Restricting Access to Specific URI Mappings

I have external access to specific Sharepoint sites and restrict access to only those sites I allow. I'm also converting from WAF Apache rules to iRules on new ASM/LTMs. Soliciting suggestions as to the optimal method or iRule to accomplish this task. I would prefer to not use the entire proxypass iRule for the task. Below is a sanitized snippet from my mod_proxy rule that does this:

 

 

SharePoint Web Application baseline mappings

 

ProxyPass /favicon.ico http://sharepoint.xyz.com/favicon.ico

 

ProxyPass /_layouts/ http://sharepoint.xyz.com/_layouts/

 

ProxyPassReverse / http://sharepoint.xyz.com/

 

 

Individual SharePoint site mappings

 

ProxyPass /sites/defg/hij http://sharepoint.xyz.com/sites/defg/hij

 

ProxyPass /sites/klmn http://sharepoint.xyz.com/sites/klmn

 

ProxyPass /sites/opq http://sharepoint.xyz.com/sites/opq

 

ProxyPass /sites/rstu http://sharepoint.xyz.com/sites/rstu

 

ProxyPass /sites/vwxy http://sharepoint.xyz.com/sites/vwxy

 

ProxyPass /sites/zab http://sharepoint.xyz.com/sites/zab

 

 

Version 10.2.1.

 

Thanks!