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

#define SETLOCALINFO bind
#define SETPEERINFO connect

#define LISTENPORT 60001

int main(int argc, char** argv) // argv = ip port intx
{
  int sockfd, x, y, result, plen, llen, slen;
  struct sockaddr_in localinfo;
  struct sockaddr_in peerinfo;
  struct sockaddr_in senderinfo;

  sockfd = socket(AF_INET,SOCK_DGRAM,0);
  localinfo.sin_family = AF_INET;
  localinfo.sin_addr.s_addr = htonl(INADDR_ANY);
  localinfo.sin_port = htons(LISTENPORT);
 
  peerinfo.sin_family = AF_INET;
  peerinfo.sin_addr.s_addr = inet_addr(argv[1]);
  peerinfo.sin_port = htons(atoi(argv[2]));
  llen = sizeof(localinfo);  plen = sizeof(peerinfo);
  slen = sizeof(senderinfo);


  SETLOCALINFO(sockfd,(struct sockaddr*)&localinfo,llen);  
  
  printf("press a key to start: "); getchar();

  x = atoi(argv[3]);
  y = htonl(x);
  result = 0;
  while (result < 4) result =
    sendto(sockfd,&y,4,0,(struct sockaddr*)&peerinfo,plen);
  result = 0;
  while (result < 4) result =
      recvfrom(sockfd,&y,4,0,
	       (struct sockaddr*)&senderinfo,&slen);
  x = ntohl(y);
  printf("got %d from peer %s, port %d\n",x,
	 inet_ntoa(senderinfo.sin_addr), 
	 ntohs(senderinfo.sin_port));

  close(sockfd);
  exit(0);
}