org.apache.sshd.common.channel.AbstractChannel Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.sshd.common.channel;
import java.io.EOFException;
import java.io.IOException;
import java.time.Duration;
import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.Function;
import java.util.function.IntUnaryOperator;
import org.apache.sshd.common.AttributeRepository;
import org.apache.sshd.common.Closeable;
import org.apache.sshd.common.FactoryManager;
import org.apache.sshd.common.PropertyResolver;
import org.apache.sshd.common.SshConstants;
import org.apache.sshd.common.channel.exception.SshChannelInvalidPacketException;
import org.apache.sshd.common.channel.throttle.ChannelStreamWriterResolver;
import org.apache.sshd.common.channel.throttle.ChannelStreamWriterResolverManager;
import org.apache.sshd.common.future.CloseFuture;
import org.apache.sshd.common.future.DefaultCloseFuture;
import org.apache.sshd.common.future.SshFutureListener;
import org.apache.sshd.common.io.AbstractIoWriteFuture;
import org.apache.sshd.common.io.IoWriteFuture;
import org.apache.sshd.common.session.ConnectionService;
import org.apache.sshd.common.session.Session;
import org.apache.sshd.common.util.EventListenerUtils;
import org.apache.sshd.common.util.ExceptionUtils;
import org.apache.sshd.common.util.GenericUtils;
import org.apache.sshd.common.util.ValidateUtils;
import org.apache.sshd.common.util.buffer.Buffer;
import org.apache.sshd.common.util.buffer.BufferUtils;
import org.apache.sshd.common.util.closeable.AbstractInnerCloseable;
import org.apache.sshd.common.util.closeable.IoBaseCloseable;
import org.apache.sshd.common.util.closeable.SimpleCloseable;
import org.apache.sshd.common.util.functors.Int2IntFunction;
import org.apache.sshd.common.util.io.IoUtils;
import org.apache.sshd.common.util.io.functors.Invoker;
import org.apache.sshd.common.util.threads.CloseableExecutorService;
import org.apache.sshd.common.util.threads.ExecutorServiceCarrier;
import org.apache.sshd.core.CoreModuleProperties;
/**
* Provides common client/server channel functionality
*
* @author Apache MINA SSHD Project
*/
public abstract class AbstractChannel extends AbstractInnerCloseable implements Channel, ExecutorServiceCarrier {
/**
* Default growth factor function used to resize response buffers
*/
public static final IntUnaryOperator RESPONSE_BUFFER_GROWTH_FACTOR = Int2IntFunction.add(Byte.SIZE);
/**
* A default {@link PacketValidator} that enforces that the packet size is not greater than the maximum packet size
* of the channel's local window.
*/
// Plus 4 because there seems to be some confusion about whether or not the maximum packet size for a channel
// includes the packet length field itself.
public static final PacketValidator DEFAULT_PACKET_VALIDATOR = (
packetSize, maxPacketSize, extendedData) -> packetSize <= maxPacketSize + 4;
protected enum GracefulState {
Opened,
CloseSent,
CloseReceived,
Closed
}
protected ConnectionService service;
protected final AtomicBoolean initialized = new AtomicBoolean(false);
protected final AtomicBoolean eofReceived = new AtomicBoolean(false);
/**
* Obsolete and unused; present only for API backwards compatibility. Use {@link #isEofSent()} to determine whether
* EOF is already sent on this channel, and {@link #sendEof()} to send EOF. The latter will return {@code null} if
* EOF already was sent.
*
* @deprecated since 2.10.1
*/
@Deprecated
protected final AtomicBoolean eofSent = new AtomicBoolean(false);
protected final AtomicBoolean unregisterSignaled = new AtomicBoolean(false);
protected final AtomicBoolean closeSignaled = new AtomicBoolean(false);
protected AtomicReference gracefulState = new AtomicReference<>(GracefulState.Opened);
protected final DefaultCloseFuture gracefulFuture;
/**
* Channel events listener
*/
protected final Collection channelListeners = new CopyOnWriteArraySet<>();
protected final ChannelListener channelListenerProxy;
// Our id for this channel
private long id = -1L;
// The peer's id for the channel. For an AbstractClientChannel, set when the SSH_MSG_CHANNEL_OPEN_CONFIRMATION is
// received.
private long recipient = -1L;
private Session sessionInstance;
private CloseableExecutorService executor;
private final List> requestHandlers = new CopyOnWriteArrayList<>();
private final LocalWindow localWindow;
private final RemoteWindow remoteWindow;
private ChannelStreamWriterResolver channelStreamPacketWriterResolver;
private AtomicReference eofFuture = new AtomicReference<>();
private PacketValidator packetValidator = DEFAULT_PACKET_VALIDATOR;
/**
* A {@link Map} of sent requests - key = request name, value = timestamp when request was sent.
