linux/net/mac80211/agg-rx.c
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   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 2007-2008, 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#include <linux/ieee80211.h>
  17#include <net/mac80211.h>
  18#include "ieee80211_i.h"
  19
  20void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  21                                    u16 initiator, u16 reason)
  22{
  23        struct ieee80211_local *local = sta->local;
  24        struct ieee80211_hw *hw = &local->hw;
  25        int i;
  26
  27        /* check if TID is in operational state */
  28        spin_lock_bh(&sta->lock);
  29        if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL) {
  30                spin_unlock_bh(&sta->lock);
  31                return;
  32        }
  33
  34        sta->ampdu_mlme.tid_state_rx[tid] =
  35                HT_AGG_STATE_REQ_STOP_BA_MSK |
  36                (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
  37        spin_unlock_bh(&sta->lock);
  38
  39#ifdef CONFIG_MAC80211_HT_DEBUG
  40        printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
  41               sta->sta.addr, tid);
  42#endif /* CONFIG_MAC80211_HT_DEBUG */
  43
  44        if (local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_STOP,
  45                                     &sta->sta, tid, NULL))
  46                printk(KERN_DEBUG "HW problem - can not stop rx "
  47                                "aggregation for tid %d\n", tid);
  48
  49        /* shutdown timer has not expired */
  50        if (initiator != WLAN_BACK_TIMER)
  51                del_timer_sync(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
  52
  53        /* check if this is a self generated aggregation halt */
  54        if (initiator == WLAN_BACK_RECIPIENT || initiator == WLAN_BACK_TIMER)
  55                ieee80211_send_delba(sta->sdata, sta->sta.addr,
  56                                     tid, 0, reason);
  57
  58        /* free the reordering buffer */
  59        for (i = 0; i < sta->ampdu_mlme.tid_rx[tid]->buf_size; i++) {
  60                if (sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]) {
  61                        /* release the reordered frames */
  62                        dev_kfree_skb(sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]);
  63                        sta->ampdu_mlme.tid_rx[tid]->stored_mpdu_num--;
  64                        sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i] = NULL;
  65                }
  66        }
  67
  68        spin_lock_bh(&sta->lock);
  69        /* free resources */
  70        kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_buf);
  71
  72        if (!sta->ampdu_mlme.tid_rx[tid]->shutdown) {
  73                kfree(sta->ampdu_mlme.tid_rx[tid]);
  74                sta->ampdu_mlme.tid_rx[tid] = NULL;
  75        }
  76
  77        sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_IDLE;
  78        spin_unlock_bh(&sta->lock);
  79}
  80
  81void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid,
  82                                        u16 initiator, u16 reason)
  83{
  84        struct ieee80211_local *local = sdata->local;
  85        struct sta_info *sta;
  86
  87        /* stop HW Rx aggregation. ampdu_action existence
  88         * already verified in session init so we add the BUG_ON */
  89        BUG_ON(!local->ops->ampdu_action);
  90
  91        rcu_read_lock();
  92
  93        sta = sta_info_get(local, ra);
  94        if (!sta) {
  95                rcu_read_unlock();
  96                return;
  97        }
  98
  99        __ieee80211_stop_rx_ba_session(sta, tid, initiator, reason);
 100
 101        rcu_read_unlock();
 102}
 103
 104/*
 105 * After accepting the AddBA Request we activated a timer,
 106 * resetting it after each frame that arrives from the originator.
 107 * if this timer expires ieee80211_sta_stop_rx_ba_session will be executed.
 108 */
 109static void sta_rx_agg_session_timer_expired(unsigned long data)
 110{
 111        /* not an elegant detour, but there is no choice as the timer passes
 112         * only one argument, and various sta_info are needed here, so init
 113         * flow in sta_info_create gives the TID as data, while the timer_to_id
 114         * array gives the sta through container_of */
 115        u8 *ptid = (u8 *)data;
 116        u8 *timer_to_id = ptid - *ptid;
 117        struct sta_info *sta = container_of(timer_to_id, struct sta_info,
 118                                         timer_to_tid[0]);
 119
 120#ifdef CONFIG_MAC80211_HT_DEBUG
 121        printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
 122#endif
 123        ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
 124                                         (u16)*ptid, WLAN_BACK_TIMER,
 125                                         WLAN_REASON_QSTA_TIMEOUT);
 126}
 127
 128static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
 129                                      u8 dialog_token, u16 status, u16 policy,
 130                                      u16 buf_size, u16 timeout)
 131{
 132        struct ieee80211_local *local = sdata->local;
 133        struct sk_buff *skb;
 134        struct ieee80211_mgmt *mgmt;
 135        u16 capab;
 136
 137        skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 138
 139        if (!skb) {
 140                printk(KERN_DEBUG "%s: failed to allocate buffer "
 141                       "for addba resp frame\n", sdata->dev->name);
 142                return;
 143        }
 144
 145        skb_reserve(skb, local->hw.extra_tx_headroom);
 146        mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 147        memset(mgmt, 0, 24);
 148        memcpy(mgmt->da, da, ETH_ALEN);
 149        memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
 150        if (sdata->vif.type == NL80211_IFTYPE_AP ||
 151            sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 152                memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
 153        else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 154                memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 155
 156        mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 157                                          IEEE80211_STYPE_ACTION);
 158
 159        skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 160        mgmt->u.action.category = WLAN_CATEGORY_BACK;
 161        mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 162        mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 163
