diff options
Diffstat (limited to 'pkg/rootlessport/rootlessport_linux.go')
| -rw-r--r-- | pkg/rootlessport/rootlessport_linux.go | 347 |
1 files changed, 2 insertions, 345 deletions
diff --git a/pkg/rootlessport/rootlessport_linux.go b/pkg/rootlessport/rootlessport_linux.go index 37fb7ce79..7b9e5bbfa 100644 --- a/pkg/rootlessport/rootlessport_linux.go +++ b/pkg/rootlessport/rootlessport_linux.go @@ -12,33 +12,12 @@ package rootlessport import ( - "context" - "encoding/json" - "fmt" - "io" - "io/ioutil" - "net" - "os" - "os/exec" - "path/filepath" - - "github.com/containernetworking/plugins/pkg/ns" "github.com/containers/podman/v3/libpod/network/types" - "github.com/containers/storage/pkg/reexec" - "github.com/pkg/errors" - rkport "github.com/rootless-containers/rootlesskit/pkg/port" - rkbuiltin "github.com/rootless-containers/rootlesskit/pkg/port/builtin" - rkportutil "github.com/rootless-containers/rootlesskit/pkg/port/portutil" - "github.com/sirupsen/logrus" - "golang.org/x/sys/unix" ) const ( - // ReexecKey is the reexec key for the parent process. - ReexecKey = "containers-rootlessport" - // reexecChildKey is used internally for the second reexec - reexecChildKey = "containers-rootlessport-child" - reexecChildEnvOpaque = "_CONTAINERS_ROOTLESSPORT_CHILD_OPAQUE" + // BinaryName is the binary name for the parent process. + BinaryName = "rootlessport" ) // Config needs to be provided to the process via stdin as a JSON string. @@ -53,325 +32,3 @@ type Config struct { ContainerID string RootlessCNI bool } - -func init() { - reexec.Register(ReexecKey, func() { - if err := parent(); err != nil { - fmt.Println(err) - os.Exit(1) - } - }) - reexec.Register(reexecChildKey, func() { - if err := child(); err != nil { - fmt.Println(err) - os.Exit(1) - } - }) -} - -func loadConfig(r io.Reader) (*Config, io.ReadCloser, io.WriteCloser, error) { - stdin, err := ioutil.ReadAll(r) - if err != nil { - return nil, nil, nil, err - } - var cfg Config - if err := json.Unmarshal(stdin, &cfg); err != nil { - return nil, nil, nil, err - } - if cfg.NetNSPath == "" { - return nil, nil, nil, errors.New("missing NetNSPath") - } - if cfg.ExitFD <= 0 { - return nil, nil, nil, errors.New("missing ExitFD") - } - exitFile := os.NewFile(uintptr(cfg.ExitFD), "exitfile") - if exitFile == nil { - return nil, nil, nil, errors.New("invalid ExitFD") - } - if cfg.ReadyFD <= 0 { - return nil, nil, nil, errors.New("missing ReadyFD") - } - readyFile := os.NewFile(uintptr(cfg.ReadyFD), "readyfile") - if readyFile == nil { - return nil, nil, nil, errors.New("invalid ReadyFD") - } - return &cfg, exitFile, readyFile, nil -} - -func parent() error { - // load config from stdin - cfg, exitR, readyW, err := loadConfig(os.Stdin) - if err != nil { - return err - } - - socketDir := filepath.Join(cfg.TmpDir, "rp") - err = os.MkdirAll(socketDir, 0700) - if err != nil { - return err - } - - // create the parent driver - stateDir, err := ioutil.TempDir(cfg.TmpDir, "rootlessport") - if err != nil { - return err - } - defer os.RemoveAll(stateDir) - driver, err := rkbuiltin.NewParentDriver(&logrusWriter{prefix: "parent: "}, stateDir) - if err != nil { - return err - } - initComplete := make(chan struct{}) - quit := make(chan struct{}) - errCh := make(chan error) - // start the parent driver. initComplete will be closed when the child connected to the parent. - logrus.Infof("Starting parent driver") - go func() { - driverErr := driver.RunParentDriver(initComplete, quit, nil) - if driverErr != nil { - logrus.WithError(driverErr).Warn("Parent driver exited") - } - errCh <- driverErr - close(errCh) - }() - opaque := driver.OpaqueForChild() - logrus.Infof("Opaque=%+v", opaque) - opaqueJSON, err := json.Marshal(opaque) - if err != nil { - return err - } - childQuitR, childQuitW, err := os.Pipe() - if err != nil { - return err - } - defer func() { - // stop the child - logrus.Info("Stopping child driver") - if err := childQuitW.Close(); err != nil { - logrus.WithError(err).Warn("Unable to close childQuitW") - } - }() - - // reexec the child process in the child netns - cmd := exec.Command("/proc/self/exe") - cmd.Args = []string{reexecChildKey} - cmd.Stdin = childQuitR - cmd.Stdout = &logrusWriter{prefix: "child"} - cmd.Stderr = cmd.Stdout - cmd.Env = append(os.Environ(), reexecChildEnvOpaque+"="+string(opaqueJSON)) - childNS, err := ns.GetNS(cfg.NetNSPath) - if err != nil { - return err - } - if err := childNS.Do(func(_ ns.NetNS) error { - logrus.Infof("Starting child driver in child netns (%q %v)", cmd.Path, cmd.Args) - return cmd.Start() - }); err != nil { - return err - } - - childErrCh := make(chan error) - go func() { - err := cmd.Wait() - childErrCh <- err - close(childErrCh) - }() - - defer func() { - if err := unix.Kill(cmd.Process.Pid, unix.SIGTERM); err != nil { - logrus.WithError(err).Warn("Kill child process") - } - }() - - logrus.Info("Waiting for initComplete") - // wait