private async Task <DnsMessageBase> ProcessMessageAsync(DnsMessageBase query, ProtocolType protocolType, IPEndPoint remoteEndpoint)
{
QueryReceivedEventArgs eventArgs = new QueryReceivedEventArgs(query, protocolType, remoteEndpoint);
await QueryReceived.RaiseAsync(this, eventArgs);
return(eventArgs.Response);
}
static async Task OnQueryReceived(object sender, QueryReceivedEventArgs e)
{
DnsMessage query = e.Query as DnsMessage;
if (query == null)
return;
DnsMessage response = query.CreateResponseInstance();
foreach (var question in query.Questions)
{
//Console.WriteLine(question.Name.ToString());
DnsMessage upstreamResponse;
Boolean useDefault = true;
foreach (var domain in domains)
{
if (question.Name.ToString().ToLower().Contains(domain))
{
useDefault = false;
}
}
if (useDefault)
{
upstreamResponse = await defaultClient.ResolveAsync(question.Name, question.RecordType, question.RecordClass);
}
else
{
upstreamResponse = await netflixClient.ResolveAsync(question.Name, question.RecordType, question.RecordClass);
}
if (upstreamResponse != null)
{
foreach (DnsRecordBase record in (upstreamResponse.AnswerRecords))
{
response.AnswerRecords.Add(record);
}
foreach (DnsRecordBase record in (upstreamResponse.AdditionalRecords))
{
response.AdditionalRecords.Add(record);
}
response.ReturnCode = ReturnCode.NoError;
e.Response = response;
}
}
}
private async Task <DnsMessageBase> ProcessMessageAsync(DnsMessageBase query, ProtocolType protocolType, IPEndPoint remoteEndpoint)
{
if (query.TSigOptions != null)
{
switch (query.TSigOptions.ValidationResult)
{
case ReturnCode.BadKey:
case ReturnCode.BadSig:
query.IsQuery = false;
query.ReturnCode = ReturnCode.NotAuthoritive;
query.TSigOptions.Error = query.TSigOptions.ValidationResult;
query.TSigOptions.KeyData = null;
#pragma warning disable 4014
InvalidSignedMessageReceived.RaiseAsync(this, new InvalidSignedMessageEventArgs(query, protocolType, remoteEndpoint));
#pragma warning restore 4014
return(query);
case ReturnCode.BadTime:
query.IsQuery = false;
query.ReturnCode = ReturnCode.NotAuthoritive;
query.TSigOptions.Error = query.TSigOptions.ValidationResult;
query.TSigOptions.OtherData = new byte[6];
int tmp = 0;
TSigRecord.EncodeDateTime(query.TSigOptions.OtherData, ref tmp, DateTime.Now);
#pragma warning disable 4014
InvalidSignedMessageReceived.RaiseAsync(this, new InvalidSignedMessageEventArgs(query, protocolType, remoteEndpoint));
#pragma warning restore 4014
return(query);
}
}
QueryReceivedEventArgs eventArgs = new QueryReceivedEventArgs(query, protocolType, remoteEndpoint);
await QueryReceived.RaiseAsync(this, eventArgs);
return(eventArgs.Response);
}
private static async Task OnQueryReceived(object sender, QueryReceivedEventArgs e)
{
var message = e.Query as DnsMessage;
var response = message?.CreateResponseInstance();
if (message?.Questions.Count == 1)
{
// send query to upstream _servers
var question = message.Questions[0];
var upstreamResponse =
await DnsClient.Default.ResolveAsync(question.Name, question.RecordType, question.RecordClass);
// if got an answer, copy it to the message sent to the client
if (upstreamResponse != null)
{
foreach (var record in (upstreamResponse.AnswerRecords))
{
response.AnswerRecords.Add(record);
}
foreach (var record in (upstreamResponse.AdditionalRecords))
{
response.AdditionalRecords.Add(record);
}
response.ReturnCode = ReturnCode.NoError;
// set the response
e.Response = response;
}
}
}
private async Task<DnsMessageBase> ProcessMessageAsync(DnsMessageBase query, ProtocolType protocolType, IPEndPoint remoteEndpoint)
{
if (query.TSigOptions != null)
{
