/*
* 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.giraph.comm.netty.handler;
import org.apache.giraph.comm.netty.NettyClient;
import org.apache.giraph.comm.netty.SaslNettyClient;
import org.apache.giraph.comm.requests.RequestType;
import org.apache.giraph.comm.requests.SaslCompleteRequest;
import org.apache.giraph.comm.requests.SaslTokenMessageRequest;
import org.apache.giraph.comm.requests.WritableRequest;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.util.ReflectionUtils;
import org.apache.log4j.Logger;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufInputStream;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.handler.codec.FixedLengthFrameDecoder;
import io.netty.util.ReferenceCountUtil;
import java.io.IOException;
/**
* Client-side Netty pipeline component that allows authentication with a
* server.
*/
public class SaslClientHandler extends ChannelInboundHandlerAdapter {
/** Class logger */
private static final Logger LOG = Logger.getLogger(SaslClientHandler.class);
/** Configuration */
private final Configuration conf;
/**
* Constructor.
*
* @param conf Configuration
*/
public SaslClientHandler(Configuration conf) {
this.conf = conf;
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg)
throws Exception {
WritableRequest decodedMessage = decode(ctx, msg);
// Generate SASL response to server using Channel-local SASL client.
SaslNettyClient saslNettyClient = ctx.attr(NettyClient.SASL).get();
if (saslNettyClient == null) {
throw new Exception("handleUpstream: saslNettyClient was unexpectedly " +
"null for channel: " + ctx.channel());
}
if (decodedMessage.getClass() == SaslCompleteRequest.class) {
if (LOG.isDebugEnabled()) {
LOG.debug("handleUpstream: Server has sent us the SaslComplete " +
"message. Allowing normal work to proceed.");
}
synchronized (saslNettyClient.getAuthenticated()) {
saslNettyClient.getAuthenticated().notify();
}
if (!saslNettyClient.isComplete()) {
LOG.error("handleUpstream: Server returned a Sasl-complete message, " +
"but as far as we can tell, we are not authenticated yet.");
throw new Exception("handleUpstream: Server returned a " +
"Sasl-complete message, but as far as " +
"we can tell, we are not authenticated yet.");
}
// Remove SaslClientHandler and replace LengthFieldBasedFrameDecoder
// from client pipeline.
ctx.pipeline().remove(this);
ctx.pipeline().replace("length-field-based-frame-decoder",
"fixed-length-frame-decoder",
new FixedLengthFrameDecoder(RequestServerHandler.RESPONSE_BYTES));
return;
}
SaslTokenMessageRequest serverToken =
(SaslTokenMessageRequest) decodedMessage;
if (LOG.isDebugEnabled()) {
LOG.debug("handleUpstream: Responding to server's token of length: " +
serverToken.getSaslToken().length);
}
// Generate SASL response (but we only actually send the response if it's
// non-null.
byte[] responseToServer = saslNettyClient.saslResponse(serverToken);
if (responseToServer == null) {
// If we generate a null response, then authentication has completed (if
// not, warn), and return without sending a response back to the server.
if (LOG.isDebugEnabled()) {
LOG.debug("handleUpstream: Response to server is null: " +
"authentication should now be complete.");
}
if (!saslNettyClient.isComplete()) {
LOG.warn("handleUpstream: Generated a null response, " +
"but authentication is not complete.");
}
return;
} else {
if (LOG.isDebugEnabled()) {
LOG.debug("handleUpstream: Response to server token has length:" +
responseToServer.length);
}
}
// Construct a message containing the SASL response and send it to the
// server.
SaslTokenMessageRequest saslResponse =
new SaslTokenMessageRequest(responseToServer);
ctx.channel().writeAndFlush(saslResponse);
}
/**
* Decode the message read by handler
*
* @param ctx channel handler context
* @param msg message to decode into a writable request
* @return decoded writablerequest object
* @throws Exception
*/
protected WritableRequest decode(ChannelHandlerContext ctx, Object msg)
throws Exception {
if (!(msg instanceof ByteBuf)) {
throw new IllegalStateException("decode: Got illegal message " + msg);
}
// Decode msg into an object whose class C implements WritableRequest:
// C will be either SaslTokenMessage or SaslComplete.
//
// 1. Convert message to a stream that can be decoded.
ByteBuf buf = (ByteBuf) msg;
ByteBufInputStream inputStream = new ByteBufInputStream(buf);
// 2. Get first byte: message type:
int enumValue = inputStream.readByte();
RequestType type = RequestType.values()[enumValue];
if (LOG.isDebugEnabled()) {
LOG.debug("decode: Got a response of type " + type + " from server:" +
ctx.channel().remoteAddress());
}
// 3. Create object of the type determined in step 2.
Class<? extends WritableRequest> writableRequestClass =
type.getRequestClass();
WritableRequest serverResponse =
ReflectionUtils.newInstance(writableRequestClass, conf);
// 4. Deserialize the inputStream's contents into the newly-constructed
// serverResponse object.
try {
serverResponse.readFields(inputStream);
} catch (IOException e) {
LOG.error("decode: Exception when trying to read server response: " + e);
}
ReferenceCountUtil.release(buf);
// serverResponse can now be used in the next stage in pipeline.
return serverResponse;
}
}