sta_info.c revision 32bfd35d4b63bd63de4bb0d791ef049c3c868726 
1/*
2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/netdevice.h>
13#include <linux/types.h>
14#include <linux/slab.h>
15#include <linux/skbuff.h>
16#include <linux/if_arp.h>
17#include <linux/timer.h>
18
19#include <net/mac80211.h>
20#include "ieee80211_i.h"
21#include "ieee80211_rate.h"
22#include "sta_info.h"
23#include "debugfs_sta.h"
24
25/* Caller must hold local->sta_lock */
26static void sta_info_hash_add(struct ieee80211_local *local,
27			      struct sta_info *sta)
28{
29	sta->hnext = local->sta_hash[STA_HASH(sta->addr)];
30	local->sta_hash[STA_HASH(sta->addr)] = sta;
31}
32
33
34/* Caller must hold local->sta_lock */
35static int sta_info_hash_del(struct ieee80211_local *local,
36			     struct sta_info *sta)
37{
38	struct sta_info *s;
39
40	s = local->sta_hash[STA_HASH(sta->addr)];
41	if (!s)
42		return -ENOENT;
43	if (s == sta) {
44		local->sta_hash[STA_HASH(sta->addr)] = s->hnext;
45		return 0;
46	}
47
48	while (s->hnext && s->hnext != sta)
49		s = s->hnext;
50	if (s->hnext) {
51		s->hnext = sta->hnext;
52		return 0;
53	}
54
55	return -ENOENT;
56}
57
58struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr)
59{
60	struct sta_info *sta;
61
62	read_lock_bh(&local->sta_lock);
63	sta = local->sta_hash[STA_HASH(addr)];
64	while (sta) {
65		if (memcmp(sta->addr, addr, ETH_ALEN) == 0) {
66			__sta_info_get(sta);
67			break;
68		}
69		sta = sta->hnext;
70	}
71	read_unlock_bh(&local->sta_lock);
72
73	return sta;
74}
75EXPORT_SYMBOL(sta_info_get);
76
77int sta_info_min_txrate_get(struct ieee80211_local *local)
78{
79	struct sta_info *sta;
80	struct ieee80211_hw_mode *mode;
81	int min_txrate = 9999999;
82	int i;
83
84	read_lock_bh(&local->sta_lock);
85	mode = local->oper_hw_mode;
86	for (i = 0; i < STA_HASH_SIZE; i++) {
87		sta = local->sta_hash[i];
88		while (sta) {
89			if (sta->txrate < min_txrate)
90				min_txrate = sta->txrate;
91			sta = sta->hnext;
92		}
93	}
94	read_unlock_bh(&local->sta_lock);
95	if (min_txrate == 9999999)
96		min_txrate = 0;
97
98	return mode->rates[min_txrate].rate;
99}
100
101
102static void sta_info_release(struct kref *kref)
103{
104	struct sta_info *sta = container_of(kref, struct sta_info, kref);
105	struct ieee80211_local *local = sta->local;
106	struct sk_buff *skb;
107	int i;
108
109	/* free sta structure; it has already been removed from
110	 * hash table etc. external structures. Make sure that all
111	 * buffered frames are release (one might have been added
112	 * after sta_info_free() was called). */
113	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
114		local->total_ps_buffered--;
115		dev_kfree_skb_any(skb);
116	}
117	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
118		dev_kfree_skb_any(skb);
119	}
120	for (i = 0; i <  STA_TID_NUM; i++)
121		del_timer_sync(&sta->ampdu_mlme.tid_rx[i].session_timer);
122	rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv);
123	rate_control_put(sta->rate_ctrl);
124	kfree(sta);
125}
126
127
128void sta_info_put(struct sta_info *sta)
129{
130	kref_put(&sta->kref, sta_info_release);
131}
132EXPORT_SYMBOL(sta_info_put);
133
134
135struct sta_info * sta_info_add(struct ieee80211_local *local,
136			       struct net_device *dev, u8 *addr, gfp_t gfp)
137{
138	struct sta_info *sta;
139	int i;
140	DECLARE_MAC_BUF(mac);
141
142	sta = kzalloc(sizeof(*sta), gfp);
143	if (!sta)
144		return NULL;
145
146	kref_init(&sta->kref);
147
148	sta->rate_ctrl = rate_control_get(local->rate_ctrl);
149	sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl, gfp);
150	if (!sta->rate_ctrl_priv) {
151		rate_control_put(sta->rate_ctrl);
152		kfree(sta);
153		return NULL;
154	}
155
156	memcpy(sta->addr, addr, ETH_ALEN);
157	sta->local = local;
158	sta->dev = dev;
159	spin_lock_init(&sta->ampdu_mlme.ampdu_rx);
160	for (i = 0; i < STA_TID_NUM; i++) {
161		/* timer_to_tid must be initialized with identity mapping to
