~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/mac80211/agg-tx.c

Version: ~ [ linux-5.5-rc1 ] ~ [ linux-5.4.2 ] ~ [ linux-5.3.15 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.88 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.158 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.206 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.206 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.78 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 
 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 
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_CTL_REQ_TX_STATUS;
140         ieee80211_tx_skb_tid(sdata, skb, tid);
141 }
142 EXPORT_SYMBOL(ieee80211_send_bar);
143 
144 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
145                              struct tid_ampdu_tx *tid_tx)
146 {
147         lockdep_assert_held(&sta->ampdu_mlme.mtx);
148         lockdep_assert_held(&sta->lock);
149         rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
150 }
151 
152 static inline int ieee80211_ac_from_tid(int tid)
153 {
154         return ieee802_1d_to_ac[tid & 7];
155 }
156 
157 /*
158  * When multiple aggregation sessions on multiple stations
159  * are being created/destroyed simultaneously, we need to
160  * refcount the global queue stop caused by that in order
161  * to not get into a situation where one of the aggregation
162  * setup or teardown re-enables queues before the other is
163  * ready to handle that.
164  *
165  * These two functions take care of this issue by keeping
166  * a global "agg_queue_stop" refcount.
167  */
168 static void __acquires(agg_queue)
169 ieee80211_stop_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
170 {
171         int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
172 
173         if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1)
174                 ieee80211_stop_queue_by_reason(
175                         &sdata->local->hw, queue,
176                         IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
177         __acquire(agg_queue);
178 }
179 
180 static void __releases(agg_queue)
181 ieee80211_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         __release(agg_queue);
190 }
191 
192 /*
193  * splice packets from the STA's pending to the local pending,
194  * requires a call to ieee80211_agg_splice_finish later
195  */
196 static void __acquires(agg_queue)
197 ieee80211_agg_splice_packets(struct ieee80211_sub_if_data *sdata,
198                              struct tid_ampdu_tx *tid_tx, u16 tid)
199 {
200         struct ieee80211_local *local = sdata->local;
201         int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
202         unsigned long flags;
203 
204         ieee80211_stop_queue_agg(sdata, tid);
205 
206         if (WARN(!tid_tx,
207                  "TID %d gone but expected when splicing aggregates from the pending queue\n",
208                  tid))
209                 return;
210 
211         if (!skb_queue_empty(&tid_tx->pending)) {
212                 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
213                 /* copy over remaining packets */
214                 skb_queue_splice_tail_init(&tid_tx->pending,
215                                            &local->pending[queue]);
216                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
217         }
218 }
219 
220 static void __releases(agg_queue)
221 ieee80211_agg_splice_finish(struct ieee80211_sub_if_data *sdata, u16 tid)
222 {
223         ieee80211_wake_queue_agg(sdata, tid);
224 }
225 
226 static void ieee80211_remove_tid_tx(struct sta_info *sta, int tid)
227 {
228         struct tid_ampdu_tx *tid_tx;
229 
230         lockdep_assert_held(&sta->ampdu_mlme.mtx);
231         lockdep_assert_held(&sta->lock);
232 
233         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
234 
235         /*
236          * When we get here, the TX path will not be lockless any more wrt.
237          * aggregation, since the OPERATIONAL bit has long been cleared.
238          * Thus it will block on getting the lock, if it occurs. So if we
239          * stop the queue now, we will not get any more packets, and any
240          * that might be being processed will wait for us here, thereby
241          * guaranteeing that no packets go to the tid_tx pending queue any
242          * more.
