net/mac80211/agg-tx.c

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This source file includes following definitions.
ieee80211_send_addba_request
ieee80211_send_bar
ieee80211_assign_tid_tx
__acquires
__releases
ieee80211_agg_stop_txq
ieee80211_agg_start_txq
__acquires
__releases
ieee80211_remove_tid_tx
___ieee80211_stop_tx_ba_session
sta_addba_resp_timer_expired
ieee80211_tx_ba_session_handle_start
sta_tx_agg_session_timer_expired
ieee80211_start_tx_ba_session
ieee80211_agg_tx_operational
ieee80211_start_tx_ba_cb
ieee80211_lookup_tid_tx
ieee80211_start_tx_ba_cb_irqsafe
__ieee80211_stop_tx_ba_session
ieee80211_stop_tx_ba_session
ieee80211_stop_tx_ba_cb
ieee80211_stop_tx_ba_cb_irqsafe
ieee80211_process_addba_resp
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * HT handling
   4  *
   5  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   6  * Copyright 2002-2005, Instant802 Networks, Inc.
   7  * Copyright 2005-2006, Devicescape Software, Inc.
   8  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   9  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
  10  * Copyright 2007-2010, Intel Corporation
  11  * Copyright(c) 2015-2017 Intel Deutschland GmbH
  12  * Copyright (C) 2018 - 2019 Intel Corporation
  13  */
  14 
  15 #include <linux/ieee80211.h>
  16 #include <linux/slab.h>
  17 #include <linux/export.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  * Note that the sta can get destroyed before the BA tear down is
  58  * complete.
  59  */
  60 
  61 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
  62                                          const u8 *da, u16 tid,
  63                                          u8 dialog_token, u16 start_seq_num,
  64                                          u16 agg_size, u16 timeout)
  65 {
  66         struct ieee80211_local *local = sdata->local;
  67         struct sk_buff *skb;
  68         struct ieee80211_mgmt *mgmt;
  69         u16 capab;
  70 
  71         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
  72 
  73         if (!skb)
  74                 return;
  75 
  76         skb_reserve(skb, local->hw.extra_tx_headroom);
  77         mgmt = skb_put_zero(skb, 24);
  78         memcpy(mgmt->da, da, ETH_ALEN);
  79         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
  80         if (sdata->vif.type == NL80211_IFTYPE_AP ||
  81             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
  82             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
  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         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
  87                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
  88 
  89         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  90                                           IEEE80211_STYPE_ACTION);
  91 
  92         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
  93 
  94         mgmt->u.action.category = WLAN_CATEGORY_BACK;
  95         mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
  96 
  97         mgmt->u.action.u.addba_req.dialog_token = dialog_token;
  98         capab = (u16)(1 << 0);          /* bit 0 A-MSDU support */
  99         capab |= (u16)(1 << 1);         /* bit 1 aggregation policy */
 100         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 101         capab |= (u16)(agg_size << 6);  /* bit 15:6 max size of aggergation */
 102 
 103         mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
 104 
 105         mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
 106         mgmt->u.action.u.addba_req.start_seq_num =
 107                                         cpu_to_le16(start_seq_num << 4);
 108 
 109         ieee80211_tx_skb(sdata, skb);
 110 }
 111 
 112 void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
 113 {
 114         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 115         struct ieee80211_local *local = sdata->local;
 116         struct sk_buff *skb;
 117         struct ieee80211_bar *bar;
 118         u16 bar_control = 0;
 119 
 120         skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
 121         if (!skb)
 122                 return;
 123 
 124         skb_reserve(skb, local->hw.extra_tx_headroom);
 125         bar = skb_put_zero(skb, sizeof(*bar));
 126         bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
 127                                          IEEE80211_STYPE_BACK_REQ);
 128         memcpy(bar->ra, ra, ETH_ALEN);
 129         memcpy(bar->ta, sdata->vif.addr, ETH_ALEN);
 130         bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
 131         bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
 132         bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT);
 133         bar->control = cpu_to_le16(bar_control);
 134         bar->start_seq_num = cpu_to_le16(ssn);
 135 
 136         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
 137                                         IEEE80211_TX_CTL_REQ_TX_STATUS;
 138         ieee80211_tx_skb_tid(sdata, skb, tid);
 139 }
 140 EXPORT_SYMBOL(ieee80211_send_bar);
 141 
 142 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
 143                              struct tid_ampdu_tx *tid_tx)
 144 {
 145         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 146         lockdep_assert_held(&sta->lock);
 147         rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
 148 }
 149 
 150 /*
 151  * When multiple aggregation sessions on multiple stations
 152  * are being created/destroyed simultaneously, we need to
 153  * refcount the global queue stop caused by that in order
 154  * to not get into a situation where one of the aggregation
 155  * setup or teardown re-enables queues before the other is
 156  * ready to handle that.
