From 891a96d5885dad7496417946f289eaa28b2d8892 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Sat, 9 Jul 2011 03:33:59 +0000
Subject: [PATCH] ath9k: add more fixes for TKIP MIC validation

SVN-Revision: 27564
---
 .../patches/550-ath9k_mmic_verify.patch       | 69 +++++++++++--------
 1 file changed, 39 insertions(+), 30 deletions(-)

diff --git a/package/mac80211/patches/550-ath9k_mmic_verify.patch b/package/mac80211/patches/550-ath9k_mmic_verify.patch
index d280dff99ce..053d543cb02 100644
--- a/package/mac80211/patches/550-ath9k_mmic_verify.patch
+++ b/package/mac80211/patches/550-ath9k_mmic_verify.patch
@@ -1,6 +1,6 @@
 --- a/drivers/net/wireless/ath/ath9k/recv.c
 +++ b/drivers/net/wireless/ath/ath9k/recv.c
-@@ -814,16 +814,17 @@ static bool ath9k_rx_accept(struct ath_c
+@@ -814,16 +814,19 @@ static bool ath9k_rx_accept(struct ath_c
  			    struct ath_rx_status *rx_stats,
  			    bool *decrypt_error)
  {
@@ -8,7 +8,7 @@
 -		(rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID && \
 -		test_bit(rx_stats->rs_keyix, common->tkip_keymap))))
 -
-+	bool is_mc, is_valid_tkip, mic_error = false;
++	bool is_mc, is_valid_tkip, strip_mic, mic_error = false;
  	struct ath_hw *ah = common->ah;
  	__le16 fc;
  	u8 rx_status_len = ah->caps.rx_status_len;
@@ -18,37 +18,40 @@
 +	is_mc = !!is_multicast_ether_addr(hdr->addr1);
 +	is_valid_tkip = rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID &&
 +		test_bit(rx_stats->rs_keyix, common->tkip_keymap);
++	strip_mic = is_valid_tkip && !(rx_stats->rs_status &
++		(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_CRC | ATH9K_RXERR_MIC));
 +
  	if (!rx_stats->rs_datalen)
  		return false;
          /*
-@@ -853,19 +854,19 @@ static bool ath9k_rx_accept(struct ath_c
- 		if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
+@@ -850,25 +853,9 @@ static bool ath9k_rx_accept(struct ath_c
+ 		if (rx_stats->rs_status & ATH9K_RXERR_PHY)
+ 			return false;
+ 
+-		if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
++		if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT)
  			*decrypt_error = true;
- 		} else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
+-		} else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
 -			bool is_mc;
- 			/*
- 			 * The MIC error bit is only valid if the frame
- 			 * is not a control frame or fragment, and it was
+-			/*
+-			 * The MIC error bit is only valid if the frame
+-			 * is not a control frame or fragment, and it was
 -			 * decrypted using a valid TKIP key.
-+			 * decrypted using a valid TKIP key. For multicast
-+			 * frames the hardware will not return a valid
-+			 * key index, so accept the MIC bit for those
-+			 * as well.
- 			 */
+-			 */
 -			is_mc = !!is_multicast_ether_addr(hdr->addr1);
--
- 			if (!ieee80211_is_ctl(fc) &&
- 			    !ieee80211_has_morefrags(fc) &&
- 			    !(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
+ 
+-			if (!ieee80211_is_ctl(fc) &&
+-			    !ieee80211_has_morefrags(fc) &&
+-			    !(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
 -			    is_mc_or_valid_tkip_keyix)
 -				rxs->flag |= RX_FLAG_MMIC_ERROR;
-+			    (is_mc || is_valid_tkip))
-+				mic_error = true;
- 			else
- 				rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
- 		}
-@@ -886,6 +887,22 @@ static bool ath9k_rx_accept(struct ath_c
+-			else
+-				rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
+-		}
+ 		/*
+ 		 * Reject error frames with the exception of
+ 		 * decryption and MIC failures. For monitor mode,
+@@ -886,6 +873,18 @@ static bool ath9k_rx_accept(struct ath_c
  			}
  		}
  	}
@@ -59,15 +62,21 @@
 +	 * False negatives are not common, so skip software verification
 +	 * if the hardware considers the MIC valid.
 +	 */
-+	if (is_valid_tkip && ieee80211_is_data_present(hdr->frame_control) &&
-+	    !(rx_stats->rs_status & (ATH9K_RXERR_DECRYPT | ATH9K_RXERR_CRC |
-+				     ATH9K_RXERR_MIC))) {
-+		/* Strip the Michael MIC */
-+		rx_stats->rs_datalen -= 8;
++	if (strip_mic)
 +		rxs->flag |= RX_FLAG_MMIC_STRIPPED;
-+	} else if (is_mc && mic_error) {
++	else if (is_mc && mic_error)
 +		rxs->flag |= RX_FLAG_MMIC_ERROR;
-+	}
++
  	return true;
  }
  
+@@ -1882,6 +1881,9 @@ int ath_rx_tasklet(struct ath_softc *sc,
+ 			ath9k_rx_skb_postprocess(common, hdr_skb, &rs,
+ 						 rxs, decrypt_error);
+ 
++		if (rxs->flag & RX_FLAG_MMIC_STRIPPED)
++			skb_trim(skb, skb->len - 8);
++
+ 		/* We will now give hardware our shiny new allocated skb */
+ 		bf->bf_mpdu = requeue_skb;
+ 		bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
-- 
2.30.2