net: Fix some corner cases in dev_can_checksum() (af1905db) · Commits · 戴 / test

dev_can_checksum() incorrectly returns true in these cases: 1. The skb has both out-of-band and in-band VLAN tags and the device supports checksum offload for the encapsulated protocol but only with one layer of encapsulation. 2. The skb has a VLAN tag and the device supports generic checksumming but not in conjunction with VLAN encapsulation. Rearrange the VLAN tag checks to avoid these. Signed-off-by:

Ben Hutchings <bhutchings@solarflare.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/core/dev.c

+6 −10

Original line number	Diff line number	Diff line
		@@ -1696,22 +1696,18 @@ static bool can_checksum_protocol(unsigned long features, __be16 protocol)

		static bool dev_can_checksum(struct net_device dev, struct sk_buff skb)
		{
		__be16 protocol = skb->protocol;
		int features = dev->features;

		if (vlan_tx_tag_present(skb))
		if (vlan_tx_tag_present(skb)) {
		features &= dev->vlan_features;

		if (can_checksum_protocol(features, skb->protocol))
		return true;

		if (skb->protocol == htons(ETH_P_8021Q)) {
		} else if (protocol == htons(ETH_P_8021Q)) {
		struct vlan_ethhdr veh = (struct vlan_ethhdr )skb->data;
		if (can_checksum_protocol(dev->features & dev->vlan_features,
		veh->h_vlan_encapsulated_proto))
		return true;
		protocol = veh->h_vlan_encapsulated_proto;
		features &= dev->vlan_features;
		}

		return false;
		return can_checksum_protocol(features, protocol);
		}

		/**

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