This is a note to let you know that I've just added the patch titled
net/core: Handle csum for CHECKSUM_COMPLETE VXLAN forwarding
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-core-handle-csum-for-checksum_complete-vxlan-forwarding.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From foo@baz Sat Jan 17 18:12:21 PST 2015
From: Jay Vosburgh <[email protected]>
Date: Fri, 19 Dec 2014 15:32:00 -0800
Subject: net/core: Handle csum for CHECKSUM_COMPLETE VXLAN forwarding
From: Jay Vosburgh <[email protected]>
[ 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 <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
net/core/dev.c | 1 +
1 file changed, 1 insertion(+)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1697,6 +1697,7 @@ int __dev_forward_skb(struct net_device
skb_scrub_packet(skb, true);
skb->protocol = eth_type_trans(skb, dev);
+ skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
return 0;
}
Patches currently in stable-queue which might be from
[email protected] are
queue-3.18/net-core-handle-csum-for-checksum_complete-vxlan-forwarding.patch
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