DefaultServlet.java
/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed 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 io.undertow.servlet.handlers;
import io.undertow.io.IoCallback;
import io.undertow.io.Sender;
import io.undertow.server.HttpServerExchange;
import io.undertow.server.handlers.resource.DefaultResourceSupplier;
import io.undertow.server.handlers.resource.DirectoryUtils;
import io.undertow.server.handlers.resource.PreCompressedResourceSupplier;
import io.undertow.server.handlers.resource.RangeAwareResource;
import io.undertow.server.handlers.resource.Resource;
import io.undertow.server.handlers.resource.ResourceSupplier;
import io.undertow.servlet.UndertowServletLogger;
import io.undertow.servlet.api.DefaultServletConfig;
import io.undertow.servlet.api.Deployment;
import io.undertow.servlet.spec.ServletContextImpl;
import io.undertow.util.ByteRange;
import io.undertow.util.CanonicalPathUtils;
import io.undertow.util.DateUtils;
import io.undertow.util.ETag;
import io.undertow.util.ETagUtils;
import io.undertow.util.Headers;
import io.undertow.util.Methods;
import io.undertow.util.StatusCodes;
import jakarta.servlet.DispatcherType;
import jakarta.servlet.RequestDispatcher;
import jakarta.servlet.ServletConfig;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Arrays;
import java.util.Collections;
import java.util.Date;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
* Default servlet responsible for serving up resources. This is both a handler and a servlet. If no filters
* match the current path then the resources will be served up asynchronously using the
* {@link io.undertow.server.HttpHandler#handleRequest(io.undertow.server.HttpServerExchange)} method,
* otherwise the request is handled as a normal servlet request.
* <p>
* By default we only allow a restricted set of extensions.
* </p>
* todo: this thing needs a lot more work. In particular:
* - caching for blocking requests
* - correct mime type
* - range/last-modified and other headers to be handled properly
* - head requests
* - and probably heaps of other things
*
* @author Stuart Douglas
*/
public class DefaultServlet extends HttpServlet {
public static final String DIRECTORY_LISTING = "directory-listing";
public static final String DEFAULT_ALLOWED = "default-allowed";
public static final String ALLOWED_EXTENSIONS = "allowed-extensions";
public static final String DISALLOWED_EXTENSIONS = "disallowed-extensions";
public static final String RESOLVE_AGAINST_CONTEXT_ROOT = "resolve-against-context-root";
public static final String ALLOW_POST = "allow-post";
private static final Set<String> DEFAULT_ALLOWED_EXTENSIONS = Collections.unmodifiableSet(new HashSet<>(Arrays.asList("js", "css", "png", "jpg", "gif", "html", "htm", "txt", "pdf", "jpeg", "xml")));
private Deployment deployment;
private ResourceSupplier resourceSupplier;
private boolean directoryListingEnabled = false;
private boolean defaultAllowed = true;
private Set<String> allowed = DEFAULT_ALLOWED_EXTENSIONS;
private Set<String> disallowed = Collections.emptySet();
private boolean resolveAgainstContextRoot;
private boolean allowPost = false;
@Override
public void init(ServletConfig config) throws ServletException {
super.init(config);
ServletContextImpl sc = (ServletContextImpl) config.getServletContext();
this.deployment = sc.getDeployment();
DefaultServletConfig defaultServletConfig = deployment.getDeploymentInfo().getDefaultServletConfig();
if (defaultServletConfig != null) {
defaultAllowed = defaultServletConfig.isDefaultAllowed();
allowed = new HashSet<>();
if (defaultServletConfig.getAllowed() != null) {
allowed.addAll(defaultServletConfig.getAllowed());
}
disallowed = new HashSet<>();
if (defaultServletConfig.getDisallowed() != null) {
disallowed.addAll(defaultServletConfig.getDisallowed());
}
}
if (config.getInitParameter(DEFAULT_ALLOWED) != null) {
defaultAllowed = Boolean.parseBoolean(config.getInitParameter(DEFAULT_ALLOWED));
}
if (config.getInitParameter(ALLOWED_EXTENSIONS) != null) {
String extensions = config.getInitParameter(ALLOWED_EXTENSIONS);
allowed = new HashSet<>(Arrays.asList(extensions.split(",")));
}
if (config.getInitParameter(DISALLOWED_EXTENSIONS) != null) {
String extensions = config.getInitParameter(DISALLOWED_EXTENSIONS);
disallowed = new HashSet<>(Arrays.asList(extensions.split(",")));
}
if (config.getInitParameter(RESOLVE_AGAINST_CONTEXT_ROOT) != null) {
resolveAgainstContextRoot = Boolean.parseBoolean(config.getInitParameter(RESOLVE_AGAINST_CONTEXT_ROOT));
}
if (config.getInitParameter(ALLOW_POST) != null) {
allowPost = Boolean.parseBoolean(config.getInitParameter(ALLOW_POST));
}
if(deployment.getDeploymentInfo().getPreCompressedResources().isEmpty()) {
