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  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  */
  15
  16 /**
  17  * DOC: RX A-MPDU aggregation
  18  *
  19  * Aggregation on the RX side requires only implementing the
  20  * @ampdu_action callback that is invoked to start/stop any
  21  * block-ack sessions for RX aggregation.
  22  *
  23  * When RX aggregation is started by the peer, the driver is
  24  * notified via @ampdu_action function, with the
  25  * %IEEE80211_AMPDU_RX_START action, and may reject the request
  26  * in which case a negative response is sent to the peer, if it
  27  * accepts it a positive response is sent.
  28  *
  29  * While the session is active, the device/driver are required
  30  * to de-aggregate frames and pass them up one by one to mac80211,
  31  * which will handle the reorder buffer.
  32  *
  33  * When the aggregation session is stopped again by the peer or
  34  * ourselves, the driver's @ampdu_action function will be called
  35  * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
  36  * call must not fail.
  37  */
  38
  39 #include <linux/ieee80211.h>
  40 #include <linux/slab.h>
  41 #include <linux/export.h>
  42 #include <net/mac80211.h>
  43 #include "ieee80211_i.h"
  44 #include "driver-ops.h"
  45
  46 static void ieee80211_free_tid_rx(struct rcu_head *h)
  47 {
  48         struct tid_ampdu_rx *tid_rx =
  49                 container_of(h, struct tid_ampdu_rx, rcu_head);
  50         int i;
  51
  52         for (i = 0; i < tid_rx->buf_size; i++)
  53                 __skb_queue_purge(&tid_rx->reorder_buf[i]);
  54         kfree(tid_rx->reorder_buf);
  55         kfree(tid_rx->reorder_time);
  56         kfree(tid_rx);
  57 }
  58
  59 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  60                                      u16 initiator, u16 reason, bool tx)
  61 {
  62         struct ieee80211_local *local = sta->local;
  63         struct tid_ampdu_rx *tid_rx;
  64
  65         lockdep_assert_held(&sta->ampdu_mlme.mtx);
  66
  67         tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
  68                                         lockdep_is_held(&sta->ampdu_mlme.mtx));
  69
  70         if (!tid_rx)
  71                 return;
  72
  73         RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
  74
  75         ht_dbg(sta->sdata,
  76                "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
  77                sta->sta.addr, tid,
  78                initiator == WLAN_BACK_RECIPIENT ? "recipient" : "inititator",
  79                (int)reason);
  80
  81         if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
  82                              &sta->sta, tid, NULL, 0))
  83                 sdata_info(sta->sdata,
  84                            "HW problem - can not stop rx aggregation for %pM tid %d\n",
  85                            sta->sta.addr, tid);
  86
  87         /* check if this is a self generated aggregation halt */
  88         if (initiator == WLAN_BACK_RECIPIENT && tx)
  89                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
  90                                      tid, WLAN_BACK_RECIPIENT, reason);
  91
  92         del_timer_sync(&tid_rx->session_timer);
  93
  94         /* make sure ieee80211_sta_reorder_release() doesn't re-arm the timer */
  95         spin_lock_bh(&tid_rx->reorder_lock);
  96         tid_rx->removed = true;
  97         spin_unlock_bh(&tid_rx->reorder_lock);
  98         del_timer_sync(&tid_rx->reorder_timer);
  99
 100         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
 101 }
 102
 103 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
 104                                     u16 initiator, u16 reason, bool tx)
 105 {
 106         mutex_lock(&sta->ampdu_mlme.mtx);
 107         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
 108         mutex_unlock(&sta->ampdu_mlme.mtx);
 109 }
 110
 111 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
 112                                   const u8 *addr)
 113 {
 114         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 115         struct sta_info *sta;
 116         int i;
 117
 118         rcu_read_lock();
 119         sta = sta_info_get_bss(sdata, addr);
 120         if (!sta) {
 121                 rcu_read_unlock();
 122                 return;
 123         }
 124
 125         for (i = 0; i < IEEE80211_NUM_TIDS; i++)
 126                 if (ba_rx_bitmap & BIT(i))
 127                         set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
 128
 129         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 130         rcu_read_unlock();
 131 }
 132 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
 133
 134 /*
 135  * After accepting the AddBA Request we activated a timer,
 136  * resetting it after each frame that arrives from the originator.
