xref: /linux/net/mac80211/status.c (revision cc04a46f11ea046ed53e2c832ae29e4790f7e35f)
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 	/*
55 	 * This skb 'survived' a round-trip through the driver, and
56 	 * hopefully the driver didn't mangle it too badly. However,
57 	 * we can definitely not rely on the control information
58 	 * being correct. Clear it so we don't get junk there, and
59 	 * indicate that it needs new processing, but must not be
60 	 * modified/encrypted again.
61 	 */
62 	memset(&info->control, 0, sizeof(info->control));
63 
64 	info->control.jiffies = jiffies;
65 	info->control.vif = &sta->sdata->vif;
66 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
67 		       IEEE80211_TX_INTFL_RETRANSMISSION;
68 	info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
69 
70 	sta->tx_filtered_count++;
71 
72 	/*
73 	 * Clear more-data bit on filtered frames, it might be set
74 	 * but later frames might time out so it might have to be
75 	 * clear again ... It's all rather unlikely (this frame
76 	 * should time out first, right?) but let's not confuse
77 	 * peers unnecessarily.
78 	 */
79 	if (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_MOREDATA))
80 		hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_MOREDATA);
81 
82 	if (ieee80211_is_data_qos(hdr->frame_control)) {
83 		u8 *p = ieee80211_get_qos_ctl(hdr);
84 		int tid = *p & IEEE80211_QOS_CTL_TID_MASK;
85 
86 		/*
87 		 * Clear EOSP if set, this could happen e.g.
88 		 * if an absence period (us being a P2P GO)
89 		 * shortens the SP.
90 		 */
91 		if (*p & IEEE80211_QOS_CTL_EOSP)
92 			*p &= ~IEEE80211_QOS_CTL_EOSP;
93 		ac = ieee802_1d_to_ac[tid & 7];
94 	} else {
95 		ac = IEEE80211_AC_BE;
96 	}
97 
98 	/*
99 	 * Clear the TX filter mask for this STA when sending the next
100 	 * packet. If the STA went to power save mode, this will happen
101 	 * when it wakes up for the next time.
102 	 */
103 	set_sta_flag(sta, WLAN_STA_CLEAR_PS_FILT);
104 
105 	/*
106 	 * This code races in the following way:
107 	 *
108 	 *  (1) STA sends frame indicating it will go to sleep and does so
109 	 *  (2) hardware/firmware adds STA to filter list, passes frame up
110 	 *  (3) hardware/firmware processes TX fifo and suppresses a frame
111 	 *  (4) we get TX status before having processed the frame and
112 	 *	knowing that the STA has gone to sleep.
113 	 *
114 	 * This is actually quite unlikely even when both those events are
115 	 * processed from interrupts coming in quickly after one another or
116 	 * even at the same time because we queue both TX status events and
117 	 * RX frames to be processed by a tasklet and process them in the
118 	 * same order that they were received or TX status last. Hence, there
119 	 * is no race as long as the frame RX is processed before the next TX
120 	 * status, which drivers can ensure, see below.
121 	 *
122 	 * Note that this can only happen if the hardware or firmware can
123 	 * actually add STAs to the filter list, if this is done by the
124 	 * driver in response to set_tim() (which will only reduce the race
125 	 * this whole filtering tries to solve, not completely solve it)
126 	 * this situation cannot happen.
127 	 *
128 	 * To completely solve this race drivers need to make sure that they
129 	 *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
130 	 *	functions and
131 	 *  (b) always process RX events before TX status events if ordering
132 	 *      can be unknown, for example with different interrupt status
133 	 *	bits.
134 	 *  (c) if PS mode transitions are manual (i.e. the flag
135 	 *      %IEEE80211_HW_AP_LINK_PS is set), always process PS state
136 	 *      changes before calling TX status events if ordering can be
137 	 *	unknown.
