/*
 * 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.catalina.connector;

import java.io.IOException;
import java.io.Serial;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.EnumSet;
import java.util.concurrent.atomic.AtomicBoolean;

import jakarta.servlet.ReadListener;
import jakarta.servlet.RequestDispatcher;
import jakarta.servlet.ServletException;
import jakarta.servlet.SessionTrackingMode;
import jakarta.servlet.WriteListener;
import jakarta.servlet.http.HttpServletResponse;

import org.apache.catalina.Authenticator;
import org.apache.catalina.Context;
import org.apache.catalina.Host;
import org.apache.catalina.Wrapper;
import org.apache.catalina.authenticator.AuthenticatorBase;
import org.apache.catalina.core.AsyncContextImpl;
import org.apache.catalina.util.ServerInfo;
import org.apache.catalina.util.SessionConfig;
import org.apache.catalina.util.URLEncoder;
import org.apache.coyote.ActionCode;
import org.apache.coyote.Adapter;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.ExceptionUtils;
import org.apache.tomcat.util.buf.B2CConverter;
import org.apache.tomcat.util.buf.ByteChunk;
import org.apache.tomcat.util.buf.CharChunk;
import org.apache.tomcat.util.buf.HexUtils;
import org.apache.tomcat.util.buf.MessageBytes;
import org.apache.tomcat.util.http.ServerCookie;
import org.apache.tomcat.util.http.ServerCookies;
import org.apache.tomcat.util.net.SSLSupport;
import org.apache.tomcat.util.net.SocketEvent;
import org.apache.tomcat.util.res.StringManager;


/**
 * Implementation of a request processor which delegates the processing to a Coyote processor.
 *
 * @author Craig R. McClanahan
 * @author Remy Maucherat
 */
public class CoyoteAdapter implements Adapter {

    private static final Log log = LogFactory.getLog(CoyoteAdapter.class);

    // -------------------------------------------------------------- Constants

    private static final String POWERED_BY = "Servlet/6.1 JSP/4.0 " + "(" + ServerInfo.getServerInfo() + " Java/" +
            System.getProperty("java.vm.vendor") + "/" + System.getProperty("java.runtime.version") + ")";

    private static final EnumSet<SessionTrackingMode> SSL_ONLY = EnumSet.of(SessionTrackingMode.SSL);

    public static final int ADAPTER_NOTES = 1;


    // ----------------------------------------------------------- Constructors

    /**
     * Construct a new CoyoteProcessor associated with the specified connector.
     *
     * @param connector CoyoteConnector that owns this processor
     */
    public CoyoteAdapter(Connector connector) {

        super();
        this.connector = connector;

    }


    // ----------------------------------------------------- Instance Variables


    /**
     * The CoyoteConnector with which this processor is associated.
     */
    private final Connector connector;


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


    // -------------------------------------------------------- Adapter Methods

    @Override
    public boolean asyncDispatch(org.apache.coyote.Request req, org.apache.coyote.Response res, SocketEvent status)
            throws Exception {

        Request request = (Request) req.getNote(ADAPTER_NOTES);
        Response response = (Response) res.getNote(ADAPTER_NOTES);

        if (request == null) {
            throw new IllegalStateException(sm.getString("coyoteAdapter.nullRequest"));
        }

        boolean success = true;
        AsyncContextImpl asyncConImpl = request.getAsyncContextInternal();

        req.setRequestThread();

        try {
            if (!request.isAsync()) {
                // Error or timeout
                // Lift any suspension (e.g. if sendError() was used by an async
                // request) to allow the response to be written to the client
                response.setSuspended(false);
            }

            if (status == SocketEvent.TIMEOUT) {
                if (!asyncConImpl.timeout()) {
                    asyncConImpl.setErrorState(null, false);
                }
            } else if (status == SocketEvent.ERROR) {
                // An I/O error occurred on a non-container thread which means
                // that the socket needs to be closed so set success as false to
                // trigger a close
                success = false;
                Throwable t = (Throwable) req.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
                Context context = request.getContext();
                ClassLoader oldCL = null;
                try {
                    oldCL = context.bind(null);
                    if (req.getReadListener() != null) {
                        req.getReadListener().onError(t);
                    }
                    if (res.getWriteListener() != null) {
                        res.getWriteListener().onError(t);
                    }
                    res.action(ActionCode.CLOSE_NOW, t);
                    asyncConImpl.setErrorState(t, true);
                } finally {
                    context.unbind(oldCL);
                }
            }

