/*
* 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.valves;
import java.io.IOException;
import java.util.regex.Pattern;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletResponse;
import org.apache.catalina.Context;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.Response;
import org.apache.juli.logging.Log;
/**
* Implementation of a Valve that performs filtering based on comparing the
* appropriate request property (selected based on which subclass you choose
* to configure into your Container's pipeline) against the regular expressions
* configured for this Valve.
* <p>
* This valve is configured by setting the <code>allow</code> and/or
* <code>deny</code> properties to a regular expressions (in the syntax
* supported by {@link Pattern}) to which the appropriate request property will
* be compared. Evaluation proceeds as follows:
* <ul>
* <li>The subclass extracts the request property to be filtered, and
* calls the common <code>process()</code> method.
* <li>If there is a deny expression configured, the property will be compared
* to the expression. If a match is found, this request will be rejected
* with a "Forbidden" HTTP response.</li>
* <li>If there is a allow expression configured, the property will be compared
* to each such expression. If a match is found, this request will be
* allowed to pass through to the next Valve in the current pipeline.</li>
* <li>If a deny expression was specified but no allow expression, allow this
* request to pass through (because none of the deny expressions matched
* it).
* <li>The request will be rejected with a "Forbidden" HTTP response.</li>
* </ul>
* <p>
* As an option the valve can generate an invalid <code>authenticate</code>
* header instead of denying the request. This can be combined with the
* context attribute <code>preemptiveAuthentication="true"</code> and an
* authenticator to force authentication instead of denial.
* <p>
* This Valve may be attached to any Container, depending on the granularity
* of the filtering you wish to perform.
*
* @author Craig R. McClanahan
*/
public abstract class RequestFilterValve extends ValveBase {
//------------------------------------------------------ Constructor
public RequestFilterValve() {
super(true);
}
// ----------------------------------------------------- Class Variables
/**
* The descriptive information related to this implementation.
*/
private static final String info =
"org.apache.catalina.valves.RequestFilterValve/1.0";
// ----------------------------------------------------- Instance Variables
/**
* The regular expression used to test for allowed requests.
*/
protected volatile Pattern allow = null;
/**
* The current allow configuration value that may or may not compile into a
* valid {@link Pattern}.
*/
protected volatile String allowValue = null;
/**
* Helper variable to catch configuration errors.
* It is <code>true</code> by default, but becomes <code>false</code>
* if there was an attempt to assign an invalid value to the
* <code>allow</code> pattern.
*/
protected volatile boolean allowValid = true;
/**
* The regular expression used to test for denied requests.
*/
protected volatile Pattern deny = null;
/**
* The current deny configuration value that may or may not compile into a
* valid {@link Pattern}.
*/
protected volatile String denyValue = null;
/**
* Helper variable to catch configuration errors.
* It is <code>true</code> by default, but becomes <code>false</code>
* if there was an attempt to assign an invalid value to the
* <code>deny</code> pattern.
*/
protected volatile boolean denyValid = true;
/**
* The HTTP response status code that is used when rejecting denied
* request. It is 403 by default, but may be changed to be 404.
*/
protected int denyStatus = HttpServletResponse.SC_FORBIDDEN;
/**
* <p>If <code>invalidAuthenticationWhenDeny</code> is true
* and the context has <code>preemptiveAuthentication</code>
* set, set an invalid authorization header to trigger basic auth
* instead of denying the request..
*/
private boolean invalidAuthenticationWhenDeny = false;
// ------------------------------------------------------------- Properties
/**
* Return the regular expression used to test for allowed requests for this
* Valve, if any; otherwise, return <code>null</code>.
*/
public String getAllow() {
return allowValue;
}
/**
* Set the regular expression used to test for allowed requests for this
* Valve, if any.
*
* @param allow The new allow expression
*/
public void setAllow(String allow) {
if (allow == null || allow.length() == 0) {
this.allow = null;
allowValue = null;
allowValid = true;
} else {
boolean success = false;
try {
allowValue = allow;
this.allow = Pattern.compile(allow);
success = true;
} finally {
allowValid = success;
}
}
}
/**
* Return the regular expression used to test for denied requests for this
* Valve, if any; otherwise, return <code>null</code>.
*/
public String getDeny() {
return denyValue;
}
/**
* Set the regular expression used to test for denied requests for this
* Valve, if any.
