From: Andrei Pavel <andrei@isc.org>
Date: Fri, 14 May 2021 14:14:05 +0000 (+0300)
Subject: [#1860] document lenient option parsing
X-Git-Tag: Kea-1.9.8~72
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5329d68c4cbfb586603157b3755fab2faee80752;p=thirdparty%2Fkea.git

[#1860] document lenient option parsing
---

diff --git a/doc/examples/kea4/all-keys.json b/doc/examples/kea4/all-keys.json
index e841456cd3..864c1eba19 100644
--- a/doc/examples/kea4/all-keys.json
+++ b/doc/examples/kea4/all-keys.json
@@ -100,6 +100,14 @@
             }
         ],
 
+        // Parameters for triggering behaviors compatible with broken or
+        // non-compliant clients, relays or other agents
+        "compatibility": {
+            // Parse options more leniently where fields can be deduced
+            // deterministically even if against RFC or common practice.
+            "lenient-option-parsing": true
+        },
+
         // Command control socket configuration parameters for Kea DHCPv4 server.
         "control-socket": {
             // Location of the unix domain socket file the DHCPv4 server uses
diff --git a/doc/examples/kea6/all-keys.json b/doc/examples/kea6/all-keys.json
index bde412bcb4..694942af62 100644
--- a/doc/examples/kea6/all-keys.json
+++ b/doc/examples/kea6/all-keys.json
@@ -51,6 +51,14 @@
             }
         ],
 
+        // Parameters for triggering behaviors compatible with broken or
+        // non-compliant clients, relays or other agents
+        "compatibility": {
+            // Parse options more leniently where fields can be deduced
+            // deterministically even if against RFC or common practice.
+            "lenient-option-parsing": true
+        },
+
         // Command control socket configuration parameters for Kea DHCPv6 server.
         "control-socket": {
             // Location of the unix domain socket file the DHCPv6 server uses
diff --git a/doc/sphinx/arm/dhcp6-srv.rst b/doc/sphinx/arm/dhcp6-srv.rst
index cffc968f3a..7520d3f76b 100644
--- a/doc/sphinx/arm/dhcp6-srv.rst
+++ b/doc/sphinx/arm/dhcp6-srv.rst
@@ -6943,3 +6943,24 @@ Configuration Backend for the DHCPv6 server:
 
 The configuration structure is almost identical to that of the DHCPv4 server
 (see :ref:`dhcp4-cb-json` for the detailed description).
+
+.. _dhcp6-compatibility:
+
+Kea DHCPv6 Compatibility Configuration Parameters
+=================================================
+
+Kea is friendly towards broken or non-compliant clients. In that purpose, flags
+have to be enabled in order to keep Kea's default behavior of conforming to RFCs
+or to common practices.
+
+Lenient Option Parsing
+----------------------
+
+By default, DHCPv6 option 16's vendor-class-data field is parsed as a set of
+length-value pairs.
+
+With ``lenient-option-parsing: "true"``, if a length ever exceeds the rest of
+the option's buffer, Kea no longer complains with the log message ``unable to
+parse the opaque data tuple, the buffer length is x, but the tuple length is y``
+with ``x < y``. Instead, the value is considered to be the rest of the buffer,
+or in terms of the log message above, the tuple length ``y`` becomes ``x``.