struct dnshdr {
        u_int16_t id;
# if __BYTE_ORDER == __BIG_ENDIAN
        u_int16_t qr:1;
        u_int16_t opco:4;
        u_int16_t aa:1;
        u_int16_t tc:1;
        u_int16_t rd:1;
        u_int16_t ra:1;
        u_int16_t zero:3;
        u_int16_t rspc:4;
# elif __BYTE_ORDER == __LITTLE_ENDIAN
        u_int16_t rd:1;
        u_int16_t tc:1;
        u_int16_t aa:1;
        u_int16_t opco:4;
        u_int16_t qr:1;
        u_int16_t rspc:4;
        u_int16_t zero:3;
        u_int16_t ra:1;
# endif
        u_int16_t qstc;
        u_int16_t recc;
        u_int16_t nmsc;
        u_int16_t adrc;
}