Golang netns.GetFromPath函數代碼示例

func (c *CNIPlugin) CmdDel(args *skel.CmdArgs) error {
	conf, err := loadNetConf(args.StdinData)
	if err != nil {
		return err
	}

	ns, err := netns.GetFromPath(args.Netns)
	if err != nil {
		return err
	}
	defer ns.Close()
	err = weavenet.WithNetNSUnsafe(ns, func() error {
		link, err := netlink.LinkByName(args.IfName)
		if err != nil {
			return err
		}
		return netlink.LinkDel(link)
	})
	if err != nil {
		return fmt.Errorf("error removing interface: %s", err)
	}

	// Default IPAM is Weave's own
	if conf.IPAM.Type == "" {
		err = ipamplugin.NewIpam(c.weave).Release(args)
	} else {
		err = ipam.ExecDel(conf.IPAM.Type, args.StdinData)
	}
	if err != nil {
		return fmt.Errorf("unable to release IP address: %s", err)
	}
	return nil
}

// NewSandbox provides a new sandbox instance created in an os specific way
// provided a key which uniquely identifies the sandbox
func NewSandbox(key string, osCreate, isRestore bool) (Sandbox, error) {
	if !isRestore {
		err := createNetworkNamespace(key, osCreate)
		if err != nil {
			return nil, err
		}
	} else {
		once.Do(createBasePath)
	}

	n := &networkNamespace{path: key, isDefault: !osCreate}

	sboxNs, err := netns.GetFromPath(n.path)
	if err != nil {
		return nil, fmt.Errorf("failed get network namespace %q: %v", n.path, err)
	}
	defer sboxNs.Close()

	n.nlHandle, err = netlink.NewHandleAt(sboxNs)
	if err != nil {
		return nil, fmt.Errorf("failed to create a netlink handle: %v", err)
	}

	if err = n.loopbackUp(); err != nil {
		n.nlHandle.Delete()
		return nil, err
	}

	return n, nil
}

// Search the network namespace of a process for interfaces matching a predicate
func FindNetDevs(procPath string, processID int, match func(string) bool) ([]NetDev, error) {
	var netDevs []NetDev

	ns, err := netns.GetFromPath(fmt.Sprintf("%s/%d/ns/net", procPath, processID))
	if err != nil {
		return nil, err
	}
	defer ns.Close()

	err = WithNetNS(ns, func() error {
		links, err := netlink.LinkList()
		if err != nil {
			return err
		}
		for _, link := range links {
			if match(link.Attrs().Name) {
				addrs, err := netlink.AddrList(link, netlink.FAMILY_V4)
				if err != nil {
					return err
				}

				netDev := NetDev{MAC: link.Attrs().HardwareAddr}
				for _, addr := range addrs {
					netDev.CIDRs = append(netDev.CIDRs, addr.IPNet)
				}
				netDevs = append(netDevs, netDev)
			}
		}
		return nil
	})

	return netDevs, err
}

// GetSandboxForExternalKey returns sandbox object for the supplied path
func GetSandboxForExternalKey(basePath string, key string) (Sandbox, error) {
	if err := createNamespaceFile(key); err != nil {
		return nil, err
	}

	if err := mountNetworkNamespace(basePath, key); err != nil {
		return nil, err
	}
	n := &networkNamespace{path: key}

	sboxNs, err := netns.GetFromPath(n.path)
	if err != nil {
		return nil, fmt.Errorf("failed get network namespace %q: %v", n.path, err)
	}
	defer sboxNs.Close()

	n.nlHandle, err = netlink.NewHandleAt(sboxNs)
	if err != nil {
		return nil, fmt.Errorf("failed to create a netlink handle: %v", err)
	}

	if err = n.loopbackUp(); err != nil {
		n.nlHandle.Delete()
		return nil, err
	}

	return n, nil
}

func verifySandbox(t *testing.T, s Sandbox, ifaceSuffixes []string) {
	_, ok := s.(*networkNamespace)
	if !ok {
		t.Fatalf("The sandox interface returned is not of type networkNamespace")
	}

	sbNs, err := netns.GetFromPath(s.Key())
	if err != nil {
		t.Fatalf("Failed top open network namespace path %q: %v", s.Key(), err)
	}
	defer sbNs.Close()

