10.2.6 Attribute Creation Functions

These are the functions used to create Radius reply attributes. An attribute creation function can take any number of arguments. The type of its return is determined by the type of Radius attribute the value will be assigned to. To invoke the function, write its name in the A/V pair of the RHS in the raddb/users file, e.g.:

DEFAULT Auth-Type = SQL
        Service-Type = Framed-User,
            Framed-IP-Address = "=get_ip_addr(10.10.10.1)"

The function get_ip_addr will be invoked after successful authentication and it will be passed the IP 10.10.10.1 as its argument. In Rewrite language, an IPv4 address is represented as a 32-bit integer number, and can be operated upon as any other integer. This is illustrated in the following function, which can be used to compute the value of the Framed-IP-Address above:

integer
get_ip_address(integer base)
{
    return base + %[NAS-Port-Id] - %[NAS-Port-Id]/16;
}