/*
* 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.client.channel;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumSet;
import java.util.Objects;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.sshd.client.channel.exit.ExitSignalChannelRequestHandler;
import org.apache.sshd.client.channel.exit.ExitStatusChannelRequestHandler;
import org.apache.sshd.client.future.DefaultOpenFuture;
import org.apache.sshd.client.future.OpenFuture;
import org.apache.sshd.common.Closeable;
import org.apache.sshd.common.FactoryManager;
import org.apache.sshd.common.SshConstants;
import org.apache.sshd.common.SshException;
import org.apache.sshd.common.channel.AbstractChannel;
import org.apache.sshd.common.channel.Channel;
import org.apache.sshd.common.channel.ChannelAsyncInputStream;
import org.apache.sshd.common.channel.ChannelAsyncOutputStream;
import org.apache.sshd.common.channel.RequestHandler;
import org.apache.sshd.common.channel.Window;
import org.apache.sshd.common.io.IoInputStream;
import org.apache.sshd.common.io.IoOutputStream;
import org.apache.sshd.common.session.Session;
import org.apache.sshd.common.util.EventNotifier;
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.ByteArrayBuffer;
import org.apache.sshd.common.util.io.IoUtils;
/**
* TODO Add javadoc
*
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public abstract class AbstractClientChannel extends AbstractChannel implements ClientChannel {
protected final AtomicBoolean opened = new AtomicBoolean();
protected final String type;
protected Streaming streaming;
protected ChannelAsyncOutputStream asyncIn;
protected ChannelAsyncInputStream asyncOut;
protected ChannelAsyncInputStream asyncErr;
protected InputStream in;
protected OutputStream invertedIn;
protected OutputStream out;
protected InputStream invertedOut;
protected OutputStream err;
protected InputStream invertedErr;
protected final AtomicReference<Integer> exitStatusHolder = new AtomicReference<>(null);
protected final AtomicReference<String> exitSignalHolder = new AtomicReference<>(null);
protected int openFailureReason;
protected String openFailureMsg;
protected String openFailureLang;
protected OpenFuture openFuture;
protected AbstractClientChannel(String type) {
this(type, Collections.emptyList());
}
protected AbstractClientChannel(String type, Collection<? extends RequestHandler<Channel>> handlers) {
super(true, handlers);
this.type = ValidateUtils.checkNotNullAndNotEmpty(type, "No channel type specified");
this.streaming = Streaming.Sync;
addChannelSignalRequestHandlers(event -> {
if (log.isDebugEnabled()) {
log.debug("notifyEvent({}): {}", AbstractClientChannel.this, event);
}
notifyStateChanged(event);
});
}
protected void addChannelSignalRequestHandlers(EventNotifier<String> notifier) {
addRequestHandler(new ExitStatusChannelRequestHandler(exitStatusHolder, notifier));
addRequestHandler(new ExitSignalChannelRequestHandler(exitSignalHolder, notifier));
}
@Override
public Streaming getStreaming() {
return streaming;
}
@Override
public void setStreaming(Streaming streaming) {
this.streaming = streaming;
}
@Override
public IoOutputStream getAsyncIn() {
return asyncIn;
}
@Override
public IoInputStream getAsyncOut() {
return asyncOut;
}
@Override
public IoInputStream getAsyncErr() {
return asyncErr;
}
@Override
public OutputStream getInvertedIn() {
return invertedIn;
}
public InputStream getIn() {
return in;
}
@Override
public void setIn(InputStream in) {
this.in = in;
}
@Override
public InputStream getInvertedOut() {
return invertedOut;
}
public OutputStream getOut() {
return out;
}
@Override
public void setOut(OutputStream out) {
this.out = out;
}
@Override
public InputStream getInvertedErr() {
return invertedErr;
}
public OutputStream getErr() {
return err;
}
@Override
public void setErr(OutputStream err) {
this.err = err;
}
@Override
protected Closeable getInnerCloseable() {
return builder()
.when(openFuture)
.run(() -> {
// If the channel has not been opened yet,
// skip the SSH_MSG_CHANNEL_CLOSE exchange
if (openFuture == null) {
gracefulFuture.setClosed();
}
// Close inverted streams after
// If the inverted stream is closed before, there's a small time window
// in which we have:
// ChannelPipedInputStream#closed = true
// ChannelPipedInputStream#writerClosed = false
// which leads to an IOException("Pipe closed") when reading.
