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root/net/mac80211/ht.c

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DEFINITIONS

This source file includes following definitions.
  1. ieee80211_ht_cap_ie_to_ht_info
  2. ieee80211_ht_addt_info_ie_to_ht_bss_info
  3. ieee80211_send_addba_request
  4. ieee80211_send_addba_resp
  5. ieee80211_send_delba
  6. ieee80211_send_bar
  7. ieee80211_sta_stop_rx_ba_session
  8. sta_addba_resp_timer_expired
  9. ieee80211_sta_tear_down_BA_sessions
  10. ieee80211_start_tx_ba_session
  11. ieee80211_stop_tx_ba_session
  12. ieee80211_start_tx_ba_cb
  13. ieee80211_stop_tx_ba_cb
  14. ieee80211_start_tx_ba_cb_irqsafe
  15. ieee80211_stop_tx_ba_cb_irqsafe
  16. sta_rx_agg_session_timer_expired
  17. ieee80211_process_addba_request
  18. ieee80211_process_addba_resp
  19. ieee80211_process_delba

/*
 * HT handling
 *
 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
 * Copyright 2007-2008, Intel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/ieee80211.h>
#include <net/wireless.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "sta_info.h"
#include "wme.h"

int ieee80211_ht_cap_ie_to_ht_info(struct ieee80211_ht_cap *ht_cap_ie,
                                   struct ieee80211_ht_info *ht_info)
{

        if (ht_info == NULL)
                return -EINVAL;

        memset(ht_info, 0, sizeof(*ht_info));

        if (ht_cap_ie) {
                u8 ampdu_info = ht_cap_ie->ampdu_params_info;

                ht_info->ht_supported = 1;
                ht_info->cap = le16_to_cpu(ht_cap_ie->cap_info);
                ht_info->ampdu_factor =
                        ampdu_info & IEEE80211_HT_CAP_AMPDU_FACTOR;
                ht_info->ampdu_density =
                        (ampdu_info & IEEE80211_HT_CAP_AMPDU_DENSITY) >> 2;
                memcpy(ht_info->supp_mcs_set, ht_cap_ie->supp_mcs_set, 16);
        } else
                ht_info->ht_supported = 0;

        return 0;
}

int ieee80211_ht_addt_info_ie_to_ht_bss_info(
                        struct ieee80211_ht_addt_info *ht_add_info_ie,
                        struct ieee80211_ht_bss_info *bss_info)
{
        if (bss_info == NULL)
                return -EINVAL;

        memset(bss_info, 0, sizeof(*bss_info));

        if (ht_add_info_ie) {
                u16 op_mode;
                op_mode = le16_to_cpu(ht_add_info_ie->operation_mode);

                bss_info->primary_channel = ht_add_info_ie->control_chan;
                bss_info->bss_cap = ht_add_info_ie->ht_param;
                bss_info->bss_op_mode = (u8)(op_mode & 0xff);
        }

        return 0;
}

static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
                                         const u8 *da, u16 tid,
                                         u8 dialog_token, u16 start_seq_num,
                                         u16 agg_size, u16 timeout)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_sta *ifsta = &sdata->u.sta;
        struct sk_buff *skb;
        struct ieee80211_mgmt *mgmt;
        u16 capab;

        skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);

        if (!skb) {
                printk(KERN_ERR "%s: failed to allocate buffer "
                                "for addba request frame\n", sdata->dev->name);
                return;
        }
        skb_reserve(skb, local->hw.extra_tx_headroom);
        mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
        memset(mgmt, 0, 24);
        memcpy(mgmt->da, da, ETH_ALEN);
        memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
        if (sdata->vif.type == NL80211_IFTYPE_AP)
                memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
        else
                memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);

        mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
                                          IEEE80211_STYPE_ACTION);

        skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));

        mgmt->u.action.category = WLAN_CATEGORY_BACK;
        mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;

