xref: /openbmc/linux/net/mac80211/status.c (revision 39b6f3aa)
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 		len += 2;
240 
241 	/* IEEE80211_RADIOTAP_TX_FLAGS */
242 	len += 2;
243 
244 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
245 	len += 1;
246 
247 	/* IEEE80211_TX_RC_MCS */
248 	if (info->status.rates[0].idx >= 0 &&
249 	    info->status.rates[0].flags & IEEE80211_TX_RC_MCS)
250 		len += 3;
251 
252 	return len;
253 }
254 
255 static void ieee80211_add_tx_radiotap_header(struct ieee80211_supported_band
256 					     *sband, struct sk_buff *skb,
257 					     int retry_count, int rtap_len)
258 {
259 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
260 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
261 	struct ieee80211_radiotap_header *rthdr;
262 	unsigned char *pos;
263 	u16 txflags;
264 
265 	rthdr = (struct ieee80211_radiotap_header *) skb_push(skb, rtap_len);
266 
267 	memset(rthdr, 0, rtap_len);
268 	rthdr->it_len = cpu_to_le16(rtap_len);
269 	rthdr->it_present =
270 		cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
271 			    (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
272 	pos = (unsigned char *)(rthdr + 1);
273 
274 	/*
275 	 * XXX: Once radiotap gets the bitmap reset thing the vendor
276 	 *	extensions proposal contains, we can actually report
277 	 *	the whole set of tries we did.
278 	 */
279 
280 	/* IEEE80211_RADIOTAP_RATE */
281 	if (info->status.rates[0].idx >= 0 &&
282 	    !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS)) {
283 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
284 		*pos = sband->bitrates[info->status.rates[0].idx].bitrate / 5;
285 		/* padding for tx flags */
286 		pos += 2;
287 	}
288 
289 	/* IEEE80211_RADIOTAP_TX_FLAGS */
290 	txflags = 0;
291 	if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
292 	    !is_multicast_ether_addr(hdr->addr1))
293 		txflags |= IEEE80211_RADIOTAP_F_TX_FAIL;
294 
295 	if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) ||
296 	    (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
297 		txflags |= IEEE80211_RADIOTAP_F_TX_CTS;
298 	else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
299 		txflags |= IEEE80211_RADIOTAP_F_TX_RTS;
300 
301 	put_unaligned_le16(txflags, pos);
302 	pos += 2;
303 
304 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
305 	/* for now report the total retry_count */
306 	*pos = retry_count;
307 	pos++;
308 
309 	/* IEEE80211_TX_RC_MCS */
310 	if (info->status.rates[0].idx >= 0 &&
311 	    info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
312 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
313 		pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
314 			 IEEE80211_RADIOTAP_MCS_HAVE_GI |
315 			 IEEE80211_RADIOTAP_MCS_HAVE_BW;
316 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
317 			pos[1] |= IEEE80211_RADIOTAP_MCS_SGI;
318 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
319 			pos[1] |= IEEE80211_RADIOTAP_MCS_BW_40;
320 		if (info->status.rates[0].flags & IEEE80211_TX_RC_GREEN_FIELD)
321 			pos[1] |= IEEE80211_RADIOTAP_MCS_FMT_GF;
322 		pos[2] = info->status.rates[0].idx;
323 		pos += 3;
324 	}
325 
326 }
327 
328 static void ieee80211_report_used_skb(struct ieee80211_local *local,
329 				      struct sk_buff *skb, bool dropped)
330 {
331 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
332 	struct ieee80211_hdr *hdr = (void *)skb->data;
333 	bool acked = info->flags & IEEE80211_TX_STAT_ACK;
334 
335 	if (dropped)
336 		acked = false;
337 
338 	if (info->flags & (IEEE80211_TX_INTFL_NL80211_FRAME_TX |
339 			   IEEE80211_TX_INTFL_MLME_CONN_TX)) {
340 		struct ieee80211_sub_if_data *sdata = NULL;
341 		struct ieee80211_sub_if_data *iter_sdata;
342 		u64 cookie = (unsigned long)skb;
343 
344 		rcu_read_lock();
