net/
websocket_loader.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5//! The websocket handler has three main responsibilities:
6//! 1) initiate the initial HTTP connection and process the response
7//! 2) ensure any DOM requests for sending/closing are propagated to the network
8//! 3) transmit any incoming messages/closing to the DOM
9//!
10//! In order to accomplish this, the handler uses a long-running loop that selects
11//! over events from the network and events from the DOM, using async/await to avoid
12//! the need for a dedicated thread per websocket.
13
14use std::sync::Arc;
15use std::sync::atomic::{AtomicBool, Ordering};
16
17use async_tungstenite::WebSocketStream;
18use async_tungstenite::tokio::{ConnectStream, client_async_tls_with_connector_and_config};
19use base64::Engine;
20use futures::stream::StreamExt;
21use http::HeaderMap;
22use http::header::{self, HeaderName, HeaderValue};
23use ipc_channel::ipc::{IpcReceiver, IpcSender};
24use ipc_channel::router::ROUTER;
25use log::{debug, trace, warn};
26use net_traits::request::{RequestBuilder, RequestMode};
27use net_traits::{CookieSource, MessageData, WebSocketDomAction, WebSocketNetworkEvent};
28use servo_url::ServoUrl;
29use tokio::net::TcpStream;
30use tokio::select;
31use tokio::sync::mpsc::{UnboundedReceiver, unbounded_channel};
32use tokio_rustls::TlsConnector;
33use tungstenite::error::{Error, ProtocolError, UrlError};
34use tungstenite::handshake::client::Response;
35use tungstenite::protocol::CloseFrame;
36use tungstenite::{ClientRequestBuilder, Message};
37
38use crate::async_runtime::spawn_task;
39use crate::connector::TlsConfig;
40use crate::cookie::ServoCookie;
41use crate::hosts::replace_host;
42use crate::http_loader::HttpState;
43
44#[allow(clippy::result_large_err)]
45/// Create a Request object for the initial HTTP request.
46/// This request contains `Origin`, `Sec-WebSocket-Protocol`, `Authorization`,
47/// and `Cookie` headers as appropriate.
48/// Returns an error if any header values are invalid or tungstenite cannot create
49/// the desired request.
50pub fn create_handshake_request(
51    request: RequestBuilder,
52    http_state: Arc<HttpState>,
53) -> Result<net_traits::request::Request, Error> {
54    let origin = request.url.origin();
55
56    let mut headers = HeaderMap::new();
57    headers.insert(
58        "Origin",
59        HeaderValue::from_str(&request.url.origin().ascii_serialization())?,
60    );
61
62    let host = format!(
63        "{}",
64        origin
65            .host()
66            .ok_or_else(|| Error::Url(UrlError::NoHostName))?
67    );
68    headers.insert("Host", HeaderValue::from_str(&host)?);
69    // https://websockets.spec.whatwg.org/#concept-websocket-establish
70    // 3. Append (`Upgrade`, `websocket`) to request’s header list.
71    headers.insert("Upgrade", HeaderValue::from_static("websocket"));
72
73    // 4. Append (`Connection`, `Upgrade`) to request’s header list.
74    headers.insert("Connection", HeaderValue::from_static("upgrade"));
75
76    // 5. Let keyValue be a nonce consisting of a randomly selected 16-byte value that has been
77    // forgiving-base64-encoded and isomorphic encoded.
78    let key = HeaderValue::from_str(&tungstenite::handshake::client::generate_key()).unwrap();
79
80    // 6. Append (`Sec-WebSocket-Key`, keyValue) to request’s header list.
81    headers.insert("Sec-WebSocket-Key", key);
82
83    // 7. Append (`Sec-WebSocket-Version`, `13`) to request’s header list.
84    headers.insert("Sec-Websocket-Version", HeaderValue::from_static("13"));
85
86    // 8. For each protocol in protocols, combine (`Sec-WebSocket-Protocol`, protocol) in request’s
87    // header list.
88    let protocols = match request.mode {
89        RequestMode::WebSocket {
90            ref protocols,
91            original_url: _,
92        } => protocols,
93        _ => unreachable!("How did we get here?"),
94    };
95    if !protocols.is_empty() {
96        let protocols = protocols.join(",");
97        headers.insert("Sec-WebSocket-Protocol", HeaderValue::from_str(&protocols)?);
98    }
99
100    let mut cookie_jar = http_state.cookie_jar.write();
101    cookie_jar.remove_expired_cookies_for_url(&request.url);
102    if let Some(cookie_list) = cookie_jar.cookies_for_url(&request.url, CookieSource::HTTP) {
103        headers.insert("Cookie", HeaderValue::from_str(&cookie_list)?);
104    }
105
106    if request.url.password().is_some() || request.url.username() != "" {
107        let basic = base64::engine::general_purpose::STANDARD.encode(format!(
108            "{}:{}",
109            request.url.username(),
110            request.url.password().unwrap_or("")
111        ));
112        headers.insert(
113            "Authorization",
114            HeaderValue::from_str(&format!("Basic {}", basic))?,
115        );
116    }
117    Ok(request.headers(headers).build())
118}
119
120#[allow(clippy::result_large_err)]
121/// Process an HTTP response resulting from a WS handshake.
