public unsafe Task <DnsEntry[]> TryResolve()
{
var records = new List <DnsEntry>();
byte[] dataBuffer = new byte[1024];
int dataLen = LinuxLib.res_query(Query, C_IN, (int)Type, dataBuffer, dataBuffer.Length);
if (dataLen > 0)
{
GCHandle handle = GCHandle.Alloc(dataBuffer, GCHandleType.Pinned);
try
{
fixed(byte *pBuffer = dataBuffer)
{
var reader = new LDnsReader
{
Buffer = pBuffer,
Current = pBuffer,
End = pBuffer + dataLen
};
// Response Header
int queryId = reader.UInt16(); // Query Identifier (Read & Ignore)
byte[] hBits = reader.Bytes(2); // Header Bits & Flags (Read & Ignore)
int qdCount = reader.UInt16(); // Question Count (Use Below)
int anCount = reader.UInt16(); // Answer Count (Use Below)
int nsCount = reader.UInt16(); // NameServer Count (Read & Ignore)
int arCount = reader.UInt16(); // Resource Count (Read & Ignore)
// Question Section (read and ignore)
for (int q = 0; q < qdCount && reader.OK(); q++)
{
string qName = reader.Name();
ushort qType = reader.UInt16();
ushort qClass = reader.UInt16();
}
// Answers (the good stuff)
for (int a = 0; a < anCount && reader.OK(); a++)
{
var ansHead = new LDnsHeader(reader);
DnsEntry dnsEntry = DnsEntry.Create(ansHead, reader);
records.Add(dnsEntry);
}
}
}
finally
{
handle.Free();
}
}
_allRecords = records.ToArray();
_typeRecords = records.Where(r => r.Type == Type).ToArray();
if (Type == DnsRecordType.SRV || Type == DnsRecordType.MX) // sort
{
_typeRecords = _typeRecords.OrderBy(r => ((IOrderedDnsEntry)r).SortOrder).ToArray();
}
return(Task.FromResult(_typeRecords));
}
private void QueryComplete(IntPtr contextPtr, IntPtr resultPtr)
{
lock (_syncLock)
{
if (_completed)
{
return;
}
_completed = true;
// stop timer
if (_timer != null)
{
_timer.Dispose();
_timer = null;
}
}
try
{
// check if timed out
if (_timedOut)
{
_taskCompletion.SetException(new DnsTimeoutException(Query));
return;
}
// process results
var records = new List <DnsEntry>();
if (resultPtr != IntPtr.Zero)
{
var queryResult = Marshal.PtrToStructure <Win32.DNS_QUERY_RESULT>(resultPtr);
if (queryResult.QueryStatus == 0) // SUCCESS
{
IntPtr ptr = queryResult.QueryRecords;
while (ptr != IntPtr.Zero)
{
var record = Marshal.PtrToStructure <Win32.DNS_RECORD>(ptr);
records.Add(DnsEntry.Create(record, ptr));
ptr = record.Next; // Next Record
}
if (queryResult.QueryRecords != IntPtr.Zero)
{
Win32.DnsRecordListFree(queryResult.QueryRecords, (int)Win32.DNS_FREE_TYPE.DnsFreeRecordList);
}
}
}
_allRecords = records.ToArray();
_typeRecords = records.Where(r => r.Type == Type).ToArray();
if (Type == DnsRecordType.SRV || Type == DnsRecordType.MX) // sort
{
_typeRecords = _typeRecords.OrderBy(r => ((IOrderedDnsEntry)r).SortOrder).ToArray();
}
_taskCompletion.SetResult(_typeRecords);
}
catch (Exception ex)
{
_taskCompletion.SetException(ex);
}
finally
{
if (resultPtr != _resultPtr)
{
Win32.FreeHGlobal(ref resultPtr);
}
Win32.FreeHGlobal(ref _resultPtr);
Win32.FreeHGlobal(ref _requestPtr);
_runningWait.Set();
GC.SuppressFinalize(this);
}
}