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 <net/mac80211.h>
  42 #include "ieee80211_i.h"
  43 #include "driver-ops.h"
  44
  45 static void ieee80211_free_tid_rx(struct rcu_head *h)
  46 {
  47         struct tid_ampdu_rx *tid_rx =
  48                 container_of(h, struct tid_ampdu_rx, rcu_head);
  49         int i;
  50
  51         for (i = 0; i < tid_rx->buf_size; i++)
  52                 dev_kfree_skb(tid_rx->reorder_buf[i]);
  53         kfree(tid_rx->reorder_buf);
  54         kfree(tid_rx->reorder_time);
  55         kfree(tid_rx);
  56 }
  57
  58 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  59                                      u16 initiator, u16 reason, bool tx)
  60 {
  61         struct ieee80211_local *local = sta->local;
  62         struct tid_ampdu_rx *tid_rx;
  63
  64         lockdep_assert_held(&sta->ampdu_mlme.mtx);
  65
  66         tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
  67                                         lockdep_is_held(&sta->ampdu_mlme.mtx));
  68
  69         if (!tid_rx)
  70                 return;
  71
  72         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], NULL);
  73
  74 #ifdef CONFIG_MAC80211_HT_DEBUG
  75         printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
  76                sta->sta.addr, tid);
  77 #endif /* CONFIG_MAC80211_HT_DEBUG */
  78
  79         if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
  80                              &sta->sta, tid, NULL, 0))
  81                 printk(KERN_DEBUG "HW problem - can not stop rx "
  82                                 "aggregation for tid %d\n", tid);
  83
  84         /* check if this is a self generated aggregation halt */
  85         if (initiator == WLAN_BACK_RECIPIENT && tx)
  86                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
  87                                      tid, 0, reason);
  88
  89         del_timer_sync(&tid_rx->session_timer);
  90         del_timer_sync(&tid_rx->reorder_timer);
  91
  92         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
  93 }
  94
  95 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  96                                     u16 initiator, u16 reason, bool tx)
  97 {
  98         mutex_lock(&sta->ampdu_mlme.mtx);
  99         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
 100         mutex_unlock(&sta->ampdu_mlme.mtx);
 101 }
 102
 103 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
 104                                   const u8 *addr)
 105 {
 106         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 107         struct sta_info *sta;
 108         int i;
 109
 110         rcu_read_lock();
 111         sta = sta_info_get(sdata, addr);
 112         if (!sta) {
 113                 rcu_read_unlock();
 114                 return;
 115         }
 116
 117         for (i = 0; i < STA_TID_NUM; i++)
 118                 if (ba_rx_bitmap & BIT(i))
 119                         set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
 120
 121         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 122         rcu_read_unlock();
 123 }
 124 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
 125
 126 /*
 127  * After accepting the AddBA Request we activated a timer,
 128  * resetting it after each frame that arrives from the originator.
 129  */
 130 static void sta_rx_agg_session_timer_expired(unsigned long data)
 131 {
 132         /* not an elegant detour, but there is no choice as the timer passes
 133          * only one argument, and various sta_info are needed here, so init
 134          * flow in sta_info_create gives the TID as data, while the timer_to_id
 135          * array gives the sta through container_of */
 136         u8 *ptid = (u8 *)data;
 137         u8 *timer_to_id = ptid - *ptid;
 138         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 139                                          timer_to_tid[0]);
 140
 141 #ifdef CONFIG_MAC80211_HT_DEBUG
 142         printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
 143 #endif
 144         set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
 145         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 146 }
 147
 148 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
 149 {
 150         u8 *ptid = (u8 *)data;
 151         u8 *timer_to_id = ptid - *ptid;
 152         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 153                         timer_to_tid[0]);
 154
 155         rcu_read_lock();
 156         ieee80211_release_reorder_timeout(sta, *ptid);
 157         rcu_read_unlock();
 158 }
 159
 160 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 161                                       u8 dialog_token, u16 status, u16 policy,
 162                                       u16 buf_size, u16 timeout)
 163 {
 164         struct ieee80211_local *local = sdata->local;
 165         struct sk_buff *skb;
 166         struct ieee80211_mgmt *mgmt;
 167         u16 capab;
 168
 169         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 170
 171         if (!skb) {
 172                 printk(KERN_DEBUG "%s: failed to allocate buffer "
 173                        "for addba resp frame\n", sdata->name);
 174                 return;
 175         }
 176
 177         skb_reserve(skb, local->hw.extra_tx_headroom);
 178         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 179         memset(mgmt, 0, 24);
 180         memcpy(mgmt->da, da, ETH_ALEN);
 181         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 182         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 183             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 184                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 185         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 186                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 187
 188         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 189                                           IEEE80211_STYPE_ACTION);
 190
 191         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 192         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 193         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 194         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 195
 196         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
 197         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 198         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 199
