// +build linux package libpod import ( "crypto/rand" "fmt" "io/ioutil" "net" "os" "os/exec" "path/filepath" "regexp" "sort" "strconv" "strings" "syscall" "time" cnitypes "github.com/containernetworking/cni/pkg/types/current" "github.com/containernetworking/plugins/pkg/ns" "github.com/containers/podman/v3/libpod/define" "github.com/containers/podman/v3/libpod/events" "github.com/containers/podman/v3/libpod/network" "github.com/containers/podman/v3/pkg/errorhandling" "github.com/containers/podman/v3/pkg/namespaces" "github.com/containers/podman/v3/pkg/netns" "github.com/containers/podman/v3/pkg/resolvconf" "github.com/containers/podman/v3/pkg/rootless" "github.com/containers/podman/v3/pkg/util" "github.com/containers/storage/pkg/lockfile" "github.com/cri-o/ocicni/pkg/ocicni" "github.com/opencontainers/selinux/go-selinux/label" "github.com/pkg/errors" "github.com/sirupsen/logrus" "github.com/vishvananda/netlink" "golang.org/x/sys/unix" ) const ( // slirp4netnsMTU the default MTU override slirp4netnsMTU = 65520 // default slirp4ns subnet defaultSlirp4netnsSubnet = "10.0.2.0/24" // rootlessCNINSName is the file name for the rootless network namespace bind mount rootlessCNINSName = "rootless-cni-ns" // persistentCNIDir is the directory where the CNI files are stored persistentCNIDir = "/var/lib/cni" ) // Get an OCICNI network config func (r *Runtime) getPodNetwork(id, name, nsPath string, networks []string, ports []ocicni.PortMapping, staticIP net.IP, staticMAC net.HardwareAddr, netDescriptions ContainerNetworkDescriptions) ocicni.PodNetwork { var networkKey string if len(networks) > 0 { // This is inconsistent for >1 ctrNetwork, but it's probably the // best we can do. networkKey = networks[0] } else { networkKey = r.netPlugin.GetDefaultNetworkName() } ctrNetwork := ocicni.PodNetwork{ Name: name, Namespace: name, // TODO is there something else we should put here? We don't know about Kube namespaces ID: id, NetNS: nsPath, RuntimeConfig: map[string]ocicni.RuntimeConfig{ networkKey: {PortMappings: ports}, }, } // If we have extra networks, add them if len(networks) > 0 { ctrNetwork.Networks = make([]ocicni.NetAttachment, len(networks)) for i, netName := range networks { ctrNetwork.Networks[i].Name = netName if eth, exists := netDescriptions.getInterfaceByName(netName); exists { ctrNetwork.Networks[i].Ifname = eth } } } if staticIP != nil || staticMAC != nil { // For static IP or MAC, we need to populate networks even if // it's just the default. if len(networks) == 0 { // If len(networks) == 0 this is guaranteed to be the // default ctrNetwork. ctrNetwork.Networks = []ocicni.NetAttachment{{Name: networkKey}} } var rt ocicni.RuntimeConfig = ocicni.RuntimeConfig{PortMappings: ports} if staticIP != nil { rt.IP = staticIP.String() } if staticMAC != nil { rt.MAC = staticMAC.String() } ctrNetwork.RuntimeConfig = map[string]ocicni.RuntimeConfig{ networkKey: rt, } } return ctrNetwork } type RootlessCNI struct { ns ns.NetNS dir string Lock lockfile.Locker } // getPath will join the given path to the rootless cni dir func (r *RootlessCNI) getPath(path string) string { return filepath.Join(r.dir, path) } // Do - run the given function in the rootless cni ns. // It does not lock the rootlessCNI lock, the caller // should only lock when needed, e.g. for cni operations. func (r *RootlessCNI) Do(toRun func() error) error { err := r.ns.Do(func(_ ns.NetNS) error { // Before we can run the given function, // we have to setup all mounts correctly. // The order of the mounts is IMPORTANT. // The idea of the extra mount ns is to make /run and /var/lib/cni writeable // for the cni plugins but not affecting the podman user namespace. // Because the plugins also need access to XDG_RUNTIME_DIR/netns some special setup is needed. // The following bind mounts are needed // 1. XDG_RUNTIME_DIR/netns -> XDG_RUNTIME_DIR/rootless-cni/XDG_RUNTIME_DIR/netns // 2. /run/systemd -> XDG_RUNTIME_DIR/rootless-cni/run/systemd (only if it exists) // 3. XDG_RUNTIME_DIR/rootless-cni/resolv.conf -> /etc/resolv.conf or XDG_RUNTIME_DIR/rootless-cni/run/symlink/target // 4. XDG_RUNTIME_DIR/rootless-cni/var/lib/cni -> /var/lib/cni (if /var/lib/cni does not exists use the parent dir) // 5. XDG_RUNTIME_DIR/rootless-cni/run -> /run // Create a new mount namespace, // this must happen inside the netns thread. err := unix.Unshare(unix.CLONE_NEWNS) if err != nil { return errors.Wrapf(err, "cannot create a new mount namespace") } netNsDir, err := netns.GetNSRunDir() if err != nil { return errors.Wrap(err, "could not get network namespace directory") } newNetNsDir := r.getPath(netNsDir) // 1. Mount the netns into the new run to keep them accessible. // Otherwise cni setup will fail because it cannot access the netns files. err = unix.Mount(netNsDir, newNetNsDir, "none", unix.MS_BIND|unix.MS_SHARED|unix.MS_REC, "") if err != nil { return errors.Wrap(err, "failed to mount netns directory for rootless cni") } // 2. Also keep /run/systemd if it exists. // Many files are symlinked into this dir, for example /dev/log. runSystemd := "/run/systemd" _, err = os.Stat(runSystemd) if err == nil { newRunSystemd := r.getPath(runSystemd) err = unix.Mount(runSystemd, newRunSystemd, "none", unix.MS_BIND|unix.MS_REC, "") if err != nil { return errors.Wrap(err, "failed to mount /run/systemd directory for rootless cni") } } // 3. On some distros /etc/resolv.conf is symlinked to somewhere under /run. // Because the kernel will follow the symlink before mounting, it is not // possible to mount a file at /etc/resolv.conf. We have to ensure that // the link target will be available in the mount ns. // see: https://github.com/containers/podman/issues/10855 resolvePath := "/etc/resolv.conf" resolvePath, err = filepath.EvalSymlinks(resolvePath) if err != nil { return err } logrus.Debugf("The actual path of /etc/resolv.conf on the host is %q", resolvePath) // When /etc/resolv.conf on the host is a symlink to /run/systemd/resolve/stub-resolv.conf, // we have to mount an empty filesystem on /run/systemd/resolve in the child namespace, // so as to isolate the directory from the host mount namespace. // // Otherwise our bind-mount for /run/systemd/resolve/stub-resolv.conf is unmounted // when systemd-resolved unlinks and recreates /run/systemd/resolve/stub-resolv.conf on the host. // see: https://github.com/containers/podman/issues/10929 if strings.HasPrefix(resolvePath, "/run/systemd/resolve/") { rsr := r.getPath("/run/systemd/resolve") err = unix.Mount("", rsr, "tmpfs", unix.MS_NOEXEC|unix.MS_NOSUID|unix.MS_NODEV, "") if err != nil { return errors.Wrapf(err, "failed to mount tmpfs on %q for rootless cni", rsr) } } if strings.HasPrefix(resolvePath, "/run/") { resolvePath = r.getPath(resolvePath) err = os.MkdirAll(filepath.Dir(resolvePath), 0700) if err != nil { return errors.Wrap(err, "failed to create rootless-cni resolv.conf directory") } // we want to bind mount on this file so we have to create the file first _, err = os.OpenFile(resolvePath, os.O_CREATE|os.O_RDONLY, 0700) if err != nil { return errors.Wrap(err, "failed to create rootless-cni resolv.conf file") } } // mount resolv.conf to make use of the host dns err = unix.Mount(r.getPath("resolv.conf"), resolvePath, "none", unix.MS_BIND, "") if err != nil { return errors.Wrap(err, "failed to mount resolv.conf for rootless cni") } // 4. CNI plugins need access to /var/lib/cni and /run varDir := "" varTarget := persistentCNIDir // we can only mount to a target dir which exists, check /var/lib/cni recursively // while we could always use /var there are cases where a user might store the cni // configs under /var/custom and this would break for { if _, err := os.Stat(varTarget); err == nil { varDir = r.getPath(varTarget) break } varTarget = filepath.Dir(varTarget) if varTarget == "/" { break } } if varDir == "" { return errors.New("failed to stat /var directory") } // make sure to mount var first err = unix.Mount(varDir, varTarget, "none", unix.MS_BIND, "") if err != nil { return errors.Wrapf(err, "failed to mount %s for rootless cni", varTarget) } // 5. Mount the new prepared run dir to /run, it has to be recursive to keep the other bind mounts. runDir := r.getPath("run") err = unix.Mount(runDir, "/run", "none", unix.MS_BIND|unix.MS_REC, "") if err != nil { return errors.Wrap(err, "failed to mount /run for rootless cni") } // run the given function in the correct namespace err = toRun() return err }) return err } // Cleanup the rootless cni namespace if needed. // It checks if we have running containers with the bridge network mode. // Cleanup() will try to lock RootlessCNI, therefore you have to call it with an unlocked func (r *RootlessCNI) Cleanup(runtime *Runtime) error { _, err := os.Stat(r.dir) if os.IsNotExist(err) { // the directory does not exists no need for cleanup return nil } r.Lock.Lock() defer r.Lock.Unlock() running := func(c *Container) bool { // we cannot use c.state() because it will try to lock the container // using c.state.State directly should be good enough for this use case state := c.state.State return state == define.ContainerStateRunning } ctrs, err := runtime.GetContainersWithoutLock(running) if err != nil { return err } cleanup := true for _, ctr := range ctrs { if ctr.config.NetMode.IsBridge() { cleanup = false } } if cleanup { // make sure the the cni results (cache) dir is empty // libpod instances with another root dir are not covered by the check above // this allows several libpod instances to use the same rootless cni ns contents, err := ioutil.ReadDir(r.getPath("var/lib/cni/results")) if (err == nil && len(contents) == 0) || os.IsNotExist(err) { logrus.Debug("Cleaning up rootless cni namespace") err = netns.UnmountNS(r.ns) if err != nil { return err } // make the following errors not fatal err = r.ns.Close() if err != nil { logrus.Error(err) } b, err := ioutil.ReadFile(r.getPath("rootless-cni-slirp4netns.pid")) if err == nil { var i int i, err = strconv.Atoi(string(b)) if err == nil { // kill the slirp process so we do not leak it err = syscall.Kill(i, syscall.SIGTERM) } } if err != nil { logrus.Errorf("failed to kill slirp4netns process: %s", err) } err = os.RemoveAll(r.dir) if err != nil { logrus.Error(err) } } else if err != nil && !os.IsNotExist(err) { logrus.Errorf("could not read rootless cni directory, skipping cleanup: %s", err) } } return nil } // GetRootlessCNINetNs returns