PAM module sequence

[Sudarshan Soma]

Hi All,
Iam trying to authenticate users based on sequence as below: Iam
planning to use PAM for that. To achieve the below sequence i plan to
use pam_set_data and pam_get_data.

1.  Try Remote Authentication PAM module (This module contacts remote
server for auth information)
The above fails with following reasons:
                  -- remote server not reachable
                  -- some fatal error
                  -- authentication failed....
                  (use pam_set_data  to set the error code)
2. Try with pam_tally.so (This module will track number of invalid
login attempts by particular user)
           -- here i increment invalid login count per user only if
the above module fails with authentication failed error(by
pam_get_data)

Please let me know if there is a better way to do the above. Any
comments/links  really helpful.

Best Regards,