 157  *
 158  * These two functions take care of this issue by keeping
 159  * a global "agg_queue_stop" refcount.
 160  */
 161 static void __acquires(agg_queue)
 162 ieee80211_stop_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
 163 {
 164         int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
 165 
 166         /* we do refcounting here, so don't use the queue reason refcounting */
 167 
 168         if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1)
 169                 ieee80211_stop_queue_by_reason(
 170                         &sdata->local->hw, queue,
 171                         IEEE80211_QUEUE_STOP_REASON_AGGREGATION,
 172                         false);
 173         __acquire(agg_queue);
 174 }
 175 
 176 static void __releases(agg_queue)
 177 ieee80211_wake_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
 178 {
 179         int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
 180 
 181         if (atomic_dec_return(&sdata->local->agg_queue_stop[queue]) == 0)
 182                 ieee80211_wake_queue_by_reason(
 183                         &sdata->local->hw, queue,
 184                         IEEE80211_QUEUE_STOP_REASON_AGGREGATION,
 185                         false);
 186         __release(agg_queue);
 187 }
 188 
 189 static void
 190 ieee80211_agg_stop_txq(struct sta_info *sta, int tid)
 191 {
 192         struct ieee80211_txq *txq = sta->sta.txq[tid];
 193         struct ieee80211_sub_if_data *sdata;
 194         struct fq *fq;
 195         struct txq_info *txqi;
 196 
 197         if (!txq)
 198                 return;
 199 
 200         txqi = to_txq_info(txq);
 201         sdata = vif_to_sdata(txq->vif);
 202         fq = &sdata->local->fq;
 203 
 204         /* Lock here to protect against further seqno updates on dequeue */
 205         spin_lock_bh(&fq->lock);
 206         set_bit(IEEE80211_TXQ_STOP, &txqi->flags);
 207         spin_unlock_bh(&fq->lock);
 208 }
 209 
 210 static void
 211 ieee80211_agg_start_txq(struct sta_info *sta, int tid, bool enable)
 212 {
 213         struct ieee80211_txq *txq = sta->sta.txq[tid];
 214         struct txq_info *txqi;
 215 
 216         if (!txq)
 217                 return;
 218 
 219         txqi = to_txq_info(txq);
 220 
 221         if (enable)
 222                 set_bit(IEEE80211_TXQ_AMPDU, &txqi->flags);
 223         else
 224                 clear_bit(IEEE80211_TXQ_AMPDU, &txqi->flags);
 225 
 226         clear_bit(IEEE80211_TXQ_STOP, &txqi->flags);
 227         local_bh_disable();
 228         rcu_read_lock();
 229         schedule_and_wake_txq(sta->sdata->local, txqi);
 230         rcu_read_unlock();
 231         local_bh_enable();
 232 }
 233 
 234 /*
 235  * splice packets from the STA's pending to the local pending,
 236  * requires a call to ieee80211_agg_splice_finish later
 237  */
 238 static void __acquires(agg_queue)
 239 ieee80211_agg_splice_packets(struct ieee80211_sub_if_data *sdata,
 240                              struct tid_ampdu_tx *tid_tx, u16 tid)
 241 {
 242         struct ieee80211_local *local = sdata->local;
 243         int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
 244         unsigned long flags;
 245 
 246         ieee80211_stop_queue_agg(sdata, tid);
 247 
 248         if (WARN(!tid_tx,
 249                  "TID %d gone but expected when splicing aggregates from the pending queue\n",
 250                  tid))
 251                 return;
 252 
 253         if (!skb_queue_empty(&tid_tx->pending)) {
 254                 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 255                 /* copy over remaining packets */
 256                 skb_queue_splice_tail_init(&tid_tx->pending,
 257                                            &local->pending[queue]);
 258                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 259         }
 260 }
 261 
 262 static void __releases(agg_queue)
 263 ieee80211_agg_splice_finish(struct ieee80211_sub_if_data *sdata, u16 tid)
 264 {
 265         ieee80211_wake_queue_agg(sdata, tid);
 266 }
 267 
 268 static void ieee80211_remove_tid_tx(struct sta_info *sta, int tid)
 269 {
 270         struct tid_ampdu_tx *tid_tx;
 271 
 272         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 273         lockdep_assert_held(&sta->lock);
 274 
 275         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 276 
 277         /*
 278          * When we get here, the TX path will not be lockless any more wrt.
