Simple SOME/IP

Simple SOME/IP is a Rust library implementing the SOME/IP automotive communication protocol — remote procedure calls, event notifications, and wire format serialization. Based on the Open SOME/IP Specification.

The library supports both std and no_std environments, making it suitable for embedded targets as well as host-side tooling and scripting.

Features

• no_std compatible — protocol, traits, transport, and e2e modules work without the standard library
• Service Discovery — SD entry/option encoding and decoding via fixed-capacity heapless collections (no heap allocation)
• End-to-End protection — Profile 4 (CRC-32) and Profile 5 (CRC-16) with zero-allocation APIs
• Executor-agnostic transport traits — TransportSocket, TransportFactory, Timer, Spawner (default tokio impls behind feature gates)
• Async client and server — tokio-based, gated behind optional feature flags
• embedded-io traits for serialization — abstracts over std::io::Read/Write

Modules

• protocol — Wire format layer: SOME/IP header, MessageId, MessageType, ReturnCode, SD entries/options
• traits — WireFormat and PayloadWireFormat traits for custom message types
• transport — Executor-agnostic UDP socket / factory / timer / spawner traits (no_std-compatible)
• e2e — End-to-End protection profiles (always available, no heap allocation)
• tokio_transport — Default std + tokio impls of the transport traits (requires feature = "client-tokio" or feature = "server-tokio")
• client — High-level async client trait surface (requires feature = "client"; add client-tokio for the Client::new convenience constructor)
• server — Async server with SD announcements and event publishing (requires feature = "server"; add server-tokio for the Server::new convenience constructor)

Usage

Add to your Cargo.toml:

[dependencies]
# Default — includes std, thiserror, and tracing
simple-someip = "0.8"

# no_std only (protocol/transport/E2E/traits, no heap allocation)
simple-someip = { version = "0.8", default-features = false }

# Client only (with tokio convenience constructors)
simple-someip = { version = "0.8", features = ["client-tokio"] }

# Server only (with tokio convenience constructors)
simple-someip = { version = "0.8", features = ["server-tokio"] }

# Both client and server
simple-someip = { version = "0.8", features = ["client-tokio", "server-tokio"] }

Feature flags

Feature	Default	Description
std	yes	Enables thiserror, tracing, and embedded-io/std. The Arc<Mutex<E2ERegistry>> / Arc<RwLock<…>> default lock-handle impls (used by the tokio backends) live behind this gate.
client	no	Client trait surface. Pure no_std-clean (does not pull extern crate alloc). Caller supplies trait impls for transport / channels / spawner / timer / lock handles.
client-tokio	no	Adds Client::new / TokioSpawner / TokioTransport defaults; implies client + std + tokio + socket2.
server	no	Server trait surface. Pulls extern crate alloc (for Arc<EventPublisher> / Arc<F::Socket>); on no_std, downstream consumers must provide a #[global_allocator].
server-tokio	no	Adds Server::new / TokioTimer / TokioTransport defaults; implies server + std + tokio + socket2.
bare_metal	no	Activates embassy-sync, no-alloc static_channels module, AtomicInterfaceHandle, StaticE2EHandle, and StaticSubscriptionHandle — all five pure no_std (no allocator required). See examples/bare_metal_client and examples/bare_metal_server; verify with cargo build -p bare_metal_client (NOT cargo build --workspace, which can unify features).
embassy_channels	no	Heap-backed EmbassySyncChannels (implies bare_metal + alloc). Useful for tests before sizing static pools.

By default the crate enables std. To use in a no_std environment (e.g., embedded targets), disable default features with default-features = false. In that mode the protocol, traits, transport, and e2e modules are always available; client / server are usable too (the trait surfaces compile in pure no_std), but the tokio convenience defaults (Client::new, Server::new) live behind client-tokio / server-tokio and require std. The cargo build --target thumbv7em-none-eabihf --no-default-features --features client,server,bare_metal cross-build is verified in CI on every PR.

Quick Start

These examples require the client-tokio and server-tokio features respectively.

Client

use simple_someip::{Client, ClientUpdate, RawPayload};
use std::net::Ipv4Addr;

#[tokio::main]
async fn main() {
    // Client::new returns a Clone-able handle, an update stream, and
    // the run-loop future. The future must be actively driven — either
    // spawned on the runtime as shown below, or awaited alongside your
    // own work in a `tokio::select!`. If the future is never polled,
    // Client method calls that send commands over the control channel
    // will hang indefinitely waiting on their oneshot response.
    // `Error::Shutdown` is returned only once the run-loop future has
    // been dropped or its task cancelled.
    let (client, mut updates, run) =
        Client::<RawPayload, _, _, _>::new(Ipv4Addr::new(192, 168, 1, 100));
    let _run_task = tokio::spawn(run);

    // Bind the SD multicast socket to discover services
    client.bind_discovery().await.unwrap();

    // Receive discovery, unicast, and error updates
    while let Some(update) = updates.recv().await {
        match update {
            ClientUpdate::DiscoveryUpdated(msg) => { /* SD message */ }
            ClientUpdate::Unicast { message, e2e_status } => { /* unicast reply */ }
            ClientUpdate::SenderRebooted(addr) => { /* remote reboot detected */ }
            ClientUpdate::Error(err) => { /* error */ }
        }
    }
}

Server

use simple_someip::server::{Server, ServerConfig};
use std::net::Ipv4Addr;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let config = ServerConfig::new(Ipv4Addr::new(192, 168, 1, 200), 30500, 0x1234, 1);
    let mut server = Server::new(config).await?;
    let announce_handle = tokio::spawn(server.announcement_loop()?);

    let publisher = server.publisher();
    let run_handle = tokio::spawn(async move { server.run().await });

    // Publish events to subscribers, e.g.:
    // publisher.publish_event(0x1234, 1, 0x01, &message).await?;

    tokio::select! {
        res = announce_handle => eprintln!("announcement loop exited unexpectedly: {res:?}"),
        res = run_handle      => eprintln!("server run loop exited: {res:?}"),
    }
    Ok(())
}

Examples

Examples are provided in the examples/ directory. To run the discovery client example:

cargo run -p discovery_client