345 
346 		if (skb->dev) {
347 			list_for_each_entry_rcu(iter_sdata, &local->interfaces,
348 						list) {
349 				if (!iter_sdata->dev)
350 					continue;
351 
352 				if (skb->dev == iter_sdata->dev) {
353 					sdata = iter_sdata;
354 					break;
355 				}
356 			}
357 		} else {
358 			sdata = rcu_dereference(local->p2p_sdata);
359 		}
360 
361 		if (!sdata) {
362 			skb->dev = NULL;
363 		} else if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) {
364 			ieee80211_mgd_conn_tx_status(sdata, hdr->frame_control,
365 						     acked);
366 		} else if (ieee80211_is_nullfunc(hdr->frame_control) ||
367 			   ieee80211_is_qos_nullfunc(hdr->frame_control)) {
368 			cfg80211_probe_status(sdata->dev, hdr->addr1,
369 					      cookie, acked, GFP_ATOMIC);
370 		} else {
371 			cfg80211_mgmt_tx_status(&sdata->wdev, cookie, skb->data,
372 						skb->len, acked, GFP_ATOMIC);
373 		}
374 
375 		rcu_read_unlock();
376 	}
377 
378 	if (unlikely(info->ack_frame_id)) {
379 		struct sk_buff *ack_skb;
380 		unsigned long flags;
381 
382 		spin_lock_irqsave(&local->ack_status_lock, flags);
383 		ack_skb = idr_find(&local->ack_status_frames,
384 				   info->ack_frame_id);
385 		if (ack_skb)
386 			idr_remove(&local->ack_status_frames,
387 				   info->ack_frame_id);
388 		spin_unlock_irqrestore(&local->ack_status_lock, flags);
389 
390 		if (ack_skb) {
391 			if (!dropped) {
392 				/* consumes ack_skb */
393 				skb_complete_wifi_ack(ack_skb, acked);
394 			} else {
395 				dev_kfree_skb_any(ack_skb);
396 			}
397 		}
398 	}
399 }
400 
401 /*
402  * Use a static threshold for now, best value to be determined
403  * by testing ...
404  * Should it depend on:
405  *  - on # of retransmissions
406  *  - current throughput (higher value for higher tpt)?
407  */
408 #define STA_LOST_PKT_THRESHOLD	50
409 
410 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
411 {
412 	struct sk_buff *skb2;
413 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
414 	struct ieee80211_local *local = hw_to_local(hw);
415 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
416 	__le16 fc;
417 	struct ieee80211_supported_band *sband;
418 	struct ieee80211_sub_if_data *sdata;
419 	struct net_device *prev_dev = NULL;
420 	struct sta_info *sta, *tmp;
421 	int retry_count = -1, i;
422 	int rates_idx = -1;
423 	bool send_to_cooked;
424 	bool acked;
425 	struct ieee80211_bar *bar;
426 	int rtap_len;
427 
428 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
429 		if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
430 		    !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
431 			/* just the first aggr frame carry status info */
432 			info->status.rates[i].idx = -1;
433 			info->status.rates[i].count = 0;
434 			break;
435 		} else if (info->status.rates[i].idx < 0) {
436 			break;
437 		} else if (i >= hw->max_report_rates) {
438 			/* the HW cannot have attempted that rate */
439 			info->status.rates[i].idx = -1;
440 			info->status.rates[i].count = 0;
441 			break;
442 		}
443 
444 		retry_count += info->status.rates[i].count;
445 	}
446 	rates_idx = i - 1;
447 
448 	if (retry_count < 0)
449 		retry_count = 0;
450 
451 	rcu_read_lock();
452 
453 	sband = local->hw.wiphy->bands[info->band];
454 	fc = hdr->frame_control;
455 
456 	for_each_sta_info(local, hdr->addr1, sta, tmp) {
457 		/* skip wrong virtual interface */
458 		if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
459 			continue;
460 
461 		if (info->flags & IEEE80211_TX_STATUS_EOSP)
462 			clear_sta_flag(sta, WLAN_STA_SP);
463 
464 		acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
465 		if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
466 			/*
467 			 * The STA is in power save mode, so assume
468 			 * that this TX packet failed because of that.
