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use std::{
any::Any,
fmt,
future::Future,
net::{IpAddr, SocketAddr},
pin::Pin,
sync::Arc,
task::{Context, Poll, Waker},
time::{Duration, Instant},
};
use crate::runtime::{AsyncTimer, Runtime};
use bytes::Bytes;
use pin_project_lite::pin_project;
use proto::{ConnectionError, ConnectionHandle, ConnectionStats, Dir, StreamEvent, StreamId};
use rustc_hash::FxHashMap;
use thiserror::Error;
use tokio::sync::{futures::Notified, mpsc, oneshot, Notify};
use tracing::debug_span;
use udp::UdpState;
use crate::{
mutex::Mutex,
recv_stream::RecvStream,
send_stream::{SendStream, WriteError},
ConnectionEvent, EndpointEvent, VarInt,
};
use proto::congestion::Controller;
/// In-progress connection attempt future
#[derive(Debug)]
#[must_use = "futures/streams/sinks do nothing unless you `.await` or poll them"]
pub struct Connecting {
conn: Option<ConnectionRef>,
connected: oneshot::Receiver<bool>,
handshake_data_ready: Option<oneshot::Receiver<()>>,
}
impl Connecting {
pub(crate) fn new(
handle: ConnectionHandle,
conn: proto::Connection,
endpoint_events: mpsc::UnboundedSender<(ConnectionHandle, EndpointEvent)>,
conn_events: mpsc::UnboundedReceiver<ConnectionEvent>,
udp_state: Arc<UdpState>,
runtime: Arc<dyn Runtime>,
) -> Self {
let (on_handshake_data_send, on_handshake_data_recv) = oneshot::channel();
let (on_connected_send, on_connected_recv) = oneshot::channel();
let conn = ConnectionRef::new(
handle,
conn,
endpoint_events,
conn_events,
on_handshake_data_send,
on_connected_send,
udp_state,
runtime.clone(),
);
runtime.spawn(Box::pin(ConnectionDriver(conn.clone())));
Self {
conn: Some(conn),
connected: on_connected_recv,
handshake_data_ready: Some(on_handshake_data_recv),
}
}
/// Convert into a 0-RTT or 0.5-RTT connection at the cost of weakened security
///
/// Opens up the connection for use before the handshake finishes, allowing the API user to
/// send data with 0-RTT encryption if the necessary key material is available. This is useful
/// for reducing start-up latency by beginning transmission of application data without waiting
/// for the handshake's cryptographic security guarantees to be established.
///
/// When the `ZeroRttAccepted` future completes, the connection has been fully established.
///
/// # Security
///
/// On outgoing connections, this enables transmission of 0-RTT data, which might be vulnerable
/// to replay attacks, and should therefore never invoke non-idempotent operations.
///
/// On incoming connections, this enables transmission of 0.5-RTT data, which might be
/// intercepted by a man-in-the-middle. If this occurs, the handshake will not complete
/// successfully.
///
/// # Errors
///
/// Outgoing connections are only 0-RTT-capable when a cryptographic session ticket cached from
/// a previous connection to the same server is available, and includes a 0-RTT key. If no such
/// ticket is found, `self` is returned unmodified.
///
/// For incoming connections, a 0.5-RTT connection will always be successfully constructed.
pub fn into_0rtt(mut self) -> Result<(Connection, ZeroRttAccepted), Self> {
// This lock borrows `self` and would normally be dropped at the end of this scope, so we'll
// have to release it explicitly before returning `self` by value.
let conn = (self.conn.as_mut().unwrap()).state.lock("into_0rtt");
let is_ok = conn.inner.has_0rtt() || conn.inner.side().is_server();
drop(conn);
if is_ok {
let conn = self.conn.take().unwrap();
Ok((Connection(conn), ZeroRttAccepted(self.connected)))
} else {
Err(self)
}
}
/// Parameters negotiated during the handshake
///
/// The dynamic type returned is determined by the configured
/// [`Session`](proto::crypto::Session). For the default `rustls` session, the return value can
/// be [`downcast`](Box::downcast) to a
/// [`crypto::rustls::HandshakeData`](crate::crypto::rustls::HandshakeData).
pub async fn handshake_data(&mut self) -> Result<Box<dyn Any>, ConnectionError> {
// Taking &mut self allows us to use a single oneshot channel rather than dealing with
// potentially many tasks waiting on the same event. It's a bit of a hack, but keeps things
// simple.
if let Some(x) = self.handshake_data_ready.take() {
let _ = x.await;
}
let conn = self.conn.as_ref().unwrap();
let inner = conn.state.lock("handshake");
inner
.inner
.crypto_session()
.handshake_data()
.ok_or_else(|| {
inner
.error
.clone()
.expect("spurious handshake data ready notification")
})
}
/// The local IP address which was used when the peer established
/// the connection
///
/// This can be different from the address the endpoint is bound to, in case
/// the endpoint is bound to a wildcard address like `0.0.0.0` or `::`.
