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 2007-2008, 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 #include <linux/ieee80211.h>
  17 #include <net/mac80211.h>
  18 #include "ieee80211_i.h"
  19
  20 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  21                                     u16 initiator, u16 reason)
  22 {
  23         struct ieee80211_local *local = sta->local;
  24         struct ieee80211_hw *hw = &local->hw;
  25         int i;
  26
  27         /* check if TID is in operational state */
  28         spin_lock_bh(&sta->lock);
  29         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL) {
  30                 spin_unlock_bh(&sta->lock);
  31                 return;
  32         }
  33
  34         sta->ampdu_mlme.tid_state_rx[tid] =
  35                 HT_AGG_STATE_REQ_STOP_BA_MSK |
  36                 (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
  37         spin_unlock_bh(&sta->lock);
  38
  39 #ifdef CONFIG_MAC80211_HT_DEBUG
  40         printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
  41                sta->sta.addr, tid);
  42 #endif /* CONFIG_MAC80211_HT_DEBUG */
  43
  44         if (local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_STOP,
  45                                      &sta->sta, tid, NULL))
  46                 printk(KERN_DEBUG "HW problem - can not stop rx "
  47                                 "aggregation for tid %d\n", tid);
  48
  49         /* shutdown timer has not expired */
  50         if (initiator != WLAN_BACK_TIMER)
  51                 del_timer_sync(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
  52
  53         /* check if this is a self generated aggregation halt */
  54         if (initiator == WLAN_BACK_RECIPIENT || initiator == WLAN_BACK_TIMER)
  55                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
  56                                      tid, 0, reason);
  57
  58         /* free the reordering buffer */
  59         for (i = 0; i < sta->ampdu_mlme.tid_rx[tid]->buf_size; i++) {
  60                 if (sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]) {
  61                         /* release the reordered frames */
  62                         dev_kfree_skb(sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]);
  63                         sta->ampdu_mlme.tid_rx[tid]->stored_mpdu_num--;
  64                         sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i] = NULL;
  65                 }
  66         }
  67
  68         spin_lock_bh(&sta->lock);
  69         /* free resources */
  70         kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_buf);
  71
  72         if (!sta->ampdu_mlme.tid_rx[tid]->shutdown) {
  73                 kfree(sta->ampdu_mlme.tid_rx[tid]);
  74                 sta->ampdu_mlme.tid_rx[tid] = NULL;
  75         }
  76
  77         sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_IDLE;
  78         spin_unlock_bh(&sta->lock);
  79 }
  80
  81 void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid,
  82                                         u16 initiator, u16 reason)
  83 {
  84         struct ieee80211_local *local = sdata->local;
  85         struct sta_info *sta;
  86
  87         /* stop HW Rx aggregation. ampdu_action existence
  88          * already verified in session init so we add the BUG_ON */
  89         BUG_ON(!local->ops->ampdu_action);
  90
  91         rcu_read_lock();
  92
  93         sta = sta_info_get(local, ra);
  94         if (!sta) {
  95                 rcu_read_unlock();
  96                 return;
  97         }
  98
  99         __ieee80211_stop_rx_ba_session(sta, tid, initiator, reason);
 100
 101         rcu_read_unlock();
 102 }
 103
 104 /*
 105  * After accepting the AddBA Request we activated a timer,
 106  * resetting it after each frame that arrives from the originator.
 107  * if this timer expires ieee80211_sta_stop_rx_ba_session will be executed.
 108  */
 109 static void sta_rx_agg_session_timer_expired(unsigned long data)
 110 {
 111         /* not an elegant detour, but there is no choice as the timer passes
 112          * only one argument, and various sta_info are needed here, so init
 113          * flow in sta_info_create gives the TID as data, while the timer_to_id
 114          * array gives the sta through container_of */
 115         u8 *ptid = (u8 *)data;
 116         u8 *timer_to_id = ptid - *ptid;
 117         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 118                                          timer_to_tid[0]);
 119
 120 #ifdef CONFIG_MAC80211_HT_DEBUG
 121         printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
 122 #endif
 123         ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
 124                                          (u16)*ptid, WLAN_BACK_TIMER,
 125                                          WLAN_REASON_QSTA_TIMEOUT);
 126 }
 127
 128 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 129                                       u8 dialog_token, u16 status, u16 policy,
 130                                       u16 buf_size, u16 timeout)
 131 {
 132         struct ieee80211_local *local = sdata->local;
 133         struct sk_buff *skb;
 134         struct ieee80211_mgmt *mgmt;
 135         u16 capab;
 136
 137         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 138
 139         if (!skb) {
 140                 printk(KERN_DEBUG "%s: failed to allocate buffer "
 141                        "for addba resp frame\n", sdata->dev->name);
 142                 return;
 143         }
 144
 145         skb_reserve(skb, local->hw.extra_tx_headroom);
 146         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 147         memset(mgmt, 0, 24);
 148         memcpy(mgmt->da, da, ETH_ALEN);
 149         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
 150         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 151             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 152                 memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
 153         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 154                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 155
 156         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 157                                           IEEE80211_STYPE_ACTION);
 158
