Initial commit - extracted urpc from monorepo

8 files changed, 929 insertions, 0 deletions

diff --git a/src/channel.rs b/src/channel.rs
new file mode 100644
index 0000000..f80ca87
--- /dev/null
+++ b/src/channel.rs
@@ -0,0 +1,162 @@
+//! MPSC channel backed channel and listener implementations.
+//!
+//! This module provides an mpsc channel based listener/channel implementation that can be useful
+//! to for tests.
+//!
+//! The current implementation uses [`tokio`]'s unbounded mpsc channels.
+//!
+//! ```
+//! #[urpc::service]
+//! trait Hello {
+//!     type Error = ();
+//!
+//!     async fn hello(name: String) -> String;
+//! }
+//!
+//! struct HelloServer;
+//!
+//! impl Hello for HelloServer {
+//!     async fn hello(&self, _ctx: urpc::Context, name: String) -> Result<String, ()> {
+//!         Ok(format!("Hello, {name}!"))
+//!     }
+//! }
+//!
+//! #[tokio::main]
+//! async fn main() -> Result<(), Box<dyn std::error::Error>>{
+//!     let (dialer, listener) = urpc::channel::new();
+//!
+//!     // spawn the server
+//!     tokio::spawn(async move {
+//!         urpc::Server::default()
+//!             .with_listener(listener)
+//!             .with_service(HelloServer.into_service())
+//!             .serve()
+//!             .await
+//!     });
+//!
+//!     // create a client
+//!     let channel = urpc::ClientChannel::new(dialer.connect()?);
+//!     let client = HelloClient::new(channel);
+//!     let greeting = client.hello("World".into()).await.unwrap();
+//!     assert_eq!(greeting, "Hello, World!");
+//!     Ok(())
+//! }
+//! ```
+
+use futures::{Sink, Stream};
+use tokio::sync::mpsc;
+
+use crate::protocol::RpcMessage;
+
+pub struct ChannelListener {
+    receiver: mpsc::UnboundedReceiver<Channel>,
+}
+
+impl Stream for ChannelListener {
+    type Item = std::io::Result<Channel>;
+
+    fn poll_next(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Option<Self::Item>> {
+        match self.get_mut().receiver.poll_recv(cx) {
+            std::task::Poll::Ready(Some(c)) => std::task::Poll::Ready(Some(Ok(c))),
+            std::task::Poll::Ready(None) => std::task::Poll::Ready(None),
+            std::task::Poll::Pending => std::task::Poll::Pending,
+        }
+    }
+}
+
+impl crate::Listener<Channel> for ChannelListener {}
+
+pub struct ChannelDialer {
+    sender: mpsc::UnboundedSender<Channel>,
+}
+
+impl ChannelDialer {
+    fn new() -> (Self, ChannelListener) {
+        let (sender, receiver) = mpsc::unbounded_channel();
+        (Self { sender }, ChannelListener { receiver })
+    }
+
+    pub fn connect(&self) -> std::io::Result<Channel> {
+        let (ch1, ch2) = Channel::new();
+        self.sender.send(ch1).expect("TODO: remove this");
+        Ok(ch2)
+    }
+}
+
+pub struct Channel {
+    sender: mpsc::UnboundedSender<RpcMessage>,
+    receiver: mpsc::UnboundedReceiver<RpcMessage>,
+}
+
+impl Channel {
+    fn new() -> (Self, Self) {
+        let (sender0, receiver0) = mpsc::unbounded_channel();
+        let (sender1, receiver1) = mpsc::unbounded_channel();
+        (
+            Self {
+                sender: sender0,
+                receiver: receiver1,
+            },
+            Self {
+                sender: sender1,
+                receiver: receiver0,
+            },
+        )
+    }
+}
+
+impl Stream for Channel {
+    type Item = std::io::Result<RpcMessage>;
+
+    fn poll_next(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Option<Self::Item>> {
+        match self.get_mut().receiver.poll_recv(cx) {
+            std::task::Poll::Ready(Some(msg)) => std::task::Poll::Ready(Some(Ok(msg))),
+            std::task::Poll::Ready(None) => std::task::Poll::Ready(None),
+            std::task::Poll::Pending => std::task::Poll::Pending,
+        }
+    }
+}
+