        mgmt->u.action.u.addba_req.dialog_token = dialog_token;
        capab = (u16)(1 << 1);          /* bit 1 aggregation policy */
        capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
        capab |= (u16)(agg_size << 6);  /* bit 15:6 max size of aggergation */

        mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);

        mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
        mgmt->u.action.u.addba_req.start_seq_num =
                                        cpu_to_le16(start_seq_num << 4);

        ieee80211_tx_skb(sdata, skb, 0);
}

static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
                                      u8 dialog_token, u16 status, u16 policy,
                                      u16 buf_size, u16 timeout)
{
        struct ieee80211_if_sta *ifsta = &sdata->u.sta;
        struct ieee80211_local *local = sdata->local;
        struct sk_buff *skb;
        struct ieee80211_mgmt *mgmt;
        u16 capab;

        skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);

        if (!skb) {
                printk(KERN_DEBUG "%s: failed to allocate buffer "
                       "for addba resp frame\n", sdata->dev->name);
                return;
        }

        skb_reserve(skb, local->hw.extra_tx_headroom);
        mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
        memset(mgmt, 0, 24);
        memcpy(mgmt->da, da, ETH_ALEN);
        memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
        if (sdata->vif.type == NL80211_IFTYPE_AP)
                memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
        else
                memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
        mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
                                          IEEE80211_STYPE_ACTION);

        skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
        mgmt->u.action.category = WLAN_CATEGORY_BACK;
        mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
        mgmt->u.action.u.addba_resp.dialog_token = dialog_token;

        capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
        capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
        capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */

        mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
        mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
        mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);

        ieee80211_tx_skb(sdata, skb, 0);
}

static void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
                                 const u8 *da, u16 tid,
                                 u16 initiator, u16 reason_code)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_if_sta *ifsta = &sdata->u.sta;
        struct sk_buff *skb;
        struct ieee80211_mgmt *mgmt;
        u16 params;

        skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);

        if (!skb) {
                printk(KERN_ERR "%s: failed to allocate buffer "
                                        "for delba frame\n", sdata->dev->name);
                return;
        }

        skb_reserve(skb, local->hw.extra_tx_headroom);
        mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
        memset(mgmt, 0, 24);
        memcpy(mgmt->da, da, ETH_ALEN);
        memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
        if (sdata->vif.type == NL80211_IFTYPE_AP)
                memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
        else
                memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
        mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
                                          IEEE80211_STYPE_ACTION);

        skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));

        mgmt->u.action.category = WLAN_CATEGORY_BACK;
        mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
        params = (u16)(initiator << 11);        /* bit 11 initiator */
        params |= (u16)(tid << 12);             /* bit 15:12 TID number */

        mgmt->u.action.u.delba.params = cpu_to_le16(params);
        mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);

        ieee80211_tx_skb(sdata, skb, 0);
}

void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
{
        struct ieee80211_local *local = sdata->local;
        struct sk_buff *skb;
        struct ieee80211_bar *bar;
        u16 bar_control = 0;

        skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
        if (!skb) {
                printk(KERN_ERR "%s: failed to allocate buffer for "
                        "bar frame\n", sdata->dev->name);
                return;
        }
        skb_reserve(skb, local->hw.extra_tx_headroom);
        bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
        memset(bar, 0, sizeof(*bar));
        bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
                                         IEEE80211_STYPE_BACK_REQ);
        memcpy(bar->ra, ra, ETH_ALEN);
        memcpy(bar->ta, sdata->dev->dev_addr, ETH_ALEN);
        bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
        bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
        bar_control |= (u16)(tid << 12);
        bar->control = cpu_to_le16(bar_control);
        bar->start_seq_num = cpu_to_le16(ssn);

        ieee80211_tx_skb(sdata, skb, 0);
}

void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid,
                                        u16 initiator, u16 reason)
{
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_hw *hw = &local->hw;
        struct sta_info *sta;
        int ret, i;
        DECLARE_MAC_BUF(mac);

        rcu_read_lock();

        sta = sta_info_get(local, ra);
        if (!sta) {
                rcu_read_unlock();
                return;
        }