*/
private final Map pendingRequests = new ConcurrentHashMap<>();
private final Map properties = new ConcurrentHashMap<>();
private final Map, Object> attributes = new ConcurrentHashMap<>();
protected AbstractChannel(boolean client) {
this("", client);
}
protected AbstractChannel(boolean client, Collection> handlers) {
this("", client, handlers, null);
}
protected AbstractChannel(String discriminator, boolean client) {
this(discriminator, client, Collections.emptyList(), null);
}
protected AbstractChannel(String discriminator, boolean client,
Collection> handlers,
CloseableExecutorService executorService) {
super(discriminator);
gracefulFuture = new DefaultCloseFuture(discriminator, futureLock);
localWindow = new LocalWindow(this, client);
remoteWindow = new RemoteWindow(this, client);
channelListenerProxy = EventListenerUtils.proxyWrapper(ChannelListener.class, channelListeners);
executor = executorService;
addRequestHandlers(handlers);
}
@Override
public List> getRequestHandlers() {
return requestHandlers;
}
@Override
public void addRequestHandler(RequestHandler handler) {
requestHandlers.add(Objects.requireNonNull(handler, "No handler instance"));
}
@Override
public void removeRequestHandler(RequestHandler handler) {
requestHandlers.remove(Objects.requireNonNull(handler, "No handler instance"));
}
@Override
public long getChannelId() {
return id;
}
@Override
public long getRecipient() {
return recipient;
}
protected void setRecipient(long recipient) {
if (log.isDebugEnabled()) {
log.debug("setRecipient({}) recipient={}", this, recipient);
}
this.recipient = recipient;
}
@Override
public LocalWindow getLocalWindow() {
return localWindow;
}
@Override
public RemoteWindow getRemoteWindow() {
return remoteWindow;
}
@Override
public Session getSession() {
return sessionInstance;
}
@Override
public PropertyResolver getParentPropertyResolver() {
return getSession();
}
@Override
public CloseableExecutorService getExecutorService() {
return executor;
}
@Override
public ChannelStreamWriterResolver getChannelStreamWriterResolver() {
return channelStreamPacketWriterResolver;
}
@Override
public void setChannelStreamWriterResolver(ChannelStreamWriterResolver resolver) {
channelStreamPacketWriterResolver = resolver;
}
@Override
public ChannelStreamWriterResolver resolveChannelStreamWriterResolver() {
ChannelStreamWriterResolver resolver = getChannelStreamWriterResolver();
if (resolver != null) {
return resolver;
}
ChannelStreamWriterResolverManager manager = getSession();
return manager.resolveChannelStreamWriterResolver();
}
/**
* Add a channel request to the tracked pending ones if reply is expected
*
* @param request The request type
* @param wantReply {@code true} if reply is expected
* @return The allocated {@link Date} timestamp - {@code null} if no reply is expected (in
* which case the request is not tracked)
* @throws IllegalArgumentException If the request is already being tracked
* @see #removePendingRequest(String)
*/
protected Date addPendingRequest(String request, boolean wantReply) {
if (!wantReply) {
return null;
}
Date pending = new Date(System.currentTimeMillis());
Date prev = pendingRequests.put(request, pending);
ValidateUtils.checkTrue(prev == null, "Multiple pending requests of type=%s", request);
if (log.isDebugEnabled()) {
log.debug("addPendingRequest({}) request={}, pending={}", this, request, pending);
}
return pending;
}
/**
* Removes a channel request from the tracked ones
*
* @param request The request type
* @return The allocated {@link Date} timestamp - {@code null} if the specified request type is not being
* tracked or has not been added to the tracked ones to begin with
* @see #addPendingRequest(String, boolean)
*/
protected Date removePendingRequest(String request) {
Date pending = pendingRequests.remove(request);
if (log.isDebugEnabled()) {
log.debug("removePendingRequest({}) request={}, pending={}", this, request, pending);
}
return pending;
}
@Override
