xref: /openbmc/linux/net/mac80211/status.c (revision 089a49b6)
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
5  * Copyright 2008-2010	Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/export.h>
13 #include <linux/etherdevice.h>
14 #include <net/mac80211.h>
15 #include <asm/unaligned.h>
16 #include "ieee80211_i.h"
17 #include "rate.h"
18 #include "mesh.h"
19 #include "led.h"
20 #include "wme.h"
21 
22 
23 void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
24 				 struct sk_buff *skb)
25 {
26 	struct ieee80211_local *local = hw_to_local(hw);
27 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
28 	int tmp;
29 
30 	skb->pkt_type = IEEE80211_TX_STATUS_MSG;
31 	skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ?
32 		       &local->skb_queue : &local->skb_queue_unreliable, skb);
33 	tmp = skb_queue_len(&local->skb_queue) +
34 		skb_queue_len(&local->skb_queue_unreliable);
35 	while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
36 	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
37 		ieee80211_free_txskb(hw, skb);
38 		tmp--;
39 		I802_DEBUG_INC(local->tx_status_drop);
40 	}
41 	tasklet_schedule(&local->tasklet);
42 }
43 EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);
44 
45 static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
46 					    struct sta_info *sta,
47 					    struct sk_buff *skb)
48 {
49 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
50 	struct ieee80211_hdr *hdr = (void *)skb->data;
51 	int ac;
52 
53 	/*
54 	 * This skb 'survived' a round-trip through the driver, and
55 	 * hopefully the driver didn't mangle it too badly. However,
56 	 * we can definitely not rely on the control information
57 	 * being correct. Clear it so we don't get junk there, and
58 	 * indicate that it needs new processing, but must not be
59 	 * modified/encrypted again.
60 	 */
61 	memset(&info->control, 0, sizeof(info->control));
62 
63 	info->control.jiffies = jiffies;
64 	info->control.vif = &sta->sdata->vif;
65 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
66 		       IEEE80211_TX_INTFL_RETRANSMISSION;
67 	info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
68 
69 	sta->tx_filtered_count++;
70 
71 	/*
72 	 * Clear more-data bit on filtered frames, it might be set
73 	 * but later frames might time out so it might have to be
74 	 * clear again ... It's all rather unlikely (this frame
75 	 * should time out first, right?) but let's not confuse
76 	 * peers unnecessarily.
77 	 */
78 	if (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_MOREDATA))
79 		hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_MOREDATA);
80 
81 	if (ieee80211_is_data_qos(hdr->frame_control)) {
82 		u8 *p = ieee80211_get_qos_ctl(hdr);
83 		int tid = *p & IEEE80211_QOS_CTL_TID_MASK;
84 
85 		/*
86 		 * Clear EOSP if set, this could happen e.g.
87 		 * if an absence period (us being a P2P GO)
88 		 * shortens the SP.
89 		 */
90 		if (*p & IEEE80211_QOS_CTL_EOSP)
91 			*p &= ~IEEE80211_QOS_CTL_EOSP;
92 		ac = ieee802_1d_to_ac[tid & 7];
93 	} else {
94 		ac = IEEE80211_AC_BE;
95 	}
96 
97 	/*
98 	 * Clear the TX filter mask for this STA when sending the next
99 	 * packet. If the STA went to power save mode, this will happen
100 	 * when it wakes up for the next time.
101 	 */
102 	set_sta_flag(sta, WLAN_STA_CLEAR_PS_FILT);
103 
104 	/*
105 	 * This code races in the following way:
106 	 *
107 	 *  (1) STA sends frame indicating it will go to sleep and does so
108 	 *  (2) hardware/firmware adds STA to filter list, passes frame up
109 	 *  (3) hardware/firmware processes TX fifo and suppresses a frame
110 	 *  (4) we get TX status before having processed the frame and
111 	 *	knowing that the STA has gone to sleep.
