[linux.git] / net / ieee80211 / softmac / ieee80211softmac_scan.c

/*
 * Scanning routines.
 *
 * These are not exported because they're assigned to the function pointers.
 *
 * Copyright (c) 2005, 2006 Johannes Berg <[email protected]>
 *                          Joseph Jezak <[email protected]>
 *                          Larry Finger <[email protected]>
 *                          Danny van Dyk <[email protected]>
 *                          Michael Buesch <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 *
 * The full GNU General Public License is included in this distribution in the
 * file called COPYING.
 */

#include <linux/completion.h>
#include "ieee80211softmac_priv.h"

/* internal, use to trigger scanning if needed.
 * Returns -EBUSY if already scanning,
 * result of start_scan otherwise */
int
ieee80211softmac_start_scan(struct ieee80211softmac_device *sm)
{
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&sm->lock, flags);
	if (sm->scanning)
	{
		spin_unlock_irqrestore(&sm->lock, flags);
		return -EINPROGRESS;
	}
	sm->scanning = 1;
	spin_unlock_irqrestore(&sm->lock, flags);

	netif_tx_disable(sm->ieee->dev);
	ret = sm->start_scan(sm->dev);
	if (ret) {
		spin_lock_irqsave(&sm->lock, flags);
		sm->scanning = 0;
		spin_unlock_irqrestore(&sm->lock, flags);
	}
	return ret;
}

void
ieee80211softmac_stop_scan(struct ieee80211softmac_device *sm)
{
	unsigned long flags;

	spin_lock_irqsave(&sm->lock, flags);
	
	if (!sm->scanning) {
		spin_unlock_irqrestore(&sm->lock, flags);
		return;
	}
	
	spin_unlock_irqrestore(&sm->lock, flags);
	sm->stop_scan(sm->dev);
}

void
ieee80211softmac_wait_for_scan(struct ieee80211softmac_device *sm)
{
	unsigned long flags;

	spin_lock_irqsave(&sm->lock, flags);
	
	if (!sm->scanning) {
		spin_unlock_irqrestore(&sm->lock, flags);
		return;
	}
	
	spin_unlock_irqrestore(&sm->lock, flags);
	sm->wait_for_scan(sm->dev);
}


/* internal scanning implementation follows */
void ieee80211softmac_scan(struct work_struct *work)
{
	int invalid_channel;
	u8 current_channel_idx;
	struct ieee80211softmac_scaninfo *si =
		container_of(work, struct ieee80211softmac_scaninfo,
			     softmac_scan.work);
	struct ieee80211softmac_device *sm = si->mac;
	unsigned long flags;

	while (!(si->stop) && (si->current_channel_idx < si->number_channels)) {
		current_channel_idx = si->current_channel_idx;
		si->current_channel_idx++; /* go to the next channel */

		invalid_channel = (si->skip_flags & si->channels[current_channel_idx].flags);

		if (!invalid_channel) {
			sm->set_channel(sm->dev, si->channels[current_channel_idx].channel);
			// FIXME make this user configurable (active/passive)
			if(ieee80211softmac_send_mgt_frame(sm, NULL, IEEE80211_STYPE_PROBE_REQ, 0))
				printkl(KERN_DEBUG PFX "Sending Probe Request Failed\n");

			/* also send directed management frame for the network we're looking for */
			// TODO: is this if correct, or should we do this only if scanning from assoc request?
			if (sm->associnfo.req_essid.len)
				ieee80211softmac_send_mgt_frame(sm, &sm->associnfo.req_essid, IEEE80211_STYPE_PROBE_REQ, 0);

			spin_lock_irqsave(&sm->lock, flags);
			if (unlikely(!sm->running)) {
				/* Prevent reschedule on workqueue flush */
				spin_unlock_irqrestore(&sm->lock, flags);
				break;
			}
			schedule_delayed_work(&si->softmac_scan, IEEE80211SOFTMAC_PROBE_DELAY);
			spin_unlock_irqrestore(&sm->lock, flags);
			return;
		} else {
			dprintk(PFX "Not probing Channel %d (not allowed here)\n", si->channels[current_channel_idx].channel);
		}
	}

