commit ac0f5363881fdce2721287bc5c756282166d9991
author Steven Luong <sluong@cisco.com> Mon Oct 12 10:43:28 2020 -0700
committer Damjan Marion <dmarion@me.com> Thu Oct 22 21:30:24 2020 +0000
tree 740b09583df4b406685e06e0fc4579007eea1467
parent bf693fff4d24d03a9f8d09e3a3a02740e4770d29

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

src/vnet/devices/virtio/vhost_user_input.c

diff --git a/src/vnet/devices/virtio/vhost_user_input.c b/src/vnet/devices/virtio/vhost_user_input.c
index 8d0ee4a..001ef07 100644
--- a/src/vnet/devices/virtio/vhost_user_input.c
+++ b/src/vnet/devices/virtio/vhost_user_input.c
@@ -292,15 +292,11 @@
       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;
     }
 

src/vnet/devices/virtio/vhost_user_output.c

diff --git a/src/vnet/devices/virtio/vhost_user_output.c b/src/vnet/devices/virtio/vhost_user_output.c
index 8ac9d0b..1f3813d 100644
--- a/src/vnet/devices/virtio/vhost_user_output.c
+++ b/src/vnet/devices/virtio/vhost_user_output.c
@@ -256,18 +256,12 @@
       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 */