public static Message FromBytes(byte[] bytes, int index, int count)
{
Message message = new Message();
using (MemoryStream stream = new MemoryStream(bytes, index, count))
using (BinaryReader reader = new BinaryReader(stream))
{
// ID
message.TransactionID = reader.ReadNetworkOrderUInt16();
// Flags
// QR, OPCODE, AA, TC, RD
byte flags = reader.ReadByte();
// QR
message.QueryResponse = flags.GetBit(7);
// OPCODE
message.Opcode = (byte)((flags >> 3) & 0x0f);
// AA
message.AuthoritativeAnswer = flags.GetBit(2);
// TC
message.Truncated = flags.GetBit(1);
// RD
message.RecursionDesired = flags.GetBit(0);
// RA, Z, AD, CD, RCODE
flags = reader.ReadByte();
// RA
message.RecursionAvailable = flags.GetBit(7);
// Z
// (zero bit)
// AD
message.AuthenticData = flags.GetBit(5);
// CD
message.CheckingDisabled = flags.GetBit(4);
// RCODE
message.ResponseCode = (byte)(flags & 0x0f);
// Number of questions and answer records
ushort questions, answers, authorityRecords, additionalRecords;
// Number of Questions
questions = reader.ReadNetworkOrderUInt16();
// Number of Answers
answers = reader.ReadNetworkOrderUInt16();
// Number of Authority Records
authorityRecords = reader.ReadNetworkOrderUInt16();
// Number of Additional Records
additionalRecords = reader.ReadNetworkOrderUInt16();
// Read each Question and Resource Record
// Questions
while (questions-- > 0)
{
message.Questions.Add(Question.FromBinaryReader(reader));
}
// Answers
while (answers-- > 0)
{
message.AnswerRecords.Add(ResourceRecord.FromBinaryReader(reader));
}
// Authority Records
while (authorityRecords-- > 0)
{
message.AnswerRecords.Add(ResourceRecord.FromBinaryReader(reader));
}
// Additional Records
while (additionalRecords-- > 0)
{
message.AdditionalRecords.Add(ResourceRecord.FromBinaryReader(reader));
}
}
return(message);
}