[squid-users] Allow specific set of IP to access a specific set of URL

[Amos Jeffries]

On 24/02/21 10:14 pm, Klaus Brandl wrote:
> The acl for the url must be of type url_regex, or something else:
> 
> acl allowedurl url_regex "url.txt"
> 

This line tells Squid to load a file full of regex patterns. Nothing more.


The http_access line is the list of rules that determines when those 
loaded values are tested against a URL, and what happens when the URL 
matches (or not) any of the patterns.


> 
> Am Dienstag, den 23.02.2021, 18:09 +0000 schrieb Arjun K:
>> Hi Team
>>
>> Could you please let me know how to define an acl so that a specific
>> set of IPs can access alone a specific set of URLs.


Have you read the docs on how Squid does access control?
 
<https://wiki.squid-cache.org/SquidFaq/SquidAcl#The_Basics:_How_the_parts_fit_together>

The example config you showed indicates a lack of understanding the 
syntax. That understanding is key to these things actually working the 
way you want.


Lets look at your stated requirements:

 >  define an acl

acl okay_urls url_regex "/etc/squid/url.txt"


 > a specific set of IPs can access alone a specific set of URLs.

That sentence is an access policy. It has three parts:

   1) "set of IPs"

  I have assumed from the "can access" words that you mean client IPs. 
Which in networking are the TCP src-IP value.

So ...

    acl set_of_IPs src 192.0.2.1 192.0.2.45 192.0.2.156

   2) "set of URLs"

So ...

     acl set_of_urls url_regex "/etc/squid/url.txt"


   3) "can access alone"

I assume that means you want these IPs to access the URLs. But no others 
to be able to access those same URLs.

So ...
   # permit set_of_ips
   http_access allow set_of_ips set_of_urls
   http_access deny set_of_urls



 > Also, I have an existing configuration which should not get affected
 > and it should not interfere in the rules which were allowed for the
 > servers previously.

The most important word there is "previously".

This is where *you* understanding how Squid access controls fit together 
matters *a lot*.

The first http_access line that matches entirely will _end_ processing 
of the 'http_access' sequence. The action (allow/deny) specified on that 
matched line will be done.

So where you place the above http_access lines determine which 
transactions will be able to reach and be tested by them.


Amos