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