trunk/activemq-jmdns_1.0/src/main/java/org/apache/activemq/jmdns/DNSOutgoing.java - activemq - Git at Google

 /**
  * Copyright 2003-2005 Arthur van Hoff, Rick Blair
  *
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF 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.apache.activemq.jmdns;

 import java.io.IOException;
 import java.util.Hashtable;
 import java.util.LinkedList;
 import java.util.logging.Level;
 import java.util.logging.Logger;

 /**
  * An outgoing DNS message.
  *
  * @version %I%, %G%
  * @author	Arthur van Hoff, Rick Blair, Werner Randelshofer
  */
 final class DNSOutgoing
 {
     private static Logger logger = Logger.getLogger(DNSOutgoing.class.toString());
     int id;
     int flags;
     private boolean multicast;
     private int numQuestions;
     private int numAnswers;
     private int numAuthorities;
     private int numAdditionals;
     private Hashtable names;

     byte data[];
     int off;
     int len;

     /**
      * Create an outgoing multicast query or response.
      */
     DNSOutgoing(int flags)
     {
         this(flags, true);
     }

     /**
      * Create an outgoing query or response.
      */
     DNSOutgoing(int flags, boolean multicast)
     {
         this.flags = flags;
         this.multicast = multicast;
         names = new Hashtable();
         data = new byte[DNSConstants.MAX_MSG_TYPICAL];
         off = 12;
     }

     /**
      * Add a question to the message.
      */
     void addQuestion(DNSQuestion rec) throws IOException
     {
         if (numAnswers > 0 || numAuthorities > 0 || numAdditionals > 0)
         {
             throw new IllegalStateException("Questions must be added before answers");
         }
         numQuestions++;
         writeQuestion(rec);
     }

     /**
      * Add an answer if it is not suppressed.
      */
     void addAnswer(DNSIncoming in, DNSRecord rec) throws IOException
     {
         if (numAuthorities > 0 || numAdditionals > 0)
         {
             throw new IllegalStateException("Answers must be added before authorities and additionals");
         }
         if (!rec.suppressedBy(in))
         {
             addAnswer(rec, 0);
         }
     }

     /**
      * Add an additional answer to the record. Omit if there is no room.
      */
     void addAdditionalAnswer(DNSIncoming in, DNSRecord rec) throws IOException
     {
         if ((off < DNSConstants.MAX_MSG_TYPICAL - 200) && !rec.suppressedBy(in))
         {
             writeRecord(rec, 0);
             numAdditionals++;
         }
     }

     /**
      * Add an answer to the message.
      */
     void addAnswer(DNSRecord rec, long now) throws IOException
     {
         if (numAuthorities > 0 || numAdditionals > 0)
         {
             throw new IllegalStateException("Questions must be added before answers");
         }
         if (rec != null)
         {
             if ((now == 0) || !rec.isExpired(now))
             {
                 writeRecord(rec, now);
                 numAnswers++;
             }
         }
     }

     private LinkedList authorativeAnswers = new LinkedList();

     /**
      * Add an authorative answer to the message.
      */
     void addAuthorativeAnswer(DNSRecord rec) throws IOException
     {
         if (numAdditionals > 0)
         {
             throw new IllegalStateException("Authorative answers must be added before additional answers");
         }
         authorativeAnswers.add(rec);
         writeRecord(rec, 0);
         numAuthorities++;

         // VERIFY:

     }

     void writeByte(int value) throws IOException
     {
         if (off >= data.length)
         {
             throw new IOException("buffer full");
         }
         data[off++] = (byte) value;
     }

     void writeBytes(String str, int off, int len) throws IOException
     {
         for (int i = 0; i < len; i++)
         {
             writeByte(str.charAt(off + i));
         }
     }

     void writeBytes(byte data[]) throws IOException
     {
         if (data != null)
         {
             writeBytes(data, 0, data.length);
         }
     }

     void writeBytes(byte data[], int off, int len) throws IOException
     {
         for (int i = 0; i < len; i++)
         {
             writeByte(data[off + i]);
         }
     }

     void writeShort(int value) throws IOException
     {
         writeByte(value >> 8);
         writeByte(value);
     }

     void writeInt(int value) throws IOException
     {
         writeShort(value >> 16);
         writeShort(value);
     }

