Valcheck 2.0 README
-------------------

Valcheck is a Palace Server plugin that validity checks the format of
messages from the clients to the server before the server processes
them.  Valcheck can prevent certain client and server crashes caused
by bad message format.

This version includes logic originally developed by Josh, Pawn, and
Martyn.  Their help is greatfully acknowleged.

Changes since Version 1.3
----------------------

New Tests
---------

* Checks draw operations for negative bounding boxes and points.

* Checks the prop index used for deleting and moving loose props.

* A configurable limit on the maximum length of a Blowthru message is
implemented.

Bug fixes
---------

* A bug where Valcheck help was displayed for any help inquiry made
by a wizards is fixed.

Installation
------------

The following installation instructions assume that the Palace server
has been installed in /usr/local/palace.

Valcheck is a standard Palace server plugin.  It is installed by
placing the plugin file, valcheck.so, in the palace binary folder,
/usr/local/palace/bin, and adding the following line to the plugin
configuration file, /usr/local/palace/<palace-name>/psdata/plugin.conf

../bin/valcheck.so <settings>

The control switches debugextendedinfo, log and page; may be set using
the <settings> parameters.  The maxblowthru setting may also be set.

For example:

../bin/valcheck.so page on log off maxblowthru 500

will  suppress the log file entries while still paging the wizards
when a badly formated message is detected.  (See below for the meaning
of these switches.)  The maximum length Blowthru message accepted will
be 500 bytes.

The default values for the switches are:

  log on
  page off
  debugextendedinfo off
  maxblowthru 32767

Wizard and god Commands
-----------------------

Valcheck also adds the following commands for users with wizard or god
status.

`valcheck list                - Show the valcheck plugin settings.
`valcheck log [on | off]      - Write a log entry when a badly formated
                                message is rejected.
`valcheck page [on | off]     - Page wizards when a badly formated
                                message is rejected.
`valcheck debugextendedinfo [on | off] -
                                Causes extendedinfo messages to be logged
                                without being suppressed.
`valcheck maxblowthru <nn>    - Set the maximum length for a blowthru
                                message.