1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * HT handling
4  *
5  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
6  * Copyright 2002-2005, Instant802 Networks, Inc.
7  * Copyright 2005-2006, Devicescape Software, Inc.
8  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
9  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10  * Copyright 2007-2010, Intel Corporation
11  * Copyright(c) 2015-2017 Intel Deutschland GmbH
12  * Copyright (C) 2018 - 2022 Intel Corporation
13  */
14 
15 #include <linux/ieee80211.h>
16 #include <linux/slab.h>
17 #include <linux/export.h>
18 #include <net/mac80211.h>
19 #include "ieee80211_i.h"
20 #include "driver-ops.h"
21 #include "wme.h"
22 
23 /**
24  * DOC: TX A-MPDU aggregation
25  *
26  * Aggregation on the TX side requires setting the hardware flag
27  * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed
28  * packets with a flag indicating A-MPDU aggregation. The driver
29  * or device is responsible for actually aggregating the frames,
30  * as well as deciding how many and which to aggregate.
31  *
32  * When TX aggregation is started by some subsystem (usually the rate
33  * control algorithm would be appropriate) by calling the
34  * ieee80211_start_tx_ba_session() function, the driver will be
35  * notified via its @ampdu_action function, with the
36  * %IEEE80211_AMPDU_TX_START action.
37  *
38  * In response to that, the driver is later required to call the
39  * ieee80211_start_tx_ba_cb_irqsafe() function, which will really
40  * start the aggregation session after the peer has also responded.
41  * If the peer responds negatively, the session will be stopped
42  * again right away. Note that it is possible for the aggregation
43  * session to be stopped before the driver has indicated that it
44  * is done setting it up, in which case it must not indicate the
45  * setup completion.
46  *
47  * Also note that, since we also need to wait for a response from
48  * the peer, the driver is notified of the completion of the
49  * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the
50  * @ampdu_action callback.
51  *
52  * Similarly, when the aggregation session is stopped by the peer
53  * or something calling ieee80211_stop_tx_ba_session(), the driver's
54  * @ampdu_action function will be called with the action
55  * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail,
56  * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe().
57  * Note that the sta can get destroyed before the BA tear down is
58  * complete.
59  */
60 
ieee80211_send_addba_request(struct ieee80211_sub_if_data * sdata,const u8 * da,u16 tid,u8 dialog_token,u16 start_seq_num,u16 agg_size,u16 timeout)61 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
62 					 const u8 *da, u16 tid,
63 					 u8 dialog_token, u16 start_seq_num,
64 					 u16 agg_size, u16 timeout)
65 {
66 	struct ieee80211_local *local = sdata->local;
67 	struct sk_buff *skb;
68 	struct ieee80211_mgmt *mgmt;
69 	u16 capab;
70 
71 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
72 
73 	if (!skb)
74 		return;
75 
76 	skb_reserve(skb, local->hw.extra_tx_headroom);
77 	mgmt = skb_put_zero(skb, 24);
78 	memcpy(mgmt->da, da, ETH_ALEN);
79 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
80 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
81 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
82 	    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
83 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
84 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
85 		memcpy(mgmt->bssid, sdata->deflink.u.mgd.bssid, ETH_ALEN);
86 	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
87 		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
88 
89 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
90 					  IEEE80211_STYPE_ACTION);
91 
92 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
93 
94 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
95 	mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
96 
97 	mgmt->u.action.u.addba_req.dialog_token = dialog_token;
98 	capab = IEEE80211_ADDBA_PARAM_AMSDU_MASK;
99 	capab |= IEEE80211_ADDBA_PARAM_POLICY_MASK;
100 	capab |= u16_encode_bits(tid, IEEE80211_ADDBA_PARAM_TID_MASK);
101 	capab |= u16_encode_bits(agg_size, IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK);
102 
103 	mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
104 
105 	mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
106 	mgmt->u.action.u.addba_req.start_seq_num =
107 					cpu_to_le16(start_seq_num << 4);
108 
109 	ieee80211_tx_skb_tid(sdata, skb, tid, -1);
110 }
111 
ieee80211_send_bar(struct ieee80211_vif * vif,u8 * ra,u16 tid,u16 ssn)112 void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
113 {
114 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
115 	struct ieee80211_local *local = sdata->local;
116 	struct sk_buff *skb;
117 	struct ieee80211_bar *bar;
118 	u16 bar_control = 0;
119 
120 	skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
121 	if (!skb)
122 		return;
123 
124 	skb_reserve(skb, local->hw.extra_tx_headroom);
125 	bar = skb_put_zero(skb, sizeof(*bar));
126 	bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
127 					 IEEE80211_STYPE_BACK_REQ);
128 	memcpy(bar->ra, ra, ETH_ALEN);
129 	memcpy(bar->ta, sdata->vif.addr, ETH_ALEN);
130 	bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
131 	bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
132 	bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT);
133 	bar->control = cpu_to_le16(bar_control);
134 	bar->start_seq_num = cpu_to_le16(ssn);
135 
136 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
137 					IEEE80211_TX_CTL_REQ_TX_STATUS;
138 	ieee80211_tx_skb_tid(sdata, skb, tid, -1);
139 }
140 EXPORT_SYMBOL(ieee80211_send_bar);
141 
ieee80211_assign_tid_tx(struct sta_info * sta,int tid,struct tid_ampdu_tx * tid_tx)142 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
143 			     struct tid_ampdu_tx *tid_tx)
144 {
145 	lockdep_assert_held(&sta->ampdu_mlme.mtx);
146 	lockdep_assert_held(&sta->lock);
147 	rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
148 }
149 
150 /*
151  * When multiple aggregation sessions on multiple stations
152  * are being created/destroyed simultaneously, we need to
153  * refcount the global queue stop caused by that in order
154  * to not get into a situation where one of the aggregation
155  * setup or teardown re-enables queues before the other is
156  * ready to handle that.
