Using apache proxy server to perform database check on browser URL

After setting up apache proxy server Im looking for a way to get the URL of the browser that is passing through the proxy from and resolve that URL to an IP or use the URL to check if it’s in my URL blocked list (in the database), then probably after that if the URL is not malicious i just forward the request else block the request.

<IfModule proxy_module>
 <IfModule proxy_http_module> 
    ProxyRequests On
    ProxyVia On
    <Proxy *>
      Order deny,allow
      Allow from

    ###perform database checking here###