#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <arpa/inet.h>

#define MAXBUF  256


int main()
{
	int ssock;
	int clen;
	struct sockaddr_in client_addr, server_addr;
	char buf[MAXBUF];

	/* ¼ÒÄÏÀ» »ý¼ºÇÑ´Ù */
	if ((ssock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
		perror("socket error : ");
		exit(1);
	}

	/* ¼ÒÄÏ¿¡ ¿¬°áÇϱâ À§ÇÑ ¼­¹ö ¿É¼Ç °áÁ¤ */
	memset(&server_addr, 0, sizeof(server_addr));
	server_addr.sin_family 	= AF_INET;
	server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	server_addr.sin_port 	= htons(3317);

	/* ¼ÒÄÏ¿¡ IP ÁÖ¼ÒµîÀÇ ¼­¹ö ¿É¼Ç ¼³Á¤ */
	if (bind(ssock, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
		perror("bind error : ");
		exit(1);
	}

	/* UDP µ¥ÀÌÅ͸¦ ¼ö½ÅÇÑ´Ù */
	recvfrom(ssock, (void *)buf, MAXBUF, 0, (struct sockaddr*)&client_addr, &clen);

	strcpy(buf, "I miss you");

	/* UDP µ¥ÀÌÅ͸¦ Àü¼ÛÇÑ´Ù */
	sendto(ssock, (void*)buf, MAXBUF, 0, (struct sockaddr*)&client_addr, sizeof(client_addr));
	
	close(ssock);

	return 0;
}