chroot command

[Bill Kuykendall]

I'm running ISC 2.0.1 and trying to set up a "padded cell" for bbs callers
who want shell privileges.  The obvious solution is to use the chroot
command or chroot() function to define a file subsystem for them.

I've duplicated the /etc, /shlib, /bin, /lib, /usr/lib, and /usr/bin
directories under the new root.  I've written a small program that does a
setuid(0), chroot(path), then execlp's login.

Here's the problem: 

If I edit the /etc/passwd file to exec either the chroot program or my
program, it aborts with a 'no shell' error message.

If I have a dummy directory with a .profile that exec's chroot /u2
/bin/login, I'm asked for login and password, and informed that there is no
utmp entry, and that login must be exec'd from the lowest level shell.

If I have a dummy directory with a .profile that exec's my program, I'm
asked for a login only and bounced with 'login incorrect' without being
asked for a password.

Does anybody have this working?  Am I going about this all wrong?  I've got
$700-800 invested in reference manuals, and all I can find are the briefest
references to the syntax of the program and c function, with no reference to
what's necessary to build a functional environment under the new root.  It's
a bit frustrating.

All suggestions welcome.  Thanks in advance.


---------------
Bill Kuykendall
Chicago, IL USA
 ...!point!wek
wek at point.UUCP