/*
* Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
* Free SoftwareFoundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.server.host;
import com.caucho.util.CharBuffer;
import com.caucho.util.L10N;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Domain name normalization
*/
public class DomainName {
static final Logger log
= Logger.getLogger(DomainName.class.getName());
static final L10N L = new L10N(DomainName.class);
private final static char ENCODE[];
private final static int DECODE[];
private final static int base = 36;
private final static int tmin = 1;
private final static int tmax = 26;
private final static int skew = 38;
private final static int damp = 700;
private final static int initialBias = 72;
private final static int initialN = 128;
/**
* Converts from the ascii "punicode" to a string.
*/
public static String fromAscii(String source)
{
CharBuffer result = CharBuffer.allocate();
CharBuffer cb = CharBuffer.allocate();
int index = 0;
int length = source.length();
boolean isFirst = true;
try {
while (index < length) {
char ch = source.charAt(index + 0);
if (isFirst && index + 4 < length
&& source.charAt(index + 0) == 'x'
&& source.charAt(index + 1) == 'n'
&& source.charAt(index + 2) == '-'
&& source.charAt(index + 3) == '-') {
int p = source.indexOf('.', index);
String seq;
if (p < 0)
seq = source.substring(index + 4);
else
seq = source.substring(index + 4, p);
decode(result, cb, seq);
index += 4 + seq.length();
continue;
}
index++;
isFirst = false;
if (ch == '.') {
isFirst = true;
result.append(ch);
}
else
result.append(Character.toLowerCase(ch));
}
return result.close();
} catch (Throwable e) {
log.log(Level.WARNING, e.toString(), e);
throw new RuntimeException(e);
}
}
/**
* Converts to the ascii "punicode".
*/
public static String toAscii(String source)
{
CharBuffer result = CharBuffer.allocate();
CharBuffer cb = CharBuffer.allocate();
int head = 0;
int length = source.length();
while (head < length) {
boolean isAscii = true;
cb.clear();
int i = head;
for (; i < length; i++) {
char ch = source.charAt(i);
if (ch == '.') {
cb.append(ch);
break;
}
else if (ch <= 0x7f)
cb.append(ch);
else {
isAscii = false;
break;
}
}
if (isAscii) {
head = i + 1;
result.append(cb);
continue;
}
cb.clear();
i = head;
for (; i < length; i++) {
char ch = source.charAt(i);
if (ch == '.')
break;
//cb.append(Character.toLowerCase(ch));
cb.append(ch);
}
head = i;
String seq = cb.toString();
cb.clear();
toAscii(cb, seq);
result.append(cb);
}
return result.close();
}
private static void decode(CharBuffer result, CharBuffer cb, String seq)
{
int length = seq.length();
int b = 0;
cb.setLength(0);
for (int i = 0; i < length; i++) {
char ch = seq.charAt(i);
if (ch == '-')
b = i;
}
for (int i = 0; i < b; i++) {
char ch = seq.charAt(i);
cb.append(Character.toLowerCase(ch));
}
int in = b > 0 ? b + 1 : 0;
int i = 0;
int bias = initialBias;
int out = cb.length();
int n = initialN;
while (in < length) {
int oldi = i;
int w = 1;
for (int k = base; true; k += base) {
char ch = seq.charAt(in++);
int digit = DECODE[ch];
i += digit * w;
int t;
if (k <= bias)
t = tmin;
else if (bias + tmax <= k)
t = tmax;
else
t = k - bias;
if (digit < t)
break;
w *= (base - t);
}
bias = adapt(i - oldi, out + 1, oldi == 0);
n += i / (out + 1);
i %= (out + 1);
cb.append(' ');
char []cBuf = cb.getBuffer();
System.arraycopy(cBuf, i, cBuf, i + 1, out - i);
cBuf[i++] = Character.toLowerCase((char) n);
out++;
}
result.append(cb);
}
private static void toAscii(CharBuffer cb, String seq)
{
cb.append("xn--");
int length = seq.length();
int index = 0;
int n = initialN;
int delta = 0;
int bias = initialBias;
int b = 0; // # of basic code points
for (int i = 0; i < length; i++) {
char ch = seq.charAt(i);
if (ch < 0x80) {
cb.append(ch);
b++;
}
}
if (b > 0)
cb.append('-');
int h = b;
while (h < length) {
int m = 0xffff;
for (int i = 0; i < length; i++) {
char ch = seq.charAt(i);
if (n <= ch && ch < m)
m = ch;
}
// XXX: overflow
delta = delta + (m - n) * (h + 1);
n = m;
for (int i = 0; i < length; i++) {
int ch = seq.charAt(i);
if (ch < n) {
delta++;
}
if (ch == n) {
int q = delta;
for (int k = base; true; k += base) {
int t;
if (k <= bias)
t = tmin;
else if (bias + tmax <= k)
t = tmax;
else
t = k - bias;
if (q < t)
break;
cb.append(ENCODE[t + (q - t) % (base - t)]);
q = (q - t) / (base - t);
}
cb.append(ENCODE[q]);
bias = adapt(delta, h + 1, h == b);
delta = 0;
h++;
}
}
delta++;
n++;
}
}
private static int adapt(int delta, int nPoints, boolean isFirst)
{
int k;
delta = isFirst ? delta / damp : delta / 2;
delta += delta / nPoints;
for (k = 0; ((base - tmin) * tmax) / 2 < delta; k += base) {
delta /= base - tmin;
}
return k + (base - tmin + 1) * delta / (delta + skew);
}
static {
ENCODE = new char[36];
for (int i = 0; i < 26; i++) {
ENCODE[i] = (char) ('a' + i);
}
for (int i = 0; i < 10; i++) {
ENCODE[i + 26] = (char) ('0' + i);
}
DECODE = new int[0x80];
for (int i = 0; i < 26; i++) {
DECODE[(char) ('a' + i)] = i;
DECODE[(char) ('A' + i)] = i;
}
for (int i = 0; i < 10; i++) {
DECODE[(char) ('0' + i)] = 26 + i;
}
}
}