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1/*
2 * HT handling
3 *
4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Copyright 2002-2005, Instant802 Networks, Inc.
6 * Copyright 2005-2006, Devicescape Software, Inc.
7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9 * Copyright 2007-2010, Intel Corporation
10 * Copyright(c) 2015 Intel Deutschland GmbH
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 */
16
17#include <linux/ieee80211.h>
18#include <linux/slab.h>
19#include <linux/export.h>
20#include <net/mac80211.h>
21#include "ieee80211_i.h"
22#include "driver-ops.h"
23#include "wme.h"
24
25/**
26 * DOC: TX A-MPDU aggregation
27 *
28 * Aggregation on the TX side requires setting the hardware flag
29 * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed
30 * packets with a flag indicating A-MPDU aggregation. The driver
31 * or device is responsible for actually aggregating the frames,
32 * as well as deciding how many and which to aggregate.
33 *
34 * When TX aggregation is started by some subsystem (usually the rate
35 * control algorithm would be appropriate) by calling the
36 * ieee80211_start_tx_ba_session() function, the driver will be
37 * notified via its @ampdu_action function, with the
38 * %IEEE80211_AMPDU_TX_START action.
39 *
40 * In response to that, the driver is later required to call the
41 * ieee80211_start_tx_ba_cb_irqsafe() function, which will really
42 * start the aggregation session after the peer has also responded.
43 * If the peer responds negatively, the session will be stopped
44 * again right away. Note that it is possible for the aggregation
45 * session to be stopped before the driver has indicated that it
46 * is done setting it up, in which case it must not indicate the
47 * setup completion.
48 *
49 * Also note that, since we also need to wait for a response from
50 * the peer, the driver is notified of the completion of the
51 * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the
52 * @ampdu_action callback.
53 *
54 * Similarly, when the aggregation session is stopped by the peer
55 * or something calling ieee80211_stop_tx_ba_session(), the driver's
56 * @ampdu_action function will be called with the action
57 * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail,
58 * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe().
59 * Note that the sta can get destroyed before the BA tear down is
60 * complete.
61 */
62
63static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
64 const u8 *da, u16 tid,
65 u8 dialog_token, u16 start_seq_num,
66 u16 agg_size, u16 timeout)
67{
68 struct ieee80211_local *local = sdata->local;
69 struct sk_buff *skb;
70 struct ieee80211_mgmt *mgmt;
71 u16 capab;
72
73 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
74
75 if (!skb)
76 return;
77
78 skb_reserve(skb, local->hw.extra_tx_headroom);
79 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
80 memset(mgmt, 0, 24);
81 memcpy(mgmt->da, da, ETH_ALEN);
82 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
83 if (sdata->vif.type == NL80211_IFTYPE_AP ||
84 sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
85 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
86 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
87 else if (sdata->vif.type == NL80211_IFTYPE_STATION)
88 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
89 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
90 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
91
92 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
93 IEEE80211_STYPE_ACTION);
94
95 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
96
97 mgmt->u.action.category = WLAN_CATEGORY_BACK;
98 mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
99
100 mgmt->u.action.u.addba_req.dialog_token = dialog_token;
101 capab = (u16)(1 << 0); /* bit 0 A-MSDU support */
102 capab |= (u16)(1 << 1); /* bit 1 aggregation policy */
103 capab |= (u16)(tid << 2); /* bit 5:2 TID number */
104 capab |= (u16)(agg_size << 6); /* bit 15:6 max size of aggergation */
105
106 mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
107
108 mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
109 mgmt->u.action.u.addba_req.start_seq_num =
110 cpu_to_le16(start_seq_num << 4);
111
112 ieee80211_tx_skb(sdata, skb);
113}
114
115void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
116{
117 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
118 struct ieee80211_local *local = sdata->local;
119 struct sk_buff *skb;
120 struct ieee80211_bar *bar;
121 u16 bar_control = 0;
122
123 skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
124 if (!skb)
125 return;
126
127 skb_reserve(skb, local->hw.extra_tx_headroom);
128 bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
129 memset(bar, 0, sizeof(*bar));
130 bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
131 IEEE80211_STYPE_BACK_REQ);
132 memcpy(bar->ra, ra, ETH_ALEN);
133 memcpy(bar->ta, sdata->vif.addr, ETH_ALEN);
134 bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
135 bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
136 bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT);
137 bar->control = cpu_to_le16(bar_control);
138 bar->start_seq_num = cpu_to_le16(ssn);
139
140 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
141 IEEE80211_TX_CTL_REQ_TX_STATUS;
142 ieee80211_tx_skb_tid(sdata, skb, tid);
143}
144EXPORT_SYMBOL(ieee80211_send_bar);
145
146void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
147 struct tid_ampdu_tx *tid_tx)
148{
149 lockdep_assert_held(&sta->ampdu_mlme.mtx);
150 lockdep_assert_held(&sta->lock);
151 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
152}
153
154/*
155 * When multiple aggregation sessions on multiple stations
156 * are being created/destroyed simultaneously, we need to
157 * refcount the global queue stop caused by that in order
158 * to not get into a situation where one of the aggregation
159 * setup or teardown re-enables queues before the other is
160 * ready to handle that.
161 *
162 * These two functions take care of this issue by keeping
163 * a global "agg_queue_stop" refcount.
164 */
165static void __acquires(agg_queue)
166ieee80211_stop_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
167{
168 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
169
170 /* we do refcounting here, so don't use the queue reason refcounting */
171
172 if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1)
173 ieee80211_stop_queue_by_reason(
174 &sdata->local->hw, queue,
175 IEEE80211_QUEUE_STOP_REASON_AGGREGATION,
176 false);
177 __acquire(agg_queue);
178}
179
180static void __releases(agg_queue)
181ieee80211_wake_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
182{
183 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
184
185 if (atomic_dec_return(&sdata->local->agg_queue_stop[queue]) == 0)
186 ieee80211_wake_queue_by_reason(
187 &sdata->local->hw, queue,
188 IEEE80211_QUEUE_STOP_REASON_AGGREGATION,
189 false);
190 __release(agg_queue);
191}
192
193static void
194ieee80211_agg_stop_txq(struct sta_info *sta, int tid)
195{
196 struct ieee80211_txq *txq = sta->sta.txq[tid];
197 struct ieee80211_sub_if_data *sdata;
198 struct fq *fq;
199 struct txq_info *txqi;
200
201 if (!txq)
202 return;
203
204 txqi = to_txq_info(txq);
205 sdata = vif_to_sdata(txq->vif);
206 fq = &sdata->local->fq;
207
208 /* Lock here to protect against further seqno updates on dequeue */
209 spin_lock_bh(&fq->lock);
210 set_bit(IEEE80211_TXQ_STOP, &txqi->flags);
211 spin_unlock_bh(&fq->lock);
212}
213
214static void
215ieee80211_agg_start_txq(struct sta_info *sta, int tid, bool enable)
216{
217 struct ieee80211_txq *txq = sta->sta.txq[tid];
218 struct txq_info *txqi;
219
220 if (!txq)
221 return;
222
223 txqi = to_txq_info(txq);
224
225 if (enable)
226 set_bit(IEEE80211_TXQ_AMPDU, &txqi->flags);
227 else
228 clear_bit(IEEE80211_TXQ_AMPDU, &txqi->flags);
229
230 clear_bit(IEEE80211_TXQ_STOP, &txqi->flags);
231 drv_wake_tx_queue(sta->sdata->local, txqi);
232}
233
234/*
235 * splice packets from the STA's pending to the local pending,
236 * requires a call to ieee80211_agg_splice_finish later
237 */
238static void __acquires(agg_queue)
239ieee80211_agg_splice_packets(struct ieee80211_sub_if_data *sdata,
240 struct tid_ampdu_tx *tid_tx, u16 tid)
241{
242 struct ieee80211_local *local = sdata->local;
243 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
244 unsigned long flags;
245
246 ieee80211_stop_queue_agg(sdata, tid);
247
248 if (WARN(!tid_tx,
249 "TID %d gone but expected when splicing aggregates from the pending queue\n",
250 tid))
251 return;
252
253 if (!skb_queue_empty(&tid_tx->pending)) {
254 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
255 /* copy over remaining packets */
256 skb_queue_splice_tail_init(&tid_tx->pending,
257 &local->pending[queue]);
258 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
259 }
260}
261
262static void __releases(agg_queue)
263ieee80211_agg_splice_finish(struct ieee80211_sub_if_data *sdata, u16 tid)
264{
265 ieee80211_wake_queue_agg(sdata, tid);
266}
267
268static void ieee80211_remove_tid_tx(struct sta_info *sta, int tid)
269{
270 struct tid_ampdu_tx *tid_tx;
271
272 lockdep_assert_held(&sta->ampdu_mlme.mtx);
273 lockdep_assert_held(&sta->lock);
274
275 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
276
277 /*
278 * When we get here, the TX path will not be lockless any more wrt.
