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 (!tid_rx)
  80                 return;
  81
  82         RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
  83
  84         ht_dbg(sta->sdata,
  85                "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
  86                sta->sta.addr, tid,
  87                initiator == WLAN_BACK_RECIPIENT ? "recipient" : "inititator",
  88                (int)reason);
  89
  90         if (drv_ampdu_action(local, sta->sdata, &params))
  91                 sdata_info(sta->sdata,
  92                            "HW problem - can not stop rx aggregation for %pM tid %d\n",
  93                            sta->sta.addr, tid);
  94
  95         /* check if this is a self generated aggregation halt */
  96         if (initiator == WLAN_BACK_RECIPIENT && tx)
  97                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
  98                                      tid, WLAN_BACK_RECIPIENT, reason);
  99
 100         del_timer_sync(&tid_rx->session_timer);
 101
 102         /* make sure ieee80211_sta_reorder_release() doesn't re-arm the timer */
 103         spin_lock_bh(&tid_rx->reorder_lock);
 104         tid_rx->removed = true;
 105         spin_unlock_bh(&tid_rx->reorder_lock);
 106         del_timer_sync(&tid_rx->reorder_timer);
 107
 108         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
 109 }
 110
 111 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
 112                                     u16 initiator, u16 reason, bool tx)
 113 {
 114         mutex_lock(&sta->ampdu_mlme.mtx);
 115         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
 116         mutex_unlock(&sta->ampdu_mlme.mtx);
 117 }
 118
 119 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
 120                                   const u8 *addr)
 121 {
 122         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 123         struct sta_info *sta;
 124         int i;
 125
 126         rcu_read_lock();
 127         sta = sta_info_get_bss(sdata, addr);
 128         if (!sta) {
 129                 rcu_read_unlock();
 130                 return;
 131         }
 132
 133         for (i = 0; i < IEEE80211_NUM_TIDS; i++)
 134                 if (ba_rx_bitmap & BIT(i))
 135                         set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
 136
 137         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 138         rcu_read_unlock();
 139 }
 140 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
 141
 142 /*
 143  * After accepting the AddBA Request we activated a timer,
 144  * resetting it after each frame that arrives from the originator.
 145  */
 146 static void sta_rx_agg_session_timer_expired(unsigned long data)
 147 {
 148         /* not an elegant detour, but there is no choice as the timer passes
 149          * only one argument, and various sta_info are needed here, so init
 150          * flow in sta_info_create gives the TID as data, while the timer_to_id
 151          * array gives the sta through container_of */
 152         u8 *ptid = (u8 *)data;
 153         u8 *timer_to_id = ptid - *ptid;
 154         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 155                                          timer_to_tid[0]);
 156         struct tid_ampdu_rx *tid_rx;
 157         unsigned long timeout;
 158
 159         rcu_read_lock();
 160         tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
 161         if (!tid_rx) {
 162                 rcu_read_unlock();
 163                 return;
 164         }
 165
 166         timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
 167         if (time_is_after_jiffies(timeout)) {
 168                 mod_timer(&tid_rx->session_timer, timeout);
 169                 rcu_read_unlock();
 170                 return;
 171         }
 172         rcu_read_unlock();
 173
 174         ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
 175                sta->sta.addr, (u16)*ptid);
 176
 177         set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
 178         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 179 }
 180
 181 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
 182 {
 183         u8 *ptid = (u8 *)data;
 184         u8 *timer_to_id = ptid - *ptid;
 185         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 186                         timer_to_tid[0]);
 187
 188         rcu_read_lock();
 189         ieee80211_release_reorder_timeout(sta, *ptid);
 190         rcu_read_unlock();
 191 }
 192
 193 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 194                                       u8 dialog_token, u16 status, u16 policy,
 195                                       u16 buf_size, u16 timeout)
 196 {
 197         struct ieee80211_local *local = sdata->local;
 198         struct sk_buff *skb;
 199         struct ieee80211_mgmt *mgmt;
 200         bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
 201         u16 capab;
 202
 203         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 204         if (!skb)
 205                 return;
 206
 207         skb_reserve(skb, local->hw.extra_tx_headroom);
 208         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 209         memset(mgmt, 0, 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
 257         int i, ret = -EOPNOTSUPP;
 258         u16 status = WLAN_STATUS_REQUEST_DECLINED;
 259
 260         if (!sta->sta.ht_cap.ht_supported) {
 261                 ht_dbg(sta->sdata,
 262                        "STA %pM erroneously requests BA session on tid %d w/o QoS\n",
 263                        sta->sta.addr, tid);
 264                 /* send a response anyway, it's an error case if we get here */
 265                 goto end_no_lock;
 266         }
 267
 268         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 269                 ht_dbg(sta->sdata,
 270                        "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
 271                        sta->sta.addr, tid);
 272                 goto end_no_lock;
 273         }
 274
 275         /* sanity check for incoming parameters:
 276          * check if configuration can support the BA policy
 277          * and if buffer size does not exceeds max value */
 278         /* XXX: check own ht delayed BA capability?? */
 279         if (((ba_policy != 1) &&
 280              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 281             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 282                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 283                 ht_dbg_ratelimited(sta->sdata,
 284                                    "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
 285                                    sta->sta.addr, tid, ba_policy, buf_size);
 286                 goto end_no_lock;
 287         }
