[Intel-wired-lan] [net PATCH 2/2] ixgbe/ixgbevf: Don't use lco_csum to compute IPv4 checksum

Alexander Duyck alexander.h.duyck at intel.com
Mon Nov 28 15:42:29 UTC 2016


In the case of IPIP and SIT tunnel frames the outer transport header
offset is actually set to the same offset as the inner transport header.
This results in the lco_csum call not doing any checksum computation over
the inner IPv4/v6 header data.

In order to account for that I am updating the code so that we determine
the location to start the checksum ourselves based on the location of the
IPv4 header and the length.

Fixes: b83e30104bd9 ("ixgbe/ixgbevf: Add support for GSO partial")
Signed-off-by: Alexander Duyck <alexander.h.duyck at intel.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c     |    8 ++++++--
 drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c |    8 ++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index b4f0374..c72f783 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -7284,11 +7284,15 @@ static int ixgbe_tso(struct ixgbe_ring *tx_ring,
 
 	/* initialize outer IP header fields */
 	if (ip.v4->version == 4) {
+		unsigned char *csum_start = skb_checksum_start(skb);
+		unsigned char *trans_start = ip.hdr + (ip.v4->ihl * 4);
+
 		/* IP header will have to cancel out any data that
 		 * is not a part of the outer IP header
 		 */
-		ip.v4->check = csum_fold(csum_add(lco_csum(skb),
-						  csum_unfold(l4.tcp->check)));
+		ip.v4->check = csum_fold(csum_partial(trans_start,
+						      csum_start - trans_start,
+						      0));
 		type_tucmd |= IXGBE_ADVTXD_TUCMD_IPV4;
 
 		ip.v4->tot_len = 0;
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index d9d6616..baa885e 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -3326,11 +3326,15 @@ static int ixgbevf_tso(struct ixgbevf_ring *tx_ring,
 
 	/* initialize outer IP header fields */
 	if (ip.v4->version == 4) {
+		unsigned char *csum_start = skb_checksum_start(skb);
+		unsigned char *trans_start = ip.hdr + (ip.v4->ihl * 4);
+
 		/* IP header will have to cancel out any data that
 		 * is not a part of the outer IP header
 		 */
-		ip.v4->check = csum_fold(csum_add(lco_csum(skb),
-						  csum_unfold(l4.tcp->check)));
+		ip.v4->check = csum_fold(csum_partial(trans_start,
+						      csum_start - trans_start,
+						      0));
 		type_tucmd |= IXGBE_ADVTXD_TUCMD_IPV4;
 
 		ip.v4->tot_len = 0;



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