469 			 */
470 			ieee80211_handle_filtered_frame(local, sta, skb);
471 			rcu_read_unlock();
472 			return;
473 		}
474 
475 		/* mesh Peer Service Period support */
476 		if (ieee80211_vif_is_mesh(&sta->sdata->vif) &&
477 		    ieee80211_is_data_qos(fc))
478 			ieee80211_mpsp_trigger_process(
479 					ieee80211_get_qos_ctl(hdr),
480 					sta, true, acked);
481 
482 		if ((local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) &&
483 		    (rates_idx != -1))
484 			sta->last_tx_rate = info->status.rates[rates_idx];
485 
486 		if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
487 		    (ieee80211_is_data_qos(fc))) {
488 			u16 tid, ssn;
489 			u8 *qc;
490 
491 			qc = ieee80211_get_qos_ctl(hdr);
492 			tid = qc[0] & 0xf;
493 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
494 						& IEEE80211_SCTL_SEQ);
495 			ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
496 					   tid, ssn);
497 		}
498 
499 		if (!acked && ieee80211_is_back_req(fc)) {
500 			u16 tid, control;
501 
502 			/*
503 			 * BAR failed, store the last SSN and retry sending
504 			 * the BAR when the next unicast transmission on the
505 			 * same TID succeeds.
506 			 */
507 			bar = (struct ieee80211_bar *) skb->data;
508 			control = le16_to_cpu(bar->control);
509 			if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
510 				u16 ssn = le16_to_cpu(bar->start_seq_num);
511 
512 				tid = (control &
513 				       IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
514 				      IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
515 
516 				ieee80211_set_bar_pending(sta, tid, ssn);
517 			}
518 		}
519 
520 		if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
521 			ieee80211_handle_filtered_frame(local, sta, skb);
522 			rcu_read_unlock();
523 			return;
524 		} else {
525 			if (!acked)
526 				sta->tx_retry_failed++;
527 			sta->tx_retry_count += retry_count;
528 		}
529 
530 		rate_control_tx_status(local, sband, sta, skb);
531 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
532 			ieee80211s_update_metric(local, sta, skb);
533 
534 		if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
535 			ieee80211_frame_acked(sta, skb);
536 
537 		if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
538 		    (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS))
539 			ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data, acked);
540 
541 		if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) {
542 			if (info->flags & IEEE80211_TX_STAT_ACK) {
543 				if (sta->lost_packets)
544 					sta->lost_packets = 0;
545 			} else if (++sta->lost_packets >= STA_LOST_PKT_THRESHOLD) {
546 				cfg80211_cqm_pktloss_notify(sta->sdata->dev,
547 							    sta->sta.addr,
548 							    sta->lost_packets,
549 							    GFP_ATOMIC);
550 				sta->lost_packets = 0;
551 			}
552 		}
553 
554 		if (acked)
555 			sta->last_ack_signal = info->status.ack_signal;
556 	}
557 
558 	rcu_read_unlock();
559 
560 	ieee80211_led_tx(local, 0);
561 
562 	/* SNMP counters
563 	 * Fragments are passed to low-level drivers as separate skbs, so these
564 	 * are actually fragments, not frames. Update frame counters only for
565 	 * the first fragment of the frame. */
566 	if (info->flags & IEEE80211_TX_STAT_ACK) {
567 		if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
568 			local->dot11TransmittedFrameCount++;
569 			if (is_multicast_ether_addr(hdr->addr1))
570 				local->dot11MulticastTransmittedFrameCount++;
571 			if (retry_count > 0)
572 				local->dot11RetryCount++;
573 			if (retry_count > 1)
574 				local->dot11MultipleRetryCount++;
