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
18#include <net/mac80211.h>
19#include "ieee80211_i.h"
20#include "ieee80211_rate.h"
21#include "sta_info.h"
22#include "debugfs_key.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 void 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;
43	if (memcmp(s->addr, sta->addr, ETH_ALEN) == 0) {
44		local->sta_hash[STA_HASH(sta->addr)] = s->hnext;
45		return;
46	}
47
48	while (s->hnext && memcmp(s->hnext->addr, sta->addr, ETH_ALEN) != 0)
49		s = s->hnext;
50	if (s->hnext)
51		s->hnext = s->hnext->hnext;
52	else
53		printk(KERN_ERR "%s: could not remove STA " MAC_FMT " from "
54		       "hash table\n", local->mdev->name, MAC_ARG(sta->addr));
55}
56
57static inline void __sta_info_get(struct sta_info *sta)
58{
59	kref_get(&sta->kref);
60}
61
62struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr)
63{
64	struct sta_info *sta;
65
66	spin_lock_bh(&local->sta_lock);
67	sta = local->sta_hash[STA_HASH(addr)];
68	while (sta) {
69		if (memcmp(sta->addr, addr, ETH_ALEN) == 0) {
70			__sta_info_get(sta);
71			break;
72		}
73		sta = sta->hnext;
74	}
75	spin_unlock_bh(&local->sta_lock);
76
77	return sta;
78}
79EXPORT_SYMBOL(sta_info_get);
80
81int sta_info_min_txrate_get(struct ieee80211_local *local)
82{
83	struct sta_info *sta;
84	struct ieee80211_hw_mode *mode;
85	int min_txrate = 9999999;
86	int i;
87
88	spin_lock_bh(&local->sta_lock);
89	mode = local->oper_hw_mode;
90	for (i = 0; i < STA_HASH_SIZE; i++) {
91		sta = local->sta_hash[i];
92		while (sta) {
93			if (sta->txrate < min_txrate)
94				min_txrate = sta->txrate;
95			sta = sta->hnext;
96		}
97	}
98	spin_unlock_bh(&local->sta_lock);
99	if (min_txrate == 9999999)
100		min_txrate = 0;
101
102	return mode->rates[min_txrate].rate;
103}
104
105
106static void sta_info_release(struct kref *kref)
107{
108	struct sta_info *sta = container_of(kref, struct sta_info, kref);
109	struct ieee80211_local *local = sta->local;
110	struct sk_buff *skb;
111
112	/* free sta structure; it has already been removed from
113	 * hash table etc. external structures. Make sure that all
114	 * buffered frames are release (one might have been added
115	 * after sta_info_free() was called). */
116	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
117		local->total_ps_buffered--;
118		dev_kfree_skb_any(skb);
119	}
120	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
121		dev_kfree_skb_any(skb);
122	}
123	rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv);
124	rate_control_put(sta->rate_ctrl);
125	if (sta->key)
126		ieee80211_debugfs_key_sta_del(sta->key, sta);
127	kfree(sta);
128}
129
130
131void sta_info_put(struct sta_info *sta)
132{
133	kref_put(&sta->kref, sta_info_release);
134}
135EXPORT_SYMBOL(sta_info_put);
136
137
138struct sta_info * sta_info_add(struct ieee80211_local *local,
139			       struct net_device *dev, u8 *addr, gfp_t gfp)
140{
141	struct sta_info *sta;
142
143	sta = kzalloc(sizeof(*sta), gfp);
144	if (!sta)
145		return NULL;
146
147	kref_init(&sta->kref);
148
149	sta->rate_ctrl = rate_control_get(local->rate_ctrl);
150	sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl, gfp);
151	if (!sta->rate_ctrl_priv) {
152		rate_control_put(sta->rate_ctrl);
153		kref_put(&sta->kref, sta_info_release);
154		kfree(sta);
155		return NULL;
156	}
157
158	memcpy(sta->addr, addr, ETH_ALEN);
159	sta->local = local;
160	sta->dev = dev;
161	skb_queue_head_init(&sta->ps_tx_buf);
162	skb_queue_head_init(&sta->tx_filtered);
163	__sta_info_get(sta);	/* sta used by caller, decremented by
164				 * sta_info_put() */
165	spin_lock_bh(&local->sta_lock);
166	list_add(&sta->list, &local->sta_list);
167	local->num_sta++;
168	sta_info_hash_add(local, sta);
169	spin_unlock_bh(&local->sta_lock);
170	if (local->ops->sta_table_notification)
171		local->ops->sta_table_notification(local_to_hw(local),
172						  local->num_sta);
173	sta->key_idx_compression = HW_KEY_IDX_INVALID;
174
175#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
176	printk(KERN_DEBUG "%s: Added STA " MAC_FMT "\n",
177	       local->mdev->name, MAC_ARG(addr));
