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 2007-2010, 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 /**
  17  * DOC: RX A-MPDU aggregation
  18  *
  19  * Aggregation on the RX side requires only implementing the
  20  * @ampdu_action callback that is invoked to start/stop any
  21  * block-ack sessions for RX aggregation.
  22  *
  23  * When RX aggregation is started by the peer, the driver is
  24  * notified via @ampdu_action function, with the
  25  * %IEEE80211_AMPDU_RX_START action, and may reject the request
  26  * in which case a negative response is sent to the peer, if it
  27  * accepts it a positive response is sent.
  28  *
  29  * While the session is active, the device/driver are required
  30  * to de-aggregate frames and pass them up one by one to mac80211,
  31  * which will handle the reorder buffer.
  32  *
  33  * When the aggregation session is stopped again by the peer or
  34  * ourselves, the driver's @ampdu_action function will be called
  35  * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
  36  * call must not fail.
  37  */
  38
  39 #include <linux/ieee80211.h>
  40 #include <linux/slab.h>
  41 #include <linux/export.h>
  42 #include <net/mac80211.h>
  43 #include "ieee80211_i.h"
  44 #include "driver-ops.h"
  45
  46 static void ieee80211_free_tid_rx(struct rcu_head *h)
  47 {
  48         struct tid_ampdu_rx *tid_rx =
  49                 container_of(h, struct tid_ampdu_rx, rcu_head);
  50         int i;
  51
  52         for (i = 0; i < tid_rx->buf_size; i++)
  53                 dev_kfree_skb(tid_rx->reorder_buf[i]);
  54         kfree(tid_rx->reorder_buf);
  55         kfree(tid_rx->reorder_time);
  56         kfree(tid_rx);
  57 }
  58
  59 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  60                                      u16 initiator, u16 reason, bool tx)
  61 {
  62         struct ieee80211_local *local = sta->local;
  63         struct tid_ampdu_rx *tid_rx;
  64
  65         lockdep_assert_held(&sta->ampdu_mlme.mtx);
  66
  67         tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
  68                                         lockdep_is_held(&sta->ampdu_mlme.mtx));
  69
  70         if (!tid_rx)
  71                 return;
  72
  73         RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
  74
  75 #ifdef CONFIG_MAC80211_HT_DEBUG
  76         printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
  77                sta->sta.addr, tid);
  78 #endif /* CONFIG_MAC80211_HT_DEBUG */
  79
  80         if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
  81                              &sta->sta, tid, NULL, 0))
  82                 printk(KERN_DEBUG "HW problem - can not stop rx "
  83                                 "aggregation for tid %d\n", tid);
  84
  85         /* check if this is a self generated aggregation halt */
  86         if (initiator == WLAN_BACK_RECIPIENT && tx)
  87                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
  88                                      tid, 0, reason);
  89
  90         del_timer_sync(&tid_rx->session_timer);
  91
  92         /* make sure ieee80211_sta_reorder_release() doesn't re-arm the timer */
  93         spin_lock_bh(&tid_rx->reorder_lock);
  94         tid_rx->removed = true;
  95         spin_unlock_bh(&tid_rx->reorder_lock);
  96         del_timer_sync(&tid_rx->reorder_timer);
  97
  98         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
  99 }
 100
 101 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
 102                                     u16 initiator, u16 reason, bool tx)
 103 {
 104         mutex_lock(&sta->ampdu_mlme.mtx);
 105         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
 106         mutex_unlock(&sta->ampdu_mlme.mtx);
 107 }
 108
 109 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
 110                                   const u8 *addr)
 111 {
 112         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 113         struct sta_info *sta;
 114         int i;
 115
 116         rcu_read_lock();
 117         sta = sta_info_get(sdata, addr);
 118         if (!sta) {
 119                 rcu_read_unlock();
 120                 return;
 121         }
 122
 123         for (i = 0; i < STA_TID_NUM; i++)
 124                 if (ba_rx_bitmap & BIT(i))
 125                         set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
 126
 127         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 128         rcu_read_unlock();
 129 }
 130 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
 131
 132 /*
 133  * After accepting the AddBA Request we activated a timer,
 134  * resetting it after each frame that arrives from the originator.
