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 #include "driver-ops.h"
  20
  21 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  22                                     u16 initiator, u16 reason)
  23 {
  24         struct ieee80211_local *local = sta->local;
  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 (drv_ampdu_action(local, 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         kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_time);
  72
  73         if (!sta->ampdu_mlme.tid_rx[tid]->shutdown) {
  74                 kfree(sta->ampdu_mlme.tid_rx[tid]);
  75                 sta->ampdu_mlme.tid_rx[tid] = NULL;
  76         }
  77
  78         sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_IDLE;
  79         spin_unlock_bh(&sta->lock);
  80 }
  81
  82 void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid,
  83                                         u16 initiator, u16 reason)
  84 {
  85         struct ieee80211_local *local = sdata->local;
  86         struct sta_info *sta;
  87
  88         /* stop HW Rx aggregation. ampdu_action existence
  89          * already verified in session init so we add the BUG_ON */
  90         BUG_ON(!local->ops->ampdu_action);
  91
  92         rcu_read_lock();
  93
  94         sta = sta_info_get(local, ra);
  95         if (!sta) {
  96                 rcu_read_unlock();
  97                 return;
  98         }
  99
 100         __ieee80211_stop_rx_ba_session(sta, tid, initiator, reason);
 101
 102         rcu_read_unlock();
 103 }
 104
 105 /*
 106  * After accepting the AddBA Request we activated a timer,
 107  * resetting it after each frame that arrives from the originator.
 108  * if this timer expires ieee80211_sta_stop_rx_ba_session will be executed.
 109  */
 110 static void sta_rx_agg_session_timer_expired(unsigned long data)
 111 {
 112         /* not an elegant detour, but there is no choice as the timer passes
 113          * only one argument, and various sta_info are needed here, so init
 114          * flow in sta_info_create gives the TID as data, while the timer_to_id
 115          * array gives the sta through container_of */
 116         u8 *ptid = (u8 *)data;
 117         u8 *timer_to_id = ptid - *ptid;
 118         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 119                                          timer_to_tid[0]);
 120
 121 #ifdef CONFIG_MAC80211_HT_DEBUG
 122         printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
 123 #endif
 124         ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
 125                                          (u16)*ptid, WLAN_BACK_TIMER,
 126                                          WLAN_REASON_QSTA_TIMEOUT);
 127 }
 128
 129 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 130                                       u8 dialog_token, u16 status, u16 policy,
 131                                       u16 buf_size, u16 timeout)
 132 {
 133         struct ieee80211_local *local = sdata->local;
 134         struct sk_buff *skb;
 135         struct ieee80211_mgmt *mgmt;
 136         u16 capab;
 137
 138         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 139
 140         if (!skb) {
 141                 printk(KERN_DEBUG "%s: failed to allocate buffer "
 142                        "for addba resp frame\n", sdata->dev->name);
 143                 return;
 144         }
 145
 146         skb_reserve(skb, local->hw.extra_tx_headroom);
 147         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 148         memset(mgmt, 0, 24);
 149         memcpy(mgmt->da, da, ETH_ALEN);
 150         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
 151         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 152             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 153                 memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
 154         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 155                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 156
 157         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 158                                           IEEE80211_STYPE_ACTION);
 159
 160         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 161         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 162         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 163         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 164
 165         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
 166         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 167         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 168
 169         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 170         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 171         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 172
 173         ieee80211_tx_skb(sdata, skb, 1);
 174 }
 175
 176 void ieee80211_process_addba_request(struct ieee80211_local *local,
 177                                      struct sta_info *sta,
 178                                      struct ieee80211_mgmt *mgmt,
 179                                      size_t len)
 180 {
 181         struct ieee80211_hw *hw = &local->hw;
 182         struct ieee80211_conf *conf = &hw->conf;
 183         struct tid_ampdu_rx *tid_agg_rx;
 184         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
 185         u8 dialog_token;
 186         int ret = -EOPNOTSUPP;
 187
 188         /* extract session parameters from addba request frame */
 189         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 190         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 191         start_seq_num =
