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 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15
16 #include <linux/ieee80211.h>
17 #include <linux/slab.h>
18 #include <linux/export.h>
19 #include <net/mac80211.h>
20 #include "ieee80211_i.h"
21 #include "driver-ops.h"
22 #include "wme.h"
23
24 /**
25 * DOC: TX A-MPDU aggregation
26 *
27 * Aggregation on the TX side requires setting the hardware flag
28 * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed
29 * packets with a flag indicating A-MPDU aggregation. The driver
30 * or device is responsible for actually aggregating the frames,
31 * as well as deciding how many and which to aggregate.
32 *
33 * When TX aggregation is started by some subsystem (usually the rate
34 * control algorithm would be appropriate) by calling the
35 * ieee80211_start_tx_ba_session() function, the driver will be
36 * notified via its @ampdu_action function, with the
37 * %IEEE80211_AMPDU_TX_START action.
38 *
39 * In response to that, the driver is later required to call the
40 * ieee80211_start_tx_ba_cb_irqsafe() function, which will really
41 * start the aggregation session after the peer has also responded.
42 * If the peer responds negatively, the session will be stopped
43 * again right away. Note that it is possible for the aggregation
44 * session to be stopped before the driver has indicated that it
45 * is done setting it up, in which case it must not indicate the
46 * setup completion.
47 *
48 * Also note that, since we also need to wait for a response from
49 * the peer, the driver is notified of the completion of the
50 * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the
51 * @ampdu_action callback.
52 *
53 * Similarly, when the aggregation session is stopped by the peer
54 * or something calling ieee80211_stop_tx_ba_session(), the driver's
55 * @ampdu_action function will be called with the action
56 * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail,
57 * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe().
58 * Note that the sta can get destroyed before the BA tear down is
59 * complete.
60 */
61
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)62 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
63 const u8 *da, u16 tid,
64 u8 dialog_token, u16 start_seq_num,
65 u16 agg_size, u16 timeout)
66 {
67 struct ieee80211_local *local = sdata->local;
68 struct sk_buff *skb;
69 struct ieee80211_mgmt *mgmt;
70 u16 capab;
71
72 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
73
74 if (!skb)
75 return;
76
77 skb_reserve(skb, local->hw.extra_tx_headroom);
78 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
79 memset(mgmt, 0, 24);
80 memcpy(mgmt->da, da, ETH_ALEN);
81 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
82 if (sdata->vif.type == NL80211_IFTYPE_AP ||
83 sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
84 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
85 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
86 else if (sdata->vif.type == NL80211_IFTYPE_STATION)
87 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
88 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
89 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
90
91 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
92 IEEE80211_STYPE_ACTION);
93
94 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
95
96 mgmt->u.action.category = WLAN_CATEGORY_BACK;
97 mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
98
99 mgmt->u.action.u.addba_req.dialog_token = dialog_token;
100 capab = (u16)(1 << 1); /* bit 1 aggregation policy */
101 capab |= (u16)(tid << 2); /* bit 5:2 TID number */
102 capab |= (u16)(agg_size << 6); /* bit 15:6 max size of aggergation */
103
104 mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
105
106 mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
107 mgmt->u.action.u.addba_req.start_seq_num =
108 cpu_to_le16(start_seq_num << 4);
109
110 ieee80211_tx_skb_tid(sdata, skb, tid);
111 }
112
ieee80211_send_bar(struct ieee80211_vif * vif,u8 * ra,u16 tid,u16 ssn)113 void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
114 {
