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