        /* check if TID is in operational state */
        spin_lock_bh(&sta->lock);
        if (sta->ampdu_mlme.tid_state_rx[tid]
                                != HT_AGG_STATE_OPERATIONAL) {
                spin_unlock_bh(&sta->lock);
                rcu_read_unlock();
                return;
        }
        sta->ampdu_mlme.tid_state_rx[tid] =
                HT_AGG_STATE_REQ_STOP_BA_MSK |
                (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
        spin_unlock_bh(&sta->lock);

        /* stop HW Rx aggregation. ampdu_action existence
         * already verified in session init so we add the BUG_ON */
        BUG_ON(!local->ops->ampdu_action);

#ifdef CONFIG_MAC80211_HT_DEBUG
        printk(KERN_DEBUG "Rx BA session stop requested for %s tid %u\n",
                                print_mac(mac, ra), tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

        ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_STOP,
                                       &sta->sta, tid, NULL);
        if (ret)
                printk(KERN_DEBUG "HW problem - can not stop rx "
                                "aggregation for tid %d\n", tid);

        /* shutdown timer has not expired */
        if (initiator != WLAN_BACK_TIMER)
                del_timer_sync(&sta->ampdu_mlme.tid_rx[tid]->session_timer);

        /* check if this is a self generated aggregation halt */
        if (initiator == WLAN_BACK_RECIPIENT || initiator == WLAN_BACK_TIMER)
                ieee80211_send_delba(sdata, ra, tid, 0, reason);

        /* free the reordering buffer */
        for (i = 0; i < sta->ampdu_mlme.tid_rx[tid]->buf_size; i++) {
                if (sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]) {
                        /* release the reordered frames */
                        dev_kfree_skb(sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]);
                        sta->ampdu_mlme.tid_rx[tid]->stored_mpdu_num--;
                        sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i] = NULL;
                }
        }
        /* free resources */
        kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_buf);
        kfree(sta->ampdu_mlme.tid_rx[tid]);
        sta->ampdu_mlme.tid_rx[tid] = NULL;
        sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_IDLE;

        rcu_read_unlock();
}


/*
 * After sending add Block Ack request we activated a timer until
 * add Block Ack response will arrive from the recipient.
 * If this timer expires sta_addba_resp_timer_expired will be executed.
 */
static void sta_addba_resp_timer_expired(unsigned long data)
{
        /* not an elegant detour, but there is no choice as the timer passes
         * only one argument, and both sta_info and TID are needed, so init
         * flow in sta_info_create gives the TID as data, while the timer_to_id
         * array gives the sta through container_of */
        u16 tid = *(u8 *)data;
        struct sta_info *temp_sta = container_of((void *)data,
                struct sta_info, timer_to_tid[tid]);

        struct ieee80211_local *local = temp_sta->local;
        struct ieee80211_hw *hw = &local->hw;
        struct sta_info *sta;
        u8 *state;

        rcu_read_lock();

        sta = sta_info_get(local, temp_sta->sta.addr);
        if (!sta) {
                rcu_read_unlock();
                return;
        }

        state = &sta->ampdu_mlme.tid_state_tx[tid];
        /* check if the TID waits for addBA response */
        spin_lock_bh(&sta->lock);
        if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
                spin_unlock_bh(&sta->lock);
                *state = HT_AGG_STATE_IDLE;
#ifdef CONFIG_MAC80211_HT_DEBUG
                printk(KERN_DEBUG "timer expired on tid %d but we are not "
                                "expecting addBA response there", tid);
#endif
                goto timer_expired_exit;
        }

#ifdef CONFIG_MAC80211_HT_DEBUG
        printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
#endif

