int iplattach()
iplattach()
int iplattach(){	int s;	SPLNET(s);	if (ipl_inited || (fr_checkp == fr_check)) {		printf("ipl: already initialized (%d)\n", iplbusy);		SPLX(s);		return EBUSY;	}	ipl_inited = 1;	fr_savep = fr_checkp;	fr_checkp = fr_check;	fr_saveslowtimo = inetsw[0].pr_slowtimo;	inetsw[0].pr_slowtimo = ipfr_slowtimer;	SPLX(s);	return 0;}