i40e: Fix tunnel checksum offload with fragmented traffic

commit 2c6482091f01ba104cf8ee549aa5c717e80d43ea upstream.

Fix checksum offload on VXLAN tunnels.
In case, when mpls protocol is not used, set l4 header to transport
header of skb. This fixes case, when user tries to offload checksums
of VXLAN tunneled traffic.

Steps for reproduction (requires link partner with tunnels):
ip l s enp130s0f0 up
ip a f enp130s0f0
ip a a 10.10.110.2/24 dev enp130s0f0
ip l s enp130s0f0 mtu 1600
ip link add vxlan12_sut type vxlan id 12 group 238.168.100.100 dev \
enp130s0f0 dstport 4789
ip l s vxlan12_sut up
ip a a 20.10.110.2/24 dev vxlan12_sut
iperf3 -c 20.10.110.1 #should connect

Without this patch, TX descriptor was using wrong data, due to
l4 header pointing wrong address. NIC would then drop those packets
internally, due to incorrect TX descriptor data, which increased
GLV_TEPC register.

Fixes: b4fb2d33514a ("i40e: Add support for MPLS + TSO")
Signed-off-by: Przemyslaw Patynowski <przemyslawx.patynowski@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: Marek Szlosek <marek.szlosek@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 7bc1174edf6b9c1803eabd05a5d2bf0c6bb65317..af69ccc6e8d2f2e7d7548a5523b23cdc7ce7530b 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -3204,11 +3204,13 @@ static int i40e_tx_enable_csum(struct sk_buff *skb, u32 *tx_flags,
 
        protocol = vlan_get_protocol(skb);
 
-       if (eth_p_mpls(protocol))
+       if (eth_p_mpls(protocol)) {
                ip.hdr = skb_inner_network_header(skb);
-       else
+               l4.hdr = skb_checksum_start(skb);
+       } else {
                ip.hdr = skb_network_header(skb);
-       l4.hdr = skb_checksum_start(skb);
+               l4.hdr = skb_transport_header(skb);
+       }
 
        /* set the tx_flags to indicate the IP protocol type. this is
         * required so that checksum header computation below is accurate.