Golang net.IPNet类代码示例

func ensureBridgeAddr(br *netlink.Bridge, ipn *net.IPNet, forceAddress bool) error {
	addrs, err := netlink.AddrList(br, syscall.AF_INET)
	if err != nil && err != syscall.ENOENT {
		return fmt.Errorf("could not get list of IP addresses: %v", err)
	}

	// if there're no addresses on the bridge, it's ok -- we'll add one
	if len(addrs) > 0 {
		ipnStr := ipn.String()
		for _, a := range addrs {
			// string comp is actually easiest for doing IPNet comps
			if a.IPNet.String() == ipnStr {
				return nil
			}

			// If forceAddress is set to true then reconfigure IP address otherwise throw error
			if forceAddress {
				if err = deleteBridgeAddr(br, a.IPNet); err != nil {
					return err
				}
			} else {
				return fmt.Errorf("%q already has an IP address different from %v", br.Name, ipn.String())
			}
		}
	}

	addr := &netlink.Addr{IPNet: ipn, Label: ""}
	if err := netlink.AddrAdd(br, addr); err != nil {
		return fmt.Errorf("could not add IP address to %q: %v", br.Name, err)
	}
	return nil
}

func TestAllocate(t *testing.T) {
	subnet := net.IPNet{
		IP:   net.IPv4(0xab, 0xcd, 0xe0, 0x00),
		Mask: net.CIDRMask(20, 32),
	}
	conflicts := map[string]struct{}{}
	ipSet := map[string]struct{}{}

	// Only 4k IPs, in 0xfffff000. Guaranteed a collision
	for i := 0; i < 5000; i++ {
		ip, err := allocateIP(ipSet, subnet)
		if err != nil {
			continue
		}

		if _, ok := conflicts[ip]; ok {
			t.Fatalf("IP Double allocation: 0x%x", ip)
		}

		require.True(t, subnet.Contains(net.ParseIP(ip)),
			fmt.Sprintf("\"%s\" is not in %s", ip, subnet))
		conflicts[ip] = struct{}{}
	}

	assert.Equal(t, len(conflicts), len(ipSet))
	if len(conflicts) < 2500 || len(conflicts) > 4096 {
		// If the code's working, this is possible but *extremely* unlikely.
		// Probably a bug.
		t.Errorf("Too few conflicts: %d", len(conflicts))
	}
}

func generateCMD(dst net.IPNet, gw net.IP, is_delete bool) []string {
	var netmask_str string = net.IP(dst.Mask).String()
	var ipaddr_str string = dst.IP.String()
	var gateway_str string = gw.String()
	var network_str string = dst.String()

	switch runtime.GOOS {
	case "darwin":
		if is_delete {
			return []string{"route", "delete", "-net",
				ipaddr_str, gateway_str, netmask_str}
		} else {
			return []string{"route", "add", "-net",
				ipaddr_str, gateway_str, netmask_str}
		}
	case "linux":
		if is_delete {
			return []string{"ip", "route", "del", network_str}
		} else {
			return []string{"ip", "route", "add", network_str, "via", gateway_str}
		}
	default:
		return nil
	}

	return nil
}

// NextSubnetIP returns the next available IP address in a given subnet.
func NextSubnetIP(subnet *net.IPNet, ipsInUse []net.IP) (net.IP, error) {
	ones, bits := subnet.Mask.Size()
	subnetMaskUint32 := ipUint32(net.IP(subnet.Mask))

	inUse := big.NewInt(0)
	for _, ip := range ipsInUse {
		if !subnet.Contains(ip) {
			continue
		}
		index := ipIndex(ip, subnetMaskUint32)
		inUse = inUse.SetBit(inUse, index, 1)
	}

