net/mac80211/agg-tx.c

   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 <net/mac80211.h>
  19 #include "ieee80211_i.h"
  20 #include "driver-ops.h"
  21 #include "wme.h"
  22
  23 /**
  24  * DOC: TX A-MPDU aggregation
  25  *
  26  * Aggregation on the TX side requires setting the hardware flag
  27  * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed
  28  * packets with a flag indicating A-MPDU aggregation. The driver
  29  * or device is responsible for actually aggregating the frames,
  30  * as well as deciding how many and which to aggregate.
  31  *
  32  * When TX aggregation is started by some subsystem (usually the rate
  33  * control algorithm would be appropriate) by calling the
  34  * ieee80211_start_tx_ba_session() function, the driver will be
  35  * notified via its @ampdu_action function, with the
  36  * %IEEE80211_AMPDU_TX_START action.
  37  *
  38  * In response to that, the driver is later required to call the
  39  * ieee80211_start_tx_ba_cb_irqsafe() function, which will really
  40  * start the aggregation session after the peer has also responded.
  41  * If the peer responds negatively, the session will be stopped
  42  * again right away. Note that it is possible for the aggregation
  43  * session to be stopped before the driver has indicated that it
  44  * is done setting it up, in which case it must not indicate the
  45  * setup completion.
  46  *
  47  * Also note that, since we also need to wait for a response from
  48  * the peer, the driver is notified of the completion of the
  49  * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the
  50  * @ampdu_action callback.
  51  *
  52  * Similarly, when the aggregation session is stopped by the peer
  53  * or something calling ieee80211_stop_tx_ba_session(), the driver's
  54  * @ampdu_action function will be called with the action
  55  * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail,
  56  * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe().
  57  */
  58
  59 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
  60                                          const u8 *da, u16 tid,
  61                                          u8 dialog_token, u16 start_seq_num,
  62                                          u16 agg_size, u16 timeout)
  63 {
  64         struct ieee80211_local *local = sdata->local;
  65         struct sk_buff *skb;
  66         struct ieee80211_mgmt *mgmt;
  67         u16 capab;
  68
  69         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
  70
  71         if (!skb) {
  72                 printk(KERN_ERR "%s: failed to allocate buffer "
  73                                 "for addba request frame\n", sdata->name);
  74                 return;
  75         }
  76         skb_reserve(skb, local->hw.extra_tx_headroom);
  77         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
  78         memset(mgmt, 0, 24);
  79         memcpy(mgmt->da, da, ETH_ALEN);
  80         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
  81         if (sdata->vif.type == NL80211_IFTYPE_AP ||
  82             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  83                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
  84         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
  85                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
  86
  87         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  88                                           IEEE80211_STYPE_ACTION);
  89
  90         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
  91
  92         mgmt->u.action.category = WLAN_CATEGORY_BACK;
  93         mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
  94
  95         mgmt->u.action.u.addba_req.dialog_token = dialog_token;
  96         capab = (u16)(1 << 1);          /* bit 1 aggregation policy */
  97         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
  98         capab |= (u16)(agg_size << 6);  /* bit 15:6 max size of aggergation */
  99
 100         mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
 101
 102         mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
 103         mgmt->u.action.u.addba_req.start_seq_num =
 104                                         cpu_to_le16(start_seq_num << 4);
 105
 106         ieee80211_tx_skb(sdata, skb);
 107 }
 108
 109 void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
 110 {
 111         struct ieee80211_local *local = sdata->local;
 112         struct sk_buff *skb;
 113         struct ieee80211_bar *bar;
 114         u16 bar_control = 0;
 115
 116         skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
 117         if (!skb) {
 118                 printk(KERN_ERR "%s: failed to allocate buffer for "
 119                         "bar frame\n", sdata->name);
 120                 return;
 121         }
 122         skb_reserve(skb, local->hw.extra_tx_headroom);
 123         bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
 124         memset(bar, 0, sizeof(*bar));
 125         bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