112 	 *
113 	 * This is actually quite unlikely even when both those events are
114 	 * processed from interrupts coming in quickly after one another or
115 	 * even at the same time because we queue both TX status events and
116 	 * RX frames to be processed by a tasklet and process them in the
117 	 * same order that they were received or TX status last. Hence, there
118 	 * is no race as long as the frame RX is processed before the next TX
119 	 * status, which drivers can ensure, see below.
120 	 *
121 	 * Note that this can only happen if the hardware or firmware can
122 	 * actually add STAs to the filter list, if this is done by the
123 	 * driver in response to set_tim() (which will only reduce the race
124 	 * this whole filtering tries to solve, not completely solve it)
125 	 * this situation cannot happen.
126 	 *
127 	 * To completely solve this race drivers need to make sure that they
128 	 *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
129 	 *	functions and
130 	 *  (b) always process RX events before TX status events if ordering
131 	 *      can be unknown, for example with different interrupt status
132 	 *	bits.
133 	 *  (c) if PS mode transitions are manual (i.e. the flag
134 	 *      %IEEE80211_HW_AP_LINK_PS is set), always process PS state
135 	 *      changes before calling TX status events if ordering can be
136 	 *	unknown.
137 	 */
138 	if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
139 	    skb_queue_len(&sta->tx_filtered[ac]) < STA_MAX_TX_BUFFER) {
140 		skb_queue_tail(&sta->tx_filtered[ac], skb);
141 		sta_info_recalc_tim(sta);
142 
143 		if (!timer_pending(&local->sta_cleanup))
144 			mod_timer(&local->sta_cleanup,
145 				  round_jiffies(jiffies +
146 						STA_INFO_CLEANUP_INTERVAL));
147 		return;
148 	}
149 
150 	if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
151 	    !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
152 		/* Software retry the packet once */
153 		info->flags |= IEEE80211_TX_INTFL_RETRIED;
154 		ieee80211_add_pending_skb(local, skb);
155 		return;
156 	}
157 
158 	ps_dbg_ratelimited(sta->sdata,
159 			   "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n",
160 			   skb_queue_len(&sta->tx_filtered[ac]),
161 			   !!test_sta_flag(sta, WLAN_STA_PS_STA), jiffies);
162 	ieee80211_free_txskb(&local->hw, skb);
163 }
164 
165 static void ieee80211_check_pending_bar(struct sta_info *sta, u8 *addr, u8 tid)
166 {
167 	struct tid_ampdu_tx *tid_tx;
168 
169 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
170 	if (!tid_tx || !tid_tx->bar_pending)
171 		return;
172 
173 	tid_tx->bar_pending = false;
174 	ieee80211_send_bar(&sta->sdata->vif, addr, tid, tid_tx->failed_bar_ssn);
175 }
176 
177 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
178 {
179 	struct ieee80211_mgmt *mgmt = (void *) skb->data;
180 	struct ieee80211_local *local = sta->local;
181 	struct ieee80211_sub_if_data *sdata = sta->sdata;
182 
183 	if (ieee80211_is_data_qos(mgmt->frame_control)) {
184 		struct ieee80211_hdr *hdr = (void *) skb->data;
185 		u8 *qc = ieee80211_get_qos_ctl(hdr);
186 		u16 tid = qc[0] & 0xf;
187 
188 		ieee80211_check_pending_bar(sta, hdr->addr1, tid);
189 	}
190 
191 	if (ieee80211_is_action(mgmt->frame_control) &&
192 	    mgmt->u.action.category == WLAN_CATEGORY_HT &&
193 	    mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS &&
194 	    sdata->vif.type == NL80211_IFTYPE_STATION &&
195 	    ieee80211_sdata_running(sdata)) {
196 		/*
197 		 * This update looks racy, but isn't -- if we come
198 		 * here we've definitely got a station that we're
199 		 * talking to, and on a managed interface that can
200 		 * only be the AP. And the only other place updating
201 		 * this variable in managed mode is before association.
