linux/net/mac80211/agg-tx.c
Sujith Manoharan bd2ce6e43f mac80211: Add timeout to BA session start API
Allow drivers or rate control algorithms to specify BlockAck session
timeout when initiating an ADDBA transaction. This is useful in cases
where maintaining persistent BA sessions does not incur any overhead.

The current timeout value of 5000 TUs is retained for all non ath9k/ath9k_htc
drivers.

Signed-off-by: Sujith Manoharan <Sujith.Manoharan@atheros.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-15 17:03:59 -05:00

788 lines
22 KiB
C

/*
* 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 2007-2010, 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 <linux/slab.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
#include "wme.h"
/**
* DOC: TX A-MPDU aggregation
*
* Aggregation on the TX side requires setting the hardware flag
* %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed
* packets with a flag indicating A-MPDU aggregation. The driver
* or device is responsible for actually aggregating the frames,
* as well as deciding how many and which to aggregate.
*
* When TX aggregation is started by some subsystem (usually the rate
* control algorithm would be appropriate) by calling the
* ieee80211_start_tx_ba_session() function, the driver will be
* notified via its @ampdu_action function, with the
* %IEEE80211_AMPDU_TX_START action.
*
* In response to that, the driver is later required to call the
* ieee80211_start_tx_ba_cb_irqsafe() function, which will really
* start the aggregation session after the peer has also responded.
* If the peer responds negatively, the session will be stopped
* again right away. Note that it is possible for the aggregation
* session to be stopped before the driver has indicated that it
* is done setting it up, in which case it must not indicate the
* setup completion.
*
* Also note that, since we also need to wait for a response from
* the peer, the driver is notified of the completion of the
* handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the
* @ampdu_action callback.
*
* Similarly, when the aggregation session is stopped by the peer
* or something calling ieee80211_stop_tx_ba_session(), the driver's
* @ampdu_action function will be called with the action
* %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail,
* and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe().
*/
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 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->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->vif.addr, ETH_ALEN);
if (sdata->vif.type == NL80211_IFTYPE_AP ||
sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
else if (sdata->vif.type == NL80211_IFTYPE_STATION)
memcpy(mgmt->bssid, sdata->u.mgd.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);
}
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->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->vif.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_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
ieee80211_tx_skb(sdata, skb);
}
static void kfree_tid_tx(struct rcu_head *rcu_head)
{
struct tid_ampdu_tx *tid_tx =
container_of(rcu_head, struct tid_ampdu_tx, rcu_head);
kfree(tid_tx);
}
int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
enum ieee80211_back_parties initiator,
bool tx)
{
struct ieee80211_local *local = sta->local;
struct tid_ampdu_tx *tid_tx = sta->ampdu_mlme.tid_tx[tid];
int ret;
lockdep_assert_held(&sta->ampdu_mlme.mtx);
if (!tid_tx)
return -ENOENT;
spin_lock_bh(&sta->lock);
if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
/* not even started yet! */
rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
spin_unlock_bh(&sta->lock);
call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
return 0;
}
spin_unlock_bh(&sta->lock);
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
sta->sta.addr, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
del_timer_sync(&tid_tx->addba_resp_timer);
/*
* After this packets are no longer handed right through
* to the driver but are put onto tid_tx->pending instead,
* with locking to ensure proper access.
*/
clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
tid_tx->stop_initiator = initiator;
tid_tx->tx_stop = tx;
ret = drv_ampdu_action(local, sta->sdata,
IEEE80211_AMPDU_TX_STOP,
&sta->sta, tid, NULL);
/* HW shall not deny going back to legacy */
if (WARN_ON(ret)) {
/*
* We may have pending packets get stuck in this case...
* Not bothering with a workaround for now.
*/
}
return ret;
}
/*
* 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 *sta = container_of((void *)data,
struct sta_info, timer_to_tid[tid]);
struct tid_ampdu_tx *tid_tx;
/* check if the TID waits for addBA response */
rcu_read_lock();
tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
if (!tid_tx ||
test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
rcu_read_unlock();
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "timer expired on tid %d but we are not "
"(or no longer) expecting addBA response there\n",
tid);
#endif
return;
}
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
#endif
ieee80211_stop_tx_ba_session(&sta->sta, tid);
rcu_read_unlock();
}
static inline int ieee80211_ac_from_tid(int tid)
{
return ieee802_1d_to_ac[tid & 7];
}
/*
* When multiple aggregation sessions on multiple stations
* are being created/destroyed simultaneously, we need to
* refcount the global queue stop caused by that in order
* to not get into a situation where one of the aggregation
* setup or teardown re-enables queues before the other is
* ready to handle that.
*
* These two functions take care of this issue by keeping
* a global "agg_queue_stop" refcount.
