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use crate::{
client::Session,
constants::CLIENT_BROADCAST_CHANNEL_CAPACITY,
data::{Request, RequestData, Response, ResponseData},
net::{DataStream, Transport, TransportReadHalf, TransportWriteHalf},
server::utils::{ConnTracker, ShutdownTask},
};
use futures::stream::{Stream, StreamExt};
use log::*;
use std::{collections::HashMap, marker::Unpin, sync::Arc};
use tokio::{
io::{self, AsyncRead, AsyncWrite},
sync::{mpsc, oneshot, Mutex},
task::{JoinError, JoinHandle},
time::Duration,
};
pub struct RelayServer {
accept_task: JoinHandle<()>,
broadcast_task: JoinHandle<()>,
forward_task: JoinHandle<()>,
conns: Arc<Mutex<HashMap<usize, Conn>>>,
}
impl RelayServer {
pub fn initialize<T1, T2, S>(
mut session: Session<T1>,
mut stream: S,
shutdown_after: Option<Duration>,
) -> io::Result<Self>
where
T1: DataStream + 'static,
T2: DataStream + Send + 'static,
S: Stream<Item = Transport<T2>> + Send + Unpin + 'static,
{
let conns: Arc<Mutex<HashMap<usize, Conn>>> = Arc::new(Mutex::new(HashMap::new()));
let conns_2 = Arc::clone(&conns);
debug!("Spawning response broadcast task");
let mut broadcast = session.broadcast.take().unwrap();
let (shutdown_broadcast_tx, mut shutdown_broadcast_rx) = mpsc::channel::<()>(1);
let broadcast_task = tokio::spawn(async move {
loop {
let res = tokio::select! {
maybe_res = broadcast.recv() => {
match maybe_res {
Some(res) => res,
None => break,
}
}
_ = shutdown_broadcast_rx.recv() => {
break;
}
};
for conn in conns_2.lock().await.values_mut() {
if conn.state.lock().await.tenant.as_deref() == Some(res.tenant.as_str()) {
debug!(
"Forwarding response of type{} {} to connection {}",
if res.payload.len() > 1 { "s" } else { "" },
res.to_payload_type_string(),
conn.id
);
if let Err(x) = conn.forward_response(res).await {
error!("Failed to pass forwarding message: {}", x);
}
break;
}
}
}
});
debug!("Spawning request forwarding task");
let (req_tx, mut req_rx) = mpsc::channel::<Request>(CLIENT_BROADCAST_CHANNEL_CAPACITY);
let (shutdown_forward_tx, mut shutdown_forward_rx) = mpsc::channel::<()>(1);
let forward_task = tokio::spawn(async move {
loop {
let req = tokio::select! {
maybe_req = req_rx.recv() => {
match maybe_req {
Some(req) => req,
None => break,
}
}
_ = shutdown_forward_rx.recv() => {
break;
}
};
debug!(
"Forwarding request of type{} {} to server",
if req.payload.len() > 1 { "s" } else { "" },
req.to_payload_type_string()
);
if let Err(x) = session.fire(req).await {
error!("Session failed to send request: {:?}", x);
break;
}
}
});
let (shutdown, tracker) = ShutdownTask::maybe_initialize(shutdown_after);
let conns_2 = Arc::clone(&conns);
let accept_task = tokio::spawn(async move {
let inner = async move {
loop {
match stream.next().await {
Some(transport) => {
let result = Conn::initialize(
transport,
req_tx.clone(),
tracker.as_ref().map(Arc::clone),
)
.await;
match result {
Ok(conn) => {
conns_2.lock().await.insert(conn.id(), conn);
}
Err(x) => {
error!("Failed to initialize connection: {}", x);
}
};
}
None => {
info!("Listener shutting down");
break;
}
};
}
};
match shutdown {
Some(shutdown) => tokio::select! {
_ = inner => {}
_ = shutdown => {
warn!("Reached shutdown timeout, so terminating");
}
},
None => inner.await,
}
drop(shutdown_broadcast_tx);
drop(shutdown_forward_tx);
});
Ok(Self {
accept_task,
broadcast_task,
forward_task,
conns,
})
}
pub async fn wait(self) -> Result<(), JoinError> {
match tokio::try_join!(self.accept_task, self.broadcast_task, self.forward_task) {
Ok(_) => Ok(()),
Err(x) => Err(x),
}
}
pub async fn abort(&self) {
self.accept_task.abort();
self.broadcast_task.abort();
self.forward_task.abort();
self.conns
