public static void Main(string[] arg)
{
Console.WriteLine("Hi. It is Dns client" +
"\nWrite domain to get IP" +
"\nParameters after domain can change configuration" +
"\n-type <mx>. Type A by default" +
"\n-host <1.1.1.1>. Host 8.8.8.8 by default");
string line = "";
while (line != "exit")
{
packet = new DnsPacket();
packet.qtype = Type.A;
line = Console.ReadLine();
var param = line.Split(' ');
packet.qname = param[0];
for (int i = 0; i < param.Length; i++)
{
if (param[i] == "-type")
{
if (param[i + 1].ToLower() == "mx")
{
packet.qtype = Type.MX;
}
if (param[i + 1].ToLower() == "txt")
{
packet.qtype = Type.TXT;
}
}
if (param[i] == "-host")
{
if (IsValid(param[i + 1]))
{
serverAddress = param[i + 1];
}
else
{
Console.WriteLine("Host invalid");
error = true;
break;
}
}
}
if (error)
{
error = false;
continue;
}
packet.qr = QR.Request;
packet.opcode = Opcode.Query;
Client();
}
}
public static byte[] Pack(DnsPacket packet)
{
var p = packet;
//byte[] bID = Encoding.UTF8.GetBytes("AAAA");//BitConverter.GetBytes(p.ID);
short parameters = (short)((byte)p.qr | (byte)p.opcode >> 1 | (byte)p.autorativeAnswer >> 5
| (byte)p.trunCation >> 6 | (byte)p.recursionDesired >> 7
| (byte)p.recursionAvailable >> 8 | (byte)p.reserved >> 9 | (byte)p.rcode >> 12);
//Console.WriteLine("Params " + parameters);
byte[] bParam = BitConverter.GetBytes(parameters);
byte[] bQd = BitConverter.GetBytes(p.qdCount);
byte[] bAn = BitConverter.GetBytes(p.anCount);
byte[] bSs = BitConverter.GetBytes(p.ssCount);
byte[] bAr = BitConverter.GetBytes(p.arCount);
string[] parts = p.qname.Split('.');
byte[] bName = new byte[p.qname.Length + 2];
var counter = 0;
for (int i = 0; i < parts.Length; i++)
{
bName[counter] = BitConverter.GetBytes(parts[i].Length)[0];
counter++;
var b = Encoding.Default.GetBytes(parts[i]);
for (int k = 0; k < b.Length; k++)
{
bName[counter] = b[k];
counter++;
}
}
bName[bName.Length - 1] = 0;
Console.WriteLine("Q TYpe " + (short)p.qtype);
byte[] bQType = BitConverter.GetBytes((short)p.qtype);
byte[] bQClass = BitConverter.GetBytes(p.qclass);
var nameSize = bName.Length;// % 16 + bName.Length;
byte[] dnsData = new byte[16 + nameSize];
dnsData[0] = 0xAA;
dnsData[1] = 0xAA;
dnsData[2] = bParam[0];
dnsData[3] = bParam[1];
dnsData[4] = bQd[1];
dnsData[5] = bQd[0];
dnsData[6] = bAn[0];
dnsData[7] = bAn[1];
dnsData[8] = bSs[0];
dnsData[9] = bSs[1];
dnsData[10] = bAr[0];
dnsData[11] = bAr[1];
dnsData[12 + nameSize] = bQType[1];
dnsData[13 + nameSize] = bQType[0];
dnsData[14 + nameSize] = bQClass[1];
dnsData[15 + nameSize] = bQClass[0];
for (int i = 0; i < bName.Length; i++)
{
dnsData[12 + i] = bName[i];
}
dnsData[11 + nameSize] = BitConverter.GetBytes((short)0)[0];
return(dnsData);
}
