Golang netns.Set函數代碼示例

func addRoute(cid, CIDR, ifc string, pid int) bool {
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	origins, err := netns.Get()
	if err != nil {
		logs.Info("Get orignal namespace failed", err)
		return false
	}
	defer origins.Close()

	ns, err := netns.GetFromPid(pid)
	if err != nil {
		logs.Info("Get container namespace failed", err)
		return false
	}

	netns.Set(ns)
	defer ns.Close()
	defer netns.Set(origins)

	if err := addRouteByLink(CIDR, ifc); err != nil {
		logs.Info("Add route failed", err)
		return false
	}

	logs.Info("Add route success", cid[:12], CIDR, ifc)
	return true
}

func nsInvoke(path string, prefunc func(nsFD int) error, postfunc func(callerFD int) error) error {
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	origns, err := netns.Get()
	if err != nil {
		return err
	}
	defer origns.Close()

	f, err := os.OpenFile(path, os.O_RDONLY, 0)
	if err != nil {
		return fmt.Errorf("failed get network namespace %q: %v", path, err)
	}
	defer f.Close()

	nsFD := f.Fd()

	// Invoked before the namespace switch happens but after the namespace file
	// handle is obtained.
	if err := prefunc(int(nsFD)); err != nil {
		return fmt.Errorf("failed in prefunc: %v", err)
	}

	if err = netns.Set(netns.NsHandle(nsFD)); err != nil {
		return err
	}
	defer netns.Set(origns)

	// Invoked after the namespace switch.
	return postfunc(int(origns))
}

func setDefaultRoute(cid, gateway string, pid int) bool {
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	origins, err := netns.Get()
	if err != nil {
		logs.Info("Get orignal namespace failed", err)
		return false
	}
	defer origins.Close()

	ns, err := netns.GetFromPid(pid)
	if err != nil {
		logs.Info("Get container namespace failed", err)
		return false
	}

	netns.Set(ns)
	defer ns.Close()
	defer netns.Set(origins)

	if err := delDefaultRoute(); err != nil {
		logs.Info("Delete default routing table failed", err)
		return false
	}

	if err := addDefaultRoute(gateway); err != nil {
		logs.Info("Add default route failed", err)
		return false
	}

	logs.Info("Set default route success", cid[:12], gateway)
	return true
}

func nsInvoke(path string, inNsfunc func(callerFD int) error) error {
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	origns, err := netns.Get()
	if err != nil {
		return err
	}
	defer origns.Close()

	f, err := os.OpenFile(path, os.O_RDONLY, 0)
	if err != nil {
		return fmt.Errorf("failed get network namespace %q: %v", path, err)
	}
	defer f.Close()

	nsFD := f.Fd()

	if err = netns.Set(netns.NsHandle(nsFD)); err != nil {
		return err
	}
	defer netns.Set(origns)

	// Invoked after the namespace switch.
	return inNsfunc(int(origns))
}

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")
	}

	origns, err := netns.Get()
	if err != nil {
		t.Fatalf("Could not get the current netns: %v", err)
	}
	defer origns.Close()

	f, err := os.OpenFile(s.Key(), os.O_RDONLY, 0)
	if err != nil {
		t.Fatalf("Failed top open network namespace path %q: %v", s.Key(), err)
	}
	defer f.Close()

	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	nsFD := f.Fd()
	if err = netns.Set(netns.NsHandle(nsFD)); err != nil {
		t.Fatalf("Setting to the namespace pointed to by the sandbox %s failed: %v", s.Key(), err)
	}
	defer netns.Set(origns)

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

func setupNetNs(nsPath string) (*os.Process, error) {
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	origns, err := netns.Get()
	if err != nil {
		return nil, err
	}
	defer origns.Close()

	f, err := os.OpenFile(nsPath, os.O_RDONLY, 0)
	if err != nil {
		return nil, fmt.Errorf("failed to get network namespace %q: %v", nsPath, err)
	}
	defer f.Close()

	nsFD := f.Fd()
	if err := netns.Set(netns.NsHandle(nsFD)); err != nil {
		return nil, fmt.Errorf("failed to set network namespace %q: %v", nsPath, err)
	}
	defer netns.Set(origns)

	cmd := exec.Command("/bin/sh", "-c", "while true; do sleep 1; done")
	if err := cmd.Start(); err != nil {
		return nil, fmt.Errorf("failed to start netns process: %v", err)
	}

	return cmd.Process, nil
}

func checkSandbox(t *testing.T, info libnetwork.EndpointInfo) {
	origns, err := netns.Get()
	if err != nil {
		t.Fatalf("Could not get the current netns: %v", err)
	}
	defer origns.Close()

	key := info.Sandbox().Key()
	f, err := os.OpenFile(key, os.O_RDONLY, 0)
	if err != nil {
		t.Fatalf("Failed to open network namespace path %q: %v", key, err)
	}
	defer f.Close()