     void writeUTF(String str, int off, int len) throws IOException
     {
         // compute utf length
         int utflen = 0;
         for (int i = 0; i < len; i++)
         {
             int ch = str.charAt(off + i);
             if ((ch >= 0x0001) && (ch <= 0x007F))
             {
                 utflen += 1;
             }
             else
             {
                 if (ch > 0x07FF)
                 {
                     utflen += 3;
                 }
                 else
                 {
                     utflen += 2;
                 }
             }
         }
         // write utf length
         writeByte(utflen);
         // write utf data
         for (int i = 0; i < len; i++)
         {
             int ch = str.charAt(off + i);
             if ((ch >= 0x0001) && (ch <= 0x007F))
             {
                 writeByte(ch);
             }
             else
             {
                 if (ch > 0x07FF)
                 {
                     writeByte(0xE0 | ((ch >> 12) & 0x0F));
                     writeByte(0x80 | ((ch >> 6) & 0x3F));
                     writeByte(0x80 | ((ch >> 0) & 0x3F));
                 }
                 else
                 {
                     writeByte(0xC0 | ((ch >> 6) & 0x1F));
                     writeByte(0x80 | ((ch >> 0) & 0x3F));
                 }
             }
         }
     }

     void writeName(String name) throws IOException
     {
         while (true)
         {
             int n = name.indexOf('.');
             if (n < 0)
             {
                 n = name.length();
             }
             if (n <= 0)
             {
                 writeByte(0);
                 return;
             }
             Integer offset = (Integer) names.get(name);
             if (offset != null)
             {
                 int val = offset.intValue();

                 if (val > off)
                 {
                     logger.log(Level.WARNING, "DNSOutgoing writeName failed val=" + val + " name=" + name);
                 }

                 writeByte((val >> 8) | 0xC0);
                 writeByte(val);
                 return;
             }
             names.put(name, new Integer(off));
             writeUTF(name, 0, n);
             name = name.substring(n);
             if (name.startsWith("."))
             {
                 name = name.substring(1);
             }
         }
     }

     void writeQuestion(DNSQuestion question) throws IOException
     {
         writeName(question.name);
         writeShort(question.type);
         writeShort(question.clazz);
     }

     void writeRecord(DNSRecord rec, long now) throws IOException
     {
         int save = off;
         try
         {
             writeName(rec.name);
             writeShort(rec.type);
             writeShort(rec.clazz | ((rec.unique && multicast) ? DNSConstants.CLASS_UNIQUE : 0));
             writeInt((now == 0) ? rec.ttl : rec.getRemainingTTL(now));
             writeShort(0);
             int start = off;
             rec.write(this);
             int len = off - start;
             data[start - 2] = (byte) (len >> 8);
             data[start - 1] = (byte) (len & 0xFF);
         }
         catch (IOException e)
         {
             off = save;
             throw e;
         }
     }

     /**
      * Finish the message before sending it off.
      */
     void finish() throws IOException
     {
         int save = off;
         off = 0;

         writeShort(multicast ? 0 : id);
         writeShort(flags);
         writeShort(numQuestions);
         writeShort(numAnswers);
         writeShort(numAuthorities);
         writeShort(numAdditionals);
         off = save;
     }

     boolean isQuery()
     {
         return (flags & DNSConstants.FLAGS_QR_MASK) == DNSConstants.FLAGS_QR_QUERY;
     }

     public boolean isEmpty()
     {
         return numQuestions == 0 && numAuthorities == 0
             && numAdditionals == 0 && numAnswers == 0;
     }


     public String toString()
     {
         StringBuffer buf = new StringBuffer();
         buf.append(isQuery() ? "dns[query," : "dns[response,");
         //buf.append(packet.getAddress().getHostAddress());
         buf.append(':');
         //buf.append(packet.getPort());
         //buf.append(",len=");
         //buf.append(packet.getLength());
         buf.append(",id=0x");
         buf.append(Integer.toHexString(id));
         if (flags != 0)
         {
             buf.append(",flags=0x");
             buf.append(Integer.toHexString(flags));
             if ((flags & DNSConstants.FLAGS_QR_RESPONSE) != 0)
             {
                 buf.append(":r");
             }
             if ((flags & DNSConstants.FLAGS_AA) != 0)
             {
                 buf.append(":aa");
             }
             if ((flags & DNSConstants.FLAGS_TC) != 0)
             {
                 buf.append(":tc");
             }
         }
         if (numQuestions > 0)
         {
             buf.append(",questions=");
             buf.append(numQuestions);
         }
         if (numAnswers > 0)
         {
             buf.append(",answers=");
             buf.append(numAnswers);
         }
         if (numAuthorities > 0)
         {
             buf.append(",authorities=");
             buf.append(numAuthorities);
         }
         if (numAdditionals > 0)
         {
             buf.append(",additionals=");
             buf.append(numAdditionals);
         }
         buf.append(",\nnames=" + names);
         buf.append(",\nauthorativeAnswers=" + authorativeAnswers);

         buf.append("]");
         return buf.toString();
     }

 }
	/**
	* Copyright 2003-2005 Arthur van Hoff, Rick Blair
	*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF 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.apache.activemq.jmdns;

	import java.io.IOException;
	import java.util.Hashtable;
	import java.util.LinkedList;
	import java.util.logging.Level;
	import java.util.logging.Logger;

