This is the apache 2.x port of mod_auth_udp (for apache 1.x).
I have rewritten it to be used with recent apache versions.
<Directory "/jail/home"> AuthBasicProvider UDP AuthUDPGetEnv $owner AuthUDPHost 192.168.10.1 AuthUDPPort 2233 AuthUDPSendPassword Off AuthUDPAuthoritative Off AuthUDPEnable On </Directory>