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authornbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>2011-07-06 09:06:39 +0000
committernbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>2011-07-06 09:06:39 +0000
commit30a93a7cd51e962aba4e0c45288466a4477daffb (patch)
tree05a026c263917d410f09eff7f59a68b1cf421d64
parentb2a31b39ba04b42c3717573ff61c82bb2d877b26 (diff)
ath9k: fix reliability issues with TKIP MIC verification
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@27481 3c298f89-4303-0410-b956-a3cf2f4a3e73
-rw-r--r--package/mac80211/patches/550-ath9k_mmic_verify.patch73
1 files changed, 73 insertions, 0 deletions
diff --git a/package/mac80211/patches/550-ath9k_mmic_verify.patch b/package/mac80211/patches/550-ath9k_mmic_verify.patch
new file mode 100644
index 000000000..d280dff99
--- /dev/null
+++ 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;
+ }
+