138 	 */
139 	if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
140 	    skb_queue_len(&sta->tx_filtered[ac]) < STA_MAX_TX_BUFFER) {
141 		skb_queue_tail(&sta->tx_filtered[ac], skb);
142 		sta_info_recalc_tim(sta);
143 
144 		if (!timer_pending(&local->sta_cleanup))
145 			mod_timer(&local->sta_cleanup,
146 				  round_jiffies(jiffies +
147 						STA_INFO_CLEANUP_INTERVAL));
148 		return;
149 	}
150 
151 	if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
152 	    !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
153 		/* Software retry the packet once */
154 		info->flags |= IEEE80211_TX_INTFL_RETRIED;
155 		ieee80211_add_pending_skb(local, skb);
156 		return;
157 	}
158 
159 	ps_dbg_ratelimited(sta->sdata,
160 			   "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n",
161 			   skb_queue_len(&sta->tx_filtered[ac]),
162 			   !!test_sta_flag(sta, WLAN_STA_PS_STA), jiffies);
163 	ieee80211_free_txskb(&local->hw, skb);
164 }
165 
166 static void ieee80211_check_pending_bar(struct sta_info *sta, u8 *addr, u8 tid)
167 {
168 	struct tid_ampdu_tx *tid_tx;
169 
170 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
171 	if (!tid_tx || !tid_tx->bar_pending)
172 		return;
173 
174 	tid_tx->bar_pending = false;
175 	ieee80211_send_bar(&sta->sdata->vif, addr, tid, tid_tx->failed_bar_ssn);
176 }
177 
178 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
179 {
180 	struct ieee80211_mgmt *mgmt = (void *) skb->data;
181 	struct ieee80211_local *local = sta->local;
182 	struct ieee80211_sub_if_data *sdata = sta->sdata;
183 
184 	if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS))
185 		sta->last_rx = jiffies;
186 
187 	if (ieee80211_is_data_qos(mgmt->frame_control)) {
188 		struct ieee80211_hdr *hdr = (void *) skb->data;
189 		u8 *qc = ieee80211_get_qos_ctl(hdr);
190 		u16 tid = qc[0] & 0xf;
191 
192 		ieee80211_check_pending_bar(sta, hdr->addr1, tid);
193 	}
194 
195 	if (ieee80211_is_action(mgmt->frame_control) &&
196 	    mgmt->u.action.category == WLAN_CATEGORY_HT &&
197 	    mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS &&
198 	    ieee80211_sdata_running(sdata)) {
199 		enum ieee80211_smps_mode smps_mode;
200 
201 		switch (mgmt->u.action.u.ht_smps.smps_control) {
202 		case WLAN_HT_SMPS_CONTROL_DYNAMIC:
203 			smps_mode = IEEE80211_SMPS_DYNAMIC;
204 			break;
205 		case WLAN_HT_SMPS_CONTROL_STATIC:
206 			smps_mode = IEEE80211_SMPS_STATIC;
207 			break;
208 		case WLAN_HT_SMPS_CONTROL_DISABLED:
209 		default: /* shouldn't happen since we don't send that */
210 			smps_mode = IEEE80211_SMPS_OFF;
211 			break;
212 		}
213 
214 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
215 			/*
216 			 * This update looks racy, but isn't -- if we come
217 			 * here we've definitely got a station that we're
218 			 * talking to, and on a managed interface that can
219 			 * only be the AP. And the only other place updating
220 			 * this variable in managed mode is before association.