157  *
158  * These two functions take care of this issue by keeping
159  * a global "agg_queue_stop" refcount.
160  */
__acquires(agg_queue)161 static void __acquires(agg_queue)
162 ieee80211_stop_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
163 {
164 	int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
165 
166 	/* we do refcounting here, so don't use the queue reason refcounting */
167 
168 	if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1)
169 		ieee80211_stop_queue_by_reason(
170 			&sdata->local->hw, queue,
171 			IEEE80211_QUEUE_STOP_REASON_AGGREGATION,
172 			false);
173 	__acquire(agg_queue);
174 }
175 
__releases(agg_queue)176 static void __releases(agg_queue)
177 ieee80211_wake_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
178 {
179 	int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
180 
181 	if (atomic_dec_return(&sdata->local->agg_queue_stop[queue]) == 0)
182 		ieee80211_wake_queue_by_reason(
183 			&sdata->local->hw, queue,
184 			IEEE80211_QUEUE_STOP_REASON_AGGREGATION,
185 			false);
186 	__release(agg_queue);
187 }
188 
189 static void
ieee80211_agg_stop_txq(struct sta_info * sta,int tid)190 ieee80211_agg_stop_txq(struct sta_info *sta, int tid)
191 {
192 	struct ieee80211_txq *txq = sta->sta.txq[tid];
193 	struct ieee80211_sub_if_data *sdata;
194 	struct fq *fq;
195 	struct txq_info *txqi;
196 
197 	if (!txq)
198 		return;
199 
200 	txqi = to_txq_info(txq);
201 	sdata = vif_to_sdata(txq->vif);
202 	fq = &sdata->local->fq;
203 
204 	/* Lock here to protect against further seqno updates on dequeue */
205 	spin_lock_bh(&fq->lock);
206 	set_bit(IEEE80211_TXQ_STOP, &txqi->flags);
207 	spin_unlock_bh(&fq->lock);
208 }
209 
210 static void
ieee80211_agg_start_txq(struct sta_info * sta,int tid,bool enable)211 ieee80211_agg_start_txq(struct sta_info *sta, int tid, bool enable)
212 {
213 	struct ieee80211_txq *txq = sta->sta.txq[tid];
214 	struct txq_info *txqi;
215 
216 	lockdep_assert_held(&sta->ampdu_mlme.mtx);
217 
218 	if (!txq)
219 		return;
220 
221 	txqi = to_txq_info(txq);
222 
223 	if (enable)
224 		set_bit(IEEE80211_TXQ_AMPDU, &txqi->flags);
225 	else
226 		clear_bit(IEEE80211_TXQ_AMPDU, &txqi->flags);
227 
228 	clear_bit(IEEE80211_TXQ_STOP, &txqi->flags);
229 	local_bh_disable();
230 	rcu_read_lock();
231 	schedule_and_wake_txq(sta->sdata->local, txqi);
232 	rcu_read_unlock();
233 	local_bh_enable();
234 }
235 
236 /*
237  * splice packets from the STA's pending to the local pending,
238  * requires a call to ieee80211_agg_splice_finish later
239  */
__acquires(agg_queue)240 static void __acquires(agg_queue)
241 ieee80211_agg_splice_packets(struct ieee80211_sub_if_data *sdata,
242 			     struct tid_ampdu_tx *tid_tx, u16 tid)
243 {
244 	struct ieee80211_local *local = sdata->local;
245 	int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
246 	unsigned long flags;
247 
248 	ieee80211_stop_queue_agg(sdata, tid);
249 
250 	if (WARN(!tid_tx,
251 		 "TID %d gone but expected when splicing aggregates from the pending queue\n",
252 		 tid))
253 		return;
254 
255 	if (!skb_queue_empty(&tid_tx->pending)) {
256 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
257 		/* copy over remaining packets */
258 		skb_queue_splice_tail_init(&tid_tx->pending,
259 					   &local->pending[queue]);
260 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
261 	}
262 }
263 
__releases(agg_queue)264 static void __releases(agg_queue)
265 ieee80211_agg_splice_finish(struct ieee80211_sub_if_data *sdata, u16 tid)
266 {
267 	ieee80211_wake_queue_agg(sdata, tid);
268 }
269 
ieee80211_remove_tid_tx(struct sta_info * sta,int tid)270 static void ieee80211_remove_tid_tx(struct sta_info *sta, int tid)
271 {
272 	struct tid_ampdu_tx *tid_tx;
273 
274 	lockdep_assert_held(&sta->ampdu_mlme.mtx);
275 	lockdep_assert_held(&sta->lock);
276 
277 	tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
278 
279 	/*
280 	 * When we get here, the TX path will not be lockless any more wrt.
