net/mac80211/agg-rx.c

   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        Intel Corporation
  13  */
  14
  15 /**
  16  * DOC: RX A-MPDU aggregation
  17  *
  18  * Aggregation on the RX side requires only implementing the
  19  * @ampdu_action callback that is invoked to start/stop any
  20  * block-ack sessions for RX aggregation.
  21  *
  22  * When RX aggregation is started by the peer, the driver is
  23  * notified via @ampdu_action function, with the
  24  * %IEEE80211_AMPDU_RX_START action, and may reject the request
  25  * in which case a negative response is sent to the peer, if it
  26  * accepts it a positive response is sent.
  27  *
  28  * While the session is active, the device/driver are required
  29  * to de-aggregate frames and pass them up one by one to mac80211,
  30  * which will handle the reorder buffer.
  31  *
  32  * When the aggregation session is stopped again by the peer or
  33  * ourselves, the driver's @ampdu_action function will be called
  34  * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
  35  * call must not fail.
  36  */
  37
  38 #include <linux/ieee80211.h>
  39 #include <linux/slab.h>
  40 #include <linux/export.h>
  41 #include <net/mac80211.h>
  42 #include "ieee80211_i.h"
  43 #include "driver-ops.h"
  44
  45 static void ieee80211_free_tid_rx(struct rcu_head *h)
  46 {
  47         struct tid_ampdu_rx *tid_rx =
  48                 container_of(h, struct tid_ampdu_rx, rcu_head);
  49         int i;
  50
  51         for (i = 0; i < tid_rx->buf_size; i++)
  52                 __skb_queue_purge(&tid_rx->reorder_buf[i]);
  53         kfree(tid_rx->reorder_buf);
  54         kfree(tid_rx->reorder_time);
  55         kfree(tid_rx);
  56 }
  57
  58 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  59                                      u16 initiator, u16 reason, bool tx)
  60 {
  61         struct ieee80211_local *local = sta->local;
  62         struct tid_ampdu_rx *tid_rx;
  63         struct ieee80211_ampdu_params params = {
  64                 .sta = &sta->sta,
  65                 .action = IEEE80211_AMPDU_RX_STOP,
  66                 .tid = tid,
  67                 .amsdu = false,
  68                 .timeout = 0,
  69                 .ssn = 0,
  70         };
  71
  72         lockdep_assert_held(&sta->ampdu_mlme.mtx);
  73
  74         tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
  75                                         lockdep_is_held(&sta->ampdu_mlme.mtx));
  76
  77         if (!test_bit(tid, sta->ampdu_mlme.agg_session_valid))
  78                 return;
  79
  80         RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
  81         __clear_bit(tid, sta->ampdu_mlme.agg_session_valid);
  82
  83         ht_dbg(sta->sdata,
  84                "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
  85                sta->sta.addr, tid,
  86                initiator == WLAN_BACK_RECIPIENT ? "recipient" : "initiator",
  87                (int)reason);
  88
  89         if (drv_ampdu_action(local, sta->sdata, &params))
  90                 sdata_info(sta->sdata,
  91                            "HW problem - can not stop rx aggregation for %pM tid %d\n",
  92                            sta->sta.addr, tid);
  93
  94         /* check if this is a self generated aggregation halt */
  95         if (initiator == WLAN_BACK_RECIPIENT && tx)
  96                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
  97                                      tid, WLAN_BACK_RECIPIENT, reason);
  98
  99         /*
 100          * return here in case tid_rx is not assigned - which will happen if
 101          * IEEE80211_HW_SUPPORTS_REORDERING_BUFFER is set.
 102          */
 103         if (!tid_rx)
 104                 return;
 105
 106         del_timer_sync(&tid_rx->session_timer);
 107
 108         /* make sure ieee80211_sta_reorder_release() doesn't re-arm the timer */
 109         spin_lock_bh(&tid_rx->reorder_lock);
 110         tid_rx->removed = true;
 111         spin_unlock_bh(&tid_rx->reorder_lock);
 112         del_timer_sync(&tid_rx->reorder_timer);
 113
 114         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
 115 }
 116
 117 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
 118                                     u16 initiator, u16 reason, bool tx)
 119 {
 120         mutex_lock(&sta->ampdu_mlme.mtx);
 121         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
 122         mutex_unlock(&sta->ampdu_mlme.mtx);
 123 }
 124
 125 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
 126                                   const u8 *addr)
 127 {
 128         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 129         struct sta_info *sta;
 130         int i;
 131
 132         rcu_read_lock();
 133         sta = sta_info_get_bss(sdata, addr);
 134         if (!sta) {
 135                 rcu_read_unlock();
 136                 return;
 137         }
 138
 139         for (i = 0; i < IEEE80211_NUM_TIDS; i++)
 140                 if (ba_rx_bitmap & BIT(i))
 141                         set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
 142
 143         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 144         rcu_read_unlock();
 145 }
 146 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
 147
 148 /*
 149  * After accepting the AddBA Request we activated a timer,
 150  * resetting it after each frame that arrives from the originator.