 288         /* determine default buffer size */
 289         if (buf_size == 0)
 290                 buf_size = IEEE80211_MAX_AMPDU_BUF;
 291
 292         /* make sure the size doesn't exceed the maximum supported by the hw */
 293         if (buf_size > sta->sta.max_rx_aggregation_subframes)
 294                 buf_size = sta->sta.max_rx_aggregation_subframes;
 295         params.buf_size = buf_size;
 296
 297         ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
 298                buf_size, sta->sta.addr);
 299
 300         /* examine state machine */
 301         mutex_lock(&sta->ampdu_mlme.mtx);
 302
 303         if (sta->ampdu_mlme.tid_rx[tid]) {
 304                 ht_dbg_ratelimited(sta->sdata,
 305                                    "unexpected AddBA Req from %pM on tid %u\n",
 306                                    sta->sta.addr, tid);
 307
 308                 /* delete existing Rx BA session on the same tid */
 309                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 310                                                 WLAN_STATUS_UNSPECIFIED_QOS,
 311                                                 false);
 312         }
 313
 314         /* prepare A-MPDU MLME for Rx aggregation */
 315         tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL);
 316         if (!tid_agg_rx)
 317                 goto end;
 318
 319         spin_lock_init(&tid_agg_rx->reorder_lock);
 320
 321         /* rx timer */
 322         tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
 323         tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 324         init_timer_deferrable(&tid_agg_rx->session_timer);
 325
 326         /* rx reorder timer */
 327         tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
 328         tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 329         init_timer(&tid_agg_rx->reorder_timer);
 330
 331         /* prepare reordering buffer */
 332         tid_agg_rx->reorder_buf =
 333                 kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
 334         tid_agg_rx->reorder_time =
 335                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
 336         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 337                 kfree(tid_agg_rx->reorder_buf);
 338                 kfree(tid_agg_rx->reorder_time);
 339                 kfree(tid_agg_rx);
 340                 goto end;
 341         }
 342
 343         for (i = 0; i < buf_size; i++)
 344                 __skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
 345
 346         ret = drv_ampdu_action(local, sta->sdata, &params);
 347         ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
 348                sta->sta.addr, tid, ret);
 349         if (ret) {
 350                 kfree(tid_agg_rx->reorder_buf);
 351                 kfree(tid_agg_rx->reorder_time);
 352                 kfree(tid_agg_rx);
 353                 goto end;
 354         }
 355
 356         /* update data */
 357         tid_agg_rx->dialog_token = dialog_token;
 358         tid_agg_rx->ssn = start_seq_num;
 359         tid_agg_rx->head_seq_num = start_seq_num;
 360         tid_agg_rx->buf_size = buf_size;
 361         tid_agg_rx->timeout = timeout;
 362         tid_agg_rx->stored_mpdu_num = 0;
 363         tid_agg_rx->auto_seq = auto_seq;
 364         status = WLAN_STATUS_SUCCESS;
 365
 366         /* activate it for RX */
 367         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
 368
 369         if (timeout) {
 370                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
 371                 tid_agg_rx->last_rx = jiffies;
 372         }
 373
 374 end:
 375         mutex_unlock(&sta->ampdu_mlme.mtx);
 376
 377 end_no_lock:
 378         if (tx)
 379                 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 380                                           dialog_token, status, 1, buf_size,
 381                                           timeout);
 382 }
 383
 384 void ieee80211_process_addba_request(struct ieee80211_local *local,
 385                                      struct sta_info *sta,
 386                                      struct ieee80211_mgmt *mgmt,
 387                                      size_t len)
 388 {
 389         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
 390         u8 dialog_token;
 391
 392         /* extract session parameters from addba request frame */
 393         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 394         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 395         start_seq_num =
 396                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 397
 398         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 399         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 400         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 401         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 402
 403         __ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
 404                                         start_seq_num, ba_policy, tid,
 405                                         buf_size, true, false);
 406 }
 407
 408 void ieee80211_start_rx_ba_session_offl(struct ieee80211_vif *vif,
 409                                         const u8 *addr, u16 tid)
 410 {
 411         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 412         struct ieee80211_local *local = sdata->local;
 413         struct ieee80211_rx_agg *rx_agg;
 414         struct sk_buff *skb = dev_alloc_skb(0);
 415
 416         if (unlikely(!skb))
 417                 return;
 418
 419         rx_agg = (struct ieee80211_rx_agg *) &skb->cb;
 420         memcpy(&rx_agg->addr, addr, ETH_ALEN);
 421         rx_agg->tid = tid;
 422
 423         skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_START;
 424         skb_queue_tail(&sdata->skb_queue, skb);
 425         ieee80211_queue_work(&local->hw, &sdata->work);
 426 }
 427 EXPORT_SYMBOL(ieee80211_start_rx_ba_session_offl);
 428
 429 void ieee80211_stop_rx_ba_session_offl(struct ieee80211_vif *vif,
 430                                        const u8 *addr, u16 tid)
 431 {
 432         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 433         struct ieee80211_local *local = sdata->local;
 434         struct ieee80211_rx_agg *rx_agg;
 435         struct sk_buff *skb = dev_alloc_skb(0);
 436
 437         if (unlikely(!skb))
 438                 return;
 439
 440         rx_agg = (struct ieee80211_rx_agg *) &skb->cb;
 441         memcpy(&rx_agg->addr, addr, ETH_ALEN);
 442         rx_agg->tid = tid;
 443
 444         skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_STOP;
 445         skb_queue_tail(&sdata->skb_queue, skb);
 446         ieee80211_queue_work(&local->hw, &sdata->work);
 447 }
 448 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session_offl);