/// <summary>
/// Initializes a new instance_ of the Response class by parsing the message reponse.
/// </summary>
/// <param name="message">A byte array that contains the response message.</param>
internal Response(byte[] message) {
if (message == null)
throw new ArgumentException("message");
// ID - 16 bits
// QR - 1 bit
// Opcode - 4 bits
// AA, TC, RD - 3 bits
byte flags1 = message[2];
// RA, Z - 2 bits
// RCODE - 4 bits
byte flags2 = message[3];
long counts = message[3];
// adjust the return code
int return_code = (flags2 & (byte)0x3c) >> 2;
return_code_ = (return_code > 6) ? ReturnCode.Other : (ReturnCode)return_code;
// other bit flags
authoritative_answer_ = ((flags1 & 4) != 0);
recursion_available_ = ((flags2 & 128) != 0);
truncated_ = ((flags1 & 2) != 0);
// create the arrays of response objects
questions_ = new Question[GetShort(message, 4)];
answers_ = new Answer[GetShort(message, 6)];
name_servers_ = new NameServer[GetShort(message, 8)];
additional_records_ = new AdditionalRecord[GetShort(message, 10)];
// need a pointer to do this, position just after the header
RecordPointer pointer = new RecordPointer(message, 12);
// and now populate them, they always follow this order
for (int i = 0; i < questions_.Length; i++) {
try {
questions_[i] = new Question(pointer);
} catch(Exception ex) {
throw new InvalidResponseException(ex);
}
}
for (int i = 0; i < answers_.Length; i++) {
answers_[i] = new Answer(pointer);
}
for (int i = 0; i < name_servers_.Length; i++) {
name_servers_[i] = new NameServer(pointer);
}
for (int i = 0; i < additional_records_.Length; i++) {
additional_records_[i] = new AdditionalRecord(pointer);
}
}
/// <summary>
/// Adds a question to the request to be sent to the DNS server.
/// </summary>
/// <param name="question">The DNS question to add to the request.</param>
public void AddQuestion(Question question) {
if(question == null)
throw new ArgumentNullException("question");
questions_.Add(question);
}
public void NewQuestionDomainBad() {
Question question = new Question("$$$$$.com", DnsType.MX, DnsClass.IN);
}
public void NewQuestionBadType() {
unchecked {
Question question = new Question("codeproject.com", (DnsType)1999, DnsClass.IN);
}
}
public void NewQuestionDomainNull() {
Question question = new Question(null, DnsType.MX, DnsClass.IN);
}