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//! This crate allows [`hyper`](https://docs.rs/hyper) servers to accept websocket connections, backed by [`tungstenite`](https://docs.rs/tungstenite). //! //! The [`upgrade`] function allows you to upgrade a HTTP connection to a websocket connection. //! It returns a HTTP response to send to the client, and a future that resolves to a [`WebSocketStream`]. //! The response must be sent to the client for the future to be resolved. //! In practise this means that you must spawn the future in a different task. //! //! Note that the [`upgrade`] function itself does not check if the request is actually an upgrade request. //! For simple cases, you can check this using the [`upgrade_requested`] function before calling [`upgrade`]. //! For more complicated cases where the server should support multiple upgrade protocols, //! you can manually inspect the `Connection` and `Upgrade` headers. //! //! # Example //! ```no_run //! use futures::{sink::SinkExt, stream::StreamExt}; //! use hyper::{Body, Request, Response}; //! use hyper_tungstenite::{tungstenite, HyperWebsocket}; //! use tungstenite::Message; //! # fn foo(message: &Message) {} //! //! /// Handle a HTTP or WebSocket request. //! async fn handle_request(request: Request<Body>) -> Result<Response<Body>, Box<dyn std::error::Error>> { //! // Check if the request is a websocket upgrade request. //! if hyper_tungstenite::upgrade_requested(&request) { //! let (response, websocket) = hyper_tungstenite::upgrade(request, None)?; //! //! // Spawn a task to handle the websocket connection. //! tokio::spawn(async move { //! if let Err(e) = serve_websocket(websocket).await { //! eprintln!("Error in websocket connection: {}", e); //! } //! }); //! //! // Return the response so the spawned future can continue. //! Ok(response) //! } else { //! // Handle regular HTTP requests here. //! Ok(Response::new(Body::from("Hello HTTP!"))) //! } //! } //! //! /// Handle a websocket connection. //! async fn serve_websocket(websocket: HyperWebsocket) -> Result<(), Box<dyn std::error::Error>> { //! let mut websocket = websocket.await?; //! while let Some(message) = websocket.next().await { //! let message = message?; //! //! // Do something with the message. //! foo(&message); //! //! // Send a reply. //! websocket.send(Message::text("Thank you, come again.")).await?; //! } //! //! Ok(()) //! } //! ``` use hyper::{Body, Request, Response}; use std::task::{Context, Poll}; use std::pin::Pin; use tungstenite::{Error, Result}; use tungstenite::protocol::{Role, WebSocketConfig}; pub use tokio_tungstenite::tungstenite; pub use tokio_tungstenite::WebSocketStream; /// A future that resolves to a websocket stream when the associated HTTP upgrade completes. pub struct HyperWebsocket { inner: hyper::upgrade::OnUpgrade, config: Option<WebSocketConfig>, } /// Try to upgrade a received `hyper::Request` to a websocket connection. /// /// The function returns a HTTP response and a future that resolves to the websocket stream. /// The response body *MUST* be sent to the client before the future can be resolved. /// /// This functions checks `Sec-WebSocket-Key` and `Sec-WebSocket-Version` headers. /// It does not inspect the `Origin`, `Sec-WebSocket-Protocol` or `Sec-WebSocket-Extensions` headers. /// You can inspect the headers manually before calling this function, /// and modify the response headers appropriately. /// /// This function also does not look at the `Connection` or `Upgrade` headers. /// To check if a request is a websocket upgrade request, you can use [`upgrade_requested`]. /// Alternatively you can inspect the `Connection` and `Upgrade` headers manually. /// pub fn upgrade(request: Request<Body>, config: Option<WebSocketConfig>) -> Result<(Response<Body>, HyperWebsocket)> { let key = request.headers().get("Sec-WebSocket-Key") .ok_or_else(|| protocol_error("missing \"Sec-WebSocket-Key\" header"))?; let version = request.headers().get("Sec-WebSocket-Version") .ok_or_else(|| protocol_error("missing \"Sec-WebSocket-Version\" header"))?; if version.as_bytes() != b"13" { return Err(protocol_error(format!("invalid websocket protocol version: expected 13, got {:?}", version))); } let response = Response::builder() .status(hyper::StatusCode::SWITCHING_PROTOCOLS) .header(hyper::header::CONNECTION, "upgrade") .header(hyper::header::UPGRADE, "websocket") .header("Sec-WebSocket-Accept", &convert_key(key.as_bytes())) .body(Body::from("switching to websocket protocol"))?; let stream = HyperWebsocket { inner: hyper::upgrade::on(request), config, }; Ok((response, stream)) } /// Check if a request is a websocket upgrade request. /// /// If the `Upgrade` header lists multiple protocols, /// this function returns true if of them are `"websocket"`, /// If the server supports multiple upgrade protocols, /// it would be more appropriate to try each listed protocol in order. pub fn upgrade_requested<B>(request: &hyper::Request<B>) -> bool { // Check for "Connection: upgrade" header. if let Some(connection) = request.headers().get(hyper::header::CONNECTION) { if !connection.as_bytes().eq_ignore_ascii_case(b"upgrade") { return false; } } // Check for "Upgrade: websocket" header. if let Some(upgrade) = request.headers().get(hyper::header::UPGRADE) { if let Ok(upgrade) = upgrade.to_str() { if upgrade.split(',').any(|x| x.trim().eq_ignore_ascii_case("websocket")) { return true; } } } false } fn protocol_error(message: impl Into<std::borrow::Cow<'static, str>>) -> Error { tungstenite::Error::Protocol(message.into()) } /// Turns a Sec-WebSocket-Key into a Sec-WebSocket-Accept. fn convert_key(input: &[u8]) -> String { use sha1::Digest; // ... field is constructed by concatenating /key/ ... // ... with the string "258EAFA5-E914-47DA-95CA-C5AB0DC85B11" (RFC 6455) const WS_GUID: &[u8] = b"258EAFA5-E914-47DA-95CA-C5AB0DC85B11"; let mut sha1 = sha1::Sha1::default(); sha1.update(input); sha1.update(WS_GUID); base64::encode(sha1.finalize()) } impl std::future::Future for HyperWebsocket { type Output = Result<WebSocketStream<hyper::upgrade::Upgraded>>; fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> { let inner = unsafe { self.as_mut().map_unchecked_mut(|x| &mut x.inner) }; let upgraded = match inner.poll(cx) { Poll::Pending => return Poll::Pending, Poll::Ready(x) => x, }; let upgraded = upgraded.map_err(|e| protocol_error(format!("failed to upgrade HTTP connection: {}", e)))?; let mut stream = WebSocketStream::from_raw_socket( upgraded, Role::Server, self.config.take(), ); let stream = unsafe { Pin::new_unchecked(&mut stream) }; // The future returned by `from_raw_socket` is always ready. // Not sure why it is a future in the first place. match stream.poll(cx) { Poll::Pending => unreachable!("from_raw_socket should always be created ready"), Poll::Ready(x) => Poll::Ready(Ok(x)), } } }