279 * aggregation, since the OPERATIONAL bit has long been cleared.
280 * Thus it will block on getting the lock, if it occurs. So if we
281 * stop the queue now, we will not get any more packets, and any
282 * that might be being processed will wait for us here, thereby
283 * guaranteeing that no packets go to the tid_tx pending queue any
284 * more.
285 */
286
287 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
288
289 /* future packets must not find the tid_tx struct any more */
290 ieee80211_assign_tid_tx(sta, tid, NULL);
291
292 ieee80211_agg_splice_finish(sta->sdata, tid);
293 ieee80211_agg_start_txq(sta, tid, false);
294
295 kfree_rcu(tid_tx, rcu_head);
296}
297
298int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
299 enum ieee80211_agg_stop_reason reason)
300{
301 struct ieee80211_local *local = sta->local;
302 struct tid_ampdu_tx *tid_tx;
303 struct ieee80211_ampdu_params params = {
304 .sta = &sta->sta,
305 .tid = tid,
306 .buf_size = 0,
307 .amsdu = false,
308 .timeout = 0,
309 .ssn = 0,
310 };
311 int ret;
312
313 lockdep_assert_held(&sta->ampdu_mlme.mtx);
314
315 switch (reason) {
316 case AGG_STOP_DECLINED:
317 case AGG_STOP_LOCAL_REQUEST:
318 case AGG_STOP_PEER_REQUEST:
319 params.action = IEEE80211_AMPDU_TX_STOP_CONT;
320 break;
321 case AGG_STOP_DESTROY_STA:
322 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH;
323 break;
324 default:
325 WARN_ON_ONCE(1);
326 return -EINVAL;
327 }
328
329 spin_lock_bh(&sta->lock);
330
331 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
332 if (!tid_tx) {
333 spin_unlock_bh(&sta->lock);
334 return -ENOENT;
335 }
336
337 /*
338 * if we're already stopping ignore any new requests to stop
339 * unless we're destroying it in which case notify the driver
340 */
341 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
342 spin_unlock_bh(&sta->lock);
343 if (reason != AGG_STOP_DESTROY_STA)
344 return -EALREADY;
345 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH_CONT;
346 ret = drv_ampdu_action(local, sta->sdata, ¶ms);
347 WARN_ON_ONCE(ret);
348 return 0;
349 }
350
351 if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
352 /* not even started yet! */
353 ieee80211_assign_tid_tx(sta, tid, NULL);
354 spin_unlock_bh(&sta->lock);
355 kfree_rcu(tid_tx, rcu_head);
356 return 0;
357 }
358
359 set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
360
361 spin_unlock_bh(&sta->lock);
362
363 ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n",
364 sta->sta.addr, tid);
365
366 del_timer_sync(&tid_tx->addba_resp_timer);
367 del_timer_sync(&tid_tx->session_timer);
368
369 /*
370 * After this packets are no longer handed right through
371 * to the driver but are put onto tid_tx->pending instead,
372 * with locking to ensure proper access.
373 */
374 clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
375
376 /*
377 * There might be a few packets being processed right now (on
378 * another CPU) that have already gotten past the aggregation
379 * check when it was still OPERATIONAL and consequently have
380 * IEEE80211_TX_CTL_AMPDU set. In that case, this code might
381 * call into the driver at the same time or even before the
382 * TX paths calls into it, which could confuse the driver.
383 *
384 * Wait for all currently running TX paths to finish before
385 * telling the driver. New packets will not go through since
386 * the aggregation session is no longer OPERATIONAL.
387 */
388 synchronize_net();
389
390 tid_tx->stop_initiator = reason == AGG_STOP_PEER_REQUEST ?
391 WLAN_BACK_RECIPIENT :
392 WLAN_BACK_INITIATOR;
393 tid_tx->tx_stop = reason == AGG_STOP_LOCAL_REQUEST;
394
395 ret = drv_ampdu_action(local, sta->sdata, ¶ms);
396
397 /* HW shall not deny going back to legacy */
398 if (WARN_ON(ret)) {
399 /*
400 * We may have pending packets get stuck in this case...
401 * Not bothering with a workaround for now.
402 */
403 }
404
405 /*
406 * In the case of AGG_STOP_DESTROY_STA, the driver won't
407 * necessarily call ieee80211_stop_tx_ba_cb(), so this may
408 * seem like we can leave the tid_tx data pending forever.
409 * This is true, in a way, but "forever" is only until the
410 * station struct is actually destroyed. In the meantime,
411 * leaving it around ensures that we don't transmit packets
412 * to the driver on this TID which might confuse it.
413 */
414
415 return 0;
416}
417
418/*
419 * After sending add Block Ack request we activated a timer until
420 * add Block Ack response will arrive from the recipient.
421 * If this timer expires sta_addba_resp_timer_expired will be executed.
422 */
423static void sta_addba_resp_timer_expired(unsigned long data)
424{
425 /* not an elegant detour, but there is no choice as the timer passes
426 * only one argument, and both sta_info and TID are needed, so init
427 * flow in sta_info_create gives the TID as data, while the timer_to_id
428 * array gives the sta through container_of */
429 u16 tid = *(u8 *)data;
430 struct sta_info *sta = container_of((void *)data,
431 struct sta_info, timer_to_tid[tid]);
432 struct tid_ampdu_tx *tid_tx;
433
434 /* check if the TID waits for addBA response */
435 rcu_read_lock();
436 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
437 if (!tid_tx ||
438 test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
439 rcu_read_unlock();
440 ht_dbg(sta->sdata,
441 "timer expired on %pM tid %d but we are not (or no longer) expecting addBA response there\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 rcu_read_unlock();
451}
452
453void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
454{
455 struct tid_ampdu_tx *tid_tx;
456 struct ieee80211_local *local = sta->local;
457 struct ieee80211_sub_if_data *sdata = sta->sdata;
458 struct ieee80211_ampdu_params params = {
459 .sta = &sta->sta,
460 .action = IEEE80211_AMPDU_TX_START,
461 .tid = tid,
462 .buf_size = 0,
463 .amsdu = false,
464 .timeout = 0,
465 };
466 int ret;
467
468 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
469
470 /*
471 * Start queuing up packets for this aggregation session.
472 * We're going to release them once the driver is OK with
473 * that.
474 */
475 clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
476
477 ieee80211_agg_stop_txq(sta, tid);
478
479 /*
480 * Make sure no packets are being processed. This ensures that
481 * we have a valid starting sequence number and that in-flight
482 * packets have been flushed out and no packets for this TID
483 * will go into the driver during the ampdu_action call.
