Golang netlink.NetworkLinkAddIp函數代碼示例

func setupNetworking(args *ContainerInitArgs) error {
	// loopback
	iface, err := net.InterfaceByName("lo")
	if err != nil {
		return fmt.Errorf("Unable to set up networking: %v", err)
	}
	if err := netlink.NetworkLinkUp(iface); err != nil {
		return fmt.Errorf("Unable to set up networking: %v", err)
	}
	if args.ip != "" {
		if iface, err = net.InterfaceByName("eth0"); err != nil {
			return fmt.Errorf("Unable to set up networking: %v", err)
		}
		ip, ipNet, err := net.ParseCIDR(args.ip)
		if err != nil {
			return fmt.Errorf("Unable to set up networking: %v", err)
		}
		if err := netlink.NetworkLinkAddIp(iface, ip, ipNet); err != nil {
			return fmt.Errorf("Unable to set up networking: %v", err)
		}
		if args.gateway != "" {
			if err := netlink.AddDefaultGw(args.gateway, "eth0"); err != nil {
				return fmt.Errorf("Unable to set up networking: %v", err)
			}
		}
		if err := netlink.NetworkLinkUp(iface); err != nil {
			return fmt.Errorf("Unable to set up networking: %v", err)
		}
	}

	return nil
}

func setupNetworking(c *Config) error {
	if c.IP == "" {
		return nil
	}

	// loopback
	iface, err := net.InterfaceByName("lo")
	if err != nil {
		return fmt.Errorf("Unable to set up networking: %v", err)
	}
	if err := netlink.NetworkLinkUp(iface); err != nil {
		return fmt.Errorf("Unable to set up networking: %v", err)
	}
	if iface, err = net.InterfaceByName("eth0"); err != nil {
		return fmt.Errorf("Unable to set up networking: %v", err)
	}
	ip, ipNet, err := net.ParseCIDR(c.IP)
	if err != nil {
		return fmt.Errorf("Unable to set up networking: %v", err)
	}
	if err := netlink.NetworkLinkAddIp(iface, ip, ipNet); err != nil {
		return fmt.Errorf("Unable to set up networking: %v", err)
	}
	if c.Gateway != "" {
		if err := netlink.AddDefaultGw(c.Gateway, "eth0"); err != nil {
			return fmt.Errorf("Unable to set up networking: %v", err)
		}
	}
	if err := netlink.NetworkLinkUp(iface); err != nil {
		return fmt.Errorf("Unable to set up networking: %v", err)
	}

	return nil
}

func createBridge(name, network, natIface string) (*Bridge, error) {
	ipAddr, ipNet, err := net.ParseCIDR(network)
	if err != nil {
		return nil, err
	}
	if err := netlink.CreateBridge(name, true); err != nil {
		return nil, err
	}
	iface, err := net.InterfaceByName(name)
	if err != nil {
		return nil, err
	}
	if err := netlink.NetworkLinkAddIp(iface, ipAddr, ipNet); err != nil {
		return nil, err
	}
	if err := netlink.NetworkLinkUp(iface); err != nil {
		return nil, err
	}
	if err := ioutil.WriteFile("/proc/sys/net/ipv4/ip_forward", []byte("1\n"), 0644); err != nil {
		return nil, err
	}
	if err := setupIPTables(name, natIface); err != nil {
		return nil, err
	}
	return &Bridge{name, iface, ipAddr, ipNet}, nil
}

func createBridge(name, network, natIface string) (*Bridge, error) {
	ipAddr, ipNet, err := net.ParseCIDR(network)
	if err != nil {
		return nil, err
	}
	if err := netlink.CreateBridge(name, true); err != nil {
		return nil, err
	}
	iface, err := net.InterfaceByName(name)
	if err != nil {
		return nil, err
	}

