/*
* 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.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import org.apache.sshd.common.SshConstants;
import org.apache.sshd.common.channel.ChannelAsyncInputStream;
import org.apache.sshd.common.channel.ChannelAsyncOutputStream;
import org.apache.sshd.common.channel.ChannelOutputStream;
import org.apache.sshd.common.channel.ChannelPipedInputStream;
import org.apache.sshd.common.channel.ChannelPipedOutputStream;
import org.apache.sshd.common.channel.RequestHandler;
import org.apache.sshd.common.channel.Window;
import org.apache.sshd.common.future.CloseFuture;
import org.apache.sshd.common.session.Session;
import org.apache.sshd.common.util.ValidateUtils;
import org.apache.sshd.common.util.buffer.Buffer;
import org.apache.sshd.common.util.threads.ThreadUtils;
/**
* TODO Add javadoc
*
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public class ChannelSession extends AbstractClientChannel {
private ExecutorService pumperService;
private Future<?> pumper;
private boolean shutdownPumper;
public ChannelSession() {
super("session");
}
@Override
protected void doOpen() throws IOException {
if (Streaming.Async.equals(streaming)) {
asyncIn = new ChannelAsyncOutputStream(this, SshConstants.SSH_MSG_CHANNEL_DATA) {
@SuppressWarnings("synthetic-access")
@Override
protected CloseFuture doCloseGracefully() {
try {
sendEof();
} catch (IOException e) {
Session session = getSession();
session.exceptionCaught(e);
}
return super.doCloseGracefully();
}
};
asyncOut = new ChannelAsyncInputStream(this);
asyncErr = new ChannelAsyncInputStream(this);
} else {
invertedIn = new ChannelOutputStream(this, getRemoteWindow(), log, SshConstants.SSH_MSG_CHANNEL_DATA, true);
Window wLocal = getLocalWindow();
if (out == null) {
ChannelPipedInputStream pis = new ChannelPipedInputStream(this, wLocal);
ChannelPipedOutputStream pos = new ChannelPipedOutputStream(pis);
out = pos;
invertedOut = pis;
}
if (err == null) {
ChannelPipedInputStream pis = new ChannelPipedInputStream(this, wLocal);
ChannelPipedOutputStream pos = new ChannelPipedOutputStream(pis);
err = pos;
invertedErr = pis;
}
if (in != null) {
// allocate a temporary executor service if none provided
ExecutorService service = getExecutorService();
if (service == null) {
pumperService = ThreadUtils.newSingleThreadExecutor("ClientInputStreamPump[" + this.toString() + "]");
} else {
pumperService = service;
}
// shutdown the temporary executor service if had to create it
shutdownPumper = (pumperService != service) || isShutdownOnExit();
// Interrupt does not really work and the thread will only exit when
// the call to read() will return. So ensure this thread is a daemon
// to avoid blocking the whole app
pumper = pumperService.submit(this::pumpInputStream);
}
}
}
@Override
protected RequestHandler.Result handleInternalRequest(String req, boolean wantReply, Buffer buffer) throws IOException {
switch (req) {
case "xon-xoff":
return handleXonXoff(buffer, wantReply);
default:
return super.handleInternalRequest(req, wantReply, buffer);
}
}
// see RFC4254 section 6.8
protected RequestHandler.Result handleXonXoff(Buffer buffer, boolean wantReply) throws IOException {
boolean clientCanDo = buffer.getBoolean();
if (log.isDebugEnabled()) {
log.debug("handleXonXoff({})[want-reply={}] client-can-do={}",
this, wantReply, clientCanDo);
}
return RequestHandler.Result.ReplySuccess;
}
@Override
protected void doCloseImmediately() {
if ((pumper != null) && (pumperService != null) && shutdownPumper && (!pumperService.isShutdown())) {
try {
if (!pumper.isDone()) {
pumper.cancel(true);
}
pumperService.shutdownNow();
} catch (Exception e) {
// we log it as DEBUG since it is relatively harmless
if (log.isDebugEnabled()) {
log.debug("doCloseImmediately({}) failed {} to shutdown stream pumper: {}",
this, e.getClass().getSimpleName(), e.getMessage());
}
if (log.isTraceEnabled()) {
log.trace("doCloseImmediately(" + this + ") stream pumper shutdown error details", e);
}
} finally {
pumper = null;
pumperService = null;
}
}
super.doCloseImmediately();
}
protected void pumpInputStream() {
try {
Session session = getSession();
Window wRemote = getRemoteWindow();
long packetSize = wRemote.getPacketSize();
ValidateUtils.checkTrue(packetSize < Integer.MAX_VALUE, "Remote packet size exceeds int boundary: %d", packetSize);
byte[] buffer = new byte[(int) packetSize];
while (!closeFuture.isClosed()) {
int len = securedRead(in, buffer, 0, buffer.length);
if (len < 0) {
if (log.isDebugEnabled()) {
log.debug("pumpInputStream({}) EOF signalled", this);
}
sendEof();
return;
}
session.resetIdleTimeout();
if (len > 0) {
invertedIn.write(buffer, 0, len);
invertedIn.flush();
}
}
if (log.isDebugEnabled()) {
log.debug("pumpInputStream({}) close future closed", this);
}
} catch (Exception e) {
if (!isClosing()) {
if (log.isDebugEnabled()) {
log.debug("pumpInputStream({}) Caught {} : {}", this, e.getClass().getSimpleName(), e.getMessage());
}
if (log.isTraceEnabled()) {
log.trace("pumpInputStream(" + this + ") caught exception details", e);
}
close(false);
}
}
}
//
// On some platforms, a call to System.in.read(new byte[65536], 0,32768) always throws an IOException.
// So we need to protect against that and chunk the call into smaller calls.
// This problem was found on Windows, JDK 1.6.0_03-b05.
//
protected int securedRead(InputStream in, byte[] buf, int off, int len) throws IOException {
int n = 0;
for (;;) {
int nread = in.read(buf, off + n, Math.min(1024, len - n));
if (nread <= 0) {
return (n == 0) ? nread : n;
}
n += nread;
if (n >= len) {
return n;
}
// if not closed but no bytes available, return
if (in.available() <= 0) {
return n;
}
}
}
}