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_free_tid_rx(struct rcu_head *h)
  23 {
  24         struct tid_ampdu_rx *tid_rx =
  25                 container_of(h, struct tid_ampdu_rx, rcu_head);
  26         int i;
  27
  28         for (i = 0; i < tid_rx->buf_size; i++)
  29                 dev_kfree_skb(tid_rx->reorder_buf[i]);
  30         kfree(tid_rx->reorder_buf);
  31         kfree(tid_rx->reorder_time);
  32         kfree(tid_rx);
  33 }
  34
  35 static void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  36                                             u16 initiator, u16 reason,
  37                                             bool from_timer)
  38 {
  39         struct ieee80211_local *local = sta->local;
  40         struct tid_ampdu_rx *tid_rx;
  41
  42         spin_lock_bh(&sta->lock);
  43
  44         tid_rx = sta->ampdu_mlme.tid_rx[tid];
  45
  46         if (!tid_rx) {
  47                 spin_unlock_bh(&sta->lock);
  48                 return;
  49         }
  50
  51         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], NULL);
  52
  53 #ifdef CONFIG_MAC80211_HT_DEBUG
  54         printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
  55                sta->sta.addr, tid);
  56 #endif /* CONFIG_MAC80211_HT_DEBUG */
  57
  58         if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
  59                              &sta->sta, tid, NULL))
  60                 printk(KERN_DEBUG "HW problem - can not stop rx "
  61                                 "aggregation for tid %d\n", tid);
  62
  63         /* check if this is a self generated aggregation halt */
  64         if (initiator == WLAN_BACK_RECIPIENT)
  65                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
  66                                      tid, 0, reason);
  67
  68         spin_unlock_bh(&sta->lock);
  69
  70         if (!from_timer)
  71                 del_timer_sync(&tid_rx->session_timer);
  72
  73         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
  74 }
  75
  76 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  77                                     u16 initiator, u16 reason)
  78 {
  79         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, false);
  80 }
  81
  82 /*
  83  * After accepting the AddBA Request we activated a timer,
  84  * resetting it after each frame that arrives from the originator.
  85  */
  86 static void sta_rx_agg_session_timer_expired(unsigned long data)
  87 {
  88         /* not an elegant detour, but there is no choice as the timer passes
  89          * only one argument, and various sta_info are needed here, so init
  90          * flow in sta_info_create gives the TID as data, while the timer_to_id
  91          * array gives the sta through container_of */
  92         u8 *ptid = (u8 *)data;
  93         u8 *timer_to_id = ptid - *ptid;
  94         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
  95                                          timer_to_tid[0]);
  96
  97 #ifdef CONFIG_MAC80211_HT_DEBUG
  98         printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
  99 #endif
 100         ___ieee80211_stop_rx_ba_session(sta, *ptid, WLAN_BACK_RECIPIENT,
 101                                         WLAN_REASON_QSTA_TIMEOUT, true);
 102 }
 103
 104 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 105                                       u8 dialog_token, u16 status, u16 policy,
 106                                       u16 buf_size, u16 timeout)
 107 {
 108         struct ieee80211_local *local = sdata->local;
 109         struct sk_buff *skb;
 110         struct ieee80211_mgmt *mgmt;
 111         u16 capab;
 112
 113         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 114
 115         if (!skb) {
 116                 printk(KERN_DEBUG "%s: failed to allocate buffer "
 117                        "for addba resp frame\n", sdata->name);
 118                 return;
 119         }
 120
 121         skb_reserve(skb, local->hw.extra_tx_headroom);
 122         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 123         memset(mgmt, 0, 24);
 124         memcpy(mgmt->da, da, ETH_ALEN);
 125         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 126         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 127             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 128                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 129         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 130                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 131
 132         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 133                                           IEEE80211_STYPE_ACTION);
 134
 135         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 136         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 137         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 138         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 139
 140         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
 141         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 142         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 143
 144         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 145         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 146         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 147
 148         ieee80211_tx_skb(sdata, skb);
 149 }
 150
 151 void ieee80211_process_addba_request(struct ieee80211_local *local,