	// We need to explicitly assign the MAC address to avoid it changing to a lower value
	// See: https://github.com/flynn/flynn/issues/223
	b := random.Bytes(5)
	mac := fmt.Sprintf("fe:%02x:%02x:%02x:%02x:%02x", b[0], b[1], b[2], b[3], b[4])
	if err := netlink.NetworkSetMacAddress(iface, mac); err != nil {
		return nil, err
	}

	if err := netlink.NetworkLinkAddIp(iface, ipAddr, ipNet); err != nil {
		return nil, err
	}
	if err := netlink.NetworkLinkUp(iface); err != nil {
		return nil, err
	}
	if err := ioutil.WriteFile("/proc/sys/net/ipv4/ip_forward", []byte("1\n"), 0644); err != nil {
		return nil, err
	}
	if err := setupIPTables(name, natIface); err != nil {
		return nil, err
	}

	bridge := &Bridge{
		name:   name,
		iface:  iface,
		ipAddr: ipAddr,
		ipNet:  ipNet,
		alloc:  ipallocator.New(),
	}
	bridge.alloc.RequestIP(ipNet, ipAddr)
	return bridge, nil
}

func (t *TapManager) NewTap(uid, gid int) (*Tap, error) {
	tap := &Tap{Name: "flynntap." + random.String(5), bridge: t.bridge}

	if err := createTap(tap.Name, uid, gid); err != nil {
		return nil, err
	}

	var err error
	tap.LocalIP, err = ipallocator.RequestIP(t.bridge.ipNet, nil)
	if err != nil {
		tap.Close()
		return nil, err
	}

	tap.RemoteIP, err = ipallocator.RequestIP(t.bridge.ipNet, nil)
	if err != nil {
		tap.Close()
		return nil, err
	}

	iface, err := net.InterfaceByName(tap.Name)
	if err != nil {
		tap.Close()
		return nil, err
	}
	if err := netlink.NetworkLinkAddIp(iface, *tap.LocalIP, t.bridge.ipNet); err != nil {
		tap.Close()
		return nil, err
	}
	if err := netlink.NetworkLinkUp(iface); err != nil {
		tap.Close()
		return nil, err
	}
	if err := netlink.AddToBridge(iface, t.bridge.iface); err != nil {
		tap.Close()
		return nil, err
	}

	return tap, nil
}

func setupIPv6Bridge(bridgeIPv6 string) error {

	iface, err := net.InterfaceByName(bridgeIface)
	if err != nil {
		return err
	}
	// Enable IPv6 on the bridge
	procFile := "/proc/sys/net/ipv6/conf/" + iface.Name + "/disable_ipv6"
	if err := ioutil.WriteFile(procFile, []byte{'0', '\n'}, 0644); err != nil {
		return fmt.Errorf("Unable to enable IPv6 addresses on bridge: %v", err)
	}

	ipAddr6, ipNet6, err := net.ParseCIDR(bridgeIPv6)
	if err != nil {
		return fmt.Errorf("Unable to parse bridge IPv6 address: %q, error: %v", bridgeIPv6, err)
	}

	if err := netlink.NetworkLinkAddIp(iface, ipAddr6, ipNet6); err != nil {
		return fmt.Errorf("Unable to add private IPv6 network: %v", err)
	}

	return nil
}

// ConfigureNetworking is called once during host startup and passed the
// strategy and identifier of the networking coordinatior job. Currently the
// only strategy implemented uses flannel.
func (l *LibvirtLXCBackend) ConfigureNetworking(config *host.NetworkConfig) error {
	var err error
	l.bridgeAddr, l.bridgeNet, err = net.ParseCIDR(config.Subnet)
	if err != nil {
		return err
	}
	l.ipalloc.RequestIP(l.bridgeNet, l.bridgeAddr)

	err = netlink.CreateBridge(bridgeName, false)
	bridgeExists := os.IsExist(err)
	if err != nil && !bridgeExists {
		return err
	}