221 			 */
222 			sdata->smps_mode = smps_mode;
223 			ieee80211_queue_work(&local->hw, &sdata->recalc_smps);
224 		} else if (sdata->vif.type == NL80211_IFTYPE_AP ||
225 			   sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
226 			sta->known_smps_mode = smps_mode;
227 		}
228 	}
229 }
230 
231 static void ieee80211_set_bar_pending(struct sta_info *sta, u8 tid, u16 ssn)
232 {
233 	struct tid_ampdu_tx *tid_tx;
234 
235 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
236 	if (!tid_tx)
237 		return;
238 
239 	tid_tx->failed_bar_ssn = ssn;
240 	tid_tx->bar_pending = true;
241 }
242 
243 static int ieee80211_tx_radiotap_len(struct ieee80211_tx_info *info)
244 {
245 	int len = sizeof(struct ieee80211_radiotap_header);
246 
247 	/* IEEE80211_RADIOTAP_RATE rate */
248 	if (info->status.rates[0].idx >= 0 &&
249 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
250 					     IEEE80211_TX_RC_VHT_MCS)))
251 		len += 2;
252 
253 	/* IEEE80211_RADIOTAP_TX_FLAGS */
254 	len += 2;
255 
256 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
257 	len += 1;
258 
259 	/* IEEE80211_RADIOTAP_MCS
260 	 * IEEE80211_RADIOTAP_VHT */
261 	if (info->status.rates[0].idx >= 0) {
262 		if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS)
263 			len += 3;
264 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS)
265 			len = ALIGN(len, 2) + 12;
266 	}
267 
268 	return len;
269 }
270 
271 static void
272 ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
273 				 struct ieee80211_supported_band *sband,
274 				 struct sk_buff *skb, int retry_count,
275 				 int rtap_len, int shift)
276 {
277 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
278 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
279 	struct ieee80211_radiotap_header *rthdr;
280 	unsigned char *pos;
281 	u16 txflags;
282 
283 	rthdr = (struct ieee80211_radiotap_header *) skb_push(skb, rtap_len);
284 
285 	memset(rthdr, 0, rtap_len);
286 	rthdr->it_len = cpu_to_le16(rtap_len);
287 	rthdr->it_present =
288 		cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
289 			    (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
290 	pos = (unsigned char *)(rthdr + 1);
291 
292 	/*
293 	 * XXX: Once radiotap gets the bitmap reset thing the vendor
294 	 *	extensions proposal contains, we can actually report
295 	 *	the whole set of tries we did.
296 	 */
297 
298 	/* IEEE80211_RADIOTAP_RATE */
299 	if (info->status.rates[0].idx >= 0 &&
300 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
301 					     IEEE80211_TX_RC_VHT_MCS))) {
302 		u16 rate;
303 
304 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
305 		rate = sband->bitrates[info->status.rates[0].idx].bitrate;
306 		*pos = DIV_ROUND_UP(rate, 5 * (1 << shift));
307 		/* padding for tx flags */
308 		pos += 2;
309 	}
310 
311 	/* IEEE80211_RADIOTAP_TX_FLAGS */
312 	txflags = 0;
313 	if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
314 	    !is_multicast_ether_addr(hdr->addr1))
315 		txflags |= IEEE80211_RADIOTAP_F_TX_FAIL;
316 
317 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
318 		txflags |= IEEE80211_RADIOTAP_F_TX_CTS;
319 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
320 		txflags |= IEEE80211_RADIOTAP_F_TX_RTS;
321 
322 	put_unaligned_le16(txflags, pos);
323 	pos += 2;
324 
325 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
326 	/* for now report the total retry_count */
327 	*pos = retry_count;
328 	pos++;
329 
330 	if (info->status.rates[0].idx < 0)
331 		return;
332 
333 	/* IEEE80211_RADIOTAP_MCS
334 	 * IEEE80211_RADIOTAP_VHT */
335 	if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
336 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
337 		pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
338 			 IEEE80211_RADIOTAP_MCS_HAVE_GI |
339 			 IEEE80211_RADIOTAP_MCS_HAVE_BW;
340 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
341 			pos[1] |= IEEE80211_RADIOTAP_MCS_SGI;
342 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
343 			pos[1] |= IEEE80211_RADIOTAP_MCS_BW_40;
344 		if (info->status.rates[0].flags & IEEE80211_TX_RC_GREEN_FIELD)
345 			pos[1] |= IEEE80211_RADIOTAP_MCS_FMT_GF;
346 		pos[2] = info->status.rates[0].idx;
347 		pos += 3;
348 	} else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS) {
349 		u16 known = local->hw.radiotap_vht_details &
350 			(IEEE80211_RADIOTAP_VHT_KNOWN_GI |
351 			 IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH);
352 
353 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
354 
355 		/* required alignment from rthdr */
356 		pos = (u8 *)rthdr + ALIGN(pos - (u8 *)rthdr, 2);
357 
358 		/* u16 known - IEEE80211_RADIOTAP_VHT_KNOWN_* */
359 		put_unaligned_le16(known, pos);
360 		pos += 2;
361 
362 		/* u8 flags - IEEE80211_RADIOTAP_VHT_FLAG_* */
363 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
364 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
365 		pos++;
366 
367 		/* u8 bandwidth */
368 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
369 			*pos = 1;
370 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_80_MHZ_WIDTH)
371 			*pos = 4;
372 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_160_MHZ_WIDTH)
373 			*pos = 11;
374 		else /* IEEE80211_TX_RC_{20_MHZ_WIDTH,FIXME:DUP_DATA} */
375 			*pos = 0;
376 		pos++;
377 
378 		/* u8 mcs_nss[4] */
379 		*pos = (ieee80211_rate_get_vht_mcs(&info->status.rates[0]) << 4) |
380 			ieee80211_rate_get_vht_nss(&info->status.rates[0]);
381 		pos += 4;
382 
383 		/* u8 coding */
384 		pos++;
385 		/* u8 group_id */
386 		pos++;
387 		/* u16 partial_aid */
388 		pos += 2;
389 	}
390 }
391 
392 /*
393  * Handles the tx for TDLS teardown frames.
