dp_packet_l4_size(const struct dp_packet *b)
{
    return OVS_LIKELY(b->l4_ofs != UINT16_MAX)
        ? (const char *)dp_packet_tail(b) - (const char *)dp_packet_l4(b)
        - dp_packet_l2_pad_size(b)
        : 0;
}
dp_packet_l4_size(const struct dp_packet *b)
{
    return OVS_LIKELY(b->l4_ofs != UINT16_MAX)
        ? (const char *)dp_packet_tail(b) - (const char *)dp_packet_l4(b)
        - dp_packet_l2_pad_size(b)
        : 0;
}