*/
static void __acquires(agg_queue)
ieee80211_stop_queue_agg(struct ieee80211_local *local, int tid)
{
int queue = ieee80211_ac_from_tid(tid);
if (atomic_inc_return(&local->agg_queue_stop[queue]) == 1)
ieee80211_stop_queue_by_reason(
&local->hw, queue,
IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
__acquire(agg_queue);
}
static void __releases(agg_queue)
ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid)
{
int queue = ieee80211_ac_from_tid(tid);
if (atomic_dec_return(&local->agg_queue_stop[queue]) == 0)
ieee80211_wake_queue_by_reason(
&local->hw, queue,
IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
__release(agg_queue);
}
void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
{
struct tid_ampdu_tx *tid_tx = sta->ampdu_mlme.tid_tx[tid];
struct ieee80211_local *local = sta->local;
struct ieee80211_sub_if_data *sdata = sta->sdata;
u16 start_seq_num;
int ret;
lockdep_assert_held(&sta->ampdu_mlme.mtx);
/*
* While we're asking the driver about the aggregation,
* stop the AC queue so that we don't have to worry
* about frames that came in while we were doing that,
* which would require us to put them to the AC pending
* afterwards which just makes the code more complex.
*/
ieee80211_stop_queue_agg(local, tid);
clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
/*
* make sure no packets are being processed to get
* valid starting sequence number
*/
synchronize_net();
start_seq_num = sta->tid_seq[tid] >> 4;
ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
&sta->sta, tid, &start_seq_num);
if (ret) {
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "BA request denied - HW unavailable for"
" tid %d\n", tid);
#endif
spin_lock_bh(&sta->lock);
rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
spin_unlock_bh(&sta->lock);
ieee80211_wake_queue_agg(local, tid);
call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
return;
}
/* we can take packets again now */
ieee80211_wake_queue_agg(local, tid);
/* activate the timer for the recipient's addBA response */
mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
#endif
spin_lock_bh(&sta->lock);
sta->ampdu_mlme.addba_req_num[tid]++;
spin_unlock_bh(&sta->lock);
/* send AddBA request */
ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
tid_tx->dialog_token, start_seq_num,
0x40, tid_tx->timeout);
}
int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
u16 timeout)
{
struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
struct ieee80211_sub_if_data *sdata = sta->sdata;
struct ieee80211_local *local = sdata->local;
struct tid_ampdu_tx *tid_tx;
int ret = 0;
trace_api_start_tx_ba_session(pubsta, tid);
if (WARN_ON(!local->ops->ampdu_action))
return -EINVAL;
if ((tid >= STA_TID_NUM) ||
!(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION))
return -EINVAL;
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
pubsta->addr, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
/*
* The aggregation code is not prepared to handle
* anything but STA/AP due to the BSSID handling.
* IBSS could work in the code but isn't supported
* by drivers or the standard.
*/
if (sdata->vif.type != NL80211_IFTYPE_STATION &&
sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
sdata->vif.type != NL80211_IFTYPE_AP)
return -EINVAL;
if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "BA sessions blocked. "
"Denying BA session request\n");
#endif
return -EINVAL;
}
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;
}
tid_tx = sta->ampdu_mlme.tid_tx[tid];
/* check if the TID is not in aggregation flow already */
if (tid_tx) {
#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 */
tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
if (!tid_tx) {
#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;
}
skb_queue_head_init(&tid_tx->pending);
__set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
tid_tx->timeout = timeout;
/* Tx timer */
tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired;
tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid];
init_timer(&tid_tx->addba_resp_timer);
/* assign a dialog token */
sta->ampdu_mlme.dialog_token_allocator++;
tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
/* finally, assign it to the array */
rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
/* this flow continues off the work */
err_unlock_sta:
spin_unlock_bh(&sta->lock);
return ret;
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
/*
* splice packets from the STA's pending to the local pending,
* requires a call to ieee80211_agg_splice_finish later
*/
static void __acquires(agg_queue)
ieee80211_agg_splice_packets(struct ieee80211_local *local,
struct tid_ampdu_tx *tid_tx, u16 tid)
{
int queue = ieee80211_ac_from_tid(tid);
unsigned long flags;
ieee80211_stop_queue_agg(local, tid);
if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates"
" from the pending queue\n", tid))
return;
if (!skb_queue_empty(&tid_tx->pending)) {
spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
/* copy over remaining packets */
skb_queue_splice_tail_init(&tid_tx->pending,
&local->pending[queue]);
spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
}
}
static void __releases(agg_queue)
ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid)
{
ieee80211_wake_queue_agg(local, tid);
}
static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
struct sta_info *sta, u16 tid)
{
lockdep_assert_held(&sta->ampdu_mlme.mtx);
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid);
#endif
drv_ampdu_action(local, sta->sdata,
IEEE80211_AMPDU_TX_OPERATIONAL,
&sta->sta, tid, NULL);
/*
* synchronize with TX path, while splicing the TX path
* should block so it won't put more packets onto pending.
*/
spin_lock_bh(&sta->lock);
ieee80211_agg_splice_packets(local, sta->ampdu_mlme.tid_tx[tid], tid);
/*
* Now mark as operational. This will be visible
* in the TX path, and lets it go lock-free in
* the common case.