public void handleRequest(Buffer buffer) throws IOException {
handleChannelRequest(buffer.getString(), buffer.getBoolean(), buffer);
}
protected void handleChannelRequest(String req, boolean wantReply, Buffer buffer) throws IOException {
boolean debugEnabled = log.isDebugEnabled();
if (debugEnabled) {
log.debug("handleChannelRequest({}) SSH_MSG_CHANNEL_REQUEST {} wantReply={}", this, req, wantReply);
}
Collection> handlers = getRequestHandlers();
boolean traceEnabled = log.isTraceEnabled();
for (RequestHandler handler : handlers) {
RequestHandler.Result result;
try {
result = handler.process(this, req, wantReply, buffer);
} catch (Throwable e) {
debug("handleRequest({}) {} while {}#process({})[want-reply={}]: {}", this,
e.getClass().getSimpleName(), handler.getClass().getSimpleName(), req, wantReply,
e.getMessage(), e);
result = RequestHandler.Result.ReplyFailure;
}
// if Unsupported then check the next handler in line
if (RequestHandler.Result.Unsupported.equals(result)) {
if (traceEnabled) {
log.trace("handleRequest({})[{}#process({})[want-reply={}]]: {}", this,
handler.getClass().getSimpleName(), req, wantReply, result);
}
} else {
sendResponse(buffer, req, result, wantReply);
return;
}
}
// none of the handlers processed the request
handleUnknownChannelRequest(req, wantReply, buffer);
}
/**
* Called when none of the register request handlers reported handling the request
*
* @param req The request type
* @param wantReply Whether reply is requested
* @param buffer The {@link Buffer} containing extra request-specific data
* @throws IOException If failed to send the response (if needed)
* @see #handleInternalRequest(String, boolean, Buffer)
*/
protected void handleUnknownChannelRequest(String req, boolean wantReply, Buffer buffer) throws IOException {
RequestHandler.Result r = handleInternalRequest(req, wantReply, buffer);
if ((r == null) || RequestHandler.Result.Unsupported.equals(r)) {
log.warn("handleUnknownChannelRequest({}) Unknown channel request: {}[want-reply={}]", this, req,
wantReply);
sendResponse(buffer, req, RequestHandler.Result.Unsupported, wantReply);
} else {
sendResponse(buffer, req, r, wantReply);
}
}
/**
* Called by {@link #handleUnknownChannelRequest(String, boolean, Buffer)} in order to allow channel request
* handling if none of the registered handlers processed the request - last chance.
*
* @param req The request type
* @param wantReply Whether reply is requested
* @param buffer The {@link Buffer} containing extra request-specific data
* @return The handling result - if {@code null} or {@code Unsupported} and reply is required then a
* failure message will be sent
* @throws IOException If failed to process the request internally
*/
protected RequestHandler.Result handleInternalRequest(String req, boolean wantReply, Buffer buffer)
throws IOException {
if (req.startsWith("keepalive@") || req.startsWith("keep-alive@")) {
if (log.isDebugEnabled()) {
log.debug("handleInternalRequest({})[want-reply={}] received keep-alive: {}", this, wantReply, req);
}
return RequestHandler.Result.ReplySuccess;
}
if (log.isDebugEnabled()) {
log.debug("handleInternalRequest({})[want-reply={}] unknown type: {}", this, wantReply, req);
}
return RequestHandler.Result.Unsupported;
}
protected IoWriteFuture sendResponse(Buffer buffer, String req, RequestHandler.Result result, boolean wantReply)
throws IOException {
if (log.isDebugEnabled()) {
log.debug("sendResponse({}) request={} result={}, want-reply={}", this, req, result, wantReply);
}
if (RequestHandler.Result.Replied.equals(result) || (!wantReply)) {
return AbstractIoWriteFuture.fulfilled(req, Boolean.TRUE);
}
byte cmd = RequestHandler.Result.ReplySuccess.equals(result)
? SshConstants.SSH_MSG_CHANNEL_SUCCESS
: SshConstants.SSH_MSG_CHANNEL_FAILURE;
Session session = getSession();
Buffer rsp = session.createBuffer(cmd, Integer.BYTES);
rsp.putUInt(recipient);
return session.writePacket(rsp);
}
@Override
