/*
 *  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.coyote.ajp;

import java.net.InetAddress;
import java.util.regex.Pattern;

import org.apache.coyote.AbstractProtocol;
import org.apache.coyote.Processor;
import org.apache.coyote.UpgradeProtocol;
import org.apache.coyote.UpgradeToken;
import org.apache.tomcat.util.net.AbstractEndpoint;
import org.apache.tomcat.util.net.SSLHostConfig;
import org.apache.tomcat.util.net.SocketWrapperBase;
import org.apache.tomcat.util.res.StringManager;

The is the base implementation for the AJP protocol handlers. Implementations typically extend this base class rather than implement ProtocolHandler. All of the implementations that ship with Tomcat are implemented this way. 
Type parameters:
<S> – The type of socket used by the implementation/**
 * The is the base implementation for the AJP protocol handlers. Implementations
 * typically extend this base class rather than implement {@link
 * org.apache.coyote.ProtocolHandler}. All of the implementations that ship with
 * Tomcat are implemented this way.
 *
 * @param <S> The type of socket used by the implementation
 */
public abstract class AbstractAjpProtocol<S> extends AbstractProtocol<S> {

    
The string manager for this package.
/**
     * The string manager for this package.
     */
    protected static final StringManager sm = StringManager.getManager(AbstractAjpProtocol.class);


    public AbstractAjpProtocol(AbstractEndpoint<S,?> endpoint) {
        super(endpoint);
        setConnectionTimeout(Constants.DEFAULT_CONNECTION_TIMEOUT);
        // AJP does not use Send File
        getEndpoint().setUseSendfile(false);
        // AJP listens on loopback by default
        getEndpoint().setAddress(InetAddress.getLoopbackAddress());
        ConnectionHandler<S> cHandler = new ConnectionHandler<>(this);
        setHandler(cHandler);
        getEndpoint().setHandler(cHandler);
    }


    @Override
    protected String getProtocolName() {
        return "Ajp";
    }


    
{@inheritDoc}
Overridden to make getter accessible to other classes in this package.
/**
     * {@inheritDoc}
     *
     * Overridden to make getter accessible to other classes in this package.
     */
    @Override
    protected AbstractEndpoint<S,?> getEndpoint() {
        return super.getEndpoint();
    }


    
{@inheritDoc}
AJP does not support protocol negotiation so this always returns null.
/**
     * {@inheritDoc}
     *
     * AJP does not support protocol negotiation so this always returns null.
     */
    @Override
    protected UpgradeProtocol getNegotiatedProtocol(String name) {
        return null;
    }


    
{@inheritDoc}
AJP does not support protocol upgrade so this always returns null.
/**
     * {@inheritDoc}
     *
     * AJP does not support protocol upgrade so this always returns null.
     */
    @Override
    protected UpgradeProtocol getUpgradeProtocol(String name) {
        return null;
    }

    // ------------------------------------------------- AJP specific properties
    // ------------------------------------------ managed in the ProtocolHandler

    private boolean ajpFlush = true;
    public boolean getAjpFlush() { return ajpFlush; }
    
Configure whether to aend an AJP flush packet when flushing. A flush
packet is a zero byte AJP13 SEND_BODY_CHUNK packet. mod_jk and
mod_proxy_ajp interpret this as a request to flush data to the client.
AJP always does flush at the and of the response, so if it is not
important, that the packets get streamed up to the client, do not use
extra flush packets. For compatibility and to stay on the safe side,
flush packets are enabled by default.
Params:
ajpFlush –  The new flush setting/**
     * Configure whether to aend an AJP flush packet when flushing. A flush
     * packet is a zero byte AJP13 SEND_BODY_CHUNK packet. mod_jk and
     * mod_proxy_ajp interpret this as a request to flush data to the client.
     * AJP always does flush at the and of the response, so if it is not
     * important, that the packets get streamed up to the client, do not use
     * extra flush packets. For compatibility and to stay on the safe side,
     * flush packets are enabled by default.
     *
     * @param ajpFlush  The new flush setting
     */
    public void setAjpFlush(boolean ajpFlush) {
        this.ajpFlush = ajpFlush;
    }


    private boolean tomcatAuthentication = true;
    
Should authentication be done in the native web server layer,
or in the Servlet container ?
Returns:
true if authentication should be performed by Tomcat, otherwise false/**
     * Should authentication be done in the native web server layer,
     * or in the Servlet container ?
     *
     * @return {@code true} if authentication should be performed by Tomcat,
     *         otherwise {@code false}
     */
    public boolean getTomcatAuthentication() { return tomcatAuthentication; }
    public void setTomcatAuthentication(boolean tomcatAuthentication) {
        this.tomcatAuthentication = tomcatAuthentication;
    }


    private boolean tomcatAuthorization = false;
    
