Is there a way to get client remote ip in appache config?

I have a folder "my_files" on my server (Apache 2.4.29 Ubuntu) that holds files with the client id as filename. Example: my_files/92.4.56.125

Now just clients with matching ip address should be allowed to download the corresponding file.

In appache2/sites-available/mydomaim.conf I added following lines:

SetEnvIf Request_URI "92.4.56.125" + "$"  owner_requesting
<Directory /home/server/my_files>
    Require env owner_requesting
</Directory>

This works perfect. But the ip is still hardcoded. What I need, is the client ip at request time. But I cannot figure out, how to use Remote_Addr.

The following does not work:

SetEnvIf Remote_Addr "(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})$" IPSTR=$1

SetEnvIf Request_URI IPSTR + "$" owner_requesting

<Directory /home/server/x3d_files>
    Require env owner_requesting
</Directory>

I checked IPSTR by passing it to header and it returned the correct IP.

Maybe SetEnvIf Request_URI is processed earlier, when SetEnvIf Remote_Addr ist not yet evaluated?

Any Idea?

Solution

Ok, setting an ENV via mod-rewrite and combining variable in condition do the trick

RewriteEngine on

RewriteCond %{REMOTE_ADDR}#$1 ^([^#]+)#\1$
RewriteRule (\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})$ - [E=owner_requesting:%{REMOTE_ADDR}]

<Directory /home/server/x3d_files>
    Require env owner_requesting
</Directory>

Short explanation:

In RewriteCond %{REMOTE_ADDR} is combined with the first match $1 from RewriteRule (actually %{REQUREST_URI} (\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3})$). Delimter is #. The ^([^#]+) matches %{REMOTE_ADDR} and is back referenced using /1. \1$ is then matched against $1. In words, if Request_URL is ending with an IP and the IP is the client IP, then RewriteCond is true.

Lastly set ENV with -

 [E=owner_requesting:%{Abitrary}]