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  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  */
  16
  17 /**
  18  * DOC: RX A-MPDU aggregation
  19  *
  20  * Aggregation on the RX side requires only implementing the
  21  * @ampdu_action callback that is invoked to start/stop any
  22  * block-ack sessions for RX aggregation.
  23  *
  24  * When RX aggregation is started by the peer, the driver is
  25  * notified via @ampdu_action function, with the
  26  * %IEEE80211_AMPDU_RX_START action, and may reject the request
  27  * in which case a negative response is sent to the peer, if it
  28  * accepts it a positive response is sent.
  29  *
  30  * While the session is active, the device/driver are required
  31  * to de-aggregate frames and pass them up one by one to mac80211,
  32  * which will handle the reorder buffer.
  33  *
  34  * When the aggregation session is stopped again by the peer or
  35  * ourselves, the driver's @ampdu_action function will be called
  36  * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
  37  * call must not fail.
  38  */
  39
  40 #include <linux/ieee80211.h>
  41 #include <linux/slab.h>
  42 #include <linux/export.h>
  43 #include <net/mac80211.h>
  44 #include "ieee80211_i.h"
  45 #include "driver-ops.h"
  46
  47 static void ieee80211_free_tid_rx(struct rcu_head *h)
  48 {
  49         struct tid_ampdu_rx *tid_rx =
  50                 container_of(h, struct tid_ampdu_rx, rcu_head);
  51         int i;
  52
  53         for (i = 0; i < tid_rx->buf_size; i++)
  54                 __skb_queue_purge(&tid_rx->reorder_buf[i]);
  55         kfree(tid_rx->reorder_buf);
  56         kfree(tid_rx->reorder_time);
  57         kfree(tid_rx);
  58 }
  59
  60 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  61                                      u16 initiator, u16 reason, bool tx)
  62 {
  63         struct ieee80211_local *local = sta->local;
  64         struct tid_ampdu_rx *tid_rx;
  65         struct ieee80211_ampdu_params params = {
  66                 .sta = &sta->sta,
  67                 .action = IEEE80211_AMPDU_RX_STOP,
  68                 .tid = tid,
  69                 .amsdu = false,
  70                 .timeout = 0,
  71                 .ssn = 0,
  72         };
  73
  74         lockdep_assert_held(&sta->ampdu_mlme.mtx);
  75
  76         tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
  77                                         lockdep_is_held(&sta->ampdu_mlme.mtx));
  78
  79         if (!test_bit(tid, sta->ampdu_mlme.agg_session_valid))
  80                 return;
  81
  82         RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
  83         __clear_bit(tid, sta->ampdu_mlme.agg_session_valid);
  84
  85         ht_dbg(sta->sdata,
  86                "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
  87                sta->sta.addr, tid,
  88                initiator == WLAN_BACK_RECIPIENT ? "recipient" : "initiator",
  89                (int)reason);
  90
  91         if (drv_ampdu_action(local, sta->sdata, &params))
  92                 sdata_info(sta->sdata,
  93                            "HW problem - can not stop rx aggregation for %pM tid %d\n",
  94                            sta->sta.addr, tid);
  95
  96         /* check if this is a self generated aggregation halt */
  97         if (initiator == WLAN_BACK_RECIPIENT && tx)
  98                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
  99                                      tid, WLAN_BACK_RECIPIENT, reason);
 100
 101         /*
 102          * return here in case tid_rx is not assigned - which will happen if
 103          * IEEE80211_HW_SUPPORTS_REORDERING_BUFFER is set.
