[PATCH net] bridge: Fix network header pointer for vlan tagged packets
From: Toshiaki Makita <hidden>
Date: 2015-07-28 10:05:37
Also in:
bridge
Subsystem:
ethernet bridge, networking [general], the rest · Maintainers:
Nikolay Aleksandrov, Ido Schimmel, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> --- net/bridge/br_forward.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-)
diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 0ff6e1b..fa7bfce 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c@@ -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 { - skb_push(skb, ETH_HLEN); - br_drop_fake_rtable(skb); - skb_sender_cpu_clear(skb); - dev_queue_xmit(skb); + if (!is_skb_forwardable(skb->dev, skb)) + goto drop; + + skb_push(skb, ETH_HLEN); + br_drop_fake_rtable(skb); + skb_sender_cpu_clear(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);
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1.8.1.2