From:   Xing Song <xing.song@mediatek.com>
To:     Felix Fietkau <nbd@nbd.name>
CC:     Lorenzo Bianconi <lorenzo.bianconi@redhat.com>,
        Shayne Chen <shayne.chen@mediatek.com>,
        Ryder Lee <ryder.lee@mediatek.com>,
        Evelyn Tsai <evelyn.tsai@mediatek.com>,
        <linux-wireless@vger.kernel.org>,
        <linux-mediatek@lists.infradead.org>,
        Xing Song <xing.song@mediatek.com>
Subject: [PATCH v4] mt76: do not pass the received frame with decryption error
Date:   Fri, 19 Nov 2021 14:37:06 +0800
Message-ID: <20211119063706.17643-1-xing.song@mediatek.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

MAC80211 doesn't care any decryption error in 802.3 path, so received
frame will be dropped if HW tell us that the cipher configuration is not
matched as well as the header has been translated to 802.3. This case only
appears when IEEE80211_FCTL_PROTECTED is 0 and cipher suit is not none in
the corresponding HW entry.

The received frame is only reported to monitor interface if HW decryption
block tell us there is ICV error or CCMP/BIP/WPI MIC error. Note in this
case the reported frame is decrypted 802.11 frame and the payload may be
malformed due to mismatched key.

Signed-off-by: Xing Song <xing.song@mediatek.com>
---
v2: check for cipher mismatch or frame format error
v3: remove the always false case (hdr_trans && MT_RXD*_NORMAL_CLM)
    report the 802.11 frame with decryption error to monitor interface
v4: fix the commit as below, sorry about that
    "IEEE80211_FCTL_PROTECTED is (0) and cipher suit is (not) none"
---
 drivers/net/wireless/mediatek/mt76/mt7603/mac.c | 4 ++++
 drivers/net/wireless/mediatek/mt76/mt7615/mac.c | 9 ++++++++-
 drivers/net/wireless/mediatek/mt76/mt7915/mac.c | 9 ++++++++-
 drivers/net/wireless/mediatek/mt76/mt7921/mac.c | 9 ++++++++-
 4 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7603/mac.c b/drivers/net/wireless/mediatek/mt76/mt7603/mac.c
index fe03e31989bb..a9ac61b9f854 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7603/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7603/mac.c
@@ -525,6 +525,10 @@ mt7603_mac_fill_rx(struct mt7603_dev *dev, struct sk_buff *skb)
 	if (rxd2 & MT_RXD2_NORMAL_TKIP_MIC_ERR)
 		status->flag |= RX_FLAG_MMIC_ERROR;
 
+	/* ICV error or CCMP/BIP/WPI MIC error */
+	if (rxd2 & MT_RXD2_NORMAL_ICV_ERR)
+		status->flag |= RX_FLAG_ONLY_MONITOR;
+
 	if (FIELD_GET(MT_RXD2_NORMAL_SEC_MODE, rxd2) != 0 &&
 	    !(rxd2 & (MT_RXD2_NORMAL_CLM | MT_RXD2_NORMAL_CM))) {
 		status->flag |= RX_FLAG_DECRYPTED;
diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
index 423f69015e3e..c79abce543f3 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
@@ -286,9 +286,16 @@ static int mt7615_mac_fill_rx(struct mt7615_dev *dev, struct sk_buff *skb)
 	if (rxd2 & MT_RXD2_NORMAL_AMSDU_ERR)
 		return -EINVAL;
 
+	hdr_trans = rxd1 & MT_RXD1_NORMAL_HDR_TRANS;
+	if (hdr_trans && (rxd2 & MT_RXD2_NORMAL_CM))
+		return -EINVAL;
+
+	/* ICV error or CCMP/BIP/WPI MIC error */
+	if (rxd2 & MT_RXD2_NORMAL_ICV_ERR)
+		status->flag |= RX_FLAG_ONLY_MONITOR;
+
 	unicast = (rxd1 & MT_RXD1_NORMAL_ADDR_TYPE) == MT_RXD1_NORMAL_U2M;
 	idx = FIELD_GET(MT_RXD2_NORMAL_WLAN_IDX, rxd2);
-	hdr_trans = rxd1 & MT_RXD1_NORMAL_HDR_TRANS;
 	status->wcid = mt7615_rx_get_wcid(dev, idx, unicast);
 
 	if (status->wcid) {
diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mac.c b/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
index 5fcf35f2d9fb..78a3cd3938b2 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
@@ -426,9 +426,16 @@ mt7915_mac_fill_rx(struct mt7915_dev *dev, struct sk_buff *skb)
 	if (rxd2 & MT_RXD2_NORMAL_AMSDU_ERR)
 		return -EINVAL;
 
+	hdr_trans = rxd2 & MT_RXD2_NORMAL_HDR_TRANS;
+	if (hdr_trans && (rxd1 & MT_RXD1_NORMAL_CM))
+		return -EINVAL;
+
+	/* ICV error or CCMP/BIP/WPI MIC error */
+	if (rxd1 & MT_RXD1_NORMAL_ICV_ERR)
+		status->flag |= RX_FLAG_ONLY_MONITOR;
+
 	unicast = FIELD_GET(MT_RXD3_NORMAL_ADDR_TYPE, rxd3) == MT_RXD3_NORMAL_U2M;
 	idx = FIELD_GET(MT_RXD1_NORMAL_WLAN_IDX, rxd1);
-	hdr_trans = rxd2 & MT_RXD2_NORMAL_HDR_TRANS;
 	status->wcid = mt7915_rx_get_wcid(dev, idx, unicast);
 
 	if (status->wcid) {
diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
index db3302b1576a..27550385c35f 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
@@ -428,10 +428,17 @@ mt7921_mac_fill_rx(struct mt7921_dev *dev, struct sk_buff *skb)
 	if (rxd2 & MT_RXD2_NORMAL_AMSDU_ERR)
 		return -EINVAL;
 
+	hdr_trans = rxd2 & MT_RXD2_NORMAL_HDR_TRANS;
+	if (hdr_trans && (rxd1 & MT_RXD1_NORMAL_CM))
+		return -EINVAL;
+
+	/* ICV error or CCMP/BIP/WPI MIC error */
+	if (rxd1 & MT_RXD1_NORMAL_ICV_ERR)
+		status->flag |= RX_FLAG_ONLY_MONITOR;
+
 	chfreq = FIELD_GET(MT_RXD3_NORMAL_CH_FREQ, rxd3);
 	unicast = FIELD_GET(MT_RXD3_NORMAL_ADDR_TYPE, rxd3) == MT_RXD3_NORMAL_U2M;
 	idx = FIELD_GET(MT_RXD1_NORMAL_WLAN_IDX, rxd1);
-	hdr_trans = rxd2 & MT_RXD2_NORMAL_HDR_TRANS;
 	status->wcid = mt7921_rx_get_wcid(dev, idx, unicast);
 
 	if (status->wcid) {
-- 
2.17.0