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, ¶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 */
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, ¶ms);
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, ¶ms);
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