            // Check to see if non-blocking writes or reads are being used
            if (!request.isAsyncDispatching() && request.isAsync()) {
                WriteListener writeListener = res.getWriteListener();
                ReadListener readListener = req.getReadListener();
                if (writeListener != null && status == SocketEvent.OPEN_WRITE) {
                    Context context = request.getContext();
                    ClassLoader oldCL = null;
                    try {
                        oldCL = context.bind(null);
                        res.onWritePossible();
                        if (request.isFinished() && req.sendAllDataReadEvent() && readListener != null) {
                            readListener.onAllDataRead();
                        }
                        // User code may have swallowed an IOException
                        if (response.getCoyoteResponse().isExceptionPresent()) {
                            throw response.getCoyoteResponse().getErrorException();
                        }
                    } catch (Throwable t) {
                        ExceptionUtils.handleThrowable(t);
                        // Allow the error handling to write to the response
                        response.setSuspended(false);
                        // Need to trigger the call to AbstractProcessor.setErrorState()
                        // before the listener is called so the listener can call complete
                        // Therefore no need to set success=false as that would trigger a
                        // second call to AbstractProcessor.setErrorState()
                        // https://bz.apache.org/bugzilla/show_bug.cgi?id=65001
                        writeListener.onError(t);
                        res.action(ActionCode.CLOSE_NOW, t);
                        asyncConImpl.setErrorState(t, true);
                    } finally {
                        context.unbind(oldCL);
                    }
                } else if (readListener != null && status == SocketEvent.OPEN_READ) {
                    Context context = request.getContext();
                    ClassLoader oldCL = null;
                    try {
                        oldCL = context.bind(null);
                        // If data is being read on a non-container thread a
                        // dispatch with status OPEN_READ will be used to get
                        // execution back on a container thread for the
                        // onAllDataRead() event. Therefore, make sure
                        // onDataAvailable() is not called in this case.
                        if (!request.isFinished()) {
                            req.onDataAvailable();
                        }
                        if (request.isFinished() && req.sendAllDataReadEvent()) {
                            readListener.onAllDataRead();
                        }
                        // User code may have swallowed an IOException
                        if (request.getCoyoteRequest().isExceptionPresent()) {
                            throw request.getCoyoteRequest().getErrorException();
                        }
                    } catch (Throwable t) {
                        ExceptionUtils.handleThrowable(t);
                        // Allow the error handling to write to the response
                        response.setSuspended(false);
                        // Need to trigger the call to AbstractProcessor.setErrorState()
                        // before the listener is called so the listener can call complete
                        // Therefore no need to set success=false as that would trigger a
                        // second call to AbstractProcessor.setErrorState()
                        // https://bz.apache.org/bugzilla/show_bug.cgi?id=65001
                        readListener.onError(t);
                        res.action(ActionCode.CLOSE_NOW, t);
                        asyncConImpl.setErrorState(t, true);
                    } finally {
                        context.unbind(oldCL);
                    }
                }
            }

            // Has an error occurred during async processing that needs to be
            // processed by the application's error page mechanism (or Tomcat's
            // if the application doesn't define one)?
            if (!request.isAsyncDispatching() && request.isAsync() && response.isErrorReportRequired()) {
                connector.getService().getContainer().getPipeline().getFirst().invoke(request, response);
            }

            if (request.isAsyncDispatching()) {
                connector.getService().getContainer().getPipeline().getFirst().invoke(request, response);
                if (response.isError()) {
                    Throwable t = (Throwable) request.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
                    asyncConImpl.setErrorState(t, true);
                }
            }

            if (!request.isAsync()) {
                request.finishRequest();
                response.finishResponse();
            }

            // Check to see if the processor is in an error state. If it is,
            // bail out now.
            AtomicBoolean error = new AtomicBoolean(false);
            res.action(ActionCode.IS_ERROR, error);
            if (error.get()) {
                if (request.isAsyncCompleting() || request.isAsyncDispatching()) {
                    // Connection will be forcibly closed which will prevent completion/dispatch happening at the usual
                    // point. Trigger post-processing here.
                    res.action(ActionCode.ASYNC_POST_PROCESS, null);
                }
                success = false;
            }
        } catch (IOException ioe) {
            // Issues that should be logged will have already been logged
            success = false;
        } catch (Throwable t) {
            ExceptionUtils.handleThrowable(t);
            success = false;
            log.error(sm.getString("coyoteAdapter.asyncDispatch"), t);
        } finally {
            if (!success) {
                res.setStatus(500);
            }

            // Access logging
            if (!success || !request.isAsync()) {
                long time = 0;
                if (req.getStartTimeNanos() != -1) {
                    time = System.nanoTime() - req.getStartTimeNanos();
                }
                Context context = request.getContext();
                if (context != null) {
                    context.logAccess(request, response, time, false);
                } else {
                    log(req, res, time);
                }
            }

            req.getRequestProcessor().setWorkerThreadName(null);
            req.clearRequestThread();
            // Recycle the wrapper request and response
            if (!success || !request.isAsync()) {
                updateWrapperErrorCount(request, response);
                request.recycle();
                response.recycle();
            }
        }
        return success;
    }


    @Override
    public void service(org.apache.coyote.Request req, org.apache.coyote.Response res) throws Exception {

        Request request = (Request) req.getNote(ADAPTER_NOTES);
        Response response = (Response) res.getNote(ADAPTER_NOTES);

        if (request == null) {
            // Create objects
            request = connector.createRequest(req);
            response = connector.createResponse(res);

            // Link objects
            request.setResponse(response);
            response.setRequest(request);

            // Set as notes
            req.setNote(ADAPTER_NOTES, request);
            res.setNote(ADAPTER_NOTES, response);