 279          * aggregation, since the OPERATIONAL bit has long been cleared.
 280          * Thus it will block on getting the lock, if it occurs. So if we
 281          * stop the queue now, we will not get any more packets, and any
 282          * that might be being processed will wait for us here, thereby
 283          * guaranteeing that no packets go to the tid_tx pending queue any
 284          * more.
 285          */
 286 
 287         ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
 288 
 289         /* future packets must not find the tid_tx struct any more */
 290         ieee80211_assign_tid_tx(sta, tid, NULL);
 291 
 292         ieee80211_agg_splice_finish(sta->sdata, tid);
 293         ieee80211_agg_start_txq(sta, tid, false);
 294 
 295         kfree_rcu(tid_tx, rcu_head);
 296 }
 297 
 298 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 299                                     enum ieee80211_agg_stop_reason reason)
 300 {
 301         struct ieee80211_local *local = sta->local;
 302         struct tid_ampdu_tx *tid_tx;
 303         struct ieee80211_ampdu_params params = {
 304                 .sta = &sta->sta,
 305                 .tid = tid,
 306                 .buf_size = 0,
 307                 .amsdu = false,
 308                 .timeout = 0,
 309                 .ssn = 0,
 310         };
 311         int ret;
 312 
 313         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 314 
 315         switch (reason) {
 316         case AGG_STOP_DECLINED:
 317         case AGG_STOP_LOCAL_REQUEST:
 318         case AGG_STOP_PEER_REQUEST:
 319                 params.action = IEEE80211_AMPDU_TX_STOP_CONT;
 320                 break;
 321         case AGG_STOP_DESTROY_STA:
 322                 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH;
 323                 break;
 324         default:
 325                 WARN_ON_ONCE(1);
 326                 return -EINVAL;
 327         }
 328 
 329         spin_lock_bh(&sta->lock);
 330 
 331         /* free struct pending for start, if present */
 332         tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
 333         kfree(tid_tx);
 334         sta->ampdu_mlme.tid_start_tx[tid] = NULL;
 335 
 336         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 337         if (!tid_tx) {
 338                 spin_unlock_bh(&sta->lock);
 339                 return -ENOENT;
 340         }
 341 
 342         /*
 343          * if we're already stopping ignore any new requests to stop
 344          * unless we're destroying it in which case notify the driver
 345          */
 346         if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
 347                 spin_unlock_bh(&sta->lock);
 348                 if (reason != AGG_STOP_DESTROY_STA)
 349                         return -EALREADY;
 350                 params.action = IEEE80211_AMPDU_TX_STOP_FLUSH_CONT;
 351                 ret = drv_ampdu_action(local, sta->sdata, &params);
 352                 WARN_ON_ONCE(ret);
 353                 return 0;
 354         }
 355 
 356         if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
 357                 /* not even started yet! */
 358                 ieee80211_assign_tid_tx(sta, tid, NULL);
 359                 spin_unlock_bh(&sta->lock);
 360                 kfree_rcu(tid_tx, rcu_head);
 361                 return 0;
 362         }
 363 
 364         set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
 365 
 366         ieee80211_agg_stop_txq(sta, tid);
 367 
 368         spin_unlock_bh(&sta->lock);
 369 
 370         ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n",
 371                sta->sta.addr, tid);
 372 
 373         del_timer_sync(&tid_tx->addba_resp_timer);
 374         del_timer_sync(&tid_tx->session_timer);
 375 
 376         /*
 377          * After this packets are no longer handed right through
 378          * to the driver but are put onto tid_tx->pending instead,
 379          * with locking to ensure proper access.