	nh, err := netlink.NewHandleAt(sbNs)
	if err != nil {
		t.Fatal(err)
	}
	defer nh.Delete()

	for _, suffix := range ifaceSuffixes {
		_, err = nh.LinkByName(sboxIfaceName + suffix)
		if err != nil {
			t.Fatalf("Could not find the interface %s inside the sandbox: %v",
				sboxIfaceName+suffix, err)
		}
	}
}

func NewNetNsContext(path string) (*NetNSContext, error) {
	runtime.LockOSThread()

	origns, err := netns.Get()
	if err != nil {
		return nil, fmt.Errorf("Error while getting current ns: %s", err.Error())
	}

	newns, err := netns.GetFromPath(path)
	if err != nil {
		origns.Close()
		return nil, fmt.Errorf("Error while opening %s: %s", path, err.Error())
	}

	if err = netns.Set(newns); err != nil {
		newns.Close()
		origns.Close()
		return nil, fmt.Errorf("Error while switching from root ns to %s: %s", path, err.Error())
	}

	return &NetNSContext{
		origns: origns,
		newns:  newns,
	}, nil
}

func deleteVxlanByVNI(path string, vni uint32) error {
	defer osl.InitOSContext()()

	nlh := ns.NlHandle()
	if path != "" {
		ns, err := netns.GetFromPath(path)
		if err != nil {
			return fmt.Errorf("failed to get ns handle for %s: %v", path, err)
		}
		defer ns.Close()

		nlh, err = netlink.NewHandleAt(ns)
		if err != nil {
			return fmt.Errorf("failed to get netlink handle for ns %s: %v", path, err)
		}
		defer nlh.Delete()
	}

	links, err := nlh.LinkList()
	if err != nil {
		return fmt.Errorf("failed to list interfaces while deleting vxlan interface by vni: %v", err)
	}

	for _, l := range links {
		if l.Type() == "vxlan" && (vni == 0 || l.(*netlink.Vxlan).VxlanId == int(vni)) {
			err = nlh.LinkDel(l)
			if err != nil {
				return fmt.Errorf("error deleting vxlan interface with id %d: %v", vni, err)
			}
			return nil
		}
	}

	return fmt.Errorf("could not find a vxlan interface to delete with id %d", vni)
}

// Redirecter reexec function.
func redirecter() {
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	if len(os.Args) < 4 {
		logrus.Error("invalid number of arguments..")
		os.Exit(1)
	}

	var ingressPorts []*PortConfig
	if os.Args[3] != "" {
		var err error
		ingressPorts, err = readPortsFromFile(os.Args[3])
		if err != nil {
			logrus.Errorf("Failed reading ingress ports file: %v", err)
			os.Exit(2)
		}
	}

	eIP, _, err := net.ParseCIDR(os.Args[2])
	if err != nil {
		logrus.Errorf("Failed to parse endpoint IP %s: %v", os.Args[2], err)
		os.Exit(3)
	}

	rules := [][]string{}
	for _, iPort := range ingressPorts {
		rule := strings.Fields(fmt.Sprintf("-t nat -A PREROUTING -d %s -p %s --dport %d -j REDIRECT --to-port %d",
			eIP.String(), strings.ToLower(PortConfig_Protocol_name[int32(iPort.Protocol)]), iPort.PublishedPort, iPort.TargetPort))
		rules = append(rules, rule)
	}

	ns, err := netns.GetFromPath(os.Args[1])
	if err != nil {
		logrus.Errorf("failed get network namespace %q: %v", os.Args[1], err)
		os.Exit(4)
	}
	defer ns.Close()

	if err := netns.Set(ns); err != nil {
		logrus.Errorf("setting into container net ns %v failed, %v", os.Args[1], err)
		os.Exit(5)
	}

	for _, rule := range rules {
		if err := iptables.RawCombinedOutputNative(rule...); err != nil {
			logrus.Errorf("setting up rule failed, %v: %v", rule, err)
			os.Exit(5)
		}
	}
}

func (nu *NetNsNetLinkTopoUpdater) Start(path string) {
	name := getNetNSName(path)

	logging.GetLogger().Debugf("Starting NetLinkTopoUpdater for NetNS: %s", name)

