xref: /linux/net/mac80211/status.c (revision b68fc09be48edbc47de1a0f3d42ef8adf6c0ac55)
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  * Copyright 2013-2014  Intel Mobile Communications GmbH
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/export.h>
14 #include <linux/etherdevice.h>
15 #include <net/mac80211.h>
16 #include <asm/unaligned.h>
17 #include "ieee80211_i.h"
18 #include "rate.h"
19 #include "mesh.h"
20 #include "led.h"
21 #include "wme.h"
22 
23 
24 void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
25 				 struct sk_buff *skb)
26 {
27 	struct ieee80211_local *local = hw_to_local(hw);
28 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
29 	int tmp;
30 
31 	skb->pkt_type = IEEE80211_TX_STATUS_MSG;
32 	skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ?
33 		       &local->skb_queue : &local->skb_queue_unreliable, skb);
34 	tmp = skb_queue_len(&local->skb_queue) +
35 		skb_queue_len(&local->skb_queue_unreliable);
36 	while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
37 	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
38 		ieee80211_free_txskb(hw, skb);
39 		tmp--;
40 		I802_DEBUG_INC(local->tx_status_drop);
41 	}
42 	tasklet_schedule(&local->tasklet);
43 }
44 EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);
45 
46 static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
47 					    struct sta_info *sta,
48 					    struct sk_buff *skb)
49 {
50 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
51 	struct ieee80211_hdr *hdr = (void *)skb->data;
52 	int ac;
53 
54 	if (info->flags & (IEEE80211_TX_CTL_NO_PS_BUFFER |
55 			   IEEE80211_TX_CTL_AMPDU)) {
56 		ieee80211_free_txskb(&local->hw, skb);
57 		return;
58 	}
59 
60 	/*
61 	 * This skb 'survived' a round-trip through the driver, and
62 	 * hopefully the driver didn't mangle it too badly. However,
63 	 * we can definitely not rely on the control information
64 	 * being correct. Clear it so we don't get junk there, and
65 	 * indicate that it needs new processing, but must not be
66 	 * modified/encrypted again.
67 	 */
68 	memset(&info->control, 0, sizeof(info->control));
69 
70 	info->control.jiffies = jiffies;
71 	info->control.vif = &sta->sdata->vif;
72 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
73 		       IEEE80211_TX_INTFL_RETRANSMISSION;
74 	info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
75 
76 	sta->status_stats.filtered++;
77 
78 	/*
79 	 * Clear more-data bit on filtered frames, it might be set
80 	 * but later frames might time out so it might have to be
81 	 * clear again ... It's all rather unlikely (this frame
82 	 * should time out first, right?) but let's not confuse
83 	 * peers unnecessarily.
84 	 */
85 	if (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_MOREDATA))
86 		hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_MOREDATA);
87 
88 	if (ieee80211_is_data_qos(hdr->frame_control)) {
89 		u8 *p = ieee80211_get_qos_ctl(hdr);
90 		int tid = *p & IEEE80211_QOS_CTL_TID_MASK;
91 
92 		/*
93 		 * Clear EOSP if set, this could happen e.g.
94 		 * if an absence period (us being a P2P GO)
95 		 * shortens the SP.
96 		 */
97 		if (*p & IEEE80211_QOS_CTL_EOSP)
98 			*p &= ~IEEE80211_QOS_CTL_EOSP;
99 		ac = ieee80211_ac_from_tid(tid);
100 	} else {
101 		ac = IEEE80211_AC_BE;
102 	}
103 
104 	/*
105 	 * Clear the TX filter mask for this STA when sending the next
106 	 * packet. If the STA went to power save mode, this will happen
107 	 * when it wakes up for the next time.
108 	 */
109 	set_sta_flag(sta, WLAN_STA_CLEAR_PS_FILT);
110 	ieee80211_clear_fast_xmit(sta);
111 
112 	/*
113 	 * This code races in the following way:
114 	 *
115 	 *  (1) STA sends frame indicating it will go to sleep and does so
116 	 *  (2) hardware/firmware adds STA to filter list, passes frame up
117 	 *  (3) hardware/firmware processes TX fifo and suppresses a frame
118 	 *  (4) we get TX status before having processed the frame and
119 	 *	knowing that the STA has gone to sleep.
120 	 *
121 	 * This is actually quite unlikely even when both those events are
122 	 * processed from interrupts coming in quickly after one another or
123 	 * even at the same time because we queue both TX status events and
124 	 * RX frames to be processed by a tasklet and process them in the
125 	 * same order that they were received or TX status last. Hence, there
126 	 * is no race as long as the frame RX is processed before the next TX
127 	 * status, which drivers can ensure, see below.