243          */
244 
245         ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
246 
247         /* future packets must not find the tid_tx struct any more */
248         ieee80211_assign_tid_tx(sta, tid, NULL);
249 
250         ieee80211_agg_splice_finish(sta->sdata, tid);
251 
252         kfree_rcu(tid_tx, rcu_head);
253 }
254 
255 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
256                                     enum ieee80211_agg_stop_reason reason)
257 {
258         struct ieee80211_local *local = sta->local;
259         struct tid_ampdu_tx *tid_tx;
260         enum ieee80211_ampdu_mlme_action action;
261         int ret;
262 
263         lockdep_assert_held(&sta->ampdu_mlme.mtx);
264 
265         switch (reason) {
266         case AGG_STOP_DECLINED:
267         case AGG_STOP_LOCAL_REQUEST:
268         case AGG_STOP_PEER_REQUEST:
269                 action = IEEE80211_AMPDU_TX_STOP_CONT;
270                 break;
271         case AGG_STOP_DESTROY_STA:
272                 action = IEEE80211_AMPDU_TX_STOP_FLUSH;
273                 break;
274         default:
275                 WARN_ON_ONCE(1);
276                 return -EINVAL;
277         }
278 
279         spin_lock_bh(&sta->lock);
280 
281         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
282         if (!tid_tx) {
283                 spin_unlock_bh(&sta->lock);
284                 return -ENOENT;
285         }
286 
287         /*
288          * if we're already stopping ignore any new requests to stop
289          * unless we're destroying it in which case notify the driver
290          */
291         if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
292                 spin_unlock_bh(&sta->lock);
293                 if (reason != AGG_STOP_DESTROY_STA)
294                         return -EALREADY;
295                 ret = drv_ampdu_action(local, sta->sdata,
296                                        IEEE80211_AMPDU_TX_STOP_FLUSH_CONT,
297                                        &sta->sta, tid, NULL, 0);
298                 WARN_ON_ONCE(ret);
299                 return 0;
300         }
301 
302         if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
303                 /* not even started yet! */
304                 ieee80211_assign_tid_tx(sta, tid, NULL);
305                 spin_unlock_bh(&sta->lock);
306                 kfree_rcu(tid_tx, rcu_head);
307                 return 0;
308         }
309 
310         set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
311 
312         spin_unlock_bh(&sta->lock);
313 
314         ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n",
315                sta->sta.addr, tid);
316 
317         del_timer_sync(&tid_tx->addba_resp_timer);
318         del_timer_sync(&tid_tx->session_timer);
319 
320         /*
321          * After this packets are no longer handed right through
322          * to the driver but are put onto tid_tx->pending instead,
323          * with locking to ensure proper access.
324          */
325         clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
326 
327         /*
328          * There might be a few packets being processed right now (on
329          * another CPU) that have already gotten past the aggregation
330          * check when it was still OPERATIONAL and consequently have
331          * IEEE80211_TX_CTL_AMPDU set. In that case, this code might
332          * call into the driver at the same time or even before the
333          * TX paths calls into it, which could confuse the driver.
334          *
335          * Wait for all currently running TX paths to finish before
336          * telling the driver. New packets will not go through since
337          * the aggregation session is no longer OPERATIONAL.
338          */
339         synchronize_net();
340 
341         tid_tx->stop_initiator = reason == AGG_STOP_PEER_REQUEST ?
342                                         WLAN_BACK_RECIPIENT :
343                                         WLAN_BACK_INITIATOR;
344         tid_tx->tx_stop = reason == AGG_STOP_LOCAL_REQUEST;
345 
346         ret = drv_ampdu_action(local, sta->sdata, action,
347                                &sta->sta, tid, NULL, 0);
348 
349         /* HW shall not deny going back to legacy */
350         if (WARN_ON(ret)) {
351                 /*
352                  * We may have pending packets get stuck in this case...
353                  * Not bothering with a workaround for now.
354                  */
355         }
356 
357         /*
358          * In the case of AGG_STOP_DESTROY_STA, the driver won't
359          * necessarily call ieee80211_stop_tx_ba_cb(), so this may
360          * seem like we can leave the tid_tx data pending forever.
361          * This is true, in a way, but "forever" is only until the
362          * station struct is actually destroyed. In the meantime,
363          * leaving it around ensures that we don't transmit packets
364          * to the driver on this TID which might confuse it.
365          */
366 
367         return 0;
368 }
369 
370 /*
371  * After sending add Block Ack request we activated a timer until
372  * add Block Ack response will arrive from the recipient.
373  * If this timer expires sta_addba_resp_timer_expired will be executed.
