func (c *linuxContainer) criuSwrk(process *Process, req *criurpc.CriuReq, opts *CriuOpts, applyCgroups bool) error { fds, err := syscall.Socketpair(syscall.AF_LOCAL, syscall.SOCK_SEQPACKET|syscall.SOCK_CLOEXEC, 0) if err != nil { return err } logPath := filepath.Join(opts.WorkDirectory, req.GetOpts().GetLogFile()) criuClient := os.NewFile(uintptr(fds[0]), "criu-transport-client") criuServer := os.NewFile(uintptr(fds[1]), "criu-transport-server") defer criuClient.Close() defer criuServer.Close() args := []string{"swrk", "3"} cmd := exec.Command(c.criuPath, args...) if process != nil { cmd.Stdin = process.Stdin cmd.Stdout = process.Stdout cmd.Stderr = process.Stderr } cmd.ExtraFiles = append(cmd.ExtraFiles, criuServer) if err := cmd.Start(); err != nil { return err } criuServer.Close() defer func() { criuClient.Close() _, err := cmd.Process.Wait() if err != nil { return } }() if applyCgroups { err := c.criuApplyCgroups(cmd.Process.Pid, req) if err != nil { return err } } var extFds []string if process != nil { extFds, err = getPipeFds(cmd.Process.Pid) if err != nil { return err } } data, err := proto.Marshal(req) if err != nil { return err } _, err = criuClient.Write(data) if err != nil { return err } buf := make([]byte, 10*4096) for true { n, err := criuClient.Read(buf) if err != nil { return err } if n == 0 { return fmt.Errorf("unexpected EOF") } if n == len(buf) { return fmt.Errorf("buffer is too small") } resp := new(criurpc.CriuResp) err = proto.Unmarshal(buf[:n], resp) if err != nil { return err } if !resp.GetSuccess() { typeString := req.GetType().String() return fmt.Errorf("criu failed: type %s errno %d\nlog file: %s", typeString, resp.GetCrErrno(), logPath) } t := resp.GetType() switch { case t == criurpc.CriuReqType_NOTIFY: if err := c.criuNotifications(resp, process, opts, extFds); err != nil { return err } t = criurpc.CriuReqType_NOTIFY req = &criurpc.CriuReq{ Type: &t, NotifySuccess: proto.Bool(true), } data, err = proto.Marshal(req) if err != nil { return err } n, err = criuClient.Write(data) if err != nil { return err } continue case t == criurpc.CriuReqType_RESTORE: case t == criurpc.CriuReqType_DUMP: break default: return fmt.Errorf("unable to parse the response %s", resp.String()) } break } // cmd.Wait() waits cmd.goroutines which are used for proxying file descriptors. // Here we want to wait only the CRIU process. st, err := cmd.Process.Wait() if err != nil { return err } if !st.Success() { return fmt.Errorf("criu failed: %s\nlog file: %s", st.String(), logPath) } return nil }