this.resourceSupplier = new DefaultResourceSupplier(deployment.getDeploymentInfo().getResourceManager());
} else {
PreCompressedResourceSupplier preCompressedResourceSupplier = new PreCompressedResourceSupplier(deployment.getDeploymentInfo().getResourceManager());
for(Map.Entry<String, String> entry : deployment.getDeploymentInfo().getPreCompressedResources().entrySet()) {
preCompressedResourceSupplier.addEncoding(entry.getKey(), entry.getValue());
}
this.resourceSupplier = preCompressedResourceSupplier;
}
String listings = config.getInitParameter(DIRECTORY_LISTING);
if (Boolean.valueOf(listings)) {
this.directoryListingEnabled = true;
}
}
@Override
protected void doGet(final HttpServletRequest req, final HttpServletResponse resp) throws ServletException, IOException {
String path = getPath(req);
if (!isAllowed(path, req.getDispatcherType())) {
resp.sendError(StatusCodes.NOT_FOUND);
return;
}
if(File.separatorChar != '/') {
//if the separator char is not / we want to replace it with a / and canonicalise
path = CanonicalPathUtils.canonicalize(path.replace(File.separatorChar, '/'));
}
HttpServerExchange exchange = SecurityActions.requireCurrentServletRequestContext().getOriginalRequest().getExchange();
final Resource resource;
//we want to disallow windows characters in the path
if(File.separatorChar == '/' || !path.contains(File.separator)) {
resource = resourceSupplier.getResource(exchange, path);
} else {
resource = null;
}
if (resource == null) {
if (req.getDispatcherType() == DispatcherType.INCLUDE) {
//servlet 9.3
UndertowServletLogger.REQUEST_LOGGER.requestedResourceDoesNotExistForIncludeMethod(path);
throw new FileNotFoundException(path);
} else {
resp.sendError(StatusCodes.NOT_FOUND);
}
return;
} else if (resource.isDirectory()) {
if (directoryListingEnabled) {
if ("css".equals(req.getQueryString())) {
resp.setContentType("text/css");
resp.getWriter().write(DirectoryUtils.Blobs.FILE_CSS);
return;
} else if ("js".equals(req.getQueryString())) {
resp.setContentType("application/javascript");
resp.getWriter().write(DirectoryUtils.Blobs.FILE_JS);
return;
}
resp.setContentType("text/html");
StringBuilder output = DirectoryUtils.renderDirectoryListing(exchange, req.getRequestURI(), resource);
resp.getWriter().write(output.toString());
} else {
resp.sendError(StatusCodes.FORBIDDEN);
}
} else {
if(path.endsWith("/")) {
//UNDERTOW-432
resp.sendError(StatusCodes.NOT_FOUND);
return;
}
serveFileBlocking(req, resp, resource, exchange);
}
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
if(allowPost) {
doGet(req, resp);
} else {
/*
* Where a servlet has received a POST request we still require the capability to include static content.
*/
switch (req.getDispatcherType()) {
case INCLUDE:
case FORWARD:
case ERROR:
doGet(req, resp);
break;
default:
super.doPost(req, resp);
}
}
}
@Override
protected void doPut(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
switch (req.getDispatcherType()) {
case INCLUDE:
case FORWARD:
case ERROR:
doGet(req, resp);
break;
default:
super.doPut(req, resp);
}
}
@Override
protected void doDelete(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
switch (req.getDispatcherType()) {
case INCLUDE:
case FORWARD:
case ERROR:
doGet(req, resp);
break;
default:
super.doDelete(req, resp);
}
}
@Override
protected void doOptions(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
switch (req.getDispatcherType()) {
case INCLUDE:
case FORWARD:
case ERROR:
doGet(req, resp);
break;
default:
super.doOptions(req, resp);
}
}
@Override
protected void doTrace(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
switch (req.getDispatcherType()) {
case INCLUDE:
case FORWARD:
case ERROR:
doGet(req, resp);
break;
default:
super.doTrace(req, resp);
}
}
private void serveFileBlocking(final HttpServletRequest req, final HttpServletResponse resp, final Resource resource, HttpServerExchange exchange) throws IOException {
final ETag etag = resource.getETag();
final Date lastModified = resource.getLastModified();
if(req.getDispatcherType() != DispatcherType.INCLUDE) {
if (!ETagUtils.handleIfMatch(req.getHeader(Headers.IF_MATCH_STRING), etag, false) ||
!DateUtils.handleIfUnmodifiedSince(req.getHeader(Headers.IF_UNMODIFIED_SINCE_STRING), lastModified)) {
resp.setStatus(StatusCodes.PRECONDITION_FAILED);
return;
}
if (!ETagUtils.handleIfNoneMatch(req.getHeader(Headers.IF_NONE_MATCH_STRING), etag, true) ||
!DateUtils.handleIfModifiedSince(req.getHeader(Headers.IF_MODIFIED_SINCE_STRING), lastModified)) {
if(req.getMethod().equals(Methods.GET_STRING) || req.getMethod().equals(Methods.HEAD_STRING)) {
resp.setStatus(StatusCodes.NOT_MODIFIED);
} else {