 104          */
 105         if (!tid_rx)
 106                 return;
 107
 108         del_timer_sync(&tid_rx->session_timer);
 109
 110         /* make sure ieee80211_sta_reorder_release() doesn't re-arm the timer */
 111         spin_lock_bh(&tid_rx->reorder_lock);
 112         tid_rx->removed = true;
 113         spin_unlock_bh(&tid_rx->reorder_lock);
 114         del_timer_sync(&tid_rx->reorder_timer);
 115
 116         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
 117 }
 118
 119 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
 120                                     u16 initiator, u16 reason, bool tx)
 121 {
 122         mutex_lock(&sta->ampdu_mlme.mtx);
 123         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
 124         mutex_unlock(&sta->ampdu_mlme.mtx);
 125 }
 126
 127 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
 128                                   const u8 *addr)
 129 {
 130         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 131         struct sta_info *sta;
 132         int i;
 133
 134         rcu_read_lock();
 135         sta = sta_info_get_bss(sdata, addr);
 136         if (!sta) {
 137                 rcu_read_unlock();
 138                 return;
 139         }
 140
 141         for (i = 0; i < IEEE80211_NUM_TIDS; i++)
 142                 if (ba_rx_bitmap & BIT(i))
 143                         set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
 144
 145         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 146         rcu_read_unlock();
 147 }
 148 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
 149
 150 /*
 151  * After accepting the AddBA Request we activated a timer,
 152  * resetting it after each frame that arrives from the originator.
 153  */
 154 static void sta_rx_agg_session_timer_expired(struct timer_list *t)
 155 {
 156         struct tid_ampdu_rx *tid_rx_timer =
 157                 from_timer(tid_rx_timer, t, session_timer);
 158         struct sta_info *sta = tid_rx_timer->sta;
 159         u8 tid = tid_rx_timer->tid;
 160         struct tid_ampdu_rx *tid_rx;
 161         unsigned long timeout;
 162
 163         rcu_read_lock();
 164         tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
 165         if (!tid_rx) {
 166                 rcu_read_unlock();
 167                 return;
 168         }
 169
 170         timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
 171         if (time_is_after_jiffies(timeout)) {
 172                 mod_timer(&tid_rx->session_timer, timeout);
 173                 rcu_read_unlock();
 174                 return;
 175         }
 176         rcu_read_unlock();
 177
 178         ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
 179                sta->sta.addr, tid);
 180
 181         set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
 182         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 183 }
 184
 185 static void sta_rx_agg_reorder_timer_expired(struct timer_list *t)
 186 {
 187         struct tid_ampdu_rx *tid_rx = from_timer(tid_rx, t, reorder_timer);
 188
 189         rcu_read_lock();
 190         ieee80211_release_reorder_timeout(tid_rx->sta, tid_rx->tid);
 191         rcu_read_unlock();
 192 }
 193
 194 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 195                                       u8 dialog_token, u16 status, u16 policy,
 196                                       u16 buf_size, u16 timeout)
 197 {
 198         struct ieee80211_local *local = sdata->local;
 199         struct sk_buff *skb;
 200         struct ieee80211_mgmt *mgmt;
 201         bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
 202         u16 capab;
 203
 204         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 205         if (!skb)
 206                 return;
 207
 208         skb_reserve(skb, local->hw.extra_tx_headroom);
 209         mgmt = skb_put_zero(skb, 24);
 210         memcpy(mgmt->da, da, ETH_ALEN);
 211         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 212         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 213             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 214             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 215                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 216         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 217                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 218         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 219                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 220
 221         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 222                                           IEEE80211_STYPE_ACTION);
 223
 224         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 225         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 226         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 227         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 228
 229         capab = (u16)(amsdu << 0);      /* bit 0 A-MSDU support */
 230         capab |= (u16)(policy << 1);    /* bit 1 aggregation policy */
 231         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 232         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 233
 234         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 235         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 236         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 237
 238         ieee80211_tx_skb(sdata, skb);
 239 }
 240
 241 void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
