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 2007-2009, 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 aggregation
  25  *
  26  * Aggregation on the TX side requires setting the hardware flag
  27  * %IEEE80211_HW_AMPDU_AGGREGATION as well as, if present, the @ampdu_queues
  28  * hardware parameter to the number of hardware AMPDU queues. If there are no
  29  * hardware queues then the driver will (currently) have to do all frame
  30  * buffering.
  31  *
  32  * When TX aggregation is started by some subsystem (usually the rate control
  33  * algorithm would be appropriate) by calling the
  34  * ieee80211_start_tx_ba_session() function, the driver will be notified via
  35  * its @ampdu_action function, with the %IEEE80211_AMPDU_TX_START action.
  36  *
  37  * In response to that, the driver is later required to call the
  38  * ieee80211_start_tx_ba_cb() (or ieee80211_start_tx_ba_cb_irqsafe())
  39  * function, which will start the aggregation session.
  40  *
  41  * Similarly, when the aggregation session is stopped by
  42  * ieee80211_stop_tx_ba_session(), the driver's @ampdu_action function will
  43  * be called with the action %IEEE80211_AMPDU_TX_STOP. In this case, the
  44  * call must not fail, and the driver must later call ieee80211_stop_tx_ba_cb()
  45  * (or ieee80211_stop_tx_ba_cb_irqsafe()).
  46  */
  47
  48 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
  49                                          const u8 *da, u16 tid,
  50                                          u8 dialog_token, u16 start_seq_num,
  51                                          u16 agg_size, u16 timeout)
  52 {
  53         struct ieee80211_local *local = sdata->local;
  54         struct sk_buff *skb;
  55         struct ieee80211_mgmt *mgmt;
  56         u16 capab;
  57
  58         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
  59
  60         if (!skb) {
  61                 printk(KERN_ERR "%s: failed to allocate buffer "
  62                                 "for addba request frame\n", sdata->name);
  63                 return;
  64         }
  65         skb_reserve(skb, local->hw.extra_tx_headroom);
  66         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
  67         memset(mgmt, 0, 24);
  68         memcpy(mgmt->da, da, ETH_ALEN);
  69         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
  70         if (sdata->vif.type == NL80211_IFTYPE_AP ||
  71             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  72                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
  73         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
  74                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
  75
  76         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  77                                           IEEE80211_STYPE_ACTION);
  78
  79         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
  80
  81         mgmt->u.action.category = WLAN_CATEGORY_BACK;
  82         mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
  83
  84         mgmt->u.action.u.addba_req.dialog_token = dialog_token;
  85         capab = (u16)(1 << 1);          /* bit 1 aggregation policy */
  86         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
  87         capab |= (u16)(agg_size << 6);  /* bit 15:6 max size of aggergation */
  88
  89         mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
  90
  91         mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
  92         mgmt->u.action.u.addba_req.start_seq_num =
  93                                         cpu_to_le16(start_seq_num << 4);
  94
  95         ieee80211_tx_skb(sdata, skb);
  96 }
  97
  98 void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
  99 {
 100         struct ieee80211_local *local = sdata->local;
 101         struct sk_buff *skb;
 102         struct ieee80211_bar *bar;
 103         u16 bar_control = 0;
 104
 105         skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
 106         if (!skb) {
 107                 printk(KERN_ERR "%s: failed to allocate buffer for "
 108                         "bar frame\n", sdata->name);
 109                 return;
 110         }
 111         skb_reserve(skb, local->hw.extra_tx_headroom);
 112         bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
 113         memset(bar, 0, sizeof(*bar));
 114         bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
 115                                          IEEE80211_STYPE_BACK_REQ);
 116         memcpy(bar->ra, ra, ETH_ALEN);
 117         memcpy(bar->ta, sdata->vif.addr, ETH_ALEN);
 118         bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
 119         bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
 120         bar_control |= (u16)(tid << 12);
 121         bar->control = cpu_to_le16(bar_control);
 122         bar->start_seq_num = cpu_to_le16(ssn);
 123
 124         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 125         ieee80211_tx_skb(sdata, skb);
 126 }
 127
 128 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 129                                     enum ieee80211_back_parties initiator)
 130 {
 131         struct ieee80211_local *local = sta->local;
 132         int ret;
 133         u8 *state;
 134
 135 #ifdef CONFIG_MAC80211_HT_DEBUG
 136         printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
 137                sta->sta.addr, tid);
 138 #endif /* CONFIG_MAC80211_HT_DEBUG */
 139
 140         state = &sta->ampdu_mlme.tid_state_tx[tid];
 141
 142         if (*state == HT_AGG_STATE_OPERATIONAL)
 143                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 144
 145         *state = HT_AGG_STATE_REQ_STOP_BA_MSK |
 146                 (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
 147
 148         ret = drv_ampdu_action(local, sta->sdata,
 149                                IEEE80211_AMPDU_TX_STOP,
 150                                &sta->sta, tid, NULL);
 151
 152         /* HW shall not deny going back to legacy */
 153         if (WARN_ON(ret)) {
 154                 /*
 155                  * We may have pending packets get stuck in this case...