115 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
116 struct ieee80211_local *local = sdata->local;
117 struct sk_buff *skb;
118 struct ieee80211_bar *bar;
119 u16 bar_control = 0;
120
121 skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
122 if (!skb)
123 return;
124
125 skb_reserve(skb, local->hw.extra_tx_headroom);
126 bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
127 memset(bar, 0, sizeof(*bar));
128 bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
129 IEEE80211_STYPE_BACK_REQ);
130 memcpy(bar->ra, ra, ETH_ALEN);
131 memcpy(bar->ta, sdata->vif.addr, ETH_ALEN);
132 bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
133 bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
134 bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT);
135 bar->control = cpu_to_le16(bar_control);
136 bar->start_seq_num = cpu_to_le16(ssn);
137
138 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
139 ieee80211_tx_skb_tid(sdata, skb, tid);
140 }
141 EXPORT_SYMBOL(ieee80211_send_bar);
142
ieee80211_assign_tid_tx(struct sta_info * sta,int tid,struct tid_ampdu_tx * tid_tx)143 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
144 struct tid_ampdu_tx *tid_tx)
145 {
146 lockdep_assert_held(&sta->ampdu_mlme.mtx);
147 lockdep_assert_held(&sta->lock);
148 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
149 }
150
___ieee80211_stop_tx_ba_session(struct sta_info * sta,u16 tid,enum ieee80211_back_parties initiator,bool tx)151 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
152 enum ieee80211_back_parties initiator,
153 bool tx)
154 {
155 struct ieee80211_local *local = sta->local;
156 struct tid_ampdu_tx *tid_tx;
157 int ret;
158
159 lockdep_assert_held(&sta->ampdu_mlme.mtx);
160
161 spin_lock_bh(&sta->lock);
162
163 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
164 if (!tid_tx) {
165 spin_unlock_bh(&sta->lock);
166 return -ENOENT;
167 }
168
169 /* if we're already stopping ignore any new requests to stop */
170 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
171 spin_unlock_bh(&sta->lock);
172 return -EALREADY;
173 }
174
175 if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
176 /* not even started yet! */
177 ieee80211_assign_tid_tx(sta, tid, NULL);
178 spin_unlock_bh(&sta->lock);
179 kfree_rcu(tid_tx, rcu_head);
180 return 0;
181 }
182
183 set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
184
185 spin_unlock_bh(&sta->lock);
186
187 #ifdef CONFIG_MAC80211_HT_DEBUG
188 printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
189 sta->sta.addr, tid);
190 #endif /* CONFIG_MAC80211_HT_DEBUG */
191
192 del_timer_sync(&tid_tx->addba_resp_timer);
193 del_timer_sync(&tid_tx->session_timer);
194
195 /*
196 * After this packets are no longer handed right through
197 * to the driver but are put onto tid_tx->pending instead,
198 * with locking to ensure proper access.
199 */
200 clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
201
202 /*
203 * There might be a few packets being processed right now (on
204 * another CPU) that have already gotten past the aggregation
205 * check when it was still OPERATIONAL and consequently have
206 * IEEE80211_TX_CTL_AMPDU set. In that case, this code might
207 * call into the driver at the same time or even before the
208 * TX paths calls into it, which could confuse the driver.
209 *
210 * Wait for all currently running TX paths to finish before
211 * telling the driver. New packets will not go through since
212 * the aggregation session is no longer OPERATIONAL.
213 */
214 synchronize_net();
215
216 tid_tx->stop_initiator = initiator;
217 tid_tx->tx_stop = tx;
218
219 ret = drv_ampdu_action(local, sta->sdata,
220 IEEE80211_AMPDU_TX_STOP,
221 &sta->sta, tid, NULL, 0);
222
223 /* HW shall not deny going back to legacy */
224 if (WARN_ON(ret)) {
225 /*
226 * We may have pending packets get stuck in this case...
227 * Not bothering with a workaround for now.
228 */
229 }
230
231 return ret;
232 }
233
234 /*
235 * After sending add Block Ack request we activated a timer until
236 * add Block Ack response will arrive from the recipient.
237 * If this timer expires sta_addba_resp_timer_expired will be executed.
