mac80211: clear txflags for ps-filtered frames

This patch fixes stale mac80211_tx_control_flags for
filtered / retried frames.

Because ieee80211_handle_filtered_frame feeds skbs back
into the tx path, they have to be stripped of some tx
flags so they won't confuse the stack, driver or device.

Cc: <stable@kernel.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/net/mac80211.h

@@ -321,6 +321,9 @@ struct ieee80211_bss_conf {
  * @IEEE80211_TX_CTL_LDPC: tells the driver to use LDPC for this frame
  * @IEEE80211_TX_CTL_STBC: Enables Space-Time Block Coding (STBC) for this
  *	frame and selects the maximum number of streams that it can use.
+ *
+ * Note: If you have to add new flags to the enumeration, then don't
+ *	 forget to update %IEEE80211_TX_TEMPORARY_FLAGS when necessary.
  */
 enum mac80211_tx_control_flags {
 	IEEE80211_TX_CTL_REQ_TX_STATUS		= BIT(0),
@@ -350,6 +353,19 @@ enum mac80211_tx_control_flags {
 
 #define IEEE80211_TX_CTL_STBC_SHIFT		23
 
+/*
+ * This definition is used as a mask to clear all temporary flags, which are
+ * set by the tx handlers for each transmission attempt by the mac80211 stack.
+ */
+#define IEEE80211_TX_TEMPORARY_FLAGS (IEEE80211_TX_CTL_NO_ACK |		      \
+	IEEE80211_TX_CTL_CLEAR_PS_FILT | IEEE80211_TX_CTL_FIRST_FRAGMENT |    \
+	IEEE80211_TX_CTL_SEND_AFTER_DTIM | IEEE80211_TX_CTL_AMPDU |	      \
+	IEEE80211_TX_STAT_TX_FILTERED |	IEEE80211_TX_STAT_ACK |		      \
+	IEEE80211_TX_STAT_AMPDU | IEEE80211_TX_STAT_AMPDU_NO_BACK |	      \
+	IEEE80211_TX_CTL_RATE_CTRL_PROBE | IEEE80211_TX_CTL_PSPOLL_RESPONSE | \
+	IEEE80211_TX_CTL_MORE_FRAMES | IEEE80211_TX_CTL_LDPC |		      \
+	IEEE80211_TX_CTL_STBC)
+
 /**
  * enum mac80211_rate_control_flags - per-rate flags set by the
  *	Rate Control algorithm.

net/mac80211/status.c

@@ -58,6 +58,7 @@ static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
 	info->control.vif = &sta->sdata->vif;
 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
 		       IEEE80211_TX_INTFL_RETRANSMISSION;
+	info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
 
 	sta->tx_filtered_count++;