cru2x
cru2x(td->td_proc->p_ucred, &unp3->unp_peercred);
cru2x(cred, &unp->unp_peercred);
cru2x(cred, &unp2->unp_peercred);
cru2x(p->p_ucred, &unp->unp_peercred);
void cru2x (struct ucred *cr, struct xucred *xcr);