the rootless cni object. If create is set to true // the rootless cni namespace will be created if it does not exists already. // If called as root it returns always nil. // On success the returned RootlessCNI lock is locked and must be unlocked by the caller. func (r *Runtime) GetRootlessCNINetNs(new bool) (*RootlessCNI, error) { if !rootless.IsRootless() { return nil, nil } var rootlessCNINS *RootlessCNI runDir, err := util.GetRuntimeDir() if err != nil { return nil, err } lfile := filepath.Join(runDir, "rootless-cni.lock") lock, err := lockfile.GetLockfile(lfile) if err != nil { return nil, errors.Wrap(err, "failed to get rootless-cni lockfile") } lock.Lock() defer func() { // In case of an error (early exit) rootlessCNINS will be nil. // Make sure to unlock otherwise we could deadlock. if rootlessCNINS == nil { lock.Unlock() } }() cniDir := filepath.Join(runDir, "rootless-cni") err = os.MkdirAll(cniDir, 0700) if err != nil { return nil, errors.Wrap(err, "could not create rootless-cni directory") } nsDir, err := netns.GetNSRunDir() if err != nil { return nil, err } path := filepath.Join(nsDir, rootlessCNINSName) ns, err := ns.GetNS(path) if err != nil { if !new { // return a error if we could not get the namespace and should no create one return nil, errors.Wrap(err, "error getting rootless cni network namespace") } // create a new namespace logrus.Debug("creating rootless cni network namespace") ns, err = netns.NewNSWithName(rootlessCNINSName) if err != nil { return nil, errors.Wrap(err, "error creating rootless cni network namespace") } // setup slirp4netns here path := r.config.Engine.NetworkCmdPath if path == "" { var err error path, err = exec.LookPath("slirp4netns") if err != nil { return nil, err } } syncR, syncW, err := os.Pipe() if err != nil { return nil, errors.Wrapf(err, "failed to open pipe") } defer errorhandling.CloseQuiet(syncR) defer errorhandling.CloseQuiet(syncW) netOptions, err := parseSlirp4netnsNetworkOptions(r, nil) if err != nil { return nil, err } slirpFeatures, err := checkSlirpFlags(path) if err != nil { return nil, errors.Wrapf(err, "error checking slirp4netns binary %s: %q", path, err) } cmdArgs, err := createBasicSlirp4netnsCmdArgs(netOptions, slirpFeatures) if err != nil { return nil, err } // Note we do not use --exit-fd, we kill this process by pid cmdArgs = append(cmdArgs, "-c", "-r", "3") cmdArgs = append(cmdArgs, "--netns-type=path", ns.Path(), "tap0") cmd := exec.Command(path, cmdArgs...) logrus.Debugf("slirp4netns command: %s", strings.Join(cmd.Args, " ")) cmd.SysProcAttr = &syscall.SysProcAttr{ Setpgid: true, } // workaround for https://github.com/rootless-containers/slirp4netns/pull/153 if !netOptions.noPivotRoot && slirpFeatures.HasEnableSandbox { cmd.SysProcAttr.Cloneflags = syscall.CLONE_NEWNS cmd.SysProcAttr.Unshareflags = syscall.CLONE_NEWNS } // Leak one end of the pipe in slirp4netns cmd.ExtraFiles = append(cmd.ExtraFiles, syncW) logPath := filepath.Join(r.config.Engine.TmpDir, "slirp4netns-rootless-cni.log") logFile, err := os.Create(logPath) if err != nil { return nil, errors.Wrapf(err, "failed to open slirp4netns log file %s", logPath) } defer logFile.Close() // Unlink immediately the file so we won't need to worry about cleaning it up later. // It is still accessible through the open fd logFile. if err := os.Remove(logPath); err != nil { return nil, errors.Wrapf(err, "delete file %s", logPath) } cmd.Stdout = logFile cmd.Stderr = logFile if err := cmd.Start(); err != nil { return nil, errors.Wrapf(err, "failed to start slirp4netns process") } // create pid file for the slirp4netns process // this is need to kill the process in the cleanup pid := strconv.Itoa(cmd.Process.Pid) err = ioutil.WriteFile(filepath.Join(cniDir, "rootless-cni-slirp4netns.pid"), []byte(pid), 0700) if err != nil { errors.Wrap(err, "unable to write rootless-cni slirp4netns pid file") } defer func() { if err := cmd.Process.Release(); err != nil { logrus.Errorf("unable to release command process: %q", err) } }() if err := waitForSync(syncR, cmd, logFile, 1*time.Second); err != nil { return nil, err } // build a new resolv.conf file which uses the slirp4netns dns server address resolveIP, err := GetSlirp4netnsDNS(nil) if err != nil { return nil, errors.Wrap(err, "failed to determine default slirp4netns DNS address") } if netOptions.cidr != "" { _, cidr, err := net.ParseCIDR(netOptions.cidr) if err != nil { return nil, errors.Wrap(err, "failed to parse slirp4netns cidr") } resolveIP, err = GetSlirp4netnsDNS(cidr) if err != nil { return nil, errors.Wrapf(err, "failed to determine slirp4netns DNS address from cidr: %s", cidr.String()) } } conf, err := resolvconf.Get() if err != nil { return nil, err } conf, err = resolvconf.FilterResolvDNS(conf.Content, netOptions.enableIPv6, true) if err != nil { return nil, err } searchDomains := resolvconf.GetSearchDomains(conf.Content) dnsOptions := resolvconf.GetOptions(conf.Content) nameServers := resolvconf.GetNameservers(conf.Content) _, err = resolvconf.Build(filepath.Join(cniDir, "resolv.conf"), append([]string{resolveIP.String()}, nameServers...), searchDomains, dnsOptions) if err != nil { return nil, errors.Wrap(err, "failed to