Should authentication be done in the native web server layer and
authorization in the Servlet container?
Returns:
true if authorization should be performed by Tomcat, otherwise false/**
     * Should authentication be done in the native web server layer and
     * authorization in the Servlet container?
     *
     * @return {@code true} if authorization should be performed by Tomcat,
     *         otherwise {@code false}
     */
    public boolean getTomcatAuthorization() { return tomcatAuthorization; }
    public void setTomcatAuthorization(boolean tomcatAuthorization) {
        this.tomcatAuthorization = tomcatAuthorization;
    }


    private String secret = null;
    
Set the secret that must be included with every request.
Params:
secret – The required secret/**
     * Set the secret that must be included with every request.
     *
     * @param secret The required secret
     */
    public void setSecret(String secret) {
        this.secret = secret;
    }
    protected String getSecret() {
        return secret;
    }
    
Set the required secret that must be included with every request.
Params:
requiredSecret – The required secret
Deprecated:
Replaced by setSecret(String). Will be removed in Tomcat 11 onwards/**
     * Set the required secret that must be included with every request.
     *
     * @param requiredSecret The required secret
     *
     * @deprecated Replaced by {@link #setSecret(String)}.
     *             Will be removed in Tomcat 11 onwards
     */
    @Deprecated
    public void setRequiredSecret(String requiredSecret) {
        setSecret(requiredSecret);
    }
    
Returns:
The current secret
Deprecated:
Replaced by getSecret(). Will be removed in Tomcat 11 onwards/**
     * @return The current secret
     *
     * @deprecated Replaced by {@link #getSecret()}.
     *             Will be removed in Tomcat 11 onwards
     */
    @Deprecated
    protected String getRequiredSecret() {
        return getSecret();
    }


    private boolean secretRequired = true;
    public void setSecretRequired(boolean secretRequired) {
        this.secretRequired = secretRequired;
    }
    public boolean getSecretRequired() {
        return secretRequired;
    }


    private Pattern allowedRequestAttributesPattern;
    public void setAllowedRequestAttributesPattern(String allowedRequestAttributesPattern) {
        this.allowedRequestAttributesPattern = Pattern.compile(allowedRequestAttributesPattern);
    }
    public String getAllowedRequestAttributesPattern() {
        return allowedRequestAttributesPattern.pattern();
    }
    protected Pattern getAllowedRequestAttributesPatternInternal() {
        return allowedRequestAttributesPattern;
    }


    
AJP packet size.
/**
     * AJP packet size.
     */
    private int packetSize = Constants.MAX_PACKET_SIZE;
    public int getPacketSize() { return packetSize; }
    public void setPacketSize(int packetSize) {
        if (packetSize < Constants.MAX_PACKET_SIZE) {
            this.packetSize = Constants.MAX_PACKET_SIZE;
        } else {
            this.packetSize = packetSize;
        }
    }


    @Override
    public int getDesiredBufferSize() {
        return getPacketSize() - Constants.SEND_HEAD_LEN;
    }


    // --------------------------------------------- SSL is not supported in AJP

    @Override
    public void addSslHostConfig(SSLHostConfig sslHostConfig) {
        getLog().warn(sm.getString("ajpprotocol.noSSL", sslHostConfig.getHostName()));
    }


    @Override
    public SSLHostConfig[] findSslHostConfigs() {
        return new SSLHostConfig[0];
    }


    @Override
    public void addUpgradeProtocol(UpgradeProtocol upgradeProtocol) {
        getLog().warn(sm.getString("ajpprotocol.noUpgrade", upgradeProtocol.getClass().getName()));
    }


    @Override
    public UpgradeProtocol[] findUpgradeProtocols() {
        return new UpgradeProtocol[0];
    }


    @Override
    protected Processor createProcessor() {
        AjpProcessor processor = new AjpProcessor(this, getAdapter());
        return processor;
    }


    @Override
    protected Processor createUpgradeProcessor(SocketWrapperBase<?> socket,
            UpgradeToken upgradeToken) {
        throw new IllegalStateException(sm.getString("ajpprotocol.noUpgradeHandler",
                upgradeToken.getHttpUpgradeHandler().getClass().getName()));
    }


    @Override
    public void start() throws Exception {
        if (getSecretRequired()) {
            String secret = getSecret();
            if (secret == null || secret.length() == 0) {
                throw new IllegalArgumentException(sm.getString("ajpprotocol.noSecret"));
            }
        }
        super.start();
    }
}