178#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
179
180#ifdef CONFIG_MAC80211_DEBUGFS
181	if (!in_interrupt()) {
182		sta->debugfs_registered = 1;
183		ieee80211_sta_debugfs_add(sta);
184		rate_control_add_sta_debugfs(sta);
185	} else {
186		/* debugfs entry adding might sleep, so schedule process
187		 * context task for adding entry for STAs that do not yet
188		 * have one. */
189		queue_work(local->hw.workqueue, &local->sta_debugfs_add);
190	}
191#endif
192
193	return sta;
194}
195
196static void finish_sta_info_free(struct ieee80211_local *local,
197				 struct sta_info *sta)
198{
199#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
200	printk(KERN_DEBUG "%s: Removed STA " MAC_FMT "\n",
201	       local->mdev->name, MAC_ARG(sta->addr));
202#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
203
204	if (sta->key) {
205		ieee80211_debugfs_key_remove(sta->key);
206		ieee80211_key_free(sta->key);
207		sta->key = NULL;
208	}
209
210	rate_control_remove_sta_debugfs(sta);
211	ieee80211_sta_debugfs_remove(sta);
212
213	sta_info_put(sta);
214}
215
216static void sta_info_remove(struct sta_info *sta)
217{
218	struct ieee80211_local *local = sta->local;
219	struct ieee80211_sub_if_data *sdata;
220
221	sta_info_hash_del(local, sta);
222	list_del(&sta->list);
223	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
224	if (sta->flags & WLAN_STA_PS) {
225		sta->flags &= ~WLAN_STA_PS;
226		if (sdata->bss)
227			atomic_dec(&sdata->bss->num_sta_ps);
228	}
229	local->num_sta--;
230	sta_info_remove_aid_ptr(sta);
231}
232
233void sta_info_free(struct sta_info *sta, int locked)
234{
235	struct sk_buff *skb;
236	struct ieee80211_local *local = sta->local;
237
238	if (!locked) {
239		spin_lock_bh(&local->sta_lock);
240		sta_info_remove(sta);
241		spin_unlock_bh(&local->sta_lock);
242	} else {
243		sta_info_remove(sta);
244	}
245	if (local->ops->sta_table_notification)
246		local->ops->sta_table_notification(local_to_hw(local),
247						  local->num_sta);
248
249	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
250		local->total_ps_buffered--;
251		dev_kfree_skb_any(skb);
252	}
253	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
254		dev_kfree_skb_any(skb);
255	}
256
257	if (sta->key) {
258		if (local->ops->set_key) {
259			struct ieee80211_key_conf *key;
260			key = ieee80211_key_data2conf(local, sta->key);
261			if (key) {
262				local->ops->set_key(local_to_hw(local),
263						   DISABLE_KEY,
264						   sta->addr, key, sta->aid);
265				kfree(key);
266			}
267		}
268	} else if (sta->key_idx_compression != HW_KEY_IDX_INVALID) {
269		struct ieee80211_key_conf conf;
270		memset(&conf, 0, sizeof(conf));
271		conf.hw_key_idx = sta->key_idx_compression;
272		conf.alg = ALG_NULL;
273		conf.flags |= IEEE80211_KEY_FORCE_SW_ENCRYPT;
274		local->ops->set_key(local_to_hw(local), DISABLE_KEY,
275				   sta->addr, &conf, sta->aid);
276		sta->key_idx_compression = HW_KEY_IDX_INVALID;
277	}
278
279#ifdef CONFIG_MAC80211_DEBUGFS
280	if (in_atomic()) {
281		list_add(&sta->list, &local->deleted_sta_list);
282		queue_work(local->hw.workqueue, &local->sta_debugfs_add);
283	} else
284#endif
285		finish_sta_info_free(local, sta);
286}
287
288
289static inline int sta_info_buffer_expired(struct ieee80211_local *local,
290					  struct sta_info *sta,
291					  struct sk_buff *skb)
292{
293	struct ieee80211_tx_packet_data *pkt_data;
294	int timeout;
295
296	if (!skb)
297		return 0;
298
299	pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
300
301	/* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
302	timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
303		   15625) * HZ;
304	if (timeout < STA_TX_BUFFER_EXPIRE)
305		timeout = STA_TX_BUFFER_EXPIRE;
306	return time_after(jiffies, pkt_data->jiffies + timeout);
307}
308
309
310static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
311					     struct sta_info *sta)
312{
313	unsigned long flags;
314	struct sk_buff *skb;
315
316	if (skb_queue_empty(&sta->ps_tx_buf))
317		return;
318
319	for (;;) {
320		spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
