@pre-client

@pre-client defines a pipeline that runs before normal client matching for a server.

Use this pipeline when client information cannot be declared statically. A common use case is dynamic client matching from a database.

Typical uses include:

• Looking up a client by source IP address in a backend or script
• Setting client properties dynamically before normal matching continues
• Rejecting unknown or unauthorized client sources early

For RADIUS servers, this pipeline can set radius.client.secret before the request proceeds to normal client resolution.

Example

servers {
    radius "RADIUS_UDP_1812" {
        listen {
            protocol udp;
            port 1812;
            ip 0.0.0.0;
        }

        @pre-client {
            # radius.client.ip is used on the backend to query and return radius.client identifier and radius.client.secret
            backend {
                name "SQL_DATABASE_CLIENTS_INTERNAL";
                query "FIND_RADIUS_CLIENT";
            }
        }
    }
}

The example above demonstrates client lookup from the database.

See also

• servers.clients - Static client list binding for servers
• accept - Continue request processing after a successful pre-client decision
• backends - Backend lookups for dynamic client data