net-dns

DNS data model with serializer/deserializer for the wire and "master file" format.

Features

• Serialization for the wire and master file formats
• Pretty printing of messages
• Supports compressed domain names
• Supports multiple strings in TXT records
• Supports the extended 12-bit RCODE
• Future proof: handles unknown resource records and EDNS options
• Graceful truncation of messages
• A name server that answeres DNS questions
• Data models for
  • RFC 1035 Domain Names (DNS)
  • RFC 1183 New DNS RR Definitions
  • RFC 1996 Zone Changes (DNS NOTIFY)
  • RFC 2136 Dynamic Updates (DNS UPDATE)
  • RFC 2845 Secret Key Transaction Authentication for DNS (TSIG)
  • RFC 2930 Secret Key Establishment for DNS (TKEY RR)
  • RFC 3225 Indicating Resolver Support of DNSSEC
  • RFC 3599 DNS Extensions to Support IPv6
  • RFC 4034 Resource Records for the DNS Security Extensions (DNSSEC)
  • RFC 5001 DNS Name Server Identifier (NSID) Option
  • RFC 6672 DNAME Redirection in the DNS
  • RFC 6891 Extension Mechanisms for DNS (EDNS(0))
  • RFC 7828 The edns-tcp-keepalive EDNS0 Option
  • RFC 7830 The EDNS(0) Padding Option
  • RFC 8914 Extended DNS Errors
• Targets .Net 6.0, 8.0

Getting started

Published releases are available on NuGet. To install, run the following command in the Package Manager Console.

PM> Install-Package Makaretu.Dns.New

Usage

Name Server

Create a name server that can answer questions for a zone.

using Makaretu.Dns.Resolving;

var catalog = new Catalog();
catalog.IncludeZone(...);
catalog.IncludeRootHints();
var resolver = new NameServer { Catalog = catalog };

Answer a question

var request = new Message();
request.Questions.Add(new Question { Name = "ns.example.com", Type = DnsType.AAAA });
var response = await resolver.ResolveAsync(request);

Data Model

using Makaretu.Dns

var msg = new Message
{
	AA = true,
	QR = true,
	Id = 1234
};
msg.Questions.Add(new Question 
{ 
	Name = "emanon.org" 
});
msg.Answers.Add(new ARecord 
{ 
	Name = "emanon.org",
	Address = IPAddress.Parse("127.0.0.1") 
});
msg.AuthorityRecords.Add(new SOARecord
{
	Name = "emanon.org",
	PrimaryName = "erehwon",
	Mailbox = "hostmaster.emanon.org"
});
msg.AdditionalRecords.Add(new ARecord 
{ 
	Name = "erehwon", 
	Address = IPAddress.Parse("127.0.0.1") 
});

Related projects

• net-mdns - client and server for multicast DNS
• net-udns - client for unicast DNS, DNS over HTTPS (DOH) and DNS over TLS (DOT)
• DNSSEC - What Is It and Why Is It Important?

License

Copyright © 2018 Richard Schneider (makaretu@gmail.com)

The package is licensed under the MIT license. Refer to the LICENSE file for more information.