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 - 2023 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 = ieee80211_mgmt_ba(skb, da, sdata);
78
79 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
80
81 mgmt->u.action.category = WLAN_CATEGORY_BACK;
82 mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
83
84 mgmt->u.action.u.addba_req.dialog_token = dialog_token;
85 capab = IEEE80211_ADDBA_PARAM_AMSDU_MASK;
86 capab |= IEEE80211_ADDBA_PARAM_POLICY_MASK;
87 capab |= u16_encode_bits(tid, IEEE80211_ADDBA_PARAM_TID_MASK);
88 capab |= u16_encode_bits(agg_size, IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK);
89
90 mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
91
92 mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
93 mgmt->u.action.u.addba_req.start_seq_num =
94 cpu_to_le16(start_seq_num << 4);
95
96 ieee80211_tx_skb_tid(sdata, skb, tid, -1);
97 }
98
ieee80211_send_bar(struct ieee80211_vif * vif,u8 * ra,u16 tid,u16 ssn)99 void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
100 {
101 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
102 struct ieee80211_local *local = sdata->local;
103 struct sk_buff *skb;
104 struct ieee80211_bar *bar;
105 u16 bar_control = 0;
106
107 skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
108 if (!skb)
109 return;
110
111 skb_reserve(skb, local->hw.extra_tx_headroom);
112 bar = skb_put_zero(skb, sizeof(*bar));
113 bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
114 IEEE80211_STYPE_BACK_REQ);
115 memcpy(bar->ra, ra, ETH_ALEN);
116 memcpy(bar->ta, sdata->vif.addr, ETH_ALEN);
117 bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
118 bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
119 bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT);
120 bar->control = cpu_to_le16(bar_control);
121 bar->start_seq_num = cpu_to_le16(ssn);
122
123 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
124 IEEE80211_TX_CTL_REQ_TX_STATUS;
125 ieee80211_tx_skb_tid(sdata, skb, tid, -1);
126 }
127 EXPORT_SYMBOL(ieee80211_send_bar);
128
ieee80211_assign_tid_tx(struct sta_info * sta,int tid,struct tid_ampdu_tx * tid_tx)129 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
130 struct tid_ampdu_tx *tid_tx)
131 {
132 lockdep_assert_wiphy(sta->local->hw.wiphy);
133 lockdep_assert_held(&sta->lock);
134 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
135 }
136
137 /*
138 * When multiple aggregation sessions on multiple stations
139 * are being created/destroyed simultaneously, we need to
140 * refcount the global queue stop caused by that in order
141 * to not get into a situation where one of the aggregation
142 * setup or teardown re-enables queues before the other is
143 * ready to handle that.
144 *
145 * These two functions take care of this issue by keeping
146 * a global "agg_queue_stop" refcount.
147 */
__acquires(agg_queue)148 static void __acquires(agg_queue)
149 ieee80211_stop_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
150 {
151 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
152
153 /* we do refcounting here, so don't use the queue reason refcounting */
154
155 if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1)
156 ieee80211_stop_queue_by_reason(
157 &sdata->local->hw, queue,
158 IEEE80211_QUEUE_STOP_REASON_AGGREGATION,
159 false);
160 __acquire(agg_queue);
161 }
162
__releases(agg_queue)163 static void __releases(agg_queue)
164 ieee80211_wake_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