 126                                          IEEE80211_STYPE_BACK_REQ);
 127         memcpy(bar->ra, ra, ETH_ALEN);
 128         memcpy(bar->ta, sdata->vif.addr, ETH_ALEN);
 129         bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
 130         bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
 131         bar_control |= (u16)(tid << 12);
 132         bar->control = cpu_to_le16(bar_control);
 133         bar->start_seq_num = cpu_to_le16(ssn);
 134
 135         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 136         ieee80211_tx_skb(sdata, skb);
 137 }
 138
 139 static void kfree_tid_tx(struct rcu_head *rcu_head)
 140 {
 141         struct tid_ampdu_tx *tid_tx =
 142             container_of(rcu_head, struct tid_ampdu_tx, rcu_head);
 143
 144         kfree(tid_tx);
 145 }
 146
 147 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 148                                     enum ieee80211_back_parties initiator)
 149 {
 150         struct ieee80211_local *local = sta->local;
 151         struct tid_ampdu_tx *tid_tx = sta->ampdu_mlme.tid_tx[tid];
 152         int ret;
 153
 154         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 155
 156         if (!tid_tx)
 157                 return -ENOENT;
 158
 159         spin_lock_bh(&sta->lock);
 160
 161         if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
 162                 /* not even started yet! */
 163                 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
 164                 spin_unlock_bh(&sta->lock);
 165                 call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
 166                 return 0;
 167         }
 168
 169         spin_unlock_bh(&sta->lock);
 170
 171 #ifdef CONFIG_MAC80211_HT_DEBUG
 172         printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
 173                sta->sta.addr, tid);
 174 #endif /* CONFIG_MAC80211_HT_DEBUG */
 175
 176         set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
 177
 178         del_timer_sync(&tid_tx->addba_resp_timer);
 179
 180         /*
 181          * After this packets are no longer handed right through
 182          * to the driver but are put onto tid_tx->pending instead,
 183          * with locking to ensure proper access.
 184          */
 185         clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
 186
 187         tid_tx->stop_initiator = initiator;
 188
 189         ret = drv_ampdu_action(local, sta->sdata,
 190                                IEEE80211_AMPDU_TX_STOP,
 191                                &sta->sta, tid, NULL);
 192
 193         /* HW shall not deny going back to legacy */
 194         if (WARN_ON(ret)) {
 195                 /*
 196                  * We may have pending packets get stuck in this case...
 197                  * Not bothering with a workaround for now.
 198                  */
 199         }
 200
 201         return ret;
 202 }
 203
 204 /*
 205  * After sending add Block Ack request we activated a timer until
 206  * add Block Ack response will arrive from the recipient.
 207  * If this timer expires sta_addba_resp_timer_expired will be executed.
 208  */
 209 static void sta_addba_resp_timer_expired(unsigned long data)
 210 {
 211         /* not an elegant detour, but there is no choice as the timer passes
 212          * only one argument, and both sta_info and TID are needed, so init
 213          * flow in sta_info_create gives the TID as data, while the timer_to_id
 214          * array gives the sta through container_of */
 215         u16 tid = *(u8 *)data;
 216         struct sta_info *sta = container_of((void *)data,
 217                 struct sta_info, timer_to_tid[tid]);
 218         struct tid_ampdu_tx *tid_tx;
 219
 220         /* check if the TID waits for addBA response */
 221         rcu_read_lock();
 222         tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
 223         if (!tid_tx ||
 224             test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
 225                 rcu_read_unlock();
 226 #ifdef CONFIG_MAC80211_HT_DEBUG
 227                 printk(KERN_DEBUG "timer expired on tid %d but we are not "
 228                                 "(or no longer) expecting addBA response there\n",
 229                         tid);
 230 #endif
 231                 return;
 232         }
 233
 234 #ifdef CONFIG_MAC80211_HT_DEBUG
 235         printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
 236 #endif
 237
 238         ieee80211_stop_tx_ba_session(&sta->sta, tid);
 239         rcu_read_unlock();
 240 }
 241
 242 static inline int ieee80211_ac_from_tid(int tid)
 243 {
 244         return ieee802_1d_to_ac[tid & 7];
 245 }
 246
 247 /*
 248  * When multiple aggregation sessions on multiple stations
 249  * are being created/destroyed simultaneously, we need to
 250  * refcount the global queue stop caused by that in order
 251  * to not get into a situation where one of the aggregation
 252  * setup or teardown re-enables queues before the other is
 253  * ready to handle that.