	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	nsFD := f.Fd()
	if err = netns.Set(netns.NsHandle(nsFD)); err != nil {
		t.Fatalf("Setting to the namespace pointed to by the sandbox %s failed: %v", key, err)
	}
	defer netns.Set(origns)

	_, err = netlink.LinkByName("eth0")
	if err != nil {
		t.Fatalf("Could not find the interface eth0 inside the sandbox: %v", err)
	}

	_, err = netlink.LinkByName("eth1")
	if err != nil {
		t.Fatalf("Could not find the interface eth1 inside the sandbox: %v", err)
	}
}

func setUpVLan(cid, ips string, pid int, veth netlink.Link) bool {
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	origns, err := netns.Get()
	if err != nil {
		logs.Info("Get orignal namespace failed", err)
		return false
	}
	defer origns.Close()

	ns, err := netns.GetFromPid(pid)
	if err != nil {
		logs.Info("Get container namespace failed", err)
		return false
	}

	netns.Set(ns)
	defer ns.Close()
	defer netns.Set(origns)

	if err := BindAndSetup(veth, ips); err != nil {
		logs.Info("Bind and setup NIC failed", err)
		DelVlan(veth)
		return false
	}

	logs.Info("Add vlan device success", cid[:12])
	return true
}

func programGateway(path string, gw net.IP) error {
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	origns, err := netns.Get()
	if err != nil {
		return err
	}
	defer origns.Close()

	f, err := os.OpenFile(path, os.O_RDONLY, 0)
	if err != nil {
		return fmt.Errorf("failed get network namespace %q: %v", path, err)
	}
	defer f.Close()

	nsFD := f.Fd()
	if err = netns.Set(netns.NsHandle(nsFD)); err != nil {
		return err
	}
	defer netns.Set(origns)

	gwRoutes, err := netlink.RouteGet(gw)
	if err != nil {
		return fmt.Errorf("route for the gateway could not be found: %v", err)
	}

	return netlink.RouteAdd(&netlink.Route{
		Scope:     netlink.SCOPE_UNIVERSE,
		LinkIndex: gwRoutes[0].LinkIndex,
		Gw:        gw,
	})
}

func (n *networkNamespace) AddInterface(i *Interface) error {
	n.Lock()
	i.DstName = fmt.Sprintf("%s%d", i.DstName, n.nextIfIndex)
	n.nextIfIndex++
	n.Unlock()

	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	origns, err := netns.Get()
	if err != nil {
		return err
	}
	defer origns.Close()

	f, err := os.OpenFile(n.path, os.O_RDONLY, 0)
	if err != nil {
		return fmt.Errorf("failed get network namespace %q: %v", n.path, err)
	}
	defer f.Close()

	// Find the network interface identified by the SrcName attribute.
	iface, err := netlink.LinkByName(i.SrcName)
	if err != nil {
		return err
	}

	// Move the network interface to the destination namespace.
	nsFD := f.Fd()
	if err := netlink.LinkSetNsFd(iface, int(nsFD)); err != nil {
		return err
	}

	if err = netns.Set(netns.NsHandle(nsFD)); err != nil {
		return err
	}
	defer netns.Set(origns)

	// Down the interface before configuring
	if err := netlink.LinkSetDown(iface); err != nil {
		return err
	}

	// Configure the interface now this is moved in the proper namespace.
	if err := configureInterface(iface, i); err != nil {
		return err
	}

