aboutsummaryrefslogtreecommitdiff
path: root/net/ieee80211/softmac/ieee80211softmac_scan.c
blob: 290ddb0951d64b303209b6d7c3a1fac33f037e30 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
/*
 * Scanning routines.
 *
 * These are not exported because they're assigned to the function pointers.
 *
 * Copyright (c) 2005, 2006 Johannes Berg <johannes@sipsolutions.net>
 *                          Joseph Jezak <josejx@gentoo.org>
 *                          Larry Finger <Larry.Finger@lwfinger.net>
 *                          Danny van Dyk <kugelfang@gentoo.org>
 *                          Michael Buesch <mbuesch@freenet.de>
 *
 * 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);

	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(void *d)
{
	int invalid_channel;
	u8 current_channel_idx;
	struct ieee80211softmac_device *sm = (struct ieee80211softmac_device *)d;
	struct ieee80211softmac_scaninfo *si = sm->scaninfo;
	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);
			schedule_delayed_work(&si->softmac_scan, IEEE80211SOFTMAC_PROBE_DELAY);
			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_WORK(&info->softmac_scan, ieee80211softmac_scan, 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_work(&sm->scaninfo->softmac_scan);
	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);
	
	ieee80211softmac_call_events(sm, IEEE80211SOFTMAC_EVENT_SCAN_FINISHED, NULL);
}
EXPORT_SYMBOL_GPL(ieee80211softmac_scan_finished);