xref: /linux/net/mac80211/sta_info.c (revision 800c5eb7b5eba6cb2a32738d763fd59f0fbcdde4)
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 #include <linux/rtnetlink.h>
19 
20 #include <net/mac80211.h>
21 #include "ieee80211_i.h"
22 #include "driver-ops.h"
23 #include "rate.h"
24 #include "sta_info.h"
25 #include "debugfs_sta.h"
26 #include "mesh.h"
27 #include "wme.h"
28 
29 /**
30  * DOC: STA information lifetime rules
31  *
32  * STA info structures (&struct sta_info) are managed in a hash table
33  * for faster lookup and a list for iteration. They are managed using
34  * RCU, i.e. access to the list and hash table is protected by RCU.
35  *
36  * Upon allocating a STA info structure with sta_info_alloc(), the caller
37  * owns that structure. It must then insert it into the hash table using
38  * either sta_info_insert() or sta_info_insert_rcu(); only in the latter
39  * case (which acquires an rcu read section but must not be called from
40  * within one) will the pointer still be valid after the call. Note that
41  * the caller may not do much with the STA info before inserting it, in
42  * particular, it may not start any mesh peer link management or add
43  * encryption keys.
44  *
45  * When the insertion fails (sta_info_insert()) returns non-zero), the
46  * structure will have been freed by sta_info_insert()!
47  *
48  * Station entries are added by mac80211 when you establish a link with a
49  * peer. This means different things for the different type of interfaces
50  * we support. For a regular station this mean we add the AP sta when we
51  * receive an association response from the AP. For IBSS this occurs when
52  * get to know about a peer on the same IBSS. For WDS we add the sta for
53  * the peer immediately upon device open. When using AP mode we add stations
54  * for each respective station upon request from userspace through nl80211.
55  *
56  * In order to remove a STA info structure, various sta_info_destroy_*()
57  * calls are available.
58  *
59  * There is no concept of ownership on a STA entry, each structure is
60  * owned by the global hash table/list until it is removed. All users of
61  * the structure need to be RCU protected so that the structure won't be
62  * freed before they are done using it.
63  */
64 
65 /* Caller must hold local->sta_mtx */
66 static int sta_info_hash_del(struct ieee80211_local *local,
67 			     struct sta_info *sta)
68 {
69 	struct sta_info *s;
70 
71 	s = rcu_dereference_protected(local->sta_hash[STA_HASH(sta->sta.addr)],
72 				      lockdep_is_held(&local->sta_mtx));
73 	if (!s)
74 		return -ENOENT;
75 	if (s == sta) {
76 		rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)],
77 				   s->hnext);
78 		return 0;
79 	}
80 
81 	while (rcu_access_pointer(s->hnext) &&
82 	       rcu_access_pointer(s->hnext) != sta)
83 		s = rcu_dereference_protected(s->hnext,
84 					lockdep_is_held(&local->sta_mtx));
85 	if (rcu_access_pointer(s->hnext)) {
86 		rcu_assign_pointer(s->hnext, sta->hnext);
87 		return 0;
88 	}
89 
90 	return -ENOENT;
91 }
92 
93 /* protected by RCU */
94 struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata,
95 			      const u8 *addr)
96 {
97 	struct ieee80211_local *local = sdata->local;
98 	struct sta_info *sta;
99 
100 	sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)],
101 				    lockdep_is_held(&local->sta_mtx));
102 	while (sta) {
103 		if (sta->sdata == sdata && !sta->dummy &&
104 		    memcmp(sta->sta.addr, addr, ETH_ALEN) == 0)
105 			break;
106 		sta = rcu_dereference_check(sta->hnext,
107 					    lockdep_is_held(&local->sta_mtx));
108 	}
109 	return sta;
110 }
111 
112 /* get a station info entry even if it is a dummy station*/
113 struct sta_info *sta_info_get_rx(struct ieee80211_sub_if_data *sdata,
114 			      const u8 *addr)
115 {
116 	struct ieee80211_local *local = sdata->local;
117 	struct sta_info *sta;
118 
119 	sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)],
120 				    lockdep_is_held(&local->sta_mtx));
121 	while (sta) {
122 		if (sta->sdata == sdata &&
123 		    memcmp(sta->sta.addr, addr, ETH_ALEN) == 0)
124 			break;
125 		sta = rcu_dereference_check(sta->hnext,
126 					    lockdep_is_held(&local->sta_mtx));
127 	}
128 	return sta;
129 }
130 
131 /*
132  * Get sta info either from the specified interface
133  * or from one of its vlans
134  */
135 struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata,
136 				  const u8 *addr)
137 {
138 	struct ieee80211_local *local = sdata->local;
139 	struct sta_info *sta;
140 
141 	sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)],
142 				    lockdep_is_held(&local->sta_mtx));
143 	while (sta) {
144 		if ((sta->sdata == sdata ||
145 		     (sta->sdata->bss && sta->sdata->bss == sdata->bss)) &&
146 		    !sta->dummy &&
147 		    memcmp(sta->sta.addr, addr, ETH_ALEN) == 0)
148 			break;
149 		sta = rcu_dereference_check(sta->hnext,
150 					    lockdep_is_held(&local->sta_mtx));
151 	}
152 	return sta;
153 }
154 
155 /*
156  * Get sta info either from the specified interface
157  * or from one of its vlans (including dummy stations)
158  */
159 struct sta_info *sta_info_get_bss_rx(struct ieee80211_sub_if_data *sdata,
160 				  const u8 *addr)
161 {
162 	struct ieee80211_local *local = sdata->local;
163 	struct sta_info *sta;
164 
165 	sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)],
166 				    lockdep_is_held(&local->sta_mtx));
167 	while (sta) {
168 		if ((sta->sdata == sdata ||
169 		     (sta->sdata->bss && sta->sdata->bss == sdata->bss)) &&
170 		    memcmp(sta->sta.addr, addr, ETH_ALEN) == 0)
171 			break;
172 		sta = rcu_dereference_check(sta->hnext,
173 					    lockdep_is_held(&local->sta_mtx));
174 	}
175 	return sta;
176 }
177 
178 struct sta_info *sta_info_get_by_idx(struct ieee80211_sub_if_data *sdata,
179 				     int idx)
180 {
181 	struct ieee80211_local *local = sdata->local;
182 	struct sta_info *sta;
183 	int i = 0;
184 
185 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
186 		if (sdata != sta->sdata)
187 			continue;
188 		if (i < idx) {
189 			++i;
190 			continue;
191 		}
192 		return sta;
193 	}
194 
195 	return NULL;
196 }
197 
198 /**
199  * sta_info_free - free STA
200  *
201  * @local: pointer to the global information
202  * @sta: STA info to free
203  *
204  * This function must undo everything done by sta_info_alloc()
205  * that may happen before sta_info_insert(). It may only be
206  * called when sta_info_insert() has not been attempted (and
207  * if that fails, the station is freed anyway.)