575 		}
576 
577 		/* This counter shall be incremented for an acknowledged MPDU
578 		 * with an individual address in the address 1 field or an MPDU
579 		 * with a multicast address in the address 1 field of type Data
580 		 * or Management. */
581 		if (!is_multicast_ether_addr(hdr->addr1) ||
582 		    ieee80211_is_data(fc) ||
583 		    ieee80211_is_mgmt(fc))
584 			local->dot11TransmittedFragmentCount++;
585 	} else {
586 		if (ieee80211_is_first_frag(hdr->seq_ctrl))
587 			local->dot11FailedCount++;
588 	}
589 
590 	if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
591 	    (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) &&
592 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
593 	    local->ps_sdata && !(local->scanning)) {
594 		if (info->flags & IEEE80211_TX_STAT_ACK) {
595 			local->ps_sdata->u.mgd.flags |=
596 					IEEE80211_STA_NULLFUNC_ACKED;
597 		} else
598 			mod_timer(&local->dynamic_ps_timer, jiffies +
599 					msecs_to_jiffies(10));
600 	}
601 
602 	ieee80211_report_used_skb(local, skb, false);
603 
604 	/* this was a transmitted frame, but now we want to reuse it */
605 	skb_orphan(skb);
606 
607 	/* Need to make a copy before skb->cb gets cleared */
608 	send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
609 			 !(ieee80211_is_data(fc));
610 
611 	/*
612 	 * This is a bit racy but we can avoid a lot of work
613 	 * with this test...
614 	 */
615 	if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
616 		dev_kfree_skb(skb);
617 		return;
618 	}
619 
620 	/* send frame to monitor interfaces now */
621 	rtap_len = ieee80211_tx_radiotap_len(info);
622 	if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
623 		pr_err("ieee80211_tx_status: headroom too small\n");
624 		dev_kfree_skb(skb);
625 		return;
626 	}
627 	ieee80211_add_tx_radiotap_header(sband, skb, retry_count, rtap_len);
628 
629 	/* XXX: is this sufficient for BPF? */
630 	skb_set_mac_header(skb, 0);
631 	skb->ip_summed = CHECKSUM_UNNECESSARY;
632 	skb->pkt_type = PACKET_OTHERHOST;
633 	skb->protocol = htons(ETH_P_802_2);
634 	memset(skb->cb, 0, sizeof(skb->cb));
635 
636 	rcu_read_lock();
637 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
638 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
639 			if (!ieee80211_sdata_running(sdata))
640 				continue;
641 
642 			if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) &&
643 			    !send_to_cooked)
644 				continue;
645 
646 			if (prev_dev) {
647 				skb2 = skb_clone(skb, GFP_ATOMIC);
648 				if (skb2) {
649 					skb2->dev = prev_dev;
650 					netif_rx(skb2);
651 				}
652 			}
653 
654 			prev_dev = sdata->dev;
655 		}
656 	}
657 	if (prev_dev) {
658 		skb->dev = prev_dev;
659 		netif_rx(skb);
660 		skb = NULL;
661 	}
662 	rcu_read_unlock();
663 	dev_kfree_skb(skb);
664 }
665 EXPORT_SYMBOL(ieee80211_tx_status);
666 
667 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
668 {
669 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
670 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
671 				    num_packets, GFP_ATOMIC);
672 }
673 EXPORT_SYMBOL(ieee80211_report_low_ack);
674 
675 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
676 {
677 	struct ieee80211_local *local = hw_to_local(hw);
678 
679 	ieee80211_report_used_skb(local, skb, true);
680 	dev_kfree_skb_any(skb);
681 }
682 EXPORT_SYMBOL(ieee80211_free_txskb);
683 
684 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
685 			      struct sk_buff_head *skbs)
686 {
687 	struct sk_buff *skb;
688 
689 	while ((skb = __skb_dequeue(skbs)))
690 		ieee80211_free_txskb(hw, skb);
691 }
692