net/mac80211/agg-rx.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  * Copyright(c) 2015-2017 Intel Deutschland GmbH
  11  * Copyright (C) 2018        Intel Corporation
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License version 2 as
  15  * published by the Free Software Foundation.
  16  */
  17
  18 /**
  19  * DOC: RX A-MPDU aggregation
  20  *
  21  * Aggregation on the RX side requires only implementing the
  22  * @ampdu_action callback that is invoked to start/stop any
  23  * block-ack sessions for RX aggregation.
  24  *
  25  * When RX aggregation is started by the peer, the driver is
  26  * notified via @ampdu_action function, with the
  27  * %IEEE80211_AMPDU_RX_START action, and may reject the request
  28  * in which case a negative response is sent to the peer, if it
  29  * accepts it a positive response is sent.
  30  *
  31  * While the session is active, the device/driver are required
  32  * to de-aggregate frames and pass them up one by one to mac80211,
  33  * which will handle the reorder buffer.
  34  *
  35  * When the aggregation session is stopped again by the peer or
  36  * ourselves, the driver's @ampdu_action function will be called
  37  * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
  38  * call must not fail.
  39  */
  40
  41 #include <linux/ieee80211.h>
  42 #include <linux/slab.h>
  43 #include <linux/export.h>
  44 #include <net/mac80211.h>
  45 #include "ieee80211_i.h"
  46 #include "driver-ops.h"
  47
  48 static void ieee80211_free_tid_rx(struct rcu_head *h)
  49 {
  50         struct tid_ampdu_rx *tid_rx =
  51                 container_of(h, struct tid_ampdu_rx, rcu_head);
  52         int i;
  53
  54         for (i = 0; i < tid_rx->buf_size; i++)
  55                 __skb_queue_purge(&tid_rx->reorder_buf[i]);
  56         kfree(tid_rx->reorder_buf);
  57         kfree(tid_rx->reorder_time);
  58         kfree(tid_rx);
  59 }
  60
  61 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  62                                      u16 initiator, u16 reason, bool tx)
  63 {
  64         struct ieee80211_local *local = sta->local;
  65         struct tid_ampdu_rx *tid_rx;
  66         struct ieee80211_ampdu_params params = {
  67                 .sta = &sta->sta,
  68                 .action = IEEE80211_AMPDU_RX_STOP,
  69                 .tid = tid,
  70                 .amsdu = false,
  71                 .timeout = 0,
  72                 .ssn = 0,
  73         };
  74
  75         lockdep_assert_held(&sta->ampdu_mlme.mtx);
  76
  77         tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
  78                                         lockdep_is_held(&sta->ampdu_mlme.mtx));
  79
  80         if (!test_bit(tid, sta->ampdu_mlme.agg_session_valid))
  81                 return;
  82
  83         RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
  84         __clear_bit(tid, sta->ampdu_mlme.agg_session_valid);
  85
  86         ht_dbg(sta->sdata,
  87                "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
  88                sta->sta.addr, tid,
  89                initiator == WLAN_BACK_RECIPIENT ? "recipient" : "initiator",
  90                (int)reason);
  91
  92         if (drv_ampdu_action(local, sta->sdata, &params))
  93                 sdata_info(sta->sdata,
  94                            "HW problem - can not stop rx aggregation for %pM tid %d\n",
  95                            sta->sta.addr, tid);
  96
  97         /* check if this is a self generated aggregation halt */
  98         if (initiator == WLAN_BACK_RECIPIENT && tx)
  99                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
 100                                      tid, WLAN_BACK_RECIPIENT, reason);
 101
 102         /*
 103          * return here in case tid_rx is not assigned - which will happen if
 104          * IEEE80211_HW_SUPPORTS_REORDERING_BUFFER is set.