484 */
485 synchronize_net();
486
487 params.ssn = sta->tid_seq[tid] >> 4;
488 ret = drv_ampdu_action(local, sdata, ¶ms);
489 if (ret) {
490 ht_dbg(sdata,
491 "BA request denied - HW unavailable for %pM tid %d\n",
492 sta->sta.addr, tid);
493 spin_lock_bh(&sta->lock);
494 ieee80211_agg_splice_packets(sdata, tid_tx, tid);
495 ieee80211_assign_tid_tx(sta, tid, NULL);
496 ieee80211_agg_splice_finish(sdata, tid);
497 spin_unlock_bh(&sta->lock);
498
499 ieee80211_agg_start_txq(sta, tid, false);
500
501 kfree_rcu(tid_tx, rcu_head);
502 return;
503 }
504
505 /* activate the timer for the recipient's addBA response */
506 mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
507 ht_dbg(sdata, "activated addBA response timer on %pM tid %d\n",
508 sta->sta.addr, tid);
509
510 spin_lock_bh(&sta->lock);
511 sta->ampdu_mlme.last_addba_req_time[tid] = jiffies;
512 sta->ampdu_mlme.addba_req_num[tid]++;
513 spin_unlock_bh(&sta->lock);
514
515 /* send AddBA request */
516 ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
517 tid_tx->dialog_token, params.ssn,
518 IEEE80211_MAX_AMPDU_BUF,
519 tid_tx->timeout);
520}
521
522/*
523 * After accepting the AddBA Response we activated a timer,
524 * resetting it after each frame that we send.
525 */
526static void sta_tx_agg_session_timer_expired(unsigned long data)
527{
528 /* not an elegant detour, but there is no choice as the timer passes
529 * only one argument, and various sta_info are needed here, so init
530 * flow in sta_info_create gives the TID as data, while the timer_to_id
531 * array gives the sta through container_of */
532 u8 *ptid = (u8 *)data;
533 u8 *timer_to_id = ptid - *ptid;
534 struct sta_info *sta = container_of(timer_to_id, struct sta_info,
535 timer_to_tid[0]);
536 struct tid_ampdu_tx *tid_tx;
537 unsigned long timeout;
538
539 rcu_read_lock();
540 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[*ptid]);
541 if (!tid_tx || test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
542 rcu_read_unlock();
543 return;
544 }
545
546 timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout);
547 if (time_is_after_jiffies(timeout)) {
548 mod_timer(&tid_tx->session_timer, timeout);
549 rcu_read_unlock();
550 return;
551 }
552
553 rcu_read_unlock();
554
555 ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n",
556 sta->sta.addr, (u16)*ptid);
557
558 ieee80211_stop_tx_ba_session(&sta->sta, *ptid);
559}
560
561int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
562 u16 timeout)
563{
564 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
565 struct ieee80211_sub_if_data *sdata = sta->sdata;
566 struct ieee80211_local *local = sdata->local;
567 struct tid_ampdu_tx *tid_tx;
568 int ret = 0;
569
570 trace_api_start_tx_ba_session(pubsta, tid);
571
572 if (WARN(sta->reserved_tid == tid,
573 "Requested to start BA session on reserved tid=%d", tid))
574 return -EINVAL;
575
576 if (!pubsta->ht_cap.ht_supported)
577 return -EINVAL;
578
579 if (WARN_ON_ONCE(!local->ops->ampdu_action))
580 return -EINVAL;
581
582 if ((tid >= IEEE80211_NUM_TIDS) ||
583 !ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION) ||
584 ieee80211_hw_check(&local->hw, TX_AMPDU_SETUP_IN_HW))
585 return -EINVAL;
586
587 if (WARN_ON(tid >= IEEE80211_FIRST_TSPEC_TSID))
588 return -EINVAL;
589
590 ht_dbg(sdata, "Open BA session requested for %pM tid %u\n",
591 pubsta->addr, tid);
592
593 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
594 sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
595 sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
596 sdata->vif.type != NL80211_IFTYPE_AP &&
597 sdata->vif.type != NL80211_IFTYPE_ADHOC)
598 return -EINVAL;
599
600 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
601 ht_dbg(sdata,
602 "BA sessions blocked - Denying BA session request %pM tid %d\n",
603 sta->sta.addr, tid);
604 return -EINVAL;
605 }
606
607 /*
608 * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a
609 * member of an IBSS, and has no other existing Block Ack agreement
610 * with the recipient STA, then the initiating STA shall transmit a
611 * Probe Request frame to the recipient STA and shall not transmit an
612 * ADDBA Request frame unless it receives a Probe Response frame
613 * from the recipient within dot11ADDBAFailureTimeout.
614 *
615 * The probe request mechanism for ADDBA is currently not implemented,
616 * but we only build up Block Ack session with HT STAs. This information
617 * is set when we receive a bss info from a probe response or a beacon.
618 */
619 if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC &&
620 !sta->sta.ht_cap.ht_supported) {
621 ht_dbg(sdata,
622 "BA request denied - IBSS STA %pM does not advertise HT support\n",
623 pubsta->addr);
624 return -EINVAL;
625 }
626
627 spin_lock_bh(&sta->lock);
628
629 /* we have tried too many times, receiver does not want A-MPDU */
630 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
631 ret = -EBUSY;
632 goto err_unlock_sta;
633 }
634
635 /*
636 * if we have tried more than HT_AGG_BURST_RETRIES times we
637 * will spread our requests in time to avoid stalling connection
638 * for too long
639 */
640 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES &&
641 time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] +
642 HT_AGG_RETRIES_PERIOD)) {
643 ht_dbg(sdata,
644 "BA request denied - waiting a grace period after %d failed requests on %pM tid %u\n",
645 sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, tid);
646 ret = -EBUSY;
647 goto err_unlock_sta;
648 }
649
650 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
651 /* check if the TID is not in aggregation flow already */
652 if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
653 ht_dbg(sdata,
654 "BA request denied - session is not idle on %pM tid %u\n",
655 sta->sta.addr, tid);
656 ret = -EAGAIN;
657 goto err_unlock_sta;
658 }
659
660 /* prepare A-MPDU MLME for Tx aggregation */
661 tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
662 if (!tid_tx) {
663 ret = -ENOMEM;
664 goto err_unlock_sta;
665 }
666
667 skb_queue_head_init(&tid_tx->pending);
668 __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
669
670 tid_tx->timeout = timeout;
671
672 /* response timer */
673 tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired;
674 tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid];
675 init_timer(&tid_tx->addba_resp_timer);
676
677 /* tx timer */
678 tid_tx->session_timer.function = sta_tx_agg_session_timer_expired;
679 tid_tx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
680 init_timer_deferrable(&tid_tx->session_timer);
681
682 /* assign a dialog token */
683 sta->ampdu_mlme.dialog_token_allocator++;
684 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
685
686 /*
687 * Finally, assign it to the start array; the work item will
688 * collect it and move it to the normal array.
689 */
690 sta->ampdu_mlme.tid_start_tx[tid] = tid_tx;
691
692 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
693
694 /* this flow continues off the work */
695 err_unlock_sta:
696 spin_unlock_bh(&sta->lock);
697 return ret;
698}
699EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
700
701static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
702 struct sta_info *sta, u16 tid)
703{
704 struct tid_ampdu_tx *tid_tx;
705 struct ieee80211_ampdu_params params = {
706 .sta = &sta->sta,
707 .action = IEEE80211_AMPDU_TX_OPERATIONAL,
708 .tid = tid,
709 .timeout = 0,
710 .ssn = 0,
711 };
712
713 lockdep_assert_held(&sta->ampdu_mlme.mtx);
714
715 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
716 params.buf_size = tid_tx->buf_size;
717 params.amsdu = tid_tx->amsdu;
718
719 ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n",
720 sta->sta.addr, tid);
721
722 drv_ampdu_action(local, sta->sdata, ¶ms);
723
724 /*
725 * synchronize with TX path, while splicing the TX path
726 * should block so it won't put more packets onto pending.