394  * If the frame wasn't ACKed by the peer - it will be re-sent through the AP
395  */
396 static void ieee80211_tdls_td_tx_handle(struct ieee80211_local *local,
397 					struct ieee80211_sub_if_data *sdata,
398 					struct sk_buff *skb, u32 flags)
399 {
400 	struct sk_buff *teardown_skb;
401 	struct sk_buff *orig_teardown_skb;
402 	bool is_teardown = false;
403 
404 	/* Get the teardown data we need and free the lock */
405 	spin_lock(&sdata->u.mgd.teardown_lock);
406 	teardown_skb = sdata->u.mgd.teardown_skb;
407 	orig_teardown_skb = sdata->u.mgd.orig_teardown_skb;
408 	if ((skb == orig_teardown_skb) && teardown_skb) {
409 		sdata->u.mgd.teardown_skb = NULL;
410 		sdata->u.mgd.orig_teardown_skb = NULL;
411 		is_teardown = true;
412 	}
413 	spin_unlock(&sdata->u.mgd.teardown_lock);
414 
415 	if (is_teardown) {
416 		/* This mechanism relies on being able to get ACKs */
417 		WARN_ON(!ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS));
418 
419 		/* Check if peer has ACKed */
420 		if (flags & IEEE80211_TX_STAT_ACK) {
421 			dev_kfree_skb_any(teardown_skb);
422 		} else {
423 			tdls_dbg(sdata,
424 				 "TDLS Resending teardown through AP\n");
425 
426 			ieee80211_subif_start_xmit(teardown_skb, skb->dev);
427 		}
428 	}
429 }
430 
431 static struct ieee80211_sub_if_data *
432 ieee80211_sdata_from_skb(struct ieee80211_local *local, struct sk_buff *skb)
433 {
434 	struct ieee80211_sub_if_data *sdata;
435 
436 	if (skb->dev) {
437 		list_for_each_entry_rcu(sdata, &local->interfaces, list) {
438 			if (!sdata->dev)
439 				continue;
440 
441 			if (skb->dev == sdata->dev)
442 				return sdata;
443 		}
444 
445 		return NULL;
446 	}
447 
448 	return rcu_dereference(local->p2p_sdata);
449 }
450 
451 static void ieee80211_report_ack_skb(struct ieee80211_local *local,
452 				     struct ieee80211_tx_info *info,
453 				     bool acked, bool dropped)
454 {
455 	struct sk_buff *skb;
456 	unsigned long flags;
457 
458 	spin_lock_irqsave(&local->ack_status_lock, flags);
459 	skb = idr_find(&local->ack_status_frames, info->ack_frame_id);
460 	if (skb)
461 		idr_remove(&local->ack_status_frames, info->ack_frame_id);
462 	spin_unlock_irqrestore(&local->ack_status_lock, flags);
463 
464 	if (!skb)
465 		return;
466 
467 	if (dropped) {
468 		dev_kfree_skb_any(skb);
469 		return;
470 	}
471 
472 	if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) {
473 		u64 cookie = IEEE80211_SKB_CB(skb)->ack.cookie;
474 		struct ieee80211_sub_if_data *sdata;
475 		struct ieee80211_hdr *hdr = (void *)skb->data;
476 
477 		rcu_read_lock();
478 		sdata = ieee80211_sdata_from_skb(local, skb);
479 		if (sdata) {
480 			if (ieee80211_is_nullfunc(hdr->frame_control) ||
481 			    ieee80211_is_qos_nullfunc(hdr->frame_control))