208  */
209 void sta_info_free(struct ieee80211_local *local, struct sta_info *sta)
210 {
211 	if (sta->rate_ctrl)
212 		rate_control_free_sta(sta);
213 
214 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
215 	wiphy_debug(local->hw.wiphy, "Destroyed STA %pM\n", sta->sta.addr);
216 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
217 
218 	kfree(sta);
219 }
220 
221 /* Caller must hold local->sta_mtx */
222 static void sta_info_hash_add(struct ieee80211_local *local,
223 			      struct sta_info *sta)
224 {
225 	lockdep_assert_held(&local->sta_mtx);
226 	sta->hnext = local->sta_hash[STA_HASH(sta->sta.addr)];
227 	rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)], sta);
228 }
229 
230 static void sta_unblock(struct work_struct *wk)
231 {
232 	struct sta_info *sta;
233 
234 	sta = container_of(wk, struct sta_info, drv_unblock_wk);
235 
236 	if (sta->dead)
237 		return;
238 
239 	if (!test_sta_flag(sta, WLAN_STA_PS_STA)) {
240 		local_bh_disable();
241 		ieee80211_sta_ps_deliver_wakeup(sta);
242 		local_bh_enable();
243 	} else if (test_and_clear_sta_flag(sta, WLAN_STA_PSPOLL)) {
244 		clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
245 
246 		local_bh_disable();
247 		ieee80211_sta_ps_deliver_poll_response(sta);
248 		local_bh_enable();
249 	} else if (test_and_clear_sta_flag(sta, WLAN_STA_UAPSD)) {
250 		clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
251 
252 		local_bh_disable();
253 		ieee80211_sta_ps_deliver_uapsd(sta);
254 		local_bh_enable();
255 	} else
256 		clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
257 }
258 
259 static int sta_prepare_rate_control(struct ieee80211_local *local,
260 				    struct sta_info *sta, gfp_t gfp)
261 {
262 	if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
263 		return 0;
264 
265 	sta->rate_ctrl = local->rate_ctrl;
266 	sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl,
267 						     &sta->sta, gfp);
268 	if (!sta->rate_ctrl_priv)
269 		return -ENOMEM;
270 
271 	return 0;
272 }
273 
274 struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
275 				const u8 *addr, gfp_t gfp)
276 {
277 	struct ieee80211_local *local = sdata->local;
278 	struct sta_info *sta;
279 	struct timespec uptime;
280 	int i;
281 
282 	sta = kzalloc(sizeof(*sta) + local->hw.sta_data_size, gfp);
283 	if (!sta)
284 		return NULL;
285 
286 	spin_lock_init(&sta->lock);
287 	INIT_WORK(&sta->drv_unblock_wk, sta_unblock);
288 	INIT_WORK(&sta->ampdu_mlme.work, ieee80211_ba_session_work);
289 	mutex_init(&sta->ampdu_mlme.mtx);
290 
291 	memcpy(sta->sta.addr, addr, ETH_ALEN);
292 	sta->local = local;
293 	sta->sdata = sdata;
294 	sta->last_rx = jiffies;
295 
296 	do_posix_clock_monotonic_gettime(&uptime);
297 	sta->last_connected = uptime.tv_sec;
298 	ewma_init(&sta->avg_signal, 1024, 8);
299 
300 	if (sta_prepare_rate_control(local, sta, gfp)) {
301 		kfree(sta);
302 		return NULL;
303 	}
304 
305 	for (i = 0; i < STA_TID_NUM; i++) {
306 		/*
307 		 * timer_to_tid must be initialized with identity mapping
308 		 * to enable session_timer's data differentiation. See
309 		 * sta_rx_agg_session_timer_expired for usage.
310 		 */
311 		sta->timer_to_tid[i] = i;
312 	}
313 	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
314 		skb_queue_head_init(&sta->ps_tx_buf[i]);
315 		skb_queue_head_init(&sta->tx_filtered[i]);
316 	}
317 
318 	for (i = 0; i < NUM_RX_DATA_QUEUES; i++)
319 		sta->last_seq_ctrl[i] = cpu_to_le16(USHRT_MAX);
320 
321 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
322 	wiphy_debug(local->hw.wiphy, "Allocated STA %pM\n", sta->sta.addr);
323 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
324 
325 #ifdef CONFIG_MAC80211_MESH
326 	sta->plink_state = NL80211_PLINK_LISTEN;
327 	init_timer(&sta->plink_timer);
328 #endif
329 
330 	return sta;
331 }
332 
333 static int sta_info_insert_check(struct sta_info *sta)
334 {
335 	struct ieee80211_sub_if_data *sdata = sta->sdata;
336 
337 	/*
338 	 * Can't be a WARN_ON because it can be triggered through a race:
339 	 * something inserts a STA (on one CPU) without holding the RTNL
340 	 * and another CPU turns off the net device.
341 	 */
342 	if (unlikely(!ieee80211_sdata_running(sdata)))
343 		return -ENETDOWN;
344 
345 	if (WARN_ON(compare_ether_addr(sta->sta.addr, sdata->vif.addr) == 0 ||
346 		    is_multicast_ether_addr(sta->sta.addr)))
347 		return -EINVAL;
348 
349 	return 0;
350 }
351 
352 /*
353  * should be called with sta_mtx locked
354  * this function replaces the mutex lock
355  * with a RCU lock
356  */
357 static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU)
358 {
359 	struct ieee80211_local *local = sta->local;
360 	struct ieee80211_sub_if_data *sdata = sta->sdata;
361 	struct sta_info *exist_sta;
362 	bool dummy_reinsert = false;
363 	int err = 0;
364 
365 	lockdep_assert_held(&local->sta_mtx);
366 
367 	/*
368 	 * check if STA exists already.
369 	 * only accept a scenario of a second call to sta_info_insert_finish
370 	 * with a dummy station entry that was inserted earlier
371 	 * in that case - assume that the dummy station flag should
372 	 * be removed.