281 	 * aggregation, since the OPERATIONAL bit has long been cleared.
282 	 * Thus it will block on getting the lock, if it occurs. So if we
283 	 * stop the queue now, we will not get any more packets, and any
284 	 * that might be being processed will wait for us here, thereby
285 	 * guaranteeing that no packets go to the tid_tx pending queue any
286 	 * more.
287 	 */
288 
289 	ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
290 
291 	/* future packets must not find the tid_tx struct any more */
292 	ieee80211_assign_tid_tx(sta, tid, NULL);
293 
294 	ieee80211_agg_splice_finish(sta->sdata, tid);
295 
296 	kfree_rcu(tid_tx, rcu_head);
297 }
298 
___ieee80211_stop_tx_ba_session(struct sta_info * sta,u16 tid,enum ieee80211_agg_stop_reason reason)299 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
300 				    enum ieee80211_agg_stop_reason reason)
301 {
302 	struct ieee80211_local *local = sta->local;
303 	struct tid_ampdu_tx *tid_tx;
304 	struct ieee80211_ampdu_params params = {
305 		.sta = &sta->sta,
306 		.tid = tid,
307 		.buf_size = 0,
308 		.amsdu = false,
309 		.timeout = 0,
310 		.ssn = 0,
311 	};
312 	int ret;
313 
314 	lockdep_assert_held(&sta->ampdu_mlme.mtx);
315 
316 	switch (reason) {
317 	case AGG_STOP_DECLINED:
318 	case AGG_STOP_LOCAL_REQUEST:
319 	case AGG_STOP_PEER_REQUEST:
320 		params.action = IEEE80211_AMPDU_TX_STOP_CONT;
321 		break;
322 	case AGG_STOP_DESTROY_STA:
323 		params.action = IEEE80211_AMPDU_TX_STOP_FLUSH;
324 		break;
325 	default:
326 		WARN_ON_ONCE(1);
327 		return -EINVAL;
328 	}
329 
330 	spin_lock_bh(&sta->lock);
331 
332 	/* free struct pending for start, if present */
333 	tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
334 	kfree(tid_tx);
335 	sta->ampdu_mlme.tid_start_tx[tid] = NULL;
336 
337 	tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
338 	if (!tid_tx) {
339 		spin_unlock_bh(&sta->lock);
340 		return -ENOENT;
341 	}
342 
343 	/*
344 	 * if we're already stopping ignore any new requests to stop
345 	 * unless we're destroying it in which case notify the driver
346 	 */
347 	if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
348 		spin_unlock_bh(&sta->lock);
349 		if (reason != AGG_STOP_DESTROY_STA)
350 			return -EALREADY;
351 		params.action = IEEE80211_AMPDU_TX_STOP_FLUSH_CONT;
352 		ret = drv_ampdu_action(local, sta->sdata, &params);
353 		WARN_ON_ONCE(ret);
354 		return 0;
355 	}
356 
357 	if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
358 		/* not even started yet! */
359 		ieee80211_assign_tid_tx(sta, tid, NULL);
360 		spin_unlock_bh(&sta->lock);
361 		kfree_rcu(tid_tx, rcu_head);
362 		return 0;
363 	}
364 
365 	set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
366 
367 	ieee80211_agg_stop_txq(sta, tid);
368 
369 	spin_unlock_bh(&sta->lock);
370 
371 	ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n",
372 	       sta->sta.addr, tid);
373 
374 	del_timer_sync(&tid_tx->addba_resp_timer);
375 	del_timer_sync(&tid_tx->session_timer);
376 
377 	/*
378 	 * After this packets are no longer handed right through
379 	 * to the driver but are put onto tid_tx->pending instead,
380 	 * with locking to ensure proper access.
381 	 */
382 	clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
383 
384 	/*
385 	 * There might be a few packets being processed right now (on
386 	 * another CPU) that have already gotten past the aggregation
387 	 * check when it was still OPERATIONAL and consequently have
388 	 * IEEE80211_TX_CTL_AMPDU set. In that case, this code might
389 	 * call into the driver at the same time or even before the
390 	 * TX paths calls into it, which could confuse the driver.