public void init(ConnectionService service, Session session, long id) throws IOException {
if (log.isDebugEnabled()) {
log.debug("init() service={} session={} id={}", service, session, id);
}
this.service = service;
this.sessionInstance = session;
this.id = id;
signalChannelInitialized();
configureWindow();
initialized.set(true);
}
protected void signalChannelInitialized() throws IOException {
try {
invokeChannelSignaller(l -> {
signalChannelInitialized(l);
return null;
});
notifyStateChanged("init");
} catch (Throwable err) {
Throwable e = ExceptionUtils.peelException(err);
if (e instanceof IOException) {
throw (IOException) e;
} else if (e instanceof RuntimeException) {
throw (RuntimeException) e;
} else {
throw new IOException("Failed (" + e.getClass().getSimpleName() + ") to notify channel " + this
+ " initialization: " + e.getMessage(),
e);
}
}
}
protected void signalChannelInitialized(ChannelListener listener) {
if (listener == null) {
return;
}
listener.channelInitialized(this);
}
protected void signalChannelOpenSuccess() {
try {
invokeChannelSignaller(l -> {
signalChannelOpenSuccess(l);
return null;
});
} catch (Error | RuntimeException err) {
throw err;
} catch (Throwable err) {
throw new IllegalStateException(err);
}
}
protected void signalChannelOpenSuccess(ChannelListener listener) {
if (listener == null) {
return;
}
listener.channelOpenSuccess(this);
}
@Override
public boolean isInitialized() {
return initialized.get();
}
@Override
public void handleChannelRegistrationResult(
ConnectionService service, Session session, long channelId,
boolean registered) {
notifyStateChanged("registered=" + registered);
if (registered) {
return;
}
RuntimeException reason = new IllegalStateException(
"Channel id=" + channelId + " not registered because session is being closed: " + this);
signalChannelClosed(reason);
throw reason;
}
protected void signalChannelOpenFailure(Throwable reason) {
try {
invokeChannelSignaller(l -> {
signalChannelOpenFailure(l, reason);
return null;
});
} catch (Throwable err) {
Throwable ignored = ExceptionUtils.peelException(err);
debug("signalChannelOpenFailure({}) failed ({}) to inform listener of open failure={}: {}", this,
ignored.getClass().getSimpleName(), reason.getClass().getSimpleName(), ignored.getMessage(),
ignored);
}
}
protected void signalChannelOpenFailure(ChannelListener listener, Throwable reason) {
if (listener == null) {
return;
}
listener.channelOpenFailure(this, reason);
}
protected void notifyStateChanged(String hint) {
try {
invokeChannelSignaller(l -> {
notifyStateChanged(l, hint);
return null;
});
} catch (Throwable err) {
Throwable e = ExceptionUtils.peelException(err);
debug("notifyStateChanged({})[{}] {} while signal channel state change: {}", this, hint,
e.getClass().getSimpleName(), e.getMessage(), e);
} finally {
synchronized (futureLock) {
futureLock.notifyAll();
}
}
}
protected void notifyStateChanged(ChannelListener listener, String hint) {
if (listener == null) {
return;
}
listener.channelStateChanged(this, hint);
}
@Override
public void addChannelListener(ChannelListener listener) {
ChannelListener.validateListener(listener);
// avoid race conditions on notifications while channel is being closed
if (!isOpen()) {
log.warn("addChannelListener({})[{}] ignore registration while channel is closing", this, listener);
return;
}
if (this.channelListeners.add(listener)) {
if (log.isTraceEnabled()) {
log.trace("addChannelListener({})[{}] registered", this, listener);
}
} else {
if (log.isTraceEnabled()) {
log.trace("addChannelListener({})[{}] ignored duplicate", this, listener);
}
}
}
@Override
public void removeChannelListener(ChannelListener listener) {
if (listener == null) {
return;
}
ChannelListener.validateListener(listener);
if (this.channelListeners.remove(listener)) {
if (log.isTraceEnabled()) {
log.trace("removeChannelListener({})[{}] removed", this, listener);
}
} else {
if (log.isTraceEnabled()) {
log.trace("removeChannelListener({})[{}] not registered", this, listener);
