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Smack for standard XMPP connections over TCP.
/**
*
* Copyright 2019-2024 Florian Schmaus
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jivesoftware.smack.tcp;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.SelectableChannel;
import java.nio.channels.SelectionKey;
import java.nio.channels.SocketChannel;
import java.security.cert.CertificateException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.IdentityHashMap;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.locks.ReentrantLock;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.net.ssl.SSLEngine;
import javax.net.ssl.SSLEngineResult;
import javax.net.ssl.SSLException;
import javax.net.ssl.SSLSession;
import org.jivesoftware.smack.ConnectionConfiguration.SecurityMode;
import org.jivesoftware.smack.SmackException;
import org.jivesoftware.smack.SmackException.SecurityRequiredByClientException;
import org.jivesoftware.smack.SmackException.SecurityRequiredByServerException;
import org.jivesoftware.smack.SmackException.SmackCertificateException;
import org.jivesoftware.smack.SmackFuture;
import org.jivesoftware.smack.SmackFuture.InternalSmackFuture;
import org.jivesoftware.smack.SmackReactor.SelectionKeyAttachment;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.XmppInputOutputFilter;
import org.jivesoftware.smack.c2s.ModularXmppClientToServerConnection.ConnectedButUnauthenticatedStateDescriptor;
import org.jivesoftware.smack.c2s.ModularXmppClientToServerConnection.LookupRemoteConnectionEndpointsStateDescriptor;
import org.jivesoftware.smack.c2s.ModularXmppClientToServerConnectionModule;
import org.jivesoftware.smack.c2s.StreamOpenAndCloseFactory;
import org.jivesoftware.smack.c2s.XmppClientToServerTransport;
import org.jivesoftware.smack.c2s.internal.ModularXmppClientToServerConnectionInternal;
import org.jivesoftware.smack.c2s.internal.WalkStateGraphContext;
import org.jivesoftware.smack.debugger.SmackDebugger;
import org.jivesoftware.smack.fsm.State;
import org.jivesoftware.smack.fsm.StateDescriptor;
import org.jivesoftware.smack.fsm.StateTransitionResult;
import org.jivesoftware.smack.internal.SmackTlsContext;
import org.jivesoftware.smack.packet.Stanza;
import org.jivesoftware.smack.packet.StartTls;
import org.jivesoftware.smack.packet.StreamClose;
import org.jivesoftware.smack.packet.StreamOpen;
import org.jivesoftware.smack.packet.TlsFailure;
import org.jivesoftware.smack.packet.TlsProceed;
import org.jivesoftware.smack.packet.TopLevelStreamElement;
import org.jivesoftware.smack.packet.XmlEnvironment;
import org.jivesoftware.smack.tcp.XmppTcpTransportModule.XmppTcpNioTransport.DiscoveredTcpEndpoints;
import org.jivesoftware.smack.tcp.rce.RemoteXmppTcpConnectionEndpoints;
import org.jivesoftware.smack.tcp.rce.RemoteXmppTcpConnectionEndpoints.Result;
import org.jivesoftware.smack.tcp.rce.Rfc6120TcpRemoteConnectionEndpoint;
import org.jivesoftware.smack.util.CollectionUtil;
import org.jivesoftware.smack.util.StringUtils;
import org.jivesoftware.smack.util.UTF8;
import org.jivesoftware.smack.util.XmlStringBuilder;
import org.jivesoftware.smack.util.rce.RemoteConnectionEndpointLookupFailure;
import org.jxmpp.jid.DomainBareJid;
import org.jxmpp.jid.Jid;
import org.jxmpp.jid.util.JidUtil;
import org.jxmpp.xml.splitter.Utf8ByteXmppXmlSplitter;
import org.jxmpp.xml.splitter.XmlPrettyPrinter;
import org.jxmpp.xml.splitter.XmlPrinter;
import org.jxmpp.xml.splitter.XmppElementCallback;
import org.jxmpp.xml.splitter.XmppXmlSplitter;
public class XmppTcpTransportModule extends ModularXmppClientToServerConnectionModule {
private static final Logger LOGGER = Logger.getLogger(XmppTcpTransportModule.class.getName());
private static final int CALLBACK_MAX_BYTES_READ = 10 * 1024 * 1024;
private static final int CALLBACK_MAX_BYTES_WRITEN = CALLBACK_MAX_BYTES_READ;
private static final int MAX_ELEMENT_SIZE = 64 * 1024;
private final XmppTcpNioTransport tcpNioTransport;
private SelectionKey selectionKey;
private SelectionKeyAttachment selectionKeyAttachment;
private SocketChannel socketChannel;
private InetSocketAddress remoteAddress;
private TlsState tlsState;
private Iterator outgoingCharSequenceIterator;
private final List currentlyOutgoingElements = new ArrayList<>();
private final IdentityHashMap> bufferToElementMap = new IdentityHashMap<>();
private ByteBuffer outgoingBuffer;
private ByteBuffer filteredOutgoingBuffer;
private final List networkOutgoingBuffers = new ArrayList<>();
private long networkOutgoingBuffersBytes;
// TODO: Make the size of the incomingBuffer configurable.
private final ByteBuffer incomingBuffer = ByteBuffer.allocateDirect(2 * 4096);
private final ReentrantLock channelSelectedCallbackLock = new ReentrantLock();
private long totalBytesRead;
private long totalBytesWritten;
private long totalBytesReadAfterFilter;
private long totalBytesWrittenBeforeFilter;
private long handledChannelSelectedCallbacks;
private long callbackPreemtBecauseBytesWritten;
private long callbackPreemtBecauseBytesRead;
private int sslEngineDelegatedTasks;
private int maxPendingSslEngineDelegatedTasks;
// TODO: Use LongAdder once Smack's minimum Android API level is 24 or higher.
private final AtomicLong setWriteInterestAfterChannelSelectedCallback = new AtomicLong();
private final AtomicLong reactorThreadAlreadyRacing = new AtomicLong();
private final AtomicLong afterOutgoingElementsQueueModifiedSetInterestOps = new AtomicLong();
private final AtomicLong rejectedChannelSelectedCallbacks = new AtomicLong();
private Jid lastDestinationAddress;
private boolean pendingInputFilterData;
private boolean pendingOutputFilterData;
private boolean pendingWriteInterestAfterRead;
/**
* Note that this field is effective final, but due to https://stackoverflow.com/q/30360824/194894 we have to declare it non-final.
