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         del_timer_sync(&tid_rx->reorder_timer);
  53
  54         for (i = 0; i < tid_rx->buf_size; i++)
  55                 dev_kfree_skb(tid_rx->reorder_buf[i]);
  56         kfree(tid_rx->reorder_buf);
  57         kfree(tid_rx->reorder_time);
  58         kfree(tid_rx);
  59 }
  60
  61 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  62                                      u16 initiator, u16 reason, bool tx)
  63 {
  64         struct ieee80211_local *local = sta->local;
  65         struct tid_ampdu_rx *tid_rx;
  66
  67         lockdep_assert_held(&sta->ampdu_mlme.mtx);
  68
  69         tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
  70                                         lockdep_is_held(&sta->ampdu_mlme.mtx));
  71
  72         if (!tid_rx)
  73                 return;
  74
  75         RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
  76
  77         ht_dbg(sta->sdata,
  78                "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
  79                sta->sta.addr, tid,
  80                initiator == WLAN_BACK_RECIPIENT ? "recipient" : "inititator",
  81                (int)reason);
  82
  83         if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
  84                              &sta->sta, tid, NULL, 0))
  85                 sdata_info(sta->sdata,
  86                            "HW problem - can not stop rx aggregation for %pM tid %d\n",
  87                            sta->sta.addr, tid);
  88
  89         /* check if this is a self generated aggregation halt */
  90         if (initiator == WLAN_BACK_RECIPIENT && tx)
  91                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
  92                                      tid, WLAN_BACK_RECIPIENT, reason);
  93
  94         del_timer_sync(&tid_rx->session_timer);
  95
  96         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
  97 }
  98
  99 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
 100                                     u16 initiator, u16 reason, bool tx)
 101 {
 102         mutex_lock(&sta->ampdu_mlme.mtx);
 103         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
 104         mutex_unlock(&sta->ampdu_mlme.mtx);
 105 }
 106
 107 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
 108                                   const u8 *addr)
 109 {
 110         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 111         struct sta_info *sta;
 112         int i;
 113
 114         rcu_read_lock();
 115         sta = sta_info_get_bss(sdata, addr);
 116         if (!sta) {
 117                 rcu_read_unlock();
 118                 return;
 119         }
 120
 121         for (i = 0; i < IEEE80211_NUM_TIDS; i++)
 122                 if (ba_rx_bitmap & BIT(i))
 123                         set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
 124
 125         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 126         rcu_read_unlock();
 127 }
 128 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
 129
 130 /*
 131  * After accepting the AddBA Request we activated a timer,
 132  * resetting it after each frame that arrives from the originator.
 133  */
 134 static void sta_rx_agg_session_timer_expired(unsigned long data)
 135 {
 136         /* not an elegant detour, but there is no choice as the timer passes
 137          * only one argument, and various sta_info are needed here, so init
 138          * flow in sta_info_create gives the TID as data, while the timer_to_id
 139          * array gives the sta through container_of */
 140         u8 *ptid = (u8 *)data;
 141         u8 *timer_to_id = ptid - *ptid;
 142         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 143                                          timer_to_tid[0]);
 144         struct tid_ampdu_rx *tid_rx;
 145         unsigned long timeout;
 146
 147         rcu_read_lock();
 148         tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
 149         if (!tid_rx) {
 150                 rcu_read_unlock();
 151                 return;
 152         }
 153
 154         timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
 155         if (time_is_after_jiffies(timeout)) {
 156                 mod_timer(&tid_rx->session_timer, timeout);
 157                 rcu_read_unlock();
 158                 return;
 159         }
 160         rcu_read_unlock();
 161
 162         ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
 163                sta->sta.addr, (u16)*ptid);
 164
 165         set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
 166         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 167 }
 168
 169 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
 170 {
 171         u8 *ptid = (u8 *)data;
 172         u8 *timer_to_id = ptid - *ptid;
 173         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 174                         timer_to_tid[0]);
 175
 176         rcu_read_lock();
 177         ieee80211_release_reorder_timeout(sta, *ptid);
 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         u16 capab;
 189
 190         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 191         if (!skb)
 192                 return;
 193
 194         skb_reserve(skb, local->hw.extra_tx_headroom);
 195         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 196         memset(mgmt, 0, 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)(policy << 1);     /* bit 1 aggregation policy */
 217         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 218         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 219
 220         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 221         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 222         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 223
