| /* |
| * 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.session; |
| |
| import java.util.List; |
| |
| import org.apache.sshd.common.io.IoWriteFuture; |
| import org.apache.sshd.common.util.SshdEventListener; |
| import org.apache.sshd.common.util.buffer.Buffer; |
| |
| /** |
| * Provides a way to listen and handle the {@code SSH_MSG_IGNORE} and {@code SSH_MSG_DEBUG} messages that are received |
| * by a session, as well as proprietary and/or extension messages and behavior. |
| * |
| * @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a> |
| */ |
| public interface ReservedSessionMessagesHandler extends SshdEventListener { |
| /** |
| * Send the initial version exchange identification in and independent manner |
| * |
| * @param session The {@code Session} through which the version is exchange is being managed |
| * @param version The version line that was resolved - <B>Note:</B> since this string is part of the KEX and is |
| * <U>cached</U> in the calling session, any changes to it require updating the session's cached |
| * value. |
| * @param extraLines Extra lines to be sent - valid only for server sessions. <B>Note:/B> the handler may modify |
| * these lines and return {@code null} thus signaling the session to proceed with sending the |
| * identification |
| * @return A {@link IoWriteFuture} that can be used to wait for the data to be sent successfully. If |
| * {@code null} then the session will send the identification, otherwise it is assumed that the |
| * handler has sent it. |
| * @throws Exception |
| * @see <A HREF="https://tools.ietf.org/html/rfc4253#section-4.2">RFC 4253 - section 4.2 - Protocol |
| * Version Exchange</A> |
| */ |
| default IoWriteFuture sendIdentification( |
| Session session, String version, List<String> extraLines) |
| throws Exception { |
| return null; |
| } |
| |
| /** |
| * Invoked when an {@code SSH_MSG_IGNORE} packet is received |
| * |
| * @param session The {@code Session} through which the message was received |
| * @param buffer The {@code Buffer} containing the data |
| * @throws Exception If failed to handle the message |
| * @see <A HREF="https://tools.ietf.org/html/rfc4253#section-11.2">RFC 4253 - section 11.2</A> |
| */ |
| default void handleIgnoreMessage(Session session, Buffer buffer) throws Exception { |
| // ignored |
| } |
| |
| /** |
| * Invoked when an {@code SSH_MSG_DEBUG} packet is received |
| * |
| * @param session The {@code Session} through which the message was received |
| * @param buffer The {@code Buffer} containing the data |
| * @throws Exception If failed to handle the message |
| * @see <A HREF="https://tools.ietf.org/html/rfc4253#section-11.3">RFC 4253 - section 11.3</A> |
| */ |
| default void handleDebugMessage(Session session, Buffer buffer) throws Exception { |
| // ignored |
| } |
| |
| /** |
| * Invoked when a packet with an un-implemented message is received - including {@code SSH_MSG_UNIMPLEMENTED} itself |
| * |
| * @param session The {@code Session} through which the message was received |
| * @param cmd The received (un-implemented) command |
| * @param buffer The {@code Buffer} containing the data - positioned just beyond the command |
| * @return {@code true} if message handled internally, {@code false} if should return a |
| * {@code SSH_MSG_UNIMPLEMENTED} reply (default behavior) |
| * @throws Exception If failed to handle the message |
| * @see <A HREF="https://tools.ietf.org/html/rfc4253#section-11.4">RFC 4253 - section 11.4</A> |
| */ |
| default boolean handleUnimplementedMessage(Session session, int cmd, Buffer buffer) throws Exception { |
| return false; |
| } |
| |
| /** |
| * Invoked if the user configured usage of a proprietary heartbeat mechanism. <B>Note:</B> by default throws |
| * {@code UnsupportedOperationException} so users who configure a proprietary heartbeat mechanism option must |
| * provide an implementation for this method. |
| * |
| * @param service The {@link ConnectionService} through which the heartbeat is being executed. |
| * @return {@code true} whether heartbeat actually sent - <B>Note:</B> used mainly for debugging purposes. |
| * @throws Exception If failed to send the heartbeat - <B>Note:</B> causes associated session termination. |
| */ |
| default boolean sendReservedHeartbeat(ConnectionService service) throws Exception { |
| throw new UnsupportedOperationException("Reserved heartbeat not implemented for " + service); |
| } |
| } |