	// Up the interface.
	if err := netlink.LinkSetUp(iface); err != nil {
		return err
	}

	n.Lock()
	n.sinfo.Interfaces = append(n.sinfo.Interfaces, i)
	n.Unlock()

	return nil
}

func (n *networkNamespace) RemoveInterface(i *Interface) error {
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	origns, err := netns.Get()
	if err != nil {
		return err
	}
	defer origns.Close()

	f, err := os.OpenFile(n.path, os.O_RDONLY, 0)
	if err != nil {
		return fmt.Errorf("failed get network namespace %q: %v", n.path, err)
	}
	defer f.Close()

	nsFD := f.Fd()
	if err = netns.Set(netns.NsHandle(nsFD)); err != nil {
		return err
	}
	defer netns.Set(origns)

	// Find the network inteerface identified by the DstName attribute.
	iface, err := netlink.LinkByName(i.DstName)
	if err != nil {
		return err
	}

	// Down the interface before configuring
	if err := netlink.LinkSetDown(iface); err != nil {
		return err
	}

	err = netlink.LinkSetName(iface, i.SrcName)
	if err != nil {
		fmt.Println("LinkSetName failed: ", err)
		return err
	}

	// Move the network interface to caller namespace.
	if err := netlink.LinkSetNsFd(iface, int(origns)); err != nil {
		fmt.Println("LinkSetNsPid failed: ", err)
		return err
	}

	n.Lock()
	for index, intf := range n.sinfo.Interfaces {
		if intf == i {
			n.sinfo.Interfaces = append(n.sinfo.Interfaces[:index], n.sinfo.Interfaces[index+1:]...)
			break
		}
	}
	n.Unlock()

	return nil
}

func (tcp *tcpProxySocket) ProxyLoop(service string, proxier *Proxier) {
	info, found := proxier.getServiceInfo(service)
	if !found {
		glog.Errorf("Failed to find service: %s", service)
		return
	}
	for {
		if !info.isActive() {
			break
		}

		// Block until a connection is made.
		inConn, err := tcp.Accept()
		if err != nil {
			glog.Errorf("Accept failed: %v", err)
			continue
		}
		glog.Infof("Accepted TCP connection from %v to %v", inConn.RemoteAddr(), inConn.LocalAddr())
		ns, endpoint, err := proxier.loadBalancer.NextEndpoint(service, inConn.RemoteAddr())
		if err != nil {
			glog.Errorf("Couldn't find an endpoint for %s %v", service, err)
			inConn.Close()
			continue
		}
		glog.Infof("Mapped service %s to endpoint %s", service, endpoint)
		// TODO: This could spin up a new goroutine to make the outbound connection,
		// and keep accepting inbound traffic.
		if ns.IsOpen() {
			glog.Infof("Using namespace %v for endpoint %s", ns, endpoint)
			runtime.LockOSThread()
			defer runtime.UnlockOSThread()
			origns, err := netns.Get()
			if err != nil {
				glog.Errorf("Failed to get original ns: %v", err)
				continue
			}
			err = netns.Set(ns)
			if err != nil {
				glog.Errorf("Failed to set ns: %v", err)
				continue
			}
			defer netns.Set(origns)
		}
		outConn, err := retryDial("tcp", endpoint, endpointDialTimeout)
		if err != nil {
			// TODO: Try another endpoint?
			glog.Errorf("Dial failed: %v", err)
			inConn.Close()
			continue
		}
		// Spin up an async copy loop.
		proxyTCP(inConn.(*net.TCPConn), outConn.(*net.TCPConn))
	}
}

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 (s *NetSetup) TearDownTest(c *C) {
	s.newNS.Close()
	s.cmd.Process.Kill()
	netns.Set(s.globalNS)
	s.globalNS.Close()
	netlink.LinkDel(s.link)
}

func nsInvoke(path string, prefunc func(nsFD int) error, postfunc func(callerFD int) error) error {
	defer InitOSContext()()

	f, err := os.OpenFile(path, os.O_RDONLY, 0)
	if err != nil {
		return fmt.Errorf("failed get network namespace %q: %v", path, err)
	}
	defer f.Close()

	nsFD := f.Fd()

	// Invoked before the namespace switch happens but after the namespace file
	// handle is obtained.
	if err := prefunc(int(nsFD)); err != nil {
		return fmt.Errorf("failed in prefunc: %v", err)
	}

	if err = netns.Set(netns.NsHandle(nsFD)); err != nil {
		return err
	}
	defer ns.SetNamespace()

	// Invoked after the namespace switch.
	return postfunc(ns.ParseHandlerInt())
}