| /* |
| * Copyright (c) 2000, 2011, 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<ResourceRecord> question = new Vector<>(); |
| Vector<ResourceRecord> answer = new Vector<>(); |
| Vector<ResourceRecord> authority = new Vector<>(); |
| Vector<ResourceRecord> 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 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 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"); |
| } |
| } |
| } |