 224         ieee80211_tx_skb(sdata, skb);
 225 }
 226
 227 void ieee80211_process_addba_request(struct ieee80211_local *local,
 228                                      struct sta_info *sta,
 229                                      struct ieee80211_mgmt *mgmt,
 230                                      size_t len)
 231 {
 232         struct tid_ampdu_rx *tid_agg_rx;
 233         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
 234         u8 dialog_token;
 235         int ret = -EOPNOTSUPP;
 236
 237         /* extract session parameters from addba request frame */
 238         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 239         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 240         start_seq_num =
 241                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 242
 243         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 244         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 245         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 246         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 247
 248         status = WLAN_STATUS_REQUEST_DECLINED;
 249
 250         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 251                 ht_dbg(sta->sdata,
 252                        "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
 253                        sta->sta.addr, tid);
 254                 goto end_no_lock;
 255         }
 256
 257         /* sanity check for incoming parameters:
 258          * check if configuration can support the BA policy
 259          * and if buffer size does not exceeds max value */
 260         /* XXX: check own ht delayed BA capability?? */
 261         if (((ba_policy != 1) &&
 262              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 263             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 264                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 265                 ht_dbg_ratelimited(sta->sdata,
 266                                    "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
 267                                    mgmt->sa, tid, ba_policy, buf_size);
 268                 goto end_no_lock;
 269         }
 270         /* determine default buffer size */
 271         if (buf_size == 0)
 272                 buf_size = IEEE80211_MAX_AMPDU_BUF;
 273
 274         /* make sure the size doesn't exceed the maximum supported by the hw */
 275         if (buf_size > local->hw.max_rx_aggregation_subframes)
 276                 buf_size = local->hw.max_rx_aggregation_subframes;
 277
 278         /* examine state machine */
 279         mutex_lock(&sta->ampdu_mlme.mtx);
 280
 281         if (sta->ampdu_mlme.tid_rx[tid]) {
 282                 ht_dbg_ratelimited(sta->sdata,
 283                                    "unexpected AddBA Req from %pM on tid %u\n",
 284                                    mgmt->sa, tid);
 285
 286                 /* delete existing Rx BA session on the same tid */
 287                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 288                                                 WLAN_STATUS_UNSPECIFIED_QOS,
 289                                                 false);
 290         }
 291
 292         /* prepare A-MPDU MLME for Rx aggregation */
 293         tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
 294         if (!tid_agg_rx)
 295                 goto end;
 296
 297         spin_lock_init(&tid_agg_rx->reorder_lock);
 298
 299         /* rx timer */
 300         tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
 301         tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 302         init_timer_deferrable(&tid_agg_rx->session_timer);
 303
 304         /* rx reorder timer */
 305         tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
 306         tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 307         init_timer(&tid_agg_rx->reorder_timer);
 308
 309         /* prepare reordering buffer */
 310         tid_agg_rx->reorder_buf =
 311                 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL);
 312         tid_agg_rx->reorder_time =
 313                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
 314         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 315                 kfree(tid_agg_rx->reorder_buf);
 316                 kfree(tid_agg_rx->reorder_time);
 317                 kfree(tid_agg_rx);
 318                 goto end;
 319         }
 320
 321         ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
 322                                &sta->sta, tid, &start_seq_num, 0);
 323         ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
 324                sta->sta.addr, tid, ret);
 325         if (ret) {
 326                 kfree(tid_agg_rx->reorder_buf);
 327                 kfree(tid_agg_rx->reorder_time);
 328                 kfree(tid_agg_rx);
 329                 goto end;
 330         }
 331
 332         /* update data */
 333         tid_agg_rx->dialog_token = dialog_token;
 334         tid_agg_rx->ssn = start_seq_num;
 335         tid_agg_rx->head_seq_num = start_seq_num;
 336         tid_agg_rx->buf_size = buf_size;
 337         tid_agg_rx->timeout = timeout;
 338         tid_agg_rx->stored_mpdu_num = 0;
 339         status = WLAN_STATUS_SUCCESS;
 340
 341         /* activate it for RX */
 342         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
 343
 344         if (timeout) {
 345                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
 346                 tid_agg_rx->last_rx = jiffies;
 347         }
 348
 349 end:
 350         mutex_unlock(&sta->ampdu_mlme.mtx);
 351
 352 end_no_lock:
 353         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 354                                   dialog_token, status, 1, buf_size, timeout);
 355 }