/* $Id: GSudpUtil_r.c,v 1.3 2008/04/11 17:44:27 tl Exp $ */

/* udp sender and receiver package */

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

/* globals */

int             s_sock;
int             r_sock;
struct sockaddr_in SocketAddr;

struct sockaddr_in name;
struct sockaddr_in sinadr;

#define MAXBUF 1024

/*-----------------------------------------------------------*/

int
SetupUdpReceiver(int port)

{
  /* declarations */

#ifdef MAC
  int             length;
#else
  socklen_t       length;
#endif

  printf("this version will use Internet Protocol Version 4 (IPv4)\n");

  /* Create socket from which to read. */

  r_sock = socket(AF_INET, SOCK_DGRAM, 0);
  if (r_sock == -1)
  {
    perror("opening datagram socket");
    exit(1);
  };

  /* Create name with wildcards. */

  bzero(&name, sizeof(name));
  bzero(&sinadr, sizeof(sinadr));
  name.sin_family = AF_INET;
  /* name.sin_addr.s6_addr = inaddr_any; */
  name.sin_port = htons(port);
  if (bind(r_sock, (struct sockaddr *) & name, sizeof name) == -1)
  {
    perror("binding datagram socket");
    exit(1);
  };

  /* Find assigned port value and print it out. */

  length = sizeof(name);
  if (getsockname(r_sock, (struct sockaddr *) & name, &length)
      == -1)
  {
    perror("getting socket name");
    exit(1);
  };

  printf("Socket port #%d\n", ntohs(name.sin_port));

  /* done */

  return (0);

}

/*-----------------------------------------------------------*/

int
UdpReceiveBuf(char *buf, size_t * nbread, int maxlen)

/* buf       : buffer to receive data         */
/* nbread    : bytes/chars received           */
/* maxlen    : maximum bytes/chars to receive */

{
  /* delarations */

  /* Read from the socket. */

  *nbread = read(r_sock, buf, maxlen);
  if ((int) *nbread == -1)
    perror("error receiving datagram packet");

  /* done */

  return (0);

}

/*-----------------------------------------------------------*/

int
CloseUdpReceiver()

{

  /* delarations */

  /* close socket */

  close(r_sock);

  /* done */

  printf("CloseUdpReceiver: socket closed\n");
  return (0);

}