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 <linux/slab.h>
  18 #include <net/mac80211.h>
  19 #include "ieee80211_i.h"
  20 #include "driver-ops.h"
  21
  22 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  23                                     u16 initiator, u16 reason)
  24 {
  25         struct ieee80211_local *local = sta->local;
  26         int i;
  27
  28         /* check if TID is in operational state */
  29         spin_lock_bh(&sta->lock);
  30         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL) {
  31                 spin_unlock_bh(&sta->lock);
  32                 return;
  33         }
  34
  35         sta->ampdu_mlme.tid_state_rx[tid] =
  36                 HT_AGG_STATE_REQ_STOP_BA_MSK |
  37                 (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
  38         spin_unlock_bh(&sta->lock);
  39
  40 #ifdef CONFIG_MAC80211_HT_DEBUG
  41         printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
  42                sta->sta.addr, tid);
  43 #endif /* CONFIG_MAC80211_HT_DEBUG */
  44
  45         if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
  46                              &sta->sta, tid, NULL))
  47                 printk(KERN_DEBUG "HW problem - can not stop rx "
  48                                 "aggregation for tid %d\n", tid);
  49
  50         /* shutdown timer has not expired */
  51         if (initiator != WLAN_BACK_TIMER)
  52                 del_timer_sync(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
  53
  54         /* check if this is a self generated aggregation halt */
  55         if (initiator == WLAN_BACK_RECIPIENT || initiator == WLAN_BACK_TIMER)
  56                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
  57                                      tid, 0, reason);
  58
  59         /* free the reordering buffer */
  60         for (i = 0; i < sta->ampdu_mlme.tid_rx[tid]->buf_size; i++) {
  61                 if (sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]) {
  62                         /* release the reordered frames */
  63                         dev_kfree_skb(sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]);
  64                         sta->ampdu_mlme.tid_rx[tid]->stored_mpdu_num--;
  65                         sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i] = NULL;
  66                 }
  67         }
  68
  69         spin_lock_bh(&sta->lock);
  70         /* free resources */
  71         kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_buf);
  72         kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_time);
  73
  74         if (!sta->ampdu_mlme.tid_rx[tid]->shutdown) {
  75                 kfree(sta->ampdu_mlme.tid_rx[tid]);
  76                 sta->ampdu_mlme.tid_rx[tid] = NULL;
  77         }
  78
  79         sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_IDLE;
  80         spin_unlock_bh(&sta->lock);
  81 }
  82
  83 void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid,
  84                                         u16 initiator, u16 reason)
  85 {
  86         struct sta_info *sta;
  87
  88         rcu_read_lock();
  89
  90         sta = sta_info_get(sdata, ra);
  91         if (!sta) {
  92                 rcu_read_unlock();
  93                 return;
  94         }
  95
  96         __ieee80211_stop_rx_ba_session(sta, tid, initiator, reason);
  97
  98         rcu_read_unlock();
  99 }
 100
 101 /*
 102  * After accepting the AddBA Request we activated a timer,
 103  * resetting it after each frame that arrives from the originator.
 104  * if this timer expires ieee80211_sta_stop_rx_ba_session will be executed.
 105  */
 106 static void sta_rx_agg_session_timer_expired(unsigned long data)
 107 {
 108         /* not an elegant detour, but there is no choice as the timer passes
 109          * only one argument, and various sta_info are needed here, so init
 110          * flow in sta_info_create gives the TID as data, while the timer_to_id
 111          * array gives the sta through container_of */
 112         u8 *ptid = (u8 *)data;
 113         u8 *timer_to_id = ptid - *ptid;
 114         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 115                                          timer_to_tid[0]);
 116
 117 #ifdef CONFIG_MAC80211_HT_DEBUG
 118         printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
 119 #endif
 120         ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
 121                                          (u16)*ptid, WLAN_BACK_TIMER,
 122                                          WLAN_REASON_QSTA_TIMEOUT);
 123 }
 124
 125 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 126                                       u8 dialog_token, u16 status, u16 policy,
 127                                       u16 buf_size, u16 timeout)
 128 {
 129         struct ieee80211_local *local = sdata->local;
 130         struct sk_buff *skb;
 131         struct ieee80211_mgmt *mgmt;
 132         u16 capab;
 133
 134         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 135
 136         if (!skb) {
 137                 printk(KERN_DEBUG "%s: failed to allocate buffer "
 138                        "for addba resp frame\n", sdata->name);
 139                 return;
 140         }
 141
 142         skb_reserve(skb, local->hw.extra_tx_headroom);
 143         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 144         memset(mgmt, 0, 24);
 145         memcpy(mgmt->da, da, ETH_ALEN);
 146         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 147         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 148             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 149                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 150         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 151                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 152
 153         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 154                                           IEEE80211_STYPE_ACTION);
 155
 156         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 157         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 158         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 159         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 160
 161         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
 162         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 163         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 164