 152                                      struct sta_info *sta,
 153                                      struct ieee80211_mgmt *mgmt,
 154                                      size_t len)
 155 {
 156         struct ieee80211_hw *hw = &local->hw;
 157         struct ieee80211_conf *conf = &hw->conf;
 158         struct tid_ampdu_rx *tid_agg_rx;
 159         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
 160         u8 dialog_token;
 161         int ret = -EOPNOTSUPP;
 162
 163         /* extract session parameters from addba request frame */
 164         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 165         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 166         start_seq_num =
 167                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 168
 169         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 170         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 171         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 172         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 173
 174         status = WLAN_STATUS_REQUEST_DECLINED;
 175
 176         if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
 177 #ifdef CONFIG_MAC80211_HT_DEBUG
 178                 printk(KERN_DEBUG "Suspend in progress. "
 179                        "Denying ADDBA request\n");
 180 #endif
 181                 goto end_no_lock;
 182         }
 183
 184         /* sanity check for incoming parameters:
 185          * check if configuration can support the BA policy
 186          * and if buffer size does not exceeds max value */
 187         /* XXX: check own ht delayed BA capability?? */
 188         if (((ba_policy != 1) &&
 189              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 190             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 191                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 192 #ifdef CONFIG_MAC80211_HT_DEBUG
 193                 if (net_ratelimit())
 194                         printk(KERN_DEBUG "AddBA Req with bad params from "
 195                                 "%pM on tid %u. policy %d, buffer size %d\n",
 196                                 mgmt->sa, tid, ba_policy,
 197                                 buf_size);
 198 #endif /* CONFIG_MAC80211_HT_DEBUG */
 199                 goto end_no_lock;
 200         }
 201         /* determine default buffer size */
 202         if (buf_size == 0) {
 203                 struct ieee80211_supported_band *sband;
 204
 205                 sband = local->hw.wiphy->bands[conf->channel->band];
 206                 buf_size = IEEE80211_MIN_AMPDU_BUF;
 207                 buf_size = buf_size << sband->ht_cap.ampdu_factor;
 208         }
 209
 210
 211         /* examine state machine */
 212         spin_lock_bh(&sta->lock);
 213
 214         if (sta->ampdu_mlme.tid_rx[tid]) {
 215 #ifdef CONFIG_MAC80211_HT_DEBUG
 216                 if (net_ratelimit())
 217                         printk(KERN_DEBUG "unexpected AddBA Req from "
 218                                 "%pM on tid %u\n",
 219                                 mgmt->sa, tid);
 220 #endif /* CONFIG_MAC80211_HT_DEBUG */
 221                 goto end;
 222         }
 223
 224         /* prepare A-MPDU MLME for Rx aggregation */
 225         tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
 226         if (!tid_agg_rx) {
 227 #ifdef CONFIG_MAC80211_HT_DEBUG
 228                 if (net_ratelimit())
 229                         printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
 230                                         tid);
 231 #endif
 232                 goto end;
 233         }
 234
 235         /* rx timer */
 236         tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
 237         tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 238         init_timer(&tid_agg_rx->session_timer);
 239
 240         /* prepare reordering buffer */
 241         tid_agg_rx->reorder_buf =
 242                 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_ATOMIC);
 243         tid_agg_rx->reorder_time =
 244                 kcalloc(buf_size, sizeof(unsigned long), GFP_ATOMIC);
 245         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 246 #ifdef CONFIG_MAC80211_HT_DEBUG
 247                 if (net_ratelimit())
 248                         printk(KERN_ERR "can not allocate reordering buffer "
 249                                "to tid %d\n", tid);
 250 #endif
 251                 kfree(tid_agg_rx->reorder_buf);
 252                 kfree(tid_agg_rx->reorder_time);
 253                 kfree(tid_agg_rx);
 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->reorder_time);
 266                 kfree(tid_agg_rx);
 267                 goto end;
 268         }
 269
 270         /* update data */
 271         tid_agg_rx->dialog_token = dialog_token;
 272         tid_agg_rx->ssn = start_seq_num;
 273         tid_agg_rx->head_seq_num = start_seq_num;
 274         tid_agg_rx->buf_size = buf_size;
 275         tid_agg_rx->timeout = timeout;
 276         tid_agg_rx->stored_mpdu_num = 0;
 277         status = WLAN_STATUS_SUCCESS;
 278
 279         /* activate it for RX */
 280         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
 281 end:
 282         spin_unlock_bh(&sta->lock);
 283
 284 end_no_lock:
 285         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 286                                   dialog_token, status, 1, buf_size, timeout);
 287 }