*/
	87	ieee80211_send_nullfunc(local, sdata, 0);
	88	mod_timer(&local->dynamic_ps_timer, jiffies +
	89	msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
	90	}
4730d597 LR	91
4730d597 LR	92	ieee80211_sta_reset_conn_monitor(sdata);
b203ffc3 JM	93	}
	94
	95	void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local)
	96	{
	97	struct ieee80211_sub_if_data *sdata;
	98
	99	mutex_lock(&local->iflist_mtx);
	100	list_for_each_entry(sdata, &local->interfaces, list) {
	101	if (!ieee80211_sdata_running(sdata))
	102	continue;
	103
	104	/* disable beaconing */
	105	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
	106	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
	107	sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
	108	ieee80211_bss_info_change_notify(
	109	sdata, BSS_CHANGED_BEACON_ENABLED);
	110
	111	/*
	112	* only handle non-STA interfaces here, STA interfaces
	113	* are handled in ieee80211_offchannel_stop_station(),
b8bc4b0a JB	114	* e.g., from the background scan state machine.
	115	*
	116	* In addition, do not stop monitor interface to allow it to be
	117	* used from user space controlled off-channel operations.
b203ffc3	118	*/
b8bc4b0a	119	if (sdata->vif.type != NL80211_IFTYPE_STATION &&
5b714c6a JB	120	sdata->vif.type != NL80211_IFTYPE_MONITOR) {
5b714c6a JB	121	set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
cfa6cb20	122	netif_tx_stop_all_queues(sdata->dev);
5b714c6a	123	}
b203ffc3 JM	124	}
	125	mutex_unlock(&local->iflist_mtx);
	126	}
	127
	128	void ieee80211_offchannel_stop_station(struct ieee80211_local *local)
	129	{
	130	struct ieee80211_sub_if_data *sdata;
	131
	132	/*
	133	* notify the AP about us leaving the channel and stop all STA interfaces
	134	*/
	135	mutex_lock(&local->iflist_mtx);
	136	list_for_each_entry(sdata, &local->interfaces, list) {
	137	if (!ieee80211_sdata_running(sdata))
	138	continue;
	139
	140	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
5b714c6a	141	set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
cfa6cb20	142	netif_tx_stop_all_queues(sdata->dev);
b203ffc3 JM	143	if (sdata->u.mgd.associated)
	144	ieee80211_offchannel_ps_enable(sdata);
	145	}
	146	}
	147	mutex_unlock(&local->iflist_mtx);
	148	}
	149
	150	void ieee80211_offchannel_return(struct ieee80211_local *local,
	151	bool enable_beaconing)
	152	{
	153	struct ieee80211_sub_if_data *sdata;
	154
	155	mutex_lock(&local->iflist_mtx);
	156	list_for_each_entry(sdata, &local->interfaces, list) {
	157	if (!ieee80211_sdata_running(sdata))
	158	continue;
	159
	160	/* Tell AP we're back */
	161	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
	162	if (sdata->u.mgd.associated)
	163	ieee80211_offchannel_ps_disable(sdata);
b203ffc3 JM	164	}
b203ffc3 JM	165
5b714c6a JB	166	if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
	167	clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
	168	/*
	169	* This may wake up queues even though the driver
	170	* currently has them stopped. This is not very
	171	* likely, since the driver won't have gotten any
	172	* (or hardly any) new packets while we weren't
	173	* on the right channel, and even if it happens
	174	* it will at most lead to queueing up one more
	175	* packet per queue in mac80211 rather than on
	176	* the interface qdisc.
	177	*/
93895757	178	netif_tx_wake_all_queues(sdata->dev);
5b714c6a	179	}
93895757	180
b203ffc3 JM	181	/* re-enable beaconing */
	182	if (enable_beaconing &&
	183	(sdata->vif.type == NL80211_IFTYPE_AP \|\|
	184	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
	185	sdata->vif.type == NL80211_IFTYPE_MESH_POINT))
	186	ieee80211_bss_info_change_notify(
	187	sdata, BSS_CHANGED_BEACON_ENABLED);
	188	}
	189	mutex_unlock(&local->iflist_mtx);
	190	}