/*
* 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 2007-2009, 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/mac80211.h>
#include "ieee80211_i.h"
#include "wme.h"
/**
* DOC: TX aggregation
*
* Aggregation on the TX side requires setting the hardware flag
* %IEEE80211_HW_AMPDU_AGGREGATION as well as, if present, the @ampdu_queues
* hardware parameter to the number of hardware AMPDU queues. If there are no
* hardware queues then the driver will (currently) have to do all frame
* buffering.
*
* 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() (or ieee80211_start_tx_ba_cb_irqsafe())
* function, which will start the aggregation session.
*
* Similarly, when the aggregation session is stopped by
* 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()
* (or 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 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 ||
sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
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, 1);
}
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);
}
static int __ieee80211_stop_tx_ba_session(struct ieee80211_local *local,
struct sta_info *sta, u16 tid,
enum ieee80211_back_parties initiator)
{
int ret;
u8 *state;
state = &sta->ampdu_mlme.tid_state_tx[tid];
if (local->hw.ampdu_queues)
ieee80211_stop_queue(&local->hw, sta->tid_to_tx_q[tid]);
*state = HT_AGG_STATE_REQ_STOP_BA_MSK |
(initiator << HT_AGG_STATE_INITIATOR_SHIFT);
ret = local->ops->ampdu_action(&local->hw, IEEE80211_AMPDU_TX_STOP,
&sta->sta, tid, NULL);
/* HW shall not deny going back to legacy */
if (WARN_ON(ret)) {
*state = HT_AGG_STATE_OPERATIONAL;
if (local->hw.ampdu_queues)
ieee80211_wake_queue(&local->hw, sta->tid_to_tx_q[tid]);
}
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 ieee80211_local *local = sta->local;
u8 *state;
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
return;
}
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
#endif
__ieee80211_stop_tx_ba_session(local, sta, tid, WLAN_BACK_INITIATOR);
spin_unlock_bh(&sta->lock);
}
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 = 0;
if (WARN_ON(!local->ops->ampdu_action))
return -EINVAL;
if ((tid >= STA_TID_NUM) || !(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",
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;
}
/*
* 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 (sta->sdata->vif.type != NL80211_IFTYPE_STATION &&
sta->sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
sta->sdata->vif.type != NL80211_IFTYPE_AP) {
ret = -EINVAL;
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);
if (hw->ampdu_queues) {
/* 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];
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 */
if (hw->ampdu_queues)
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 */
if (hw->ampdu_queues)
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);
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;
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: %pM\n", 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
if (hw->ampdu_queues)
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_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);
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;
if (WARN_ON(!local->ops->ampdu_action))
return -EINVAL;
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 unlock;
}
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
ra, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
ret = __ieee80211_stop_tx_ba_session(local, sta, tid, initiator);
unlock:
spin_unlock_bh(&sta->lock);
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
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;
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 */
rcu_read_lock();
sta = sta_info_get(local, ra);
if (!sta) {
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Could not find station: %pM\n", 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);
if (hw->ampdu_queues) {
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_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);
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, start_seq_num;
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 &&
local->hw.ampdu_queues)
ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
if (local->ops->ampdu_action) {
(void)local->ops->ampdu_action(hw,
IEEE80211_AMPDU_TX_RESUME,
&sta->sta, tid, &start_seq_num);
}
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Resuming TX aggregation for tid %d\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
spin_unlock_bh(&sta->lock);
} else {
sta->ampdu_mlme.addba_req_num[tid]++;
__ieee80211_stop_tx_ba_session(local, sta, tid,
WLAN_BACK_INITIATOR);
spin_unlock_bh(&sta->lock);
}
}
