/**
* The contents of this file are subject to the license and copyright
* detailed in the LICENSE and NOTICE files at the root of the source
* tree and available online at
*
* http://www.dspace.org/license/
*/
package org.dspace.authenticate;
import org.apache.log4j.Logger;
import java.net.Inet6Address;
import java.net.UnknownHostException;
/**
* <p>
* Quickly tests whether a given IP address matches an IP range. An
* {@code IPMatcher} is initialized with a particular IP range specification.
* Calls to {@link IPMatcher#match(String) match} method will then quickly
* determine whether a given IP falls within that range.
* </p>
* <p>
* Supported range specifications are:
* </p>
* <ul>
* <li>Full IPv4 address, e.g. {@code 12.34.56.78}</li>
* <li>Full IPv6 address, e.g. {@code 2001:18e8:3:171:218:8bff:fe2a:56a4}</li>
* <li>Partial IPv4 address, e.g. {@code 12.34} (which matches any IP starting
* {@code 12.34})</li>
* <li>IPv4 network/netmask, e.g. {@code 18.25.0.0/255.255.0.0}</li>
* <li>IPv4 or IPv6 CIDR slash notation, e.g. {@code 18.25.0.0/16},
* {@code 2001:18e8:3:171::/64}</li>
* </ul>
*
* @version $Revision$
* @author Robert Tansley
* @author Ben Bosman
* @author Roeland Dillen
*/
public class IPMatcher
{
private static Logger log = Logger.getLogger(IPMatcher.class);
/** Network to match */
private byte[] network;
/** Network mask */
private byte[] netmask;
/**
* Construct an IPMatcher that will test for the given IP specification
*
* @param ipSpec
* IP specification (full or partial address, network/netmask,
* network/cidr)
* @throws IPMatcherException
* if there is an error parsing the specification (i.e. it is
* somehow malformed)
*/
public IPMatcher(String ipSpec) throws IPMatcherException
{
// Boil all specs down to network + mask
String ipPart = ipSpec;
String[] parts = ipSpec.split("/");
if (parts[0].indexOf(':') >= 0)
{ // looks like IPv6
try
{
network = Inet6Address.getByName(parts[0]).getAddress();
}
catch (UnknownHostException e)
{
throw new IPMatcherException(
"Malformed IP range specification " + ipSpec, e);
}
netmask = new byte[16];
switch(parts.length)
{
case 2: // CIDR notation: calculate the mask
int maskBits;
try {
maskBits = Integer.parseInt(parts[1]);
} catch (NumberFormatException nfe) {
throw new IPMatcherException(
"Malformed IP range specification " + ipSpec, nfe);
}
if (maskBits < 0 || maskBits > 128)
throw new IPMatcherException("Mask bits out of range 0-128 "
+ ipSpec);
int maskBytes = maskBits/8;
for (int i = 0; i < maskBytes; i++)
netmask[i] = (byte) 0Xff;
netmask[maskBytes] = (byte) ((byte) 0Xff << 8-(maskBits % 8)); // FIXME test!
for (int i = maskBytes+1; i < (128/8); i++)
netmask[i] = 0;
break;
case 1: // No explicit mask: fill the mask with 1s
for (int i = 0; i < netmask.length; i++)
netmask[i] = (byte) 0Xff;
break;
default:
throw new IPMatcherException("Malformed IP range specification "
+ ipSpec);
}
}
else
{ // assume IPv4
// Allow partial IP
boolean mustHave4 = false;
network = new byte[4];
netmask = new byte[4];
switch (parts.length)
{
case 2:
// Some kind of slash notation -- we'll need a full network IP
ipPart = parts[0];
mustHave4 = true;
String[] maskParts = parts[1].split("\\.");
if (maskParts.length == 1)
{
// CIDR slash notation
int x;
try
{
x = Integer.parseInt(maskParts[0]);
}
catch (NumberFormatException nfe)
{
throw new IPMatcherException(
"Malformed IP range specification " + ipSpec, nfe);
}
if (x < 0 || x > 32)
{
throw new IPMatcherException();
}
int fullMask = -1 << (32 - x);
netmask[0] = (byte) ((fullMask & 0xFF000000) >>> 24);
netmask[1] = (byte) ((fullMask & 0x00FF0000) >>> 16);
netmask[2] = (byte) ((fullMask & 0x0000FF00) >>> 8);
netmask[3] = (byte) (fullMask & 0x000000FF);
ipToBytes(ipPart, network, mustHave4);
if (log.isDebugEnabled()) {
log.debug("fullMask: "+fullMask);
for (int i = 0; i < network.length; i++) {
log.debug("network[" + i + "]: "+network[i]);
}
for (int i = 0; i < netmask.length; i++) {
log.debug("netmask[" + i + "]: "+netmask[i]);
}
}
}
else
{
// full netmask specified