}
}
}
@Override
public ChannelListener getChannelListenerProxy() {
return channelListenerProxy;
}
@Override
public void handleClose() throws IOException {
boolean debugEnabled = log.isDebugEnabled();
if (debugEnabled) {
log.debug("handleClose({}) SSH_MSG_CHANNEL_CLOSE", this);
}
try {
IoWriteFuture eofPrevention = AbstractIoWriteFuture.fulfilled(getChannelId(), futureLock);
if (eofFuture.compareAndSet(null, eofPrevention)) {
if (debugEnabled) {
log.debug("handleClose({}) prevent sending EOF", this);
}
eofSent.set(true); // Just for API backwards compatibility
}
if (gracefulState.compareAndSet(GracefulState.Opened, GracefulState.CloseReceived)) {
close(false);
} else if (gracefulState.compareAndSet(GracefulState.CloseSent, GracefulState.Closed)) {
gracefulFuture.setClosed();
}
} finally {
notifyStateChanged("SSH_MSG_CHANNEL_CLOSE");
}
}
@Override
protected Closeable getInnerCloseable() {
Closeable closer = builder() //
.close(new SimpleCloseable(this, futureLock) {
@Override
protected void doClose(boolean immediately) {
IoWriteFuture eofWritten = eofFuture.get();
if (immediately || eofWritten == null) {
super.doClose(immediately);
} else {
eofWritten.addListener(f -> super.doClose(immediately));
}
}
}) //
.sequential(new GracefulChannelCloseable(), getExecutorService()) //
.run(toString(), () -> {
if (service != null) {
service.unregisterChannel(AbstractChannel.this);
}
}) //
.build();
closer.addCloseFutureListener(future -> clearAttributes());
return closer;
}
public class GracefulChannelCloseable extends IoBaseCloseable {
private final AtomicBoolean closing = new AtomicBoolean(false);
public GracefulChannelCloseable() {
super();
}
@Override
public void addCloseFutureListener(SshFutureListener listener) {
gracefulFuture.addListener(listener);
}
@Override
public void removeCloseFutureListener(SshFutureListener listener) {
gracefulFuture.removeListener(listener);
}
@Override
public boolean isClosing() {
return closing.get();
}
public void setClosing(boolean on) {
closing.set(on);
}
@Override
public boolean isClosed() {
return gracefulFuture.isClosed();
}
@Override
public CloseFuture close(boolean immediately) {
Channel channel = AbstractChannel.this;
boolean debugEnabled = log.isDebugEnabled();
if (debugEnabled) {
log.debug("close({})[immediately={}] processing", channel, immediately);
}
setClosing(true);
long recipient = getRecipient();
if (immediately || recipient < 0) {
// Recipient < 0: an AbstractClientChannel never got the SSH_MSG_OPEN_CONFIRMATION -- no point in
// sending a SSH_MSG_CHANNEL_CLOSE
gracefulFuture.setClosed();
} else if (!gracefulFuture.isClosed()) {
if (debugEnabled) {
log.debug("close({})[immediately={}] send SSH_MSG_CHANNEL_CLOSE", channel, immediately);
}
Session s = getSession();
Buffer buffer = s.createBuffer(SshConstants.SSH_MSG_CHANNEL_CLOSE, Short.SIZE);
buffer.putUInt(recipient);
try {
Duration timeout = CoreModuleProperties.CHANNEL_CLOSE_TIMEOUT.getRequired(channel);
s.writePacket(buffer, timeout).addListener(future -> {
if (future.isWritten()) {
handleClosePacketWritten(channel, immediately);
} else {
handleClosePacketWriteFailure(channel, immediately, future.getException());
}
});
} catch (IOException e) {
debug("close({})[immediately={}] {} while writing SSH_MSG_CHANNEL_CLOSE packet on channel: {}",
channel, immediately, e.getClass().getSimpleName(), e.getMessage(), e);
channel.close(true);
}
}
CloseableExecutorService service = getExecutorService();
if ((service != null) && (!service.isShutdown())) {
Collection running = service.shutdownNow();
if (debugEnabled) {
log.debug("close({})[immediately={}] shutdown executor service on close - running count={}",
channel, immediately, GenericUtils.size(running));
}
}
return gracefulFuture;
}
protected void handleClosePacketWritten(Channel channel, boolean immediately) {
if (log.isDebugEnabled()) {
log.debug("handleClosePacketWritten({})[immediately={}] SSH_MSG_CHANNEL_CLOSE written on channel",
