xref: /linux/net/mac80211/status.c (revision a8cb826aeab84553a30af22ca6d6b95a6513adb2)
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_free_txskb(&local->hw, skb);
56 		return;
57 	}
58 
59 	/*
60 	 * This skb 'survived' a round-trip through the driver, and
61 	 * hopefully the driver didn't mangle it too badly. However,
62 	 * we can definitely not rely on the control information
63 	 * being correct. Clear it so we don't get junk there, and
64 	 * indicate that it needs new processing, but must not be
65 	 * modified/encrypted again.
66 	 */
67 	memset(&info->control, 0, sizeof(info->control));
68 
69 	info->control.jiffies = jiffies;
70 	info->control.vif = &sta->sdata->vif;
71 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
72 		       IEEE80211_TX_INTFL_RETRANSMISSION;
73 	info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
74 
75 	sta->status_stats.filtered++;
76 
77 	/*
78 	 * Clear more-data bit on filtered frames, it might be set
79 	 * but later frames might time out so it might have to be
80 	 * clear again ... It's all rather unlikely (this frame
81 	 * should time out first, right?) but let's not confuse
82 	 * peers unnecessarily.
83 	 */
84 	if (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_MOREDATA))
85 		hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_MOREDATA);
86 
87 	if (ieee80211_is_data_qos(hdr->frame_control)) {
88 		u8 *p = ieee80211_get_qos_ctl(hdr);
89 		int tid = *p & IEEE80211_QOS_CTL_TID_MASK;
90 
91 		/*
92 		 * Clear EOSP if set, this could happen e.g.
93 		 * if an absence period (us being a P2P GO)
94 		 * shortens the SP.
95 		 */
96 		if (*p & IEEE80211_QOS_CTL_EOSP)
97 			*p &= ~IEEE80211_QOS_CTL_EOSP;
98 		ac = ieee802_1d_to_ac[tid & 7];
99 	} else {
100 		ac = IEEE80211_AC_BE;
101 	}
102 
103 	/*
104 	 * Clear the TX filter mask for this STA when sending the next
105 	 * packet. If the STA went to power save mode, this will happen
106 	 * when it wakes up for the next time.
107 	 */
108 	set_sta_flag(sta, WLAN_STA_CLEAR_PS_FILT);
109 	ieee80211_clear_fast_xmit(sta);
110 
111 	/*
112 	 * This code races in the following way:
113 	 *
114 	 *  (1) STA sends frame indicating it will go to sleep and does so
115 	 *  (2) hardware/firmware adds STA to filter list, passes frame up
116 	 *  (3) hardware/firmware processes TX fifo and suppresses a frame
117 	 *  (4) we get TX status before having processed the frame and
118 	 *	knowing that the STA has gone to sleep.
119 	 *
120 	 * This is actually quite unlikely even when both those events are
121 	 * processed from interrupts coming in quickly after one another or
122 	 * even at the same time because we queue both TX status events and
123 	 * RX frames to be processed by a tasklet and process them in the
124 	 * same order that they were received or TX status last. Hence, there
125 	 * is no race as long as the frame RX is processed before the next TX
126 	 * status, which drivers can ensure, see below.
127 	 *
128 	 * Note that this can only happen if the hardware or firmware can
129 	 * actually add STAs to the filter list, if this is done by the
130 	 * driver in response to set_tim() (which will only reduce the race
131 	 * this whole filtering tries to solve, not completely solve it)
132 	 * this situation cannot happen.
133 	 *
134 	 * To completely solve this race drivers need to make sure that they
135 	 *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
136 	 *	functions and
137 	 *  (b) always process RX events before TX status events if ordering
138 	 *      can be unknown, for example with different interrupt status
139 	 *	bits.
140 	 *  (c) if PS mode transitions are manual (i.e. the flag
141 	 *      %IEEE80211_HW_AP_LINK_PS is set), always process PS state
142 	 *      changes before calling TX status events if ordering can be
143 	 *	unknown.