*/
private Utf8ByteXmppXmlSplitter splitter;
/**
* Note that this field is effective final, but due to https://stackoverflow.com/q/30360824/194894 we have to declare it non-final.
*/
private XmppXmlSplitter outputDebugSplitter;
private static final Level STREAM_OPEN_CLOSE_DEBUG_LOG_LEVEL = Level.FINER;
XmppTcpTransportModule(XmppTcpTransportModuleDescriptor moduleDescriptor, ModularXmppClientToServerConnectionInternal connectionInternal) {
super(moduleDescriptor, connectionInternal);
tcpNioTransport = new XmppTcpNioTransport(connectionInternal);
XmlPrinter incomingDebugPrettyPrinter = null;
final SmackDebugger debugger = connectionInternal.smackDebugger;
if (debugger != null) {
// Incoming stream debugging.
incomingDebugPrettyPrinter = XmlPrettyPrinter.builder()
.setPrettyWriter(sb -> debugger.incomingStreamSink(sb))
.build();
// Outgoing stream debugging.
XmlPrinter outgoingDebugPrettyPrinter = XmlPrettyPrinter.builder()
.setPrettyWriter(sb -> debugger.outgoingStreamSink(sb))
.build();
outputDebugSplitter = new XmppXmlSplitter(outgoingDebugPrettyPrinter);
}
XmppXmlSplitter xmppXmlSplitter = new XmppXmlSplitter(MAX_ELEMENT_SIZE, xmppElementCallback,
incomingDebugPrettyPrinter);
splitter = new Utf8ByteXmppXmlSplitter(xmppXmlSplitter);
}
private final XmppElementCallback xmppElementCallback = new XmppElementCallback() {
private String streamOpen;
private String streamClose;
@Override
public void onCompleteElement(String completeElement) {
assert streamOpen != null;
assert streamClose != null;
connectionInternal.withSmackDebugger(debugger -> debugger.onIncomingElementCompleted());
String wrappedCompleteElement = streamOpen + completeElement + streamClose;
connectionInternal.parseAndProcessElement(wrappedCompleteElement);
}
@Override
public void streamOpened(String prefix, Map attributes) {
if (LOGGER.isLoggable(STREAM_OPEN_CLOSE_DEBUG_LOG_LEVEL)) {
LOGGER.log(STREAM_OPEN_CLOSE_DEBUG_LOG_LEVEL,
"Stream of " + this + " opened. prefix=" + prefix + " attributes=" + attributes);
}
final String prefixXmlns = "xmlns:" + prefix;
// TODO: Use the return value of onStreamOpen(), which now returns the
// corresponding stream close tag, instead of creating it here.
final StringBuilder streamClose = new StringBuilder(32);
final StringBuilder streamOpen = new StringBuilder(256);
streamOpen.append('<');
streamClose.append("");
for (Map.Entry entry : attributes.entrySet()) {
String attributeName = entry.getKey();
String attributeValue = entry.getValue();
switch (attributeName) {
case "to":
case "from":
case "id":
case "version":
break;
case "xml:lang":
streamOpen.append(" xml:lang='").append(attributeValue).append('\'');
break;
case "xmlns":
streamOpen.append(" xmlns='").append(attributeValue).append('\'');
break;
default:
if (attributeName.equals(prefixXmlns)) {
streamOpen.append(' ').append(prefixXmlns).append("='").append(attributeValue).append('\'');
break;
}
LOGGER.info("Unknown sendElements = bufferToElementMap.remove(prunedBuffer);
if (sendElements == null) {
continue;
}
for (TopLevelStreamElement elementJustSend : sendElements) {
connectionInternal.fireFirstLevelElementSendListeners(elementJustSend);
}
}
// Prevent one callback from dominating the reactor thread. Break out of the write-loop if we have
// written a certain amount.
if (callbackBytesWritten > CALLBACK_MAX_BYTES_WRITEN) {
newInterestedOps |= SelectionKey.OP_WRITE;
callbackPreemtBecauseBytesWritten++;
break;
}
} else if (outgoingBuffer != null || pendingOutputFilterData) {
pendingOutputFilterData = false;
if (outgoingBuffer != null) {
totalBytesWrittenBeforeFilter += outgoingBuffer.remaining();
if (isLastPartOfElement) {
assert currentlyOutgonigTopLevelStreamElement != null;
currentlyOutgoingElements.add(currentlyOutgonigTopLevelStreamElement);
}
}
ByteBuffer outputFilterInputData = outgoingBuffer;
// We can now null the outgoingBuffer since the filter step will take care of it from now on.
outgoingBuffer = null;
for (ListIterator it = connectionInternal.getXmppInputOutputFilterBeginIterator(); it.hasNext();) {
XmppInputOutputFilter inputOutputFilter = it.next();
XmppInputOutputFilter.OutputResult outputResult;
try {
outputResult = inputOutputFilter.output(outputFilterInputData, isLastPartOfElement,
destinationAddressChanged, moreDataAvailable);
} catch (IOException e) {
connectionInternal.notifyConnectionError(e);
break writeLoop;
}
newPendingOutputFilterData |= outputResult.pendingFilterData;
outputFilterInputData = outputResult.filteredOutputData;
if (outputFilterInputData != null) {
((java.nio.Buffer) outputFilterInputData).flip();
}
}
// It is ok if outputFilterInputData is 'null' here, this is expected behavior.
if (outputFilterInputData != null && outputFilterInputData.hasRemaining()) {
filteredOutgoingBuffer = outputFilterInputData;
} else {
filteredOutgoingBuffer = null;
}
// If the filters did eventually not produce any output data but if there is
// pending output data then we have a pending write request after read.
if (filteredOutgoingBuffer == null && newPendingOutputFilterData) {
pendingWriteInterestAfterRead = true;
}
if (filteredOutgoingBuffer != null && isLastPartOfElement) {
bufferToElementMap.put(filteredOutgoingBuffer, new ArrayList<>(currentlyOutgoingElements));
currentlyOutgoingElements.clear();
}
// Reset that the destination address has changed.
