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         ht_vdbg("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
  82         if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
  83                              &sta->sta, tid, NULL, 0))
  84                 pr_debug("HW problem - can not stop rx aggregation for tid %d\n",
  85                          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, WLAN_BACK_RECIPIENT, 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_bss(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         struct tid_ampdu_rx *tid_rx;
 143         unsigned long timeout;
 144
 145         rcu_read_lock();
 146         tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
 147         if (!tid_rx) {
 148                 rcu_read_unlock();
 149                 return;
 150         }
 151
 152         timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
 153         if (time_is_after_jiffies(timeout)) {
 154                 mod_timer(&tid_rx->session_timer, timeout);
 155                 rcu_read_unlock();
 156                 return;
 157         }
 158         rcu_read_unlock();
 159
 160         ht_vdbg("rx session timer expired on tid %d\n", (u16)*ptid);
 161
 162         set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
 163         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 164 }
 165
 166 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
 167 {
 168         u8 *ptid = (u8 *)data;
 169         u8 *timer_to_id = ptid - *ptid;
 170         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 171                         timer_to_tid[0]);
 172
 173         rcu_read_lock();
 174         ieee80211_release_reorder_timeout(sta, *ptid);
 175         rcu_read_unlock();
 176 }
 177
 178 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 179                                       u8 dialog_token, u16 status, u16 policy,
 180                                       u16 buf_size, u16 timeout)
 181 {
 182         struct ieee80211_local *local = sdata->local;
 183         struct sk_buff *skb;
 184         struct ieee80211_mgmt *mgmt;
 185         u16 capab;
 186
 187         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 188         if (!skb)
 189                 return;
 190
 191         skb_reserve(skb, local->hw.extra_tx_headroom);
 192         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 193         memset(mgmt, 0, 24);
 194         memcpy(mgmt->da, da, ETH_ALEN);
 195         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 196         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 197             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 198             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 199                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 200         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 201                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 202         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 203                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 204
 205         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 206                                           IEEE80211_STYPE_ACTION);
 207
 208         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 209         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 210         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 211         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 212
 213         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
 214         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 215         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 216
 217         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 218         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 219         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 220
 221         ieee80211_tx_skb(sdata, skb);
 222 }
 223
 224 void ieee80211_process_addba_request(struct ieee80211_local *local,
 225                                      struct sta_info *sta,
 226                                      struct ieee80211_mgmt *mgmt,
 227                                      size_t len)
 228 {
 229         struct tid_ampdu_rx *tid_agg_rx;
 230         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
 231         u8 dialog_token;
 232         int ret = -EOPNOTSUPP;
 233
 234         /* extract session parameters from addba request frame */
 235         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 236         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 237         start_seq_num =
 238                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 239
 240         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 241         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 242         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 243         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 244
 245         status = WLAN_STATUS_REQUEST_DECLINED;
 246
 247         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 248                 ht_vdbg("Suspend in progress - Denying ADDBA request\n");
 249                 goto end_no_lock;
 250         }
 251
 252         /* sanity check for incoming parameters:
 253          * check if configuration can support the BA policy
 254          * and if buffer size does not exceeds max value */
 255         /* XXX: check own ht delayed BA capability?? */
 256         if (((ba_policy != 1) &&
 257              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 258             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 259                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 260 #ifdef CONFIG_MAC80211_HT_DEBUG
 261                 net_dbg_ratelimited("AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
 262                                     mgmt->sa, tid, ba_policy, buf_size);
 263 #endif /* CONFIG_MAC80211_HT_DEBUG */
 264                 goto end_no_lock;
 265         }
 266         /* determine default buffer size */
 267         if (buf_size == 0)
 268                 buf_size = IEEE80211_MAX_AMPDU_BUF;
 269
 270         /* make sure the size doesn't exceed the maximum supported by the hw */
 271         if (buf_size > local->hw.max_rx_aggregation_subframes)
 272                 buf_size = local->hw.max_rx_aggregation_subframes;
 273
 274         /* examine state machine */
 275         mutex_lock(&sta->ampdu_mlme.mtx);
 276
 277         if (sta->ampdu_mlme.tid_rx[tid]) {
 278 #ifdef CONFIG_MAC80211_HT_DEBUG
 279                 net_dbg_ratelimited("unexpected AddBA Req from %pM on tid %u\n",
 280                                     mgmt->sa, tid);
 281 #endif /* CONFIG_MAC80211_HT_DEBUG */
 282
 283                 /* delete existing Rx BA session on the same tid */
 284                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 285                                                 WLAN_STATUS_UNSPECIFIED_QOS,
 286                                                 false);
 287         }
 288
 289         /* prepare A-MPDU MLME for Rx aggregation */
 290         tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
 291         if (!tid_agg_rx)
 292                 goto end;
 293
 294         spin_lock_init(&tid_agg_rx->reorder_lock);
 295
 296         /* rx timer */
 297         tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
 298         tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 299         init_timer_deferrable(&tid_agg_rx->session_timer);
 300
 301         /* rx reorder timer */
 302         tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
 303         tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 304         init_timer(&tid_agg_rx->reorder_timer);
 305
 306         /* prepare reordering buffer */
 307         tid_agg_rx->reorder_buf =
 308                 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL);
 309         tid_agg_rx->reorder_time =
 310                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
 311         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 312                 kfree(tid_agg_rx->reorder_buf);
 313                 kfree(tid_agg_rx->reorder_time);
 314                 kfree(tid_agg_rx);
 315                 goto end;
 316         }
 317
 318         ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
 319                                &sta->sta, tid, &start_seq_num, 0);
 320         ht_vdbg("Rx A-MPDU request on tid %d result %d\n", tid, ret);
 321         if (ret) {
 322                 kfree(tid_agg_rx->reorder_buf);
 323                 kfree(tid_agg_rx->reorder_time);
 324                 kfree(tid_agg_rx);
 325                 goto end;
 326         }
 327
 328         /* update data */
 329         tid_agg_rx->dialog_token = dialog_token;
 330         tid_agg_rx->ssn = start_seq_num;
 331         tid_agg_rx->head_seq_num = start_seq_num;
 332         tid_agg_rx->buf_size = buf_size;
 333         tid_agg_rx->timeout = timeout;
 334         tid_agg_rx->stored_mpdu_num = 0;
 335         status = WLAN_STATUS_SUCCESS;
 336
 337         /* activate it for RX */
 338         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
 339
 340         if (timeout) {
 341                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
 342                 tid_agg_rx->last_rx = jiffies;
 343         }
 344
 345 end:
 346         mutex_unlock(&sta->ampdu_mlme.mtx);
 347
 348 end_no_lock:
 349         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 350                                   dialog_token, status, 1, buf_size, timeout);
 351 }