202 		 */
203 		switch (mgmt->u.action.u.ht_smps.smps_control) {
204 		case WLAN_HT_SMPS_CONTROL_DYNAMIC:
205 			sdata->smps_mode = IEEE80211_SMPS_DYNAMIC;
206 			break;
207 		case WLAN_HT_SMPS_CONTROL_STATIC:
208 			sdata->smps_mode = IEEE80211_SMPS_STATIC;
209 			break;
210 		case WLAN_HT_SMPS_CONTROL_DISABLED:
211 		default: /* shouldn't happen since we don't send that */
212 			sdata->smps_mode = IEEE80211_SMPS_OFF;
213 			break;
214 		}
215 
216 		ieee80211_queue_work(&local->hw, &sdata->recalc_smps);
217 	}
218 }
219 
220 static void ieee80211_set_bar_pending(struct sta_info *sta, u8 tid, u16 ssn)
221 {
222 	struct tid_ampdu_tx *tid_tx;
223 
224 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
225 	if (!tid_tx)
226 		return;
227 
228 	tid_tx->failed_bar_ssn = ssn;
229 	tid_tx->bar_pending = true;
230 }
231 
232 static int ieee80211_tx_radiotap_len(struct ieee80211_tx_info *info)
233 {
234 	int len = sizeof(struct ieee80211_radiotap_header);
235 
236 	/* IEEE80211_RADIOTAP_RATE rate */
237 	if (info->status.rates[0].idx >= 0 &&
238 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
239 					     IEEE80211_TX_RC_VHT_MCS)))
240 		len += 2;
241 
242 	/* IEEE80211_RADIOTAP_TX_FLAGS */
243 	len += 2;
244 
245 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
246 	len += 1;
247 
248 	/* IEEE80211_RADIOTAP_MCS
249 	 * IEEE80211_RADIOTAP_VHT */
250 	if (info->status.rates[0].idx >= 0) {
251 		if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS)
252 			len += 3;
253 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS)
254 			len = ALIGN(len, 2) + 12;
255 	}
256 
257 	return len;
258 }
259 
260 static void
261 ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
262 				 struct ieee80211_supported_band *sband,
263 				 struct sk_buff *skb, int retry_count,
264 				 int rtap_len, int shift)
265 {
266 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
267 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
268 	struct ieee80211_radiotap_header *rthdr;
269 	unsigned char *pos;
270 	u16 txflags;
271 
272 	rthdr = (struct ieee80211_radiotap_header *) skb_push(skb, rtap_len);
273 
274 	memset(rthdr, 0, rtap_len);
275 	rthdr->it_len = cpu_to_le16(rtap_len);
276 	rthdr->it_present =
277 		cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
278 			    (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
279 	pos = (unsigned char *)(rthdr + 1);
280 
281 	/*
282 	 * XXX: Once radiotap gets the bitmap reset thing the vendor
283 	 *	extensions proposal contains, we can actually report
284 	 *	the whole set of tries we did.
