Beispiel #1
0
func (l *Link) toggle(action string, ignoreErrors bool) error {
	for _, p := range l.Ports {
		if output, err := iptables.Raw(action, "FORWARD",
			"-i", l.BridgeInterface, "-o", l.BridgeInterface,
			"-p", p.Proto(),
			"-s", l.ParentIP,
			"--dport", p.Port(),
			"-d", l.ChildIP,
			"-j", "ACCEPT"); !ignoreErrors && err != nil {
			return err
		} else if len(output) != 0 {
			return fmt.Errorf("Error toggle iptables forward: %s", output)
		}

		if output, err := iptables.Raw(action, "FORWARD",
			"-i", l.BridgeInterface, "-o", l.BridgeInterface,
			"-p", p.Proto(),
			"-s", l.ChildIP,
			"--sport", p.Port(),
			"-d", l.ParentIP,
			"-j", "ACCEPT"); !ignoreErrors && err != nil {
			return err
		} else if len(output) != 0 {
			return fmt.Errorf("Error toggle iptables forward: %s", output)
		}
	}
	return nil
}
Beispiel #2
0
func TestIptables(t *testing.T) {
	if _, err := iptables.Raw("-L"); err != nil {
		t.Fatal(err)
	}
	path := os.Getenv("PATH")
	os.Setenv("PATH", "")
	defer os.Setenv("PATH", path)
	if _, err := iptables.Raw("-L"); err == nil {
		t.Fatal("Not finding iptables in the PATH should cause an error")
	}
}
Beispiel #3
0
func (l *Link) toggle(action string, ignoreErrors bool) error {
	for _, p := range l.Ports {
		if err := iptables.Raw(action, "FORWARD",
			"-i", l.BridgeInterface, "-o", l.BridgeInterface,
			"-p", p.Proto(),
			"-s", l.ParentIP,
			"--dport", p.Port(),
			"-d", l.ChildIP,
			"-j", "ACCEPT"); !ignoreErrors && err != nil {
			return err
		}

		if err := iptables.Raw(action, "FORWARD",
			"-i", l.BridgeInterface, "-o", l.BridgeInterface,
			"-p", p.Proto(),
			"-s", l.ChildIP,
			"--sport", p.Port(),
			"-d", l.ParentIP,
			"-j", "ACCEPT"); !ignoreErrors && err != nil {
			return err
		}
	}
	return nil
}
Beispiel #4
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(config *DaemonConfig) 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",
	}

	nameservers := []string{}
	resolvConf, _ := utils.GetResolvConf()
	// we don't check for an error here, because we don't really care
	// if we can't read /etc/resolv.conf. So instead we skip the append
	// if resolvConf is nil. It either doesn't exist, or we can't read it
	// for some reason.
	if resolvConf != nil {
		nameservers = append(nameservers, utils.GetNameserversAsCIDR(resolvConf)...)
	}

	var ifaceAddr string
	for _, addr := range addrs {
		_, dockerNetwork, err := net.ParseCIDR(addr)
		if err != nil {
			return err
		}
		routes, err := netlink.NetworkGetRoutes()
		if err != nil {
			return err
		}
		if err := checkRouteOverlaps(routes, dockerNetwork); err == nil {
			if err := checkNameserverOverlaps(nameservers, 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'", config.BridgeIface, config.BridgeIface)
	}
	utils.Debugf("Creating bridge %s with network %s", config.BridgeIface, ifaceAddr)

	if err := netlink.NetworkLinkAdd(config.BridgeIface, "bridge"); err != nil {
		return fmt.Errorf("Error creating bridge: %s", err)
	}
	iface, err := net.InterfaceByName(config.BridgeIface)
	if err != nil {
		return err
	}
	ipAddr, ipNet, err := net.ParseCIDR(ifaceAddr)
	if err != nil {
		return err
	}
	if netlink.NetworkLinkAddIp(iface, ipAddr, ipNet); err != nil {
		return fmt.Errorf("Unable to add private network: %s", err)
	}
	if err := netlink.NetworkLinkUp(iface); err != nil {
		return fmt.Errorf("Unable to start network bridge: %s", err)
	}

	if config.EnableIptables {
		// Enable NAT
		if output, err := iptables.Raw("-t", "nat", "-A", "POSTROUTING", "-s", ifaceAddr,
			"!", "-d", ifaceAddr, "-j", "MASQUERADE"); err != nil {
			return fmt.Errorf("Unable to enable network bridge NAT: %s", err)
		} else if len(output) != 0 {
			return fmt.Errorf("Error iptables postrouting: %s", output)
		}