 137  */
 138 static void sta_rx_agg_session_timer_expired(unsigned long data)
 139 {
 140         /* not an elegant detour, but there is no choice as the timer passes
 141          * only one argument, and various sta_info are needed here, so init
 142          * flow in sta_info_create gives the TID as data, while the timer_to_id
 143          * array gives the sta through container_of */
 144         u8 *ptid = (u8 *)data;
 145         u8 *timer_to_id = ptid - *ptid;
 146         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 147                                          timer_to_tid[0]);
 148         struct tid_ampdu_rx *tid_rx;
 149         unsigned long timeout;
 150
 151         rcu_read_lock();
 152         tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
 153         if (!tid_rx) {
 154                 rcu_read_unlock();
 155                 return;
 156         }
 157
 158         timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
 159         if (time_is_after_jiffies(timeout)) {
 160                 mod_timer(&tid_rx->session_timer, timeout);
 161                 rcu_read_unlock();
 162                 return;
 163         }
 164         rcu_read_unlock();
 165
 166         ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
 167                sta->sta.addr, (u16)*ptid);
 168
 169         set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
 170         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 171 }
 172
 173 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
 174 {
 175         u8 *ptid = (u8 *)data;
 176         u8 *timer_to_id = ptid - *ptid;
 177         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 178                         timer_to_tid[0]);
 179
 180         rcu_read_lock();
 181         ieee80211_release_reorder_timeout(sta, *ptid);
 182         rcu_read_unlock();
 183 }
 184
 185 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 186                                       u8 dialog_token, u16 status, u16 policy,
 187                                       u16 buf_size, u16 timeout)
 188 {
 189         struct ieee80211_local *local = sdata->local;
 190         struct sk_buff *skb;
 191         struct ieee80211_mgmt *mgmt;
 192         u16 capab;
 193
 194         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 195         if (!skb)
 196                 return;
 197
 198         skb_reserve(skb, local->hw.extra_tx_headroom);
 199         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 200         memset(mgmt, 0, 24);
 201         memcpy(mgmt->da, da, ETH_ALEN);
 202         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 203         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 204             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 205             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 206                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 207         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 208                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 209         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 210                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 211
 212         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 213                                           IEEE80211_STYPE_ACTION);
 214
 215         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 216         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 217         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 218         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 219
 220         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
 221         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 222         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 223
 224         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 225         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 226         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 227
 228         ieee80211_tx_skb(sdata, skb);
 229 }
 230
 231 void __ieee80211_start_rx_ba_session(struct sta_info *sta,
 232                                      u8 dialog_token, u16 timeout,
 233                                      u16 start_seq_num, u16 ba_policy, u16 tid,
 234                                      u16 buf_size, bool tx, bool auto_seq)
 235 {
 236         struct ieee80211_local *local = sta->sdata->local;
 237         struct tid_ampdu_rx *tid_agg_rx;
 238         int i, ret = -EOPNOTSUPP;
 239         u16 status = WLAN_STATUS_REQUEST_DECLINED;
 240
 241         if (!sta->sta.ht_cap.ht_supported) {
 242                 ht_dbg(sta->sdata,
 243                        "STA %pM erroneously requests BA session on tid %d w/o QoS\n",
 244                        sta->sta.addr, tid);
 245                 /* send a response anyway, it's an error case if we get here */
 246                 goto end_no_lock;
 247         }
 248
 249         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 250                 ht_dbg(sta->sdata,
 251                        "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
 252                        sta->sta.addr, tid);
 253                 goto end_no_lock;
 254         }
 255
 256         /* sanity check for incoming parameters:
 257          * check if configuration can support the BA policy
 258          * and if buffer size does not exceeds max value */
 259         /* XXX: check own ht delayed BA capability?? */
 260         if (((ba_policy != 1) &&
 261              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 262             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 263                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 264                 ht_dbg_ratelimited(sta->sdata,
 265                                    "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
 266                                    sta->sta.addr, tid, ba_policy, buf_size);
 267                 goto end_no_lock;
 268         }
 269         /* determine default buffer size */
 270         if (buf_size == 0)
 271                 buf_size = IEEE80211_MAX_AMPDU_BUF;
 272
 273         /* make sure the size doesn't exceed the maximum supported by the hw */
 274         if (buf_size > local->hw.max_rx_aggregation_subframes)
 275                 buf_size = local->hw.max_rx_aggregation_subframes;