165 {
166 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
167
168 if (atomic_dec_return(&sdata->local->agg_queue_stop[queue]) == 0)
169 ieee80211_wake_queue_by_reason(
170 &sdata->local->hw, queue,
171 IEEE80211_QUEUE_STOP_REASON_AGGREGATION,
172 false);
173 __release(agg_queue);
174 }
175
176 static void
ieee80211_agg_stop_txq(struct sta_info * sta,int tid)177 ieee80211_agg_stop_txq(struct sta_info *sta, int tid)
178 {
179 struct ieee80211_txq *txq = sta->sta.txq[tid];
180 struct ieee80211_sub_if_data *sdata;
181 struct fq *fq;
182 struct txq_info *txqi;
183
184 if (!txq)
185 return;
186
187 txqi = to_txq_info(txq);
188 sdata = vif_to_sdata(txq->vif);
189 fq = &sdata->local->fq;
190
191 /* Lock here to protect against further seqno updates on dequeue */
192 spin_lock_bh(&fq->lock);
193 set_bit(IEEE80211_TXQ_STOP, &txqi->flags);
194 spin_unlock_bh(&fq->lock);
195 }
196
197 static void
ieee80211_agg_start_txq(struct sta_info * sta,int tid,bool enable)198 ieee80211_agg_start_txq(struct sta_info *sta, int tid, bool enable)
199 {
200 struct ieee80211_txq *txq = sta->sta.txq[tid];
201 struct txq_info *txqi;
202
203 lockdep_assert_wiphy(sta->local->hw.wiphy);
204
205 if (!txq)
206 return;
207
208 txqi = to_txq_info(txq);
209
210 if (enable)
211 set_bit(IEEE80211_TXQ_AMPDU, &txqi->flags);
212 else
213 clear_bit(IEEE80211_TXQ_AMPDU, &txqi->flags);
214
215 clear_bit(IEEE80211_TXQ_STOP, &txqi->flags);
216 local_bh_disable();
217 rcu_read_lock();
218 schedule_and_wake_txq(sta->sdata->local, txqi);
219 rcu_read_unlock();
220 local_bh_enable();
221 }
222
223 /*
224 * splice packets from the STA's pending to the local pending,
225 * requires a call to ieee80211_agg_splice_finish later
226 */
__acquires(agg_queue)227 static void __acquires(agg_queue)
228 ieee80211_agg_splice_packets(struct ieee80211_sub_if_data *sdata,
229 struct tid_ampdu_tx *tid_tx, u16 tid)
230 {
231 struct ieee80211_local *local = sdata->local;
232 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
233 unsigned long flags;
234
235 ieee80211_stop_queue_agg(sdata, tid);
236
237 if (WARN(!tid_tx,
238 "TID %d gone but expected when splicing aggregates from the pending queue\n",
239 tid))
240 return;
241
242 if (!skb_queue_empty(&tid_tx->pending)) {
243 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
244 /* copy over remaining packets */
245 skb_queue_splice_tail_init(&tid_tx->pending,
246 &local->pending[queue]);
247 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
248 }
249 }
250
__releases(agg_queue)251 static void __releases(agg_queue)
252 ieee80211_agg_splice_finish(struct ieee80211_sub_if_data *sdata, u16 tid)
253 {
254 ieee80211_wake_queue_agg(sdata, tid);
255 }
256
ieee80211_remove_tid_tx(struct sta_info * sta,int tid)257 static void ieee80211_remove_tid_tx(struct sta_info *sta, int tid)
258 {
259 struct tid_ampdu_tx *tid_tx;
260
261 lockdep_assert_wiphy(sta->local->hw.wiphy);
262 lockdep_assert_held(&sta->lock);
263
264 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
265
266 /*
267 * When we get here, the TX path will not be lockless any more wrt.
268 * aggregation, since the OPERATIONAL bit has long been cleared.
269 * Thus it will block on getting the lock, if it occurs. So if we
270 * stop the queue now, we will not get any more packets, and any
271 * that might be being processed will wait for us here, thereby
272 * guaranteeing that no packets go to the tid_tx pending queue any
273 * more.
