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SpaceKit for Perl, page 3
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1 Introduction
2 Example Client Applications
»  Example Server Implementation (bxxd.pl)
4 Example For The Impatient - Utilites
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Example Server Implementation (bxxd.pl)

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      The example server implementation is a simple Blocks server that can be used for testing basic connectivity with Blocks client applications. It does not provide datastore support, so it is not possible to perform any of the more advanced client operations, such as: fetch, store, search, etc.

      The sample server does provide support for authentication for testing.

      The example server application is located in the top-level examples/server directory.

Configuration

Configuration File Format

      bxxd.pl requires a configuration file in order to start.

      The configuration file defines general server parameters as well as the available profiles and their associated parameters. The formal definition of the BXXD configuration file is available in the BXXD configuration DTD.

      Global configuration parameters:

homeDirectory:
      all relative pathnames are relative to this directory

moduleDirectory:
      all relative module files are relative to this directory

logFile:
      file to log events

debugLevel:
      debug events, any of: "all", "trace", "timing", and "info" (seperated by spaces) or just "none"

      Per profile configuration parameters:

acl:
      access control list for the profile

authDirectory:
      all authentication files are relative to this directory

mode:
      mode requested if the profile supports multiple modes of operation

      A typical configuration file contains the following parameters and profiles: 


  <?xml version="1.0"?>
 
  <!DOCTYPE config PUBLIC "-//Blocks//DTD BXXD CONFIG//EN"
            "http://xml.resource.org/blocks/software/bxxd/config.dtd">

  <config>
    <bxxd port="10288">
      <parameter name="homeDirectory"   value="/path/to/bxxd" />
      <parameter name="moduleDirectory" value="modules" />
      <parameter name="logFile"         value="logs/bxxd.log" />
      <parameter name="debugLevel"      value="none" />

      <profile uri="http://xml.resource.org/profiles/sasl/ANONYMOUS" module="sasl-anon">
        <parameter name="acl"           value='subtree "" privs "fetch"' />
      </profile>

      <profile uri="http://xml.resource.org/profiles/sasl/OTP" module="sasl-otp">
        <parameter name="authDirectory" value="auth/" />
      </profile>

      <profile uri="http://xml.resource.org/profiles/NULL/ECHO" module="null">
        <parameter name="mode"          value="echo" />
      </profile>

      <profile uri="http://xml.resource.org/profiles/NULL/SINK" module="null">
        <parameter name="mode"          value="sink" />
      </profile>
    </bxxd>
  </config>

      This is a configuration file for the default port 10288.

Running bxxd.pl from INETD

      To run the server under the supervision of inetd, first add the following to /etc/services: 


bxxp            10288/tcp             # Blocks eXtensible eXchange Protocol

      Secondly, add the following to /etc/inetd.conf (Note: this should actually be one line, but was split for readability): 


bxxp	stream	tcp	nowait	bxxpuser	/path/to/bxxd/bin/bxxd.pl	/path/to/bxxd/bin/bxxd.pl
-config /path/to/bxxd/etc/bxxd-config.xml

      Where:

  1. bxxpuser is the supervisory username of the server.
  2. /path/to/bxxd/bin is the full pathname to the Blocks SpaceKit server bin directory.
  3. /path/to/bxxd/etc/bxxd-config.xml is the full pathname to the server configuration file.

      You will need to reload inetd as super-user for the change to take effect.

Running bxxd.pl from the Command Line

      bxxd.pl can run from the command line in "stand-alone daemon" mode. Once started, it continues to run indefinitely. When a client connects, they are the exclusive connection to the server until the close of the session. This mode of running is typically used for testing purposes.

      This example starts the server on port 12345 using the configuration file in the current directory named bxxd-config.xml: 


bxxd.pl -daemon -port 12345 -config bxxd-config.xml

      Without "-port" the server uses the default port, 10288.

Simple Authentication and Authorization Layer (SASL)

      Authentication and authorization for the Blocks server is provided via either anonymous[5] or One-Time-Password[4] (OTP) SASL[3] user profiles. The location of this user data is in the configuration file as the "authDirectory" profile parameter. It is a combination of the server "homeDirectory" and the "authDirectory" parameters if authDirectory is a relative path name.

      To create an anonymous or OTP user profile, see the SASL Administration utility.

A Complete Module Example For The Impatient

      You can create your own modules by defining a new profile and implementing a new server module as well as the client using the new profile.

      In the example, we create a module named "reverse" that receives a server request, reverses the order of the octets in the request, and responds back to the client with the reversed results.

Profile Definition

      To access your new module, first define the new profile and its corresponding module in the configuration file for the port using the new profile:


      <profile uri="http://xml.resource.org/profiles/REVERSE" module="reverse">
      </profile>

      If you are using the server in stand-alone mode, you will need to restart since the configuration file loads at start time.

Module Structure

Utilities

SASL Administration Tool

      The SASL administration utility is found under the example server directory as etc/sasl-adm.pl. This utility will allow you to create, delete, list, and update the SASL anonymous and SASL OTP user accounts. 


Usage:

% etc/sasl-adm.pl [-action create|delete|list|update]
                  [-authdir path/to/authdirectory]
                  [-logfile path/to/logfile]
                  [-mechanism anonymous|otp]
                  [-version]
                  [username]
                  [subtree ...]

  where

    -action    action to perform, defaults to create
    -authdir   path to authentication database directory, defaults to ./auth,
               and will be created as needed
    -logfile   path to log file, defaults to logs/sasl-adm.log
    -mechanism SASL mechanism, defaults to otp
    -version   display application version and exit
    username   user account to access, defaults to anonymous
    subtree    list of subtrees user account will be given full access to,
               default subtree is empty and allows fetch operations on any
               subtree


Next » A Complete Module Example For The Impatient - Utilities

Footnotes

      » [3] Myers, J.G., "Simple Authentication and Security Layer (SASL)", RFC 2222, October 1997.

      » [4] Newman, C. and J. G. Myers, "ACAP -- Application Configuration Access Protocol", RFC 2244, November 1997.

      » [5] Newman, C., "Anonymous SASL Mechanism", RFC 2245, November 1997.


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