482 				cfg80211_probe_status(sdata->dev, hdr->addr1,
483 						      cookie, acked,
484 						      GFP_ATOMIC);
485 			else
486 				cfg80211_mgmt_tx_status(&sdata->wdev, cookie,
487 							skb->data, skb->len,
488 							acked, GFP_ATOMIC);
489 		}
490 		rcu_read_unlock();
491 
492 		dev_kfree_skb_any(skb);
493 	} else {
494 		/* consumes skb */
495 		skb_complete_wifi_ack(skb, acked);
496 	}
497 }
498 
499 static void ieee80211_report_used_skb(struct ieee80211_local *local,
500 				      struct sk_buff *skb, bool dropped)
501 {
502 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
503 	struct ieee80211_hdr *hdr = (void *)skb->data;
504 	bool acked = info->flags & IEEE80211_TX_STAT_ACK;
505 
506 	if (dropped)
507 		acked = false;
508 
509 	if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) {
510 		struct ieee80211_sub_if_data *sdata;
511 
512 		rcu_read_lock();
513 
514 		sdata = ieee80211_sdata_from_skb(local, skb);
515 
516 		if (!sdata) {
517 			skb->dev = NULL;
518 		} else {
519 			unsigned int hdr_size =
520 				ieee80211_hdrlen(hdr->frame_control);
521 
522 			/* Check to see if packet is a TDLS teardown packet */
523 			if (ieee80211_is_data(hdr->frame_control) &&
524 			    (ieee80211_get_tdls_action(skb, hdr_size) ==
525 			     WLAN_TDLS_TEARDOWN))
526 				ieee80211_tdls_td_tx_handle(local, sdata, skb,
527 							    info->flags);
528 			else
529 				ieee80211_mgd_conn_tx_status(sdata,
530 							     hdr->frame_control,
531 							     acked);
532 		}
533 
534 		rcu_read_unlock();
535 	} else if (info->ack_frame_id) {
536 		ieee80211_report_ack_skb(local, info, acked, dropped);
537 	}
538 }
539 
540 /*
541  * Use a static threshold for now, best value to be determined
542  * by testing ...
543  * Should it depend on:
544  *  - on # of retransmissions
545  *  - current throughput (higher value for higher tpt)?
546  */
547 #define STA_LOST_PKT_THRESHOLD	50
548 #define STA_LOST_TDLS_PKT_THRESHOLD	10
549 #define STA_LOST_TDLS_PKT_TIME		(10*HZ) /* 10secs since last ACK */
550 
551 static void ieee80211_lost_packet(struct sta_info *sta,
552 				  struct ieee80211_tx_info *info)
553 {
554 	/* This packet was aggregated but doesn't carry status info */
555 	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
556 	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
557 		return;
558 
559 	sta->lost_packets++;
560 	if (!sta->sta.tdls && sta->lost_packets < STA_LOST_PKT_THRESHOLD)
561 		return;
562 
563 	/*
564 	 * If we're in TDLS mode, make sure that all STA_LOST_TDLS_PKT_THRESHOLD
565 	 * of the last packets were lost, and that no ACK was received in the
566 	 * last STA_LOST_TDLS_PKT_TIME ms, before triggering the CQM packet-loss
567 	 * mechanism.