IoUtils.closeQuietly(in, out, err);
IoUtils.closeQuietly(invertedIn, invertedOut, invertedErr);
})
.parallel(asyncIn, asyncOut, asyncErr)
.close(new GracefulChannelCloseable())
.build();
}
@Override
public Set<ClientChannelEvent> waitFor(Collection<ClientChannelEvent> mask, long timeout) {
Objects.requireNonNull(mask, "No mask specified");
long t = 0;
synchronized (lock) {
for (Set<ClientChannelEvent> cond = EnumSet.noneOf(ClientChannelEvent.class);; cond.clear()) {
updateCurrentChannelState(cond);
if (log.isDebugEnabled()) {
if (cond.contains(ClientChannelEvent.EXIT_STATUS)) {
log.debug("waitFor({}) mask={} - exit status={}", this, mask, exitStatusHolder);
}
if (cond.contains(ClientChannelEvent.EXIT_SIGNAL)) {
log.debug("waitFor({}) mask={} - exit signal={}", this, mask, exitSignalHolder);
}
}
boolean nothingInCommon = Collections.disjoint(mask, cond);
if (!nothingInCommon) {
if (log.isTraceEnabled()) {
log.trace("WaitFor call returning on channel {}, mask={}, cond={}", this, mask, cond);
}
return cond;
}
if (timeout > 0L) {
if (t == 0L) {
t = System.currentTimeMillis() + timeout;
} else {
timeout = t - System.currentTimeMillis();
if (timeout <= 0L) {
if (log.isTraceEnabled()) {
log.trace("WaitFor call timeout on channel {}, mask={}", this, mask);
}
cond.add(ClientChannelEvent.TIMEOUT);
return cond;
}
}
}
if (log.isTraceEnabled()) {
log.trace("Waiting {} millis for lock on channel {}, mask={}, cond={}", timeout, this, mask, cond);
}
long nanoStart = System.nanoTime();
try {
if (timeout > 0L) {
lock.wait(timeout);
} else {
lock.wait();
}
long nanoEnd = System.nanoTime();
long nanoDuration = nanoEnd - nanoStart;
if (log.isTraceEnabled()) {
log.trace("Lock notified on channel {} after {} nanos", this, nanoDuration);
}
} catch (InterruptedException e) {
long nanoEnd = System.nanoTime();
long nanoDuration = nanoEnd - nanoStart;
if (log.isTraceEnabled()) {
log.trace("waitFor({}) mask={} - ignoring interrupted exception after {} nanos", this, mask, nanoDuration);
}
}
}
}
}
@Override
public Set<ClientChannelEvent> getChannelState() {
Set<ClientChannelEvent> cond = EnumSet.noneOf(ClientChannelEvent.class);
synchronized (lock) {
return updateCurrentChannelState(cond);
}
}
// NOTE: assumed to be called under lock
protected <C extends Collection<ClientChannelEvent>> C updateCurrentChannelState(C state) {
if ((openFuture != null) && openFuture.isOpened()) {
state.add(ClientChannelEvent.OPENED);
}
if (closeFuture.isClosed()) {
state.add(ClientChannelEvent.CLOSED);
}
if (isEofSignalled()) {
state.add(ClientChannelEvent.EOF);
}
if (exitStatusHolder.get() != null) {
state.add(ClientChannelEvent.EXIT_STATUS);
}
if (exitSignalHolder.get() != null) {
state.add(ClientChannelEvent.EXIT_SIGNAL);
}
return state;
}
@Override
public synchronized OpenFuture open() throws IOException {
if (isClosing()) {
throw new SshException("Session has been closed");
}
openFuture = new DefaultOpenFuture(lock);
if (log.isDebugEnabled()) {
log.debug("open({}) Send SSH_MSG_CHANNEL_OPEN - type={}", this, type);
}
Session session = getSession();
Window wLocal = getLocalWindow();
Buffer buffer = session.createBuffer(SshConstants.SSH_MSG_CHANNEL_OPEN, type.length() + Integer.SIZE);
buffer.putString(type);