 192                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 193
 194         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 195         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 196         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 197         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 198
 199         status = WLAN_STATUS_REQUEST_DECLINED;
 200
 201         if (test_sta_flags(sta, WLAN_STA_SUSPEND)) {
 202 #ifdef CONFIG_MAC80211_HT_DEBUG
 203                 printk(KERN_DEBUG "Suspend in progress. "
 204                        "Denying ADDBA request\n");
 205 #endif
 206                 goto end_no_lock;
 207         }
 208
 209         /* sanity check for incoming parameters:
 210          * check if configuration can support the BA policy
 211          * and if buffer size does not exceeds max value */
 212         /* XXX: check own ht delayed BA capability?? */
 213         if (((ba_policy != 1)
 214                 && (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA)))
 215                 || (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 216                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 217 #ifdef CONFIG_MAC80211_HT_DEBUG
 218                 if (net_ratelimit())
 219                         printk(KERN_DEBUG "AddBA Req with bad params from "
 220                                 "%pM on tid %u. policy %d, buffer size %d\n",
 221                                 mgmt->sa, tid, ba_policy,
 222                                 buf_size);
 223 #endif /* CONFIG_MAC80211_HT_DEBUG */
 224                 goto end_no_lock;
 225         }
 226         /* determine default buffer size */
 227         if (buf_size == 0) {
 228                 struct ieee80211_supported_band *sband;
 229
 230                 sband = local->hw.wiphy->bands[conf->channel->band];
 231                 buf_size = IEEE80211_MIN_AMPDU_BUF;
 232                 buf_size = buf_size << sband->ht_cap.ampdu_factor;
 233         }
 234
 235
 236         /* examine state machine */
 237         spin_lock_bh(&sta->lock);
 238
 239         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_IDLE) {
 240 #ifdef CONFIG_MAC80211_HT_DEBUG
 241                 if (net_ratelimit())
 242                         printk(KERN_DEBUG "unexpected AddBA Req from "
 243                                 "%pM on tid %u\n",
 244                                 mgmt->sa, tid);
 245 #endif /* CONFIG_MAC80211_HT_DEBUG */
 246                 goto end;
 247         }
 248
 249         /* prepare A-MPDU MLME for Rx aggregation */
 250         sta->ampdu_mlme.tid_rx[tid] =
 251                         kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
 252         if (!sta->ampdu_mlme.tid_rx[tid]) {
 253 #ifdef CONFIG_MAC80211_HT_DEBUG
 254                 if (net_ratelimit())
 255                         printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
 256                                         tid);
 257 #endif
 258                 goto end;
 259         }
 260         /* rx timer */
 261         sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
 262                                 sta_rx_agg_session_timer_expired;
 263         sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
 264                                 (unsigned long)&sta->timer_to_tid[tid];
 265         init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
 266
 267         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
 268
 269         /* prepare reordering buffer */
 270         tid_agg_rx->reorder_buf =
 271                 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_ATOMIC);
 272         tid_agg_rx->reorder_time =
 273                 kcalloc(buf_size, sizeof(unsigned long), GFP_ATOMIC);
 274         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 275 #ifdef CONFIG_MAC80211_HT_DEBUG
 276                 if (net_ratelimit())
 277                         printk(KERN_ERR "can not allocate reordering buffer "
 278                                "to tid %d\n", tid);
 279 #endif
 280                 kfree(tid_agg_rx->reorder_buf);
 281                 kfree(tid_agg_rx->reorder_time);
 282                 kfree(sta->ampdu_mlme.tid_rx[tid]);
 283                 sta->ampdu_mlme.tid_rx[tid] = NULL;
 284                 goto end;
 285         }
 286
 287         ret = drv_ampdu_action(local, IEEE80211_AMPDU_RX_START,
 288                                &sta->sta, tid, &start_seq_num);
 289 #ifdef CONFIG_MAC80211_HT_DEBUG
 290         printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
 291 #endif /* CONFIG_MAC80211_HT_DEBUG */
 292
 293         if (ret) {
 294                 kfree(tid_agg_rx->reorder_buf);
 295                 kfree(tid_agg_rx);
 296                 sta->ampdu_mlme.tid_rx[tid] = NULL;
 297                 goto end;
 298         }
 299
 300         /* change state and send addba resp */
 301         sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_OPERATIONAL;
 302         tid_agg_rx->dialog_token = dialog_token;
 303         tid_agg_rx->ssn = start_seq_num;
 304         tid_agg_rx->head_seq_num = start_seq_num;
 305         tid_agg_rx->buf_size = buf_size;
 306         tid_agg_rx->timeout = timeout;
 307         tid_agg_rx->stored_mpdu_num = 0;
 308         status = WLAN_STATUS_SUCCESS;
 309 end:
 310         spin_unlock_bh(&sta->lock);
 311
 312 end_no_lock:
 313         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 314                                   dialog_token, status, 1, buf_size, timeout);
 315 }