Files
regorus/bindings/csharp/Regorus/SafeHandles.cs
Anand Krishnamoorthi 86b4a279fa fix(ffi): eliminate aliasing UB + add Azure Policy JSON compilation FFI (#727)
* fix(ffi): eliminate aliasing UB via to_shared_ref migration

Add to_shared_ref() helper that creates &T (shared reference) from raw
pointers instead of &mut T. This eliminates undefined behavior caused by
violating Rust's aliasing invariant when C# SafeHandle permits concurrent
FFI calls on the same handle.

With &mut T, the compiler may assume exclusive (noalias) access and
reorder or elide reads/writes — a miscompilation risk when another thread
holds a reference to the same object. Switching to &T removes that
assumption; actual mutation is mediated by the interior RwLock inside
Handle<T>, which is the sole synchronization mechanism.

Migrated sites:
- rvm.rs: 20 non-drop call sites
- engine.rs: 30 non-drop call sites + with_unwind_guard for timer fns
- compiled_policy.rs: 2 call sites
- Fix null-data UB in regorus_program_deserialize_binary

Drop paths retain to_ref() where exclusive access is guaranteed by the
caller contract (preventing use-after-free).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* feat(ffi): add Azure Policy JSON compilation FFI and C# bindings

- AliasRegistry builder pattern: RegorusAliasRegistryBuilder (mutable,
  single-threaded) + RegorusAliasRegistry (immutable, Arc-wrapped)
- Azure Policy JSON compilation: regorus_compile_azure_policy_rule and
  regorus_compile_azure_policy_definition with alias registry support
- regorus_rvm_set_context for host-supplied ambient data
- C# AliasRegistryBuilder and AliasRegistry classes with convenience
  factories (FromJson, FromManifest, Empty)
- C# AzurePolicyCompiler static class for policy rule/definition compilation
- Compile functions take *const RegorusAliasRegistry (read-only via
  to_shared_ref for concurrent compilation safety)
- Fix pre-existing clippy warnings across multiple crates

