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 static void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  23                                             u16 initiator, u16 reason,
  24                                             bool from_timer)
  25 {
  26         struct ieee80211_local *local = sta->local;
  27         struct tid_ampdu_rx *tid_rx;
  28         int i;
  29
  30         spin_lock_bh(&sta->lock);
  31
  32         /* check if TID is in operational state */
  33         if (!sta->ampdu_mlme.tid_active_rx[tid]) {
  34                 spin_unlock_bh(&sta->lock);
  35                 return;
  36         }
  37
  38         sta->ampdu_mlme.tid_active_rx[tid] = false;
  39
  40         tid_rx = sta->ampdu_mlme.tid_rx[tid];
  41
  42 #ifdef CONFIG_MAC80211_HT_DEBUG
  43         printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
  44                sta->sta.addr, tid);
  45 #endif /* CONFIG_MAC80211_HT_DEBUG */
  46
  47         if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
  48                              &sta->sta, tid, NULL))
  49                 printk(KERN_DEBUG "HW problem - can not stop rx "
  50                                 "aggregation for tid %d\n", tid);
  51
  52         /* check if this is a self generated aggregation halt */
  53         if (initiator == WLAN_BACK_RECIPIENT)
  54                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
  55                                      tid, 0, reason);
  56
  57         /* free the reordering buffer */
  58         for (i = 0; i < tid_rx->buf_size; i++) {
  59                 if (tid_rx->reorder_buf[i]) {
  60                         /* release the reordered frames */
  61                         dev_kfree_skb(tid_rx->reorder_buf[i]);
  62                         tid_rx->stored_mpdu_num--;
  63                         tid_rx->reorder_buf[i] = NULL;
  64                 }
  65         }
  66
  67         /* free resources */
  68         kfree(tid_rx->reorder_buf);
  69         kfree(tid_rx->reorder_time);
  70         sta->ampdu_mlme.tid_rx[tid] = NULL;
  71
  72         spin_unlock_bh(&sta->lock);
  73
  74         if (!from_timer)
  75                 del_timer_sync(&tid_rx->session_timer);
  76         kfree(tid_rx);
  77 }
  78
  79 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  80                                     u16 initiator, u16 reason)
  81 {
  82         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, false);
  83 }
  84
  85 /*
  86  * After accepting the AddBA Request we activated a timer,
  87  * resetting it after each frame that arrives from the originator.
  88  */
  89 static void sta_rx_agg_session_timer_expired(unsigned long data)
  90 {
  91         /* not an elegant detour, but there is no choice as the timer passes
  92          * only one argument, and various sta_info are needed here, so init
  93          * flow in sta_info_create gives the TID as data, while the timer_to_id
  94          * array gives the sta through container_of */
  95         u8 *ptid = (u8 *)data;
  96         u8 *timer_to_id = ptid - *ptid;
  97         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
  98                                          timer_to_tid[0]);
  99
 100 #ifdef CONFIG_MAC80211_HT_DEBUG
 101         printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
 102 #endif
 103         ___ieee80211_stop_rx_ba_session(sta, *ptid, WLAN_BACK_RECIPIENT,
 104                                         WLAN_REASON_QSTA_TIMEOUT, true);
 105 }
 106
 107 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 108                                       u8 dialog_token, u16 status, u16 policy,
 109                                       u16 buf_size, u16 timeout)
 110 {
 111         struct ieee80211_local *local = sdata->local;
 112         struct sk_buff *skb;
 113         struct ieee80211_mgmt *mgmt;
 114         u16 capab;
 115
 116         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 117
 118         if (!skb) {
 119                 printk(KERN_DEBUG "%s: failed to allocate buffer "
 120                        "for addba resp frame\n", sdata->name);
 121                 return;
 122         }
 123
 124         skb_reserve(skb, local->hw.extra_tx_headroom);
 125         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 126         memset(mgmt, 0, 24);
 127         memcpy(mgmt->da, da, ETH_ALEN);
 128         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 129         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 130             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 131                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 132         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 133                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 134
 135         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 136                                           IEEE80211_STYPE_ACTION);
 137
 138         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 139         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 140         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 141         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 142
 143         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
 144         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 145         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 146
 147         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 148         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 149         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 150
 151         ieee80211_tx_skb(sdata, skb);
 152 }
 153
 154 void ieee80211_process_addba_request(struct ieee80211_local *local,
 155                                      struct sta_info *sta,
 156                                      struct ieee80211_mgmt *mgmt,
 157                                      size_t len)
 158 {
 159         struct ieee80211_hw *hw = &local->hw;