 254  *
 255  * These two functions take care of this issue by keeping
 256  * a global "agg_queue_stop" refcount.
 257  */
 258 static void __acquires(agg_queue)
 259 ieee80211_stop_queue_agg(struct ieee80211_local *local, int tid)
 260 {
 261         int queue = ieee80211_ac_from_tid(tid);
 262
 263         if (atomic_inc_return(&local->agg_queue_stop[queue]) == 1)
 264                 ieee80211_stop_queue_by_reason(
 265                         &local->hw, queue,
 266                         IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 267         __acquire(agg_queue);
 268 }
 269
 270 static void __releases(agg_queue)
 271 ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid)
 272 {
 273         int queue = ieee80211_ac_from_tid(tid);
 274
 275         if (atomic_dec_return(&local->agg_queue_stop[queue]) == 0)
 276                 ieee80211_wake_queue_by_reason(
 277                         &local->hw, queue,
 278                         IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 279         __release(agg_queue);
 280 }
 281
 282 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 283 {
 284         struct tid_ampdu_tx *tid_tx = sta->ampdu_mlme.tid_tx[tid];
 285         struct ieee80211_local *local = sta->local;
 286         struct ieee80211_sub_if_data *sdata = sta->sdata;
 287         u16 start_seq_num;
 288         int ret;
 289
 290         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 291
 292         /*
 293          * While we're asking the driver about the aggregation,
 294          * stop the AC queue so that we don't have to worry
 295          * about frames that came in while we were doing that,
 296          * which would require us to put them to the AC pending
 297          * afterwards which just makes the code more complex.
 298          */
 299         ieee80211_stop_queue_agg(local, tid);
 300
 301         clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
 302
 303         /*
 304          * make sure no packets are being processed to get
 305          * valid starting sequence number
 306          */
 307         synchronize_net();
 308
 309         start_seq_num = sta->tid_seq[tid] >> 4;
 310
 311         ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
 312                                &sta->sta, tid, &start_seq_num);
 313         if (ret) {
 314 #ifdef CONFIG_MAC80211_HT_DEBUG
 315                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
 316                                         " tid %d\n", tid);
 317 #endif
 318                 spin_lock_bh(&sta->lock);
 319                 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
 320                 spin_unlock_bh(&sta->lock);
 321
 322                 ieee80211_wake_queue_agg(local, tid);
 323                 call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
 324                 return;
 325         }
 326
 327         /* we can take packets again now */
 328         ieee80211_wake_queue_agg(local, tid);
 329
 330         /* activate the timer for the recipient's addBA response */
 331         mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
 332 #ifdef CONFIG_MAC80211_HT_DEBUG
 333         printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
 334 #endif
 335
 336         spin_lock_bh(&sta->lock);
 337         sta->ampdu_mlme.addba_req_num[tid]++;
 338         spin_unlock_bh(&sta->lock);
 339
 340         /* send AddBA request */
 341         ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
 342                                      tid_tx->dialog_token, start_seq_num,
 343                                      0x40, 5000);
 344 }
 345
 346 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 347 {
 348         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 349         struct ieee80211_sub_if_data *sdata = sta->sdata;
 350         struct ieee80211_local *local = sdata->local;
 351         struct tid_ampdu_tx *tid_tx;
 352         int ret = 0;
 353
 354         trace_api_start_tx_ba_session(pubsta, tid);
 355
 356         if (WARN_ON(!local->ops->ampdu_action))
 357                 return -EINVAL;
 358
 359         if ((tid >= STA_TID_NUM) ||
 360             !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION))
 361                 return -EINVAL;
 362
 363 #ifdef CONFIG_MAC80211_HT_DEBUG
 364         printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
 365                pubsta->addr, tid);
 366 #endif /* CONFIG_MAC80211_HT_DEBUG */
 367
 368         /*
 369          * The aggregation code is not prepared to handle
 370          * anything but STA/AP due to the BSSID handling.
 371          * IBSS could work in the code but isn't supported
 372          * by drivers or the standard.
