func: static void unix_wait_for_connect(int fd, Error *err, void *opaque)
  
  {
  
      MigrationState *s = opaque;
  
  
  
      if (fd < 0) {
  
          DPRINTF("migrate connect error: %s\n", error_get_pretty(err));
  
          s->file = NULL;
  
          migrate_fd_error(s);
  
      } else {
  
          DPRINTF("migrate connect success\n");
  
          s->file = qemu_fopen_socket(fd, "wb");
  
          migrate_fd_connect(s);
  
      }
  
  }
  