summaryrefslogtreecommitdiffstats
path: root/net/mac80211/sta_info.c
blob: c17172abb21c4f8e7baca64078a9dedcec0c762a (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
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 *
 * 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/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>

#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "ieee80211_rate.h"
#include "sta_info.h"
#include "debugfs_sta.h"

/* Caller must hold local->sta_lock */
static void sta_info_hash_add(struct ieee80211_local *local,
			      struct sta_info *sta)
{
	sta->hnext = local->sta_hash[STA_HASH(sta->addr)];
	local->sta_hash[STA_HASH(sta->addr)] = sta;
}


/* Caller must hold local->sta_lock */
static int sta_info_hash_del(struct ieee80211_local *local,
			     struct sta_info *sta)
{
	struct sta_info *s;

	s = local->sta_hash[STA_HASH(sta->addr)];
	if (!s)
		return -ENOENT;
	if (s == sta) {
		local->sta_hash[STA_HASH(sta->addr)] = s->hnext;
		return 0;
	}

	while (s->hnext && s->hnext != sta)
		s = s->hnext;
	if (s->hnext) {
		s->hnext = sta->hnext;
		return 0;
	}

	return -ENOENT;
}

struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr)
{
	struct sta_info *sta;

	read_lock_bh(&local->sta_lock);
	sta = local->sta_hash[STA_HASH(addr)];
	while (sta) {
		if (memcmp(sta->addr, addr, ETH_ALEN) == 0) {
			__sta_info_get(sta);
			break;
		}
		sta = sta->hnext;
	}
	read_unlock_bh(&local->sta_lock);

	return sta;
}
EXPORT_SYMBOL(sta_info_get);

int sta_info_min_txrate_get(struct ieee80211_local *local)
{
	struct sta_info *sta;
	struct ieee80211_hw_mode *mode;
	int min_txrate = 9999999;
	int i;

	read_lock_bh(&local->sta_lock);
	mode = local->oper_hw_mode;
	for (i = 0; i < STA_HASH_SIZE; i++) {
		sta = local->sta_hash[i];
		while (sta) {
			if (sta->txrate < min_txrate)
				min_txrate = sta->txrate;
			sta = sta->hnext;
		}
	}
	read_unlock_bh(&local->sta_lock);
	if (min_txrate == 9999999)
		min_txrate = 0;

	return mode->rates[min_txrate].rate;
}


static void sta_info_release(struct kref *kref)
{
	struct sta_info *sta = container_of(kref, struct sta_info, kref);
	struct ieee80211_local *local = sta->local;
	struct sk_buff *skb;

	/* free sta structure; it has already been removed from
	 * hash table etc. external structures. Make sure that all
	 * buffered frames are release (one might have been added
	 * after sta_info_free() was called). */
	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
		local->total_ps_buffered--;
		dev_kfree_skb_any(skb);
	}
	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
		dev_kfree_skb_any(skb);
	}
	rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv);
	rate_control_put(sta->rate_ctrl);
	kfree(sta);
}


void sta_info_put(struct sta_info *sta)
{
	kref_put(&sta->kref, sta_info_release);
}
EXPORT_SYMBOL(sta_info_put);


struct sta_info * sta_info_add(struct ieee80211_local *local,
			       struct net_device *dev, u8 *addr, gfp_t gfp)
{
	struct sta_info *sta;

	sta = kzalloc(sizeof(*sta), gfp);
	if (!sta)
		return NULL;

	kref_init(&sta->kref);

	sta->rate_ctrl = rate_control_get(local->rate_ctrl);
	sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl, gfp);
	if (!sta->rate_ctrl_priv) {
		rate_control_put(sta->rate_ctrl);
		kfree(sta);
		return NULL;
	}

	memcpy(sta->addr, addr, ETH_ALEN);
	sta->local = local;
	sta->dev = dev;
	skb_queue_head_init(&sta->ps_tx_buf);
	skb_queue_head_init(&sta->tx_filtered);
	__sta_info_get(sta);	/* sta used by caller, decremented by
				 * sta_info_put() */
	write_lock_bh(&local->sta_lock);
	list_add(&sta->list, &local->sta_list);
	local->num_sta++;
	sta_info_hash_add(local, sta);
	if (local->ops->sta_table_notification)
		local->ops->sta_table_notification(local_to_hw(local),
						  local->num_sta);
	write_unlock_bh(&local->sta_lock);

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
	printk(KERN_DEBUG "%s: Added STA " MAC_FMT "\n",
	       local->mdev->name, MAC_ARG(addr));
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */

#ifdef CONFIG_MAC80211_DEBUGFS
	/* debugfs entry adding might sleep, so schedule process
	 * context task for adding entry for STAs that do not yet
	 * have one. */
	queue_work(local->hw.workqueue, &local->sta_debugfs_add);
#endif

	return sta;
}

/* Caller must hold local->sta_lock */
void sta_info_remove(struct sta_info *sta)
{
	struct ieee80211_local *local = sta->local;
	struct ieee80211_sub_if_data *sdata;