+impl Sink<RpcMessage> for Channel {
+    type Error = std::io::Error;
+
+    fn poll_ready(
+        self: std::pin::Pin<&mut Self>,
+        _cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Result<(), Self::Error>> {
+        return std::task::Poll::Ready(Ok(()));
+    }
+
+    fn start_send(self: std::pin::Pin<&mut Self>, item: RpcMessage) -> Result<(), Self::Error> {
+        match self.sender.send(item) {
+            Ok(()) => Ok(()),
+            Err(err) => Err(std::io::Error::other(err)),
+        }
+    }
+
+    fn poll_flush(
+        self: std::pin::Pin<&mut Self>,
+        _cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Result<(), Self::Error>> {
+        std::task::Poll::Ready(Ok(()))
+    }
+
+    fn poll_close(
+        self: std::pin::Pin<&mut Self>,
+        _cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Result<(), Self::Error>> {
+        std::task::Poll::Ready(Ok(()))
+    }
+}
+
+impl crate::Channel for Channel {}
+
+pub fn new() -> (ChannelDialer, ChannelListener) {
+    ChannelDialer::new()
+}
diff --git a/src/client_channel.rs b/src/client_channel.rs
new file mode 100644
index 0000000..5666a16
--- /dev/null
+++ b/src/client_channel.rs
@@ -0,0 +1,124 @@
+use std::{collections::HashMap, sync::Arc};
+
+use bytes::Bytes;
+use futures::{SinkExt, StreamExt};
+use tokio::{
+    sync::{mpsc, oneshot},
+    task::AbortHandle,
+};
+
+use crate::{
+    Channel,
+    protocol::{RpcCall, RpcMessage, RpcResponse},
+};
+
+const CLIENT_CHANNEL_BUFFER_SIZE: usize = 64;
+
+struct ClientChannelMessage {
+    service: String,
+    method: String,
+    arguments: Bytes,
+    responder: oneshot::Sender<std::io::Result<Bytes>>,
+}
+
+struct ClientChannelInner {
+    sender: mpsc::Sender<ClientChannelMessage>,
+    abort_handle: AbortHandle,
+}
+
+impl Drop for ClientChannelInner {
+    fn drop(&mut self) {
+        self.abort_handle.abort();
+    }
+}
+
+#[derive(Clone)]
+pub struct ClientChannel(Arc<ClientChannelInner>);
+
+impl ClientChannel {
+    pub fn new<C: Channel>(channel: C) -> Self {
+        let (tx, rx) = mpsc::channel(CLIENT_CHANNEL_BUFFER_SIZE);
+        let abort_handle = tokio::spawn(client_channel_loop(channel, rx)).abort_handle();
+        Self(Arc::new(ClientChannelInner {
+            sender: tx,
+            abort_handle,
+        }))
+    }
+
+    pub async fn call(
+        &self,
+        service: String,
+        method: String,
+        arguments: Bytes,
+    ) -> std::io::Result<Bytes> {
+        let (tx, rx) = oneshot::channel();
+        self.0
+            .sender
+            .send(ClientChannelMessage {
+                service,
+                method,
+                arguments,
+                responder: tx,
+            })
+            .await
+            .expect("client channel task should never shutdown while a client is alive");
+        rx.await
+            .expect("client channel task should never shutdown while a client is alive")
+    }
+}
+
+async fn client_channel_loop<C: Channel>(
+    mut channel: C,
+    mut rx: mpsc::Receiver<ClientChannelMessage>,
+) {
+    enum Select {
+        RpcMessage(RpcMessage),
+        ClientChannelMessage(ClientChannelMessage),
+    }
+
+    let mut responders = HashMap::<u64, oneshot::Sender<std::io::Result<Bytes>>>::default();
+    let mut rpc_call_id = 0;
+
+    loop {
+        let select = tokio::select! {
+            Some(Ok(v)) = channel.next() => Select::RpcMessage(v),
+            Some(v) = rx.recv() => Select::ClientChannelMessage(v),
+        };
+
+        match select {
+            Select::RpcMessage(RpcMessage::Response(RpcResponse { id, value })) => {
+                if let Some(responder) = responders.remove(&id) {
+                    let _ = responder.send(Ok(value));
+                }
+            }