391 	 *
392 	 * Wait for all currently running TX paths to finish before
393 	 * telling the driver. New packets will not go through since
394 	 * the aggregation session is no longer OPERATIONAL.
395 	 */
396 	if (!local->in_reconfig)
397 		synchronize_net();
398 
399 	tid_tx->stop_initiator = reason == AGG_STOP_PEER_REQUEST ?
400 					WLAN_BACK_RECIPIENT :
401 					WLAN_BACK_INITIATOR;
402 	tid_tx->tx_stop = reason == AGG_STOP_LOCAL_REQUEST;
403 
404 	ret = drv_ampdu_action(local, sta->sdata, &params);
405 
406 	/* HW shall not deny going back to legacy */
407 	if (WARN_ON(ret)) {
408 		/*
409 		 * We may have pending packets get stuck in this case...
410 		 * Not bothering with a workaround for now.
411 		 */
412 	}
413 
414 	/*
415 	 * In the case of AGG_STOP_DESTROY_STA, the driver won't
416 	 * necessarily call ieee80211_stop_tx_ba_cb(), so this may
417 	 * seem like we can leave the tid_tx data pending forever.
418 	 * This is true, in a way, but "forever" is only until the
419 	 * station struct is actually destroyed. In the meantime,
420 	 * leaving it around ensures that we don't transmit packets
421 	 * to the driver on this TID which might confuse it.
422 	 */
423 
424 	return 0;
425 }
426 
427 /*
428  * After sending add Block Ack request we activated a timer until
429  * add Block Ack response will arrive from the recipient.
430  * If this timer expires sta_addba_resp_timer_expired will be executed.
431  */
sta_addba_resp_timer_expired(struct timer_list * t)432 static void sta_addba_resp_timer_expired(struct timer_list *t)
433 {
434 	struct tid_ampdu_tx *tid_tx = from_timer(tid_tx, t, addba_resp_timer);
435 	struct sta_info *sta = tid_tx->sta;
436 	u8 tid = tid_tx->tid;
437 
438 	/* check if the TID waits for addBA response */
439 	if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
440 		ht_dbg(sta->sdata,
441 		       "timer expired on %pM tid %d not expecting addBA response\n",
442 		       sta->sta.addr, tid);
443 		return;
444 	}
445 
446 	ht_dbg(sta->sdata, "addBA response timer expired on %pM tid %d\n",
447 	       sta->sta.addr, tid);
448 
449 	ieee80211_stop_tx_ba_session(&sta->sta, tid);
450 }
451 
ieee80211_send_addba_with_timeout(struct sta_info * sta,struct tid_ampdu_tx * tid_tx)452 static void ieee80211_send_addba_with_timeout(struct sta_info *sta,
453 					      struct tid_ampdu_tx *tid_tx)
454 {
455 	struct ieee80211_sub_if_data *sdata = sta->sdata;
456 	struct ieee80211_local *local = sta->local;
457 	u8 tid = tid_tx->tid;
458 	u16 buf_size;
459 
460 	/* activate the timer for the recipient's addBA response */
461 	mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
462 	ht_dbg(sdata, "activated addBA response timer on %pM tid %d\n",
463 	       sta->sta.addr, tid);
464 
465 	spin_lock_bh(&sta->lock);
466 	sta->ampdu_mlme.last_addba_req_time[tid] = jiffies;
467 	sta->ampdu_mlme.addba_req_num[tid]++;
468 	spin_unlock_bh(&sta->lock);
469 
470 	if (sta->sta.deflink.he_cap.has_he) {
471 		buf_size = local->hw.max_tx_aggregation_subframes;
472 	} else {
473 		/*
474 		 * We really should use what the driver told us it will
475 		 * transmit as the maximum, but certain APs (e.g. the
476 		 * LinkSys WRT120N with FW v1.0.07 build 002 Jun 18 2012)
477 		 * will crash when we use a lower number.
478 		 */
479 		buf_size = IEEE80211_MAX_AMPDU_BUF_HT;
480 	}
481 
482 	/* send AddBA request */
483 	ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
484 				     tid_tx->dialog_token, tid_tx->ssn,
485 				     buf_size, tid_tx->timeout);
486 
487 	WARN_ON(test_and_set_bit(HT_AGG_STATE_SENT_ADDBA, &tid_tx->state));
488 }
489 
ieee80211_tx_ba_session_handle_start(struct sta_info * sta,int tid)490 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
491 {
492 	struct tid_ampdu_tx *tid_tx;
493 	struct ieee80211_local *local = sta->local;
494 	struct ieee80211_sub_if_data *sdata;
495 	struct ieee80211_ampdu_params params = {
496 		.sta = &sta->sta,
497 		.action = IEEE80211_AMPDU_TX_START,
498 		.tid = tid,
499 		.buf_size = 0,
500 		.amsdu = false,
501 		.timeout = 0,
502 	};
503 	int ret;
504 
505 	tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
506 
507 	/*
508 	 * Start queuing up packets for this aggregation session.
