dotnet-core_mail-server/MailServer/DNSClient/Enums/NsFlags.cs

298 lines
11 KiB
C#

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* All rights reserved. *
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using System;
using System.Collections.Generic;
using System.Text;
namespace DnDns.Enums
{
// DNS HEADER: http://www.faqs.org/rfcs/rfc1035.html
// 1 1 1 1 1 1
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | Query Identifier |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// |QR| Opcode |AA|TC|RD|RA| Z|AD|CD| RCODE | <-- The Enums below are combined to create this 16 bit (2 byte) field
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | QDCOUNT |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | ANCOUNT |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | NSCOUNT |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// | ARCOUNT |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
/// <summary>
/// FlagMasks are used as a bitmask to isolate bits 16 through 31 of the DNS header to convert
/// them to their appropriate Enum types
/// </summary>
internal enum FlagMasks : ushort
{
QueryResponseMask = 0x8000,
OpCodeMask = 0x7800,
NsFlagMask = 0x07F0,
RCodeMask = 0x000F
}
/// <summary>
/// |QR| - Starts at bit 16 of DNS Header, size: 1 bit
///
/// RFC 1035:
/// A one bit field that specifies whether this message is a
/// query (0), or a response (1).
///
/// </summary>
[Flags()]
public enum QueryResponse : ushort
{
/// <summary>
/// // QR Query or Response [RFC1035] ( 0 = Query )
/// </summary>
Query = 0x0,
/// <summary>
/// // QR Query or Response [RFC1035] ( 1 = Response )
/// </summary>
Response = 0x8000
}
/// <summary>
/// | OpCode | - 4 bits of Dns header, Bit 17 - 20, see RFC 1035
///
/// RFC 1035:
///
/// 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.
///
/// The values are:
///
/// 0 a standard query (QUERY)
///
/// 1 an inverse query (IQUERY)
///
/// 2 a server status request (STATUS)
///
/// 3-15 reserved for future
/// </summary>
[Flags()]
public enum OpCode : ushort
{
/// <summary>
/// Standard query
/// [RFC1035] (QUERY)
/// </summary>
QUERY = 0x0000,
/// <summary>
/// Inverse query
/// [RFC1035] (IQUERY)
/// </summary>
IQUERY = 0x0800,
/// <summary>
/// Server status request
/// [RFC1035] (STATUS)
/// </summary>
STATUS = 0x1000,
}
/// <summary>
/// |AA|TC|RD|RA| Z|AD|CD| - 8 bits (1 byte) flag fields
///
/// reference: http://www.networksorcery.com/enp/protocol/dns.htm
/// </summary>
[Flags()]
public enum NsFlags : ushort
{
/// <summary>
/// AA - Authorative Answer [RFC1035] ( 0 = Not authoritative, 1 = Is authoritative )
/// Authoritative Answer - this bit is valid in responses,
/// and specifies that the responding name server is an
/// authority for the domain name in question section.
///
/// Note that the contents of the answer section may have
/// multiple owner names because of aliases. The AA bit
/// corresponds to the name which matches the query name, or
/// the first owner name in the answer section.
/// </summary>
AA = 0x0400,
/// <summary>
/// TC - Truncated Response [RFC1035] ( 0 = Not truncated, 1 = Message truncated )
///
/// TrunCation - specifies that this message was truncated
/// due to length greater than that permitted on the
/// transmission channel.
/// </summary>
TC = 0x0200,
/// <summary>
/// RD - Recursion Desired [RFC1035] ( 0 = Recursion not desired, 1 = Recursion desired )
///
/// Recursion Desired - this bit may be set in a query and
/// is copied into the response. If RD is set, it directs
/// the name server to pursue the query recursively.
/// Recursive query support is optional.
/// </summary>
RD = 0x0100,
/// <summary>
/// RA - Recursion Allowed [RFC1035] ( 0 = Recursive query support not available, 1 = Recursive query support available )
///
/// Recursion Available - this be is set or cleared in a
/// response, and denotes whether recursive query support is
/// available in the name server.
/// </summary>
RA = 0x0080,
/// <summary>
/// AD - Authentic Data [RFC4035] ( Authenticated data. 1 bit ) [NOT IMPLEMENTED]
///
/// Indicates in a response that all data included in the answer and authority
/// sections of the response have been authenticated by the server according to
/// the policies of that server. It should be set only if all data in the response
/// has been cryptographically verified or otherwise meets the server's local security
/// policy.
/// </summary>
AD = 0x0020,
/// <summary>
/// CD - Checking Disabled [RFC4035] ( Checking Disabled. 1 bit ) [NOT IMPLEMENTED]
/// </summary>
CD = 0x0010
}
/// <summary>
/// | RCODE | - 4 bits error codes
///
/// Response code - this 4 bit field is set as part of
/// responses. The values have the following interpretation:
///
/// Fields 6-15 Reserved for future use.
///
/// reference: http://www.networksorcery.com/enp/protocol/dns.htm
/// </summary>
[Flags()]
public enum RCode : ushort
{
/// <summary>
/// No error condition
/// </summary>
NoError = 0,
/// <summary>
/// Format error - The name server was unable to
/// interpret the query.
/// </summary>
FormatError = 1,
/// <summary>
/// Server failure - The name server was unable to process
/// this query due to a problem with the name server.
/// </summary>
ServerFailure = 2,
/// <summary>
/// Name Error - Meaningful only for responses from an
/// authoritative name server, this code signifies that
/// the domain name referenced in the query does not
/// exist.
/// </summary>
NameError = 3,
/// <summary>
/// Not Implemented - The name server does not support
/// the requested kind of query.
/// </summary>
NotImplemented = 4,
/// <summary>
/// Refused - The name server refuses to perform the
/// specified operation for policy reasons. For example,
/// a name server may not wish to provide the information
/// to the particular requester, or a name server may not
/// wish to perform a particular operation (e.g., zone
/// transfer) for particular data.
/// </summary>
Refused = 5,
/// <summary>
/// RFC 2136
/// Name Exists when it should not.
/// </summary>
YXDomain = 6,
/// <summary>
/// RFC 2136
/// RR Set Exists when it should not.
/// </summary>
YXRRSet = 7,
/// <summary>
/// RFC 2136
/// RR Set that should exist does not.
/// </summary>
NXRRSet = 8,
/// <summary>
/// RFC 2136
/// Server Not Authoritative for zone.
/// </summary>
NotAuth = 9,
/// <summary>
/// RFC 2136
/// Name not contained in zone.
/// </summary>
NotZone = 10,
/// <summary>
/// RFC 2671
/// RFC 2845
///
/// BADVERS Bad OPT Version.
/// BADSIG TSIG Signature Failure.
/// </summary>
BADVERS_BADSIG = 16,
/// <summary>
/// RFC 2845
/// Key not recognized.
/// </summary>
BADKEY = 17,
/// <summary>
/// RFC 2845
/// Signature out of time window.
/// </summary>
BADTIME = 18,
/// <summary>
/// RFC 2930
/// Bad TKEY Mode.
/// </summary>
BADMODE = 19,
/// <summary>
/// RFC 2930
/// Duplicate key name.
/// </summary>
BADNAME = 20,
/// <summary>
/// RFC 2930
/// Algorithm not supported.
/// </summary>
BADALG = 21
}
}