238 */
sta_addba_resp_timer_expired(unsigned long data)239 static void sta_addba_resp_timer_expired(unsigned long data)
240 {
241 /* not an elegant detour, but there is no choice as the timer passes
242 * only one argument, and both sta_info and TID are needed, so init
243 * flow in sta_info_create gives the TID as data, while the timer_to_id
244 * array gives the sta through container_of */
245 u16 tid = *(u8 *)data;
246 struct sta_info *sta = container_of((void *)data,
247 struct sta_info, timer_to_tid[tid]);
248 struct tid_ampdu_tx *tid_tx;
249
250 /* check if the TID waits for addBA response */
251 rcu_read_lock();
252 tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
253 if (!tid_tx ||
254 test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
255 rcu_read_unlock();
256 #ifdef CONFIG_MAC80211_HT_DEBUG
257 printk(KERN_DEBUG "timer expired on tid %d but we are not "
258 "(or no longer) expecting addBA response there\n",
259 tid);
260 #endif
261 return;
262 }
263
264 #ifdef CONFIG_MAC80211_HT_DEBUG
265 printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
266 #endif
267
268 ieee80211_stop_tx_ba_session(&sta->sta, tid);
269 rcu_read_unlock();
270 }
271
ieee80211_ac_from_tid(int tid)272 static inline int ieee80211_ac_from_tid(int tid)
273 {
274 return ieee802_1d_to_ac[tid & 7];
275 }
276
277 /*
278 * When multiple aggregation sessions on multiple stations
279 * are being created/destroyed simultaneously, we need to
280 * refcount the global queue stop caused by that in order
281 * to not get into a situation where one of the aggregation
282 * setup or teardown re-enables queues before the other is
283 * ready to handle that.
284 *
285 * These two functions take care of this issue by keeping
286 * a global "agg_queue_stop" refcount.
287 */
__acquires(agg_queue)288 static void __acquires(agg_queue)
289 ieee80211_stop_queue_agg(struct ieee80211_local *local, int tid)
290 {
291 int queue = ieee80211_ac_from_tid(tid);
292
293 if (atomic_inc_return(&local->agg_queue_stop[queue]) == 1)
294 ieee80211_stop_queue_by_reason(
295 &local->hw, queue,
296 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
297 __acquire(agg_queue);
298 }
299
__releases(agg_queue)300 static void __releases(agg_queue)
301 ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid)
302 {
303 int queue = ieee80211_ac_from_tid(tid);
304
305 if (atomic_dec_return(&local->agg_queue_stop[queue]) == 0)
306 ieee80211_wake_queue_by_reason(
307 &local->hw, queue,
308 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
309 __release(agg_queue);
310 }
311
312 /*
313 * splice packets from the STA's pending to the local pending,
314 * requires a call to ieee80211_agg_splice_finish later
315 */
__acquires(agg_queue)316 static void __acquires(agg_queue)
317 ieee80211_agg_splice_packets(struct ieee80211_local *local,
318 struct tid_ampdu_tx *tid_tx, u16 tid)
319 {
320 int queue = ieee80211_ac_from_tid(tid);
321 unsigned long flags;
322
323 ieee80211_stop_queue_agg(local, tid);
324
325 if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates"
326 " from the pending queue\n", tid))
327 return;
328
329 if (!skb_queue_empty(&tid_tx->pending)) {
330 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
331 /* copy over remaining packets */
332 skb_queue_splice_tail_init(&tid_tx->pending,
333 &local->pending[queue]);
334 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
335 }
336 }
337
__releases(agg_queue)338 static void __releases(agg_queue)
339 ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid)
340 {
341 ieee80211_wake_queue_agg(local, tid);
342 }
343
ieee80211_tx_ba_session_handle_start(struct sta_info * sta,int tid)344 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
345 {
346 struct tid_ampdu_tx *tid_tx;
347 struct ieee80211_local *local = sta->local;
348 struct ieee80211_sub_if_data *sdata = sta->sdata;
349 u16 start_seq_num;
350 int ret;
351
352 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
353
354 /*
355 * Start queuing up packets for this aggregation session.
356 * We're going to release them once the driver is OK with
357 * that.
358 */
359 clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
360
361 /*
362 * Make sure no packets are being processed. This ensures that
363 * we have a valid starting sequence number and that in-flight
364 * packets have been flushed out and no packets for this TID
365 * will go into the driver during the ampdu_action call.