128 	 *
129 	 * Note that this can only happen if the hardware or firmware can
130 	 * actually add STAs to the filter list, if this is done by the
131 	 * driver in response to set_tim() (which will only reduce the race
132 	 * this whole filtering tries to solve, not completely solve it)
133 	 * this situation cannot happen.
134 	 *
135 	 * To completely solve this race drivers need to make sure that they
136 	 *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
137 	 *	functions and
138 	 *  (b) always process RX events before TX status events if ordering
139 	 *      can be unknown, for example with different interrupt status
140 	 *	bits.
141 	 *  (c) if PS mode transitions are manual (i.e. the flag
142 	 *      %IEEE80211_HW_AP_LINK_PS is set), always process PS state
143 	 *      changes before calling TX status events if ordering can be
144 	 *	unknown.
145 	 */
146 	if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
147 	    skb_queue_len(&sta->tx_filtered[ac]) < STA_MAX_TX_BUFFER) {
148 		skb_queue_tail(&sta->tx_filtered[ac], skb);
149 		sta_info_recalc_tim(sta);
150 
151 		if (!timer_pending(&local->sta_cleanup))
152 			mod_timer(&local->sta_cleanup,
153 				  round_jiffies(jiffies +
154 						STA_INFO_CLEANUP_INTERVAL));
155 		return;
156 	}
157 
158 	if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
159 	    !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
160 		/* Software retry the packet once */
161 		info->flags |= IEEE80211_TX_INTFL_RETRIED;
162 		ieee80211_add_pending_skb(local, skb);
163 		return;
164 	}
165 
166 	ps_dbg_ratelimited(sta->sdata,
167 			   "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n",
168 			   skb_queue_len(&sta->tx_filtered[ac]),
169 			   !!test_sta_flag(sta, WLAN_STA_PS_STA), jiffies);
170 	ieee80211_free_txskb(&local->hw, skb);
171 }
172 
173 static void ieee80211_check_pending_bar(struct sta_info *sta, u8 *addr, u8 tid)
174 {
175 	struct tid_ampdu_tx *tid_tx;
176 
177 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
178 	if (!tid_tx || !tid_tx->bar_pending)
179 		return;
180 
181 	tid_tx->bar_pending = false;
182 	ieee80211_send_bar(&sta->sdata->vif, addr, tid, tid_tx->failed_bar_ssn);
183 }
184 
185 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
186 {
187 	struct ieee80211_mgmt *mgmt = (void *) skb->data;
188 	struct ieee80211_local *local = sta->local;
189 	struct ieee80211_sub_if_data *sdata = sta->sdata;
190 	struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
191 
192 	if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
193 		sta->status_stats.last_ack = jiffies;
194 		if (txinfo->status.is_valid_ack_signal) {
195 			sta->status_stats.last_ack_signal =
196 					 (s8)txinfo->status.ack_signal;
197 			sta->status_stats.ack_signal_filled = true;
198 			ewma_avg_signal_add(&sta->status_stats.avg_ack_signal,
199 					    -txinfo->status.ack_signal);
200 		}
201 	}
202 
203 	if (ieee80211_is_data_qos(mgmt->frame_control)) {
204 		struct ieee80211_hdr *hdr = (void *) skb->data;
205 		u8 *qc = ieee80211_get_qos_ctl(hdr);
206 		u16 tid = qc[0] & 0xf;
207 
208 		ieee80211_check_pending_bar(sta, hdr->addr1, tid);
209 	}
210 
211 	if (ieee80211_is_action(mgmt->frame_control) &&
212 	    !ieee80211_has_protected(mgmt->frame_control) &&
213 	    mgmt->u.action.category == WLAN_CATEGORY_HT &&
214 	    mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS &&
215 	    ieee80211_sdata_running(sdata)) {
216 		enum ieee80211_smps_mode smps_mode;
217 
218 		switch (mgmt->u.action.u.ht_smps.smps_control) {
219 		case WLAN_HT_SMPS_CONTROL_DYNAMIC:
220 			smps_mode = IEEE80211_SMPS_DYNAMIC;
221 			break;
222 		case WLAN_HT_SMPS_CONTROL_STATIC:
223 			smps_mode = IEEE80211_SMPS_STATIC;
224 			break;
225 		case WLAN_HT_SMPS_CONTROL_DISABLED:
226 		default: /* shouldn't happen since we don't send that */
227 			smps_mode = IEEE80211_SMPS_OFF;
228 			break;
229 		}
230 
231 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
232 			/*
233 			 * This update looks racy, but isn't -- if we come
234 			 * here we've definitely got a station that we're
235 			 * talking to, and on a managed interface that can
236 			 * only be the AP. And the only other place updating
237 			 * this variable in managed mode is before association.
