UDP 에코 서버<윈도우 기반>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <winsock2.h>

 

#pragma comment(lib,"ws2_32.lib")

 

#define BUFSIZE 30

void ErrorHandling(char *message);

 

int main(int argc,char **argv)

 

{

           WSADATA                    wsaData;

           SOCKET            hServSock;

           char message[BUFSIZE];

           int strLen;

 

           SOCKADDR_IN servAddr;

           SOCKADDR_IN    clntAddr;

           int clntAddrSize;

 

           if (argc!=2)

           {

                     printf("Usage : %s <port>\n", argv[0]);

                     exit(1);

           }

 

           if (WSAStartup(MAKEWORD(2, 2),&wsaData) !=0)

                     ErrorHandling("WSAStartup() error!");

 

           hServSock=socket(PF_INET, SOCK_DGRAM,0);

           if (hServSock == INVALID_SOCKET)

                     ErrorHandling("socket() error!");

          

           memset(&servAddr, 0, sizeof(servAddr));

           servAddr.sin_family=AF_INET;

           servAddr.sin_addr.s_addr=htonl(INADDR_ANY);

           servAddr.sin_port=htons(atoi(argv[1]));

           if(bind(hServSock, (SOCKADDR*) &servAddr,

                                          sizeof(servAddr))==SOCKET_ERROR)

                     ErrorHandling("bind() error");

 

           while(1)

           {

                     clntAddrSize=sizeof(clntAddr);

                     strLen = recvfrom(hServSock, message, BUFSIZE, 0, (SOCKADDR*)&clntAddr, &clntAddrSize);

                     sendto(hServSock, message, strLen, 0, (SOCKADDR*)&clntAddr, sizeof(clntAddr));

           }

 

           closesocket(hServSock);

           WSACleanup();

           return 0;

}

 

void ErrorHandling(char *message)

{

           fputs(message, stderr);

           fputc('\n', stderr);

           exit(1);

}