ipToBytes(parts[0],network,true);
ipToBytes(parts[1], netmask, true);
}
break;
case 1:
// Get IP
for (int i = 0; i < netmask.length; i++)
netmask[i] = -1;
int partCount = ipToBytes(ipPart, network, mustHave4);
// If partial IP, set mask for remaining bytes
for (int i = 3; i >= partCount; i--)
{
netmask[i] = 0;
}
break;
default:
throw new IPMatcherException("Malformed IP range specification "
+ ipSpec);
}
network = ip4ToIp6(network);
netmask = ip4MaskToIp6(netmask);
if (log.isDebugEnabled()) {
for (int i = 0; i < network.length; i++) {
log.debug("network[" + i + "]: "+network[i]);
}
for (int i = 0; i < netmask.length; i++) {
log.debug("netmask[" + i + "]: "+netmask[i]);
}
}
}
}
/**
* Fill out a given four-byte array with the IPv4 address specified in the
* given String
*
* @param ip
* IPv4 address as a dot-delimited String
* @param bytes
* 4-byte array to fill out
* @param mustHave4
* if true, will require that the given IP string specify all
* four bytes
* @return the number of actual IP bytes found in the given IP address
* String
* @throws IPMatcherException
* if there is a problem parsing the IP string -- e.g. number
* outside of range 0-255, too many numbers, less than 4 numbers
* if {@code mustHave4} is true
*/
private static int ipToBytes(String ip, byte[] bytes, boolean mustHave4)
throws IPMatcherException
{
String[] parts = ip.split("\\.");
if (parts.length > 4 || mustHave4 && parts.length != 4)
{
throw new IPMatcherException("Malformed IP specification " + ip);
}
try
{
for (int i = 0; i < parts.length; i++)
{
int p = Integer.parseInt(parts[i]);
if (p < 0 || p > 255)
{
throw new IPMatcherException("Malformed IP specification "
+ ip);
}
bytes[i] = (byte) (p < 128 ? p : p - 256);
}
}
catch (NumberFormatException nfe)
{
throw new IPMatcherException("Malformed IP specification " + ip,
nfe);
}
return parts.length;
}
/**
* Determine whether the given full IP falls within the range this
* {@code IPMatcher} was initialized with.
*
* @param ipIn
* IP address as dot-delimited String
* @return {@code true} if the IP matches the range of this
* {@code IPMatcher}; {@code false} otherwise
* @throws IPMatcherException
* if the IP passed in cannot be parsed correctly (i.e. is
* malformed)
*/
public boolean match(String ipIn) throws IPMatcherException
{
log.debug("ipIn: "+ipIn);
byte[] candidate;
if (ipIn.indexOf(':') < 0)
{
candidate = new byte[4];
ipToBytes(ipIn, candidate, true);
candidate = ip4ToIp6(candidate);
}
else
try
{
candidate = Inet6Address.getByName(ipIn).getAddress();
}
catch (UnknownHostException e)
{
throw new IPMatcherException("Malformed IPv6 address ",e);
}
for (int i = 0; i < netmask.length; i++)
{
if ((candidate[i] & netmask[i]) != (network[i] & netmask[i]))
{
if (log.isDebugEnabled()) {
log.debug("candidate[i]: "+candidate[i]);
log.debug("netmask[i]: "+netmask[i]);
log.debug("candidate[i] & netmask[i]: "+(candidate[i] & netmask[i]));
log.debug("network[i]: "+network[i]);
log.debug("network[i] & netmask[i]: "+(network[i] & netmask[i]));
}
return false;
}
}
return true;
}
/**
* Convert an IPv4 address to an IPv6 IPv4-compatible address.
* @param ip4 an IPv4 address
* @return the corresponding IPv6 address
* @throws IllegalArgumentException if ip4 is not exactly four octets long.
*/
private static byte[] ip4ToIp6(byte[] ip4)
{
if (ip4.length != 4)
throw new IllegalArgumentException("IPv4 address must be four octets");
byte[] ip6 = new byte[16];
for (int i = 0; i < 16-4; i++)
ip6[i] = 0;
for (int i = 0; i < 4; i++)
ip6[12+i] = ip4[i];
return ip6;
}
/**
* Convert an IPv4 mask to the equivalent IPv6 mask.
* @param ip4 an IPv4 mask
* @return the corresponding IPv6 mask
* @throws IllegalArgumentException if ip4 is not exactly four octets long.
*/
private static byte[] ip4MaskToIp6(byte[] ip4)
{
if (ip4.length != 4)
throw new IllegalArgumentException("IPv4 mask must be four octets");
byte[] ip6 = new byte[16];
for (int i = 0; i < 16-4; i++)
ip6[i] = (byte) 0Xff;
for (int i = 0; i < 4; i++)
ip6[12+i] = ip4[i];
return ip6;
}
}