727 */
728 spin_lock_bh(&sta->lock);
729
730 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
731 /*
732 * Now mark as operational. This will be visible
733 * in the TX path, and lets it go lock-free in
734 * the common case.
735 */
736 set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
737 ieee80211_agg_splice_finish(sta->sdata, tid);
738
739 spin_unlock_bh(&sta->lock);
740
741 ieee80211_agg_start_txq(sta, tid, true);
742}
743
744void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
745{
746 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
747 struct ieee80211_local *local = sdata->local;
748 struct sta_info *sta;
749 struct tid_ampdu_tx *tid_tx;
750
751 trace_api_start_tx_ba_cb(sdata, ra, tid);
752
753 if (tid >= IEEE80211_NUM_TIDS) {
754 ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
755 tid, IEEE80211_NUM_TIDS);
756 return;
757 }
758
759 mutex_lock(&local->sta_mtx);
760 sta = sta_info_get_bss(sdata, ra);
761 if (!sta) {
762 mutex_unlock(&local->sta_mtx);
763 ht_dbg(sdata, "Could not find station: %pM\n", ra);
764 return;
765 }
766
767 mutex_lock(&sta->ampdu_mlme.mtx);
768 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
769
770 if (WARN_ON(!tid_tx)) {
771 ht_dbg(sdata, "addBA was not requested!\n");
772 goto unlock;
773 }
774
775 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
776 goto unlock;
777
778 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
779 ieee80211_agg_tx_operational(local, sta, tid);
780
781 unlock:
782 mutex_unlock(&sta->ampdu_mlme.mtx);
783 mutex_unlock(&local->sta_mtx);
784}
785
786void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
787 const u8 *ra, u16 tid)
788{
789 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
790 struct ieee80211_local *local = sdata->local;
791 struct ieee80211_ra_tid *ra_tid;
792 struct sk_buff *skb = dev_alloc_skb(0);
793
794 if (unlikely(!skb))
795 return;
796
797 ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
798 memcpy(&ra_tid->ra, ra, ETH_ALEN);
799 ra_tid->tid = tid;
800
801 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START;
802 skb_queue_tail(&sdata->skb_queue, skb);
803 ieee80211_queue_work(&local->hw, &sdata->work);
804}
805EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
806
807int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
808 enum ieee80211_agg_stop_reason reason)
809{
810 int ret;
811
812 mutex_lock(&sta->ampdu_mlme.mtx);
813
814 ret = ___ieee80211_stop_tx_ba_session(sta, tid, reason);
815
816 mutex_unlock(&sta->ampdu_mlme.mtx);
817
818 return ret;
819}
820
821int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
822{
823 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
824 struct ieee80211_sub_if_data *sdata = sta->sdata;
825 struct ieee80211_local *local = sdata->local;
826 struct tid_ampdu_tx *tid_tx;
827 int ret = 0;
828
829 trace_api_stop_tx_ba_session(pubsta, tid);
830
831 if (!local->ops->ampdu_action)
832 return -EINVAL;
833
834 if (tid >= IEEE80211_NUM_TIDS)
835 return -EINVAL;
836
837 spin_lock_bh(&sta->lock);
838 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
839
840 if (!tid_tx) {
841 ret = -ENOENT;
842 goto unlock;
843 }
844
845 WARN(sta->reserved_tid == tid,
846 "Requested to stop BA session on reserved tid=%d", tid);
847
848 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
849 /* already in progress stopping it */
850 ret = 0;
851 goto unlock;
852 }
853
854 set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state);
855 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
856
857 unlock:
858 spin_unlock_bh(&sta->lock);
859 return ret;
860}
861EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
862
863void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
864{
865 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
866 struct ieee80211_local *local = sdata->local;
867 struct sta_info *sta;
868 struct tid_ampdu_tx *tid_tx;
869 bool send_delba = false;
870
871 trace_api_stop_tx_ba_cb(sdata, ra, tid);
872
873 if (tid >= IEEE80211_NUM_TIDS) {
874 ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
875 tid, IEEE80211_NUM_TIDS);
876 return;
877 }
878
879 ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", ra, tid);
880
881 mutex_lock(&local->sta_mtx);
882
883 sta = sta_info_get_bss(sdata, ra);
884 if (!sta) {
885 ht_dbg(sdata, "Could not find station: %pM\n", ra);
886 goto unlock;
887 }
888
889 mutex_lock(&sta->ampdu_mlme.mtx);
890 spin_lock_bh(&sta->lock);
891 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
892
893 if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
894 ht_dbg(sdata,
895 "unexpected callback to A-MPDU stop for %pM tid %d\n",
896 sta->sta.addr, tid);
897 goto unlock_sta;
898 }
899
900 if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop)
901 send_delba = true;
902
903 ieee80211_remove_tid_tx(sta, tid);
904
905 unlock_sta:
906 spin_unlock_bh(&sta->lock);
907
908 if (send_delba)
909 ieee80211_send_delba(sdata, ra, tid,
910 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
911
912 mutex_unlock(&sta->ampdu_mlme.mtx);
913 unlock:
914 mutex_unlock(&local->sta_mtx);
915}
916
917void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
918 const u8 *ra, u16 tid)
919{
920 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
921 struct ieee80211_local *local = sdata->local;
922 struct ieee80211_ra_tid *ra_tid;
923 struct sk_buff *skb = dev_alloc_skb(0);
924
925 if (unlikely(!skb))
926 return;
927
928 ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
929 memcpy(&ra_tid->ra, ra, ETH_ALEN);
930 ra_tid->tid = tid;
931
932 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP;
933 skb_queue_tail(&sdata->skb_queue, skb);
934 ieee80211_queue_work(&local->hw, &sdata->work);
935}
936EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
937
938
939void ieee80211_process_addba_resp(struct ieee80211_local *local,
940 struct sta_info *sta,
941 struct ieee80211_mgmt *mgmt,
942 size_t len)
943{
944 struct tid_ampdu_tx *tid_tx;
945 struct ieee80211_txq *txq;
946 u16 capab, tid;
947 u8 buf_size;
948 bool amsdu;
949
950 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
951 amsdu = capab & IEEE80211_ADDBA_PARAM_AMSDU_MASK;
952 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
953 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
954 buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes);
955
956 txq = sta->sta.txq[tid];
957 if (!amsdu && txq)
958 set_bit(IEEE80211_TXQ_NO_AMSDU, &to_txq_info(txq)->flags);
959
960 mutex_lock(&sta->ampdu_mlme.mtx);
961
962 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
963 if (!tid_tx)
964 goto out;
965
966 if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
967 ht_dbg(sta->sdata, "wrong addBA response token, %pM tid %d\n",
968 sta->sta.addr, tid);
969 goto out;
970 }
971
972 del_timer_sync(&tid_tx->addba_resp_timer);
973
974 ht_dbg(sta->sdata, "switched off addBA timer for %pM tid %d\n",
975 sta->sta.addr, tid);
976
977 /*
978 * addba_resp_timer may have fired before we got here, and
979 * caused WANT_STOP to be set. If the stop then was already
980 * processed further, STOPPING might be set.
981 */
982 if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) ||
983 test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
984 ht_dbg(sta->sdata,
985 "got addBA resp for %pM tid %d but we already gave up\n",
986 sta->sta.addr, tid);
987 goto out;
988 }
989
990 /*
991 * IEEE 802.11-2007 7.3.1.14:
992 * In an ADDBA Response frame, when the Status Code field
993 * is set to 0, the Buffer Size subfield is set to a value
994 * of at least 1.