        /* go through the state check in stop_BA_session */
        *state = HT_AGG_STATE_OPERATIONAL;
        spin_unlock_bh(&sta->lock);
        ieee80211_stop_tx_ba_session(hw, temp_sta->sta.addr, tid,
                                     WLAN_BACK_INITIATOR);

timer_expired_exit:
        rcu_read_unlock();
}

void ieee80211_sta_tear_down_BA_sessions(struct ieee80211_sub_if_data *sdata, u8 *addr)
{
        struct ieee80211_local *local = sdata->local;
        int i;

        for (i = 0; i <  STA_TID_NUM; i++) {
                ieee80211_stop_tx_ba_session(&local->hw, addr, i,
                                             WLAN_BACK_INITIATOR);
                ieee80211_sta_stop_rx_ba_session(sdata, addr, i,
                                                 WLAN_BACK_RECIPIENT,
                                                 WLAN_REASON_QSTA_LEAVE_QBSS);
        }
}

int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct sta_info *sta;
        struct ieee80211_sub_if_data *sdata;
        u16 start_seq_num;
        u8 *state;
        int ret;
        DECLARE_MAC_BUF(mac);

        if (tid >= STA_TID_NUM)
                return -EINVAL;

#ifdef CONFIG_MAC80211_HT_DEBUG
        printk(KERN_DEBUG "Open BA session requested for %s tid %u\n",
                                print_mac(mac, ra), tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

        rcu_read_lock();

        sta = sta_info_get(local, ra);
        if (!sta) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                printk(KERN_DEBUG "Could not find the station\n");
#endif
                ret = -ENOENT;
                goto exit;
        }

        spin_lock_bh(&sta->lock);

        /* we have tried too many times, receiver does not want A-MPDU */
        if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
                ret = -EBUSY;
                goto err_unlock_sta;
        }

        state = &sta->ampdu_mlme.tid_state_tx[tid];
        /* check if the TID is not in aggregation flow already */
        if (*state != HT_AGG_STATE_IDLE) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                printk(KERN_DEBUG "BA request denied - session is not "
                                 "idle on tid %u\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
                ret = -EAGAIN;
                goto err_unlock_sta;
        }

        /* prepare A-MPDU MLME for Tx aggregation */
        sta->ampdu_mlme.tid_tx[tid] =
                        kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
        if (!sta->ampdu_mlme.tid_tx[tid]) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                if (net_ratelimit())
                        printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
                                        tid);
#endif
                ret = -ENOMEM;
                goto err_unlock_sta;
        }
        /* Tx timer */
        sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
                        sta_addba_resp_timer_expired;
        sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
                        (unsigned long)&sta->timer_to_tid[tid];
        init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);

        /* create a new queue for this aggregation */
        ret = ieee80211_ht_agg_queue_add(local, sta, tid);

        /* case no queue is available to aggregation
         * don't switch to aggregation */
        if (ret) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                printk(KERN_DEBUG "BA request denied - queue unavailable for"
                                        " tid %d\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
                goto err_unlock_queue;
        }
        sdata = sta->sdata;

        /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
         * call back right away, it must see that the flow has begun */
        *state |= HT_ADDBA_REQUESTED_MSK;

        /* This is slightly racy because the queue isn't stopped */
        start_seq_num = sta->tid_seq[tid];

        if (local->ops->ampdu_action)
                ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_START,
                                               &sta->sta, tid, &start_seq_num);

        if (ret) {
                /* No need to requeue the packets in the agg queue, since we
                 * held the tx lock: no packet could be enqueued to the newly
                 * allocated queue */
                ieee80211_ht_agg_queue_remove(local, sta, tid, 0);
#ifdef CONFIG_MAC80211_HT_DEBUG
                printk(KERN_DEBUG "BA request denied - HW unavailable for"
                                        " tid %d\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
                *state = HT_AGG_STATE_IDLE;
                goto err_unlock_queue;
        }

