/*
* 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.IOException;
import org.apache.sshd.common.Channel;
import org.apache.sshd.common.FactoryManager;
import org.apache.sshd.common.SshConstants;
import org.apache.sshd.common.future.CloseFuture;
import org.apache.sshd.common.future.DefaultCloseFuture;
import org.apache.sshd.common.session.AbstractSession;
import org.apache.sshd.common.util.Buffer;
import org.apache.sshd.common.util.BufferUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* TODO Add javadoc
*
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public abstract class AbstractChannel implements Channel {
public static final int DEFAULT_WINDOW_SIZE = 0x200000;
public static final int DEFAULT_PACKET_SIZE = 0x8000;
protected final Logger log = LoggerFactory.getLogger(getClass());
protected final Object lock = new Object();
protected final Window localWindow = new Window(this, null, getClass().getName().contains(".client."), true);
protected final Window remoteWindow = new Window(this, null, getClass().getName().contains(".client."), false);
protected AbstractSession session;
protected int id;
protected int recipient;
protected boolean eof;
protected final CloseFuture closeFuture = new DefaultCloseFuture(lock);
protected boolean closing;
public int getId() {
return id;
}
public int getRecipient() {
return recipient;
}
public Window getLocalWindow() {
return localWindow;
}
public AbstractSession getSession() {
return session;
}
public CloseFuture close(boolean immediately) {
try {
synchronized (lock) {
if (immediately) {
log.info("Closing channel {} immediately", id);
closeFuture.setClosed();
session.channelForget(this);
} else {
if (!closing) {
closing = true;
log.info("Send SSH_MSG_CHANNEL_CLOSE on channel {}", id);
Buffer buffer = session.createBuffer(SshConstants.Message.SSH_MSG_CHANNEL_CLOSE);
buffer.putInt(recipient);
session.writePacket(buffer);
}
}
}
} catch (IOException e) {
session.exceptionCaught(e);
closeFuture.setClosed();
}
return closeFuture;
}
public void handleClose() throws IOException {
log.info("Received SSH_MSG_CHANNEL_CLOSE on channel {}", id);
synchronized (lock) {
doClose();
close(false).setClosed();
lock.notifyAll();
}
}
protected void doClose() {
}
public void handleData(Buffer buffer) throws IOException {
int len = buffer.getInt();
if (len < 0 || len > 32768) {
throw new IllegalStateException("Bad item length: " + len);
}
log.debug("Received SSH_MSG_CHANNEL_DATA on channel {}", id);
if (log.isTraceEnabled()) {
log.trace("Received channel data: {}", BufferUtils.printHex(buffer.array(), buffer.rpos(), len));
}
doWriteData(buffer.array(), buffer.rpos(), len);
}
public void handleExtendedData(Buffer buffer) throws IOException {
int ex = buffer.getInt();
// Only accept extended data for stderr
if (ex != 1) {
log.info("Send SSH_MSG_CHANNEL_FAILURE on channel {}", id);
buffer = session.createBuffer(SshConstants.Message.SSH_MSG_CHANNEL_FAILURE);
buffer.putInt(recipient);
session.writePacket(buffer);
return;
}
int len = buffer.getInt();
if (len < 0 || len > 32768) {
throw new IllegalStateException("Bad item length: " + len);
}
log.debug("Received SSH_MSG_CHANNEL_EXTENDED_DATA on channel {}", id);
if (log.isTraceEnabled()) {
log.trace("Received channel extended data: {}", BufferUtils.printHex(buffer.array(), buffer.rpos(), len));
}
doWriteExtendedData(buffer.array(), buffer.rpos(), len);
}
public void handleEof() throws IOException {
log.info("Received SSH_MSG_CHANNEL_EOF on channel {}", id);
synchronized (lock) {
eof = true;
lock.notifyAll();
}
}
public void handleWindowAdjust(Buffer buffer) throws IOException {
log.info("Received SSH_MSG_CHANNEL_WINDOW_ADJUST on channel {}", id);
int window = buffer.getInt();
remoteWindow.expand(window);
}
public void handleFailure() throws IOException {
log.info("Received SSH_MSG_CHANNEL_FAILURE on channel {}", id);
// TODO: do something to report failed requests?
}
protected abstract void doWriteData(byte[] data, int off, int len) throws IOException;
protected abstract void doWriteExtendedData(byte[] data, int off, int len) throws IOException;
protected void sendEof() throws IOException {
log.info("Send SSH_MSG_CHANNEL_EOF on channel {}", id);
Buffer buffer = session.createBuffer(SshConstants.Message.SSH_MSG_CHANNEL_EOF);
buffer.putInt(recipient);
session.writePacket(buffer);
}
protected void configureWindow() {
int window = session.getIntProperty(FactoryManager.WINDOW_SIZE, DEFAULT_WINDOW_SIZE);
int packet = session.getIntProperty(FactoryManager.MAX_PACKET_SIZE, DEFAULT_PACKET_SIZE);
localWindow.init(window, packet);
}
protected void sendWindowAdjust(int len) throws IOException {
log.info("Send SSH_MSG_CHANNEL_WINDOW_ADJUST on channel {}", id);
Buffer buffer = session.createBuffer(SshConstants.Message.SSH_MSG_CHANNEL_WINDOW_ADJUST);
buffer.putInt(recipient);
buffer.putInt(len);
session.writePacket(buffer);
}
}