rlm_jradius 

JRadius is a Java RADIUS client and server framework. As a client, it
provides a pure Java interface. When ran as a (pure Java) server, JRadius
listens for requests from the rlm_jradius module running in FreeRADIUS. The
module sends JRadius the RADIUS request, reply, and the internal FreeRADIUS
'config_items' attribute list and returns the same after processing. 

Configuring rlm_jradius for use with a running JRadius server starts with
the module definition, in jradius.conf, as follows:

  jradius {
    name             = "example"           # Name of the JRadius Application
                                           # (known as "Sender" in JRadius)
    primary          = "127.0.0.1"         # Primary JRadius Server
                                           # (using default port of 1814)
    secondary        = "192.168.1.2:1815"  # Secondary JRadius Server (port 1815)
    tertiary         = "192.168.1.2:1816"  # Tertiary JRadius Server
    timeout          = 1                   # JRadius Server Connect Timeout (default 5)
    onfail           = NOOP                # What to do if no JRadius
                                           # Server is found. Options are:
                                           # FAIL (default), OK, REJECT, NOOP
    keepalive        = yes                 # Keep connections to JRadius pooled
    connections      = 8                   # Number of pooled JRadius connections
    allow_codechange = yes                 # Allow the changing the RADIUS code/type
    allow_idchange   = yes                 # Allow the change of the RADIUS pkt id
  }

The 'name' can be used in the JRadius server to define a specific logic
"chain" of handlers. Three JRadius servers can be defined for redundancy -
making it easier to upgrade JRadius and its handlers. It is recommended to
run the FreeRADIUS module in 'keepalive' mode whereby connections to JRadius
are pool, similar to the rlm_sql module. 

The jradius.conf configuration file then needs to be included into the
radiusd.conf modules block, for instance:

  modules {
    ...

    $INCLUDE  ${confdir}/jradius.conf
  }

And the 'jradius' module must be added to the appropriate handler blocks,
commonly:

  authorize {
    ...

    jradius
  }

  preacct {
    ...

    jradius
  }

  accounting {
    ...

    jradius
  }

  ...and so on...

JRadius Quick-start:

  Starting JRadius server:

    wget http://jradius.net/dist/jradius-current.zip
    unzip jradius-current.zip
    cd jradius
    sh jradius.sh

  Running the JRadius Simulator:

    sh jRadiusSimulator.sh

  Using RadClient:

    echo "User-Name = test"        > radius.pkt
    echo "User-Password = test"   >> radius.pkt

    sh radclient.sh localhost testing123 radius.pkt

  To build a new jradius-dictionary.jar for your specific FreeRADIUS
  dictionary, see the ant's build.xml or maven's dictionary/pom.xml in the
  source svn.

  JRadius does have some Vendor Specific Attributes; see dictionary.jradius
  and ensure it is included in your main dictionary file. 

For more information, see http://jradius.net/