122/// This ensures that any `Cookie` or HSTS headers are recognized.
123/// Returns an error if the protocol selected by the handshake doesn't
124/// match the list of provided protocols in the original request.
125fn process_ws_response(
126    http_state: &HttpState,
127    response: &Response,
128    resource_url: &ServoUrl,
129    protocols: &[String],
130) -> Result<Option<String>, Error> {
131    trace!("processing websocket http response for {}", resource_url);
132    let mut protocol_in_use = None;
133    if let Some(protocol_name) = response.headers().get("Sec-WebSocket-Protocol") {
134        let protocol_name = protocol_name.to_str().unwrap_or("");
135        if !protocols.is_empty() && !protocols.iter().any(|p| protocol_name == (*p)) {
136            return Err(Error::Protocol(ProtocolError::InvalidHeader(Box::new(
137                HeaderName::from_static("sec-websocket-protocol"),
138            ))));
139        }
140        protocol_in_use = Some(protocol_name.to_string());
141    }
142
143    let mut jar = http_state.cookie_jar.write();
144    // TODO(eijebong): Replace thise once typed headers settled on a cookie impl
145    for cookie in response.headers().get_all(header::SET_COOKIE) {
146        let cookie_bytes = cookie.as_bytes();
147        if !ServoCookie::is_valid_name_or_value(cookie_bytes) {
148            continue;
149        }
150        if let Ok(s) = std::str::from_utf8(cookie_bytes) {
151            if let Some(cookie) =
152                ServoCookie::from_cookie_string(s, resource_url, CookieSource::HTTP)
153            {
154                jar.push(cookie, resource_url, CookieSource::HTTP);
155            }
156        }
157    }
158
159    http_state
160        .hsts_list
161        .write()
162        .update_hsts_list_from_response(resource_url, response.headers());
163
164    Ok(protocol_in_use)
165}
166
167#[derive(Debug)]
168enum DomMsg {
169    Send(Message),
170    Close(Option<(u16, String)>),
171}
172
173/// Initialize a listener for DOM actions. These are routed from the IPC channel
174/// to a tokio channel that the main WS client task uses to receive them.
175fn setup_dom_listener(
176    dom_action_receiver: IpcReceiver<WebSocketDomAction>,
177    initiated_close: Arc<AtomicBool>,
178) -> UnboundedReceiver<DomMsg> {
179    let (sender, receiver) = unbounded_channel();
180
181    ROUTER.add_typed_route(
182        dom_action_receiver,
183        Box::new(move |message| {
184            let dom_action = message.expect("Ws dom_action message to deserialize");
185            trace!("handling WS DOM action: {:?}", dom_action);
186            match dom_action {
187                WebSocketDomAction::SendMessage(MessageData::Text(data)) => {
188                    if let Err(e) = sender.send(DomMsg::Send(Message::Text(data.into()))) {
189                        warn!("Error sending websocket message: {:?}", e);
190                    }
191                },
192                WebSocketDomAction::SendMessage(MessageData::Binary(data)) => {
193                    if let Err(e) = sender.send(DomMsg::Send(Message::Binary(data.into()))) {
194                        warn!("Error sending websocket message: {:?}", e);
195                    }
196                },
197                WebSocketDomAction::Close(code, reason) => {
198                    if initiated_close.fetch_or(true, Ordering::SeqCst) {
199                        return;
200                    }
201                    let frame = code.map(move |c| (c, reason.unwrap_or_default()));
202                    if let Err(e) = sender.send(DomMsg::Close(frame)) {
203                        warn!("Error closing websocket: {:?}", e);
204                    }
205                },
206            }
207        }),
208    );
209
210    receiver
211}
212
213/// Listen for WS events from the DOM and the network until one side
214/// closes the connection or an error occurs. Since this is an async
215/// function that uses the select operation, it will run as a task
216/// on the WS tokio runtime.