+            Select::RpcMessage(_) => todo!(),
+            Select::ClientChannelMessage(ClientChannelMessage {
+                service,
+                method,
+                arguments,
+                responder,
+            }) => {
+                let id = rpc_call_id;
+                rpc_call_id += 1;
+
+                let result = channel
+                    .send(RpcMessage::Call(RpcCall {
+                        id,
+                        service,
+                        method,
+                        arguments,
+                    }))
+                    .await;
+
+                match result {
+                    Ok(()) => {
+                        responders.insert(id, responder);
+                    }
+                    Err(err) => {
+                        let _ = responder.send(Err(err));
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/src/internal.rs b/src/internal.rs
new file mode 100644
index 0000000..a3c203a
--- /dev/null
+++ b/src/internal.rs
@@ -0,0 +1,2 @@
+pub use bincode;
+pub use bytes;
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..e65f659
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,52 @@
+#[doc(hidden)]
+pub mod internal;
+
+pub mod channel;
+pub mod protocol;
+pub mod tcp;
+pub mod unix;
+
+mod client_channel;
+mod server;
+
+pub use client_channel::ClientChannel;
+pub use server::Server;
+pub use urpc_macro::service;
+
+use protocol::RpcMessage;
+
+use std::pin::Pin;
+use std::future::Future;
+
+use bytes::Bytes;
+use futures::{Sink, Stream};
+
+#[derive(Debug, Default)]
+pub struct Context;
+
+pub trait Service: Send + Sync + 'static {
+    fn name() -> &'static str
+    where
+        Self: Sized;
+
+    fn call(
+        &self,
+        method: String,
+        arguments: Bytes,
+    ) -> Pin<Box<dyn Future<Output = std::io::Result<Bytes>> + Send + '_>>;
+}
+
+pub trait Channel:
+    Stream<Item = std::io::Result<RpcMessage>>
+    + Sink<RpcMessage, Error = std::io::Error>
+    + Send
+    + Unpin
+    + 'static
+{
+}
+
+pub trait Listener<C>: Stream<Item = std::io::Result<C>> + Send + Unpin + 'static
+where
+    C: Channel,
+{
+}
diff --git a/src/protocol.rs b/src/protocol.rs
new file mode 100644
index 0000000..baf886b
--- /dev/null
+++ b/src/protocol.rs
@@ -0,0 +1,107 @@
+//! Types used by the RPC protocol.
+use bytes::Bytes;
+use serde::{Deserialize, Serialize};
+use tokio_util::codec::{Decoder, Encoder, LengthDelimitedCodec};
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct RpcCall {
+    pub id: u64,
+    pub service: String,
+    pub method: String,
+    pub arguments: Bytes,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct RpcCancel {
+    pub id: u64,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct RpcResponse {
+    pub id: u64,
+    pub value: Bytes,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub enum RpcMessage {
+    Call(RpcCall),
+    Response(RpcResponse),
+    Cancel(RpcCancel),
+}
+
+#[derive(Debug)]
+pub enum RpcError<E> {
+    Transport(std::io::Error),
+    Remote(E),
+}
+
+impl<E> std::fmt::Display for RpcError<E>
+where
+    E: std::fmt::Display,
+{
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            RpcError::Transport(error) => write!(f, "transport error: {error}"),
+            RpcError::Remote(error) => write!(f, "remote error: {error}"),
+        }
+    }
+}
+
+impl<E> std::error::Error for RpcError<E>
+where
+    E: std::error::Error,
+{
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        match self {
+            RpcError::Transport(error) => error.source(),
+            RpcError::Remote(error) => error.source(),
+        }
+    }
+}
+
+impl<E> From<std::io::Error> for RpcError<E> {
+    fn from(value: std::io::Error) -> Self {
+        Self::Transport(value)
+    }
