virtio: fix the tcp/udp checksum offloads

Some vhost-backend calculates the wrong checksum in
case of tcp/udp offload when driver resets tcp/udp
checksum field to '0'.

Type: fix

Change-Id: I1d2a9b95b3d5cc1decac38027104a04df2af4680
Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>

2 files changed, 0 insertions, 28 deletions

diff --git a/src/vnet/devices/virtio/device.c b/src/vnet/devices/virtio/device.c
index 76f85588ec8..e812b373a89 100644
--- a/src/vnet/devices/virtio/device.c
+++ b/src/vnet/devices/virtio/device.c
@@ -159,18 +159,10 @@ set_checksum_offsets (vlib_main_t * vm, virtio_if_t * vif, vlib_buffer_t * b,
       hdr->csum_start = gho.l4_hdr_offset;	// 0x22;
       if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
 	{
-	  tcp_header_t *tcp =
-	    (tcp_header_t *) (vlib_buffer_get_current (b) +
-			      gho.l4_hdr_offset);
-	  tcp->checksum = 0;
 	  hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
 	}
       else if (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)
 	{
-	  udp_header_t *udp =
-	    (udp_header_t *) (vlib_buffer_get_current (b) +
-			      gho.l4_hdr_offset);
-	  udp->checksum = 0;
 	  hdr->csum_offset = STRUCT_OFFSET_OF (udp_header_t, checksum);
 	}
 
@@ -190,18 +182,10 @@ set_checksum_offsets (vlib_main_t * vm, virtio_if_t * vif, vlib_buffer_t * b,
       hdr->csum_start = gho.l4_hdr_offset;	// 0x36;
       if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
 	{
-	  tcp_header_t *tcp =
-	    (tcp_header_t *) (vlib_buffer_get_current (b) +
-			      gho.l4_hdr_offset);
-	  tcp->checksum = 0;
 	  hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
 	}
       else if (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)
 	{
-	  udp_header_t *udp =
-	    (udp_header_t *) (vlib_buffer_get_current (b) +
-			      gho.l4_hdr_offset);
-	  udp->checksum = 0;
 	  hdr->csum_offset = STRUCT_OFFSET_OF (udp_header_t, checksum);
 	}
     }
@@ -226,15 +210,10 @@ add_buffer_to_slot (vlib_main_t * vm, virtio_if_t * vif,
       if (b->flags & VNET_BUFFER_F_IS_IP4)
 	{
 	  ip4_header_t *ip4;
-	  tcp_header_t *tcp;
 	  gso_header_offset_t gho = vnet_gso_header_offset_parser (b, 0);
 	  hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 	  hdr->gso_size = vnet_buffer2 (b)->gso_size;
 	  hdr->hdr_len = gho.l4_hdr_offset + gho.l4_hdr_sz;
-	  tcp =
-	    (tcp_header_t *) (vlib_buffer_get_current (b) +
-			      gho.l4_hdr_offset);
-	  tcp->checksum = 0;
 	  hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 	  hdr->csum_start = gho.l4_hdr_offset;	// 0x22;
 	  hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
@@ -250,16 +229,11 @@ add_buffer_to_slot (vlib_main_t * vm, virtio_if_t * vif,
 	}
       else if (b->flags & VNET_BUFFER_F_IS_IP6)
 	{
-	  tcp_header_t *tcp;
 	  gso_header_offset_t gho = vnet_gso_header_offset_parser (b, 1);
 	  hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 	  hdr->gso_size = vnet_buffer2 (b)->gso_size;
 	  hdr->hdr_len = gho.l4_hdr_offset + gho.l4_hdr_sz;
 	  hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-	  tcp =
-	    (tcp_header_t *) (vlib_buffer_get_current (b) +
-			      gho.l4_hdr_offset);
-	  tcp->checksum = 0;
 	  hdr->csum_start = gho.l4_hdr_offset;	// 0x36;
 	  hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
 	}
diff --git a/src/vnet/devices/virtio/node.c b/src/vnet/devices/virtio/node.c
index 78a8dd54428..3bb23662c50 100644
--- a/src/vnet/devices/virtio/node.c
+++ b/src/vnet/devices/virtio/node.c
@@ -201,7 +201,6 @@ virtio_needs_csum (vlib_buffer_t * b0, struct virtio_net_hdr_v1 *hdr,
 						vnet_buffer
 						(b0)->l4_hdr_offset);
 	  *l4_hdr_sz = tcp_header_bytes (tcp);
-	  tcp->checksum = 0;
 	}
       else if (*l4_proto == IP_PROTOCOL_UDP)
 	{
@@ -210,7 +209,6 @@ virtio_needs_csum (vlib_buffer_t * b0, struct virtio_net_hdr_v1 *hdr,
 						vnet_buffer
 						(b0)->l4_hdr_offset);
 	  *l4_hdr_sz = sizeof (*udp);
-	  udp->checksum = 0;
 	}
     }