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authorJay Vosburgh <jay.vosburgh@canonical.com>2014-12-19 15:32:00 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-01-27 08:18:53 -0800
commita81b0a4f949b912d318926001b72592ab6043a03 (patch)
treecfa1234dec150ec121be5f87b5d7f9ea0b490c52 /net/core/dev.c
parent0042721e23933b6e56cf2766557addbd6d16a018 (diff)
downloadlinux-linaro-stable-a81b0a4f949b912d318926001b72592ab6043a03.tar.gz
net/core: Handle csum for CHECKSUM_COMPLETE VXLAN forwarding
[ Upstream commit 2c26d34bbcc0b3f30385d5587aa232289e2eed8e ] When using VXLAN tunnels and a sky2 device, I have experienced checksum failures of the following type: [ 4297.761899] eth0: hw csum failure [...] [ 4297.765223] Call Trace: [ 4297.765224] <IRQ> [<ffffffff8172f026>] dump_stack+0x46/0x58 [ 4297.765235] [<ffffffff8162ba52>] netdev_rx_csum_fault+0x42/0x50 [ 4297.765238] [<ffffffff8161c1a0>] ? skb_push+0x40/0x40 [ 4297.765240] [<ffffffff8162325c>] __skb_checksum_complete+0xbc/0xd0 [ 4297.765243] [<ffffffff8168c602>] tcp_v4_rcv+0x2e2/0x950 [ 4297.765246] [<ffffffff81666ca0>] ? ip_rcv_finish+0x360/0x360 These are reliably reproduced in a network topology of: container:eth0 == host(OVS VXLAN on VLAN) == bond0 == eth0 (sky2) -> switch When VXLAN encapsulated traffic is received from a similarly configured peer, the above warning is generated in the receive processing of the encapsulated packet. Note that the warning is associated with the container eth0. The skbs from sky2 have ip_summed set to CHECKSUM_COMPLETE, and because the packet is an encapsulated Ethernet frame, the checksum generated by the hardware includes the inner protocol and Ethernet headers. The receive code is careful to update the skb->csum, except in __dev_forward_skb, as called by dev_forward_skb. __dev_forward_skb calls eth_type_trans, which in turn calls skb_pull_inline(skb, ETH_HLEN) to skip over the Ethernet header, but does not update skb->csum when doing so. This patch resolves the problem by adding a call to skb_postpull_rcsum to update the skb->csum after the call to eth_type_trans. Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/core/dev.c')
-rw-r--r--net/core/dev.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 8ee8f9b39355..a507b6646e7f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1709,6 +1709,7 @@ int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
skb_scrub_packet(skb, true);
skb->protocol = eth_type_trans(skb, dev);
+ skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
return netif_rx_internal(skb);
}