 156                  * Not bothering with a workaround for now.
 157                  */
 158         }
 159
 160         return ret;
 161 }
 162
 163 /*
 164  * After sending add Block Ack request we activated a timer until
 165  * add Block Ack response will arrive from the recipient.
 166  * If this timer expires sta_addba_resp_timer_expired will be executed.
 167  */
 168 static void sta_addba_resp_timer_expired(unsigned long data)
 169 {
 170         /* not an elegant detour, but there is no choice as the timer passes
 171          * only one argument, and both sta_info and TID are needed, so init
 172          * flow in sta_info_create gives the TID as data, while the timer_to_id
 173          * array gives the sta through container_of */
 174         u16 tid = *(u8 *)data;
 175         struct sta_info *sta = container_of((void *)data,
 176                 struct sta_info, timer_to_tid[tid]);
 177         u8 *state;
 178
 179         state = &sta->ampdu_mlme.tid_state_tx[tid];
 180
 181         /* check if the TID waits for addBA response */
 182         spin_lock_bh(&sta->lock);
 183         if ((*state & (HT_ADDBA_REQUESTED_MSK | HT_ADDBA_RECEIVED_MSK |
 184                        HT_AGG_STATE_REQ_STOP_BA_MSK)) !=
 185                                                 HT_ADDBA_REQUESTED_MSK) {
 186                 spin_unlock_bh(&sta->lock);
 187                 *state = HT_AGG_STATE_IDLE;
 188 #ifdef CONFIG_MAC80211_HT_DEBUG
 189                 printk(KERN_DEBUG "timer expired on tid %d but we are not "
 190                                 "(or no longer) expecting addBA response there",
 191                         tid);
 192 #endif
 193                 return;
 194         }
 195
 196 #ifdef CONFIG_MAC80211_HT_DEBUG
 197         printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
 198 #endif
 199
 200         ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 201         spin_unlock_bh(&sta->lock);
 202 }
 203
 204 static inline int ieee80211_ac_from_tid(int tid)
 205 {
 206         return ieee802_1d_to_ac[tid & 7];
 207 }
 208
 209 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 210 {
 211         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 212         struct ieee80211_sub_if_data *sdata = sta->sdata;
 213         struct ieee80211_local *local = sdata->local;
 214         u8 *state;
 215         int ret = 0;
 216         u16 start_seq_num;
 217
 218         if (WARN_ON(!local->ops->ampdu_action))
 219                 return -EINVAL;
 220
 221         if ((tid >= STA_TID_NUM) ||
 222             !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION))
 223                 return -EINVAL;
 224
 225 #ifdef CONFIG_MAC80211_HT_DEBUG
 226         printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
 227                pubsta->addr, tid);
 228 #endif /* CONFIG_MAC80211_HT_DEBUG */
 229
 230         /*
 231          * The aggregation code is not prepared to handle
 232          * anything but STA/AP due to the BSSID handling.
 233          * IBSS could work in the code but isn't supported
 234          * by drivers or the standard.