 380          */
 381         clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
 382 
 383         /*
 384          * There might be a few packets being processed right now (on
 385          * another CPU) that have already gotten past the aggregation
 386          * check when it was still OPERATIONAL and consequently have
 387          * IEEE80211_TX_CTL_AMPDU set. In that case, this code might
 388          * call into the driver at the same time or even before the
 389          * TX paths calls into it, which could confuse the driver.
 390          *
 391          * Wait for all currently running TX paths to finish before
 392          * telling the driver. New packets will not go through since
 393          * the aggregation session is no longer OPERATIONAL.
 394          */
 395         if (!local->in_reconfig)
 396                 synchronize_net();
 397 
 398         tid_tx->stop_initiator = reason == AGG_STOP_PEER_REQUEST ?
 399                                         WLAN_BACK_RECIPIENT :
 400                                         WLAN_BACK_INITIATOR;
 401         tid_tx->tx_stop = reason == AGG_STOP_LOCAL_REQUEST;
 402 
 403         ret = drv_ampdu_action(local, sta->sdata, &params);
 404 
 405         /* HW shall not deny going back to legacy */
 406         if (WARN_ON(ret)) {
 407                 /*
 408                  * We may have pending packets get stuck in this case...
 409                  * Not bothering with a workaround for now.
 410                  */
 411         }
 412 
 413         /*
 414          * In the case of AGG_STOP_DESTROY_STA, the driver won't
 415          * necessarily call ieee80211_stop_tx_ba_cb(), so this may
 416          * seem like we can leave the tid_tx data pending forever.
 417          * This is true, in a way, but "forever" is only until the
 418          * station struct is actually destroyed. In the meantime,
 419          * leaving it around ensures that we don't transmit packets
 420          * to the driver on this TID which might confuse it.
 421          */
 422 
 423         return 0;
 424 }
 425 
 426 /*
 427  * After sending add Block Ack request we activated a timer until
 428  * add Block Ack response will arrive from the recipient.
 429  * If this timer expires sta_addba_resp_timer_expired will be executed.
 430  */
 431 static void sta_addba_resp_timer_expired(struct timer_list *t)
 432 {
 433         struct tid_ampdu_tx *tid_tx = from_timer(tid_tx, t, addba_resp_timer);
 434         struct sta_info *sta = tid_tx->sta;
 435         u8 tid = tid_tx->tid;
 436 
 437         /* check if the TID waits for addBA response */
 438         if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
 439                 ht_dbg(sta->sdata,
 440                        "timer expired on %pM tid %d not expecting addBA response\n",
 441                        sta->sta.addr, tid);
 442                 return;
 443         }
 444 
 445         ht_dbg(sta->sdata, "addBA response timer expired on %pM tid %d\n",
 446                sta->sta.addr, tid);
 447 
 448         ieee80211_stop_tx_ba_session(&sta->sta, tid);
 449 }
 450 
 451 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 452 {
 453         struct tid_ampdu_tx *tid_tx;
 454         struct ieee80211_local *local = sta->local;
 455         struct ieee80211_sub_if_data *sdata = sta->sdata;
 456         struct ieee80211_ampdu_params params = {
 457                 .sta = &sta->sta,
 458                 .action = IEEE80211_AMPDU_TX_START,
 459                 .tid = tid,
 460                 .buf_size = 0,
 461                 .amsdu = false,
 462                 .timeout = 0,
 463         };
 464         int ret;
 465         u16 buf_size;
 466 
 467         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 468 
 469         /*
 470          * Start queuing up packets for this aggregation session.
 471          * We're going to release them once the driver is OK with
 472          * that.
 473          */
 474         clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
 475 
 476         ieee80211_agg_stop_txq(sta, tid);
 477 
 478         /*
 479          * Make sure no packets are being processed. This ensures that
 480          * we have a valid starting sequence number and that in-flight
 481          * packets have been flushed out and no packets for this TID
 482          * will go into the driver during the ampdu_action call.
