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
  77                "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
  78                sta->sta.addr, tid,
  79                initiator == WLAN_BACK_RECIPIENT ? "recipient" : "inititator",
  80                (int)reason);
  81 #endif /* CONFIG_MAC80211_HT_DEBUG */
  82
  83         if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
  84                              &sta->sta, tid, NULL, 0))
  85                 printk(KERN_DEBUG "HW problem - can not stop rx "
  86                                 "aggregation for tid %d\n", tid);
  87
  88         /* check if this is a self generated aggregation halt */
  89         if (initiator == WLAN_BACK_RECIPIENT && tx)
  90                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
  91                                      tid, WLAN_BACK_RECIPIENT, reason);
  92
  93         del_timer_sync(&tid_rx->session_timer);
  94         del_timer_sync(&tid_rx->reorder_timer);
  95
  96         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
  97 }
  98
  99 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
 100                                     u16 initiator, u16 reason, bool tx)
 101 {
 102         mutex_lock(&sta->ampdu_mlme.mtx);
 103         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
 104         mutex_unlock(&sta->ampdu_mlme.mtx);
 105 }
 106
 107 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
 108                                   const u8 *addr)
 109 {
 110         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 111         struct sta_info *sta;
 112         int i;
 113
 114         rcu_read_lock();
 115         sta = sta_info_get_bss(sdata, addr);
 116         if (!sta) {
 117                 rcu_read_unlock();
 118                 return;
 119         }
 120
 121         for (i = 0; i < STA_TID_NUM; i++)
 122                 if (ba_rx_bitmap & BIT(i))
 123                         set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
 124
 125         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 126         rcu_read_unlock();
 127 }
 128 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
 129
 130 /*
 131  * After accepting the AddBA Request we activated a timer,
 132  * resetting it after each frame that arrives from the originator.
 133  */
 134 static void sta_rx_agg_session_timer_expired(unsigned long data)
 135 {
 136         /* not an elegant detour, but there is no choice as the timer passes
 137          * only one argument, and various sta_info are needed here, so init
 138          * flow in sta_info_create gives the TID as data, while the timer_to_id
 139          * array gives the sta through container_of */
 140         u8 *ptid = (u8 *)data;
 141         u8 *timer_to_id = ptid - *ptid;
 142         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 143                                          timer_to_tid[0]);
 144
 145 #ifdef CONFIG_MAC80211_HT_DEBUG
 146         printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
 147 #endif
 148         set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
 149         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 150 }
 151
 152 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
 153 {
 154         u8 *ptid = (u8 *)data;
 155         u8 *timer_to_id = ptid - *ptid;
 156         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 157                         timer_to_tid[0]);
 158
 159         rcu_read_lock();
 160         ieee80211_release_reorder_timeout(sta, *ptid);
 161         rcu_read_unlock();
 162 }
 163
 164 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 165                                       u8 dialog_token, u16 status, u16 policy,
 166                                       u16 buf_size, u16 timeout)
 167 {
 168         struct ieee80211_local *local = sdata->local;
 169         struct sk_buff *skb;
 170         struct ieee80211_mgmt *mgmt;
 171         u16 capab;
 172
 173         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 174         if (!skb)
 175                 return;
 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             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 185                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 186         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 187                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 188
 189         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 190                                           IEEE80211_STYPE_ACTION);
 191
 192         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 193         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 194         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 195         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 196
 197         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
 198         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 199         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 200
 201         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 202         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 203         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 204
 205         ieee80211_tx_skb(sdata, skb);
 206 }
 207
 208 void ieee80211_process_addba_request(struct ieee80211_local *local,
 209                                      struct sta_info *sta,
 210                                      struct ieee80211_mgmt *mgmt,
 211                                      size_t len)
 212 {
 213         struct tid_ampdu_rx *tid_agg_rx;
 214         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
