chore(msg-sim,linux): spin up loopback device on namespaced environment

msg-sim/src/lib.rs

@@ -195,6 +195,22 @@ impl Simulation {
  .status()?;
  assert_status(status, "Failed to set up the namespaced veth device")?;
 
+ // Spin up also the loopback interface on namespaced environment
+ let status = Command::new("sudo")
+ .args([
+ "ip",
+ "netns",
+ "exec",
+ &network_namespace,
+ "ip",
+ "link",
+ "set",
+ "lo",
+ "up",
+ ])
+ .status()?;
+ assert_status(status, "Failed to set up the namespaced loopback device")?;
+
  // Add network emulation parameters (delay, loss) on namespaced veth device
  //
  // The behaviour is specified on the top-level ("root"),
@@ -348,11 +364,11 @@ mod test {
  #[test]
  fn start_simulation() {
  let config = SimulationConfig {
- latency: Some(Duration::new(3, 0)),
+ latency: Some(Duration::new(0, 5_000_000)),
  bw: Some(1_000),
  burst: Some(32),
  limit: None,
- plr: Some(50_f64),
+ plr: Some(10_f64),
  protocols: vec![Protocol::TCP],
  };
  let simulation = Simulation::new(1, IpAddr::V4(Ipv4Addr::new(192, 168, 1, 1)), config);