366 */
367 synchronize_net();
368
369 start_seq_num = sta->tid_seq[tid] >> 4;
370
371 ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
372 &sta->sta, tid, &start_seq_num, 0);
373 if (ret) {
374 #ifdef CONFIG_MAC80211_HT_DEBUG
375 printk(KERN_DEBUG "BA request denied - HW unavailable for"
376 " tid %d\n", tid);
377 #endif
378 spin_lock_bh(&sta->lock);
379 ieee80211_agg_splice_packets(local, tid_tx, tid);
380 ieee80211_assign_tid_tx(sta, tid, NULL);
381 ieee80211_agg_splice_finish(local, tid);
382 spin_unlock_bh(&sta->lock);
383
384 kfree_rcu(tid_tx, rcu_head);
385 return;
386 }
387
388 /* activate the timer for the recipient's addBA response */
389 mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
390 #ifdef CONFIG_MAC80211_HT_DEBUG
391 printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
392 #endif
393
394 spin_lock_bh(&sta->lock);
395 sta->ampdu_mlme.last_addba_req_time[tid] = jiffies;
396 sta->ampdu_mlme.addba_req_num[tid]++;
397 spin_unlock_bh(&sta->lock);
398
399 /* send AddBA request */
400 ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
401 tid_tx->dialog_token, start_seq_num,
402 local->hw.max_tx_aggregation_subframes,
403 tid_tx->timeout);
404 }
405
406 /*
407 * After accepting the AddBA Response we activated a timer,
408 * resetting it after each frame that we send.
409 */
sta_tx_agg_session_timer_expired(unsigned long data)410 static void sta_tx_agg_session_timer_expired(unsigned long data)
411 {
412 /* not an elegant detour, but there is no choice as the timer passes
413 * only one argument, and various sta_info are needed here, so init
414 * flow in sta_info_create gives the TID as data, while the timer_to_id
415 * array gives the sta through container_of */
416 u8 *ptid = (u8 *)data;
417 u8 *timer_to_id = ptid - *ptid;
418 struct sta_info *sta = container_of(timer_to_id, struct sta_info,
419 timer_to_tid[0]);
420
421 #ifdef CONFIG_MAC80211_HT_DEBUG
422 printk(KERN_DEBUG "tx session timer expired on tid %d\n", (u16)*ptid);
423 #endif
424
425 ieee80211_stop_tx_ba_session(&sta->sta, *ptid);
426 }
427
ieee80211_start_tx_ba_session(struct ieee80211_sta * pubsta,u16 tid,u16 timeout)428 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
429 u16 timeout)
430 {
431 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
432 struct ieee80211_sub_if_data *sdata = sta->sdata;
433 struct ieee80211_local *local = sdata->local;
434 struct tid_ampdu_tx *tid_tx;
435 int ret = 0;
436
437 trace_api_start_tx_ba_session(pubsta, tid);
438
439 if (WARN_ON(!local->ops->ampdu_action))
440 return -EINVAL;
441
442 if ((tid >= STA_TID_NUM) ||
443 !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) ||
444 (local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW))
445 return -EINVAL;
446
447 #ifdef CONFIG_MAC80211_HT_DEBUG
448 printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
449 pubsta->addr, tid);
450 #endif /* CONFIG_MAC80211_HT_DEBUG */
451
452 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
453 sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
454 sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
455 sdata->vif.type != NL80211_IFTYPE_AP &&
456 sdata->vif.type != NL80211_IFTYPE_ADHOC)
457 return -EINVAL;
458
459 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
460 #ifdef CONFIG_MAC80211_HT_DEBUG
461 printk(KERN_DEBUG "BA sessions blocked. "
462 "Denying BA session request\n");
463 #endif
464 return -EINVAL;
465 }
466
467 /*
468 * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a
469 * member of an IBSS, and has no other existing Block Ack agreement
470 * with the recipient STA, then the initiating STA shall transmit a
471 * Probe Request frame to the recipient STA and shall not transmit an
472 * ADDBA Request frame unless it receives a Probe Response frame
473 * from the recipient within dot11ADDBAFailureTimeout.
474 *
475 * The probe request mechanism for ADDBA is currently not implemented,
476 * but we only build up Block Ack session with HT STAs. This information
477 * is set when we receive a bss info from a probe response or a beacon.
