/*
* Copyright 2012 The Netty Project
*
* The Netty Project 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.jboss.netty.util;
import java.util.ArrayList;
import java.util.StringTokenizer;
/**
* A class that holds a number of network-related constants.
* <p/>
* This class borrowed some of its methods from a modified fork of the
* <a href="http://svn.apache.org/repos/asf/harmony/enhanced/java/branches/java6/classlib/modules/luni/
* src/main/java/org/apache/harmony/luni/util/Inet6Util.java">Inet6Util class</a> which was part of Apache Harmony.
*/
public final class NetUtil {
/**
* Creates an byte[] based on an ipAddressString. No error handling is
* performed here.
*/
public static byte[] createByteArrayFromIpAddressString(
String ipAddressString) {
if (isValidIpV4Address(ipAddressString)) {
StringTokenizer tokenizer = new StringTokenizer(ipAddressString,
".");
String token;
int tempInt;
byte[] byteAddress = new byte[4];
for (int i = 0; i < 4; i++) {
token = tokenizer.nextToken();
tempInt = Integer.parseInt(token);
byteAddress[i] = (byte) tempInt;
}
return byteAddress;
}
if (isValidIpV6Address(ipAddressString)) {
if (ipAddressString.charAt(0) == '[') {
ipAddressString = ipAddressString.substring(1, ipAddressString
.length() - 1);
}
StringTokenizer tokenizer = new StringTokenizer(ipAddressString, ":.",
true);
ArrayList<String> hexStrings = new ArrayList<String>();
ArrayList<String> decStrings = new ArrayList<String>();
String token = "";
String prevToken = "";
int doubleColonIndex = -1; // If a double colon exists, we need to
// insert 0s.
// Go through the tokens, including the seperators ':' and '.'
// When we hit a : or . the previous token will be added to either
// the hex list or decimal list. In the case where we hit a ::
// we will save the index of the hexStrings so we can add zeros
// in to fill out the string
while (tokenizer.hasMoreTokens()) {
prevToken = token;
token = tokenizer.nextToken();
if (":".equals(token)) {
if (":".equals(prevToken)) {
doubleColonIndex = hexStrings.size();
} else if (prevToken.length() > 0) {
hexStrings.add(prevToken);
}
} else if (".".equals(token)) {
decStrings.add(prevToken);
}
}
if (":".equals(prevToken)) {
if (":".equals(token)) {
doubleColonIndex = hexStrings.size();
} else {
hexStrings.add(token);
}
} else if (".".equals(prevToken)) {
decStrings.add(token);
}
// figure out how many hexStrings we should have
// also check if it is a IPv4 address
int hexStringsLength = 8;
// If we have an IPv4 address tagged on at the end, subtract
// 4 bytes, or 2 hex words from the total
if (!decStrings.isEmpty()) {
hexStringsLength -= 2;
}
// if we hit a double Colon add the appropriate hex strings
if (doubleColonIndex != -1) {
int numberToInsert = hexStringsLength - hexStrings.size();
for (int i = 0; i < numberToInsert; i++) {
hexStrings.add(doubleColonIndex, "0");
}
}
byte[] ipByteArray = new byte[16];
// Finally convert these strings to bytes...
for (int i = 0; i < hexStrings.size(); i++) {
convertToBytes(hexStrings.get(i), ipByteArray, i * 2);
}
// Now if there are any decimal values, we know where they go...
for (int i = 0; i < decStrings.size(); i++) {
ipByteArray[i + 12] = (byte) (Integer.parseInt(decStrings
.get(i)) & 255);
}
return ipByteArray;
}
return null;
}
/**
* Converts a 4 character hex word into a 2 byte word equivalent
*/
private static void convertToBytes(String hexWord, byte[] ipByteArray,
int byteIndex) {
int hexWordLength = hexWord.length();
int hexWordIndex = 0;
ipByteArray[byteIndex] = 0;
ipByteArray[byteIndex + 1] = 0;
int charValue;
// high order 4 bits of first byte
if (hexWordLength > 3) {
charValue = getIntValue(hexWord.charAt(hexWordIndex++));
ipByteArray[byteIndex] |= charValue << 4;
}
// low order 4 bits of the first byte
if (hexWordLength > 2) {
charValue = getIntValue(hexWord.charAt(hexWordIndex++));
ipByteArray[byteIndex] |= charValue;
}
// high order 4 bits of second byte
if (hexWordLength > 1) {
charValue = getIntValue(hexWord.charAt(hexWordIndex++));
ipByteArray[byteIndex + 1] |= charValue << 4;
}
// low order 4 bits of the first byte
charValue = getIntValue(hexWord.charAt(hexWordIndex));
ipByteArray[byteIndex + 1] |= charValue & 15;
}
static int getIntValue(char c) {
switch (c) {
case '0':
return 0;
case '1':
return 1;
case '2':
return 2;
case '3':
return 3;
case '4':
return 4;
case '5':
return 5;
case '6':
return 6;
case '7':
return 7;
case '8':
return 8;
case '9':
return 9;
}
c = Character.toLowerCase(c);
switch (c) {
case 'a':
return 10;
case 'b':
return 11;
case 'c':
return 12;
case 'd':
return 13;
case 'e':
return 14;
case 'f':
return 15;
}
return 0;
}