238 			 */
239 			sdata->smps_mode = smps_mode;
240 			ieee80211_queue_work(&local->hw, &sdata->recalc_smps);
241 		} else if (sdata->vif.type == NL80211_IFTYPE_AP ||
242 			   sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
243 			sta->known_smps_mode = smps_mode;
244 		}
245 	}
246 }
247 
248 static void ieee80211_set_bar_pending(struct sta_info *sta, u8 tid, u16 ssn)
249 {
250 	struct tid_ampdu_tx *tid_tx;
251 
252 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
253 	if (!tid_tx)
254 		return;
255 
256 	tid_tx->failed_bar_ssn = ssn;
257 	tid_tx->bar_pending = true;
258 }
259 
260 static int ieee80211_tx_radiotap_len(struct ieee80211_tx_info *info)
261 {
262 	int len = sizeof(struct ieee80211_radiotap_header);
263 
264 	/* IEEE80211_RADIOTAP_RATE rate */
265 	if (info->status.rates[0].idx >= 0 &&
266 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
267 					     IEEE80211_TX_RC_VHT_MCS)))
268 		len += 2;
269 
270 	/* IEEE80211_RADIOTAP_TX_FLAGS */
271 	len += 2;
272 
273 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
274 	len += 1;
275 
276 	/* IEEE80211_RADIOTAP_MCS
277 	 * IEEE80211_RADIOTAP_VHT */
278 	if (info->status.rates[0].idx >= 0) {
279 		if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS)
280 			len += 3;
281 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS)
282 			len = ALIGN(len, 2) + 12;
283 	}
284 
285 	return len;
286 }
287 
288 static void
289 ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
290 				 struct ieee80211_supported_band *sband,
291 				 struct sk_buff *skb, int retry_count,
292 				 int rtap_len, int shift)
293 {
294 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
295 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
296 	struct ieee80211_radiotap_header *rthdr;
297 	unsigned char *pos;
298 	u16 txflags;
299 
300 	rthdr = skb_push(skb, rtap_len);
301 
302 	memset(rthdr, 0, rtap_len);
303 	rthdr->it_len = cpu_to_le16(rtap_len);
304 	rthdr->it_present =
305 		cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
306 			    (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
307 	pos = (unsigned char *)(rthdr + 1);
308 
309 	/*
310 	 * XXX: Once radiotap gets the bitmap reset thing the vendor
311 	 *	extensions proposal contains, we can actually report
312 	 *	the whole set of tries we did.
313 	 */
314 
315 	/* IEEE80211_RADIOTAP_RATE */
316 	if (info->status.rates[0].idx >= 0 &&
317 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
318 					     IEEE80211_TX_RC_VHT_MCS))) {
319 		u16 rate;
320 
321 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
322 		rate = sband->bitrates[info->status.rates[0].idx].bitrate;
323 		*pos = DIV_ROUND_UP(rate, 5 * (1 << shift));
324 		/* padding for tx flags */
325 		pos += 2;
326 	}
327 
328 	/* IEEE80211_RADIOTAP_TX_FLAGS */
329 	txflags = 0;
330 	if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
331 	    !is_multicast_ether_addr(hdr->addr1))
332 		txflags |= IEEE80211_RADIOTAP_F_TX_FAIL;
333 
334 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
335 		txflags |= IEEE80211_RADIOTAP_F_TX_CTS;
336 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
337 		txflags |= IEEE80211_RADIOTAP_F_TX_RTS;
338 
339 	put_unaligned_le16(txflags, pos);
340 	pos += 2;
341 
342 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
343 	/* for now report the total retry_count */
344 	*pos = retry_count;
345 	pos++;
346 
347 	if (info->status.rates[0].idx < 0)
348 		return;
349 
350 	/* IEEE80211_RADIOTAP_MCS
351 	 * IEEE80211_RADIOTAP_VHT */
352 	if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
353 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
354 		pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
355 			 IEEE80211_RADIOTAP_MCS_HAVE_GI |
356 			 IEEE80211_RADIOTAP_MCS_HAVE_BW;
357 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