162		 * enable session_timer's data differentiation. refer to
163		 * sta_rx_agg_session_timer_expired for useage */
164		sta->timer_to_tid[i] = i;
165		/* rx timers */
166		sta->ampdu_mlme.tid_rx[i].session_timer.function =
167			sta_rx_agg_session_timer_expired;
168		sta->ampdu_mlme.tid_rx[i].session_timer.data =
169			(unsigned long)&sta->timer_to_tid[i];
170		init_timer(&sta->ampdu_mlme.tid_rx[i].session_timer);
171	}
172	skb_queue_head_init(&sta->ps_tx_buf);
173	skb_queue_head_init(&sta->tx_filtered);
174	__sta_info_get(sta);	/* sta used by caller, decremented by
175				 * sta_info_put() */
176	write_lock_bh(&local->sta_lock);
177	list_add(&sta->list, &local->sta_list);
178	local->num_sta++;
179	sta_info_hash_add(local, sta);
180	if (local->ops->sta_notify) {
181		struct ieee80211_sub_if_data *sdata;
182
183		sdata = IEEE80211_DEV_TO_SUB_IF(dev);
184		if (sdata->type == IEEE80211_IF_TYPE_VLAN)
185			sdata = sdata->u.vlan.ap;
186
187		local->ops->sta_notify(local_to_hw(local), &sdata->vif,
188				       STA_NOTIFY_ADD, addr);
189	}
190	write_unlock_bh(&local->sta_lock);
191
192#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
193	printk(KERN_DEBUG "%s: Added STA %s\n",
194	       wiphy_name(local->hw.wiphy), print_mac(mac, addr));
195#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
196
197#ifdef CONFIG_MAC80211_DEBUGFS
198	/* debugfs entry adding might sleep, so schedule process
199	 * context task for adding entry for STAs that do not yet
200	 * have one. */
201	queue_work(local->hw.workqueue, &local->sta_debugfs_add);
202#endif
203
204	return sta;
205}
206
207/* Caller must hold local->sta_lock */
208void sta_info_remove(struct sta_info *sta)
209{
210	struct ieee80211_local *local = sta->local;
211	struct ieee80211_sub_if_data *sdata;
212
213	/* don't do anything if we've been removed already */
214	if (sta_info_hash_del(local, sta))
215		return;
216
217	list_del(&sta->list);
218	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
219	if (sta->flags & WLAN_STA_PS) {
220		sta->flags &= ~WLAN_STA_PS;
221		if (sdata->bss)
222			atomic_dec(&sdata->bss->num_sta_ps);
223	}
224	local->num_sta--;
225	sta_info_remove_aid_ptr(sta);
226
227}
228
229void sta_info_free(struct sta_info *sta)
230{
231	struct sk_buff *skb;
232	struct ieee80211_local *local = sta->local;
233	DECLARE_MAC_BUF(mac);
234
235	might_sleep();
236
237	write_lock_bh(&local->sta_lock);
238	sta_info_remove(sta);
239	write_unlock_bh(&local->sta_lock);
240
241	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
242		local->total_ps_buffered--;
243		dev_kfree_skb(skb);
244	}
245	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
246		dev_kfree_skb(skb);
247	}
248
249#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
250	printk(KERN_DEBUG "%s: Removed STA %s\n",
251	       wiphy_name(local->hw.wiphy), print_mac(mac, sta->addr));
252#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
253
254	ieee80211_key_free(sta->key);
255	sta->key = NULL;
256
257	if (local->ops->sta_notify) {
258		struct ieee80211_sub_if_data *sdata;
259
260		sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
261
262		if (sdata->type == IEEE80211_IF_TYPE_VLAN)
263			sdata = sdata->u.vlan.ap;
264
265		local->ops->sta_notify(local_to_hw(local), &sdata->vif,
266				       STA_NOTIFY_REMOVE, sta->addr);
267	}
268
269	rate_control_remove_sta_debugfs(sta);
270	ieee80211_sta_debugfs_remove(sta);
271
272	sta_info_put(sta);
273}
274
275
276static inline int sta_info_buffer_expired(struct ieee80211_local *local,
277					  struct sta_info *sta,
278					  struct sk_buff *skb)
279{
280	struct ieee80211_tx_packet_data *pkt_data;
281	int timeout;
282
283	if (!skb)
284		return 0;
285
286	pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
287
288	/* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
289	timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
290		   15625) * HZ;
291	if (timeout < STA_TX_BUFFER_EXPIRE)
292		timeout = STA_TX_BUFFER_EXPIRE;