 242                                       u8 dialog_token, u16 timeout,
 243                                       u16 start_seq_num, u16 ba_policy, u16 tid,
 244                                       u16 buf_size, bool tx, bool auto_seq)
 245 {
 246         struct ieee80211_local *local = sta->sdata->local;
 247         struct tid_ampdu_rx *tid_agg_rx;
 248         struct ieee80211_ampdu_params params = {
 249                 .sta = &sta->sta,
 250                 .action = IEEE80211_AMPDU_RX_START,
 251                 .tid = tid,
 252                 .amsdu = false,
 253                 .timeout = timeout,
 254                 .ssn = start_seq_num,
 255         };
 256         int i, ret = -EOPNOTSUPP;
 257         u16 status = WLAN_STATUS_REQUEST_DECLINED;
 258
 259         if (tid >= IEEE80211_FIRST_TSPEC_TSID) {
 260                 ht_dbg(sta->sdata,
 261                        "STA %pM requests BA session on unsupported tid %d\n",
 262                        sta->sta.addr, tid);
 263                 goto end;
 264         }
 265
 266         if (!sta->sta.ht_cap.ht_supported) {
 267                 ht_dbg(sta->sdata,
 268                        "STA %pM erroneously requests BA session on tid %d w/o QoS\n",
 269                        sta->sta.addr, tid);
 270                 /* send a response anyway, it's an error case if we get here */
 271                 goto end;
 272         }
 273
 274         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 275                 ht_dbg(sta->sdata,
 276                        "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
 277                        sta->sta.addr, tid);
 278                 goto end;
 279         }
 280
 281         /* sanity check for incoming parameters:
 282          * check if configuration can support the BA policy
 283          * and if buffer size does not exceeds max value */
 284         /* XXX: check own ht delayed BA capability?? */
 285         if (((ba_policy != 1) &&
 286              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 287             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 288                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 289                 ht_dbg_ratelimited(sta->sdata,
 290                                    "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
 291                                    sta->sta.addr, tid, ba_policy, buf_size);
 292                 goto end;
 293         }
 294         /* determine default buffer size */
 295         if (buf_size == 0)
 296                 buf_size = IEEE80211_MAX_AMPDU_BUF;
 297
 298         /* make sure the size doesn't exceed the maximum supported by the hw */
 299         if (buf_size > sta->sta.max_rx_aggregation_subframes)
 300                 buf_size = sta->sta.max_rx_aggregation_subframes;
 301         params.buf_size = buf_size;
 302
 303         ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
 304                buf_size, sta->sta.addr);
 305
 306         /* examine state machine */
 307         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 308
 309         if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) {
 310                 if (sta->ampdu_mlme.tid_rx_token[tid] == dialog_token) {
 311                         ht_dbg_ratelimited(sta->sdata,
 312                                            "updated AddBA Req from %pM on tid %u\n",
 313                                            sta->sta.addr, tid);
 314                         /* We have no API to update the timeout value in the
 315                          * driver so reject the timeout update.
 316                          */
 317                         status = WLAN_STATUS_REQUEST_DECLINED;
 318                         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr,
 319                                                   tid, dialog_token, status,
 320                                                   1, buf_size, timeout);
 321                         goto end;
 322                 }
 323
 324                 ht_dbg_ratelimited(sta->sdata,
 325                                    "unexpected AddBA Req from %pM on tid %u\n",
 326                                    sta->sta.addr, tid);
 327
 328                 /* delete existing Rx BA session on the same tid */
 329                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 330                                                 WLAN_STATUS_UNSPECIFIED_QOS,
 331                                                 false);
 332         }
 333
 334         if (ieee80211_hw_check(&local->hw, SUPPORTS_REORDERING_BUFFER)) {
 335                 ret = drv_ampdu_action(local, sta->sdata, &params);
 336                 ht_dbg(sta->sdata,
 337                        "Rx A-MPDU request on %pM tid %d result %d\n",
 338                        sta->sta.addr, tid, ret);
 339                 if (!ret)
 340                         status = WLAN_STATUS_SUCCESS;
 341                 goto end;
 342         }
 343
 344         /* prepare A-MPDU MLME for Rx aggregation */
 345         tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL);
 346         if (!tid_agg_rx)
 347                 goto end;
 348
 349         spin_lock_init(&tid_agg_rx->reorder_lock);
 350
 351         /* rx timer */
 352         timer_setup(&tid_agg_rx->session_timer,
 353                     sta_rx_agg_session_timer_expired, TIMER_DEFERRABLE);
 354
 355         /* rx reorder timer */
 356         timer_setup(&tid_agg_rx->reorder_timer,
 357                     sta_rx_agg_reorder_timer_expired, 0);
 358
