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