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ath9k: fix reliability issues with TKIP MIC verification

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SVN-Revision: 27481
This commit is contained in:
Felix Fietkau 2011-07-06 09:06:39 +00:00
parent e68ea8543b
commit 3ad9a3e992
1 changed files with 73 additions and 0 deletions
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73
package/mac80211/patches/550-ath9k_mmic_verify.patch Normal file
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@ -0,0 +1,73 @@
--- 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
struct ath_rx_status *rx_stats,
bool *decrypt_error)
{
-#define is_mc_or_valid_tkip_keyix ((is_mc || \
- (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;
struct ath_hw *ah = common->ah;
__le16 fc;
u8 rx_status_len = ah->caps.rx_status_len;
fc = hdr->frame_control;
+ 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);
+
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) {
*decrypt_error = true;
} 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
- * 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) &&
- 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
}
}
}
+
+ /*
+ * For unicast frames the MIC error bit can have false positives,
+ * so all MIC error reports need to be validated in software.
+ * 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;
+ rxs->flag |= RX_FLAG_MMIC_STRIPPED;
+ } else if (is_mc && mic_error) {
+ rxs->flag |= RX_FLAG_MMIC_ERROR;
+ }
return true;
}