	spin_lock_irqsave(&sm->lock, flags);
	cancel_delayed_work(&si->softmac_scan);
	si->started = 0;
	spin_unlock_irqrestore(&sm->lock, flags);

	dprintk(PFX "Scanning finished\n");
	ieee80211softmac_scan_finished(sm);
	complete_all(&sm->scaninfo->finished);
}

static inline struct ieee80211softmac_scaninfo *allocate_scaninfo(struct ieee80211softmac_device *mac)
{
	/* ugh. can we call this without having the spinlock held? */
	struct ieee80211softmac_scaninfo *info = kmalloc(sizeof(struct ieee80211softmac_scaninfo), GFP_ATOMIC);
	if (unlikely(!info))
		return NULL;
	INIT_DELAYED_WORK(&info->softmac_scan, ieee80211softmac_scan);
	info->mac = mac;
	init_completion(&info->finished);
	return info;
}

int ieee80211softmac_start_scan_implementation(struct net_device *dev)
{
	struct ieee80211softmac_device *sm = ieee80211_priv(dev);
	unsigned long flags;
	
	if (!(dev->flags & IFF_UP))
		return -ENODEV;

	assert(ieee80211softmac_scan_handlers_check_self(sm));
	if (!ieee80211softmac_scan_handlers_check_self(sm))
		return -EINVAL;
		
	spin_lock_irqsave(&sm->lock, flags);
	/* it looks like we need to hold the lock here
	 * to make sure we don't allocate two of these... */
	if (unlikely(!sm->scaninfo))
		sm->scaninfo = allocate_scaninfo(sm);
	if (unlikely(!sm->scaninfo)) {
		spin_unlock_irqrestore(&sm->lock, flags);
		return -ENOMEM;
	}

	sm->scaninfo->skip_flags = IEEE80211_CH_INVALID;
	if (0 /* not scanning in IEEE802.11b */)//TODO
		sm->scaninfo->skip_flags |= IEEE80211_CH_B_ONLY;
	if (0 /* IEEE802.11a */) {//TODO
		sm->scaninfo->channels = sm->ieee->geo.a;
		sm->scaninfo->number_channels = sm->ieee->geo.a_channels;
	} else {
		sm->scaninfo->channels = sm->ieee->geo.bg;
		sm->scaninfo->number_channels = sm->ieee->geo.bg_channels;
	}
	dprintk(PFX "Start scanning with channel: %d\n", sm->scaninfo->channels[0].channel);
	dprintk(PFX "Scanning %d channels\n", sm->scaninfo->number_channels);
	sm->scaninfo->current_channel_idx = 0;
	sm->scaninfo->started = 1;
	sm->scaninfo->stop = 0;
	INIT_COMPLETION(sm->scaninfo->finished);
	schedule_delayed_work(&sm->scaninfo->softmac_scan, 0);
	spin_unlock_irqrestore(&sm->lock, flags);
	return 0;
}

void ieee80211softmac_stop_scan_implementation(struct net_device *dev)
{
	struct ieee80211softmac_device *sm = ieee80211_priv(dev);
	unsigned long flags;

	assert(ieee80211softmac_scan_handlers_check_self(sm));
	if (!ieee80211softmac_scan_handlers_check_self(sm))
		return;

	spin_lock_irqsave(&sm->lock, flags);
	assert(sm->scaninfo != NULL);
	if (sm->scaninfo) {
		if (sm->scaninfo->started)
			sm->scaninfo->stop = 1;
		else
			complete_all(&sm->scaninfo->finished);
	}
	spin_unlock_irqrestore(&sm->lock, flags);
}

void ieee80211softmac_wait_for_scan_implementation(struct net_device *dev)
{
	struct ieee80211softmac_device *sm = ieee80211_priv(dev);
	unsigned long flags;

	assert(ieee80211softmac_scan_handlers_check_self(sm));
	if (!ieee80211softmac_scan_handlers_check_self(sm))
		return;

	spin_lock_irqsave(&sm->lock, flags);
	if (!sm->scaninfo->started) {
		spin_unlock_irqrestore(&sm->lock, flags);
		return;
	}
	spin_unlock_irqrestore(&sm->lock, flags);
	wait_for_completion(&sm->scaninfo->finished);
}