995 */
996 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
997 == WLAN_STATUS_SUCCESS && buf_size) {
998 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
999 &tid_tx->state)) {
1000 /* ignore duplicate response */
1001 goto out;
1002 }
1003
1004 tid_tx->buf_size = buf_size;
1005 tid_tx->amsdu = amsdu;
1006
1007 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
1008 ieee80211_agg_tx_operational(local, sta, tid);
1009
1010 sta->ampdu_mlme.addba_req_num[tid] = 0;
1011
1012 if (tid_tx->timeout) {
1013 mod_timer(&tid_tx->session_timer,
1014 TU_TO_EXP_TIME(tid_tx->timeout));
1015 tid_tx->last_tx = jiffies;
1016 }
1017
1018 } else {
1019 ___ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_DECLINED);
1020 }
1021
1022 out:
1023 mutex_unlock(&sta->ampdu_mlme.mtx);
1024}
1/*
2 * HT handling
3 *
4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Copyright 2002-2005, Instant802 Networks, Inc.
6 * Copyright 2005-2006, Devicescape Software, Inc.
7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9 * Copyright 2007-2010, Intel Corporation
10 * Copyright(c) 2015 Intel Deutschland GmbH
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 */
16
17#include <linux/ieee80211.h>
18#include <linux/slab.h>
19#include <linux/export.h>
20#include <net/mac80211.h>
21#include "ieee80211_i.h"
22#include "driver-ops.h"
23#include "wme.h"
24
25/**
26 * DOC: TX A-MPDU aggregation
27 *
28 * Aggregation on the TX side requires setting the hardware flag
29 * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed
30 * packets with a flag indicating A-MPDU aggregation. The driver
31 * or device is responsible for actually aggregating the frames,
32 * as well as deciding how many and which to aggregate.
33 *
34 * When TX aggregation is started by some subsystem (usually the rate
35 * control algorithm would be appropriate) by calling the
36 * ieee80211_start_tx_ba_session() function, the driver will be
37 * notified via its @ampdu_action function, with the
38 * %IEEE80211_AMPDU_TX_START action.
39 *
40 * In response to that, the driver is later required to call the
41 * ieee80211_start_tx_ba_cb_irqsafe() function, which will really
42 * start the aggregation session after the peer has also responded.
43 * If the peer responds negatively, the session will be stopped
44 * again right away. Note that it is possible for the aggregation
45 * session to be stopped before the driver has indicated that it
46 * is done setting it up, in which case it must not indicate the
47 * setup completion.
48 *
49 * Also note that, since we also need to wait for a response from
50 * the peer, the driver is notified of the completion of the
51 * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the
52 * @ampdu_action callback.
53 *
54 * Similarly, when the aggregation session is stopped by the peer
55 * or something calling ieee80211_stop_tx_ba_session(), the driver's
56 * @ampdu_action function will be called with the action
57 * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail,
58 * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe().
59 * Note that the sta can get destroyed before the BA tear down is
60 * complete.
61 */
62
63static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
64 const u8 *da, u16 tid,
65 u8 dialog_token, u16 start_seq_num,
66 u16 agg_size, u16 timeout)
67{
68 struct ieee80211_local *local = sdata->local;
69 struct sk_buff *skb;
70 struct ieee80211_mgmt *mgmt;
71 u16 capab;
72
73 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
74
75 if (!skb)
76 return;
77
78 skb_reserve(skb, local->hw.extra_tx_headroom);
79 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
80 memset(mgmt, 0, 24);
81 memcpy(mgmt->da, da, ETH_ALEN);
82 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
83 if (sdata->vif.type == NL80211_IFTYPE_AP ||
84 sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
85 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
86 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
87 else if (sdata->vif.type == NL80211_IFTYPE_STATION)
88 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
89 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
90 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
91
92 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
93 IEEE80211_STYPE_ACTION);
94
95 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
96
97 mgmt->u.action.category = WLAN_CATEGORY_BACK;
98 mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
99
100 mgmt->u.action.u.addba_req.dialog_token = dialog_token;
101 capab = (u16)(1 << 0); /* bit 0 A-MSDU support */
102 capab |= (u16)(1 << 1); /* bit 1 aggregation policy */
103 capab |= (u16)(tid << 2); /* bit 5:2 TID number */
104 capab |= (u16)(agg_size << 6); /* bit 15:6 max size of aggergation */
105
106 mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
107
108 mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
109 mgmt->u.action.u.addba_req.start_seq_num =
110 cpu_to_le16(start_seq_num << 4);
111
112 ieee80211_tx_skb(sdata, skb);
113}
114
115void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
116{
117 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
118 struct ieee80211_local *local = sdata->local;
119 struct sk_buff *skb;
120 struct ieee80211_bar *bar;
121 u16 bar_control = 0;
122
123 skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
124 if (!skb)
125 return;
126
127 skb_reserve(skb, local->hw.extra_tx_headroom);
128 bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
129 memset(bar, 0, sizeof(*bar));
130 bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
131 IEEE80211_STYPE_BACK_REQ);
132 memcpy(bar->ra, ra, ETH_ALEN);
133 memcpy(bar->ta, sdata->vif.addr, ETH_ALEN);
134 bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
135 bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
136 bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT);
137 bar->control = cpu_to_le16(bar_control);
138 bar->start_seq_num = cpu_to_le16(ssn);
139
140 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
141 IEEE80211_TX_CTL_REQ_TX_STATUS;
142 ieee80211_tx_skb_tid(sdata, skb, tid);
143}
144EXPORT_SYMBOL(ieee80211_send_bar);
145
146void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
147 struct tid_ampdu_tx *tid_tx)
148{
149 lockdep_assert_held(&sta->ampdu_mlme.mtx);
150 lockdep_assert_held(&sta->lock);
151 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
152}
153
154/*
155 * When multiple aggregation sessions on multiple stations
156 * are being created/destroyed simultaneously, we need to
157 * refcount the global queue stop caused by that in order
158 * to not get into a situation where one of the aggregation
159 * setup or teardown re-enables queues before the other is
160 * ready to handle that.
161 *
162 * These two functions take care of this issue by keeping
163 * a global "agg_queue_stop" refcount.