switch (query.TSigOptions.ValidationResult)
{
case ReturnCode.BadKey:
case ReturnCode.BadSig:
query.IsQuery = false;
query.ReturnCode = ReturnCode.NotAuthoritive;
query.TSigOptions.Error = query.TSigOptions.ValidationResult;
query.TSigOptions.KeyData = null;
#pragma warning disable 4014
InvalidSignedMessageReceived.RaiseAsync(this, new InvalidSignedMessageEventArgs(query, protocolType, remoteEndpoint));
#pragma warning restore 4014
return query;
case ReturnCode.BadTime:
query.IsQuery = false;
query.ReturnCode = ReturnCode.NotAuthoritive;
query.TSigOptions.Error = query.TSigOptions.ValidationResult;
query.TSigOptions.OtherData = new byte[6];
int tmp = 0;
TSigRecord.EncodeDateTime(query.TSigOptions.OtherData, ref tmp, DateTime.Now);
#pragma warning disable 4014
InvalidSignedMessageReceived.RaiseAsync(this, new InvalidSignedMessageEventArgs(query, protocolType, remoteEndpoint));
#pragma warning restore 4014
return query;
}
}
QueryReceivedEventArgs eventArgs = new QueryReceivedEventArgs(query, protocolType, remoteEndpoint);
await QueryReceived.RaiseAsync(this, eventArgs);
return eventArgs.Response;
}
private static void OnQueryReceived(object sender, QueryReceivedEventArgs e)
{
StringBuilder sb = new StringBuilder();
try
{
DnsMessage message = e.Query as DnsMessage;
message.IsQuery = false;
if (message == null || message.Questions.Count == 0)
{
e.Response = message;
message.ReturnCode = ReturnCode.ServerFailure;
e.Response = message;
Console.WriteLine(sb);
return;
}
//Log DNS query
sb.AppendFormat("* {0}\r\n", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff"));
for (int i = 0; i < message.Questions.Count; i++)
{
sb.AppendFormat("[{0}]\t{1}\t{2}\r\n",
i, message.Questions[i].RecordType.ToString(), message.Questions[i].Name);
}
if (message.Questions.Count > 1)
{
sb.AppendFormat("Response: (x) ServerFailure -- Multiple questions\r\n");
e.Response = message;
message.ReturnCode = ReturnCode.ServerFailure;
e.Response = message;
Console.WriteLine(sb);
return;
}
DnsQuestion question = message.Questions[0];
if (!question.Name.Equals(domain, StringComparison.CurrentCultureIgnoreCase)
&& !question.Name.EndsWith(string.Concat(".", domain), StringComparison.CurrentCultureIgnoreCase))
{
e.Response = message;
message.ReturnCode = ReturnCode.ServerFailure;
e.Response = message;
sb.AppendFormat("Response: (x) ServerFailure -- Domain \"{0}\" is invalid\r\n", question.Name);
Console.WriteLine(sb);
return;
}
if (question.RecordType == RecordType.Txt)
{
//MX
message.ReturnCode = ReturnCode.NoError;
message.AnswerRecords.Add(new TxtRecord(domain, ttlSeconds, "Hello world"));
message.ReturnCode = ReturnCode.NoError;
e.Response = message;
sb.AppendFormat("Response: OK!\r\n", question.Name);
Console.WriteLine(sb);
return;
}
else if (question.RecordType == RecordType.A)
{
//A
string subdomain = question.Name.Substring(0, question.Name.LastIndexOf(domain));
if (subdomain.Length > 0)
subdomain = subdomain.Substring(0, subdomain.Length - 1); //remove o ponto
if (subdomain.Length == 0)
{
//raiz do domínio
var record = new ARecord(question.Name, ttlSeconds, System.Net.IPAddress.Parse("192.168.1.1"));
message.AnswerRecords.Add(record);
message.ReturnCode = ReturnCode.NoError;
e.Response = message;
sb.AppendFormat("Response: OK!\r\n", question.Name);
return;
}
else
{
//subdomínios
if (subdomain.Length > 0 && subdomain.StartsWith("local_", StringComparison.CurrentCultureIgnoreCase))
{
//recebe: local_192-168-10-10.[domain] e retorna: "192.168.10.10"
string ipString = subdomain.Substring("local_".Length);
ipString = ipString.Replace("-", ".");
System.Net.IPAddress ipAddress;