 235          */
 236         if (sdata->vif.type != NL80211_IFTYPE_STATION &&
 237             sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
 238             sdata->vif.type != NL80211_IFTYPE_AP)
 239                 return -EINVAL;
 240
 241         if (test_sta_flags(sta, WLAN_STA_DISASSOC)) {
 242 #ifdef CONFIG_MAC80211_HT_DEBUG
 243                 printk(KERN_DEBUG "Disassociation is in progress. "
 244                        "Denying BA session request\n");
 245 #endif
 246                 return -EINVAL;
 247         }
 248
 249         if (test_sta_flags(sta, WLAN_STA_SUSPEND)) {
 250 #ifdef CONFIG_MAC80211_HT_DEBUG
 251                 printk(KERN_DEBUG "Suspend in progress. "
 252                        "Denying BA session request\n");
 253 #endif
 254                 return -EINVAL;
 255         }
 256
 257         spin_lock_bh(&sta->lock);
 258         spin_lock(&local->ampdu_lock);
 259
 260         /* we have tried too many times, receiver does not want A-MPDU */
 261         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 262                 ret = -EBUSY;
 263                 goto err_unlock_sta;
 264         }
 265
 266         state = &sta->ampdu_mlme.tid_state_tx[tid];
 267         /* check if the TID is not in aggregation flow already */
 268         if (*state != HT_AGG_STATE_IDLE) {
 269 #ifdef CONFIG_MAC80211_HT_DEBUG
 270                 printk(KERN_DEBUG "BA request denied - session is not "
 271                                  "idle on tid %u\n", tid);
 272 #endif /* CONFIG_MAC80211_HT_DEBUG */
 273                 ret = -EAGAIN;
 274                 goto err_unlock_sta;
 275         }
 276
 277         /*
 278          * While we're asking the driver about the aggregation,
 279          * stop the AC queue so that we don't have to worry
 280          * about frames that came in while we were doing that,
 281          * which would require us to put them to the AC pending
 282          * afterwards which just makes the code more complex.
 283          */
 284         ieee80211_stop_queue_by_reason(
 285                 &local->hw, ieee80211_ac_from_tid(tid),
 286                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 287
 288         /* prepare A-MPDU MLME for Tx aggregation */
 289         sta->ampdu_mlme.tid_tx[tid] =
 290                         kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 291         if (!sta->ampdu_mlme.tid_tx[tid]) {
 292 #ifdef CONFIG_MAC80211_HT_DEBUG
 293                 if (net_ratelimit())
 294                         printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
 295                                         tid);
 296 #endif
 297                 ret = -ENOMEM;
 298                 goto err_wake_queue;
 299         }
 300
 301         skb_queue_head_init(&sta->ampdu_mlme.tid_tx[tid]->pending);
 302
 303         /* Tx timer */
 304         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
 305                         sta_addba_resp_timer_expired;
 306         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
 307                         (unsigned long)&sta->timer_to_tid[tid];
 308         init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 309
 310         /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
 311          * call back right away, it must see that the flow has begun */
 312         *state |= HT_ADDBA_REQUESTED_MSK;
 313
 314         start_seq_num = sta->tid_seq[tid] >> 4;
 315
 316         ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
 317                                pubsta, tid, &start_seq_num);
 318
 319         if (ret) {
 320 #ifdef CONFIG_MAC80211_HT_DEBUG
 321                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
 322                                         " tid %d\n", tid);
 323 #endif /* CONFIG_MAC80211_HT_DEBUG */
 324                 *state = HT_AGG_STATE_IDLE;
 325                 goto err_free;
 326         }
 327
 328         /* Driver vetoed or OKed, but we can take packets again now */
 329         ieee80211_wake_queue_by_reason(
 330                 &local->hw, ieee80211_ac_from_tid(tid),
