want to restrict root to su only

[Jay Hiser]

As delivered by CCI and used by my predecessors for years, my hosts
allow root to login directly.  Politics prevent me from limiting
access to the root password as much as I'd like, but I can get away
with making them use su only (they probably don't even know about the
su.log :) ).  Unfortunately, I don't have access to the source for
login.  My sys uses System V Rev 2 (CCI 2.22)).  Root currently uses
sh, since I'm the only one who knows csh (no ksh yet).

While I'm on the subject of security, I'm also interested in
monitoring login attempts -- especially attempts through the dial-in
modem.  getty doesn't offer much help for a dial-in, but its what I've
got.

Thank you for your suggestions,