/* this is what drivers (that do scanning) call when they're done */
void ieee80211softmac_scan_finished(struct ieee80211softmac_device *sm)
{
	unsigned long flags;

	spin_lock_irqsave(&sm->lock, flags);
	sm->scanning = 0;
	spin_unlock_irqrestore(&sm->lock, flags);
	
	if (sm->associnfo.bssvalid) {
		struct ieee80211softmac_network *net;

		net = ieee80211softmac_get_network_by_bssid(sm, sm->associnfo.bssid);
		if (net)
			sm->set_channel(sm->dev, net->channel);
	}
	netif_wake_queue(sm->ieee->dev);
	ieee80211softmac_call_events(sm, IEEE80211SOFTMAC_EVENT_SCAN_FINISHED, NULL);
}
EXPORT_SYMBOL_GPL(ieee80211softmac_scan_finished);
Commit	Line	Data
370121e5 JB	1	/*
	2	* Scanning routines.
	3	*
	4	* These are not exported because they're assigned to the function pointers.
4855d25b	5	*
79859051 JB	6	* Copyright (c) 2005, 2006 Johannes Berg <[email protected]>
	7	* Joseph Jezak <[email protected]>
	8	* Larry Finger <[email protected]>
	9	* Danny van Dyk <[email protected]>
	10	* Michael Buesch <[email protected]>
4855d25b JB	11	*
	12	* This program is free software; you can redistribute it and/or modify it
	13	* under the terms of version 2 of the GNU General Public License as
	14	* published by the Free Software Foundation.
	15	*
	16	* This program is distributed in the hope that it will be useful, but WITHOUT
	17	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	18	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	19	* more details.
	20	*
	21	* You should have received a copy of the GNU General Public License
	22	* along with this program; if not, write to the Free Software
	23	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	24	*
	25	* The full GNU General Public License is included in this distribution in the
	26	* file called COPYING.
370121e5 JB	27	*/
	28
	29	#include <linux/completion.h>
	30	#include "ieee80211softmac_priv.h"
	31
	32	/* internal, use to trigger scanning if needed.
	33	* Returns -EBUSY if already scanning,
	34	* result of start_scan otherwise */
	35	int
	36	ieee80211softmac_start_scan(struct ieee80211softmac_device *sm)
	37	{
	38	unsigned long flags;
	39	int ret;
	40
	41	spin_lock_irqsave(&sm->lock, flags);
	42	if (sm->scanning)
	43	{
	44	spin_unlock_irqrestore(&sm->lock, flags);
	45	return -EINPROGRESS;
	46	}
	47	sm->scanning = 1;
	48	spin_unlock_irqrestore(&sm->lock, flags);
	49
fc242746	50	netif_tx_disable(sm->ieee->dev);
370121e5 JB	51	ret = sm->start_scan(sm->dev);
	52	if (ret) {
	53	spin_lock_irqsave(&sm->lock, flags);
	54	sm->scanning = 0;
	55	spin_unlock_irqrestore(&sm->lock, flags);
	56	}
	57	return ret;
	58	}
	59
	60	void
	61	ieee80211softmac_stop_scan(struct ieee80211softmac_device *sm)
	62	{
	63	unsigned long flags;
	64
	65	spin_lock_irqsave(&sm->lock, flags);
	66
	67	if (!sm->scanning) {
	68	spin_unlock_irqrestore(&sm->lock, flags);
	69	return;
	70	}
	71
	72	spin_unlock_irqrestore(&sm->lock, flags);
	73	sm->stop_scan(sm->dev);
	74	}
	75
	76	void
	77	ieee80211softmac_wait_for_scan(struct ieee80211softmac_device *sm)
	78	{
	79	unsigned long flags;
	80
	81	spin_lock_irqsave(&sm->lock, flags);
	82
	83	if (!sm->scanning) {
	84	spin_unlock_irqrestore(&sm->lock, flags);
	85	return;