if (destinationAddressChanged) {
destinationAddressChanged = false;
}
} else if (outgoingCharSequenceIterator != null) {
CharSequence nextCharSequence = outgoingCharSequenceIterator.next();
outgoingBuffer = UTF8.encode(nextCharSequence);
if (!outgoingCharSequenceIterator.hasNext()) {
outgoingCharSequenceIterator = null;
isLastPartOfElement = true;
} else {
isLastPartOfElement = false;
}
final SmackDebugger debugger = connectionInternal.smackDebugger;
if (debugger != null) {
if (outgoingStreamForDebugger == null) {
outgoingStreamForDebugger = new StringBuilder();
}
outgoingStreamForDebugger.append(nextCharSequence);
if (isLastPartOfElement) {
try {
outputDebugSplitter.append(outgoingStreamForDebugger);
} catch (IOException e) {
throw new AssertionError(e);
}
debugger.onOutgoingElementCompleted();
outgoingStreamForDebugger = null;
}
}
} else if (!connectionInternal.outgoingElementsQueue.isEmpty()) {
currentlyOutgonigTopLevelStreamElement = connectionInternal.outgoingElementsQueue.poll();
if (currentlyOutgonigTopLevelStreamElement instanceof Stanza) {
Stanza currentlyOutgoingStanza = (Stanza) currentlyOutgonigTopLevelStreamElement;
Jid currentDestinationAddress = currentlyOutgoingStanza.getTo();
destinationAddressChanged = !JidUtil.equals(lastDestinationAddress, currentDestinationAddress);
lastDestinationAddress = currentDestinationAddress;
}
CharSequence nextCharSequence = currentlyOutgonigTopLevelStreamElement.toXML(StreamOpen.CLIENT_NAMESPACE);
if (nextCharSequence instanceof XmlStringBuilder) {
XmlStringBuilder xmlStringBuilder = (XmlStringBuilder) nextCharSequence;
XmlEnvironment outgoingStreamXmlEnvironment = connectionInternal.getOutgoingStreamXmlEnvironment();
outgoingCharSequenceIterator = xmlStringBuilder.toList(outgoingStreamXmlEnvironment).iterator();
} else {
outgoingCharSequenceIterator = Collections.singletonList(nextCharSequence).iterator();
}
assert outgoingCharSequenceIterator != null;
} else {
// There is nothing more to write.
break;
}
}
pendingOutputFilterData = newPendingOutputFilterData;
if (!pendingWriteInterestAfterRead && pendingOutputFilterData) {
newInterestedOps |= SelectionKey.OP_WRITE;
}
readLoop: while (true) {
// Prevent one callback from dominating the reactor thread. Break out of the read-loop if we have
// read a certain amount.
if (callbackBytesRead > CALLBACK_MAX_BYTES_READ) {
callbackPreemtBecauseBytesRead++;
break;
}
int bytesRead;
((java.nio.Buffer) incomingBuffer).clear();
try {
bytesRead = selectedSocketChannel.read(incomingBuffer);
} catch (IOException e) {
handleReadWriteIoException(e);
return;
}
if (bytesRead < 0) {
LOGGER.finer("NIO read() returned " + bytesRead
+ " for " + this + ". This probably means that the TCP connection was terminated.");
// According to the socket channel javadoc section about "asynchronous reads" a socket channel's
// read() may return -1 if the input side of a socket is shut down.
// Note that we do not call notifyConnectionError() here because the connection may be
// cleanly shutdown which would also cause read() to return '-1. I assume that this socket
// will be selected again, on which read() would throw an IOException, which will be caught
// and invoke notifyConnectionError() (see a few lines above).
/*
IOException exception = new IOException("NIO read() returned " + bytesRead);
notifyConnectionError(exception);
*/
return;
}
if (!pendingInputFilterData) {
if (bytesRead == 0) {
// Nothing more to read.
break;
}
} else {
pendingInputFilterData = false;
}
if (pendingWriteInterestAfterRead) {
// We have successfully read something and someone announced a write interest after a read. It is
// now possible that a filter is now also able to write additional data (for example SSLEngine).
pendingWriteInterestAfterRead = false;
newInterestedOps |= SelectionKey.OP_WRITE;
}
callbackBytesRead += bytesRead;
ByteBuffer filteredIncomingBuffer = incomingBuffer;
for (ListIterator it = connectionInternal.getXmppInputOutputFilterEndIterator(); it.hasPrevious();) {
((java.nio.Buffer) filteredIncomingBuffer).flip();
ByteBuffer newFilteredIncomingBuffer;
try {
newFilteredIncomingBuffer = it.previous().input(filteredIncomingBuffer);
} catch (IOException e) {
connectionInternal.notifyConnectionError(e);
return;
}
if (newFilteredIncomingBuffer == null) {
break readLoop;
}
filteredIncomingBuffer = newFilteredIncomingBuffer;
}
((java.nio.Buffer) filteredIncomingBuffer).flip();
final int bytesReadAfterFilter = filteredIncomingBuffer.remaining();
totalBytesReadAfterFilter += bytesReadAfterFilter;
try {
splitter.write(filteredIncomingBuffer);
} catch (IOException e) {
connectionInternal.notifyConnectionError(e);
return;
}
}
} finally {
totalBytesWritten += callbackBytesWritten;
totalBytesRead += callbackBytesRead;
channelSelectedCallbackLock.unlock();
}
// Indicate that there is no reactor thread racing towards handling this selection key.
final SelectionKeyAttachment selectionKeyAttachment = this.selectionKeyAttachment;
if (selectionKeyAttachment != null) {
selectionKeyAttachment.resetReactorThreadRacing();
}
// Check the queue again to prevent lost wakeups caused by elements inserted before we
// called resetReactorThreadRacing() a few lines above.
if (!connectionInternal.outgoingElementsQueue.isEmpty()) {
setWriteInterestAfterChannelSelectedCallback.incrementAndGet();
newInterestedOps |= SelectionKey.OP_WRITE;
}
connectionInternal.setInterestOps(selectionKey, newInterestedOps);
}
private void handleReadWriteIoException(IOException e) {
if (e instanceof ClosedChannelException && !tcpNioTransport.isConnected()) {
// The connection is already closed.
return;
}
connectionInternal.notifyConnectionError(e);
}
/**
* This is the interface between the "lookup remote connection endpoints" state and the "establish TCP connection"
* state. The field is indirectly populated by {@link XmppTcpNioTransport#lookupConnectionEndpoints()} and consumed
* by {@link ConnectionAttemptState}.