144 	 */
145 	if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
146 	    skb_queue_len(&sta->tx_filtered[ac]) < STA_MAX_TX_BUFFER) {
147 		skb_queue_tail(&sta->tx_filtered[ac], skb);
148 		sta_info_recalc_tim(sta);
149 
150 		if (!timer_pending(&local->sta_cleanup))
151 			mod_timer(&local->sta_cleanup,
152 				  round_jiffies(jiffies +
153 						STA_INFO_CLEANUP_INTERVAL));
154 		return;
155 	}
156 
157 	if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
158 	    !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
159 		/* Software retry the packet once */
160 		info->flags |= IEEE80211_TX_INTFL_RETRIED;
161 		ieee80211_add_pending_skb(local, skb);
162 		return;
163 	}
164 
165 	ps_dbg_ratelimited(sta->sdata,
166 			   "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n",
167 			   skb_queue_len(&sta->tx_filtered[ac]),
168 			   !!test_sta_flag(sta, WLAN_STA_PS_STA), jiffies);
169 	ieee80211_free_txskb(&local->hw, skb);
170 }
171 
172 static void ieee80211_check_pending_bar(struct sta_info *sta, u8 *addr, u8 tid)
173 {
174 	struct tid_ampdu_tx *tid_tx;
175 
176 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
177 	if (!tid_tx || !tid_tx->bar_pending)
178 		return;
179 
180 	tid_tx->bar_pending = false;
181 	ieee80211_send_bar(&sta->sdata->vif, addr, tid, tid_tx->failed_bar_ssn);
182 }
183 
184 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
185 {
186 	struct ieee80211_mgmt *mgmt = (void *) skb->data;
187 	struct ieee80211_local *local = sta->local;
188 	struct ieee80211_sub_if_data *sdata = sta->sdata;
189 
190 	if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS))
191 		sta->rx_stats.last_rx = jiffies;
192 
193 	if (ieee80211_is_data_qos(mgmt->frame_control)) {
194 		struct ieee80211_hdr *hdr = (void *) skb->data;
195 		u8 *qc = ieee80211_get_qos_ctl(hdr);
196 		u16 tid = qc[0] & 0xf;
197 
198 		ieee80211_check_pending_bar(sta, hdr->addr1, tid);
199 	}
200 
201 	if (ieee80211_is_action(mgmt->frame_control) &&
202 	    mgmt->u.action.category == WLAN_CATEGORY_HT &&
203 	    mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS &&
204 	    ieee80211_sdata_running(sdata)) {
205 		enum ieee80211_smps_mode smps_mode;
206 
207 		switch (mgmt->u.action.u.ht_smps.smps_control) {
208 		case WLAN_HT_SMPS_CONTROL_DYNAMIC:
209 			smps_mode = IEEE80211_SMPS_DYNAMIC;
210 			break;
211 		case WLAN_HT_SMPS_CONTROL_STATIC:
212 			smps_mode = IEEE80211_SMPS_STATIC;
213 			break;
214 		case WLAN_HT_SMPS_CONTROL_DISABLED:
215 		default: /* shouldn't happen since we don't send that */
216 			smps_mode = IEEE80211_SMPS_OFF;
217 			break;
218 		}
219 
220 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
221 			/*
222 			 * This update looks racy, but isn't -- if we come
223 			 * here we've definitely got a station that we're
224 			 * talking to, and on a managed interface that can
225 			 * only be the AP. And the only other place updating
226 			 * this variable in managed mode is before association.