374  */
375 static void sta_addba_resp_timer_expired(unsigned long data)
376 {
377         /* not an elegant detour, but there is no choice as the timer passes
378          * only one argument, and both sta_info and TID are needed, so init
379          * flow in sta_info_create gives the TID as data, while the timer_to_id
380          * array gives the sta through container_of */
381         u16 tid = *(u8 *)data;
382         struct sta_info *sta = container_of((void *)data,
383                 struct sta_info, timer_to_tid[tid]);
384         struct tid_ampdu_tx *tid_tx;
385 
386         /* check if the TID waits for addBA response */
387         rcu_read_lock();
388         tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
389         if (!tid_tx ||
390             test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
391                 rcu_read_unlock();
392                 ht_dbg(sta->sdata,
393                        "timer expired on %pM tid %d but we are not (or no longer) expecting addBA response there\n",
394                        sta->sta.addr, tid);
395                 return;
396         }
397 
398         ht_dbg(sta->sdata, "addBA response timer expired on %pM tid %d\n",
399                sta->sta.addr, tid);
400 
401         ieee80211_stop_tx_ba_session(&sta->sta, tid);
402         rcu_read_unlock();
403 }
404 
405 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
406 {
407         struct tid_ampdu_tx *tid_tx;
408         struct ieee80211_local *local = sta->local;
409         struct ieee80211_sub_if_data *sdata = sta->sdata;
410         u16 start_seq_num;
411         int ret;
412 
413         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
414 
415         /*
416          * Start queuing up packets for this aggregation session.
417          * We're going to release them once the driver is OK with
418          * that.
419          */
420         clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
421 
422         /*
423          * Make sure no packets are being processed. This ensures that
424          * we have a valid starting sequence number and that in-flight
425          * packets have been flushed out and no packets for this TID
426          * will go into the driver during the ampdu_action call.
427          */
428         synchronize_net();
429 
430         start_seq_num = sta->tid_seq[tid] >> 4;
431 
432         ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
433                                &sta->sta, tid, &start_seq_num, 0);
434         if (ret) {
435                 ht_dbg(sdata,
436                        "BA request denied - HW unavailable for %pM tid %d\n",
437                        sta->sta.addr, tid);
438                 spin_lock_bh(&sta->lock);
439                 ieee80211_agg_splice_packets(sdata, tid_tx, tid);
440                 ieee80211_assign_tid_tx(sta, tid, NULL);
441                 ieee80211_agg_splice_finish(sdata, tid);
442                 spin_unlock_bh(&sta->lock);
443 
444                 kfree_rcu(tid_tx, rcu_head);
445                 return;
446         }
447 
448         /* activate the timer for the recipient's addBA response */
449         mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
450         ht_dbg(sdata, "activated addBA response timer on %pM tid %d\n",
451                sta->sta.addr, tid);
452 
453         spin_lock_bh(&sta->lock);
454         sta->ampdu_mlme.last_addba_req_time[tid] = jiffies;
455         sta->ampdu_mlme.addba_req_num[tid]++;
456         spin_unlock_bh(&sta->lock);
457 
458         /* send AddBA request */
459         ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
460                                      tid_tx->dialog_token, start_seq_num,
461                                      local->hw.max_tx_aggregation_subframes,
462                                      tid_tx->timeout);
463 }
464 
465 /*
466  * After accepting the AddBA Response we activated a timer,
467  * resetting it after each frame that we send.
468  */
469 static void sta_tx_agg_session_timer_expired(unsigned long data)
470 {
471         /* not an elegant detour, but there is no choice as the timer passes
472          * only one argument, and various sta_info are needed here, so init
473          * flow in sta_info_create gives the TID as data, while the timer_to_id
474          * array gives the sta through container_of */
475         u8 *ptid = (u8 *)data;
476         u8 *timer_to_id = ptid - *ptid;
477         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
478                                          timer_to_tid[0]);
479         struct tid_ampdu_tx *tid_tx;
480         unsigned long timeout;
481 
482         rcu_read_lock();
483         tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[*ptid]);
484         if (!tid_tx || test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
485                 rcu_read_unlock();
486                 return;
487         }
488 
489         timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout);
490         if (time_is_after_jiffies(timeout)) {
491                 mod_timer(&tid_tx->session_timer, timeout);
492                 rcu_read_unlock();
493                 return;
494         }
495 
496         rcu_read_unlock();
497 
498         ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n",
499                sta->sta.addr, (u16)*ptid);
500 
501         ieee80211_stop_tx_ba_session(&sta->sta, *ptid);
502 }
503 
504 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
505                                   u16 timeout)
506 {
507         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
508         struct ieee80211_sub_if_data *sdata = sta->sdata;
509         struct ieee80211_local *local = sdata->local;
510         struct tid_ampdu_tx *tid_tx;
511         int ret = 0;
512 
513         trace_api_start_tx_ba_session(pubsta, tid);
514 
515         if (WARN_ON_ONCE(!local->ops->ampdu_action))