public static boolean isValidIpV6Address(String ipAddress) {
int length = ipAddress.length();
boolean doubleColon = false;
int numberOfColons = 0;
int numberOfPeriods = 0;
int numberOfPercent = 0;
StringBuilder word = new StringBuilder();
char c = 0;
char prevChar;
int offset = 0; // offset for [] ip addresses
if (length < 2) {
return false;
}
for (int i = 0; i < length; i++) {
prevChar = c;
c = ipAddress.charAt(i);
switch (c) {
// case for an open bracket [x:x:x:...x]
case '[':
if (i != 0) {
return false; // must be first character
}
if (ipAddress.charAt(length - 1) != ']') {
return false; // must have a close ]
}
offset = 1;
if (length < 4) {
return false;
}
break;
// case for a closed bracket at end of IP [x:x:x:...x]
case ']':
if (i != length - 1) {
return false; // must be last charcter
}
if (ipAddress.charAt(0) != '[') {
return false; // must have a open [
}
break;
// case for the last 32-bits represented as IPv4 x:x:x:x:x:x:d.d.d.d
case '.':
numberOfPeriods++;
if (numberOfPeriods > 3) {
return false;
}
if (!isValidIp4Word(word.toString())) {
return false;
}
if (numberOfColons != 6 && !doubleColon) {
return false;
}
// a special case ::1:2:3:4:5:d.d.d.d allows 7 colons with an
// IPv4 ending, otherwise 7 :'s is bad
if (numberOfColons == 7 && ipAddress.charAt(offset) != ':'
&& ipAddress.charAt(1 + offset) != ':') {
return false;
}
word.delete(0, word.length());
break;
case ':':
// FIX "IP6 mechanism syntax #ip6-bad1"
// An IPV6 address cannot start with a single ":".
// Either it can starti with "::" or with a number.
if (i == offset && (ipAddress.length() <= i || ipAddress.charAt(i + 1) != ':')) {
return false;
}
// END FIX "IP6 mechanism syntax #ip6-bad1"
numberOfColons++;
if (numberOfColons > 7) {
return false;
}
if (numberOfPeriods > 0) {
return false;
}
if (prevChar == ':') {
if (doubleColon) {
return false;
}
doubleColon = true;
}
word.delete(0, word.length());
break;
case '%':
if (numberOfColons == 0) {
return false;
}
numberOfPercent++;
// validate that the stuff after the % is valid
if (i + 1 >= length) {
// in this case the percent is there but no number is
// available
return false;
}
try {
Integer.parseInt(ipAddress.substring(i + 1));
} catch (NumberFormatException e) {
// right now we just support an integer after the % so if
// this is not
// what is there then return
return false;
}
break;
default:
if (numberOfPercent == 0) {
if (word != null && word.length() > 3) {
return false;
}
if (!isValidHexChar(c)) {
return false;
}
}
word.append(c);
}
}
// Check if we have an IPv4 ending
if (numberOfPeriods > 0) {
// There is a test case with 7 colons and valid ipv4 this should resolve it
if (numberOfPeriods != 3 || !(isValidIp4Word(word.toString()) && numberOfColons < 7)) {
return false;
}
} else {
// If we're at then end and we haven't had 7 colons then there is a
// problem unless we encountered a doubleColon
if (numberOfColons != 7 && !doubleColon) {
return false;
}
// If we have an empty word at the end, it means we ended in either
// a : or a .
// If we did not end in :: then this is invalid
if (numberOfPercent == 0) {
if (word.length() == 0 && ipAddress.charAt(length - 1 - offset) == ':'
&& ipAddress.charAt(length - 2 - offset) != ':') {
return false;
}
}
}
return true;
}
public static boolean isValidIp4Word(String word) {
char c;
if (word.length() < 1 || word.length() > 3) {
return false;
}
for (int i = 0; i < word.length(); i++) {
c = word.charAt(i);
if (!(c >= '0' && c <= '9')) {
return false;
}
}
if (Integer.parseInt(word) > 255) {
return false;
}
return true;
}
static boolean isValidHexChar(char c) {
return c >= '0' && c <= '9' || c >= 'A' && c <= 'F'
|| c >= 'a' && c <= 'f';
}
/**
* Takes a string and parses it to see if it is a valid IPV4 address.
*
* @return true, if the string represents an IPV4 address in dotted
* notation, false otherwise
*/
public static boolean isValidIpV4Address(String value) {
int periods = 0;
int i;
int length = value.length();
if (length > 15) {
return false;
}
char c;
StringBuilder word = new StringBuilder();
for (i = 0; i < length; i++) {
c = value.charAt(i);
if (c == '.') {
periods++;
if (periods > 3) {
return false;
}
if (word.length() == 0) {
return false;
}
if (Integer.parseInt(word.toString()) > 255) {
return false;
}
word.delete(0, word.length());
} else if (!Character.isDigit(c)) {
return false;
} else {
if (word.length() > 2) {
return false;
}
word.append(c);
}
}
if (word.length() == 0 || Integer.parseInt(word.toString()) > 255) {
return false;
}
if (periods != 3) {
return false;
}
return true;
}
/**
* A constructor to stop this class being constructed.
*/
private NetUtil() {
// Unused
}
}