nm_vnet_hdr
req->nr_hdr_len != sizeof(struct nm_vnet_hdr) &&
vnet_hdr_is_bad(struct nm_vnet_hdr *vh)
struct nm_vnet_hdr *vh = NULL;
vh = (struct nm_vnet_hdr *)src;
memcpy(dst, src, sizeof(struct nm_vnet_hdr));