568 	 */
569 	if (sta->sta.tdls &&
570 	    (sta->lost_packets < STA_LOST_TDLS_PKT_THRESHOLD ||
571 	     time_before(jiffies,
572 			 sta->last_tdls_pkt_time + STA_LOST_TDLS_PKT_TIME)))
573 		return;
574 
575 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
576 				    sta->lost_packets, GFP_ATOMIC);
577 	sta->lost_packets = 0;
578 }
579 
580 static int ieee80211_tx_get_rates(struct ieee80211_hw *hw,
581 				  struct ieee80211_tx_info *info,
582 				  int *retry_count)
583 {
584 	int rates_idx = -1;
585 	int count = -1;
586 	int i;
587 
588 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
589 		if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
590 		    !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
591 			/* just the first aggr frame carry status info */
592 			info->status.rates[i].idx = -1;
593 			info->status.rates[i].count = 0;
594 			break;
595 		} else if (info->status.rates[i].idx < 0) {
596 			break;
597 		} else if (i >= hw->max_report_rates) {
598 			/* the HW cannot have attempted that rate */
599 			info->status.rates[i].idx = -1;
600 			info->status.rates[i].count = 0;
601 			break;
602 		}
603 
604 		count += info->status.rates[i].count;
605 	}
606 	rates_idx = i - 1;
607 
608 	if (count < 0)
609 		count = 0;
610 
611 	*retry_count = count;
612 	return rates_idx;
613 }
614 
615 void ieee80211_tx_status_noskb(struct ieee80211_hw *hw,
616 			       struct ieee80211_sta *pubsta,
617 			       struct ieee80211_tx_info *info)
618 {
619 	struct ieee80211_local *local = hw_to_local(hw);
620 	struct ieee80211_supported_band *sband;
621 	int retry_count;
622 	int rates_idx;
623 	bool acked, noack_success;
624 
625 	rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
626 
627 	sband = hw->wiphy->bands[info->band];
628 
629 	acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
630 	noack_success = !!(info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED);
631 
632 	if (pubsta) {
633 		struct sta_info *sta;
634 
635 		sta = container_of(pubsta, struct sta_info, sta);
636 
637 		if (!acked)
638 			sta->tx_retry_failed++;
639 		sta->tx_retry_count += retry_count;
640 
641 		if (acked) {
642 			sta->last_rx = jiffies;
643 
644 			if (sta->lost_packets)
645 				sta->lost_packets = 0;
646 
647 			/* Track when last TDLS packet was ACKed */
648 			if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
649 				sta->last_tdls_pkt_time = jiffies;
650 		} else {
651 			ieee80211_lost_packet(sta, info);
652 		}
653 
654 		rate_control_tx_status_noskb(local, sband, sta, info);
655 	}
656 
657 	if (acked || noack_success) {
658 		I802_DEBUG_INC(local->dot11TransmittedFrameCount);
659 		if (!pubsta)
660 			I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
661 		if (retry_count > 0)
662 			I802_DEBUG_INC(local->dot11RetryCount);
663 		if (retry_count > 1)
664 			I802_DEBUG_INC(local->dot11MultipleRetryCount);
665 	} else {
666 		I802_DEBUG_INC(local->dot11FailedCount);
667 	}
668 }
669 EXPORT_SYMBOL(ieee80211_tx_status_noskb);
670 
671 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
672 {
673 	struct sk_buff *skb2;
674 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
675 	struct ieee80211_local *local = hw_to_local(hw);
676 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
677 	__le16 fc;
678 	struct ieee80211_supported_band *sband;
679 	struct ieee80211_sub_if_data *sdata;
680 	struct net_device *prev_dev = NULL;
681 	struct sta_info *sta;
682 	struct rhash_head *tmp;
683 	int retry_count;
684 	int rates_idx;
685 	bool send_to_cooked;
686 	bool acked;
687 	struct ieee80211_bar *bar;
688 	int rtap_len;
689 	int shift = 0;
690 	int tid = IEEE80211_NUM_TIDS;
691 	const struct bucket_table *tbl;
692 
693 	rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
694 
695 	rcu_read_lock();
696 
697 	sband = local->hw.wiphy->bands[info->band];
698 	fc = hdr->frame_control;
699 
700 	tbl = rht_dereference_rcu(local->sta_hash.tbl, &local->sta_hash);
701 
702 	for_each_sta_info(local, tbl, hdr->addr1, sta, tmp) {
703 		/* skip wrong virtual interface */
704 		if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
705 			continue;
706 
707 		shift = ieee80211_vif_get_shift(&sta->sdata->vif);
708 
709 		if (info->flags & IEEE80211_TX_STATUS_EOSP)
710 			clear_sta_flag(sta, WLAN_STA_SP);
711 
712 		acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
713 		if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
714 			/*
715 			 * The STA is in power save mode, so assume
716 			 * that this TX packet failed because of that.
