sshd-core/src/main/java/org/apache/sshd/common/forward/TcpipForwarder.java

/*
 * 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.common.forward;


import java.io.IOException;

import org.apache.sshd.common.Closeable;
import org.apache.sshd.common.util.net.SshdSocketAddress;

public interface TcpipForwarder extends Closeable {

    /**
     * Start forwarding the given local address on the client to the given address on the server.
     *
     * @param remote The remote address
     * @param local  The local address
     * @return The bound {@link SshdSocketAddress}
     * @throws IOException If failed to handle request
     */
    SshdSocketAddress startLocalPortForwarding(SshdSocketAddress local, SshdSocketAddress remote) throws IOException;

    /**
     * Stop forwarding the given local address.
     *
     * @param local The local address
     * @throws IOException If failed to handle request
     */
    void stopLocalPortForwarding(SshdSocketAddress local) throws IOException;

    /**
     * <P>
     * Start forwarding tcp/ip from the given remote address to the
     * given local address.
     * </P>
     *
     * <P>
     * The remote host name is the address to bind to on the server:
     * </P>
     * <ul>
     * <li>
     * &quot;&quot; means that connections are to be accepted on all protocol families
     * supported by the SSH implementation
     * </li>
     *
     * <li>
     * &quot;0.0.0.0&quot; means to listen on all IPv4 addresses
     * </li>
     *
     * <li>
     * &quot;::&quot; means to listen on all IPv6 addresses
     * </li>
     *
     * <li>
     * &quot;localhost&quot; means to listen on all protocol families supported by the SSH
     * implementation on loopback addresses only, [RFC3330] and RFC3513]
     * </li>
     *
     * <li>
     * &quot;127.0.0.1&quot; and &quot;::1&quot; indicate listening on the loopback interfaces for
     * IPv4 and IPv6 respectively
     * </li>
     * </ul>
     *
     * @param remote The remote address
     * @param local  The local address
     * @return The bound {@link SshdSocketAddress}
     * @throws IOException If failed to handle request
     */
    SshdSocketAddress startRemotePortForwarding(SshdSocketAddress remote, SshdSocketAddress local) throws IOException;

    /**
     * Stop forwarding of the given remote address.
     *
     * @param remote The remote {@link SshdSocketAddress}
     * @throws IOException If failed to handle request
     */
    void stopRemotePortForwarding(SshdSocketAddress remote) throws IOException;

    /**
     * @param remotePort The remote port
     * @return The local {@link SshdSocketAddress} that the remote port is forwarded to
     */
    SshdSocketAddress getForwardedPort(int remotePort);

    /**
     * Called when the other side requested a remote port forward.
     *
     * @param local The request address
     * @return The bound local {@link SshdSocketAddress} - {@code null} if not allowed to forward
     * @throws IOException If failed to handle request
     */
    SshdSocketAddress localPortForwardingRequested(SshdSocketAddress local) throws IOException;

    /**
     * Called when the other side cancelled a remote port forward.
     *
     * @param local The local {@link SshdSocketAddress}
     * @throws IOException If failed to handle request
     */
    void localPortForwardingCancelled(SshdSocketAddress local) throws IOException;

    SshdSocketAddress startDynamicPortForwarding(SshdSocketAddress local) throws IOException;

    void stopDynamicPortForwarding(SshdSocketAddress local) throws IOException;

}