358 			pos[1] |= IEEE80211_RADIOTAP_MCS_SGI;
359 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
360 			pos[1] |= IEEE80211_RADIOTAP_MCS_BW_40;
361 		if (info->status.rates[0].flags & IEEE80211_TX_RC_GREEN_FIELD)
362 			pos[1] |= IEEE80211_RADIOTAP_MCS_FMT_GF;
363 		pos[2] = info->status.rates[0].idx;
364 		pos += 3;
365 	} else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS) {
366 		u16 known = local->hw.radiotap_vht_details &
367 			(IEEE80211_RADIOTAP_VHT_KNOWN_GI |
368 			 IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH);
369 
370 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
371 
372 		/* required alignment from rthdr */
373 		pos = (u8 *)rthdr + ALIGN(pos - (u8 *)rthdr, 2);
374 
375 		/* u16 known - IEEE80211_RADIOTAP_VHT_KNOWN_* */
376 		put_unaligned_le16(known, pos);
377 		pos += 2;
378 
379 		/* u8 flags - IEEE80211_RADIOTAP_VHT_FLAG_* */
380 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
381 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
382 		pos++;
383 
384 		/* u8 bandwidth */
385 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
386 			*pos = 1;
387 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_80_MHZ_WIDTH)
388 			*pos = 4;
389 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_160_MHZ_WIDTH)
390 			*pos = 11;
391 		else /* IEEE80211_TX_RC_{20_MHZ_WIDTH,FIXME:DUP_DATA} */
392 			*pos = 0;
393 		pos++;
394 
395 		/* u8 mcs_nss[4] */
396 		*pos = (ieee80211_rate_get_vht_mcs(&info->status.rates[0]) << 4) |
397 			ieee80211_rate_get_vht_nss(&info->status.rates[0]);
398 		pos += 4;
399 
400 		/* u8 coding */
401 		pos++;
402 		/* u8 group_id */
403 		pos++;
404 		/* u16 partial_aid */
405 		pos += 2;
406 	}
407 }
408 
409 /*
410  * Handles the tx for TDLS teardown frames.
411  * If the frame wasn't ACKed by the peer - it will be re-sent through the AP
412  */
413 static void ieee80211_tdls_td_tx_handle(struct ieee80211_local *local,
414 					struct ieee80211_sub_if_data *sdata,
415 					struct sk_buff *skb, u32 flags)
416 {
417 	struct sk_buff *teardown_skb;
418 	struct sk_buff *orig_teardown_skb;
419 	bool is_teardown = false;
420 
421 	/* Get the teardown data we need and free the lock */
422 	spin_lock(&sdata->u.mgd.teardown_lock);
423 	teardown_skb = sdata->u.mgd.teardown_skb;
424 	orig_teardown_skb = sdata->u.mgd.orig_teardown_skb;
425 	if ((skb == orig_teardown_skb) && teardown_skb) {
426 		sdata->u.mgd.teardown_skb = NULL;
427 		sdata->u.mgd.orig_teardown_skb = NULL;
428 		is_teardown = true;
429 	}
430 	spin_unlock(&sdata->u.mgd.teardown_lock);
431 
432 	if (is_teardown) {
433 		/* This mechanism relies on being able to get ACKs */
434 		WARN_ON(!ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS));
435 
436 		/* Check if peer has ACKed */
437 		if (flags & IEEE80211_TX_STAT_ACK) {
438 			dev_kfree_skb_any(teardown_skb);
439 		} else {
440 			tdls_dbg(sdata,
441 				 "TDLS Resending teardown through AP\n");
442 
443 			ieee80211_subif_start_xmit(teardown_skb, skb->dev);
444 		}
445 	}
446 }
447 
448 static struct ieee80211_sub_if_data *
449 ieee80211_sdata_from_skb(struct ieee80211_local *local, struct sk_buff *skb)
450 {
451 	struct ieee80211_sub_if_data *sdata;
452 
453 	if (skb->dev) {
454 		list_for_each_entry_rcu(sdata, &local->interfaces, list) {
455 			if (!sdata->dev)
456 				continue;
457 
458 			if (skb->dev == sdata->dev)
459 				return sdata;
460 		}
461 
462 		return NULL;
463 	}
464 
465 	return rcu_dereference(local->p2p_sdata);
466 }
467 
468 static void ieee80211_report_ack_skb(struct ieee80211_local *local,
469 				     struct ieee80211_tx_info *info,
470 				     bool acked, bool dropped)
471 {
472 	struct sk_buff *skb;
473 	unsigned long flags;
474 
475 	spin_lock_irqsave(&local->ack_status_lock, flags);
