script/dom/document/

websocket.rs

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */

use std::cell::Cell;
use std::ptr::{self, NonNull};
use std::rc::Rc;

use dom_struct::dom_struct;
use js::context::JSContext;
use js::conversions::ToJSValConvertible;
use js::jsapi::JSObject;
use js::jsval::UndefinedValue;
use js::realm::AutoRealm;
use js::rust::{CustomAutoRooterGuard, HandleObject};
use js::typedarray::{ArrayBuffer, ArrayBufferU8, ArrayBufferView};
use net_traits::blob_url_store::UrlWithBlobClaim;
use net_traits::request::{
    CacheMode, CredentialsMode, RedirectMode, Referrer, RequestBuilder, RequestMode,
    ServiceWorkersMode,
};
use net_traits::{
    CoreResourceMsg, FetchChannels, MessageData, WebSocketDomAction, WebSocketNetworkEvent,
};
use profile_traits::generic_callback::GenericCallback as ProfileGenericCallback;
use script_bindings::cell::DomRefCell;
use script_bindings::reflector::{DomObject, reflect_weak_referenceable_dom_object_with_proto};
use servo_base::generic_channel::{LazyCallback, lazy_callback};
use servo_constellation_traits::BlobImpl;
use servo_url::{ImmutableOrigin, ServoUrl};

use crate::dom::bindings::buffer_source::create_buffer_source;
use crate::dom::bindings::codegen::Bindings::BlobBinding::BlobMethods;
use crate::dom::bindings::codegen::Bindings::WebSocketBinding::{BinaryType, WebSocketMethods};
use crate::dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
use crate::dom::bindings::codegen::UnionTypes::StringOrStringSequence;
use crate::dom::bindings::error::{Error, ErrorResult, Fallible};
use crate::dom::bindings::inheritance::Castable;
use crate::dom::bindings::refcounted::Trusted;
use crate::dom::bindings::reflector::DomGlobal;
use crate::dom::bindings::root::DomRoot;
use crate::dom::bindings::str::{DOMString, USVString, is_token};
use crate::dom::blob::Blob;
use crate::dom::closeevent::CloseEvent;
use crate::dom::csp::{GlobalCspReporting, Violation};
use crate::dom::event::{Event, EventBubbles, EventCancelable};
use crate::dom::eventtarget::EventTarget;
use crate::dom::globalscope::GlobalScope;
use crate::dom::messageevent::MessageEvent;
use crate::dom::window::Window;
use crate::fetch::fetch::RequestWithGlobalScope;
use crate::tasks::task::TaskOnce;
use crate::tasks::task_source::SendableTaskSource;

#[derive(Clone, Copy, Debug, JSTraceable, MallocSizeOf, PartialEq)]
enum WebSocketRequestState {
    Connecting = 0,
    Open = 1,
    Closing = 2,
    Closed = 3,
}

// Close codes defined in https://tools.ietf.org/html/rfc6455#section-7.4.1
// Names are from https://github.com/mozilla/gecko-dev/blob/master/netwerk/protocol/websocket/nsIWebSocketChannel.idl
#[expect(dead_code)]
mod close_code {
    pub(crate) const NORMAL: u16 = 1000;
    pub(crate) const GOING_AWAY: u16 = 1001;
    pub(crate) const PROTOCOL_ERROR: u16 = 1002;
    pub(crate) const UNSUPPORTED_DATATYPE: u16 = 1003;
    pub(crate) const NO_STATUS: u16 = 1005;
    pub(crate) const ABNORMAL: u16 = 1006;
    pub(crate) const INVALID_PAYLOAD: u16 = 1007;
    pub(crate) const POLICY_VIOLATION: u16 = 1008;
    pub(crate) const TOO_LARGE: u16 = 1009;
    pub(crate) const EXTENSION_MISSING: u16 = 1010;
    pub(crate) const INTERNAL_ERROR: u16 = 1011;
    pub(crate) const TLS_FAILED: u16 = 1015;
}

fn close_the_websocket_connection(
    address: Trusted<WebSocket>,
    task_source: &SendableTaskSource,
    code: Option<u16>,
    reason: String,
) {
    task_source.queue(CloseTask {
        address,
        failed: false,
        code,
        reason: Some(reason),
    });
}

fn fail_the_websocket_connection(address: Trusted<WebSocket>, task_source: &SendableTaskSource) {
    task_source.queue(CloseTask {
        address,
        failed: true,
        code: Some(close_code::ABNORMAL),
        reason: None,
    });
}