*/
set_bit(HT_AGG_STATE_OPERATIONAL, &sta->ampdu_mlme.tid_tx[tid]->state);
ieee80211_agg_splice_finish(local, tid);
spin_unlock_bh(&sta->lock);
}
void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
{
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
struct tid_ampdu_tx *tid_tx;
trace_api_start_tx_ba_cb(sdata, ra, tid);
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;
}
mutex_lock(&local->sta_mtx);
sta = sta_info_get(sdata, ra);
if (!sta) {
mutex_unlock(&local->sta_mtx);
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Could not find station: %pM\n", ra);
#endif
return;
}
mutex_lock(&sta->ampdu_mlme.mtx);
tid_tx = sta->ampdu_mlme.tid_tx[tid];
if (WARN_ON(!tid_tx)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "addBA was not requested!\n");
#endif
goto unlock;
}
if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
goto unlock;
if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
ieee80211_agg_tx_operational(local, sta, tid);
unlock:
mutex_unlock(&sta->ampdu_mlme.mtx);
mutex_unlock(&local->sta_mtx);
}
void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
const u8 *ra, u16 tid)
{
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct ieee80211_local *local = sdata->local;
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", sdata->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_SDATA_QUEUE_AGG_START;
skb_queue_tail(&sdata->skb_queue, skb);
ieee80211_queue_work(&local->hw, &sdata->work);
}
EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
enum ieee80211_back_parties initiator,
bool tx)
{
int ret;
mutex_lock(&sta->ampdu_mlme.mtx);
ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator, tx);
mutex_unlock(&sta->ampdu_mlme.mtx);
return ret;
}
int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
{
struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
struct ieee80211_sub_if_data *sdata = sta->sdata;
struct ieee80211_local *local = sdata->local;
struct tid_ampdu_tx *tid_tx;
int ret = 0;
trace_api_stop_tx_ba_session(pubsta, tid);
if (!local->ops->ampdu_action)
return -EINVAL;
if (tid >= STA_TID_NUM)
return -EINVAL;
spin_lock_bh(&sta->lock);
tid_tx = sta->ampdu_mlme.tid_tx[tid];
if (!tid_tx) {
ret = -ENOENT;
goto unlock;
}
if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
/* already in progress stopping it */
ret = 0;
goto unlock;
}
set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state);
ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
unlock:
spin_unlock_bh(&sta->lock);
return ret;
}
EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
{
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
struct tid_ampdu_tx *tid_tx;
trace_api_stop_tx_ba_cb(sdata, ra, tid);
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 %pM tid %d\n",
ra, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
mutex_lock(&local->sta_mtx);
sta = sta_info_get(sdata, ra);
if (!sta) {
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Could not find station: %pM\n", ra);
#endif
goto unlock;
}
mutex_lock(&sta->ampdu_mlme.mtx);
spin_lock_bh(&sta->lock);
tid_tx = sta->ampdu_mlme.tid_tx[tid];
if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
#endif
goto unlock_sta;
}
if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop)
ieee80211_send_delba(sta->sdata, ra, tid,
WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
/*
* When we get here, the TX path will not be lockless any more wrt.
* aggregation, since the OPERATIONAL bit has long been cleared.
* Thus it will block on getting the lock, if it occurs. So if we
* stop the queue now, we will not get any more packets, and any
* that might be being processed will wait for us here, thereby
* guaranteeing that no packets go to the tid_tx pending queue any
* more.
*/
ieee80211_agg_splice_packets(local, tid_tx, tid);
/* future packets must not find the tid_tx struct any more */
rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
ieee80211_agg_splice_finish(local, tid);
call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
unlock_sta:
spin_unlock_bh(&sta->lock);
mutex_unlock(&sta->ampdu_mlme.mtx);
unlock:
mutex_unlock(&local->sta_mtx);
}
void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
const u8 *ra, u16 tid)
{
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct ieee80211_local *local = sdata->local;
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", sdata->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_SDATA_QUEUE_AGG_STOP;
skb_queue_tail(&sdata->skb_queue, skb);
ieee80211_queue_work(&local->hw, &sdata->work);
}
EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
void ieee80211_process_addba_resp(struct ieee80211_local *local,
struct sta_info *sta,
struct ieee80211_mgmt *mgmt,
size_t len)
{
struct tid_ampdu_tx *tid_tx;
u16 capab, tid;
capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
mutex_lock(&sta->ampdu_mlme.mtx);
tid_tx = sta->ampdu_mlme.tid_tx[tid];
if (!tid_tx)
goto out;
if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
#endif
goto out;
}
del_timer(&tid_tx->addba_resp_timer);
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid);
#endif
if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
== WLAN_STATUS_SUCCESS) {
if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
&tid_tx->state)) {
/* ignore duplicate response */
goto out;
}
if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
ieee80211_agg_tx_operational(local, sta, tid);
sta->ampdu_mlme.addba_req_num[tid] = 0;
} else {
___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR,
true);
}
out:
mutex_unlock(&sta->ampdu_mlme.mtx);
}