Commit 46e371f0 authored Mar 07, 2018 by William Tu Committed by David S. Miller Mar 08, 2018

openvswitch: fix vport packet length check.

When sending a packet to a tunnel device, the dev's hard_header_len
could be larger than the skb->len in function packet_length().
In the case of ip6gretap/erspan, hard_header_len = LL_MAX_HEADER + t_hlen,
which is around 180, and an ARP packet sent to this tunnel has
skb->len = 42. This causes the 'unsign int length' to become super
large because it is negative value, causing the later ovs_vport_send
to drop it due to over-mtu size. The patch fixes it by setting it to 0.

Signed-off-by: William Tu <u9012063@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 55a165a7

net/openvswitch/vport.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -464,10 +464,10 @@ int ovs_vport_receive(struct vport vport, struct sk_buff skb,
		return 0;
		}

		static unsigned int packet_length(const struct sk_buff *skb,
		static int packet_length(const struct sk_buff *skb,
		struct net_device *dev)
		{
		unsigned int length = skb->len - dev->hard_header_len;
		int length = skb->len - dev->hard_header_len;

		if (!skb_vlan_tag_present(skb) &&
		eth_type_vlan(skb->protocol))
		@@ -478,7 +478,7 @@ static unsigned int packet_length(const struct sk_buff *skb,
		* account for 802.1ad. e.g. is_skb_forwardable().
		*/

		return length;
		return length > 0 ? length : 0;
		}

		void ovs_vport_send(struct vport vport, struct sk_buff skb, u8 mac_proto)

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