Example #1
0
func (proxy *UDPProxy) replyLoop(proxyConn *net.UDPConn, clientAddr *net.UDPAddr, clientKey *connTrackKey) {
	defer func() {
		proxy.connTrackLock.Lock()
		delete(proxy.connTrackTable, *clientKey)
		proxy.connTrackLock.Unlock()
		utils.Debugf("Done proxying between udp/%v and udp/%v", clientAddr.String(), proxy.backendAddr.String())
		proxyConn.Close()
	}()

	readBuf := make([]byte, UDPBufSize)
	for {
		proxyConn.SetReadDeadline(time.Now().Add(UDPConnTrackTimeout))
	again:
		read, err := proxyConn.Read(readBuf)
		if err != nil {
			if err, ok := err.(*net.OpError); ok && err.Err == syscall.ECONNREFUSED {
				// This will happen if the last write failed
				// (e.g: nothing is actually listening on the
				// proxied port on the container), ignore it
				// and continue until UDPConnTrackTimeout
				// expires:
				goto again
			}
			return
		}
		for i := 0; i != read; {
			written, err := proxy.listener.WriteToUDP(readBuf[i:read], clientAddr)
			if err != nil {
				return
			}
			i += written
			utils.Debugf("Forwarded %v/%v bytes to udp/%v", i, read, clientAddr.String())
		}
	}
}
Example #2
0
// CreateBridgeIface creates a network bridge interface on the host system with the name `ifaceName`,
// and attempts to configure it with an address which doesn't conflict with any other interface on the host.
// If it can't find an address which doesn't conflict, it will return an error.
func CreateBridgeIface(ifaceName string) error {
	addrs := []string{
		// Here we don't follow the convention of using the 1st IP of the range for the gateway.
		// This is to use the same gateway IPs as the /24 ranges, which predate the /16 ranges.
		// In theory this shouldn't matter - in practice there's bound to be a few scripts relying
		// on the internal addressing or other stupid things like that.
		// The shouldn't, but hey, let's not break them unless we really have to.
		"172.17.42.1/16", // Don't use 172.16.0.0/16, it conflicts with EC2 DNS 172.16.0.23
		"10.0.42.1/16",   // Don't even try using the entire /8, that's too intrusive
		"10.1.42.1/16",
		"10.42.42.1/16",
		"172.16.42.1/24",
		"172.16.43.1/24",
		"172.16.44.1/24",
		"10.0.42.1/24",
		"10.0.43.1/24",
		"192.168.42.1/24",
		"192.168.43.1/24",
		"192.168.44.1/24",
	}

	var ifaceAddr string
	for _, addr := range addrs {
		_, dockerNetwork, err := net.ParseCIDR(addr)
		if err != nil {
			return err
		}
		routes, err := ip("route")
		if err != nil {
			return err
		}
		if err := checkRouteOverlaps(routes, dockerNetwork); err == nil {
			ifaceAddr = addr
			break
		} else {
			utils.Debugf("%s: %s", addr, err)
		}
	}
	if ifaceAddr == "" {
		return fmt.Errorf("Could not find a free IP address range for interface '%s'. Please configure its address manually and run 'docker -b %s'", ifaceName, ifaceName)
	}
	utils.Debugf("Creating bridge %s with network %s", ifaceName, ifaceAddr)

	if output, err := ip("link", "add", ifaceName, "type", "bridge"); err != nil {
		return fmt.Errorf("Error creating bridge: %s (output: %s)", err, output)
	}