+}
+
+#[derive(Default)]
+pub struct RpcMessageCodec(LengthDelimitedCodec);
+
+impl Encoder<RpcMessage> for RpcMessageCodec {
+    type Error = std::io::Error;
+
+    fn encode(
+        &mut self,
+        item: RpcMessage,
+        dst: &mut bytes::BytesMut,
+    ) -> std::result::Result<(), Self::Error> {
+        let encoded = bincode::serde::encode_to_vec(&item, bincode::config::standard())
+            .map_err(std::io::Error::other)?;
+        let encoded = Bytes::from(encoded);
+        self.0.encode(encoded, dst).map_err(std::io::Error::other)?;
+        Ok(())
+    }
+}
+
+impl Decoder for RpcMessageCodec {
+    type Item = RpcMessage;
+
+    type Error = std::io::Error;
+
+    fn decode(
+        &mut self,
+        src: &mut bytes::BytesMut,
+    ) -> std::result::Result<Option<Self::Item>, Self::Error> {
+        match self.0.decode(src) {
+            Ok(Some(frame)) => {
+                let (message, _) =
+                    bincode::serde::decode_from_slice(&frame, bincode::config::standard())
+                        .map_err(std::io::Error::other)?;
+                Ok(Some(message))
+            }
+            Ok(None) => Ok(None),
+            Err(err) => Err(std::io::Error::other(err)),
+        }
+    }
+}
diff --git a/src/server.rs b/src/server.rs
new file mode 100644
index 0000000..414340e
--- /dev/null
+++ b/src/server.rs
@@ -0,0 +1,166 @@
+use std::{collections::HashMap, sync::Arc};
+
+use futures::{SinkExt, StreamExt};
+use tokio::task::{AbortHandle, JoinSet};
+
+use crate::{
+    Channel, Listener, Service,
+    protocol::{RpcCall, RpcCancel, RpcMessage, RpcResponse},
+};
+
+#[derive(Clone)]
+struct Services(Arc<HashMap<String, Arc<dyn Service>>>);
+
+impl Services {
+    fn new(services: HashMap<String, Arc<dyn Service>>) -> Self {
+        Self(Arc::new(services))
+    }
+
+    fn get_service(&self, name: &str) -> std::io::Result<Arc<dyn Service>> {
+        match self.0.get(name) {
+            Some(service) => Ok(service.clone()),
+            None => Err(std::io::Error::new(
+                std::io::ErrorKind::NotFound,
+                "service not found",
+            )),
+        }
+    }
+}
+
+type ListenerSpawner =
+    Box<dyn FnOnce(&mut JoinSet<std::io::Result<()>>, Services) -> AbortHandle + Send + 'static>;
+
+#[derive(Debug, Default)]
+struct AbortHandles(Vec<AbortHandle>);
+
+impl Drop for AbortHandles {
+    fn drop(&mut self) {
+        for handle in &self.0 {
+            handle.abort();
+        }
+    }
+}
+
+impl AbortHandles {
+    pub fn push(&mut self, handle: AbortHandle) {
+        self.0.push(handle);
+    }
+}
+
+#[derive(Default)]
+pub struct Server {
+    services: HashMap<String, Arc<dyn Service>>,
+    listener_spawners: Vec<ListenerSpawner>,
+}
+
+impl Server {
+    pub fn with_service<T>(mut self, service: T) -> Self
+    where
+        T: Service,
+    {
+        let name = T::name();
+        let service = Arc::new(service);
+        self.services.insert(name.to_string(), service);
+        self
+    }
+
+    pub fn with_listener<L, C>(mut self, listener: L) -> Self
+    where
+        C: Channel,
+        L: Listener<C>,
+    {
+        self.listener_spawners
+            .push(Box::new(move |join_set, services| {
+                join_set.spawn(listener_loop(listener, services))
+            }));
+        self
+    }
+
+    pub async fn serve(self) -> std::io::Result<()> {
+        let services = Services::new(self.services);
+        let mut join_set = JoinSet::default();
+        let mut abort_handles = AbortHandles::default();
+        for spawner in self.listener_spawners {
+            let abort_handle = (spawner)(&mut join_set, services.clone());
+            abort_handles.push(abort_handle);
+        }
+        match join_set.join_next().await {
