47 lines
1.9 KiB
C#
47 lines
1.9 KiB
C#
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using System;
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namespace DnsClient
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{
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/* Reference: https://tools.ietf.org/html/rfc6895#section-2
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* Response header fields
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*
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1 1 1 1 1 1
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
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+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
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| ID |
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+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
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==> |QR| OpCode |AA|TC|RD|RA| Z|AD|CD| RCODE | <==
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+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
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| QDCOUNT/ZOCOUNT |
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+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
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| ANCOUNT/PRCOUNT |
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+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
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| NSCOUNT/UPCOUNT |
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+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
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| ARCOUNT |
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+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
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* */
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/// <summary>
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/// The flags of the header's second 16bit value
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/// </summary>
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public enum DnsHeaderFlag : ushort
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{
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IsCheckingDisabled = 0x0010,
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IsAuthenticData = 0x0020,
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FutureUse = 0x0040, // Z bit seems to be ignored now, see https://tools.ietf.org/html/rfc6895#section-2.1
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RecursionAvailable = 0x0080,
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RecursionDesired = 0x0100,
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ResultTruncated = 0x0200,
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HasAuthorityAnswer = 0x0400,
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HasQuery = 0x8000,
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}
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public static class DnsHeader
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{
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public static readonly ushort OPCODE_MASK = 0x7800;
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public static readonly ushort OPCODE_SHIFT = 11;
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public static readonly ushort RCODE_MASK = 0x000F;
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}
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}
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