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