///
/// This will return `None` for clients.
///
/// Retrieving the local IP address is currently supported on the following
/// platforms:
/// - Linux
/// - FreeBSD
/// - macOS
///
/// On all non-supported platforms the local IP address will not be available,
/// and the method will return `None`.
pub fn local_ip(&self) -> Option<IpAddr> {
let conn = self.conn.as_ref().unwrap();
let inner = conn.state.lock("local_ip");
inner.inner.local_ip()
}
}
impl Future for Connecting {
type Output = Result<Connection, ConnectionError>;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
Pin::new(&mut self.connected).poll(cx).map(|_| {
let conn = self.conn.take().unwrap();
let inner = conn.state.lock("connecting");
if inner.connected {
drop(inner);
Ok(Connection(conn))
} else {
Err(inner
.error
.clone()
.expect("connected signaled without connection success or error"))
}
})
}
}
impl Connecting {
/// The peer's UDP address.
///
/// Will panic if called after `poll` has returned `Ready`.
pub fn remote_address(&self) -> SocketAddr {
let conn_ref: &ConnectionRef = self.conn.as_ref().expect("used after yielding Ready");
conn_ref.state.lock("remote_address").inner.remote_address()
}
}
/// Future that completes when a connection is fully established
///
/// For clients, the resulting value indicates if 0-RTT was accepted. For servers, the resulting
/// value is meaningless.
#[must_use = "futures/streams/sinks do nothing unless you `.await` or poll them"]
pub struct ZeroRttAccepted(oneshot::Receiver<bool>);
impl Future for ZeroRttAccepted {
type Output = bool;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
Pin::new(&mut self.0).poll(cx).map(|x| x.unwrap_or(false))
}
}
/// A future that drives protocol logic for a connection
///
/// This future handles the protocol logic for a single connection, routing events from the
/// `Connection` API object to the `Endpoint` task and the related stream-related interfaces.
/// It also keeps track of outstanding timeouts for the `Connection`.
///
/// If the connection encounters an error condition, this future will yield an error. It will
/// terminate (yielding `Ok(())`) if the connection was closed without error. Unlike other
/// connection-related futures, this waits for the draining period to complete to ensure that
/// packets still in flight from the peer are handled gracefully.
#[must_use = "connection drivers must be spawned for their connections to function"]
#[derive(Debug)]
struct ConnectionDriver(ConnectionRef);
impl Future for ConnectionDriver {
type Output = ();
#[allow(unused_mut)] // MSRV
fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
let conn = &mut *self.0.state.lock("poll");
let span = debug_span!("drive", id = conn.handle.0);
let _guard = span.enter();
if let Err(e) = conn.process_conn_events(&self.0.shared, cx) {
conn.terminate(e, &self.0.shared);
return Poll::Ready(());
}
let mut keep_going = conn.drive_transmit();
// If a timer expires, there might be more to transmit. When we transmit something, we
// might need to reset a timer. Hence, we must loop until neither happens.
keep_going |= conn.drive_timer(cx);
conn.forward_endpoint_events();
conn.forward_app_events(&self.0.shared);
if !conn.inner.is_drained() {
if keep_going {
// If the connection hasn't processed all tasks, schedule it again
cx.waker().wake_by_ref();
} else {
conn.driver = Some(cx.waker().clone());
}
return Poll::Pending;
}
if conn.error.is_none() {
unreachable!("drained connections always have an error");
}
Poll::Ready(())
}
}
/// A QUIC connection.
///
/// If all references to a connection (including every clone of the `Connection` handle, streams of
/// incoming streams, and the various stream types) have been dropped, then the connection will be
/// automatically closed with an `error_code` of 0 and an empty `reason`. You can also close the
/// connection explicitly by calling [`Connection::close()`].
///
/// May be cloned to obtain another handle to the same connection.
///
/// [`Connection::close()`]: Connection::close
#[derive(Debug, Clone)]
pub struct Connection(ConnectionRef);
impl Connection {
/// Initiate a new outgoing unidirectional stream.
///
/// Streams are cheap and instantaneous to open unless blocked by flow control. As a
/// consequence, the peer won't be notified that a stream has been opened until the stream is
/// actually used.
pub fn open_uni(&self) -> OpenUni<'_> {
OpenUni {
conn: &self.0,
notify: self.0.shared.stream_budget_available[Dir::Uni as usize].notified(),
}
}
/// Initiate a new outgoing bidirectional stream.
