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      1 // Copyright (c) 1999-2004 Brian Wellington (bwelling (at) xbill.org)
      2 
      3 package org.xbill.DNS;
      4 
      5 import java.io.*;
      6 import java.util.*;
      7 
      8 /**
      9  * Next name - this record contains the following name in an ordered list
     10  * of names in the zone, and a set of types for which records exist for
     11  * this name.  The presence of this record in a response signifies a
     12  * failed query for data in a DNSSEC-signed zone.
     13  *
     14  * @author Brian Wellington
     15  */
     16 
     17 public class NXTRecord extends Record {
     18 
     19 private static final long serialVersionUID = -8851454400765507520L;
     20 
     21 private Name next;
     22 private BitSet bitmap;
     23 
     24 NXTRecord() {}
     25 
     26 Record
     27 getObject() {
     28 	return new NXTRecord();
     29 }
     30 
     31 /**
     32  * Creates an NXT Record from the given data
     33  * @param next The following name in an ordered list of the zone
     34  * @param bitmap The set of type for which records exist at this name
     35 */
     36 public
     37 NXTRecord(Name name, int dclass, long ttl, Name next, BitSet bitmap) {
     38 	super(name, Type.NXT, dclass, ttl);
     39 	this.next = checkName("next", next);
     40 	this.bitmap = bitmap;
     41 }
     42 
     43 void
     44 rrFromWire(DNSInput in) throws IOException {
     45 	next = new Name(in);
     46 	bitmap = new BitSet();
     47 	int bitmapLength = in.remaining();
     48 	for (int i = 0; i < bitmapLength; i++) {
     49 		int t = in.readU8();
     50 		for (int j = 0; j < 8; j++)
     51 			if ((t & (1 << (7 - j))) != 0)
     52 				bitmap.set(i * 8 + j);
     53 	}
     54 }
     55 
     56 void
     57 rdataFromString(Tokenizer st, Name origin) throws IOException {
     58 	next = st.getName(origin);
     59 	bitmap = new BitSet();
     60 	while (true) {
     61 		Tokenizer.Token t = st.get();
     62 		if (!t.isString())
     63 			break;
     64 		int typecode = Type.value(t.value, true);
     65 		if (typecode <= 0 || typecode > 128)
     66 			throw st.exception("Invalid type: " + t.value);
     67 		bitmap.set(typecode);
     68 	}
     69 	st.unget();
     70 }
     71 
     72 /** Converts rdata to a String */
     73 String
     74 rrToString() {
     75 	StringBuffer sb = new StringBuffer();
     76 	sb.append(next);
     77 	int length = bitmap.length();
     78 	for (short i = 0; i < length; i++)
     79 		if (bitmap.get(i)) {
     80 			sb.append(" ");
     81 			sb.append(Type.string(i));
     82 		}
     83 	return sb.toString();
     84 }
     85 
     86 /** Returns the next name */
     87 public Name
     88 getNext() {
     89 	return next;
     90 }
     91 
     92 /** Returns the set of types defined for this name */
     93 public BitSet
     94 getBitmap() {
     95 	return bitmap;
     96 }
     97 
     98 void
     99 rrToWire(DNSOutput out, Compression c, boolean canonical) {
    100 	next.toWire(out, null, canonical);
    101 	int length = bitmap.length();
    102 	for (int i = 0, t = 0; i < length; i++) {
    103 		t |= (bitmap.get(i) ? (1 << (7 - i % 8)) : 0);
    104 		if (i % 8 == 7 || i == length - 1) {
    105 			out.writeU8(t);
    106 			t = 0;
    107 		}
    108 	}
    109 }
    110 
    111 }
    112