/////////////////////////////////////////////////////////////////////////////
// Rev 11/12/2003                                               
// 
// 
//                         SENDMULTICAST.C
//                         ---------------
// 
// 
// Sylvain MARECHAL - sylvain.marechal1@libertysurf.fr
/////////////////////////////////////////////////////////////////////////////
// 
//Sending an IP Multicast Datagram Sample
//The following sample application shows how to send an IP multicast datagram.
// 
// 
/////////////////////////////////////////////////////////////////////////////

#ifdef _WIN32

#include <stdio.h> 
#include <winsock.h>

#else

#include <stdio.h>          /* printf(), snprintf() */
#include <stdlib.h>         /* strtol(), exit() */
#include <sys/types.h>
#include <sys/socket.h>     /* socket(), setsockopt(), bind(), 
                                         recvfrom(), sendto() */
#include <errno.h>          /* perror() */
#include <netinet/in.h>     /* IPPROTO_IP, sockaddr_in, htons(), 
                                         htonl() */
#include <arpa/inet.h>      /* inet_addr() */
#include <unistd.h>         /* fork(), sleep() */
#include <sys/utsname.h>    /* uname() */
#include <string.h>         /* memset() */

#define SOCKET int
#define FAR
#define FALSE	0
#define TRUE	1
#define INVALID_SOCKET	-1
#define SOCKET_ERROR	-1
#define SOCKADDR_IN		struct sockaddr_in
#define closesocket	close
#endif

#ifdef _WIN32
#define SOCKET_ERRNO	WSAGetLastError()
#else
#define SOCKET_ERRNO	errno
#endif


#define DEST_MCAST        "234.5.6.7"     
#define DESTINATION_PORT  4567            
#define SOURCE_PORT       0               





int main()
{
  int iOptVal = 64;                   
  char szMessage[] = "Multicasting message!";                      
                                    // Sent message string
  SOCKET Sock = INVALID_SOCKET;     // Datagram window socket

  SOCKADDR_IN source_sin,           // Source socket address
              dest_sin;             // Destination socket address

#ifdef _WIN32
  WSADATA WSAData;                  // Contains details of the 
                                    // Winsock implementation
    
  // Initialize Winsock. 
  if (WSAStartup (MAKEWORD(1,1), &WSAData) != 0) 
  {
    printf( "WSAStartup failed! Error: %d\n", SOCKET_ERRNO );
    return FALSE;
  }
#endif

  // Create a datagram window socket, Sock.
  if ((Sock = socket (AF_INET, SOCK_DGRAM, 0)) == INVALID_SOCKET) 
  {
    printf( "Allocating socket failed! Error: %d", SOCKET_ERRNO);
    return FALSE;
  }

  // Fill out source socket's address information.
  source_sin.sin_family = AF_INET;
  source_sin.sin_port = htons (SOURCE_PORT);  
  source_sin.sin_addr.s_addr = htonl (INADDR_ANY);

  // Associate the source socket's address with the socket, Sock.
  if (bind (Sock, 
            (struct sockaddr FAR *) &source_sin, 
            sizeof (source_sin)) == SOCKET_ERROR) 
  {
    printf( "Binding socket failed! Error: %d\n", SOCKET_ERRNO);
    closesocket (Sock);
    return FALSE;
  }
  
  // Set the Time-to-Live of the multicast.
  if (setsockopt (Sock, 
                  IPPROTO_IP, 
                  IP_MULTICAST_TTL, 
                  (char FAR *)&iOptVal, 
                  sizeof (int)) == SOCKET_ERROR)
  {
    printf( "setsockopt failed! Error: %d\n", SOCKET_ERRNO);
    closesocket (Sock);
    return FALSE;
  }
  
  // Fill out the desination socket's address information.
  dest_sin.sin_family = AF_INET;
  dest_sin.sin_port = htons (DESTINATION_PORT);  
  dest_sin.sin_addr.s_addr = inet_addr (DEST_MCAST);
  
  // Send a message to the multicasting address.
  if (sendto (Sock, 
              szMessage,
              strlen (szMessage) + 1,
              0,
              (struct sockaddr FAR *) &dest_sin,
              sizeof (dest_sin)) == SOCKET_ERROR)
  {
    printf( "sendto failed! Error: %d\n", SOCKET_ERRNO);
    closesocket (Sock);
    return FALSE;
  }

  // Disable sending on Sock before closing it.
  shutdown (Sock, 0x01);

  // Close Sock.
  closesocket (Sock);


  return TRUE;
}