164 */
165static void __acquires(agg_queue)
166ieee80211_stop_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
167{
168 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
169
170 /* we do refcounting here, so don't use the queue reason refcounting */
171
172 if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1)
173 ieee80211_stop_queue_by_reason(
174 &sdata->local->hw, queue,
175 IEEE80211_QUEUE_STOP_REASON_AGGREGATION,
176 false);
177 __acquire(agg_queue);
178}
179
180static void __releases(agg_queue)
181ieee80211_wake_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
182{
183 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
184
185 if (atomic_dec_return(&sdata->local->agg_queue_stop[queue]) == 0)
186 ieee80211_wake_queue_by_reason(
187 &sdata->local->hw, queue,
188 IEEE80211_QUEUE_STOP_REASON_AGGREGATION,
189 false);
190 __release(agg_queue);
191}
192
193static void
194ieee80211_agg_stop_txq(struct sta_info *sta, int tid)
195{
196 struct ieee80211_txq *txq = sta->sta.txq[tid];
197 struct txq_info *txqi;
198
199 if (!txq)
200 return;
201
202 txqi = to_txq_info(txq);
203
204 /* Lock here to protect against further seqno updates on dequeue */
205 spin_lock_bh(&txqi->queue.lock);
206 set_bit(IEEE80211_TXQ_STOP, &txqi->flags);
207 spin_unlock_bh(&txqi->queue.lock);
208}
209
210static void
211ieee80211_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 if (!txq)
217 return;
218
219 txqi = to_txq_info(txq);
220
221 if (enable)
222 set_bit(IEEE80211_TXQ_AMPDU, &txqi->flags);
223 else
224 clear_bit(IEEE80211_TXQ_AMPDU, &txqi->flags);
225
226 clear_bit(IEEE80211_TXQ_STOP, &txqi->flags);
227 drv_wake_tx_queue(sta->sdata->local, txqi);
228}
229
230/*
231 * splice packets from the STA's pending to the local pending,
232 * requires a call to ieee80211_agg_splice_finish later
233 */
234static void __acquires(agg_queue)
235ieee80211_agg_splice_packets(struct ieee80211_sub_if_data *sdata,
236 struct tid_ampdu_tx *tid_tx, u16 tid)
237{
238 struct ieee80211_local *local = sdata->local;
239 int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
240 unsigned long flags;
241
242 ieee80211_stop_queue_agg(sdata, tid);
243
244 if (WARN(!tid_tx,
245 "TID %d gone but expected when splicing aggregates from the pending queue\n",
246 tid))
247 return;
248
249 if (!skb_queue_empty(&tid_tx->pending)) {
250 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
251 /* copy over remaining packets */
252 skb_queue_splice_tail_init(&tid_tx->pending,
253 &local->pending[queue]);
254 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
255 }
256}
257
258static void __releases(agg_queue)
259ieee80211_agg_splice_finish(struct ieee80211_sub_if_data *sdata, u16 tid)
260{
261 ieee80211_wake_queue_agg(sdata, tid);
262}
263
264static void ieee80211_remove_tid_tx(struct sta_info *sta, int tid)
265{
266 struct tid_ampdu_tx *tid_tx;
267
268 lockdep_assert_held(&sta->ampdu_mlme.mtx);
269 lockdep_assert_held(&sta->lock);
270
271 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
272
273 /*
274 * When we get here, the TX path will not be lockless any more wrt.
275 * aggregation, since the OPERATIONAL bit has long been cleared.
276 * Thus it will block on getting the lock, if it occurs. So if we
277 * stop the queue now, we will not get any more packets, and any
278 * that might be being processed will wait for us here, thereby
279 * guaranteeing that no packets go to the tid_tx pending queue any
280 * more.
281 */
282
283 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
284
285 /* future packets must not find the tid_tx struct any more */
286 ieee80211_assign_tid_tx(sta, tid, NULL);
287
288 ieee80211_agg_splice_finish(sta->sdata, tid);
289 ieee80211_agg_start_txq(sta, tid, false);
290
291 kfree_rcu(tid_tx, rcu_head);
292}
293
294int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
295 enum ieee80211_agg_stop_reason reason)
296{
297 struct ieee80211_local *local = sta->local;
298 struct tid_ampdu_tx *tid_tx;
299 struct ieee80211_ampdu_params params = {
300 .sta = &sta->sta,
301 .tid = tid,
302 .buf_size = 0,
303 .amsdu = false,
304 .timeout = 0,
305 .ssn = 0,
306 };
307 int ret;
308
309 lockdep_assert_held(&sta->ampdu_mlme.mtx);
310
311 switch (reason) {
312 case AGG_STOP_DECLINED:
313 case AGG_STOP_LOCAL_REQUEST:
314 case AGG_STOP_PEER_REQUEST:
315 params.action = IEEE80211_AMPDU_TX_STOP_CONT;
316 break;
317 case AGG_STOP_DESTROY_STA:
318 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH;
319 break;
320 default:
321 WARN_ON_ONCE(1);
322 return -EINVAL;
323 }
324
325 spin_lock_bh(&sta->lock);
326
327 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
328 if (!tid_tx) {
329 spin_unlock_bh(&sta->lock);
330 return -ENOENT;
331 }
332
333 /*
334 * if we're already stopping ignore any new requests to stop
335 * unless we're destroying it in which case notify the driver
336 */
337 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
338 spin_unlock_bh(&sta->lock);
339 if (reason != AGG_STOP_DESTROY_STA)
340 return -EALREADY;
341 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH_CONT;
342 ret = drv_ampdu_action(local, sta->sdata, ¶ms);
343 WARN_ON_ONCE(ret);
344 return 0;
345 }
346
347 if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
348 /* not even started yet! */
349 ieee80211_assign_tid_tx(sta, tid, NULL);
350 spin_unlock_bh(&sta->lock);
351 kfree_rcu(tid_tx, rcu_head);
352 return 0;
353 }
354
355 set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
356
357 spin_unlock_bh(&sta->lock);
358
359 ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n",
360 sta->sta.addr, tid);
361
362 del_timer_sync(&tid_tx->addba_resp_timer);
363 del_timer_sync(&tid_tx->session_timer);
364
365 /*
366 * After this packets are no longer handed right through
367 * to the driver but are put onto tid_tx->pending instead,
368 * with locking to ensure proper access.
369 */
370 clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
371
372 /*
373 * There might be a few packets being processed right now (on
374 * another CPU) that have already gotten past the aggregation
375 * check when it was still OPERATIONAL and consequently have
376 * IEEE80211_TX_CTL_AMPDU set. In that case, this code might
377 * call into the driver at the same time or even before the
378 * TX paths calls into it, which could confuse the driver.
379 *
380 * Wait for all currently running TX paths to finish before
381 * telling the driver. New packets will not go through since
382 * the aggregation session is no longer OPERATIONAL.
383 */
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 */
419static void sta_addba_resp_timer_expired(unsigned long data)
420{
421 /* not an elegant detour, but there is no choice as the timer passes
422 * only one argument, and both sta_info and TID are needed, so init
423 * flow in sta_info_create gives the TID as data, while the timer_to_id
424 * array gives the sta through container_of */
425 u16 tid = *(u8 *)data;
426 struct sta_info *sta = container_of((void *)data,
427 struct sta_info, timer_to_tid[tid]);
428 struct tid_ampdu_tx *tid_tx;
429
430 /* check if the TID waits for addBA response */
431 rcu_read_lock();
432 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
433 if (!tid_tx ||
434 test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
435 rcu_read_unlock();
436 ht_dbg(sta->sdata,
437 "timer expired on %pM tid %d but we are not (or no longer) expecting addBA response there\n",
438 sta->sta.addr, tid);
439 return;
440 }
441
442 ht_dbg(sta->sdata, "addBA response timer expired on %pM tid %d\n",
443 sta->sta.addr, tid);
444
445 ieee80211_stop_tx_ba_session(&sta->sta, tid);
446 rcu_read_unlock();
447}
448
449void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
450{
451 struct tid_ampdu_tx *tid_tx;
452 struct ieee80211_local *local = sta->local;
453 struct ieee80211_sub_if_data *sdata = sta->sdata;
454 struct ieee80211_ampdu_params params = {
455 .sta = &sta->sta,
456 .action = IEEE80211_AMPDU_TX_START,
457 .tid = tid,
458 .buf_size = 0,
459 .amsdu = false,
460 .timeout = 0,
461 };
462 int ret;
463
464 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
465
466 /*
467 * Start queuing up packets for this aggregation session.
468 * We're going to release them once the driver is OK with
469 * that.
470 */
471 clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
472
473 ieee80211_agg_stop_txq(sta, tid);
474
475 /*
476 * Make sure no packets are being processed. This ensures that
477 * we have a valid starting sequence number and that in-flight
478 * packets have been flushed out and no packets for this TID
479 * will go into the driver during the ampdu_action call.
