udp echo server example

Cargo.toml

@@ -30,6 +30,7 @@ members = [
   "tls",
   "rustls",
   "unix-socket",
+  "udp-echo",
   "web-cors/backend",
   "websocket",
   "websocket-chat",

udp-echo/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "udp-echo"
+version = "0.1.0"
+authors = ["Anton Patrushev <apatrushev@gmail.com>"]
+edition = "2018"
+
+[dependencies]
+actix = "0.7"
+tokio = "*"
+futures = "*"
+bytes = "*"

udp-echo/README.md

@@ -0,0 +1,18 @@
+# udp-echo
+
+## Usage
+
+### server
+
+```bash
+cd examples/udp-echo
+cargo run
+# Started http server: 127.0.0.1:12345
+```
+
+### socat client
+Copy port provided in server output and run following command to communicate
+with the udp server:
+```bash
+socat - UDP4:localhost:12345
+```

udp-echo/src/main.rs

@@ -0,0 +1,47 @@
+extern crate actix;
+extern crate bytes;
+extern crate futures;
+extern crate tokio;
+
+use actix::{Actor, AsyncContext, Context, Message, StreamHandler};
+use bytes::BytesMut;
+use futures::stream::SplitSink;
+use futures::{Future, Sink, Stream};
+use std::net::SocketAddr;
+use tokio::codec::BytesCodec;
+use tokio::net::{UdpFramed, UdpSocket};
+
+struct UdpActor {
+    sink: SplitSink<UdpFramed<BytesCodec>>,
+}
+impl Actor for UdpActor {
+    type Context = Context<Self>;
+}
+
+#[derive(Message)]
+struct UdpPacket(BytesMut, SocketAddr);
+impl StreamHandler<UdpPacket, std::io::Error> for UdpActor {
+    fn handle(&mut self, msg: UdpPacket, _: &mut Context<Self>) {
+        println!("Received: ({:?}, {:?})", msg.0, msg.1);
+        (&mut self.sink).send((msg.0.into(), msg.1)).wait().unwrap();
+    }
+}
+
+fn main() {
+    let sys = actix::System::new("echo-udp");
+
+    let addr: SocketAddr = "127.0.0.1:0".parse().unwrap();
+    let sock = UdpSocket::bind(&addr).unwrap();
+    println!(
+        "Started udp server on: 127.0.0.1:{:?}",
+        sock.local_addr().unwrap().port()
+    );
+
+    let (sink, stream) = UdpFramed::new(sock, BytesCodec::new()).split();
+    UdpActor::create(|ctx| {
+        ctx.add_stream(stream.map(|(data, sender)| UdpPacket(data, sender)));
+        UdpActor { sink: sink }
+    });
+
+    std::process::exit(sys.run());
+}