windows-drivers-rs

This repo is a collection of Rust crates that enable developers to develop Windows Drivers in Rust. It is the intention to support both WDM and WDF driver development models. This repo contains the following crates:

• wdk-build: A library to configure a Cargo build script for binding generation and downstream linking of the WDK (Windows Driver Kit). While this crate is written to be flexible with different WDK releases and different WDF version, it is currently only tested for NI eWDK, KMDF 1.33, UMDF 2.33, and WDM Drivers. There may be missing linker options for older DDKs.
• wdk-sys: Direct FFI bindings to APIs available in the Windows Development Kit (WDK). This includes both autogenerated ffi bindings from bindgen, and also manual re-implementations of macros that bindgen fails to generate.
• wdk: Safe idiomatic bindings to APIs available in the Windows Development Kit (WDK)
• wdk-panic: Default panic handler implementations for programs built with WDK
• wdk-alloc: alloc support for binaries compiled with the Windows Development Kit (WDK)
• wdk-macros: A collection of macros that help make it easier to interact with wdk-sys's direct bindings. This crate is re-exported via wdk-sys and crates should typically never need to directly depend on wdk-macros

To see an example of this repo used to create drivers, see Windows-rust-driver-samples.

Note: This project is still in early stages of development and is not yet recommended for production use. We encourage community experimentation, suggestions and discussions! We will be using our GitHub Discussions forum as the main form of engagement with the community!

Supported Configurations

This project was built with support of WDM, KMDF, and UMDF drivers in mind, as well as Win32 Services. This includes support for all versions of WDF included in WDK 22H2 and newer. Currently, the crates available on crates.io only support KMDF v1.33, but bindings can be generated for everything else by cloning windows-drivers-rs and modifying the config specified in build.rs of wdk-sys. Crates.io support for other WDK configurations is planned in the near future.

Repo Layout

• crates: Contains all the main crates that are a part of the Cargo workspace.
• examples: Contains workspace-level examples. These examples consist of different types of minimal Windows drivers (ie. WDM, KMDF, UMDF).
• tests: Contains workspace-level tests, inlcuding tests for metadata-based wdk configuration in packages and workspaces.

Note:: Since the workspace level examples and tests use different WDK configurations, and WDR only supports one WDK configuration per workspace, the workspace-level examples and tests folder are excluded from the repository root's Cargo manifest.

Getting Started

Build Requirements

• Binding generation via bindgen requires libclang. The easiest way to acquire this is via winget

  • winget install -i LLVM.LLVM --version 17.0.6 --force
    • Ensure you select the GUI option to add LLVM to the PATH
    • LLVM 18 has a bug that causes bindings to fail to generate for ARM64. Continue using LLVM 17 until LLVM 19 comes out with the fix. See this for more details.

• To execute post-build tasks (ie. inf2cat, infverif, etc.), cargo make is used

  • cargo install --locked cargo-make --no-default-features --features tls-native

• Building programs with the WDK also requires being in a valid WDK environment. The recommended way to do this is to enter an eWDK developer prompt

Adding windows-drivers-rs to Your Driver Package

The crates in this repository are available from crates.io, but take into account the current limitations outlined in Supported Configurations. If you need to support a different config, try cloning this repo and using path dependencies

1. Create a new Cargo package with a lib crate:

   cargo new <driver_name> --lib

2. Add dependencies on windows-drivers-rs crates:

   cd <driver_name>
   cargo add --build wdk-build
   cargo add wdk wdk-sys wdk-alloc wdk-panic

3. Set the crate type to cdylib by adding the following snippet to Cargo.toml:

   [lib]
   crate-type = ["cdylib"]

4. Add a wdk metadata section and configure the wdk for your use case. This also lets the cargo-make tasks know that the package is a driver and that the driver packaging steps need to run.

