001/*
002 * (C) Copyright 2006-2011 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Gagnavarslan ehf
018 */
019package org.nuxeo.ecm.webdav.service;
020
021import java.io.IOException;
022
023import javax.servlet.Filter;
024import javax.servlet.FilterChain;
025import javax.servlet.FilterConfig;
026import javax.servlet.ServletException;
027import javax.servlet.ServletRequest;
028import javax.servlet.ServletResponse;
029import javax.servlet.http.HttpServletRequest;
030import javax.servlet.http.HttpServletResponse;
031
032import org.apache.commons.lang.StringUtils;
033import org.nuxeo.ecm.platform.web.common.requestcontroller.filter.BufferingHttpServletResponse;
034import org.nuxeo.runtime.transaction.TransactionHelper;
035import org.nuxeo.runtime.transaction.TransactionRuntimeException;
036
037/**
038 * Windows Integration Request filter, bound to /nuxeo. Allows Windows user agents to bind to the root as the expect
039 * (not /nuxeo/site/dav) and still work.
040 */
041public class WIRequestFilter implements Filter {
042
043    public static String WEBDAV_USERAGENT = "Microsoft-WebDAV-MiniRedir";
044
045    public static String MSOFFICE_USERAGENT = "Microsoft Office Existence Discovery";
046
047    public static final String BACKEND_KEY = "org.nuxeo.ecm.webdav.service.backend";
048
049    @Override
050    public void init(FilterConfig filterConfig) throws ServletException {
051    }
052
053    @Override
054    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
055            ServletException {
056
057        HttpServletRequest httpRequest = (HttpServletRequest) request;
058        HttpServletResponse httpResponse = (HttpServletResponse) response;
059
060        if (!isWIRequest(httpRequest)) {
061            chain.doFilter(request, response);
062            return;
063        }
064
065        // do what WebEngineFilter does:
066        // - start a transaction
067        // - do response buffering
068        boolean txStarted = false;
069        boolean ok = false;
070        try {
071            if (!TransactionHelper.isTransactionActive()) {
072                txStarted = TransactionHelper.startTransaction();
073                if (!txStarted) {
074                    throw new ServletException("A transaction is needed.");
075                }
076                response = new BufferingHttpServletResponse(httpResponse);
077            }
078            chain.doFilter(request, response);
079            ok = true;
080        } finally {
081            if (txStarted) {
082                try {
083                    if (!ok) {
084                        TransactionHelper.setTransactionRollbackOnly();
085                    }
086                    TransactionHelper.commitOrRollbackTransaction();
087                } catch (TransactionRuntimeException e) {
088                    // commit failed, report this to the client before stopping buffering
089                    ((HttpServletResponse) response).sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
090                            e.getMessage());
091                    throw e;
092                } finally {
093                    ((BufferingHttpServletResponse) response).stopBuffering();
094                }
095            }
096        }
097    }
098
099    @Override
100    public void destroy() {
101    }
102
103    private boolean isWIRequest(HttpServletRequest request) {
104        String ua = request.getHeader("User-Agent");
105        return StringUtils.isNotEmpty(ua) && (ua.contains(WEBDAV_USERAGENT) || ua.contains(MSOFFICE_USERAGENT));
106    }
107
108}