buffer.putInt(getId());
buffer.putInt(wLocal.getSize());
buffer.putInt(wLocal.getPacketSize());
writePacket(buffer);
return openFuture;
}
@Override
public OpenFuture open(int recipient, long rwSize, long packetSize, Buffer buffer) {
throw new UnsupportedOperationException("open(" + recipient + "," + rwSize + "," + packetSize + ") N/A");
}
@Override
public void handleOpenSuccess(int recipient, long rwSize, long packetSize, Buffer buffer) {
setRecipient(recipient);
Session session = getSession();
FactoryManager manager = Objects.requireNonNull(session.getFactoryManager(), "No factory manager");
Window wRemote = getRemoteWindow();
wRemote.init(rwSize, packetSize, manager);
String changeEvent = "SSH_MSG_CHANNEL_OPEN_CONFIRMATION";
try {
doOpen();
signalChannelOpenSuccess();
this.opened.set(true);
this.openFuture.setOpened();
} catch (Throwable t) {
Throwable e = GenericUtils.peelException(t);
changeEvent = e.getClass().getName();
signalChannelOpenFailure(e);
this.openFuture.setException(e);
this.closeFuture.setClosed();
this.doCloseImmediately();
} finally {
notifyStateChanged(changeEvent);
}
}
protected abstract void doOpen() throws IOException;
@Override
public void handleOpenFailure(Buffer buffer) {
int reason = buffer.getInt();
String msg = buffer.getString();
String lang = buffer.getString();
if (log.isDebugEnabled()) {
log.debug("handleOpenFailure({}) reason={}, lang={}, msg={}",
this, SshConstants.getOpenErrorCodeName(reason), lang, msg);
}
this.openFailureReason = reason;
this.openFailureMsg = msg;
this.openFailureLang = lang;
this.openFuture.setException(new SshException(msg));
this.closeFuture.setClosed();
this.doCloseImmediately();
notifyStateChanged("SSH_MSG_CHANNEL_OPEN_FAILURE");
}
@Override
protected void doWriteData(byte[] data, int off, long len) throws IOException {
// If we're already closing, ignore incoming data
if (isClosing()) {
return;
}
ValidateUtils.checkTrue(len <= Integer.MAX_VALUE, "Data length exceeds int boundaries: %d", len);
if (asyncOut != null) {
asyncOut.write(new ByteArrayBuffer(data, off, (int) len));
} else if (out != null) {
out.write(data, off, (int) len);
out.flush();
if (invertedOut == null) {
Window wLocal = getLocalWindow();
wLocal.consumeAndCheck(len);
}
} else {
throw new IllegalStateException("No output stream for channel");
}
}
@Override
protected void doWriteExtendedData(byte[] data, int off, long len) throws IOException {
// If we're already closing, ignore incoming data
if (isClosing()) {
return;
}
ValidateUtils.checkTrue(len <= Integer.MAX_VALUE, "Extended data length exceeds int boundaries: %d", len);
if (asyncErr != null) {
asyncErr.write(new ByteArrayBuffer(data, off, (int) len));
} else if (err != null) {
err.write(data, off, (int) len);
err.flush();
if (invertedErr == null) {
Window wLocal = getLocalWindow();
wLocal.consumeAndCheck(len);
}
} else {
throw new IllegalStateException("No error stream for channel");
}
}
@Override
public void handleWindowAdjust(Buffer buffer) throws IOException {
super.handleWindowAdjust(buffer);
if (asyncIn != null) {
asyncIn.onWindowExpanded();
}
}
@Override
public Integer getExitStatus() {
return exitStatusHolder.get();
}
@Override
public String getExitSignal() {
return exitSignalHolder.get();
}
}