[PATCH net-next 1/1] hyperv: Properly handle checksum offload

["K. Y. Srinivasan" <kys@microsoft.com>]

Do checksum offload only if the client of the driver wants checksum to be
offloaded. Also Windows hosts support ip header checksum offload as well -
take advantage of that.

This patch fixes a bug that is exposed in gateway scenarios.


Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Cc: stable@kernel.org
---
 drivers/net/hyperv/netvsc_drv.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 939e3af..706b341 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -467,6 +467,9 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 	if (skb_is_gso(skb))
 		goto do_lso;
 
+	if (skb->ip_summed != CHECKSUM_PARTIAL)
+		goto do_send;
+
 	rndis_msg_size += NDIS_CSUM_PPI_SIZE;
 	ppi = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
 			    TCPIP_CHKSUM_PKTINFO);
@@ -474,6 +477,9 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 	csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
 			ppi->ppi_offset);
 
+	ip_hdr(skb)->check = 0;
+	csum_info->transmit.ip_header_checksum = 1;
+
 	if (net_trans_info & (INFO_IPV4 << 16))
 		csum_info->transmit.is_ipv4 = 1;
 	else
-- 
1.7.4.1