Someone

int can_ioctl( __LDDK_IOCTL_PARAM )
{
void *argp;
int retval = -EIO;

  DBGin("can_ioctl");
  DBGprint(DBG_DATA,("cmd=%d", cmd));
  Can_errno = 0;

  switch(cmd){

        case COMMAND:
          if( !access_ok(VERIFY_READ, (void *)arg, sizeof(Command_par_t))) {
             DBGout(); return(retval);
          }
          if( !access_ok(VERIFY_WRITE, (void *)arg, sizeof(Command_par_t))) {
             DBGout(); return(retval);
          }
          argp = (void *) kmalloc( sizeof(Command_par_t) +1 , GFP_KERNEL );
          __lddk_copy_from_user( (void *) argp,(Command_par_t *) arg,
                                                sizeof(Command_par_t));
          ((Command_par_t *) argp)->retval =
                        can_Command(inode, ((Command_par_t *) argp)->cmd );
          ((Command_par_t *) argp)->error = Can_errno;
          __lddk_copy_to_user( (Command_par_t *)arg, (void *)argp,
                                                sizeof(Command_par_t));
          kfree(argp);
          break;