 331                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 332
 333         spin_unlock(&local->ampdu_lock);
 334         spin_unlock_bh(&sta->lock);
 335
 336         /* send an addBA request */
 337         sta->ampdu_mlme.dialog_token_allocator++;
 338         sta->ampdu_mlme.tid_tx[tid]->dialog_token =
 339                         sta->ampdu_mlme.dialog_token_allocator;
 340         sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
 341
 342         ieee80211_send_addba_request(sdata, pubsta->addr, tid,
 343                          sta->ampdu_mlme.tid_tx[tid]->dialog_token,
 344                          sta->ampdu_mlme.tid_tx[tid]->ssn,
 345                          0x40, 5000);
 346         sta->ampdu_mlme.addba_req_num[tid]++;
 347         /* activate the timer for the recipient's addBA response */
 348         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
 349                                 jiffies + ADDBA_RESP_INTERVAL;
 350         add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 351 #ifdef CONFIG_MAC80211_HT_DEBUG
 352         printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
 353 #endif
 354         return 0;
 355
 356  err_free:
 357         kfree(sta->ampdu_mlme.tid_tx[tid]);
 358         sta->ampdu_mlme.tid_tx[tid] = NULL;
 359  err_wake_queue:
 360         ieee80211_wake_queue_by_reason(
 361                 &local->hw, ieee80211_ac_from_tid(tid),
 362                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 363  err_unlock_sta:
 364         spin_unlock(&local->ampdu_lock);
 365         spin_unlock_bh(&sta->lock);
 366         return ret;
 367 }
 368 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
 369
 370 /*
 371  * splice packets from the STA's pending to the local pending,
 372  * requires a call to ieee80211_agg_splice_finish and holding
 373  * local->ampdu_lock across both calls.
 374  */
 375 static void ieee80211_agg_splice_packets(struct ieee80211_local *local,
 376                                          struct sta_info *sta, u16 tid)
 377 {
 378         unsigned long flags;
 379         u16 queue = ieee80211_ac_from_tid(tid);
 380
 381         ieee80211_stop_queue_by_reason(
 382                 &local->hw, queue,
 383                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 384
 385         if (!(sta->ampdu_mlme.tid_state_tx[tid] & HT_ADDBA_REQUESTED_MSK))
 386                 return;
 387
 388         if (WARN(!sta->ampdu_mlme.tid_tx[tid],
 389                  "TID %d gone but expected when splicing aggregates from"
 390                  "the pending queue\n", tid))
 391                 return;
 392
 393         if (!skb_queue_empty(&sta->ampdu_mlme.tid_tx[tid]->pending)) {
 394                 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 395                 /* copy over remaining packets */
 396                 skb_queue_splice_tail_init(
 397                         &sta->ampdu_mlme.tid_tx[tid]->pending,
 398                         &local->pending[queue]);
 399                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 400         }
 401 }
 402
 403 static void ieee80211_agg_splice_finish(struct ieee80211_local *local,
 404                                         struct sta_info *sta, u16 tid)
 405 {
 406         u16 queue = ieee80211_ac_from_tid(tid);
 407
 408         ieee80211_wake_queue_by_reason(
 409                 &local->hw, queue,
 410                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 411 }
 412
 413 /* caller must hold sta->lock */
 414 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
 415                                          struct sta_info *sta, u16 tid)
 416 {
 417 #ifdef CONFIG_MAC80211_HT_DEBUG
 418         printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
 419 #endif
 420
 421         spin_lock(&local->ampdu_lock);
 422         ieee80211_agg_splice_packets(local, sta, tid);
 423         /*
 424          * NB: we rely on sta->lock being taken in the TX
 425          * processing here when adding to the pending queue,
 426          * otherwise we could only change the state of the
 427          * session to OPERATIONAL _here_.
