ZOOKEEPER-4281: Allow packet of max packet length to be deserialized
### Problem
Resolves https://issues.apache.org/jira/browse/ZOOKEEPER-4281
There are sanity checks for packet size when deserializing a packet. One place has the inclusion: len >= packetLen. It rejects to deserialize the bytes that are exactly sized jute.maxbuffer. It's confusing. This check should use ">" so the maxbuffer length packet can still be deserialized, like the other checks.
```
if (len < 0 || len >= packetLen) {
throw new IOException("Packet len " + len + " is out of range!");
}
```
### Solution
Change: `len >= packetLen` -> `len > packetLen`
```
if (len < 0 || len > packetLen) {
```
Author: Huizhi Lu <5187721+pkuwm@users.noreply.github.com>
Reviewers: Enrico Olivelli <eolivelli@apache.org>, Mohammad Arshad <arshad@apache.org>, Michael Han <hanm@apache.org>
Closes #1683 from pkuwm/maxPacketLength
diff --git a/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocket.java b/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocket.java
index 315d81f..9b53107 100644
--- a/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocket.java
+++ b/zookeeper-server/src/main/java/org/apache/zookeeper/ClientCnxnSocket.java
@@ -117,7 +117,7 @@
void readLength() throws IOException {
int len = incomingBuffer.getInt();
- if (len < 0 || len >= packetLen) {
+ if (len < 0 || len > packetLen) {
throw new IOException("Packet len " + len + " is out of range!");
}
incomingBuffer = ByteBuffer.allocate(len);
diff --git a/zookeeper-server/src/test/java/org/apache/zookeeper/ClientCnxnSocketTest.java b/zookeeper-server/src/test/java/org/apache/zookeeper/ClientCnxnSocketTest.java
index a24b13f..e707cb3 100644
--- a/zookeeper-server/src/test/java/org/apache/zookeeper/ClientCnxnSocketTest.java
+++ b/zookeeper-server/src/test/java/org/apache/zookeeper/ClientCnxnSocketTest.java
@@ -18,6 +18,7 @@
package org.apache.zookeeper;
+import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.junit.jupiter.api.Assertions.fail;
import java.io.IOException;
@@ -63,4 +64,30 @@
}
+ /*
+ * Tests readLength():
+ * 1. successfully read packet if length == jute.maxbuffer;
+ * 2. IOException is thrown if packet length is greater than jute.maxbuffer.
+ */
+ @Test
+ public void testIOExceptionIsThrownWhenPacketLenExceedsJuteMaxBuffer() throws IOException {
+ ClientCnxnSocket clientCnxnSocket = new ClientCnxnSocketNIO(new ZKClientConfig());
+
+ // Should successfully read packet length == jute.maxbuffer
+ int length = ZKClientConfig.CLIENT_MAX_PACKET_LENGTH_DEFAULT;
+ clientCnxnSocket.incomingBuffer.putInt(length);
+ clientCnxnSocket.incomingBuffer.rewind();
+ clientCnxnSocket.readLength();
+
+ // Failed to read packet length > jute.maxbuffer
+ length = ZKClientConfig.CLIENT_MAX_PACKET_LENGTH_DEFAULT + 1;
+ clientCnxnSocket.incomingBuffer.putInt(length);
+ clientCnxnSocket.incomingBuffer.rewind();
+ try {
+ clientCnxnSocket.readLength();
+ fail("IOException is expected.");
+ } catch (IOException e) {
+ assertEquals("Packet len " + length + " is out of range!", e.getMessage());
+ }
+ }
}