channel, immediately);
}
if (gracefulState.compareAndSet(GracefulState.Opened, GracefulState.CloseSent)) {
// Waiting for CLOSE message to come back from the remote side
return;
} else if (gracefulState.compareAndSet(GracefulState.CloseReceived, GracefulState.Closed)) {
gracefulFuture.setClosed();
}
}
protected void handleClosePacketWriteFailure(Channel channel, boolean immediately, Throwable t) {
debug("handleClosePacketWriteFailure({})[immediately={}] failed ({}) to write SSH_MSG_CHANNEL_CLOSE on channel: {}",
this, immediately, t.getClass().getSimpleName(), t.getMessage(), t);
channel.close(true);
}
@Override
public String toString() {
return getClass().getSimpleName() + "[" + AbstractChannel.this + "]";
}
}
@Override
protected void preClose() {
if (!isEofSent()) {
log.debug("close({}) no EOF sent", this);
}
try {
signalChannelClosed(null);
} finally {
// clear the listeners since we are closing the channel (quicker GC)
this.channelListeners.clear();
}
IOException err = IoUtils.closeQuietly(getLocalWindow(), getRemoteWindow());
if (err != null) {
debug("Failed ({}) to pre-close window(s) of {}: {}", err.getClass().getSimpleName(), this,
err.getMessage(), err);
}
super.preClose();
}
@Override
public void handleChannelUnregistration(ConnectionService service) {
if (!unregisterSignaled.getAndSet(true)) {
if (log.isTraceEnabled()) {
log.trace("handleChannelUnregistration({}) via service={}", this, service);
}
}
notifyStateChanged("unregistered");
}
public void signalChannelClosed(Throwable reason) {
String event = (reason == null) ? "signalChannelClosed" : reason.getClass().getSimpleName();
try {
if (!closeSignaled.getAndSet(true)) {
if (log.isTraceEnabled()) {
log.trace("signalChannelClosed({})[{}]", this, event);
}
}
invokeChannelSignaller(l -> {
signalChannelClosed(l, reason);
return null;
});
} catch (Throwable err) {
Throwable e = ExceptionUtils.peelException(err);
debug("signalChannelClosed({}) {} while signal channel closed: {}", this, e.getClass().getSimpleName(),
e.getMessage(), e);
} finally {
notifyStateChanged(event);
}
}
protected void signalChannelClosed(ChannelListener listener, Throwable reason) {
if (listener == null) {
return;
}
listener.channelClosed(this, reason);
}
protected void invokeChannelSignaller(Invoker invoker) throws Throwable {
Session session = getSession();
FactoryManager manager = (session == null) ? null : session.getFactoryManager();
ChannelListener[] listeners = {
(manager == null) ? null : manager.getChannelListenerProxy(),
(session == null) ? null : session.getChannelListenerProxy(), getChannelListenerProxy() };
Throwable err = null;
for (ChannelListener l : listeners) {
if (l == null) {
continue;
}
try {
invoker.invoke(l);
} catch (Throwable t) {
err = ExceptionUtils.accumulateException(err, t);
}
}
if (err != null) {
throw err;
}
}
@Override
public IoWriteFuture writePacket(Buffer buffer) throws IOException {
if (mayWrite()) {
Session s = getSession();
return s.writePacket(buffer);
}
if (log.isDebugEnabled()) {
log.debug("writePacket({}) Discarding output packet because channel state={}", this, state);
}
return AbstractIoWriteFuture.fulfilled(toString(), new EOFException("Channel is being closed"));
}
protected boolean mayWrite() {
return !isClosing();
}
@Override
public void handleData(Buffer buffer) throws IOException {
long len = validateIncomingDataSize(SshConstants.SSH_MSG_CHANNEL_DATA, buffer.getUInt());
if (log.isDebugEnabled()) {
log.debug("handleData({}) SSH_MSG_CHANNEL_DATA len={}", this, len);
}
if (log.isTraceEnabled()) {
BufferUtils.dumpHex(getSimplifiedLogger(), BufferUtils.DEFAULT_HEXDUMP_LEVEL, "handleData(" + this + ")",
this, BufferUtils.DEFAULT_HEX_SEPARATOR, buffer.array(), buffer.rpos(), (int) len);
}
if (isEofSignalled()) {
// TODO consider throwing an exception
log.warn("handleData({}) extra {} bytes sent after EOF", this, len);
}
doWriteData(buffer.array(), buffer.rpos(), len);
}
@Override
