| /* |
| * 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.helpers; |
| |
| import java.io.IOException; |
| |
| import org.apache.sshd.common.SshConstants; |
| import org.apache.sshd.common.channel.Channel; |
| import org.apache.sshd.common.io.IoWriteFuture; |
| import org.apache.sshd.common.session.ConnectionService; |
| import org.apache.sshd.common.session.Session; |
| import org.apache.sshd.common.session.UnknownChannelReferenceHandler; |
| import org.apache.sshd.common.util.buffer.Buffer; |
| import org.apache.sshd.common.util.logging.AbstractLoggingBean; |
| import org.apache.sshd.core.CoreModuleProperties; |
| |
| /** |
| * @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a> |
| */ |
| public class DefaultUnknownChannelReferenceHandler |
| extends AbstractLoggingBean |
| implements UnknownChannelReferenceHandler { |
| |
| public static final DefaultUnknownChannelReferenceHandler INSTANCE = new DefaultUnknownChannelReferenceHandler(); |
| |
| public DefaultUnknownChannelReferenceHandler() { |
| super(); |
| } |
| |
| @Override |
| public Channel handleUnknownChannelCommand( |
| ConnectionService service, byte cmd, int channelId, Buffer buffer) |
| throws IOException { |
| Session session = service.getSession(); |
| // Use DEBUG level to avoid log overflow due to invalid messages flood |
| boolean debugEnabled = log.isDebugEnabled(); |
| if (debugEnabled) { |
| log.debug("handleUnknownChannelCommand({}) received {} command for unknown channel: {}", |
| session, SshConstants.getCommandMessageName(cmd), channelId); |
| } |
| |
| boolean wantReply = false; |
| switch (cmd) { |
| case SshConstants.SSH_MSG_CHANNEL_REQUEST: { |
| /* |
| * From RFC 4252 - section 5.4: |
| * |
| * If the request is not recognized or is not supported for the channel, SSH_MSG_CHANNEL_FAILURE is |
| * returned |
| */ |
| String req = buffer.getString(); |
| wantReply = buffer.getBoolean(); |
| // Use DEBUG level to avoid log overflow due to invalid messages flood |
| if (debugEnabled) { |
| log.debug( |
| "handleUnknownChannelCommand({}) Received SSH_MSG_CHANNEL_REQUEST={} (wantReply={}) for unknown channel: {}", |
| session, req, wantReply, channelId); |
| } |
| break; |
| } |
| |
| case SshConstants.SSH_MSG_CHANNEL_DATA: |
| case SshConstants.SSH_MSG_CHANNEL_EXTENDED_DATA: |
| wantReply = CoreModuleProperties.SEND_REPLY_FOR_CHANNEL_DATA.getRequired(session); |
| // Use TRACE level to avoid log overflow due to invalid messages flood |
| if (log.isTraceEnabled()) { |
| log.trace("handleUnknownChannelCommand({}) received msg channel data (opcode={}) reply={}", |
| session, cmd, wantReply); |
| } |
| break; |
| |
| default: // do nothing |
| } |
| |
| if (wantReply) { |
| sendFailureResponse(service, cmd, channelId); |
| } |
| |
| return null; |
| } |
| |
| protected IoWriteFuture sendFailureResponse( |
| ConnectionService service, byte cmd, int channelId) |
| throws IOException { |
| Session session = service.getSession(); |
| // Use DEBUG level to avoid log overflow due to invalid messages flood |
| if (log.isDebugEnabled()) { |
| log.debug("sendFailureResponse({}) send SSH_MSG_CHANNEL_FAILURE for {} command on unknown channel: {}", |
| session, SshConstants.getCommandMessageName(cmd), channelId); |
| } |
| |
| Buffer rsp = session.createBuffer(SshConstants.SSH_MSG_CHANNEL_FAILURE, Integer.BYTES); |
| rsp.putInt(channelId); |
| return session.writePacket(rsp); |
| } |
| } |