dce_mcast.c

Ho Chi Minh City University of Technology Computer Science Department Distributed Computing E

/***************************************
Ho Chi Minh City University of Technology
    Computer Science Department 
Distributed Computing Environment (DCE)
Written by Nguyen Van Noi -59406114
File dce_mcast.c on Tue Dec 15 10:15:09 1998
****************************************/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <signal.h>
#include "dce_utils.h"

int
dce_mcastsockrecv (u_long uAddr, int nPort)
{
  struct sockaddr_in addr;
  int addrlen, sock;
  int one = 1;
  struct ip_mreq mreq;
  if ((sock = socket (AF_INET, SOCK_DGRAM, 0)) < 0)
    return 0;
  setsockopt (sock, SOL_SOCKET, SO_REUSEADDR, (char *) &one, sizeof (one));
  one = 32;
  setsockopt (sock, IPPROTO_IP, IP_MULTICAST_LOOP,
	      (char *) &one, sizeof (one));
  one = 0;
  setsockopt (sock, IPPROTO_IP, IP_MULTICAST_TTL,
	      (char *) &one, sizeof (one));

  memset (&addr, 0, sizeof (addr));
  addr.sin_family = AF_INET;
  addr.sin_addr.s_addr = uAddr;
  addr.sin_port = htons (nPort);

  if (bind (sock, (struct sockaddr *) &addr, sizeof (addr)) < 0)
    {
      close (sock);
      return 0;
    }

  mreq.imr_multiaddr.s_addr = uAddr;
  mreq.imr_interface.s_addr = getmyaddr ();
  if (setsockopt (sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
		  (char *) &mreq, sizeof (mreq)) < 0)
    {
      close (sock);
      return 0;
    }
  return sock;
}
void
dce_mcastcloserecv (int sock, u_long uAddr)
{
  struct ip_mreq mreq;
  mreq.imr_multiaddr.s_addr = uAddr;
  mreq.imr_interface.s_addr = getmyaddr ();
  setsockopt (sock, IPPROTO_IP, IP_DROP_MEMBERSHIP,
	      (char *) &mreq, sizeof (mreq));
  close (sock);
}
int
dce_mcastrecvrecv (int sock, u_long uAddr, int nPort, char *buf, int len)
{
  int nbytes;
  struct sockaddr_in addr;
  int addrlen = sizeof (addr);
  memset (&addr, 0, sizeof (addr));
  addr.sin_family = AF_INET;
  addr.sin_addr.s_addr = htonl (INADDR_ANY);
  addr.sin_port = htons (nPort);

  if ((nbytes = recvfrom (sock, buf, len, 0,
			  (struct sockaddr *) &addr, &addrlen)) < 0)
    return -1;
  return nbytes;

}

int
dce_mcastsocksend ()
{
  int sock, one = 1;
  if ((sock = socket (AF_INET, SOCK_DGRAM, 0)) < 0)
    return -1;
  setsockopt (sock, SOL_SOCKET, SO_REUSEADDR, (char *) &one, sizeof (one));
  return sock;
}

int
dce_mcastsendsend (int sock, u_long uAddr, int nPort, char *buf, int len)
{
  struct sockaddr_in addr;
  int addrlen = sizeof (addr);
  int n = -1;
  memset (&addr, 0, addrlen);
  addr.sin_family = AF_INET;
  addr.sin_addr.s_addr = uAddr;
  addr.sin_port = htons (nPort);
  if ((n = sendto (sock, buf, len, 0, (struct sockaddr *) &addr, addrlen)) < 0)
    return -1;
  return n;
}