274 */
275
276 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
277
278 /* future packets must not find the tid_tx struct any more */
279 ieee80211_assign_tid_tx(sta, tid, NULL);
280
281 ieee80211_agg_splice_finish(sta->sdata, tid);
282
283 kfree_rcu(tid_tx, rcu_head);
284 }
285
__ieee80211_stop_tx_ba_session(struct sta_info * sta,u16 tid,enum ieee80211_agg_stop_reason reason)286 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
287 enum ieee80211_agg_stop_reason reason)
288 {
289 struct ieee80211_local *local = sta->local;
290 struct tid_ampdu_tx *tid_tx;
291 struct ieee80211_ampdu_params params = {
292 .sta = &sta->sta,
293 .tid = tid,
294 .buf_size = 0,
295 .amsdu = false,
296 .timeout = 0,
297 .ssn = 0,
298 };
299 int ret;
300
301 lockdep_assert_wiphy(sta->local->hw.wiphy);
302
303 switch (reason) {
304 case AGG_STOP_DECLINED:
305 case AGG_STOP_LOCAL_REQUEST:
306 case AGG_STOP_PEER_REQUEST:
307 params.action = IEEE80211_AMPDU_TX_STOP_CONT;
308 break;
309 case AGG_STOP_DESTROY_STA:
310 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH;
311 break;
312 default:
313 WARN_ON_ONCE(1);
314 return -EINVAL;
315 }
316
317 spin_lock_bh(&sta->lock);
318
319 /* free struct pending for start, if present */
320 tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
321 kfree(tid_tx);
322 sta->ampdu_mlme.tid_start_tx[tid] = NULL;
323
324 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
325 if (!tid_tx) {
326 spin_unlock_bh(&sta->lock);
327 return -ENOENT;
328 }
329
330 /*
331 * if we're already stopping ignore any new requests to stop
332 * unless we're destroying it in which case notify the driver
333 */
334 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
335 spin_unlock_bh(&sta->lock);
336 if (reason != AGG_STOP_DESTROY_STA)
337 return -EALREADY;
338 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH_CONT;
339 ret = drv_ampdu_action(local, sta->sdata, ¶ms);
340 WARN_ON_ONCE(ret);
341 return 0;
342 }
343
344 if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
345 /* not even started yet! */
346 ieee80211_assign_tid_tx(sta, tid, NULL);
347 spin_unlock_bh(&sta->lock);
348 kfree_rcu(tid_tx, rcu_head);
349 return 0;
350 }
351
352 set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
353
354 ieee80211_agg_stop_txq(sta, tid);
355
356 spin_unlock_bh(&sta->lock);
357
358 ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n",
359 sta->sta.addr, tid);
360
361 del_timer_sync(&tid_tx->addba_resp_timer);
362 del_timer_sync(&tid_tx->session_timer);
363
364 /*
365 * After this packets are no longer handed right through
366 * to the driver but are put onto tid_tx->pending instead,
367 * with locking to ensure proper access.
368 */
369 clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
370
371 /*
372 * There might be a few packets being processed right now (on
373 * another CPU) that have already gotten past the aggregation
374 * check when it was still OPERATIONAL and consequently have
375 * IEEE80211_TX_CTL_AMPDU set. In that case, this code might
376 * call into the driver at the same time or even before the
377 * TX paths calls into it, which could confuse the driver.
378 *
379 * Wait for all currently running TX paths to finish before
380 * telling the driver. New packets will not go through since
381 * the aggregation session is no longer OPERATIONAL.
382 */
383 if (!local->in_reconfig)
384 synchronize_net();
385
386 tid_tx->stop_initiator = reason == AGG_STOP_PEER_REQUEST ?
387 WLAN_BACK_RECIPIENT :
388 WLAN_BACK_INITIATOR;
389 tid_tx->tx_stop = reason == AGG_STOP_LOCAL_REQUEST;
390
391 ret = drv_ampdu_action(local, sta->sdata, ¶ms);
392
393 /* HW shall not deny going back to legacy */
394 if (WARN_ON(ret)) {
395 /*
396 * We may have pending packets get stuck in this case...
397 * Not bothering with a workaround for now.
398 */
399 }
400
401 /*
402 * In the case of AGG_STOP_DESTROY_STA, the driver won't
403 * necessarily call ieee80211_stop_tx_ba_cb(), so this may
404 * seem like we can leave the tid_tx data pending forever.
405 * This is true, in a way, but "forever" is only until the
406 * station struct is actually destroyed. In the meantime,
407 * leaving it around ensures that we don't transmit packets
408 * to the driver on this TID which might confuse it.
409 */
410
411 return 0;
412 }
413
414 /*
415 * After sending add Block Ack request we activated a timer until
416 * add Block Ack response will arrive from the recipient.
417 * If this timer expires sta_addba_resp_timer_expired will be executed.
