From: Steven Luong <sluong@cisco.com>
Date: Mon, 12 Oct 2020 17:43:28 +0000 (-0700)
Subject: virtio: checksum error reported for ip6 traffic with GSO enable
X-Git-Tag: v21.06-rc0~287
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=ac0f5363881fdce2721287bc5c756282166d9991;p=vpp.git

virtio: checksum error reported for ip6 traffic with GSO enable

When GSO is enabled, vhost clears the checksum field prior to transmitting
the packet. Some newer kernel version does not like that and complains
about checksum error. This was seen with ip6 traffic.

Type: fix

Signed-off-by: Steven Luong <sluong@cisco.com>
Change-Id: I7c6f2a6148f4a30107bfa8b078f5990e64300cf1
---

diff --git a/src/vnet/devices/virtio/vhost_user_input.c b/src/vnet/devices/virtio/vhost_user_input.c
index 8d0ee4a4803..001ef075985 100644
--- a/src/vnet/devices/virtio/vhost_user_input.c
+++ b/src/vnet/devices/virtio/vhost_user_input.c
@@ -292,15 +292,11 @@ vhost_user_handle_rx_offload (vlib_buffer_t * b0, u8 * b0_data,
       tcp_header_t *tcp = (tcp_header_t *)
 	(b0_data + vnet_buffer (b0)->l4_hdr_offset);
       l4_hdr_sz = tcp_header_bytes (tcp);
-      tcp->checksum = 0;
       b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
     }
   else if (l4_proto == IP_PROTOCOL_UDP)
     {
-      udp_header_t *udp =
-	(udp_header_t *) (b0_data + vnet_buffer (b0)->l4_hdr_offset);
-      l4_hdr_sz = sizeof (*udp);
-      udp->checksum = 0;
+      l4_hdr_sz = sizeof (udp_header_t);
       b0->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
     }
 
diff --git a/src/vnet/devices/virtio/vhost_user_output.c b/src/vnet/devices/virtio/vhost_user_output.c
index 8ac9d0bba2a..1f3813dd134 100644
--- a/src/vnet/devices/virtio/vhost_user_output.c
+++ b/src/vnet/devices/virtio/vhost_user_output.c
@@ -256,18 +256,12 @@ vhost_user_handle_tx_offload (vhost_user_intf_t * vui, vlib_buffer_t * b,
       hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
       hdr->csum_start = gho.l4_hdr_offset;
       hdr->csum_offset = offsetof (udp_header_t, checksum);
-      udp_header_t *udp =
-	(udp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);
-      udp->checksum = 0;
     }
   else if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
     {
       hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
       hdr->csum_start = gho.l4_hdr_offset;
       hdr->csum_offset = offsetof (tcp_header_t, checksum);
-      tcp_header_t *tcp =
-	(tcp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);
-      tcp->checksum = 0;
     }
 
   /* GSO offload */