373 	 */
374 	exist_sta = sta_info_get_bss_rx(sdata, sta->sta.addr);
375 	if (exist_sta) {
376 		if (exist_sta == sta && sta->dummy) {
377 			dummy_reinsert = true;
378 		} else {
379 			err = -EEXIST;
380 			goto out_err;
381 		}
382 	}
383 
384 	if (!sta->dummy || dummy_reinsert) {
385 		/* notify driver */
386 		err = drv_sta_add(local, sdata, &sta->sta);
387 		if (err) {
388 			if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
389 				goto out_err;
390 			printk(KERN_DEBUG "%s: failed to add IBSS STA %pM to "
391 					  "driver (%d) - keeping it anyway.\n",
392 			       sdata->name, sta->sta.addr, err);
393 		} else
394 			sta->uploaded = true;
395 	}
396 
397 	if (!dummy_reinsert) {
398 		local->num_sta++;
399 		local->sta_generation++;
400 		smp_mb();
401 
402 		/* make the station visible */
403 		sta_info_hash_add(local, sta);
404 
405 		list_add(&sta->list, &local->sta_list);
406 
407 		set_sta_flag(sta, WLAN_STA_INSERTED);
408 	} else {
409 		sta->dummy = false;
410 	}
411 
412 	if (!sta->dummy) {
413 		struct station_info sinfo;
414 
415 		ieee80211_sta_debugfs_add(sta);
416 		rate_control_add_sta_debugfs(sta);
417 
418 		memset(&sinfo, 0, sizeof(sinfo));
419 		sinfo.filled = 0;
420 		sinfo.generation = local->sta_generation;
421 		cfg80211_new_sta(sdata->dev, sta->sta.addr, &sinfo, GFP_KERNEL);
422 	}
423 
424 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
425 	wiphy_debug(local->hw.wiphy, "Inserted %sSTA %pM\n",
426 			sta->dummy ? "dummy " : "", sta->sta.addr);
427 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
428 
429 	/* move reference to rcu-protected */
430 	rcu_read_lock();
431 	mutex_unlock(&local->sta_mtx);
432 
433 	if (ieee80211_vif_is_mesh(&sdata->vif))
434 		mesh_accept_plinks_update(sdata);
435 
436 	return 0;
437  out_err:
438 	mutex_unlock(&local->sta_mtx);
439 	rcu_read_lock();
440 	return err;
441 }
442 
443 int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU)
444 {
445 	struct ieee80211_local *local = sta->local;
446 	int err = 0;
447 
448 	might_sleep();
449 
450 	err = sta_info_insert_check(sta);
451 	if (err) {
452 		rcu_read_lock();
453 		goto out_free;
454 	}
455 
456 	mutex_lock(&local->sta_mtx);
457 
458 	err = sta_info_insert_finish(sta);
459 	if (err)
460 		goto out_free;
461 
462 	return 0;
463  out_free:
464 	BUG_ON(!err);
465 	sta_info_free(local, sta);
466 	return err;
467 }
468 
469 int sta_info_insert(struct sta_info *sta)
470 {
471 	int err = sta_info_insert_rcu(sta);
472 
473 	rcu_read_unlock();
474 
475 	return err;
476 }
477 
478 /* Caller must hold sta->local->sta_mtx */
479 int sta_info_reinsert(struct sta_info *sta)
480 {
481 	struct ieee80211_local *local = sta->local;
482 	int err = 0;
483 
484 	err = sta_info_insert_check(sta);
485 	if (err) {
486 		mutex_unlock(&local->sta_mtx);
487 		return err;
488 	}
489 
490 	might_sleep();
491 
492 	err = sta_info_insert_finish(sta);
493 	rcu_read_unlock();
494 	return err;
495 }
496 
497 static inline void __bss_tim_set(struct ieee80211_if_ap *bss, u16 aid)
498 {
499 	/*
500 	 * This format has been mandated by the IEEE specifications,
501 	 * so this line may not be changed to use the __set_bit() format.
502 	 */
503 	bss->tim[aid / 8] |= (1 << (aid % 8));
504 }
505 
506 static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, u16 aid)
507 {
508 	/*
509 	 * This format has been mandated by the IEEE specifications,
510 	 * so this line may not be changed to use the __clear_bit() format.
511 	 */
512 	bss->tim[aid / 8] &= ~(1 << (aid % 8));
513 }
514 
515 static unsigned long ieee80211_tids_for_ac(int ac)
516 {
517 	/* If we ever support TIDs > 7, this obviously needs to be adjusted */
518 	switch (ac) {
519 	case IEEE80211_AC_VO:
520 		return BIT(6) | BIT(7);
521 	case IEEE80211_AC_VI:
522 		return BIT(4) | BIT(5);
523 	case IEEE80211_AC_BE:
524 		return BIT(0) | BIT(3);
525 	case IEEE80211_AC_BK:
526 		return BIT(1) | BIT(2);
527 	default:
528 		WARN_ON(1);
529 		return 0;
530 	}
531 }
532 
533 void sta_info_recalc_tim(struct sta_info *sta)
534 {
535 	struct ieee80211_local *local = sta->local;
536 	struct ieee80211_if_ap *bss = sta->sdata->bss;
537 	unsigned long flags;
538 	bool indicate_tim = false;
539 	u8 ignore_for_tim = sta->sta.uapsd_queues;
540 	int ac;
541 
542 	if (WARN_ON_ONCE(!sta->sdata->bss))
543 		return;
544 
545 	/* No need to do anything if the driver does all */
546 	if (local->hw.flags & IEEE80211_HW_AP_LINK_PS)
547 		return;
548 
549 	if (sta->dead)
550 		goto done;
551 
552 	/*
553 	 * If all ACs are delivery-enabled then we should build
554 	 * the TIM bit for all ACs anyway; if only some are then
555 	 * we ignore those and build the TIM bit using only the
556 	 * non-enabled ones.
