/*
 * File:   Opdracht6.c
 * Author: Wouter
 *
 * Created on 20 oktober 2011, 19:05
 */

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

#define MAXDATASIZE 1024

int main(int argc, char** argv)
{
    int sockfd, bytes;
    int PORT = 123;
    unsigned long buffer[1024];
    char size[INET_ADDRSTRLEN];
    struct sockaddr_in server_addr;
    struct sockaddr_storage their_addr;
	socklen_t fromlen;
    struct protoent *proto;
    char msg[48]={010,0,0,0,0,0,0,0,0}; //the packet that will be send
    time_t servertime;
    char *ip="193.190.198.10"; // IP address from ntp.belnet.be

    memset(&server_addr, 0, sizeof server_addr); //memset cleart hints
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = inet_addr(ip);

    server_addr.sin_port = htons(PORT);

    proto=getprotobyname("udp");

	if ((sockfd = socket(PF_INET, SOCK_DGRAM, proto->p_proto))==-1)
	{
		perror("socket returns -1");
	}

	printf("client: connecting to: %s\n", size);

    printf("%s", msg);

    int sendinfo = sendto(sockfd, msg, sizeof(msg), 0, (struct sockaddr *)&server_addr, sizeof(server_addr));

    if (sendinfo == -1)
    {
        perror("send returns -1");
        exit(1);
    }

	fromlen = sizeof(their_addr);

    bytes = recvfrom(sockfd, buffer, sizeof(buffer),0, (struct sockaddr *)&their_addr, &fromlen);

	if (bytes == -1)
    {
        perror("");
    }

    servertime=((time_t)buffer[10]);
    servertime = ntohl(servertime);
    servertime -= 2208988800U;

    printf("Time: %s", ctime(&servertime));

    close(sockfd);

    return (EXIT_SUCCESS);
    return 0;
}