dp_packet_data(const struct dp_packet *b)
{
    return __packet_data(b) != UINT16_MAX
           ? (char *) dp_packet_base(b) + __packet_data(b) : NULL;
}
dp_packet_data(const struct dp_packet *b)
{
    return __packet_data(b) != UINT16_MAX
           ? (char *) dp_packet_base(b) + __packet_data(b) : NULL;
}