	// Now iterate through all addresses in the subnet and return the
	// first address that is not in use. We start at the first non-
	// reserved address, and stop short of the last address in the
	// subnet (i.e. all non-mask bits set), which is the broadcast
	// address for the subnet.
	n := ipUint32(subnet.IP)
	for i := reservedAddressRangeEnd + 1; i < (1<<uint64(bits-ones) - 1); i++ {
		ip := uint32IP(n + uint32(i))
		if !ip.IsGlobalUnicast() {
			continue
		}
		index := ipIndex(ip, subnetMaskUint32)
		if inUse.Bit(index) == 0 {
			return ip, nil
		}
	}
	return nil, errors.Errorf("no addresses available in %s", subnet)
}

func (a *Allocator) insertBitMask(key SubnetKey, pool *net.IPNet) error {
	log.Debugf("Inserting bitmask (%s, %s)", key.String(), pool.String())

	store := a.getStore(key.AddressSpace)
	if store == nil {
		return fmt.Errorf("could not find store for address space %s while inserting bit mask", key.AddressSpace)
	}

	ipVer := getAddressVersion(pool.IP)
	ones, bits := pool.Mask.Size()
	numAddresses := uint32(1 << uint(bits-ones))

	if ipVer == v4 {
		// Do not let broadcast address be reserved
		numAddresses--
	}

	// Generate the new address masks. AddressMask content may come from datastore
	h, err := bitseq.NewHandle(dsDataKey, store, key.String(), numAddresses)
	if err != nil {
		return err
	}

	if ipVer == v4 {
		// Do not let network identifier address be reserved
		h.Set(0)
	}

	a.Lock()
	a.addresses[key] = h
	a.Unlock()
	return nil
}

// hasIP6Connected parses the list of remote addresses in /proc/net/{tcp,udp}6 or in
// /proc/<pid>/net/{tcp,udp}6 and returns addresses that are contained within
// the ipnet submitted. It always uses CIDR inclusion, even when only
// searching for a single IP (but assuming a /128 bitmask).
// Remote addresses exposed in /proc are in hexadecimal notation, and converted into byte slices
// to use in ipnet.Contains()
func hasIP6Connected(ip net.IP, ipnet *net.IPNet) (found bool, elements []element, err error) {
	defer func() {
		if e := recover(); e != nil {
			err = fmt.Errorf("hasIP6Connected(): %v", e)
		}
	}()
	lns, err := procIP6Entries()
	if err != nil {
		panic(err)
	}
	// if the ipnet is nil, assume that its a full 128bits mask
	if ipnet == nil {
		ipnet = new(net.IPNet)
		ipnet.IP = ip
		ipnet.Mask = net.CIDRMask(net.IPv6len*8, net.IPv6len*8)
	}
	for _, ipent := range lns {
		fields := strings.Fields(ipent.line)
		if len(fields) < 4 {
			panic("/proc doesn't respect the expected format")
		}
		remote := strings.Split(fields[2], ":")
		if len(remote) != 2 {
			panic("remote isn't in the form <ip>:<port>")
		}
		remoteIP := hexToIP6(remote[0])
		if remoteIP == nil {
			panic("failed to convert remote IP")
		}
		// if we've got a match, store the element
		if ipnet.Contains(remoteIP) {
			var el element
			el.RemoteAddr = remoteIP.String()
			remotePort, err := strconv.ParseUint(remote[1], 16, 16)
			if err != nil {
				panic("failed to convert remote port")
			}
			el.RemotePort = float64(remotePort)
			local := strings.Split(fields[1], ":")
			if len(local) != 2 {
				panic("local isn't in the form <ip>:<port>")
			}
			localAddr := hexToIP6(local[0])
			if localAddr == nil {
				panic("failed to convert local ip")
			}
			el.LocalAddr = localAddr.String()
			localPort, err := strconv.ParseUint(local[1], 16, 16)
			if err != nil {
				panic("failed to convert local port")
			}
			el.LocalPort = float64(localPort)
			el.Namespace = ipent.nsIdentifier
			elements = append(elements, el)
			found = true
		}
		stats.Examined++
	}
	return
}