 105          */
 106         if (!tid_rx)
 107                 return;
 108
 109         del_timer_sync(&tid_rx->session_timer);
 110
 111         /* make sure ieee80211_sta_reorder_release() doesn't re-arm the timer */
 112         spin_lock_bh(&tid_rx->reorder_lock);
 113         tid_rx->removed = true;
 114         spin_unlock_bh(&tid_rx->reorder_lock);
 115         del_timer_sync(&tid_rx->reorder_timer);
 116
 117         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
 118 }
 119
 120 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
 121                                     u16 initiator, u16 reason, bool tx)
 122 {
 123         mutex_lock(&sta->ampdu_mlme.mtx);
 124         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
 125         mutex_unlock(&sta->ampdu_mlme.mtx);
 126 }
 127
 128 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
 129                                   const u8 *addr)
 130 {
 131         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 132         struct sta_info *sta;
 133         int i;
 134
 135         rcu_read_lock();
 136         sta = sta_info_get_bss(sdata, addr);
 137         if (!sta) {
 138                 rcu_read_unlock();
 139                 return;
 140         }
 141
 142         for (i = 0; i < IEEE80211_NUM_TIDS; i++)
 143                 if (ba_rx_bitmap & BIT(i))
 144                         set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
 145
 146         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 147         rcu_read_unlock();
 148 }
 149 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
 150
 151 /*
 152  * After accepting the AddBA Request we activated a timer,
 153  * resetting it after each frame that arrives from the originator.
 154  */
 155 static void sta_rx_agg_session_timer_expired(struct timer_list *t)
 156 {
 157         struct tid_ampdu_rx *tid_rx = from_timer(tid_rx, t, session_timer);
 158         struct sta_info *sta = tid_rx->sta;
 159         u8 tid = tid_rx->tid;
 160         unsigned long timeout;
 161
 162         timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
 163         if (time_is_after_jiffies(timeout)) {
 164                 mod_timer(&tid_rx->session_timer, timeout);
 165                 return;
 166         }
 167
 168         ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
 169                sta->sta.addr, tid);
 170
 171         set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
 172         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 173 }
 174
 175 static void sta_rx_agg_reorder_timer_expired(struct timer_list *t)
 176 {
 177         struct tid_ampdu_rx *tid_rx = from_timer(tid_rx, t, reorder_timer);
 178
 179         rcu_read_lock();
 180         ieee80211_release_reorder_timeout(tid_rx->sta, tid_rx->tid);
 181         rcu_read_unlock();
 182 }
 183
 184 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 185                                       u8 dialog_token, u16 status, u16 policy,
 186                                       u16 buf_size, u16 timeout)
 187 {
 188         struct ieee80211_local *local = sdata->local;
 189         struct sk_buff *skb;
 190         struct ieee80211_mgmt *mgmt;
 191         bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
 192         u16 capab;
 193
 194         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 195         if (!skb)
 196                 return;
 197
 198         skb_reserve(skb, local->hw.extra_tx_headroom);
 199         mgmt = skb_put_zero(skb, 24);
 200         memcpy(mgmt->da, da, ETH_ALEN);
 201         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 202         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 203             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 204             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 205                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 206         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 207                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 208         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 209                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 210
 211         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 212                                           IEEE80211_STYPE_ACTION);
 213
 214         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 215         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 216         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 217         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 218
 219         capab = (u16)(amsdu << 0);      /* bit 0 A-MSDU support */
 220         capab |= (u16)(policy << 1);    /* bit 1 aggregation policy */
 221         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 222         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 223
 224         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 225         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 226         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 227
 228         ieee80211_tx_skb(sdata, skb);
 229 }
 230
 231 void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
 232                                       u8 dialog_token, u16 timeout,
 233                                       u16 start_seq_num, u16 ba_policy, u16 tid,
 234                                       u16 buf_size, bool tx, bool auto_seq)
 235 {
 236         struct ieee80211_local *local = sta->sdata->local;
 237         struct tid_ampdu_rx *tid_agg_rx;
 238         struct ieee80211_ampdu_params params = {
