Esempio n. 1
0
func Run(sm *subnet.SubnetManager, tepIface *net.Interface, tepIP net.IP, port int, ipMasq bool, ready backend.ReadyFunc) {
	sn, err := acquireLease(sm, tepIP)
	if err != nil {
		log.Error("Failed to acquire lease: ", err)
		return
	}

	tun, tunName, err := ip.OpenTun("rudder%d")
	if err != nil {
		log.Error("Failed to open TUN device: ", err)
		return
	}

	localAddr := net.UDPAddr{
		Port: port,
	}

	conn, err := net.ListenUDP("udp4", &localAddr)
	if err != nil {
		log.Error("Failed to start listening on UDP socket: ", err)
		return
	}

	// Interface's subnet is that of the whole overlay network (e.g. /16)
	// and not that of the individual host (e.g. /24)
	tunNet := ip.IP4Net{
		IP:        sn.IP,
		PrefixLen: sm.GetConfig().Network.PrefixLen,
	}

	// TUN MTU will be smaller b/c of encap (IP+UDP hdrs)
	var mtu int
	if tepIface.MTU > 0 {
		mtu = tepIface.MTU - encapOverhead
	} else {
		log.Errorf("Failed to determine MTU for %s interface", tepIP)
		return
	}

	err = configureIface(tunName, tunNet, mtu)
	if err != nil {
		return
	}

	if ipMasq {
		err = setupIpMasq(tunNet.Network(), tunName)
		if err != nil {
			return
		}
	}

	// all initialized and ready for business
	log.Info("UDP encapsulation initialized")
	ready(sn, mtu)

	fastProxy(sm, tun, conn, tunNet.IP, uint(mtu), port)
}
Esempio n. 2
0
func configureIface(ifname string, ipn ip.IP4Net, mtu int) error {
	iface, err := net.InterfaceByName(ifname)
	if err != nil {
		log.Error("Failed to lookup interface ", ifname)
		return err
	}

	n := ipn.ToIPNet()
	err = netlink.NetworkLinkAddIp(iface, n.IP, n)
	if err != nil {
		log.Errorf("Failed to add IP address %s to %s: %s", n.IP, ifname, err)
		return err
	}

	err = netlink.NetworkSetMTU(iface, mtu)
	if err != nil {
		log.Errorf("Failed to set MTU for %s: %v", ifname, err)
		return err
	}

	err = netlink.NetworkLinkUp(iface)
	if err != nil {
		log.Errorf("Failed to set interface %s to UP state: %s", ifname, err)
		return err
	}

	// explicitly add a route since there might be a route for a subnet already
	// installed by Docker and then it won't get auto added
	err = netlink.AddRoute(ipn.Network().String(), "", "", ifname)
	if err != nil && err != syscall.EEXIST {
		log.Errorf("Failed to add route (%s -> %s): %v", ipn.Network().String(), ifname, err)
		return err
	}

	return nil
}