418 */
sta_addba_resp_timer_expired(struct timer_list * t)419 static void sta_addba_resp_timer_expired(struct timer_list *t)
420 {
421 struct tid_ampdu_tx *tid_tx = from_timer(tid_tx, t, addba_resp_timer);
422 struct sta_info *sta = tid_tx->sta;
423 u8 tid = tid_tx->tid;
424
425 /* check if the TID waits for addBA response */
426 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
427 ht_dbg(sta->sdata,
428 "timer expired on %pM tid %d not expecting addBA response\n",
429 sta->sta.addr, tid);
430 return;
431 }
432
433 ht_dbg(sta->sdata, "addBA response timer expired on %pM tid %d\n",
434 sta->sta.addr, tid);
435
436 ieee80211_stop_tx_ba_session(&sta->sta, tid);
437 }
438
ieee80211_send_addba_with_timeout(struct sta_info * sta,struct tid_ampdu_tx * tid_tx)439 static void ieee80211_send_addba_with_timeout(struct sta_info *sta,
440 struct tid_ampdu_tx *tid_tx)
441 {
442 struct ieee80211_sub_if_data *sdata = sta->sdata;
443 struct ieee80211_local *local = sta->local;
444 u8 tid = tid_tx->tid;
445 u16 buf_size;
446
447 if (WARN_ON_ONCE(test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state) ||
448 test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state)))
449 return;
450
451 lockdep_assert_wiphy(sta->local->hw.wiphy);
452
453 /* activate the timer for the recipient's addBA response */
454 mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
455 ht_dbg(sdata, "activated addBA response timer on %pM tid %d\n",
456 sta->sta.addr, tid);
457
458 spin_lock_bh(&sta->lock);
459 sta->ampdu_mlme.last_addba_req_time[tid] = jiffies;
460 sta->ampdu_mlme.addba_req_num[tid]++;
461 spin_unlock_bh(&sta->lock);
462
463 if (sta->sta.deflink.he_cap.has_he) {
464 buf_size = local->hw.max_tx_aggregation_subframes;
465 } else {
466 /*
467 * We really should use what the driver told us it will
468 * transmit as the maximum, but certain APs (e.g. the
469 * LinkSys WRT120N with FW v1.0.07 build 002 Jun 18 2012)
470 * will crash when we use a lower number.
471 */
472 buf_size = IEEE80211_MAX_AMPDU_BUF_HT;
473 }
474
475 /* send AddBA request */
476 ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
477 tid_tx->dialog_token, tid_tx->ssn,
478 buf_size, tid_tx->timeout);
479
480 WARN_ON(test_and_set_bit(HT_AGG_STATE_SENT_ADDBA, &tid_tx->state));
481 }
482
ieee80211_tx_ba_session_handle_start(struct sta_info * sta,int tid)483 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
484 {
485 struct tid_ampdu_tx *tid_tx;
486 struct ieee80211_local *local = sta->local;
487 struct ieee80211_sub_if_data *sdata = sta->sdata;
488 struct ieee80211_ampdu_params params = {
489 .sta = &sta->sta,
490 .action = IEEE80211_AMPDU_TX_START,
491 .tid = tid,
492 .buf_size = 0,
493 .amsdu = false,
494 .timeout = 0,
495 };
496 int ret;
497
498 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
499
500 /*
501 * Start queuing up packets for this aggregation session.
502 * We're going to release them once the driver is OK with
503 * that.
504 */
505 clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
506
507 /*
508 * Make sure no packets are being processed. This ensures that
509 * we have a valid starting sequence number and that in-flight
510 * packets have been flushed out and no packets for this TID
511 * will go into the driver during the ampdu_action call.
512 */
513 synchronize_net();
514
515 params.ssn = sta->tid_seq[tid] >> 4;
516 ret = drv_ampdu_action(local, sdata, ¶ms);
517 tid_tx->ssn = params.ssn;
518 if (ret == IEEE80211_AMPDU_TX_START_DELAY_ADDBA) {
519 return;
520 } else if (ret == IEEE80211_AMPDU_TX_START_IMMEDIATE) {
521 /*
522 * We didn't send the request yet, so don't need to check
523 * here if we already got a response, just mark as driver
524 * ready immediately.
