/*
* 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.
*/
/**
* DOC: RX A-MPDU aggregation
*
* Aggregation on the RX side requires only implementing the
* @ampdu_action callback that is invoked to start/stop any
* block-ack sessions for RX aggregation.
*
* When RX aggregation is started by the peer, the driver is
* notified via @ampdu_action function, with the
* %IEEE80211_AMPDU_RX_START action, and may reject the request
* in which case a negative response is sent to the peer, if it
* accepts it a positive response is sent.
*
* While the session is active, the device/driver are required
* to de-aggregate frames and pass them up one by one to mac80211,
* which will handle the reorder buffer.
*
* When the aggregation session is stopped again by the peer or
* ourselves, the driver's @ampdu_action function will be called
* with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
* call must not fail.
*/
#include <linux/ieee80211.h>
#include <linux/slab.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
static void ieee80211_free_tid_rx(struct rcu_head *h)
{
struct tid_ampdu_rx *tid_rx =
container_of(h, struct tid_ampdu_rx, rcu_head);
int i;
for (i = 0; i < tid_rx->buf_size; i++)
dev_kfree_skb(tid_rx->reorder_buf[i]);
kfree(tid_rx->reorder_buf);
kfree(tid_rx->reorder_time);
kfree(tid_rx);
}
void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
u16 initiator, u16 reason, bool tx)
{
struct ieee80211_local *local = sta->local;
struct tid_ampdu_rx *tid_rx;
lockdep_assert_held(&sta->ampdu_mlme.mtx);
tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
lockdep_is_held(&sta->ampdu_mlme.mtx));
if (!tid_rx)
return;
rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], NULL);
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
sta->sta.addr, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
&sta->sta, tid, NULL, 0))
printk(KERN_DEBUG "HW problem - can not stop rx "
"aggregation for tid %d\n", tid);
/* check if this is a self generated aggregation halt */
if (initiator == WLAN_BACK_RECIPIENT && tx)
ieee80211_send_delba(sta->sdata, sta->sta.addr,
tid, 0, reason);
del_timer_sync(&tid_rx->session_timer);
del_timer_sync(&tid_rx->reorder_timer);
call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
}
void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
u16 initiator, u16 reason, bool tx)
{
mutex_lock(&sta->ampdu_mlme.mtx);
___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
mutex_unlock(&sta->ampdu_mlme.mtx);
}
/*
* After accepting the AddBA Request we activated a timer,
* resetting it after each frame that arrives from the originator.
*/
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
set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
}
static void sta_rx_agg_reorder_timer_expired(unsigned long data)
{
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]);
rcu_read_lock();
ieee80211_release_reorder_timeout(sta, *ptid);
rcu_read_unlock();
}
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_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->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_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);
}
void ieee80211_process_addba_request(struct ieee80211_local *local,
struct sta_info *sta,
struct ieee80211_mgmt *mgmt,
size_t len)
{
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;
/* 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;
if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "Suspend in progress. "
"Denying ADDBA request\n");
#endif
goto end_no_lock;
}
/* sanity check for incoming parameters:
* check if configuration can support the BA policy
* and if buffer size does not exceeds max value */
/* XXX: check own ht delayed BA capability?? */
if (((ba_policy != 1) &&
(!(sta->sta.ht_cap.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 "
"%pM on tid %u. policy %d, buffer size %d\n",
mgmt->sa, tid, ba_policy,
buf_size);
#endif /* CONFIG_MAC80211_HT_DEBUG */
goto end_no_lock;
}
/* determine default buffer size */
if (buf_size == 0)
buf_size = IEEE80211_MAX_AMPDU_BUF;
/* make sure the size doesn't exceed the maximum supported by the hw */
if (buf_size > local->hw.max_rx_aggregation_subframes)
buf_size = local->hw.max_rx_aggregation_subframes;
/* examine state machine */
mutex_lock(&sta->ampdu_mlme.mtx);
if (sta->ampdu_mlme.tid_rx[tid]) {
#ifdef CONFIG_MAC80211_HT_DEBUG
if (net_ratelimit())
printk(KERN_DEBUG "unexpected AddBA Req from "
"%pM on tid %u\n",
mgmt->sa, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
goto end;
}
/* prepare A-MPDU MLME for Rx aggregation */
tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
if (!tid_agg_rx) {
#ifdef CONFIG_MAC80211_HT_DEBUG
if (net_ratelimit())
printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
tid);
#endif
goto end;
}
spin_lock_init(&tid_agg_rx->reorder_lock);
/* rx timer */
tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
init_timer(&tid_agg_rx->session_timer);
/* rx reorder timer */
tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
init_timer(&tid_agg_rx->reorder_timer);
/* prepare reordering buffer */
tid_agg_rx->reorder_buf =
kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL);
tid_agg_rx->reorder_time =
kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
#ifdef CONFIG_MAC80211_HT_DEBUG
if (net_ratelimit())
printk(KERN_ERR "can not allocate reordering buffer "
"to tid %d\n", tid);
#endif
kfree(tid_agg_rx->reorder_buf);
kfree(tid_agg_rx->reorder_time);
kfree(tid_agg_rx);
goto end;
}
ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
&sta->sta, tid, &start_seq_num, 0);
#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->reorder_time);
kfree(tid_agg_rx);
goto end;
}
/* update data */
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;
/* activate it for RX */
rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
if (timeout)
mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
end:
mutex_unlock(&sta->ampdu_mlme.mtx);
end_no_lock:
ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
dialog_token, status, 1, buf_size, timeout);
}