509 	 * We're going to release them once the driver is OK with
510 	 * that.
511 	 */
512 	clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
513 
514 	/*
515 	 * Make sure no packets are being processed. This ensures that
516 	 * we have a valid starting sequence number and that in-flight
517 	 * packets have been flushed out and no packets for this TID
518 	 * will go into the driver during the ampdu_action call.
519 	 */
520 	synchronize_net();
521 
522 	sdata = sta->sdata;
523 	params.ssn = sta->tid_seq[tid] >> 4;
524 	ret = drv_ampdu_action(local, sdata, &params);
525 	tid_tx->ssn = params.ssn;
526 	if (ret == IEEE80211_AMPDU_TX_START_DELAY_ADDBA) {
527 		return;
528 	} else if (ret == IEEE80211_AMPDU_TX_START_IMMEDIATE) {
529 		/*
530 		 * We didn't send the request yet, so don't need to check
531 		 * here if we already got a response, just mark as driver
532 		 * ready immediately.
533 		 */
534 		set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state);
535 	} else if (ret) {
536 		if (!sdata)
537 			return;
538 
539 		ht_dbg(sdata,
540 		       "BA request denied - HW unavailable for %pM tid %d\n",
541 		       sta->sta.addr, tid);
542 		spin_lock_bh(&sta->lock);
543 		ieee80211_agg_splice_packets(sdata, tid_tx, tid);
544 		ieee80211_assign_tid_tx(sta, tid, NULL);
545 		ieee80211_agg_splice_finish(sdata, tid);
546 		spin_unlock_bh(&sta->lock);
547 
548 		ieee80211_agg_start_txq(sta, tid, false);
549 
550 		kfree_rcu(tid_tx, rcu_head);
551 		return;
552 	}
553 
554 	ieee80211_send_addba_with_timeout(sta, tid_tx);
555 }
556 
557 /*
558  * After accepting the AddBA Response we activated a timer,
559  * resetting it after each frame that we send.
560  */
sta_tx_agg_session_timer_expired(struct timer_list * t)561 static void sta_tx_agg_session_timer_expired(struct timer_list *t)
562 {
563 	struct tid_ampdu_tx *tid_tx = from_timer(tid_tx, t, session_timer);
564 	struct sta_info *sta = tid_tx->sta;
565 	u8 tid = tid_tx->tid;
566 	unsigned long timeout;
567 
568 	if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
569 		return;
570 	}
571 
572 	timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout);
573 	if (time_is_after_jiffies(timeout)) {
574 		mod_timer(&tid_tx->session_timer, timeout);
575 		return;
576 	}
577 
578 	ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n",
579 	       sta->sta.addr, tid);
580 
581 	ieee80211_stop_tx_ba_session(&sta->sta, tid);
582 }
583 
ieee80211_start_tx_ba_session(struct ieee80211_sta * pubsta,u16 tid,u16 timeout)584 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
585 				  u16 timeout)
586 {
587 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
588 	struct ieee80211_sub_if_data *sdata = sta->sdata;
589 	struct ieee80211_local *local = sdata->local;
590 	struct tid_ampdu_tx *tid_tx;
591 	int ret = 0;
592 
593 	trace_api_start_tx_ba_session(pubsta, tid);
594 
595 	if (WARN(sta->reserved_tid == tid,
596 		 "Requested to start BA session on reserved tid=%d", tid))
597 		return -EINVAL;
598 
599 	if (!pubsta->deflink.ht_cap.ht_supported &&
600 	    sta->sdata->vif.bss_conf.chandef.chan->band != NL80211_BAND_6GHZ)
601 		return -EINVAL;
602 
603 	if (WARN_ON_ONCE(!local->ops->ampdu_action))
604 		return -EINVAL;
605 
606 	if ((tid >= IEEE80211_NUM_TIDS) ||
607 	    !ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION) ||
608 	    ieee80211_hw_check(&local->hw, TX_AMPDU_SETUP_IN_HW))
609 		return -EINVAL;
610 
611 	if (WARN_ON(tid >= IEEE80211_FIRST_TSPEC_TSID))
612 		return -EINVAL;
613 
614 	ht_dbg(sdata, "Open BA session requested for %pM tid %u\n",
615 	       pubsta->addr, tid);
616 
617 	if (sdata->vif.type != NL80211_IFTYPE_STATION &&
618 	    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
619 	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
620 	    sdata->vif.type != NL80211_IFTYPE_AP &&
621 	    sdata->vif.type != NL80211_IFTYPE_ADHOC)
622 		return -EINVAL;
623 
624 	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
625 		ht_dbg(sdata,
626 		       "BA sessions blocked - Denying BA session request %pM tid %d\n",
627 		       sta->sta.addr, tid);
628 		return -EINVAL;
629 	}
630 
631 	if (test_sta_flag(sta, WLAN_STA_MFP) &&
632 	    !test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
633 		ht_dbg(sdata,
634 		       "MFP STA not authorized - deny BA session request %pM tid %d\n",
635 		       sta->sta.addr, tid);
636 		return -EINVAL;
637 	}
638 
639 	/*
640 	 * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a
641 	 * member of an IBSS, and has no other existing Block Ack agreement
642 	 * with the recipient STA, then the initiating STA shall transmit a
643 	 * Probe Request frame to the recipient STA and shall not transmit an
644 	 * ADDBA Request frame unless it receives a Probe Response frame
645 	 * from the recipient within dot11ADDBAFailureTimeout.
