Time for action – using the if statement in unlang

The if statement itself is not very complex. It has the following format:

if(condition){
    ...
}

The condition part can become complex due to its many possibilities.

Obtaining a return code using the if statement

We will now look at the return code of a module and use this code to compare against the specified condition. Each module in FreeRADIUS is required to return a code after it is called. The value of this code can subsequently be used as a conditional check in the if statement.

Authorizing a user using the if statement

This exercise uses the if condition to reject an Access-Request if the user is not in the users file.

1. Edit the sites-available/default virtual server under the FreeRADIUS configuration directory and add the following lines below the files entry inside the authorize section:

   if(noop){
       reject
   }

2. Restart FreeRADIUS in debug mode and try to authenticate with a username and password not present in the users file. We...