org.xins.server

Class IPFilter

java.lang.Object

org.xins.server.IPFilter

public final class IPFilter
extends Object

Filter for IP addresses.

Filter expression format

An IPFilter instance is created using a so-called filter expression. This filter expression specifies the IP address and mask to use for matching a subject IP address.

IPv4 filters will only accept IPv4 addresses and IPv6 filters will only accept IPv6 addresses.

Example code

An IPFilter object is created and used as follows:

IPFilter filter = IPFilter.parseFilter("10.0.0.0/24");
if (filter.match("10.0.0.1")) {
// IP is granted access
} else {
// IP is denied access
}

IPFilter filter = IPFilter.parseFilter("3FFE:200::/32");
if (filter.match("1fff:0:a88:85a3::ac1f:8001")) {
// IP is granted access
} else {
// IP is denied access
}

Since:

XINS 1.0.0

Version:

$Revision: 1.48 $ $Date: 2013/01/29 10:48:17 $

Author:

Ernst de Haan, Peter Troon, Anthony Goubard

Method Summary

Methods

Modifier and Type	Method and Description
String	getBaseIP() Returns the base IP address.
String	getExpression() Returns the filter expression.
int	getMask() Returns the mask.
boolean	match(String ipString) Determines if the specified IP address is authorized.
static IPFilter	parseIPFilter(String expression) Creates an IPFilter object for the specified filter expression.
String	toString() Returns a textual representation of this filter.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

parseIPFilter

public static final IPFilter parseIPFilter(String expression)
                                    throws IllegalArgumentException,
                                           ParseException

Creates an IPFilter object for the specified filter expression. The expression consists of a base IP address and a bit count. The bit count indicates how many bits in an IP address must match the bits in the base IP address.

Parameters:

expression - the filter expression, cannot be null and must match the format for a filter expression. if no mask is passed 32 is assumed for IPv4 addresses and 128 for IPv6 addresses.

Returns:

the constructed IPFilter object, never null.

Throws:

IllegalArgumentException - if expression == null.

ParseException - if expression does not match the specified format.

getExpression

public final String getExpression()

Returns the filter expression.

Returns:

the original filter expression, never null.

getBaseIP

public final String getBaseIP()

Returns the base IP address.

Returns:

the base IP address, in the form a.a.a.a/n, where a is a number between 0 and 255, with no leading zeroes; never null.

getMask

public final int getMask()

Returns the mask.

Returns:

the mask, between 0 and 128.

match

public final boolean match(String ipString)
                    throws IllegalArgumentException,
                           ParseException

Determines if the specified IP address is authorized.

Note IPv6 addresses are only accepted by IPv6 ACLs and IPv4 addresses are only accepted by IPv4 ACLs.

Parameters:

ipString - the IP address of which must be determined if it is authorized, cannot be null.

Returns:

true if the IP address is authorized to access the protected resource, otherwise false.

Throws:

IllegalArgumentException - if ipString == null.

ParseException - if ip does not match the specified format.

toString

public final String toString()

Returns a textual representation of this filter. The implementation of this method returns the filter expression passed.

Overrides:

toString in class Object

Returns:

a textual presentation, never null.