[PATCH ath-next] wifi: ath12k: Handle DP_RX_DECAP_TYPE_8023 type in Rx path

[Tamizh Chelvam Raja <tamizh.raja@oss.qualcomm.com>]

The driver does not currently set any rx_flag for frames received with
decap type DP_RX_DECAP_TYPE_8023. When the hardware reports
LLC-encapsulated packets whose length field is below 0x0600, the MSDU_END
descriptor may indicate decap type DP_RX_DECAP_TYPE_8023.

These frames are effectively equivalent to Ethernet-II (DIX) packets,
similar to those decoded as DP_RX_DECAP_TYPE_ETHERNET2_DIX. If the
driver does not set RX_FLAG_8023 for these frames, mac80211 will
misinterpret them as 802.11 frames. This causes valid frames such as
Bridge Protocol Data Units (BPDUs) to be dropped. BPDUs are exchanged
between switches to maintain and manage network topology, and must
be treated as Ethernet frames.

Set RX_FLAG_8023 for decap type DP_RX_DECAP_TYPE_8023 in
ath12k_dp_rx_h_undecap() to ensure mac80211 handles these frames
correctly. Also add multicast packet handling support for the
DP_RX_DECAP_TYPE_8023 decap type.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.6-01243-QCAHKSWPL_SILICONZ-1

Signed-off-by: Tamizh Chelvam Raja <tamizh.raja@oss.qualcomm.com>
---
 drivers/net/wireless/ath/ath12k/dp_rx.c | 57 ++++++++++++++++---------
 1 file changed, 37 insertions(+), 20 deletions(-)

diff --git a/drivers/net/wireless/ath/ath12k/dp_rx.c b/drivers/net/wireless/ath/ath12k/dp_rx.c
index 250459facff3..cae00e0539df 100644
--- a/drivers/net/wireless/ath/ath12k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath12k/dp_rx.c
@@ -1092,7 +1092,8 @@ static void ath12k_get_dot11_hdr_from_rx_desc(struct ath12k_pdev_dp *dp_pdev,
 static void ath12k_dp_rx_h_undecap_eth(struct ath12k_pdev_dp *dp_pdev,
 				       struct sk_buff *msdu,
 				       enum hal_encrypt_type enctype,
-				       struct hal_rx_desc_data *rx_info)
+				       struct hal_rx_desc_data *rx_info,
+				       enum ath12k_dp_rx_decap_type decap_type)
 {
 	struct ieee80211_hdr *hdr;
 	struct ethhdr *eth;
@@ -1100,12 +1101,24 @@ static void ath12k_dp_rx_h_undecap_eth(struct ath12k_pdev_dp *dp_pdev,
 	u8 sa[ETH_ALEN];
 	struct ath12k_skb_rxcb *rxcb = ATH12K_SKB_RXCB(msdu);
 	struct ath12k_dp_rx_rfc1042_hdr rfc = {0xaa, 0xaa, 0x03, {0x00, 0x00, 0x00}};
+	struct ath12k_dp_rx_rfc1042_hdr *llc;
 
 	eth = (struct ethhdr *)msdu->data;
 	ether_addr_copy(da, eth->h_dest);
 	ether_addr_copy(sa, eth->h_source);
-	rfc.snap_type = eth->h_proto;
-	skb_pull(msdu, sizeof(*eth));
+	if (decap_type == DP_RX_DECAP_TYPE_8023) {
+		/*
+		 * For 802.3 frames, eth->h_proto carries a length field, not
+		 * an EtherType. The actual EtherType is in the LLC/SNAP header
+		 * that follows the Ethernet header.
+		 */
+		llc = (struct ath12k_dp_rx_rfc1042_hdr *)(msdu->data + sizeof(*eth));
+		rfc.snap_type = llc->snap_type;
+		skb_pull(msdu, sizeof(*eth) + sizeof(*llc));
+	} else {
+		rfc.snap_type = eth->h_proto;
+		skb_pull(msdu, sizeof(*eth));
+	}
 	memcpy(skb_push(msdu, sizeof(rfc)), &rfc,
 	       sizeof(rfc));
 	ath12k_get_dot11_hdr_from_rx_desc(dp_pdev, msdu, rxcb, enctype, rx_info);
@@ -1123,9 +1136,10 @@ void ath12k_dp_rx_h_undecap(struct ath12k_pdev_dp *dp_pdev, struct sk_buff *msdu
 			    bool decrypted,
 			    struct hal_rx_desc_data *rx_info)
 {
+	enum ath12k_dp_rx_decap_type decap_type = rx_info->decap_type;
 	struct ethhdr *ehdr;
 
