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(unsigned long data)
 156 {
 157         /* not an elegant detour, but there is no choice as the timer passes
 158          * only one argument, and various sta_info are needed here, so init
 159          * flow in sta_info_create gives the TID as data, while the timer_to_id
 160          * array gives the sta through container_of */
 161         u8 *ptid = (u8 *)data;
 162         u8 *timer_to_id = ptid - *ptid;
 163         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 164                                          timer_to_tid[0]);
 165         struct tid_ampdu_rx *tid_rx;
 166         unsigned long timeout;
 167
 168         rcu_read_lock();
 169         tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
 170         if (!tid_rx) {
 171                 rcu_read_unlock();
 172                 return;
 173         }
 174
 175         timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
 176         if (time_is_after_jiffies(timeout)) {
 177                 mod_timer(&tid_rx->session_timer, timeout);
 178                 rcu_read_unlock();
 179                 return;
 180         }
 181         rcu_read_unlock();
 182
 183         ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
 184                sta->sta.addr, (u16)*ptid);
 185
 186         set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
 187         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 188 }
 189
 190 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
 191 {
 192         u8 *ptid = (u8 *)data;
 193         u8 *timer_to_id = ptid - *ptid;
 194         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 195                         timer_to_tid[0]);
 196
 197         rcu_read_lock();
 198         ieee80211_release_reorder_timeout(sta, *ptid);
 199         rcu_read_unlock();
 200 }
 201
 202 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 203                                       u8 dialog_token, u16 status, u16 policy,
 204                                       u16 buf_size, u16 timeout)
 205 {
 206         struct ieee80211_local *local = sdata->local;
 207         struct sk_buff *skb;
 208         struct ieee80211_mgmt *mgmt;
 209         bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
 210         u16 capab;
 211
 212         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 213         if (!skb)
 214                 return;
 215
 216         skb_reserve(skb, local->hw.extra_tx_headroom);
 217         mgmt = skb_put_zero(skb, 24);
 218         memcpy(mgmt->da, da, ETH_ALEN);
 219         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 220         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 221             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 222             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 223                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 224         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 225                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 226         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 227                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 228
 229         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 230                                           IEEE80211_STYPE_ACTION);
 231
 232         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 233         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 234         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 235         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 236
 237         capab = (u16)(amsdu << 0);      /* bit 0 A-MSDU support */
 238         capab |= (u16)(policy << 1);    /* bit 1 aggregation policy */
 239         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 240         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 241
 242         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 243         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 244         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 245
 246         ieee80211_tx_skb(sdata, skb);
 247 }
 248
 249 void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
 250                                       u8 dialog_token, u16 timeout,
 251                                       u16 start_seq_num, u16 ba_policy, u16 tid,
 252                                       u16 buf_size, bool tx, bool auto_seq)
 253 {
 254         struct ieee80211_local *local = sta->sdata->local;
 255         struct tid_ampdu_rx *tid_agg_rx;
 256         struct ieee80211_ampdu_params params = {
 257                 .sta = &sta->sta,
 258                 .action = IEEE80211_AMPDU_RX_START,
 259                 .tid = tid,
 260                 .amsdu = false,
 261                 .timeout = timeout,
 262                 .ssn = start_seq_num,
 263         };
 264         int i, ret = -EOPNOTSUPP;
 265         u16 status = WLAN_STATUS_REQUEST_DECLINED;
 266
 267         if (tid >= IEEE80211_FIRST_TSPEC_TSID) {
 268                 ht_dbg(sta->sdata,