*/
DiscoveredTcpEndpoints discoveredTcpEndpoints;
final class XmppTcpNioTransport extends XmppClientToServerTransport {
XmppTcpNioTransport(ModularXmppClientToServerConnectionInternal connectionInternal) {
super(connectionInternal);
}
@Override
public StreamOpenAndCloseFactory getStreamOpenAndCloseFactory() {
return new StreamOpenAndCloseFactory() {
@Override
public StreamOpen createStreamOpen(DomainBareJid to, CharSequence from, String id, String lang) {
String xmlLang = connectionInternal.connection.getConfiguration().getXmlLang();
StreamOpen streamOpen = new StreamOpen(to, from, id, xmlLang, StreamOpen.StreamContentNamespace.client);
return streamOpen;
}
@Override
public StreamClose createStreamClose() {
return StreamClose.INSTANCE;
}
};
}
@Override
protected void resetDiscoveredConnectionEndpoints() {
discoveredTcpEndpoints = null;
}
@Override
public boolean hasUseableConnectionEndpoints() {
return discoveredTcpEndpoints != null;
}
@Override
protected List> lookupConnectionEndpoints() {
// Assert that there are no stale discovered endpoints prior performing the lookup.
assert discoveredTcpEndpoints == null;
List> futures = new ArrayList<>(2);
InternalSmackFuture tcpEndpointsLookupFuture = new InternalSmackFuture<>();
connectionInternal.asyncGo(() -> {
Result result = RemoteXmppTcpConnectionEndpoints.lookup(
connectionInternal.connection.getConfiguration());
LookupConnectionEndpointsResult endpointsResult;
if (result.discoveredRemoteConnectionEndpoints.isEmpty()) {
endpointsResult = new TcpEndpointDiscoveryFailed(result);
} else {
endpointsResult = new DiscoveredTcpEndpoints(result);
}
tcpEndpointsLookupFuture.setResult(endpointsResult);
});
futures.add(tcpEndpointsLookupFuture);
if (moduleDescriptor.isDirectTlsEnabled()) {
// TODO: Implement this.
throw new IllegalArgumentException("DirectTLS is not implemented yet");
}
return futures;
}
@Override
protected void loadConnectionEndpoints(LookupConnectionEndpointsSuccess lookupConnectionEndpointsSuccess) {
// The API contract stats that we will be given the instance we handed out with lookupConnectionEndpoints,
// which must be of type DiscoveredTcpEndpoints here. Hence, if we can not cast it, then there is an internal
// Smack error.
discoveredTcpEndpoints = (DiscoveredTcpEndpoints) lookupConnectionEndpointsSuccess;
}
@Override
protected void afterFiltersClosed() {
pendingInputFilterData = pendingOutputFilterData = true;
afterOutgoingElementsQueueModified();
}
@Override
protected void disconnect() {
XmppTcpTransportModule.this.closeSocketAndCleanup();
}
@Override
protected void notifyAboutNewOutgoingElements() {
afterOutgoingElementsQueueModified();
}
@Override
public SSLSession getSslSession() {
TlsState tlsState = XmppTcpTransportModule.this.tlsState;
if (tlsState == null) {
return null;
}
return tlsState.engine.getSession();
}
public boolean isConnected() {
SocketChannel socketChannel = XmppTcpTransportModule.this.socketChannel;
if (socketChannel == null) {
return false;
}
return socketChannel.isConnected();
}
@Override
public boolean isTransportSecured() {
final TlsState tlsState = XmppTcpTransportModule.this.tlsState;
return tlsState != null && tlsState.handshakeStatus == TlsHandshakeStatus.successful;
}
@Override
public XmppTcpTransportModule.Stats getStats() {
return XmppTcpTransportModule.this.getStats();
}
final class DiscoveredTcpEndpoints implements LookupConnectionEndpointsSuccess {
final RemoteXmppTcpConnectionEndpoints.Result result;
DiscoveredTcpEndpoints(RemoteXmppTcpConnectionEndpoints.Result result) {
this.result = result;
}
}
final class TcpEndpointDiscoveryFailed implements LookupConnectionEndpointsFailed {
final List lookupFailures;
TcpEndpointDiscoveryFailed(RemoteXmppTcpConnectionEndpoints.Result result) {
lookupFailures = result.lookupFailures;
}
}
}
private void afterOutgoingElementsQueueModified() {
final SelectionKeyAttachment selectionKeyAttachment = this.selectionKeyAttachment;
if (selectionKeyAttachment != null && selectionKeyAttachment.isReactorThreadRacing()) {
// A reactor thread is already racing to the channel selected callback and will take care of this.
reactorThreadAlreadyRacing.incrementAndGet();
return;
}
afterOutgoingElementsQueueModifiedSetInterestOps.incrementAndGet();
// Add OP_WRITE to the interested Ops, since we have now new things to write. Note that this may cause
// multiple reactor threads to race to the channel selected callback in case we perform this right after
// a select() returned with this selection key in the selected-key set. Hence, we use tryLock() in the
// channel selected callback to keep the invariant that only exactly one thread is performing the
// callback.
// Note that we need to perform setInterestedOps() *without* holding the channelSelectedCallbackLock, as
// otherwise the reactor thread racing to the channel selected callback may found the lock still locked, which
// would result in the outgoingElementsQueue not being handled.
connectionInternal.setInterestOps(selectionKey, SelectionKey.OP_WRITE | SelectionKey.OP_READ);
}
@Override
protected XmppTcpNioTransport getTransport() {
return tcpNioTransport;
}
static final class EstablishingTcpConnectionStateDescriptor extends StateDescriptor {
private EstablishingTcpConnectionStateDescriptor() {
super(XmppTcpTransportModule.EstablishingTcpConnectionState.class);
addPredeccessor(LookupRemoteConnectionEndpointsStateDescriptor.class);
addSuccessor(EstablishTlsStateDescriptor.class);
addSuccessor(ConnectedButUnauthenticatedStateDescriptor.class);
}
@Override
protected XmppTcpTransportModule.EstablishingTcpConnectionState constructState(ModularXmppClientToServerConnectionInternal connectionInternal) {
XmppTcpTransportModule tcpTransportModule = connectionInternal.connection.getConnectionModuleFor(XmppTcpTransportModuleDescriptor.class);
return tcpTransportModule.constructEstablishingTcpConnectionState(this, connectionInternal);
}
}
private EstablishingTcpConnectionState constructEstablishingTcpConnectionState(
EstablishingTcpConnectionStateDescriptor stateDescriptor,
ModularXmppClientToServerConnectionInternal connectionInternal) {
return new EstablishingTcpConnectionState(stateDescriptor, connectionInternal);
}
final class EstablishingTcpConnectionState extends State.AbstractTransport {
private EstablishingTcpConnectionState(EstablishingTcpConnectionStateDescriptor stateDescriptor,
ModularXmppClientToServerConnectionInternal connectionInternal) {
super(tcpNioTransport, stateDescriptor, connectionInternal);
}
@Override
public StateTransitionResult.AttemptResult transitionInto(WalkStateGraphContext walkStateGraphContext)
throws InterruptedException, IOException, SmackException, XMPPException {
// The fields inetSocketAddress and failedAddresses are handed over from LookupHostAddresses to
// ConnectingToHost.