            // Set query string encoding
            req.getParameters().setQueryStringCharset(connector.getURICharset());
        }

        if (connector.getXpoweredBy()) {
            response.addHeader("X-Powered-By", POWERED_BY);
        }

        boolean async = false;
        boolean postParseSuccess = false;

        req.setRequestThread();

        try {
            // Parse and set Catalina and configuration specific
            // request parameters
            postParseSuccess = postParseRequest(req, request, res, response);
            if (postParseSuccess) {
                // check valves if we support async
                request.setAsyncSupported(connector.getService().getContainer().getPipeline().isAsyncSupported());
                // Calling the container
                connector.getService().getContainer().getPipeline().getFirst().invoke(request, response);
            }
            if (request.isAsync()) {
                async = true;
                ReadListener readListener = req.getReadListener();
                if (readListener != null && request.isFinished()) {
                    // Possible the all data may have been read during service()
                    // method so this needs to be checked here
                    ClassLoader oldCL = null;
                    try {
                        oldCL = request.getContext().bind(null);
                        if (req.sendAllDataReadEvent()) {
                            req.getReadListener().onAllDataRead();
                        }
                    } finally {
                        request.getContext().unbind(oldCL);
                    }
                }

                Throwable throwable = (Throwable) request.getAttribute(RequestDispatcher.ERROR_EXCEPTION);

                // If an async request was started, is not going to end once
                // this container thread finishes and an error occurred, trigger
                // the async error process
                if (!request.isAsyncCompleting() && throwable != null) {
                    request.getAsyncContextInternal().setErrorState(throwable, true);
                }
            } else {
                request.finishRequest();
                response.finishResponse();
            }

        } catch (IOException ignore) {
            // Issues that should be logged will have already been logged
        } finally {
            AtomicBoolean error = new AtomicBoolean(false);
            res.action(ActionCode.IS_ERROR, error);

            if (request.isAsyncCompleting() && error.get()) {
                // Connection will be forcibly closed which will prevent
                // completion happening at the usual point. Need to trigger
                // call to onComplete() here.
                res.action(ActionCode.ASYNC_POST_PROCESS, null);
                async = false;
            }

            // Access log
            if (!async && postParseSuccess) {
                // Log only if processing was invoked.
                // If postParseRequest() failed, it has already logged it.
                Context context = request.getContext();
                Host host = request.getHost();
                // If the context is null, it is likely that the endpoint was
                // shutdown, this connection closed and the request recycled in
                // a different thread. That thread will have updated the access
                // log so it is OK not to update the access log here in that
                // case.
                // The other possibility is that an error occurred early in
                // processing and the request could not be mapped to a Context.
                // Log via the host or engine in that case.
                long time = System.nanoTime() - req.getStartTimeNanos();
                if (context != null) {
                    context.logAccess(request, response, time, false);
                } else if (response.isError()) {
                    if (host != null) {
                        host.logAccess(request, response, time, false);
                    } else {
                        connector.getService().getContainer().logAccess(request, response, time, false);
                    }
                }
            }

            req.getRequestProcessor().setWorkerThreadName(null);
            req.clearRequestThread();

            // Recycle the wrapper request and response
            if (!async) {
                updateWrapperErrorCount(request, response);
                request.recycle();
                response.recycle();
            }
        }
    }


    private void updateWrapperErrorCount(Request request, Response response) {
        if (response.isError()) {
            Wrapper wrapper = request.getWrapper();
            if (wrapper != null) {
                wrapper.incrementErrorCount();
            }
        }
    }


    @Override
    public boolean prepare(org.apache.coyote.Request req, org.apache.coyote.Response res)
            throws IOException, ServletException {
        Request request = (Request) req.getNote(ADAPTER_NOTES);
        Response response = (Response) res.getNote(ADAPTER_NOTES);

        return postParseRequest(req, request, res, response);
    }


    @Override
    public void log(org.apache.coyote.Request req, org.apache.coyote.Response res, long time) {

        Request request = (Request) req.getNote(ADAPTER_NOTES);
        Response response = (Response) res.getNote(ADAPTER_NOTES);

        if (request == null) {
            // Create objects
            request = connector.createRequest(req);
            response = connector.createResponse(res);

            // Link objects
            request.setResponse(response);
            response.setRequest(request);

            // Set as notes
            req.setNote(ADAPTER_NOTES, request);
            res.setNote(ADAPTER_NOTES, response);

            // Set query string encoding
            req.getParameters().setQueryStringCharset(connector.getURICharset());
        }

        try {
            // Log at the lowest level available. logAccess() will be
            // automatically called on parent containers.
            boolean logged = false;
            Context context = request.mappingData.context;
            Host host = request.mappingData.host;
            if (context != null) {
                logged = true;
                context.logAccess(request, response, time, true);
            } else if (host != null) {
                logged = true;
                host.logAccess(request, response, time, true);
            }
            if (!logged) {
                connector.getService().getContainer().logAccess(request, response, time, true);
            }
        } catch (Throwable t) {
            ExceptionUtils.handleThrowable(t);
            log.warn(sm.getString("coyoteAdapter.accesslogFail"), t);
        } finally {
            updateWrapperErrorCount(request, response);
            request.recycle();
            response.recycle();
        }
    }


    private static class RecycleRequiredException extends Exception {
        @Serial
        private static final long serialVersionUID = 1L;
    }

