Auto merge of #15358 - asajeffrey:script-browsingcontext-xorigin-wind…

…ow, r=jdm

Allow browsing contexts to resolve to cross-origin windows

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This PR implements cross-thread `WindowProxy` objects.

At the moment, if a `Window` performs a non-similar-origin navigation, the old script thread does not update its `WindowProxy`, since the new `Window` is in the new script thread. With this PR, the `WindowProxy` is updated to a dummy `XOriginWindow` object, that only implements the whitelisted methods that are allowed to be called cross-origin.

This PR does not include working implementations of some of the cross-origin `Window` or `Location` methods.

This PR causes some cross-origin wpt tests to now pass, in particular `/html/browsers/origin/cross-origin-objects/cross-origin-objects.html ` now passes `Only whitelisted properties are accessible cross-origin`. There are some CORS failures in `fetch`, I suspect caused by the incorrect setting of `origin` in fetch requests.

Although there are some functions that now throw `SecurityException`, it is not meant to be a complete implementation, which will have to wait for XOWs to land.

---
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #15180.
- [X] There are tests for these changes

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components/script/dom/browsingcontext.rs

@@ -3,13 +3,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use dom::bindings::conversions::{ToJSValConvertible, root_from_handleobject};
+use dom::bindings::error::{Error, throw_dom_exception};
+use dom::bindings::inheritance::Castable;
 use dom::bindings::js::{JS, Root, RootedReference};
 use dom::bindings::proxyhandler::{fill_property_descriptor, get_property_descriptor};
 use dom::bindings::reflector::{DomObject, Reflector};
 use dom::bindings::trace::JSTraceable;
 use dom::bindings::utils::WindowProxyHandler;
 use dom::bindings::utils::get_array_index_from_id;
+use dom::dissimilaroriginwindow::DissimilarOriginWindow;
 use dom::element::Element;
+use dom::globalscope::GlobalScope;
 use dom::window::Window;
 use js::JSCLASS_IS_GLOBAL;
 use js::glue::{CreateWrapperProxyHandler, ProxyTraps, NewWindowProxy};
@@ -18,12 +22,13 @@ use js::jsapi::{Handle, HandleId, HandleObject, HandleValue};
 use js::jsapi::{JSAutoCompartment, JSContext, JSErrNum, JSFreeOp, JSObject};
 use js::jsapi::{JSPROP_READONLY, JSTracer, JS_DefinePropertyById};
 use js::jsapi::{JS_ForwardGetPropertyTo, JS_ForwardSetPropertyTo};
-use js::jsapi::{JS_GetOwnPropertyDescriptorById, JS_HasPropertyById};
-use js::jsapi::{JS_TransplantObject, SetWindowProxy};
+use js::jsapi::{JS_GetOwnPropertyDescriptorById, JS_HasPropertyById, JS_HasOwnPropertyById};
+use js::jsapi::{JS_IsExceptionPending, JS_TransplantObject, SetWindowProxy};
 use js::jsapi::{MutableHandle, MutableHandleObject, MutableHandleValue};
 use js::jsapi::{ObjectOpResult, PropertyDescriptor};
 use js::jsval::{UndefinedValue, PrivateValue};
 use js::rust::get_object_class;
+use msg::constellation_msg::PipelineId;
 use std::cell::Cell;
 use std::ptr;
 
@@ -39,6 +44,13 @@ pub struct BrowsingContext {
     /// changes Window.
     reflector: Reflector,
 
+    /// The pipeline id of the currently active document.
+    /// May be None, when the currently active document is in another script thread.
+    /// We do not try to keep the pipeline id for documents in other threads,
+    /// as this would require the constellation notifying many script threads about
+    /// the change, which could be expensive.
+    currently_active: Cell<Option<PipelineId>>,
+
     /// Has this browsing context been discarded?
     discarded: Cell<bool>,
 
