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