} // End Class DbDnsRecord
static async Task <bool> ResolveMessage(DnsMessage query, QueryReceivedEventArgs e, DnsMessage response)
{
DbDnsRecord rec = null;
using (System.Data.Common.DbCommand cmd = s_sql.CreateCommand(@"
-- DECLARE @in_recordType int
-- DECLARE @in_recordName varchar(4000)
-- SET @in_recordType = 1 -- A
-- SET @in_recordName = 'vortex.data.microsoft.com'
SELECT
REC_Id
--,T_Records.REC_DOM_Id
,T_Records.REC_RT_Id
,T_Records.REC_Name
,T_Records.REC_Content
,T_Records.REC_ResponsibleName
,COALESCE(T_Records.REC_TTL, 100) AS REC_TTL
,T_Records.REC_Prio
,T_Records.REC_Weight
,T_Records.REC_Port
,T_Records.REC_SerialNumber
,T_Records.REC_RefreshInterval
,T_Records.REC_RetryInterval
,T_Records.REC_ExpireInterval
,T_Records.REC_NegativeCachingTTL
,T_Records.REC_AfsSubType
,T_Records.REC_ChangeDate
FROM T_Records
WHERE REC_RT_Id = @in_recordType
AND T_Records.REC_Name = @in_recordName
;
"))
{
try
{
string name = query.Questions[0].Name.ToString();
s_sql.AddParameter(cmd, "in_recordType", (int)query.Questions[0].RecordType);
s_sql.AddParameter(cmd, "in_recordName", name);
// TODO: Can return multiple records...
rec = s_sql.GetClass <DbDnsRecord>(cmd);
}
catch (System.Exception ex)
{
System.Console.WriteLine(ex.Message);
System.Console.WriteLine(ex.StackTrace);
}
} // End Using cmd
if (rec != null)
{
int ttl = 3600;
DnsRecordBase record = null;
// https://blog.dnsimple.com/2015/04/common-dns-records/
// https://en.wikipedia.org/wiki/List_of_DNS_record_types
switch ((RecordType)rec.REC_RT_Id)
{
case RecordType.Soa:
// SoaRecord(DomainName name, int timeToLive, DomainName masterName
// , DomainName responsibleName, uint serialNumber, int refreshInterval
// , int retryInterval, int expireInterval, int negativeCachingTTL)
record = new ARSoft.Tools.Net.Dns.SoaRecord(
DomainName.Parse(rec.REC_Name)
, rec.REC_TTL.Value
, DomainName.Parse(rec.REC_Content)
, DomainName.Parse(rec.REC_ResponsibleName)
, rec.REC_SerialNumber.Value
, rec.REC_RefreshInterval.Value
, rec.REC_RetryInterval.Value
, rec.REC_ExpireInterval.Value
, rec.REC_NegativeCachingTTL.Value
);
break;
case RecordType.Ns:
record = new ARSoft.Tools.Net.Dns.NsRecord(DomainName.Parse(rec.REC_Name), ttl, DomainName.Parse(rec.REC_Content));
break;
case RecordType.Srv:
// SrvRecord(DomainName name, int timeToLive, ushort priority, ushort weight, ushort port, DomainName target)
record = new ARSoft.Tools.Net.Dns.SrvRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, (ushort)rec.REC_Prio.Value, (ushort)rec.REC_Weight.Value, (ushort)rec.REC_Port.Value, DomainName.Parse(rec.REC_Content));
break;
// https://www.openafs.org/
// https://en.wikipedia.org/wiki/OpenAFS
// http://www.rjsystems.nl/en/2100-dns-discovery-openafs.php
// OpenAFS is an open source implementation of the Andrew distributed file system(AFS).
case RecordType.Afsdb:
// http://www.rjsystems.nl/en/2100-dns-discovery-openafs.php
record = new ARSoft.Tools.Net.Dns.AfsdbRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, (AfsdbRecord.AfsSubType)(uint) rec.REC_AfsSubType.Value, DomainName.Parse(rec.REC_Content));
break;
// A DNS-based Authentication of Named Entities (DANE) method
// for publishing and locating OpenPGP public keys in DNS
// for a specific email address using an OPENPGPKEY DNS resource record.
case RecordType.OpenPGPKey:
byte[] publicKey = null;
// hexdump(sha256(truncate(utf8(ocalpart), 28)
// https://www.huque.com/bin/openpgpkey
// The OPENPGPKEY DNS record is specied in RFC 7929.
// The localpart of the uid is encoded as a DNS label
// containing the hexdump of the SHA-256 hash
// of the utf-8 encoded localpart, truncated to 28 octets.
// Normally the "Standard" output format should be used.
// The "Generic Encoding" output format is provided to help work
// with older DNS software that does not yet understand the OPENPGPKEY record type.
record = new ARSoft.Tools.Net.Dns.OpenPGPKeyRecord(DomainName.Parse(rec.REC_Name), ttl, publicKey);
break;
// Canonical name records, or CNAME records, are often called alias records because they map an alias to the canonical name. When a name server finds a CNAME record, it replaces the name with the canonical name and looks up the new name.
case RecordType.CName:
record = new ARSoft.Tools.Net.Dns.CNameRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, DomainName.Parse(rec.REC_Content));
break;
case RecordType.Ptr:
record = new ARSoft.Tools.Net.Dns.PtrRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, DomainName.Parse(rec.REC_Content));
break;
case RecordType.A:
record = new ARSoft.Tools.Net.Dns.ARecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, System.Net.IPAddress.Parse(rec.REC_Content));
break;
case RecordType.Aaaa:
record = new ARSoft.Tools.Net.Dns.AaaaRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, System.Net.IPAddress.Parse(rec.REC_Content));
break;
case RecordType.Mx:
record = new ARSoft.Tools.Net.Dns.MxRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, 0, DomainName.Parse(rec.REC_Content));
break;
case RecordType.Txt:
record = new ARSoft.Tools.Net.Dns.TxtRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, rec.REC_Content);
break;
case RecordType.SshFp:
// https://unix.stackexchange.com/questions/121880/how-do-i-generate-sshfp-records
// SshFpRecord(DomainName name, int timeToLive, SshFpAlgorithm algorithm
// , SshFpFingerPrintType fingerPrintType, byte[] fingerPrint)
ARSoft.Tools.Net.Dns.SshFpRecord.SshFpAlgorithm sfa = ARSoft.Tools.Net.Dns.SshFpRecord
.SshFpAlgorithm.Rsa;
ARSoft.Tools.Net.Dns.SshFpRecord.SshFpFingerPrintType sfp = ARSoft.Tools.Net.Dns.SshFpRecord
.SshFpFingerPrintType.Sha256;
byte[] fp = null;
record = new ARSoft.Tools.Net.Dns.SshFpRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, sfa, sfp, fp);
break;
default:
break;
} // End Switch
if (record != null)
{
response.AnswerRecords.Add(record);
}
response.ReturnCode = ReturnCode.NoError;
e.Response = response;
return(await Task <bool> .FromResult(true));
} // End if (rec != null)
return(await Task <bool> .FromResult(false));
} // End Function ResolveMessage
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());
}