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-05-22 12:50:16 -05:00

255 lines
7.1 KiB
C#

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.
using System;
using System.Runtime.InteropServices;
using Microsoft.Win32.SafeHandles;
#nullable enable
namespace Regorus
{
internal sealed class RegorusEngineHandle : SafeHandleZeroOrMinusOneIsInvalid
{
private RegorusEngineHandle() : base(ownsHandle: true)
{
}
internal static RegorusEngineHandle Create()
{
unsafe
{
var raw = Internal.API.regorus_engine_new();
if (raw is null)
{
throw new InvalidOperationException("Failed to create Regorus engine.");
}
var handle = new RegorusEngineHandle();
handle.SetHandle((IntPtr)raw);
return handle;
}
}
internal static RegorusEngineHandle FromPointer(IntPtr pointer)
{
if (pointer == IntPtr.Zero)
{
throw new ArgumentException("Pointer cannot be zero.", nameof(pointer));
}
var handle = new RegorusEngineHandle();
handle.SetHandle(pointer);
return handle;
}
protected override bool ReleaseHandle()
{
if (!IsInvalid)
{
unsafe
{
Internal.API.regorus_engine_drop((Internal.RegorusEngine*)handle);
}
SetHandle(IntPtr.Zero);
}
return true;
}
}
internal sealed class RegorusCompiledPolicyHandle : SafeHandleZeroOrMinusOneIsInvalid
{
private RegorusCompiledPolicyHandle() : base(ownsHandle: true)
{
}
internal static RegorusCompiledPolicyHandle FromPointer(IntPtr pointer)
{
if (pointer == IntPtr.Zero)
{
throw new ArgumentException("Pointer cannot be zero.", nameof(pointer));
}
var handle = new RegorusCompiledPolicyHandle();
handle.SetHandle(pointer);
return handle;
}
protected override bool ReleaseHandle()
{
if (!IsInvalid)
{
unsafe
{
Internal.API.regorus_compiled_policy_drop((Internal.RegorusCompiledPolicy*)handle);
}
SetHandle(IntPtr.Zero);
}
return true;
}
}
internal sealed class RegorusProgramHandle : SafeHandleZeroOrMinusOneIsInvalid
{
private RegorusProgramHandle() : base(ownsHandle: true)
{
}
internal static RegorusProgramHandle Create()
{
unsafe
{
var raw = Internal.API.regorus_program_new();
if (raw is null)
{
throw new InvalidOperationException("Failed to create Regorus program.");
}
var handle = new RegorusProgramHandle();
handle.SetHandle((IntPtr)raw);
return handle;
}
}
internal static RegorusProgramHandle FromPointer(IntPtr pointer)
{
if (pointer == IntPtr.Zero)
{
throw new ArgumentException("Pointer cannot be zero.", nameof(pointer));
}
var handle = new RegorusProgramHandle();
handle.SetHandle(pointer);
return handle;
}
protected override bool ReleaseHandle()
{
if (!IsInvalid)
{
unsafe
{
Internal.API.regorus_program_drop((Internal.RegorusProgram*)handle);
}
SetHandle(IntPtr.Zero);
}
return true;
}
}
internal sealed class RegorusRvmHandle : SafeHandleZeroOrMinusOneIsInvalid
{
private RegorusRvmHandle() : base(ownsHandle: true)
{
}
internal static RegorusRvmHandle Create()
{
unsafe
{
var raw = Internal.API.regorus_rvm_new();
if (raw is null)
{
throw new InvalidOperationException("Failed to create Regorus RVM.");
}
var handle = new RegorusRvmHandle();
handle.SetHandle((IntPtr)raw);
return handle;
}
}
internal static RegorusRvmHandle FromPointer(IntPtr pointer)
{
if (pointer == IntPtr.Zero)
{
throw new ArgumentException("Pointer cannot be zero.", nameof(pointer));
}
var handle = new RegorusRvmHandle();
handle.SetHandle(pointer);
return handle;
}
protected override bool ReleaseHandle()
{
if (!IsInvalid)
{
unsafe
{
Internal.API.regorus_rvm_drop((Internal.RegorusRvm*)handle);
}
SetHandle(IntPtr.Zero);
}
return true;
}
}
internal sealed class RegorusAliasRegistryBuilderHandle : SafeHandleZeroOrMinusOneIsInvalid
{
private RegorusAliasRegistryBuilderHandle() : base(ownsHandle: true)
{
}
internal static RegorusAliasRegistryBuilderHandle Create()
{
unsafe
{
var raw = Internal.API.regorus_alias_registry_builder_new();
if (raw is null)
{
throw new InvalidOperationException("Failed to create Regorus alias registry builder.");
}
var handle = new RegorusAliasRegistryBuilderHandle();
handle.SetHandle((IntPtr)raw);
return handle;
}
}
protected override bool ReleaseHandle()
{
if (!IsInvalid)
{
unsafe
{
Internal.API.regorus_alias_registry_builder_drop((Internal.RegorusAliasRegistryBuilder*)handle);
}
SetHandle(IntPtr.Zero);
}
return true;
}
}
internal sealed class RegorusAliasRegistryHandle : SafeHandleZeroOrMinusOneIsInvalid
{
private RegorusAliasRegistryHandle() : base(ownsHandle: true)
{
}
internal static RegorusAliasRegistryHandle FromPointer(IntPtr pointer)
{
if (pointer == IntPtr.Zero)
{
throw new ArgumentException("Pointer cannot be zero.", nameof(pointer));
}
var handle = new RegorusAliasRegistryHandle();
handle.SetHandle(pointer);
return handle;
}
protected override bool ReleaseHandle()
{
if (!IsInvalid)
{
unsafe
{
Internal.API.regorus_alias_registry_drop((Internal.RegorusAliasRegistry*)handle);
}
SetHandle(IntPtr.Zero);
}
return true;
}
}
}