ConnectionAttemptState connectionAttemptState = new ConnectionAttemptState(connectionInternal, discoveredTcpEndpoints,
this);
StateTransitionResult.Failure failure = connectionAttemptState.establishTcpConnection();
if (failure != null) {
return failure;
}
socketChannel = connectionAttemptState.socketChannel;
remoteAddress = (InetSocketAddress) socketChannel.socket().getRemoteSocketAddress();
selectionKey = connectionInternal.registerWithSelector(socketChannel, SelectionKey.OP_READ,
XmppTcpTransportModule.this::onChannelSelected);
selectionKeyAttachment = (SelectionKeyAttachment) selectionKey.attachment();
connectionInternal.setTransport(tcpNioTransport);
// TODO: It appears this should be done in a generic way. I'd assume we always
// have to wait for stream features after the connection was established. If this is true then consider
// moving this into State.AbstractTransport. But I am not yet 100% positive that this is the case for every
// transport. Hence, keep it here for now.
connectionInternal.newStreamOpenWaitForFeaturesSequence("stream features after initial connection");
return new TcpSocketConnectedResult(remoteAddress);
}
@Override
public void resetState() {
closeSocketAndCleanup();
}
}
public static final class TcpSocketConnectedResult extends StateTransitionResult.Success {
private final InetSocketAddress remoteAddress;
private TcpSocketConnectedResult(InetSocketAddress remoteAddress) {
super("TCP connection established to " + remoteAddress);
this.remoteAddress = remoteAddress;
}
public InetSocketAddress getRemoteAddress() {
return remoteAddress;
}
}
public static final class TlsEstablishedResult extends StateTransitionResult.Success {
private TlsEstablishedResult(SSLEngine sslEngine) {
super("TLS established: " + sslEngine.getSession());
}
}
static final class EstablishTlsStateDescriptor extends StateDescriptor {
private EstablishTlsStateDescriptor() {
super(XmppTcpTransportModule.EstablishTlsState.class, "RFC 6120 § 5");
addSuccessor(ConnectedButUnauthenticatedStateDescriptor.class);
declarePrecedenceOver(ConnectedButUnauthenticatedStateDescriptor.class);
}
@Override
protected EstablishTlsState constructState(ModularXmppClientToServerConnectionInternal connectionInternal) {
XmppTcpTransportModule tcpTransportModule = connectionInternal.connection.getConnectionModuleFor(XmppTcpTransportModuleDescriptor.class);
return tcpTransportModule.constructEstablishingTlsState(this, connectionInternal);
}
}
private EstablishTlsState constructEstablishingTlsState(
EstablishTlsStateDescriptor stateDescriptor,
ModularXmppClientToServerConnectionInternal connectionInternal) {
return new EstablishTlsState(stateDescriptor, connectionInternal);
}
private final class EstablishTlsState extends State {
private EstablishTlsState(EstablishTlsStateDescriptor stateDescriptor,
ModularXmppClientToServerConnectionInternal connectionInternal) {
super(stateDescriptor, connectionInternal);
}
@Override
public StateTransitionResult.TransitionImpossible isTransitionToPossible(WalkStateGraphContext walkStateGraphContext)
throws SecurityRequiredByClientException, SecurityRequiredByServerException {
StartTls startTlsFeature = connectionInternal.connection.getFeature(StartTls.class);
SecurityMode securityMode = connectionInternal.connection.getConfiguration().getSecurityMode();
switch (securityMode) {
case required:
case ifpossible:
if (startTlsFeature == null) {
if (securityMode == SecurityMode.ifpossible) {
return new StateTransitionResult.TransitionImpossibleReason("Server does not announce support for TLS and we do not required it");
}
throw new SecurityRequiredByClientException();
}
// Allows transition by returning null.
return null;
case disabled:
if (startTlsFeature != null && startTlsFeature.required()) {
throw new SecurityRequiredByServerException();
}
return new StateTransitionResult.TransitionImpossibleReason("TLS disabled in client settings and server does not require it");
default:
throw new AssertionError("Unknown security mode: " + securityMode);
}
}
@Override
public StateTransitionResult.AttemptResult transitionInto(WalkStateGraphContext walkStateGraphContext)
throws IOException, InterruptedException, SmackException, XMPPException {
connectionInternal.sendAndWaitForResponse(StartTls.INSTANCE, TlsProceed.class, TlsFailure.class);
SmackTlsContext smackTlsContext = connectionInternal.getSmackTlsContext();
tlsState = new TlsState(smackTlsContext);
connectionInternal.addXmppInputOutputFilter(tlsState);
channelSelectedCallbackLock.lock();
try {
pendingOutputFilterData = true;
// The beginHandshake() is possibly not really required here, but it does not hurt either.
