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());
}
private static void MakeDnsRequest(string domainName, IPEndPoint[] dnsServers, QueryCompletionContext context, out IntPtr requestBuffer, out IntPtr addrBuffer, out IntPtr contextBuffer)
{
requestBuffer = IntPtr.Zero;
addrBuffer = IntPtr.Zero;
contextBuffer = IntPtr.Zero;
DNS_ADDR[] addrList = new DNS_ADDR[dnsServers.Length];
int curAddress = 0;
foreach (var endpoint in dnsServers)
{
addrList[curAddress] = new DNS_ADDR();
if (endpoint.AddressFamily == AddressFamily.InterNetwork)
{
byte[] ipv4AddressBytes = endpoint.Address.GetAddressBytes();
SockAddrIn sockAddrIn = new SockAddrIn();
Buffer.BlockCopy(ipv4AddressBytes, 0, sockAddrIn.SinAddr, 0, IpAddressV4LengthBytes);
sockAddrIn.SinFamily = AFInet;
sockAddrIn.SinPort = (ushort)IPAddress.HostToNetworkOrder((short)endpoint.Port);
IntPtr sockAddrInPtr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(SockAddrIn)));
Marshal.StructureToPtr(sockAddrIn, sockAddrInPtr, false);
Marshal.Copy(sockAddrInPtr, addrList[curAddress].MaxSa, 0, Marshal.SizeOf(typeof(SockAddrIn)));
Marshal.FreeHGlobal(sockAddrInPtr);
}
else if (endpoint.AddressFamily == AddressFamily.InterNetworkV6)
{
SockAddrIn6 sockAddrIn6 = new SockAddrIn6();
sockAddrIn6.Sin6Family = AFInet16;
sockAddrIn6.Sin6Port = (ushort)IPAddress.HostToNetworkOrder((short)endpoint.Port);
sockAddrIn6.Sin6FlowInfo = 0;
byte[] ipv6AddressBytes = endpoint.Address.GetAddressBytes();
Buffer.BlockCopy(ipv6AddressBytes, 0, sockAddrIn6.Sin6Addr, 0, IpAddressV6LengthBytes);
sockAddrIn6.Sin6ScopeId = 0;
IntPtr sockAddrv6InPtr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(SockAddrIn6)));
Marshal.StructureToPtr(sockAddrIn6, sockAddrv6InPtr, false);
Marshal.Copy(sockAddrv6InPtr, addrList[curAddress].MaxSa, 0, Marshal.SizeOf(typeof(SockAddrIn6)));
Marshal.FreeHGlobal(sockAddrv6InPtr);
}
else
{
throw new Exception(string.Format("Address family {0} not supported", endpoint.AddressFamily.ToString()));
}
curAddress++;
}
int bufSize = Marshal.SizeOf(typeof(DNS_ADDR_ARRAY)) + (addrList.Length * Marshal.SizeOf(typeof(DNS_ADDR)));
DNS_ADDR_ARRAY addrArray = new DNS_ADDR_ARRAY();
addrArray.MaxCount = (uint)dnsServers.Length;
addrArray.AddrCount = (uint)dnsServers.Length;
addrBuffer = Marshal.AllocHGlobal(bufSize);
Marshal.StructureToPtr(addrArray, addrBuffer, false);
IntPtr addrArrayPointer = new IntPtr(addrBuffer.ToInt64() + Marshal.SizeOf(typeof(DNS_ADDR_ARRAY)));
for (int i = 0; i < addrList.Length; i++)
{
Marshal.StructureToPtr(addrList[i], addrArrayPointer, false);
addrArrayPointer = new IntPtr(addrArrayPointer.ToInt64() + Marshal.SizeOf(typeof(DNS_ADDR)));
}
DNS_QUERY_REQUEST request = new DNS_QUERY_REQUEST();
request.Version = DnsQueryRequestVersion1;
request.QueryName = domainName;
request.QueryType = (ushort)context.requestType;
request.QueryOptions = (ulong)(DnsQueryOptions.DNS_QUERY_STANDARD);
request.DnsServerList = addrBuffer;
request.InterfaceIndex = 0;
// request.QueryCompletionCallback = Marshal.GetFunctionPointerForDelegate(new QueryCompletionRoutineFunctionPointer(QueryCompletionRoutine));
contextBuffer = Marshal.AllocHGlobal(Marshal.SizeOf(context));
Marshal.StructureToPtr(context, contextBuffer, false);
request.QueryContext = contextBuffer;
requestBuffer = Marshal.AllocHGlobal(Marshal.SizeOf(request));
Marshal.StructureToPtr(request, requestBuffer, false);
}
