Provided by: freeradius_1.1.7-1build4_i386
rlm_attr_filter - FreeRADIUS Module
The rlm_attr_filter module exists for filtering certain attributes and
values in received ( or transmitted ) radius packets from ( or to )
remote proxy servers. It gives the proxier ( us ) a flexible framework
to filter the attributes we send to or receive from these remote
proxies. This makes sense, for example, in an out-sourced dialup
situation to various policy decisions, such as restricting a client to
certain ranges of Idle-Timeout or Session-Timeout.
Filter rules are defined and applied on a per-realm basis, where the
realm is anything that is defined and matched based on the
configuration of the rlm_realm module.
The file that defines the attribute filtering rules follows a similar
syntax to the users file. There are a few differences however:
There are no check-items allowed other than the realm.
There can only be a single DEFAULT entry.
The rules for each entry are parsed to top to bottom, and an attribute
must pass *all* the rules which affect it in order to make it past the
filter. Order of the rules is important. The operators and their
purpose in defining the rules are as follows:
= THIS OPERATOR IS NOT ALLOWED. If used, and warning message is
printed and it is treated as ==
:= Set, this attribute and value will always be placed in the
output A/V Pairs. If the attribute exists, it is overwritten.
== Equal, value must match exactly.
=* Always Equal, allow all values for the specified attribute.
!* Never Equal, disallow all values for the specified attribute. (
This is redundant, as any A/V Pair not explicitly permitted will
be dropped ).
!= Not Equal, value must not match.
>= Greater Than or Equal
<= Less Than or Equal
> Greather Than
< Less Than
If regular expressions are enabled the following operators are also
possible. ( Regular Expressions are included by default unless your
system doesn’t support them, which should be rare ). The value field
uses standard regular expression syntax.
=~ Regular Expression Equal
!~ Regular Expression Not Equal
See the default /etc/raddb/attrs for working examples of sample rule
ordering and how to use the different operators.
The main configuration item is:
This specifies the location of the file used to load the filter
authorization, accounting, preproxy, postproxy
Chris Parker, email@example.com
3 February 2004 rlm_attr_filter(5)