    @Override
    public void checkRecycled(org.apache.coyote.Request req, org.apache.coyote.Response res) {
        Request request = (Request) req.getNote(ADAPTER_NOTES);
        Response response = (Response) res.getNote(ADAPTER_NOTES);
        String messageKey = null;
        if (request != null && request.getHost() != null) {
            messageKey = "coyoteAdapter.checkRecycled.request";
        } else if (response != null && response.getContentWritten() != 0) {
            messageKey = "coyoteAdapter.checkRecycled.response";
        }
        if (messageKey != null) {
            // Log this request, as it has probably skipped the access log.
            // The log() method will take care of recycling.
            log(req, res, 0L);

            if (connector.getState().isAvailable()) {
                if (log.isInfoEnabled()) {
                    log.info(sm.getString(messageKey), new RecycleRequiredException());
                }
            } else {
                // There may be some aborted requests.
                // When connector shuts down, the request and response will not
                // be reused, so there is no issue to warn about here.
                if (log.isDebugEnabled()) {
                    log.debug(sm.getString(messageKey), new RecycleRequiredException());
                }
            }
        }
    }


    @Override
    public String getDomain() {
        return connector.getDomain();
    }


    // ------------------------------------------------------ Protected Methods

    /**
     * Perform the necessary processing after the HTTP headers have been parsed to enable the request/response pair to
     * be passed to the start of the container pipeline for processing.
     *
     * @param req      The coyote request object
     * @param request  The catalina request object
     * @param res      The coyote response object
     * @param response The catalina response object
     *
     * @return <code>true</code> if the request should be passed on to the start of the container pipeline, otherwise
     *             <code>false</code>
     *
     * @throws IOException      If there is insufficient space in a buffer while processing headers
     * @throws ServletException If the supported methods of the target servlet cannot be determined
     */
    protected boolean postParseRequest(org.apache.coyote.Request req, Request request, org.apache.coyote.Response res,
            Response response) throws IOException, ServletException {

        // If the processor has set the scheme (AJP does this, HTTP does this if
        // SSL is enabled) use this to set the secure flag as well. If the
        // processor hasn't set it, use the settings from the connector
        if (req.scheme().isNull()) {
            // Use connector scheme and secure configuration, (defaults to
            // "http" and false respectively)
            req.scheme().setString(connector.getScheme());
            request.setSecure(connector.getSecure());
        } else {
            // Use processor specified scheme to determine secure state
            request.setSecure(req.scheme().equals("https"));
        }

        // At this point the Host header has been processed.
        // Override if the proxyPort/proxyHost are set
        String proxyName = connector.getProxyName();
        int proxyPort = connector.getProxyPort();
        if (proxyPort != 0) {
            req.setServerPort(proxyPort);
        } else if (req.getServerPort() == -1) {
            // Not explicitly set. Use default ports based on the scheme
            if (req.scheme().equals("https")) {
                req.setServerPort(443);
            } else {
                req.setServerPort(80);
            }
        }
        if (proxyName != null) {
            req.serverName().setString(proxyName);
        }

        MessageBytes undecodedURI = req.requestURI();

        // Check for ping OPTIONS * request
        if (undecodedURI.equals("*")) {
            if (req.method().equals("OPTIONS")) {
                StringBuilder allow = new StringBuilder();
                allow.append("GET, HEAD, POST, PUT, DELETE, OPTIONS");
                // Trace if allowed
                if (connector.getAllowTrace()) {
                    allow.append(", TRACE");
                }
                res.setHeader("Allow", allow.toString());
                // Access log entry as processing won't reach AccessLogValve
                connector.getService().getContainer().logAccess(request, response, 0, true);
                return false;
            } else {
                response.sendError(400, sm.getString("coyoteAdapter.invalidURI"));
            }
        }

        MessageBytes decodedURI = req.decodedURI();

        // Filter CONNECT method
        if (req.method().equals("CONNECT")) {
            response.sendError(HttpServletResponse.SC_NOT_IMPLEMENTED, sm.getString("coyoteAdapter.connect"));
        } else {
            // No URI for CONNECT requests
            if (undecodedURI.getType() == MessageBytes.T_BYTES) {
                if (connector.getRejectSuspiciousURIs()) {
                    if (checkSuspiciousURIs(undecodedURI.getByteChunk())) {
                        response.sendError(400, sm.getString("coyoteAdapter.invalidURI"));
                    }
                }

                // Copy the raw URI to the decodedURI
                decodedURI.duplicate(undecodedURI);

                // Parse (and strip out) the path parameters
                parsePathParameters(req, request);

                // URI decoding
                // %xx decoding of the URL
                try {
                    req.getURLDecoder().convert(decodedURI.getByteChunk(),
                            connector.getEncodedSolidusHandlingInternal(),
                            connector.getEncodedReverseSolidusHandlingInternal());
                } catch (IOException ioe) {
                    response.sendError(400, sm.getString("coyoteAdapter.invalidURIWithMessage", ioe.getMessage()));
                }
                // Normalization
                if (normalize(req.decodedURI(), connector.getAllowBackslash())) {
                    // Character decoding
                    convertURI(decodedURI, request);
                    // URIEncoding values are limited to US-ASCII supersets.
                    // Therefore, it is not necessary to check that the URI remains
                    // normalized after character decoding
                } else {
                    response.sendError(400, sm.getString("coyoteAdapter.invalidURI"));
                }
            } else {
                /*
                 * The URI is chars or String, and has been sent using an in-memory protocol handler. The following
                 * assumptions are made:
                 *
                 * - req.requestURI() has been set to the 'original' non-decoded, non-normalized URI that includes path
                 * parameters (if any)
                 *
                 * - req.decodedURI() has been set to the decoded, normalized form of req.requestURI() with any path
                 * parameters removed
                 *
                 * - 'suspicious' URI filtering, if required, has already been performed
                 */
                decodedURI.toChars();
            }
        }