227 			 */
228 			sdata->smps_mode = smps_mode;
229 			ieee80211_queue_work(&local->hw, &sdata->recalc_smps);
230 		} else if (sdata->vif.type == NL80211_IFTYPE_AP ||
231 			   sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
232 			sta->known_smps_mode = smps_mode;
233 		}
234 	}
235 }
236 
237 static void ieee80211_set_bar_pending(struct sta_info *sta, u8 tid, u16 ssn)
238 {
239 	struct tid_ampdu_tx *tid_tx;
240 
241 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
242 	if (!tid_tx)
243 		return;
244 
245 	tid_tx->failed_bar_ssn = ssn;
246 	tid_tx->bar_pending = true;
247 }
248 
249 static int ieee80211_tx_radiotap_len(struct ieee80211_tx_info *info)
250 {
251 	int len = sizeof(struct ieee80211_radiotap_header);
252 
253 	/* IEEE80211_RADIOTAP_RATE rate */
254 	if (info->status.rates[0].idx >= 0 &&
255 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
256 					     IEEE80211_TX_RC_VHT_MCS)))
257 		len += 2;
258 
259 	/* IEEE80211_RADIOTAP_TX_FLAGS */
260 	len += 2;
261 
262 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
263 	len += 1;
264 
265 	/* IEEE80211_RADIOTAP_MCS
266 	 * IEEE80211_RADIOTAP_VHT */
267 	if (info->status.rates[0].idx >= 0) {
268 		if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS)
269 			len += 3;
270 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS)
271 			len = ALIGN(len, 2) + 12;
272 	}
273 
274 	return len;
275 }
276 
277 static void
278 ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
279 				 struct ieee80211_supported_band *sband,
280 				 struct sk_buff *skb, int retry_count,
281 				 int rtap_len, int shift)
282 {
283 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
284 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
285 	struct ieee80211_radiotap_header *rthdr;
286 	unsigned char *pos;
287 	u16 txflags;
288 
289 	rthdr = (struct ieee80211_radiotap_header *) skb_push(skb, rtap_len);
290 
291 	memset(rthdr, 0, rtap_len);
292 	rthdr->it_len = cpu_to_le16(rtap_len);
293 	rthdr->it_present =
294 		cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
295 			    (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
296 	pos = (unsigned char *)(rthdr + 1);
297 
298 	/*
299 	 * XXX: Once radiotap gets the bitmap reset thing the vendor
300 	 *	extensions proposal contains, we can actually report
301 	 *	the whole set of tries we did.
302 	 */
303 
304 	/* IEEE80211_RADIOTAP_RATE */
305 	if (info->status.rates[0].idx >= 0 &&
306 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
307 					     IEEE80211_TX_RC_VHT_MCS))) {
308 		u16 rate;
309 
310 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
311 		rate = sband->bitrates[info->status.rates[0].idx].bitrate;
312 		*pos = DIV_ROUND_UP(rate, 5 * (1 << shift));
313 		/* padding for tx flags */
314 		pos += 2;
315 	}
316 
317 	/* IEEE80211_RADIOTAP_TX_FLAGS */
318 	txflags = 0;
319 	if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
320 	    !is_multicast_ether_addr(hdr->addr1))
321 		txflags |= IEEE80211_RADIOTAP_F_TX_FAIL;
322 
323 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
324 		txflags |= IEEE80211_RADIOTAP_F_TX_CTS;
325 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
326 		txflags |= IEEE80211_RADIOTAP_F_TX_RTS;
327 
328 	put_unaligned_le16(txflags, pos);
329 	pos += 2;
330 
331 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
332 	/* for now report the total retry_count */
333 	*pos = retry_count;
334 	pos++;
335 
336 	if (info->status.rates[0].idx < 0)
337 		return;
338 
339 	/* IEEE80211_RADIOTAP_MCS
340 	 * IEEE80211_RADIOTAP_VHT */
341 	if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
342 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
343 		pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
344 			 IEEE80211_RADIOTAP_MCS_HAVE_GI |
345 			 IEEE80211_RADIOTAP_MCS_HAVE_BW;
346 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
347 			pos[1] |= IEEE80211_RADIOTAP_MCS_SGI;
348 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
349 			pos[1] |= IEEE80211_RADIOTAP_MCS_BW_40;
350 		if (info->status.rates[0].flags & IEEE80211_TX_RC_GREEN_FIELD)
351 			pos[1] |= IEEE80211_RADIOTAP_MCS_FMT_GF;
352 		pos[2] = info->status.rates[0].idx;
353 		pos += 3;
354 	} else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS) {
355 		u16 known = local->hw.radiotap_vht_details &
356 			(IEEE80211_RADIOTAP_VHT_KNOWN_GI |
357 			 IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH);
358 
359 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
360 
361 		/* required alignment from rthdr */
362 		pos = (u8 *)rthdr + ALIGN(pos - (u8 *)rthdr, 2);
363 
364 		/* u16 known - IEEE80211_RADIOTAP_VHT_KNOWN_* */
365 		put_unaligned_le16(known, pos);
366 		pos += 2;
367 
368 		/* u8 flags - IEEE80211_RADIOTAP_VHT_FLAG_* */
369 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
370 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
371 		pos++;
372 
373 		/* u8 bandwidth */
374 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
375 			*pos = 1;
376 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_80_MHZ_WIDTH)
377 			*pos = 4;
378 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_160_MHZ_WIDTH)
379 			*pos = 11;
380 		else /* IEEE80211_TX_RC_{20_MHZ_WIDTH,FIXME:DUP_DATA} */
381 			*pos = 0;
382 		pos++;
383 
384 		/* u8 mcs_nss[4] */
385 		*pos = (ieee80211_rate_get_vht_mcs(&info->status.rates[0]) << 4) |
386 			ieee80211_rate_get_vht_nss(&info->status.rates[0]);
387 		pos += 4;
388 
389 		/* u8 coding */
390 		pos++;
391 		/* u8 group_id */
392 		pos++;
393 		/* u16 partial_aid */
394 		pos += 2;
395 	}
396 }
397 
398 /*
399  * Handles the tx for TDLS teardown frames.
