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
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->vif.cfg.ap_addr, 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
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
142 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
143 struct tid_ampdu_tx *tid_tx)
144 {
145 lockdep_assert_wiphy(sta->local->hw.wiphy);
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 */
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
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
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
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_wiphy(sta->local->hw.wiphy);
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 */
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
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
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_wiphy(sta->local->hw.wiphy);
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
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_wiphy(sta->local->hw.wiphy);
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, ¶ms);
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, ¶ms);
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 */
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
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 if (WARN_ON_ONCE(test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state) ||
461 test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state)))
462 return;
463
464 lockdep_assert_wiphy(sta->local->hw.wiphy);
465
466 /* activate the timer for the recipient's addBA response */
467 mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
468 ht_dbg(sdata, "activated addBA response timer on %pM tid %d\n",
469 sta->sta.addr, tid);
470
471 spin_lock_bh(&sta->lock);
472 sta->ampdu_mlme.last_addba_req_time[tid] = jiffies;
473 sta->ampdu_mlme.addba_req_num[tid]++;
474 spin_unlock_bh(&sta->lock);
475
476 if (sta->sta.deflink.he_cap.has_he) {
477 buf_size = local->hw.max_tx_aggregation_subframes;
478 } else {
479 /*
480 * We really should use what the driver told us it will
481 * transmit as the maximum, but certain APs (e.g. the
482 * LinkSys WRT120N with FW v1.0.07 build 002 Jun 18 2012)
483 * will crash when we use a lower number.
484 */
485 buf_size = IEEE80211_MAX_AMPDU_BUF_HT;
486 }
487
488 /* send AddBA request */
489 ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
490 tid_tx->dialog_token, tid_tx->ssn,
491 buf_size, tid_tx->timeout);
492
493 WARN_ON(test_and_set_bit(HT_AGG_STATE_SENT_ADDBA, &tid_tx->state));
494 }
495
496 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
497 {
498 struct tid_ampdu_tx *tid_tx;
499 struct ieee80211_local *local = sta->local;
500 struct ieee80211_sub_if_data *sdata = sta->sdata;
501 struct ieee80211_ampdu_params params = {
502 .sta = &sta->sta,
503 .action = IEEE80211_AMPDU_TX_START,
504 .tid = tid,
505 .buf_size = 0,
506 .amsdu = false,
507 .timeout = 0,
508 };
509 int ret;
510
511 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
512
513 /*
514 * Start queuing up packets for this aggregation session.
515 * We're going to release them once the driver is OK with
516 * that.
517 */
518 clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
519
520 /*
521 * Make sure no packets are being processed. This ensures that
522 * we have a valid starting sequence number and that in-flight
523 * packets have been flushed out and no packets for this TID
524 * will go into the driver during the ampdu_action call.
525 */
526 synchronize_net();
527
528 params.ssn = sta->tid_seq[tid] >> 4;
529 ret = drv_ampdu_action(local, sdata, ¶ms);
530 tid_tx->ssn = params.ssn;
531 if (ret == IEEE80211_AMPDU_TX_START_DELAY_ADDBA) {
532 return;
533 } else if (ret == IEEE80211_AMPDU_TX_START_IMMEDIATE) {
534 /*
535 * We didn't send the request yet, so don't need to check
536 * here if we already got a response, just mark as driver
537 * ready immediately.
