mac80211: consolidate MIC failure report handling

Currently, mac80211 handles MIC failures differently
depending on whenever they are detected by the stack's
own software crypto or when are handed down from the
driver.

This patch tries to unify both by moving the special
branch out of mac80211 rx hotpath and into into the
software crypto part. This has the advantage that we
can run a few more sanity checks on the data and verify
if the key type was TKIP. This is very handy because
several devices generate false postive MIC failure
reports. Like carl9170, ath9k and wl12xx:
<http://www.spinics.net/lists/linux-wireless/msg68494.html>
"mac80211: report MIC failure for truncated packets in AP mode"

Cc: Luciano Coelho <coelho@ti.com>
Cc: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 0 insertions, 47 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index b04a437..81241e1 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2368,47 +2368,6 @@ ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
 	return RX_QUEUED;
 }
 
-static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
-					    struct ieee80211_rx_data *rx)
-{
-	int keyidx;
-	unsigned int hdrlen;
-
-	hdrlen = ieee80211_hdrlen(hdr->frame_control);
-	if (rx->skb->len >= hdrlen + 4)
-		keyidx = rx->skb->data[hdrlen + 3] >> 6;
-	else
-		keyidx = -1;
-
-	if (!rx->sta) {
-		/*
-		 * Some hardware seem to generate incorrect Michael MIC
-		 * reports; ignore them to avoid triggering countermeasures.
-		 */
-		return;
-	}
-
-	if (!ieee80211_has_protected(hdr->frame_control))
-		return;
-
-	if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
-		/*
-		 * APs with pairwise keys should never receive Michael MIC
-		 * errors for non-zero keyidx because these are reserved for
-		 * group keys and only the AP is sending real multicast
-		 * frames in the BSS.
-		 */
-		return;
-	}
-
-	if (!ieee80211_is_data(hdr->frame_control) &&
-	    !ieee80211_is_auth(hdr->frame_control))
-		return;
-
-	mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
-					GFP_ATOMIC);
-}
-
 /* TODO: use IEEE80211_RX_FRAGMENTED */
 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
 					struct ieee80211_rate *rate)
@@ -2752,12 +2711,6 @@ static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
 	if (!prepares)
 		return false;
 
-	if (status->flag & RX_FLAG_MMIC_ERROR) {
-		if (status->rx_flags & IEEE80211_RX_RA_MATCH)
-			ieee80211_rx_michael_mic_report(hdr, rx);
-		return false;
-	}
-
 	if (!consume) {
 		skb = skb_copy(skb, GFP_ATOMIC);
 		if (!skb) {