[023/289] ath9k: fix spurious MIC failure reports

Greg KH
2010-12-08T02:00:25Z

From: Felix Fietkau <nbd@openwrt.org>

commit 56363ddeeed3afc5277ca227209773bc1042cc7b upstream.

According to the hardware documentation, the MIC failure bit is only
valid if the frame was decrypted using a valid TKIP key and is not a
fragment.
In some setups I've seen hardware-reported MIC failures on an AP that
was configured for CCMP only, so it's clear that additional checks are
necessary.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/net/wireless/ath/ath.h | 1 +
drivers/net/wireless/ath/ath9k/common.c | 11 +++++++++++
drivers/net/wireless/ath/ath9k/mac.c | 3 ++-
drivers/net/wireless/ath/ath9k/recv.c | 19 +++++++++++--------
4 files changed, 25 insertions(+), 9 deletions(-)

--- a/drivers/net/wireless/ath/ath.h
+++ b/drivers/net/wireless/ath/ath.h
@@ -119,6 +119,7 @@ struct ath_common {

u32 keymax;
DECLARE_BITMAP(keymap, ATH_KEYMAX);
+ DECLARE_BITMAP(tkip_keymap, ATH_KEYMAX);
u8 splitmic;

struct ath_regulatory regulatory;
--- a/drivers/net/wireless/ath/ath9k/common.c
+++ b/drivers/net/wireless/ath/ath9k/common.c
@@ -366,9 +366,13 @@ int ath9k_cmn_key_config(struct ath_comm
set_bit(idx, common->keymap);
if (key->alg == ALG_TKIP) {
set_bit(idx + 64, common->keymap);
+ set_bit(idx, common->tkip_keymap);
+ set_bit(idx + 64, common->tkip_keymap);
if (common->splitmic) {
set_bit(idx + 32, common->keymap);
set_bit(idx + 64 + 32, common->keymap);
+ set_bit(idx + 32, common->tkip_keymap);
+ set_bit(idx + 64 + 32, common->tkip_keymap);
}
}

@@ -393,10 +397,17 @@ void ath9k_cmn_key_delete(struct ath_com
return;

clear_bit(key->hw_key_idx + 64, common->keymap);
+
+ clear_bit(key->hw_key_idx, common->tkip_keymap);
+ clear_bit(key->hw_key_idx + 64, common->tkip_keymap);
+
if (common->splitmic) {
ath9k_hw_keyreset(ah, key->hw_key_idx + 32);
clear_bit(key->hw_key_idx + 32, common->keymap);
clear_bit(key->hw_key_idx + 64 + 32, common->keymap);
+
+ clear_bit(key->hw_key_idx + 32, common->tkip_keymap);
+ clear_bit(key->hw_key_idx + 64 + 32, common->tkip_keymap);
}
}
EXPORT_SYMBOL(ath9k_cmn_key_delete);
--- a/drivers/net/wireless/ath/ath9k/mac.c
+++ b/drivers/net/wireless/ath/ath9k/mac.c
@@ -711,7 +711,8 @@ int ath9k_hw_rxprocdesc(struct ath_hw *a
rs->rs_phyerr = phyerr;
} else if (ads.ds_rxstatus8 & AR_DecryptCRCErr)
rs->rs_status |= ATH9K_RXERR_DECRYPT;
- else if (ads.ds_rxstatus8 & AR_MichaelErr)
+ else if ((ads.ds_rxstatus8 & AR_MichaelErr) &&
+ rs->rs_keyix != ATH9K_RXKEYIX_INVALID)
rs->rs_status |= ATH9K_RXERR_MIC;
else if (ads.ds_rxstatus8 & AR_KeyMiss)
rs->rs_status |= ATH9K_RXERR_DECRYPT;
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -870,15 +870,18 @@ 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) {
- if (ieee80211_is_ctl(fc))
- /*
- * Sometimes, we get invalid
- * MIC failures on valid control frames.
- * Remove these mic errors.
- */
- rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
- else
+ /*
+ * 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.
+ */
+ if (!ieee80211_is_ctl(fc) &&
+ !ieee80211_has_morefrags(fc) &&
+ !(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
+ test_bit(rx_stats->rs_keyix, common->tkip_keymap))
rxs->flag |= RX_FLAG_MMIC_ERROR;
+ else
+ rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
}
/*
* Reject error frames with the exception of