557 	 */
558 	if (ignore_for_tim == BIT(IEEE80211_NUM_ACS) - 1)
559 		ignore_for_tim = 0;
560 
561 	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
562 		unsigned long tids;
563 
564 		if (ignore_for_tim & BIT(ac))
565 			continue;
566 
567 		indicate_tim |= !skb_queue_empty(&sta->tx_filtered[ac]) ||
568 				!skb_queue_empty(&sta->ps_tx_buf[ac]);
569 		if (indicate_tim)
570 			break;
571 
572 		tids = ieee80211_tids_for_ac(ac);
573 
574 		indicate_tim |=
575 			sta->driver_buffered_tids & tids;
576 	}
577 
578  done:
579 	spin_lock_irqsave(&local->tim_lock, flags);
580 
581 	if (indicate_tim)
582 		__bss_tim_set(bss, sta->sta.aid);
583 	else
584 		__bss_tim_clear(bss, sta->sta.aid);
585 
586 	if (local->ops->set_tim) {
587 		local->tim_in_locked_section = true;
588 		drv_set_tim(local, &sta->sta, indicate_tim);
589 		local->tim_in_locked_section = false;
590 	}
591 
592 	spin_unlock_irqrestore(&local->tim_lock, flags);
593 }
594 
595 static bool sta_info_buffer_expired(struct sta_info *sta, struct sk_buff *skb)
596 {
597 	struct ieee80211_tx_info *info;
598 	int timeout;
599 
600 	if (!skb)
601 		return false;
602 
603 	info = IEEE80211_SKB_CB(skb);
604 
605 	/* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
606 	timeout = (sta->listen_interval *
607 		   sta->sdata->vif.bss_conf.beacon_int *
608 		   32 / 15625) * HZ;
609 	if (timeout < STA_TX_BUFFER_EXPIRE)
610 		timeout = STA_TX_BUFFER_EXPIRE;
611 	return time_after(jiffies, info->control.jiffies + timeout);
612 }
613 
614 
615 static bool sta_info_cleanup_expire_buffered_ac(struct ieee80211_local *local,
616 						struct sta_info *sta, int ac)
617 {
618 	unsigned long flags;
619 	struct sk_buff *skb;
620 
621 	/*
622 	 * First check for frames that should expire on the filtered
623 	 * queue. Frames here were rejected by the driver and are on
624 	 * a separate queue to avoid reordering with normal PS-buffered
625 	 * frames. They also aren't accounted for right now in the
626 	 * total_ps_buffered counter.
627 	 */
628 	for (;;) {
629 		spin_lock_irqsave(&sta->tx_filtered[ac].lock, flags);
630 		skb = skb_peek(&sta->tx_filtered[ac]);
631 		if (sta_info_buffer_expired(sta, skb))
632 			skb = __skb_dequeue(&sta->tx_filtered[ac]);
633 		else
634 			skb = NULL;
635 		spin_unlock_irqrestore(&sta->tx_filtered[ac].lock, flags);
636 
637 		/*
638 		 * Frames are queued in order, so if this one
639 		 * hasn't expired yet we can stop testing. If
640 		 * we actually reached the end of the queue we
641 		 * also need to stop, of course.
642 		 */
643 		if (!skb)
644 			break;
645 		dev_kfree_skb(skb);
646 	}
647 
648 	/*
649 	 * Now also check the normal PS-buffered queue, this will
650 	 * only find something if the filtered queue was emptied
651 	 * since the filtered frames are all before the normal PS
652 	 * buffered frames.
653 	 */
654 	for (;;) {
655 		spin_lock_irqsave(&sta->ps_tx_buf[ac].lock, flags);
656 		skb = skb_peek(&sta->ps_tx_buf[ac]);
657 		if (sta_info_buffer_expired(sta, skb))
658 			skb = __skb_dequeue(&sta->ps_tx_buf[ac]);
659 		else
660 			skb = NULL;
661 		spin_unlock_irqrestore(&sta->ps_tx_buf[ac].lock, flags);
662 
663 		/*
664 		 * frames are queued in order, so if this one
665 		 * hasn't expired yet (or we reached the end of
666 		 * the queue) we can stop testing
667 		 */
668 		if (!skb)
669 			break;
670 
671 		local->total_ps_buffered--;
672 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
673 		printk(KERN_DEBUG "Buffered frame expired (STA %pM)\n",
674 		       sta->sta.addr);
675 #endif
676 		dev_kfree_skb(skb);
677 	}
678 
679 	/*
680 	 * Finally, recalculate the TIM bit for this station -- it might
681 	 * now be clear because the station was too slow to retrieve its
682 	 * frames.
683 	 */
684 	sta_info_recalc_tim(sta);
685 
686 	/*
687 	 * Return whether there are any frames still buffered, this is
688 	 * used to check whether the cleanup timer still needs to run,
689 	 * if there are no frames we don't need to rearm the timer.
690 	 */
691 	return !(skb_queue_empty(&sta->ps_tx_buf[ac]) &&
692 		 skb_queue_empty(&sta->tx_filtered[ac]));
693 }
694 
695 static bool sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
696 					     struct sta_info *sta)
697 {
698 	bool have_buffered = false;
699 	int ac;
700 
701 	/* This is only necessary for stations on BSS interfaces */
702 	if (!sta->sdata->bss)
703 		return false;
704 
705 	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
706 		have_buffered |=
707 			sta_info_cleanup_expire_buffered_ac(local, sta, ac);
708 
709 	return have_buffered;
710 }
711 
712 int __must_check __sta_info_destroy(struct sta_info *sta)
713 {
714 	struct ieee80211_local *local;
715 	struct ieee80211_sub_if_data *sdata;
716 	int ret, i, ac;
717 	struct tid_ampdu_tx *tid_tx;
718 
719 	might_sleep();
720 
721 	if (!sta)
722 		return -ENOENT;
723 
724 	local = sta->local;
725 	sdata = sta->sdata;
726 
727 	lockdep_assert_held(&local->sta_mtx);
728 
729 	/*
730 	 * Before removing the station from the driver and
731 	 * rate control, it might still start new aggregation
732 	 * sessions -- block that to make sure the tear-down
733 	 * will be sufficient.
734 	 */
735 	set_sta_flag(sta, WLAN_STA_BLOCK_BA);
736 	ieee80211_sta_tear_down_BA_sessions(sta, true);
737 
738 	ret = sta_info_hash_del(local, sta);
739 	if (ret)
740 		return ret;
741 
742 	list_del(&sta->list);
743 
744 	mutex_lock(&local->key_mtx);
745 	for (i = 0; i < NUM_DEFAULT_KEYS; i++)
746 		__ieee80211_key_free(key_mtx_dereference(local, sta->gtk[i]));
747 	if (sta->ptk)
748 		__ieee80211_key_free(key_mtx_dereference(local, sta->ptk));
749 	mutex_unlock(&local->key_mtx);
750 
751 	sta->dead = true;
752 
753 	local->num_sta--;
754 	local->sta_generation++;
755 
756 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
757 		RCU_INIT_POINTER(sdata->u.vlan.sta, NULL);
758 
759 	while (sta->sta_state > IEEE80211_STA_NONE) {
760 		int err = sta_info_move_state(sta, sta->sta_state - 1);
761 		if (err) {
762 			WARN_ON_ONCE(1);
763 			break;
764 		}
765 	}
766 
767 	if (sta->uploaded) {
768 		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
769 			sdata = container_of(sdata->bss,
770 					     struct ieee80211_sub_if_data,
771 					     u.ap);
772 		drv_sta_remove(local, sdata, &sta->sta);
773 		sdata = sta->sdata;
774 	}
775 
776 	/*
777 	 * At this point, after we wait for an RCU grace period,
778 	 * neither mac80211 nor the driver can reference this
779 	 * sta struct any more except by still existing timers
780 	 * associated with this station that we clean up below.