646 	 *
647 	 * The probe request mechanism for ADDBA is currently not implemented,
648 	 * but we only build up Block Ack session with HT STAs. This information
649 	 * is set when we receive a bss info from a probe response or a beacon.
650 	 */
651 	if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC &&
652 	    !sta->sta.deflink.ht_cap.ht_supported) {
653 		ht_dbg(sdata,
654 		       "BA request denied - IBSS STA %pM does not advertise HT support\n",
655 		       pubsta->addr);
656 		return -EINVAL;
657 	}
658 
659 	spin_lock_bh(&sta->lock);
660 
661 	/* we have tried too many times, receiver does not want A-MPDU */
662 	if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
663 		ret = -EBUSY;
664 		goto err_unlock_sta;
665 	}
666 
667 	/*
668 	 * if we have tried more than HT_AGG_BURST_RETRIES times we
669 	 * will spread our requests in time to avoid stalling connection
670 	 * for too long
671 	 */
672 	if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES &&
673 	    time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] +
674 			HT_AGG_RETRIES_PERIOD)) {
675 		ht_dbg(sdata,
676 		       "BA request denied - %d failed requests on %pM tid %u\n",
677 		       sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, tid);
678 		ret = -EBUSY;
679 		goto err_unlock_sta;
680 	}
681 
682 	tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
683 	/* check if the TID is not in aggregation flow already */
684 	if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
685 		ht_dbg(sdata,
686 		       "BA request denied - session is not idle on %pM tid %u\n",
687 		       sta->sta.addr, tid);
688 		ret = -EAGAIN;
689 		goto err_unlock_sta;
690 	}
691 
692 	/* prepare A-MPDU MLME for Tx aggregation */
693 	tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
694 	if (!tid_tx) {
695 		ret = -ENOMEM;
696 		goto err_unlock_sta;
697 	}
698 
699 	skb_queue_head_init(&tid_tx->pending);
700 	__set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
701 
702 	tid_tx->timeout = timeout;
703 	tid_tx->sta = sta;
704 	tid_tx->tid = tid;
705 
706 	/* response timer */
707 	timer_setup(&tid_tx->addba_resp_timer, sta_addba_resp_timer_expired, 0);
708 
709 	/* tx timer */
710 	timer_setup(&tid_tx->session_timer,
711 		    sta_tx_agg_session_timer_expired, TIMER_DEFERRABLE);
712 
713 	/* assign a dialog token */
714 	sta->ampdu_mlme.dialog_token_allocator++;
715 	tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
716 
717 	/*
718 	 * Finally, assign it to the start array; the work item will
719 	 * collect it and move it to the normal array.
720 	 */
721 	sta->ampdu_mlme.tid_start_tx[tid] = tid_tx;
722 
723 	ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
724 
725 	/* this flow continues off the work */
726  err_unlock_sta:
727 	spin_unlock_bh(&sta->lock);
728 	return ret;
729 }
730 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
731 
ieee80211_agg_tx_operational(struct ieee80211_local * local,struct sta_info * sta,u16 tid)732 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
733 					 struct sta_info *sta, u16 tid)
734 {
735 	struct tid_ampdu_tx *tid_tx;
736 	struct ieee80211_ampdu_params params = {
737 		.sta = &sta->sta,
738 		.action = IEEE80211_AMPDU_TX_OPERATIONAL,
739 		.tid = tid,
740 		.timeout = 0,
741 		.ssn = 0,
742 	};
743 
744 	lockdep_assert_held(&sta->ampdu_mlme.mtx);
745 
746 	tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
747 	params.buf_size = tid_tx->buf_size;
748 	params.amsdu = tid_tx->amsdu;
749 
750 	ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n",
751 	       sta->sta.addr, tid);
752 
753 	drv_ampdu_action(local, sta->sdata, &params);
754 
755 	/*
756 	 * synchronize with TX path, while splicing the TX path
757 	 * should block so it won't put more packets onto pending.
758 	 */
759 	spin_lock_bh(&sta->lock);
760 
761 	ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
762 	/*
763 	 * Now mark as operational. This will be visible
764 	 * in the TX path, and lets it go lock-free in
765 	 * the common case.