 276
 277         /* examine state machine */
 278         mutex_lock(&sta->ampdu_mlme.mtx);
 279
 280         if (sta->ampdu_mlme.tid_rx[tid]) {
 281                 ht_dbg_ratelimited(sta->sdata,
 282                                    "unexpected AddBA Req from %pM on tid %u\n",
 283                                    sta->sta.addr, tid);
 284
 285                 /* delete existing Rx BA session on the same tid */
 286                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 287                                                 WLAN_STATUS_UNSPECIFIED_QOS,
 288                                                 false);
 289         }
 290
 291         /* prepare A-MPDU MLME for Rx aggregation */
 292         tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
 293         if (!tid_agg_rx)
 294                 goto end;
 295
 296         spin_lock_init(&tid_agg_rx->reorder_lock);
 297
 298         /* rx timer */
 299         tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
 300         tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 301         init_timer_deferrable(&tid_agg_rx->session_timer);
 302
 303         /* rx reorder timer */
 304         tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
 305         tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 306         init_timer(&tid_agg_rx->reorder_timer);
 307
 308         /* prepare reordering buffer */
 309         tid_agg_rx->reorder_buf =
 310                 kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
 311         tid_agg_rx->reorder_time =
 312                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
 313         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 314                 kfree(tid_agg_rx->reorder_buf);
 315                 kfree(tid_agg_rx->reorder_time);
 316                 kfree(tid_agg_rx);
 317                 goto end;
 318         }
 319
 320         for (i = 0; i < buf_size; i++)
 321                 __skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
 322
 323         ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
 324                                &sta->sta, tid, &start_seq_num, 0);
 325         ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
 326                sta->sta.addr, tid, ret);
 327         if (ret) {
 328                 kfree(tid_agg_rx->reorder_buf);
 329                 kfree(tid_agg_rx->reorder_time);
 330                 kfree(tid_agg_rx);
 331                 goto end;
 332         }
 333
 334         /* update data */
 335         tid_agg_rx->dialog_token = dialog_token;
 336         tid_agg_rx->ssn = start_seq_num;
 337         tid_agg_rx->head_seq_num = start_seq_num;
 338         tid_agg_rx->buf_size = buf_size;
 339         tid_agg_rx->timeout = timeout;
 340         tid_agg_rx->stored_mpdu_num = 0;
 341         tid_agg_rx->auto_seq = auto_seq;
 342         status = WLAN_STATUS_SUCCESS;
 343
 344         /* activate it for RX */
 345         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
 346
 347         if (timeout) {
 348                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
 349                 tid_agg_rx->last_rx = jiffies;
 350         }
 351
 352 end:
 353         mutex_unlock(&sta->ampdu_mlme.mtx);
 354
 355 end_no_lock:
 356         if (tx)
 357                 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 358                                           dialog_token, status, 1, buf_size,
 359                                           timeout);
 360 }
 361
 362 void ieee80211_process_addba_request(struct ieee80211_local *local,
 363                                      struct sta_info *sta,
 364                                      struct ieee80211_mgmt *mgmt,
 365                                      size_t len)
 366 {
 367         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
 368         u8 dialog_token;
 369
 370         /* extract session parameters from addba request frame */
 371         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 372         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 373         start_seq_num =
 374                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 375
 376         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 377         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 378         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 379         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 380
 381         __ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
 382                                         start_seq_num, ba_policy, tid,
 383                                         buf_size, true, false);
 384 }
 385
 386 void ieee80211_start_rx_ba_session_offl(struct ieee80211_vif *vif,
 387                                         const u8 *addr, u16 tid)
 388 {
 389         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 390         struct ieee80211_local *local = sdata->local;
 391         struct ieee80211_rx_agg *rx_agg;
 392         struct sk_buff *skb = dev_alloc_skb(0);
 393
 394         if (unlikely(!skb))
 395                 return;
 396
 397         rx_agg = (struct ieee80211_rx_agg *) &skb->cb;
 398         memcpy(&rx_agg->addr, addr, ETH_ALEN);
 399         rx_agg->tid = tid;
 400
 401         skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_START;
 402         skb_queue_tail(&sdata->skb_queue, skb);
 403         ieee80211_queue_work(&local->hw, &sdata->work);
 404 }
 405 EXPORT_SYMBOL(ieee80211_start_rx_ba_session_offl);
 406
 407 void ieee80211_stop_rx_ba_session_offl(struct ieee80211_vif *vif,
 408                                        const u8 *addr, u16 tid)
 409 {
 410         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 411         struct ieee80211_local *local = sdata->local;
 412         struct ieee80211_rx_agg *rx_agg;
 413         struct sk_buff *skb = dev_alloc_skb(0);
 414
 415         if (unlikely(!skb))
 416                 return;
 417
 418         rx_agg = (struct ieee80211_rx_agg *) &skb->cb;
 419         memcpy(&rx_agg->addr, addr, ETH_ALEN);
 420         rx_agg->tid = tid;
 421
 422         skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_STOP;
 423         skb_queue_tail(&sdata->skb_queue, skb);
 424         ieee80211_queue_work(&local->hw, &sdata->work);
 425 }
 426 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session_offl);