	bridge, err := net.InterfaceByName(bridgeName)
	if err != nil {
		return err
	}
	if !bridgeExists {
		// We need to explicitly assign the MAC address to avoid it changing to a lower value
		// See: https://github.com/flynn/flynn/issues/223
		b := random.Bytes(5)
		bridgeMAC := fmt.Sprintf("fe:%02x:%02x:%02x:%02x:%02x", b[0], b[1], b[2], b[3], b[4])
		if err := netlink.NetworkSetMacAddress(bridge, bridgeMAC); err != nil {
			return err
		}
	}
	currAddrs, err := bridge.Addrs()
	if err != nil {
		return err
	}
	setIP := true
	for _, addr := range currAddrs {
		ip, net, _ := net.ParseCIDR(addr.String())
		if ip.Equal(l.bridgeAddr) && net.String() == l.bridgeNet.String() {
			setIP = false
		} else {
			if err := netlink.NetworkLinkDelIp(bridge, ip, net); err != nil {
				return err
			}
		}
	}
	if setIP {
		if err := netlink.NetworkLinkAddIp(bridge, l.bridgeAddr, l.bridgeNet); err != nil {
			return err
		}
	}
	if err := netlink.NetworkLinkUp(bridge); err != nil {
		return err
	}

	network, err := l.libvirt.LookupNetworkByName(libvirtNetName)
	if err != nil {
		// network doesn't exist
		networkConfig := &lt.Network{
			Name:    libvirtNetName,
			Bridge:  lt.Bridge{Name: bridgeName},
			Forward: lt.Forward{Mode: "bridge"},
		}
		network, err = l.libvirt.NetworkDefineXML(string(networkConfig.XML()))
		if err != nil {
			return err
		}
	}
	active, err := network.IsActive()
	if err != nil {
		return err
	}
	if !active {
		if err := network.Create(); err != nil {
			return err
		}
	}
	if defaultNet, err := l.libvirt.LookupNetworkByName("default"); err == nil {
		// The default network causes dnsmasq to run and bind to all interfaces,
		// including ours. This prevents discoverd from binding its DNS server.
		// We don't use it, so destroy it if it exists.
		defaultNet.Destroy()
	}

	// enable IP forwarding
	if err := ioutil.WriteFile("/proc/sys/net/ipv4/ip_forward", []byte("1\n"), 0644); err != nil {
		return err
	}

	// Set up iptables for outbound traffic masquerading from containers to the
	// rest of the network.
	if err := iptables.EnableOutboundNAT(bridgeName, l.bridgeNet.String()); err != nil {
		return err
	}

	// Read DNS config, discoverd uses the nameservers
	dnsConf, err := dns.ClientConfigFromFile("/etc/resolv.conf")
	if err != nil {
		return err
	}
	config.Resolvers = dnsConf.Servers
//.........這裏部分代碼省略.........

// 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 createBridge(bridgeIP string) error {
	nameservers := []string{}
	resolvConf, _ := resolvconf.Get()
	// 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, resolvconf.GetNameserversAsCIDR(resolvConf)...)
	}

	var ifaceAddr string
	if len(bridgeIP) != 0 {
		_, _, err := net.ParseCIDR(bridgeIP)
		if err != nil {
			return err
		}
		ifaceAddr = bridgeIP
	} else {
		for _, addr := range addrs {
			_, dockerNetwork, err := net.ParseCIDR(addr)
			if err != nil {
				return err
			}
			if err := networkdriver.CheckNameserverOverlaps(nameservers, dockerNetwork); err == nil {
				if err := networkdriver.CheckRouteOverlaps(dockerNetwork); err == nil {
					ifaceAddr = addr
					break
				} else {
					log.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'", bridgeIface, bridgeIface)
	}
	log.Debugf("Creating bridge %s with network %s", bridgeIface, ifaceAddr)

	if err := createBridgeIface(bridgeIface); err != nil {
		return err
	}

	iface, err := net.InterfaceByName(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)
	}
	return nil
}