476 	skb = idr_remove(&local->ack_status_frames, info->ack_frame_id);
477 	spin_unlock_irqrestore(&local->ack_status_lock, flags);
478 
479 	if (!skb)
480 		return;
481 
482 	if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) {
483 		u64 cookie = IEEE80211_SKB_CB(skb)->ack.cookie;
484 		struct ieee80211_sub_if_data *sdata;
485 		struct ieee80211_hdr *hdr = (void *)skb->data;
486 
487 		rcu_read_lock();
488 		sdata = ieee80211_sdata_from_skb(local, skb);
489 		if (sdata) {
490 			if (ieee80211_is_nullfunc(hdr->frame_control) ||
491 			    ieee80211_is_qos_nullfunc(hdr->frame_control))
492 				cfg80211_probe_status(sdata->dev, hdr->addr1,
493 						      cookie, acked,
494 						      info->status.ack_signal,
495 						      info->status.is_valid_ack_signal,
496 						      GFP_ATOMIC);
497 			else
498 				cfg80211_mgmt_tx_status(&sdata->wdev, cookie,
499 							skb->data, skb->len,
500 							acked, GFP_ATOMIC);
501 		}
502 		rcu_read_unlock();
503 
504 		dev_kfree_skb_any(skb);
505 	} else if (dropped) {
506 		dev_kfree_skb_any(skb);
507 	} else {
508 		/* consumes skb */
509 		skb_complete_wifi_ack(skb, acked);
510 	}
511 }
512 
513 static void ieee80211_report_used_skb(struct ieee80211_local *local,
514 				      struct sk_buff *skb, bool dropped)
515 {
516 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
517 	struct ieee80211_hdr *hdr = (void *)skb->data;
518 	bool acked = info->flags & IEEE80211_TX_STAT_ACK;
519 
520 	if (dropped)
521 		acked = false;
522 
523 	if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) {
524 		struct ieee80211_sub_if_data *sdata;
525 
526 		rcu_read_lock();
527 
528 		sdata = ieee80211_sdata_from_skb(local, skb);
529 
530 		if (!sdata) {
531 			skb->dev = NULL;
532 		} else {
533 			unsigned int hdr_size =
534 				ieee80211_hdrlen(hdr->frame_control);
535 
536 			/* Check to see if packet is a TDLS teardown packet */
537 			if (ieee80211_is_data(hdr->frame_control) &&
538 			    (ieee80211_get_tdls_action(skb, hdr_size) ==
539 			     WLAN_TDLS_TEARDOWN))
540 				ieee80211_tdls_td_tx_handle(local, sdata, skb,
541 							    info->flags);
542 			else
543 				ieee80211_mgd_conn_tx_status(sdata,
544 							     hdr->frame_control,
545 							     acked);
546 		}
547 
548 		rcu_read_unlock();
549 	} else if (info->ack_frame_id) {
550 		ieee80211_report_ack_skb(local, info, acked, dropped);
551 	}
552 
553 	if (!dropped && skb->destructor) {
554 		skb->wifi_acked_valid = 1;
555 		skb->wifi_acked = acked;
556 	}
557 
558 	ieee80211_led_tx(local);
559 }
560 
561 /*
562  * Use a static threshold for now, best value to be determined
563  * by testing ...
564  * Should it depend on:
565  *  - on # of retransmissions
566  *  - current throughput (higher value for higher tpt)?
567  */
568 #define STA_LOST_PKT_THRESHOLD	50
569 #define STA_LOST_TDLS_PKT_THRESHOLD	10
570 #define STA_LOST_TDLS_PKT_TIME		(10*HZ) /* 10secs since last ACK */
571 
572 static void ieee80211_lost_packet(struct sta_info *sta,
573 				  struct ieee80211_tx_info *info)
574 {
575 	/* If driver relies on its own algorithm for station kickout, skip
576 	 * mac80211 packet loss mechanism.
577 	 */
578 	if (ieee80211_hw_check(&sta->local->hw, REPORTS_LOW_ACK))
579 		return;
580 
581 	/* This packet was aggregated but doesn't carry status info */
582 	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
583 	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
584 		return;
585 
586 	sta->status_stats.lost_packets++;
587 	if (!sta->sta.tdls &&
588 	    sta->status_stats.lost_packets < STA_LOST_PKT_THRESHOLD)
589 		return;
590 
591 	/*
592 	 * If we're in TDLS mode, make sure that all STA_LOST_TDLS_PKT_THRESHOLD
593 	 * of the last packets were lost, and that no ACK was received in the
594 	 * last STA_LOST_TDLS_PKT_TIME ms, before triggering the CQM packet-loss
595 	 * mechanism.