 135  */
 136 static void sta_rx_agg_session_timer_expired(unsigned long data)
 137 {
 138         /* not an elegant detour, but there is no choice as the timer passes
 139          * only one argument, and various sta_info are needed here, so init
 140          * flow in sta_info_create gives the TID as data, while the timer_to_id
 141          * array gives the sta through container_of */
 142         u8 *ptid = (u8 *)data;
 143         u8 *timer_to_id = ptid - *ptid;
 144         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 145                                          timer_to_tid[0]);
 146
 147 #ifdef CONFIG_MAC80211_HT_DEBUG
 148         printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
 149 #endif
 150         set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
 151         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 152 }
 153
 154 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
 155 {
 156         u8 *ptid = (u8 *)data;
 157         u8 *timer_to_id = ptid - *ptid;
 158         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 159                         timer_to_tid[0]);
 160
 161         rcu_read_lock();
 162         ieee80211_release_reorder_timeout(sta, *ptid);
 163         rcu_read_unlock();
 164 }
 165
 166 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 167                                       u8 dialog_token, u16 status, u16 policy,
 168                                       u16 buf_size, u16 timeout)
 169 {
 170         struct ieee80211_local *local = sdata->local;
 171         struct sk_buff *skb;
 172         struct ieee80211_mgmt *mgmt;
 173         u16 capab;
 174
 175         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 176         if (!skb)
 177                 return;
 178
 179         skb_reserve(skb, local->hw.extra_tx_headroom);
 180         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 181         memset(mgmt, 0, 24);
 182         memcpy(mgmt->da, da, ETH_ALEN);
 183         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 184         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 185             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 186                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 187         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 188                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 189
 190         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 191                                           IEEE80211_STYPE_ACTION);
 192
 193         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 194         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 195         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 196         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 197
 198         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
 199         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 200         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 201
 202         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 203         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 204         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 205
 206         ieee80211_tx_skb(sdata, skb);
 207 }
 208
 209 void ieee80211_process_addba_request(struct ieee80211_local *local,
 210                                      struct sta_info *sta,
 211                                      struct ieee80211_mgmt *mgmt,
 212                                      size_t len)
 213 {
 214         struct tid_ampdu_rx *tid_agg_rx;
 215         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
 216         u8 dialog_token;
 217         int ret = -EOPNOTSUPP;
 218
 219         /* extract session parameters from addba request frame */
 220         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 221         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 222         start_seq_num =
 223                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 224
 225         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 226         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 227         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 228         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 229
 230         status = WLAN_STATUS_REQUEST_DECLINED;
 231
 232         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 233 #ifdef CONFIG_MAC80211_HT_DEBUG
 234                 printk(KERN_DEBUG "Suspend in progress. "
 235                        "Denying ADDBA request\n");
 236 #endif
 237                 goto end_no_lock;
 238         }
 239
 240         /* sanity check for incoming parameters:
 241          * check if configuration can support the BA policy
 242          * and if buffer size does not exceeds max value */
 243         /* XXX: check own ht delayed BA capability?? */
 244         if (((ba_policy != 1) &&
 245              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 246             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 247                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 248 #ifdef CONFIG_MAC80211_HT_DEBUG
 249                 if (net_ratelimit())
 250                         printk(KERN_DEBUG "AddBA Req with bad params from "
 251                                 "%pM on tid %u. policy %d, buffer size %d\n",
 252                                 mgmt->sa, tid, ba_policy,
 253                                 buf_size);
 254 #endif /* CONFIG_MAC80211_HT_DEBUG */
 255                 goto end_no_lock;
 256         }
 257         /* determine default buffer size */
 258         if (buf_size == 0)
 259                 buf_size = IEEE80211_MAX_AMPDU_BUF;
 260
 261         /* make sure the size doesn't exceed the maximum supported by the hw */
 262         if (buf_size > local->hw.max_rx_aggregation_subframes)
 263                 buf_size = local->hw.max_rx_aggregation_subframes;
 264
 265         /* examine state machine */
 266         mutex_lock(&sta->ampdu_mlme.mtx);
 267
 268         if (sta->ampdu_mlme.tid_rx[tid]) {
 269 #ifdef CONFIG_MAC80211_HT_DEBUG
 270                 if (net_ratelimit())
 271                         printk(KERN_DEBUG "unexpected AddBA Req from "
 272                                 "%pM on tid %u\n",
 273                                 mgmt->sa, tid);
 274 #endif /* CONFIG_MAC80211_HT_DEBUG */
 275
 276                 /* delete existing Rx BA session on the same tid */
 277                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 278                                                 WLAN_STATUS_UNSPECIFIED_QOS,
 279                                                 false);
 280         }
 281
 282         /* prepare A-MPDU MLME for Rx aggregation */
 283         tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
 284         if (!tid_agg_rx)
 285                 goto end;
 286
 287         spin_lock_init(&tid_agg_rx->reorder_lock);
 288
 289         /* rx timer */
 290         tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
 291         tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 292         init_timer(&tid_agg_rx->session_timer);
 293
 294         /* rx reorder timer */
 295         tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
 296         tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 297         init_timer(&tid_agg_rx->reorder_timer);
 298
 299         /* prepare reordering buffer */
 300         tid_agg_rx->reorder_buf =
 301                 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL);
 302         tid_agg_rx->reorder_time =
 303                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
 304         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 305                 kfree(tid_agg_rx->reorder_buf);
 306                 kfree(tid_agg_rx->reorder_time);
 307                 kfree(tid_agg_rx);
 308                 goto end;
 309         }
 310
 311         ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
 312                                &sta->sta, tid, &start_seq_num, 0);
 313 #ifdef CONFIG_MAC80211_HT_DEBUG
 314         printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
 315 #endif /* CONFIG_MAC80211_HT_DEBUG */
 316
 317         if (ret) {
 318                 kfree(tid_agg_rx->reorder_buf);
 319                 kfree(tid_agg_rx->reorder_time);
 320                 kfree(tid_agg_rx);
 321                 goto end;
 322         }
 323
 324         /* update data */
 325         tid_agg_rx->dialog_token = dialog_token;
 326         tid_agg_rx->ssn = start_seq_num;
 327         tid_agg_rx->head_seq_num = start_seq_num;
 328         tid_agg_rx->buf_size = buf_size;
 329         tid_agg_rx->timeout = timeout;
 330         tid_agg_rx->stored_mpdu_num = 0;
 331         status = WLAN_STATUS_SUCCESS;
 332
 333         /* activate it for RX */
 334         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
 335
 336         if (timeout)
 337                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
 338
 339 end:
 340         mutex_unlock(&sta->ampdu_mlme.mtx);
 341
 342 end_no_lock:
 343         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 344                                   dialog_token, status, 1, buf_size, timeout);
 345 }