for the child to connect to the parent -outer: - for { - select { - case <-initComplete: - logrus.Infof("initComplete is closed; parent and child established the communication channel") - break outer - case err := <-childErrCh: - if err != nil { - return err - } - case err := <-errCh: - if err != nil { - return err - } - } - } - - defer func() { - logrus.Info("Stopping parent driver") - quit <- struct{}{} - if err := <-errCh; err != nil { - logrus.WithError(err).Warn("Parent driver returned error on exit") - } - }() - - // let parent expose ports - logrus.Infof("Exposing ports %v", cfg.Mappings) - if err := exposePorts(driver, cfg.Mappings, cfg.ChildIP); err != nil { - return err - } - - // we only need to have a socket to reload ports when we run under rootless cni - if cfg.RootlessCNI { - socketfile := filepath.Join(socketDir, cfg.ContainerID) - // make sure to remove the file if it exists to prevent EADDRINUSE - _ = os.Remove(socketfile) - // workaround to bypass the 108 char socket path limit - // open the fd and use the path to the fd as bind argument - fd, err := unix.Open(socketDir, unix.O_PATH, 0) - if err != nil { - return err - } - socket, err := net.ListenUnix("unixpacket", &net.UnixAddr{Name: fmt.Sprintf("/proc/self/fd/%d/%s", fd, cfg.ContainerID), Net: "unixpacket"}) - if err != nil { - return err - } - err = unix.Close(fd) - // remove the socket file on exit - defer os.Remove(socketfile) - if err != nil { - logrus.Warnf("Failed to close the socketDir fd: %v", err) - } - defer socket.Close() - go serve(socket, driver) - } - - logrus.Info("Ready") - - // https://github.com/containers/podman/issues/11248 - // Copy /dev/null to stdout and stderr to prevent SIGPIPE errors - if f, err := os.OpenFile("/dev/null", os.O_WRONLY, 0755); err == nil { - unix.Dup2(int(f.Fd()), 1) // nolint:errcheck - unix.Dup2(int(f.Fd()), 2) // nolint:errcheck - f.Close() - } - // write and close ReadyFD (convention is same as slirp4netns --ready-fd) - if _, err := readyW.Write([]byte("1")); err != nil { - return err - } - if err := readyW.Close(); err != nil { - return err - } - - // wait for ExitFD to be closed - logrus.Info("Waiting for exitfd to be closed") - if _, err := ioutil.ReadAll(exitR); err != nil { - return err - } - return nil -} - -func serve(listener net.Listener, pm rkport.Manager) { - for { - conn, err := listener.Accept() - if err != nil { - // we cannot log this error, stderr is already closed - continue - } - ctx := context.TODO() - err = handler(ctx, conn, pm) - if err != nil { - conn.Write([]byte(err.Error())) - } else { - conn.Write([]byte("OK")) - } - conn.Close() - } -} - -func handler(ctx context.Context, conn io.Reader, pm rkport.Manager) error { - var childIP string - dec := json.NewDecoder(conn) - err := dec.Decode(&childIP) - if err != nil { - return errors.Wrap(err, "rootless port failed to decode ports") - } - portStatus, err := pm.ListPorts(ctx) - if err != nil { - return errors.Wrap(err, "rootless port failed to list ports") - } - for _, status := range portStatus { - err = pm.RemovePort(ctx, status.ID) - if err != nil { - return errors.Wrap(err, "rootless port failed to remove port") - } - } - // add the ports with the new child IP - for _, status := range portStatus { - // set the new child IP - status.Spec.ChildIP = childIP - _, err = pm.AddPort(ctx, status.Spec) - if err != nil { - return errors.Wrap(err, "rootless port failed to add port") - } - } - return nil -} - -func exposePorts(pm rkport.Manager, portMappings []types.OCICNIPortMapping, childIP string) error { - ctx := context.TODO() - for _, i := range portMappings { - hostIP := i.HostIP - if hostIP == "" { - hostIP = "0.0.0.0" - } - spec := rkport.Spec{ - Proto: i.Protocol, - ParentIP: hostIP, - ParentPort: int(i.HostPort), - ChildPort: int(i.ContainerPort), - ChildIP: childIP, - } - if err := rkportutil.ValidatePortSpec(spec, nil); err != nil { - return err - } - if _, err := pm.AddPort(ctx, spec); err != nil { - return err - } - } - return nil -} - -func child() error { - // load the config from the parent - var opaque map[string]string - if err := json.Unmarshal([]byte(os.Getenv(reexecChildEnvOpaque)), &opaque); err != nil { - return err - } - - // start the child driver - quit := make(chan struct{}) - errCh := make(chan error) - go func() { - d := rkbuiltin.NewChildDriver(os.Stderr) - dErr := d.RunChildDriver(opaque, quit) - errCh <- dErr - }() - defer func() { - logrus.Info("Stopping child driver") - quit <- struct{}{} - if err := <-errCh; err != nil { - logrus.WithError(err).Warn("Child driver returned error on exit") - } - }() - - // wait for stdin to be closed - if _, err := ioutil.ReadAll(os.Stdin); err != nil { - return err - } - return nil -} - -type logrusWriter struct { - prefix string -} - -func (w *logrusWriter) Write(p []byte) (int, error) { - logrus.Infof("%s%s", w.prefix, string(p)) - return len(p), nil -} |