        // Request mapping.
        MessageBytes serverName;
        if (connector.getUseIPVHosts()) {
            serverName = req.localName();
            if (serverName.isNull()) {
                // well, they did ask for it
                res.action(ActionCode.REQ_LOCAL_NAME_ATTRIBUTE, null);
            }
        } else {
            serverName = req.serverName();
        }

        // Version for the second mapping loop and
        // Context that we expect to get for that version
        String version = null;
        Context versionContext = null;
        boolean mapRequired = true;

        if (response.isError()) {
            // An error this early means the URI is invalid. Ensure invalid data
            // is not passed to the mapper. Note we still want the mapper to
            // find the correct host.
            decodedURI.recycle();
        }

        while (mapRequired) {
            // This will map the latest version by default
            connector.getService().getMapper().map(serverName, decodedURI, version, request.getMappingData());

            // If there is no context at this point, either this is a 404
            // because no ROOT context has been deployed or the URI was invalid
            // so no context could be mapped.
            if (request.getContext() == null) {
                // Allow processing to continue.
                // If present, the rewrite Valve may rewrite this to a valid
                // request.
                // The StandardEngineValve will handle the case of a missing
                // Host and the StandardHostValve the case of a missing Context.
                // If present, the error reporting valve will provide a response
                // body.
                return true;
            }

            // Now we have the context, we can parse the session ID from the URL
            // (if any). Need to do this before we redirect in case we need to
            // include the session id in the redirect
            String sessionID;
            if (request.getServletContext().getEffectiveSessionTrackingModes().contains(SessionTrackingMode.URL)) {

                // Get the session ID if there was one
                sessionID = request.getPathParameter(SessionConfig.getSessionUriParamName(request.getContext()));
                if (sessionID != null) {
                    request.setRequestedSessionId(sessionID);
                    request.setRequestedSessionURL(true);
                }
            }

            // Look for session ID in cookies and SSL session
            try {
                parseSessionCookiesId(request);
            } catch (IllegalArgumentException e) {
                // Too many cookies
                if (!response.isError()) {
                    response.setError();
                    response.sendError(400, e.getMessage());
                }
                return true;
            }
            parseSessionSslId(request);

            sessionID = request.getRequestedSessionId();

            mapRequired = false;
            if (version != null && request.getContext() == versionContext) {
                // We got the version that we asked for. That is it.
            } else {
                version = null;
                versionContext = null;

                Context[] contexts = request.getMappingData().contexts;
                // Single contextVersion means no need to remap
                // No session ID means no possibility of remap
                if (contexts != null && sessionID != null) {
                    // Find the context associated with the session
                    for (int i = contexts.length; i > 0; i--) {
                        Context ctxt = contexts[i - 1];
                        if (ctxt.getManager().findSession(sessionID) != null) {
                            // We found a context. Is it the one that has
                            // already been mapped?
                            if (!ctxt.equals(request.getMappingData().context)) {
                                // Set version so second time through mapping
                                // the correct context is found
                                version = ctxt.getWebappVersion();
                                versionContext = ctxt;
                                // Reset mapping
                                request.getMappingData().recycle();
                                mapRequired = true;
                                // Recycle cookies and session info in case the
                                // correct context is configured with different
                                // settings
                                request.recycleSessionInfo();
                                request.recycleCookieInfo(true);
                            }
                            break;
                        }
                    }
                }
            }

            if (!mapRequired && request.getContext().getPaused()) {
                // Found a matching context but it is paused. Mapping data will
                // be wrong since some Wrappers may not be registered at this
                // point.
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException ignore) {
                    // Should never happen but, if it does, just continue looping
                }
                // Reset mapping
                request.getMappingData().recycle();
                mapRequired = true;
            }
        }

        // Possible redirect
        MessageBytes redirectPathMB = request.getMappingData().redirectPath;
        if (!redirectPathMB.isNull()) {
            String redirectPath = URLEncoder.DEFAULT.encode(redirectPathMB.toString(), StandardCharsets.UTF_8);
            String query = request.getQueryString();
            if (request.isRequestedSessionIdFromURL()) {
                // This is not optimal, but as this is not very common, it
                // shouldn't matter
                redirectPath = redirectPath + ";" + SessionConfig.getSessionUriParamName(request.getContext()) + "=" +
                        request.getRequestedSessionId();
            }
            if (query != null) {
                // This is not optimal, but as this is not very common, it
                // shouldn't matter
                redirectPath = redirectPath + "?" + query;
            }
            response.sendRedirect(redirectPath);
            request.getContext().logAccess(request, response, 0, true);
            return false;
        }