538 */
539 set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state);
540 } else if (ret) {
541 ht_dbg(sdata,
542 "BA request denied - HW unavailable for %pM tid %d\n",
543 sta->sta.addr, tid);
544 spin_lock_bh(&sta->lock);
545 ieee80211_agg_splice_packets(sdata, tid_tx, tid);
546 ieee80211_assign_tid_tx(sta, tid, NULL);
547 ieee80211_agg_splice_finish(sdata, tid);
548 spin_unlock_bh(&sta->lock);
549
550 ieee80211_agg_start_txq(sta, tid, false);
551
552 kfree_rcu(tid_tx, rcu_head);
553 return;
554 }
555
556 ieee80211_send_addba_with_timeout(sta, tid_tx);
557 }
558
559 void ieee80211_refresh_tx_agg_session_timer(struct ieee80211_sta *pubsta,
560 u16 tid)
561 {
562 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
563 struct tid_ampdu_tx *tid_tx;
564
565 if (WARN_ON_ONCE(tid >= IEEE80211_NUM_TIDS))
566 return;
567
568 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
569 if (!tid_tx)
570 return;
571
572 tid_tx->last_tx = jiffies;
573 }
574 EXPORT_SYMBOL(ieee80211_refresh_tx_agg_session_timer);
575
576 /*
577 * After accepting the AddBA Response we activated a timer,
578 * resetting it after each frame that we send.
579 */
580 static void sta_tx_agg_session_timer_expired(struct timer_list *t)
581 {
582 struct tid_ampdu_tx *tid_tx = from_timer(tid_tx, t, session_timer);
583 struct sta_info *sta = tid_tx->sta;
584 u8 tid = tid_tx->tid;
585 unsigned long timeout;
586
587 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
588 return;
589 }
590
591 timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout);
592 if (time_is_after_jiffies(timeout)) {
593 mod_timer(&tid_tx->session_timer, timeout);
594 return;
595 }
596
597 ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n",
598 sta->sta.addr, tid);
599
600 ieee80211_stop_tx_ba_session(&sta->sta, tid);
601 }
602
603 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
604 u16 timeout)
605 {
606 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
607 struct ieee80211_sub_if_data *sdata = sta->sdata;
608 struct ieee80211_local *local = sdata->local;
609 struct tid_ampdu_tx *tid_tx;
610 int ret = 0;
611
612 trace_api_start_tx_ba_session(pubsta, tid);
613
614 if (WARN(sta->reserved_tid == tid,
615 "Requested to start BA session on reserved tid=%d", tid))
616 return -EINVAL;
617
618 if (!pubsta->deflink.ht_cap.ht_supported &&
619 !pubsta->deflink.vht_cap.vht_supported &&
620 !pubsta->deflink.he_cap.has_he &&
621 !pubsta->deflink.eht_cap.has_eht)
622 return -EINVAL;
623
624 if (WARN_ON_ONCE(!local->ops->ampdu_action))
625 return -EINVAL;
626
627 if ((tid >= IEEE80211_NUM_TIDS) ||
628 !ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION) ||
629 ieee80211_hw_check(&local->hw, TX_AMPDU_SETUP_IN_HW))
630 return -EINVAL;
631
632 if (WARN_ON(tid >= IEEE80211_FIRST_TSPEC_TSID))
633 return -EINVAL;
634
635 ht_dbg(sdata, "Open BA session requested for %pM tid %u\n",
636 pubsta->addr, tid);
637
638 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
639 sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
640 sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
641 sdata->vif.type != NL80211_IFTYPE_AP &&
642 sdata->vif.type != NL80211_IFTYPE_ADHOC)
643 return -EINVAL;
644
645 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
646 ht_dbg(sdata,
647 "BA sessions blocked - Denying BA session request %pM tid %d\n",
648 sta->sta.addr, tid);
649 return -EINVAL;
650 }
651
652 if (test_sta_flag(sta, WLAN_STA_MFP) &&
653 !test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
654 ht_dbg(sdata,
655 "MFP STA not authorized - deny BA session request %pM tid %d\n",
656 sta->sta.addr, tid);
657 return -EINVAL;
658 }
659
660 /*
661 * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a
662 * member of an IBSS, and has no other existing Block Ack agreement
663 * with the recipient STA, then the initiating STA shall transmit a
664 * Probe Request frame to the recipient STA and shall not transmit an
665 * ADDBA Request frame unless it receives a Probe Response frame
666 * from the recipient within dot11ADDBAFailureTimeout.
667 *
668 * The probe request mechanism for ADDBA is currently not implemented,
669 * but we only build up Block Ack session with HT STAs. This information
670 * is set when we receive a bss info from a probe response or a beacon.
