#include <stdint.h>

#define REQ_MAGIC 0x179E08EF

typedef struct {
    uint32_t magic;
#define REQ_VERSION 1
    uint8_t version;
#define REQ_REQ  1
#define REQ_RESP 0
    uint8_t req;
#define REQ_IPV4  32
#define REQ_IPV6 128
    uint8_t err;
    uint8_t ip_type; // 4 or 6
    uint32_t flags;
    union {
        uint32_t ipv4;
        struct {
            uint32_t a;
            uint32_t b;
            uint32_t c;
            uint32_t d;
        }ipv6;
    };
    uint8_t country_code[4];
} request_t;

enum {
    REQ_ERR_NO_ERR = 0,
    REQ_ERR_BAD_MAGIC,
    REQ_ERR_BAD_VERSION,
    REQ_ERR_BAD_REQ_FIELD,
    REQ_ERR_BAD_IP_VERSION,
    REQ_ERR_UNSUPPORTED_IP_VERSION, // 5
    REQ_IP_NOT_FOUND, // Not really an error
};