+            Some(Ok(Ok(()))) => Ok(()),
+            Some(Ok(Err(err))) => Err(err),
+            Some(Err(err)) => Err(std::io::Error::other(err)),
+            None => Ok(()),
+        }
+    }
+}
+
+async fn listener_loop<L, C>(mut listener: L, services: Services) -> std::io::Result<()>
+where
+    C: Channel,
+    L: Listener<C>,
+{
+    while let Some(result) = listener.next().await {
+        let channel = result?;
+        let services = services.clone();
+        tokio::spawn(channel_handler(channel, services));
+    }
+    Ok(())
+}
+
+async fn channel_handler<C: Channel>(mut channel: C, services: Services) -> std::io::Result<()> {
+    enum Select {
+        Empty,
+        Message(RpcMessage),
+    }
+
+    let (response_tx, mut response_rx) =
+        tokio::sync::mpsc::unbounded_channel::<std::io::Result<RpcResponse>>();
+    let mut requests: HashMap<u64, AbortHandle> = Default::default();
+    loop {
+        let select = tokio::select! {
+            reqopt = channel.next() => match reqopt {
+                Some(Ok(message)) => Select::Message(message),
+                Some(Err(err)) => return Err(err),
+                None => Select::Empty,
+            },
+            Some(response) = response_rx.recv() => match response {
+                Ok(response) => Select::Message(RpcMessage::Response(response)),
+                Err(err) => return Err(err),
+            }
+        };
+
+        match select {
+            Select::Empty => break,
+            Select::Message(message) => match message {
+                RpcMessage::Call(RpcCall {
+                    id,
+                    service,
+                    method,
+                    arguments,
+                }) => {
+                    let response_tx = response_tx.clone();
+                    let service = services.get_service(&service)?;
+                    let handle = tokio::spawn(async move {
+                        let response = match service.call(method, arguments).await {
+                            Ok(value) => Ok(RpcResponse { id, value }),
+                            Err(err) => Err(err),
+                        };
+                        let _ = response_tx.send(response);
+                    })
+                    .abort_handle();
+                    requests.insert(id, handle);
+                }
+                RpcMessage::Cancel(RpcCancel { id }) => {
+                    if let Some(handle) = requests.remove(&id) {
+                        handle.abort();
+                    }
+                }
+                RpcMessage::Response(response) => {
+                    requests.remove(&response.id);
+                    channel.send(RpcMessage::Response(response)).await?;
+                }
+            },
+        }
+    }
+
+    Ok(())
+}
diff --git a/src/tcp.rs b/src/tcp.rs
new file mode 100644
index 0000000..5684c41
--- /dev/null
+++ b/src/tcp.rs
@@ -0,0 +1,156 @@
+//! TCP backed channel and listener implementations.
+//!
+//! ```no_run
+//! #[urpc::service]
+//! trait Hello {
+//!     type Error = ();
+//!
+//!     async fn hello(name: String) -> String;
+//! }
+//!
+//! struct HelloServer;
+//!
+//! impl Hello for HelloServer {
+//!     async fn hello(&self, _ctx: urpc::Context, name: String) -> Result<String, ()> {
+//!         Ok(format!("Hello, {name}!"))
+//!     }
+//! }
+//!
+//! #[tokio::main]
+//! async fn main() -> Result<(), Box<dyn std::error::Error>>{
+//!     let listener = urpc::tcp::bind("0.0.0.0:3000").await?;
+//!
+//!     // spawn the server
+//!     tokio::spawn(async move {
+//!         urpc::Server::default()
+//!             .with_listener(listener)
+//!             .with_service(HelloServer.into_service())
+//!             .serve()
+//!             .await
+//!     });
+//!