	/**
	* An outgoing DNS message.
	*
	* @version %I%, %G%
	* @author Arthur van Hoff, Rick Blair, Werner Randelshofer
	*/
	final class DNSOutgoing
	{
	private static Logger logger = Logger.getLogger(DNSOutgoing.class.toString());
	int id;
	int flags;
	private boolean multicast;
	private int numQuestions;
	private int numAnswers;
	private int numAuthorities;
	private int numAdditionals;
	private Hashtable names;

	byte data[];
	int off;
	int len;

	/**
	* Create an outgoing multicast query or response.
	*/
	DNSOutgoing(int flags)
	{
	this(flags, true);
	}

	/**
	* Create an outgoing query or response.
	*/
	DNSOutgoing(int flags, boolean multicast)
	{
	this.flags = flags;
	this.multicast = multicast;
	names = new Hashtable();
	data = new byte[DNSConstants.MAX_MSG_TYPICAL];
	off = 12;
	}

	/**
	* Add a question to the message.
	*/
	void addQuestion(DNSQuestion rec) throws IOException
	{
	if (numAnswers > 0 \|\| numAuthorities > 0 \|\| numAdditionals > 0)
	{
	throw new IllegalStateException("Questions must be added before answers");
	}
	numQuestions++;
	writeQuestion(rec);
	}

	/**
	* Add an answer if it is not suppressed.
	*/
	void addAnswer(DNSIncoming in, DNSRecord rec) throws IOException
	{
	if (numAuthorities > 0 \|\| numAdditionals > 0)
	{
	throw new IllegalStateException("Answers must be added before authorities and additionals");
	}
	if (!rec.suppressedBy(in))
	{
	addAnswer(rec, 0);
	}
	}

	/**
	* Add an additional answer to the record. Omit if there is no room.
	*/
	void addAdditionalAnswer(DNSIncoming in, DNSRecord rec) throws IOException
	{
	if ((off < DNSConstants.MAX_MSG_TYPICAL - 200) && !rec.suppressedBy(in))
	{
	writeRecord(rec, 0);
	numAdditionals++;
	}
	}

	/**
	* Add an answer to the message.
	*/
	void addAnswer(DNSRecord rec, long now) throws IOException
	{
	if (numAuthorities > 0 \|\| numAdditionals > 0)
	{
	throw new IllegalStateException("Questions must be added before answers");
	}
	if (rec != null)
	{
	if ((now == 0) \|\| !rec.isExpired(now))
	{
	writeRecord(rec, now);
	numAnswers++;
	}
	}
	}

	private LinkedList authorativeAnswers = new LinkedList();

	/**
	* Add an authorative answer to the message.
	*/
	void addAuthorativeAnswer(DNSRecord rec) throws IOException
	{
	if (numAdditionals > 0)
	{
	throw new IllegalStateException("Authorative answers must be added before additional answers");
	}
	authorativeAnswers.add(rec);
	writeRecord(rec, 0);
	numAuthorities++;

	// VERIFY:

	}

	void writeByte(int value) throws IOException
	{
	if (off >= data.length)
	{
	throw new IOException("buffer full");
	}
	data[off++] = (byte) value;
	}

	void writeBytes(String str, int off, int len) throws IOException
	{
	for (int i = 0; i < len; i++)
	{
	writeByte(str.charAt(off + i));
	}
	}

	void writeBytes(byte data[]) throws IOException
	{
	if (data != null)
	{
	writeBytes(data, 0, data.length);
	}
	}

	void writeBytes(byte data[], int off, int len) throws IOException
	{
	for (int i = 0; i < len; i++)
	{
	writeByte(data[off + i]);
	}
	}

	void writeShort(int value) throws IOException
	{
	writeByte(value >> 8);
	writeByte(value);
	}

	void writeInt(int value) throws IOException
	{
	writeShort(value >> 16);
	writeShort(value);
	}

