From 7898522514c1ea532da7d7d0760c586f39c482c5 Mon Sep 17 00:00:00 2001
From: Simon Willnauer <simonw@apache.org>
Date: Fri, 18 Mar 2016 09:51:00 +0100
Subject: [PATCH] Provide better error message when an incompatible node
 connects to a node

We should give a better exception message when an incompatible node connects
and we receive a messeage. This commit adds a clear excpetion based on the
protocol version received instead of throwing cryptic messages about not fully reaed
buffer etc.

Relates to #17090
---
 .../elasticsearch/transport/netty/MessageChannelHandler.java  | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/core/src/main/java/org/elasticsearch/transport/netty/MessageChannelHandler.java b/core/src/main/java/org/elasticsearch/transport/netty/MessageChannelHandler.java
index 302f8296ad3..9eef4401144 100644
--- a/core/src/main/java/org/elasticsearch/transport/netty/MessageChannelHandler.java
+++ b/core/src/main/java/org/elasticsearch/transport/netty/MessageChannelHandler.java
@@ -127,6 +127,10 @@ public class MessageChannelHandler extends SimpleChannelUpstreamHandler {
                 }
                 streamIn = compressor.streamInput(streamIn);
             }
+            if (version.onOrAfter(Version.CURRENT.minimumCompatibilityVersion()) == false || version.major != Version.CURRENT.major) {
+                throw new IllegalStateException("Received message from unsupported version: [" + version
+                    + "] minimal compatible version is: [" +Version.CURRENT.minimumCompatibilityVersion() + "]");
+            }
             streamIn.setVersion(version);
             if (TransportStatus.isRequest(status)) {
                 threadContext.readHeaders(streamIn);