480 */
481 synchronize_net();
482
483 params.ssn = sta->tid_seq[tid] >> 4;
484 ret = drv_ampdu_action(local, sdata, ¶ms);
485 if (ret) {
486 ht_dbg(sdata,
487 "BA request denied - HW unavailable for %pM tid %d\n",
488 sta->sta.addr, tid);
489 spin_lock_bh(&sta->lock);
490 ieee80211_agg_splice_packets(sdata, tid_tx, tid);
491 ieee80211_assign_tid_tx(sta, tid, NULL);
492 ieee80211_agg_splice_finish(sdata, tid);
493 spin_unlock_bh(&sta->lock);
494
495 ieee80211_agg_start_txq(sta, tid, false);
496
497 kfree_rcu(tid_tx, rcu_head);
498 return;
499 }
500
501 /* activate the timer for the recipient's addBA response */
502 mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
503 ht_dbg(sdata, "activated addBA response timer on %pM tid %d\n",
504 sta->sta.addr, tid);
505
506 spin_lock_bh(&sta->lock);
507 sta->ampdu_mlme.last_addba_req_time[tid] = jiffies;
508 sta->ampdu_mlme.addba_req_num[tid]++;
509 spin_unlock_bh(&sta->lock);
510
511 /* send AddBA request */
512 ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
513 tid_tx->dialog_token, params.ssn,
514 IEEE80211_MAX_AMPDU_BUF,
515 tid_tx->timeout);
516}
517
518/*
519 * After accepting the AddBA Response we activated a timer,
520 * resetting it after each frame that we send.
521 */
522static void sta_tx_agg_session_timer_expired(unsigned long data)
523{
524 /* not an elegant detour, but there is no choice as the timer passes
525 * only one argument, and various sta_info are needed here, so init
526 * flow in sta_info_create gives the TID as data, while the timer_to_id
527 * array gives the sta through container_of */
528 u8 *ptid = (u8 *)data;
529 u8 *timer_to_id = ptid - *ptid;
530 struct sta_info *sta = container_of(timer_to_id, struct sta_info,
531 timer_to_tid[0]);
532 struct tid_ampdu_tx *tid_tx;
533 unsigned long timeout;
534
535 rcu_read_lock();
536 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[*ptid]);
537 if (!tid_tx || test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
538 rcu_read_unlock();
539 return;
540 }
541
542 timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout);
543 if (time_is_after_jiffies(timeout)) {
544 mod_timer(&tid_tx->session_timer, timeout);
545 rcu_read_unlock();
546 return;
547 }
548
549 rcu_read_unlock();
550
551 ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n",
552 sta->sta.addr, (u16)*ptid);
553
554 ieee80211_stop_tx_ba_session(&sta->sta, *ptid);
555}
556
557int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
558 u16 timeout)
559{
560 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
561 struct ieee80211_sub_if_data *sdata = sta->sdata;
562 struct ieee80211_local *local = sdata->local;
563 struct tid_ampdu_tx *tid_tx;
564 int ret = 0;
565
566 trace_api_start_tx_ba_session(pubsta, tid);
567
568 if (WARN(sta->reserved_tid == tid,
569 "Requested to start BA session on reserved tid=%d", tid))
570 return -EINVAL;
571
572 if (!pubsta->ht_cap.ht_supported)
573 return -EINVAL;
574
575 if (WARN_ON_ONCE(!local->ops->ampdu_action))
576 return -EINVAL;
577
578 if ((tid >= IEEE80211_NUM_TIDS) ||
579 !ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION) ||
580 ieee80211_hw_check(&local->hw, TX_AMPDU_SETUP_IN_HW))
581 return -EINVAL;
582
583 ht_dbg(sdata, "Open BA session requested for %pM tid %u\n",
584 pubsta->addr, tid);
585
586 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
587 sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
588 sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
589 sdata->vif.type != NL80211_IFTYPE_AP &&
590 sdata->vif.type != NL80211_IFTYPE_ADHOC)
591 return -EINVAL;
592
593 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
594 ht_dbg(sdata,
595 "BA sessions blocked - Denying BA session request %pM tid %d\n",
596 sta->sta.addr, tid);
597 return -EINVAL;
598 }
599
600 /*
601 * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a
602 * member of an IBSS, and has no other existing Block Ack agreement
603 * with the recipient STA, then the initiating STA shall transmit a
604 * Probe Request frame to the recipient STA and shall not transmit an
605 * ADDBA Request frame unless it receives a Probe Response frame
606 * from the recipient within dot11ADDBAFailureTimeout.
607 *
608 * The probe request mechanism for ADDBA is currently not implemented,
609 * but we only build up Block Ack session with HT STAs. This information
610 * is set when we receive a bss info from a probe response or a beacon.
611 */
612 if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC &&
613 !sta->sta.ht_cap.ht_supported) {
614 ht_dbg(sdata,
615 "BA request denied - IBSS STA %pM does not advertise HT support\n",
616 pubsta->addr);
617 return -EINVAL;
618 }
619
620 spin_lock_bh(&sta->lock);
621
622 /* we have tried too many times, receiver does not want A-MPDU */
623 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
624 ret = -EBUSY;
625 goto err_unlock_sta;
626 }
627
628 /*
629 * if we have tried more than HT_AGG_BURST_RETRIES times we
630 * will spread our requests in time to avoid stalling connection
631 * for too long
632 */
633 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES &&
634 time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] +
635 HT_AGG_RETRIES_PERIOD)) {
636 ht_dbg(sdata,
637 "BA request denied - waiting a grace period after %d failed requests on %pM tid %u\n",
638 sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, tid);
639 ret = -EBUSY;
640 goto err_unlock_sta;
641 }
642
643 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
644 /* check if the TID is not in aggregation flow already */
645 if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
646 ht_dbg(sdata,
647 "BA request denied - session is not idle on %pM tid %u\n",
648 sta->sta.addr, tid);
649 ret = -EAGAIN;
650 goto err_unlock_sta;
651 }
652
653 /* prepare A-MPDU MLME for Tx aggregation */
654 tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
655 if (!tid_tx) {
656 ret = -ENOMEM;
657 goto err_unlock_sta;
658 }
659
660 skb_queue_head_init(&tid_tx->pending);
661 __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
662
663 tid_tx->timeout = timeout;
664
665 /* response timer */
666 tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired;
667 tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid];
668 init_timer(&tid_tx->addba_resp_timer);
669
670 /* tx timer */
671 tid_tx->session_timer.function = sta_tx_agg_session_timer_expired;
672 tid_tx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
673 init_timer_deferrable(&tid_tx->session_timer);
674
675 /* assign a dialog token */
676 sta->ampdu_mlme.dialog_token_allocator++;
677 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
678
679 /*
680 * Finally, assign it to the start array; the work item will
681 * collect it and move it to the normal array.
682 */
683 sta->ampdu_mlme.tid_start_tx[tid] = tid_tx;
684
685 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
686
687 /* this flow continues off the work */
688 err_unlock_sta:
689 spin_unlock_bh(&sta->lock);
690 return ret;
691}
692EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
693
694static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
695 struct sta_info *sta, u16 tid)
696{
697 struct tid_ampdu_tx *tid_tx;
698 struct ieee80211_ampdu_params params = {
699 .sta = &sta->sta,
700 .action = IEEE80211_AMPDU_TX_OPERATIONAL,
701 .tid = tid,
702 .timeout = 0,
703 .ssn = 0,
704 };
705
706 lockdep_assert_held(&sta->ampdu_mlme.mtx);
707
708 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
709 params.buf_size = tid_tx->buf_size;
710 params.amsdu = tid_tx->amsdu;
711
712 ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n",
713 sta->sta.addr, tid);
714
715 drv_ampdu_action(local, sta->sdata, ¶ms);
716
717 /*
718 * synchronize with TX path, while splicing the TX path
719 * should block so it won't put more packets onto pending.
720 */
721 spin_lock_bh(&sta->lock);
722
723 ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
724 /*
725 * Now mark as operational. This will be visible
726 * in the TX path, and lets it go lock-free in
727 * the common case.