+//!     // create a client
+//!     let channel = urpc::ClientChannel::new(urpc::tcp::connect("127.0.0.1:3000").await?);
+//!     let client = HelloClient::new(channel);
+//!     let greeting = client.hello("World".into()).await.unwrap();
+//!     assert_eq!(greeting, "Hello, World!");
+//!     Ok(())
+//! }
+//! ```
+use std::pin::Pin;
+
+use futures::{Sink, Stream};
+use tokio::{
+    net::{TcpListener, TcpStream, ToSocketAddrs},
+    sync::mpsc::Receiver,
+    task::AbortHandle,
+};
+use tokio_util::codec::Framed;
+
+use crate::{
+    Channel, Listener,
+    protocol::{RpcMessage, RpcMessageCodec},
+};
+
+pub struct TcpChannel(Framed<TcpStream, RpcMessageCodec>);
+
+impl TcpChannel {
+    fn new(stream: TcpStream) -> Self {
+        Self(Framed::new(stream, RpcMessageCodec::default()))
+    }
+
+    pub async fn connect(addrs: impl ToSocketAddrs) -> std::io::Result<Self> {
+        let stream = TcpStream::connect(addrs).await?;
+        Ok(Self::new(stream))
+    }
+}
+
+impl Sink<RpcMessage> for TcpChannel {
+    type Error = std::io::Error;
+
+    fn poll_ready(
+        self: Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<std::result::Result<(), Self::Error>> {
+        Sink::poll_ready(Pin::new(&mut self.get_mut().0), cx)
+    }
+
+    fn start_send(self: Pin<&mut Self>, item: RpcMessage) -> std::result::Result<(), Self::Error> {
+        Sink::start_send(Pin::new(&mut self.get_mut().0), item)
+    }
+
+    fn poll_flush(
+        self: Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<std::result::Result<(), Self::Error>> {
+        Sink::poll_flush(Pin::new(&mut self.get_mut().0), cx)
+    }
+
+    fn poll_close(
+        self: Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<std::result::Result<(), Self::Error>> {
+        Sink::poll_close(Pin::new(&mut self.get_mut().0), cx)
+    }
+}
+
+impl Stream for TcpChannel {
+    type Item = std::io::Result<RpcMessage>;
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Option<Self::Item>> {
+        Stream::poll_next(Pin::new(&mut self.get_mut().0), cx)
+    }
+}
+
+impl Channel for TcpChannel {}
+
+pub struct TcpChannelListener {
+    receiver: Receiver<TcpChannel>,
+    abort: AbortHandle,
+}
+
+impl Drop for TcpChannelListener {
+    fn drop(&mut self) {
+        self.abort.abort();
+    }
+}
+
+impl TcpChannelListener {
+    pub async fn bind(addrs: impl ToSocketAddrs) -> std::io::Result<Self> {
+        let listener = TcpListener::bind(addrs).await?;
+        let (sender, receiver) = tokio::sync::mpsc::channel(8);
+        let abort = tokio::spawn(async move {
+            while let Ok((stream, _addr)) = listener.accept().await {
+                if sender.send(TcpChannel::new(stream)).await.is_err() {
+                    break;
+                }
+            }
+        })
+        .abort_handle();
+        Ok(Self { receiver, abort })
+    }
+}
+
+impl Stream for TcpChannelListener {
+    type Item = std::io::Result<TcpChannel>;
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Option<Self::Item>> {
+        self.get_mut().receiver.poll_recv(cx).map(|v| v.map(Ok))
+    }
+}
+
+impl Listener<TcpChannel> for TcpChannelListener {}
+
+pub async fn bind(addrs: impl ToSocketAddrs) -> std::io::Result<TcpChannelListener> {
+    TcpChannelListener::bind(addrs).await
+}
+
+pub async fn connect(addrs: impl ToSocketAddrs) -> std::io::Result<TcpChannel> {
+    TcpChannel::connect(addrs).await
+}
diff --git a/src/unix.rs b/src/unix.rs
new file mode 100644
index 0000000..e241b64
--- /dev/null
+++ b/src/unix.rs
@@ -0,0 +1,160 @@
+//! UNIX Domain Socket backed channel and listener implementations.
+//!
+//! ```no_run
+//! #[urpc::service]
+//! trait Hello {
+//!     type Error = ();
+//!
+//!     async fn hello(name: String) -> String;
+//! }
+//!
+//! struct HelloServer;
+//!
+//! impl Hello for HelloServer {
+//!     async fn hello(&self, _ctx: urpc::Context, name: String) -> Result<String, ()> {
+//!         Ok(format!("Hello, {name}!"))
+//!     }
+//! }
+//!
+//! #[tokio::main]
+//! async fn main() -> Result<(), Box<dyn std::error::Error>>{
+//!     let listener = urpc::unix::bind("./hello.service").await?;
+//!
