I wanted user s registered in one sub site to login to another sub site without re registering , i came accross this module called single sign on but it needs user to be registered in one master site to login to other ubb sites automatically , i need the opposite all sub sites to be treated as master site i.e he can register anywhere and log in anywhere. i have written one user module which uses core drupal user methods to login/register previously.is there a way to override the sessions used by user module of drupal ?
The easiest way to set this up would be to use a single site with domain access rather than a multi site install. It's likely you're past that point, though. So I'd recommend you do the following - write a custom module that alters the user login form on all sites except the single sign on multi site to point to the master site, and set a redirect back to the subsite. For example.
function mymodule_form_alter(&$form, &$form_state, $form_id) {
if ('user_login' == $form_id) {
$form['#action'] = 'http://masterdomain.com/user/login';
$form['#redirect'] = url('user', array('absolute' => TRUE));
}
}