781 	 */
782 	synchronize_rcu();
783 
784 	if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
785 		BUG_ON(!sdata->bss);
786 
787 		clear_sta_flag(sta, WLAN_STA_PS_STA);
788 
789 		atomic_dec(&sdata->bss->num_sta_ps);
790 		sta_info_recalc_tim(sta);
791 	}
792 
793 	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
794 		local->total_ps_buffered -= skb_queue_len(&sta->ps_tx_buf[ac]);
795 		__skb_queue_purge(&sta->ps_tx_buf[ac]);
796 		__skb_queue_purge(&sta->tx_filtered[ac]);
797 	}
798 
799 #ifdef CONFIG_MAC80211_MESH
800 	if (ieee80211_vif_is_mesh(&sdata->vif))
801 		mesh_accept_plinks_update(sdata);
802 #endif
803 
804 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
805 	wiphy_debug(local->hw.wiphy, "Removed STA %pM\n", sta->sta.addr);
806 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
807 	cancel_work_sync(&sta->drv_unblock_wk);
808 
809 	cfg80211_del_sta(sdata->dev, sta->sta.addr, GFP_KERNEL);
810 
811 	rate_control_remove_sta_debugfs(sta);
812 	ieee80211_sta_debugfs_remove(sta);
813 
814 #ifdef CONFIG_MAC80211_MESH
815 	if (ieee80211_vif_is_mesh(&sta->sdata->vif)) {
816 		mesh_plink_deactivate(sta);
817 		del_timer_sync(&sta->plink_timer);
818 	}
819 #endif
820 
821 	/*
822 	 * Destroy aggregation state here. It would be nice to wait for the
823 	 * driver to finish aggregation stop and then clean up, but for now
824 	 * drivers have to handle aggregation stop being requested, followed
825 	 * directly by station destruction.
826 	 */
827 	for (i = 0; i < STA_TID_NUM; i++) {
828 		tid_tx = rcu_dereference_raw(sta->ampdu_mlme.tid_tx[i]);
829 		if (!tid_tx)
830 			continue;
831 		__skb_queue_purge(&tid_tx->pending);
832 		kfree(tid_tx);
833 	}
834 
835 	sta_info_free(local, sta);
836 
837 	return 0;
838 }
839 
840 int sta_info_destroy_addr(struct ieee80211_sub_if_data *sdata, const u8 *addr)
841 {
842 	struct sta_info *sta;
843 	int ret;
844 
845 	mutex_lock(&sdata->local->sta_mtx);
846 	sta = sta_info_get_rx(sdata, addr);
847 	ret = __sta_info_destroy(sta);
848 	mutex_unlock(&sdata->local->sta_mtx);
849 
850 	return ret;
851 }
852 
853 int sta_info_destroy_addr_bss(struct ieee80211_sub_if_data *sdata,
854 			      const u8 *addr)
855 {
856 	struct sta_info *sta;
857 	int ret;
858 
859 	mutex_lock(&sdata->local->sta_mtx);
860 	sta = sta_info_get_bss_rx(sdata, addr);
861 	ret = __sta_info_destroy(sta);
862 	mutex_unlock(&sdata->local->sta_mtx);
863 
864 	return ret;
865 }
866 
867 static void sta_info_cleanup(unsigned long data)
868 {
869 	struct ieee80211_local *local = (struct ieee80211_local *) data;
870 	struct sta_info *sta;
871 	bool timer_needed = false;
872 
873 	rcu_read_lock();
874 	list_for_each_entry_rcu(sta, &local->sta_list, list)
875 		if (sta_info_cleanup_expire_buffered(local, sta))
876 			timer_needed = true;
877 	rcu_read_unlock();
878 
879 	if (local->quiescing)
880 		return;
881 
882 	if (!timer_needed)
883 		return;
884 
885 	mod_timer(&local->sta_cleanup,
886 		  round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL));
887 }
888 
889 void sta_info_init(struct ieee80211_local *local)
890 {
891 	spin_lock_init(&local->tim_lock);
892 	mutex_init(&local->sta_mtx);
893 	INIT_LIST_HEAD(&local->sta_list);
894 
895 	setup_timer(&local->sta_cleanup, sta_info_cleanup,
896 		    (unsigned long)local);
897 }
898 
899 void sta_info_stop(struct ieee80211_local *local)
900 {
901 	del_timer(&local->sta_cleanup);
902 	sta_info_flush(local, NULL);
903 }
904 
905 /**
906  * sta_info_flush - flush matching STA entries from the STA table
907  *
908  * Returns the number of removed STA entries.
909  *
910  * @local: local interface data
911  * @sdata: matching rule for the net device (sta->dev) or %NULL to match all STAs
912  */
913 int sta_info_flush(struct ieee80211_local *local,
914 		   struct ieee80211_sub_if_data *sdata)
915 {
916 	struct sta_info *sta, *tmp;
917 	int ret = 0;
918 
919 	might_sleep();
920 
921 	mutex_lock(&local->sta_mtx);
922 	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
923 		if (!sdata || sdata == sta->sdata)
924 			WARN_ON(__sta_info_destroy(sta));
925 	}
926 	mutex_unlock(&local->sta_mtx);
927 
928 	return ret;
929 }
930 
931 void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
932 			  unsigned long exp_time)
933 {
934 	struct ieee80211_local *local = sdata->local;
935 	struct sta_info *sta, *tmp;
936 
937 	mutex_lock(&local->sta_mtx);
938 
939 	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
940 		if (sdata != sta->sdata)
941 			continue;
942 
943 		if (time_after(jiffies, sta->last_rx + exp_time)) {
944 #ifdef CONFIG_MAC80211_IBSS_DEBUG
945 			printk(KERN_DEBUG "%s: expiring inactive STA %pM\n",
946 			       sdata->name, sta->sta.addr);
947 #endif
948 			WARN_ON(__sta_info_destroy(sta));
949 		}
950 	}
951 
952 	mutex_unlock(&local->sta_mtx);
953 }
954 
955 struct ieee80211_sta *ieee80211_find_sta_by_ifaddr(struct ieee80211_hw *hw,
956 					       const u8 *addr,
957 					       const u8 *localaddr)
958 {
959 	struct sta_info *sta, *nxt;
960 
961 	/*
962 	 * Just return a random station if localaddr is NULL
963 	 * ... first in list.
