Commit 838fcae7 authored by Felix Fietkau's avatar Felix Fietkau
Browse files

mt76: mt7615: fix decap offload corner case with 4-addr VLAN frames 



With 4-address mode VLAN frames, an internal header translation step fails,
leaving behind an extra 2-byte length field that must be reomved by the driver.
Add a check for this condition to fix receiving such packets

Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
parent 1eeff0b4

drivers/net/wireless/mediatek/mt76/mt7615/mac.c

+21 −2
Original line number Diff line number Diff line
@@ -600,10 +600,29 @@ static int mt7615_mac_fill_rx(struct mt7615_dev *dev, struct sk_buff *skb) 
			return -EINVAL;

		hdr_trans = false;

	} else {

		int pad_start = 0;



		skb_pull(skb, hdr_gap);

		if (!hdr_trans && status->amsdu) {

			memmove(skb->data + 2, skb->data,

				ieee80211_get_hdrlen_from_skb(skb));

			pad_start = ieee80211_get_hdrlen_from_skb(skb);

		} else if (hdr_trans && (rxd2 & MT_RXD2_NORMAL_HDR_TRANS_ERROR)) {

			/*

			 * When header translation failure is indicated,

			 * the hardware will insert an extra 2-byte field

			 * containing the data length after the protocol

			 * type field.

			 */

			pad_start = 12;

			if (get_unaligned_be16(skb->data + pad_start) == ETH_P_8021Q)

				pad_start += 4;



			if (get_unaligned_be16(skb->data + pad_start) !=

			    skb->len - pad_start - 2)

				pad_start = 0;

		}



		if (pad_start) {

			memmove(skb->data + 2, skb->data, pad_start);

			skb_pull(skb, 2);

		}

	}