///
/// Streams are cheap and instantaneous to open unless blocked by flow control. As a
/// consequence, the peer won't be notified that a stream has been opened until the stream is
/// actually used.
pub fn open_bi(&self) -> OpenBi<'_> {
OpenBi {
conn: &self.0,
notify: self.0.shared.stream_budget_available[Dir::Bi as usize].notified(),
}
}
/// Accept the next incoming uni-directional stream
pub fn accept_uni(&self) -> AcceptUni<'_> {
AcceptUni {
conn: &self.0,
notify: self.0.shared.stream_incoming[Dir::Uni as usize].notified(),
}
}
/// Accept the next incoming bidirectional stream
pub fn accept_bi(&self) -> AcceptBi<'_> {
AcceptBi {
conn: &self.0,
notify: self.0.shared.stream_incoming[Dir::Bi as usize].notified(),
}
}
/// Receive an application datagram
pub fn read_datagram(&self) -> ReadDatagram<'_> {
ReadDatagram {
conn: &self.0,
notify: self.0.shared.datagrams.notified(),
}
}
/// Wait for the connection to be closed for any reason
///
/// Despite the return type's name, closed connections are often not an error condition at the
/// application layer. Cases that might be routine include [`ConnectionError::LocallyClosed`]
/// and [`ConnectionError::ApplicationClosed`].
pub async fn closed(&self) -> ConnectionError {
{
let conn = self.0.state.lock("closed");
if let Some(error) = conn.error.as_ref() {
return error.clone();
}
// Construct the future while the lock is held to ensure we can't miss a wakeup if
// the `Notify` is signaled immediately after we release the lock. `await` it after
// the lock guard is out of scope.
self.0.shared.closed.notified()
}
.await;
self.0
.state
.lock("closed")
.error
.as_ref()
.expect("closed without an error")
.clone()
}
/// If the connection is closed, the reason why.
///
/// Returns `None` if the connection is still open.
pub fn close_reason(&self) -> Option<ConnectionError> {
self.0.state.lock("close_reason").error.clone()
}
/// Close the connection immediately.
///
/// Pending operations will fail immediately with [`ConnectionError::LocallyClosed`]. Delivery
/// of data on unfinished streams is not guaranteed, so the application must call this only
/// when all important communications have been completed, e.g. by calling [`finish`] on
/// outstanding [`SendStream`]s and waiting for the resulting futures to complete.
///
/// `error_code` and `reason` are not interpreted, and are provided directly to the peer.
///
/// `reason` will be truncated to fit in a single packet with overhead; to improve odds that it
/// is preserved in full, it should be kept under 1KiB.
///
/// [`ConnectionError::LocallyClosed`]: crate::ConnectionError::LocallyClosed
/// [`finish`]: crate::SendStream::finish
/// [`SendStream`]: crate::SendStream
pub fn close(&self, error_code: VarInt, reason: &[u8]) {
let conn = &mut *self.0.state.lock("close");
conn.close(error_code, Bytes::copy_from_slice(reason), &self.0.shared);
}
/// Transmit `data` as an unreliable, unordered application datagram
///
/// Application datagrams are a low-level primitive. They may be lost or delivered out of order,
/// and `data` must both fit inside a single QUIC packet and be smaller than the maximum
/// dictated by the peer.
pub fn send_datagram(&self, data: Bytes) -> Result<(), SendDatagramError> {
let conn = &mut *self.0.state.lock("send_datagram");
if let Some(ref x) = conn.error {
return Err(SendDatagramError::ConnectionLost(x.clone()));
}
use proto::SendDatagramError::*;
match conn.inner.datagrams().send(data) {
Ok(()) => {
conn.wake();
Ok(())
}
Err(e) => Err(match e {
UnsupportedByPeer => SendDatagramError::UnsupportedByPeer,
Disabled => SendDatagramError::Disabled,
TooLarge => SendDatagramError::TooLarge,
}),
}
}
/// Compute the maximum size of datagrams that may be passed to [`send_datagram()`].
///
/// Returns `None` if datagrams are unsupported by the peer or disabled locally.
///
/// This may change over the lifetime of a connection according to variation in the path MTU
/// estimate. The peer can also enforce an arbitrarily small fixed limit, but if the peer's
/// limit is large this is guaranteed to be a little over a kilobyte at minimum.
///
/// Not necessarily the maximum size of received datagrams.