create rootless cni resolv.conf") } // create cni directories to store files // they will be bind mounted to the correct location in a extra mount ns err = os.MkdirAll(filepath.Join(cniDir, strings.TrimPrefix(persistentCNIDir, "/")), 0700) if err != nil { return nil, errors.Wrap(err, "could not create rootless-cni var directory") } runDir := filepath.Join(cniDir, "run") err = os.MkdirAll(runDir, 0700) if err != nil { return nil, errors.Wrap(err, "could not create rootless-cni run directory") } // relabel the new run directory to the iptables /run label // this is important, otherwise the iptables command will fail err = label.Relabel(runDir, "system_u:object_r:iptables_var_run_t:s0", false) if err != nil { return nil, errors.Wrap(err, "could not create relabel rootless-cni run directory") } // create systemd run directory err = os.MkdirAll(filepath.Join(runDir, "systemd"), 0700) if err != nil { return nil, errors.Wrap(err, "could not create rootless-cni systemd directory") } // create the directory for the netns files at the same location // relative to the rootless-cni location err = os.MkdirAll(filepath.Join(cniDir, nsDir), 0700) if err != nil { return nil, errors.Wrap(err, "could not create rootless-cni netns directory") } } // The CNI plugins need access to iptables in $PATH. As it turns out debian doesn't put // /usr/sbin in $PATH for rootless users. This will break rootless cni completely. // We might break existing users and we cannot expect everyone to change their $PATH so // lets add /usr/sbin to $PATH ourselves. path = os.Getenv("PATH") if !strings.Contains(path, "/usr/sbin") { path = path + ":/usr/sbin" os.Setenv("PATH", path) } // Important set rootlessCNINS as last step. // Do not return any errors after this. rootlessCNINS = &RootlessCNI{ ns: ns, dir: cniDir, Lock: lock, } return rootlessCNINS, nil } // setPrimaryMachineIP is used for podman-machine and it sets // and environment variable with the IP address of the podman-machine // host. func setPrimaryMachineIP() error { // no connection is actually made here conn, err := net.Dial("udp", "8.8.8.8:80") if err != nil { return err } defer func() { if err := conn.Close(); err != nil { logrus.Error(err) } }() addr := conn.LocalAddr().(*net.UDPAddr) return os.Setenv("PODMAN_MACHINE_HOST", addr.IP.String()) } // setUpOCICNIPod will set up the cni networks, on error it will also tear down the cni // networks. If rootless it will join/create the rootless cni namespace. func (r *Runtime) setUpOCICNIPod(podNetwork ocicni.PodNetwork) ([]ocicni.NetResult, error) { if r.config.MachineEnabled() { if err := setPrimaryMachineIP(); err != nil { return nil, err } } rootlessCNINS, err := r.GetRootlessCNINetNs(true) if err != nil { return nil, err } var results []ocicni.NetResult setUpPod := func() error { results, err = r.netPlugin.SetUpPod(podNetwork) if err != nil { if err2 := r.netPlugin.TearDownPod(podNetwork); err2 != nil { logrus.Errorf("Error tearing down partially created network namespace for container %s: %v", podNetwork.ID, err2) } return errors.Wrapf(err, "error configuring network namespace for container %s", podNetwork.ID) } return nil } // rootlessCNINS is nil if we are root if rootlessCNINS != nil { // execute the cni setup in the rootless net ns err = rootlessCNINS.Do(setUpPod) rootlessCNINS.Lock.Unlock() } else { err = setUpPod() } return results, err } // getCNIPodName return the pod name (hostname) used by CNI and the dnsname plugin. // If we are in the pod network namespace use the pod name otherwise the container name func getCNIPodName(c *Container) string { if c.config.NetMode.IsPod() || c.IsInfra() { pod, err := c.runtime.GetPod(c.PodID()) if err == nil { return pod.Name() } } return c.Name() } // Create and configure a new network namespace for a container func (r *Runtime) configureNetNS(ctr *Container, ctrNS ns.NetNS) ([]*cnitypes.Result, error) { var requestedIP net.IP if ctr.requestedIP != nil { requestedIP = ctr.requestedIP // cancel request for a specific IP in case the container is reused later ctr.requestedIP = nil } else { requestedIP = ctr.config.StaticIP } var requestedMAC net.HardwareAddr if ctr.requestedMAC != nil { requestedMAC = ctr.requestedMAC // cancel request for a specific MAC in case the container is reused later ctr.requestedMAC = nil } else { requestedMAC = ctr.config.StaticMAC } podName := getCNIPodName(ctr) networks, _, err := ctr.networks() if err != nil { return nil, err } // All networks have been removed from the container. // This is effectively forcing net=none. if len(networks) == 0 { return nil, nil } // Update container map of interface descriptions if err := ctr.setupNetworkDescriptions(networks); err != nil { return nil, err } podNetwork := r.getPodNetwork(ctr.ID(), podName, ctrNS.Path(), networks, ctr.config.PortMappings, requestedIP, requestedMAC, ctr.state.NetInterfaceDescriptions) aliases, err := ctr.runtime.state.GetAllNetworkAliases(ctr) if err != nil { return nil, err } if len(aliases) > 0 { podNetwork.Aliases = aliases } results, err := r.setUpOCICNIPod(podNetwork) if err != nil { return nil, err } networkStatus := make([]*cnitypes.Result, 0) for idx, r := range results { logrus.Debugf("[%d] CNI result: %v", idx, r.Result) resultCurrent, err := cnitypes.GetResult(r.Result) if err != nil { return nil, errors.Wrapf(err, "error parsing CNI plugin result %q: %v", r.Result, err) } networkStatus = append(networkStatus, resultCurrent) } return networkStatus, nil } // Create and configure a new network namespace for a container func (r *Runtime) createNetNS(ctr *Container) (n ns.NetNS, q []*cnitypes.Result, retErr error) { ctrNS, err := netns.NewNS() if err != nil { return nil, nil, errors.Wrapf(err, "error creating network namespace for container %s", ctr.ID()) } defer func() { if retErr != nil { if err := netns.UnmountNS(ctrNS); err != nil { logrus.Errorf("Error unmounting partially created network namespace for container %s: %v", ctr.ID(), err) } if err := ctrNS.Close(); err != nil { logrus.Errorf("Error closing partially created network namespace for container %s: %v", ctr.ID(), err) } } }() logrus.Debugf("Made network namespace at %s for container %s", ctrNS.Path(), ctr.ID()) networkStatus := []*cnitypes.Result{} if !ctr.config.NetMode.IsSlirp4netns() { networkStatus, err = r.configureNetNS(ctr, ctrNS) } return ctrNS, networkStatus, err } // Configure the network namespace for a rootless container func (r *Runtime) setupRootlessNetNS(ctr *Container) error { if ctr.config.NetMode.IsSlirp4netns() { return r.setupSlirp4netns(ctr) } networks, _, err := ctr.networks() if err != nil { return err } if len(networks) > 0 && len(ctr.config.PortMappings) > 0 { // set up port forwarder for CNI-in-slirp4netns netnsPath := ctr.state.NetNS.Path() // TODO: support slirp4netns port forwarder as well return r.setupRootlessPortMappingViaRLK(ctr, netnsPath) } return nil } // Configure the network namespace using the container process func (r *Runtime) setupNetNS(ctr *Container) error { nsProcess := fmt.Sprintf("/proc/%d/ns/net", ctr.state.PID) b := make([]byte, 16) if _, err := rand.Reader.Read(b); err != nil { return errors.Wrapf(err, "failed to generate random netns name") } nsPath, err := netns.GetNSRunDir() if err != nil { return err } nsPath = filepath.Join(nsPath, fmt.Sprintf("cni-%x-%x-%x-%x-%x", b[0:4], b[4:6], b[6:8], b[8:10], b[10:])) if err := os.MkdirAll(filepath.Dir(nsPath), 0711); err != nil { return err } mountPointFd, err := os.Create(nsPath) if err != nil { return err } if err := mountPointFd.Close(); err != nil { return err } if err := unix.Mount(nsProcess, nsPath, "none", unix.MS_BIND, ""); err != nil { return errors.Wrapf(err, "cannot mount %s", nsPath) } netNS, err := ns.GetNS(nsPath) if err != nil { return err } networkStatus, err := r.configureNetNS(ctr, netNS) // Assign NetNS attributes to container ctr.state.NetNS = netNS ctr.state.NetworkStatus = networkStatus return err } // Join an existing network namespace func joinNetNS(path string) (ns.NetNS, error) { netNS, err := ns.GetNS(path) if err != nil { return nil, errors.Wrapf(err, "error retrieving network namespace at %s", path) } return netNS, nil } // Close a network namespace. // Differs from teardownNetNS() in that it will not attempt to undo the setup of // the namespace, but will instead only close the open file descriptor func (r *Runtime) closeNetNS(ctr *Container) error { if ctr.state.NetNS == nil { // The container has no network namespace, we're set return nil } if err := ctr.state.NetNS.Close(); err != nil { return errors.Wrapf(err, "error closing network namespace for container %s", ctr.ID()) } ctr.state.NetNS = nil return nil } // Tear down a container's CNI network configuration and joins the // rootless net ns as rootless user func (r *Runtime) teardownOCICNIPod(podNetwork ocicni.PodNetwork) error { rootlessCNINS, err := r.GetRootlessCNINetNs(false) if err != nil { return err } tearDownPod := func() error { err := r.netPlugin.TearDownPod(podNetwork) return errors.Wrapf(err, "error tearing down CNI namespace configuration for container %s", podNetwork.ID) } // rootlessCNINS is nil if we are root if rootlessCNINS != nil { // execute the cni setup in the rootless net ns err = rootlessCNINS.Do(tearDownPod) rootlessCNINS.Lock.Unlock() if err == nil { err = rootlessCNINS.Cleanup(r) } } else { err = tearDownPod() } return err } // Tear down a container's CNI network configuration, but do not tear down the // namespace itself. func (r *Runtime) teardownCNI(ctr *Container) error { if ctr.state.NetNS == nil { // The container has no network namespace, we're set return nil } logrus.Debugf("Tearing down network namespace at %s for container %s", ctr.state.NetNS.Path(), ctr.ID()) networks, _, err := ctr.networks() if err != nil { return err } if !ctr.config.NetMode.IsSlirp4netns() && len(networks) > 0 { var requestedIP net.IP if ctr.requestedIP != nil { requestedIP = ctr.requestedIP // cancel request for a specific IP in case the container is reused later ctr.requestedIP = nil } else { requestedIP = ctr.config.StaticIP } var requestedMAC net.HardwareAddr if ctr.requestedMAC != nil { requestedMAC = ctr.requestedMAC // cancel request for a specific MAC in case the container is reused later ctr.requestedMAC = nil } else { requestedMAC = ctr.config.StaticMAC } podNetwork := r.getPodNetwork(ctr.ID(), ctr.Name(), ctr.state.NetNS.Path(), networks, ctr.config.PortMappings, requestedIP, requestedMAC, ctr.state.NetInterfaceDescriptions) err = r.teardownOCICNIPod(podNetwork) return err } return nil } // Tear down a network namespace, undoing all state associated with it. func (r *Runtime) teardownNetNS(ctr *Container) error { if err := r.teardownCNI(ctr); err != nil { return err } // First unmount the namespace if err := netns.UnmountNS(ctr.state.NetNS); err != nil { return errors.Wrapf(err, "error unmounting network namespace for container %s", ctr.ID()) } // Now close the open file descriptor if err := ctr.state.NetNS.Close(); err != nil { return errors.Wrapf(err, "error closing network namespace for container %s", ctr.ID()) } ctr.state.NetNS = nil return nil } func getContainerNetNS(ctr *Container) (string, error) { if ctr.state.NetNS != nil { return ctr.state.NetNS.Path(), nil } if ctr.config.NetNsCtr != "" { c, err := ctr.runtime.GetContainer(ctr.config.NetNsCtr) if err != nil { return "", err } if err = c.syncContainer(); err != nil { return "", err } return getContainerNetNS(c) } return "", nil } // isBridgeNetMode checks if the given network mode is bridge. // It returns nil when it is set to bridge and an error otherwise. func isBridgeNetMode(n namespaces.NetworkMode) error { if !n.IsBridge() { return errors.Wrapf(define.ErrNetworkModeInvalid, "%q is not supported", n) } return nil } // Reload only works with containers with a configured network. // It will tear down, and then reconfigure, the network of the container. // This is mainly used when a reload of firewall rules wipes out existing // firewall configuration. // Efforts will be made to preserve MAC and IP addresses, but this only works if // the container only joined a single CNI network, and was only assigned a // single MAC or IP. // Only works on root containers at present, though in the future we could // extend this to stop + restart slirp4netns func (r *Runtime) reloadContainerNetwork(ctr *Container) ([]*cnitypes.Result, error) { if ctr.state.NetNS == nil { return nil, errors.Wrapf(define.ErrCtrStateInvalid, "container %s network is not configured, refusing to reload", ctr.ID()) } if err := isBridgeNetMode(ctr.config.NetMode); err != nil { return nil, err } logrus.Infof("Going to reload container %s network", ctr.ID()) var requestedIP net.IP var requestedMAC net.HardwareAddr // Set requested IP and MAC address, if possible. if len(ctr.state.NetworkStatus) == 1 { result := ctr.state.NetworkStatus[0] if len(result.IPs) == 1 { resIP := result.IPs[0] requestedIP = resIP.Address.IP ctr.requestedIP = requestedIP logrus.Debugf("Going to preserve container %s IP address %s", ctr.ID(), ctr.requestedIP.String()) if resIP.Interface != nil && *resIP.Interface < len(result.Interfaces) && *resIP.Interface >= 0 { var err error requestedMAC, err = net.ParseMAC(result.Interfaces[*resIP.Interface].Mac) if err != nil { return nil, errors.Wrapf(err, "error parsing container %s MAC address %s", ctr.ID(), result.Interfaces[*resIP.Interface].Mac) } ctr.requestedMAC = requestedMAC logrus.Debugf("Going to preserve container %s MAC address %s", ctr.ID(), ctr.requestedMAC.String()) } } } err := r.teardownCNI(ctr) if err != nil { // teardownCNI will error if the iptables rules do not exists and this is the case after // a firewall reload. The purpose of network reload is to recreate the rules if they do // not exists so we should not log this specific error as error. This would confuse users otherwise. // iptables-legacy and iptables-nft will create different errors make sure to match both. b, rerr := regexp.MatchString("Couldn't load target `CNI-[a-f0-9]{24}':No such file or directory|Chain 'CNI-[a-f0-9]{24}' does not exist", err.Error()) if rerr == nil && !b { logrus.Error(err) } else { logrus.Info(err) } } // teardownCNI will clean the requested IP and MAC so we need to set them again ctr.requestedIP = requestedIP ctr.requestedMAC = requestedMAC return r.configureNetNS(ctr, ctr.state.NetNS) } func getContainerNetIO(ctr *Container) (*netlink.LinkStatistics, error) { var netStats *netlink.LinkStatistics // With slirp4netns, we can't collect statistics at present. // For now, we allow stats to at least run by returning nil if rootless.IsRootless() || ctr.config.NetMode.IsSlirp4netns() { return netStats, nil } netNSPath, netPathErr := getContainerNetNS(ctr) if netPathErr != nil { return nil, netPathErr } if netNSPath == "" { // If netNSPath is empty, it was set as none, and no netNS was set up // this is a valid state and thus return no error, nor any statistics return nil, nil } err := ns.WithNetNSPath(netNSPath, func(_ ns.NetNS) error { link, err := netlink.LinkByName(ocicni.DefaultInterfaceName) if err != nil { return err } netStats = link.Attrs().Statistics return nil }) return netStats, err } // Produce an InspectNetworkSettings containing information on the container // network. func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, error) { if c.config.NetNsCtr != "" { netNsCtr, err := c.runtime.GetContainer(c.config.NetNsCtr) if err != nil { return nil, err } // see https://github.com/containers/podman/issues/10090 // the container has to be locked