766 	 */
767 	set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
768 	ieee80211_agg_splice_finish(sta->sdata, tid);
769 
770 	spin_unlock_bh(&sta->lock);
771 
772 	ieee80211_agg_start_txq(sta, tid, true);
773 }
774 
ieee80211_start_tx_ba_cb(struct sta_info * sta,int tid,struct tid_ampdu_tx * tid_tx)775 void ieee80211_start_tx_ba_cb(struct sta_info *sta, int tid,
776 			      struct tid_ampdu_tx *tid_tx)
777 {
778 	struct ieee80211_sub_if_data *sdata = sta->sdata;
779 	struct ieee80211_local *local = sdata->local;
780 
781 	if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
782 		return;
783 
784 	if (!test_bit(HT_AGG_STATE_SENT_ADDBA, &tid_tx->state)) {
785 		ieee80211_send_addba_with_timeout(sta, tid_tx);
786 		/* RESPONSE_RECEIVED state whould trigger the flow again */
787 		return;
788 	}
789 
790 	if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
791 		ieee80211_agg_tx_operational(local, sta, tid);
792 }
793 
794 static struct tid_ampdu_tx *
ieee80211_lookup_tid_tx(struct ieee80211_sub_if_data * sdata,const u8 * ra,u16 tid,struct sta_info ** sta)795 ieee80211_lookup_tid_tx(struct ieee80211_sub_if_data *sdata,
796 			const u8 *ra, u16 tid, struct sta_info **sta)
797 {
798 	struct tid_ampdu_tx *tid_tx;
799 
800 	if (tid >= IEEE80211_NUM_TIDS) {
801 		ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
802 		       tid, IEEE80211_NUM_TIDS);
803 		return NULL;
804 	}
805 
806 	*sta = sta_info_get_bss(sdata, ra);
807 	if (!*sta) {
808 		ht_dbg(sdata, "Could not find station: %pM\n", ra);
809 		return NULL;
810 	}
811 
812 	tid_tx = rcu_dereference((*sta)->ampdu_mlme.tid_tx[tid]);
813 
814 	if (WARN_ON(!tid_tx))
815 		ht_dbg(sdata, "addBA was not requested!\n");
816 
817 	return tid_tx;
818 }
819 
ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif * vif,const u8 * ra,u16 tid)820 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
821 				      const u8 *ra, u16 tid)
822 {
823 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
824 	struct ieee80211_local *local = sdata->local;
825 	struct sta_info *sta;
826 	struct tid_ampdu_tx *tid_tx;
827 
828 	trace_api_start_tx_ba_cb(sdata, ra, tid);
829 
830 	rcu_read_lock();
831 	tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta);
832 	if (!tid_tx)
833 		goto out;
834 
835 	set_bit(HT_AGG_STATE_START_CB, &tid_tx->state);
836 	ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
837  out:
838 	rcu_read_unlock();
839 }
840 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
841 
__ieee80211_stop_tx_ba_session(struct sta_info * sta,u16 tid,enum ieee80211_agg_stop_reason reason)842 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
843 				   enum ieee80211_agg_stop_reason reason)
844 {
845 	int ret;
846 
847 	mutex_lock(&sta->ampdu_mlme.mtx);
848 
849 	ret = ___ieee80211_stop_tx_ba_session(sta, tid, reason);
850 
851 	mutex_unlock(&sta->ampdu_mlme.mtx);
852 
853 	return ret;
854 }
855 
ieee80211_stop_tx_ba_session(struct ieee80211_sta * pubsta,u16 tid)856 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
857 {
858 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
859 	struct ieee80211_sub_if_data *sdata = sta->sdata;
860 	struct ieee80211_local *local = sdata->local;
861 	struct tid_ampdu_tx *tid_tx;
862 	int ret = 0;
863 
864 	trace_api_stop_tx_ba_session(pubsta, tid);
865 
866 	if (!local->ops->ampdu_action)
867 		return -EINVAL;
868 
869 	if (tid >= IEEE80211_NUM_TIDS)
870 		return -EINVAL;
871 
872 	spin_lock_bh(&sta->lock);
873 	tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
874 
875 	if (!tid_tx) {
876 		ret = -ENOENT;
877 		goto unlock;
878 	}
879 
880 	WARN(sta->reserved_tid == tid,
881 	     "Requested to stop BA session on reserved tid=%d", tid);
882 
883 	if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
884 		/* already in progress stopping it */
885 		ret = 0;
886 		goto unlock;
887 	}
888 
889 	set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state);
890 	ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
891 
892  unlock:
893 	spin_unlock_bh(&sta->lock);
894 	return ret;
895 }
896 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
897 
ieee80211_stop_tx_ba_cb(struct sta_info * sta,int tid,struct tid_ampdu_tx * tid_tx)898 void ieee80211_stop_tx_ba_cb(struct sta_info *sta, int tid,
899 			     struct tid_ampdu_tx *tid_tx)
900 {
901 	struct ieee80211_sub_if_data *sdata = sta->sdata;
902 	bool send_delba = false;
903 	bool start_txq = false;
904 
905 	ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n",
