bool ............::setupInterface(const QHostAddress &ip, const QHostAddress &mcastgroup, int ttl, int port);
{
    struct sockaddr_in saddr;
    struct ip_mreq mcast;
    
    int sd;
    int opt = 1;
    
    udpsd = new QUdpSocket(this);

    sd = udpsd->socketDescriptor();

    if (!udpsd->bind(ip, port, QUdpSocket::DontShareAddress | QUdpSocket::ReuseAddressHint))
    {
        qDebug() << "Connection error";
        return false;
    }

    memset(&saddr, 0, sizeof(saddr));
    saddr.sin_family = AF_INET;
    saddr.sin_addr.s_addr = inet_addr(mcastgroup.toString());
    saddr.sin_port = htons(port);

    memset(&mcast, 0, sizeof(struct ip_mreq));
    mcast.imr_multiaddr.s_addr = inet_addr(mcastgroup.toString());
    mcast.imr_interface.s_addr = inet_addr(ip.toString());

    if ((setsockopt(sd, IPPROTO_IP, IP_MULTICAST_LOOP, &opt, sizeof(int)) < 0) || (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) || (setsockopt(recvsd, IPPROTO_IP, IP_MULTICAST_IF, &mcast.imr_interface.s_addr, sizeof(struct in_addr)) < 0))
    {
        qDebug() << "Connection error";
        return false;
    }

    if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *)&mcast, sizeof(mcast)) < 0)
    {
        qDebug() << "Connection error";
        return false;
    }
}

net send * foo