 215         u8 dialog_token;
 216         int ret = -EOPNOTSUPP;
 217
 218         /* extract session parameters from addba request frame */
 219         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 220         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 221         start_seq_num =
 222                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 223
 224         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 225         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 226         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 227         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 228
 229         status = WLAN_STATUS_REQUEST_DECLINED;
 230
 231         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 232 #ifdef CONFIG_MAC80211_HT_DEBUG
 233                 printk(KERN_DEBUG "Suspend in progress. "
 234                        "Denying ADDBA request\n");
 235 #endif
 236                 goto end_no_lock;
 237         }
 238
 239         /* sanity check for incoming parameters:
 240          * check if configuration can support the BA policy
 241          * and if buffer size does not exceeds max value */
 242         /* XXX: check own ht delayed BA capability?? */
 243         if (((ba_policy != 1) &&
 244              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 245             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 246                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 247 #ifdef CONFIG_MAC80211_HT_DEBUG
 248                 if (net_ratelimit())
 249                         printk(KERN_DEBUG "AddBA Req with bad params from "
 250                                 "%pM on tid %u. policy %d, buffer size %d\n",
 251                                 mgmt->sa, tid, ba_policy,
 252                                 buf_size);
 253 #endif /* CONFIG_MAC80211_HT_DEBUG */
 254                 goto end_no_lock;
 255         }
 256         /* determine default buffer size */
 257         if (buf_size == 0)
 258                 buf_size = IEEE80211_MAX_AMPDU_BUF;
 259
 260         /* make sure the size doesn't exceed the maximum supported by the hw */
 261         if (buf_size > local->hw.max_rx_aggregation_subframes)
 262                 buf_size = local->hw.max_rx_aggregation_subframes;
 263
 264         /* examine state machine */
 265         mutex_lock(&sta->ampdu_mlme.mtx);
 266
 267         if (sta->ampdu_mlme.tid_rx[tid]) {
 268 #ifdef CONFIG_MAC80211_HT_DEBUG
 269                 if (net_ratelimit())
 270                         printk(KERN_DEBUG "unexpected AddBA Req from "
 271                                 "%pM on tid %u\n",
 272                                 mgmt->sa, tid);
 273 #endif /* CONFIG_MAC80211_HT_DEBUG */
 274
 275                 /* delete existing Rx BA session on the same tid */
 276                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 277                                                 WLAN_STATUS_UNSPECIFIED_QOS,
 278                                                 false);
 279         }
 280
 281         /* prepare A-MPDU MLME for Rx aggregation */
 282         tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
 283         if (!tid_agg_rx)
 284                 goto end;
 285
 286         spin_lock_init(&tid_agg_rx->reorder_lock);
 287
 288         /* rx timer */
 289         tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
 290         tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 291         init_timer(&tid_agg_rx->session_timer);
 292
 293         /* rx reorder timer */
 294         tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
 295         tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 296         init_timer(&tid_agg_rx->reorder_timer);
 297
 298         /* prepare reordering buffer */
 299         tid_agg_rx->reorder_buf =
 300                 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL);
 301         tid_agg_rx->reorder_time =
 302                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
 303         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 304                 kfree(tid_agg_rx->reorder_buf);
 305                 kfree(tid_agg_rx->reorder_time);
 306                 kfree(tid_agg_rx);
 307                 goto end;
 308         }
 309
 310         ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
 311                                &sta->sta, tid, &start_seq_num, 0);
 312 #ifdef CONFIG_MAC80211_HT_DEBUG
 313         printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
 314 #endif /* CONFIG_MAC80211_HT_DEBUG */
 315
 316         if (ret) {
 317                 kfree(tid_agg_rx->reorder_buf);
 318                 kfree(tid_agg_rx->reorder_time);
 319                 kfree(tid_agg_rx);
 320                 goto end;
 321         }
 322
 323         /* update data */
 324         tid_agg_rx->dialog_token = dialog_token;
 325         tid_agg_rx->ssn = start_seq_num;
 326         tid_agg_rx->head_seq_num = start_seq_num;
 327         tid_agg_rx->buf_size = buf_size;
 328         tid_agg_rx->timeout = timeout;
 329         tid_agg_rx->stored_mpdu_num = 0;
 330         status = WLAN_STATUS_SUCCESS;
 331
 332         /* activate it for RX */
 333         RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
 334
 335         if (timeout)
 336                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
 337
 338 end:
 339         mutex_unlock(&sta->ampdu_mlme.mtx);
 340
 341 end_no_lock:
 342         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 343                                   dialog_token, status, 1, buf_size, timeout);
 344 }