/*
* Copyright (C)2009 - SSHJ Contributors
*
* 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.
*/
package net.schmizz.sshj.connection.channel;
import net.schmizz.sshj.common.ErrorNotifiable;
import net.schmizz.sshj.common.LoggerFactory;
import net.schmizz.sshj.common.SSHPacketHandler;
import net.schmizz.sshj.connection.ConnectionException;
import net.schmizz.sshj.transport.TransportException;
import java.io.Closeable;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.charset.Charset;
import java.util.concurrent.TimeUnit;
/**
* A channel is the basic medium for application-layer data on top of an SSH transport.
*/
public interface Channel extends Closeable, SSHPacketHandler, ErrorNotifiable {
/**
* Direct channels are those that are initiated by us.
*/
interface Direct extends Channel {
/**
* Request opening this channel from remote end.
*
* @throws OpenFailException in case the channel open request was rejected
* @throws ConnectionException other connection-layer error
* @throws TransportException error writing packets etc.
*/
void open() throws ConnectionException, TransportException;
}
/**
* Forwarded channels are those that are initiated by the server.
*/
interface Forwarded extends Channel {
/**
* Confirm {@code CHANNEL_OPEN} request.
*
* @throws TransportException error sending confirmation packet
*/
void confirm() throws TransportException;
/**
* @return the IP of where the forwarded connection originates.
*/
String getOriginatorIP();
/**
* @return port from which the forwarded connection originates.
*/
int getOriginatorPort();
/**
* Indicate rejection to remote end.
*
* @param reason indicate {@link OpenFailException.Reason reason} for rejection of the request
* @param message indicate a message for why the request is rejected
* @throws TransportException error sending rejection packet
*/
void reject(OpenFailException.Reason reason, String message) throws TransportException;
}
/**
* Close this channel.
*/
@Override
void close() throws TransportException, ConnectionException;
/**
* @return whether auto-expansion of local window is set.
* @see #setAutoExpand(boolean)
*/
boolean getAutoExpand();
/**
* @return the channel ID
*/
int getID();
/**
* @return the {@code InputStream} for this channel.
*/
InputStream getInputStream();
/**
* @return the maximum packet size that we have specified.
*/
int getLocalMaxPacketSize();
/**
* @return the current local window size.
*/
long getLocalWinSize();
/**
* @return an {@code OutputStream} for this channel.
*/
OutputStream getOutputStream();
/**
* @return the channel ID at the remote end.
*/
int getRecipient();
/** @return the character set used to communicate with the remote machine for certain strings (like paths). */
Charset getRemoteCharset();
/**
* @return the maximum packet size as specified by the remote end.
*/
int getRemoteMaxPacketSize();
/**
* @return the current remote window size.
*/
long getRemoteWinSize();
/**
* @return the channel type identifier.
*/
String getType();
/**
* @return whether the channel is open.
*/
boolean isOpen();
/**
* Set whether local window should automatically expand when data is received, irrespective of whether data has been
* read from that stream. This is useful e.g. when a remote command produces a lot of output that would fill the
* local window but you are not interested in reading from its {@code InputStream}.
*
* @param autoExpand whether local windows should automatically expand
*/
void setAutoExpand(boolean autoExpand);
void join() throws ConnectionException;
void join(long timeout, TimeUnit unit) throws ConnectionException;
/**
* Returns whether EOF has been received.
*/
boolean isEOF();
/**
* Get the LoggerFactory associated with the SSH client.
*/
LoggerFactory getLoggerFactory();
}