/**********************************************************************
* Copyright (c) 2010, j. montgomery *
* All rights reserved. *
* *
* Redistribution and use in source and binary forms, with or without *
* modification, are permitted provided that the following conditions *
* are met: *
* *
* + Redistributions of source code must retain the above copyright *
* notice, this list of conditions and the following disclaimer. *
* *
* + Redistributions in binary form must reproduce the above copyright*
* notice, this list of conditions and the following disclaimer *
* in the documentation and/or other materials provided with the *
* distribution. *
* *
* + Neither the name of j. montgomery's employer nor the names of *
* its contributors may be used to endorse or promote products *
* derived from this software without specific prior written *
* permission. *
* *
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS*
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT *
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS *
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE *
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,*
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES *
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR *
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) *
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,*
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) *
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED*
* OF THE POSSIBILITY OF SUCH DAMAGE. *
**********************************************************************/
using System;
using System.Collections.Generic;
using System.Text;
using DnDns.Enums;
using DnDns.Records;
namespace DnDns.Query
{
///
/// DnsQueryBase maintains the common state of DNS Queries (both responses and requests)
///
public abstract class DnsQueryBase
{
#region Fields
// RFC 1034
//
// 4.1.1. Header section format
//
// 1 1 1 1 1 1
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | ID |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// |QR| Opcode |AA|TC|RD|RA| Z | RCODE |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | QDCOUNT |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | ANCOUNT |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | NSCOUNT |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | ARCOUNT |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
///
/// ID - A 16 bit identifier. This identifier is copied
/// the corresponding reply and can be used by the requester
/// to match up replies to outstanding queries.
///
protected ushort _transactionId;
///
/// _flags will store a combination of the enums that make up the 16 bits after the
/// TransactionID in the DNS protocol header
///
protected ushort _flags;
///
/// A one bit field that specifies whether this message is a
/// query (0), or a response (1).
///
protected QueryResponse _queryResponse;
///
/// OPCODE - A four bit field that specifies kind of query in this
/// message. This value is set by the originator of a query
/// and copied into the response.
///
protected OpCode _opCode;
///
/// - A combination of flag fields in the DNS header (|AA|TC|RD|RA|)
///
protected NsFlags _nsFlags;
///
/// Response code - this 4 bit field is set as part of
/// responses only.
///
protected RCode _rCode;
///
/// QDCOUNT - an unsigned 16 bit integer specifying the number of
/// entries in the question section.
///
protected ushort _questions;
///
/// ANCOUNT - an unsigned 16 bit integer specifying the number of
/// resource records in the answer section.
///
protected ushort _answerRRs;
///
/// NSCOUNT - an unsigned 16 bit integer specifying the number of name
/// server resource records in the authority records
/// section.
///
protected ushort _authorityRRs;
// RFC 1034
// 4.1.2. Question section format
// 1 1 1 1 1 1
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | |
// / QNAME /
// / /
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | QTYPE |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | QCLASS |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
///
/// QNAME - a domain name represented as a sequence of labels, where
/// each label consists of a length octet followed by that
/// number of octets. The domain name terminates with the
/// zero length octet for the null label of the root. Note
/// that this field may be an odd number of octets; no
/// padding is used
///
protected string _name;
///
/// QTYPE - a two octet code which specifies the type of the query.
/// The values for this field include all codes valid for a
/// TYPE field, together with some more general codes which
/// can match more than one type of RR.
///
protected NsType _nsType;
///
/// QCLASS - a two octet code that specifies the class of the query.
/// For example, the QCLASS field is IN for the Internet.
///
protected NsClass _nsClass;
///
/// The additional records for the DNS Query
///
protected List _additionalRecords = new List();
#endregion Fields
#region Properties
/// ID - A 16 bit identifier. This identifier is copied
/// the corresponding reply and can be used by the requester
/// to match up replies to outstanding queries.
///
public ushort TransactionID
{
get { return _transactionId; }
}
///
/// A one bit field that specifies whether this message is a
/// query (0), or a response (1).
///
public QueryResponse QueryResponse
{
get { return _queryResponse; }
}
///
/// OPCODE - A four bit field that specifies kind of query in this
/// message. This value is set by the originator of a query
/// and copied into the response.
///
public OpCode OpCode
{
get { return _opCode; }
}
///
/// NsFlags - A combination of flag fields in the DNS header (|AA|TC|RD|RA|)
///
public NsFlags NsFlags
{
get { return _nsFlags; }
}
///
/// Response code - this 4 bit field is set as part of
/// responses only.
///
public RCode RCode
{
get { return _rCode; }
}
///
/// QDCOUNT - an unsigned 16 bit integer specifying the number of
/// entries in the question section.
///
public ushort Questions
{
get { return _questions; }
}
///
/// ANCOUNT - an unsigned 16 bit integer specifying the number of
/// resource records in the answer section.
///
public ushort AnswerRRs
{
get { return _answerRRs; }
}
///
/// NSCOUNT - an unsigned 16 bit integer specifying the number of name
/// server resource records in the authority records
/// section.
///
public ushort AuthorityRRs
{
get { return _authorityRRs; }
}
///
/// ARCOUNT - an unsigned 16 bit integer specifying the number of
/// resource records in the additional records section.
///
public ushort AdditionalRRs
{
get { return (ushort) _additionalRecords.Count; }
}
///
/// QNAME - a domain name represented as a sequence of labels, where
/// each label consists of a length octet followed by that
/// number of octets. The domain name terminates with the
/// zero length octet for the null label of the root. Note
/// that this field may be an odd number of octets; no
/// padding is used
///
public string Name
{
get { return _name; }
set { _name = value; }
}
///
/// QTYPE - a two octet code which specifies the type of the query.
/// The values for this field include all codes valid for a
/// TYPE field, together with some more general codes which
/// can match more than one type of RR.
///
public NsType NsType
{
get { return _nsType; }
set { _nsType = value; }
}
///
/// QCLASS - a two octet code that specifies the class of the query.
/// For example, the QCLASS field is IN for the Internet.
///
public NsClass NsClass
{
get { return _nsClass; }
set { _nsClass = value; }
}
public List AdditionalRRecords
{
get { return _additionalRecords; }
}
#endregion
}
}