.lock()
.await
.values()
.for_each(|conn| conn.abort());
}
}
struct Conn {
id: usize,
req_task: JoinHandle<()>,
res_task: JoinHandle<()>,
_cleanup_task: JoinHandle<()>,
res_tx: mpsc::Sender<Response>,
state: Arc<Mutex<ConnState>>,
}
#[derive(Default)]
struct ConnState {
tenant: Option<String>,
processes: Vec<usize>,
}
impl Conn {
pub async fn initialize<T>(
transport: Transport<T>,
req_tx: mpsc::Sender<Request>,
ct: Option<Arc<Mutex<ConnTracker>>>,
) -> io::Result<Self>
where
T: DataStream + 'static,
{
let id: usize = rand::random();
let (t_read, t_write) = transport.into_split();
let (tenant_tx, tenant_rx) = oneshot::channel();
debug!("<Conn @ {}> Initializing internal state", id);
let state = Arc::new(Mutex::new(ConnState::default()));
if let Some(ct) = ct.as_ref() {
ct.lock().await.increment();
}
let (res_tx, res_rx) = mpsc::channel::<Response>(CLIENT_BROADCAST_CHANNEL_CAPACITY);
let (res_task_tx, res_task_rx) = oneshot::channel();
let state_2 = Arc::clone(&state);
let res_task = tokio::spawn(async move {
handle_conn_outgoing(id, state_2, t_write, tenant_rx, res_rx).await;
let _ = res_task_tx.send(());
});
let req_tx = req_tx.clone();
let (req_task_tx, req_task_rx) = oneshot::channel();
let state_2 = Arc::clone(&state);
let req_task = tokio::spawn(async move {
handle_conn_incoming(id, state_2, t_read, tenant_tx, req_tx).await;
let _ = req_task_tx.send(());
});
let _cleanup_task = tokio::spawn(async move {
let _ = tokio::join!(req_task_rx, res_task_rx);
if let Some(ct) = ct.as_ref() {
ct.lock().await.decrement();
}
debug!("<Conn @ {}> Disconnected", id);
});
Ok(Self {
id,
req_task,
res_task,
_cleanup_task,
res_tx,
state,
})
}
pub fn id(&self) -> usize {
self.id
}
pub fn abort(&self) {
self.req_task.abort();
self.res_task.abort();
}
pub async fn forward_response(
&mut self,
res: Response,
) -> Result<(), mpsc::error::SendError<Response>> {
self.res_tx.send(res).await
}
}
async fn handle_conn_incoming<T>(
conn_id: usize,
state: Arc<Mutex<ConnState>>,
mut reader: TransportReadHalf<T>,
tenant_tx: oneshot::Sender<String>,
req_tx: mpsc::Sender<Request>,
) where
T: AsyncRead + Unpin,
{
macro_rules! process_req {
($on_success:expr; $done:expr) => {
match reader.receive::<Request>().await {
Ok(Some(req)) => {
$on_success(&req);
if let Err(x) = req_tx.send(req).await {
error!(
"Failed to pass along request received on unix socket: {:?}",
x
);
$done;
}
}
Ok(None) => $done,
Err(x) => {
error!("Failed to receive request from unix stream: {:?}", x);
$done;
}
}
};
}
let mut tenant = None;
process_req!(
|req: &Request| {
tenant = Some(req.tenant.clone());
if let Err(x) = tenant_tx.send(req.tenant.clone()) {
error!("Failed to send along acquired tenant name: {:?}", x);
return;
}
};
return
);
loop {
process_req!(|_| {}; break);
}
let tenant = tenant.unwrap();
if let Err(x) = req_tx
.send(Request::new(
tenant.clone(),
state
.lock()
.await
.processes
.iter()
.map(|id| RequestData::ProcKill { id: *id })
.collect(),
))
.await
{
error!("<Conn @ {}> Failed to send kill signals: {}", conn_id, x);
}
}
async fn handle_conn_outgoing<T>(
conn_id: usize,
state: Arc<Mutex<ConnState>>,
mut writer: TransportWriteHalf<T>,
tenant_rx: oneshot::Receiver<String>,
mut res_rx: mpsc::Receiver<Response>,
) where
T: AsyncWrite + Unpin,
{
if let Ok(tenant) = tenant_rx.await {
debug!("Associated tenant {} with conn {}", tenant, conn_id);
state.lock().await.tenant = Some(tenant.clone());
while let Some(res) = res_rx.recv().await {
debug!(
"Conn {} being sent response of type{} {}",
conn_id,
if res.payload.len() > 1 { "s" } else { "" },
res.to_payload_type_string(),
);
let ids = res.payload.iter().filter_map(|x| match x {
