#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

#define MAX_SIZE 4096
#define HEADER_SIZE 8



int get_dns_message(char* host)
{
    char dns_mes[MAX_SIZE];
    char header[MAX_SIZE] = {0xAA, 0xAA, 0x01, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

    for(int i = 0; i < HEADER_SIZE; i++){
        dns_mes[i] = header[i];
    }

    int before_dot_len = 0;
    int add_pos = HEADER_SIZE + 1;


    for(int i = 0; i < strlen(host); i++){
        if(host[i] == '.'){
            before_dot_len = i;
            dns_mes[HEADER_SIZE] = before_dot_len;
        }
        else{
            dns_mes[i + add_pos] = host[i];
        }
    }


    dns_mes[HEADER_SIZE + before_dot_len + 1] = (int)strlen(host) - before_dot_len - 1;

    int end_pos = HEADER_SIZE + (int)strlen(host) - 1 + 2;
    dns_mes[end_pos] = '\x00';
    dns_mes[end_pos + 1] = '\x00';
    dns_mes[end_pos + 2] = '\x01';
    dns_mes[end_pos + 3] = '\x00';
    dns_mes[end_pos + 4] = '\x01';


    int dns_req_len = end_pos + 5;

    for(int i = 0; i < dns_req_len; i++){
        printf("%x ", dns_mes[i]);
        fflush(stdout);
    }
    printf("\n");

    return dns_req_len;
}





int main(int argc, char *argv[]) {
    int sock = socket(AF_INET, SOCK_DGRAM, 0);

    struct sockaddr_in addr = {
            .sin_family = AF_INET,
            .sin_addr = inet_addr("8.8.8.8"),
            .sin_port = htons(53)
    };

    char host[MAX_SIZE];
    char dns_mes[MAX_SIZE];

    while(scanf("%s", host) > 0){
        int dns_req_len = get_dns_message(host);

//        sendto(sock, &dns_mes, dns_req_len,0,
//               (const struct sockaddr*)&addr, sizeof(addr));
//
//        memset(dns_mes, 0, MAX_SIZE);
//
//        recvfrom(sock,
//                &dns_mes, MAX_SIZE,
//                0, NULL, NULL);
//
//
//        char c1 = dns_mes[dns_req_len + 12];
//        char c2 = dns_mes[dns_req_len + 13];
//        char c3 = dns_mes[dns_req_len + 14];
//        char c4 = dns_mes[dns_req_len + 15];
//
//        printf("%d.%d.%d.%d\n", c1, c2, c3, c4);
//        fflush(stdout);
//        memset(dns_mes, 0, MAX_SIZE);
    }

    close(sock);
    return 0;
}