/*
* The MIT License
*
* Copyright (c) 2004-2009, Sun Microsystems, Inc., Kohsuke Kawaguchi, Tom Huybrechts
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package hudson.util;
import hudson.ExtensionPoint;
import hudson.security.SecurityRealm;
import java.util.ArrayList;
import jenkins.model.Jenkins;
import javax.annotation.CheckForNull;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import java.util.Vector;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.kohsuke.accmod.Restricted;
import org.kohsuke.accmod.restrictions.NoExternalUse;
/**
* Servlet {@link Filter} that chains multiple {@link Filter}s, provided by plugins
*
* <p>
* While this class by itself is not an extension point, I'm marking this class
* as an extension point so that this class will be more discoverable.
*
* <p>
* {@link SecurityRealm} that wants to contribute {@link Filter}s should first
* check if {@link SecurityRealm#createFilter(FilterConfig)} is more appropriate.
*
* @see SecurityRealm
*/
public class PluginServletFilter implements Filter, ExtensionPoint {
private final List<Filter> list = new CopyOnWriteArrayList<Filter>();
private /*almost final*/ FilterConfig config;
/**
* For backward compatibility with plugins that might register filters before Jenkins.getInstance()
* starts functioning, when we are not sure which Jenkins instance a filter belongs to, put it here,
* and let the first Jenkins instance take over.
*/
private static final List<Filter> LEGACY = new Vector<Filter>();
private static final String KEY = PluginServletFilter.class.getName();
/**
* Lookup the instance from servlet context.
*
* @param c the ServletContext most of the time taken from a Jenkins instance
* @return get the current PluginServletFilter if it is already available
*/
private static @CheckForNull PluginServletFilter getInstance(ServletContext c) {
return (PluginServletFilter)c.getAttribute(KEY);
}
public void init(FilterConfig config) throws ServletException {
this.config = config;
synchronized (LEGACY) {
list.addAll(LEGACY);
LEGACY.clear();
}
for (Filter f : list) {
f.init(config);
}
config.getServletContext().setAttribute(KEY,this);
}
public static void addFilter(Filter filter) throws ServletException {
Jenkins j = Jenkins.getInstanceOrNull();
PluginServletFilter container = null;
if(j != null) {
container = getInstance(j.servletContext);
}
// https://marvelution.atlassian.net/browse/JJI-188
if (j==null || container == null) {
// report who is doing legacy registration
LOGGER.log(Level.WARNING, "Filter instance is registered too early: "+filter, new Exception());
LEGACY.add(filter);
} else {
filter.init(container.config);
container.list.add(filter);
}
}
public static void removeFilter(Filter filter) throws ServletException {
Jenkins j = Jenkins.getInstanceOrNull();
if (j==null || getInstance(j.servletContext) == null) {
LEGACY.remove(filter);
} else {
getInstance(j.servletContext).list.remove(filter);
}
}
public void doFilter(ServletRequest request, ServletResponse response, final FilterChain chain) throws IOException, ServletException {
new FilterChain() {
private final Iterator<Filter> itr = list.iterator();
public void doFilter(ServletRequest request, ServletResponse response) throws IOException, ServletException {
if(itr.hasNext()) {
// call next
itr.next().doFilter(request, response, this);
} else {
// reached to the end
chain.doFilter(request,response);
}
}
}.doFilter(request,response);
}
public void destroy() {
for (Filter f : list) {
f.destroy();
}
list.clear();
}
@Restricted(NoExternalUse.class)
public static void cleanUp() {
PluginServletFilter instance = getInstance(Jenkins.getInstance().servletContext);
if (instance != null) {
// While we could rely on the current implementation of list being a CopyOnWriteArrayList
// safer to just take an explicit copy of the list and operate on the copy
for (Filter f: new ArrayList<>(instance.list)) {
instance.list.remove(f);
// remove from the list even if destroy() fails as a failed destroy is still a destroy
try {
f.destroy();
} catch (RuntimeException e) {
LOGGER.log(Level.WARNING, "Filter " + f + " propagated an exception from its destroy method",
e);
} catch (Error e) {
throw e; // we are not supposed to catch errors, don't log as could be an OOM
} catch (Throwable e) {
LOGGER.log(Level.SEVERE, "Filter " + f + " propagated an exception from its destroy method", e);
}
}
// if some fool adds a filter while we are terminating, we should just log the fact
if (!instance.list.isEmpty()) {
LOGGER.log(Level.SEVERE, "The following filters appear to have been added during clean up: {0}",
instance.list);
}
}
}
private static final Logger LOGGER = Logger.getLogger(PluginServletFilter.class.getName());
}