671 */
672 if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC &&
673 !sta->sta.deflink.ht_cap.ht_supported) {
674 ht_dbg(sdata,
675 "BA request denied - IBSS STA %pM does not advertise HT support\n",
676 pubsta->addr);
677 return -EINVAL;
678 }
679
680 spin_lock_bh(&sta->lock);
681
682 /* we have tried too many times, receiver does not want A-MPDU */
683 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
684 ret = -EBUSY;
685 goto err_unlock_sta;
686 }
687
688 /*
689 * if we have tried more than HT_AGG_BURST_RETRIES times we
690 * will spread our requests in time to avoid stalling connection
691 * for too long
692 */
693 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES &&
694 time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] +
695 HT_AGG_RETRIES_PERIOD)) {
696 ht_dbg(sdata,
697 "BA request denied - %d failed requests on %pM tid %u\n",
698 sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, tid);
699 ret = -EBUSY;
700 goto err_unlock_sta;
701 }
702
703 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
704 /* check if the TID is not in aggregation flow already */
705 if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
706 ht_dbg(sdata,
707 "BA request denied - session is not idle on %pM tid %u\n",
708 sta->sta.addr, tid);
709 ret = -EAGAIN;
710 goto err_unlock_sta;
711 }
712
713 /* prepare A-MPDU MLME for Tx aggregation */
714 tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
715 if (!tid_tx) {
716 ret = -ENOMEM;
717 goto err_unlock_sta;
718 }
719
720 skb_queue_head_init(&tid_tx->pending);
721 __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
722
723 tid_tx->timeout = timeout;
724 tid_tx->sta = sta;
725 tid_tx->tid = tid;
726
727 /* response timer */
728 timer_setup(&tid_tx->addba_resp_timer, sta_addba_resp_timer_expired, 0);
729
730 /* tx timer */
731 timer_setup(&tid_tx->session_timer,
732 sta_tx_agg_session_timer_expired, TIMER_DEFERRABLE);
733
734 /* assign a dialog token */
735 sta->ampdu_mlme.dialog_token_allocator++;
736 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
737
738 /*
739 * Finally, assign it to the start array; the work item will
740 * collect it and move it to the normal array.
741 */
742 sta->ampdu_mlme.tid_start_tx[tid] = tid_tx;
743
744 wiphy_work_queue(local->hw.wiphy, &sta->ampdu_mlme.work);
745
746 /* this flow continues off the work */
747 err_unlock_sta:
748 spin_unlock_bh(&sta->lock);
749 return ret;
750 }
751 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
752
753 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
754 struct sta_info *sta, u16 tid)
755 {
756 struct tid_ampdu_tx *tid_tx;
757 struct ieee80211_ampdu_params params = {
758 .sta = &sta->sta,
759 .action = IEEE80211_AMPDU_TX_OPERATIONAL,
760 .tid = tid,
761 .timeout = 0,
762 .ssn = 0,
763 };
764
765 lockdep_assert_wiphy(sta->local->hw.wiphy);
766
767 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
768 params.buf_size = tid_tx->buf_size;
769 params.amsdu = tid_tx->amsdu;
770
771 ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n",
772 sta->sta.addr, tid);
773
774 drv_ampdu_action(local, sta->sdata, ¶ms);
775
776 /*
777 * synchronize with TX path, while splicing the TX path
778 * should block so it won't put more packets onto pending.
779 */
780 spin_lock_bh(&sta->lock);
781
782 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
783 /*
784 * Now mark as operational. This will be visible
785 * in the TX path, and lets it go lock-free in
786 * the common case.
