/*
* 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.session;
import java.io.IOException;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import org.apache.sshd.agent.common.AgentForwardSupport;
import org.apache.sshd.client.ClientFactoryManager;
import org.apache.sshd.common.FactoryManager;
import org.apache.sshd.common.SshConstants;
import org.apache.sshd.common.SshException;
import org.apache.sshd.common.io.AbstractIoWriteFuture;
import org.apache.sshd.common.io.IoWriteFuture;
import org.apache.sshd.common.session.helpers.AbstractConnectionService;
import org.apache.sshd.common.util.buffer.Buffer;
import org.apache.sshd.server.x11.X11ForwardSupport;
/**
* Client side <code>ssh-connection</code> service.
*
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public class ClientConnectionService extends AbstractConnectionService<AbstractClientSession> implements ClientSessionHolder {
public ClientConnectionService(AbstractClientSession s) throws SshException {
super(s);
}
@Override
public final ClientSession getClientSession() {
return getSession();
}
@Override
public void start() {
ClientSession session = getClientSession();
if (!session.isAuthenticated()) {
throw new IllegalStateException("Session is not authenticated");
}
startHeartBeat();
}
protected void startHeartBeat() {
ClientSession session = getClientSession();
long interval = session.getLongProperty(ClientFactoryManager.HEARTBEAT_INTERVAL, ClientFactoryManager.DEFAULT_HEARTBEAT_INTERVAL);
if (interval > 0L) {
FactoryManager manager = session.getFactoryManager();
ScheduledExecutorService service = manager.getScheduledExecutorService();
service.scheduleAtFixedRate(this::sendHeartBeat, interval, interval, TimeUnit.MILLISECONDS);
if (log.isDebugEnabled()) {
log.debug("startHeartbeat - started at interval={}", interval);
}
}
}
/**
* Sends a heartbeat message
* @return The {@link IoWriteFuture} that can be used to wait for the
* message write completion
*/
protected IoWriteFuture sendHeartBeat() {
ClientSession session = getClientSession();
String request = session.getStringProperty(ClientFactoryManager.HEARTBEAT_REQUEST, ClientFactoryManager.DEFAULT_KEEP_ALIVE_HEARTBEAT_STRING);
try {
Buffer buf = session.createBuffer(SshConstants.SSH_MSG_GLOBAL_REQUEST, request.length() + Byte.SIZE);
buf.putString(request);
buf.putBoolean(false);
return session.writePacket(buf);
} catch (IOException e) {
if (log.isDebugEnabled()) {
log.debug("Error (" + e.getClass().getSimpleName() + ") sending keepalive message=" + request + ": " + e.getMessage());
}
final Throwable t = e;
return new AbstractIoWriteFuture(null) {
{
setValue(t);
}
};
}
}
@Override
public AgentForwardSupport getAgentForwardSupport() {
throw new IllegalStateException("Server side operation");
}
@Override
public X11ForwardSupport getX11ForwardSupport() {
throw new IllegalStateException("Server side operation");
}
}