#[dom_struct]
pub(crate) struct WebSocket {
    eventtarget: EventTarget,
    #[no_trace]
    url: ServoUrl,
    ready_state: Cell<WebSocketRequestState>,
    buffered_amount: Cell<u64>,
    clearing_buffer: Cell<bool>, // Flag to tell if there is a running thread to clear buffered_amount
    #[no_trace]
    callback: LazyCallback<WebSocketDomAction>,
    binary_type: Cell<BinaryType>,
    protocol: DomRefCell<String>, // Subprotocol selected by server
}

impl WebSocket {
    fn new_inherited(url: ServoUrl, callback: LazyCallback<WebSocketDomAction>) -> WebSocket {
        WebSocket {
            eventtarget: EventTarget::new_inherited(),
            url,
            ready_state: Cell::new(WebSocketRequestState::Connecting),
            buffered_amount: Cell::new(0),
            clearing_buffer: Cell::new(false),
            callback,
            binary_type: Cell::new(BinaryType::Blob),
            protocol: Default::default(),
        }
    }

    fn new(
        cx: &mut JSContext,
        global: &GlobalScope,
        proto: Option<HandleObject>,
        url: ServoUrl,
        sender: LazyCallback<WebSocketDomAction>,
    ) -> DomRoot<WebSocket> {
        let websocket = reflect_weak_referenceable_dom_object_with_proto(
            cx,
            Rc::new(WebSocket::new_inherited(url, sender)),
            global,
            proto,
        );
        if let Some(window) = global.downcast::<Window>() {
            window.Document().track_websocket(&websocket);
        }
        websocket
    }

    /// <https://websockets.spec.whatwg.org/#dom-websocket-send>
    fn send_impl(&self, data_byte_len: u64) -> Fallible<bool> {
        let return_after_buffer = match self.ready_state.get() {
            WebSocketRequestState::Connecting => {
                return Err(Error::InvalidState(Some(
                    "Cannot send while socket is connecting".into(),
                )));
            },
            WebSocketRequestState::Open => false,
            WebSocketRequestState::Closing | WebSocketRequestState::Closed => true,
        };

        let address = Trusted::new(self);

        match data_byte_len.checked_add(self.buffered_amount.get()) {
            None => panic!(),
            Some(new_amount) => self.buffered_amount.set(new_amount),
        };

        if return_after_buffer {
            return Ok(false);
        }

        if !self.clearing_buffer.get() && self.ready_state.get() == WebSocketRequestState::Open {
            self.clearing_buffer.set(true);

            // TODO(mrobinson): Should this task be cancellable?
            self.global()
                .task_manager()
                .websocket_task_source()
                .queue_unconditionally(BufferedAmountTask { address });
        }

        Ok(true)
    }

    pub(crate) fn origin(&self) -> ImmutableOrigin {
        self.url.origin()
    }

    /// <https://websockets.spec.whatwg.org/#make-disappear>
    /// Returns true if any action was taken.
    pub(crate) fn make_disappear(&self) -> bool {
        let result = self.ready_state.get() != WebSocketRequestState::Closed;
        let _ = self.Close(Some(1001), None);
        result
    }
}

impl WebSocketMethods<crate::DomTypeHolder> for WebSocket {
    /// <https://websockets.spec.whatwg.org/#dom-websocket-websocket>
    fn Constructor(
        cx: &mut JSContext,
        global: &GlobalScope,
        proto: Option<HandleObject>,
        url: DOMString,
        protocols: Option<StringOrStringSequence>,
    ) -> Fallible<DomRoot<WebSocket>> {
        // Step 1. Let baseURL be this's relevant settings object's API base URL.
        let base_url = global.api_base_url();
        // Step 2. Let urlRecord be the result of applying the URL parser to url with baseURL.
        // Step 3. If urlRecord is failure, then throw a "SyntaxError" DOMException.
        let mut url_record = ServoUrl::parse_with_base(Some(&base_url), &url.str())
            .or(Err(Error::Syntax(Some("Failed to parse url".into()))))?;

