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 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" : "inititator",
  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(unsigned long data)
 155 {
 156         /* not an elegant detour, but there is no choice as the timer passes
 157          * only one argument, and various sta_info are needed here, so init
 158          * flow in sta_info_create gives the TID as data, while the timer_to_id
 159          * array gives the sta through container_of */
 160         u8 *ptid = (u8 *)data;
 161         u8 *timer_to_id = ptid - *ptid;
 162         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 163                                          timer_to_tid[0]);
 164         struct tid_ampdu_rx *tid_rx;
 165         unsigned long timeout;
 166
 167         rcu_read_lock();
 168         tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
 169         if (!tid_rx) {
 170                 rcu_read_unlock();
 171                 return;
 172         }
 173
 174         timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
 175         if (time_is_after_jiffies(timeout)) {
 176                 mod_timer(&tid_rx->session_timer, timeout);
 177                 rcu_read_unlock();
 178                 return;
 179         }
 180         rcu_read_unlock();
 181
 182         ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
 183                sta->sta.addr, (u16)*ptid);
 184
 185         set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
 186         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 187 }
 188
 189 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
 190 {
 191         u8 *ptid = (u8 *)data;
 192         u8 *timer_to_id = ptid - *ptid;
 193         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 194                         timer_to_tid[0]);
 195
 196         rcu_read_lock();
 197         ieee80211_release_reorder_timeout(sta, *ptid);
 198         rcu_read_unlock();
 199 }
 200
 201 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 202                                       u8 dialog_token, u16 status, u16 policy,
 203                                       u16 buf_size, u16 timeout)
 204 {
 205         struct ieee80211_local *local = sdata->local;
 206         struct sk_buff *skb;
 207         struct ieee80211_mgmt *mgmt;
 208         bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
 209         u16 capab;
 210
 211         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 212         if (!skb)
 213                 return;
 214
 215         skb_reserve(skb, local->hw.extra_tx_headroom);
 216         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 217         memset(mgmt, 0, 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
 265         int i, ret = -EOPNOTSUPP;
 266         u16 status = WLAN_STATUS_REQUEST_DECLINED;
 267
 268         if (!sta->sta.ht_cap.ht_supported) {
 269                 ht_dbg(sta->sdata,
 270                        "STA %pM erroneously requests BA session on tid %d w/o QoS\n",
 271                        sta->sta.addr, tid);
 272                 /* send a response anyway, it's an error case if we get here */
 273                 goto end_no_lock;
 274         }
 275
 276         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 277                 ht_dbg(sta->sdata,
 278                        "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
 279                        sta->sta.addr, tid);
 280                 goto end_no_lock;
 281         }
 282
 283         /* sanity check for incoming parameters:
 284          * check if configuration can support the BA policy
 285          * and if buffer size does not exceeds max value */
 286         /* XXX: check own ht delayed BA capability?? */
 287         if (((ba_policy != 1) &&
 288              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 289             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 290                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 291                 ht_dbg_ratelimited(sta->sdata,
 292                                    "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
 293                                    sta->sta.addr, tid, ba_policy, buf_size);
 294                 goto end_no_lock;
 295         }
 296         /* determine default buffer size */
 297         if (buf_size == 0)
 298                 buf_size = IEEE80211_MAX_AMPDU_BUF;
 299
 300         /* make sure the size doesn't exceed the maximum supported by the hw */
 301         if (buf_size > local->hw.max_rx_aggregation_subframes)
 302                 buf_size = local->hw.max_rx_aggregation_subframes;
 303         params.buf_size = buf_size;
 304
 305         /* examine state machine */
 306         mutex_lock(&sta->ampdu_mlme.mtx);
 307
 308         if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) {
 309                 ht_dbg_ratelimited(sta->sdata,
 310                                    "unexpected AddBA Req from %pM on tid %u\n",
 311                                    sta->sta.addr, tid);
 312
 313                 /* delete existing Rx BA session on the same tid */
 314                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 315                                                 WLAN_STATUS_UNSPECIFIED_QOS,
 316                                                 false);
 317         }
 318
 319         if (ieee80211_hw_check(&local->hw, SUPPORTS_REORDERING_BUFFER)) {
 320                 ret = drv_ampdu_action(local, sta->sdata, &params);
 321                 ht_dbg(sta->sdata,
 322                        "Rx A-MPDU request on %pM tid %d result %d\n",
 323                        sta->sta.addr, tid, ret);
 324                 if (!ret)