400  * If the frame wasn't ACKed by the peer - it will be re-sent through the AP
401  */
402 static void ieee80211_tdls_td_tx_handle(struct ieee80211_local *local,
403 					struct ieee80211_sub_if_data *sdata,
404 					struct sk_buff *skb, u32 flags)
405 {
406 	struct sk_buff *teardown_skb;
407 	struct sk_buff *orig_teardown_skb;
408 	bool is_teardown = false;
409 
410 	/* Get the teardown data we need and free the lock */
411 	spin_lock(&sdata->u.mgd.teardown_lock);
412 	teardown_skb = sdata->u.mgd.teardown_skb;
413 	orig_teardown_skb = sdata->u.mgd.orig_teardown_skb;
414 	if ((skb == orig_teardown_skb) && teardown_skb) {
415 		sdata->u.mgd.teardown_skb = NULL;
416 		sdata->u.mgd.orig_teardown_skb = NULL;
417 		is_teardown = true;
418 	}
419 	spin_unlock(&sdata->u.mgd.teardown_lock);
420 
421 	if (is_teardown) {
422 		/* This mechanism relies on being able to get ACKs */
423 		WARN_ON(!ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS));
424 
425 		/* Check if peer has ACKed */
426 		if (flags & IEEE80211_TX_STAT_ACK) {
427 			dev_kfree_skb_any(teardown_skb);
428 		} else {
429 			tdls_dbg(sdata,
430 				 "TDLS Resending teardown through AP\n");
431 
432 			ieee80211_subif_start_xmit(teardown_skb, skb->dev);
433 		}
434 	}
435 }
436 
437 static struct ieee80211_sub_if_data *
438 ieee80211_sdata_from_skb(struct ieee80211_local *local, struct sk_buff *skb)
439 {
440 	struct ieee80211_sub_if_data *sdata;
441 
442 	if (skb->dev) {
443 		list_for_each_entry_rcu(sdata, &local->interfaces, list) {
444 			if (!sdata->dev)
445 				continue;
446 
447 			if (skb->dev == sdata->dev)
448 				return sdata;
449 		}
450 
451 		return NULL;
452 	}
453 
454 	return rcu_dereference(local->p2p_sdata);
455 }
456 
457 static void ieee80211_report_ack_skb(struct ieee80211_local *local,
458 				     struct ieee80211_tx_info *info,
459 				     bool acked, bool dropped)
460 {
461 	struct sk_buff *skb;
462 	unsigned long flags;
463 
464 	spin_lock_irqsave(&local->ack_status_lock, flags);
465 	skb = idr_find(&local->ack_status_frames, info->ack_frame_id);
466 	if (skb)
467 		idr_remove(&local->ack_status_frames, info->ack_frame_id);
468 	spin_unlock_irqrestore(&local->ack_status_lock, flags);
469 
470 	if (!skb)
471 		return;
472 
473 	if (dropped) {
474 		dev_kfree_skb_any(skb);
475 		return;
476 	}
477 
478 	if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) {
479 		u64 cookie = IEEE80211_SKB_CB(skb)->ack.cookie;
480 		struct ieee80211_sub_if_data *sdata;
481 		struct ieee80211_hdr *hdr = (void *)skb->data;
482 
483 		rcu_read_lock();
484 		sdata = ieee80211_sdata_from_skb(local, skb);
485 		if (sdata) {
486 			if (ieee80211_is_nullfunc(hdr->frame_control) ||
487 			    ieee80211_is_qos_nullfunc(hdr->frame_control))