	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	origns, err := netns.Get()
	if err != nil {
		logging.GetLogger().Errorf("Error while switching from root ns to %s: %s", name, err.Error())
		return
	}
	defer origns.Close()

	time.Sleep(1 * time.Second)

	newns, err := netns.GetFromPath(path)
	if err != nil {
		logging.GetLogger().Errorf("Error while switching from root ns to %s: %s", name, err.Error())
		return
	}
	defer newns.Close()

	err = netns.Set(newns)
	if err != nil {
		logging.GetLogger().Errorf("Error while switching from root ns to %s: %s", name, err.Error())
		return
	}

	/* start a netlinks updater inside this namespace */
	nu.Lock()
	nu.nlProbe = NewNetLinkProbe(nu.Graph, nu.Root)
	nu.Unlock()

	/* NOTE(safchain) don't Start just Run, need to keep it alive for the time life of the netns
	 * and there is no need to have a new goroutine here
	 */
	nu.nlProbe.Run()

	nu.Lock()
	nu.nlProbe = nil
	nu.Unlock()

	logging.GetLogger().Debugf("NetLinkTopoUpdater stopped for NetNS: %s", name)

	netns.Set(origns)
}

func populateVNITbl() {
	filepath.Walk(filepath.Dir(osl.GenerateKey("walk")),
		func(path string, info os.FileInfo, err error) error {
			_, fname := filepath.Split(path)

			if len(strings.Split(fname, "-")) <= 1 {
				return nil
			}

			ns, err := netns.GetFromPath(path)
			if err != nil {
				logrus.Errorf("Could not open namespace path %s during vni population: %v", path, err)
				return nil
			}
			defer ns.Close()

			nlh, err := netlink.NewHandleAt(ns, syscall.NETLINK_ROUTE)
			if err != nil {
				logrus.Errorf("Could not open netlink handle during vni population for ns %s: %v", path, err)
				return nil
			}
			defer nlh.Delete()

			err = nlh.SetSocketTimeout(soTimeout)
			if err != nil {
				logrus.Warnf("Failed to set the timeout on the netlink handle sockets for vni table population: %v", err)
			}

			links, err := nlh.LinkList()
			if err != nil {
				logrus.Errorf("Failed to list interfaces during vni population for ns %s: %v", path, err)
				return nil
			}

			for _, l := range links {
				if l.Type() == "vxlan" {
					vniTbl[uint32(l.(*netlink.Vxlan).VxlanId)] = path
				}
			}

			return nil
		})
}

func child() {
	// Create temp file for NS
	path := "/proc/self/ns/net"

	must(syscall.Mount("fs/rootfs", "fs/rootfs", "", syscall.MS_BIND, ""))
	must(os.MkdirAll("fs/rootfs/oldrootfs", 0700))
	must(syscall.PivotRoot("fs/rootfs", "fs/rootfs/oldrootfs"))
	must(os.Chdir("/"))

	must(syscall.Unmount("/oldrootfs", syscall.MNT_DETACH))
	must(os.Remove("/oldrootfs"))
	must(syscall.Mount("proc", "/proc", "proc", 0, ""))

	// Some devices
	syscall.Mknod("/dev/null", 0666, Mkdev(int64(1), int64(3)))
	syscall.Mknod("/dev/zero", 0666, Mkdev(int64(1), int64(5)))
	syscall.Mknod("/dev/random", 0666, Mkdev(int64(1), int64(8)))
	syscall.Mknod("/dev/urandom", 0666, Mkdev(int64(1), int64(9)))

	fmt.Println("Pid:", os.Getpid())

	ns, err := netns.GetFromPath(path)
	if err != nil {
		fmt.Println("cant find ns")
	}
	must(netns.Set(ns))

	routingUp()

	cmd := exec.Command(os.Args[2], os.Args[3:]...)
	cmd.Stdin = os.Stdin
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	if err := cmd.Run(); err != nil {
		fmt.Println("ERROR", err)
		os.Exit(1)
	}

	routingDown()