if (System.Net.IPAddress.TryParse(ipString, out ipAddress))
{
var record = new ARecord(question.Name, ttlSeconds, ipAddress);
message.AnswerRecords.Add(record);
message.ReturnCode = ReturnCode.NoError;
e.Response = message;
sb.AppendFormat("Response: OK!\r\n", question.Name);
Console.WriteLine(sb);
return;
}
else
{
sb.AppendFormat("Response: (x) ServerFailure -- Invalid IP \"{0}\" invalid. Example of subdomain valid: \"local_192-168-10-10\"\r\n", ipString);
message.ReturnCode = ReturnCode.ServerFailure;
e.Response = message;
Console.WriteLine(sb);
return;
}
}
else
{
sb.AppendFormat("Response: (x) ServerFailure -- Subdomain \"{0}\" invalid. Example of subdomain valid: \"local_192-168-10-10\"\r\n", subdomain);
message.ReturnCode = ReturnCode.ServerFailure;
e.Response = message;
Console.WriteLine(sb);
return;
}
}
}
sb.AppendFormat("Response: (x) ServerFailure -- Record Type \"{0}\" invalid\r\n", question.RecordType.ToString());
message.ReturnCode = ReturnCode.ServerFailure;
e.Response = message;
}
catch (System.Exception ex)
{
sb.AppendFormat("{0} EXCEPTION: {1}\r\n{2}\r\n\r\n",
DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff"),
ex.Message,
ex.StackTrace);
}
Console.WriteLine(sb.ToString());
}
private async Task Server_QueryReceived(object sender, ARSoft.Tools.Net.Dns.QueryReceivedEventArgs e)
{
bool foundQuery = false;
DnsMessage query = e.Query as DnsMessage;
if (query == null)
{
return;
}
DnsMessage response = query.CreateResponseInstance();
try {
C.WriteLine($"DnsServer: Questions: {query.Questions.Count}", true, "DNS");
for (int idx = 0; idx < query.Questions.Count; idx++)
{
var question = query.Questions[idx];
using (var connection = db.Connection()) {
using (var command = new SqliteCommand(
"SELECT * FROM DnsEntries WHERE RecordType = @RecordType AND RecordClass = @RecordClass AND DomainName = @DomainName;", connection)) {
command.Parameters.AddWithValue("@RecordType", question.RecordType.ToString());
command.Parameters.AddWithValue("@RecordClass", question.RecordClass.ToString());
command.Parameters.AddWithValue("@DomainName", question.Name.ToString());
using (var reader = command.ExecuteReader()) {
C.WriteLine($" Questions [{idx:000}] RES({reader.HasRows}): Type({question.RecordType}), Class({question.RecordClass}), {question.Name}", true, "DNS");
//Every new row will create a new dictionary that holds the columns
while (reader.Read())
{
try {
var dnStr = reader["DomainName"] as string;
var dn = DomainName.Parse(dnStr);
if (dn == null)
{
continue;
}
var ttl = (System.Int64)reader["TTL"];
var rt = (RecordType)Enum.Parse(typeof(RecordType), reader["RecordType"] as string);
var rc = (RecordClass)Enum.Parse(typeof(RecordClass), reader["RecordClass"] as string);
if (rt == RecordType.A)
{
if (reader["Address"] == null)
{
continue;
}
var addr = reader["Address"] as string;
var aRec = new ARecord(dn, Convert.ToInt32(ttl), IPAddress.Parse(addr));
response.AnswerRecords.Add(aRec);
foundQuery = true;
}
} catch (Exception ex) {
C.WriteLine($" Questions [{idx:000}]: {C.Red}Exception: {ex.ToString()}", true, "DNS:ERROR");
}
}
}
}
}
}
// Fallback
if (dnsFallback != null && !foundQuery)
{
DnsQuestion question = query.Questions[0];
var resolve = dnsFallback.Resolve(question.Name);
DnsMessage upstreamResponse = await dnsFallback.ResolveAsync(
question.Name, question.RecordType, question.RecordClass);
e.Response = upstreamResponse;
return;
}
response.ReturnCode = ReturnCode.NoError;
} catch (Exception ex) {
response.ReturnCode = ReturnCode.ServerFailure;
C.WriteLine($"{C.Red}{ex.ToString()}", true, "DNS:ERROR");
}
// set the response
e.Response = response;
}