making non-tty login sessions

I want to do the following:

main()
{
[code to listen and accept connections on port xxx]
s = accept(....

fork()
[the child process]
setpgrp();
close(0);
close(1);
close(2);
dup(s);
dup(s);
dup(s);

write(1, "Login:", 6);
n = read(0, buf, 99); /* not exactly stellar code but you get the
drift */

[do some processing on the input buf. this is the reason why I have to
do things this way.]

execl("/bin/login", "login", buf, NULL);
}

code runs, but after the execl, login fails with a "FATAL: bad tty" on
the system log.

How can I do this?

Thanks in advance

BING

On Aug 31, 3:36 pm, Bill Marcum <marcumb... RemoveThis @bellsouth.net> wrote:
> On 2009-08-31, bing1351 <bi... RemoveThis @tcsaa.com> wrote:> I want to do the following:
>
> > execl("/bin/login", "login", buf, NULL);
> > }
>
> > code runs, but after the execl, login fails with a "FATAL: bad tty" on
> > the system log.
>
> > How can I do this?
>
> Use a pty, or replace /bin/login with some other method to authenticate the
> user and start a shell as that user.

Can I prompt for the password and make the right calls into PAM right
in my code?
Pointers to example code links would be appreciated. I'm not well
versed in PAM.