dp_packet_l3(const struct dp_packet *b)
{
    return b->l3_ofs != UINT16_MAX
           ? (char *) dp_packet_data(b) + b->l3_ofs
           : NULL;
}
dp_packet_l3(const struct dp_packet *b)
{
    return b->l3_ofs != UINT16_MAX
           ? (char *) dp_packet_data(b) + b->l3_ofs
           : NULL;
}