sameaddr
if (a1 == NULL || sameaddr(a, a1))
if (sameaddr(a, b))
if (sameaddr(b, c))
if (sameaddr(b, c))
if (sameaddr(ctladdr, a))
(sameaddr(q, &a) ||
if (sameaddr(q, new) &&
extern bool sameaddr __P((ADDRESS *, ADDRESS *));