217async fn run_ws_loop(
218    mut dom_receiver: UnboundedReceiver<DomMsg>,
219    resource_event_sender: IpcSender<WebSocketNetworkEvent>,
220    mut stream: WebSocketStream<ConnectStream>,
221) {
222    loop {
223        select! {
224            dom_msg = dom_receiver.recv() => {
225                trace!("processing dom msg: {:?}", dom_msg);
226                let dom_msg = match dom_msg {
227                    Some(msg) => msg,
228                    None => break,
229                };
230                match dom_msg {
231                    DomMsg::Send(m) => {
232                        if let Err(e) = stream.send(m).await {
233                            warn!("error sending websocket message: {:?}", e);
234                        }
235                    },
236                    DomMsg::Close(frame) => {
237                        if let Err(e) = stream.close(frame.map(|(code, reason)| {
238                            CloseFrame {
239                                code: code.into(),
240                                reason: reason.into(),
241                            }
242                        })).await {
243                            warn!("error closing websocket: {:?}", e);
244                        }
245                    },
246                }
247            }
248            ws_msg = stream.next() => {
249                trace!("processing WS stream: {:?}", ws_msg);
250                let msg = match ws_msg {
251                    Some(Ok(msg)) => msg,
252                    Some(Err(e)) => {
253                        warn!("Error in WebSocket communication: {:?}", e);
254                        let _ = resource_event_sender.send(WebSocketNetworkEvent::Fail);
255                        break;
256                    },
257                    None => {
258                        warn!("Error in WebSocket communication");
259                        let _ = resource_event_sender.send(WebSocketNetworkEvent::Fail);
260                        break;
261                    }
262                };
263                match msg {
264                    Message::Text(s) => {
265                        let message = MessageData::Text(s.as_str().to_owned());
266                        if let Err(e) = resource_event_sender
267                            .send(WebSocketNetworkEvent::MessageReceived(message))
268                        {
269                            warn!("Error sending websocket notification: {:?}", e);
270                            break;
271                        }
272                    }
273
274                    Message::Binary(v) => {
275                        let message = MessageData::Binary(v.to_vec());
276                        if let Err(e) = resource_event_sender
277                            .send(WebSocketNetworkEvent::MessageReceived(message))
278                        {
279                            warn!("Error sending websocket notification: {:?}", e);
280                            break;
281                        }
282                    }
283
284                    Message::Ping(_) | Message::Pong(_) => {}
285
286                    Message::Close(frame) => {
287                        let (reason, code) = match frame {
288                            Some(frame) => (frame.reason, Some(frame.code.into())),
289                            None => ("".into(), None),
290                        };
291                        debug!("Websocket connection closing due to ({:?}) {}", code, reason);
292                        let _ = resource_event_sender.send(WebSocketNetworkEvent::Close(
293                            code,
294                            reason.to_string(),
295                        ));
296                        break;
297                    }
298
299                    Message::Frame(_) => {
300                        warn!("Unexpected websocket frame message");
301                    }
302                }
303            }
304        }
305    }
306}
307
308/// Initiate a new async WS connection. Returns an error if the connection fails
309/// for any reason, or if the response isn't valid. Otherwise, the endless WS
310/// listening loop will be started.
311pub(crate) async fn start_websocket(
312    http_state: Arc<HttpState>,
313    resource_event_sender: IpcSender<WebSocketNetworkEvent>,
314    protocols: &[String],
315    client: &net_traits::request::Request,
316    tls_config: TlsConfig,
317    dom_action_receiver: IpcReceiver<WebSocketDomAction>,
318) -> Result<Response, Error> {
319    trace!("starting WS connection to {}", client.url());
320
321    let initiated_close = Arc::new(AtomicBool::new(false));
322    let dom_receiver = setup_dom_listener(dom_action_receiver, initiated_close.clone());
323
324    let url = client.url();
325    let host = replace_host(url.host_str().expect("URL has no host"));
326    let mut net_url = client.url().into_url();
327    net_url
328        .set_host(Some(&host))
329        .map_err(|e| Error::Url(UrlError::UnableToConnect(e.to_string())))?;
330
331    let domain = net_url
332        .host()
333        .ok_or_else(|| Error::Url(UrlError::NoHostName))?;
334    let port = net_url
335        .port_or_known_default()
336        .ok_or_else(|| Error::Url(UrlError::UnableToConnect("Unknown port".into())))?;
337
338    let try_socket = TcpStream::connect((&*domain.to_string(), port)).await;
339    let socket = try_socket.map_err(Error::Io)?;
340    let connector = TlsConnector::from(Arc::new(tls_config));
341
342    // TODO(pylbrecht): move request conversion to a separate function
343    let mut original_url = client.original_url();
344    if original_url.scheme() == "ws" && url.scheme() == "https" {
345        original_url.as_mut_url().set_scheme("wss").unwrap();
346    }
347    let mut builder =
348        ClientRequestBuilder::new(original_url.as_str().parse().expect("unable to parse URI"));
349    for (key, value) in client.headers.iter() {
350        builder = builder.with_header(
351            key.as_str(),
352            value
353                .to_str()
354                .expect("unable to convert header value to string"),
355        );
356    }
357
358    let (stream, response) =
359        client_async_tls_with_connector_and_config(builder, socket, Some(connector), None).await?;
360
361    let protocol_in_use = process_ws_response(&http_state, &response, &url, protocols)?;
362
363    if !initiated_close.load(Ordering::SeqCst) {
364        if resource_event_sender
365            .send(WebSocketNetworkEvent::ConnectionEstablished { protocol_in_use })
366            .is_err()
367        {
368            return Ok(response);
369        }
370
371        trace!("about to start ws loop for {}", url);
372        spawn_task(run_ws_loop(dom_receiver, resource_event_sender, stream));
373    } else {
374        trace!("client closed connection for {}, not running loop", url);
375    }
376    Ok(response)
377}
net/websocket_loader.rs

net/
websocket_loader.rs
