Example #1
0
func proxy(sm *subnet.SubnetManager, tun *os.File, conn *net.UDPConn, tunMTU uint, port int) {
	log.Info("Running slow proxy loop")

	rtr := NewRouter(port)

	go proxyTunToUdp(rtr, tun, conn, tunMTU)
	go proxyUdpToTun(conn, tun, tunMTU)

	log.Info("Watching for new subnet leases")
	evts := make(chan subnet.EventBatch)
	sm.Start(evts)

	for evtBatch := range evts {
		for _, evt := range evtBatch {
			if evt.Type == subnet.SubnetAdded {
				log.Info("Subnet added: ", evt.Lease.Network)
				var attrs subnet.BaseAttrs
				if err := json.Unmarshal([]byte(evt.Lease.Data), &attrs); err != nil {
					log.Error("Error decoding subnet lease JSON: ", err)
					continue
				}
				rtr.SetRoute(evt.Lease.Network, attrs.PublicIP)

			} else if evt.Type == subnet.SubnetRemoved {
				log.Info("Subnet removed: ", evt.Lease.Network)
				rtr.DelRoute(evt.Lease.Network)

			} else {
				log.Error("Internal error: unknown event type: ", int(evt.Type))
			}
		}
	}
}
Example #2
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)
}
Example #3
0
func (sm *SubnetManager) leaseRenewer() {
	dur := sm.leaseExp.Sub(time.Now()) - renewMargin

	for {
		select {
		case <-time.After(dur):
			resp, err := sm.registry.updateSubnet(sm.myLease.Network.StringSep(".", "-"), sm.myLease.Data, subnetTTL)
			if err != nil {
				log.Error("Error renewing lease (trying again in 1 min): ", err)
				dur = time.Minute
				continue
			}

			sm.leaseExp = *resp.Node.Expiration
			log.Info("Lease renewed, new expiration: ", sm.leaseExp)
			dur = sm.leaseExp.Sub(time.Now()) - renewMargin

		case <-sm.stop:
			return
		}
	}
}
Example #4
0
func lookupIface() (*net.Interface, net.IP) {
	var iface *net.Interface
	var tep net.IP
	var err error

	if len(opts.iface) > 0 {
		if tep = net.ParseIP(opts.iface); tep != nil {
			iface, err = ip.GetInterfaceByIP(tep)
			if err != nil {
				log.Errorf("Error looking up interface %s: %s", opts.iface, err)
				return nil, nil
			}
		} else {
			iface, err = net.InterfaceByName(opts.iface)
			if err != nil {
				log.Errorf("Error looking up interface %s: %s", opts.iface, err)
				return nil, nil
			}
		}
	} else {
		log.Info("Determining IP address of default interface")
		for {
			if iface, err = ip.GetDefaultGatewayIface(); err == nil {
				break
			}
			log.Error("Failed to get default interface: ", err)
			time.Sleep(time.Second)
		}
	}

	if tep == nil {
		tep, err = ip.GetIfaceIP4Addr(iface)
		if err != nil {
			log.Error("Failed to find IPv4 address for interface ", iface.Name)
		}
	}

	return iface, tep
}
Example #5
0
func acquireLease(sm *subnet.SubnetManager, pubIP net.IP) (ip.IP4Net, error) {
	attrs := subnet.BaseAttrs{
		PublicIP: ip.FromIP(pubIP),
	}
	data, err := json.Marshal(&attrs)
	if err != nil {
		return ip.IP4Net{}, err
	}

	var sn ip.IP4Net
	for {
		sn, err = sm.AcquireLease(attrs.PublicIP, string(data))
		if err == nil {
			log.Info("Subnet lease acquired: ", sn)
			break
		}
		log.Error("Failed to acquire subnet: ", err)
		time.Sleep(time.Second)
	}

	return sn, nil
}
Example #6
0
func setupIpMasq(ipn ip.IP4Net, iface string) error {
	ipt, err := ip.NewIPTables()
	if err != nil {
		log.Error("Failed to setup IP Masquerade. iptables was not found")
		return err
	}

	err = ipt.ClearChain("nat", "RUDDER")
	if err != nil {
		log.Error("Failed to create/clear RUDDER chain in NAT table: ", err)
		return err
	}

	rules := [][]string{
		// This rule makes sure we don't NAT traffic within overlay network (e.g. coming out of docker0)
		[]string{"RUDDER", "-d", ipn.String(), "-j", "ACCEPT"},
		// This rule makes sure we don't NAT multicast traffic within overlay network
		[]string{"RUDDER", "-d", "224.0.0.0/4", "-j", "ACCEPT"},
		// This rule will NAT everything originating from our overlay network and
		[]string{"RUDDER", "!", "-o", iface, "-j", "MASQUERADE"},
		// This rule will take everything coming from overlay and sent it to RUDDER chain
		[]string{"POSTROUTING", "-s", ipn.String(), "-j", "RUDDER"},
	}

	for _, args := range rules {
		log.Info("Adding iptables rule: ", strings.Join(args, " "))

		err = ipt.AppendUnique("nat", args...)
		if err != nil {
			log.Error("Failed to insert IP masquerade rule: ", err)
			return err
		}
	}

	return nil
}
Example #7
0
func fastProxy(sm *subnet.SubnetManager, tun *os.File, conn *net.UDPConn, tunIP ip.IP4, tunMTU uint, port int) {
	log.Info("Running fast proxy loop")

	c, err := conn.File()
	if err != nil {
		log.Error("Converting UDPConn to File failed: ", err)
		return
	}
	defer c.Close()

	ctl, peerCtl, err := newCtlSockets()
	if err != nil {
		log.Error("Failed to create control socket: ", err)
		return
	}
	defer ctl.Close()
	defer peerCtl.Close()

	go runCProxy(tun, c, peerCtl, tunIP, tunMTU)

	log.Info("Watching for new subnet leases")
	evts := make(chan subnet.EventBatch)
	sm.Start(evts)

	for evtBatch := range evts {
		for _, evt := range evtBatch {
			if evt.Type == subnet.SubnetAdded {
				log.Info("Subnet added: ", evt.Lease.Network)
				var attrs subnet.BaseAttrs
				if err := json.Unmarshal([]byte(evt.Lease.Data), &attrs); err != nil {
					log.Error("Error decoding subnet lease JSON: ", err)
					continue
				}

				cmd := C.command{
					cmd:           C.CMD_SET_ROUTE,
					dest_net:      C.in_addr_t(evt.Lease.Network.IP.NetworkOrder()),
					dest_net_len:  C.int(evt.Lease.Network.PrefixLen),
					next_hop_ip:   C.in_addr_t(attrs.PublicIP.NetworkOrder()),
					next_hop_port: C.short(port),
				}

				writeCommand(ctl, &cmd)

			} else if evt.Type == subnet.SubnetRemoved {
				log.Info("Subnet removed: ", evt.Lease.Network)

				cmd := C.command{
					cmd:          C.CMD_DEL_ROUTE,
					dest_net:     C.in_addr_t(evt.Lease.Network.IP.NetworkOrder()),
					dest_net_len: C.int(evt.Lease.Network.PrefixLen),
				}

				writeCommand(ctl, &cmd)

			} else {
				log.Error("Internal error: unknown event type: ", int(evt.Type))
			}
		}
	}
}