Bind documented DNS query export exactly and match Microsoft server buffer

scripts/DnsClientProbeNative.cs

@@ -17,7 +17,8 @@ namespace Wela.DnsClientProbe {
   }
   [StructLayout(LayoutKind.Sequential)] struct QueryResult { public uint Version,Status; public ulong Options; public IntPtr Records,Reserved; }
   [StructLayout(LayoutKind.Sequential)] struct Record { public IntPtr Next,Name; public ushort Type,Length; public uint Flags,Ttl,Reserved; }
-  [DllImport("dnsapi.dll",CharSet=CharSet.Unicode)] static extern uint DnsQueryEx(ref Request request,ref QueryResult result,IntPtr cancel);
+  // DnsQueryEx is the documented exact export; do not allow a W-suffixed name probe.
+  [DllImport("dnsapi.dll",EntryPoint="DnsQueryEx",ExactSpelling=true)] static extern uint DnsQueryEx(ref Request request,ref QueryResult result,IntPtr cancel);
   [DllImport("dnsapi.dll")] static extern void DnsRecordListFree(IntPtr records,int freeType);
   public static string ValidateResolver(string resolver) {
    if(resolver==null||!Regex.IsMatch(resolver,@"^(0|[1-9][0-9]{0,2})(\.(0|[1-9][0-9]{0,2})){3}$"))throw new ArgumentException("One canonical dotted-decimal IPv4 resolver is required.");
@@ -30,10 +31,11 @@ namespace Wela.DnsClientProbe {
    if(name==null||!Regex.IsMatch(name,@"^wela-[a-f0-9]{32}\.wela\.test\.\z"))throw new ArgumentException("Only the fixed random probe name is accepted.");
    ValidateResolver(resolver);
    // SDK DNS_ADDR_ARRAY header32 + one DNS_ADDR64; sockaddr_in in its first16 bytes.
-   // DNS_ADDR_ARRAY.MaxCount is the structure size in bytes; AddrCount is the element count.
-   byte[] server=new byte[96];BitConverter.GetBytes((uint)server.Length).CopyTo(server,0);BitConverter.GetBytes((uint)1).CopyTo(server,4);
-   BitConverter.GetBytes((ushort)2).CopyTo(server,12);BitConverter.GetBytes((ushort)2).CopyTo(server,32);
-   server[34]=0;server[35]=53;IPAddress.Parse(resolver).GetAddressBytes().CopyTo(server,36);
+   // Match Microsoft Windows-classic-samples/DNSAsyncQuery CreateDnsServerList:
+   // one address, unspecified aggregate family, sockaddr IPv4 with default DNS port.
+   byte[] server=new byte[96];BitConverter.GetBytes((uint)1).CopyTo(server,0);BitConverter.GetBytes((uint)1).CopyTo(server,4);
+   BitConverter.GetBytes((ushort)2).CopyTo(server,32);
+   IPAddress.Parse(resolver).GetAddressBytes().CopyTo(server,36);
    IntPtr servers=Marshal.AllocHGlobal(server.Length);QueryResult result=new QueryResult {Version=1};
    try {
     Marshal.Copy(server,0,servers,server.Length);

tests/DnsClientProbe.Diagnostics.ps1

@@ -0,0 +1,11 @@
+# Temporary native ABI diagnostic: called only inside the explicitly gated owned DNS fixture.
+param([ValidateRange(0,4)][int]$Variant)
+$ErrorActionPreference='Stop'
+if($env:GITHUB_ACTIONS -ne 'true' -or $env:RUNNER_ENVIRONMENT -ne 'github-hosted' -or $env:OS -ne 'Windows_NT'){throw 'Disposable native fixture only.'}
+$source=[IO.File]::ReadAllText((Join-Path $PSScriptRoot '../scripts/DnsClientProbeNative.cs'))
+# Keep the fixed product query name/options and explicit loopback resolver. Vary only server buffer ABI.
+$variants=@(@(1,0,0),@(96,0,0),@(1,2,0),@(1,0,53),@(96,2,53))
+$v=$variants[$Variant]
+$source=$source.Replace('BitConverter.GetBytes((uint)1).CopyTo(server,0);',('BitConverter.GetBytes((uint)'+$v[0]+').CopyTo(server,0);BitConverter.GetBytes((ushort)'+$v[1]+').CopyTo(server,12);server[35]='+$v[2]+';'))
+Add-Type -TypeDefinition $source
+[pscustomobject]@{Variant=$Variant;MaxCount=$v[0];Family=$v[1];Port=$v[2];Result=[Wela.DnsClientProbe.Native]::Query(('wela-'+[guid]::NewGuid().ToString('N')+'.wela.test.'),'127.0.0.1')}|ConvertTo-Json -Depth 8 -Compress

