org.apache.catalina.valves
Class RequestFilterValve

java.lang.Object
  org.apache.catalina.valves.ValveBase
      org.apache.catalina.valves.RequestFilterValve

All Implemented Interfaces:

javax.management.MBeanRegistration, Contained, Lifecycle, Valve

Direct Known Subclasses:

RemoteAddrValve, RemoteHostValve

public abstract class RequestFilterValve
extends ValveBase
implements Lifecycle

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 a set of regular expressions configured for this Valve.

This valve is configured by setting the allow and/or deny properties to a comma-delimited list of regular expressions (in the syntax supported by the jakarta-regexp library) to which the appropriate request property will be compared. Evaluation proceeds as follows:

• The subclass extracts the request property to be filtered, and calls the common process() method.
• If there are any deny expressions configured, the property will be compared to each such expression. If a match is found, this request will be rejected with a "Forbidden" HTTP response.
• If there are any allow expressions 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.
• If one or more deny expressions was specified but no allow expressions, allow this request to pass through (because none of the deny expressions matched it).
• The request will be rejected with a "Forbidden" HTTP response.

This Valve may be attached to any Container, depending on the granularity of the filtering you wish to perform.

Author:

Craig R. McClanahan

sm

protected static StringManager sm

The StringManager for this package.

allow

protected volatile java.lang.String allow

The comma-delimited set of allow expressions.

allowValid

protected volatile boolean allowValid

Helper variable to catch configuration errors. It is true by default, but becomes false if there was an attempt to assign an invalid value to the allow pattern.

allows

protected volatile java.util.regex.Pattern[] allows

The set of allow regular expressions we will evaluate.

denies

protected volatile java.util.regex.Pattern[] denies

The set of deny regular expressions we will evaluate.

deny

protected volatile java.lang.String deny

The comma-delimited set of deny expressions.

denyValid

protected volatile boolean denyValid

Helper variable to catch configuration errors. It is true by default, but becomes false if there was an attempt to assign an invalid value to the deny pattern.

denyStatus

protected int denyStatus

The HTTP response status code that is used when rejecting denied request. It is 403 by default, but may be changed to be 404.

lifecycle

protected LifecycleSupport lifecycle

The lifecycle event support for this component.

started

protected boolean started

Has this component been started yet?

RequestFilterValve

public RequestFilterValve()

getAllow

public java.lang.String getAllow()

Return a comma-delimited set of the allow expressions configured for this Valve, if any; otherwise, return null.

setAllow

public void setAllow(java.lang.String allow)

Set the comma-delimited set of the allow expressions configured for this Valve, if any.

Parameters:

allow - The new set of allow expressions

getDeny

public java.lang.String getDeny()

Return a comma-delimited set of the deny expressions configured for this Valve, if any; otherwise, return null.

setDeny

public void setDeny(java.lang.String deny)

Set the comma-delimited set of the deny expressions configured for this Valve, if any.

Parameters:

deny - The new set of deny expressions

isAllowValid

public final boolean isAllowValid()

Returns false if the last change to the allow pattern did not apply successfully. E.g. if the pattern is syntactically invalid.

isDenyValid

public final boolean isDenyValid()

Returns false if the last change to the deny pattern did not apply successfully. E.g. if the pattern is syntactically invalid.

getDenyStatus

public int getDenyStatus()

Return response status code that is used to reject denied request.

setDenyStatus

public void setDenyStatus(int denyStatus)

Set response status code that is used to reject denied request.

getInfo

public java.lang.String getInfo()

Return descriptive information about this Valve implementation.

Specified by:

getInfo in interface Valve

Overrides:

getInfo in class ValveBase

invoke

public abstract void invoke(Request request,
                            Response response)
                     throws java.io.IOException,
                            javax.servlet.ServletException

Extract the desired request property, and pass it (along with the specified request and response objects) to the protected process() method to perform the actual filtering. This method must be implemented by a concrete subclass.

Specified by:

invoke in interface Valve

Specified by:

invoke in class ValveBase

Parameters:

request - The servlet request to be processed

response - The servlet response to be created

Throws:

java.io.IOException - if an input/output error occurs

javax.servlet.ServletException - if a servlet error occurs

precalculate

protected java.util.regex.Pattern[] precalculate(java.lang.String list)

Return an array of regular expression objects initialized from the specified argument, which must be null or a comma-delimited list of regular expression patterns.

Parameters:

list - The comma-separated list of patterns

Throws:

java.lang.IllegalArgumentException - if one of the patterns has invalid syntax

process

protected void process(java.lang.String property,
                       Request request,
                       Response response)
                throws java.io.IOException,
                       javax.servlet.ServletException

Perform the filtering that has been configured for this Valve, matching against the specified request property.

Parameters:

property - The request property on which to filter

request - The servlet request to be processed

response - The servlet response to be processed

Throws:

java.io.IOException - if an input/output error occurs

javax.servlet.ServletException - if a servlet error occurs

denyRequest

protected void denyRequest(Request request,
                           Response response)
                    throws java.io.IOException,
                           javax.servlet.ServletException

Reject the request that was denied by this valve.

Parameters:

request - The servlet request to be processed

response - The servlet response to be processed

Throws:

java.io.IOException - if an input/output error occurs

javax.servlet.ServletException - if a servlet error occurs

isAllowed

public boolean isAllowed(java.lang.String property)

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.

Parameters:

property - The request property value on which to filter

addLifecycleListener

public void addLifecycleListener(LifecycleListener listener)

Add a lifecycle event listener to this component.

Specified by:

addLifecycleListener in interface Lifecycle

Parameters:

listener - The listener to add

findLifecycleListeners

public LifecycleListener[] findLifecycleListeners()

Get the lifecycle listeners associated with this lifecycle. If this Lifecycle has no listeners registered, a zero-length array is returned.

Specified by:

findLifecycleListeners in interface Lifecycle

removeLifecycleListener

public void removeLifecycleListener(LifecycleListener listener)

Remove a lifecycle event listener from this component.

Specified by:

removeLifecycleListener in interface Lifecycle

Parameters:

listener - The listener to add

start

public void start()
           throws LifecycleException

Prepare for the beginning of active use of the public methods of this component. This method should be called after configure(), and before any of the public methods of the component are utilized.

Specified by:

start in interface Lifecycle

Throws:

LifecycleException - if this component detects a fatal error that prevents this component from being used

stop

public void stop()
          throws LifecycleException

Gracefully terminate the active use of the public methods of this component. This method should be the last one called on a given instance of this component.

Specified by:

stop in interface Lifecycle

Throws:

LifecycleException - if this component detects a fatal error that needs to be reported