        // Step 4. If urlRecord’s scheme is "http", then set urlRecord’s scheme to "ws".
        // Step 5. Otherwise, if urlRecord’s scheme is "https", set urlRecord’s scheme to "wss".
        // Step 6. If urlRecord’s scheme is not "ws" or "wss", then throw a "SyntaxError" DOMException.
        match url_record.scheme() {
            "http" => {
                url_record
                    .as_mut_url()
                    .set_scheme("ws")
                    .expect("Can't set scheme from http to ws");
            },
            "https" => {
                url_record
                    .as_mut_url()
                    .set_scheme("wss")
                    .expect("Can't set scheme from https to wss");
            },
            "ws" | "wss" => {},
            _ => {
                return Err(Error::Syntax(Some("Forbidden URL scheme".into())));
            },
        }

        // Step 7. If urlRecord’s fragment is non-null, then throw a "SyntaxError" DOMException.
        if url_record.fragment().is_some() {
            return Err(Error::Syntax(Some("Forbidden URL fragment".into())));
        }

        // Step 8. If protocols is a string, set protocols to a sequence consisting of just that string.
        let protocols = protocols.map_or(vec![], |p| match p {
            StringOrStringSequence::String(string) => vec![string.into()],
            StringOrStringSequence::StringSequence(seq) => {
                seq.into_iter().map(String::from).collect()
            },
        });

        // Step 9. If any of the values in protocols occur more than once or otherwise fail to match the requirements
        // for elements that comprise the value of `Sec-WebSocket-Protocol` fields as defined by The WebSocket protocol,
        // then throw a "SyntaxError" DOMException.
        for (i, protocol) in protocols.iter().enumerate() {
            // https://tools.ietf.org/html/rfc6455#section-4.1
            // Handshake requirements, step 10

            if protocols[i + 1..]
                .iter()
                .any(|p| p.eq_ignore_ascii_case(protocol))
            {
                return Err(Error::Syntax(Some("Duplicate protocol header".into())));
            }

            // https://tools.ietf.org/html/rfc6455#section-4.1
            if !is_token(protocol.as_bytes()) {
                return Err(Error::Syntax(Some(
                    "Protocol header field is not a valid token".into(),
                )));
            }
        }

        // Create the interface for communication with the resource thread
        let (dom_action_sender, resource_action_receiver) = lazy_callback();

        // Step 12. Establish a WebSocket connection given urlRecord, protocols, and client.
        let ws = WebSocket::new(cx, global, proto, url_record.clone(), dom_action_sender);
        let address = Trusted::new(&*ws);

        // https://websockets.spec.whatwg.org/#concept-websocket-establish
        //
        // Let request be a new request, whose URL is requestURL, client is client, service-workers
        // mode is "none", referrer is "no-referrer", mode is "websocket", credentials mode is
        // "include", cache mode is "no-store" , and redirect mode is "error"
        let request = RequestBuilder::new(
            global.webview_id(),
            UrlWithBlobClaim::from_url_without_having_claimed_blob(url_record.clone()),
            Referrer::NoReferrer,
        )
        .with_global_scope(global)
        .mode(RequestMode::WebSocket {
            protocols,
            original_url: url_record,
        })
        .service_workers_mode(ServiceWorkersMode::None)
        .credentials_mode(CredentialsMode::Include)
        .cache_mode(CacheMode::NoCache)
        .redirect_mode(RedirectMode::Error);

