func (c *linuxContainer) criuSwrk(process *Process, req *criurpc.CriuReq, opts *CriuOpts) error {
fds, err := syscall.Socketpair(syscall.AF_LOCAL, syscall.SOCK_SEQPACKET|syscall.SOCK_CLOEXEC, 0)
if err != nil {
return err
}
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
}
}()
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() {
return fmt.Errorf("criu failed: type %s errno %d", req.GetType().String(), resp.GetCrErrno())
}
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", st.String())
}
return nil
}