		// Accept incoming packets for existing connections
		if output, err := iptables.Raw("-I", "FORWARD", "-o", config.BridgeIface, "-m", "conntrack", "--ctstate", "RELATED,ESTABLISHED", "-j", "ACCEPT"); err != nil {
			return fmt.Errorf("Unable to allow incoming packets: %s", err)
		} else if len(output) != 0 {
			return fmt.Errorf("Error iptables allow incoming: %s", output)
		}

		// Accept all non-intercontainer outgoing packets
		if output, err := iptables.Raw("-I", "FORWARD", "-i", config.BridgeIface, "!", "-o", config.BridgeIface, "-j", "ACCEPT"); err != nil {
			return fmt.Errorf("Unable to allow outgoing packets: %s", err)
		} else if len(output) != 0 {
			return fmt.Errorf("Error iptables allow outgoing: %s", output)
		}

	}
	return nil
}
Beispiel #5
0
func newNetworkManager(config *DaemonConfig) (*NetworkManager, error) {
	if config.BridgeIface == DisableNetworkBridge {
		manager := &NetworkManager{
			disabled: true,
		}
		return manager, nil
	}

	addr, err := getIfaceAddr(config.BridgeIface)
	if err != nil {
		// If the iface is not found, try to create it
		if err := CreateBridgeIface(config); err != nil {
			return nil, err
		}
		addr, err = getIfaceAddr(config.BridgeIface)
		if err != nil {
			return nil, err
		}
	}
	network := addr.(*net.IPNet)

	// Configure iptables for link support
	if config.EnableIptables {
		args := []string{"FORWARD", "-i", config.BridgeIface, "-o", config.BridgeIface, "-j"}
		acceptArgs := append(args, "ACCEPT")
		dropArgs := append(args, "DROP")

		if !config.InterContainerCommunication {
			iptables.Raw(append([]string{"-D"}, acceptArgs...)...)
			if !iptables.Exists(dropArgs...) {
				utils.Debugf("Disable inter-container communication")
				if output, err := iptables.Raw(append([]string{"-I"}, dropArgs...)...); err != nil {
					return nil, fmt.Errorf("Unable to prevent intercontainer communication: %s", err)
				} else if len(output) != 0 {
					return nil, fmt.Errorf("Error disabling intercontainer communication: %s", output)
				}
			}
		} else {
			iptables.Raw(append([]string{"-D"}, dropArgs...)...)
			if !iptables.Exists(acceptArgs...) {
				utils.Debugf("Enable inter-container communication")
				if output, err := iptables.Raw(append([]string{"-I"}, acceptArgs...)...); err != nil {
					return nil, fmt.Errorf("Unable to allow intercontainer communication: %s", err)
				} else if len(output) != 0 {
					return nil, fmt.Errorf("Error enabling intercontainer communication: %s", output)
				}
			}
		}
	}

	ipAllocator := newIPAllocator(network)

	tcpPortAllocator, err := newPortAllocator()
	if err != nil {
		return nil, err
	}

	udpPortAllocator, err := newPortAllocator()
	if err != nil {
		return nil, err
	}

	portMapper, err := newPortMapper(config)
	if err != nil {
		return nil, err
	}

	manager := &NetworkManager{
		bridgeIface:      config.BridgeIface,
		bridgeNetwork:    network,
		ipAllocator:      ipAllocator,
		tcpPortAllocator: tcpPortAllocator,
		udpPortAllocator: udpPortAllocator,
		portMapper:       portMapper,
	}

	return manager, nil
}
Beispiel #6
0
func newNetworkManager(config *DaemonConfig) (*NetworkManager, error) {
	if config.BridgeIface == DisableNetworkBridge {
		manager := &NetworkManager{
			disabled: true,
		}
		return manager, nil
	}

	addr, err := getIfaceAddr(config.BridgeIface)
	if err != nil {
		// If the iface is not found, try to create it
		if err := CreateBridgeIface(config); err != nil {
			return nil, err
		}
		addr, err = getIfaceAddr(config.BridgeIface)
		if err != nil {
			return nil, err
		}
	}
	network := addr.(*net.IPNet)