 373          */
 374         if (sdata->vif.type != NL80211_IFTYPE_STATION &&
 375             sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
 376             sdata->vif.type != NL80211_IFTYPE_AP)
 377                 return -EINVAL;
 378
 379         if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
 380 #ifdef CONFIG_MAC80211_HT_DEBUG
 381                 printk(KERN_DEBUG "BA sessions blocked. "
 382                        "Denying BA session request\n");
 383 #endif
 384                 return -EINVAL;
 385         }
 386
 387         spin_lock_bh(&sta->lock);
 388
 389         /* we have tried too many times, receiver does not want A-MPDU */
 390         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 391                 ret = -EBUSY;
 392                 goto err_unlock_sta;
 393         }
 394
 395         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 396         /* check if the TID is not in aggregation flow already */
 397         if (tid_tx) {
 398 #ifdef CONFIG_MAC80211_HT_DEBUG
 399                 printk(KERN_DEBUG "BA request denied - session is not "
 400                                  "idle on tid %u\n", tid);
 401 #endif /* CONFIG_MAC80211_HT_DEBUG */
 402                 ret = -EAGAIN;
 403                 goto err_unlock_sta;
 404         }
 405
 406         /* prepare A-MPDU MLME for Tx aggregation */
 407         tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 408         if (!tid_tx) {
 409 #ifdef CONFIG_MAC80211_HT_DEBUG
 410                 if (net_ratelimit())
 411                         printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
 412                                         tid);
 413 #endif
 414                 ret = -ENOMEM;
 415                 goto err_unlock_sta;
 416         }
 417
 418         skb_queue_head_init(&tid_tx->pending);
 419         __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
 420
 421         /* Tx timer */
 422         tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired;
 423         tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 424         init_timer(&tid_tx->addba_resp_timer);
 425
 426         /* assign a dialog token */
 427         sta->ampdu_mlme.dialog_token_allocator++;
 428         tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
 429
 430         /* finally, assign it to the array */
 431         rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
 432
 433         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 434
 435         /* this flow continues off the work */
 436  err_unlock_sta:
 437         spin_unlock_bh(&sta->lock);
 438         return ret;
 439 }
 440 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
 441
 442 /*
 443  * splice packets from the STA's pending to the local pending,
 444  * requires a call to ieee80211_agg_splice_finish later
 445  */
 446 static void __acquires(agg_queue)
 447 ieee80211_agg_splice_packets(struct ieee80211_local *local,
 448                              struct tid_ampdu_tx *tid_tx, u16 tid)
 449 {
 450         int queue = ieee80211_ac_from_tid(tid);
 451         unsigned long flags;
 452
 453         ieee80211_stop_queue_agg(local, tid);
 454
 455         if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates"
 456                           " from the pending queue\n", tid))
 457                 return;
 458
 459         if (!skb_queue_empty(&tid_tx->pending)) {
 460                 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 461                 /* copy over remaining packets */
 462                 skb_queue_splice_tail_init(&tid_tx->pending,
 463                                            &local->pending[queue]);
 464                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 465         }
 466 }
 467
 468 static void __releases(agg_queue)
 469 ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid)
 470 {
 471         ieee80211_wake_queue_agg(local, tid);
 472 }
 473
 474 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
 475                                          struct sta_info *sta, u16 tid)
 476 {
 477         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 478
 479 #ifdef CONFIG_MAC80211_HT_DEBUG
 480         printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid);
 481 #endif
 482
 483         drv_ampdu_action(local, sta->sdata,
 484                          IEEE80211_AMPDU_TX_OPERATIONAL,
 485                          &sta->sta, tid, NULL);
 486
 487         /*
 488          * synchronize with TX path, while splicing the TX path
 489          * should block so it won't put more packets onto pending.
 490          */
 491         spin_lock_bh(&sta->lock);
 492
 493         ieee80211_agg_splice_packets(local, sta->ampdu_mlme.tid_tx[tid], tid);
 494         /*
 495          * Now mark as operational. This will be visible
 496          * in the TX path, and lets it go lock-free in
 497          * the common case.
