Best way to only allow specific file extensions?

[David Taveras]

Hello,

Iam running a reverse proxy and I would like only to relay certain
type of extensions to the backend.. (and ofcourse any directory)

      location / {
        proxy_pass  http://www.domain.org:80/;
        proxy_pass_header  Set-Cookie;
        proxy_set_header  X-Real-IP  $remote_addr;

      }

     ## Only allow these file types to document root
      location / {
        if ($request_uri ~*
(^\/|\.html|\.jpg|\.php|\.png|\.css|\.ico|\.js|\.swf|\.gif|robots\.txt)$
) {
          break;
        }
        return 444;
      }

I have that.. but that is complaining that my config shouldnt have
double / location. What is the best way to do what i want to anyways?

thanks

David