717 			 */
718 			ieee80211_handle_filtered_frame(local, sta, skb);
719 			rcu_read_unlock();
720 			return;
721 		}
722 
723 		/* mesh Peer Service Period support */
724 		if (ieee80211_vif_is_mesh(&sta->sdata->vif) &&
725 		    ieee80211_is_data_qos(fc))
726 			ieee80211_mpsp_trigger_process(
727 					ieee80211_get_qos_ctl(hdr),
728 					sta, true, acked);
729 
730 		if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL) &&
731 		    (ieee80211_is_data(hdr->frame_control)) &&
732 		    (rates_idx != -1))
733 			sta->last_tx_rate = info->status.rates[rates_idx];
734 
735 		if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
736 		    (ieee80211_is_data_qos(fc))) {
737 			u16 ssn;
738 			u8 *qc;
739 
740 			qc = ieee80211_get_qos_ctl(hdr);
741 			tid = qc[0] & 0xf;
742 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
743 						& IEEE80211_SCTL_SEQ);
744 			ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
745 					   tid, ssn);
746 		} else if (ieee80211_is_data_qos(fc)) {
747 			u8 *qc = ieee80211_get_qos_ctl(hdr);
748 
749 			tid = qc[0] & 0xf;
750 		}
751 
752 		if (!acked && ieee80211_is_back_req(fc)) {
753 			u16 control;
754 
755 			/*
756 			 * BAR failed, store the last SSN and retry sending
757 			 * the BAR when the next unicast transmission on the
758 			 * same TID succeeds.
759 			 */
760 			bar = (struct ieee80211_bar *) skb->data;
761 			control = le16_to_cpu(bar->control);
762 			if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
763 				u16 ssn = le16_to_cpu(bar->start_seq_num);
764 
765 				tid = (control &
766 				       IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
767 				      IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
768 
769 				ieee80211_set_bar_pending(sta, tid, ssn);
770 			}
771 		}
772 
773 		if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
774 			ieee80211_handle_filtered_frame(local, sta, skb);
775 			rcu_read_unlock();
776 			return;
777 		} else {
778 			if (!acked)
779 				sta->tx_retry_failed++;
780 			sta->tx_retry_count += retry_count;
781 
782 			if (ieee80211_is_data_present(fc)) {
783 				if (!acked)
784 					sta->tx_msdu_failed[tid]++;
785 				sta->tx_msdu_retries[tid] += retry_count;
786 			}
787 		}
788 
789 		rate_control_tx_status(local, sband, sta, skb);
790 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
791 			ieee80211s_update_metric(local, sta, skb);
792 
793 		if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
794 			ieee80211_frame_acked(sta, skb);
795 
796 		if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
797 		    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS))
798 			ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data,
799 						acked, info->status.tx_time);
800 
801 		if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
802 			if (info->flags & IEEE80211_TX_STAT_ACK) {
803 				if (sta->lost_packets)
804 					sta->lost_packets = 0;
805 
806 				/* Track when last TDLS packet was ACKed */
807 				if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
808 					sta->last_tdls_pkt_time = jiffies;
809 			} else {
810 				ieee80211_lost_packet(sta, info);
811 			}
812 		}
813 
814 		if (acked)
815 			sta->last_ack_signal = info->status.ack_signal;
816 	}
817 
818 	rcu_read_unlock();
819 
820 	ieee80211_led_tx(local);
821 
822 	/* SNMP counters
823 	 * Fragments are passed to low-level drivers as separate skbs, so these
824 	 * are actually fragments, not frames. Update frame counters only for
825 	 * the first fragment of the frame. */
826 	if ((info->flags & IEEE80211_TX_STAT_ACK) ||
827 	    (info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED)) {
828 		if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
829 			I802_DEBUG_INC(local->dot11TransmittedFrameCount);
830 			if (is_multicast_ether_addr(ieee80211_get_DA(hdr)))