 498          */
 499         set_bit(HT_AGG_STATE_OPERATIONAL, &sta->ampdu_mlme.tid_tx[tid]->state);
 500         ieee80211_agg_splice_finish(local, tid);
 501
 502         spin_unlock_bh(&sta->lock);
 503 }
 504
 505 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
 506 {
 507         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 508         struct ieee80211_local *local = sdata->local;
 509         struct sta_info *sta;
 510         struct tid_ampdu_tx *tid_tx;
 511
 512         trace_api_start_tx_ba_cb(sdata, ra, tid);
 513
 514         if (tid >= STA_TID_NUM) {
 515 #ifdef CONFIG_MAC80211_HT_DEBUG
 516                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 517                                 tid, STA_TID_NUM);
 518 #endif
 519                 return;
 520         }
 521
 522         mutex_lock(&local->sta_mtx);
 523         sta = sta_info_get(sdata, ra);
 524         if (!sta) {
 525                 mutex_unlock(&local->sta_mtx);
 526 #ifdef CONFIG_MAC80211_HT_DEBUG
 527                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 528 #endif
 529                 return;
 530         }
 531
 532         mutex_lock(&sta->ampdu_mlme.mtx);
 533         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 534
 535         if (WARN_ON(!tid_tx)) {
 536 #ifdef CONFIG_MAC80211_HT_DEBUG
 537                 printk(KERN_DEBUG "addBA was not requested!\n");
 538 #endif
 539                 goto unlock;
 540         }
 541
 542         if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
 543                 goto unlock;
 544
 545         if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
 546                 ieee80211_agg_tx_operational(local, sta, tid);
 547
 548  unlock:
 549         mutex_unlock(&sta->ampdu_mlme.mtx);
 550         mutex_unlock(&local->sta_mtx);
 551 }
 552
 553 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 554                                       const u8 *ra, u16 tid)
 555 {
 556         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 557         struct ieee80211_local *local = sdata->local;
 558         struct ieee80211_ra_tid *ra_tid;
 559         struct sk_buff *skb = dev_alloc_skb(0);
 560
 561         if (unlikely(!skb)) {
 562 #ifdef CONFIG_MAC80211_HT_DEBUG
 563                 if (net_ratelimit())
 564                         printk(KERN_WARNING "%s: Not enough memory, "
 565                                "dropping start BA session", sdata->name);
 566 #endif
 567                 return;
 568         }
 569         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 570         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 571         ra_tid->tid = tid;
 572
 573         skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START;
 574         skb_queue_tail(&sdata->skb_queue, skb);
 575         ieee80211_queue_work(&local->hw, &sdata->work);
 576 }
 577 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
 578
 579 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 580                                    enum ieee80211_back_parties initiator)
 581 {
 582         int ret;
 583
 584         mutex_lock(&sta->ampdu_mlme.mtx);
 585
 586         ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator);
 587
 588         mutex_unlock(&sta->ampdu_mlme.mtx);
 589
 590         return ret;
 591 }
 592
 593 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 594 {
 595         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 596         struct ieee80211_sub_if_data *sdata = sta->sdata;
 597         struct ieee80211_local *local = sdata->local;
 598         struct tid_ampdu_tx *tid_tx;
 599         int ret = 0;
 600
 601         trace_api_stop_tx_ba_session(pubsta, tid);
 602
 603         if (!local->ops->ampdu_action)
 604                 return -EINVAL;
 605
 606         if (tid >= STA_TID_NUM)
 607                 return -EINVAL;
 608
 609         spin_lock_bh(&sta->lock);
 610         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 611
 612         if (!tid_tx) {
 613                 ret = -ENOENT;
 614                 goto unlock;
 615         }
 616
 617         if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
 618                 /* already in progress stopping it */
 619                 ret = 0;
 620                 goto unlock;
 621         }
 622
 623         set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state);
 624         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 625
 626  unlock:
 627         spin_unlock_bh(&sta->lock);
 628         return ret;
 629 }
 630 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
 631
 632 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
 633 {
 634         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 635         struct ieee80211_local *local = sdata->local;
 636         struct sta_info *sta;
 637         struct tid_ampdu_tx *tid_tx;
 638
 639         trace_api_stop_tx_ba_cb(sdata, ra, tid);
 640
 641         if (tid >= STA_TID_NUM) {
 642 #ifdef CONFIG_MAC80211_HT_DEBUG
 643                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 644                                 tid, STA_TID_NUM);
 645 #endif
 646                 return;
 647         }
 648
 649 #ifdef CONFIG_MAC80211_HT_DEBUG
 650         printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
 651                ra, tid);
 652 #endif /* CONFIG_MAC80211_HT_DEBUG */
 653
 654         mutex_lock(&local->sta_mtx);
 655
 656         sta = sta_info_get(sdata, ra);
 657         if (!sta) {
 658 #ifdef CONFIG_MAC80211_HT_DEBUG
 659                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 660 #endif
 661                 goto unlock;
 662         }
 663
 664         mutex_lock(&sta->ampdu_mlme.mtx);
 665         spin_lock_bh(&sta->lock);
 666         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 667
 668         if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
 669 #ifdef CONFIG_MAC80211_HT_DEBUG
 670                 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
 671 #endif
 672                 goto unlock_sta;
 673         }
 674
 675         if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR)
 676                 ieee80211_send_delba(sta->sdata, ra, tid,
 677                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
 678
 679         /*
 680          * When we get here, the TX path will not be lockless any more wrt.
