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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/***************************************************************************
* multicast.cc
*
* Mon Sep 26 12:25:22 CEST 2005
* Copyright 2005 Bent Bisballe Nyeng
* deva@aasimon.org
****************************************************************************/
/*
* This file is part of MIaV.
*
* MIaV is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* MIaV is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with MIaV; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include "config.h"
#include "multicast.h"
#include <netinet/in.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <arpa/inet.h>
Multicast::Multicast(Info *i)
{
/*
Multicast adresses:
224.0.0.1 All systems on this subnet
224.0.0.2 All routers on this subnet
224.0.0.5 OSPF routers
224.0.0.6 OSPF designated routers
224.0.0.12 DHCP server/relay agent
*/
// Multicast to all systems on this subnet
char addr[] = "224.0.0.1";
int port = 1234;
info = i;
if(!UDPOpen(addr, port)) info->error("Error creating socket %s:%d", addr, port);
}
Multicast::~Multicast()
{
}
void Multicast::Write(void* buf, int size)
{
// char addr[] = "192.168.0.10";
// int port = 1234;
if(write(sock, buf, size) != size) {
info->error("Error Writing to socket.");
// if(!UDPOpen(addr, port)) info->error("Error creating socket %s:%d", addr, port);
}
}
#define USE_MULTICAST
bool Multicast::is_address_multicast(unsigned long address)
{
if((address & 255) >= 224 && (address & 255) <= 239) {
info->info("Address is multicast.");
return true;
}
info->info("Address is NOT multicast.");
return false;
}
/*
* open UDP socket
*/
bool Multicast::UDPOpen(char *address, int port)
{
int enable = 1L;
struct sockaddr_in stAddr;
struct sockaddr_in stLclAddr;
struct hostent * host;
// int sock;
stAddr.sin_family = AF_INET;
stAddr.sin_port = htons(port);
if((host = gethostbyname(address)) == NULL) return false;
stAddr.sin_addr = *((struct in_addr *) host->h_addr_list[0]);
// Create a UDP socket
if((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
return false;
// Allow multiple instance of the client to share the same address and port
if(setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *) &enable, sizeof(unsigned long int)) < 0)
return false;
#ifdef USE_MULTICAST
// If the address is multicast, register to the multicast group
if(is_address_multicast(stAddr.sin_addr.s_addr))
{
struct ip_mreq stMreq;
// Bind the socket to port
stLclAddr.sin_family = AF_INET;
stLclAddr.sin_addr.s_addr = htonl(INADDR_ANY);
stLclAddr.sin_port = stAddr.sin_port;
if(bind(sock, (struct sockaddr*) & stLclAddr, sizeof(stLclAddr)) < 0) return false;
// Register to a multicast address
stMreq.imr_multiaddr.s_addr = stAddr.sin_addr.s_addr;
stMreq.imr_interface.s_addr = INADDR_ANY;
if(setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *) & stMreq, sizeof(stMreq)) < 0)
return false;
}
else
#endif
{
// Bind the socket to port
stLclAddr.sin_family = AF_INET;
stLclAddr.sin_addr.s_addr = htonl(INADDR_ANY);
stLclAddr.sin_port = htons(0);
if(bind(sock, (struct sockaddr*) & stLclAddr, sizeof(stLclAddr)) < 0)
return false;
}
connect(sock, (struct sockaddr*) & stAddr, sizeof(stAddr));
return true;
}
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