285 	 */
286 
287 	/* IEEE80211_RADIOTAP_RATE */
288 	if (info->status.rates[0].idx >= 0 &&
289 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
290 					     IEEE80211_TX_RC_VHT_MCS))) {
291 		u16 rate;
292 
293 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
294 		rate = sband->bitrates[info->status.rates[0].idx].bitrate;
295 		*pos = DIV_ROUND_UP(rate, 5 * (1 << shift));
296 		/* padding for tx flags */
297 		pos += 2;
298 	}
299 
300 	/* IEEE80211_RADIOTAP_TX_FLAGS */
301 	txflags = 0;
302 	if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
303 	    !is_multicast_ether_addr(hdr->addr1))
304 		txflags |= IEEE80211_RADIOTAP_F_TX_FAIL;
305 
306 	if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) ||
307 	    (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
308 		txflags |= IEEE80211_RADIOTAP_F_TX_CTS;
309 	else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
310 		txflags |= IEEE80211_RADIOTAP_F_TX_RTS;
311 
312 	put_unaligned_le16(txflags, pos);
313 	pos += 2;
314 
315 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
316 	/* for now report the total retry_count */
317 	*pos = retry_count;
318 	pos++;
319 
320 	if (info->status.rates[0].idx < 0)
321 		return;
322 
323 	/* IEEE80211_RADIOTAP_MCS
324 	 * IEEE80211_RADIOTAP_VHT */
325 	if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
326 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
327 		pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
328 			 IEEE80211_RADIOTAP_MCS_HAVE_GI |
329 			 IEEE80211_RADIOTAP_MCS_HAVE_BW;
330 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
331 			pos[1] |= IEEE80211_RADIOTAP_MCS_SGI;
332 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
333 			pos[1] |= IEEE80211_RADIOTAP_MCS_BW_40;
334 		if (info->status.rates[0].flags & IEEE80211_TX_RC_GREEN_FIELD)
335 			pos[1] |= IEEE80211_RADIOTAP_MCS_FMT_GF;
336 		pos[2] = info->status.rates[0].idx;
337 		pos += 3;
338 	} else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS) {
339 		u16 known = local->hw.radiotap_vht_details &
340 			(IEEE80211_RADIOTAP_VHT_KNOWN_GI |
341 			 IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH);
342 
343 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
344 
345 		/* required alignment from rthdr */
346 		pos = (u8 *)rthdr + ALIGN(pos - (u8 *)rthdr, 2);
347 
348 		/* u16 known - IEEE80211_RADIOTAP_VHT_KNOWN_* */
349 		put_unaligned_le16(known, pos);
350 		pos += 2;
351 
352 		/* u8 flags - IEEE80211_RADIOTAP_VHT_FLAG_* */
353 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
354 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
355 		pos++;
356 
357 		/* u8 bandwidth */
358 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
359 			*pos = 1;
360 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_80_MHZ_WIDTH)
361 			*pos = 4;
362 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_160_MHZ_WIDTH)
363 			*pos = 11;
364 		else /* IEEE80211_TX_RC_{20_MHZ_WIDTH,FIXME:DUP_DATA} */
365 			*pos = 0;
366 		pos++;
367 
368 		/* u8 mcs_nss[4] */
369 		*pos = (ieee80211_rate_get_vht_mcs(&info->status.rates[0]) << 4) |
370 			ieee80211_rate_get_vht_nss(&info->status.rates[0]);
371 		pos += 4;
372 
373 		/* u8 coding */
374 		pos++;
375 		/* u8 group_id */
376 		pos++;
377 		/* u16 partial_aid */
378 		pos += 2;
379 	}
380 }
381 
382 static void ieee80211_report_used_skb(struct ieee80211_local *local,
383 				      struct sk_buff *skb, bool dropped)
384 {
385 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
386 	struct ieee80211_hdr *hdr = (void *)skb->data;
387 	bool acked = info->flags & IEEE80211_TX_STAT_ACK;
388 
389 	if (dropped)
390 		acked = false;
391 
392 	if (info->flags & (IEEE80211_TX_INTFL_NL80211_FRAME_TX |
393 			   IEEE80211_TX_INTFL_MLME_CONN_TX)) {
394 		struct ieee80211_sub_if_data *sdata = NULL;
395 		struct ieee80211_sub_if_data *iter_sdata;
396 		u64 cookie = (unsigned long)skb;
