Commit eefce91a authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville
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mac80211: dont allow fragmentation and requeuing on A-MPDU queues 



There really is no reason for a driver to reject a frame on
an A-MPDU queue when it can stop that queue for any period
of time and is given frames one by one. Hence, disallow it
with a big warning and reduce mac80211-internal state.

Also add a warning when we try to fragment a frame destined
for an A-MPDU queue and drop it, the actual bug needs to be
fixed elsewhere but I'm not exactly sure how to yet.

Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Cc: Ron Rindjunsky <ron.rindjunsky@intel.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent e9304882

include/net/mac80211.h

+4 −2
Original line number Diff line number Diff line
@@ -986,8 +986,10 @@ enum ieee80211_ampdu_mlme_action { 
 * @tx: Handler that 802.11 module calls for each transmitted frame.

 *	skb contains the buffer starting from the IEEE 802.11 header.

 *	The low-level driver should send the frame out based on

 *	configuration in the TX control data. Must be implemented and

 *	atomic.

 *	configuration in the TX control data. This handler should,

 *	preferably, never fail and stop queues appropriately, more

 *	importantly, however, it must never fail for A-MPDU-queues.

 *	Must be implemented and atomic.

 *

 * @start: Called before the first netdevice attached to the hardware

 *	is enabled. This should turn on the hardware and must turn on

net/mac80211/ieee80211_i.h

+1 −1
Original line number Diff line number Diff line
@@ -595,7 +595,7 @@ struct ieee80211_local { 
	struct timer_list sta_cleanup;



	unsigned long state[IEEE80211_MAX_QUEUES + IEEE80211_MAX_AMPDU_QUEUES];

	struct ieee80211_tx_stored_packet pending_packet[IEEE80211_MAX_QUEUES + IEEE80211_MAX_AMPDU_QUEUES];

	struct ieee80211_tx_stored_packet pending_packet[IEEE80211_MAX_QUEUES];

	struct tasklet_struct tx_pending_tasklet;



	/* number of interfaces with corresponding IFF_ flags */

net/mac80211/tx.c

+21 −2
Original line number Diff line number Diff line
@@ -673,6 +673,16 @@ ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx) 
	if (!(tx->flags & IEEE80211_TX_FRAGMENTED))

		return TX_CONTINUE;



	/*

	 * Warn when submitting a fragmented A-MPDU frame and drop it.

	 * This is an error and needs to be fixed elsewhere, but when

	 * done needs to take care of monitor interfaces (injection)

	 * etc.

	 */

	if (WARN_ON(tx->flags & IEEE80211_TX_CTL_AMPDU ||

		    IEEE80211_SKB_CB(tx->skb)->queue >= tx->local->hw.queues))

		return TX_DROP;



	first = tx->skb;



	hdrlen = ieee80211_get_hdrlen(tx->fc);
@@ -1216,8 +1226,17 @@ static int ieee80211_tx(struct net_device *dev, struct sk_buff *skb) 
retry:

	ret = __ieee80211_tx(local, skb, &tx);

	if (ret) {

		struct ieee80211_tx_stored_packet *store =

			&local->pending_packet[info->queue];

		struct ieee80211_tx_stored_packet *store;



		/*

		 * Since there are no fragmented frames on A-MPDU

		 * queues, there's no reason for a driver to reject

		 * a frame there, warn and drop it.

		 */

		if (WARN_ON(queue >= local->hw.queues))

			goto drop;



		store = &local->pending_packet[queue];



		if (ret == IEEE80211_TX_FRAG_AGAIN)

			skb = NULL;

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