public void handleExtendedData(Buffer buffer) throws IOException {
int ex = buffer.getInt();
// Only accept extended data for stderr
if (ex != SshConstants.SSH_EXTENDED_DATA_STDERR) {
if (log.isDebugEnabled()) {
log.debug("handleExtendedData({}) SSH_MSG_CHANNEL_FAILURE - non STDERR type: {}", this, ex);
}
Session s = getSession();
Buffer rsp = s.createBuffer(SshConstants.SSH_MSG_CHANNEL_FAILURE, Integer.BYTES);
rsp.putUInt(getRecipient());
writePacket(rsp);
return;
}
long len = validateIncomingDataSize(SshConstants.SSH_MSG_CHANNEL_EXTENDED_DATA, buffer.getUInt());
if (log.isDebugEnabled()) {
log.debug("handleExtendedData({}) SSH_MSG_CHANNEL_EXTENDED_DATA len={}", this, len);
}
if (log.isTraceEnabled()) {
BufferUtils.dumpHex(getSimplifiedLogger(), BufferUtils.DEFAULT_HEXDUMP_LEVEL,
"handleExtendedData(" + this + ")", this, BufferUtils.DEFAULT_HEX_SEPARATOR, buffer.array(),
buffer.rpos(), (int) len);
}
if (isEofSignalled()) {
// TODO consider throwing an exception
log.warn("handleExtendedData({}) extra {} bytes sent after EOF", this, len);
}
doWriteExtendedData(buffer.array(), buffer.rpos(), len);
}
protected long validateIncomingDataSize(
int cmd, long len /* actually a uint32 */)
throws IOException {
if (!BufferUtils.isValidUint32Value(len)) {
throw new IllegalArgumentException(
"Non UINT32 length (" + len + ") for command=" + SshConstants.getCommandMessageName(cmd));
}
/*
* According to RFC 4254 section 5.1
*
* The 'maximum packet size' specifies the maximum size of an individual
* data packet that can be sent to the sender
*
* The local window reflects our preference - i.e., how much our peer
* should send at most
*/
LocalWindow wLocal = getLocalWindow();
long maxLocalSize = wLocal.getPacketSize();
PacketValidator validator = getPacketValidator();
if (!validator.isValid(len, maxLocalSize, cmd == SshConstants.SSH_MSG_CHANNEL_EXTENDED_DATA)) {
throw new SshChannelInvalidPacketException(getChannelId(), "Bad length (" + len + ") " + " for cmd="
+ SshConstants.getCommandMessageName(cmd)
+ " - max. allowed=" + maxLocalSize);
}
wLocal.consume(len);
return len;
}
/**
* Retrieves the currently set {@link PacketValidator}.
*
* @return the validator, never {@code null}
*/
public PacketValidator getPacketValidator() {
return packetValidator;
}
/**
* Sets a {@link PacketValidator}.
*
* @param validator the validator to set, if {@code null} the {@link #DEFAULT_PACKET_VALIDATOR} is set
*/
public void setPacketValidator(PacketValidator validator) {
if (validator == null) {
packetValidator = DEFAULT_PACKET_VALIDATOR;
} else {
packetValidator = validator;
}
}
@Override
public void handleEof() throws IOException {
if (eofReceived.getAndSet(true)) {
// TODO consider throwing an exception
log.warn("handleEof({}) already signalled", this);
} else {
if (log.isDebugEnabled()) {
log.debug("handleEof({}) SSH_MSG_CHANNEL_EOF", this);
}
}
notifyStateChanged("SSH_MSG_CHANNEL_EOF");
}
@Override
public boolean isEofSignalled() {
return eofReceived.get();
}
@Override
public void handleWindowAdjust(Buffer buffer) throws IOException {
long window = buffer.getUInt();
if (log.isDebugEnabled()) {
log.debug("handleWindowAdjust({}) SSH_MSG_CHANNEL_WINDOW_ADJUST window={}", this, window);
}
RemoteWindow wRemote = getRemoteWindow();
wRemote.expand(window);
notifyStateChanged("SSH_MSG_CHANNEL_WINDOW_ADJUST");
}
@Override
public void handleSuccess() throws IOException {
if (log.isDebugEnabled()) {
log.debug("handleFhandleSuccessailure({}) SSH_MSG_CHANNEL_SUCCESS", this);
}
}
@Override
public void handleFailure() throws IOException {
if (log.isDebugEnabled()) {
log.debug("handleFailure({}) SSH_MSG_CHANNEL_FAILURE", this);
}
// TODO: do something to report failed requests?
}
protected abstract void doWriteData(byte[] data, int off, long len) throws IOException;
protected abstract void doWriteExtendedData(byte[] data, int off, long len) throws IOException;
/**
* Sends {@code SSH_MSG_CHANNEL_EOF} provided not already sent and current channel state allows it.