728 */
729 set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
730 ieee80211_agg_splice_finish(sta->sdata, tid);
731
732 spin_unlock_bh(&sta->lock);
733
734 ieee80211_agg_start_txq(sta, tid, true);
735}
736
737void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
738{
739 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
740 struct ieee80211_local *local = sdata->local;
741 struct sta_info *sta;
742 struct tid_ampdu_tx *tid_tx;
743
744 trace_api_start_tx_ba_cb(sdata, ra, tid);
745
746 if (tid >= IEEE80211_NUM_TIDS) {
747 ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
748 tid, IEEE80211_NUM_TIDS);
749 return;
750 }
751
752 mutex_lock(&local->sta_mtx);
753 sta = sta_info_get_bss(sdata, ra);
754 if (!sta) {
755 mutex_unlock(&local->sta_mtx);
756 ht_dbg(sdata, "Could not find station: %pM\n", ra);
757 return;
758 }
759
760 mutex_lock(&sta->ampdu_mlme.mtx);
761 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
762
763 if (WARN_ON(!tid_tx)) {
764 ht_dbg(sdata, "addBA was not requested!\n");
765 goto unlock;
766 }
767
768 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
769 goto unlock;
770
771 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
772 ieee80211_agg_tx_operational(local, sta, tid);
773
774 unlock:
775 mutex_unlock(&sta->ampdu_mlme.mtx);
776 mutex_unlock(&local->sta_mtx);
777}
778
779void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
780 const u8 *ra, u16 tid)
781{
782 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
783 struct ieee80211_local *local = sdata->local;
784 struct ieee80211_ra_tid *ra_tid;
785 struct sk_buff *skb = dev_alloc_skb(0);
786
787 if (unlikely(!skb))
788 return;
789
790 ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
791 memcpy(&ra_tid->ra, ra, ETH_ALEN);
792 ra_tid->tid = tid;
793
794 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START;
795 skb_queue_tail(&sdata->skb_queue, skb);
796 ieee80211_queue_work(&local->hw, &sdata->work);
797}
798EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
799
800int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
801 enum ieee80211_agg_stop_reason reason)
802{
803 int ret;
804
805 mutex_lock(&sta->ampdu_mlme.mtx);
806
807 ret = ___ieee80211_stop_tx_ba_session(sta, tid, reason);
808
809 mutex_unlock(&sta->ampdu_mlme.mtx);
810
811 return ret;
812}
813
814int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
815{
816 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
817 struct ieee80211_sub_if_data *sdata = sta->sdata;
818 struct ieee80211_local *local = sdata->local;
819 struct tid_ampdu_tx *tid_tx;
820 int ret = 0;
821
822 trace_api_stop_tx_ba_session(pubsta, tid);
823
824 if (!local->ops->ampdu_action)
825 return -EINVAL;
826
827 if (tid >= IEEE80211_NUM_TIDS)
828 return -EINVAL;
829
830 spin_lock_bh(&sta->lock);
831 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
832
833 if (!tid_tx) {
834 ret = -ENOENT;
835 goto unlock;
836 }
837
838 WARN(sta->reserved_tid == tid,
839 "Requested to stop BA session on reserved tid=%d", tid);
840
841 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
842 /* already in progress stopping it */
843 ret = 0;
844 goto unlock;
845 }
846
847 set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state);
848 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
849
850 unlock:
851 spin_unlock_bh(&sta->lock);
852 return ret;
853}
854EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
855
856void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
857{
858 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
859 struct ieee80211_local *local = sdata->local;
860 struct sta_info *sta;
861 struct tid_ampdu_tx *tid_tx;
862 bool send_delba = false;
863
864 trace_api_stop_tx_ba_cb(sdata, ra, tid);
865
866 if (tid >= IEEE80211_NUM_TIDS) {
867 ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
868 tid, IEEE80211_NUM_TIDS);
869 return;
870 }
871
872 ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", ra, tid);
873
874 mutex_lock(&local->sta_mtx);
875
876 sta = sta_info_get_bss(sdata, ra);
877 if (!sta) {
878 ht_dbg(sdata, "Could not find station: %pM\n", ra);
879 goto unlock;
880 }
881
882 mutex_lock(&sta->ampdu_mlme.mtx);
883 spin_lock_bh(&sta->lock);
884 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
885
886 if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
887 ht_dbg(sdata,
888 "unexpected callback to A-MPDU stop for %pM tid %d\n",
889 sta->sta.addr, tid);
890 goto unlock_sta;
891 }
892
893 if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop)
894 send_delba = true;
895
896 ieee80211_remove_tid_tx(sta, tid);
897
898 unlock_sta:
899 spin_unlock_bh(&sta->lock);
900
901 if (send_delba)
902 ieee80211_send_delba(sdata, ra, tid,
903 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
904
905 mutex_unlock(&sta->ampdu_mlme.mtx);
906 unlock:
907 mutex_unlock(&local->sta_mtx);
908}
909
910void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
911 const u8 *ra, u16 tid)
912{
913 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
914 struct ieee80211_local *local = sdata->local;
915 struct ieee80211_ra_tid *ra_tid;
916 struct sk_buff *skb = dev_alloc_skb(0);
917
918 if (unlikely(!skb))
919 return;
920
921 ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
922 memcpy(&ra_tid->ra, ra, ETH_ALEN);
923 ra_tid->tid = tid;
924
925 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP;
926 skb_queue_tail(&sdata->skb_queue, skb);
927 ieee80211_queue_work(&local->hw, &sdata->work);
928}
929EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
930
931
932void ieee80211_process_addba_resp(struct ieee80211_local *local,
933 struct sta_info *sta,
934 struct ieee80211_mgmt *mgmt,
935 size_t len)
936{
937 struct tid_ampdu_tx *tid_tx;
938 u16 capab, tid;
939 u8 buf_size;
940 bool amsdu;
941
942 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
943 amsdu = capab & IEEE80211_ADDBA_PARAM_AMSDU_MASK;
944 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
945 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
946 buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes);
947
948 mutex_lock(&sta->ampdu_mlme.mtx);
949
950 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
951 if (!tid_tx)
952 goto out;
953
954 if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
955 ht_dbg(sta->sdata, "wrong addBA response token, %pM tid %d\n",
956 sta->sta.addr, tid);
957 goto out;
958 }
959
960 del_timer_sync(&tid_tx->addba_resp_timer);
961
962 ht_dbg(sta->sdata, "switched off addBA timer for %pM tid %d\n",
963 sta->sta.addr, tid);
964
965 /*
966 * addba_resp_timer may have fired before we got here, and
967 * caused WANT_STOP to be set. If the stop then was already
968 * processed further, STOPPING might be set.
969 */
970 if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) ||
971 test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
972 ht_dbg(sta->sdata,
973 "got addBA resp for %pM tid %d but we already gave up\n",
974 sta->sta.addr, tid);
975 goto out;
976 }
977
978 /*
979 * IEEE 802.11-2007 7.3.1.14:
980 * In an ADDBA Response frame, when the Status Code field
981 * is set to 0, the Buffer Size subfield is set to a value
982 * of at least 1.
983 */
984 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
985 == WLAN_STATUS_SUCCESS && buf_size) {
986 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
987 &tid_tx->state)) {
988 /* ignore duplicate response */
989 goto out;
990 }
991
992 tid_tx->buf_size = buf_size;
993 tid_tx->amsdu = amsdu;
994
995 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
996 ieee80211_agg_tx_operational(local, sta, tid);
997
998 sta->ampdu_mlme.addba_req_num[tid] = 0;
999
1000 if (tid_tx->timeout) {
1001 mod_timer(&tid_tx->session_timer,
1002 TU_TO_EXP_TIME(tid_tx->timeout));
1003 tid_tx->last_tx = jiffies;
1004 }
1005
1006 } else {
1007 ___ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_DECLINED);
1008 }
1009
1010 out:
1011 mutex_unlock(&sta->ampdu_mlme.mtx);
1012}