596 	 */
597 	if (sta->sta.tdls &&
598 	    (sta->status_stats.lost_packets < STA_LOST_TDLS_PKT_THRESHOLD ||
599 	     time_before(jiffies,
600 			 sta->status_stats.last_tdls_pkt_time +
601 			 STA_LOST_TDLS_PKT_TIME)))
602 		return;
603 
604 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
605 				    sta->status_stats.lost_packets, GFP_ATOMIC);
606 	sta->status_stats.lost_packets = 0;
607 }
608 
609 static int ieee80211_tx_get_rates(struct ieee80211_hw *hw,
610 				  struct ieee80211_tx_info *info,
611 				  int *retry_count)
612 {
613 	int rates_idx = -1;
614 	int count = -1;
615 	int i;
616 
617 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
618 		if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
619 		    !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
620 			/* just the first aggr frame carry status info */
621 			info->status.rates[i].idx = -1;
622 			info->status.rates[i].count = 0;
623 			break;
624 		} else if (info->status.rates[i].idx < 0) {
625 			break;
626 		} else if (i >= hw->max_report_rates) {
627 			/* the HW cannot have attempted that rate */
628 			info->status.rates[i].idx = -1;
629 			info->status.rates[i].count = 0;
630 			break;
631 		}
632 
633 		count += info->status.rates[i].count;
634 	}
635 	rates_idx = i - 1;
636 
637 	if (count < 0)
638 		count = 0;
639 
640 	*retry_count = count;
641 	return rates_idx;
642 }
643 
644 void ieee80211_tx_monitor(struct ieee80211_local *local, struct sk_buff *skb,
645 			  struct ieee80211_supported_band *sband,
646 			  int retry_count, int shift, bool send_to_cooked)
647 {
648 	struct sk_buff *skb2;
649 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
650 	struct ieee80211_sub_if_data *sdata;
651 	struct net_device *prev_dev = NULL;
652 	int rtap_len;
653 
654 	/* send frame to monitor interfaces now */
655 	rtap_len = ieee80211_tx_radiotap_len(info);
656 	if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
657 		pr_err("ieee80211_tx_status: headroom too small\n");
658 		dev_kfree_skb(skb);
659 		return;
660 	}
661 	ieee80211_add_tx_radiotap_header(local, sband, skb, retry_count,
662 					 rtap_len, shift);
663 
664 	/* XXX: is this sufficient for BPF? */
665 	skb_reset_mac_header(skb);
666 	skb->ip_summed = CHECKSUM_UNNECESSARY;
667 	skb->pkt_type = PACKET_OTHERHOST;
668 	skb->protocol = htons(ETH_P_802_2);
669 	memset(skb->cb, 0, sizeof(skb->cb));
670 
671 	rcu_read_lock();
672 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
673 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
674 			if (!ieee80211_sdata_running(sdata))
675 				continue;
676 
677 			if ((sdata->u.mntr.flags & MONITOR_FLAG_COOK_FRAMES) &&
678 			    !send_to_cooked)
679 				continue;
680 
681 			if (prev_dev) {
682 				skb2 = skb_clone(skb, GFP_ATOMIC);
683 				if (skb2) {
684 					skb2->dev = prev_dev;
685 					netif_rx(skb2);
686 				}
687 			}
688 
689 			prev_dev = sdata->dev;
690 		}
691 	}
692 	if (prev_dev) {
693 		skb->dev = prev_dev;
694 		netif_rx(skb);
695 		skb = NULL;
696 	}
697 	rcu_read_unlock();
698 	dev_kfree_skb(skb);
699 }
700 
701 static void __ieee80211_tx_status(struct ieee80211_hw *hw,
702 				  struct ieee80211_tx_status *status)
703 {
704 	struct sk_buff *skb = status->skb;
705 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
706 	struct ieee80211_local *local = hw_to_local(hw);
707 	struct ieee80211_tx_info *info = status->info;
708 	struct sta_info *sta;
709 	__le16 fc;
710 	struct ieee80211_supported_band *sband;
711 	int retry_count;
712 	int rates_idx;
713 	bool send_to_cooked;
714 	bool acked;
715 	struct ieee80211_bar *bar;
716 	int shift = 0;
717 	int tid = IEEE80211_NUM_TIDS;
718 
719 	rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
720 
721 	sband = local->hw.wiphy->bands[info->band];
722 	fc = hdr->frame_control;
723 
724 	if (status->sta) {
725 		sta = container_of(status->sta, struct sta_info, sta);
726 		shift = ieee80211_vif_get_shift(&sta->sdata->vif);
727 
728 		if (info->flags & IEEE80211_TX_STATUS_EOSP)
729 			clear_sta_flag(sta, WLAN_STA_SP);
730 
731 		acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
732 
733 		/* mesh Peer Service Period support */
734 		if (ieee80211_vif_is_mesh(&sta->sdata->vif) &&
735 		    ieee80211_is_data_qos(fc))
736 			ieee80211_mpsp_trigger_process(
737 				ieee80211_get_qos_ctl(hdr), sta, true, acked);
738 
739 		if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
740 			/*
741 			 * The STA is in power save mode, so assume
742 			 * that this TX packet failed because of that.
