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/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.transport;
import org.elasticsearch.Version;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.common.bytes.BytesReference;
import org.elasticsearch.common.io.stream.BytesStreamOutput;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.metrics.CounterMetric;
import org.elasticsearch.core.TimeValue;
import org.elasticsearch.threadpool.ThreadPool;
import java.io.EOFException;
import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* Sends and receives transport-level connection handshakes. This class will send the initial handshake,
* manage state/timeouts while the handshake is in transit, and handle the eventual response.
*/
final class TransportHandshaker {
static final String HANDSHAKE_ACTION_NAME = "internal:tcp/handshake";
private final ConcurrentMap pendingHandshakes = new ConcurrentHashMap<>();
private final CounterMetric numHandshakes = new CounterMetric();
private final Version version;
private final ThreadPool threadPool;
private final HandshakeRequestSender handshakeRequestSender;
private final boolean ignoreDeserializationErrors;
TransportHandshaker(
Version version,
ThreadPool threadPool,
HandshakeRequestSender handshakeRequestSender,
boolean ignoreDeserializationErrors
) {
this.version = version;
this.threadPool = threadPool;
this.handshakeRequestSender = handshakeRequestSender;
this.ignoreDeserializationErrors = ignoreDeserializationErrors;
}
void sendHandshake(long requestId, DiscoveryNode node, TcpChannel channel, TimeValue timeout, ActionListener listener) {
numHandshakes.inc();
final HandshakeResponseHandler handler = new HandshakeResponseHandler(requestId, version, listener);
pendingHandshakes.put(requestId, handler);
channel.addCloseListener(
ActionListener.wrap(() -> handler.handleLocalException(new TransportException("handshake failed because connection reset")))
);
boolean success = false;
try {
// for the request we use the minCompatVersion since we don't know what's the version of the node we talk to
// we also have no payload on the request but the response will contain the actual version of the node we talk
// to as the payload.
final Version minCompatVersion = version.minimumCompatibilityVersion();
handshakeRequestSender.sendRequest(node, channel, requestId, minCompatVersion);
threadPool.schedule(
() -> handler.handleLocalException(new ConnectTransportException(node, "handshake_timeout[" + timeout + "]")),
timeout,
ThreadPool.Names.GENERIC
);
success = true;
} catch (Exception e) {
handler.handleLocalException(new ConnectTransportException(node, "failure to send " + HANDSHAKE_ACTION_NAME, e));
} finally {
if (success == false) {
TransportResponseHandler removed = pendingHandshakes.remove(requestId);
assert removed == null : "Handshake should not be pending if exception was thrown";
}
}
}
void handleHandshake(TransportChannel channel, long requestId, StreamInput stream) throws IOException {
try {
// Must read the handshake request to exhaust the stream
new HandshakeRequest(stream);
} catch (Exception e) {
assert ignoreDeserializationErrors : e;
throw e;
}
final int nextByte = stream.read();
if (nextByte != -1) {
final IllegalStateException exception = new IllegalStateException(
"Handshake request not fully read for requestId ["
+ requestId
+ "], action ["
+ TransportHandshaker.HANDSHAKE_ACTION_NAME
+ "], available ["
+ stream.available()
+ "]; resetting"
);
assert ignoreDeserializationErrors : exception;
throw exception;
}
channel.sendResponse(new HandshakeResponse(this.version));
}
TransportResponseHandler removeHandlerForHandshake(long requestId) {
return pendingHandshakes.remove(requestId);
}
int getNumPendingHandshakes() {
return pendingHandshakes.size();
}
long getNumHandshakes() {
return numHandshakes.count();
}
private class HandshakeResponseHandler implements TransportResponseHandler {
private final long requestId;
private final Version currentVersion;
private final ActionListener listener;
private final AtomicBoolean isDone = new AtomicBoolean(false);
private HandshakeResponseHandler(long requestId, Version currentVersion, ActionListener listener) {
this.requestId = requestId;
this.currentVersion = currentVersion;
this.listener = listener;
}
@Override
public HandshakeResponse read(StreamInput in) throws IOException {
return new HandshakeResponse(in);
}
@Override
public void handleResponse(HandshakeResponse response) {
if (isDone.compareAndSet(false, true)) {
Version responseVersion = response.responseVersion;
if (currentVersion.isCompatible(responseVersion) == false) {
listener.onFailure(
new IllegalStateException(
"Received message from unsupported version: ["
+ responseVersion
+ "] minimal compatible version is: ["
+ currentVersion.minimumCompatibilityVersion()
+ "]"
)
);
} else {
listener.onResponse(responseVersion);
}
}
}
@Override
public void handleException(TransportException e) {
if (isDone.compareAndSet(false, true)) {
listener.onFailure(new IllegalStateException("handshake failed", e));
}
}
void handleLocalException(TransportException e) {
if (removeHandlerForHandshake(requestId) != null && isDone.compareAndSet(false, true)) {
listener.onFailure(e);
}
}
}
static final class HandshakeRequest extends TransportRequest {
private final Version version;
HandshakeRequest(Version version) {
this.version = version;
}
HandshakeRequest(StreamInput streamInput) throws IOException {
super(streamInput);
BytesReference remainingMessage;
try {
remainingMessage = streamInput.readBytesReference();
} catch (EOFException e) {
remainingMessage = null;
}
if (remainingMessage == null) {
version = null;
} else {
try (StreamInput messageStreamInput = remainingMessage.streamInput()) {
this.version = Version.readVersion(messageStreamInput);
}
}
}
@Override
public void writeTo(StreamOutput streamOutput) throws IOException {
super.writeTo(streamOutput);
assert version != null;
try (BytesStreamOutput messageStreamOutput = new BytesStreamOutput(4)) {
Version.writeVersion(version, messageStreamOutput);
BytesReference reference = messageStreamOutput.bytes();
streamOutput.writeBytesReference(reference);
}
}
}
static final class HandshakeResponse extends TransportResponse {
private final Version responseVersion;
HandshakeResponse(Version responseVersion) {
this.responseVersion = responseVersion;
}
private HandshakeResponse(StreamInput in) throws IOException {
super(in);
responseVersion = Version.readVersion(in);
}
@Override
public void writeTo(StreamOutput out) throws IOException {
assert responseVersion != null;
Version.writeVersion(responseVersion, out);
}
Version getResponseVersion() {
return responseVersion;
}
}
@FunctionalInterface
interface HandshakeRequestSender {
void sendRequest(DiscoveryNode node, TcpChannel channel, long requestId, Version version) throws IOException;
}
}