478 */
479 if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC &&
480 !sta->sta.ht_cap.ht_supported) {
481 #ifdef CONFIG_MAC80211_HT_DEBUG
482 printk(KERN_DEBUG "BA request denied - IBSS STA %pM"
483 "does not advertise HT support\n", pubsta->addr);
484 #endif /* CONFIG_MAC80211_HT_DEBUG */
485 return -EINVAL;
486 }
487
488 spin_lock_bh(&sta->lock);
489
490 /* we have tried too many times, receiver does not want A-MPDU */
491 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
492 ret = -EBUSY;
493 goto err_unlock_sta;
494 }
495
496 /*
497 * if we have tried more than HT_AGG_BURST_RETRIES times we
498 * will spread our requests in time to avoid stalling connection
499 * for too long
500 */
501 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES &&
502 time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] +
503 HT_AGG_RETRIES_PERIOD)) {
504 #ifdef CONFIG_MAC80211_HT_DEBUG
505 printk(KERN_DEBUG "BA request denied - "
506 "waiting a grace period after %d failed requests "
507 "on tid %u\n",
508 sta->ampdu_mlme.addba_req_num[tid], tid);
509 #endif /* CONFIG_MAC80211_HT_DEBUG */
510 ret = -EBUSY;
511 goto err_unlock_sta;
512 }
513
514 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
515 /* check if the TID is not in aggregation flow already */
516 if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
517 #ifdef CONFIG_MAC80211_HT_DEBUG
518 printk(KERN_DEBUG "BA request denied - session is not "
519 "idle on tid %u\n", tid);
520 #endif /* CONFIG_MAC80211_HT_DEBUG */
521 ret = -EAGAIN;
522 goto err_unlock_sta;
523 }
524
525 /* prepare A-MPDU MLME for Tx aggregation */
526 tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
527 if (!tid_tx) {
528 ret = -ENOMEM;
529 goto err_unlock_sta;
530 }
531
532 skb_queue_head_init(&tid_tx->pending);
533 __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
534
535 tid_tx->timeout = timeout;
536
537 /* response timer */
538 tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired;
539 tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid];
540 init_timer(&tid_tx->addba_resp_timer);
541
542 /* tx timer */
543 tid_tx->session_timer.function = sta_tx_agg_session_timer_expired;
544 tid_tx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
545 init_timer(&tid_tx->session_timer);
546
547 /* assign a dialog token */
548 sta->ampdu_mlme.dialog_token_allocator++;
549 tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
550
551 /*
552 * Finally, assign it to the start array; the work item will
553 * collect it and move it to the normal array.
554 */
555 sta->ampdu_mlme.tid_start_tx[tid] = tid_tx;
556
557 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
558
559 /* this flow continues off the work */
560 err_unlock_sta:
561 spin_unlock_bh(&sta->lock);
562 return ret;
563 }
564 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
565
ieee80211_agg_tx_operational(struct ieee80211_local * local,struct sta_info * sta,u16 tid)566 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
567 struct sta_info *sta, u16 tid)
568 {
569 struct tid_ampdu_tx *tid_tx;
570
571 lockdep_assert_held(&sta->ampdu_mlme.mtx);
572
573 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
574
575 #ifdef CONFIG_MAC80211_HT_DEBUG
576 printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid);
577 #endif
578
579 drv_ampdu_action(local, sta->sdata,
580 IEEE80211_AMPDU_TX_OPERATIONAL,
581 &sta->sta, tid, NULL, tid_tx->buf_size);
582
583 /*
584 * synchronize with TX path, while splicing the TX path
585 * should block so it won't put more packets onto pending.
586 */
587 spin_lock_bh(&sta->lock);
588
589 ieee80211_agg_splice_packets(local, tid_tx, tid);
590 /*
591 * Now mark as operational. This will be visible
592 * in the TX path, and lets it go lock-free in
593 * the common case.