   UMDF Example:

   [package.metadata.wdk.driver-model]
   driver-type = "UMDF"
   umdf-version-major = 1
   target-umdf-version-minor = 33

5. For Kernel Mode crates (ex. KMDF drivers, WDM drivers): Set crate panic strategy to abort in Cargo.toml:

   [profile.dev]
   panic = "abort"
   
   [profile.release]
   panic = "abort"

6. Create a build.rs and add the following snippet:

   fn main() -> Result<(), wdk_build::ConfigError> {
      wdk_build::configure_binary_build()
   }

7. For Kernel Mode crates (ex. KMDF drivers, WDM drivers): Mark your driver crate as no_std in lib.rs:

   #![no_std]

8. For Kernel Mode crates (ex. KMDF drivers, WDM drivers): Add a panic handler in lib.rs:

   #[cfg(not(test))]
   extern crate wdk_panic;

9. For Kernel Mode crates (ex. KMDF drivers, WDM drivers): Add an optional global allocator in lib.rs:

   #[cfg(not(test))]
   use wdk_alloc::WdkAllocator;
   
   #[cfg(not(test))]
   #[global_allocator]
   static GLOBAL_ALLOCATOR: WdkAllocator = WdkAllocator;

   This is only required if you want to be able to use the alloc modules in the rust standard library.

10. Add a DriverEntry in lib.rs:

    use wdk_sys::{
       DRIVER_OBJECT,
       NTSTATUS,
       PCUNICODE_STRING,
    };
    
    #[export_name = "DriverEntry"] // WDF expects a symbol with the name DriverEntry
    pub unsafe extern "system" fn driver_entry(
       driver: PDRIVER_OBJECT,
       registry_path: PCUNICODE_STRING,
    ) -> NTSTATUS {
       0
    }

    Note: In Kernel Mode crates, you can use driver: &mut DRIVER_OBJECT instead of driver: PDRIVER_OBJECT.

11. Add a Makefile.toml:

    extend = "target/rust-driver-makefile.toml"
    
    [config]
    load_script = '''
    #!@rust
    //! ```cargo
    //! [dependencies]
    //! wdk-build = "0.2.0"
    //! ```
    #![allow(unused_doc_comments)]
    
    wdk_build::cargo_make::load_rust_driver_makefile()?
    '''

12. Add an inx file that matches the name of your cdylib crate.

13. Enable static crt linkage. One approach is to add this to your .cargo/config.toml:

    [build]
    rustflags = ["-C", "target-feature=+crt-static"]

14. Build the driver:

    cargo make

A signed driver package, including a WDRLocalTestCert.cer file, will be generated at target/<Cargo profile>/package. If a specific target architecture was specified, the driver package will be generated at target/<target architecture>/<Cargo profile>/package

Minimal examples of WDM, KMDF, and UMDF drivers can be found in the examples directory.

Cargo Make

cargo-make is used to facilitate builds using windows-drivers-rs, including for executing post-build driver packaging steps.

To execute the default action (build and package driver):

cargo make default

When executing the default task, just cargo make make also works since the default task is implied.

Argument Forwarding

windows-drivers-rs extends cargo make to forward specific arguments to the underlying cargo commands. In order to specify arguments to forward, they must be provided after explicitly specifying the cargo-make task name (ie. omitting the name for the default task is not supported).

Examples

For a specific target:

cargo make default --target <TARGET TRIPLE>

For release builds:

cargo make default --release or cargo make default --profile release

To specify specific features:

cargo make default --features <FEATURES>

To specify a specific rust toolchain:

cargo make default +<TOOLCHAIN>

To display help and see the full list of supported CLI args to forward to Cargo:

cargo make help

Driver Package Signature Verification

The WDK_BUILD_ENABLE_SIGNTOOL_VERIFY cargo-make environment variable can be set to true to enable tasks that handle signature verification of the generated .sys and .cat files. signtool verify requires the certificate to be installed as in the Trusted Root Certification Authorities for this verification to function. These tasks are not enabled by default as the default behavior of WDR is to sign with a generated test certificate. These test certificates are typically only installed into Trusted Root Certification Authorities on computers dedicated to testing drivers, and not personal development machines, given the security implications of installing your own root certificates.

If you understand these implications, and have installed the test certificate, then you may validate the signatures as follows:

cargo make --env WDK_BUILD_ENABLE_SIGNTOOL_VERIFY=true

Crates.io Release Policy

Releases to crates.io are not made after every change merged to main. Releases will only be made when requested by the community, or when the windows-drivers-rs team believes there is sufficient value in pushing a release.

Trademark Notice

Trademarks This project may contain trademarks or logos for projects, products, or services. Authorized use of Microsoft trademarks or logos is subject to and must follow Microsoft’s Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship. Any use of third-party trademarks or logos are subject to those third-party’s policies.