 483          */
 484         synchronize_net();
 485 
 486         params.ssn = sta->tid_seq[tid] >> 4;
 487         ret = drv_ampdu_action(local, sdata, &params);
 488         if (ret) {
 489                 ht_dbg(sdata,
 490                        "BA request denied - HW unavailable for %pM tid %d\n",
 491                        sta->sta.addr, tid);
 492                 spin_lock_bh(&sta->lock);
 493                 ieee80211_agg_splice_packets(sdata, tid_tx, tid);
 494                 ieee80211_assign_tid_tx(sta, tid, NULL);
 495                 ieee80211_agg_splice_finish(sdata, tid);
 496                 spin_unlock_bh(&sta->lock);
 497 
 498                 ieee80211_agg_start_txq(sta, tid, false);
 499 
 500                 kfree_rcu(tid_tx, rcu_head);
 501                 return;
 502         }
 503 
 504         /* activate the timer for the recipient's addBA response */
 505         mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
 506         ht_dbg(sdata, "activated addBA response timer on %pM tid %d\n",
 507                sta->sta.addr, tid);
 508 
 509         spin_lock_bh(&sta->lock);
 510         sta->ampdu_mlme.last_addba_req_time[tid] = jiffies;
 511         sta->ampdu_mlme.addba_req_num[tid]++;
 512         spin_unlock_bh(&sta->lock);
 513 
 514         if (sta->sta.he_cap.has_he) {
 515                 buf_size = local->hw.max_tx_aggregation_subframes;
 516         } else {
 517                 /*
 518                  * We really should use what the driver told us it will
 519                  * transmit as the maximum, but certain APs (e.g. the
 520                  * LinkSys WRT120N with FW v1.0.07 build 002 Jun 18 2012)
 521                  * will crash when we use a lower number.
 522                  */
 523                 buf_size = IEEE80211_MAX_AMPDU_BUF_HT;
 524         }
 525 
 526         /* send AddBA request */
 527         ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
 528                                      tid_tx->dialog_token, params.ssn,
 529                                      buf_size, tid_tx->timeout);
 530 }
 531 
 532 /*
 533  * After accepting the AddBA Response we activated a timer,
 534  * resetting it after each frame that we send.
 535  */
 536 static void sta_tx_agg_session_timer_expired(struct timer_list *t)
 537 {
 538         struct tid_ampdu_tx *tid_tx = from_timer(tid_tx, t, session_timer);
 539         struct sta_info *sta = tid_tx->sta;
 540         u8 tid = tid_tx->tid;
 541         unsigned long timeout;
 542 
 543         if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
 544                 return;
 545         }
 546 
 547         timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout);
 548         if (time_is_after_jiffies(timeout)) {
 549                 mod_timer(&tid_tx->session_timer, timeout);
 550                 return;
 551         }
 552 
 553         ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n",
 554                sta->sta.addr, tid);
 555 
 556         ieee80211_stop_tx_ba_session(&sta->sta, tid);
 557 }
 558 
 559 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
 560                                   u16 timeout)
 561 {
 562         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 563         struct ieee80211_sub_if_data *sdata = sta->sdata;
 564         struct ieee80211_local *local = sdata->local;
 565         struct tid_ampdu_tx *tid_tx;
 566         int ret = 0;
 567 
 568         trace_api_start_tx_ba_session(pubsta, tid);
 569 
 570         if (WARN(sta->reserved_tid == tid,
 571                  "Requested to start BA session on reserved tid=%d", tid))
 572                 return -EINVAL;
 573 
 574         if (!pubsta->ht_cap.ht_supported)
 575                 return -EINVAL;
 576 
 577         if (WARN_ON_ONCE(!local->ops->ampdu_action))
 578                 return -EINVAL;
 579 
 580         if ((tid >= IEEE80211_NUM_TIDS) ||
 581             !ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION) ||
 582             ieee80211_hw_check(&local->hw, TX_AMPDU_SETUP_IN_HW))
 583                 return -EINVAL;
 584 
 585         if (WARN_ON(tid >= IEEE80211_FIRST_TSPEC_TSID))
 586                 return -EINVAL;
 587 
 588         ht_dbg(sdata, "Open BA session requested for %pM tid %u\n",
 589                pubsta->addr, tid);
 590 
 591         if (sdata->vif.type != NL80211_IFTYPE_STATION &&
 592             sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
 593             sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
 594             sdata->vif.type != NL80211_IFTYPE_AP &&
 595             sdata->vif.type != NL80211_IFTYPE_ADHOC)
 596                 return -EINVAL;
 597 
 598         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 599                 ht_dbg(sdata,
 600                        "BA sessions blocked - Denying BA session request %pM tid %d\n",
 601                        sta->sta.addr, tid);
 602                 return -EINVAL;
 603         }
 604 
 605         /*
 606          * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a
 607          * member of an IBSS, and has no other existing Block Ack agreement
 608          * with the recipient STA, then the initiating STA shall transmit a
 609          * Probe Request frame to the recipient STA and shall not transmit an
 610          * ADDBA Request frame unless it receives a Probe Response frame
 611          * from the recipient within dot11ADDBAFailureTimeout.