        // Filter TRACE method
        if (!connector.getAllowTrace() && req.method().equals("TRACE")) {
            Wrapper wrapper = request.getWrapper();
            StringBuilder header = null;
            if (wrapper != null) {
                String[] methods = wrapper.getServletMethods();
                if (methods != null) {
                    for (String method : methods) {
                        if ("TRACE".equals(method)) {
                            continue;
                        }
                        if (header == null) {
                            header = new StringBuilder(method);
                        } else {
                            header.append(", ").append(method);
                        }
                    }
                }
            }
            if (header != null) {
                res.addHeader("Allow", header.toString());
            }
            response.sendError(405, sm.getString("coyoteAdapter.trace"));
            // Safe to skip the remainder of this method.
            return true;
        }

        doConnectorAuthenticationAuthorization(req, request);

        return true;
    }


    private void doConnectorAuthenticationAuthorization(org.apache.coyote.Request req, Request request) {
        // Set the remote principal
        String username = req.getRemoteUser().toString();
        if (username != null) {
            if (log.isDebugEnabled()) {
                log.debug(sm.getString("coyoteAdapter.authenticate", username));
            }
            if (req.getRemoteUserNeedsAuthorization()) {
                Authenticator authenticator = request.getContext().getAuthenticator();
                if (!(authenticator instanceof AuthenticatorBase)) {
                    if (log.isDebugEnabled()) {
                        log.debug(sm.getString("coyoteAdapter.authorize", username));
                    }
                    // Custom authenticator that may not trigger authorization.
                    // Do the authorization here to make sure it is done.
                    request.setUserPrincipal(request.getContext().getRealm().authenticate(username));
                }
                // If the Authenticator is an instance of AuthenticatorBase then
                // it will check req.getRemoteUserNeedsAuthorization() and
                // trigger authorization as necessary. It will also cache the
                // result preventing excessive calls to the Realm.
            } else {
                // The connector isn't configured for authorization. Create a
                // user without any roles using the supplied username.
                request.setUserPrincipal(new CoyotePrincipal(username));
            }
        }

        // Set the authorization type
        String authType = req.getAuthType().toString();
        if (authType != null) {
            request.setAuthType(authType);
        }
    }


    /**
     * Extract the path parameters from the request. This assumes parameters are of the form
     * /path;name=value;name2=value2/ etc. Currently only really interested in the session ID that will be in this form.
     * Other parameters can safely be ignored.
     *
     * @param req     The Coyote request object
     * @param request The Servlet request object
     */
    protected void parsePathParameters(org.apache.coyote.Request req, Request request) {

        // Process in bytes (this is default format so this is normally a NO-OP
        req.decodedURI().toBytes();

        ByteChunk uriBC = req.decodedURI().getByteChunk();
        // The first character must always be '/' so start search at position 1.
        // If the first character is ';' the URI will be rejected at the
        // normalization stage
        int semicolon = uriBC.indexOf(';', 1);
        // Performance optimisation. Return as soon as it is known there are no
        // path parameters;
        if (semicolon == -1) {
            return;
        }

        // What encoding to use? Some platforms, eg z/os, use a default
        // encoding that doesn't give the expected result so be explicit
        Charset charset = connector.getURICharset();

        if (log.isTraceEnabled()) {
            log.trace(sm.getString("coyoteAdapter.debug", "uriBC", uriBC.toString()));
            log.trace(sm.getString("coyoteAdapter.debug", "semicolon", String.valueOf(semicolon)));
            log.trace(sm.getString("coyoteAdapter.debug", "enc", charset.name()));
        }

        while (semicolon > -1) {
            // Parse path param, and extract it from the decoded request URI
            int start = uriBC.getStart();
            int end = uriBC.getEnd();

            int pathParamStart = semicolon + 1;
            int pathParamEnd =
                    ByteChunk.findBytes(uriBC.getBuffer(), start + pathParamStart, end, new byte[] { ';', '/' });

            String pv = null;

            if (pathParamEnd >= 0) {
                if (charset != null) {
                    pv = new String(uriBC.getBuffer(), start + pathParamStart, pathParamEnd - pathParamStart, charset);
                }
                // Extract path param from decoded request URI
                byte[] buf = uriBC.getBuffer();
                for (int i = 0; i < end - start - pathParamEnd; i++) {
                    buf[start + semicolon + i] = buf[start + i + pathParamEnd];
                }
                uriBC.setBytes(buf, start, end - start - pathParamEnd + semicolon);
            } else {
                if (charset != null) {
                    pv = new String(uriBC.getBuffer(), start + pathParamStart, (end - start) - pathParamStart, charset);
                }
                uriBC.setEnd(start + semicolon);
            }

            if (log.isTraceEnabled()) {
                log.trace(sm.getString("coyoteAdapter.debug", "pathParamStart", String.valueOf(pathParamStart)));
                log.trace(sm.getString("coyoteAdapter.debug", "pathParamEnd", String.valueOf(pathParamEnd)));
                log.trace(sm.getString("coyoteAdapter.debug", "pv", pv));
            }

            if (pv != null) {
                int equals = pv.indexOf('=');
                if (equals > -1) {
                    String name = pv.substring(0, equals);
                    String value = pv.substring(equals + 1);
                    request.addPathParameter(name, value);
                    if (log.isTraceEnabled()) {
                        log.trace(sm.getString("coyoteAdapter.debug", "equals", String.valueOf(equals)));
                        log.trace(sm.getString("coyoteAdapter.debug", "name", name));
                        log.trace(sm.getString("coyoteAdapter.debug", "value", value));
                    }
                }
            }