        /* Will put all the packets in the new SW queue */
        ieee80211_requeue(local, ieee802_1d_to_ac[tid]);
        spin_unlock_bh(&sta->lock);

        /* send an addBA request */
        sta->ampdu_mlme.dialog_token_allocator++;
        sta->ampdu_mlme.tid_tx[tid]->dialog_token =
                        sta->ampdu_mlme.dialog_token_allocator;
        sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;


        ieee80211_send_addba_request(sta->sdata, ra, tid,
                         sta->ampdu_mlme.tid_tx[tid]->dialog_token,
                         sta->ampdu_mlme.tid_tx[tid]->ssn,
                         0x40, 5000);
        /* activate the timer for the recipient's addBA response */
        sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
                                jiffies + ADDBA_RESP_INTERVAL;
        add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
#ifdef CONFIG_MAC80211_HT_DEBUG
        printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
#endif
        goto exit;

err_unlock_queue:
        kfree(sta->ampdu_mlme.tid_tx[tid]);
        sta->ampdu_mlme.tid_tx[tid] = NULL;
        ret = -EBUSY;
err_unlock_sta:
        spin_unlock_bh(&sta->lock);
exit:
        rcu_read_unlock();
        return ret;
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_session);

int ieee80211_stop_tx_ba_session(struct ieee80211_hw *hw,
                                 u8 *ra, u16 tid,
                                 enum ieee80211_back_parties initiator)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct sta_info *sta;
        u8 *state;
        int ret = 0;
        DECLARE_MAC_BUF(mac);

        if (tid >= STA_TID_NUM)
                return -EINVAL;

        rcu_read_lock();
        sta = sta_info_get(local, ra);
        if (!sta) {
                rcu_read_unlock();
                return -ENOENT;
        }

        /* check if the TID is in aggregation */
        state = &sta->ampdu_mlme.tid_state_tx[tid];
        spin_lock_bh(&sta->lock);

        if (*state != HT_AGG_STATE_OPERATIONAL) {
                ret = -ENOENT;
                goto stop_BA_exit;
        }

#ifdef CONFIG_MAC80211_HT_DEBUG
        printk(KERN_DEBUG "Tx BA session stop requested for %s tid %u\n",
                                print_mac(mac, ra), tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

        ieee80211_stop_queue(hw, sta->tid_to_tx_q[tid]);

        *state = HT_AGG_STATE_REQ_STOP_BA_MSK |
                (initiator << HT_AGG_STATE_INITIATOR_SHIFT);

        if (local->ops->ampdu_action)
                ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_STOP,
                                               &sta->sta, tid, NULL);

        /* case HW denied going back to legacy */
        if (ret) {
                WARN_ON(ret != -EBUSY);
                *state = HT_AGG_STATE_OPERATIONAL;
                ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
                goto stop_BA_exit;
        }

stop_BA_exit:
        spin_unlock_bh(&sta->lock);
        rcu_read_unlock();
        return ret;
}
EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);

void ieee80211_start_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u16 tid)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct sta_info *sta;
        u8 *state;
        DECLARE_MAC_BUF(mac);

        if (tid >= STA_TID_NUM) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
                                tid, STA_TID_NUM);
#endif
                return;
        }

        rcu_read_lock();
        sta = sta_info_get(local, ra);
        if (!sta) {
                rcu_read_unlock();
#ifdef CONFIG_MAC80211_HT_DEBUG
                printk(KERN_DEBUG "Could not find station: %s\n",
                                print_mac(mac, ra));
#endif
                return;
        }

        state = &sta->ampdu_mlme.tid_state_tx[tid];
        spin_lock_bh(&sta->lock);

        if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
                                *state);
#endif
                spin_unlock_bh(&sta->lock);
                rcu_read_unlock();
                return;
        }

        WARN_ON_ONCE(*state & HT_ADDBA_DRV_READY_MSK);