516                 return -EINVAL;
517 
518         if ((tid >= IEEE80211_NUM_TIDS) ||
519             !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) ||
520             (local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW))
521                 return -EINVAL;
522 
523         ht_dbg(sdata, "Open BA session requested for %pM tid %u\n",
524                pubsta->addr, tid);
525 
526         if (sdata->vif.type != NL80211_IFTYPE_STATION &&
527             sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
528             sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
529             sdata->vif.type != NL80211_IFTYPE_AP &&
530             sdata->vif.type != NL80211_IFTYPE_ADHOC)
531                 return -EINVAL;
532 
533         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
534                 ht_dbg(sdata,
535                        "BA sessions blocked - Denying BA session request %pM tid %d\n",
536                        sta->sta.addr, tid);
537                 return -EINVAL;
538         }
539 
540         /*
541          * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a
542          * member of an IBSS, and has no other existing Block Ack agreement
543          * with the recipient STA, then the initiating STA shall transmit a
544          * Probe Request frame to the recipient STA and shall not transmit an
545          * ADDBA Request frame unless it receives a Probe Response frame
546          * from the recipient within dot11ADDBAFailureTimeout.
547          *
548          * The probe request mechanism for ADDBA is currently not implemented,
549          * but we only build up Block Ack session with HT STAs. This information
550          * is set when we receive a bss info from a probe response or a beacon.
551          */
552         if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC &&
553             !sta->sta.ht_cap.ht_supported) {
554                 ht_dbg(sdata,
555                        "BA request denied - IBSS STA %pM does not advertise HT support\n",
556                        pubsta->addr);
557                 return -EINVAL;
558         }
559 
560         spin_lock_bh(&sta->lock);
561 
562         /* we have tried too many times, receiver does not want A-MPDU */
563         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
564                 ret = -EBUSY;
565                 goto err_unlock_sta;
566         }
567 
568         /*
569          * if we have tried more than HT_AGG_BURST_RETRIES times we
570          * will spread our requests in time to avoid stalling connection
571          * for too long
572          */
573         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES &&
574             time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] +
575                         HT_AGG_RETRIES_PERIOD)) {
576                 ht_dbg(sdata,
577                        "BA request denied - waiting a grace period after %d failed requests on %pM tid %u\n",
578                        sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, tid);
579                 ret = -EBUSY;
580                 goto err_unlock_sta;
581         }
582 
583         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
584         /* check if the TID is not in aggregation flow already */
585         if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
586                 ht_dbg(sdata,
587                        "BA request denied - session is not idle on %pM tid %u\n",
588                        sta->sta.addr, tid);
589                 ret = -EAGAIN;
590                 goto err_unlock_sta;
591         }
592 
593         /* prepare A-MPDU MLME for Tx aggregation */
594         tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
595         if (!tid_tx) {
596                 ret = -ENOMEM;
597                 goto err_unlock_sta;
598         }
599 
600         skb_queue_head_init(&tid_tx->pending);
601         __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
602 
603         tid_tx->timeout = timeout;
604 
605         /* response timer */
606         tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired;
607         tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid];
608         init_timer(&tid_tx->addba_resp_timer);
609 
610         /* tx timer */
611         tid_tx->session_timer.function = sta_tx_agg_session_timer_expired;
612         tid_tx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
613         init_timer_deferrable(&tid_tx->session_timer);
614 
615         /* assign a dialog token */
616         sta->ampdu_mlme.dialog_token_allocator++;
617         tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
618 
619         /*
620          * Finally, assign it to the start array; the work item will
621          * collect it and move it to the normal array.
622          */
623         sta->ampdu_mlme.tid_start_tx[tid] = tid_tx;
624 
625         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
626 
627         /* this flow continues off the work */
628  err_unlock_sta:
629         spin_unlock_bh(&sta->lock);
630         return ret;
631 }
632 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
633 
634 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
635                                          struct sta_info *sta, u16 tid)
636 {
637         struct tid_ampdu_tx *tid_tx;
638 
639         lockdep_assert_held(&sta->ampdu_mlme.mtx);
640 
641         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
642 
643         ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n",
644                sta->sta.addr, tid);
645 
646         drv_ampdu_action(local, sta->sdata,
647                          IEEE80211_AMPDU_TX_OPERATIONAL,
648                          &sta->sta, tid, NULL, tid_tx->buf_size);
649 
650         /*
651          * synchronize with TX path, while splicing the TX path
652          * should block so it won't put more packets onto pending.