tlsState.engine.beginHandshake();
tlsState.handshakeStatus = TlsHandshakeStatus.initiated;
} finally {
channelSelectedCallbackLock.unlock();
}
connectionInternal.setInterestOps(selectionKey, SelectionKey.OP_WRITE | SelectionKey.OP_READ);
try {
tlsState.waitForHandshakeFinished();
} catch (CertificateException e) {
throw new SmackCertificateException(e);
}
connectionInternal.newStreamOpenWaitForFeaturesSequence("stream features after TLS established");
return new TlsEstablishedResult(tlsState.engine);
}
@Override
public void resetState() {
tlsState = null;
}
}
private enum TlsHandshakeStatus {
initial,
initiated,
successful,
failed,
}
private static final Level SSL_ENGINE_DEBUG_LOG_LEVEL = Level.FINEST;
private static void debugLogSslEngineResult(String operation, SSLEngineResult result) {
if (!LOGGER.isLoggable(SSL_ENGINE_DEBUG_LOG_LEVEL)) {
return;
}
LOGGER.log(SSL_ENGINE_DEBUG_LOG_LEVEL, "SSLEngineResult of " + operation + "(): " + result);
}
private final class TlsState implements XmppInputOutputFilter {
private static final int MAX_PENDING_OUTPUT_BYTES = 8096;
private final SmackTlsContext smackTlsContext;
private final SSLEngine engine;
private TlsHandshakeStatus handshakeStatus = TlsHandshakeStatus.initial;
private SSLException handshakeException;
private ByteBuffer myNetData;
private ByteBuffer peerAppData;
private final List pendingOutputData = new ArrayList<>();
private int pendingOutputBytes;
private ByteBuffer pendingInputData;
private final AtomicInteger pendingDelegatedTasks = new AtomicInteger();
private long wrapInBytes;
private long wrapOutBytes;
private long unwrapInBytes;
private long unwrapOutBytes;
private TlsState(SmackTlsContext smackTlsContext) throws IOException {
this.smackTlsContext = smackTlsContext;
// Call createSSLEngine()'s variant with two parameters as this allows for TLS session resumption.
// Note that it is not really clear what the value of peer host should be. It could be A) the XMPP service's
// domainpart or B) the DNS name of the host we are connecting to (usually the DNS SRV RR target name). While
// the javadoc of createSSLEngine(String, int) indicates with "Some cipher suites (such as Kerberos) require
// remote hostname information, in which case peerHost needs to be specified." that A should be used. TLS
// session resumption may would need or at least benefit from B. Variant A would also be required if the
// String is used for certificate verification. And it appears at least likely that TLS session resumption
// would not be hurt by using variant A. Therefore we currently use variant A.
// TODO: Should we use the ACE representation of the XMPP service domain? Compare with f60e4055ec529f0b8160acedf13275592ab10a4b
// If yes, then we should probably introduce getXmppServiceDomainAceEncodedIfPossible().
String peerHost = connectionInternal.connection.getConfiguration().getXMPPServiceDomain().toString();
engine = smackTlsContext.sslContext.createSSLEngine(peerHost, remoteAddress.getPort());
engine.setUseClientMode(true);
SSLSession session = engine.getSession();
int applicationBufferSize = session.getApplicationBufferSize();
int packetBufferSize = session.getPacketBufferSize();
myNetData = ByteBuffer.allocateDirect(packetBufferSize);
peerAppData = ByteBuffer.allocate(applicationBufferSize);
}
@Override
public OutputResult output(ByteBuffer outputData, boolean isFinalDataOfElement, boolean destinationAddressChanged,
boolean moreDataAvailable) throws SSLException {
if (outputData != null) {
pendingOutputData.add(outputData);
pendingOutputBytes += outputData.remaining();
if (moreDataAvailable && pendingOutputBytes < MAX_PENDING_OUTPUT_BYTES) {
return OutputResult.NO_OUTPUT;
}
}
ByteBuffer[] outputDataArray = pendingOutputData.toArray(new ByteBuffer[pendingOutputData.size()]);
((java.nio.Buffer) myNetData).clear();
while (true) {
SSLEngineResult result;
try {
result = engine.wrap(outputDataArray, myNetData);
} catch (SSLException e) {
handleSslException(e);
throw e;
}
debugLogSslEngineResult("wrap", result);
SSLEngineResult.Status engineResultStatus = result.getStatus();
pendingOutputBytes -= result.bytesConsumed();
if (engineResultStatus == SSLEngineResult.Status.OK) {
wrapInBytes += result.bytesConsumed();
wrapOutBytes += result.bytesProduced();
SSLEngineResult.HandshakeStatus handshakeStatus = handleHandshakeStatus(result);
switch (handshakeStatus) {
case NEED_UNWRAP:
// NEED_UNWRAP means that we need to receive something in order to continue the handshake. The
// standard channelSelectedCallback logic will take care of this, as there is eventually always
// a interest to read from the socket.
break;
case NEED_WRAP:
// Same as need task: Cycle the reactor.
case NEED_TASK:
// Note that we also set pendingOutputFilterData in the OutputResult in the NEED_TASK case, as
// we also want to retry the wrap() operation above in this case.
return new OutputResult(true, myNetData);
default:
break;
}
}
switch (engineResultStatus) {
case OK:
// No need to outputData.compact() here, since we do not reuse the buffer.
// Clean up the pending output data.
pruneBufferList(pendingOutputData);
return new OutputResult(!pendingOutputData.isEmpty(), myNetData);
case CLOSED:
pendingOutputData.clear();
return OutputResult.NO_OUTPUT;
case BUFFER_OVERFLOW:
LOGGER.warning("SSLEngine status BUFFER_OVERFLOW, this is hopefully uncommon");
int outputDataRemaining = outputData != null ? outputData.remaining() : 0;
int newCapacity = (int) (1.3 * outputDataRemaining);
// If newCapacity would not increase myNetData, then double it.
if (newCapacity <= myNetData.capacity()) {
newCapacity = 2 * myNetData.capacity();
}
ByteBuffer newMyNetData = ByteBuffer.allocateDirect(newCapacity);
((java.nio.Buffer) myNetData).flip();
newMyNetData.put(myNetData);
myNetData = newMyNetData;
continue;
case BUFFER_UNDERFLOW:
throw new IllegalStateException(
"Buffer underflow as result of SSLEngine.wrap() should never happen");
}
}
}
@SuppressWarnings("ReferenceEquality")
@Override
public ByteBuffer input(ByteBuffer inputData) throws SSLException {
ByteBuffer accumulatedData;
if (pendingInputData == null) {
accumulatedData = inputData;
} else {
assert pendingInputData != inputData;
int accumulatedDataBytes = pendingInputData.remaining() + inputData.remaining();
accumulatedData = ByteBuffer.allocate(accumulatedDataBytes);
accumulatedData.put(pendingInputData)
.put(inputData);
((java.nio.Buffer) accumulatedData).flip();
pendingInputData = null;
}
((java.nio.Buffer) peerAppData).clear();
while (true) {
SSLEngineResult result;
try {
result = engine.unwrap(accumulatedData, peerAppData);
} catch (SSLException e) {
handleSslException(e);
throw e;
}
debugLogSslEngineResult("unwrap", result);
SSLEngineResult.Status engineResultStatus = result.getStatus();
if (engineResultStatus == SSLEngineResult.Status.OK) {
unwrapInBytes += result.bytesConsumed();
unwrapOutBytes += result.bytesProduced();
SSLEngineResult.HandshakeStatus handshakeStatus = handleHandshakeStatus(result);
switch (handshakeStatus) {
case NEED_TASK:
// A delegated task is asynchronously running. Take care of the remaining accumulatedData.