 612          *
 613          * The probe request mechanism for ADDBA is currently not implemented,
 614          * but we only build up Block Ack session with HT STAs. This information
 615          * is set when we receive a bss info from a probe response or a beacon.
 616          */
 617         if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 618             !sta->sta.ht_cap.ht_supported) {
 619                 ht_dbg(sdata,
 620                        "BA request denied - IBSS STA %pM does not advertise HT support\n",
 621                        pubsta->addr);
 622                 return -EINVAL;
 623         }
 624 
 625         spin_lock_bh(&sta->lock);
 626 
 627         /* we have tried too many times, receiver does not want A-MPDU */
 628         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 629                 ret = -EBUSY;
 630                 goto err_unlock_sta;
 631         }
 632 
 633         /*
 634          * if we have tried more than HT_AGG_BURST_RETRIES times we
 635          * will spread our requests in time to avoid stalling connection
 636          * for too long
 637          */
 638         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES &&
 639             time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] +
 640                         HT_AGG_RETRIES_PERIOD)) {
 641                 ht_dbg(sdata,
 642                        "BA request denied - %d failed requests on %pM tid %u\n",
 643                        sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, tid);
 644                 ret = -EBUSY;
 645                 goto err_unlock_sta;
 646         }
 647 
 648         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 649         /* check if the TID is not in aggregation flow already */
 650         if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
 651                 ht_dbg(sdata,
 652                        "BA request denied - session is not idle on %pM tid %u\n",
 653                        sta->sta.addr, tid);
 654                 ret = -EAGAIN;
 655                 goto err_unlock_sta;
 656         }
 657 
 658         /* prepare A-MPDU MLME for Tx aggregation */
 659         tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 660         if (!tid_tx) {
 661                 ret = -ENOMEM;
 662                 goto err_unlock_sta;
 663         }
 664 
 665         skb_queue_head_init(&tid_tx->pending);
 666         __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
 667 
 668         tid_tx->timeout = timeout;
 669         tid_tx->sta = sta;
 670         tid_tx->tid = tid;
 671 
 672         /* response timer */
 673         timer_setup(&tid_tx->addba_resp_timer, sta_addba_resp_timer_expired, 0);
 674 
 675         /* tx timer */
 676         timer_setup(&tid_tx->session_timer,
 677                     sta_tx_agg_session_timer_expired, TIMER_DEFERRABLE);
 678 
 679         /* assign a dialog token */
 680         sta->ampdu_mlme.dialog_token_allocator++;
 681         tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
 682 
 683         /*
 684          * Finally, assign it to the start array; the work item will
 685          * collect it and move it to the normal array.
 686          */
 687         sta->ampdu_mlme.tid_start_tx[tid] = tid_tx;
 688 
 689         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 690 
 691         /* this flow continues off the work */
 692  err_unlock_sta:
 693         spin_unlock_bh(&sta->lock);
 694         return ret;
 695 }
 696 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
 697 
 698 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
 699                                          struct sta_info *sta, u16 tid)
 700 {
 701         struct tid_ampdu_tx *tid_tx;
 702         struct ieee80211_ampdu_params params = {
 703                 .sta = &sta->sta,
 704                 .action = IEEE80211_AMPDU_TX_OPERATIONAL,
 705                 .tid = tid,
 706                 .timeout = 0,
 707                 .ssn = 0,
 708         };
 709 
 710         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 711 
 712         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 713         params.buf_size = tid_tx->buf_size;
 714         params.amsdu = tid_tx->amsdu;
 715 
 716         ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n",
 717                sta->sta.addr, tid);
 718 
 719         drv_ampdu_action(local, sta->sdata, &params);
 720 
 721         /*
 722          * synchronize with TX path, while splicing the TX path
 723          * should block so it won't put more packets onto pending.
 724          */
 725         spin_lock_bh(&sta->lock);
 726 
 727         ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
 728         /*
 729          * Now mark as operational. This will be visible
 730          * in the TX path, and lets it go lock-free in
 731          * the common case.