321		skb = skb_peek(&sta->ps_tx_buf);
322		if (sta_info_buffer_expired(local, sta, skb)) {
323			skb = __skb_dequeue(&sta->ps_tx_buf);
324			if (skb_queue_empty(&sta->ps_tx_buf))
325				sta->flags &= ~WLAN_STA_TIM;
326		} else
327			skb = NULL;
328		spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
329
330		if (skb) {
331			local->total_ps_buffered--;
332			printk(KERN_DEBUG "Buffered frame expired (STA "
333			       MAC_FMT ")\n", MAC_ARG(sta->addr));
334			dev_kfree_skb(skb);
335		} else
336			break;
337	}
338}
339
340
341static void sta_info_cleanup(unsigned long data)
342{
343	struct ieee80211_local *local = (struct ieee80211_local *) data;
344	struct sta_info *sta;
345
346	spin_lock_bh(&local->sta_lock);
347	list_for_each_entry(sta, &local->sta_list, list) {
348		__sta_info_get(sta);
349		sta_info_cleanup_expire_buffered(local, sta);
350		sta_info_put(sta);
351	}
352	spin_unlock_bh(&local->sta_lock);
353
354	local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
355	add_timer(&local->sta_cleanup);
356}
357
358#ifdef CONFIG_MAC80211_DEBUGFS
359static void sta_info_debugfs_add_task(struct work_struct *work)
360{
361	struct ieee80211_local *local =
362		container_of(work, struct ieee80211_local, sta_debugfs_add);
363	struct sta_info *sta, *tmp;
364
365	while (1) {
366		spin_lock_bh(&local->sta_lock);
367		if (!list_empty(&local->deleted_sta_list)) {
368			sta = list_entry(local->deleted_sta_list.next,
369					 struct sta_info, list);
370			list_del(local->deleted_sta_list.next);
371		} else
372			sta = NULL;
373		spin_unlock_bh(&local->sta_lock);
374		if (!sta)
375			break;
376		finish_sta_info_free(local, sta);
377	}
378
379	while (1) {
380		sta = NULL;
381		spin_lock_bh(&local->sta_lock);
382		list_for_each_entry(tmp, &local->sta_list, list) {
383			if (!tmp->debugfs_registered) {
384				sta = tmp;
385				__sta_info_get(sta);
386				break;
387			}
388		}
389		spin_unlock_bh(&local->sta_lock);
390
391		if (!sta)
392			break;
393
394		sta->debugfs_registered = 1;
395		ieee80211_sta_debugfs_add(sta);
396		rate_control_add_sta_debugfs(sta);
397		sta_info_put(sta);
398	}
399}
400#endif
401
402void sta_info_init(struct ieee80211_local *local)
403{
404	spin_lock_init(&local->sta_lock);
405	INIT_LIST_HEAD(&local->sta_list);
406	INIT_LIST_HEAD(&local->deleted_sta_list);
407
408	init_timer(&local->sta_cleanup);
409	local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
410	local->sta_cleanup.data = (unsigned long) local;
411	local->sta_cleanup.function = sta_info_cleanup;
412
413#ifdef CONFIG_MAC80211_DEBUGFS
414	INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_task);
415#endif
416}
417
418int sta_info_start(struct ieee80211_local *local)
419{
420	add_timer(&local->sta_cleanup);
421	return 0;
422}
423
424void sta_info_stop(struct ieee80211_local *local)
425{
426	struct sta_info *sta, *tmp;
427
428	del_timer(&local->sta_cleanup);
429
430	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
431		/* sta_info_free must be called with 0 as the last
432		 * parameter to ensure all debugfs sta entries are
433		 * unregistered. We don't need locking at this
434		 * point. */
435		sta_info_free(sta, 0);
436	}
437}
438
439void sta_info_remove_aid_ptr(struct sta_info *sta)
440{
441	struct ieee80211_sub_if_data *sdata;
442
443	if (sta->aid <= 0)
444		return;
445
446	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
447
448	if (sdata->local->ops->set_tim)
449		sdata->local->ops->set_tim(local_to_hw(sdata->local),
450					  sta->aid, 0);
451	if (sdata->bss)
452		__bss_tim_clear(sdata->bss, sta->aid);
453}
454
455
456/**
457 * sta_info_flush - flush matching STA entries from the STA table
458 * @local: local interface data
459 * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs
460 */
461void sta_info_flush(struct ieee80211_local *local, struct net_device *dev)
462{
463	struct sta_info *sta, *tmp;
464
465	spin_lock_bh(&local->sta_lock);
466	list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
467		if (!dev || dev == sta->dev)
468			sta_info_free(sta, 1);
469	spin_unlock_bh(&local->sta_lock);
470}
471