///
/// [`send_datagram()`]: Connection::send_datagram
pub fn max_datagram_size(&self) -> Option<usize> {
self.0
.state
.lock("max_datagram_size")
.inner
.datagrams()
.max_size()
}
/// Bytes available in the outgoing datagram buffer
///
/// When greater than zero, calling [`send_datagram()`](Self::send_datagram) with a datagram of
/// at most this size is guaranteed not to cause older datagrams to be dropped.
pub fn datagram_send_buffer_space(&self) -> usize {
self.0
.state
.lock("datagram_send_buffer_space")
.inner
.datagrams()
.send_buffer_space()
}
/// The peer's UDP address
///
/// If `ServerConfig::migration` is `true`, clients may change addresses at will, e.g. when
/// switching to a cellular internet connection.
pub fn remote_address(&self) -> SocketAddr {
self.0.state.lock("remote_address").inner.remote_address()
}
/// The local IP address which was used when the peer established
/// the connection
///
/// This can be different from the address the endpoint is bound to, in case
/// the endpoint is bound to a wildcard address like `0.0.0.0` or `::`.
///
/// This will return `None` for clients.
///
/// Retrieving the local IP address is currently supported on the following
/// platforms:
/// - Linux
///
/// On all non-supported platforms the local IP address will not be available,
/// and the method will return `None`.
pub fn local_ip(&self) -> Option<IpAddr> {
self.0.state.lock("local_ip").inner.local_ip()
}
/// Current best estimate of this connection's latency (round-trip-time)
pub fn rtt(&self) -> Duration {
self.0.state.lock("rtt").inner.rtt()
}
/// Returns connection statistics
pub fn stats(&self) -> ConnectionStats {
self.0.state.lock("stats").inner.stats()
}
/// Current state of the congestion control algorithm, for debugging purposes
pub fn congestion_state(&self) -> Box<dyn Controller> {
self.0
.state
.lock("congestion_state")
.inner
.congestion_state()
.clone_box()
}
/// Parameters negotiated during the handshake
///
/// Guaranteed to return `Some` on fully established connections or after
/// [`Connecting::handshake_data()`] succeeds. See that method's documentations for details on
/// the returned value.
///
/// [`Connection::handshake_data()`]: crate::Connecting::handshake_data
pub fn handshake_data(&self) -> Option<Box<dyn Any>> {
self.0
.state
.lock("handshake_data")
.inner
.crypto_session()
.handshake_data()
}
/// Cryptographic identity of the peer
///
/// The dynamic type returned is determined by the configured
/// [`Session`](proto::crypto::Session). For the default `rustls` session, the return value can
/// be [`downcast`](Box::downcast) to a <code>Vec<[rustls::Certificate](rustls::Certificate)></code>
pub fn peer_identity(&self) -> Option<Box<dyn Any>> {
self.0
.state
.lock("peer_identity")
.inner
.crypto_session()
.peer_identity()
}
/// A stable identifier for this connection
///
/// Peer addresses and connection IDs can change, but this value will remain
/// fixed for the lifetime of the connection.
pub fn stable_id(&self) -> usize {
self.0.stable_id()
}
// Update traffic keys spontaneously for testing purposes.
#[doc(hidden)]
pub fn force_key_update(&self) {
self.0
.state
.lock("force_key_update")
.inner
.initiate_key_update()
}
/// Derive keying material from this connection's TLS session secrets.
///
/// When both peers call this method with the same `label` and `context`
/// arguments and `output` buffers of equal length, they will get the
/// same sequence of bytes in `output`. These bytes are cryptographically
/// strong and pseudorandom, and are suitable for use as keying material.
///
/// See [RFC5705](https://tools.ietf.org/html/rfc5705) for more information.
pub fn export_keying_material(
&self,
output: &mut [u8],
label: &[u8],
context: &[u8],
) -> Result<(), proto::crypto::ExportKeyingMaterialError> {
self.0
.state
.lock("export_keying_material")
.inner
.crypto_session()
.export_keying_material(output, label, context)
}
/// Modify the number of remotely initiated unidirectional streams that may be concurrently open
///
/// No streams may be opened by the peer unless fewer than `count` are already open. Large
/// `count`s increase both minimum and worst-case memory consumption.
pub fn set_max_concurrent_uni_streams(&self, count: VarInt) {
let mut conn = self.0.state.lock("set_max_concurrent_uni_streams");
conn.inner.set_max_concurrent_streams(Dir::Uni, count);
// May need to send MAX_STREAMS to make progress
conn.wake();
}
/// See [`proto::TransportConfig::receive_window()`]
pub fn set_receive_window(&self, receive_window: VarInt) {
let mut conn = self.0.state.lock("set_receive_window");
conn.inner.set_receive_window(receive_window);
conn.wake();
}
/// Modify the number of remotely initiated bidirectional streams that may be concurrently open
///
/// No streams may be opened by the peer unless fewer than `count` are already open. Large
/// `count`s increase both minimum and worst-case memory consumption.