	86	}
	87
	88	spin_unlock_irqrestore(&sm->lock, flags);
	89	sm->wait_for_scan(sm->dev);
	90	}
	91
	92
	93	/* internal scanning implementation follows */
c4028958	94	void ieee80211softmac_scan(struct work_struct *work)
370121e5 JB	95	{
	96	int invalid_channel;
	97	u8 current_channel_idx;
c4028958 DH	98	struct ieee80211softmac_scaninfo *si =
	99	container_of(work, struct ieee80211softmac_scaninfo,
	100	softmac_scan.work);
	101	struct ieee80211softmac_device *sm = si->mac;
370121e5 JB	102	unsigned long flags;
	103
	104	while (!(si->stop) && (si->current_channel_idx < si->number_channels)) {
	105	current_channel_idx = si->current_channel_idx;
	106	si->current_channel_idx++; /* go to the next channel */
	107
	108	invalid_channel = (si->skip_flags & si->channels[current_channel_idx].flags);
	109
	110	if (!invalid_channel) {
	111	sm->set_channel(sm->dev, si->channels[current_channel_idx].channel);
370121e5 JB	112	// FIXME make this user configurable (active/passive)
	113	if(ieee80211softmac_send_mgt_frame(sm, NULL, IEEE80211_STYPE_PROBE_REQ, 0))
	114	printkl(KERN_DEBUG PFX "Sending Probe Request Failed\n");
	115
	116	/* also send directed management frame for the network we're looking for */
	117	// TODO: is this if correct, or should we do this only if scanning from assoc request?
	118	if (sm->associnfo.req_essid.len)
	119	ieee80211softmac_send_mgt_frame(sm, &sm->associnfo.req_essid, IEEE80211_STYPE_PROBE_REQ, 0);
d57336e3 DD	120
	121	spin_lock_irqsave(&sm->lock, flags);
	122	if (unlikely(!sm->running)) {
	123	/* Prevent reschedule on workqueue flush */
	124	spin_unlock_irqrestore(&sm->lock, flags);
	125	break;
	126	}
5c4df6da	127	schedule_delayed_work(&si->softmac_scan, IEEE80211SOFTMAC_PROBE_DELAY);
d57336e3	128	spin_unlock_irqrestore(&sm->lock, flags);
370121e5 JB	129	return;
	130	} else {
	131	dprintk(PFX "Not probing Channel %d (not allowed here)\n", si->channels[current_channel_idx].channel);
	132	}
	133	}
	134
	135	spin_lock_irqsave(&sm->lock, flags);
	136	cancel_delayed_work(&si->softmac_scan);
	137	si->started = 0;
	138	spin_unlock_irqrestore(&sm->lock, flags);
	139
	140	dprintk(PFX "Scanning finished\n");
	141	ieee80211softmac_scan_finished(sm);
	142	complete_all(&sm->scaninfo->finished);
	143	}
	144
	145	static inline struct ieee80211softmac_scaninfo allocate_scaninfo(struct ieee80211softmac_device mac)
	146	{
	147	/* ugh. can we call this without having the spinlock held? */
	148	struct ieee80211softmac_scaninfo *info = kmalloc(sizeof(struct ieee80211softmac_scaninfo), GFP_ATOMIC);
	149	if (unlikely(!info))
	150	return NULL;
c4028958 DH	151	INIT_DELAYED_WORK(&info->softmac_scan, ieee80211softmac_scan);
c4028958 DH	152	info->mac = mac;
370121e5 JB	153	init_completion(&info->finished);
	154	return info;
	155	}
	156
	157	int ieee80211softmac_start_scan_implementation(struct net_device *dev)
	158	{
	159	struct ieee80211softmac_device *sm = ieee80211_priv(dev);
	160	unsigned long flags;
	161
	162	if (!(dev->flags & IFF_UP))
	163	return -ENODEV;
	164
	165	assert(ieee80211softmac_scan_handlers_check_self(sm));
	166	if (!ieee80211softmac_scan_handlers_check_self(sm))
	167	return -EINVAL;
	168
	169	spin_lock_irqsave(&sm->lock, flags);