 325                         status = WLAN_STATUS_SUCCESS;
 326                 goto end;
 327         }
 328
 329         /* prepare A-MPDU MLME for Rx aggregation */
 330         tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL);
 331         if (!tid_agg_rx)
 332                 goto end;
 333
 334         spin_lock_init(&tid_agg_rx->reorder_lock);
 335
 336         /* rx timer */
 337         tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
 338         tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 339         init_timer_deferrable(&tid_agg_rx->session_timer);
 340
 341         /* rx reorder timer */
 342         tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
 343         tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 344         init_timer(&tid_agg_rx->reorder_timer);
 345
 346         /* prepare reordering buffer */
 347         tid_agg_rx->reorder_buf =
 348                 kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
 349         tid_agg_rx->reorder_time =
 350                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
 351         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 352                 kfree(tid_agg_rx->reorder_buf);
 353                 kfree(tid_agg_rx->reorder_time);
 354                 kfree(tid_agg_rx);
 355                 goto end;
 356         }
 357
 358         for (i = 0; i < buf_size; i++)
 359                 __skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
 360
 361         ret = drv_ampdu_action(local, sta->sdata, &params);
 362         ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
 363                sta->sta.addr, tid, ret);
 364         if (ret) {
 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         /* update data */
 372         tid_agg_rx->dialog_token = dialog_token;
 373         tid_agg_rx->ssn = start_seq_num;
 374         tid_agg_rx->head_seq_num = start_seq_num;
 375         tid_agg_rx->buf_size = buf_size;
 376         tid_agg_rx->timeout = timeout;
 377         tid_agg_rx->stored_mpdu_num = 0;
 378         tid_agg_rx->auto_seq = auto_seq;
 379         tid_agg_rx->reorder_buf_filtered = 0;
 380         status = WLAN_STATUS_SUCCESS;
 381
 382         /* activate it for RX */
 383         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
 384
 385         if (timeout) {
 386                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
 387                 tid_agg_rx->last_rx = jiffies;
 388         }
 389
 390 end:
 391         if (status == WLAN_STATUS_SUCCESS)
 392                 __set_bit(tid, sta->ampdu_mlme.agg_session_valid);
 393         mutex_unlock(&sta->ampdu_mlme.mtx);
 394
 395 end_no_lock:
 396         if (tx)
 397                 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 398                                           dialog_token, status, 1, buf_size,
 399                                           timeout);
 400 }
 401
 402 void ieee80211_process_addba_request(struct ieee80211_local *local,
 403                                      struct sta_info *sta,
 404                                      struct ieee80211_mgmt *mgmt,
 405                                      size_t len)
 406 {
 407         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
 408         u8 dialog_token;
 409
 410         /* extract session parameters from addba request frame */
 411         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 412         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 413         start_seq_num =
 414                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 415
 416         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 417         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 418         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 419         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 420
 421         __ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
 422                                         start_seq_num, ba_policy, tid,
 423                                         buf_size, true, false);
 424 }
 425
 426 void ieee80211_start_rx_ba_session_offl(struct ieee80211_vif *vif,
 427                                         const u8 *addr, u16 tid)
 428 {
 429         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 430         struct ieee80211_local *local = sdata->local;
 431         struct ieee80211_rx_agg *rx_agg;
 432         struct sk_buff *skb = dev_alloc_skb(0);
 433
 434         if (unlikely(!skb))
 435                 return;
 436
 437         rx_agg = (struct ieee80211_rx_agg *) &skb->cb;
 438         memcpy(&rx_agg->addr, addr, ETH_ALEN);
 439         rx_agg->tid = tid;
 440
 441         skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_START;
 442         skb_queue_tail(&sdata->skb_queue, skb);
 443         ieee80211_queue_work(&local->hw, &sdata->work);
 444 }
 445 EXPORT_SYMBOL(ieee80211_start_rx_ba_session_offl);
 446
 447 void ieee80211_stop_rx_ba_session_offl(struct ieee80211_vif *vif,
 448                                        const u8 *addr, u16 tid)
 449 {
 450         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 451         struct ieee80211_local *local = sdata->local;
 452         struct ieee80211_rx_agg *rx_agg;
 453         struct sk_buff *skb = dev_alloc_skb(0);
 454
 455         if (unlikely(!skb))
 456                 return;
 457
 458         rx_agg = (struct ieee80211_rx_agg *) &skb->cb;
 459         memcpy(&rx_agg->addr, addr, ETH_ALEN);
 460         rx_agg->tid = tid;
 461
 462         skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_STOP;
 463         skb_queue_tail(&sdata->skb_queue, skb);
 464         ieee80211_queue_work(&local->hw, &sdata->work);
 465 }
 466 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session_offl);