 200         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 201         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 202         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 203
 204         ieee80211_tx_skb(sdata, skb);
 205 }
 206
 207 void ieee80211_process_addba_request(struct ieee80211_local *local,
 208                                      struct sta_info *sta,
 209                                      struct ieee80211_mgmt *mgmt,
 210                                      size_t len)
 211 {
 212         struct tid_ampdu_rx *tid_agg_rx;
 213         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
 214         u8 dialog_token;
 215         int ret = -EOPNOTSUPP;
 216
 217         /* extract session parameters from addba request frame */
 218         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 219         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 220         start_seq_num =
 221                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 222
 223         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 224         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 225         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 226         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 227
 228         status = WLAN_STATUS_REQUEST_DECLINED;
 229
 230         if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
 231 #ifdef CONFIG_MAC80211_HT_DEBUG
 232                 printk(KERN_DEBUG "Suspend in progress. "
 233                        "Denying ADDBA request\n");
 234 #endif
 235                 goto end_no_lock;
 236         }
 237
 238         /* sanity check for incoming parameters:
 239          * check if configuration can support the BA policy
 240          * and if buffer size does not exceeds max value */
 241         /* XXX: check own ht delayed BA capability?? */
 242         if (((ba_policy != 1) &&
 243              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 244             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 245                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 246 #ifdef CONFIG_MAC80211_HT_DEBUG
 247                 if (net_ratelimit())
 248                         printk(KERN_DEBUG "AddBA Req with bad params from "
 249                                 "%pM on tid %u. policy %d, buffer size %d\n",
 250                                 mgmt->sa, tid, ba_policy,
 251                                 buf_size);
 252 #endif /* CONFIG_MAC80211_HT_DEBUG */
 253                 goto end_no_lock;
 254         }
 255         /* determine default buffer size */
 256         if (buf_size == 0)
 257                 buf_size = IEEE80211_MAX_AMPDU_BUF;
 258
 259         /* make sure the size doesn't exceed the maximum supported by the hw */
 260         if (buf_size > local->hw.max_rx_aggregation_subframes)
 261                 buf_size = local->hw.max_rx_aggregation_subframes;
 262
 263         /* examine state machine */
 264         mutex_lock(&sta->ampdu_mlme.mtx);
 265
 266         if (sta->ampdu_mlme.tid_rx[tid]) {
 267 #ifdef CONFIG_MAC80211_HT_DEBUG
 268                 if (net_ratelimit())
 269                         printk(KERN_DEBUG "unexpected AddBA Req from "
 270                                 "%pM on tid %u\n",
 271                                 mgmt->sa, tid);
 272 #endif /* CONFIG_MAC80211_HT_DEBUG */
 273
 274                 /* delete existing Rx BA session on the same tid */
 275                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 276                                                 WLAN_STATUS_UNSPECIFIED_QOS,
 277                                                 false);
 278         }
 279
 280         /* prepare A-MPDU MLME for Rx aggregation */
 281         tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
 282         if (!tid_agg_rx) {
 283 #ifdef CONFIG_MAC80211_HT_DEBUG
 284                 if (net_ratelimit())
 285                         printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
 286                                         tid);
 287 #endif
 288                 goto end;
 289         }
 290
 291         spin_lock_init(&tid_agg_rx->reorder_lock);
 292
 293         /* rx timer */
 294         tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
 295         tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 296         init_timer(&tid_agg_rx->session_timer);
 297
 298         /* rx reorder timer */
 299         tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
 300         tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 301         init_timer(&tid_agg_rx->reorder_timer);
 302
 303         /* prepare reordering buffer */
 304         tid_agg_rx->reorder_buf =
 305                 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL);
 306         tid_agg_rx->reorder_time =
 307                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
 308         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 309 #ifdef CONFIG_MAC80211_HT_DEBUG
 310                 if (net_ratelimit())
 311                         printk(KERN_ERR "can not allocate reordering buffer "
 312                                "to tid %d\n", tid);
 313 #endif
 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         ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
 321                                &sta->sta, tid, &start_seq_num, 0);
 322 #ifdef CONFIG_MAC80211_HT_DEBUG
 323         printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
 324 #endif /* CONFIG_MAC80211_HT_DEBUG */
 325
 326         if (ret) {
 327                 kfree(tid_agg_rx->reorder_buf);
 328                 kfree(tid_agg_rx->reorder_time);
 329                 kfree(tid_agg_rx);
 330                 goto end;
 331         }
 332
 333         /* update data */
 334         tid_agg_rx->dialog_token = dialog_token;
 335         tid_agg_rx->ssn = start_seq_num;
 336         tid_agg_rx->head_seq_num = start_seq_num;
 337         tid_agg_rx->buf_size = buf_size;
 338         tid_agg_rx->timeout = timeout;
 339         tid_agg_rx->stored_mpdu_num = 0;
 340         status = WLAN_STATUS_SUCCESS;
 341
 342         /* activate it for RX */
 343         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
 344
 345         if (timeout)
 346                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
 347
 348 end:
 349         mutex_unlock(&sta->ampdu_mlme.mtx);
 350
 351 end_no_lock:
 352         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 353                                   dialog_token, status, 1, buf_size, timeout);
 354 }