pub fn set_max_concurrent_bi_streams(&self, count: VarInt) {
let mut conn = self.0.state.lock("set_max_concurrent_bi_streams");
conn.inner.set_max_concurrent_streams(Dir::Bi, count);
// May need to send MAX_STREAMS to make progress
conn.wake();
}
}
pin_project! {
/// Future produced by [`Connection::open_uni`]
pub struct OpenUni<'a> {
conn: &'a ConnectionRef,
#[pin]
notify: Notified<'a>,
}
}
impl Future for OpenUni<'_> {
type Output = Result<SendStream, ConnectionError>;
fn poll(self: Pin<&mut Self>, ctx: &mut Context<'_>) -> Poll<Self::Output> {
let this = self.project();
let (conn, id, is_0rtt) = ready!(poll_open(ctx, this.conn, this.notify, Dir::Uni))?;
Poll::Ready(Ok(SendStream::new(conn, id, is_0rtt)))
}
}
pin_project! {
/// Future produced by [`Connection::open_bi`]
pub struct OpenBi<'a> {
conn: &'a ConnectionRef,
#[pin]
notify: Notified<'a>,
}
}
impl Future for OpenBi<'_> {
type Output = Result<(SendStream, RecvStream), ConnectionError>;
fn poll(self: Pin<&mut Self>, ctx: &mut Context<'_>) -> Poll<Self::Output> {
let this = self.project();
let (conn, id, is_0rtt) = ready!(poll_open(ctx, this.conn, this.notify, Dir::Bi))?;
Poll::Ready(Ok((
SendStream::new(conn.clone(), id, is_0rtt),
RecvStream::new(conn, id, is_0rtt),
)))
}
}
fn poll_open<'a>(
ctx: &mut Context<'_>,
conn: &'a ConnectionRef,
mut notify: Pin<&mut Notified<'a>>,
dir: Dir,
) -> Poll<Result<(ConnectionRef, StreamId, bool), ConnectionError>> {
let mut state = conn.state.lock("poll_open");
if let Some(ref e) = state.error {
return Poll::Ready(Err(e.clone()));
} else if let Some(id) = state.inner.streams().open(dir) {
let is_0rtt = state.inner.side().is_client() && state.inner.is_handshaking();
drop(state); // Release the lock so clone can take it
return Poll::Ready(Ok((conn.clone(), id, is_0rtt)));
}
loop {
match notify.as_mut().poll(ctx) {
// `state` lock ensures we didn't race with readiness
Poll::Pending => return Poll::Pending,
// Spurious wakeup, get a new future
Poll::Ready(()) => {
notify.set(conn.shared.stream_budget_available[dir as usize].notified())
}
}
}
}
pin_project! {
/// Future produced by [`Connection::accept_uni`]
pub struct AcceptUni<'a> {
conn: &'a ConnectionRef,
#[pin]
notify: Notified<'a>,
}
}
impl Future for AcceptUni<'_> {
type Output = Result<RecvStream, ConnectionError>;
fn poll(self: Pin<&mut Self>, ctx: &mut Context<'_>) -> Poll<Self::Output> {
let this = self.project();
let (conn, id, is_0rtt) = ready!(poll_accept(ctx, this.conn, this.notify, Dir::Uni))?;
Poll::Ready(Ok(RecvStream::new(conn, id, is_0rtt)))
}
}
pin_project! {
/// Future produced by [`Connection::accept_bi`]
pub struct AcceptBi<'a> {
conn: &'a ConnectionRef,
#[pin]
notify: Notified<'a>,
}
}
impl Future for AcceptBi<'_> {
type Output = Result<(SendStream, RecvStream), ConnectionError>;
fn poll(self: Pin<&mut Self>, ctx: &mut Context<'_>) -> Poll<Self::Output> {
let this = self.project();
let (conn, id, is_0rtt) = ready!(poll_accept(ctx, this.conn, this.notify, Dir::Bi))?;
Poll::Ready(Ok((
SendStream::new(conn.clone(), id, is_0rtt),
RecvStream::new(conn, id, is_0rtt),
)))
}
}
fn poll_accept<'a>(
ctx: &mut Context<'_>,
conn: &'a ConnectionRef,
mut notify: Pin<&mut Notified<'a>>,
dir: Dir,
) -> Poll<Result<(ConnectionRef, StreamId, bool), ConnectionError>> {
let mut state = conn.state.lock("poll_accept");
// Check for incoming streams before checking `state.error` so that already-received streams,
// which are necessarily finite, can be drained from a closed connection.