525 */
526 set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state);
527 } else if (ret) {
528 ht_dbg(sdata,
529 "BA request denied - HW unavailable for %pM tid %d\n",
530 sta->sta.addr, tid);
531 spin_lock_bh(&sta->lock);
532 ieee80211_agg_splice_packets(sdata, tid_tx, tid);
533 ieee80211_assign_tid_tx(sta, tid, NULL);
534 ieee80211_agg_splice_finish(sdata, tid);
535 spin_unlock_bh(&sta->lock);
536
537 ieee80211_agg_start_txq(sta, tid, false);
538
539 kfree_rcu(tid_tx, rcu_head);
540 return;
541 }
542
543 ieee80211_send_addba_with_timeout(sta, tid_tx);
544 }
545
ieee80211_refresh_tx_agg_session_timer(struct ieee80211_sta * pubsta,u16 tid)546 void ieee80211_refresh_tx_agg_session_timer(struct ieee80211_sta *pubsta,
547 u16 tid)
548 {
549 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
550 struct tid_ampdu_tx *tid_tx;
551
552 if (WARN_ON_ONCE(tid >= IEEE80211_NUM_TIDS))
553 return;
554
555 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
556 if (!tid_tx)
557 return;
558
559 tid_tx->last_tx = jiffies;
560 }
561 EXPORT_SYMBOL(ieee80211_refresh_tx_agg_session_timer);
562
563 /*
564 * After accepting the AddBA Response we activated a timer,
565 * resetting it after each frame that we send.
566 */
sta_tx_agg_session_timer_expired(struct timer_list * t)567 static void sta_tx_agg_session_timer_expired(struct timer_list *t)
568 {
569 struct tid_ampdu_tx *tid_tx = from_timer(tid_tx, t, session_timer);
570 struct sta_info *sta = tid_tx->sta;
571 u8 tid = tid_tx->tid;
572 unsigned long timeout;
573
574 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
575 return;
576 }
577
578 timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout);
579 if (time_is_after_jiffies(timeout)) {
580 mod_timer(&tid_tx->session_timer, timeout);
581 return;
582 }
583
584 ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n",
585 sta->sta.addr, tid);
586
587 ieee80211_stop_tx_ba_session(&sta->sta, tid);
588 }
589
ieee80211_start_tx_ba_session(struct ieee80211_sta * pubsta,u16 tid,u16 timeout)590 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
591 u16 timeout)
592 {
593 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
594 struct ieee80211_sub_if_data *sdata = sta->sdata;
595 struct ieee80211_local *local = sdata->local;
596 struct tid_ampdu_tx *tid_tx;
597 int ret = 0;
598
599 trace_api_start_tx_ba_session(pubsta, tid);
600
601 if (WARN(sta->reserved_tid == tid,
602 "Requested to start BA session on reserved tid=%d", tid))
603 return -EINVAL;
604
605 if (!pubsta->deflink.ht_cap.ht_supported &&
606 !pubsta->deflink.vht_cap.vht_supported &&
607 !pubsta->deflink.he_cap.has_he &&
608 !pubsta->deflink.eht_cap.has_eht)
609 return -EINVAL;
610
611 if (WARN_ON_ONCE(!local->ops->ampdu_action))
612 return -EINVAL;
613
614 if ((tid >= IEEE80211_NUM_TIDS) ||
615 !ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION) ||
616 ieee80211_hw_check(&local->hw, TX_AMPDU_SETUP_IN_HW))
617 return -EINVAL;
618
619 if (WARN_ON(tid >= IEEE80211_FIRST_TSPEC_TSID))
620 return -EINVAL;
621
622 ht_dbg(sdata, "Open BA session requested for %pM tid %u\n",
623 pubsta->addr, tid);
624
625 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
626 sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
627 sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
628 sdata->vif.type != NL80211_IFTYPE_AP &&
629 sdata->vif.type != NL80211_IFTYPE_ADHOC)
630 return -EINVAL;
631
632 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
633 ht_dbg(sdata,
634 "BA sessions blocked - Denying BA session request %pM tid %d\n",
635 sta->sta.addr, tid);
636 return -EINVAL;
637 }
638
639 if (test_sta_flag(sta, WLAN_STA_MFP) &&
640 !test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
641 ht_dbg(sdata,
642 "MFP STA not authorized - deny BA session request %pM tid %d\n",
643 sta->sta.addr, tid);
644 return -EINVAL;
645 }
646
647 /*
648 * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a
649 * member of an IBSS, and has no other existing Block Ack agreement
650 * with the recipient STA, then the initiating STA shall transmit a
651 * Probe Request frame to the recipient STA and shall not transmit an
652 * ADDBA Request frame unless it receives a Probe Response frame
653 * from the recipient within dot11ADDBAFailureTimeout.