 732          */
 733         set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
 734         ieee80211_agg_splice_finish(sta->sdata, tid);
 735 
 736         spin_unlock_bh(&sta->lock);
 737 
 738         ieee80211_agg_start_txq(sta, tid, true);
 739 }
 740 
 741 void ieee80211_start_tx_ba_cb(struct sta_info *sta, int tid,
 742                               struct tid_ampdu_tx *tid_tx)
 743 {
 744         struct ieee80211_sub_if_data *sdata = sta->sdata;
 745         struct ieee80211_local *local = sdata->local;
 746 
 747         if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
 748                 return;
 749 
 750         if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
 751                 ieee80211_agg_tx_operational(local, sta, tid);
 752 }
 753 
 754 static struct tid_ampdu_tx *
 755 ieee80211_lookup_tid_tx(struct ieee80211_sub_if_data *sdata,
 756                         const u8 *ra, u16 tid, struct sta_info **sta)
 757 {
 758         struct tid_ampdu_tx *tid_tx;
 759 
 760         if (tid >= IEEE80211_NUM_TIDS) {
 761                 ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
 762                        tid, IEEE80211_NUM_TIDS);
 763                 return NULL;
 764         }
 765 
 766         *sta = sta_info_get_bss(sdata, ra);
 767         if (!*sta) {
 768                 ht_dbg(sdata, "Could not find station: %pM\n", ra);
 769                 return NULL;
 770         }
 771 
 772         tid_tx = rcu_dereference((*sta)->ampdu_mlme.tid_tx[tid]);
 773 
 774         if (WARN_ON(!tid_tx))
 775                 ht_dbg(sdata, "addBA was not requested!\n");
 776 
 777         return tid_tx;
 778 }
 779 
 780 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 781                                       const u8 *ra, u16 tid)
 782 {
 783         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 784         struct ieee80211_local *local = sdata->local;
 785         struct sta_info *sta;
 786         struct tid_ampdu_tx *tid_tx;
 787 
 788         trace_api_start_tx_ba_cb(sdata, ra, tid);
 789 
 790         rcu_read_lock();
 791         tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta);
 792         if (!tid_tx)
 793                 goto out;
 794 
 795         set_bit(HT_AGG_STATE_START_CB, &tid_tx->state);
 796         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 797  out:
 798         rcu_read_unlock();
 799 }
 800 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
 801 
 802 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 803                                    enum ieee80211_agg_stop_reason reason)
 804 {
 805         int ret;
 806 
 807         mutex_lock(&sta->ampdu_mlme.mtx);
 808 
 809         ret = ___ieee80211_stop_tx_ba_session(sta, tid, reason);
 810 
 811         mutex_unlock(&sta->ampdu_mlme.mtx);
 812 
 813         return ret;
 814 }
 815 
 816 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 817 {
 818         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 819         struct ieee80211_sub_if_data *sdata = sta->sdata;
 820         struct ieee80211_local *local = sdata->local;
 821         struct tid_ampdu_tx *tid_tx;
 822         int ret = 0;
 823 
 824         trace_api_stop_tx_ba_session(pubsta, tid);
 825 
 826         if (!local->ops->ampdu_action)
 827                 return -EINVAL;
 828 
 829         if (tid >= IEEE80211_NUM_TIDS)
 830                 return -EINVAL;
 831 
 832         spin_lock_bh(&sta->lock);
 833         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 834 
 835         if (!tid_tx) {
 836                 ret = -ENOENT;
 837                 goto unlock;
 838         }
 839 
 840         WARN(sta->reserved_tid == tid,
 841              "Requested to stop BA session on reserved tid=%d", tid);
 842 
 843         if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
 844                 /* already in progress stopping it */
 845                 ret = 0;
 846                 goto unlock;
 847         }
 848 
 849         set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state);
 850         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 851 
 852  unlock:
 853         spin_unlock_bh(&sta->lock);
 854         return ret;
 855 }
 856 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
 857 
 858 void ieee80211_stop_tx_ba_cb(struct sta_info *sta, int tid,
 859                              struct tid_ampdu_tx *tid_tx)
 860 {
 861         struct ieee80211_sub_if_data *sdata = sta->sdata;
 862         bool send_delba = false;
 863 
 864         ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n",
 865                sta->sta.addr, tid);
 866 
 867         spin_lock_bh(&sta->lock);
 868 
 869         if (!test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
 870                 ht_dbg(sdata,
 871                        "unexpected callback to A-MPDU stop for %pM tid %d\n",
 872                        sta->sta.addr, tid);
 873                 goto unlock_sta;
 874         }
 875 