        let task_source = global.task_manager().websocket_task_source().to_sendable();
        let resource_event_sender =
            ProfileGenericCallback::new(move |message| match message.unwrap() {
                WebSocketNetworkEvent::ReportCSPViolations(violations) => {
                    let task = ReportCSPViolationTask {
                        websocket: address.clone(),
                        violations,
                    };
                    task_source.queue(task);
                },
                WebSocketNetworkEvent::ConnectionEstablished { protocol_in_use } => {
                    let open_thread = ConnectionEstablishedTask {
                        address: address.clone(),
                        protocol_in_use,
                    };
                    task_source.queue(open_thread);
                },
                WebSocketNetworkEvent::MessageReceived(message) => {
                    let message_thread = MessageReceivedTask {
                        address: address.clone(),
                        message,
                    };
                    task_source.queue(message_thread);
                },
                WebSocketNetworkEvent::Fail => {
                    fail_the_websocket_connection(address.clone(), &task_source);
                },
                WebSocketNetworkEvent::Close(code, reason) => {
                    close_the_websocket_connection(address.clone(), &task_source, code, reason);
                },
            })
            .expect("Couldn't create web socket callback.");

        let channels = FetchChannels::WebSocket {
            event_sender: resource_event_sender,
            action_receiver: resource_action_receiver,
        };
        let _ = global
            .core_resource_thread()
            .send(CoreResourceMsg::Fetch(request, channels));

        Ok(ws)
    }

    // https://html.spec.whatwg.org/multipage/#handler-websocket-onopen
    event_handler!(open, GetOnopen, SetOnopen);

    // https://html.spec.whatwg.org/multipage/#handler-websocket-onclose
    event_handler!(close, GetOnclose, SetOnclose);

    // https://html.spec.whatwg.org/multipage/#handler-websocket-onerror
    event_handler!(error, GetOnerror, SetOnerror);

    // https://html.spec.whatwg.org/multipage/#handler-websocket-onmessage
    event_handler!(message, GetOnmessage, SetOnmessage);

    /// <https://html.spec.whatwg.org/multipage/#dom-websocket-url>
    fn Url(&self) -> DOMString {
        DOMString::from(self.url.as_str())
    }

    /// <https://html.spec.whatwg.org/multipage/#dom-websocket-readystate>
    fn ReadyState(&self) -> u16 {
        self.ready_state.get() as u16
    }

    /// <https://html.spec.whatwg.org/multipage/#dom-websocket-bufferedamount>
    fn BufferedAmount(&self) -> u64 {
        self.buffered_amount.get()
    }

    /// <https://html.spec.whatwg.org/multipage/#dom-websocket-binarytype>
    fn BinaryType(&self) -> BinaryType {
        self.binary_type.get()
    }

    /// <https://html.spec.whatwg.org/multipage/#dom-websocket-binarytype>
    fn SetBinaryType(&self, btype: BinaryType) {
        self.binary_type.set(btype)
    }

    /// <https://html.spec.whatwg.org/multipage/#dom-websocket-protocol>
    fn Protocol(&self) -> DOMString {
        DOMString::from(self.protocol.borrow().clone())
    }

    /// <https://html.spec.whatwg.org/multipage/#dom-websocket-send>
    fn Send(&self, data: USVString) -> ErrorResult {
        let data_byte_len = data.0.len() as u64;
        let send_data = self.send_impl(data_byte_len)?;

        if send_data {
            let _ = self
                .callback
                .send(WebSocketDomAction::SendMessage(MessageData::Text(data.0)));
        }

        Ok(())
    }

    /// <https://html.spec.whatwg.org/multipage/#dom-websocket-send>
    fn Send_(&self, blob: &Blob) -> ErrorResult {
        /* As per https://html.spec.whatwg.org/multipage/#websocket
           the buffered amount needs to be clamped to u32, even though Blob.Size() is u64
           If the buffer limit is reached in the first place, there are likely other major problems
        */
        let data_byte_len = blob.Size();
        let send_data = self.send_impl(data_byte_len)?;

        if send_data {
            let bytes = blob.get_bytes().unwrap_or_default();
            let _ = self
                .callback
                .send(WebSocketDomAction::SendMessage(MessageData::Binary(bytes)));
        }