        *state |= HT_ADDBA_DRV_READY_MSK;

        if (*state == HT_AGG_STATE_OPERATIONAL) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
#endif
                ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
        }
        spin_unlock_bh(&sta->lock);
        rcu_read_unlock();
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);

void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct sta_info *sta;
        u8 *state;
        int agg_queue;
        DECLARE_MAC_BUF(mac);

        if (tid >= STA_TID_NUM) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
                                tid, STA_TID_NUM);
#endif
                return;
        }

#ifdef CONFIG_MAC80211_HT_DEBUG
        printk(KERN_DEBUG "Stopping Tx BA session for %s tid %d\n",
                                print_mac(mac, ra), tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

        rcu_read_lock();
        sta = sta_info_get(local, ra);
        if (!sta) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                printk(KERN_DEBUG "Could not find station: %s\n",
                                print_mac(mac, ra));
#endif
                rcu_read_unlock();
                return;
        }
        state = &sta->ampdu_mlme.tid_state_tx[tid];

        /* NOTE: no need to use sta->lock in this state check, as
         * ieee80211_stop_tx_ba_session will let only one stop call to
         * pass through per sta/tid
         */
        if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
#endif
                rcu_read_unlock();
                return;
        }

        if (*state & HT_AGG_STATE_INITIATOR_MSK)
                ieee80211_send_delba(sta->sdata, ra, tid,
                        WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);

        agg_queue = sta->tid_to_tx_q[tid];

        ieee80211_ht_agg_queue_remove(local, sta, tid, 1);

        /* We just requeued the all the frames that were in the
         * removed queue, and since we might miss a softirq we do
         * netif_schedule_queue.  ieee80211_wake_queue is not used
         * here as this queue is not necessarily stopped
         */
        netif_schedule_queue(netdev_get_tx_queue(local->mdev, agg_queue));
        spin_lock_bh(&sta->lock);
        *state = HT_AGG_STATE_IDLE;
        sta->ampdu_mlme.addba_req_num[tid] = 0;
        kfree(sta->ampdu_mlme.tid_tx[tid]);
        sta->ampdu_mlme.tid_tx[tid] = NULL;
        spin_unlock_bh(&sta->lock);

        rcu_read_unlock();
}
EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);

void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
                                      const u8 *ra, u16 tid)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct ieee80211_ra_tid *ra_tid;
        struct sk_buff *skb = dev_alloc_skb(0);

        if (unlikely(!skb)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                if (net_ratelimit())
                        printk(KERN_WARNING "%s: Not enough memory, "
                               "dropping start BA session", skb->dev->name);
#endif
                return;
        }
        ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
        memcpy(&ra_tid->ra, ra, ETH_ALEN);
        ra_tid->tid = tid;

        skb->pkt_type = IEEE80211_ADDBA_MSG;
        skb_queue_tail(&local->skb_queue, skb);
        tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);

void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
                                     const u8 *ra, u16 tid)
{
        struct ieee80211_local *local = hw_to_local(hw);
        struct ieee80211_ra_tid *ra_tid;
        struct sk_buff *skb = dev_alloc_skb(0);

        if (unlikely(!skb)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                if (net_ratelimit())
                        printk(KERN_WARNING "%s: Not enough memory, "
                               "dropping stop BA session", skb->dev->name);
#endif
                return;
        }
        ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
        memcpy(&ra_tid->ra, ra, ETH_ALEN);
        ra_tid->tid = tid;

        skb->pkt_type = IEEE80211_DELBA_MSG;
        skb_queue_tail(&local->skb_queue, skb);
        tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);

/*
 * After accepting the AddBA Request we activated a timer,
 * resetting it after each frame that arrives from the originator.
 * if this timer expires ieee80211_sta_stop_rx_ba_session will be executed.
 */
static void sta_rx_agg_session_timer_expired(unsigned long data)
{
        /* not an elegant detour, but there is no choice as the timer passes
         * only one argument, and various sta_info are needed here, so init
         * flow in sta_info_create gives the TID as data, while the timer_to_id
         * array gives the sta through container_of */
        u8 *ptid = (u8 *)data;
        u8 *timer_to_id = ptid - *ptid;
        struct sta_info *sta = container_of(timer_to_id, struct sta_info,
                                         timer_to_tid[0]);

