/*
* 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.util.Date;
import org.apache.sshd.common.SshConstants;
import org.apache.sshd.common.channel.Channel;
import org.apache.sshd.common.session.Session;
import org.apache.sshd.common.util.ValidateUtils;
import org.apache.sshd.common.util.buffer.Buffer;
/**
* Client channel to run a subsystem
*
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public class ChannelSubsystem extends ChannelSession {
/**
* Configure whether reply for the "subsystem&quoot; request is required
* @see #DEFAULT_REQUEST_SUBSYSTEM_REPLY
*/
public static final String REQUEST_SUBSYSTEM_REPLY = "channel-subsystem-want-reply";
/**
* <P>
* Default value for {@link #REQUEST_SUBSYSTEM_REPLY} - according to
* <A HREF="https://tools.ietf.org/html/rfc4254#section-6.5">RFC4254 section 6.5:</A>
* </P>
* <P>
* It is RECOMMENDED that the reply to these messages be requested and checked.
* </P>
*/
public static final boolean DEFAULT_REQUEST_SUBSYSTEM_REPLY = true;
private final String subsystem;
/**
* @param subsystem The subsystem name for the channel - never {@code null} or empty
*/
public ChannelSubsystem(String subsystem) {
this.subsystem = ValidateUtils.checkNotNullAndNotEmpty(subsystem, "Subsystem may not be null/empty");
}
/**
* The subsystem name
*
* @return The subsystem name for the channel - never {@code null} or empty
*/
public final String getSubsystem() {
return subsystem;
}
@Override
protected void doOpen() throws IOException {
String systemName = getSubsystem();
if (log.isDebugEnabled()) {
log.debug("doOpen({}) SSH_MSG_CHANNEL_REQUEST subsystem={}", this, systemName);
}
Session session = getSession();
boolean wantReply = this.getBooleanProperty(REQUEST_SUBSYSTEM_REPLY, DEFAULT_REQUEST_SUBSYSTEM_REPLY);
Buffer buffer = session.createBuffer(SshConstants.SSH_MSG_CHANNEL_REQUEST,
Channel.CHANNEL_SUBSYSTEM.length() + systemName.length() + Integer.SIZE);
buffer.putInt(getRecipient());
buffer.putString(Channel.CHANNEL_SUBSYSTEM);
buffer.putBoolean(wantReply);
buffer.putString(systemName);
addPendingRequest(Channel.CHANNEL_SUBSYSTEM, wantReply);
writePacket(buffer);
super.doOpen();
}
@Override
public void handleSuccess() throws IOException {
String systemName = getSubsystem();
Date pending = removePendingRequest(Channel.CHANNEL_SUBSYSTEM);
if (log.isDebugEnabled()) {
log.debug("handleSuccess({}) subsystem={}, pending since={}", this, systemName, pending);
}
}
@Override
public void handleFailure() throws IOException {
String systemName = getSubsystem();
Date pending = removePendingRequest(Channel.CHANNEL_SUBSYSTEM);
if (pending != null) {
log.warn("handleFailure({}) subsystem={}, pending since={}", this, systemName, pending);
close(true);
}
}
public void onClose(final Runnable run) {
closeFuture.addListener(future -> run.run());
}
@Override
public String toString() {
return super.toString() + "[" + getSubsystem() + "]";
}
}