 239                 .sta = &sta->sta,
 240                 .action = IEEE80211_AMPDU_RX_START,
 241                 .tid = tid,
 242                 .amsdu = false,
 243                 .timeout = timeout,
 244                 .ssn = start_seq_num,
 245         };
 246         int i, ret = -EOPNOTSUPP;
 247         u16 status = WLAN_STATUS_REQUEST_DECLINED;
 248
 249         if (tid >= IEEE80211_FIRST_TSPEC_TSID) {
 250                 ht_dbg(sta->sdata,
 251                        "STA %pM requests BA session on unsupported tid %d\n",
 252                        sta->sta.addr, tid);
 253                 goto end;
 254         }
 255
 256         if (!sta->sta.ht_cap.ht_supported) {
 257                 ht_dbg(sta->sdata,
 258                        "STA %pM erroneously requests BA session on tid %d w/o QoS\n",
 259                        sta->sta.addr, tid);
 260                 /* send a response anyway, it's an error case if we get here */
 261                 goto end;
 262         }
 263
 264         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 265                 ht_dbg(sta->sdata,
 266                        "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
 267                        sta->sta.addr, tid);
 268                 goto end;
 269         }
 270
 271         /* sanity check for incoming parameters:
 272          * check if configuration can support the BA policy
 273          * and if buffer size does not exceeds max value */
 274         /* XXX: check own ht delayed BA capability?? */
 275         if (((ba_policy != 1) &&
 276              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 277             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 278                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 279                 ht_dbg_ratelimited(sta->sdata,
 280                                    "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
 281                                    sta->sta.addr, tid, ba_policy, buf_size);
 282                 goto end;
 283         }
 284         /* determine default buffer size */
 285         if (buf_size == 0)
 286                 buf_size = IEEE80211_MAX_AMPDU_BUF;
 287
 288         /* make sure the size doesn't exceed the maximum supported by the hw */
 289         if (buf_size > sta->sta.max_rx_aggregation_subframes)
 290                 buf_size = sta->sta.max_rx_aggregation_subframes;
 291         params.buf_size = buf_size;
 292
 293         ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
 294                buf_size, sta->sta.addr);
 295
 296         /* examine state machine */
 297         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 298
 299         if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) {
 300                 if (sta->ampdu_mlme.tid_rx_token[tid] == dialog_token) {
 301                         struct tid_ampdu_rx *tid_rx;
 302
 303                         ht_dbg_ratelimited(sta->sdata,
 304                                            "updated AddBA Req from %pM on tid %u\n",
 305                                            sta->sta.addr, tid);
 306                         /* We have no API to update the timeout value in the
 307                          * driver so reject the timeout update if the timeout
 308                          * changed. If if did not change, i.e., no real update,
 309                          * just reply with success.
 310                          */
 311                         rcu_read_lock();
 312                         tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
 313                         if (tid_rx && tid_rx->timeout == timeout)
 314                                 status = WLAN_STATUS_SUCCESS;
 315                         else
 316                                 status = WLAN_STATUS_REQUEST_DECLINED;
 317                         rcu_read_unlock();
 318                         goto end;
 319                 }
 320
 321                 ht_dbg_ratelimited(sta->sdata,
 322                                    "unexpected AddBA Req from %pM on tid %u\n",
 323                                    sta->sta.addr, tid);
 324
 325                 /* delete existing Rx BA session on the same tid */
 326                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 327                                                 WLAN_STATUS_UNSPECIFIED_QOS,
 328                                                 false);
 329         }
 330
 331         if (ieee80211_hw_check(&local->hw, SUPPORTS_REORDERING_BUFFER)) {
 332                 ret = drv_ampdu_action(local, sta->sdata, &params);
 333                 ht_dbg(sta->sdata,
 334                        "Rx A-MPDU request on %pM tid %d result %d\n",
 335                        sta->sta.addr, tid, ret);
 336                 if (!ret)
 337                         status = WLAN_STATUS_SUCCESS;
 338                 goto end;
 339         }
 340
 341         /* prepare A-MPDU MLME for Rx aggregation */
 342         tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL);
 343         if (!tid_agg_rx)
 344                 goto end;
 345
 346         spin_lock_init(&tid_agg_rx->reorder_lock);
 347
 348         /* rx timer */
 349         timer_setup(&tid_agg_rx->session_timer,
 350                     sta_rx_agg_session_timer_expired, TIMER_DEFERRABLE);
 351
 352         /* rx reorder timer */
 353         timer_setup(&tid_agg_rx->reorder_timer,
 354                     sta_rx_agg_reorder_timer_expired, 0);
 355
 356         /* prepare reordering buffer */
 357         tid_agg_rx->reorder_buf =