 428          */
 429         ieee80211_agg_splice_finish(local, sta, tid);
 430         spin_unlock(&local->ampdu_lock);
 431
 432         drv_ampdu_action(local, sta->sdata,
 433                          IEEE80211_AMPDU_TX_OPERATIONAL,
 434                          &sta->sta, tid, NULL);
 435 }
 436
 437 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
 438 {
 439         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 440         struct ieee80211_local *local = sdata->local;
 441         struct sta_info *sta;
 442         u8 *state;
 443
 444         if (tid >= STA_TID_NUM) {
 445 #ifdef CONFIG_MAC80211_HT_DEBUG
 446                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 447                                 tid, STA_TID_NUM);
 448 #endif
 449                 return;
 450         }
 451
 452         rcu_read_lock();
 453         sta = sta_info_get(sdata, ra);
 454         if (!sta) {
 455                 rcu_read_unlock();
 456 #ifdef CONFIG_MAC80211_HT_DEBUG
 457                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 458 #endif
 459                 return;
 460         }
 461
 462         state = &sta->ampdu_mlme.tid_state_tx[tid];
 463         spin_lock_bh(&sta->lock);
 464
 465         if (WARN_ON(!(*state & HT_ADDBA_REQUESTED_MSK))) {
 466 #ifdef CONFIG_MAC80211_HT_DEBUG
 467                 printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
 468                                 *state);
 469 #endif
 470                 spin_unlock_bh(&sta->lock);
 471                 rcu_read_unlock();
 472                 return;
 473         }
 474
 475         if (WARN_ON(*state & HT_ADDBA_DRV_READY_MSK))
 476                 goto out;
 477
 478         *state |= HT_ADDBA_DRV_READY_MSK;
 479
 480         if (*state == HT_AGG_STATE_OPERATIONAL)
 481                 ieee80211_agg_tx_operational(local, sta, tid);
 482
 483  out:
 484         spin_unlock_bh(&sta->lock);
 485         rcu_read_unlock();
 486 }
 487 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
 488
 489 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 490                                       const u8 *ra, u16 tid)
 491 {
 492         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 493         struct ieee80211_local *local = sdata->local;
 494         struct ieee80211_ra_tid *ra_tid;
 495         struct sk_buff *skb = dev_alloc_skb(0);
 496
 497         if (unlikely(!skb)) {
 498 #ifdef CONFIG_MAC80211_HT_DEBUG
 499                 if (net_ratelimit())
 500                         printk(KERN_WARNING "%s: Not enough memory, "
 501                                "dropping start BA session", sdata->name);
 502 #endif
 503                 return;
 504         }
 505         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 506         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 507         ra_tid->tid = tid;
 508         ra_tid->vif = vif;
 509
 510         skb->pkt_type = IEEE80211_ADDBA_MSG;
 511         skb_queue_tail(&local->skb_queue, skb);
 512         tasklet_schedule(&local->tasklet);
 513 }
 514 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
 515
 516 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 517                                    enum ieee80211_back_parties initiator)
 518 {
 519         u8 *state;
 520         int ret;
 521
 522         /* check if the TID is in aggregation */
 523         state = &sta->ampdu_mlme.tid_state_tx[tid];
 524         spin_lock_bh(&sta->lock);
 525
 526         if (*state != HT_AGG_STATE_OPERATIONAL) {
 527                 ret = -ENOENT;
 528                 goto unlock;
 529         }
 530
 531         ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator);
 532
 533  unlock:
 534         spin_unlock_bh(&sta->lock);
 535         return ret;
 536 }
 537
 538 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
 539                                  enum ieee80211_back_parties initiator)
 540 {
 541         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 542         struct ieee80211_sub_if_data *sdata = sta->sdata;
 543         struct ieee80211_local *local = sdata->local;
 544
 545         if (!local->ops->ampdu_action)
 546                 return -EINVAL;
 547
 548         if (tid >= STA_TID_NUM)
 549                 return -EINVAL;
 550
 551         return __ieee80211_stop_tx_ba_session(sta, tid, initiator);
 552 }
 553 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
 554
 555 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
 556 {
 557         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 558         struct ieee80211_local *local = sdata->local;
 559         struct sta_info *sta;
 560         u8 *state;
 561
 562         if (tid >= STA_TID_NUM) {
 563 #ifdef CONFIG_MAC80211_HT_DEBUG
 564                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 565                                 tid, STA_TID_NUM);