            semicolon = uriBC.indexOf(';', semicolon);
        }
    }


    /**
     * Look for SSL session ID if required. Only look for SSL Session ID if it is the only tracking method enabled.
     *
     * @param request The Servlet request object
     */
    protected void parseSessionSslId(Request request) {
        if (request.getRequestedSessionId() == null &&
                SSL_ONLY.equals(request.getServletContext().getEffectiveSessionTrackingModes()) &&
                request.connector.secure) {
            String sessionId = (String) request.getAttribute(SSLSupport.SESSION_ID_KEY);
            if (sessionId != null) {
                request.setRequestedSessionId(sessionId);
                request.setRequestedSessionSSL(true);
            }
        }
    }


    /**
     * Parse session id in Cookie.
     *
     * @param request The Servlet request object
     */
    protected void parseSessionCookiesId(Request request) {

        // If session tracking via cookies has been disabled for the current
        // context, don't go looking for a session ID in a cookie as a cookie
        // from a parent context with a session ID may be present which would
        // overwrite the valid session ID encoded in the URL
        Context context = request.getMappingData().context;
        if (context != null &&
                !context.getServletContext().getEffectiveSessionTrackingModes().contains(SessionTrackingMode.COOKIE)) {
            return;
        }

        // Parse session id from cookies
        ServerCookies serverCookies = request.getServerCookies();
        int count = serverCookies.getCookieCount();
        if (count <= 0) {
            return;
        }

        String sessionCookieName = SessionConfig.getSessionCookieName(context);

        for (int i = 0; i < count; i++) {
            ServerCookie scookie = serverCookies.getCookie(i);
            if (scookie.getName().equals(sessionCookieName)) {
                // Override anything requested in the URL
                if (!request.isRequestedSessionIdFromCookie()) {
                    // Accept only the first session id cookie
                    convertMB(scookie.getValue());
                    request.setRequestedSessionId(scookie.getValue().toString());
                    request.setRequestedSessionCookie(true);
                    request.setRequestedSessionURL(false);
                    if (log.isTraceEnabled()) {
                        log.trace(" Requested cookie session id is " + request.getRequestedSessionId());
                    }
                } else {
                    if (!request.isRequestedSessionIdValid()) {
                        // Replace the session id until one is valid
                        convertMB(scookie.getValue());
                        request.setRequestedSessionId(scookie.getValue().toString());
                    }
                }
            }
        }

    }


    /**
     * Character conversion of the URI.
     *
     * @param uri     MessageBytes object containing the URI
     * @param request The Servlet request object
     *
     * @throws IOException if a IO exception occurs sending an error to the client
     */
    protected void convertURI(MessageBytes uri, Request request) throws IOException {

        ByteChunk bc = uri.getByteChunk();
        int length = bc.getLength();
        CharChunk cc = uri.getCharChunk();
        cc.allocate(length, -1);

        Charset charset = connector.getURICharset();

        B2CConverter conv = request.getURIConverter();
        if (conv == null) {
            conv = new B2CConverter(charset, false);
            request.setURIConverter(conv);
        } else {
            conv.recycle();
        }

        try {
            conv.convert(bc, cc, true);
            uri.setChars(cc.getBuffer(), cc.getStart(), cc.getLength());
        } catch (IOException ioe) {
            // Should never happen as B2CConverter should replace
            // problematic characters
            request.getResponse().sendError(HttpServletResponse.SC_BAD_REQUEST);
        }
    }


    /**
     * Character conversion of the US-ASCII MessageBytes.
     *
     * @param mb The MessageBytes instance containing the bytes that should be converted to chars
     */
    protected void convertMB(MessageBytes mb) {

        // This is of course only meaningful for bytes
        if (mb.getType() != MessageBytes.T_BYTES) {
            return;
        }

        ByteChunk bc = mb.getByteChunk();
        CharChunk cc = mb.getCharChunk();
        int length = bc.getLength();
        cc.allocate(length, -1);

        // Default encoding: fast conversion
        byte[] bbuf = bc.getBuffer();
        char[] cbuf = cc.getBuffer();
        int start = bc.getStart();
        for (int i = 0; i < length; i++) {
            cbuf[i] = (char) (bbuf[i + start] & 0xff);
        }
        mb.setChars(cbuf, 0, length);

    }


    /**
     * This method normalizes "\", "//", "/./" and "/../".
     *
     * @param uriMB          URI to be normalized
     * @param allowBackslash <code>true</code> if backslash characters are allowed in URLs
     *
     * @return <code>false</code> if normalizing this URI would require going above the root, or if the URI contains a
     *             null byte, otherwise <code>true</code>
     */
    public static boolean normalize(MessageBytes uriMB, boolean allowBackslash) {

        ByteChunk uriBC = uriMB.getByteChunk();
        final byte[] b = uriBC.getBytes();
        final int start = uriBC.getStart();
        int end = uriBC.getEnd();
        boolean appendedSlash = false;

        // An empty URL is not acceptable
        if (start == end) {
            return false;
        }

        // The URL must start with '/' (or '\' that will be replaced soon)
        if (b[start] != (byte) '/' && b[start] != (byte) '\\') {
            return false;
        }

        int pos;