 160         struct ieee80211_conf *conf = &hw->conf;
 161         struct tid_ampdu_rx *tid_agg_rx;
 162         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
 163         u8 dialog_token;
 164         int ret = -EOPNOTSUPP;
 165
 166         /* extract session parameters from addba request frame */
 167         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 168         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 169         start_seq_num =
 170                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 171
 172         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 173         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 174         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 175         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 176
 177         status = WLAN_STATUS_REQUEST_DECLINED;
 178
 179         if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
 180 #ifdef CONFIG_MAC80211_HT_DEBUG
 181                 printk(KERN_DEBUG "Suspend in progress. "
 182                        "Denying ADDBA request\n");
 183 #endif
 184                 goto end_no_lock;
 185         }
 186
 187         /* sanity check for incoming parameters:
 188          * check if configuration can support the BA policy
 189          * and if buffer size does not exceeds max value */
 190         /* XXX: check own ht delayed BA capability?? */
 191         if (((ba_policy != 1) &&
 192              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 193             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 194                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 195 #ifdef CONFIG_MAC80211_HT_DEBUG
 196                 if (net_ratelimit())
 197                         printk(KERN_DEBUG "AddBA Req with bad params from "
 198                                 "%pM on tid %u. policy %d, buffer size %d\n",
 199                                 mgmt->sa, tid, ba_policy,
 200                                 buf_size);
 201 #endif /* CONFIG_MAC80211_HT_DEBUG */
 202                 goto end_no_lock;
 203         }
 204         /* determine default buffer size */
 205         if (buf_size == 0) {
 206                 struct ieee80211_supported_band *sband;
 207
 208                 sband = local->hw.wiphy->bands[conf->channel->band];
 209                 buf_size = IEEE80211_MIN_AMPDU_BUF;
 210                 buf_size = buf_size << sband->ht_cap.ampdu_factor;
 211         }
 212
 213
 214         /* examine state machine */
 215         spin_lock_bh(&sta->lock);
 216
 217         if (sta->ampdu_mlme.tid_active_rx[tid]) {
 218 #ifdef CONFIG_MAC80211_HT_DEBUG
 219                 if (net_ratelimit())
 220                         printk(KERN_DEBUG "unexpected AddBA Req from "
 221                                 "%pM on tid %u\n",
 222                                 mgmt->sa, tid);
 223 #endif /* CONFIG_MAC80211_HT_DEBUG */
 224                 goto end;
 225         }
 226
 227         /* prepare A-MPDU MLME for Rx aggregation */
 228         sta->ampdu_mlme.tid_rx[tid] =
 229                         kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
 230         if (!sta->ampdu_mlme.tid_rx[tid]) {
 231 #ifdef CONFIG_MAC80211_HT_DEBUG
 232                 if (net_ratelimit())
 233                         printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
 234                                         tid);
 235 #endif
 236                 goto end;
 237         }
 238         /* rx timer */
 239         sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
 240                                 sta_rx_agg_session_timer_expired;
 241         sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
 242                                 (unsigned long)&sta->timer_to_tid[tid];
 243         init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
 244
 245         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
 246
 247         /* prepare reordering buffer */
 248         tid_agg_rx->reorder_buf =
 249                 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_ATOMIC);
 250         tid_agg_rx->reorder_time =
 251                 kcalloc(buf_size, sizeof(unsigned long), GFP_ATOMIC);
 252         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 253 #ifdef CONFIG_MAC80211_HT_DEBUG
 254                 if (net_ratelimit())
 255                         printk(KERN_ERR "can not allocate reordering buffer "
 256                                "to tid %d\n", tid);
 257 #endif
 258                 kfree(tid_agg_rx->reorder_buf);
 259                 kfree(tid_agg_rx->reorder_time);
 260                 kfree(sta->ampdu_mlme.tid_rx[tid]);
 261                 sta->ampdu_mlme.tid_rx[tid] = NULL;
 262                 goto end;
 263         }
 264
 265         ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
 266                                &sta->sta, tid, &start_seq_num);
 267 #ifdef CONFIG_MAC80211_HT_DEBUG
 268         printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
 269 #endif /* CONFIG_MAC80211_HT_DEBUG */
 270
 271         if (ret) {
 272                 kfree(tid_agg_rx->reorder_buf);
 273                 kfree(tid_agg_rx);
 274                 sta->ampdu_mlme.tid_rx[tid] = NULL;
 275                 goto end;
 276         }
 277
 278         /* change state and send addba resp */
 279         sta->ampdu_mlme.tid_active_rx[tid] = true;
 280         tid_agg_rx->dialog_token = dialog_token;
 281         tid_agg_rx->ssn = start_seq_num;
 282         tid_agg_rx->head_seq_num = start_seq_num;
 283         tid_agg_rx->buf_size = buf_size;
 284         tid_agg_rx->timeout = timeout;
 285         tid_agg_rx->stored_mpdu_num = 0;
 286         status = WLAN_STATUS_SUCCESS;
 287 end:
 288         spin_unlock_bh(&sta->lock);
 289
 290 end_no_lock:
 291         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 292                                   dialog_token, status, 1, buf_size, timeout);
 293 }