397 
398 		rcu_read_lock();
399 
400 		if (skb->dev) {
401 			list_for_each_entry_rcu(iter_sdata, &local->interfaces,
402 						list) {
403 				if (!iter_sdata->dev)
404 					continue;
405 
406 				if (skb->dev == iter_sdata->dev) {
407 					sdata = iter_sdata;
408 					break;
409 				}
410 			}
411 		} else {
412 			sdata = rcu_dereference(local->p2p_sdata);
413 		}
414 
415 		if (!sdata) {
416 			skb->dev = NULL;
417 		} else if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) {
418 			ieee80211_mgd_conn_tx_status(sdata, hdr->frame_control,
419 						     acked);
420 		} else if (ieee80211_is_nullfunc(hdr->frame_control) ||
421 			   ieee80211_is_qos_nullfunc(hdr->frame_control)) {
422 			cfg80211_probe_status(sdata->dev, hdr->addr1,
423 					      cookie, acked, GFP_ATOMIC);
424 		} else {
425 			cfg80211_mgmt_tx_status(&sdata->wdev, cookie, skb->data,
426 						skb->len, acked, GFP_ATOMIC);
427 		}
428 
429 		rcu_read_unlock();
430 	}
431 
432 	if (unlikely(info->ack_frame_id)) {
433 		struct sk_buff *ack_skb;
434 		unsigned long flags;
435 
436 		spin_lock_irqsave(&local->ack_status_lock, flags);
437 		ack_skb = idr_find(&local->ack_status_frames,
438 				   info->ack_frame_id);
439 		if (ack_skb)
440 			idr_remove(&local->ack_status_frames,
441 				   info->ack_frame_id);
442 		spin_unlock_irqrestore(&local->ack_status_lock, flags);
443 
444 		if (ack_skb) {
445 			if (!dropped) {
446 				/* consumes ack_skb */
447 				skb_complete_wifi_ack(ack_skb, acked);
448 			} else {
449 				dev_kfree_skb_any(ack_skb);
450 			}
451 		}
452 	}
453 }
454 
455 /*
456  * Use a static threshold for now, best value to be determined
457  * by testing ...
458  * Should it depend on:
459  *  - on # of retransmissions
460  *  - current throughput (higher value for higher tpt)?
461  */
462 #define STA_LOST_PKT_THRESHOLD	50
463 
464 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
465 {
466 	struct sk_buff *skb2;
467 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
468 	struct ieee80211_local *local = hw_to_local(hw);
469 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
470 	__le16 fc;
471 	struct ieee80211_supported_band *sband;
472 	struct ieee80211_sub_if_data *sdata;
473 	struct net_device *prev_dev = NULL;
474 	struct sta_info *sta, *tmp;
475 	int retry_count = -1, i;
476 	int rates_idx = -1;
477 	bool send_to_cooked;
478 	bool acked;
479 	struct ieee80211_bar *bar;
480 	int rtap_len;
481 	int shift = 0;
482 
483 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
484 		if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
485 		    !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
486 			/* just the first aggr frame carry status info */
487 			info->status.rates[i].idx = -1;
488 			info->status.rates[i].count = 0;
489 			break;
490 		} else if (info->status.rates[i].idx < 0) {
491 			break;
492 		} else if (i >= hw->max_report_rates) {
493 			/* the HW cannot have attempted that rate */
494 			info->status.rates[i].idx = -1;
495 			info->status.rates[i].count = 0;
496 			break;
497 		}
498 
499 		retry_count += info->status.rates[i].count;
500 	}
501 	rates_idx = i - 1;
502 
503 	if (retry_count < 0)
504 		retry_count = 0;
505 
506 	rcu_read_lock();
507 
508 	sband = local->hw.wiphy->bands[info->band];
509 	fc = hdr->frame_control;
510 
511 	for_each_sta_info(local, hdr->addr1, sta, tmp) {
512 		/* skip wrong virtual interface */
513 		if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
514 			continue;
515 
516 		shift = ieee80211_vif_get_shift(&sta->sdata->vif);
517 
518 		if (info->flags & IEEE80211_TX_STATUS_EOSP)
519 			clear_sta_flag(sta, WLAN_STA_SP);
520 
521 		acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
522 		if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
523 			/*
524 			 * The STA is in power save mode, so assume
525 			 * that this TX packet failed because of that.