594 */
595 set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
596 ieee80211_agg_splice_finish(local, tid);
597
598 spin_unlock_bh(&sta->lock);
599 }
600
ieee80211_start_tx_ba_cb(struct ieee80211_vif * vif,u8 * ra,u16 tid)601 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
602 {
603 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
604 struct ieee80211_local *local = sdata->local;
605 struct sta_info *sta;
606 struct tid_ampdu_tx *tid_tx;
607
608 trace_api_start_tx_ba_cb(sdata, ra, tid);
609
610 if (tid >= STA_TID_NUM) {
611 #ifdef CONFIG_MAC80211_HT_DEBUG
612 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
613 tid, STA_TID_NUM);
614 #endif
615 return;
616 }
617
618 mutex_lock(&local->sta_mtx);
619 sta = sta_info_get_bss(sdata, ra);
620 if (!sta) {
621 mutex_unlock(&local->sta_mtx);
622 #ifdef CONFIG_MAC80211_HT_DEBUG
623 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
624 #endif
625 return;
626 }
627
628 mutex_lock(&sta->ampdu_mlme.mtx);
629 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
630
631 if (WARN_ON(!tid_tx)) {
632 #ifdef CONFIG_MAC80211_HT_DEBUG
633 printk(KERN_DEBUG "addBA was not requested!\n");
634 #endif
635 goto unlock;
636 }
637
638 if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
639 goto unlock;
640
641 if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
642 ieee80211_agg_tx_operational(local, sta, tid);
643
644 unlock:
645 mutex_unlock(&sta->ampdu_mlme.mtx);
646 mutex_unlock(&local->sta_mtx);
647 }
648
ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif * vif,const u8 * ra,u16 tid)649 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
650 const u8 *ra, u16 tid)
651 {
652 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
653 struct ieee80211_local *local = sdata->local;
654 struct ieee80211_ra_tid *ra_tid;
655 struct sk_buff *skb = dev_alloc_skb(0);
656
657 if (unlikely(!skb))
658 return;
659
660 ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
661 memcpy(&ra_tid->ra, ra, ETH_ALEN);
662 ra_tid->tid = tid;
663
664 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START;
665 skb_queue_tail(&sdata->skb_queue, skb);
666 ieee80211_queue_work(&local->hw, &sdata->work);
667 }
668 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
669
__ieee80211_stop_tx_ba_session(struct sta_info * sta,u16 tid,enum ieee80211_back_parties initiator,bool tx)670 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
671 enum ieee80211_back_parties initiator,
672 bool tx)
673 {
674 int ret;
675
676 mutex_lock(&sta->ampdu_mlme.mtx);
677
678 ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator, tx);
679
680 mutex_unlock(&sta->ampdu_mlme.mtx);
681
682 return ret;
683 }
684
ieee80211_stop_tx_ba_session(struct ieee80211_sta * pubsta,u16 tid)685 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
686 {
687 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
688 struct ieee80211_sub_if_data *sdata = sta->sdata;
689 struct ieee80211_local *local = sdata->local;
690 struct tid_ampdu_tx *tid_tx;
691 int ret = 0;
692
693 trace_api_stop_tx_ba_session(pubsta, tid);
694
695 if (!local->ops->ampdu_action)
696 return -EINVAL;
697
698 if (tid >= STA_TID_NUM)
699 return -EINVAL;
700
701 spin_lock_bh(&sta->lock);
702 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
703
704 if (!tid_tx) {
705 ret = -ENOENT;
706 goto unlock;
707 }
708
709 if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
710 /* already in progress stopping it */
711 ret = 0;
712 goto unlock;
713 }
714
715 set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state);
716 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
717
718 unlock:
719 spin_unlock_bh(&sta->lock);
720 return ret;
721 }
722 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
723
ieee80211_stop_tx_ba_cb(struct ieee80211_vif * vif,u8 * ra,u8 tid)724 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
725 {
726 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
727 struct ieee80211_local *local = sdata->local;
728 struct sta_info *sta;
729 struct tid_ampdu_tx *tid_tx;
730
731 trace_api_stop_tx_ba_cb(sdata, ra, tid);
732
733 if (tid >= STA_TID_NUM) {
734 #ifdef CONFIG_MAC80211_HT_DEBUG
735 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
736 tid, STA_TID_NUM);
737 #endif
738 return;
739 }
740
741 #ifdef CONFIG_MAC80211_HT_DEBUG
742 printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
743 ra, tid);
744 #endif /* CONFIG_MAC80211_HT_DEBUG */
745
746 mutex_lock(&local->sta_mtx);
747
748 sta = sta_info_get_bss(sdata, ra);
749 if (!sta) {
750 #ifdef CONFIG_MAC80211_HT_DEBUG
751 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
752 #endif
753 goto unlock;
754 }
755
756 mutex_lock(&sta->ampdu_mlme.mtx);
757 spin_lock_bh(&sta->lock);
758 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
759
760 if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
761 #ifdef CONFIG_MAC80211_HT_DEBUG
762 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
763 #endif
764 goto unlock_sta;
765 }
766
767 if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop)
768 ieee80211_send_delba(sta->sdata, ra, tid,
769 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
770
771 /*
772 * When we get here, the TX path will not be lockless any more wrt.