 159         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 160         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 161         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 162         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 163
 164         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
 165         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 166         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 167
 168         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 169         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 170         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 171
 172         ieee80211_tx_skb(sdata, skb, 1);
 173 }
 174
 175 void ieee80211_process_addba_request(struct ieee80211_local *local,
 176                                      struct sta_info *sta,
 177                                      struct ieee80211_mgmt *mgmt,
 178                                      size_t len)
 179 {
 180         struct ieee80211_hw *hw = &local->hw;
 181         struct ieee80211_conf *conf = &hw->conf;
 182         struct tid_ampdu_rx *tid_agg_rx;
 183         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
 184         u8 dialog_token;
 185         int ret = -EOPNOTSUPP;
 186
 187         /* extract session parameters from addba request frame */
 188         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 189         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 190         start_seq_num =
 191                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 192
 193         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 194         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 195         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 196         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 197
 198         status = WLAN_STATUS_REQUEST_DECLINED;
 199
 200         /* sanity check for incoming parameters:
 201          * check if configuration can support the BA policy
 202          * and if buffer size does not exceeds max value */
 203         /* XXX: check own ht delayed BA capability?? */
 204         if (((ba_policy != 1)
 205                 && (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA)))
 206                 || (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 207                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 208 #ifdef CONFIG_MAC80211_HT_DEBUG
 209                 if (net_ratelimit())
 210                         printk(KERN_DEBUG "AddBA Req with bad params from "
 211                                 "%pM on tid %u. policy %d, buffer size %d\n",
 212                                 mgmt->sa, tid, ba_policy,
 213                                 buf_size);
 214 #endif /* CONFIG_MAC80211_HT_DEBUG */
 215                 goto end_no_lock;
 216         }
 217         /* determine default buffer size */
 218         if (buf_size == 0) {
 219                 struct ieee80211_supported_band *sband;
 220
 221                 sband = local->hw.wiphy->bands[conf->channel->band];
 222                 buf_size = IEEE80211_MIN_AMPDU_BUF;
 223                 buf_size = buf_size << sband->ht_cap.ampdu_factor;
 224         }
 225
 226
 227         /* examine state machine */
 228         spin_lock_bh(&sta->lock);
 229
 230         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_IDLE) {
 231 #ifdef CONFIG_MAC80211_HT_DEBUG
 232                 if (net_ratelimit())
 233                         printk(KERN_DEBUG "unexpected AddBA Req from "
 234                                 "%pM on tid %u\n",
 235                                 mgmt->sa, tid);
 236 #endif /* CONFIG_MAC80211_HT_DEBUG */
 237                 goto end;
 238         }
 239
 240         /* prepare A-MPDU MLME for Rx aggregation */
 241         sta->ampdu_mlme.tid_rx[tid] =
 242                         kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
 243         if (!sta->ampdu_mlme.tid_rx[tid]) {
 244 #ifdef CONFIG_MAC80211_HT_DEBUG
 245                 if (net_ratelimit())
 246                         printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
 247                                         tid);
 248 #endif
 249                 goto end;
 250         }
 251         /* rx timer */
 252         sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
 253                                 sta_rx_agg_session_timer_expired;
 254         sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
 255                                 (unsigned long)&sta->timer_to_tid[tid];
 256         init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
 257
 258         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
 259
 260         /* prepare reordering buffer */
 261         tid_agg_rx->reorder_buf =
 262                 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_ATOMIC);
 263         if (!tid_agg_rx->reorder_buf) {
 264 #ifdef CONFIG_MAC80211_HT_DEBUG
 265                 if (net_ratelimit())
 266                         printk(KERN_ERR "can not allocate reordering buffer "
 267                                "to tid %d\n", tid);
 268 #endif
 269                 kfree(sta->ampdu_mlme.tid_rx[tid]);
 270                 goto end;
 271         }
 272
 273         if (local->ops->ampdu_action)
 274                 ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_START,
 275                                                &sta->sta, tid, &start_seq_num);
 276 #ifdef CONFIG_MAC80211_HT_DEBUG
 277         printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
 278 #endif /* CONFIG_MAC80211_HT_DEBUG */
 279
 280         if (ret) {
 281                 kfree(tid_agg_rx->reorder_buf);
 282                 kfree(tid_agg_rx);
 283                 sta->ampdu_mlme.tid_rx[tid] = NULL;
 284                 goto end;
 285         }
 286
 287         /* change state and send addba resp */
 288         sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_OPERATIONAL;
 289         tid_agg_rx->dialog_token = dialog_token;
 290         tid_agg_rx->ssn = start_seq_num;
 291         tid_agg_rx->head_seq_num = start_seq_num;
 292         tid_agg_rx->buf_size = buf_size;
 293         tid_agg_rx->timeout = timeout;
 294         tid_agg_rx->stored_mpdu_num = 0;
 295         status = WLAN_STATUS_SUCCESS;
 296 end:
 297         spin_unlock_bh(&sta->lock);
 298
 299 end_no_lock:
 300         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 301                                   dialog_token, status, 1, buf_size, timeout);
 302 }