From: Francis Dupont <fdupont@isc.org>
Date: Sat, 8 Jun 2024 17:05:03 +0000 (+0200)
Subject: [#3170] Updated doc and ChangeLog
X-Git-Tag: Kea-2.7.0~50
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=0c210f551a999b4e0c1c740237514b40f323686b;p=thirdparty%2Fkea.git

[#3170] Updated doc and ChangeLog
---

diff --git a/ChangeLog b/ChangeLog
index 3e8b106873..85efeb9519 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2253.	[func]		fdupont
+	Added the predicate token "match" which evaluates regular
+	expression matching.
+	(Gitlab #3170)
+
 2252.	[bug]		fdupont
 	Corrected an issue in kea-dhcp6 which caused reserved prefixes
 	to not be removed when their host reservation was deleted by
diff --git a/doc/sphinx/arm/classify.rst b/doc/sphinx/arm/classify.rst
index 94be28f5a2..c620d22633 100644
--- a/doc/sphinx/arm/classify.rst
+++ b/doc/sphinx/arm/classify.rst
@@ -474,6 +474,10 @@ Notes:
    |                       |                         | values and return     |
    |                       |                         | ``true`` or ``false`` |
    +-----------------------+-------------------------+-----------------------+
+   | Match                 | match('foo.*', 'foobar')| Match a regular       |
+   |                       |                         | expression with a     |
+   |                       |                         | value.                |
+   +-----------------------+-------------------------+-----------------------+
    | Not                   | not ('foo' == 'bar')    | Logical negation      |
    +-----------------------+-------------------------+-----------------------+
    | And                   | ('foo' == 'bar') and    | Logical and           |
@@ -563,6 +567,27 @@ addresses. The ``Int8ToText`` and ``UInt8ToText`` tokens expect 1 byte, the ``In
 ``UInt16ToText`` tokens expect 2 bytes, and ``Int32ToText`` and ``UInt32ToText`` expect 4 bytes.
 For all conversion tokens, if the data length is 0, the result string is empty.
 
+Predicates
+----------
+
+The two predicates are Equal and Match. They can be used to build other
+common predicates, for instance:
+::
+           not (substring('foobar', 3, 3) == 'bar')
+           match('foo.*', lcase('FooBar'))
+           match('.*foo.*', 'is it foo or bar')
+           match('^.*foo.*$', 'is it foo or bar')
+
+So inequality, case insensitive pattern matching or pattern search.
+
+.. note::
+
+   Detected invalid regular expressions are considered as syntax errors,
+   runtime exceptions during match are handled as no match.
+   Be careful with the match operator as it can show extremely bad
+   performance leading to regular expression denial of service (ReDoS).
+
+
 Logical Operators
 -----------------