1 files changed, 167 insertions, 61 deletions

diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index b3f65520e7a..76be6174419 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -55,6 +55,8 @@
  * @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,
@@ -78,10 +80,13 @@ static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
 	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_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);
@@ -102,7 +107,7 @@ static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
 	mgmt->u.action.u.addba_req.start_seq_num =
 					cpu_to_le16(start_seq_num << 4);
 
-	ieee80211_tx_skb(sdata, skb);
+	ieee80211_tx_skb_tid(sdata, skb, tid);
 }
 
 void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
@@ -131,7 +136,7 @@ void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
 	bar->start_seq_num = cpu_to_le16(ssn);
 
 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
-	ieee80211_tx_skb(sdata, skb);
+	ieee80211_tx_skb_tid(sdata, skb, tid);
 }
 EXPORT_SYMBOL(ieee80211_send_bar);
 
@@ -161,6 +166,12 @@ int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 		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);
@@ -169,6 +180,8 @@ int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 		return 0;
 	}
 
+	set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
+
 	spin_unlock_bh(&sta->lock);
 
 #ifdef CONFIG_MAC80211_HT_DEBUG
@@ -176,9 +189,8 @@ int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 	       sta->sta.addr, tid);
 #endif /* CONFIG_MAC80211_HT_DEBUG */
 
-	set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
-
 	del_timer_sync(&tid_tx->addba_resp_timer);
+	del_timer_sync(&tid_tx->session_timer);
 
 	/*
 	 * After this packets are no longer handed right through
@@ -187,6 +199,20 @@ int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 	 */
 	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;
 
@@ -283,6 +309,38 @@ ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid)
 	__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_local *local,
+			     struct tid_ampdu_tx *tid_tx, u16 tid)
+{
+	int queue = ieee80211_ac_from_tid(tid);
+	unsigned long flags;
+
+	ieee80211_stop_queue_agg(local, 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_local *local, u16 tid)
+{
+	ieee80211_wake_queue_agg(local, tid);
+}
+
 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 {
 	struct tid_ampdu_tx *tid_tx;
@@ -294,19 +352,17 @@ void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 	tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 
 	/*
-	 * While we're asking the driver about the aggregation,
-	 * stop the AC queue so that we don't have to worry
-	 * about frames that came in while we were doing that,
-	 * which would require us to put them to the AC pending
-	 * afterwards which just makes the code more complex.
+	 * Start queuing up packets for this aggregation session.
+	 * We're going to release them once the driver is OK with
+	 * that.
 	 */
-	ieee80211_stop_queue_agg(local, tid);
-
 	clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
 
 	/*
-	 * make sure no packets are being processed to get
-	 * valid starting sequence number
+	 * 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();
 
@@ -320,17 +376,15 @@ void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 					" tid %d\n", tid);
 #endif
 		spin_lock_bh(&sta->lock);
+		ieee80211_agg_splice_packets(local, tid_tx, tid);
 		ieee80211_assign_tid_tx(sta, tid, NULL);
+		ieee80211_agg_splice_finish(local, tid);
 		spin_unlock_bh(&sta->lock);
 
-		ieee80211_wake_queue_agg(local, tid);
 		kfree_rcu(tid_tx, rcu_head);
 		return;
 	}
 
-	/* we can take packets again now */
-	ieee80211_wake_queue_agg(local, tid);
-
 	/* activate the timer for the recipient's addBA response */
 	mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
 #ifdef CONFIG_MAC80211_HT_DEBUG
@@ -338,6 +392,7 @@ void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 #endif
 
 	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);
 
@@ -348,6 +403,28 @@ void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 				     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]);
+
+#ifdef CONFIG_MAC80211_HT_DEBUG
+	printk(KERN_DEBUG "tx session timer expired on tid %d\n", (u16)*ptid);
+#endif
+
+	ieee80211_stop_tx_ba_session(&sta->sta, *ptid);
+}
+
 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
 				  u16 timeout)
 {
@@ -372,15 +449,11 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
 	       pubsta->addr, tid);
 #endif /* CONFIG_MAC80211_HT_DEBUG */
 
-	/*
-	 * 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 (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_AP &&
+	    sdata->vif.type != NL80211_IFTYPE_ADHOC)
 		return -EINVAL;
 
 	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
@@ -391,6 +464,27 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 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) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+		printk(KERN_DEBUG "BA request denied - IBSS STA %pM"
+		       "does not advertise HT support\n", pubsta->addr);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+		return -EINVAL;
+	}
+
 	spin_lock_bh(&sta->lock);
 
 	/* we have tried too many times, receiver does not want A-MPDU */
@@ -399,6 +493,24 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
 		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)) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+		printk(KERN_DEBUG "BA request denied - "
+		       "waiting a grace period after %d failed requests "
+		       "on tid %u\n",
+		       sta->ampdu_mlme.addba_req_num[tid], tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+		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]) {
@@ -422,11 +534,16 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
 
 	tid_tx->timeout = timeout;
 
-	/* Tx timer */
+	/* 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(&tid_tx->session_timer);
+
 	/* assign a dialog token */
 	sta->ampdu_mlme.dialog_token_allocator++;
 	tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
@@ -446,38 +563,6 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
 }
 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
 
-/*
- * 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_local *local,
-			     struct tid_ampdu_tx *tid_tx, u16 tid)
-{
-	int queue = ieee80211_ac_from_tid(tid);
-	unsigned long flags;
-
-	ieee80211_stop_queue_agg(local, 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_local *local, u16 tid)
-{
-	ieee80211_wake_queue_agg(local, tid);
-}
-
 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
 					 struct sta_info *sta, u16 tid)
 {
@@ -531,7 +616,7 @@ void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
 	}
 
 	mutex_lock(&local->sta_mtx);
-	sta = sta_info_get(sdata, ra);
+	sta = sta_info_get_bss(sdata, ra);
 	if (!sta) {
 		mutex_unlock(&local->sta_mtx);
 #ifdef CONFIG_MAC80211_HT_DEBUG
@@ -660,7 +745,7 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
 
 	mutex_lock(&local->sta_mtx);
 
-	sta = sta_info_get(sdata, ra);
+	sta = sta_info_get_bss(sdata, ra);
 	if (!sta) {
 #ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "Could not find station: %pM\n", ra);
@@ -757,11 +842,27 @@ void ieee80211_process_addba_resp(struct ieee80211_local *local,
 		goto out;
 	}
 
-	del_timer(&tid_tx->addba_resp_timer);
+	del_timer_sync(&tid_tx->addba_resp_timer);
 
 #ifdef CONFIG_MAC80211_HT_DEBUG
 	printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid);
 #endif
+
+	/*
+	 * 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)) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+		printk(KERN_DEBUG
+		       "got addBA resp for tid %d but we already gave up\n",
+		       tid);
+#endif
+		goto out;
+	}
+
 	/*
 	 * IEEE 802.11-2007 7.3.1.14:
 	 * In an ADDBA Response frame, when the Status Code field
@@ -782,6 +883,11 @@ void ieee80211_process_addba_resp(struct ieee80211_local *local,
 			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));
+
 	} else {
 		___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR,
 						true);