964 	 */
965 	for_each_sta_info(hw_to_local(hw), addr, sta, nxt) {
966 		if (localaddr &&
967 		    compare_ether_addr(sta->sdata->vif.addr, localaddr) != 0)
968 			continue;
969 		if (!sta->uploaded)
970 			return NULL;
971 		return &sta->sta;
972 	}
973 
974 	return NULL;
975 }
976 EXPORT_SYMBOL_GPL(ieee80211_find_sta_by_ifaddr);
977 
978 struct ieee80211_sta *ieee80211_find_sta(struct ieee80211_vif *vif,
979 					 const u8 *addr)
980 {
981 	struct sta_info *sta;
982 
983 	if (!vif)
984 		return NULL;
985 
986 	sta = sta_info_get_bss(vif_to_sdata(vif), addr);
987 	if (!sta)
988 		return NULL;
989 
990 	if (!sta->uploaded)
991 		return NULL;
992 
993 	return &sta->sta;
994 }
995 EXPORT_SYMBOL(ieee80211_find_sta);
996 
997 static void clear_sta_ps_flags(void *_sta)
998 {
999 	struct sta_info *sta = _sta;
1000 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1001 
1002 	clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
1003 	if (test_and_clear_sta_flag(sta, WLAN_STA_PS_STA))
1004 		atomic_dec(&sdata->bss->num_sta_ps);
1005 }
1006 
1007 /* powersave support code */
1008 void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta)
1009 {
1010 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1011 	struct ieee80211_local *local = sdata->local;
1012 	struct sk_buff_head pending;
1013 	int filtered = 0, buffered = 0, ac;
1014 
1015 	clear_sta_flag(sta, WLAN_STA_SP);
1016 
1017 	BUILD_BUG_ON(BITS_TO_LONGS(STA_TID_NUM) > 1);
1018 	sta->driver_buffered_tids = 0;
1019 
1020 	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
1021 		drv_sta_notify(local, sdata, STA_NOTIFY_AWAKE, &sta->sta);
1022 
1023 	skb_queue_head_init(&pending);
1024 
1025 	/* Send all buffered frames to the station */
1026 	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
1027 		int count = skb_queue_len(&pending), tmp;
1028 
1029 		skb_queue_splice_tail_init(&sta->tx_filtered[ac], &pending);
1030 		tmp = skb_queue_len(&pending);
1031 		filtered += tmp - count;
1032 		count = tmp;
1033 
1034 		skb_queue_splice_tail_init(&sta->ps_tx_buf[ac], &pending);
1035 		tmp = skb_queue_len(&pending);
1036 		buffered += tmp - count;
1037 	}
1038 
1039 	ieee80211_add_pending_skbs_fn(local, &pending, clear_sta_ps_flags, sta);
1040 
1041 	local->total_ps_buffered -= buffered;
1042 
1043 	sta_info_recalc_tim(sta);
1044 
1045 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1046 	printk(KERN_DEBUG "%s: STA %pM aid %d sending %d filtered/%d PS frames "
1047 	       "since STA not sleeping anymore\n", sdata->name,
1048 	       sta->sta.addr, sta->sta.aid, filtered, buffered);
1049 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1050 }
1051 
1052 static void ieee80211_send_null_response(struct ieee80211_sub_if_data *sdata,
1053 					 struct sta_info *sta, int tid,
1054 					 enum ieee80211_frame_release_type reason)
1055 {
1056 	struct ieee80211_local *local = sdata->local;
1057 	struct ieee80211_qos_hdr *nullfunc;
1058 	struct sk_buff *skb;
1059 	int size = sizeof(*nullfunc);
1060 	__le16 fc;
1061 	bool qos = test_sta_flag(sta, WLAN_STA_WME);
1062 	struct ieee80211_tx_info *info;
1063 
1064 	if (qos) {
1065 		fc = cpu_to_le16(IEEE80211_FTYPE_DATA |
1066 				 IEEE80211_STYPE_QOS_NULLFUNC |
1067 				 IEEE80211_FCTL_FROMDS);
1068 	} else {
1069 		size -= 2;
1070 		fc = cpu_to_le16(IEEE80211_FTYPE_DATA |
1071 				 IEEE80211_STYPE_NULLFUNC |
1072 				 IEEE80211_FCTL_FROMDS);
1073 	}
1074 
1075 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + size);
1076 	if (!skb)
1077 		return;
1078 
1079 	skb_reserve(skb, local->hw.extra_tx_headroom);
1080 
1081 	nullfunc = (void *) skb_put(skb, size);
1082 	nullfunc->frame_control = fc;
1083 	nullfunc->duration_id = 0;
1084 	memcpy(nullfunc->addr1, sta->sta.addr, ETH_ALEN);
1085 	memcpy(nullfunc->addr2, sdata->vif.addr, ETH_ALEN);
1086 	memcpy(nullfunc->addr3, sdata->vif.addr, ETH_ALEN);
1087 
1088 	skb->priority = tid;
1089 	skb_set_queue_mapping(skb, ieee802_1d_to_ac[tid]);
1090 	if (qos) {
1091 		nullfunc->qos_ctrl = cpu_to_le16(tid);
1092 
1093 		if (reason == IEEE80211_FRAME_RELEASE_UAPSD)
1094 			nullfunc->qos_ctrl |=
1095 				cpu_to_le16(IEEE80211_QOS_CTL_EOSP);
1096 	}
1097 
1098 	info = IEEE80211_SKB_CB(skb);
1099 
1100 	/*
1101 	 * Tell TX path to send this frame even though the
1102 	 * STA may still remain is PS mode after this frame
1103 	 * exchange. Also set EOSP to indicate this packet
1104 	 * ends the poll/service period.
1105 	 */
1106 	info->flags |= IEEE80211_TX_CTL_POLL_RESPONSE |
1107 		       IEEE80211_TX_STATUS_EOSP |
1108 		       IEEE80211_TX_CTL_REQ_TX_STATUS;
1109 
1110 	drv_allow_buffered_frames(local, sta, BIT(tid), 1, reason, false);
1111 
1112 	ieee80211_xmit(sdata, skb);
1113 }
1114 
1115 static void
1116 ieee80211_sta_ps_deliver_response(struct sta_info *sta,
1117 				  int n_frames, u8 ignored_acs,
1118 				  enum ieee80211_frame_release_type reason)
1119 {
1120 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1121 	struct ieee80211_local *local = sdata->local;
1122 	bool found = false;
1123 	bool more_data = false;
1124 	int ac;
1125 	unsigned long driver_release_tids = 0;
1126 	struct sk_buff_head frames;
1127 
1128 	/* Service or PS-Poll period starts */
1129 	set_sta_flag(sta, WLAN_STA_SP);
1130 
1131 	__skb_queue_head_init(&frames);
1132 
1133 	/*
1134 	 * Get response frame(s) and more data bit for it.