 151  */
 152 static void sta_rx_agg_session_timer_expired(struct timer_list *t)
 153 {
 154         struct tid_ampdu_rx *tid_rx = from_timer(tid_rx, t, session_timer);
 155         struct sta_info *sta = tid_rx->sta;
 156         u8 tid = tid_rx->tid;
 157         unsigned long timeout;
 158
 159         timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
 160         if (time_is_after_jiffies(timeout)) {
 161                 mod_timer(&tid_rx->session_timer, timeout);
 162                 return;
 163         }
 164
 165         ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
 166                sta->sta.addr, tid);
 167
 168         set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
 169         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 170 }
 171
 172 static void sta_rx_agg_reorder_timer_expired(struct timer_list *t)
 173 {
 174         struct tid_ampdu_rx *tid_rx = from_timer(tid_rx, t, reorder_timer);
 175
 176         rcu_read_lock();
 177         ieee80211_release_reorder_timeout(tid_rx->sta, tid_rx->tid);
 178         rcu_read_unlock();
 179 }
 180
 181 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 182                                       u8 dialog_token, u16 status, u16 policy,
 183                                       u16 buf_size, u16 timeout)
 184 {
 185         struct ieee80211_local *local = sdata->local;
 186         struct sk_buff *skb;
 187         struct ieee80211_mgmt *mgmt;
 188         bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
 189         u16 capab;
 190
 191         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 192         if (!skb)
 193                 return;
 194
 195         skb_reserve(skb, local->hw.extra_tx_headroom);
 196         mgmt = skb_put_zero(skb, 24);
 197         memcpy(mgmt->da, da, ETH_ALEN);
 198         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 199         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 200             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 201             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 202                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 203         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 204                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 205         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 206                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 207
 208         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 209                                           IEEE80211_STYPE_ACTION);
 210
 211         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 212         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 213         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 214         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 215
 216         capab = (u16)(amsdu << 0);      /* bit 0 A-MSDU support */
 217         capab |= (u16)(policy << 1);    /* bit 1 aggregation policy */
 218         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 219         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 220
 221         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 222         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 223         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 224
 225         ieee80211_tx_skb(sdata, skb);
 226 }
 227
 228 void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
 229                                       u8 dialog_token, u16 timeout,
 230                                       u16 start_seq_num, u16 ba_policy, u16 tid,
 231                                       u16 buf_size, bool tx, bool auto_seq)
 232 {
 233         struct ieee80211_local *local = sta->sdata->local;
 234         struct tid_ampdu_rx *tid_agg_rx;
 235         struct ieee80211_ampdu_params params = {
 236                 .sta = &sta->sta,
 237                 .action = IEEE80211_AMPDU_RX_START,
 238                 .tid = tid,
 239                 .amsdu = false,
 240                 .timeout = timeout,
 241                 .ssn = start_seq_num,
 242         };
 243         int i, ret = -EOPNOTSUPP;
 244         u16 status = WLAN_STATUS_REQUEST_DECLINED;
 245         u16 max_buf_size;
 246
 247         if (tid >= IEEE80211_FIRST_TSPEC_TSID) {
 248                 ht_dbg(sta->sdata,
 249                        "STA %pM requests BA session on unsupported tid %d\n",
 250                        sta->sta.addr, tid);
 251                 goto end;
 252         }
 253
 254         if (!sta->sta.ht_cap.ht_supported) {
 255                 ht_dbg(sta->sdata,
 256                        "STA %pM erroneously requests BA session on tid %d w/o QoS\n",
 257                        sta->sta.addr, tid);
 258                 /* send a response anyway, it's an error case if we get here */
 259                 goto end;
 260         }
 261
 262         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 263                 ht_dbg(sta->sdata,
 264                        "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
 265                        sta->sta.addr, tid);
 266                 goto end;
 267         }
 268
 269         if (sta->sta.he_cap.has_he)
 270                 max_buf_size = IEEE80211_MAX_AMPDU_BUF;
 271         else
 272                 max_buf_size = IEEE80211_MAX_AMPDU_BUF_HT;
 273
 274         /* sanity check for incoming parameters:
 275          * check if configuration can support the BA policy
 276          * and if buffer size does not exceeds max value */
 277         /* XXX: check own ht delayed BA capability?? */
