dp_packet_at_assert(const struct dp_packet *b, size_t offset, size_t size)
{
    ovs_assert(offset + size <= dp_packet_size(b));
    return ((char *) dp_packet_data(b)) + offset;
}
dp_packet_at_assert(const struct dp_packet *b, size_t offset, size_t size)
{
    ovs_assert(offset + size <= dp_packet_size(b));
    return ((char *) dp_packet_data(b)) + offset;
}