526 			 */
527 			ieee80211_handle_filtered_frame(local, sta, skb);
528 			rcu_read_unlock();
529 			return;
530 		}
531 
532 		/* mesh Peer Service Period support */
533 		if (ieee80211_vif_is_mesh(&sta->sdata->vif) &&
534 		    ieee80211_is_data_qos(fc))
535 			ieee80211_mpsp_trigger_process(
536 					ieee80211_get_qos_ctl(hdr),
537 					sta, true, acked);
538 
539 		if ((local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) &&
540 		    (rates_idx != -1))
541 			sta->last_tx_rate = info->status.rates[rates_idx];
542 
543 		if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
544 		    (ieee80211_is_data_qos(fc))) {
545 			u16 tid, ssn;
546 			u8 *qc;
547 
548 			qc = ieee80211_get_qos_ctl(hdr);
549 			tid = qc[0] & 0xf;
550 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
551 						& IEEE80211_SCTL_SEQ);
552 			ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
553 					   tid, ssn);
554 		}
555 
556 		if (!acked && ieee80211_is_back_req(fc)) {
557 			u16 tid, control;
558 
559 			/*
560 			 * BAR failed, store the last SSN and retry sending
561 			 * the BAR when the next unicast transmission on the
562 			 * same TID succeeds.
563 			 */
564 			bar = (struct ieee80211_bar *) skb->data;
565 			control = le16_to_cpu(bar->control);
566 			if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
567 				u16 ssn = le16_to_cpu(bar->start_seq_num);
568 
569 				tid = (control &
570 				       IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
571 				      IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
572 
573 				ieee80211_set_bar_pending(sta, tid, ssn);
574 			}
575 		}
576 
577 		if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
578 			ieee80211_handle_filtered_frame(local, sta, skb);
579 			rcu_read_unlock();
580 			return;
581 		} else {
582 			if (!acked)
583 				sta->tx_retry_failed++;
584 			sta->tx_retry_count += retry_count;
585 		}
586 
587 		rate_control_tx_status(local, sband, sta, skb);
588 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
589 			ieee80211s_update_metric(local, sta, skb);
590 
591 		if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
592 			ieee80211_frame_acked(sta, skb);
593 
594 		if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
595 		    (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS))
596 			ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data, acked);
597 
598 		if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) {
599 			if (info->flags & IEEE80211_TX_STAT_ACK) {
600 				if (sta->lost_packets)
601 					sta->lost_packets = 0;
602 			} else if (++sta->lost_packets >= STA_LOST_PKT_THRESHOLD) {
603 				cfg80211_cqm_pktloss_notify(sta->sdata->dev,
604 							    sta->sta.addr,
605 							    sta->lost_packets,
606 							    GFP_ATOMIC);
607 				sta->lost_packets = 0;
608 			}
609 		}
610 
611 		if (acked)
612 			sta->last_ack_signal = info->status.ack_signal;
613 	}
614 
615 	rcu_read_unlock();
616 
617 	ieee80211_led_tx(local);
618 
619 	/* SNMP counters
620 	 * Fragments are passed to low-level drivers as separate skbs, so these
621 	 * are actually fragments, not frames. Update frame counters only for
622 	 * the first fragment of the frame. */
623 	if (info->flags & IEEE80211_TX_STAT_ACK) {
624 		if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
625 			local->dot11TransmittedFrameCount++;
626 			if (is_multicast_ether_addr(hdr->addr1))
627 				local->dot11MulticastTransmittedFrameCount++;
628 			if (retry_count > 0)
629 				local->dot11RetryCount++;
630 			if (retry_count > 1)
631 				local->dot11MultipleRetryCount++;
632 		}
633 
