public static DnsQuery ParseQuery(BinaryReader reader, byte[] query, int position,
Dictionary <int, byte[]> cache = null)
{
var(domain, shift) = ParseDomain(query, position, cache);
var _ = reader.BaseStream.Seek(shift, SeekOrigin.Begin);
var type = (AnswerType)reader.ReadUInt16();
var queryClass = (Class)reader.ReadUInt16();
var result = new DnsQuery
{
Name = domain,
Class = queryClass,
AnswerType = type
};
return(result);
}
public static byte[] CreateQuery(DnsQuery query, int position, Dictionary <string, int> cache)
{
var result = new List <byte>();
var encodedDomain = EncodeDomain(query.Name, position, cache, false);
var type = (short)query.AnswerType;
var typeBytes = BitConverter.GetBytes(type);
Array.Reverse(typeBytes);
var classValue = (short)query.Class;
var classBytes = BitConverter.GetBytes(classValue);
Array.Reverse(classBytes);
result.AddRange(encodedDomain);
result.AddRange(typeBytes);
result.AddRange(classBytes);
return(result.ToArray());
}
public static DnsPacket CreateSimpleErrorPacket(DnsQuery query, ushort queryId, byte replyCode)
{
var flags = new DnsFlags
{
RecursionDesired = true,
RecursionAvailable = true,
ReplyCode = replyCode
};
var packet = new DnsPacket
{
QueryId = queryId,
Flags = flags,
Queries = new List <DnsQuery> {
query
},
Answers = new List <DnsAnswer>(),
AdditionalAnswers = new List <DnsAnswer>(),
AuthorityAnswers = new List <DnsAnswer>()
};
return(packet);
}