+//!     // spawn the server
+//!     tokio::spawn(async move {
+//!         urpc::Server::default()
+//!             .with_listener(listener)
+//!             .with_service(HelloServer.into_service())
+//!             .serve()
+//!             .await
+//!     });
+//!
+//!     // create a client
+//!     let channel = urpc::ClientChannel::new(urpc::unix::connect("./hello.service").await?);
+//!     let client = HelloClient::new(channel);
+//!     let greeting = client.hello("World".into()).await.unwrap();
+//!     assert_eq!(greeting, "Hello, World!");
+//!     Ok(())
+//! }
+//! ```
+use std::{path::Path, pin::Pin};
+
+use futures::{Sink, Stream};
+use tokio::{
+    net::{UnixListener, UnixStream},
+    sync::mpsc::Receiver,
+    task::AbortHandle,
+};
+use tokio_util::codec::Framed;
+
+use crate::{
+    Channel, Listener,
+    protocol::{RpcMessage, RpcMessageCodec},
+};
+
+pub struct UnixChannel(Framed<UnixStream, RpcMessageCodec>);
+
+impl UnixChannel {
+    fn new(stream: UnixStream) -> Self {
+        Self(Framed::new(stream, RpcMessageCodec::default()))
+    }
+
+    pub async fn connect(path: impl AsRef<Path>) -> std::io::Result<Self> {
+        let stream = UnixStream::connect(path).await?;
+        Ok(Self::new(stream))
+    }
+}
+
+impl Sink<RpcMessage> for UnixChannel {
+    type Error = std::io::Error;
+
+    fn poll_ready(
+        self: Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<std::result::Result<(), Self::Error>> {
+        Sink::poll_ready(Pin::new(&mut self.get_mut().0), cx)
+    }
+
+    fn start_send(self: Pin<&mut Self>, item: RpcMessage) -> std::result::Result<(), Self::Error> {
+        Sink::start_send(Pin::new(&mut self.get_mut().0), item)
+    }
+
+    fn poll_flush(
+        self: Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<std::result::Result<(), Self::Error>> {
+        Sink::poll_flush(Pin::new(&mut self.get_mut().0), cx)
+    }
+
+    fn poll_close(
+        self: Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<std::result::Result<(), Self::Error>> {
+        Sink::poll_close(Pin::new(&mut self.get_mut().0), cx)
+    }
+}
+
+impl Stream for UnixChannel {
+    type Item = std::io::Result<RpcMessage>;
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Option<Self::Item>> {
+        Stream::poll_next(Pin::new(&mut self.get_mut().0), cx)
+    }
+}
+
+impl Channel for UnixChannel {}
+
+pub struct UnixChannelListener {
+    receiver: Receiver<UnixChannel>,
+    abort: AbortHandle,
+}
+
+impl Drop for UnixChannelListener {
+    fn drop(&mut self) {
+        self.abort.abort();
+    }
+}
+
+impl UnixChannelListener {
+    pub async fn bind(path: impl AsRef<Path>) -> std::io::Result<Self> {
+        let path = path.as_ref();
+        if tokio::fs::try_exists(path).await? {
+            tokio::fs::remove_file(path).await?;
+        }
+        let listener = UnixListener::bind(path)?;
+        let (sender, receiver) = tokio::sync::mpsc::channel(8);
+        let abort = tokio::spawn(async move {
+            while let Ok((stream, _addr)) = listener.accept().await {
+                if sender.send(UnixChannel::new(stream)).await.is_err() {
+                    break;
+                }
+            }
+        })
+        .abort_handle();
+        Ok(Self { receiver, abort })
+    }
+}
+
+impl Stream for UnixChannelListener {
+    type Item = std::io::Result<UnixChannel>;
+
+    fn poll_next(
+        self: Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Option<Self::Item>> {
+        self.get_mut().receiver.poll_recv(cx).map(|v| v.map(Ok))
+    }
+}
+
+impl Listener<UnixChannel> for UnixChannelListener {}
+
+pub async fn bind(path: impl AsRef<Path>) -> std::io::Result<UnixChannelListener> {
+    UnixChannelListener::bind(path).await
+}
+
+pub async fn connect(path: impl AsRef<Path>) -> std::io::Result<UnixChannel> {
+    UnixChannel::connect(path).await
+}