 566 #endif
 567                 return;
 568         }
 569
 570 #ifdef CONFIG_MAC80211_HT_DEBUG
 571         printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
 572                ra, tid);
 573 #endif /* CONFIG_MAC80211_HT_DEBUG */
 574
 575         rcu_read_lock();
 576         sta = sta_info_get(sdata, ra);
 577         if (!sta) {
 578 #ifdef CONFIG_MAC80211_HT_DEBUG
 579                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 580 #endif
 581                 rcu_read_unlock();
 582                 return;
 583         }
 584         state = &sta->ampdu_mlme.tid_state_tx[tid];
 585
 586         /* NOTE: no need to use sta->lock in this state check, as
 587          * ieee80211_stop_tx_ba_session will let only one stop call to
 588          * pass through per sta/tid
 589          */
 590         if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
 591 #ifdef CONFIG_MAC80211_HT_DEBUG
 592                 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
 593 #endif
 594                 rcu_read_unlock();
 595                 return;
 596         }
 597
 598         if (*state & HT_AGG_STATE_INITIATOR_MSK)
 599                 ieee80211_send_delba(sta->sdata, ra, tid,
 600                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
 601
 602         spin_lock_bh(&sta->lock);
 603         spin_lock(&local->ampdu_lock);
 604
 605         ieee80211_agg_splice_packets(local, sta, tid);
 606
 607         *state = HT_AGG_STATE_IDLE;
 608         /* from now on packets are no longer put onto sta->pending */
 609         kfree(sta->ampdu_mlme.tid_tx[tid]);
 610         sta->ampdu_mlme.tid_tx[tid] = NULL;
 611
 612         ieee80211_agg_splice_finish(local, sta, tid);
 613
 614         spin_unlock(&local->ampdu_lock);
 615         spin_unlock_bh(&sta->lock);
 616
 617         rcu_read_unlock();
 618 }
 619 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
 620
 621 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 622                                      const u8 *ra, u16 tid)
 623 {
 624         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 625         struct ieee80211_local *local = sdata->local;
 626         struct ieee80211_ra_tid *ra_tid;
 627         struct sk_buff *skb = dev_alloc_skb(0);
 628
 629         if (unlikely(!skb)) {
 630 #ifdef CONFIG_MAC80211_HT_DEBUG
 631                 if (net_ratelimit())
 632                         printk(KERN_WARNING "%s: Not enough memory, "
 633                                "dropping stop BA session", sdata->name);
 634 #endif
 635                 return;
 636         }
 637         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 638         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 639         ra_tid->tid = tid;
 640         ra_tid->vif = vif;
 641
 642         skb->pkt_type = IEEE80211_DELBA_MSG;
 643         skb_queue_tail(&local->skb_queue, skb);
 644         tasklet_schedule(&local->tasklet);
 645 }
 646 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
 647
 648
 649 void ieee80211_process_addba_resp(struct ieee80211_local *local,
 650                                   struct sta_info *sta,
 651                                   struct ieee80211_mgmt *mgmt,
 652                                   size_t len)
 653 {
 654         u16 capab, tid;
 655         u8 *state;
 656
 657         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 658         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 659
 660         state = &sta->ampdu_mlme.tid_state_tx[tid];
 661
 662         spin_lock_bh(&sta->lock);
 663
 664         if (!(*state & HT_ADDBA_REQUESTED_MSK))
 665                 goto out;
 666
 667         if (mgmt->u.action.u.addba_resp.dialog_token !=
 668                 sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
 669 #ifdef CONFIG_MAC80211_HT_DEBUG
 670                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 671 #endif /* CONFIG_MAC80211_HT_DEBUG */
 672                 goto out;
 673         }
 674
 675         del_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 676
 677 #ifdef CONFIG_MAC80211_HT_DEBUG
 678         printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
 679 #endif /* CONFIG_MAC80211_HT_DEBUG */
 680
 681         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 682                         == WLAN_STATUS_SUCCESS) {
 683                 u8 curstate = *state;
 684
 685                 *state |= HT_ADDBA_RECEIVED_MSK;
 686
 687                 if (*state != curstate && *state == HT_AGG_STATE_OPERATIONAL)
 688                         ieee80211_agg_tx_operational(local, sta, tid);
 689
 690                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 691         } else {
 692                 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 693         }
 694
 695  out:
 696         spin_unlock_bh(&sta->lock);
 697 }