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