	/* don't do anything if we've been removed already */
	if (sta_info_hash_del(local, sta))
		return;

	list_del(&sta->list);
	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
	if (sta->flags & WLAN_STA_PS) {
		sta->flags &= ~WLAN_STA_PS;
		if (sdata->bss)
			atomic_dec(&sdata->bss->num_sta_ps);
	}
	local->num_sta--;
	sta_info_remove_aid_ptr(sta);

	if (local->ops->sta_table_notification)
		local->ops->sta_table_notification(local_to_hw(local),
						   local->num_sta);
}

void sta_info_free(struct sta_info *sta)
{
	struct sk_buff *skb;
	struct ieee80211_local *local = sta->local;

	might_sleep();

	write_lock_bh(&local->sta_lock);
	sta_info_remove(sta);
	write_unlock_bh(&local->sta_lock);

	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
		local->total_ps_buffered--;
		dev_kfree_skb(skb);
	}
	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
		dev_kfree_skb(skb);
	}

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
	printk(KERN_DEBUG "%s: Removed STA " MAC_FMT "\n",
	       local->mdev->name, MAC_ARG(sta->addr));
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */

	ieee80211_key_free(sta->key);
	sta->key = NULL;

	rate_control_remove_sta_debugfs(sta);
	ieee80211_sta_debugfs_remove(sta);

	sta_info_put(sta);
}


static inline int sta_info_buffer_expired(struct ieee80211_local *local,
					  struct sta_info *sta,
					  struct sk_buff *skb)
{
	struct ieee80211_tx_packet_data *pkt_data;
	int timeout;

	if (!skb)
		return 0;

	pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;

	/* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
	timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
		   15625) * HZ;
	if (timeout < STA_TX_BUFFER_EXPIRE)
		timeout = STA_TX_BUFFER_EXPIRE;
	return time_after(jiffies, pkt_data->jiffies + timeout);
}


static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
					     struct sta_info *sta)
{
	unsigned long flags;
	struct sk_buff *skb;

	if (skb_queue_empty(&sta->ps_tx_buf))
		return;

	for (;;) {
		spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
		skb = skb_peek(&sta->ps_tx_buf);
		if (sta_info_buffer_expired(local, sta, skb)) {
			skb = __skb_dequeue(&sta->ps_tx_buf);
			if (skb_queue_empty(&sta->ps_tx_buf))
				sta->flags &= ~WLAN_STA_TIM;
		} else
			skb = NULL;
		spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);

		if (skb) {
			local->total_ps_buffered--;
			printk(KERN_DEBUG "Buffered frame expired (STA "
			       MAC_FMT ")\n", MAC_ARG(sta->addr));
			dev_kfree_skb(skb);
		} else
			break;
	}
}


static void sta_info_cleanup(unsigned long data)
{
	struct ieee80211_local *local = (struct ieee80211_local *) data;
	struct sta_info *sta;

	read_lock_bh(&local->sta_lock);
	list_for_each_entry(sta, &local->sta_list, list) {
		__sta_info_get(sta);
		sta_info_cleanup_expire_buffered(local, sta);
		sta_info_put(sta);
	}
	read_unlock_bh(&local->sta_lock);

	local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
	add_timer(&local->sta_cleanup);
}

#ifdef CONFIG_MAC80211_DEBUGFS
static void sta_info_debugfs_add_task(struct work_struct *work)
{
	struct ieee80211_local *local =
		container_of(work, struct ieee80211_local, sta_debugfs_add);
	struct sta_info *sta, *tmp;

	while (1) {
		sta = NULL;
		read_lock_bh(&local->sta_lock);
		list_for_each_entry(tmp, &local->sta_list, list) {
			if (!tmp->debugfs.dir) {
				sta = tmp;
				__sta_info_get(sta);
				break;
			}
		}
		read_unlock_bh(&local->sta_lock);

		if (!sta)
			break;

		ieee80211_sta_debugfs_add(sta);
		rate_control_add_sta_debugfs(sta);
		sta_info_put(sta);
	}
}
#endif

void sta_info_init(struct ieee80211_local *local)
{
	rwlock_init(&local->sta_lock);
	INIT_LIST_HEAD(&local->sta_list);

	init_timer(&local->sta_cleanup);
	local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
	local->sta_cleanup.data = (unsigned long) local;
	local->sta_cleanup.function = sta_info_cleanup;

#ifdef CONFIG_MAC80211_DEBUGFS
	INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_task);
#endif
}

int sta_info_start(struct ieee80211_local *local)
{
	add_timer(&local->sta_cleanup);
	return 0;
}

void sta_info_stop(struct ieee80211_local *local)
{
	del_timer(&local->sta_cleanup);
	sta_info_flush(local, NULL);
}

void sta_info_remove_aid_ptr(struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata;

	if (sta->aid <= 0)
		return;

	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);

	if (sdata->local->ops->set_tim)
		sdata->local->ops->set_tim(local_to_hw(sdata->local),
					  sta->aid, 0);
	if (sdata->bss)
		__bss_tim_clear(sdata->bss, sta->aid);
}


/**
 * sta_info_flush - flush matching STA entries from the STA table
 * @local: local interface data
 * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs
 */
void sta_info_flush(struct ieee80211_local *local, struct net_device *dev)
{
	struct sta_info *sta, *tmp;
	LIST_HEAD(tmp_list);

	write_lock_bh(&local->sta_lock);
	list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
		if (!dev || dev == sta->dev) {
			__sta_info_get(sta);
			sta_info_remove(sta);
			list_add_tail(&sta->list, &tmp_list);
		}
	write_unlock_bh(&local->sta_lock);

	list_for_each_entry_safe(sta, tmp, &tmp_list, list) {
		sta_info_free(sta);
		sta_info_put(sta);
	}
}
OpenPOWER on IntegriCloud