- th = (tcp_header_t *) (b->data + vnet_buffer (b)->l4_hdr_offset);
- uh = (udp_header_t *) (b->data + vnet_buffer (b)->l4_hdr_offset);
+ gho = vnet_gso_header_offset_parser (b, is_ip6);
+ th = (tcp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);
+ uh = (udp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);