#ifdef CONFIG_MAC80211_HT_DEBUG
        printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
#endif
        ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
                                         (u16)*ptid, WLAN_BACK_TIMER,
                                         WLAN_REASON_QSTA_TIMEOUT);
}

void ieee80211_process_addba_request(struct ieee80211_local *local,
                                     struct sta_info *sta,
                                     struct ieee80211_mgmt *mgmt,
                                     size_t len)
{
        struct ieee80211_hw *hw = &local->hw;
        struct ieee80211_conf *conf = &hw->conf;
        struct tid_ampdu_rx *tid_agg_rx;
        u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
        u8 dialog_token;
        int ret = -EOPNOTSUPP;
        DECLARE_MAC_BUF(mac);

        /* extract session parameters from addba request frame */
        dialog_token = mgmt->u.action.u.addba_req.dialog_token;
        timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
        start_seq_num =
                le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;

        capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
        ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
        tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
        buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;

        status = WLAN_STATUS_REQUEST_DECLINED;

        /* sanity check for incoming parameters:
         * check if configuration can support the BA policy
         * and if buffer size does not exceeds max value */
        if (((ba_policy != 1)
                && (!(conf->ht_conf.cap & IEEE80211_HT_CAP_DELAY_BA)))
                || (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
                status = WLAN_STATUS_INVALID_QOS_PARAM;
#ifdef CONFIG_MAC80211_HT_DEBUG
                if (net_ratelimit())
                        printk(KERN_DEBUG "AddBA Req with bad params from "
                                "%s on tid %u. policy %d, buffer size %d\n",
                                print_mac(mac, mgmt->sa), tid, ba_policy,
                                buf_size);
#endif /* CONFIG_MAC80211_HT_DEBUG */
                goto end_no_lock;
        }
        /* determine default buffer size */
        if (buf_size == 0) {
                struct ieee80211_supported_band *sband;

                sband = local->hw.wiphy->bands[conf->channel->band];
                buf_size = IEEE80211_MIN_AMPDU_BUF;
                buf_size = buf_size << sband->ht_info.ampdu_factor;
        }


        /* examine state machine */
        spin_lock_bh(&sta->lock);

        if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_IDLE) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                if (net_ratelimit())
                        printk(KERN_DEBUG "unexpected AddBA Req from "
                                "%s on tid %u\n",
                                print_mac(mac, mgmt->sa), tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
                goto end;
        }

        /* prepare A-MPDU MLME for Rx aggregation */
        sta->ampdu_mlme.tid_rx[tid] =
                        kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
        if (!sta->ampdu_mlme.tid_rx[tid]) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                if (net_ratelimit())
                        printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
                                        tid);
#endif
                goto end;
        }
        /* rx timer */
        sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
                                sta_rx_agg_session_timer_expired;
        sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
                                (unsigned long)&sta->timer_to_tid[tid];
        init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);

        tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];

        /* prepare reordering buffer */
        tid_agg_rx->reorder_buf =
                kmalloc(buf_size * sizeof(struct sk_buff *), GFP_ATOMIC);
        if (!tid_agg_rx->reorder_buf) {
#ifdef CONFIG_MAC80211_HT_DEBUG
                if (net_ratelimit())
                        printk(KERN_ERR "can not allocate reordering buffer "
                               "to tid %d\n", tid);
#endif
                kfree(sta->ampdu_mlme.tid_rx[tid]);
                goto end;
        }
        memset(tid_agg_rx->reorder_buf, 0,
                buf_size * sizeof(struct sk_buff *));

        if (local->ops->ampdu_action)
                ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_START,
                                               &sta->sta, tid, &start_seq_num);
#ifdef CONFIG_MAC80211_HT_DEBUG
        printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
#endif /* CONFIG_MAC80211_HT_DEBUG */

        if (ret) {
                kfree(tid_agg_rx->reorder_buf);
                kfree(tid_agg_rx);
                sta->ampdu_mlme.tid_rx[tid] = NULL;
                goto end;
        }