 164        capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
 165        capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
 166        capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
 167
 168        mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 169        mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 170        mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 171
 172        ieee80211_tx_skb(sdata, skb, 1);
 173}
 174
 175void ieee80211_process_addba_request(struct ieee80211_local *local,
 176                                     struct sta_info *sta,
 177                                     struct ieee80211_mgmt *mgmt,
 178                                     size_t len)
 179{
 180        struct ieee80211_hw *hw = &local->hw;
 181        struct ieee80211_conf *conf = &hw->conf;
 182        struct tid_ampdu_rx *tid_agg_rx;
 183        u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
 184        u8 dialog_token;
 185        int ret = -EOPNOTSUPP;
 186
 187        /* extract session parameters from addba request frame */
 188        dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 189        timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 190        start_seq_num =
 191                le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 192
 193        capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 194        ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 195        tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 196        buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 197
 198        status = WLAN_STATUS_REQUEST_DECLINED;
 199
 200        if (test_sta_flags(sta, WLAN_STA_SUSPEND)) {
 201#ifdef CONFIG_MAC80211_HT_DEBUG
 202                printk(KERN_DEBUG "Suspend in progress. "
 203                       "Denying ADDBA request\n");
 204#endif
 205                goto end_no_lock;
 206        }
 207
 208        /* sanity check for incoming parameters:
 209         * check if configuration can support the BA policy
 210         * and if buffer size does not exceeds max value */
 211        /* XXX: check own ht delayed BA capability?? */
 212        if (((ba_policy != 1)
 213                && (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA)))
 214                || (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
 215                status = WLAN_STATUS_INVALID_QOS_PARAM;
 216#ifdef CONFIG_MAC80211_HT_DEBUG
 217                if (net_ratelimit())
 218                        printk(KERN_DEBUG "AddBA Req with bad params from "
 219                                "%pM on tid %u. policy %d, buffer size %d\n",
 220                                mgmt->sa, tid, ba_policy,
 221                                buf_size);
 222#endif /* CONFIG_MAC80211_HT_DEBUG */
 223                goto end_no_lock;
 224        }
 225        /* determine default buffer size */
 226        if (buf_size == 0) {
 227                struct ieee80211_supported_band *sband;
 228
 229                sband = local->hw.wiphy->bands[conf->channel->band];
 230                buf_size = IEEE80211_MIN_AMPDU_BUF;
 231                buf_size = buf_size << sband->ht_cap.ampdu_factor;
 232        }
 233
 234
 235        /* examine state machine */
 236        spin_lock_bh(&sta->lock);
 237
 238        if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_IDLE) {
 239#ifdef CONFIG_MAC80211_HT_DEBUG
 240                if (net_ratelimit())
 241                        printk(KERN_DEBUG "unexpected AddBA Req from "
 242                                "%pM on tid %u\n",
 243                                mgmt->sa, tid);
 244#endif /* CONFIG_MAC80211_HT_DEBUG */
 245                goto end;
 246        }
 247
 248        /* prepare A-MPDU MLME for Rx aggregation */
 249        sta->ampdu_mlme.tid_rx[tid] =
 250                        kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
 251        if (!sta->ampdu_mlme.tid_rx[tid]) {
 252#ifdef CONFIG_MAC80211_HT_DEBUG
 253                if (net_ratelimit())
 254                        printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
 255                                        tid);
 256#endif
 257                goto end;
 258        }
 259        /* rx timer */
 260        sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
 261                                sta_rx_agg_session_timer_expired;
 262        sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
 263                                (unsigned long)&sta->timer_to_tid[tid];
 264        init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
 265
 266        tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
 267
 268        /* prepare reordering buffer */
 269        tid_agg_rx->reorder_buf =
 270                kcalloc(buf_size, sizeof(struct sk_buff *), GFP_ATOMIC);
 271        if (!tid_agg_rx->reorder_buf) {
 272#ifdef CONFIG_MAC80211_HT_DEBUG
 273                if (net_ratelimit())
 274                        printk(KERN_ERR "can not allocate reordering buffer "
 275                               "to tid %d\n", tid);
 276#endif
 277                kfree(sta->ampdu_mlme.tid_rx[tid]);
 278                goto end;
 279        }
 280
 281        if (local->ops->ampdu_action)
 282                ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_START,
 283                                               &sta->sta, tid, &start_seq_num);
 284#ifdef CONFIG_MAC80211_HT_DEBUG
 285        printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
 286#endif /* CONFIG_MAC80211_HT_DEBUG */
 287
 288        if (ret) {
 289                kfree(tid_agg_rx->reorder_buf);
 290                kfree(tid_agg_rx);
 291                sta->ampdu_mlme.tid_rx[tid] = NULL;
 292                goto end;
 293        }
 294
 295        /* change state and send addba resp */
 296        sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_OPERATIONAL;
 297        tid_agg_rx->dialog_token = dialog_token;
 298        tid_agg_rx->ssn = start_seq_num;
 299        tid_agg_rx->head_seq_num = start_seq_num;
 300        tid_agg_rx->buf_size = buf_size;
 301        tid_agg_rx->timeout = timeout;
 302        tid_agg_rx->stored_mpdu_num = 0;
 303        status = WLAN_STATUS_SUCCESS;
 304end:
 305        spin_unlock_bh(&sta->lock);
 306
 307end_no_lock:
 308        ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
 309                                  dialog_token, status, 1, buf_size, timeout);
 310}
 311