488 				cfg80211_probe_status(sdata->dev, hdr->addr1,
489 						      cookie, acked,
490 						      GFP_ATOMIC);
491 			else
492 				cfg80211_mgmt_tx_status(&sdata->wdev, cookie,
493 							skb->data, skb->len,
494 							acked, GFP_ATOMIC);
495 		}
496 		rcu_read_unlock();
497 
498 		dev_kfree_skb_any(skb);
499 	} else {
500 		/* consumes skb */
501 		skb_complete_wifi_ack(skb, acked);
502 	}
503 }
504 
505 static void ieee80211_report_used_skb(struct ieee80211_local *local,
506 				      struct sk_buff *skb, bool dropped)
507 {
508 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
509 	struct ieee80211_hdr *hdr = (void *)skb->data;
510 	bool acked = info->flags & IEEE80211_TX_STAT_ACK;
511 
512 	if (dropped)
513 		acked = false;
514 
515 	if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) {
516 		struct ieee80211_sub_if_data *sdata;
517 
518 		rcu_read_lock();
519 
520 		sdata = ieee80211_sdata_from_skb(local, skb);
521 
522 		if (!sdata) {
523 			skb->dev = NULL;
524 		} else {
525 			unsigned int hdr_size =
526 				ieee80211_hdrlen(hdr->frame_control);
527 
528 			/* Check to see if packet is a TDLS teardown packet */
529 			if (ieee80211_is_data(hdr->frame_control) &&
530 			    (ieee80211_get_tdls_action(skb, hdr_size) ==
531 			     WLAN_TDLS_TEARDOWN))
532 				ieee80211_tdls_td_tx_handle(local, sdata, skb,
533 							    info->flags);
534 			else
535 				ieee80211_mgd_conn_tx_status(sdata,
536 							     hdr->frame_control,
537 							     acked);
538 		}
539 
540 		rcu_read_unlock();
541 	} else if (info->ack_frame_id) {
542 		ieee80211_report_ack_skb(local, info, acked, dropped);
543 	}
544 }
545 
546 /*
547  * Use a static threshold for now, best value to be determined
548  * by testing ...
549  * Should it depend on:
550  *  - on # of retransmissions
551  *  - current throughput (higher value for higher tpt)?
552  */
553 #define STA_LOST_PKT_THRESHOLD	50
554 #define STA_LOST_TDLS_PKT_THRESHOLD	10
555 #define STA_LOST_TDLS_PKT_TIME		(10*HZ) /* 10secs since last ACK */
556 
557 static void ieee80211_lost_packet(struct sta_info *sta,
558 				  struct ieee80211_tx_info *info)
559 {
560 	/* This packet was aggregated but doesn't carry status info */
561 	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
562 	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
563 		return;
564 
565 	sta->status_stats.lost_packets++;
566 	if (!sta->sta.tdls &&
567 	    sta->status_stats.lost_packets < STA_LOST_PKT_THRESHOLD)
568 		return;
569 
570 	/*
571 	 * If we're in TDLS mode, make sure that all STA_LOST_TDLS_PKT_THRESHOLD
572 	 * of the last packets were lost, and that no ACK was received in the
573 	 * last STA_LOST_TDLS_PKT_TIME ms, before triggering the CQM packet-loss
574 	 * mechanism.