 876         if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop)
 877                 send_delba = true;
 878 
 879         ieee80211_remove_tid_tx(sta, tid);
 880 
 881  unlock_sta:
 882         spin_unlock_bh(&sta->lock);
 883 
 884         if (send_delba)
 885                 ieee80211_send_delba(sdata, sta->sta.addr, tid,
 886                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
 887 }
 888 
 889 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 890                                      const u8 *ra, u16 tid)
 891 {
 892         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 893         struct ieee80211_local *local = sdata->local;
 894         struct sta_info *sta;
 895         struct tid_ampdu_tx *tid_tx;
 896 
 897         trace_api_stop_tx_ba_cb(sdata, ra, tid);
 898 
 899         rcu_read_lock();
 900         tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta);
 901         if (!tid_tx)
 902                 goto out;
 903 
 904         set_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state);
 905         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 906  out:
 907         rcu_read_unlock();
 908 }
 909 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
 910 
 911 
 912 void ieee80211_process_addba_resp(struct ieee80211_local *local,
 913                                   struct sta_info *sta,
 914                                   struct ieee80211_mgmt *mgmt,
 915                                   size_t len)
 916 {
 917         struct tid_ampdu_tx *tid_tx;
 918         struct ieee80211_txq *txq;
 919         u16 capab, tid, buf_size;
 920         bool amsdu;
 921 
 922         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 923         amsdu = capab & IEEE80211_ADDBA_PARAM_AMSDU_MASK;
 924         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 925         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 926         buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes);
 927 
 928         txq = sta->sta.txq[tid];
 929         if (!amsdu && txq)
 930                 set_bit(IEEE80211_TXQ_NO_AMSDU, &to_txq_info(txq)->flags);
 931 
 932         mutex_lock(&sta->ampdu_mlme.mtx);
 933 
 934         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 935         if (!tid_tx)
 936                 goto out;
 937 
 938         if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
 939                 ht_dbg(sta->sdata, "wrong addBA response token, %pM tid %d\n",
 940                        sta->sta.addr, tid);
 941                 goto out;
 942         }
 943 
 944         del_timer_sync(&tid_tx->addba_resp_timer);
 945 
 946         ht_dbg(sta->sdata, "switched off addBA timer for %pM tid %d\n",
 947                sta->sta.addr, tid);
 948 
 949         /*
 950          * addba_resp_timer may have fired before we got here, and
 951          * caused WANT_STOP to be set. If the stop then was already
 952          * processed further, STOPPING might be set.
 953          */
 954         if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) ||
 955             test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
 956                 ht_dbg(sta->sdata,
 957                        "got addBA resp for %pM tid %d but we already gave up\n",
 958                        sta->sta.addr, tid);
 959                 goto out;
 960         }
 961 
 962         /*
 963          * IEEE 802.11-2007 7.3.1.14:
 964          * In an ADDBA Response frame, when the Status Code field
 965          * is set to 0, the Buffer Size subfield is set to a value
 966          * of at least 1.
 967          */
 968         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 969                         == WLAN_STATUS_SUCCESS && buf_size) {
 970                 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
 971                                      &tid_tx->state)) {
 972                         /* ignore duplicate response */
 973                         goto out;
 974                 }
 975 
 976                 tid_tx->buf_size = buf_size;
 977                 tid_tx->amsdu = amsdu;
 978 
 979                 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
 980                         ieee80211_agg_tx_operational(local, sta, tid);
 981 
 982                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 983 
 984                 tid_tx->timeout =
 985                         le16_to_cpu(mgmt->u.action.u.addba_resp.timeout);
 986 
 987                 if (tid_tx->timeout) {
 988                         mod_timer(&tid_tx->session_timer,
 989                                   TU_TO_EXP_TIME(tid_tx->timeout));
 990                         tid_tx->last_tx = jiffies;
 991                 }
 992 
 993         } else {
 994                 ___ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_DECLINED);
 995         }
 996 
 997  out:
 998         mutex_unlock(&sta->ampdu_mlme.mtx);
 999 }
/* [<][>][^][v][top][bottom][index][help] */
root/net/mac80211/agg-tx.c

DEFINITIONS