 269                        "STA %pM requests BA session on unsupported tid %d\n",
 270                        sta->sta.addr, tid);
 271                 goto end;
 272         }
 273
 274         if (!sta->sta.ht_cap.ht_supported) {
 275                 ht_dbg(sta->sdata,
 276                        "STA %pM erroneously requests BA session on tid %d w/o QoS\n",
 277                        sta->sta.addr, tid);
 278                 /* send a response anyway, it's an error case if we get here */
 279                 goto end;
 280         }
 281
 282         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 283                 ht_dbg(sta->sdata,
 284                        "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
 285                        sta->sta.addr, tid);
 286                 goto end;
 287         }
 288
 289         /* sanity check for incoming parameters:
 290          * check if configuration can support the BA policy
 291          * and if buffer size does not exceeds max value */
 292         /* XXX: check own ht delayed BA capability?? */
 293         if (((ba_policy != 1) &&
 294              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 295             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 296                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 297                 ht_dbg_ratelimited(sta->sdata,
 298                                    "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
 299                                    sta->sta.addr, tid, ba_policy, buf_size);
 300                 goto end;
 301         }
 302         /* determine default buffer size */
 303         if (buf_size == 0)
 304                 buf_size = IEEE80211_MAX_AMPDU_BUF;
 305
 306         /* make sure the size doesn't exceed the maximum supported by the hw */
 307         if (buf_size > sta->sta.max_rx_aggregation_subframes)
 308                 buf_size = sta->sta.max_rx_aggregation_subframes;
 309         params.buf_size = buf_size;
 310
 311         ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
 312                buf_size, sta->sta.addr);
 313
 314         /* examine state machine */
 315         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 316
 317         if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) {
 318                 if (sta->ampdu_mlme.tid_rx_token[tid] == dialog_token) {
 319                         ht_dbg_ratelimited(sta->sdata,
 320                                            "updated AddBA Req from %pM on tid %u\n",
 321                                            sta->sta.addr, tid);
 322                         /* We have no API to update the timeout value in the
 323                          * driver so reject the timeout update.
 324                          */
 325                         status = WLAN_STATUS_REQUEST_DECLINED;
 326                         goto end;
 327                 }
 328
 329                 ht_dbg_ratelimited(sta->sdata,
 330                                    "unexpected AddBA Req from %pM on tid %u\n",
 331                                    sta->sta.addr, tid);
 332
 333                 /* delete existing Rx BA session on the same tid */
 334                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 335                                                 WLAN_STATUS_UNSPECIFIED_QOS,
 336                                                 false);
 337         }
 338
 339         if (ieee80211_hw_check(&local->hw, SUPPORTS_REORDERING_BUFFER)) {
 340                 ret = drv_ampdu_action(local, sta->sdata, &params);
 341                 ht_dbg(sta->sdata,
 342                        "Rx A-MPDU request on %pM tid %d result %d\n",
 343                        sta->sta.addr, tid, ret);
 344                 if (!ret)
 345                         status = WLAN_STATUS_SUCCESS;
 346                 goto end;
 347         }
 348
 349         /* prepare A-MPDU MLME for Rx aggregation */
 350         tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL);
 351         if (!tid_agg_rx)
 352                 goto end;
 353
 354         spin_lock_init(&tid_agg_rx->reorder_lock);
 355
 356         /* rx timer */
 357         setup_deferrable_timer(&tid_agg_rx->session_timer,
 358                                sta_rx_agg_session_timer_expired,
 359                                (unsigned long)&sta->timer_to_tid[tid]);
 360
 361         /* rx reorder timer */
 362         setup_timer(&tid_agg_rx->reorder_timer,
 363                     sta_rx_agg_reorder_timer_expired,
 364                     (unsigned long)&sta->timer_to_tid[tid]);
 365
 366         /* prepare reordering buffer */
 367         tid_agg_rx->reorder_buf =
 368                 kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
 369         tid_agg_rx->reorder_time =
 370                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
 371         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 372                 kfree(tid_agg_rx->reorder_buf);
 373                 kfree(tid_agg_rx->reorder_time);