906 	       sta->sta.addr, tid);
907 
908 	spin_lock_bh(&sta->lock);
909 
910 	if (!test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
911 		ht_dbg(sdata,
912 		       "unexpected callback to A-MPDU stop for %pM tid %d\n",
913 		       sta->sta.addr, tid);
914 		goto unlock_sta;
915 	}
916 
917 	if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop)
918 		send_delba = true;
919 
920 	ieee80211_remove_tid_tx(sta, tid);
921 	start_txq = true;
922 
923  unlock_sta:
924 	spin_unlock_bh(&sta->lock);
925 
926 	if (start_txq)
927 		ieee80211_agg_start_txq(sta, tid, false);
928 
929 	if (send_delba)
930 		ieee80211_send_delba(sdata, sta->sta.addr, tid,
931 			WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
932 }
933 
ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif * vif,const u8 * ra,u16 tid)934 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
935 				     const u8 *ra, u16 tid)
936 {
937 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
938 	struct ieee80211_local *local = sdata->local;
939 	struct sta_info *sta;
940 	struct tid_ampdu_tx *tid_tx;
941 
942 	trace_api_stop_tx_ba_cb(sdata, ra, tid);
943 
944 	rcu_read_lock();
945 	tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta);
946 	if (!tid_tx)
947 		goto out;
948 
949 	set_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state);
950 	ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
951  out:
952 	rcu_read_unlock();
953 }
954 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
955 
956 
ieee80211_process_addba_resp(struct ieee80211_local * local,struct sta_info * sta,struct ieee80211_mgmt * mgmt,size_t len)957 void ieee80211_process_addba_resp(struct ieee80211_local *local,
958 				  struct sta_info *sta,
959 				  struct ieee80211_mgmt *mgmt,
960 				  size_t len)
961 {
962 	struct tid_ampdu_tx *tid_tx;
963 	struct ieee80211_txq *txq;
964 	u16 capab, tid, buf_size;
965 	bool amsdu;
966 
967 	capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
968 	amsdu = capab & IEEE80211_ADDBA_PARAM_AMSDU_MASK;
969 	tid = u16_get_bits(capab, IEEE80211_ADDBA_PARAM_TID_MASK);
970 	buf_size = u16_get_bits(capab, IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK);
971 	buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes);
972 
973 	txq = sta->sta.txq[tid];
974 	if (!amsdu && txq)
975 		set_bit(IEEE80211_TXQ_NO_AMSDU, &to_txq_info(txq)->flags);
976 
977 	mutex_lock(&sta->ampdu_mlme.mtx);
978 
979 	tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
980 	if (!tid_tx)
981 		goto out;
982 
983 	if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
984 		ht_dbg(sta->sdata, "wrong addBA response token, %pM tid %d\n",
985 		       sta->sta.addr, tid);
986 		goto out;
987 	}
988 
989 	del_timer_sync(&tid_tx->addba_resp_timer);
990 
991 	ht_dbg(sta->sdata, "switched off addBA timer for %pM tid %d\n",
992 	       sta->sta.addr, tid);
993 
994 	/*
995 	 * addba_resp_timer may have fired before we got here, and
996 	 * caused WANT_STOP to be set. If the stop then was already
997 	 * processed further, STOPPING might be set.
998 	 */
999 	if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) ||
1000 	    test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
1001 		ht_dbg(sta->sdata,
1002 		       "got addBA resp for %pM tid %d but we already gave up\n",
1003 		       sta->sta.addr, tid);
1004 		goto out;
1005 	}
1006 
1007 	/*
1008 	 * IEEE 802.11-2007 7.3.1.14:
1009 	 * In an ADDBA Response frame, when the Status Code field
1010 	 * is set to 0, the Buffer Size subfield is set to a value
1011 	 * of at least 1.
1012 	 */
1013 	if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
1014 			== WLAN_STATUS_SUCCESS && buf_size) {
1015 		if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
1016 				     &tid_tx->state)) {
1017 			/* ignore duplicate response */
1018 			goto out;
1019 		}
1020 
1021 		tid_tx->buf_size = buf_size;
1022 		tid_tx->amsdu = amsdu;
1023 
1024 		if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
1025 			ieee80211_agg_tx_operational(local, sta, tid);
1026 
1027 		sta->ampdu_mlme.addba_req_num[tid] = 0;
1028 
1029 		tid_tx->timeout =
1030 			le16_to_cpu(mgmt->u.action.u.addba_resp.timeout);
1031 
1032 		if (tid_tx->timeout) {
1033 			mod_timer(&tid_tx->session_timer,
1034 				  TU_TO_EXP_TIME(tid_tx->timeout));
1035 			tid_tx->last_tx = jiffies;
1036 		}
1037 
1038 	} else {
1039 		___ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_DECLINED);
1040 	}
1041 
1042  out:
1043 	mutex_unlock(&sta->ampdu_mlme.mtx);
1044 }
1045