575 	 */
576 	if (sta->sta.tdls &&
577 	    (sta->status_stats.lost_packets < STA_LOST_TDLS_PKT_THRESHOLD ||
578 	     time_before(jiffies,
579 			 sta->status_stats.last_tdls_pkt_time +
580 			 STA_LOST_TDLS_PKT_TIME)))
581 		return;
582 
583 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
584 				    sta->status_stats.lost_packets, GFP_ATOMIC);
585 	sta->status_stats.lost_packets = 0;
586 }
587 
588 static int ieee80211_tx_get_rates(struct ieee80211_hw *hw,
589 				  struct ieee80211_tx_info *info,
590 				  int *retry_count)
591 {
592 	int rates_idx = -1;
593 	int count = -1;
594 	int i;
595 
596 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
597 		if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
598 		    !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
599 			/* just the first aggr frame carry status info */
600 			info->status.rates[i].idx = -1;
601 			info->status.rates[i].count = 0;
602 			break;
603 		} else if (info->status.rates[i].idx < 0) {
604 			break;
605 		} else if (i >= hw->max_report_rates) {
606 			/* the HW cannot have attempted that rate */
607 			info->status.rates[i].idx = -1;
608 			info->status.rates[i].count = 0;
609 			break;
610 		}
611 
612 		count += info->status.rates[i].count;
613 	}
614 	rates_idx = i - 1;
615 
616 	if (count < 0)
617 		count = 0;
618 
619 	*retry_count = count;
620 	return rates_idx;
621 }
622 
623 void ieee80211_tx_status_noskb(struct ieee80211_hw *hw,
624 			       struct ieee80211_sta *pubsta,
625 			       struct ieee80211_tx_info *info)
626 {
627 	struct ieee80211_local *local = hw_to_local(hw);
628 	struct ieee80211_supported_band *sband;
629 	int retry_count;
630 	int rates_idx;
631 	bool acked, noack_success;
632 
633 	rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
634 
635 	sband = hw->wiphy->bands[info->band];
636 
637 	acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
638 	noack_success = !!(info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED);
639 
640 	if (pubsta) {
641 		struct sta_info *sta;
642 
643 		sta = container_of(pubsta, struct sta_info, sta);
644 
645 		if (!acked)
646 			sta->status_stats.retry_failed++;
647 		sta->status_stats.retry_count += retry_count;
648 
649 		if (acked) {
650 			sta->rx_stats.last_rx = jiffies;
651 
652 			if (sta->status_stats.lost_packets)
653 				sta->status_stats.lost_packets = 0;
654 
655 			/* Track when last TDLS packet was ACKed */
656 			if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
657 				sta->status_stats.last_tdls_pkt_time = jiffies;
658 		} else {
659 			ieee80211_lost_packet(sta, info);
660 		}
661 
662 		rate_control_tx_status_noskb(local, sband, sta, info);
663 	}
664 
665 	if (acked || noack_success) {
666 		I802_DEBUG_INC(local->dot11TransmittedFrameCount);
667 		if (!pubsta)
668 			I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
669 		if (retry_count > 0)
670 			I802_DEBUG_INC(local->dot11RetryCount);
671 		if (retry_count > 1)
672 			I802_DEBUG_INC(local->dot11MultipleRetryCount);
673 	} else {
674 		I802_DEBUG_INC(local->dot11FailedCount);
675 	}
676 }
677 EXPORT_SYMBOL(ieee80211_tx_status_noskb);
678 
679 void ieee80211_tx_monitor(struct ieee80211_local *local, struct sk_buff *skb,
680 			  struct ieee80211_supported_band *sband,
681 			  int retry_count, int shift, bool send_to_cooked)
682 {
683 	struct sk_buff *skb2;
684 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
685 	struct ieee80211_sub_if_data *sdata;
686 	struct net_device *prev_dev = NULL;
687 	int rtap_len;
688 
689 	/* send frame to monitor interfaces now */
690 	rtap_len = ieee80211_tx_radiotap_len(info);
691 	if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
692 		pr_err("ieee80211_tx_status: headroom too small\n");
693 		dev_kfree_skb(skb);
694 		return;