if let Some(id) = state.inner.streams().accept(dir) {
let is_0rtt = state.inner.is_handshaking();
state.wake(); // To send additional stream ID credit
drop(state); // Release the lock so clone can take it
return Poll::Ready(Ok((conn.clone(), id, is_0rtt)));
} else if let Some(ref e) = state.error {
return Poll::Ready(Err(e.clone()));
}
loop {
match notify.as_mut().poll(ctx) {
// `state` lock ensures we didn't race with readiness
Poll::Pending => return Poll::Pending,
// Spurious wakeup, get a new future
Poll::Ready(()) => notify.set(conn.shared.stream_incoming[dir as usize].notified()),
}
}
}
pin_project! {
/// Future produced by [`Connection::read_datagram`]
pub struct ReadDatagram<'a> {
conn: &'a ConnectionRef,
#[pin]
notify: Notified<'a>,
}
}
impl Future for ReadDatagram<'_> {
type Output = Result<Bytes, ConnectionError>;
fn poll(self: Pin<&mut Self>, ctx: &mut Context<'_>) -> Poll<Self::Output> {
let mut this = self.project();
let mut state = this.conn.state.lock("ReadDatagram::poll");
// Check for buffered datagrams before checking `state.error` so that already-received
// datagrams, which are necessarily finite, can be drained from a closed connection.
if let Some(x) = state.inner.datagrams().recv() {
return Poll::Ready(Ok(x));
} else if let Some(ref e) = state.error {
return Poll::Ready(Err(e.clone()));
}
loop {
match this.notify.as_mut().poll(ctx) {
// `state` lock ensures we didn't race with readiness
Poll::Pending => return Poll::Pending,
// Spurious wakeup, get a new future
Poll::Ready(()) => this.notify.set(this.conn.shared.datagrams.notified()),
}
}
}
}
#[derive(Debug)]
pub(crate) struct ConnectionRef(Arc<ConnectionInner>);
impl ConnectionRef {
#[allow(clippy::too_many_arguments)]
fn new(
handle: ConnectionHandle,
conn: proto::Connection,
endpoint_events: mpsc::UnboundedSender<(ConnectionHandle, EndpointEvent)>,
conn_events: mpsc::UnboundedReceiver<ConnectionEvent>,
on_handshake_data: oneshot::Sender<()>,
on_connected: oneshot::Sender<bool>,
udp_state: Arc<UdpState>,
runtime: Arc<dyn Runtime>,
) -> Self {
Self(Arc::new(ConnectionInner {
state: Mutex::new(State {
inner: conn,
driver: None,
handle,
on_handshake_data: Some(on_handshake_data),
on_connected: Some(on_connected),
connected: false,
timer: None,
timer_deadline: None,
conn_events,
endpoint_events,
blocked_writers: FxHashMap::default(),
blocked_readers: FxHashMap::default(),
finishing: FxHashMap::default(),
stopped: FxHashMap::default(),
error: None,
ref_count: 0,
udp_state,
runtime,
}),
shared: Shared::default(),
}))
}
fn stable_id(&self) -> usize {
&*self.0 as *const _ as usize
}
}
impl Clone for ConnectionRef {
fn clone(&self) -> Self {
self.state.lock("clone").ref_count += 1;
Self(self.0.clone())
}
}
impl Drop for ConnectionRef {
fn drop(&mut self) {
let conn = &mut *self.state.lock("drop");
if let Some(x) = conn.ref_count.checked_sub(1) {
conn.ref_count = x;
if x == 0 && !conn.inner.is_closed() {
// If the driver is alive, it's just it and us, so we'd better shut it down. If it's
// not, we can't do any harm. If there were any streams being opened, then either
// the connection will be closed for an unrelated reason or a fresh reference will
// be constructed for the newly opened stream.
conn.implicit_close(&self.shared);
}
}
}
}
impl std::ops::Deref for ConnectionRef {
type Target = ConnectionInner;
fn deref(&self) -> &Self::Target {
&self.0
}
}
#[derive(Debug)]
pub(crate) struct ConnectionInner {
pub(crate) state: Mutex<State>,
pub(crate) shared: Shared,
}
#[derive(Debug, Default)]
pub(crate) struct Shared {
/// Notified when new streams may be locally initiated due to an increase in stream ID flow
/// control budget
stream_budget_available: [Notify; 2],
/// Notified when the peer has initiated a new stream
stream_incoming: [Notify; 2],
datagrams: Notify,
closed: Notify,
}
pub(crate) struct State {
pub(crate) inner: proto::Connection,
driver: Option<Waker>,
handle: ConnectionHandle,
on_handshake_data: Option<oneshot::Sender<()>>,
on_connected: Option<oneshot::Sender<bool>>,
connected: bool,
timer: Option<Pin<Box<dyn AsyncTimer>>>,
timer_deadline: Option<Instant>,
conn_events: mpsc::UnboundedReceiver<ConnectionEvent>,
endpoint_events: mpsc::UnboundedSender<(ConnectionHandle, EndpointEvent)>,
pub(crate) blocked_writers: FxHashMap<StreamId, Waker>,
pub(crate) blocked_readers: FxHashMap<StreamId, Waker>,
pub(crate) finishing: FxHashMap<StreamId, oneshot::Sender<Option<WriteError>>>,
pub(crate) stopped: FxHashMap<StreamId, Waker>,
/// Always set to Some before the connection becomes drained
pub(crate) error: Option<ConnectionError>,
/// Number of live handles that can be used to initiate or handle I/O; excludes the driver
ref_count: usize,
udp_state: Arc<UdpState>,
runtime: Arc<dyn Runtime>,
}
impl State {
fn drive_transmit(&mut self) -> bool {
let now = Instant::now();
let mut transmits = 0;
let max_datagrams = self.udp_state.max_gso_segments();
while let Some(t) = self.inner.poll_transmit(now, max_datagrams) {
transmits += match t.segment_size {
None => 1,
Some(s) => (t.contents.len() + s - 1) / s, // round up
};
// If the endpoint driver is gone, noop.
