mac80211: add flag for duplication check

Add an option for driver to check for packet duplication
by itself.
This is needed for example by the iwlwifi driver which
parallelizes the RX path and does the duplication check
per queue.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -1063,7 +1063,7 @@ enum mac80211_rx_flags {
 	RX_FLAG_HT_GF			= BIT(13),
 	RX_FLAG_AMPDU_DETAILS		= BIT(14),
 	RX_FLAG_PN_VALIDATED		= BIT(15),
-	/* bit 16 free */
+	RX_FLAG_DUP_VALIDATED		= BIT(16),
 	RX_FLAG_AMPDU_LAST_KNOWN	= BIT(17),
 	RX_FLAG_AMPDU_IS_LAST		= BIT(18),
 	RX_FLAG_AMPDU_DELIM_CRC_ERROR	= BIT(19),

net/mac80211/rx.c

@@ -1099,6 +1099,9 @@ ieee80211_rx_h_check_dup(struct ieee80211_rx_data *rx)
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 
+	if (status->flag & RX_FLAG_DUP_VALIDATED)
+		return RX_CONTINUE;
+
 	/*
 	 * Drop duplicate 802.11 retransmissions
 	 * (IEEE 802.11-2012: 9.3.2.10 "Duplicate detection and recovery")