}

// New provides a new ipvs handle in the namespace pointed to by the
// passed path. It will return a valid handle or an error in case an
// error occured while creating the handle.
func New(path string) (*Handle, error) {
	setup()

	n := netns.None()
	if path != "" {
		var err error
		n, err = netns.GetFromPath(path)
		if err != nil {
			return nil, err
		}
	}
	defer n.Close()

	sock, err := nl.GetNetlinkSocketAt(n, netns.None(), syscall.NETLINK_GENERIC)
	if err != nil {
		return nil, err
	}

	return &Handle{sock: sock}, nil
}

// NewSandbox provides a new sandbox instance created in an os specific way
// provided a key which uniquely identifies the sandbox
func NewSandbox(key string, osCreate, isRestore bool) (Sandbox, error) {
	if !isRestore {
		err := createNetworkNamespace(key, osCreate)
		if err != nil {
			return nil, err
		}
	} else {
		once.Do(createBasePath)
	}

	n := &networkNamespace{path: key, isDefault: !osCreate}

	sboxNs, err := netns.GetFromPath(n.path)
	if err != nil {
		return nil, fmt.Errorf("failed get network namespace %q: %v", n.path, err)
	}
	defer sboxNs.Close()

	n.nlHandle, err = netlink.NewHandleAt(sboxNs, syscall.NETLINK_ROUTE)
	if err != nil {
		return nil, fmt.Errorf("failed to create a netlink handle: %v", err)
	}

	err = n.nlHandle.SetSocketTimeout(ns.NetlinkSocketsTimeout)
	if err != nil {
		logrus.Warnf("Failed to set the timeout on the sandbox netlink handle sockets: %v", err)
	}

	// As starting point, disable IPv6 on all interfaces
	err = setIPv6(n.path, "all", false)
	if err != nil {
		logrus.Warnf("Failed to disable IPv6 on all interfaces on network namespace %q: %v", n.path, err)
	}

	if err = n.loopbackUp(); err != nil {
		n.nlHandle.Delete()
		return nil, err
	}

	return n, nil
}

func reexecSetIPv6() {
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	if len(os.Args) < 3 {
		logrus.Errorf("invalid number of arguments for %s", os.Args[0])
		os.Exit(1)
	}

	ns, err := netns.GetFromPath(os.Args[1])
	if err != nil {
		logrus.Errorf("failed get network namespace %q: %v", os.Args[1], err)
		os.Exit(2)
	}
	defer ns.Close()

	if err = netns.Set(ns); err != nil {
		logrus.Errorf("setting into container netns %q failed: %v", os.Args[1], err)
		os.Exit(3)
	}

	var (
		action = "disable"
		value  = byte('1')
		path   = fmt.Sprintf("/proc/sys/net/ipv6/conf/%s/disable_ipv6", os.Args[2])
	)

	if os.Args[3] == "true" {
		action = "enable"
		value = byte('0')
	}

	if err = ioutil.WriteFile(path, []byte{value, '\n'}, 0644); err != nil {
		logrus.Errorf("failed to %s IPv6 forwarding for container's interface %s: %v", action, os.Args[2], err)
		os.Exit(4)
	}

	os.Exit(0)
}

// GetSandboxForExternalKey returns sandbox object for the supplied path
func GetSandboxForExternalKey(basePath string, key string) (Sandbox, error) {
	if err := createNamespaceFile(key); err != nil {
		return nil, err
	}

	if err := mountNetworkNamespace(basePath, key); err != nil {
		return nil, err
	}
	n := &networkNamespace{path: key}

	sboxNs, err := netns.GetFromPath(n.path)
	if err != nil {
		return nil, fmt.Errorf("failed get network namespace %q: %v", n.path, err)
	}
	defer sboxNs.Close()

	n.nlHandle, err = netlink.NewHandleAt(sboxNs, syscall.NETLINK_ROUTE)
	if err != nil {
		return nil, fmt.Errorf("failed to create a netlink handle: %v", err)
	}

	err = n.nlHandle.SetSocketTimeout(ns.NetlinkSocketsTimeout)
	if err != nil {
		logrus.Warnf("Failed to set the timeout on the sandbox netlink handle sockets: %v", err)
	}

	// As starting point, disable IPv6 on all interfaces
	err = setIPv6(n.path, "all", false)
	if err != nil {
		logrus.Warnf("Failed to disable IPv6 on all interfaces on network namespace %q: %v", n.path, err)
	}

	if err = n.loopbackUp(); err != nil {
		n.nlHandle.Delete()
		return nil, err
	}

	return n, nil
}