tests/DnsClientProbe.Tests.ps1

@@ -10,6 +10,8 @@ foreach($resolver in @('','localhost','127.1','127.0.0.01','127.0.0.1:53','127.0
 Throws {[Wela.DnsClientProbe.Native]::Query('arbitrary.example.','127.0.0.1')} 'fixed random'
 foreach($entry in @(@('Request',64),@('QueryResult',32),@('Record',32))){$nativeType=[Wela.DnsClientProbe.Native].GetNestedType($entry[0],[Reflection.BindingFlags]::NonPublic);Assert ([Runtime.InteropServices.Marshal].GetMethod('SizeOf',[type[]]@([type])).Invoke($null,@($nativeType)) -eq $entry[1]) ('Native64 SDK layout: '+$entry[0])}
 Assert ([Wela.DnsClientProbe.Native].GetField('SourceSha256').IsLiteral) 'Compiled source fingerprint cannot be reassigned.'
+$queryImport=[Wela.DnsClientProbe.Native].GetMethod('DnsQueryEx',[Reflection.BindingFlags]'NonPublic,Static').GetCustomAttributes([Runtime.InteropServices.DllImportAttribute],$false)[0]
+Assert ($queryImport.ExactSpelling -and $queryImport.EntryPoint -ceq 'DnsQueryEx') 'Bind the documented DnsQueryEx export exactly; no W suffix with a different ABI.'
 Assert ([Wela.DnsClientProbe.Native]::Options -eq 2103790) 'Fixed documented DNS flags retained.'
 $fields=@(foreach($name in @('QueryName','QueryType','QueryOptions','QueryStatus','QueryResults')){[pscustomobject]@{Name=$name;InType=$(if($name -in @('QueryName','QueryResults')){'win:UnicodeString'}elseif($name -eq 'QueryOptions'){'win:UInt64'}else{'win:UInt32'})}})
 $state=[pscustomobject]@{Computer='host';Host=[pscustomobject]@{DomainJoined=$false;Domain='WORKGROUP'};Service='Running';Channel=[pscustomobject]@{State='Enabled';Name='Microsoft-Windows-DNS-Client/Operational';SecurityDescriptor='O:SYG:SYD:(A;;0x1;;;SY)';MetadataErrors=@{};Error=$null;IsEnabled=$true;MaximumSizeInBytes=1048576;LogMode='Circular'};Schema=[pscustomobject]@{State='Observed';Provider='Microsoft-Windows-DNS-Client';ProviderGuid='1c95126e-7eea-49a9-a3fe-a378b03ddb4d';ChannelType='Operational';Events=@([pscustomobject]@{Id=3008;Version=0;Channel='Microsoft-Windows-DNS-Client/Operational';Fields=$fields})}}

tests/DnsClientProbe.Windows.Tests.ps1

@@ -53,6 +53,10 @@ try {
  $passed=$true;Write-Host "PASS: $script:count native DNS Client checks through $TestEngine."
 }catch{
  Write-Host ('Native DNS Client failure: '+($_|Out-String));Write-Host $_.ScriptStackTrace
+ if($zoneCreated){foreach($variant in 0..4){
+  $diagnostic=[Diagnostics.Process]::new();$info=[Diagnostics.ProcessStartInfo]::new();$info.FileName=$engine;$info.Arguments='-NoLogo -NoProfile -NonInteractive -File "'+(Join-Path $PSScriptRoot 'DnsClientProbe.Diagnostics.ps1')+'" -Variant '+$variant;$info.UseShellExecute=$false;$info.RedirectStandardOutput=$true;$info.RedirectStandardError=$true;$diagnostic.StartInfo=$info
+  try{$null=$diagnostic.Start();$stdout=$diagnostic.StandardOutput.ReadToEndAsync();$stderr=$diagnostic.StandardError.ReadToEndAsync();if(-not $diagnostic.WaitForExit(20000)){throw 'Owned diagnostic worker timeout.'};if(-not [Threading.Tasks.Task]::WaitAll([Threading.Tasks.Task[]]@($stdout,$stderr),5000)){throw 'Diagnostic output timeout.'};Write-Host ('Owned ABI variant '+$variant+' exit '+$diagnostic.ExitCode);Write-Host $stdout.Result;Write-Host $stderr.Result}catch{Write-Host $_}finally{if(-not $diagnostic.HasExited){$diagnostic.Kill();$null=$diagnostic.WaitForExit(5000)};$diagnostic.Dispose()}
+ }}
  # Small owned diagnostics only; avoid dumping unrelated channel payloads.
  if(Test-Path (Join-Path $private 'evidence')){Get-ChildItem (Join-Path $private 'evidence') -File|Where-Object {$_.Name -in @('manifest.json','operation.json','worker.json') -or $_.Name -like 'candidate-*.xml'}|ForEach-Object{Write-Host $_.Name;Write-Host ([IO.File]::ReadAllText($_.FullName))}}
  throw