        /* change state and send addba resp */
        sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_OPERATIONAL;
        tid_agg_rx->dialog_token = dialog_token;
        tid_agg_rx->ssn = start_seq_num;
        tid_agg_rx->head_seq_num = start_seq_num;
        tid_agg_rx->buf_size = buf_size;
        tid_agg_rx->timeout = timeout;
        tid_agg_rx->stored_mpdu_num = 0;
        status = WLAN_STATUS_SUCCESS;
end:
        spin_unlock_bh(&sta->lock);

end_no_lock:
        ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
                                  dialog_token, status, 1, buf_size, timeout);
}

void ieee80211_process_addba_resp(struct ieee80211_local *local,
                                  struct sta_info *sta,
                                  struct ieee80211_mgmt *mgmt,
                                  size_t len)
{
        struct ieee80211_hw *hw = &local->hw;
        u16 capab;
        u16 tid;
        u8 *state;

        capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
        tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;

        state = &sta->ampdu_mlme.tid_state_tx[tid];

        spin_lock_bh(&sta->lock);

        if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
                spin_unlock_bh(&sta->lock);
                return;
        }

        if (mgmt->u.action.u.addba_resp.dialog_token !=
                sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
                spin_unlock_bh(&sta->lock);
#ifdef CONFIG_MAC80211_HT_DEBUG
                printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
                return;
        }

        del_timer_sync(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
#ifdef CONFIG_MAC80211_HT_DEBUG
        printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
        if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
                        == WLAN_STATUS_SUCCESS) {
                *state |= HT_ADDBA_RECEIVED_MSK;
                sta->ampdu_mlme.addba_req_num[tid] = 0;

                if (*state == HT_AGG_STATE_OPERATIONAL)
                        ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);

                spin_unlock_bh(&sta->lock);
        } else {
                sta->ampdu_mlme.addba_req_num[tid]++;
                /* this will allow the state check in stop_BA_session */
                *state = HT_AGG_STATE_OPERATIONAL;
                spin_unlock_bh(&sta->lock);
                ieee80211_stop_tx_ba_session(hw, sta->sta.addr, tid,
                                             WLAN_BACK_INITIATOR);
        }
}

void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
                             struct sta_info *sta,
                             struct ieee80211_mgmt *mgmt, size_t len)
{
        struct ieee80211_local *local = sdata->local;
        u16 tid, params;
        u16 initiator;
        DECLARE_MAC_BUF(mac);

        params = le16_to_cpu(mgmt->u.action.u.delba.params);
        tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
        initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;

#ifdef CONFIG_MAC80211_HT_DEBUG
        if (net_ratelimit())
                printk(KERN_DEBUG "delba from %s (%s) tid %d reason code %d\n",
                        print_mac(mac, mgmt->sa),
                        initiator ? "initiator" : "recipient", tid,
                        mgmt->u.action.u.delba.reason_code);
#endif /* CONFIG_MAC80211_HT_DEBUG */

        if (initiator == WLAN_BACK_INITIATOR)
                ieee80211_sta_stop_rx_ba_session(sdata, sta->sta.addr, tid,
                                                 WLAN_BACK_INITIATOR, 0);
        else { /* WLAN_BACK_RECIPIENT */
                spin_lock_bh(&sta->lock);
                sta->ampdu_mlme.tid_state_tx[tid] =
                                HT_AGG_STATE_OPERATIONAL;
                spin_unlock_bh(&sta->lock);
                ieee80211_stop_tx_ba_session(&local->hw, sta->sta.addr, tid,
                                             WLAN_BACK_RECIPIENT);
        }
}

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