net.schmizz.sshj.connection.channel.Channel Maven / Gradle / Ivy
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/**
* Copyright 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.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.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 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(int timeout, TimeUnit unit)
throws ConnectionException;
}