ResponseData::ProcStart { id } => Some(*id),
_ => None,
});
for id in ids {
debug!("Tracking proc {} for conn {}", id, conn_id);
state.lock().await.processes.push(id);
}
if let Err(x) = writer.send(res).await {
error!("Failed to send response through unix connection: {}", x);
break;
}
}
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::net::InmemoryStream;
use std::{pin::Pin, time::Duration};
fn make_session() -> (Transport<InmemoryStream>, Session<InmemoryStream>) {
let (t1, t2) = Transport::make_pair();
(t1, Session::initialize(t2).unwrap())
}
#[allow(clippy::type_complexity)]
fn make_transport_stream() -> (
mpsc::Sender<Transport<InmemoryStream>>,
Pin<Box<dyn Stream<Item = Transport<InmemoryStream>> + Send>>,
) {
let (tx, rx) = mpsc::channel::<Transport<InmemoryStream>>(1);
let stream = futures::stream::unfold(rx, |mut rx| async move {
rx.recv().await.map(move |transport| (transport, rx))
});
(tx, Box::pin(stream))
}
#[tokio::test]
async fn wait_should_return_ok_when_all_inner_tasks_complete() {
let (transport, session) = make_session();
let (tx, stream) = make_transport_stream();
let server = RelayServer::initialize(session, stream, None).unwrap();
drop(transport);
drop(tx);
let result = server.wait().await;
assert!(result.is_ok(), "Unexpected result: {:?}", result);
}
#[tokio::test]
async fn wait_should_return_error_when_server_aborted() {
let (_transport, session) = make_session();
let (_tx, stream) = make_transport_stream();
let server = RelayServer::initialize(session, stream, None).unwrap();
server.abort().await;
match server.wait().await {
Err(x) if x.is_cancelled() => {}
x => panic!("Unexpected result: {:?}", x),
}
}
#[tokio::test]
async fn server_should_forward_requests_using_session() {
let (mut transport, session) = make_session();
let (tx, stream) = make_transport_stream();
let _server = RelayServer::initialize(session, stream, None).unwrap();
let (mut t1, t2) = Transport::make_pair();
tx.send(t2).await.unwrap();
let req = Request::new("test-tenant", vec![RequestData::SystemInfo {}]);
t1.send(req.clone()).await.unwrap();
let outbound_req = transport.receive().await.unwrap().unwrap();
assert_eq!(req, outbound_req);
}
#[tokio::test]
async fn server_should_send_back_response_with_tenant_matching_connection() {
let (mut transport, session) = make_session();
let (tx, stream) = make_transport_stream();
let _server = RelayServer::initialize(session, stream, None).unwrap();
let (mut t1, t2) = Transport::make_pair();
tx.send(t2).await.unwrap();
let (mut t2, t3) = Transport::make_pair();
tx.send(t3).await.unwrap();
t1.send(Request::new(
"test-tenant-1",
vec![RequestData::SystemInfo {}],
))
.await
.unwrap();
t2.send(Request::new(
"test-tenant-2",
vec![RequestData::SystemInfo {}],
))
.await
.unwrap();
let _ = transport.receive::<Request>().await.unwrap().unwrap();
let _ = transport.receive::<Request>().await.unwrap().unwrap();
let res = Response::new("test-tenant-2", None, vec![ResponseData::Ok]);
transport.send(res.clone()).await.unwrap();
let inbound_res = t2.receive().await.unwrap().unwrap();
assert_eq!(res, inbound_res);
let no_inbound = tokio::select! {
_ = t1.receive::<Response>() => {false}
_ = tokio::time::sleep(Duration::from_millis(50)) => {true}
};
assert!(no_inbound, "Unexpectedly got response for wrong connection");
}
#[tokio::test]
async fn server_should_shutdown_if_no_connections_after_shutdown_duration() {
let (_transport, session) = make_session();
let (_tx, stream) = make_transport_stream();
let server =
RelayServer::initialize(session, stream, Some(Duration::from_millis(50))).unwrap();
let result = server.wait().await;
assert!(result.is_ok(), "Unexpected result: {:?}", result);
}
}