787 */
788 set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
789 ieee80211_agg_splice_finish(sta->sdata, tid);
790
791 spin_unlock_bh(&sta->lock);
792
793 ieee80211_agg_start_txq(sta, tid, true);
794 }
795
796 void ieee80211_start_tx_ba_cb(struct sta_info *sta, int tid,
797 struct tid_ampdu_tx *tid_tx)
798 {
799 struct ieee80211_sub_if_data *sdata = sta->sdata;
800 struct ieee80211_local *local = sdata->local;
801
802 lockdep_assert_wiphy(sta->local->hw.wiphy);
803
804 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
805 return;
806
807 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state) ||
808 test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state))
809 return;
810
811 if (!test_bit(HT_AGG_STATE_SENT_ADDBA, &tid_tx->state)) {
812 ieee80211_send_addba_with_timeout(sta, tid_tx);
813 /* RESPONSE_RECEIVED state whould trigger the flow again */
814 return;
815 }
816
817 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
818 ieee80211_agg_tx_operational(local, sta, tid);
819 }
820
821 static struct tid_ampdu_tx *
822 ieee80211_lookup_tid_tx(struct ieee80211_sub_if_data *sdata,
823 const u8 *ra, u16 tid, struct sta_info **sta)
824 {
825 struct tid_ampdu_tx *tid_tx;
826
827 if (tid >= IEEE80211_NUM_TIDS) {
828 ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
829 tid, IEEE80211_NUM_TIDS);
830 return NULL;
831 }
832
833 *sta = sta_info_get_bss(sdata, ra);
834 if (!*sta) {
835 ht_dbg(sdata, "Could not find station: %pM\n", ra);
836 return NULL;
837 }
838
839 tid_tx = rcu_dereference((*sta)->ampdu_mlme.tid_tx[tid]);
840
841 if (WARN_ON(!tid_tx))
842 ht_dbg(sdata, "addBA was not requested!\n");
843
844 return tid_tx;
845 }
846
847 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
848 const u8 *ra, u16 tid)
849 {
850 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
851 struct ieee80211_local *local = sdata->local;
852 struct sta_info *sta;
853 struct tid_ampdu_tx *tid_tx;
854
855 trace_api_start_tx_ba_cb(sdata, ra, tid);
856
857 rcu_read_lock();
858 tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta);
859 if (!tid_tx)
860 goto out;
861
862 set_bit(HT_AGG_STATE_START_CB, &tid_tx->state);
863 wiphy_work_queue(local->hw.wiphy, &sta->ampdu_mlme.work);
864 out:
865 rcu_read_unlock();
866 }
867 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
868
869 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
870 {
871 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
872 struct ieee80211_sub_if_data *sdata = sta->sdata;
873 struct ieee80211_local *local = sdata->local;
874 struct tid_ampdu_tx *tid_tx;
875 int ret = 0;
876
877 trace_api_stop_tx_ba_session(pubsta, tid);
878
879 if (!local->ops->ampdu_action)
880 return -EINVAL;
881
882 if (tid >= IEEE80211_NUM_TIDS)
883 return -EINVAL;
884
885 spin_lock_bh(&sta->lock);
886 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
887
888 if (!tid_tx) {
889 ret = -ENOENT;
890 goto unlock;
891 }
892
893 WARN(sta->reserved_tid == tid,
894 "Requested to stop BA session on reserved tid=%d", tid);
895
896 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
897 /* already in progress stopping it */
898 ret = 0;
899 goto unlock;
900 }
901
902 set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state);
903 wiphy_work_queue(local->hw.wiphy, &sta->ampdu_mlme.work);
904
905 unlock:
906 spin_unlock_bh(&sta->lock);
907 return ret;
908 }
909 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
910
911 void ieee80211_stop_tx_ba_cb(struct sta_info *sta, int tid,
912 struct tid_ampdu_tx *tid_tx)
913 {
914 struct ieee80211_sub_if_data *sdata = sta->sdata;
915 bool send_delba = false;
916 bool start_txq = false;
917
918 ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n",
919 sta->sta.addr, tid);
920
921 spin_lock_bh(&sta->lock);
922
923 if (!test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
924 ht_dbg(sdata,
