public async Task<IPAddress[]> ResolveAsync(string hostname, int timeout = 2000)
{
IPEndPoint mdnsEndPoint = new IPEndPoint(MulticastAddress, Port);
UdpClient client = new UdpClient();
DnsPacket questionPacket = new DnsPacket();
if (!hostname.EndsWith(HostnameSuffix))
{
hostname += HostnameSuffix;
}
questionPacket.Questions.Add(new DnsQuestion(hostname, DnsRecordType.A, DnsRecordClass.InterNetwork));
byte[] data = questionPacket.ToBytes();
client.JoinMulticastGroup(MulticastAddress);
client.Send(data, data.Length, mdnsEndPoint);
client.Client.ReceiveTimeout = timeout;
DateTime endTime = DateTime.Now + new TimeSpan(0, 0, 0, 0, timeout);
CancellationTokenSource cancellationTokenSource = new CancellationTokenSource(timeout);
while (DateTime.Now < endTime)
{
UdpReceiveResult receiveTask = await Task.Run(client.ReceiveAsync, cancellationTokenSource.Token);
DnsPacket responsePacket = DnsPacket.FromBytes(receiveTask.Buffer);
if (responsePacket.ID == questionPacket.ID && responsePacket.AnswerCount > 0)
{
List<IPAddress> results = new List<IPAddress>();
foreach (var answer in responsePacket.Answers)
{
DnsARecord aRecord = answer as DnsARecord;
if (aRecord != null)
{
results.Add(aRecord.IPAddress);
}
}
if (results.Count > 0)
{
return results.ToArray();
}
}
}
return null;
}
static void Main(string[] args)
{
// connect to DNS server
using (var server = new MockDnsServer())
{
// create zone
var zone = server.CreateZone("myzone.mock");
// get zone by name
var myZoneRef = server.GetZone("myzone.mock");
// get records
var myServerRecords = zone.GetRecords(DnsRecordTypes.A, "myserver.myzone.mock");
// search records
var allMyServerRecords = zone.SearchRecords("MyServer");
var hostMyServerRecords = zone.SearchRecords(DnsRecordTypes.A, "MyServer");
// update record
var soa = zone.StartOfAuthority;
soa.TimeToLive = TimeSpan.FromMinutes(30);
soa.ResponsiblePerson = "responsible.hostmaster.";
soa.Save();
// or: zone.SaveRecord(soa);
// create host record
var hostTemplate = new DnsARecord("myhost.myzone.mock", TimeSpan.FromHours(1), "192.168.1.50");
var hostRecord = zone.CreateRecord(hostTemplate);
// add second host record
hostTemplate.IpAddress = "192.168.1.51";
var hostRecord2 = zone.CreateRecord(hostTemplate);
// create alias record
var cnameTemplate = new DnsCNAMERecord("myhostalias.myzone.mock", TimeSpan.FromHours(1), "myhost.myzone.mock");
var cnameRecord = zone.CreateRecord(cnameTemplate);
// create service locator record
var srvTemplate = new DnsSRVRecord(
domainName: "myzone.mock",
service: DnsSRVRecord.ServiceNames.LDAP,
protocol: DnsSRVRecord.ProtocolNames.TCP,
timeToLive: TimeSpan.FromHours(1),
priority: 0,
weight: 10,
port: DnsSRVRecord.ServicePorts.LDAP,
targetDomainName: "mycontroller.myzone.mock");
var srvRecord = zone.CreateRecord(srvTemplate);
// delete record
hostRecord.Delete();
// or: zone.DeleteRecord(aRecord);
DumpDnsServer(server);
// delete zone
zone.Delete();
// or: server.DeleteZone(zone);
// or: server.DeleteZone("myzone.mock");
}
}
public static IDnsRecord Create(ref MemoryStream ms)
{
IDnsRecord dnsRecord;
// Have to start out with an unknown record, since we have to parse the entire
// header before we can determine the type of DNS record it is.
// TODO: Consider other options.
// start as an unknown type, then create a known type, parse the response
// and return the object.
//DnsRecordBase dr = new DnsUnknownRecord();
//dr.ParseRecordHeader(ref ms);
DnsRecordHeader dnsHeader = new DnsRecordHeader();
dnsHeader.ParseRecordHeader(ref ms);
switch (dnsHeader.NsType)
{
case NsType.A:
{
dnsRecord = new DnsARecord(dnsHeader);
break;
}
case NsType.AAAA:
{
dnsRecord = new DnsAaaaRecord(dnsHeader);
break;
}
case NsType.MX:
{
dnsRecord = new DnsMxRecord(dnsHeader);
break;
}
case NsType.RP:
{
dnsRecord = new DnsRpRecord(dnsHeader);
break;
}
case NsType.MR:
{
dnsRecord = new DnsMrRecord(dnsHeader);
break;
}
case NsType.MB:
{
dnsRecord = new DnsMbRecord(dnsHeader);
break;
}
case NsType.MG:
{
dnsRecord = new DnsMgRecord(dnsHeader);
break;
}
case NsType.NS:
{
dnsRecord = new DnsNsRecord(dnsHeader);
break;
}
case NsType.CNAME:
{
dnsRecord = new DnsCnameRecord(dnsHeader);
break;
}
case NsType.PTR:
{
dnsRecord = new DnsPtrRecord(dnsHeader);
break;
}
case NsType.HINFO:
{
dnsRecord = new DnsHinfoRecord(dnsHeader);
break;
}
case NsType.MINFO:
{
dnsRecord = new DnsMinfoRecord(dnsHeader);
break;
}
case NsType.X25:
{
dnsRecord = new DnsX25Record(dnsHeader);
break;
}
case NsType.TXT:
{
dnsRecord = new DnsTxtRecord(dnsHeader);
break;
}
case NsType.LOC:
{
dnsRecord = new DnsLocRecord(dnsHeader);
break;
}
case NsType.SOA:
{
dnsRecord = new DnsSoaRecord(dnsHeader);
break;
}
case NsType.SRV:
{
dnsRecord = new DnsSrvRecord(dnsHeader);
break;
}
case NsType.AFSDB:
{
dnsRecord = new DnsAfsdbRecord(dnsHeader);
break;
}
case NsType.ATMA:
{
dnsRecord = new DnsAtmaRecord(dnsHeader);
break;
}
case NsType.ISDN:
{
dnsRecord = new DnsIsdnRecord(dnsHeader);
break;
}
case NsType.RT:
{
dnsRecord = new DnsRtRecord(dnsHeader);
break;
}
case NsType.WKS:
{
dnsRecord = new DnsWksRecord(dnsHeader);
break;
}
default:
{
// Unknown type. parse and return the DnsUnknownRecord
dnsRecord = new DnsUnknownRecord(dnsHeader);
break;
}
}
//dnsRecord.ParseRecordHeader(ref ms);
dnsRecord.ParseRecord(ref ms);
return dnsRecord;
}
