private static void QueryCompletionRoutine(IntPtr queryContext, IntPtr queryResults)
{
QueryCompletionContext context = (QueryCompletionContext)Marshal.PtrToStructure(queryContext, typeof(QueryCompletionContext));
DNSQueryResult queryResult = (DNSQueryResult)Marshal.PtrToStructure(queryResults, typeof(DNSQueryResult));
Marshal.WriteInt32(context.resultCode, queryResult.QueryStatus);
if (queryResult.QueryStatus != 0)
{
if (queryResult.QueryRecords != IntPtr.Zero)
{
DnsRecordListFree(queryResult.QueryRecords, DNS_FREE_TYPE.DnsFreeRecordList);
}
context.eventHandle.Set();
return;
}
List <IDictionary <string, object> > records = GCHandle.FromIntPtr(context.dnsRecords).Target as List <IDictionary <string, object> >;
records.AddRange(ParseRecords(queryResult.QueryRecords, context.requestType));
if (queryResult.QueryRecords != IntPtr.Zero)
{
DnsRecordListFree(queryResult.QueryRecords, DNS_FREE_TYPE.DnsFreeRecordList);
}
context.eventHandle.Set();
}
public static IDictionary <string, object>[] QueryDNSForRecordTypeSpecificNameServers(string domainName, IPEndPoint[] dnsServers, DnsRecordTypes recordType)
{
if (dnsServers == null || dnsServers.Length == 0)
{
throw new Exception("At least one DNS Server must be provided to do the query");
}
IntPtr dnsRequest, addrRequestBuffer, contextBuffer;
QueryCompletionContext context = new QueryCompletionContext();
context.eventHandle = new EventWaitHandle(false, EventResetMode.ManualReset);
context.requestType = recordType;
context.resultCode = Marshal.AllocHGlobal(Marshal.SizeOf <int>());
List <IDictionary <string, object> > dnsRecords = new List <IDictionary <string, object> >();
GCHandle handle = GCHandle.Alloc(dnsRecords, GCHandleType.Normal);
context.dnsRecords = GCHandle.ToIntPtr(handle);
MakeDnsRequest(domainName, dnsServers, context, out dnsRequest, out addrRequestBuffer, out contextBuffer);
DNSQueryResult queryResult = new DNSQueryResult();
queryResult.Version = DnsQueryRequestVersion1;
IntPtr result = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(DNSQueryResult)));
Marshal.StructureToPtr(queryResult, result, false);
IntPtr cancelBuffer = Marshal.AllocHGlobal(DNSQueryCancelSize);
int resCode = DnsQueryEx(dnsRequest, result, cancelBuffer);
FreeDnsRequest(dnsRequest, addrRequestBuffer, contextBuffer);
bool requestPending = false;
switch (resCode)
{
case 0:
{
queryResult = (DNSQueryResult)Marshal.PtrToStructure(result, typeof(DNSQueryResult));
Marshal.FreeHGlobal(result);
}
break;
case DnsRequestPending:
{
Marshal.FreeHGlobal(result);
requestPending = true;
}
break;
case DnsRecordsNoInfo:
{
Marshal.FreeHGlobal(result);
Marshal.FreeHGlobal(cancelBuffer);
handle.Free();
return(new Dictionary <string, object> [0]);
}
default:
{
Marshal.FreeHGlobal(result);
Marshal.FreeHGlobal(cancelBuffer);
handle.Free();
throw new Win32Exception(resCode);
}
}
if (!requestPending)
{
Marshal.FreeHGlobal(cancelBuffer);
handle.Free();
if (queryResult.QueryStatus != 0)
{
if (queryResult.QueryRecords != IntPtr.Zero)
{
DnsRecordListFree(queryResult.QueryRecords, DNS_FREE_TYPE.DnsFreeRecordList);
}
throw new Win32Exception(queryResult.QueryStatus);
}
dnsRecords.AddRange(ParseRecords(queryResult.QueryRecords, recordType));
if (queryResult.QueryRecords != IntPtr.Zero)
{
DnsRecordListFree(queryResult.QueryRecords, DNS_FREE_TYPE.DnsFreeRecordList);
}
return(dnsRecords.ToArray());
}
if (!context.eventHandle.WaitOne(5000))
{
resCode = DnsCancelQuery(cancelBuffer);
context.eventHandle.WaitOne();
if (resCode != 0)
{
Marshal.FreeHGlobal(cancelBuffer);
handle.Free();
throw new Win32Exception(resCode);
}
}
Marshal.FreeHGlobal(cancelBuffer);
handle.Free();
int retCode = Marshal.ReadInt32(context.resultCode);
Marshal.FreeHGlobal(context.resultCode);
if (retCode != 0)
{
throw new Win32Exception(retCode);
}
return(dnsRecords.ToArray());
}