634 		/* This counter shall be incremented for an acknowledged MPDU
635 		 * with an individual address in the address 1 field or an MPDU
636 		 * with a multicast address in the address 1 field of type Data
637 		 * or Management. */
638 		if (!is_multicast_ether_addr(hdr->addr1) ||
639 		    ieee80211_is_data(fc) ||
640 		    ieee80211_is_mgmt(fc))
641 			local->dot11TransmittedFragmentCount++;
642 	} else {
643 		if (ieee80211_is_first_frag(hdr->seq_ctrl))
644 			local->dot11FailedCount++;
645 	}
646 
647 	if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
648 	    (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) &&
649 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
650 	    local->ps_sdata && !(local->scanning)) {
651 		if (info->flags & IEEE80211_TX_STAT_ACK) {
652 			local->ps_sdata->u.mgd.flags |=
653 					IEEE80211_STA_NULLFUNC_ACKED;
654 		} else
655 			mod_timer(&local->dynamic_ps_timer, jiffies +
656 					msecs_to_jiffies(10));
657 	}
658 
659 	ieee80211_report_used_skb(local, skb, false);
660 
661 	/* this was a transmitted frame, but now we want to reuse it */
662 	skb_orphan(skb);
663 
664 	/* Need to make a copy before skb->cb gets cleared */
665 	send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
666 			 !(ieee80211_is_data(fc));
667 
668 	/*
669 	 * This is a bit racy but we can avoid a lot of work
670 	 * with this test...
671 	 */
672 	if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
673 		dev_kfree_skb(skb);
674 		return;
675 	}
676 
677 	/* send frame to monitor interfaces now */
678 	rtap_len = ieee80211_tx_radiotap_len(info);
679 	if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
680 		pr_err("ieee80211_tx_status: headroom too small\n");
681 		dev_kfree_skb(skb);
682 		return;
683 	}
684 	ieee80211_add_tx_radiotap_header(local, sband, skb, retry_count,
685 					 rtap_len, shift);
686 
687 	/* XXX: is this sufficient for BPF? */
688 	skb_set_mac_header(skb, 0);
689 	skb->ip_summed = CHECKSUM_UNNECESSARY;
690 	skb->pkt_type = PACKET_OTHERHOST;
691 	skb->protocol = htons(ETH_P_802_2);
692 	memset(skb->cb, 0, sizeof(skb->cb));
693 
694 	rcu_read_lock();
695 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
696 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
697 			if (!ieee80211_sdata_running(sdata))
698 				continue;
699 
700 			if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) &&
701 			    !send_to_cooked)
702 				continue;
703 
704 			if (prev_dev) {
705 				skb2 = skb_clone(skb, GFP_ATOMIC);
706 				if (skb2) {
707 					skb2->dev = prev_dev;
708 					netif_rx(skb2);
709 				}
710 			}
711 
712 			prev_dev = sdata->dev;
713 		}
714 	}
715 	if (prev_dev) {
716 		skb->dev = prev_dev;
717 		netif_rx(skb);
718 		skb = NULL;
719 	}
720 	rcu_read_unlock();
721 	dev_kfree_skb(skb);
722 }
723 EXPORT_SYMBOL(ieee80211_tx_status);
724 
725 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
726 {
727 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
728 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
729 				    num_packets, GFP_ATOMIC);
730 }
731 EXPORT_SYMBOL(ieee80211_report_low_ack);
732 
733 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
734 {
735 	struct ieee80211_local *local = hw_to_local(hw);
736 
737 	ieee80211_report_used_skb(local, skb, true);
738 	dev_kfree_skb_any(skb);
739 }
740 EXPORT_SYMBOL(ieee80211_free_txskb);
741 
742 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
743 			      struct sk_buff_head *skbs)
744 {
745 	struct sk_buff *skb;
746 
747 	while ((skb = __skb_dequeue(skbs)))
748 		ieee80211_free_txskb(hw, skb);
749 }
750