653          */
654         spin_lock_bh(&sta->lock);
655 
656         ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
657         /*
658          * Now mark as operational. This will be visible
659          * in the TX path, and lets it go lock-free in
660          * the common case.
661          */
662         set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
663         ieee80211_agg_splice_finish(sta->sdata, tid);
664 
665         spin_unlock_bh(&sta->lock);
666 }
667 
668 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
669 {
670         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
671         struct ieee80211_local *local = sdata->local;
672         struct sta_info *sta;
673         struct tid_ampdu_tx *tid_tx;
674 
675         trace_api_start_tx_ba_cb(sdata, ra, tid);
676 
677         if (tid >= IEEE80211_NUM_TIDS) {
678                 ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
679                        tid, IEEE80211_NUM_TIDS);
680                 return;
681         }
682 
683         mutex_lock(&local->sta_mtx);
684         sta = sta_info_get_bss(sdata, ra);
685         if (!sta) {
686                 mutex_unlock(&local->sta_mtx);
687                 ht_dbg(sdata, "Could not find station: %pM\n", ra);
688                 return;
689         }
690 
691         mutex_lock(&sta->ampdu_mlme.mtx);
692         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
693 
694         if (WARN_ON(!tid_tx)) {
695                 ht_dbg(sdata, "addBA was not requested!\n");
696                 goto unlock;
697         }
698 
699         if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
700                 goto unlock;
701 
702         if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
703                 ieee80211_agg_tx_operational(local, sta, tid);
704 
705  unlock:
706         mutex_unlock(&sta->ampdu_mlme.mtx);
707         mutex_unlock(&local->sta_mtx);
708 }
709 
710 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
711                                       const u8 *ra, u16 tid)
712 {
713         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
714         struct ieee80211_local *local = sdata->local;
715         struct ieee80211_ra_tid *ra_tid;
716         struct sk_buff *skb = dev_alloc_skb(0);
717 
718         if (unlikely(!skb))
719                 return;
720 
721         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
722         memcpy(&ra_tid->ra, ra, ETH_ALEN);
723         ra_tid->tid = tid;
724 
725         skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START;
726         skb_queue_tail(&sdata->skb_queue, skb);
727         ieee80211_queue_work(&local->hw, &sdata->work);
728 }
729 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
730 
731 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
732                                    enum ieee80211_agg_stop_reason reason)
733 {
734         int ret;
735 
736         mutex_lock(&sta->ampdu_mlme.mtx);
737 
738         ret = ___ieee80211_stop_tx_ba_session(sta, tid, reason);
739 
740         mutex_unlock(&sta->ampdu_mlme.mtx);
741 
742         return ret;
743 }
744 
745 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
746 {
747         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
748         struct ieee80211_sub_if_data *sdata = sta->sdata;
749         struct ieee80211_local *local = sdata->local;
750         struct tid_ampdu_tx *tid_tx;
751         int ret = 0;
752 
753         trace_api_stop_tx_ba_session(pubsta, tid);
754 
755         if (!local->ops->ampdu_action)
756                 return -EINVAL;
757 
758         if (tid >= IEEE80211_NUM_TIDS)
759                 return -EINVAL;
760 
761         spin_lock_bh(&sta->lock);
762         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
763 
764         if (!tid_tx) {
765                 ret = -ENOENT;
766                 goto unlock;
767         }
768 
769         if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
770                 /* already in progress stopping it */
771                 ret = 0;
772                 goto unlock;
773         }
774 
775         set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state);
776         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
777 
778  unlock:
779         spin_unlock_bh(&sta->lock);
780         return ret;
781 }
782 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
783 
784 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
785 {
786         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
787         struct ieee80211_local *local = sdata->local;
788         struct sta_info *sta;
789         struct tid_ampdu_tx *tid_tx;
790 
791         trace_api_stop_tx_ba_cb(sdata, ra, tid);
792 
793         if (tid >= IEEE80211_NUM_TIDS) {
794                 ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
795                        tid, IEEE80211_NUM_TIDS);
796                 return;
797         }
798 
799         ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", ra, tid);
800 
801         mutex_lock(&local->sta_mtx);
