package org.jolokia.util;
/*
* Copyright 2009-2013 Roland Huss
*
* Licensed 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.
*/
/**
* Checks whether a certain ip adresse is either equal another
* address or falls within a subnet
*
* @author roland
* @since Oct 8, 2009
*/
public final class IpChecker {
private IpChecker() { }
/**
* Check whether a given IP Adress falls within a subnet or is equal to
*
* @param pExpected either a simple IP adress (without "/") or a net specification
* including a netmask (e.g "/24" or "/255.255.255.0")
* @param pToCheck the ip address to check
* @return true if either the address to check is the same as the address expected
* of falls within the subnet if a netmask is given
*/
public static boolean matches(String pExpected, String pToCheck) {
String[] parts = pExpected.split("/",2);
if (parts.length == 1) {
// No Net part given, check for equality ...
// Check for valid ips
convertToIntTuple(pExpected);
convertToIntTuple(pToCheck);
return pExpected.equals(pToCheck);
} else if (parts.length == 2) {
int ipToCheck[] = convertToIntTuple(pToCheck);
int ipPattern[] = convertToIntTuple(parts[0]);
int netmask[];
if (parts[1].length() <= 2) {
netmask = transformCidrToNetmask(parts[1]);
} else {
netmask = convertToIntTuple(parts[1]);
}
for (int i = 0; i<ipToCheck.length; i++) {
if ((ipPattern[i] & netmask[i]) != (ipToCheck[i] & netmask[i])) {
return false;
}
}
return true;
} else {
throw new IllegalArgumentException("Invalid IP adress specification " + pExpected);
}
}
private static int[] transformCidrToNetmask(String pCidrString) {
try {
int pCidr = Integer.parseInt(pCidrString);
if (pCidr < 0 || pCidr > 32) {
throw new IllegalArgumentException("Invalid netmask specification " + pCidr);
}
StringBuffer buf = new StringBuffer();
for (int i=0;i<pCidr;i++) {
buf.append("1");
}
for (int i=pCidr;i<32;i++) {
buf.append("0");
}
int[] ret = new int[4];
int start = 0,end = 8;
for (int j=0;j<4;j++) {
ret[j] = (Integer.parseInt(buf.substring(start,end), 2));
start += 8; end += 8;
}
return ret;
} catch (NumberFormatException exp) {
throw new IllegalArgumentException("Invalid netmask specification " + pCidrString,exp);
}
}
private static int[] convertToIntTuple(String pAddress) {
String[] parts = pAddress.split("\\.");
if (parts.length != 4) {
throw new IllegalArgumentException("Invalid IP-Adresse " + pAddress);
}
int ret[] = new int[4];
for (int i = 0; i < 4; i++) {
try {
ret[i] = Integer.parseInt(parts[i]);
if (ret[i] < 0 || ret[i] > 255) {
throw new IllegalArgumentException("Invalid IP-Adresse " + pAddress);
}
} catch (NumberFormatException exp) {
throw new IllegalArgumentException("Invalid IP-Adresse " + pAddress,exp);
}
}
return ret;
}
}