773 * aggregation, since the OPERATIONAL bit has long been cleared.
774 * Thus it will block on getting the lock, if it occurs. So if we
775 * stop the queue now, we will not get any more packets, and any
776 * that might be being processed will wait for us here, thereby
777 * guaranteeing that no packets go to the tid_tx pending queue any
778 * more.
779 */
780
781 ieee80211_agg_splice_packets(local, tid_tx, tid);
782
783 /* future packets must not find the tid_tx struct any more */
784 ieee80211_assign_tid_tx(sta, tid, NULL);
785
786 ieee80211_agg_splice_finish(local, tid);
787
788 kfree_rcu(tid_tx, rcu_head);
789
790 unlock_sta:
791 spin_unlock_bh(&sta->lock);
792 mutex_unlock(&sta->ampdu_mlme.mtx);
793 unlock:
794 mutex_unlock(&local->sta_mtx);
795 }
796
ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif * vif,const u8 * ra,u16 tid)797 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
798 const u8 *ra, u16 tid)
799 {
800 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
801 struct ieee80211_local *local = sdata->local;
802 struct ieee80211_ra_tid *ra_tid;
803 struct sk_buff *skb = dev_alloc_skb(0);
804
805 if (unlikely(!skb))
806 return;
807
808 ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
809 memcpy(&ra_tid->ra, ra, ETH_ALEN);
810 ra_tid->tid = tid;
811
812 skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP;
813 skb_queue_tail(&sdata->skb_queue, skb);
814 ieee80211_queue_work(&local->hw, &sdata->work);
815 }
816 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
817
818
ieee80211_process_addba_resp(struct ieee80211_local * local,struct sta_info * sta,struct ieee80211_mgmt * mgmt,size_t len)819 void ieee80211_process_addba_resp(struct ieee80211_local *local,
820 struct sta_info *sta,
821 struct ieee80211_mgmt *mgmt,
822 size_t len)
823 {
824 struct tid_ampdu_tx *tid_tx;
825 u16 capab, tid;
826 u8 buf_size;
827
828 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
829 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
830 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
831
832 mutex_lock(&sta->ampdu_mlme.mtx);
833
834 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
835 if (!tid_tx)
836 goto out;
837
838 if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
839 #ifdef CONFIG_MAC80211_HT_DEBUG
840 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
841 #endif
842 goto out;
843 }
844
845 del_timer_sync(&tid_tx->addba_resp_timer);
846
847 #ifdef CONFIG_MAC80211_HT_DEBUG
848 printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid);
849 #endif
850
851 /*
852 * addba_resp_timer may have fired before we got here, and
853 * caused WANT_STOP to be set. If the stop then was already
854 * processed further, STOPPING might be set.
855 */
856 if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) ||
857 test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
858 #ifdef CONFIG_MAC80211_HT_DEBUG
859 printk(KERN_DEBUG
860 "got addBA resp for tid %d but we already gave up\n",
861 tid);
862 #endif
863 goto out;
864 }
865
866 /*
867 * IEEE 802.11-2007 7.3.1.14:
868 * In an ADDBA Response frame, when the Status Code field
869 * is set to 0, the Buffer Size subfield is set to a value
870 * of at least 1.
871 */
872 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
873 == WLAN_STATUS_SUCCESS && buf_size) {
874 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
875 &tid_tx->state)) {
876 /* ignore duplicate response */
877 goto out;
878 }
879
880 tid_tx->buf_size = buf_size;
881
882 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
883 ieee80211_agg_tx_operational(local, sta, tid);
884
885 sta->ampdu_mlme.addba_req_num[tid] = 0;
886
887 if (tid_tx->timeout)
888 mod_timer(&tid_tx->session_timer,
889 TU_TO_EXP_TIME(tid_tx->timeout));
890
891 } else {
892 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR,
893 true);
894 }
895
896 out:
897 mutex_unlock(&sta->ampdu_mlme.mtx);
898 }
899