// return an available ip if one is currently available.  If not,
// return the next available ip for the nextwork
func getNextIp(address *net.IPNet) (*net.IP, error) {
	var (
		ownIP     = ipToInt(&address.IP)
		allocated = allocatedIPs[address.String()]
		first, _  = networkdriver.NetworkRange(address)
		base      = ipToInt(&first)
		size      = int(networkdriver.NetworkSize(address.Mask))
		max       = int32(size - 2) // size -1 for the broadcast address, -1 for the gateway address
		pos       = atomic.LoadInt32(&allocated.last)
	)

	var (
		firstNetIP = address.IP.To4().Mask(address.Mask)
		firstAsInt = ipToInt(&firstNetIP) + 1
	)

	for i := int32(0); i < max; i++ {
		pos = pos%max + 1
		next := int32(base + pos)

		if next == ownIP || next == firstAsInt {
			continue
		}

		if !allocated.Exists(int(pos)) {
			ip := intToIP(next)
			allocated.Push(int(pos))
			atomic.StoreInt32(&allocated.last, pos)
			return ip, nil
		}
	}
	return nil, ErrNoAvailableIPs
}

func createCBR0(wantCIDR *net.IPNet) error {
	// recreate cbr0 with wantCIDR
	if err := exec.Command("brctl", "addbr", "cbr0").Run(); err != nil {
		glog.Error(err)
		return err
	}
	if err := exec.Command("ip", "addr", "add", wantCIDR.String(), "dev", "cbr0").Run(); err != nil {
		glog.Error(err)
		return err
	}
	if err := exec.Command("ip", "link", "set", "dev", "cbr0", "mtu", "1460", "up").Run(); err != nil {
		glog.Error(err)
		return err
	}
	// restart docker
	// For now just log the error. The containerRuntime check will catch docker failures.
	// TODO (dawnchen) figure out what we should do for rkt here.
	if util.UsingSystemdInitSystem() {
		if err := exec.Command("systemctl", "restart", "docker").Run(); err != nil {
			glog.Error(err)
		}
	} else {
		if err := exec.Command("service", "docker", "restart").Run(); err != nil {
			glog.Error(err)
		}
	}
	glog.V(2).Info("Recreated cbr0 and restarted docker")
	return nil
}

func (mgr *filterChain) Setup(instanceChain, bridgeName string, ip net.IP, network *net.IPNet) error {
	commands := []*exec.Cmd{
		// Create filter instance chain
		exec.Command("iptables", "--wait", "-N", instanceChain),
		// Allow intra-subnet traffic (Linux ethernet bridging goes through ip stack)
		exec.Command("iptables", "--wait", "-A", instanceChain, "-s", network.String(), "-d", network.String(), "-j", "ACCEPT"),
		// Otherwise, use the default filter chain
		exec.Command("iptables", "--wait", "-A", instanceChain, "--goto", mgr.cfg.DefaultChain),
		// Bind filter instance chain to filter forward chain
		exec.Command("iptables", "--wait", "-I", mgr.cfg.ForwardChain, "2", "--in-interface", bridgeName, "--source", ip.String(), "--goto", instanceChain),
	}

	for _, cmd := range commands {
		buffer := &bytes.Buffer{}
		cmd.Stderr = buffer
		logger := mgr.logger.Session("setup", lager.Data{"cmd": cmd})
		logger.Debug("starting")
		if err := mgr.runner.Run(cmd); err != nil {
			stderr, _ := ioutil.ReadAll(buffer)
			logger.Error("failed", err, lager.Data{"stderr": string(stderr)})
			return fmt.Errorf("iptables_manager: filter: %s", err)
		}
		logger.Debug("ended")
	}

	return nil
}

// sets IP4 addr on link removing any existing ones first
func setAddr4(link *netlink.Vxlan, ipn *net.IPNet) error {
	addrs, err := netlink.AddrList(link, syscall.AF_INET)
	if err != nil {
		return err
	}

