+ if (PREDICT_FALSE (b->flags & VNET_BUFFER_F_GSO))
+ {
+ vnet_buffer2 (b)->outer_l3_hdr_offset = (u8 *) ip4 - b->data;
+ vnet_buffer_offload_flags_set (b, VNET_BUFFER_OFFLOAD_F_OUTER_IP_CKSUM |
+ VNET_BUFFER_OFFLOAD_F_TNL_IPIP);
+ }
+ else
+ ip4->checksum = ip4_header_checksum (ip4);