654 *
655 * The probe request mechanism for ADDBA is currently not implemented,
656 * but we only build up Block Ack session with HT STAs. This information
657 * is set when we receive a bss info from a probe response or a beacon.
658 */
659 if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC &&
660 !sta->sta.deflink.ht_cap.ht_supported) {
661 ht_dbg(sdata,
662 "BA request denied - IBSS STA %pM does not advertise HT support\n",
663 pubsta->addr);
664 return -EINVAL;
665 }
666
667 spin_lock_bh(&sta->lock);
668
669 /* we have tried too many times, receiver does not want A-MPDU */
670 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
671 ret = -EBUSY;
672 goto err_unlock_sta;
673 }
674
675 /*
676 * if we have tried more than HT_AGG_BURST_RETRIES times we
677 * will spread our requests in time to avoid stalling connection
678 * for too long
679 */
680 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES &&
681 time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] +
682 HT_AGG_RETRIES_PERIOD)) {
683 ht_dbg(sdata,
684 "BA request denied - %d failed requests on %pM tid %u\n",
685 sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, tid);
686 ret = -EBUSY;
687 goto err_unlock_sta;
688 }
689
690 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
691 /* check if the TID is not in aggregation flow already */
692 if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
693 ht_dbg(sdata,
694 "BA request denied - session is not idle on %pM tid %u\n",
695 sta->sta.addr, tid);
696 ret = -EAGAIN;
697 goto err_unlock_sta;
698 }
699
700 /* prepare A-MPDU MLME for Tx aggregation */
701 tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
702 if (!tid_tx) {
703 ret = -ENOMEM;
704 goto err_unlock_sta;
705 }
706
707 skb_queue_head_init(&tid_tx->pending);
708 __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
709
710 tid_tx->timeout = timeout;
711 tid_tx->sta = sta;
712 tid_tx->tid = tid;
713
714 /* response timer */
715 timer_setup(&tid_tx->addba_resp_timer, sta_addba_resp_timer_expired, 0);
716
717 /* tx timer */
718 timer_setup(&tid_tx->session_timer,
719 sta_tx_agg_session_timer_expired, TIMER_DEFERRABLE);
720
721 /* assign a dialog token */
722 sta->ampdu_mlme.dialog_token_allocator++;
723 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
724
725 /*
726 * Finally, assign it to the start array; the work item will
727 * collect it and move it to the normal array.
728 */
729 sta->ampdu_mlme.tid_start_tx[tid] = tid_tx;
730
731 wiphy_work_queue(local->hw.wiphy, &sta->ampdu_mlme.work);
732
733 /* this flow continues off the work */
734 err_unlock_sta:
735 spin_unlock_bh(&sta->lock);
736 return ret;
737 }
738 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
739
ieee80211_agg_tx_operational(struct ieee80211_local * local,struct sta_info * sta,u16 tid)740 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
741 struct sta_info *sta, u16 tid)
742 {
743 struct tid_ampdu_tx *tid_tx;
744 struct ieee80211_ampdu_params params = {
745 .sta = &sta->sta,
746 .action = IEEE80211_AMPDU_TX_OPERATIONAL,
747 .tid = tid,
748 .timeout = 0,
749 .ssn = 0,
750 };
751
752 lockdep_assert_wiphy(sta->local->hw.wiphy);
753
754 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
755 params.buf_size = tid_tx->buf_size;
756 params.amsdu = tid_tx->amsdu;
757
758 ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n",
759 sta->sta.addr, tid);
760
761 drv_ampdu_action(local, sta->sdata, ¶ms);
762
763 /*
764 * synchronize with TX path, while splicing the TX path
765 * should block so it won't put more packets onto pending.
