WebdavFixFilter.java
/*
* 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.filters;
import java.io.IOException;
import jakarta.servlet.FilterChain;
import jakarta.servlet.GenericFilter;
import jakarta.servlet.ServletException;
import jakarta.servlet.ServletRequest;
import jakarta.servlet.ServletResponse;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.apache.tomcat.util.res.StringManager;
/**
* Filter that attempts to force MS WebDAV clients connecting on port 80 to use a WebDAV client that actually works.
* Other workarounds that might help include:
* <ul>
* <li>Specifying the port, even if it is port 80, when trying to connect.</li>
* <li>Cancelling the first authentication dialog box and then trying to reconnect.</li>
* </ul>
* Generally each different version of the MS client has a different set of problems.
* <p>
* TODO: Update this filter to recognise specific MS clients and apply the appropriate workarounds for that particular
* client
* <p>
* As a filter, this is configured in web.xml like any other Filter. You usually want to map this filter to whatever
* your WebDAV servlet is mapped to.
* <p>
* In addition to the issues fixed by this Filter, the following issues have also been observed that cannot be fixed by
* this filter. Where possible the filter will add an message to the logs.
* <p>
* XP x64 SP2 (MiniRedir Version 3790)
* <ul>
* <li>Only connects to port 80</li>
* <li>Unknown issue means it doesn't work</li>
* </ul>
*
* @deprecated This will be removed in Tomcat 11 onwards. This filter is no longer required. The WebDAV client in
* Windows 10 / Windows Server 2012 onwards works correctly without this filter.
*/
@Deprecated
public class WebdavFixFilter extends GenericFilter {
private static final long serialVersionUID = 1L;
protected static final StringManager sm = StringManager.getManager(WebdavFixFilter.class);
/* Start string for all versions */
private static final String UA_MINIDIR_START = "Microsoft-WebDAV-MiniRedir";
/* XP 32-bit SP3 */
private static final String UA_MINIDIR_5_1_2600 = "Microsoft-WebDAV-MiniRedir/5.1.2600";
/* XP 64-bit SP2 */
private static final String UA_MINIDIR_5_2_3790 = "Microsoft-WebDAV-MiniRedir/5.2.3790";
/**
* Check for the broken MS WebDAV client and if detected issue a re-direct that hopefully will cause the non-broken
* client to be used.
*/
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
if (!(request instanceof HttpServletRequest) || !(response instanceof HttpServletResponse)) {
chain.doFilter(request, response);
return;
}
HttpServletRequest httpRequest = ((HttpServletRequest) request);
HttpServletResponse httpResponse = ((HttpServletResponse) response);
String ua = httpRequest.getHeader("User-Agent");
if (ua == null || ua.length() == 0 || !ua.startsWith(UA_MINIDIR_START)) {
// No UA or starts with non MS value
// Hope everything just works...
chain.doFilter(request, response);
} else if (ua.startsWith(UA_MINIDIR_5_1_2600)) {
// XP 32-bit SP3 - needs redirect with explicit port
httpResponse.sendRedirect(buildRedirect(httpRequest));
} else if (ua.startsWith(UA_MINIDIR_5_2_3790)) {
// XP 64-bit SP2
if (!httpRequest.getContextPath().isEmpty()) {
getServletContext().log(sm.getString("webDavFilter.xpRootContext"));
}
// Namespace issue maybe
// see http://greenbytes.de/tech/webdav/webdav-redirector-list.html
getServletContext().log(sm.getString("webDavFilter.xpProblem"));
chain.doFilter(request, response);
} else {
// Don't know which MS client it is - try the redirect with an
// explicit port in the hope that it moves the client to a different
// WebDAV implementation that works
httpResponse.sendRedirect(buildRedirect(httpRequest));
}
}
private String buildRedirect(HttpServletRequest request) {
StringBuilder location = new StringBuilder(request.getRequestURL().length());
location.append(request.getScheme());
location.append("://");
location.append(request.getServerName());
location.append(':');
// If we include the port, even if it is 80, then MS clients will use
// a WebDAV client that works rather than the MiniRedir that has
// problems with BASIC authentication
location.append(request.getServerPort());
location.append(request.getRequestURI());
return location.toString();
}
}