	170	/* it looks like we need to hold the lock here
	171	* to make sure we don't allocate two of these... */
	172	if (unlikely(!sm->scaninfo))
	173	sm->scaninfo = allocate_scaninfo(sm);
	174	if (unlikely(!sm->scaninfo)) {
	175	spin_unlock_irqrestore(&sm->lock, flags);
	176	return -ENOMEM;
	177	}
	178
	179	sm->scaninfo->skip_flags = IEEE80211_CH_INVALID;
	180	if (0 /* not scanning in IEEE802.11b */)//TODO
	181	sm->scaninfo->skip_flags \|= IEEE80211_CH_B_ONLY;
	182	if (0 /* IEEE802.11a */) {//TODO
	183	sm->scaninfo->channels = sm->ieee->geo.a;
	184	sm->scaninfo->number_channels = sm->ieee->geo.a_channels;
	185	} else {
	186	sm->scaninfo->channels = sm->ieee->geo.bg;
	187	sm->scaninfo->number_channels = sm->ieee->geo.bg_channels;
	188	}
	189	dprintk(PFX "Start scanning with channel: %d\n", sm->scaninfo->channels[0].channel);
	190	dprintk(PFX "Scanning %d channels\n", sm->scaninfo->number_channels);
	191	sm->scaninfo->current_channel_idx = 0;
	192	sm->scaninfo->started = 1;
fe0b06b1	193	sm->scaninfo->stop = 0;
370121e5	194	INIT_COMPLETION(sm->scaninfo->finished);
c4028958	195	schedule_delayed_work(&sm->scaninfo->softmac_scan, 0);
370121e5 JB	196	spin_unlock_irqrestore(&sm->lock, flags);
	197	return 0;
	198	}
	199
	200	void ieee80211softmac_stop_scan_implementation(struct net_device *dev)
	201	{
	202	struct ieee80211softmac_device *sm = ieee80211_priv(dev);
	203	unsigned long flags;
	204
	205	assert(ieee80211softmac_scan_handlers_check_self(sm));
	206	if (!ieee80211softmac_scan_handlers_check_self(sm))
	207	return;
	208
	209	spin_lock_irqsave(&sm->lock, flags);
	210	assert(sm->scaninfo != NULL);
	211	if (sm->scaninfo) {
	212	if (sm->scaninfo->started)
	213	sm->scaninfo->stop = 1;
	214	else
	215	complete_all(&sm->scaninfo->finished);
	216	}
	217	spin_unlock_irqrestore(&sm->lock, flags);
	218	}
	219
	220	void ieee80211softmac_wait_for_scan_implementation(struct net_device *dev)
	221	{
	222	struct ieee80211softmac_device *sm = ieee80211_priv(dev);
	223	unsigned long flags;
	224
	225	assert(ieee80211softmac_scan_handlers_check_self(sm));
	226	if (!ieee80211softmac_scan_handlers_check_self(sm))
	227	return;
	228
	229	spin_lock_irqsave(&sm->lock, flags);
	230	if (!sm->scaninfo->started) {
	231	spin_unlock_irqrestore(&sm->lock, flags);
	232	return;
	233	}
	234	spin_unlock_irqrestore(&sm->lock, flags);
	235	wait_for_completion(&sm->scaninfo->finished);
	236	}
	237
	238	/* this is what drivers (that do scanning) call when they're done */
	239	void ieee80211softmac_scan_finished(struct ieee80211softmac_device *sm)
	240	{
	241	unsigned long flags;
	242
	243	spin_lock_irqsave(&sm->lock, flags);
	244	sm->scanning = 0;
	245	spin_unlock_irqrestore(&sm->lock, flags);
	246
4edac92f DW	247	if (sm->associnfo.bssvalid) {
	248	struct ieee80211softmac_network *net;
	249
	250	net = ieee80211softmac_get_network_by_bssid(sm, sm->associnfo.bssid);
	251	if (net)
	252	sm->set_channel(sm->dev, net->channel);
	253	}
fc242746	254	netif_wake_queue(sm->ieee->dev);
370121e5 JB	255	ieee80211softmac_call_events(sm, IEEE80211SOFTMAC_EVENT_SCAN_FINISHED, NULL);
370121e5 JB	256	}
370121e5	257	EXPORT_SYMBOL_GPL(ieee80211softmac_scan_finished);