addAsPendingInputData(accumulatedData);
// Return here, as the async task created by handleHandshakeStatus will continue calling the
// channelSelectedCallback.
return null;
case NEED_UNWRAP:
continue;
case NEED_WRAP:
// NEED_WRAP means that the SSLEngine needs to send data, probably without consuming data.
// We exploit here the fact that the channelSelectedCallback is single threaded and that the
// input processing is after the output processing.
addAsPendingInputData(accumulatedData);
// Note that it is ok that we the provided argument for pending input filter data to channel
// selected callback is false, as setPendingInputFilterData() will have set the internal state
// boolean accordingly.
connectionInternal.asyncGo(() -> callChannelSelectedCallback(false, true));
// Do not break here, but instead return and let the asynchronously invoked
// callChannelSelectedCallback() do its work.
return null;
default:
break;
}
}
switch (engineResultStatus) {
case OK:
// SSLEngine's unwrap() may not consume all bytes from the source buffer. If this is the case, then
// simply perform another unwrap until accumulatedData has no remaining bytes.
if (accumulatedData.hasRemaining()) {
continue;
}
return peerAppData;
case CLOSED:
return null;
case BUFFER_UNDERFLOW:
// There were not enough source bytes available to make a complete packet. Let it in
// pendingInputData. Note that we do not resize SSLEngine's source buffer - inputData in our case -
// as it is not possible.
addAsPendingInputData(accumulatedData);
return null;
case BUFFER_OVERFLOW:
int applicationBufferSize = engine.getSession().getApplicationBufferSize();
assert peerAppData.remaining() < applicationBufferSize;
peerAppData = ByteBuffer.allocate(applicationBufferSize);
continue;
}
}
}
private void addAsPendingInputData(ByteBuffer byteBuffer) {
// Note that we can not simply write
// pendingInputData = byteBuffer;
// we have to copy the provided byte buffer, because it is possible that this byteBuffer is re-used by some
// higher layer. That is, here 'byteBuffer' is typically 'incomingBuffer', which is a direct buffer only
// allocated once per connection for performance reasons and hence re-used for read() calls.
pendingInputData = ByteBuffer.allocate(byteBuffer.remaining());
pendingInputData.put(byteBuffer);
((java.nio.Buffer) pendingInputData).flip();
pendingInputFilterData = pendingInputData.hasRemaining();
}
private SSLEngineResult.HandshakeStatus handleHandshakeStatus(SSLEngineResult sslEngineResult) {
SSLEngineResult.HandshakeStatus handshakeStatus = sslEngineResult.getHandshakeStatus();
switch (handshakeStatus) {
case NEED_TASK:
while (true) {
final Runnable delegatedTask = engine.getDelegatedTask();
if (delegatedTask == null) {
break;
}
sslEngineDelegatedTasks++;
int currentPendingDelegatedTasks = pendingDelegatedTasks.incrementAndGet();
if (currentPendingDelegatedTasks > maxPendingSslEngineDelegatedTasks) {
maxPendingSslEngineDelegatedTasks = currentPendingDelegatedTasks;
}
Runnable wrappedDelegatedTask = () -> {
delegatedTask.run();
int wrappedCurrentPendingDelegatedTasks = pendingDelegatedTasks.decrementAndGet();
if (wrappedCurrentPendingDelegatedTasks == 0) {
callChannelSelectedCallback(true, true);
}
};
connectionInternal.asyncGo(wrappedDelegatedTask);
}
break;
case FINISHED:
onHandshakeFinished();
break;
default:
break;
}
SSLEngineResult.HandshakeStatus afterHandshakeStatus = engine.getHandshakeStatus();
return afterHandshakeStatus;
}
private void handleSslException(SSLException e) {
handshakeException = e;
handshakeStatus = TlsHandshakeStatus.failed;
connectionInternal.notifyWaitingThreads();
}
private void onHandshakeFinished() {
handshakeStatus = TlsHandshakeStatus.successful;
connectionInternal.notifyWaitingThreads();
}
private boolean isHandshakeFinished() {
return handshakeStatus == TlsHandshakeStatus.successful || handshakeStatus == TlsHandshakeStatus.failed;
}
private void waitForHandshakeFinished() throws InterruptedException, CertificateException, SSLException, SmackException, XMPPException {
connectionInternal.waitForConditionOrThrowConnectionException(() -> isHandshakeFinished(), "TLS handshake to finish");
if (handshakeStatus == TlsHandshakeStatus.failed) {
throw handshakeException;
}
assert handshakeStatus == TlsHandshakeStatus.successful;
if (smackTlsContext.daneVerifier != null) {
smackTlsContext.daneVerifier.finish(engine.getSession());
}
}
@Override
public Object getStats() {
return new TlsStateStats(this);
}
@Override
public void closeInputOutput() {
engine.closeOutbound();
try {
engine.closeInbound();
} catch (SSLException e) {
LOGGER.log(Level.FINEST,
"SSLException when closing inbound TLS session. This can likely be ignored if a possible truncation attack is suggested."
