dp_packet_get_tcp_payload_length(const struct dp_packet *pkt)
{
    const char *tcp_payload = dp_packet_get_tcp_payload(pkt);
    if (tcp_payload) {
        return ((char *) dp_packet_tail(pkt) - dp_packet_l2_pad_size(pkt)
                - tcp_payload);
    } else {
        return 0;
    }
}
dp_packet_get_tcp_payload_length(const struct dp_packet *pkt)
{
    const char *tcp_payload = dp_packet_get_tcp_payload(pkt);
    if (tcp_payload) {
        return ((char *) dp_packet_tail(pkt) - dp_packet_l2_pad_size(pkt)
                - tcp_payload);
    } else {
        return 0;
    }
}