/*
* 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 <linux/export.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().
* Note that the sta can get destroyed before the BA tear down is
* complete.
*/
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)
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 ||
sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
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);
else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
memcpy(mgmt->bssid, sdata->u.ibss.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_tid(sdata, skb, tid);
}
void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
{
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
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)
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 << IEEE80211_BAR_CTRL_TID_INFO_SHIFT);
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_CTL_REQ_TX_STATUS;
ieee80211_tx_skb_tid(sdata, skb, tid);
}
EXPORT_SYMBOL(ieee80211_send_bar);
void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
struct tid_ampdu_tx *tid_tx)
{
lockdep_assert_held(&sta->ampdu_mlme.mtx);
lockdep_assert_held(&sta->lock);
rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], 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;
int ret;
lockdep_assert_held(&sta->ampdu_mlme.mtx);
spin_lock_bh(&sta->lock);
tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
if (!tid_tx) {
spin_unlock_bh(&sta->lock);
return -ENOENT;
}
/* if we're already stopping ignore any new requests to stop */
if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
spin_unlock_bh(&sta->lock);
return -EALREADY;
}
if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
/* not even started yet! */
ieee80211_assign_tid_tx(sta, tid, NULL);
spin_unlock_bh(&sta->lock);
kfree_rcu(tid_tx, rcu_head);
return 0;
}
set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
spin_unlock_bh(&sta->lock);
ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n",
sta->sta.addr, tid);
del_timer_sync(&tid_tx->addba_resp_timer);
del_timer_sync(&tid_tx->session_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);
/*
* There might be a few packets being processed right now (on
* another CPU) that have already gotten past the aggregation
* check when it was still OPERATIONAL and consequently have
* IEEE80211_TX_CTL_AMPDU set. In that case, this code might
* call into the driver at the same time or even before the
* TX paths calls into it, which could confuse the driver.
*
* Wait for all currently running TX paths to finish before
* telling the driver. New packets will not go through since
* the aggregation session is no longer OPERATIONAL.
*/
synchronize_net();
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, 0);
/* 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();
ht_dbg(sta->sdata,
"timer expired on tid %d but we are not (or no longer) expecting addBA response there\n",
tid);
return;
}
ht_dbg(sta->sdata, "addBA response timer expired on tid %d\n", tid);
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_sub_if_data *sdata, int tid)
{
int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1)
ieee80211_stop_queue_by_reason(
&sdata->local->hw, queue,
IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
__acquire(agg_queue);
}
static void __releases(agg_queue)
ieee80211_wake_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
{
int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
if (atomic_dec_return(&sdata->local->agg_queue_stop[queue]) == 0)
ieee80211_wake_queue_by_reason(
&sdata->local->hw, queue,
IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
__release(agg_queue);
}
/*
* 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_sub_if_data *sdata,
struct tid_ampdu_tx *tid_tx, u16 tid)
{
struct ieee80211_local *local = sdata->local;
int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
unsigned long flags;
ieee80211_stop_queue_agg(sdata, 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_sub_if_data *sdata, u16 tid)
{
ieee80211_wake_queue_agg(sdata, tid);
}
void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
{
struct tid_ampdu_tx *tid_tx;
struct ieee80211_local *local = sta->local;
struct ieee80211_sub_if_data *sdata = sta->sdata;
u16 start_seq_num;
int ret;
tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
/*
* Start queuing up packets for this aggregation session.
* We're going to release them once the driver is OK with
* that.
*/
clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
/*
* Make sure no packets are being processed. This ensures that
* we have a valid starting sequence number and that in-flight
* packets have been flushed out and no packets for this TID
* will go into the driver during the ampdu_action call.
*/
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, 0);
if (ret) {
ht_dbg(sdata,
"BA request denied - HW unavailable for tid %d\n", tid);
spin_lock_bh(&sta->lock);
ieee80211_agg_splice_packets(sdata, tid_tx, tid);
ieee80211_assign_tid_tx(sta, tid, NULL);
ieee80211_agg_splice_finish(sdata, tid);
spin_unlock_bh(&sta->lock);
kfree_rcu(tid_tx, rcu_head);
return;
}
/* activate the timer for the recipient's addBA response */
mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
ht_dbg(sdata, "activated addBA response timer on tid %d\n", tid);
spin_lock_bh(&sta->lock);
sta->ampdu_mlme.last_addba_req_time[tid] = jiffies;
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,
local->hw.max_tx_aggregation_subframes,
tid_tx->timeout);
}
/*
* After accepting the AddBA Response we activated a timer,
* resetting it after each frame that we send.
*/
static void sta_tx_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]);
struct tid_ampdu_tx *tid_tx;
unsigned long timeout;
rcu_read_lock();
tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[*ptid]);
if (!tid_tx || test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
rcu_read_unlock();
return;
}
timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout);
if (time_is_after_jiffies(timeout)) {
mod_timer(&tid_tx->session_timer, timeout);
rcu_read_unlock();
return;
}
rcu_read_unlock();
ht_dbg(sta->sdata, "tx session timer expired on tid %d\n", (u16)*ptid);
ieee80211_stop_tx_ba_session(&sta->sta, *ptid);
}
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) ||
(local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW))
return -EINVAL;
ht_dbg(sdata, "Open BA session requested for %pM tid %u\n",
pubsta->addr, tid);
if (sdata->vif.type != NL80211_IFTYPE_STATION &&
sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
sdata->vif.type != NL80211_IFTYPE_AP &&
sdata->vif.type != NL80211_IFTYPE_ADHOC)
return -EINVAL;
if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
ht_dbg(sdata,
"BA sessions blocked - Denying BA session request\n");
return -EINVAL;
}
/*
* 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a
* member of an IBSS, and has no other existing Block Ack agreement
* with the recipient STA, then the initiating STA shall transmit a
* Probe Request frame to the recipient STA and shall not transmit an
* ADDBA Request frame unless it receives a Probe Response frame
* from the recipient within dot11ADDBAFailureTimeout.