 374                 kfree(tid_agg_rx);
 375                 goto end;
 376         }
 377
 378         for (i = 0; i < buf_size; i++)
 379                 __skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
 380
 381         ret = drv_ampdu_action(local, sta->sdata, &params);
 382         ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
 383                sta->sta.addr, tid, ret);
 384         if (ret) {
 385                 kfree(tid_agg_rx->reorder_buf);
 386                 kfree(tid_agg_rx->reorder_time);
 387                 kfree(tid_agg_rx);
 388                 goto end;
 389         }
 390
 391         /* update data */
 392         tid_agg_rx->ssn = start_seq_num;
 393         tid_agg_rx->head_seq_num = start_seq_num;
 394         tid_agg_rx->buf_size = buf_size;
 395         tid_agg_rx->timeout = timeout;
 396         tid_agg_rx->stored_mpdu_num = 0;
 397         tid_agg_rx->auto_seq = auto_seq;
 398         tid_agg_rx->started = false;
 399         tid_agg_rx->reorder_buf_filtered = 0;
 400         status = WLAN_STATUS_SUCCESS;
 401
 402         /* activate it for RX */
 403         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
 404
 405         if (timeout) {
 406                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
 407                 tid_agg_rx->last_rx = jiffies;
 408         }
 409
 410 end:
 411         if (status == WLAN_STATUS_SUCCESS) {
 412                 __set_bit(tid, sta->ampdu_mlme.agg_session_valid);
 413                 __clear_bit(tid, sta->ampdu_mlme.unexpected_agg);
 414                 sta->ampdu_mlme.tid_rx_token[tid] = dialog_token;
 415         }
 416
 417         if (tx)
 418                 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 419                                           dialog_token, status, 1, buf_size,
 420                                           timeout);
 421 }
 422
 423 void __ieee80211_start_rx_ba_session(struct sta_info *sta,
 424                                      u8 dialog_token, u16 timeout,
 425                                      u16 start_seq_num, u16 ba_policy, u16 tid,
 426                                      u16 buf_size, bool tx, bool auto_seq)
 427 {
 428         mutex_lock(&sta->ampdu_mlme.mtx);
 429         ___ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
 430                                          start_seq_num, ba_policy, tid,
 431                                          buf_size, tx, auto_seq);
 432         mutex_unlock(&sta->ampdu_mlme.mtx);
 433 }
 434
 435 void ieee80211_process_addba_request(struct ieee80211_local *local,
 436                                      struct sta_info *sta,
 437                                      struct ieee80211_mgmt *mgmt,
 438                                      size_t len)
 439 {
 440         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
 441         u8 dialog_token;
 442
 443         /* extract session parameters from addba request frame */
 444         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 445         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 446         start_seq_num =
 447                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 448
 449         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 450         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 451         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 452         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 453
 454         __ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
 455                                         start_seq_num, ba_policy, tid,
 456                                         buf_size, true, false);
 457 }
 458
 459 void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,
 460                                  const u8 *addr, unsigned int bit)
 461 {
 462         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 463         struct ieee80211_local *local = sdata->local;
 464         struct sta_info *sta;
 465
 466         rcu_read_lock();
 467         sta = sta_info_get_bss(sdata, addr);
 468         if (!sta)
 469                 goto unlock;
 470
 471         set_bit(bit, sta->ampdu_mlme.tid_rx_manage_offl);
 472         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 473  unlock:
 474         rcu_read_unlock();
 475 }
 476 EXPORT_SYMBOL(ieee80211_manage_rx_ba_offl);
 477
 478 void ieee80211_rx_ba_timer_expired(struct ieee80211_vif *vif,
 479                                    const u8 *addr, unsigned int tid)
 480 {
 481         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 482         struct ieee80211_local *local = sdata->local;
 483         struct sta_info *sta;
 484
 485         rcu_read_lock();
 486         sta = sta_info_get_bss(sdata, addr);
 487         if (!sta)
 488                 goto unlock;
 489
 490         set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
 491         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 492
 493  unlock:
 494         rcu_read_unlock();
 495 }
 496 EXPORT_SYMBOL(ieee80211_rx_ba_timer_expired);