Add UDP multicast simulation

examples/udp_vpv4_multicast/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "udp_ipv4_multicast"
+version = "0.1.0"
+edition = "2024"
+publish = false
+
+[dependencies]
+tokio = "1"
+turmoil = { path = "../.." }
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }

examples/udp_vpv4_multicast/src/main.rs

@@ -0,0 +1,56 @@
+use std::{net::Ipv4Addr, time::Duration};
+use tracing::info;
+use turmoil::{IpVersion, net::UdpSocket};
+
+const N_STEPS: usize = 3;
+
+fn main() {
+    tracing_subscriber::fmt()
+        .with_env_filter(
+            tracing_subscriber::EnvFilter::builder()
+                .with_default_directive(tracing::level_filters::LevelFilter::INFO.into())
+                .from_env_lossy(),
+        )
+        .init();
+
+    let tick = Duration::from_millis(100);
+    let mut sim = turmoil::Builder::new()
+        .tick_duration(tick)
+        .ip_version(IpVersion::V4)
+        .build();
+
+    let server_port = 9000;
+    let multicast_group = "239.0.0.1".parse().unwrap();
+
+    for server_index in 0..2 {
+        sim.client(format!("server-{server_index}"), async move {
+            let socket = UdpSocket::bind((Ipv4Addr::UNSPECIFIED, server_port)).await?;
+            socket.join_multicast_v4(multicast_group, Ipv4Addr::UNSPECIFIED)?;
+
+            let mut buf = [0; 1024];
+            for _ in 0..N_STEPS {
+                let (n, addr) = socket.recv_from(&mut buf).await?;
+                let data = &buf[0..n];
+
+                info!("UDP packet from {} has been received: {:?}", addr, data);
+            }
+            Ok(())
+        });
+    }
+
+    sim.client("client", async move {
+        let socket = UdpSocket::bind((Ipv4Addr::UNSPECIFIED, 0)).await?;
+        let dst = (multicast_group, server_port);
+
+        for _ in 0..N_STEPS {
+            let _ = socket.send_to(&[1, 2, 3], dst).await?;
+            info!("UDP packet has been sent");
+
+            tokio::time::sleep(tick).await;
+        }
+
+        Ok(())
+    });
+
+    sim.run().unwrap();
+}

examples/udp_vpv6_multicast/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "udp_ipv6_multicast"
+version = "0.1.0"
+edition = "2024"
+publish = false
+
+[dependencies]
+tokio = "1"
+turmoil = { path = "../.." }
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }

examples/udp_vpv6_multicast/src/main.rs

@@ -0,0 +1,56 @@
+use std::{net::Ipv6Addr, time::Duration};
+use tracing::info;
+use turmoil::{IpVersion, net::UdpSocket};
+
+const N_STEPS: usize = 3;
+
+fn main() {
+    tracing_subscriber::fmt()
+        .with_env_filter(
+            tracing_subscriber::EnvFilter::builder()
+                .with_default_directive(tracing::level_filters::LevelFilter::INFO.into())
+                .from_env_lossy(),
+        )
+        .init();
+
+    let tick = Duration::from_millis(100);
+    let mut sim = turmoil::Builder::new()
+        .tick_duration(tick)
+        .ip_version(IpVersion::V6)
+        .build();
+
+    let server_port = 9000;
+    let multicast_group = "ff08::1".parse().unwrap();
+
+    for host_index in 0..2 {
+        sim.client(format!("server-{host_index}"), async move {
+            let socket = UdpSocket::bind((Ipv6Addr::UNSPECIFIED, server_port)).await?;
+            socket.join_multicast_v6(&multicast_group, 0)?;
+
+            let mut buf = [0; 1024];
+            for _ in 0..N_STEPS {
+                let (n, addr) = socket.recv_from(&mut buf).await?;
+                let data = &buf[0..n];
+
+                info!("UDP packet from {} has been received: {:?}", addr, data);
+            }
+            Ok(())
+        });
+    }
+
+    sim.client("client", async move {
+        let socket = UdpSocket::bind((Ipv6Addr::UNSPECIFIED, 0)).await?;
+        let dst = (multicast_group, server_port);
+
+        for _ in 0..N_STEPS {
+            let _ = socket.send_to(&[1, 2, 3], dst).await?;
+            info!("UDP packet has been sent");
+
+            tokio::time::sleep(tick).await;
+        }
+
+        Ok(())
+    });
+
+    sim.run().unwrap();
+}

src/envelope.rs

@@ -18,7 +18,7 @@ pub enum Protocol {
 }
 
 /// UDP datagram.
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Datagram(pub Bytes);
 
 /// This is a simplification of real TCP.

src/net/mod.rs

@@ -8,7 +8,7 @@ use std::net::SocketAddr;
 pub mod tcp;
 pub use tcp::{listener::TcpListener, stream::TcpStream};
 
-mod udp;
+pub(crate) mod udp;
 pub use udp::UdpSocket;
 
 #[derive(Debug, Copy, Clone, Hash, Eq, PartialEq)]