/*
 * skeletonudp.c
 *
 * CS 3251 Programming Assignment 2, Client Skeleton
 *
 * $Id: udpskeleton.c,v 1.1 1999/11/12 22:20:46 ewz Exp ewz $
 */

#include <stdio.h> 
#include <stdlib.h>
#include <ctype.h> /* for atoi() */
#include <errno.h> /* for perror() */
#include <signal.h> /* for sigvec(), etc. */
#include <sys/types.h> /* for u_short, etc */
#include <sys/socket.h> 
#include <netinet/in.h> 
#include <unistd.h>

#include "hw8.h"

long random();
int srandom(unsigned);

#define LINESIZE 80
#define BUFSIZE 256

void
syserror(char *s)
{
  perror(s);
  exit(1);
}

u_short
msgchecksum(u_short *mp)
{
  u_short sum = 0;
  int i;

  for (i=0; i<sizeof(HWMSG)/sizeof(u_short); i++)
    {
    /* ADD: line to implement the checksum calculation. */
    }
  return sum;
}

int main(int argc, char **argv)
{
  int mySocket;
  struct sockaddr_in serverAddr;
  int sizeofServerAddr;
  HWMSG send_pkt = {0};
  HWMSG recv_pkt = {0};
  char linebuf[LINESIZE], ipstring[BUFSIZE];
  int myCookie;

  srandom(getpid());   /* seed random number generator for cookie */

  /* ADD: create a datagram socket */

  /* ADD: set up server's address structure */

  /* ADD:  Zero out and fill in constant parts of packet. */
  /* Note: You will need to convert multi-byte fields     */
  /*       to network order before sending.               */

  /* loop getting user input, constructing message,  */
  /* sending message, receiving response             */
  while (1)
    {

    /* ADD: Get user input (SSN) and add it to the packet */

    /* Get the random number and add it to the packet. */
    myCookie = random();
    send_pkt.cookie = myCookie;

    /* ADD: Do byte swapping here */

    /* ADD: Calculate the checksum on the packet in network order */

    /* ADD: Send the packet using sendto(). */

    /* ADD: Get the server reply using recvfrom().      */

    /* ADD: Calculate the checksum on the reply in network order */

    /* ADD: Do byte swapping of the reply here */

    /* ADD: Sanity check the reply: checksum, cookie, etc. */

    /* ADD: Output P.O. Box and Reply Cookie or print error. */

    } /* while (1) */

  exit(0);

} /* main */