SessionChannel.java

/*
 * Copyright 2010 netling project <http://netling.org>
 *
 * Licensed 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.
 *
 * This file may incorporate work covered by the following copyright and
 * permission notice:
 *
 *     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.netling.ssh.connection.channel.direct;

import java.io.IOException;
import java.io.InputStream;
import java.util.Collections;
import java.util.Map;
import java.util.concurrent.TimeUnit;

import org.netling.io.StreamCopier;
import org.netling.ssh.common.Buffer;
import org.netling.ssh.common.SSHException;
import org.netling.ssh.common.SSHPacket;
import org.netling.ssh.common.SSHRuntimeException;
import org.netling.ssh.connection.Connection;
import org.netling.ssh.connection.ConnectionException;
import org.netling.ssh.connection.channel.ChannelInputStream;
import org.netling.ssh.transport.TransportException;

/** {@link Session} implementation. */
public class
SessionChannel
extends AbstractDirectChannel
implements Session, Session.Command, Session.Shell, Session.Subsystem {

	private final ChannelInputStream err = new ChannelInputStream(this, trans, lwin);

	private Integer exitStatus;

	private Signal exitSignal;
	private Boolean wasCoreDumped;
	private String exitErrMsg;

	private Boolean canDoFlowControl;

	private boolean usedUp;

	public SessionChannel(Connection conn) {
		super(conn, "session");
	}

	@Override
		public void allocateDefaultPTY()
		throws ConnectionException, TransportException {
			allocatePTY("vt100", 80, 24, 0, 0, Collections.<PTYMode, Integer>emptyMap());
		}

	@Override
		public void allocatePTY(String term, int cols, int rows, int width, int height, Map<PTYMode, Integer> modes)
		throws ConnectionException, TransportException {
			sendChannelRequest(
					"pty-req",
					true,
					new Buffer.PlainBuffer()
					.putString(term)
					.putInt(cols)
					.putInt(rows)
					.putInt(width)
					.putInt(height)
					.putBytes(PTYMode.encode(modes))
					).await(conn.getTimeout(), TimeUnit.SECONDS);
		}

	@Override
		public Boolean canDoFlowControl() {
			return canDoFlowControl;
		}

	@Override
		public void changeWindowDimensions(int cols, int rows, int width, int height)
		throws TransportException {
			sendChannelRequest(
					"pty-req",
					false,
					new Buffer.PlainBuffer()
					.putInt(cols)
					.putInt(rows)
					.putInt(width)
					.putInt(height)
					);
		}

	@Override
		public Command exec(String command)
		throws ConnectionException, TransportException {
			checkReuse();
			log.info("Will request to exec `{}`", command);
			sendChannelRequest("exec", true, new Buffer.PlainBuffer().putString(command))
				.await(conn.getTimeout(), TimeUnit.SECONDS);
			usedUp = true;
			return this;
		}

	@Override
		public String getErrorAsString()
		throws IOException {
			return StreamCopier.copyStreamToString(err);
		}

	@Override
		public InputStream getErrorStream() {
			return err;
		}

	@Override
		public String getExitErrorMessage() {
			return exitErrMsg;
		}

	@Override
		public Signal getExitSignal() {
			return exitSignal;
		}

	@Override
		public Integer getExitStatus() {
			return exitStatus;
		}

	@Override
		public String getOutputAsString()
		throws IOException {
			return StreamCopier.copyStreamToString(getInputStream());
		}

	@Override
		public void handleRequest(String req, SSHPacket buf)
		throws ConnectionException, TransportException {
			if ("xon-xoff".equals(req))
				canDoFlowControl = buf.readBoolean();
			else if ("exit-status".equals(req))
				exitStatus = buf.readInt();
			else if ("exit-signal".equals(req)) {
				exitSignal = Signal.fromString(buf.readString());
				wasCoreDumped = buf.readBoolean(); // core dumped
				exitErrMsg = buf.readString();
				sendClose();
			} else
				super.handleRequest(req, buf);
		}

	@Override
		public void reqX11Forwarding(String authProto, String authCookie, int screen)
		throws ConnectionException,
		       TransportException {
			       sendChannelRequest(
					       "x11-req",
					       true,
					       new Buffer.PlainBuffer()
					       .putBoolean(false)
					       .putString(authProto)
					       .putString(authCookie)
					       .putInt(screen)
					       ).await(conn.getTimeout(), TimeUnit.SECONDS);
		       }

	@Override
		public void setEnvVar(String name, String value)
		throws ConnectionException, TransportException {
			sendChannelRequest("env", true, new Buffer.PlainBuffer().putString(name).putString(value))
				.await(conn.getTimeout(), TimeUnit.SECONDS);
		}

	@Override
		public void signal(Signal sig)
		throws TransportException {
			sendChannelRequest("signal", false, new Buffer.PlainBuffer().putString(sig.toString()));
		}

	@Override
		public Shell startShell()
		throws ConnectionException, TransportException {
			checkReuse();
			sendChannelRequest("shell", true, null).await(conn.getTimeout(), TimeUnit.SECONDS);
			usedUp = true;
			return this;
		}

	@Override
		public Subsystem startSubsystem(String name)
		throws ConnectionException, TransportException {
			checkReuse();
			log.info("Will request `{}` subsystem", name);
			sendChannelRequest("subsystem", true, new Buffer.PlainBuffer().putString(name))
				.await(conn.getTimeout(), TimeUnit.SECONDS);
			usedUp = true;
			return this;
		}

	@Override
		public Boolean getExitWasCoreDumped() {
			return wasCoreDumped;
		}

	@Override
		protected void closeAllStreams() {
			org.netling.io.Util.closeQuietly(err);
			super.closeAllStreams();
		}

	@Override
		protected void eofInputStreams() {
			err.eof(); // also close the stderr stream
			super.eofInputStreams();
		}

	@Override
		protected void gotExtendedData(int dataTypeCode, SSHPacket buf)
		throws ConnectionException, TransportException {
			if (dataTypeCode == 1)
				receiveInto(err, buf);
			else
				super.gotExtendedData(dataTypeCode, buf);
		}
	
	public void notifyError(SSHException error) {
		err.notifyError(error);
		super.notifyError(error);
	} 

	private void checkReuse() {
		if (usedUp)
			throw new SSHRuntimeException("This session channel is used up");
	}

}