695 	}
696 	ieee80211_add_tx_radiotap_header(local, sband, skb, retry_count,
697 					 rtap_len, shift);
698 
699 	/* XXX: is this sufficient for BPF? */
700 	skb_reset_mac_header(skb);
701 	skb->ip_summed = CHECKSUM_UNNECESSARY;
702 	skb->pkt_type = PACKET_OTHERHOST;
703 	skb->protocol = htons(ETH_P_802_2);
704 	memset(skb->cb, 0, sizeof(skb->cb));
705 
706 	rcu_read_lock();
707 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
708 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
709 			if (!ieee80211_sdata_running(sdata))
710 				continue;
711 
712 			if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) &&
713 			    !send_to_cooked)
714 				continue;
715 
716 			if (prev_dev) {
717 				skb2 = skb_clone(skb, GFP_ATOMIC);
718 				if (skb2) {
719 					skb2->dev = prev_dev;
720 					netif_rx(skb2);
721 				}
722 			}
723 
724 			prev_dev = sdata->dev;
725 		}
726 	}
727 	if (prev_dev) {
728 		skb->dev = prev_dev;
729 		netif_rx(skb);
730 		skb = NULL;
731 	}
732 	rcu_read_unlock();
733 	dev_kfree_skb(skb);
734 }
735 
736 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
737 {
738 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
739 	struct ieee80211_local *local = hw_to_local(hw);
740 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
741 	__le16 fc;
742 	struct ieee80211_supported_band *sband;
743 	struct sta_info *sta;
744 	struct rhash_head *tmp;
745 	int retry_count;
746 	int rates_idx;
747 	bool send_to_cooked;
748 	bool acked;
749 	struct ieee80211_bar *bar;
750 	int shift = 0;
751 	int tid = IEEE80211_NUM_TIDS;
752 	const struct bucket_table *tbl;
753 
754 	rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
755 
756 	rcu_read_lock();
757 
758 	sband = local->hw.wiphy->bands[info->band];
759 	fc = hdr->frame_control;
760 
761 	tbl = rht_dereference_rcu(local->sta_hash.tbl, &local->sta_hash);
762 
763 	for_each_sta_info(local, tbl, hdr->addr1, sta, tmp) {
764 		/* skip wrong virtual interface */
765 		if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
766 			continue;
767 
768 		shift = ieee80211_vif_get_shift(&sta->sdata->vif);
769 
770 		if (info->flags & IEEE80211_TX_STATUS_EOSP)
771 			clear_sta_flag(sta, WLAN_STA_SP);
772 
773 		acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
774 		if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
775 			/*
776 			 * The STA is in power save mode, so assume
777 			 * that this TX packet failed because of that.
778 			 */
779 			ieee80211_handle_filtered_frame(local, sta, skb);
780 			rcu_read_unlock();
781 			return;
782 		}
783 
784 		/* mesh Peer Service Period support */
785 		if (ieee80211_vif_is_mesh(&sta->sdata->vif) &&
786 		    ieee80211_is_data_qos(fc))
787 			ieee80211_mpsp_trigger_process(
788 					ieee80211_get_qos_ctl(hdr),
789 					sta, true, acked);
790 
791 		if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL) &&
792 		    (ieee80211_is_data(hdr->frame_control)) &&
793 		    (rates_idx != -1))
794 			sta->tx_stats.last_rate =
795 				info->status.rates[rates_idx];
796 
797 		if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
798 		    (ieee80211_is_data_qos(fc))) {
799 			u16 ssn;
800 			u8 *qc;
801 
802 			qc = ieee80211_get_qos_ctl(hdr);
803 			tid = qc[0] & 0xf;
804 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
805 						& IEEE80211_SCTL_SEQ);
806 			ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
807 					   tid, ssn);
808 		} else if (ieee80211_is_data_qos(fc)) {
809 			u8 *qc = ieee80211_get_qos_ctl(hdr);
810 
811 			tid = qc[0] & 0xf;
812 		}
813 
814 		if (!acked && ieee80211_is_back_req(fc)) {
815 			u16 control;
816 
817 			/*
818 			 * BAR failed, store the last SSN and retry sending
819 			 * the BAR when the next unicast transmission on the
820 			 * same TID succeeds.