	if output, err := ip("addr", "add", ifaceAddr, "dev", ifaceName); err != nil {
		return fmt.Errorf("Unable to add private network: %s (%s)", err, output)
	}
	if output, err := ip("link", "set", ifaceName, "up"); err != nil {
		return fmt.Errorf("Unable to start network bridge: %s (%s)", err, output)
	}
	if err := iptables("-t", "nat", "-A", "POSTROUTING", "-s", ifaceAddr,
		"!", "-d", ifaceAddr, "-j", "MASQUERADE"); err != nil {
		return fmt.Errorf("Unable to enable network bridge NAT: %s", err)
	}
	return nil
}
Example #3
0
func (proxy *TCPProxy) Run() {
	quit := make(chan bool)
	defer close(quit)
	utils.Debugf("Starting proxy on tcp/%v for tcp/%v", proxy.frontendAddr, proxy.backendAddr)
	for {
		client, err := proxy.listener.Accept()
		if err != nil {
			utils.Debugf("Stopping proxy on tcp/%v for tcp/%v (%v)", proxy.frontendAddr, proxy.backendAddr, err.Error())
			return
		}
		go proxy.clientLoop(client.(*net.TCPConn), quit)
	}
}
Example #4
0
func Unmount(target string) error {
	_, err := os.Stat(target)

	if err != nil {
		return err
	}

	if err := exec.Command("auplink", target, "flush").Run(); err != nil {
		utils.Debugf("[warning]: couldn't run auplink before unmount: %s", err)
	}

	if err := syscall.Unmount(target, 0); err != nil {
		return err
	}
	// Even though we just unmounted the filesystem, AUFS will prevent deleting the mntpoint
	// for some time. We'll just keep retrying until it succeeds.
	for retries := 0; retries < 1000; retries++ {
		err := os.Remove(target)
		if err == nil {
			// rm mntpoint succeeded
			return nil
		}
		if os.IsNotExist(err) {
			// mntpoint doesn't exist anymore. Success.
			return nil
		}
		// fmt.Printf("(%v) Remove %v returned: %v\n", retries, target, err)
		time.Sleep(10 * time.Millisecond)
	}

	return fmt.Errorf("Umount: Failed to umount %v", target)
}
Example #5
0
func checkRouteOverlaps(routes string, dockerNetwork *net.IPNet) error {
	utils.Debugf("Routes:\n\n%s", routes)
	for _, line := range strings.Split(routes, "\n") {
		if strings.Trim(line, "\r\n\t ") == "" || strings.Contains(line, "default") {
			continue
		}
		_, network, err := net.ParseCIDR(strings.Split(line, " ")[0])
		if err != nil {
			// is this a mask-less IP address?
			if ip := net.ParseIP(strings.Split(line, " ")[0]); ip == nil {
				// fail only if it's neither a network nor a mask-less IP address
				return fmt.Errorf("Unexpected ip route output: %s (%s)", err, line)
			} else {
				_, network, err = net.ParseCIDR(ip.String() + "/32")
				if err != nil {
					return err
				}
			}
		}
		if err == nil && network != nil {
			if networkOverlaps(dockerNetwork, network) {
				return fmt.Errorf("Network %s is already routed: '%s'", dockerNetwork, line)
			}
		}
	}
	return nil
}
Example #6
0
func (b *buildFile) addContext(container *env.Container, orig, dest string) error {
	origPath := path.Join(b.context, orig)
	destPath := path.Join(container.RootfsPath(), dest)

	// Preserve the trailing '/'
	if strings.HasSuffix(dest, "/") {
		destPath = destPath + "/"
	}

	fi, err := os.Stat(origPath)
	if err != nil {
		return err
	}

	if fi.IsDir() {
		if err := utils.CopyWithTar(origPath, destPath); err != nil {
			return err
		}
		// First try to unpack the source as an archive
	} else if err := utils.UntarPath(origPath, destPath); err != nil {
		utils.Debugf("Couldn't untar %s to %s: %s", origPath, destPath, err)
		// If that fails, just copy it as a regular file
		if err := os.MkdirAll(path.Dir(destPath), 0755); err != nil {
			return err
		}

		if err := utils.CopyWithTar(origPath, destPath); err != nil {
			return err
		}
	}

	return nil
}
Example #7
0
func (proxy *TCPProxy) clientLoop(client *net.TCPConn, quit chan bool) {
	backend, err := net.DialTCP("tcp", nil, proxy.backendAddr)
	if err != nil {
		log.Printf("Can't forward traffic to backend tcp/%v: %v\n", proxy.backendAddr, err.Error())
		client.Close()
		return
	}

