/* * HT handling * * Copyright 2003, Jouni Malinen * Copyright 2002-2005, Instant802 Networks, Inc. * Copyright 2005-2006, Devicescape Software, Inc. * Copyright 2006-2007 Jiri Benc * Copyright 2007, Michael Wu * 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 #include #include #include #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_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, true); } out: mutex_unlock(&sta->ampdu_mlme.mtx); }