resp.setStatus(StatusCodes.PRECONDITION_FAILED);
}
return;
}
}
//we are going to proceed. Set the appropriate headers
if(resp.getContentType() == null) {
if(!resource.isDirectory()) {
final String contentType = deployment.getServletContext().getMimeType(resource.getName());
if (contentType != null) {
resp.setContentType(contentType);
} else {
resp.setContentType("application/octet-stream");
}
}
}
if (lastModified != null) {
resp.setHeader(Headers.LAST_MODIFIED_STRING, resource.getLastModifiedString());
}
if (etag != null) {
resp.setHeader(Headers.ETAG_STRING, etag.toString());
}
ByteRange.RangeResponseResult rangeResponse = null;
long start = -1, end = -1;
try {
//only set the content length if we are using a stream
//if we are using a writer who knows what the length will end up being
//todo: if someone installs a filter this can cause problems
//not sure how best to deal with this
//we also can't deal with range requests if a writer is in use
Long contentLength = resource.getContentLength();
if (contentLength != null) {
resp.getOutputStream();
if(contentLength > Integer.MAX_VALUE) {
resp.setContentLengthLong(contentLength);
} else {
resp.setContentLength(contentLength.intValue());
}
if(resource instanceof RangeAwareResource && ((RangeAwareResource)resource).isRangeSupported() && resource.getContentLength() != null) {
resp.setHeader(Headers.ACCEPT_RANGES_STRING, "bytes");
//TODO: figure out what to do with the content encoded resource manager
final ByteRange range = ByteRange.parse(req.getHeader(Headers.RANGE_STRING));
if(range != null) {
rangeResponse = range.getResponseResult(resource.getContentLength(), req.getHeader(Headers.IF_RANGE_STRING), resource.getLastModified(), resource.getETag() == null ? null : resource.getETag().getTag());
if(rangeResponse != null){
start = rangeResponse.getStart();
end = rangeResponse.getEnd();
resp.setStatus(rangeResponse.getStatusCode());
resp.setHeader(Headers.CONTENT_RANGE_STRING, rangeResponse.getContentRange());
long length = rangeResponse.getContentLength();
if(length > Integer.MAX_VALUE) {
resp.setContentLengthLong(length);
} else {
resp.setContentLength((int) length);
}
if(rangeResponse.getStatusCode() == StatusCodes.REQUEST_RANGE_NOT_SATISFIABLE) {
return;
}
}
}
}
}
} catch (IllegalStateException e) {
}
final boolean include = req.getDispatcherType() == DispatcherType.INCLUDE;
if (!req.getMethod().equals(Methods.HEAD_STRING)) {
if(rangeResponse == null) {
resource.serve(exchange.getResponseSender(), exchange, completionCallback(include));
} else {
((RangeAwareResource)resource).serveRange(exchange.getResponseSender(), exchange, start, end, completionCallback(include));
}
}
}
private IoCallback completionCallback(final boolean include) {
return new IoCallback() {
@Override
public void onComplete(final HttpServerExchange exchange, final Sender sender) {
if (!include) {
sender.close();
}
}
@Override
public void onException(final HttpServerExchange exchange, final Sender sender, final IOException exception) {
//not much we can do here, the connection is broken
sender.close();
}
};
}
private String getPath(final HttpServletRequest request) {
String servletPath;
String pathInfo;
if (request.getDispatcherType() == DispatcherType.INCLUDE && request.getAttribute(RequestDispatcher.INCLUDE_REQUEST_URI) != null) {
pathInfo = (String) request.getAttribute(RequestDispatcher.INCLUDE_PATH_INFO);
servletPath = (String) request.getAttribute(RequestDispatcher.INCLUDE_SERVLET_PATH);
} else {
pathInfo = request.getPathInfo();
servletPath = request.getServletPath();
}
String result = pathInfo;
if (result == null) {
result = CanonicalPathUtils.canonicalize(servletPath);
} else if(resolveAgainstContextRoot) {
result = servletPath + CanonicalPathUtils.canonicalize(pathInfo);
} else {
result = CanonicalPathUtils.canonicalize(result);
}
if ((result == null) || (result.isEmpty())) {
result = "/";
}
return result;
}
private boolean isAllowed(String path, DispatcherType dispatcherType) {
if (!path.isEmpty()) {
if(dispatcherType == DispatcherType.REQUEST) {
//WFLY-3543 allow the dispatcher to access stuff in web-inf and meta inf
if (Paths.isForbidden(path)) {
return false;
}
}
}
if(defaultAllowed && disallowed.isEmpty()) {
return true;
}
int pos = path.lastIndexOf('/');
final String lastSegment;
if (pos == -1) {
lastSegment = path;
} else {
lastSegment = path.substring(pos + 1);
}
if (lastSegment.isEmpty()) {
return true;
}
int ext = lastSegment.lastIndexOf('.');
if (ext == -1) {
//no extension
return true;
}
final String extension = lastSegment.substring(ext + 1, lastSegment.length());
if (defaultAllowed) {
return !disallowed.contains(extension);
} else {
return allowed.contains(extension);
}
}
}