1135 	 */
1136 	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
1137 		unsigned long tids;
1138 
1139 		if (ignored_acs & BIT(ac))
1140 			continue;
1141 
1142 		tids = ieee80211_tids_for_ac(ac);
1143 
1144 		if (!found) {
1145 			driver_release_tids = sta->driver_buffered_tids & tids;
1146 			if (driver_release_tids) {
1147 				found = true;
1148 			} else {
1149 				struct sk_buff *skb;
1150 
1151 				while (n_frames > 0) {
1152 					skb = skb_dequeue(&sta->tx_filtered[ac]);
1153 					if (!skb) {
1154 						skb = skb_dequeue(
1155 							&sta->ps_tx_buf[ac]);
1156 						if (skb)
1157 							local->total_ps_buffered--;
1158 					}
1159 					if (!skb)
1160 						break;
1161 					n_frames--;
1162 					found = true;
1163 					__skb_queue_tail(&frames, skb);
1164 				}
1165 			}
1166 
1167 			/*
1168 			 * If the driver has data on more than one TID then
1169 			 * certainly there's more data if we release just a
1170 			 * single frame now (from a single TID).
1171 			 */
1172 			if (reason == IEEE80211_FRAME_RELEASE_PSPOLL &&
1173 			    hweight16(driver_release_tids) > 1) {
1174 				more_data = true;
1175 				driver_release_tids =
1176 					BIT(ffs(driver_release_tids) - 1);
1177 				break;
1178 			}
1179 		}
1180 
1181 		if (!skb_queue_empty(&sta->tx_filtered[ac]) ||
1182 		    !skb_queue_empty(&sta->ps_tx_buf[ac])) {
1183 			more_data = true;
1184 			break;
1185 		}
1186 	}
1187 
1188 	if (!found) {
1189 		int tid;
1190 
1191 		/*
1192 		 * For PS-Poll, this can only happen due to a race condition
1193 		 * when we set the TIM bit and the station notices it, but
1194 		 * before it can poll for the frame we expire it.
1195 		 *
1196 		 * For uAPSD, this is said in the standard (11.2.1.5 h):
1197 		 *	At each unscheduled SP for a non-AP STA, the AP shall
1198 		 *	attempt to transmit at least one MSDU or MMPDU, but no
1199 		 *	more than the value specified in the Max SP Length field
1200 		 *	in the QoS Capability element from delivery-enabled ACs,
1201 		 *	that are destined for the non-AP STA.
1202 		 *
1203 		 * Since we have no other MSDU/MMPDU, transmit a QoS null frame.
1204 		 */
1205 
1206 		/* This will evaluate to 1, 3, 5 or 7. */
1207 		tid = 7 - ((ffs(~ignored_acs) - 1) << 1);
1208 
1209 		ieee80211_send_null_response(sdata, sta, tid, reason);
1210 		return;
1211 	}
1212 
1213 	if (!driver_release_tids) {
1214 		struct sk_buff_head pending;
1215 		struct sk_buff *skb;
1216 		int num = 0;
1217 		u16 tids = 0;
1218 
1219 		skb_queue_head_init(&pending);
1220 
1221 		while ((skb = __skb_dequeue(&frames))) {
1222 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1223 			struct ieee80211_hdr *hdr = (void *) skb->data;
1224 			u8 *qoshdr = NULL;
1225 
1226 			num++;
1227 
1228 			/*
1229 			 * Tell TX path to send this frame even though the
1230 			 * STA may still remain is PS mode after this frame
1231 			 * exchange.
1232 			 */
1233 			info->flags |= IEEE80211_TX_CTL_POLL_RESPONSE;
1234 
1235 			/*
1236 			 * Use MoreData flag to indicate whether there are
1237 			 * more buffered frames for this STA
1238 			 */
1239 			if (more_data || !skb_queue_empty(&frames))
1240 				hdr->frame_control |=
1241 					cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1242 			else
1243 				hdr->frame_control &=
1244 					cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1245 
1246 			if (ieee80211_is_data_qos(hdr->frame_control) ||
1247 			    ieee80211_is_qos_nullfunc(hdr->frame_control))
1248 				qoshdr = ieee80211_get_qos_ctl(hdr);
1249 
1250 			/* set EOSP for the frame */
1251 			if (reason == IEEE80211_FRAME_RELEASE_UAPSD &&
1252 			    qoshdr && skb_queue_empty(&frames))
1253 				*qoshdr |= IEEE80211_QOS_CTL_EOSP;
1254 
1255 			info->flags |= IEEE80211_TX_STATUS_EOSP |
1256 				       IEEE80211_TX_CTL_REQ_TX_STATUS;
1257 
1258 			if (qoshdr)
1259 				tids |= BIT(*qoshdr & IEEE80211_QOS_CTL_TID_MASK);
1260 			else
1261 				tids |= BIT(0);
1262 
1263 			__skb_queue_tail(&pending, skb);
1264 		}
1265 
1266 		drv_allow_buffered_frames(local, sta, tids, num,
1267 					  reason, more_data);
1268 
1269 		ieee80211_add_pending_skbs(local, &pending);
1270 
1271 		sta_info_recalc_tim(sta);
1272 	} else {
1273 		/*
1274 		 * We need to release a frame that is buffered somewhere in the
1275 		 * driver ... it'll have to handle that.
1276 		 * Note that, as per the comment above, it'll also have to see
1277 		 * if there is more than just one frame on the specific TID that
1278 		 * we're releasing from, and it needs to set the more-data bit
1279 		 * accordingly if we tell it that there's no more data. If we do
1280 		 * tell it there's more data, then of course the more-data bit
1281 		 * needs to be set anyway.
1282 		 */
1283 		drv_release_buffered_frames(local, sta, driver_release_tids,
1284 					    n_frames, reason, more_data);
1285 
1286 		/*
1287 		 * Note that we don't recalculate the TIM bit here as it would
1288 		 * most likely have no effect at all unless the driver told us
1289 		 * that the TID became empty before returning here from the
1290 		 * release function.
1291 		 * Either way, however, when the driver tells us that the TID
1292 		 * became empty we'll do the TIM recalculation.