293	return time_after(jiffies, pkt_data->jiffies + timeout);
294}
295
296
297static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
298					     struct sta_info *sta)
299{
300	unsigned long flags;
301	struct sk_buff *skb;
302	DECLARE_MAC_BUF(mac);
303
304	if (skb_queue_empty(&sta->ps_tx_buf))
305		return;
306
307	for (;;) {
308		spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
309		skb = skb_peek(&sta->ps_tx_buf);
310		if (sta_info_buffer_expired(local, sta, skb)) {
311			skb = __skb_dequeue(&sta->ps_tx_buf);
312			if (skb_queue_empty(&sta->ps_tx_buf))
313				sta->flags &= ~WLAN_STA_TIM;
314		} else
315			skb = NULL;
316		spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
317
318		if (skb) {
319			local->total_ps_buffered--;
320			printk(KERN_DEBUG "Buffered frame expired (STA "
321			       "%s)\n", print_mac(mac, sta->addr));
322			dev_kfree_skb(skb);
323		} else
324			break;
325	}
326}
327
328
329static void sta_info_cleanup(unsigned long data)
330{
331	struct ieee80211_local *local = (struct ieee80211_local *) data;
332	struct sta_info *sta;
333
334	read_lock_bh(&local->sta_lock);
335	list_for_each_entry(sta, &local->sta_list, list) {
336		__sta_info_get(sta);
337		sta_info_cleanup_expire_buffered(local, sta);
338		sta_info_put(sta);
339	}
340	read_unlock_bh(&local->sta_lock);
341
342	local->sta_cleanup.expires =
343		round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
344	add_timer(&local->sta_cleanup);
345}
346
347#ifdef CONFIG_MAC80211_DEBUGFS
348static void sta_info_debugfs_add_task(struct work_struct *work)
349{
350	struct ieee80211_local *local =
351		container_of(work, struct ieee80211_local, sta_debugfs_add);
352	struct sta_info *sta, *tmp;
353
354	while (1) {
355		sta = NULL;
356		read_lock_bh(&local->sta_lock);
357		list_for_each_entry(tmp, &local->sta_list, list) {
358			if (!tmp->debugfs.dir) {
359				sta = tmp;
360				__sta_info_get(sta);
361				break;
362			}
363		}
364		read_unlock_bh(&local->sta_lock);
365
366		if (!sta)
367			break;
368
369		ieee80211_sta_debugfs_add(sta);
370		rate_control_add_sta_debugfs(sta);
371		sta_info_put(sta);
372	}
373}
374#endif
375
376void sta_info_init(struct ieee80211_local *local)
377{
378	rwlock_init(&local->sta_lock);
379	INIT_LIST_HEAD(&local->sta_list);
380
381	setup_timer(&local->sta_cleanup, sta_info_cleanup,
382		    (unsigned long)local);
383	local->sta_cleanup.expires =
384		round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
385
386#ifdef CONFIG_MAC80211_DEBUGFS
387	INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_task);
388#endif
389}
390
391int sta_info_start(struct ieee80211_local *local)
392{
393	add_timer(&local->sta_cleanup);
394	return 0;
395}
396
397void sta_info_stop(struct ieee80211_local *local)
398{
399	del_timer(&local->sta_cleanup);
400	sta_info_flush(local, NULL);
401}
402
403void sta_info_remove_aid_ptr(struct sta_info *sta)
404{
405	struct ieee80211_sub_if_data *sdata;
406
407	if (sta->aid <= 0)
408		return;
409
410	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
411
412	if (sdata->local->ops->set_tim)
413		sdata->local->ops->set_tim(local_to_hw(sdata->local),
414					  sta->aid, 0);
415	if (sdata->bss)
416		__bss_tim_clear(sdata->bss, sta->aid);
417}
418
419
420/**
421 * sta_info_flush - flush matching STA entries from the STA table
422 * @local: local interface data
423 * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs
424 */
425void sta_info_flush(struct ieee80211_local *local, struct net_device *dev)
426{
427	struct sta_info *sta, *tmp;
428	LIST_HEAD(tmp_list);
429
430	write_lock_bh(&local->sta_lock);
431	list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
432		if (!dev || dev == sta->dev) {
433			__sta_info_get(sta);
434			sta_info_remove(sta);
435			list_add_tail(&sta->list, &tmp_list);
436		}
437	write_unlock_bh(&local->sta_lock);
438
439	list_for_each_entry_safe(sta, tmp, &tmp_list, list) {
440		sta_info_free(sta);
441		sta_info_put(sta);
442	}
443}
444