for syncContainer() netNsCtr.lock.Lock() defer netNsCtr.lock.Unlock() // Have to sync to ensure that state is populated if err := netNsCtr.syncContainer(); err != nil { return nil, err } logrus.Debugf("Container %s shares network namespace, retrieving network info of container %s", c.ID(), c.config.NetNsCtr) return netNsCtr.getContainerNetworkInfo() } settings := new(define.InspectNetworkSettings) settings.Ports = makeInspectPortBindings(c.config.PortMappings) networks, isDefault, err := c.networks() if err != nil { return nil, err } // We can't do more if the network is down. if c.state.NetNS == nil { // We still want to make dummy configurations for each CNI net // the container joined. if len(networks) > 0 { settings.Networks = make(map[string]*define.InspectAdditionalNetwork, len(networks)) for _, net := range networks { cniNet := new(define.InspectAdditionalNetwork) cniNet.NetworkID = net settings.Networks[net] = cniNet } } return settings, nil } // Set network namespace path settings.SandboxKey = c.state.NetNS.Path() // If this is empty, we're probably slirp4netns if len(c.state.NetworkStatus) == 0 { return settings, nil } // If we have CNI networks - handle that here if len(networks) > 0 { if len(networks) != len(c.state.NetworkStatus) { return nil, errors.Wrapf(define.ErrInternal, "network inspection mismatch: asked to join %d CNI network(s) %v, but have information on %d network(s)", len(networks), networks, len(c.state.NetworkStatus)) } settings.Networks = make(map[string]*define.InspectAdditionalNetwork) // CNI results should be in the same order as the list of // networks we pass into CNI. for index, name := range networks { cniResult := c.state.NetworkStatus[index] addedNet := new(define.InspectAdditionalNetwork) addedNet.NetworkID = name basicConfig, err := resultToBasicNetworkConfig(cniResult) if err != nil { return nil, err } aliases, err := c.runtime.state.GetNetworkAliases(c, name) if err != nil { return nil, err } addedNet.Aliases = aliases addedNet.InspectBasicNetworkConfig = basicConfig settings.Networks[name] = addedNet } if !isDefault { return settings, nil } } // If not joining networks, we should have at most 1 result if len(c.state.NetworkStatus) > 1 { return nil, errors.Wrapf(define.ErrInternal, "should have at most 1 CNI result if not joining networks, instead got %d", len(c.state.NetworkStatus)) } if len(c.state.NetworkStatus) == 1 { basicConfig, err := resultToBasicNetworkConfig(c.state.NetworkStatus[0]) if err != nil { return nil, err } settings.InspectBasicNetworkConfig = basicConfig } return settings, nil } // setupNetworkDescriptions adds networks and eth values to the container's // network descriptions func (c *Container) setupNetworkDescriptions(networks []string) error { // if the map is nil and we have networks if c.state.NetInterfaceDescriptions == nil && len(networks) > 0 { c.state.NetInterfaceDescriptions = make(ContainerNetworkDescriptions) } origLen := len(c.state.NetInterfaceDescriptions) for _, n := range networks { // if the network is not in the map, add it if _, exists := c.state.NetInterfaceDescriptions[n]; !exists { c.state.NetInterfaceDescriptions.add(n) } } // if the map changed, we need to save the container state if origLen != len(c.state.NetInterfaceDescriptions) { if err := c.save(); err != nil { return err } } return nil } // resultToBasicNetworkConfig produces an InspectBasicNetworkConfig from a CNI // result func resultToBasicNetworkConfig(result *cnitypes.Result) (define.InspectBasicNetworkConfig, error) { config := define.InspectBasicNetworkConfig{} for _, ctrIP := range result.IPs { size, _ := ctrIP.Address.Mask.Size() switch { case ctrIP.Version == "4" && config.IPAddress == "": config.IPAddress = ctrIP.Address.IP.String() config.IPPrefixLen = size config.Gateway = ctrIP.Gateway.String() if ctrIP.Interface != nil && *ctrIP.Interface < len(result.Interfaces) && *ctrIP.Interface >= 0 { config.MacAddress = result.Interfaces[*ctrIP.Interface].Mac } case ctrIP.Version == "4" && config.IPAddress != "": config.SecondaryIPAddresses = append(config.SecondaryIPAddresses, ctrIP.Address.String()) if ctrIP.Interface != nil && *ctrIP.Interface < len(result.Interfaces) && *ctrIP.Interface >= 0 { config.AdditionalMacAddresses = append(config.AdditionalMacAddresses, result.Interfaces[*ctrIP.Interface].Mac) } case ctrIP.Version == "6" && config.IPAddress == "": config.GlobalIPv6Address = ctrIP.Address.IP.String() config.GlobalIPv6PrefixLen = size config.IPv6Gateway = ctrIP.Gateway.String() case ctrIP.Version == "6" && config.IPAddress != "": config.SecondaryIPv6Addresses = append(config.SecondaryIPv6Addresses, ctrIP.Address.String()) default: return config, errors.Wrapf(define.ErrInternal, "unrecognized IP version %q", ctrIP.Version) } } return config, nil } // This is a horrible hack, necessary because CNI does not properly clean up // after itself on an unclean reboot. Return what we're pretty sure is the path // to CNI's internal files (it's not really exposed to us). func getCNINetworksDir() (string, error) { return filepath.Join(persistentCNIDir, "networks"), nil } type logrusDebugWriter struct { prefix string } func (w *logrusDebugWriter) Write(p []byte) (int, error) { logrus.Debugf("%s%s", w.prefix, string(p)) return len(p), nil } // NetworkDisconnect removes a container from the network func (c *Container) NetworkDisconnect(nameOrID, netName string, force bool) error { // only the bridge mode supports cni networks if err := isBridgeNetMode(c.config.NetMode); err != nil { return err } networks, err := c.networksByNameIndex() if err != nil { return err } // check if network exists and if the input is a ID we get the name // ocicni only uses names so it is important that we only use the name netName, err = network.NormalizeName(c.runtime.config, netName) if err != nil { return err } index, nameExists := networks[netName] if !nameExists && len(networks) > 0 { return errors.Errorf("container %s is not connected to network %s", nameOrID, netName) } c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } if err := c.runtime.state.NetworkDisconnect(c, netName); err != nil { return err } c.newNetworkEvent(events.NetworkDisconnect, netName) if !c.ensureState(define.ContainerStateRunning, define.ContainerStateCreated) { return nil } if c.state.NetNS == nil { return errors.Wrapf(define.ErrNoNetwork, "unable to disconnect %s from %s", nameOrID, netName) } podConfig := c.runtime.getPodNetwork(c.ID(), c.Name(), c.state.NetNS.Path(), []string{netName}, c.config.PortMappings, nil, nil, c.state.NetInterfaceDescriptions) if err := c.runtime.teardownOCICNIPod(podConfig); err != nil { return err } // update network status if container is not running networkStatus := c.state.NetworkStatus // clip out the index of the network tmpNetworkStatus := make([]*cnitypes.Result, 0, len(networkStatus)-1) for k, v := range networkStatus { if index != k { tmpNetworkStatus = append(tmpNetworkStatus, v) } } c.state.NetworkStatus = tmpNetworkStatus return c.save() } // ConnectNetwork connects a container to a given network func (c *Container) NetworkConnect(nameOrID, netName string, aliases []string) error { // only the bridge mode supports cni networks if err := isBridgeNetMode(c.config.NetMode); err != nil { return err } networks, err := c.networksByNameIndex() if err != nil { return err } // check if network exists and if the input is a ID we get the name // ocicni only uses names so it is important that we only use the name netName, err = network.NormalizeName(c.runtime.config, netName) if err != nil { return err } c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } if err := c.runtime.state.NetworkConnect(c, netName, aliases); err != nil { return err } c.newNetworkEvent(events.NetworkConnect, netName) if !c.ensureState(define.ContainerStateRunning, define.ContainerStateCreated) { return nil } if c.state.NetNS == nil { return errors.Wrapf(define.ErrNoNetwork, "unable to connect %s to %s", nameOrID, netName) } ctrNetworks, _, err := c.networks() if err != nil { return err } // Update network descriptions if err := c.setupNetworkDescriptions(ctrNetworks); err != nil { return err } podConfig := c.runtime.getPodNetwork(c.ID(), c.Name(), c.state.NetNS.Path(), []string{netName}, c.config.PortMappings, nil, nil, c.state.NetInterfaceDescriptions) podConfig.Aliases = make(map[string][]string, 1) podConfig.Aliases[netName] = aliases results, err := c.runtime.setUpOCICNIPod(podConfig) if err != nil { return err } if len(results) != 1 { return errors.New("when adding aliases, results must be of length 1") } networkResults := make([]*cnitypes.Result, 0) for _, r := range results { resultCurrent, err := cnitypes.GetResult(r.Result) if err != nil { return errors.Wrapf(err, "error parsing CNI plugin result %q: %v", r.Result, err) } networkResults = append(networkResults, resultCurrent) } // update network status networkStatus := c.state.NetworkStatus // if len is one and we confirmed earlier that the container is in // fact connected to the network, then just return an empty slice if len(networkStatus) == 0 { c.state.NetworkStatus = append(c.state.NetworkStatus, networkResults...) } else { // build a list of network names so we can sort and // get the new name's index var networkNames []string for name := range networks { networkNames = append(networkNames, name) } networkNames = append(networkNames, netName) // sort sort.Strings(networkNames) // get index of new network name index := sort.SearchStrings(networkNames, netName) // Append a zero value to to the slice networkStatus = append(networkStatus, &cnitypes.Result{}) // populate network status copy(networkStatus[index+1:], networkStatus[index:]) networkStatus[index] = networkResults[0] c.state.NetworkStatus = networkStatus } return c.save() } // DisconnectContainerFromNetwork removes a container from its CNI network func (r *Runtime) DisconnectContainerFromNetwork(nameOrID, netName string, force bool) error { ctr, err := r.LookupContainer(nameOrID) if err != nil { return err } return ctr.NetworkDisconnect(nameOrID, netName, force) } // ConnectContainerToNetwork connects a container to a CNI network func (r *Runtime) ConnectContainerToNetwork(nameOrID, netName string, aliases []string) error { ctr, err := r.LookupContainer(nameOrID) if err != nil { return err } return ctr.NetworkConnect(nameOrID, netName, aliases) }