        // Replace '\' with '/'
        // Check for null byte
        for (pos = start; pos < end; pos++) {
            if (b[pos] == (byte) '\\') {
                if (allowBackslash) {
                    b[pos] = (byte) '/';
                } else {
                    return false;
                }
            } else if (b[pos] == (byte) 0) {
                return false;
            }
        }

        // Replace "//" with "/"
        for (pos = start; pos < (end - 1); pos++) {
            if (b[pos] == (byte) '/') {
                while ((pos + 1 < end) && (b[pos + 1] == (byte) '/')) {
                    copyBytes(b, pos, pos + 1, end - pos - 1);
                    end--;
                }
            }
        }

        // If the URI ends with "/." or "/..", then we append an extra "/"
        // Note: It is possible to extend the URI by 1 without any side effect
        // as the next character is a non-significant WS.
        if (((end - start) >= 2) && (b[end - 1] == (byte) '.')) {
            if ((b[end - 2] == (byte) '/') || ((b[end - 2] == (byte) '.') && (b[end - 3] == (byte) '/'))) {
                b[end] = (byte) '/';
                end++;
                appendedSlash = true;
            }
        }

        uriBC.setEnd(end);

        int index = 0;

        // Resolve occurrences of "/./" in the normalized path
        while (true) {
            index = uriBC.indexOf("/./", 0, 3, index);
            if (index < 0) {
                break;
            }
            copyBytes(b, start + index, start + index + 2, end - start - index - 2);
            end = end - 2;
            uriBC.setEnd(end);
        }

        index = 0;

        // Resolve occurrences of "/../" in the normalized path
        while (true) {
            index = uriBC.indexOf("/../", 0, 4, index);
            if (index < 0) {
                break;
            }
            // Prevent from going outside our context
            if (index == 0) {
                return false;
            }
            int index2 = -1;
            for (pos = start + index - 1; (pos >= 0) && (index2 < 0); pos--) {
                if (b[pos] == (byte) '/') {
                    index2 = pos;
                }
            }
            copyBytes(b, start + index2, start + index + 3, end - start - index - 3);
            end = end + index2 - index - 3;
            uriBC.setEnd(end);
            index = index2;
        }

        // If a slash was appended to help normalize "/." or "/.." then remove
        // any trailing "/" from the result unless the result is "/".
        if (appendedSlash && end > 1 && b[end - 1] == '/') {
            uriBC.setEnd(end - 1);
        }

        return true;
    }


    /**
     * Copy an array of bytes to a different position. Used during normalization.
     *
     * @param b    The bytes that should be copied
     * @param dest Destination offset
     * @param src  Source offset
     * @param len  Length
     */
    protected static void copyBytes(byte[] b, int dest, int src, int len) {
        System.arraycopy(b, src, b, dest, len);
    }


    /*
     * Examine URI segment by segment for 'suspicious' URIs.
     */
    private static boolean checkSuspiciousURIs(ByteChunk undecodedURI) {
        byte[] bytes = undecodedURI.getBytes();
        int start = undecodedURI.getStart();
        int end = undecodedURI.getEnd();

        // Find first segment
        int segmentStart = undecodedURI.indexOf('/', 0);
        int segmentEnd = -1;
        if (segmentStart > -1) {
            segmentEnd = undecodedURI.indexOf('/', segmentStart + 1);
        }

        while (segmentStart > -1) {
            int pos = start + segmentStart + 1;

            // Empty segment other than final segment with path parameters
            if (segmentEnd > 0 && bytes[pos] == ';') {
                return true;
            }

            // encoded dot-segments and/or dot-segments with path parameters
            int dotCount = 0;
            boolean encodedDot = false;
            while (pos < end) {
                if (bytes[pos] == '.') {
                    dotCount++;
                    pos++;
                } else if (pos + 2 < end && bytes[pos] == '%' && bytes[pos + 1] == '2' &&
                        (bytes[pos + 2] == 'e' || bytes[pos + 2] == 'E')) {
                    encodedDot = true;
                    dotCount++;
                    pos += 3;
                } else if (bytes[pos] == ';') {
                    if (dotCount > 0) {
                        return true;
                    }
                    break;
                } else if (bytes[pos] == '/') {
                    break;
                } else {
                    dotCount = 0;
                    break;
                }
            }
            if (dotCount > 0 && encodedDot) {
                return true;
            }

            // %nn encoded controls or '/'
            pos = start + segmentStart + 1;
            while (pos < end) {
                if (pos + 2 < end && bytes[pos] == '%') {
                    byte b1 = bytes[pos + 1];
                    byte b2 = bytes[pos + 2];
                    pos += 3;
                    int decoded = (HexUtils.getDec(b1) << 4) + HexUtils.getDec(b2);
                    if (decoded < 20 || decoded == 0x7F || decoded == 0x2F) {
                        return true;
                    }
                } else {
                    pos++;
                }
            }

            // Move to next segment
            if (segmentEnd == -1) {
                segmentStart = -1;
            } else {
                segmentStart = segmentEnd;
                if (segmentStart > -1) {
                    segmentEnd = undecodedURI.indexOf('/', segmentStart + 1);
                }
            }
        }

        return false;
    }
}
