/* * Copyright (c) 2000, 2001, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */package com.sun.jndi.dns;import java.util.Vector;import javax.naming.*;/** * The ResourceRecords class represents the resource records in the * four sections of a DNS message. * * The additional records section is currently ignored. * * @author Scott Seligman */class ResourceRecords { // Four sections: question, answer, authority, additional. // The question section is treated as being made up of (shortened) // resource records, although this isn't technically how it's defined. Vector question = new Vector(); Vector answer = new Vector(); Vector authority = new Vector(); Vector additional = new Vector(); /* * True if these resource records are from a zone transfer. In * that case only answer records are read (as per * draft-ietf-dnsext-axfr-clarify-02.txt). Also, the rdata of * those answer records is not decoded (for efficiency) except * for SOA records. */ boolean zoneXfer; /* * Returns a representation of the resource records in a DNS message. * Does not modify or store a reference to the msg array. */ ResourceRecords(byte[] msg, int msgLen, Header hdr, boolean zoneXfer) throws NamingException { if (zoneXfer) { answer.ensureCapacity(8192); // an arbitrary "large" number } this.zoneXfer = zoneXfer; add(msg, msgLen, hdr); } /* * Returns the type field of the first answer record, or -1 if * there are no answer records. */ int getFirstAnsType() { if (answer.size() == 0) { return -1; } return ((ResourceRecord) answer.firstElement()).getType(); } /* * Returns the type field of the last answer record, or -1 if * there are no answer records. */ int getLastAnsType() { if (answer.size() == 0) { return -1; } return ((ResourceRecord) answer.lastElement()).getType(); } /* * Decodes the resource records in a DNS message and adds * them to this object. * Does not modify or store a reference to the msg array. */ void add(byte[] msg, int msgLen, Header hdr) throws NamingException { ResourceRecord rr; int pos = Header.HEADER_SIZE; // current offset into msg try { for (int i = 0; i < hdr.numQuestions; i++) { rr = new ResourceRecord(msg, msgLen, pos, true, false); if (!zoneXfer) { question.addElement(rr); } pos += rr.size(); } for (int i = 0; i < hdr.numAnswers; i++) { rr = new ResourceRecord( msg, msgLen, pos, false, !zoneXfer); answer.addElement(rr); pos += rr.size(); } if (zoneXfer) { return; } for (int i = 0; i < hdr.numAuthorities; i++) { rr = new ResourceRecord(msg, msgLen, pos, false, true); authority.addElement(rr); pos += rr.size(); } // The additional records section is currently ignored. } catch (IndexOutOfBoundsException e) { throw new CommunicationException( "DNS error: corrupted message"); } }}
/*
* Copyright (c) 2000, 2001, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.sun.jndi.dns;
import java.util.Vector;
import javax.naming.*;
/**
* The ResourceRecords class represents the resource records in the
* four sections of a DNS message.
*
* The additional records section is currently ignored.
*
* @author Scott Seligman
*/
class ResourceRecords {
// Four sections: question, answer, authority, additional.
// The question section is treated as being made up of (shortened)
// resource records, although this isn't technically how it's defined.
Vector question = new Vector();
Vector answer = new Vector();
Vector authority = new Vector();
Vector additional = new Vector();
/*
* True if these resource records are from a zone transfer. In
* that case only answer records are read (as per
* draft-ietf-dnsext-axfr-clarify-02.txt). Also, the rdata of
* those answer records is not decoded (for efficiency) except
* for SOA records.
*/
boolean zoneXfer;
/*
* Returns a representation of the resource records in a DNS message.
* Does not modify or store a reference to the msg array.
*/
ResourceRecords(byte[] msg, int msgLen, Header hdr, boolean zoneXfer)
throws NamingException {
if (zoneXfer) {
answer.ensureCapacity(8192); // an arbitrary "large" number
}
this.zoneXfer = zoneXfer;
add(msg, msgLen, hdr);
}
/*
* Returns the type field of the first answer record, or -1 if
* there are no answer records.
*/
int getFirstAnsType() {
if (answer.size() == 0) {
return -1;
}
return ((ResourceRecord) answer.firstElement()).getType();
}
/*
* Returns the type field of the last answer record, or -1 if
* there are no answer records.
*/
int getLastAnsType() {
if (answer.size() == 0) {
return -1;
}
return ((ResourceRecord) answer.lastElement()).getType();
}
/*
* Decodes the resource records in a DNS message and adds
* them to this object.
* Does not modify or store a reference to the msg array.
*/
void add(byte[] msg, int msgLen, Header hdr) throws NamingException {
ResourceRecord rr;
int pos = Header.HEADER_SIZE; // current offset into msg
try {
for (int i = 0; i < hdr.numQuestions; i++) {
rr = new ResourceRecord(msg, msgLen, pos, true, false);
if (!zoneXfer) {
question.addElement(rr);
}
pos += rr.size();
}
for (int i = 0; i < hdr.numAnswers; i++) {
rr = new ResourceRecord(
msg, msgLen, pos, false, !zoneXfer);
answer.addElement(rr);
pos += rr.size();
}
if (zoneXfer) {
return;
}
for (int i = 0; i < hdr.numAuthorities; i++) {
rr = new ResourceRecord(msg, msgLen, pos, false, true);
authority.addElement(rr);
pos += rr.size();
}
// The additional records section is currently ignored.
} catch (IndexOutOfBoundsException e) {
throw new CommunicationException(
"DNS error: corrupted message");
}
}
}