Assembly.GetTypes fails on System.DirectoryServices assembly

[gamingrobot]

Description

When calling Assembly.GetTypes on the assembly System.DirectoryServices a ReflectionTypeLoadException is thrown.

Unhandled exception. System.Reflection.ReflectionTypeLoadException: Unable to load one or more of the requested types.
Could not load type 'System.DirectoryServices.ActiveDirectory.LSA_FOREST_TRUST_RECORD' from assembly 'System.DirectoryServices, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' because it contains an object field at offset 16 that is incorrectly aligned or overlapped by a non-object field.
   at System.Reflection.RuntimeModule.GetTypes(RuntimeModule module)
   at System.Reflection.Assembly.GetTypes()
   at DirectoryServicesIssue.Program.Main(String[] args) in C:\Development\test\carebear\DirectoryServicesIssue\Program.cs:line 13
System.TypeLoadException: Could not load type 'System.DirectoryServices.ActiveDirectory.LSA_FOREST_TRUST_RECORD' from assembly 'System.DirectoryServices, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' because it contains an object field at offset 16 that is incorrectly aligned or overlapped by a non-object field.

Reproduction Steps

1. Create new console app using .NET 7.0.0 Preview 3
2. Add System.DirectoryServices package <PackageReference Include="System.DirectoryServices" Version="7.0.0-preview.3.22175.4" />
3. Add the code below to Program.cs
4. Run

//Use System.DirectoryServices
var _ = new DirectorySearcher("testing");
//GetTypes
var assembly = AppDomain.CurrentDomain.GetAssemblies().Single(x => x.GetName().Name == "System.DirectoryServices");
assembly.GetTypes();

Expected behavior

ReflectionTypeLoadException should not be thrown

Actual behavior

ReflectionTypeLoadException is thrown

Regression?

Yes, works as expected when using the 6.0.0 version of the System.DirectoryServices nuget package

Known Workarounds

Don't call GetTypes on the System.DirectoryServices assembly

Configuration

.NET 7.0.0 Preview 3
Windows 10 21H2
x64

Other information

I think it is due to this change here a61c1a3#diff-bb93fc33786f17ce709a25bd79b94cf4e6c5e2ba8ac5b4b0f728dcb35d2ac77dL415

LSA_UNICODE_STRING (class) was replaced with global::Interop.UNICODE_STRING (struct) causing a mismatch since LSA_FOREST_TRUST_BINARY_DATA and LSA_FOREST_TRUST_DOMAIN_INFO are both classes and use the same FieldOffset

Tagging subscribers to this area: @dotnet/area-system-directoryservices, @jay98014
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Issue Details

---

Description

When calling Assembly.GetTypes on the assembly System.DirectoryServices a ReflectionTypeLoadException is thrown.

Unhandled exception. System.Reflection.ReflectionTypeLoadException: Unable to load one or more of the requested types.
Could not load type 'System.DirectoryServices.ActiveDirectory.LSA_FOREST_TRUST_RECORD' from assembly 'System.DirectoryServices, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' because it contains an object field at offset 16 that is incorrectly aligned or overlapped by a non-object field.
   at System.Reflection.RuntimeModule.GetTypes(RuntimeModule module)
   at System.Reflection.Assembly.GetTypes()
   at DirectoryServicesIssue.Program.Main(String[] args) in C:\Development\test\carebear\DirectoryServicesIssue\Program.cs:line 13
System.TypeLoadException: Could not load type 'System.DirectoryServices.ActiveDirectory.LSA_FOREST_TRUST_RECORD' from assembly 'System.DirectoryServices, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' because it contains an object field at offset 16 that is incorrectly aligned or overlapped by a non-object field.

Reproduction Steps

1. Create new console app using .NET 7.0.0 Preview 3
2. Add System.DirectoryServices package <PackageReference Include="System.DirectoryServices" Version="7.0.0-preview.3.22175.4" />
3. Add the code below to Program.cs
4. Run

//Use System.DirectoryServices
var _ = new DirectorySearcher("testing");
//GetTypes
var assembly = AppDomain.CurrentDomain.GetAssemblies().Single(x => x.GetName().Name == "System.DirectoryServices");
assembly.GetTypes();

Expected behavior

ReflectionTypeLoadException should not be thrown

Actual behavior

ReflectionTypeLoadException is thrown

Regression?

Yes, works as expected when using the 6.0.0 version of the System.DirectoryServices nuget package

Known Workarounds

Don't call GetTypes on the System.DirectoryServices assembly

Configuration

.NET 7.0.0 Preview 3
Windows 10 21H2
x64

Other information

I think it is due to this change here a61c1a3#diff-bb93fc33786f17ce709a25bd79b94cf4e6c5e2ba8ac5b4b0f728dcb35d2ac77dL415

LSA_UNICODE_STRING (class) was replaced with global::Interop.UNICODE_STRING (struct) causing a mismatch since LSA_FOREST_TRUST_BINARY_DATA and LSA_FOREST_TRUST_DOMAIN_INFO are both classes and use the same FieldOffset

Author:	gamingrobot
Assignees:	-
Labels:	area-System.DirectoryServices, untriaged
Milestone:	-

[danmoseley]

@elinor-fung it indeed looks like this was introduced by your change, as noted above. Curious though, why does this not give an error when the type is loaded at runtime? Perhaps our tests simply don't use LSA_FOREST_TRUST_RECORD so it never loads? This makes me wonder whether we almost should have a test that simply loads all types in the shared framework.

[elinor-fung]

This makes me wonder whether we almost should have a test that simply loads all types in the shared framework.

That does seem reasonable. I'm pretty sad that nothing caught this.

[danmoseley]

It's possible it broke the manual tests, if you didn't get a chance to run those. But coverage of DS is generally not great.

[elinor-fung]

It's possible it broke the manual tests, if you didn't get a chance to run those.

Definitely did not run those (did not know they existed). Could you point me at them?

[danmoseley]

See https://github.com/dotnet/runtime/blob/327291967503180b4079720063819da59c3395e3/src/libraries/Common/tests/System/DirectoryServices/LDAP.Configuration.xml

The first two configs are docker based and should not be too difficult. The AD server one (which appears to be the relevant one here) involves at least one VM, which takes time to set up, and I have not always been successful. ideally we can make this easier. If you don't feel like doing this, I fully understand. Perhaps time would be better spent on writing a "Assembly.Load everything in the bin directory" test.

cc @joperezr in case he still has a VM on his machine that one can use for the AD server, or has a trick to set one up easily in the cloud. I did it locally last time.

[elinor-fung]

Thanks for the info. I'm not sure I'm feeling ambitious enough to go through the setup. I ran things manually that use the affected code to query for information (on my machine that is connected to Microsoft's Azure AD) and added a test (only for System.DirectoryServices) to get all types in #68274

[danmoseley]

That sounds good to me @elinor-fung

[joperezr]

It's possible it broke the manual tests, if you didn't get a chance to run those.

I'm unfamiliar with @elinor-fung's recent changes, but in case you are referring to these tests, they are specifically for System.DirectoryServices.Protocols, and looks like the changes made on the linked changeset are touching System.DirectoryServices assembly, so those tests don't apply there. I do have both an AD server to test , and the LdapConfiguration.xml instructions for testing against a docker container should all work as well (I run them sort of regularly with no issues).