+ " You may want to ask your XMPP server vendor to implement a clean TLS session shutdown sending close_notify after ",
e);
}
}
@Override
public void waitUntilInputOutputClosed() throws IOException, CertificateException, InterruptedException,
SmackException, XMPPException {
waitForHandshakeFinished();
}
@Override
public String getFilterName() {
return "TLS (" + engine + ')';
}
}
public static final class TlsStateStats {
public final long wrapInBytes;
public final long wrapOutBytes;
public final double wrapRatio;
public final long unwrapInBytes;
public final long unwrapOutBytes;
public final double unwrapRatio;
private TlsStateStats(TlsState tlsState) {
wrapOutBytes = tlsState.wrapOutBytes;
wrapInBytes = tlsState.wrapInBytes;
wrapRatio = (double) wrapOutBytes / wrapInBytes;
unwrapOutBytes = tlsState.unwrapOutBytes;
unwrapInBytes = tlsState.unwrapInBytes;
unwrapRatio = (double) unwrapInBytes / unwrapOutBytes;
}
private transient String toStringCache;
@Override
public String toString() {
if (toStringCache != null) {
return toStringCache;
}
toStringCache =
"wrap-in-bytes: " + wrapInBytes + '\n'
+ "wrap-out-bytes: " + wrapOutBytes + '\n'
+ "wrap-ratio: " + wrapRatio + '\n'
+ "unwrap-in-bytes: " + unwrapInBytes + '\n'
+ "unwrap-out-bytes: " + unwrapOutBytes + '\n'
+ "unwrap-ratio: " + unwrapRatio + '\n'
;
return toStringCache;
}
}
private void callChannelSelectedCallback(boolean setPendingInputFilterData, boolean setPendingOutputFilterData) {
final SocketChannel channel = socketChannel;
final SelectionKey key = selectionKey;
if (channel == null || key == null) {
LOGGER.info("Not calling channel selected callback because the connection was eventually disconnected");
return;
}
channelSelectedCallbackLock.lock();
try {
// Note that it is important that we send the pending(Input|Output)FilterData flags while holding the lock.
if (setPendingInputFilterData) {
pendingInputFilterData = true;
}
if (setPendingOutputFilterData) {
pendingOutputFilterData = true;
}
onChannelSelected(channel, key);
} finally {
channelSelectedCallbackLock.unlock();
}
}
private void closeSocketAndCleanup() {
final SelectionKey selectionKey = this.selectionKey;
if (selectionKey != null) {
selectionKey.cancel();
}
final SocketChannel socketChannel = this.socketChannel;
if (socketChannel != null) {
try {
socketChannel.close();
} catch (IOException e) {
LOGGER.log(Level.FINE, "Closing the socket channel failed", e);
}
}
this.selectionKey = null;
this.socketChannel = null;
selectionKeyAttachment = null;
remoteAddress = null;
}
private static List pruneBufferList(Collection buffers) {
return CollectionUtil.removeUntil(buffers, b -> b.hasRemaining());
}
public XmppTcpTransportModule.Stats getStats() {
return new Stats(this);
}
public static final class Stats extends XmppClientToServerTransport.Stats {
public final long totalBytesWritten;
public final long totalBytesWrittenBeforeFilter;
public final double writeRatio;
public final long totalBytesRead;
public final long totalBytesReadAfterFilter;
public final double readRatio;
public final long handledChannelSelectedCallbacks;
public final long setWriteInterestAfterChannelSelectedCallback;
public final long reactorThreadAlreadyRacing;
public final long afterOutgoingElementsQueueModifiedSetInterestOps;
public final long rejectedChannelSelectedCallbacks;
public final long totalCallbackRequests;
public final long callbackPreemtBecauseBytesWritten;
public final long callbackPreemtBecauseBytesRead;
public final int sslEngineDelegatedTasks;
public final int maxPendingSslEngineDelegatedTasks;
private Stats(XmppTcpTransportModule connection) {
totalBytesWritten = connection.totalBytesWritten;
totalBytesWrittenBeforeFilter = connection.totalBytesWrittenBeforeFilter;
writeRatio = (double) totalBytesWritten / totalBytesWrittenBeforeFilter;
totalBytesReadAfterFilter = connection.totalBytesReadAfterFilter;
totalBytesRead = connection.totalBytesRead;
readRatio = (double) totalBytesRead / totalBytesReadAfterFilter;
handledChannelSelectedCallbacks = connection.handledChannelSelectedCallbacks;
setWriteInterestAfterChannelSelectedCallback = connection.setWriteInterestAfterChannelSelectedCallback.get();
reactorThreadAlreadyRacing = connection.reactorThreadAlreadyRacing.get();
afterOutgoingElementsQueueModifiedSetInterestOps = connection.afterOutgoingElementsQueueModifiedSetInterestOps
.get();
rejectedChannelSelectedCallbacks = connection.rejectedChannelSelectedCallbacks.get();
totalCallbackRequests = handledChannelSelectedCallbacks + rejectedChannelSelectedCallbacks;
callbackPreemtBecauseBytesRead = connection.callbackPreemtBecauseBytesRead;
callbackPreemtBecauseBytesWritten = connection.callbackPreemtBecauseBytesWritten;
sslEngineDelegatedTasks = connection.sslEngineDelegatedTasks;
maxPendingSslEngineDelegatedTasks = connection.maxPendingSslEngineDelegatedTasks;
}
private transient String toStringCache;
@Override
public String toString() {
if (toStringCache != null) {
return toStringCache;
}
toStringCache =
"Total bytes\n"
+ "recv: " + totalBytesRead + '\n'
+ "send: " + totalBytesWritten + '\n'
+ "recv-aft-filter: " + totalBytesReadAfterFilter + '\n'
+ "send-bef-filter: " + totalBytesWrittenBeforeFilter + '\n'
+ "read-ratio: " + readRatio + '\n'
+ "write-ratio: " + writeRatio + '\n'
+ "Events\n"
+ "total-callback-requests: " + totalCallbackRequests + '\n'
+ "handled-channel-selected-callbacks: " + handledChannelSelectedCallbacks + '\n'
+ "rejected-channel-selected-callbacks: " + rejectedChannelSelectedCallbacks + '\n'
+ "set-write-interest-after-callback: " + setWriteInterestAfterChannelSelectedCallback + '\n'
+ "reactor-thread-already-racing: " + reactorThreadAlreadyRacing + '\n'
+ "after-queue-modified-set-interest-ops: " + afterOutgoingElementsQueueModifiedSetInterestOps + '\n'
+ "callback-preemt-because-bytes-read: " + callbackPreemtBecauseBytesRead + '\n'
+ "callback-preemt-because-bytes-written: " + callbackPreemtBecauseBytesWritten + '\n'
+ "ssl-engine-delegated-tasks: " + sslEngineDelegatedTasks + '\n'
+ "max-pending-ssl-engine-delegated-tasks: " + maxPendingSslEngineDelegatedTasks + '\n'
;
return toStringCache;
}
}
}