Problem in before_filter

Hi,

I’ve a session data that is generated when a user logs in.
I’m trying to access that session data, in before_filter, in a different
controller for passing parameter to the before_filter function.

before_filter :only => [:index] do |obj|
user = session[:user]
has_permission_in_any(user.id,component_id,permission_id,user.communities)
end

But i’m not able to do that. What might be the reason?

One more thing,
I’m not able to call params[],redirect,or anything inside before_filter.
Could anyone help? Thanks