743 			 */
744 			ieee80211_handle_filtered_frame(local, sta, skb);
745 			return;
746 		}
747 
748 		if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL) &&
749 		    (ieee80211_is_data(hdr->frame_control)) &&
750 		    (rates_idx != -1))
751 			sta->tx_stats.last_rate =
752 				info->status.rates[rates_idx];
753 
754 		if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
755 		    (ieee80211_is_data_qos(fc))) {
756 			u16 ssn;
757 			u8 *qc;
758 
759 			qc = ieee80211_get_qos_ctl(hdr);
760 			tid = qc[0] & 0xf;
761 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
762 						& IEEE80211_SCTL_SEQ);
763 			ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
764 					   tid, ssn);
765 		} else if (ieee80211_is_data_qos(fc)) {
766 			u8 *qc = ieee80211_get_qos_ctl(hdr);
767 
768 			tid = qc[0] & 0xf;
769 		}
770 
771 		if (!acked && ieee80211_is_back_req(fc)) {
772 			u16 control;
773 
774 			/*
775 			 * BAR failed, store the last SSN and retry sending
776 			 * the BAR when the next unicast transmission on the
777 			 * same TID succeeds.
778 			 */
779 			bar = (struct ieee80211_bar *) skb->data;
780 			control = le16_to_cpu(bar->control);
781 			if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
782 				u16 ssn = le16_to_cpu(bar->start_seq_num);
783 
784 				tid = (control &
785 				       IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
786 				      IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
787 
788 				ieee80211_set_bar_pending(sta, tid, ssn);
789 			}
790 		}
791 
792 		if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
793 			ieee80211_handle_filtered_frame(local, sta, skb);
794 			return;
795 		} else {
796 			if (!acked)
797 				sta->status_stats.retry_failed++;
798 			sta->status_stats.retry_count += retry_count;
799 
800 			if (ieee80211_is_data_present(fc)) {
801 				if (!acked)
802 					sta->status_stats.msdu_failed[tid]++;
803 
804 				sta->status_stats.msdu_retries[tid] +=
805 					retry_count;
806 			}
807 		}
808 
809 		rate_control_tx_status(local, sband, status);
810 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
811 			ieee80211s_update_metric(local, sta, status);
812 
813 		if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
814 			ieee80211_frame_acked(sta, skb);
815 
816 		if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
817 		    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS))
818 			ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data,
819 						acked, info->status.tx_time);
820 
821 		if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
822 			if (info->flags & IEEE80211_TX_STAT_ACK) {
823 				if (sta->status_stats.lost_packets)
824 					sta->status_stats.lost_packets = 0;
825 
826 				/* Track when last TDLS packet was ACKed */
827 				if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
828 					sta->status_stats.last_tdls_pkt_time =
829 						jiffies;
830 			} else {
831 				ieee80211_lost_packet(sta, info);
832 			}
833 		}
834 	}
835 
836 	/* SNMP counters
837 	 * Fragments are passed to low-level drivers as separate skbs, so these
838 	 * are actually fragments, not frames. Update frame counters only for
839 	 * the first fragment of the frame. */
840 	if ((info->flags & IEEE80211_TX_STAT_ACK) ||
841 	    (info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED)) {
842 		if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
843 			I802_DEBUG_INC(local->dot11TransmittedFrameCount);
844 			if (is_multicast_ether_addr(ieee80211_get_DA(hdr)))
845 				I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
846 			if (retry_count > 0)
847 				I802_DEBUG_INC(local->dot11RetryCount);
848 			if (retry_count > 1)
849 				I802_DEBUG_INC(local->dot11MultipleRetryCount);
850 		}
851 
852 		/* This counter shall be incremented for an acknowledged MPDU
853 		 * with an individual address in the address 1 field or an MPDU
854 		 * with a multicast address in the address 1 field of type Data
855 		 * or Management. */
856 		if (!is_multicast_ether_addr(hdr->addr1) ||
857 		    ieee80211_is_data(fc) ||
858 		    ieee80211_is_mgmt(fc))
859 			I802_DEBUG_INC(local->dot11TransmittedFragmentCount);
860 	} else {
861 		if (ieee80211_is_first_frag(hdr->seq_ctrl))
862 			I802_DEBUG_INC(local->dot11FailedCount);
863 	}
864 
865 	if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
866 	    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS) &&
867 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
868 	    local->ps_sdata && !(local->scanning)) {
869 		if (info->flags & IEEE80211_TX_STAT_ACK) {
870 			local->ps_sdata->u.mgd.flags |=
871 					IEEE80211_STA_NULLFUNC_ACKED;
872 		} else
873 			mod_timer(&local->dynamic_ps_timer, jiffies +
874 					msecs_to_jiffies(10));
875 	}
876 
877 	ieee80211_report_used_skb(local, skb, false);
878 
879 	/* this was a transmitted frame, but now we want to reuse it */
880 	skb_orphan(skb);
881 
882 	/* Need to make a copy before skb->cb gets cleared */
883 	send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
884 			 !(ieee80211_is_data(fc));
885 
886 	/*
887 	 * This is a bit racy but we can avoid a lot of work
888 	 * with this test...
