ath9k: fix reliability issues with TKIP MIC verification

SVN-Revision: 27481
14 years ago · 3ad9a3e992
parent e68ea8543b
commit 3ad9a3e992
1 changed files with 73 additions and 0 deletions
--- a/package/mac80211/patches/550-ath9k_mmic_verify.patch
+++ b/package/mac80211/patches/550-ath9k_mmic_verify.patch
@ -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;
+ }
+