        Ok(())
    }

    /// <https://html.spec.whatwg.org/multipage/#dom-websocket-send>
    fn Send__(&self, array: CustomAutoRooterGuard<ArrayBuffer>) -> ErrorResult {
        let bytes = array.to_vec().unwrap_or_default();
        let data_byte_len = bytes.len();
        let send_data = self.send_impl(data_byte_len as u64)?;

        if send_data {
            let _ = self
                .callback
                .send(WebSocketDomAction::SendMessage(MessageData::Binary(bytes)));
        }
        Ok(())
    }

    /// <https://html.spec.whatwg.org/multipage/#dom-websocket-send>
    fn Send___(&self, array: CustomAutoRooterGuard<ArrayBufferView>) -> ErrorResult {
        let bytes = array.to_vec().unwrap_or_default();
        let data_byte_len = bytes.len();
        let send_data = self.send_impl(data_byte_len as u64)?;

        if send_data {
            let _ = self
                .callback
                .send(WebSocketDomAction::SendMessage(MessageData::Binary(bytes)));
        }
        Ok(())
    }

    /// <https://websockets.spec.whatwg.org/#dom-websocket-close>
    fn Close(&self, code: Option<u16>, reason: Option<USVString>) -> ErrorResult {
        // Step 1. If code is present, but is neither an integer equal to 1000 nor an integer in the range 3000 to 4999, inclusive, throw an "InvalidAccessError" DOMException.
        if let Some(code) = code &&
            code != close_code::NORMAL &&
            !(3000..=4999).contains(&code)
        {
            return Err(Error::InvalidAccess(Some(
                "Invalid WebSocket connection close code".into(),
            )));
        }

        // Step 2.2. If reasonBytes is longer than 123 bytes, then throw a "SyntaxError" DOMException.
        if let Some(ref reason) = reason &&
            reason.0.len() > 123
        {
            return Err(Error::Syntax(Some("Reason too long".to_string())));
        }

        // Step 3. Run the first matching steps from the following list:
        match self.ready_state.get() {
            WebSocketRequestState::Closing | WebSocketRequestState::Closed => {}, // Do nothing
            WebSocketRequestState::Connecting => {
                // If the WebSocket connection is not yet established [WSP] Fail the WebSocket connection and set this’s ready state to CLOSING (2).
                self.ready_state.set(WebSocketRequestState::Closing);

                fail_the_websocket_connection(
                    Trusted::new(self),
                    &self
                        .global()
                        .task_manager()
                        .websocket_task_source()
                        .to_sendable(),
                );
            },
            WebSocketRequestState::Open => {
                // If the WebSocket closing handshake has not yet been started [WSP] Start the WebSocket closing handshake and set this’s ready state to CLOSING (2). [WSP]
                self.ready_state.set(WebSocketRequestState::Closing);

                // Kick off _Start the WebSocket Closing Handshake_
                // https://tools.ietf.org/html/rfc6455#section-7.1.2
                let reason = reason.map(|reason| reason.0);
                let _ = self.callback.send(WebSocketDomAction::Close(code, reason));
            },
        }
        Ok(()) // Return Ok
    }
}

struct ReportCSPViolationTask {
    websocket: Trusted<WebSocket>,
    violations: Vec<Violation>,
}

impl TaskOnce for ReportCSPViolationTask {
    fn run_once(self, cx: &mut JSContext) {
        let global = self.websocket.root().global();
        global.report_csp_violations(cx, self.violations, None, None);
    }
}

/// Task queued when *the WebSocket connection is established*.
/// <https://html.spec.whatwg.org/multipage/#feedback-from-the-protocol:concept-websocket-established>
struct ConnectionEstablishedTask {
    address: Trusted<WebSocket>,
    protocol_in_use: Option<String>,
}

impl TaskOnce for ConnectionEstablishedTask {
    /// <https://html.spec.whatwg.org/multipage/#feedback-from-the-protocol:concept-websocket-established>
    fn run_once(self, cx: &mut JSContext) {
        let ws = self.address.root();

        // Step 1.
        ws.ready_state.set(WebSocketRequestState::Open);

        // Step 2: Extensions.
        // TODO: Set extensions to extensions in use.