	event := make(chan int64)
	var broker = func(to, from *net.TCPConn) {
		written, err := io.Copy(to, from)
		if err != nil {
			err, ok := err.(*net.OpError)
			// If the socket we are writing to is shutdown with
			// SHUT_WR, forward it to the other end of the pipe:
			if ok && err.Err == syscall.EPIPE {
				from.CloseWrite()
			}
		}
		to.CloseRead()
		event <- written
	}
	utils.Debugf("Forwarding traffic between tcp/%v and tcp/%v", client.RemoteAddr(), backend.RemoteAddr())
	go broker(client, backend)
	go broker(backend, client)

	var transferred int64 = 0
	for i := 0; i < 2; i++ {
		select {
		case written := <-event:
			transferred += written
		case <-quit:
			// Interrupt the two brokers and "join" them.
			client.Close()
			backend.Close()
			for ; i < 2; i++ {
				transferred += <-event
			}
			goto done
		}
	}
	client.Close()
	backend.Close()
done:
	utils.Debugf("%v bytes transferred between tcp/%v and tcp/%v", transferred, client.RemoteAddr(), backend.RemoteAddr())
}
Example #8
0
func (b *buildFile) CmdCmd(args string) error {
	var cmd []string

	if err := json.Unmarshal([]byte(args), &cmd); err != nil {
		utils.Debugf("Error unmarshalling: %s, setting cmd to /bin/sh -c", err)
		cmd = []string{"/bin/sh", "-c", args}
	}

	b.config.Cmd = cmd
	return nil
}
Example #9
0
func (proxy *UDPProxy) Run() {
	readBuf := make([]byte, UDPBufSize)
	utils.Debugf("Starting proxy on udp/%v for udp/%v", proxy.frontendAddr, proxy.backendAddr)
	for {
		read, from, err := proxy.listener.ReadFromUDP(readBuf)
		if err != nil {
			// NOTE: Apparently ReadFrom doesn't return
			// ECONNREFUSED like Read do (see comment in
			// UDPProxy.replyLoop)
			utils.Debugf("Stopping proxy on udp/%v for udp/%v (%v)", proxy.frontendAddr, proxy.backendAddr, err.Error())
			break
		}

		fromKey := newConnTrackKey(from)
		proxy.connTrackLock.Lock()
		proxyConn, hit := proxy.connTrackTable[*fromKey]
		if !hit {
			proxyConn, err = net.DialUDP("udp", nil, proxy.backendAddr)
			if err != nil {
				log.Printf("Can't proxy a datagram to udp/%s: %v\n", proxy.backendAddr.String(), err)
				continue
			}
			proxy.connTrackTable[*fromKey] = proxyConn
			go proxy.replyLoop(proxyConn, from, fromKey)
		}
		proxy.connTrackLock.Unlock()
		for i := 0; i != read; {
			written, err := proxyConn.Write(readBuf[i:read])
			if err != nil {
				log.Printf("Can't proxy a datagram to udp/%s: %v\n", proxy.backendAddr.String(), err)
				break
			}
			i += written
			utils.Debugf("Forwarded %v/%v bytes to udp/%v", i, read, proxy.backendAddr.String())
		}
	}
}
Example #10
0
// Release: Network cleanup - release all resources
func (iface *NetworkInterface) Release() {

	if iface.disabled {
		return
	}

	for _, nat := range iface.extPorts {
		utils.Debugf("Unmaping %v/%v", nat.Proto, nat.Frontend)
		if err := iface.manager.portMapper.Unmap(nat.Frontend, nat.Proto); err != nil {
			log.Printf("Unable to unmap port %v/%v: %v", nat.Proto, nat.Frontend, err)
		}
		if nat.Proto == "tcp" {
			if err := iface.manager.ipAllocator.ReleaseTCPPort(nat.Frontend); err != nil {
				log.Printf("Unable to release port tcp/%v: %v", nat.Frontend, err)
			}
		} else if err := iface.manager.ipAllocator.ReleaseUDPPort(nat.Frontend); err != nil {
			log.Printf("Unable to release port udp/%v: %v", nat.Frontend, err)
		}
	}

	iface.manager.ipAllocator.Release(iface.IPNet.IP)
}