let _ = self
.endpoint_events
.send((self.handle, EndpointEvent::Transmit(t)));
if transmits >= MAX_TRANSMIT_DATAGRAMS {
// TODO: What isn't ideal here yet is that if we don't poll all
// datagrams that could be sent we don't go into the `app_limited`
// state and CWND continues to grow until we get here the next time.
// See https://github.com/quinn-rs/quinn/issues/1126
return true;
}
}
false
}
fn forward_endpoint_events(&mut self) {
while let Some(event) = self.inner.poll_endpoint_events() {
// If the endpoint driver is gone, noop.
let _ = self
.endpoint_events
.send((self.handle, EndpointEvent::Proto(event)));
}
}
/// If this returns `Err`, the endpoint is dead, so the driver should exit immediately.
fn process_conn_events(
&mut self,
shared: &Shared,
cx: &mut Context,
) -> Result<(), ConnectionError> {
loop {
match self.conn_events.poll_recv(cx) {
Poll::Ready(Some(ConnectionEvent::Ping)) => {
self.inner.ping();
}
Poll::Ready(Some(ConnectionEvent::Proto(event))) => {
self.inner.handle_event(event);
}
Poll::Ready(Some(ConnectionEvent::Close { reason, error_code })) => {
self.close(error_code, reason, shared);
}
Poll::Ready(None) => {
return Err(ConnectionError::TransportError(proto::TransportError {
code: proto::TransportErrorCode::INTERNAL_ERROR,
frame: None,
reason: "endpoint driver future was dropped".to_string(),
}));
}
Poll::Pending => {
return Ok(());
}
}
}
}
fn forward_app_events(&mut self, shared: &Shared) {
while let Some(event) = self.inner.poll() {
use proto::Event::*;
match event {
HandshakeDataReady => {
if let Some(x) = self.on_handshake_data.take() {
let _ = x.send(());
}
}
Connected => {
self.connected = true;
if let Some(x) = self.on_connected.take() {
// We don't care if the on-connected future was dropped
let _ = x.send(self.inner.accepted_0rtt());
}
}
ConnectionLost { reason } => {
self.terminate(reason, shared);
}
Stream(StreamEvent::Writable { id }) => {
if let Some(writer) = self.blocked_writers.remove(&id) {
writer.wake();
}
}
Stream(StreamEvent::Opened { dir: Dir::Uni }) => {
shared.stream_incoming[Dir::Uni as usize].notify_waiters();
}
Stream(StreamEvent::Opened { dir: Dir::Bi }) => {
shared.stream_incoming[Dir::Bi as usize].notify_waiters();
}
DatagramReceived => {
shared.datagrams.notify_waiters();
}
Stream(StreamEvent::Readable { id }) => {
if let Some(reader) = self.blocked_readers.remove(&id) {
reader.wake();
}
}
Stream(StreamEvent::Available { dir }) => {
// Might mean any number of streams are ready, so we wake up everyone
shared.stream_budget_available[dir as usize].notify_waiters();
}
Stream(StreamEvent::Finished { id }) => {
if let Some(finishing) = self.finishing.remove(&id) {
// If the finishing stream was already dropped, there's nothing more to do.
let _ = finishing.send(None);
}
if let Some(stopped) = self.stopped.remove(&id) {
stopped.wake();
}
}
Stream(StreamEvent::Stopped { id, error_code }) => {
if let Some(stopped) = self.stopped.remove(&id) {
stopped.wake();
}
if let Some(finishing) = self.finishing.remove(&id) {
let _ = finishing.send(Some(WriteError::Stopped(error_code)));
}
if let Some(writer) = self.blocked_writers.remove(&id) {
writer.wake();
}
}
}
}
}
fn drive_timer(&mut self, cx: &mut Context) -> bool {
// Check whether we need to (re)set the timer. If so, we must poll again to ensure the
// timer is registered with the runtime (and check whether it's already
// expired).