925 "unexpected callback to A-MPDU stop for %pM tid %d\n",
926 sta->sta.addr, tid);
927 goto unlock_sta;
928 }
929
930 if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop)
931 send_delba = true;
932
933 ieee80211_remove_tid_tx(sta, tid);
934 start_txq = true;
935
936 unlock_sta:
937 spin_unlock_bh(&sta->lock);
938
939 if (start_txq)
940 ieee80211_agg_start_txq(sta, tid, false);
941
942 if (send_delba)
943 ieee80211_send_delba(sdata, sta->sta.addr, tid,
944 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
945 }
946
947 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
948 const u8 *ra, u16 tid)
949 {
950 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
951 struct ieee80211_local *local = sdata->local;
952 struct sta_info *sta;
953 struct tid_ampdu_tx *tid_tx;
954
955 trace_api_stop_tx_ba_cb(sdata, ra, tid);
956
957 rcu_read_lock();
958 tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta);
959 if (!tid_tx)
960 goto out;
961
962 set_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state);
963 wiphy_work_queue(local->hw.wiphy, &sta->ampdu_mlme.work);
964 out:
965 rcu_read_unlock();
966 }
967 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
968
969
970 void ieee80211_process_addba_resp(struct ieee80211_local *local,
971 struct sta_info *sta,
972 struct ieee80211_mgmt *mgmt,
973 size_t len)
974 {
975 struct tid_ampdu_tx *tid_tx;
976 struct ieee80211_txq *txq;
977 u16 capab, tid, buf_size;
978 bool amsdu;
979
980 lockdep_assert_wiphy(sta->local->hw.wiphy);
981
982 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
983 amsdu = capab & IEEE80211_ADDBA_PARAM_AMSDU_MASK;
984 tid = u16_get_bits(capab, IEEE80211_ADDBA_PARAM_TID_MASK);
985 buf_size = u16_get_bits(capab, IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK);
986 buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes);
987
988 txq = sta->sta.txq[tid];
989 if (!amsdu && txq)
990 set_bit(IEEE80211_TXQ_NO_AMSDU, &to_txq_info(txq)->flags);
991
992 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
993 if (!tid_tx)
994 return;
995
996 if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
997 ht_dbg(sta->sdata, "wrong addBA response token, %pM tid %d\n",
998 sta->sta.addr, tid);
999 return;
1000 }
1001
1002 del_timer_sync(&tid_tx->addba_resp_timer);
1003
1004 ht_dbg(sta->sdata, "switched off addBA timer for %pM tid %d\n",
1005 sta->sta.addr, tid);
1006
1007 /*
1008 * addba_resp_timer may have fired before we got here, and
1009 * caused WANT_STOP to be set. If the stop then was already
1010 * processed further, STOPPING might be set.
1011 */
1012 if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) ||
1013 test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
1014 ht_dbg(sta->sdata,
1015 "got addBA resp for %pM tid %d but we already gave up\n",
1016 sta->sta.addr, tid);
1017 return;
1018 }
1019
1020 /*
1021 * IEEE 802.11-2007 7.3.1.14:
1022 * In an ADDBA Response frame, when the Status Code field
1023 * is set to 0, the Buffer Size subfield is set to a value
1024 * of at least 1.
1025 */
1026 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
1027 == WLAN_STATUS_SUCCESS && buf_size) {
1028 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
1029 &tid_tx->state)) {
1030 /* ignore duplicate response */
1031 return;
1032 }
1033
1034 tid_tx->buf_size = buf_size;
1035 tid_tx->amsdu = amsdu;
1036
1037 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
1038 ieee80211_agg_tx_operational(local, sta, tid);
1039
1040 sta->ampdu_mlme.addba_req_num[tid] = 0;
1041
1042 tid_tx->timeout =
1043 le16_to_cpu(mgmt->u.action.u.addba_resp.timeout);
1044
1045 if (tid_tx->timeout) {
1046 mod_timer(&tid_tx->session_timer,
1047 TU_TO_EXP_TIME(tid_tx->timeout));
1048 tid_tx->last_tx = jiffies;
1049 }
1050
1051 } else {
1052 __ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_DECLINED);
1053 }
1054 }
1055
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