889 	 */
890 	if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
891 		dev_kfree_skb(skb);
892 		return;
893 	}
894 
895 	/* send to monitor interfaces */
896 	ieee80211_tx_monitor(local, skb, sband, retry_count, shift, send_to_cooked);
897 }
898 
899 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
900 {
901 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
902 	struct ieee80211_local *local = hw_to_local(hw);
903 	struct ieee80211_tx_status status = {
904 		.skb = skb,
905 		.info = IEEE80211_SKB_CB(skb),
906 	};
907 	struct rhlist_head *tmp;
908 	struct sta_info *sta;
909 
910 	rcu_read_lock();
911 
912 	for_each_sta_info(local, hdr->addr1, sta, tmp) {
913 		/* skip wrong virtual interface */
914 		if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
915 			continue;
916 
917 		status.sta = &sta->sta;
918 		break;
919 	}
920 
921 	__ieee80211_tx_status(hw, &status);
922 	rcu_read_unlock();
923 }
924 EXPORT_SYMBOL(ieee80211_tx_status);
925 
926 void ieee80211_tx_status_ext(struct ieee80211_hw *hw,
927 			     struct ieee80211_tx_status *status)
928 {
929 	struct ieee80211_local *local = hw_to_local(hw);
930 	struct ieee80211_tx_info *info = status->info;
931 	struct ieee80211_sta *pubsta = status->sta;
932 	struct ieee80211_supported_band *sband;
933 	int retry_count;
934 	bool acked, noack_success;
935 
936 	if (status->skb)
937 		return __ieee80211_tx_status(hw, status);
938 
939 	if (!status->sta)
940 		return;
941 
942 	ieee80211_tx_get_rates(hw, info, &retry_count);
943 
944 	sband = hw->wiphy->bands[info->band];
945 
946 	acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
947 	noack_success = !!(info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED);
948 
949 	if (pubsta) {
950 		struct sta_info *sta;
951 
952 		sta = container_of(pubsta, struct sta_info, sta);
953 
954 		if (!acked)
955 			sta->status_stats.retry_failed++;
956 		sta->status_stats.retry_count += retry_count;
957 
958 		if (acked) {
959 			sta->status_stats.last_ack = jiffies;
960 
961 			if (sta->status_stats.lost_packets)
962 				sta->status_stats.lost_packets = 0;
963 
964 			/* Track when last TDLS packet was ACKed */
965 			if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
966 				sta->status_stats.last_tdls_pkt_time = jiffies;
967 		} else {
968 			ieee80211_lost_packet(sta, info);
969 		}
970 
971 		rate_control_tx_status(local, sband, status);
972 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
973 			ieee80211s_update_metric(local, sta, status);
974 	}
975 
976 	if (acked || noack_success) {
977 		I802_DEBUG_INC(local->dot11TransmittedFrameCount);
978 		if (!pubsta)
979 			I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
980 		if (retry_count > 0)
981 			I802_DEBUG_INC(local->dot11RetryCount);
982 		if (retry_count > 1)
983 			I802_DEBUG_INC(local->dot11MultipleRetryCount);
984 	} else {
985 		I802_DEBUG_INC(local->dot11FailedCount);
986 	}
987 }
988 EXPORT_SYMBOL(ieee80211_tx_status_ext);
989 
990 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
991 {
992 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
993 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
994 				    num_packets, GFP_ATOMIC);
995 }
996 EXPORT_SYMBOL(ieee80211_report_low_ack);
997 
998 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
999 {
1000 	struct ieee80211_local *local = hw_to_local(hw);
1001 
1002 	ieee80211_report_used_skb(local, skb, true);
1003 	dev_kfree_skb_any(skb);
1004 }
1005 EXPORT_SYMBOL(ieee80211_free_txskb);
1006 
1007 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
1008 			      struct sk_buff_head *skbs)
1009 {
1010 	struct sk_buff *skb;
1011 
1012 	while ((skb = __skb_dequeue(skbs)))
1013 		ieee80211_free_txskb(hw, skb);
1014 }
1015