 359         /* prepare reordering buffer */
 360         tid_agg_rx->reorder_buf =
 361                 kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
 362         tid_agg_rx->reorder_time =
 363                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
 364         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 365                 kfree(tid_agg_rx->reorder_buf);
 366                 kfree(tid_agg_rx->reorder_time);
 367                 kfree(tid_agg_rx);
 368                 goto end;
 369         }
 370
 371         for (i = 0; i < buf_size; i++)
 372                 __skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
 373
 374         ret = drv_ampdu_action(local, sta->sdata, &params);
 375         ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
 376                sta->sta.addr, tid, ret);
 377         if (ret) {
 378                 kfree(tid_agg_rx->reorder_buf);
 379                 kfree(tid_agg_rx->reorder_time);
 380                 kfree(tid_agg_rx);
 381                 goto end;
 382         }
 383
 384         /* update data */
 385         tid_agg_rx->ssn = start_seq_num;
 386         tid_agg_rx->head_seq_num = start_seq_num;
 387         tid_agg_rx->buf_size = buf_size;
 388         tid_agg_rx->timeout = timeout;
 389         tid_agg_rx->stored_mpdu_num = 0;
 390         tid_agg_rx->auto_seq = auto_seq;
 391         tid_agg_rx->started = false;
 392         tid_agg_rx->reorder_buf_filtered = 0;
 393         tid_agg_rx->tid = tid;
 394         tid_agg_rx->sta = sta;
 395         status = WLAN_STATUS_SUCCESS;
 396
 397         /* activate it for RX */
 398         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
 399
 400         if (timeout) {
 401                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
 402                 tid_agg_rx->last_rx = jiffies;
 403         }
 404
 405 end:
 406         if (status == WLAN_STATUS_SUCCESS) {
 407                 __set_bit(tid, sta->ampdu_mlme.agg_session_valid);
 408                 __clear_bit(tid, sta->ampdu_mlme.unexpected_agg);
 409                 sta->ampdu_mlme.tid_rx_token[tid] = dialog_token;
 410         }
 411
 412         if (tx)
 413                 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 414                                           dialog_token, status, 1, buf_size,
 415                                           timeout);
 416 }
 417
 418 void __ieee80211_start_rx_ba_session(struct sta_info *sta,
 419                                      u8 dialog_token, u16 timeout,
 420                                      u16 start_seq_num, u16 ba_policy, u16 tid,
 421                                      u16 buf_size, bool tx, bool auto_seq)
 422 {
 423         mutex_lock(&sta->ampdu_mlme.mtx);
 424         ___ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
 425                                          start_seq_num, ba_policy, tid,
 426                                          buf_size, tx, auto_seq);
 427         mutex_unlock(&sta->ampdu_mlme.mtx);
 428 }
 429
 430 void ieee80211_process_addba_request(struct ieee80211_local *local,
 431                                      struct sta_info *sta,
 432                                      struct ieee80211_mgmt *mgmt,
 433                                      size_t len)
 434 {
 435         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
 436         u8 dialog_token;
 437
 438         /* extract session parameters from addba request frame */
 439         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 440         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 441         start_seq_num =
 442                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 443
 444         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 445         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 446         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 447         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 448
 449         __ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
 450                                         start_seq_num, ba_policy, tid,
 451                                         buf_size, true, false);
 452 }
 453
 454 void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,
 455                                  const u8 *addr, unsigned int tid)
 456 {
 457         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 458         struct ieee80211_local *local = sdata->local;
 459         struct sta_info *sta;
 460
 461         rcu_read_lock();
 462         sta = sta_info_get_bss(sdata, addr);
 463         if (!sta)
 464                 goto unlock;
 465
 466         set_bit(tid, sta->ampdu_mlme.tid_rx_manage_offl);
 467         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 468  unlock:
 469         rcu_read_unlock();
 470 }
 471 EXPORT_SYMBOL(ieee80211_manage_rx_ba_offl);
 472
 473 void ieee80211_rx_ba_timer_expired(struct ieee80211_vif *vif,
 474                                    const u8 *addr, unsigned int tid)
 475 {
 476         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 477         struct ieee80211_local *local = sdata->local;
 478         struct sta_info *sta;
 479
 480         rcu_read_lock();
 481         sta = sta_info_get_bss(sdata, addr);
 482         if (!sta)
 483                 goto unlock;
 484
 485         set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
 486         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 487
 488  unlock:
 489         rcu_read_unlock();
 490 }
 491 EXPORT_SYMBOL(ieee80211_rx_ba_timer_expired);