Commit 796f2da8 authored Dec 22, 2014 by Toshiaki Makita Committed by David S. Miller Dec 24, 2014

net: Fix stacked vlan offload features computation

When vlan tags are stacked, it is very likely that the outer tag is stored
in skb->vlan_tci and skb->protocol shows the inner tag's vlan_proto.
Currently netif_skb_features() first looks at skb->protocol even if there
is the outer tag in vlan_tci, thus it incorrectly retrieves the protocol
encapsulated by the inner vlan instead of the inner vlan protocol.
This allows GSO packets to be passed to HW and they end up being
corrupted.

Fixes: 58e998c6 ("offloading: Force software GSO for multiple vlan tags.")
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent e51a08b8

net/core/dev.c

+8 −5

Original line number	Diff line number	Diff line
		@@ -2570,12 +2570,15 @@ netdev_features_t netif_skb_features(struct sk_buff *skb)
		if (gso_segs > dev->gso_max_segs \|\| gso_segs < dev->gso_min_segs)
		features &= ~NETIF_F_GSO_MASK;

		if (protocol == htons(ETH_P_8021Q) \|\| protocol == htons(ETH_P_8021AD)) {
		if (!vlan_tx_tag_present(skb)) {
		if (unlikely(protocol == htons(ETH_P_8021Q) \|\|
		protocol == htons(ETH_P_8021AD))) {
		struct vlan_ethhdr veh = (struct vlan_ethhdr )skb->data;
		protocol = veh->h_vlan_encapsulated_proto;
		} else if (!vlan_tx_tag_present(skb)) {
		} else {
		return harmonize_features(skb, features);
		}
		}

		features = netdev_intersect_features(features,
		dev->vlan_features \|

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