Re: issue, motd, or what?

[Jeff Licquia <jeff@luci.org>]

On Sun, Dec 19, 1999 at 06:48:00PM -0600, charles@lunarmedia.net wrote:
> 
> Yeah, I already did that. But I am still trying to figure out where the
> information presented before and after login comes from.

As I understand it:

The login prompt is printed by getty, telnetd, or whatever.  This then 
calls login to get the password, and login then exec()'s the right
shell.

The common getty programs are all configured to use /etc/issue, while
telnetd (and some others) use /etc/issue.net.  The information printed 
immediately after login is controlled by the PAM configuration; for
example, these lines appear in my /etc/pam.d/login:

# Prints the last login info upon succesful login
# (Replaces the `LASTLOG_ENAB' option from login.defs)
session    optional   pam_lastlog.so

# Prints the motd upon succesful login
# (Replaces the `MOTD_FILE' option in login.defs)
session    optional   pam_motd.so

# Prints the status of the user's mailbox upon succesful login
# (Replaces the `MAIL_CHECK_ENAB' option from login.defs)
session    optional   pam_mail.so standard

Finally, many systems enable a boot-time program which generates the
/etc/issue* files automatically at boot, thus enabling them to report
the proper kernel version, systemname, or whatever.  Many gettys also
support escaped tags in issue files, which are replaced with
information about the system.

I should point out here that reporting information in issue files
before authentication, especially things such as kernel version, can
be a security risk.

> Also, on a slack box the login appears as:
> 
> servername login:
> 
> While on a RedHat machine, I am presented with just:
> 
> login:
> 
> Where is all this config hiding?

I believe this is getty-specific.  FWIW, Debian's getty does report
the system name.

For mgetty, look in the info documentation for the 'login-prompt'
option to mgetty.config.

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