        // Step 3.
        if let Some(protocol_name) = self.protocol_in_use {
            *ws.protocol.borrow_mut() = protocol_name;
        };

        // Step 4.
        ws.upcast().fire_event(cx, atom!("open"));
    }
}

struct BufferedAmountTask {
    address: Trusted<WebSocket>,
}

impl TaskOnce for BufferedAmountTask {
    // See https://html.spec.whatwg.org/multipage/#dom-websocket-bufferedamount
    //
    // To be compliant with standards, we need to reset bufferedAmount only when the event loop
    // reaches step 1.  In our implementation, the bytes will already have been sent on a background
    // thread.
    fn run_once(self, _cx: &mut JSContext) {
        let ws = self.address.root();

        ws.buffered_amount.set(0);
        ws.clearing_buffer.set(false);
    }
}

struct CloseTask {
    address: Trusted<WebSocket>,
    failed: bool,
    code: Option<u16>,
    reason: Option<String>,
}

impl TaskOnce for CloseTask {
    fn run_once(self, cx: &mut JSContext) {
        let ws = self.address.root();

        if ws.ready_state.get() == WebSocketRequestState::Closed {
            // Do nothing if already closed.
            return;
        }

        // Perform _the WebSocket connection is closed_ steps.
        // https://html.spec.whatwg.org/multipage/#closeWebSocket

        // Step 1.
        ws.ready_state.set(WebSocketRequestState::Closed);

        // Step 2.
        if self.failed {
            ws.upcast().fire_event(cx, atom!("error"));
        }

        // Step 3.
        let clean_close = !self.failed;
        let code = self.code.unwrap_or(close_code::NO_STATUS);
        let reason = DOMString::from(self.reason.unwrap_or_default());
        let close_event = CloseEvent::new(
            cx,
            &ws.global(),
            atom!("close"),
            EventBubbles::DoesNotBubble,
            EventCancelable::NotCancelable,
            clean_close,
            code,
            reason,
        );
        close_event.upcast::<Event>().fire(cx, ws.upcast());
    }
}

struct MessageReceivedTask {
    address: Trusted<WebSocket>,
    message: MessageData,
}

impl TaskOnce for MessageReceivedTask {
    fn run_once(self, cx: &mut JSContext) {
        let ws = self.address.root();
        debug!(
            "MessageReceivedTask::handler({:p}): readyState={:?}",
            &*ws,
            ws.ready_state.get()
        );

        // Step 1.
        if ws.ready_state.get() != WebSocketRequestState::Open {
            return;
        }

        // Step 2-5.
        let global = ws.global();
        let mut realm = AutoRealm::new(
            cx,
            NonNull::new(ws.reflector().get_jsobject().get()).unwrap(),
        );
        let cx = &mut *realm;
        rooted!(&in(cx) let mut message = UndefinedValue());
        match self.message {
            MessageData::Text(text) => text.to_jsval(cx, message.handle_mut()),
            MessageData::Binary(data) => match ws.binary_type.get() {
                BinaryType::Blob => {
                    let blob =
                        Blob::new(cx, &global, BlobImpl::new_from_bytes(data, String::new()));
                    blob.to_jsval(cx, message.handle_mut());
                },
                BinaryType::Arraybuffer => {
                    rooted!(&in(cx) let mut array_buffer = ptr::null_mut::<JSObject>());
                    assert!(
                        create_buffer_source::<ArrayBufferU8>(cx, &data, array_buffer.handle_mut())
                            .is_ok()
                    );

                    (*array_buffer).to_jsval(cx, message.handle_mut());
                },
            },
        }
        MessageEvent::dispatch_jsval(
            cx,
            ws.upcast(),
            &global,
            message.handle(),
            Some(ws.origin().ascii_serialization().as_ref()),
            None,
            vec![],
        );
    }
}