766 */
767 spin_lock_bh(&sta->lock);
768
769 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
770 /*
771 * Now mark as operational. This will be visible
772 * in the TX path, and lets it go lock-free in
773 * the common case.
774 */
775 set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
776 ieee80211_agg_splice_finish(sta->sdata, tid);
777
778 spin_unlock_bh(&sta->lock);
779
780 ieee80211_agg_start_txq(sta, tid, true);
781 }
782
ieee80211_start_tx_ba_cb(struct sta_info * sta,int tid,struct tid_ampdu_tx * tid_tx)783 void ieee80211_start_tx_ba_cb(struct sta_info *sta, int tid,
784 struct tid_ampdu_tx *tid_tx)
785 {
786 struct ieee80211_sub_if_data *sdata = sta->sdata;
787 struct ieee80211_local *local = sdata->local;
788
789 lockdep_assert_wiphy(sta->local->hw.wiphy);
790
791 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
792 return;
793
794 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state) ||
795 test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state))
796 return;
797
798 if (!test_bit(HT_AGG_STATE_SENT_ADDBA, &tid_tx->state)) {
799 ieee80211_send_addba_with_timeout(sta, tid_tx);
800 /* RESPONSE_RECEIVED state whould trigger the flow again */
801 return;
802 }
803
804 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
805 ieee80211_agg_tx_operational(local, sta, tid);
806 }
807
808 static struct tid_ampdu_tx *
ieee80211_lookup_tid_tx(struct ieee80211_sub_if_data * sdata,const u8 * ra,u16 tid,struct sta_info ** sta)809 ieee80211_lookup_tid_tx(struct ieee80211_sub_if_data *sdata,
810 const u8 *ra, u16 tid, struct sta_info **sta)
811 {
812 struct tid_ampdu_tx *tid_tx;
813
814 if (tid >= IEEE80211_NUM_TIDS) {
815 ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
816 tid, IEEE80211_NUM_TIDS);
817 return NULL;
818 }
819
820 *sta = sta_info_get_bss(sdata, ra);
821 if (!*sta) {
822 ht_dbg(sdata, "Could not find station: %pM\n", ra);
823 return NULL;
824 }
825
826 tid_tx = rcu_dereference((*sta)->ampdu_mlme.tid_tx[tid]);
827
828 if (WARN_ON(!tid_tx))
829 ht_dbg(sdata, "addBA was not requested!\n");
830
831 return tid_tx;
832 }
833
ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif * vif,const u8 * ra,u16 tid)834 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
835 const u8 *ra, u16 tid)
836 {
837 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
838 struct ieee80211_local *local = sdata->local;
839 struct sta_info *sta;
840 struct tid_ampdu_tx *tid_tx;
841
842 trace_api_start_tx_ba_cb(sdata, ra, tid);
843
844 rcu_read_lock();
845 tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta);
846 if (!tid_tx)
847 goto out;
848
849 set_bit(HT_AGG_STATE_START_CB, &tid_tx->state);
850 wiphy_work_queue(local->hw.wiphy, &sta->ampdu_mlme.work);
851 out:
852 rcu_read_unlock();
853 }
854 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
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 wiphy_work_queue(local->hw.wiphy, &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 wiphy_work_queue(local->hw.wiphy, &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 lockdep_assert_wiphy(sta->local->hw.wiphy);
968
969 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
970 amsdu = capab & IEEE80211_ADDBA_PARAM_AMSDU_MASK;
971 tid = u16_get_bits(capab, IEEE80211_ADDBA_PARAM_TID_MASK);
972 buf_size = u16_get_bits(capab, IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK);
973 buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes);
974
975 txq = sta->sta.txq[tid];
976 if (!amsdu && txq)
977 set_bit(IEEE80211_TXQ_NO_AMSDU, &to_txq_info(txq)->flags);
978
979 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
980 if (!tid_tx)
981 return;
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 return;
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 return;
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 return;
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