	addr := netlink.Addr{ipn, ""}
	existing := false
	for _, old := range addrs {
		if old.IPNet.String() == addr.IPNet.String() {
			existing = true
			continue
		}
		if err = netlink.AddrDel(link, &old); err != nil {
			return fmt.Errorf("failed to delete IPv4 addr %s from %s", old.String(), link.Attrs().Name)
		}
	}

	if !existing {
		if err = netlink.AddrAdd(link, &addr); err != nil {
			return fmt.Errorf("failed to add IP address %s to %s: %s", ipn.String(), link.Attrs().Name, err)
		}
	}

	return nil
}

// GetIndexedIP returns a net.IP that is subnet.IP + index in the contiguous IP space.
func GetIndexedIP(subnet *net.IPNet, index int) (net.IP, error) {
	ip := addIPOffset(bigForIP(subnet.IP), index)
	if !subnet.Contains(ip) {
		return nil, fmt.Errorf("can't generate IP with index %d from subnet. subnet too small. subnet: %q", index, subnet)
	}
	return ip, nil
}

func checkAddress(address *net.IPNet) {
	key := address.String()
	if _, exists := allocatedIPs[key]; !exists {
		allocatedIPs[key] = collections.NewOrderedIntSet()
		availableIPS[key] = collections.NewOrderedIntSet()
	}
}

func generateRandomNetwork(address *net.IPNet) string {
	tick := float64(time.Now().UnixNano() / 1000000)

	ones, bits := address.Mask.Size()
	zeros := bits - ones
	uniqIPsAmount := math.Pow(2.0, float64(zeros))

	rawIP := math.Mod(tick, uniqIPsAmount)

	remainder := rawIP

	remainder, octet4 := math.Modf(remainder / 255.0)
	remainder, octet3 := math.Modf(remainder / 255.0)
	remainder, octet2 := math.Modf(remainder / 255.0)

	base := address.IP

	address.IP = net.IPv4(
		byte(remainder)|base[0],
		byte(octet2*255)|base[1],
		byte(octet3*255)|base[2],
		byte(octet4*255)|base[3],
	)

	address.IP.Mask(address.Mask)

	return address.String()
}

// Initialize the repo to be used to announce/write config.
// A seperate repo is initialized to read incoming announcements
func initConfigWrite(networkCidr *net.IPNet, hostIface, gitRepoURL string) {
	var err error
	if !pathExists(EndpointPushSubDir) {
		log.Debugf("[ %s ] dir not found, creating it..", EndpointPushSubDir)
		if err = CreatePaths(EndpointPushSubDir); err != nil {
			log.Fatalf("Could not create the directory [ %s ]: %s", EndpointPushSubDir, err)
		} else {
			log.Warnf("Succesfully created the config path [ %s ]", EndpointPushSubDir)
		}
	}
	// Create the cache subdirectories
	time.Sleep(1 * time.Second)
	localEndpointIP, _ := getIfaceAddrStr(hostIface)
	// Fun Go fact: using a + with sprintf is faster then %s since it uses reflection
	endpointFile := fmt.Sprintf(localEndpointIP + dotjson)
	log.Debugf("The endpoint file name is [ %s ] ", endpointFile)
	log.Debugf("Anouncing this endpoint using the source [ %s ] and advertsing network [ %s ] to datastore file [ %s ]", networkCidr, localEndpointIP, endpointFile)
	endpointConfig := &LocalEndpoint{
		Endpoint: localEndpointIP,
		Network:  networkCidr.String(),
		Meta:     "",
	}
	var configAnnounce []LocalEndpoint
	configAnnounce = append(configAnnounce, *endpointConfig)
	marshallConfig(configAnnounce, configFormat, endpointFile)
	if log.GetLevel().String() == "debug" {
		printPretty(configAnnounce, "json")
	}
	// Parse the repo name
	defer gitPushConfig()
}

func checkAddress(address *net.IPNet) {
	key := address.String()
	if _, exists := allocatedIPs[key]; !exists {
		allocatedIPs[key] = &iPSet{}
		availableIPS[key] = &iPSet{}
	}
}