	// Configure iptables for link support
	if config.EnableIptables {

		// Enable NAT
		natArgs := []string{"POSTROUTING", "-t", "nat", "-s", addr.String(), "!", "-d", addr.String(), "-j", "MASQUERADE"}

		if !iptables.Exists(natArgs...) {
			if output, err := iptables.Raw(append([]string{"-A"}, natArgs...)...); err != nil {
				return nil, fmt.Errorf("Unable to enable network bridge NAT: %s", err)
			} else if len(output) != 0 {
				return nil, fmt.Errorf("Error iptables postrouting: %s", output)
			}
		}

		// Accept incoming packets for existing connections
		existingArgs := []string{"FORWARD", "-o", config.BridgeIface, "-m", "conntrack", "--ctstate", "RELATED,ESTABLISHED", "-j", "ACCEPT"}

		if !iptables.Exists(existingArgs...) {
			if output, err := iptables.Raw(append([]string{"-I"}, existingArgs...)...); err != nil {
				return nil, fmt.Errorf("Unable to allow incoming packets: %s", err)
			} else if len(output) != 0 {
				return nil, fmt.Errorf("Error iptables allow incoming: %s", output)
			}
		}

		// Accept all non-intercontainer outgoing packets
		outgoingArgs := []string{"FORWARD", "-i", config.BridgeIface, "!", "-o", config.BridgeIface, "-j", "ACCEPT"}

		if !iptables.Exists(outgoingArgs...) {
			if output, err := iptables.Raw(append([]string{"-I"}, outgoingArgs...)...); err != nil {
				return nil, fmt.Errorf("Unable to allow outgoing packets: %s", err)
			} else if len(output) != 0 {
				return nil, fmt.Errorf("Error iptables allow outgoing: %s", output)
			}
		}

		args := []string{"FORWARD", "-i", config.BridgeIface, "-o", config.BridgeIface, "-j"}
		acceptArgs := append(args, "ACCEPT")
		dropArgs := append(args, "DROP")

		if !config.InterContainerCommunication {
			iptables.Raw(append([]string{"-D"}, acceptArgs...)...)
			if !iptables.Exists(dropArgs...) {
				utils.Debugf("Disable inter-container communication")
				if output, err := iptables.Raw(append([]string{"-I"}, dropArgs...)...); err != nil {
					return nil, fmt.Errorf("Unable to prevent intercontainer communication: %s", err)
				} else if len(output) != 0 {
					return nil, fmt.Errorf("Error disabling intercontainer communication: %s", output)
				}
			}
		} else {
			iptables.Raw(append([]string{"-D"}, dropArgs...)...)
			if !iptables.Exists(acceptArgs...) {
				utils.Debugf("Enable inter-container communication")
				if output, err := iptables.Raw(append([]string{"-I"}, acceptArgs...)...); err != nil {
					return nil, fmt.Errorf("Unable to allow intercontainer communication: %s", err)
				} else if len(output) != 0 {
					return nil, fmt.Errorf("Error enabling intercontainer communication: %s", output)
				}
			}
		}
	}

	ipAllocator := newIPAllocator(network)

	tcpPortAllocator, err := newPortAllocator()
	if err != nil {
		return nil, err
	}

	udpPortAllocator, err := newPortAllocator()
	if err != nil {
		return nil, err
	}

	portMapper, err := newPortMapper(config)
	if err != nil {
		return nil, err
	}

	manager := &NetworkManager{
		bridgeIface:      config.BridgeIface,
		bridgeNetwork:    network,
		ipAllocator:      ipAllocator,
		tcpPortAllocator: tcpPortAllocator,
		udpPortAllocator: udpPortAllocator,
		portMapper:       portMapper,
	}

	return manager, nil
}
Beispiel #7
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(config *DaemonConfig) 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 := netlink.NetworkGetRoutes()
		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'", config.BridgeIface, config.BridgeIface)
	}
	utils.Debugf("Creating bridge %s with network %s", config.BridgeIface, ifaceAddr)

	if err := netlink.NetworkLinkAdd(config.BridgeIface, "bridge"); err != nil {
		return fmt.Errorf("Error creating bridge: %s", err)
	}
	iface, err := net.InterfaceByName(config.BridgeIface)
	if err != nil {
		return err
	}
	ipAddr, ipNet, err := net.ParseCIDR(ifaceAddr)
	if err != nil {
		return err
	}
	if netlink.NetworkLinkAddIp(iface, ipAddr, ipNet); err != nil {
		return fmt.Errorf("Unable to add private network: %s", err)
	}
	if err := netlink.NetworkLinkUp(iface); err != nil {
		return fmt.Errorf("Unable to start network bridge: %s", err)
	}

	if config.EnableIptables {
		if err := iptables.Raw("-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
}