 165         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 166         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 167         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 168
 169         ieee80211_tx_skb(sdata, skb);
 170 }
 171
 172 void ieee80211_process_addba_request(struct ieee80211_local *local,
 173                                      struct sta_info *sta,
 174                                      struct ieee80211_mgmt *mgmt,
 175                                      size_t len)
 176 {
 177         struct ieee80211_hw *hw = &local->hw;
 178         struct ieee80211_conf *conf = &hw->conf;
 179         struct tid_ampdu_rx *tid_agg_rx;
 180         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
 181         u8 dialog_token;
 182         int ret = -EOPNOTSUPP;
 183
 184         /* extract session parameters from addba request frame */
 185         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 186         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 187         start_seq_num =
 188                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 189
 190         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 191         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 192         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 193         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 194
 195         status = WLAN_STATUS_REQUEST_DECLINED;
 196
 197         if (test_sta_flags(sta, WLAN_STA_SUSPEND)) {
 198 #ifdef CONFIG_MAC80211_HT_DEBUG
 199                 printk(KERN_DEBUG "Suspend in progress. "
 200                        "Denying ADDBA request\n");
 201 #endif
 202                 goto end_no_lock;
 203         }
 204
 205         /* sanity check for incoming parameters:
 206          * check if configuration can support the BA policy
 207          * and if buffer size does not exceeds max value */
 208         /* XXX: check own ht delayed BA capability?? */
 209         if (((ba_policy != 1) &&
 210              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 211             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 212                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 213 #ifdef CONFIG_MAC80211_HT_DEBUG
 214                 if (net_ratelimit())
 215                         printk(KERN_DEBUG "AddBA Req with bad params from "
 216                                 "%pM on tid %u. policy %d, buffer size %d\n",
 217                                 mgmt->sa, tid, ba_policy,
 218                                 buf_size);
 219 #endif /* CONFIG_MAC80211_HT_DEBUG */
 220                 goto end_no_lock;
 221         }
 222         /* determine default buffer size */
 223         if (buf_size == 0) {
 224                 struct ieee80211_supported_band *sband;
 225
 226                 sband = local->hw.wiphy->bands[conf->channel->band];
 227                 buf_size = IEEE80211_MIN_AMPDU_BUF;
 228                 buf_size = buf_size << sband->ht_cap.ampdu_factor;
 229         }
 230
 231
 232         /* examine state machine */
 233         spin_lock_bh(&sta->lock);
 234
 235         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_IDLE) {
 236 #ifdef CONFIG_MAC80211_HT_DEBUG
 237                 if (net_ratelimit())
 238                         printk(KERN_DEBUG "unexpected AddBA Req from "
 239                                 "%pM on tid %u\n",
 240                                 mgmt->sa, tid);
 241 #endif /* CONFIG_MAC80211_HT_DEBUG */
 242                 goto end;
 243         }
 244
 245         /* prepare A-MPDU MLME for Rx aggregation */
 246         sta->ampdu_mlme.tid_rx[tid] =
 247                         kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
 248         if (!sta->ampdu_mlme.tid_rx[tid]) {
 249 #ifdef CONFIG_MAC80211_HT_DEBUG
 250                 if (net_ratelimit())
 251                         printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
 252                                         tid);
 253 #endif
 254                 goto end;
 255         }
 256         /* rx timer */
 257         sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
 258                                 sta_rx_agg_session_timer_expired;
 259         sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
 260                                 (unsigned long)&sta->timer_to_tid[tid];
 261         init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
 262
 263         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
 264
 265         /* prepare reordering buffer */
 266         tid_agg_rx->reorder_buf =
 267                 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_ATOMIC);
 268         tid_agg_rx->reorder_time =
 269                 kcalloc(buf_size, sizeof(unsigned long), GFP_ATOMIC);
 270         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 271 #ifdef CONFIG_MAC80211_HT_DEBUG
 272                 if (net_ratelimit())
 273                         printk(KERN_ERR "can not allocate reordering buffer "
 274                                "to tid %d\n", tid);
 275 #endif
 276                 kfree(tid_agg_rx->reorder_buf);
 277                 kfree(tid_agg_rx->reorder_time);
 278                 kfree(sta->ampdu_mlme.tid_rx[tid]);
 279                 sta->ampdu_mlme.tid_rx[tid] = NULL;
 280                 goto end;
 281         }
 282
 283         ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
 284                                &sta->sta, tid, &start_seq_num);
 285 #ifdef CONFIG_MAC80211_HT_DEBUG
 286         printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
 287 #endif /* CONFIG_MAC80211_HT_DEBUG */
 288
 289         if (ret) {
 290                 kfree(tid_agg_rx->reorder_buf);
 291                 kfree(tid_agg_rx);
 292                 sta->ampdu_mlme.tid_rx[tid] = NULL;
 293                 goto end;
 294         }
 295
 296         /* change state and send addba resp */
 297         sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_OPERATIONAL;
 298         tid_agg_rx->dialog_token = dialog_token;
 299         tid_agg_rx->ssn = start_seq_num;
 300         tid_agg_rx->head_seq_num = start_seq_num;
 301         tid_agg_rx->buf_size = buf_size;
 302         tid_agg_rx->timeout = timeout;
 303         tid_agg_rx->stored_mpdu_num = 0;
 304         status = WLAN_STATUS_SUCCESS;
 305 end:
 306         spin_unlock_bh(&sta->lock);
 307
 308 end_no_lock:
 309         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 310                                   dialog_token, status, 1, buf_size, timeout);
 311 }