linux/net/mac80211/agg-rx.c
Michal Kazior 4549cf2b18 mac80211: fix offloaded BA session traffic after hw restart
When starting an offloaded BA session it is
unknown what starting sequence number should be
used. Using last_seq worked in most cases except
after hw restart.

When hw restart is requested last_seq is
(rightfully so) kept unmodified. This ended up
with BA sessions being restarted with an aribtrary
BA window values resulting in dropped frames until
sequence numbers caught up.

Instead of last_seq pick seqno of a first Rxed
frame of a given BA session.

This fixes stalled traffic after hw restart with
offloaded BA sessions (currently only ath10k).

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2014-09-03 13:40:38 +02:00

415 lines
13 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.
*/
/**
* 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 <linux/export.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;
del_timer_sync(&tid_rx->reorder_timer);
for (i = 0; i < tid_rx->buf_size; i++)
__skb_queue_purge(&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_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
ht_dbg(sta->sdata,
"Rx BA session stop requested for %pM tid %u %s reason: %d\n",
sta->sta.addr, tid,
initiator == WLAN_BACK_RECIPIENT ? "recipient" : "inititator",
(int)reason);
if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
&sta->sta, tid, NULL, 0))
sdata_info(sta->sdata,
"HW problem - can not stop rx aggregation for %pM tid %d\n",
sta->sta.addr, 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, WLAN_BACK_RECIPIENT, reason);
del_timer_sync(&tid_rx->session_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);
}
void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
const u8 *addr)
{
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct sta_info *sta;
int i;
rcu_read_lock();
sta = sta_info_get_bss(sdata, addr);
if (!sta) {
rcu_read_unlock();
return;
}
for (i = 0; i < IEEE80211_NUM_TIDS; i++)
if (ba_rx_bitmap & BIT(i))
set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
rcu_read_unlock();
}
EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
/*
* 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]);
struct tid_ampdu_rx *tid_rx;
unsigned long timeout;
rcu_read_lock();
tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
if (!tid_rx) {
rcu_read_unlock();
return;
}
timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
if (time_is_after_jiffies(timeout)) {
mod_timer(&tid_rx->session_timer, timeout);
rcu_read_unlock();
return;
}
rcu_read_unlock();
ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
sta->sta.addr, (u16)*ptid);
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)
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_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_start_rx_ba_session(struct sta_info *sta,
u8 dialog_token, u16 timeout,
u16 start_seq_num, u16 ba_policy, u16 tid,
u16 buf_size, bool tx, bool auto_seq)
{
struct ieee80211_local *local = sta->sdata->local;
struct tid_ampdu_rx *tid_agg_rx;
int i, ret = -EOPNOTSUPP;
u16 status = WLAN_STATUS_REQUEST_DECLINED;
if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
ht_dbg(sta->sdata,
"Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
sta->sta.addr, tid);
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;
ht_dbg_ratelimited(sta->sdata,
"AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
sta->sta.addr, tid, ba_policy, buf_size);
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]) {
ht_dbg_ratelimited(sta->sdata,
"unexpected AddBA Req from %pM on tid %u\n",
sta->sta.addr, tid);
/* delete existing Rx BA session on the same tid */
___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
WLAN_STATUS_UNSPECIFIED_QOS,
false);
}
/* prepare A-MPDU MLME for Rx aggregation */
tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
if (!tid_agg_rx)
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_deferrable(&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_head), 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) {
kfree(tid_agg_rx->reorder_buf);
kfree(tid_agg_rx->reorder_time);
kfree(tid_agg_rx);
goto end;
}
for (i = 0; i < buf_size; i++)
__skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
&sta->sta, tid, &start_seq_num, 0);
ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
sta->sta.addr, tid, ret);
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;
tid_agg_rx->auto_seq = auto_seq;
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));
tid_agg_rx->last_rx = jiffies;
}
end:
mutex_unlock(&sta->ampdu_mlme.mtx);
end_no_lock:
if (tx)
ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
dialog_token, status, 1, buf_size,
timeout);
}
void ieee80211_process_addba_request(struct ieee80211_local *local,
struct sta_info *sta,
struct ieee80211_mgmt *mgmt,
size_t len)
{
u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
u8 dialog_token;
/* 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;
__ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
start_seq_num, ba_policy, tid,
buf_size, true, false);
}
void ieee80211_start_rx_ba_session_offl(struct ieee80211_vif *vif,
const u8 *addr, u16 tid)
{
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct ieee80211_local *local = sdata->local;
struct ieee80211_rx_agg *rx_agg;
struct sk_buff *skb = dev_alloc_skb(0);
if (unlikely(!skb))
return;
rx_agg = (struct ieee80211_rx_agg *) &skb->cb;
memcpy(&rx_agg->addr, addr, ETH_ALEN);
rx_agg->tid = tid;
skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_START;
skb_queue_tail(&sdata->skb_queue, skb);
ieee80211_queue_work(&local->hw, &sdata->work);
}
EXPORT_SYMBOL(ieee80211_start_rx_ba_session_offl);
void ieee80211_stop_rx_ba_session_offl(struct ieee80211_vif *vif,
const u8 *addr, u16 tid)
{
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct ieee80211_local *local = sdata->local;
struct ieee80211_rx_agg *rx_agg;
struct sk_buff *skb = dev_alloc_skb(0);
if (unlikely(!skb))
return;
rx_agg = (struct ieee80211_rx_agg *) &skb->cb;
memcpy(&rx_agg->addr, addr, ETH_ALEN);
rx_agg->tid = tid;
skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_STOP;
skb_queue_tail(&sdata->skb_queue, skb);
ieee80211_queue_work(&local->hw, &sdata->work);
}
EXPORT_SYMBOL(ieee80211_stop_rx_ba_session_offl);