 358                 kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
 359         tid_agg_rx->reorder_time =
 360                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
 361         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 362                 kfree(tid_agg_rx->reorder_buf);
 363                 kfree(tid_agg_rx->reorder_time);
 364                 kfree(tid_agg_rx);
 365                 goto end;
 366         }
 367
 368         for (i = 0; i < buf_size; i++)
 369                 __skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
 370
 371         ret = drv_ampdu_action(local, sta->sdata, &params);
 372         ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
 373                sta->sta.addr, tid, ret);
 374         if (ret) {
 375                 kfree(tid_agg_rx->reorder_buf);
 376                 kfree(tid_agg_rx->reorder_time);
 377                 kfree(tid_agg_rx);
 378                 goto end;
 379         }
 380
 381         /* update data */
 382         tid_agg_rx->ssn = start_seq_num;
 383         tid_agg_rx->head_seq_num = start_seq_num;
 384         tid_agg_rx->buf_size = buf_size;
 385         tid_agg_rx->timeout = timeout;
 386         tid_agg_rx->stored_mpdu_num = 0;
 387         tid_agg_rx->auto_seq = auto_seq;
 388         tid_agg_rx->started = false;
 389         tid_agg_rx->reorder_buf_filtered = 0;
 390         tid_agg_rx->tid = tid;
 391         tid_agg_rx->sta = sta;
 392         status = WLAN_STATUS_SUCCESS;
 393
 394         /* activate it for RX */
 395         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
 396
 397         if (timeout) {
 398                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
 399                 tid_agg_rx->last_rx = jiffies;
 400         }
 401
 402 end:
 403         if (status == WLAN_STATUS_SUCCESS) {
 404                 __set_bit(tid, sta->ampdu_mlme.agg_session_valid);
 405                 __clear_bit(tid, sta->ampdu_mlme.unexpected_agg);
 406                 sta->ampdu_mlme.tid_rx_token[tid] = dialog_token;
 407         }
 408
 409         if (tx)
 410                 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 411                                           dialog_token, status, 1, buf_size,
 412                                           timeout);
 413 }
 414
 415 static void __ieee80211_start_rx_ba_session(struct sta_info *sta,
 416                                             u8 dialog_token, u16 timeout,
 417                                             u16 start_seq_num, u16 ba_policy,
 418                                             u16 tid, u16 buf_size, bool tx,
 419                                             bool auto_seq)
 420 {
 421         mutex_lock(&sta->ampdu_mlme.mtx);
 422         ___ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
 423                                          start_seq_num, ba_policy, tid,
 424                                          buf_size, tx, auto_seq);
 425         mutex_unlock(&sta->ampdu_mlme.mtx);
 426 }
 427
 428 void ieee80211_process_addba_request(struct ieee80211_local *local,
 429                                      struct sta_info *sta,
 430                                      struct ieee80211_mgmt *mgmt,
 431                                      size_t len)
 432 {
 433         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
 434         u8 dialog_token;
 435
 436         /* extract session parameters from addba request frame */
 437         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 438         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 439         start_seq_num =
 440                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 441
 442         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 443         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 444         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 445         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 446
 447         __ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
 448                                         start_seq_num, ba_policy, tid,
 449                                         buf_size, true, false);
 450 }
 451
 452 void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,
 453                                  const u8 *addr, unsigned int tid)
 454 {
 455         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 456         struct ieee80211_local *local = sdata->local;
 457         struct sta_info *sta;
 458
 459         rcu_read_lock();
 460         sta = sta_info_get_bss(sdata, addr);
 461         if (!sta)
 462                 goto unlock;
 463
 464         set_bit(tid, sta->ampdu_mlme.tid_rx_manage_offl);
 465         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 466  unlock:
 467         rcu_read_unlock();
 468 }
 469 EXPORT_SYMBOL(ieee80211_manage_rx_ba_offl);
 470
 471 void ieee80211_rx_ba_timer_expired(struct ieee80211_vif *vif,
 472                                    const u8 *addr, unsigned int tid)
 473 {
 474         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 475         struct ieee80211_local *local = sdata->local;
 476         struct sta_info *sta;
 477
 478         rcu_read_lock();
 479         sta = sta_info_get_bss(sdata, addr);
 480         if (!sta)
 481                 goto unlock;
 482
 483         set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
 484         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 485
 486  unlock:
 487         rcu_read_unlock();
 488 }
 489 EXPORT_SYMBOL(ieee80211_rx_ba_timer_expired);