unix udp server side problemer

Kode 

#include <netdb.h>
#include <netinet/in.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <iostream>
using namespace std;


int error(char *errmsg)
{
        cout<<errmsg<<endl;
        exit(0);
}

int main()
{
        int sck = socket(AF_INET,SOCK_DGRAM,0);
        if (sck< 0)
                error("make socket failed!");

        sockaddr_in addr;
        addr.sin_addr.s_addr = INADDR_ANY;
        addr.sin_port = htonl(3456);
        addr.sin_family = AF_INET;
        if (bind(sck,(sockaddr*)&addr,sizeof(sockaddr_in)) != 0 )
                error("Binding failed!");
        
	char buffer[1024];
        sockaddr_in addrfrom;
        socklen_t addrfromsize = sizeof(sockaddr_in);
	recvfrom(sck,buffer,1024,0,(struct sockaddr*)&addrfrom,&addrfromsize);
	cout<<buffer<<endl;
	return 0;
}