public async Task <bool> GetHost(string url, DNSState state)
{
try
{
IPHostEntry ret = await Dns.GetHostEntryAsync(url).ConfigureAwait(false);
Log_Info("Success Lookup of " + url);
state.AddAnswer(url, ret.AddressList[0].GetAddressBytes());
}
catch (SocketException ex)
{
Log_Error("Failed Lookup of " + url);
if (ex.NativeErrorCode != 11001 & //Host not found (Authoritative)
ex.NativeErrorCode != 11002) //Host not found (Non-Authoritative)
{
Log_Error("Unexpected error of " + ex.NativeErrorCode);
lock (errSentry)
lastTaskError = ex;
return(false);
}
}
if (state.DecCounter() == 0)
{
FinDNS(state);
}
return(true);
}
public void FinDNS(DNSState state)
{
Log_Info("DNS Packet Sent From CLR_DEV9 DNS server");
DNS retPay = state.DNS;
string[] reqs = state.Questions;
ConcurrentDictionary <string, byte[]> answers = state.GetAnswers();
foreach (string req in reqs)
{
if (answers.ContainsKey(req))
{
DNSResponseEntry ans = new DNSResponseEntry(req, 1, 1, answers[req], 10800);
retPay.Answers.Add(ans);
}
else
{
//Log_Error("Missing an Answer");
retPay.RCode = 2; //ServerFailure
}
}
byte[] udpPayload = retPay.GetBytes();
if (udpPayload.Length > 512)
{
throw new NotImplementedException("DNS packet larger than 512bytes");
}
UDP retudp = new UDP(udpPayload);
retudp.SourcePort = 53;
retudp.DestinationPort = state.ClientPort;
_recvBuff.Enqueue(retudp);
//Interlocked.Decrement(ref open);
}
public bool CheckHost(string url, DNSState state)
{
if (hosts.ContainsKey(url.ToLower()))
{
state.AddAnswer(url, hosts[url]);
Log_Info(url + " found in hosts");
//Add entry to DNS state
if (state.DecCounter() == 0)
{
FinDNS(state);
}
return(true);
}
return(false);
}
public override bool Send(IPPayload payload)
{
Log_Info("DNS Packet Sent To CLR_DEV9 DNS server");
Log_Info("Contents");
DNS dns = new DNS(payload.GetPayload());
if (dns.OPCode == (byte)DNSOPCode.Query & dns.QuestionCount > 0 & dns.QR == false)
{
List <string> reqs = new List <string>();
foreach (DNSQuestionEntry q in dns.Questions)
{
if (q.Type == 1 & q.Class == 1)
{
reqs.Add(q.Name);
}
else
{
Log_Error("Unexpected question type of class, T:" + q.Type.ToString() + " C:" + q.Class.ToString());
}
}
if (reqs.Count == 0)
{
return(true);
}
if (dns.TC == true)
{
throw new NotImplementedException("Truncated DNS packet");
}
//Interlocked.Increment(ref open);
DNS ret = new DNS
{
ID = dns.ID, //TODO, drop duplicate requests based on ID
QR = true,
OPCode = (byte)DNSOPCode.Query,
AA = false,
TC = false,
RD = true,
RA = true,
AD = false,
CD = false,
RCode = (byte)DNSRCode.NoError,
//Counts
Questions = dns.Questions
};
DNSState state = new DNSState(reqs.Count, reqs.ToArray(), ret, ((UDP)payload).SourcePort);
foreach (string req in reqs)
{
if (CheckHost(req, state))
{
continue;
}
Task <bool> res = GetHost(req, state);
}
return(true);
}
else
{
Log_Error("Unexpected OPCode, Code:" + dns.OPCode);
return(true);
}
}