821 			 */
822 			bar = (struct ieee80211_bar *) skb->data;
823 			control = le16_to_cpu(bar->control);
824 			if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
825 				u16 ssn = le16_to_cpu(bar->start_seq_num);
826 
827 				tid = (control &
828 				       IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
829 				      IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
830 
831 				ieee80211_set_bar_pending(sta, tid, ssn);
832 			}
833 		}
834 
835 		if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
836 			ieee80211_handle_filtered_frame(local, sta, skb);
837 			rcu_read_unlock();
838 			return;
839 		} else {
840 			if (!acked)
841 				sta->status_stats.retry_failed++;
842 			sta->status_stats.retry_count += retry_count;
843 
844 			if (ieee80211_is_data_present(fc)) {
845 				if (!acked)
846 					sta->status_stats.msdu_failed[tid]++;
847 
848 				sta->status_stats.msdu_retries[tid] +=
849 					retry_count;
850 			}
851 		}
852 
853 		rate_control_tx_status(local, sband, sta, skb);
854 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
855 			ieee80211s_update_metric(local, sta, skb);
856 
857 		if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
858 			ieee80211_frame_acked(sta, skb);
859 
860 		if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
861 		    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS))
862 			ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data,
863 						acked, info->status.tx_time);
864 
865 		if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
866 			if (info->flags & IEEE80211_TX_STAT_ACK) {
867 				if (sta->status_stats.lost_packets)
868 					sta->status_stats.lost_packets = 0;
869 
870 				/* Track when last TDLS packet was ACKed */
871 				if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
872 					sta->status_stats.last_tdls_pkt_time =
873 						jiffies;
874 			} else {
875 				ieee80211_lost_packet(sta, info);
876 			}
877 		}
878 	}
879 
880 	rcu_read_unlock();
881 
882 	ieee80211_led_tx(local);
883 
884 	/* SNMP counters
885 	 * Fragments are passed to low-level drivers as separate skbs, so these
886 	 * are actually fragments, not frames. Update frame counters only for
887 	 * the first fragment of the frame. */
888 	if ((info->flags & IEEE80211_TX_STAT_ACK) ||
889 	    (info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED)) {
890 		if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
891 			I802_DEBUG_INC(local->dot11TransmittedFrameCount);
892 			if (is_multicast_ether_addr(ieee80211_get_DA(hdr)))
893 				I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
894 			if (retry_count > 0)
895 				I802_DEBUG_INC(local->dot11RetryCount);
896 			if (retry_count > 1)
897 				I802_DEBUG_INC(local->dot11MultipleRetryCount);
898 		}
899 
900 		/* This counter shall be incremented for an acknowledged MPDU
901 		 * with an individual address in the address 1 field or an MPDU
902 		 * with a multicast address in the address 1 field of type Data
903 		 * or Management. */
904 		if (!is_multicast_ether_addr(hdr->addr1) ||
905 		    ieee80211_is_data(fc) ||
906 		    ieee80211_is_mgmt(fc))
907 			I802_DEBUG_INC(local->dot11TransmittedFragmentCount);
908 	} else {
909 		if (ieee80211_is_first_frag(hdr->seq_ctrl))
910 			I802_DEBUG_INC(local->dot11FailedCount);
911 	}
912 
913 	if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
914 	    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS) &&
915 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
916 	    local->ps_sdata && !(local->scanning)) {
917 		if (info->flags & IEEE80211_TX_STAT_ACK) {
918 			local->ps_sdata->u.mgd.flags |=
919 					IEEE80211_STA_NULLFUNC_ACKED;
920 		} else
921 			mod_timer(&local->dynamic_ps_timer, jiffies +
922 					msecs_to_jiffies(10));
923 	}
924 
925 	ieee80211_report_used_skb(local, skb, false);
926 
927 	/* this was a transmitted frame, but now we want to reuse it */
928 	skb_orphan(skb);
929 
930 	/* Need to make a copy before skb->cb gets cleared */
931 	send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
932 			 !(ieee80211_is_data(fc));
933 
934 	/*
935 	 * This is a bit racy but we can avoid a lot of work
936 	 * with this test...
937 	 */
938 	if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
939 		dev_kfree_skb(skb);
940 		return;
941 	}
942 
943 	/* send to monitor interfaces */
944 	ieee80211_tx_monitor(local, skb, sband, retry_count, shift, send_to_cooked);
945 }
946 EXPORT_SYMBOL(ieee80211_tx_status);
947 
948 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
949 {
950 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
951 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
952 				    num_packets, GFP_ATOMIC);
953 }
954 EXPORT_SYMBOL(ieee80211_report_low_ack);
955 
956 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
957 {
958 	struct ieee80211_local *local = hw_to_local(hw);
959 
960 	ieee80211_report_used_skb(local, skb, true);
961 	dev_kfree_skb_any(skb);
962 }
963 EXPORT_SYMBOL(ieee80211_free_txskb);
964 
965 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
966 			      struct sk_buff_head *skbs)
967 {
968 	struct sk_buff *skb;
969 
970 	while ((skb = __skb_dequeue(skbs)))
971 		ieee80211_free_txskb(hw, skb);
972 }
973