*
* @return The {@link IoWriteFuture} of the sent packet - {@code null} if message not sent due to
* channel state (or already sent)
* @throws IOException If failed to send the packet
*/
protected IoWriteFuture sendEof() throws IOException {
State channelState = state.get();
// OK to send EOF if channel is open or being closed gracefully
if ((channelState != State.Opened) && (channelState != State.Graceful)) {
if (log.isDebugEnabled()) {
log.debug("sendEof({}) already closing or closed - state={}", this, state);
}
return null;
}
AbstractIoWriteFuture eofWritten = new AbstractIoWriteFuture(getChannelId(), futureLock) {
// Nothin extra
};
if (!eofFuture.compareAndSet(null, eofWritten)) {
if (log.isDebugEnabled()) {
log.debug("sendEof({}) already sent (state={})", this, channelState);
}
return null;
}
eofSent.set(true);// Just for API backwards compatibility
if (log.isDebugEnabled()) {
log.debug("sendEof({}) SSH_MSG_CHANNEL_EOF (state={})", this, channelState);
}
IoWriteFuture inner = null;
try {
Session s = getSession();
Buffer buffer = s.createBuffer(SshConstants.SSH_MSG_CHANNEL_EOF, Short.SIZE);
buffer.putUInt(getRecipient());
/*
* The default "writePacket" does not send packets if state is not open so we need to bypass it.
*/
inner = s.writePacket(buffer);
} catch (IOException e) {
// Marks the future as done, so that later channel closing will not be blocked.
eofWritten.setValue(e);
throw e;
} catch (RuntimeException e) {
eofWritten.setValue(e);
throw new IOException(e.getMessage(), e);
}
return inner.addListener(f -> {
Throwable error = f.getException();
eofWritten.setValue(error != null ? error : Boolean.TRUE);
});
}
public boolean isEofSent() {
return eofFuture.get() != null;
}
@Override
public Map getProperties() {
return properties;
}
@Override
public int getAttributesCount() {
return attributes.size();
}
@Override
@SuppressWarnings("unchecked")
public T getAttribute(AttributeRepository.AttributeKey key) {
return (T) attributes.get(Objects.requireNonNull(key, "No key"));
}
@Override
public Collection> attributeKeys() {
return attributes.isEmpty() ? Collections.emptySet() : new HashSet<>(attributes.keySet());
}
@Override
@SuppressWarnings({ "unchecked", "rawtypes" })
public T computeAttributeIfAbsent(
AttributeRepository.AttributeKey key,
Function, ? extends T> resolver) {
return (T) attributes.computeIfAbsent(Objects.requireNonNull(key, "No key"), (Function) resolver);
}
@Override
@SuppressWarnings("unchecked")
public T setAttribute(AttributeRepository.AttributeKey key, T value) {
return (T) attributes.put(Objects.requireNonNull(key, "No key"), Objects.requireNonNull(value, "No value"));
}
@Override
@SuppressWarnings("unchecked")
public T removeAttribute(AttributeRepository.AttributeKey key) {
return (T) attributes.remove(Objects.requireNonNull(key, "No key"));
}
@Override
public void clearAttributes() {
attributes.clear();
}
protected void configureWindow() {
localWindow.init(this);
}
protected void sendWindowAdjust(long len) throws IOException {
if (log.isDebugEnabled()) {
log.debug("sendWindowAdjust({}) SSH_MSG_CHANNEL_WINDOW_ADJUST len={}", this, len);
}
Session s = getSession();
Buffer buffer = s.createBuffer(SshConstants.SSH_MSG_CHANNEL_WINDOW_ADJUST, Short.SIZE);
buffer.putUInt(getRecipient());
buffer.putUInt(len);
writePacket(buffer);
}
@Override
public String toString() {
return getClass().getSimpleName() + "[id=" + getChannelId() + ", recipient=" + getRecipient() + "]" + "-"
+ getSession();
}
/**
* A {@link PacketValidator} can validate packet lengths. Used for {@link SshConstants#SSH_MSG_CHANNEL_DATA} and
* {@link SshConstants#SSH_MSG_CHANNEL_EXTENDED_DATA} messages.
*/
@FunctionalInterface
public interface PacketValidator {
/**
* Tells whether a packet received of {@code len} bytes is valid given a channel's {@code maximumPacketSize}.
*
* @param packetSize as read from the SSH packet
* @param maximumPacketSize from the channel's local window
* @param extendedData whether it's a {@link SshConstants#SSH_MSG_CHANNEL_EXTENDED_DATA} packet
* @return {@code true} if the packet is to be considered valid.
*/
boolean isValid(long packetSize, long maximumPacketSize, boolean extendedData);
}
}
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