-	switch (rx_info->decap_type) {
+	switch (decap_type) {
 	case DP_RX_DECAP_TYPE_NATIVE_WIFI:
 		ath12k_dp_rx_h_undecap_nwifi(dp_pdev, msdu, enctype, rx_info);
 		break;
@@ -1139,19 +1153,33 @@ void ath12k_dp_rx_h_undecap(struct ath12k_pdev_dp *dp_pdev, struct sk_buff *msdu
 		/* mac80211 allows fast path only for authorized STA */
 		if (ehdr->h_proto == cpu_to_be16(ETH_P_PAE)) {
 			ATH12K_SKB_RXCB(msdu)->is_eapol = true;
-			ath12k_dp_rx_h_undecap_eth(dp_pdev, msdu, enctype, rx_info);
+			ath12k_dp_rx_h_undecap_eth(dp_pdev, msdu, enctype, rx_info,
+						   decap_type);
 			break;
 		}
 
 		/* PN for mcast packets will be validated in mac80211;
 		 * remove eth header and add 802.11 header.
 		 */
-		if (ATH12K_SKB_RXCB(msdu)->is_mcbc && decrypted)
-			ath12k_dp_rx_h_undecap_eth(dp_pdev, msdu, enctype, rx_info);
+		if (ATH12K_SKB_RXCB(msdu)->is_mcbc && decrypted) {
+			ath12k_dp_rx_h_undecap_eth(dp_pdev, msdu, enctype, rx_info,
+						   decap_type);
+			break;
+		}
+
+		rx_info->rx_status->flag |= RX_FLAG_8023;
 		break;
 	case DP_RX_DECAP_TYPE_8023:
-		/* TODO: Handle undecap for these formats */
-		break;
+		/*
+		 * Note that ethernet decap format indicates that the decapped
+		 * packet is either Ethernet 2 (DIX)  or 802.3 (uses SNAP/LLC).
+		 */
+		if (ATH12K_SKB_RXCB(msdu)->is_mcbc && decrypted) {
+			ath12k_dp_rx_h_undecap_eth(dp_pdev, msdu, enctype, rx_info,
+						   decap_type);
+			break;
+		}
+		rx_info->rx_status->flag |= RX_FLAG_8023;
 	}
 }
 EXPORT_SYMBOL(ath12k_dp_rx_h_undecap);
@@ -1333,9 +1361,7 @@ void ath12k_dp_rx_deliver_msdu(struct ath12k_pdev_dp *dp_pdev, struct napi_struc
 	struct ath12k_dp_peer *peer;
 	struct ath12k_skb_rxcb *rxcb = ATH12K_SKB_RXCB(msdu);
 	struct ieee80211_rx_status *status = rx_info->rx_status;
-	u8 decap = rx_info->decap_type;
 	bool is_mcbc = rxcb->is_mcbc;
-	bool is_eapol = rxcb->is_eapol;
 
 	peer = ath12k_dp_peer_find_by_peerid(dp_pdev, rx_info->peer_id);
 
@@ -1380,15 +1406,6 @@ void ath12k_dp_rx_deliver_msdu(struct ath12k_pdev_dp *dp_pdev, struct napi_struc
 
 	/* TODO: trace rx packet */
 
-	/* PN for multicast packets are not validate in HW,
-	 * so skip 802.3 rx path
-	 * Also, fast_rx expects the STA to be authorized, hence
-	 * eapol packets are sent in slow path.
-	 */
-	if (decap == DP_RX_DECAP_TYPE_ETHERNET2_DIX && !is_eapol &&
-	    !(is_mcbc && rx_status->flag & RX_FLAG_DECRYPTED))
-		rx_status->flag |= RX_FLAG_8023;
-
 	ieee80211_rx_napi(ath12k_pdev_dp_to_hw(dp_pdev), pubsta, msdu, napi);
 }
 EXPORT_SYMBOL(ath12k_dp_rx_deliver_msdu);

base-commit: 9a4f673eb08d2a7713b258d671b4a45f2a6e68b7
-- 
2.34.1