Commit df356d5e authored Jul 28, 2015 by Toshiaki Makita Committed by David S. Miller Jul 29, 2015

bridge: Fix network header pointer for vlan tagged packets

There are several devices that can receive vlan tagged packets with
CHECKSUM_PARTIAL like tap, possibly veth and xennet.
When (multiple) vlan tagged packets with CHECKSUM_PARTIAL are forwarded
by bridge to a device with the IP_CSUM feature, they end up with checksum
error because before entering bridge, the network header is set to
ETH_HLEN (not including vlan header length) in __netif_receive_skb_core(),
get_rps_cpu(), or drivers' rx functions, and nobody fixes the pointer later.

Since the network header is exepected to be ETH_HLEN in flow-dissection
and hash-calculation in RPS in rx path, and since the header pointer fix
is needed only in tx path, set the appropriate network header on forwarding
packets.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent dbd46ab4

net/bridge/br_forward.c

+22 −7

Original line number	Diff line number	Diff line
		@@ -37,15 +37,30 @@ static inline int should_deliver(const struct net_bridge_port *p,

		int br_dev_queue_push_xmit(struct sock sk, struct sk_buff skb)
		{
		if (!is_skb_forwardable(skb->dev, skb)) {
		kfree_skb(skb);
		} else {
		if (!is_skb_forwardable(skb->dev, skb))
		goto drop;

		skb_push(skb, ETH_HLEN);
		br_drop_fake_rtable(skb);
		skb_sender_cpu_clear(skb);
		dev_queue_xmit(skb);

		if (skb->ip_summed == CHECKSUM_PARTIAL &&
		(skb->protocol == htons(ETH_P_8021Q) \|\|
		skb->protocol == htons(ETH_P_8021AD))) {
		int depth;

		if (!__vlan_get_protocol(skb, skb->protocol, &depth))
		goto drop;

		skb_set_network_header(skb, depth);
		}

		dev_queue_xmit(skb);

		return 0;

		drop:
		kfree_skb(skb);
		return 0;
		}
		EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);