802 
803         sta = sta_info_get_bss(sdata, ra);
804         if (!sta) {
805                 ht_dbg(sdata, "Could not find station: %pM\n", ra);
806                 goto unlock;
807         }
808 
809         mutex_lock(&sta->ampdu_mlme.mtx);
810         spin_lock_bh(&sta->lock);
811         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
812 
813         if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
814                 ht_dbg(sdata,
815                        "unexpected callback to A-MPDU stop for %pM tid %d\n",
816                        sta->sta.addr, tid);
817                 goto unlock_sta;
818         }
819 
820         if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop)
821                 ieee80211_send_delba(sta->sdata, ra, tid,
822                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
823 
824         ieee80211_remove_tid_tx(sta, tid);
825 
826  unlock_sta:
827         spin_unlock_bh(&sta->lock);
828         mutex_unlock(&sta->ampdu_mlme.mtx);
829  unlock:
830         mutex_unlock(&local->sta_mtx);
831 }
832 
833 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
834                                      const u8 *ra, u16 tid)
835 {
836         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
837         struct ieee80211_local *local = sdata->local;
838         struct ieee80211_ra_tid *ra_tid;
839         struct sk_buff *skb = dev_alloc_skb(0);
840 
841         if (unlikely(!skb))
842                 return;
843 
844         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
845         memcpy(&ra_tid->ra, ra, ETH_ALEN);
846         ra_tid->tid = tid;
847 
848         skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP;
849         skb_queue_tail(&sdata->skb_queue, skb);
850         ieee80211_queue_work(&local->hw, &sdata->work);
851 }
852 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
853 
854 
855 void ieee80211_process_addba_resp(struct ieee80211_local *local,
856                                   struct sta_info *sta,
857                                   struct ieee80211_mgmt *mgmt,
858                                   size_t len)
859 {
860         struct tid_ampdu_tx *tid_tx;
861         u16 capab, tid;
862         u8 buf_size;
863 
864         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
865         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
866         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
867 
868         mutex_lock(&sta->ampdu_mlme.mtx);
869 
870         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
871         if (!tid_tx)
872                 goto out;
873 
874         if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
875                 ht_dbg(sta->sdata, "wrong addBA response token, %pM tid %d\n",
876                        sta->sta.addr, tid);
877                 goto out;
878         }
879 
880         del_timer_sync(&tid_tx->addba_resp_timer);
881 
882         ht_dbg(sta->sdata, "switched off addBA timer for %pM tid %d\n",
883                sta->sta.addr, tid);
884 
885         /*
886          * addba_resp_timer may have fired before we got here, and
887          * caused WANT_STOP to be set. If the stop then was already
888          * processed further, STOPPING might be set.
889          */
890         if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) ||
891             test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
892                 ht_dbg(sta->sdata,
893                        "got addBA resp for %pM tid %d but we already gave up\n",
894                        sta->sta.addr, tid);
895                 goto out;
896         }
897 
898         /*
899          * IEEE 802.11-2007 7.3.1.14:
900          * In an ADDBA Response frame, when the Status Code field
901          * is set to 0, the Buffer Size subfield is set to a value
902          * of at least 1.
903          */
904         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
905                         == WLAN_STATUS_SUCCESS && buf_size) {
906                 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
907                                      &tid_tx->state)) {
908                         /* ignore duplicate response */
909                         goto out;
910                 }
911 
912                 tid_tx->buf_size = buf_size;
913 
914                 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
915                         ieee80211_agg_tx_operational(local, sta, tid);
916 
917                 sta->ampdu_mlme.addba_req_num[tid] = 0;
918 
919                 if (tid_tx->timeout) {
920                         mod_timer(&tid_tx->session_timer,
921                                   TU_TO_EXP_TIME(tid_tx->timeout));
922                         tid_tx->last_tx = jiffies;
923                 }
924 
925         } else {
926                 ___ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_DECLINED);
927         }
928 
929  out:
930         mutex_unlock(&sta->ampdu_mlme.mtx);
931 }
932 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp