diff options
Diffstat (limited to 'net/mac80211/agg-tx.c')
| -rw-r--r-- | net/mac80211/agg-tx.c | 1002 |
1 files changed, 1002 insertions, 0 deletions
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c new file mode 100644 index 0000000..bef516e --- /dev/null +++ b/net/mac80211/agg-tx.c @@ -0,0 +1,1002 @@ +/* + * 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 + * Copyright(c) 2015-2017 Intel Deutschland GmbH + * + * 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 = skb_put_zero(skb, 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 << 0); /* bit 0 A-MSDU support */ + 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_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 = skb_put_zero(skb, 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); +} + +/* + * 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)]; + + /* we do refcounting here, so don't use the queue reason refcounting */ + + 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, + false); + __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, + false); + __release(agg_queue); +} + +static void +ieee80211_agg_stop_txq(struct sta_info *sta, int tid) +{ + struct ieee80211_txq *txq = sta->sta.txq[tid]; + struct ieee80211_sub_if_data *sdata; + struct fq *fq; + struct txq_info *txqi; + + if (!txq) + return; + + txqi = to_txq_info(txq); + sdata = vif_to_sdata(txq->vif); + fq = &sdata->local->fq; + + /* Lock here to protect against further seqno updates on dequeue */ + spin_lock_bh(&fq->lock); + set_bit(IEEE80211_TXQ_STOP, &txqi->flags); + spin_unlock_bh(&fq->lock); +} + +static void +ieee80211_agg_start_txq(struct sta_info *sta, int tid, bool enable) +{ + struct ieee80211_txq *txq = sta->sta.txq[tid]; + struct txq_info *txqi; + + if (!txq) + return; + + txqi = to_txq_info(txq); + + if (enable) + set_bit(IEEE80211_TXQ_AMPDU, &txqi->flags); + else + clear_bit(IEEE80211_TXQ_AMPDU, &txqi->flags); + + clear_bit(IEEE80211_TXQ_STOP, &txqi->flags); + local_bh_disable(); + rcu_read_lock(); + drv_wake_tx_queue(sta->sdata->local, txqi); + rcu_read_unlock(); + local_bh_enable(); +} + +/* + * 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); +} + +static void ieee80211_remove_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); + + tid_tx = rcu_dereference_protected_tid_tx(sta, tid); + + /* + * 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); + ieee80211_agg_start_txq(sta, tid, false); + + kfree_rcu(tid_tx, rcu_head); +} + +int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, + enum ieee80211_agg_stop_reason reason) +{ + struct ieee80211_local *local = sta->local; + struct tid_ampdu_tx *tid_tx; + struct ieee80211_ampdu_params params = { + .sta = &sta->sta, + .tid = tid, + .buf_size = 0, + .amsdu = false, + .timeout = 0, + .ssn = 0, + }; + int ret; + + lockdep_assert_held(&sta->ampdu_mlme.mtx); + + switch (reason) { + case AGG_STOP_DECLINED: + case AGG_STOP_LOCAL_REQUEST: + case AGG_STOP_PEER_REQUEST: + params.action = IEEE80211_AMPDU_TX_STOP_CONT; + break; + case AGG_STOP_DESTROY_STA: + params.action = IEEE80211_AMPDU_TX_STOP_FLUSH; + break; + default: + WARN_ON_ONCE(1); + return -EINVAL; + } + + 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 + * unless we're destroying it in which case notify the driver + */ + if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { + spin_unlock_bh(&sta->lock); + if (reason != AGG_STOP_DESTROY_STA) + return -EALREADY; + params.action = IEEE80211_AMPDU_TX_STOP_FLUSH_CONT; + ret = drv_ampdu_action(local, sta->sdata, ¶ms); + WARN_ON_ONCE(ret); + return 0; + } + + 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 = reason == AGG_STOP_PEER_REQUEST ? + WLAN_BACK_RECIPIENT : + WLAN_BACK_INITIATOR; + tid_tx->tx_stop = reason == AGG_STOP_LOCAL_REQUEST; + + ret = drv_ampdu_action(local, sta->sdata, ¶ms); + + /* 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. + */ + } + + /* + * In the case of AGG_STOP_DESTROY_STA, the driver won't + * necessarily call ieee80211_stop_tx_ba_cb(), so this may + * seem like we can leave the tid_tx data pending forever. + * This is true, in a way, but "forever" is only until the + * station struct is actually destroyed. In the meantime, + * leaving it around ensures that we don't transmit packets + * to the driver on this TID which might confuse it. + */ + + return 0; +} + +/* + * 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 %pM tid %d not expecting addBA response\n", + sta->sta.addr, tid); + return; + } + + ht_dbg(sta->sdata, "addBA response timer expired on %pM tid %d\n", + sta->sta.addr, tid); + + ieee80211_stop_tx_ba_session(&sta->sta, tid); + rcu_read_unlock(); +} + +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; + struct ieee80211_ampdu_params params = { + .sta = &sta->sta, + .action = IEEE80211_AMPDU_TX_START, + .tid = tid, + .buf_size = 0, + .amsdu = false, + .timeout = 0, + }; + 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); + + ieee80211_agg_stop_txq(sta, tid); + + /* + * 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(); + + params.ssn = sta->tid_seq[tid] >> 4; + ret = drv_ampdu_action(local, sdata, ¶ms); + if (ret) { + ht_dbg(sdata, + "BA request denied - HW unavailable for %pM tid %d\n", + sta->sta.addr, 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); + + ieee80211_agg_start_txq(sta, tid, false); + + 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 %pM tid %d\n", + sta->sta.addr, 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, params.ssn, + IEEE80211_MAX_AMPDU_BUF, + 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 %pM tid %d\n", + sta->sta.addr, (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(sta->reserved_tid == tid, + "Requested to start BA session on reserved tid=%d", tid)) + return -EINVAL; + + if (!pubsta->ht_cap.ht_supported) + return -EINVAL; + + if (WARN_ON_ONCE(!local->ops->ampdu_action)) + return -EINVAL; + + if ((tid >= IEEE80211_NUM_TIDS) || + !ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION) || + ieee80211_hw_check(&local->hw, TX_AMPDU_SETUP_IN_HW)) + return -EINVAL; + + if (WARN_ON(tid >= IEEE80211_FIRST_TSPEC_TSID)) + 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 %pM tid %d\n", + sta->sta.addr, tid); + 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 - %d failed requests on %pM tid %u\n", + sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, 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 %pM tid %u\n", + sta->sta.addr, 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 */ + setup_timer(&tid_tx->addba_resp_timer, + sta_addba_resp_timer_expired, + (unsigned long)&sta->timer_to_tid[tid]); + + /* tx timer */ + setup_deferrable_timer(&tid_tx->session_timer, + sta_tx_agg_session_timer_expired, + (unsigned long)&sta->timer_to_tid[tid]); + + /* 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; + struct ieee80211_ampdu_params params = { + .sta = &sta->sta, + .action = IEEE80211_AMPDU_TX_OPERATIONAL, + .tid = tid, + .timeout = 0, + .ssn = 0, + }; + + lockdep_assert_held(&sta->ampdu_mlme.mtx); + + tid_tx = rcu_dereference_protected_tid_tx(sta, tid); + params.buf_size = tid_tx->buf_size; + params.amsdu = tid_tx->amsdu; + + ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n", + sta->sta.addr, tid); + + drv_ampdu_action(local, sta->sdata, ¶ms); + + /* + * 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); + + ieee80211_agg_start_txq(sta, tid, true); +} + +void ieee80211_start_tx_ba_cb(struct sta_info *sta, int tid, + struct tid_ampdu_tx *tid_tx) +{ + struct ieee80211_sub_if_data *sdata = sta->sdata; + struct ieee80211_local *local = sdata->local; + + if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) + return; + + if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) + ieee80211_agg_tx_operational(local, sta, tid); +} + +static struct tid_ampdu_tx * +ieee80211_lookup_tid_tx(struct ieee80211_sub_if_data *sdata, + const u8 *ra, u16 tid, struct sta_info **sta) +{ + struct tid_ampdu_tx *tid_tx; + + if (tid >= IEEE80211_NUM_TIDS) { + ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n", + tid, IEEE80211_NUM_TIDS); + return NULL; + } + + *sta = sta_info_get_bss(sdata, ra); + if (!*sta) { + ht_dbg(sdata, "Could not find station: %pM\n", ra); + return NULL; + } + + tid_tx = rcu_dereference((*sta)->ampdu_mlme.tid_tx[tid]); + + if (WARN_ON(!tid_tx)) + ht_dbg(sdata, "addBA was not requested!\n"); + + return tid_tx; +} + +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 sta_info *sta; + struct tid_ampdu_tx *tid_tx; + + trace_api_start_tx_ba_cb(sdata, ra, tid); + + rcu_read_lock(); + tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta); + if (!tid_tx) + goto out; + + set_bit(HT_AGG_STATE_START_CB, &tid_tx->state); + ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); + out: + rcu_read_unlock(); +} +EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe); + +int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, + enum ieee80211_agg_stop_reason reason) +{ + int ret; + + mutex_lock(&sta->ampdu_mlme.mtx); + + ret = ___ieee80211_stop_tx_ba_session(sta, tid, reason); + + 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 >= IEEE80211_NUM_TIDS) + return -EINVAL; + + spin_lock_bh(&sta->lock); + tid_tx = rcu_dereference_protected_tid_tx(sta, tid); + + if (!tid_tx) { + ret = -ENOENT; + goto unlock; + } + + WARN(sta->reserved_tid == tid, + "Requested to stop BA session on reserved tid=%d", tid); + + 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 sta_info *sta, int tid, + struct tid_ampdu_tx *tid_tx) +{ + struct ieee80211_sub_if_data *sdata = sta->sdata; + bool send_delba = false; + + ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", + sta->sta.addr, tid); + + spin_lock_bh(&sta->lock); + + if (!test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { + ht_dbg(sdata, + "unexpected callback to A-MPDU stop for %pM tid %d\n", + sta->sta.addr, tid); + goto unlock_sta; + } + + if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop) + send_delba = true; + + ieee80211_remove_tid_tx(sta, tid); + + unlock_sta: + spin_unlock_bh(&sta->lock); + + if (send_delba) + ieee80211_send_delba(sdata, sta->sta.addr, tid, + WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); +} + +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 sta_info *sta; + struct tid_ampdu_tx *tid_tx; + + trace_api_stop_tx_ba_cb(sdata, ra, tid); + + rcu_read_lock(); + tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta); + if (!tid_tx) + goto out; + + set_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state); + ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); + out: + rcu_read_unlock(); +} +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; + struct ieee80211_txq *txq; + u16 capab, tid; + u8 buf_size; + bool amsdu; + + capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab); + amsdu = capab & IEEE80211_ADDBA_PARAM_AMSDU_MASK; + tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; + buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; + buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes); + + txq = sta->sta.txq[tid]; + if (!amsdu && txq) + set_bit(IEEE80211_TXQ_NO_AMSDU, &to_txq_info(txq)->flags); + + 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, %pM tid %d\n", + sta->sta.addr, tid); + goto out; + } + + del_timer_sync(&tid_tx->addba_resp_timer); + + ht_dbg(sta->sdata, "switched off addBA timer for %pM tid %d\n", + sta->sta.addr, 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 %pM tid %d but we already gave up\n", + sta->sta.addr, 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; + tid_tx->amsdu = amsdu; + + 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, AGG_STOP_DECLINED); + } + + out: + mutex_unlock(&sta->ampdu_mlme.mtx); +} |