 681          * aggregation, since the OPERATIONAL bit has long been cleared.
 682          * Thus it will block on getting the lock, if it occurs. So if we
 683          * stop the queue now, we will not get any more packets, and any
 684          * that might be being processed will wait for us here, thereby
 685          * guaranteeing that no packets go to the tid_tx pending queue any
 686          * more.
 687          */
 688
 689         ieee80211_agg_splice_packets(local, tid_tx, tid);
 690
 691         /* future packets must not find the tid_tx struct any more */
 692         rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
 693
 694         ieee80211_agg_splice_finish(local, tid);
 695
 696         call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
 697
 698  unlock_sta:
 699         spin_unlock_bh(&sta->lock);
 700         mutex_unlock(&sta->ampdu_mlme.mtx);
 701  unlock:
 702         mutex_unlock(&local->sta_mtx);
 703 }
 704
 705 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 706                                      const u8 *ra, u16 tid)
 707 {
 708         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 709         struct ieee80211_local *local = sdata->local;
 710         struct ieee80211_ra_tid *ra_tid;
 711         struct sk_buff *skb = dev_alloc_skb(0);
 712
 713         if (unlikely(!skb)) {
 714 #ifdef CONFIG_MAC80211_HT_DEBUG
 715                 if (net_ratelimit())
 716                         printk(KERN_WARNING "%s: Not enough memory, "
 717                                "dropping stop BA session", sdata->name);
 718 #endif
 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_STOP;
 726         skb_queue_tail(&sdata->skb_queue, skb);
 727         ieee80211_queue_work(&local->hw, &sdata->work);
 728 }
 729 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
 730
 731
 732 void ieee80211_process_addba_resp(struct ieee80211_local *local,
 733                                   struct sta_info *sta,
 734                                   struct ieee80211_mgmt *mgmt,
 735                                   size_t len)
 736 {
 737         struct tid_ampdu_tx *tid_tx;
 738         u16 capab, tid;
 739
 740         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 741         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 742
 743         mutex_lock(&sta->ampdu_mlme.mtx);
 744
 745         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 746         if (!tid_tx)
 747                 goto out;
 748
 749         if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
 750 #ifdef CONFIG_MAC80211_HT_DEBUG
 751                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 752 #endif
 753                 goto out;
 754         }
 755
 756         del_timer(&tid_tx->addba_resp_timer);
 757
 758 #ifdef CONFIG_MAC80211_HT_DEBUG
 759         printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid);
 760 #endif
 761
 762         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 763                         == WLAN_STATUS_SUCCESS) {
 764                 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
 765                                      &tid_tx->state)) {
 766                         /* ignore duplicate response */
 767                         goto out;
 768                 }
 769
 770                 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
 771                         ieee80211_agg_tx_operational(local, sta, tid);
 772
 773                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 774         } else {
 775                 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 776         }
 777
 778  out:
 779         mutex_unlock(&sta->ampdu_mlme.mtx);
 780 }