*
* The probe request mechanism for ADDBA is currently not implemented,
* but we only build up Block Ack session with HT STAs. This information
* is set when we receive a bss info from a probe response or a beacon.
*/
if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC &&
!sta->sta.ht_cap.ht_supported) {
ht_dbg(sdata,
"BA request denied - IBSS STA %pM does not advertise HT support\n",
pubsta->addr);
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;
}
/*
* if we have tried more than HT_AGG_BURST_RETRIES times we
* will spread our requests in time to avoid stalling connection
* for too long
*/
if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES &&
time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] +
HT_AGG_RETRIES_PERIOD)) {
ht_dbg(sdata,
"BA request denied - waiting a grace period after %d failed requests on tid %u\n",
sta->ampdu_mlme.addba_req_num[tid], tid);
ret = -EBUSY;
goto err_unlock_sta;
}
tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
/* check if the TID is not in aggregation flow already */
if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
ht_dbg(sdata,
"BA request denied - session is not idle on tid %u\n",
tid);
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) {
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;
/* response 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);
/* tx timer */
tid_tx->session_timer.function = sta_tx_agg_session_timer_expired;
tid_tx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
init_timer_deferrable(&tid_tx->session_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 start array; the work item will
* collect it and move it to the normal array.
*/
sta->ampdu_mlme.tid_start_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);
static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
struct sta_info *sta, u16 tid)
{
struct tid_ampdu_tx *tid_tx;
lockdep_assert_held(&sta->ampdu_mlme.mtx);
tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
ht_dbg(sta->sdata, "Aggregation is on for tid %d\n", tid);
drv_ampdu_action(local, sta->sdata,
IEEE80211_AMPDU_TX_OPERATIONAL,
&sta->sta, tid, NULL, tid_tx->buf_size);
/*
* 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(sta->sdata, tid_tx, 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, &tid_tx->state);
ieee80211_agg_splice_finish(sta->sdata, 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) {
ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
tid, STA_TID_NUM);
return;
}
mutex_lock(&local->sta_mtx);
sta = sta_info_get_bss(sdata, ra);
if (!sta) {
mutex_unlock(&local->sta_mtx);
ht_dbg(sdata, "Could not find station: %pM\n", ra);
return;
}
mutex_lock(&sta->ampdu_mlme.mtx);
tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
if (WARN_ON(!tid_tx)) {
ht_dbg(sdata, "addBA was not requested!\n");
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))
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 = rcu_dereference_protected_tid_tx(sta, 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) {
ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n",
tid, STA_TID_NUM);
return;
}
ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", ra, tid);
mutex_lock(&local->sta_mtx);
sta = sta_info_get_bss(sdata, ra);
if (!sta) {
ht_dbg(sdata, "Could not find station: %pM\n", ra);
goto unlock;
}
mutex_lock(&sta->ampdu_mlme.mtx);
spin_lock_bh(&sta->lock);
tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
ht_dbg(sdata, "unexpected callback to A-MPDU stop\n");
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(sta->sdata, tid_tx, tid);
/* future packets must not find the tid_tx struct any more */
ieee80211_assign_tid_tx(sta, tid, NULL);
ieee80211_agg_splice_finish(sta->sdata, tid);
kfree_rcu(tid_tx, rcu_head);
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))
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;
u8 buf_size;
capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
mutex_lock(&sta->ampdu_mlme.mtx);
tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
if (!tid_tx)
goto out;
if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
ht_dbg(sta->sdata, "wrong addBA response token, tid %d\n", tid);
goto out;
}
del_timer_sync(&tid_tx->addba_resp_timer);
ht_dbg(sta->sdata, "switched off addBA timer for tid %d\n", tid);
/*
* addba_resp_timer may have fired before we got here, and
* caused WANT_STOP to be set. If the stop then was already
* processed further, STOPPING might be set.
*/
if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) ||
test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
ht_dbg(sta->sdata,
"got addBA resp for tid %d but we already gave up\n",
tid);
goto out;
}
/*
* IEEE 802.11-2007 7.3.1.14:
* In an ADDBA Response frame, when the Status Code field
* is set to 0, the Buffer Size subfield is set to a value
* of at least 1.
*/
if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
== WLAN_STATUS_SUCCESS && buf_size) {
if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
&tid_tx->state)) {
/* ignore duplicate response */
goto out;
}
tid_tx->buf_size = buf_size;
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;
if (tid_tx->timeout) {
mod_timer(&tid_tx->session_timer,
TU_TO_EXP_TIME(tid_tx->timeout));
tid_tx->last_tx = jiffies;
}
} else {
___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR,
false);
}
out:
mutex_unlock(&sta->ampdu_mlme.mtx);
}