 278         if (((ba_policy != 1) &&
 279              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 280             (buf_size > max_buf_size)) {
 281                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 282                 ht_dbg_ratelimited(sta->sdata,
 283                                    "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
 284                                    sta->sta.addr, tid, ba_policy, buf_size);
 285                 goto end;
 286         }
 287         /* determine default buffer size */
 288         if (buf_size == 0)
 289                 buf_size = max_buf_size;
 290
 291         /* make sure the size doesn't exceed the maximum supported by the hw */
 292         if (buf_size > sta->sta.max_rx_aggregation_subframes)
 293                 buf_size = sta->sta.max_rx_aggregation_subframes;
 294         params.buf_size = buf_size;
 295
 296         ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
 297                buf_size, sta->sta.addr);
 298
 299         /* examine state machine */
 300         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 301
 302         if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) {
 303                 if (sta->ampdu_mlme.tid_rx_token[tid] == dialog_token) {
 304                         struct tid_ampdu_rx *tid_rx;
 305
 306                         ht_dbg_ratelimited(sta->sdata,
 307                                            "updated AddBA Req from %pM on tid %u\n",
 308                                            sta->sta.addr, tid);
 309                         /* We have no API to update the timeout value in the
 310                          * driver so reject the timeout update if the timeout
 311                          * changed. If if did not change, i.e., no real update,
 312                          * just reply with success.
 313                          */
 314                         rcu_read_lock();
 315                         tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
 316                         if (tid_rx && tid_rx->timeout == timeout)
 317                                 status = WLAN_STATUS_SUCCESS;
 318                         else
 319                                 status = WLAN_STATUS_REQUEST_DECLINED;
 320                         rcu_read_unlock();
 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 static void __ieee80211_start_rx_ba_session(struct sta_info *sta,
 419                                             u8 dialog_token, u16 timeout,
 420                                             u16 start_seq_num, u16 ba_policy,
 421                                             u16 tid, u16 buf_size, bool tx,
 422                                             bool auto_seq)
 423 {
 424         mutex_lock(&sta->ampdu_mlme.mtx);
 425         ___ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
 426                                          start_seq_num, ba_policy, tid,
 427                                          buf_size, tx, auto_seq);
 428         mutex_unlock(&sta->ampdu_mlme.mtx);
 429 }
 430
 431 void ieee80211_process_addba_request(struct ieee80211_local *local,
 432                                      struct sta_info *sta,
 433                                      struct ieee80211_mgmt *mgmt,
 434                                      size_t len)
 435 {
 436         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
 437         u8 dialog_token;
 438
 439         /* extract session parameters from addba request frame */
 440         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 441         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 442         start_seq_num =
 443                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 444
 445         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 446         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 447         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 448         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 449
 450         __ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
 451                                         start_seq_num, ba_policy, tid,
 452                                         buf_size, true, false);
 453 }
 454
 455 void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,
 456                                  const u8 *addr, unsigned int tid)
 457 {
 458         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 459         struct ieee80211_local *local = sdata->local;
 460         struct sta_info *sta;
 461
 462         rcu_read_lock();
 463         sta = sta_info_get_bss(sdata, addr);
 464         if (!sta)
 465                 goto unlock;
 466
 467         set_bit(tid, sta->ampdu_mlme.tid_rx_manage_offl);
 468         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 469  unlock:
 470         rcu_read_unlock();
 471 }
 472 EXPORT_SYMBOL(ieee80211_manage_rx_ba_offl);
 473
 474 void ieee80211_rx_ba_timer_expired(struct ieee80211_vif *vif,
 475                                    const u8 *addr, unsigned int tid)
 476 {
 477         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 478         struct ieee80211_local *local = sdata->local;
 479         struct sta_info *sta;
 480
 481         rcu_read_lock();
 482         sta = sta_info_get_bss(sdata, addr);
 483         if (!sta)
 484                 goto unlock;
 485
 486         set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
 487         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 488
 489  unlock:
 490         rcu_read_unlock();
 491 }
 492 EXPORT_SYMBOL(ieee80211_rx_ba_timer_expired);