1293 		 */
1294 	}
1295 }
1296 
1297 void ieee80211_sta_ps_deliver_poll_response(struct sta_info *sta)
1298 {
1299 	u8 ignore_for_response = sta->sta.uapsd_queues;
1300 
1301 	/*
1302 	 * If all ACs are delivery-enabled then we should reply
1303 	 * from any of them, if only some are enabled we reply
1304 	 * only from the non-enabled ones.
1305 	 */
1306 	if (ignore_for_response == BIT(IEEE80211_NUM_ACS) - 1)
1307 		ignore_for_response = 0;
1308 
1309 	ieee80211_sta_ps_deliver_response(sta, 1, ignore_for_response,
1310 					  IEEE80211_FRAME_RELEASE_PSPOLL);
1311 }
1312 
1313 void ieee80211_sta_ps_deliver_uapsd(struct sta_info *sta)
1314 {
1315 	int n_frames = sta->sta.max_sp;
1316 	u8 delivery_enabled = sta->sta.uapsd_queues;
1317 
1318 	/*
1319 	 * If we ever grow support for TSPEC this might happen if
1320 	 * the TSPEC update from hostapd comes in between a trigger
1321 	 * frame setting WLAN_STA_UAPSD in the RX path and this
1322 	 * actually getting called.
1323 	 */
1324 	if (!delivery_enabled)
1325 		return;
1326 
1327 	switch (sta->sta.max_sp) {
1328 	case 1:
1329 		n_frames = 2;
1330 		break;
1331 	case 2:
1332 		n_frames = 4;
1333 		break;
1334 	case 3:
1335 		n_frames = 6;
1336 		break;
1337 	case 0:
1338 		/* XXX: what is a good value? */
1339 		n_frames = 8;
1340 		break;
1341 	}
1342 
1343 	ieee80211_sta_ps_deliver_response(sta, n_frames, ~delivery_enabled,
1344 					  IEEE80211_FRAME_RELEASE_UAPSD);
1345 }
1346 
1347 void ieee80211_sta_block_awake(struct ieee80211_hw *hw,
1348 			       struct ieee80211_sta *pubsta, bool block)
1349 {
1350 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
1351 
1352 	trace_api_sta_block_awake(sta->local, pubsta, block);
1353 
1354 	if (block)
1355 		set_sta_flag(sta, WLAN_STA_PS_DRIVER);
1356 	else if (test_sta_flag(sta, WLAN_STA_PS_DRIVER))
1357 		ieee80211_queue_work(hw, &sta->drv_unblock_wk);
1358 }
1359 EXPORT_SYMBOL(ieee80211_sta_block_awake);
1360 
1361 void ieee80211_sta_eosp_irqsafe(struct ieee80211_sta *pubsta)
1362 {
1363 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
1364 	struct ieee80211_local *local = sta->local;
1365 	struct sk_buff *skb;
1366 	struct skb_eosp_msg_data *data;
1367 
1368 	trace_api_eosp(local, pubsta);
1369 
1370 	skb = alloc_skb(0, GFP_ATOMIC);
1371 	if (!skb) {
1372 		/* too bad ... but race is better than loss */
1373 		clear_sta_flag(sta, WLAN_STA_SP);
1374 		return;
1375 	}
1376 
1377 	data = (void *)skb->cb;
1378 	memcpy(data->sta, pubsta->addr, ETH_ALEN);
1379 	memcpy(data->iface, sta->sdata->vif.addr, ETH_ALEN);
1380 	skb->pkt_type = IEEE80211_EOSP_MSG;
1381 	skb_queue_tail(&local->skb_queue, skb);
1382 	tasklet_schedule(&local->tasklet);
1383 }
1384 EXPORT_SYMBOL(ieee80211_sta_eosp_irqsafe);
1385 
1386 void ieee80211_sta_set_buffered(struct ieee80211_sta *pubsta,
1387 				u8 tid, bool buffered)
1388 {
1389 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
1390 
1391 	if (WARN_ON(tid >= STA_TID_NUM))
1392 		return;
1393 
1394 	if (buffered)
1395 		set_bit(tid, &sta->driver_buffered_tids);
1396 	else
1397 		clear_bit(tid, &sta->driver_buffered_tids);
1398 
1399 	sta_info_recalc_tim(sta);
1400 }
1401 EXPORT_SYMBOL(ieee80211_sta_set_buffered);
1402 
1403 int sta_info_move_state(struct sta_info *sta,
1404 			enum ieee80211_sta_state new_state)
1405 {
1406 	might_sleep();
1407 
1408 	if (sta->sta_state == new_state)
1409 		return 0;
1410 
1411 	switch (new_state) {
1412 	case IEEE80211_STA_NONE:
1413 		if (sta->sta_state == IEEE80211_STA_AUTH)
1414 			clear_bit(WLAN_STA_AUTH, &sta->_flags);
1415 		else
1416 			return -EINVAL;
1417 		break;
1418 	case IEEE80211_STA_AUTH:
1419 		if (sta->sta_state == IEEE80211_STA_NONE)
1420 			set_bit(WLAN_STA_AUTH, &sta->_flags);
1421 		else if (sta->sta_state == IEEE80211_STA_ASSOC)
1422 			clear_bit(WLAN_STA_ASSOC, &sta->_flags);
1423 		else
1424 			return -EINVAL;
1425 		break;
1426 	case IEEE80211_STA_ASSOC:
1427 		if (sta->sta_state == IEEE80211_STA_AUTH) {
1428 			set_bit(WLAN_STA_ASSOC, &sta->_flags);
1429 		} else if (sta->sta_state == IEEE80211_STA_AUTHORIZED) {
1430 			if (sta->sdata->vif.type == NL80211_IFTYPE_AP)
1431 				atomic_dec(&sta->sdata->u.ap.num_sta_authorized);
1432 			clear_bit(WLAN_STA_AUTHORIZED, &sta->_flags);
1433 		} else
1434 			return -EINVAL;
1435 		break;
1436 	case IEEE80211_STA_AUTHORIZED:
1437 		if (sta->sta_state == IEEE80211_STA_ASSOC) {
1438 			if (sta->sdata->vif.type == NL80211_IFTYPE_AP)
1439 				atomic_inc(&sta->sdata->u.ap.num_sta_authorized);
1440 			set_bit(WLAN_STA_AUTHORIZED, &sta->_flags);
1441 		} else
1442 			return -EINVAL;
1443 		break;
1444 	default:
1445 		WARN(1, "invalid state %d", new_state);
1446 		return -EINVAL;
1447 	}
1448 
1449 	printk(KERN_DEBUG "%s: moving STA %pM to state %d\n",
1450 		sta->sdata->name, sta->sta.addr, new_state);
1451 	sta->sta_state = new_state;
1452 
1453 	return 0;
1454 }
1455