*
* @param deny The new deny expression
*/
public void setDeny(String deny) {
if (deny == null || deny.length() == 0) {
this.deny = null;
denyValue = null;
denyValid = true;
} else {
boolean success = false;
try {
denyValue = deny;
this.deny = Pattern.compile(deny);
success = true;
} finally {
denyValid = success;
}
}
}
/**
* Returns {@code false} if the last change to the {@code allow} pattern did
* not apply successfully. E.g. if the pattern is syntactically
* invalid.
*/
public final boolean isAllowValid() {
return allowValid;
}
/**
* Returns {@code false} if the last change to the {@code deny} pattern did
* not apply successfully. E.g. if the pattern is syntactically
* invalid.
*/
public final boolean isDenyValid() {
return denyValid;
}
/**
* Return response status code that is used to reject denied request.
*/
public int getDenyStatus() {
return denyStatus;
}
/**
* Set response status code that is used to reject denied request.
*/
public void setDenyStatus(int denyStatus) {
this.denyStatus = denyStatus;
}
/**
* Return descriptive information about this Valve implementation.
*/
@Override
public String getInfo() {
return (info);
}
/**
* Return true if a deny is handled by setting an invalid auth header.
*/
public boolean getInvalidAuthenticationWhenDeny() {
return invalidAuthenticationWhenDeny;
}
/**
* Set invalidAuthenticationWhenDeny property.
*/
public void setInvalidAuthenticationWhenDeny(boolean value) {
invalidAuthenticationWhenDeny = value;
}
// --------------------------------------------------------- Public Methods
/**
* Extract the desired request property, and pass it (along with the
* specified request and response objects) to the protected
* <code>process()</code> method to perform the actual filtering.
* This method must be implemented by a concrete subclass.
*
* @param request The servlet request to be processed
* @param response The servlet response to be created
*
* @exception IOException if an input/output error occurs
* @exception ServletException if a servlet error occurs
*/
@Override
public abstract void invoke(Request request, Response response)
throws IOException, ServletException;
// ------------------------------------------------------ Protected Methods
@Override
protected void initInternal() throws LifecycleException {
super.initInternal();
if (!allowValid || !denyValid) {
throw new LifecycleException(
sm.getString("requestFilterValve.configInvalid"));
}
}
@Override
protected synchronized void startInternal() throws LifecycleException {
if (!allowValid || !denyValid) {
throw new LifecycleException(
sm.getString("requestFilterValve.configInvalid"));
}
super.startInternal();
}
/**
* Perform the filtering that has been configured for this Valve, matching
* against the specified request property.
*
* @param property The request property on which to filter
* @param request The servlet request to be processed
* @param response The servlet response to be processed
*
* @exception IOException if an input/output error occurs
* @exception ServletException if a servlet error occurs
*/
protected void process(String property, Request request, Response response)
throws IOException, ServletException {
if (isAllowed(property)) {
getNext().invoke(request, response);
return;
}
if (getLog().isDebugEnabled()) {
getLog().debug(sm.getString("requestFilterValve.deny",
request.getRequestURI(), property));
}
// Deny this request
denyRequest(request, response);
}
protected abstract Log getLog();
/**
* Reject the request that was denied by this valve.
* <p>If <code>invalidAuthenticationWhenDeny</code> is true
* and the context has <code>preemptiveAuthentication</code>
* set, set an invalid authorization header to trigger basic auth.
*
* @param request The servlet request to be processed
* @param response The servlet response to be processed
* @exception IOException if an input/output error occurs
* @exception ServletException if a servlet error occurs
*/
protected void denyRequest(Request request, Response response)
throws IOException, ServletException {
if (invalidAuthenticationWhenDeny) {
Context context = request.getContext();
if (context != null && context.getPreemptiveAuthentication()) {
if (request.getCoyoteRequest().getMimeHeaders().getValue("authorization") == null) {
request.getCoyoteRequest().getMimeHeaders().addValue("authorization").setString("invalid");
}
getNext().invoke(request, response);
return;
}
}
response.sendError(denyStatus);
}
/**
* Perform the test implemented by this Valve, matching against the
* specified request property value. This method is public so that it can be
* called through JMX, e.g. to test whether certain IP address is allowed or
* denied by the valve configuration.
*
* @param property
* The request property value on which to filter
*/
public boolean isAllowed(String property) {
// Use local copies for thread safety
Pattern deny = this.deny;
Pattern allow = this.allow;
// Check the deny patterns, if any
if (deny != null && deny.matcher(property).matches()) {
return false;
}
// Check the allow patterns, if any
if (allow != null && allow.matcher(property).matches()) {
return true;
}
// Allow if denies specified but not allows
if (deny != null && allow == null) {
return true;
}
// Deny this request
return false;
}
}