Commit b77cf4f8 authored by Johannes Berg's avatar Johannes Berg
Browse files

mac80211: handle MMPDUs at EOSP correctly 



If a uAPSD service period ends with an MMPDU, we currently just
send that MMPDU, but it obviously won't get the EOSP bit set as
it doesn't have a QoS header. This contradicts the standard, so
add a QoS-nulldata frame after the MMPDU to properly terminate
the service period with a frame that has EOSP set.

Also fix a bug wrt. the TID for the MMPDU, it shouldn't be set
to 0 unconditionally but use the actual TID that was assigned.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 03c8c06f

include/net/mac80211.h

+5 −0
Original line number Diff line number Diff line
@@ -2119,6 +2119,11 @@ void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb); 
 * appropriately (only the last frame may have %IEEE80211_TX_STATUS_EOSP)

 * and also take care of the EOSP and MORE_DATA bits in the frame.

 * The driver may also use ieee80211_sta_eosp() in this case.

 *

 * Note that if the driver ever buffers frames other than QoS-data

 * frames, it must take care to never send a non-QoS-data frame as

 * the last frame in a service period, adding a QoS-nulldata frame

 * after a non-QoS-data frame if needed.

 */



/**

net/mac80211/sta_info.c

+57 −13
Original line number Diff line number Diff line
@@ -1153,7 +1153,8 @@ void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta) 


static void ieee80211_send_null_response(struct ieee80211_sub_if_data *sdata,

					 struct sta_info *sta, int tid,

					 enum ieee80211_frame_release_type reason)

					 enum ieee80211_frame_release_type reason,

					 bool call_driver)

{

	struct ieee80211_local *local = sdata->local;

	struct ieee80211_qos_hdr *nullfunc;
@@ -1211,7 +1212,9 @@ static void ieee80211_send_null_response(struct ieee80211_sub_if_data *sdata, 
		       IEEE80211_TX_STATUS_EOSP |

		       IEEE80211_TX_CTL_REQ_TX_STATUS;



	drv_allow_buffered_frames(local, sta, BIT(tid), 1, reason, false);

	if (call_driver)

		drv_allow_buffered_frames(local, sta, BIT(tid), 1,

					  reason, false);



	skb->dev = sdata->dev;
@@ -1334,12 +1337,13 @@ ieee80211_sta_ps_deliver_response(struct sta_info *sta, 
		/* This will evaluate to 1, 3, 5 or 7. */

		tid = 7 - ((ffs(~ignored_acs) - 1) << 1);



		ieee80211_send_null_response(sdata, sta, tid, reason);

		ieee80211_send_null_response(sdata, sta, tid, reason, true);

	} else if (!driver_release_tids) {

		struct sk_buff_head pending;

		struct sk_buff *skb;

		int num = 0;

		u16 tids = 0;

		bool need_null = false;



		skb_queue_head_init(&pending);
@@ -1373,22 +1377,57 @@ ieee80211_sta_ps_deliver_response(struct sta_info *sta, 
			    ieee80211_is_qos_nullfunc(hdr->frame_control))

				qoshdr = ieee80211_get_qos_ctl(hdr);



			/* end service period after last frame */

			if (skb_queue_empty(&frames)) {

				if (reason == IEEE80211_FRAME_RELEASE_UAPSD &&

				    qoshdr)

					*qoshdr |= IEEE80211_QOS_CTL_EOSP;

			tids |= BIT(skb->priority);



			__skb_queue_tail(&pending, skb);



			/* end service period after last frame or add one */

			if (!skb_queue_empty(&frames))

				continue;



			if (reason != IEEE80211_FRAME_RELEASE_UAPSD) {

				/* for PS-Poll, there's only one frame */

				info->flags |= IEEE80211_TX_STATUS_EOSP |

					       IEEE80211_TX_CTL_REQ_TX_STATUS;

				break;

			}



			if (qoshdr)

				tids |= BIT(*qoshdr & IEEE80211_QOS_CTL_TID_MASK);

			else

				tids |= BIT(0);

			/* For uAPSD, things are a bit more complicated. If the

			 * last frame has a QoS header (i.e. is a QoS-data or

			 * QoS-nulldata frame) then just set the EOSP bit there

			 * and be done.

			 * If the frame doesn't have a QoS header (which means

			 * it should be a bufferable MMPDU) then we can't set

			 * the EOSP bit in the QoS header; add a QoS-nulldata

			 * frame to the list to send it after the MMPDU.

			 *

			 * Note that this code is only in the mac80211-release

			 * code path, we assume that the driver will not buffer

			 * anything but QoS-data frames, or if it does, will

			 * create the QoS-nulldata frame by itself if needed.

			 *

			 * Cf. 802.11-2012 10.2.1.10 (c).

			 */

			if (qoshdr) {

				*qoshdr |= IEEE80211_QOS_CTL_EOSP;



			__skb_queue_tail(&pending, skb);

				info->flags |= IEEE80211_TX_STATUS_EOSP |

					       IEEE80211_TX_CTL_REQ_TX_STATUS;

			} else {

				/* The standard isn't completely clear on this

				 * as it says the more-data bit should be set

				 * if there are more BUs. The QoS-Null frame

				 * we're about to send isn't buffered yet, we

				 * only create it below, but let's pretend it

				 * was buffered just in case some clients only

				 * expect more-data=0 when eosp=1.

				 */

				hdr->frame_control |=

					cpu_to_le16(IEEE80211_FCTL_MOREDATA);

				need_null = true;

				num++;

			}

			break;

		}



		drv_allow_buffered_frames(local, sta, tids, num,
@@ -1396,6 +1435,11 @@ ieee80211_sta_ps_deliver_response(struct sta_info *sta, 


		ieee80211_add_pending_skbs(local, &pending);



		if (need_null)

			ieee80211_send_null_response(

				sdata, sta, find_highest_prio_tid(tids),

				reason, false);



		sta_info_recalc_tim(sta);

	} else {

		/*

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