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