831 				I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
832 			if (retry_count > 0)
833 				I802_DEBUG_INC(local->dot11RetryCount);
834 			if (retry_count > 1)
835 				I802_DEBUG_INC(local->dot11MultipleRetryCount);
836 		}
837 
838 		/* This counter shall be incremented for an acknowledged MPDU
839 		 * with an individual address in the address 1 field or an MPDU
840 		 * with a multicast address in the address 1 field of type Data
841 		 * or Management. */
842 		if (!is_multicast_ether_addr(hdr->addr1) ||
843 		    ieee80211_is_data(fc) ||
844 		    ieee80211_is_mgmt(fc))
845 			I802_DEBUG_INC(local->dot11TransmittedFragmentCount);
846 	} else {
847 		if (ieee80211_is_first_frag(hdr->seq_ctrl))
848 			I802_DEBUG_INC(local->dot11FailedCount);
849 	}
850 
851 	if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
852 	    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS) &&
853 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
854 	    local->ps_sdata && !(local->scanning)) {
855 		if (info->flags & IEEE80211_TX_STAT_ACK) {
856 			local->ps_sdata->u.mgd.flags |=
857 					IEEE80211_STA_NULLFUNC_ACKED;
858 		} else
859 			mod_timer(&local->dynamic_ps_timer, jiffies +
860 					msecs_to_jiffies(10));
861 	}
862 
863 	ieee80211_report_used_skb(local, skb, false);
864 
865 	/* this was a transmitted frame, but now we want to reuse it */
866 	skb_orphan(skb);
867 
868 	/* Need to make a copy before skb->cb gets cleared */
869 	send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
870 			 !(ieee80211_is_data(fc));
871 
872 	/*
873 	 * This is a bit racy but we can avoid a lot of work
874 	 * with this test...
875 	 */
876 	if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
877 		dev_kfree_skb(skb);
878 		return;
879 	}
880 
881 	/* send frame to monitor interfaces now */
882 	rtap_len = ieee80211_tx_radiotap_len(info);
883 	if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
884 		pr_err("ieee80211_tx_status: headroom too small\n");
885 		dev_kfree_skb(skb);
886 		return;
887 	}
888 	ieee80211_add_tx_radiotap_header(local, sband, skb, retry_count,
889 					 rtap_len, shift);
890 
891 	/* XXX: is this sufficient for BPF? */
892 	skb_set_mac_header(skb, 0);
893 	skb->ip_summed = CHECKSUM_UNNECESSARY;
894 	skb->pkt_type = PACKET_OTHERHOST;
895 	skb->protocol = htons(ETH_P_802_2);
896 	memset(skb->cb, 0, sizeof(skb->cb));
897 
898 	rcu_read_lock();
899 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
900 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
901 			if (!ieee80211_sdata_running(sdata))
902 				continue;
903 
904 			if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) &&
905 			    !send_to_cooked)
906 				continue;
907 
908 			if (prev_dev) {
909 				skb2 = skb_clone(skb, GFP_ATOMIC);
910 				if (skb2) {
911 					skb2->dev = prev_dev;
912 					netif_rx(skb2);
913 				}
914 			}
915 
916 			prev_dev = sdata->dev;
917 		}
918 	}
919 	if (prev_dev) {
920 		skb->dev = prev_dev;
921 		netif_rx(skb);
922 		skb = NULL;
923 	}
924 	rcu_read_unlock();
925 	dev_kfree_skb(skb);
926 }
927 EXPORT_SYMBOL(ieee80211_tx_status);
928 
929 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
930 {
931 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
932 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
933 				    num_packets, GFP_ATOMIC);
934 }
935 EXPORT_SYMBOL(ieee80211_report_low_ack);
936 
937 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
938 {
939 	struct ieee80211_local *local = hw_to_local(hw);
940 
941 	ieee80211_report_used_skb(local, skb, true);
942 	dev_kfree_skb_any(skb);
943 }
944 EXPORT_SYMBOL(ieee80211_free_txskb);
945 
946 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
947 			      struct sk_buff_head *skbs)
948 {
949 	struct sk_buff *skb;
950 
951 	while ((skb = __skb_dequeue(skbs)))
952 		ieee80211_free_txskb(hw, skb);
953 }
954