match self.inner.poll_timeout() {
Some(deadline) => {
if let Some(delay) = &mut self.timer {
// There is no need to reset the tokio timer if the deadline
// did not change
if self
.timer_deadline
.map(|current_deadline| current_deadline != deadline)
.unwrap_or(true)
{
delay.as_mut().reset(deadline);
}
} else {
self.timer = Some(self.runtime.new_timer(deadline));
}
// Store the actual expiration time of the timer
self.timer_deadline = Some(deadline);
}
None => {
self.timer_deadline = None;
return false;
}
}
if self.timer_deadline.is_none() {
return false;
}
let delay = self
.timer
.as_mut()
.expect("timer must exist in this state")
.as_mut();
if delay.poll(cx).is_pending() {
// Since there wasn't a timeout event, there is nothing new
// for the connection to do
return false;
}
// A timer expired, so the caller needs to check for
// new transmits, which might cause new timers to be set.
self.inner.handle_timeout(Instant::now());
self.timer_deadline = None;
true
}
/// Wake up a blocked `Driver` task to process I/O
pub(crate) fn wake(&mut self) {
if let Some(x) = self.driver.take() {
x.wake();
}
}
/// Used to wake up all blocked futures when the connection becomes closed for any reason
fn terminate(&mut self, reason: ConnectionError, shared: &Shared) {
self.error = Some(reason.clone());
if let Some(x) = self.on_handshake_data.take() {
let _ = x.send(());
}
for (_, writer) in self.blocked_writers.drain() {
writer.wake()
}
for (_, reader) in self.blocked_readers.drain() {
reader.wake()
}
shared.stream_budget_available[Dir::Uni as usize].notify_waiters();
shared.stream_budget_available[Dir::Bi as usize].notify_waiters();
shared.stream_incoming[Dir::Uni as usize].notify_waiters();
shared.stream_incoming[Dir::Bi as usize].notify_waiters();
shared.datagrams.notify_waiters();
for (_, x) in self.finishing.drain() {
let _ = x.send(Some(WriteError::ConnectionLost(reason.clone())));
}
if let Some(x) = self.on_connected.take() {
let _ = x.send(false);
}
for (_, waker) in self.stopped.drain() {
waker.wake();
}
shared.closed.notify_waiters();
}
fn close(&mut self, error_code: VarInt, reason: Bytes, shared: &Shared) {
self.inner.close(Instant::now(), error_code, reason);
self.terminate(ConnectionError::LocallyClosed, shared);
self.wake();
}
/// Close for a reason other than the application's explicit request
pub(crate) fn implicit_close(&mut self, shared: &Shared) {
self.close(0u32.into(), Bytes::new(), shared);
}
pub(crate) fn check_0rtt(&self) -> Result<(), ()> {
if self.inner.is_handshaking()
|| self.inner.accepted_0rtt()
|| self.inner.side().is_server()
{
Ok(())
} else {
Err(())
}
}
}
impl Drop for State {
fn drop(&mut self) {
if !self.inner.is_drained() {
// Ensure the endpoint can tidy up
let _ = self.endpoint_events.send((
self.handle,
EndpointEvent::Proto(proto::EndpointEvent::drained()),
));
}
}
}
impl fmt::Debug for State {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("State").field("inner", &self.inner).finish()
}
}
/// Errors that can arise when sending a datagram
#[derive(Debug, Error, Clone, Eq, PartialEq)]
pub enum SendDatagramError {
/// The peer does not support receiving datagram frames
#[error("datagrams not supported by peer")]
UnsupportedByPeer,
/// Datagram support is disabled locally
#[error("datagram support disabled")]
Disabled,
/// The datagram is larger than the connection can currently accommodate
///
/// Indicates that the path MTU minus overhead or the limit advertised by the peer has been
/// exceeded.
#[error("datagram too large")]
TooLarge,
/// The connection was lost
#[error("connection lost")]
ConnectionLost(#[from] ConnectionError),
}
/// The maximum amount of datagrams which will be produced in a single `drive_transmit` call
///
/// This limits the amount of CPU resources consumed by datagram generation,
/// and allows other tasks (like receiving ACKs) to run in between.
const MAX_TRANSMIT_DATAGRAMS: usize = 20;
/// Error indicating that a stream has already been finished or reset
#[derive(Debug, Error, Clone, PartialEq, Eq)]
#[error("unknown stream")]
pub struct UnknownStream {
_private: (),
}
impl From<proto::UnknownStream> for UnknownStream {
fn from(_: proto::UnknownStream) -> Self {
Self { _private: () }
}
}