public async Task <DnsResult> GetDnsTxtRecord(string domain, string dnsServer)
{
DnsResult result = new DnsResult();
var dns = new MyDns();
if (!await dns.Search(domain, QueryType.TXT, dnsServer, null))
{
result.Success = false;
result.RecordValue = string.Empty;
switch (dns.header.ResultCode)
{
case ResultCode.OK:
result.ErrorMessage = "ok";
break;
case ResultCode.FormatErr:
result.ErrorMessage = "格式错误";
break;
case ResultCode.DNSErr:
result.ErrorMessage = "DNS出错";
break;
case ResultCode.DomainNoExist:
result.ErrorMessage = "域名不存在";
break;
case ResultCode.DNSNoSuppot:
result.ErrorMessage = "DNS不支持这类查询";
break;
case ResultCode.DNSRefuse:
result.ErrorMessage = "DNS拒绝查询";
break;
default:
result.ErrorMessage = "未知错误";
break;
}
return(result);
}
else
{
result.Success = true;
result.RecordValue = dns.record?.Records?.FirstOrDefault()?.RDDate?.ToString();
}
return(result);
}
public void Parse(byte[] data, int offset)
{
while (offset < data.Length)
{
int labelLen;
MyDnsRecord RecordItem = new MyDnsRecord();
RecordItem.Name = MyDns.GetLabelName(data, offset, out labelLen);
offset += labelLen;
//
offset++;
RecordItem.QType = (QueryType)data[++offset];
//
offset++;
RecordItem.QClass = (QueryClass)data[++offset];
//
offset++;
RecordItem.TTL = data[offset++] * 256 * 256 * 256 + data[offset++] * 256 * 256 + data[offset++] * 256 + data[offset++];
//
RecordItem.RDLength = data[offset++] * 256 + data[offset++];
//
switch (RecordItem.QType)
{
case QueryType.A:
RecordItem.RDDate = new A_RR(data, offset, RecordItem.RDLength);
break;
case QueryType.CNAME:
RecordItem.RDDate = new CNAME_RR(data, offset, RecordItem.RDLength);
break;
case QueryType.MX:
RecordItem.RDDate = new MX_RR(data, offset, RecordItem.RDLength);
break;
case QueryType.NS:
RecordItem.RDDate = new NS_RR(data, offset, RecordItem.RDLength);
break;
case QueryType.SOA:
RecordItem.RDDate = new SOA_RR(data, offset, RecordItem.RDLength);
break;
case QueryType.TXT:
RecordItem.RDDate = new TXT_RR(data, offset, RecordItem.RDLength);
break;
}
Records.Add(RecordItem);
offset += RecordItem.RDLength;
}
}