	void writeUTF(String str, int off, int len) throws IOException
	{
	// compute utf length
	int utflen = 0;
	for (int i = 0; i < len; i++)
	{
	int ch = str.charAt(off + i);
	if ((ch >= 0x0001) && (ch <= 0x007F))
	{
	utflen += 1;
	}
	else
	{
	if (ch > 0x07FF)
	{
	utflen += 3;
	}
	else
	{
	utflen += 2;
	}
	}
	}
	// write utf length
	writeByte(utflen);
	// write utf data
	for (int i = 0; i < len; i++)
	{
	int ch = str.charAt(off + i);
	if ((ch >= 0x0001) && (ch <= 0x007F))
	{
	writeByte(ch);
	}
	else
	{
	if (ch > 0x07FF)
	{
	writeByte(0xE0 \| ((ch >> 12) & 0x0F));
	writeByte(0x80 \| ((ch >> 6) & 0x3F));
	writeByte(0x80 \| ((ch >> 0) & 0x3F));
	}
	else
	{
	writeByte(0xC0 \| ((ch >> 6) & 0x1F));
	writeByte(0x80 \| ((ch >> 0) & 0x3F));
	}
	}
	}
	}

	void writeName(String name) throws IOException
	{
	while (true)
	{
	int n = name.indexOf('.');
	if (n < 0)
	{
	n = name.length();
	}
	if (n <= 0)
	{
	writeByte(0);
	return;
	}
	Integer offset = (Integer) names.get(name);
	if (offset != null)
	{
	int val = offset.intValue();

	if (val > off)
	{
	logger.log(Level.WARNING, "DNSOutgoing writeName failed val=" + val + " name=" + name);
	}

	writeByte((val >> 8) \| 0xC0);
	writeByte(val);
	return;
	}
	names.put(name, new Integer(off));
	writeUTF(name, 0, n);
	name = name.substring(n);
	if (name.startsWith("."))
	{
	name = name.substring(1);
	}
	}
	}

	void writeQuestion(DNSQuestion question) throws IOException
	{
	writeName(question.name);
	writeShort(question.type);
	writeShort(question.clazz);
	}

	void writeRecord(DNSRecord rec, long now) throws IOException
	{
	int save = off;
	try
	{
	writeName(rec.name);
	writeShort(rec.type);
	writeShort(rec.clazz \| ((rec.unique && multicast) ? DNSConstants.CLASS_UNIQUE : 0));
	writeInt((now == 0) ? rec.ttl : rec.getRemainingTTL(now));
	writeShort(0);
	int start = off;
	rec.write(this);
	int len = off - start;
	data[start - 2] = (byte) (len >> 8);
	data[start - 1] = (byte) (len & 0xFF);
	}
	catch (IOException e)
	{
	off = save;
	throw e;
	}
	}

	/**
	* Finish the message before sending it off.
	*/
	void finish() throws IOException
	{
	int save = off;
	off = 0;

	writeShort(multicast ? 0 : id);
	writeShort(flags);
	writeShort(numQuestions);
	writeShort(numAnswers);
	writeShort(numAuthorities);
	writeShort(numAdditionals);
	off = save;
	}

	boolean isQuery()
	{
	return (flags & DNSConstants.FLAGS_QR_MASK) == DNSConstants.FLAGS_QR_QUERY;
	}

	public boolean isEmpty()
	{
	return numQuestions == 0 && numAuthorities == 0
	&& numAdditionals == 0 && numAnswers == 0;
	}


	public String toString()
	{
	StringBuffer buf = new StringBuffer();
	buf.append(isQuery() ? "dns[query," : "dns[response,");
	//buf.append(packet.getAddress().getHostAddress());
	buf.append(':');
	//buf.append(packet.getPort());
	//buf.append(",len=");
	//buf.append(packet.getLength());
	buf.append(",id=0x");
	buf.append(Integer.toHexString(id));
	if (flags != 0)
	{
	buf.append(",flags=0x");
	buf.append(Integer.toHexString(flags));
	if ((flags & DNSConstants.FLAGS_QR_RESPONSE) != 0)
	{
	buf.append(":r");
	}
	if ((flags & DNSConstants.FLAGS_AA) != 0)
	{
	buf.append(":aa");
	}
	if ((flags & DNSConstants.FLAGS_TC) != 0)
	{
	buf.append(":tc");
	}
	}
	if (numQuestions > 0)
	{
	buf.append(",questions=");
	buf.append(numQuestions);
	}
	if (numAnswers > 0)
	{
	buf.append(",answers=");
	buf.append(numAnswers);
	}
	if (numAuthorities > 0)
	{
	buf.append(",authorities=");
	buf.append(numAuthorities);
	}
	if (numAdditionals > 0)
	{
	buf.append(",additionals=");
	buf.append(numAdditionals);
	}
	buf.append(",\nnames=" + names);
	buf.append(",\nauthorativeAnswers=" + authorativeAnswers);

	buf.append("]");
	return buf.toString();
	}

	}