@@ -47,9 +59,10 @@ pub struct BrowsingContext {
 }
 
 impl BrowsingContext {
-    pub fn new_inherited(frame_element: Option<&Element>) -> BrowsingContext {
+    pub fn new_inherited(currently_active: PipelineId, frame_element: Option<&Element>) -> BrowsingContext {
         BrowsingContext {
             reflector: Reflector::new(),
+            currently_active: Cell::new(Some(currently_active)),
             discarded: Cell::new(false),
             frame_element: frame_element.map(JS::from_ref),
         }
@@ -72,7 +85,8 @@ impl BrowsingContext {
             assert!(!window_proxy.is_null());
 
             // Create a new browsing context.
-            let mut browsing_context = box BrowsingContext::new_inherited(frame_element);
+            let currently_active = window.global().pipeline_id();
+            let mut browsing_context = box BrowsingContext::new_inherited(currently_active, frame_element);
 
             // The window proxy owns the browsing context.
             // When we finalize the window proxy, it drops the browsing context it owns.
@@ -104,10 +118,10 @@ impl BrowsingContext {
     /// Change the Window that this browsing context's WindowProxy resolves to.
     // TODO: support setting the window proxy to a dummy value,
     // to handle the case when the active document is in another script thread.
-    pub fn set_window_proxy(&self, window: &Window) {
+    fn set_window_proxy(&self, window: &GlobalScope, traps: &ProxyTraps) {
         unsafe {
             debug!("Setting window proxy of {:p}.", self);
-            let WindowProxyHandler(handler) = window.windowproxy_handler();
+            let handler = CreateWrapperProxyHandler(traps);
             assert!(!handler.is_null());
 
             let cx = window.get_cx();
@@ -144,6 +158,22 @@ impl BrowsingContext {
         }
     }
 
+    pub fn set_currently_active(&self, window: &Window) {
+        let globalscope = window.upcast();
+        self.set_window_proxy(&*globalscope, &PROXY_HANDLER);
+        self.currently_active.set(Some(globalscope.pipeline_id()));
+    }
+
+    pub fn unset_currently_active(&self) {
+        let window = DissimilarOriginWindow::new(self);
+        self.set_window_proxy(&*window.upcast(), &XORIGIN_PROXY_HANDLER);
+        self.currently_active.set(None);
+    }
+
+    pub fn currently_active(&self) -> Option<PipelineId> {
+        self.currently_active.get()
+    }
+
     pub fn window_proxy(&self) -> *mut JSObject {
         let window_proxy = self.reflector.get_jsobject();
         assert!(!window_proxy.get().is_null());
@@ -332,6 +362,145 @@ static PROXY_HANDLER: ProxyTraps = ProxyTraps {
     isConstructor: None,
 };
 
+#[allow(unsafe_code)]
+pub fn new_window_proxy_handler() -> WindowProxyHandler {
+    unsafe {
+        WindowProxyHandler(CreateWrapperProxyHandler(&PROXY_HANDLER))
+    }
+}
+
+// The proxy traps for cross-origin windows.
+// These traps often throw security errors, and only pass on calls to methods
+// defined in the DissimilarOriginWindow IDL.
+
+#[allow(unsafe_code)]
+unsafe fn throw_security_error(cx: *mut JSContext) -> bool {
+    if !JS_IsExceptionPending(cx) {
+        let global = GlobalScope::from_context(cx);
+        throw_dom_exception(cx, &*global, Error::Security);
+    }
+    false
+}
+
+#[allow(unsafe_code)]
+unsafe extern "C" fn has_xorigin(cx: *mut JSContext,
+                                 proxy: HandleObject,
+                                 id: HandleId,
+                                 bp: *mut bool)
+                                 -> bool
+{
+    rooted!(in(cx) let target = GetProxyPrivate(*proxy.ptr).to_object());
+    let mut found = false;
+    JS_HasOwnPropertyById(cx, target.handle(), id, &mut found);
+    if found {
+        *bp = true;
+        true
+    } else {
+        throw_security_error(cx)
+    }
+}
+
+#[allow(unsafe_code)]
+unsafe extern "C" fn get_xorigin(cx: *mut JSContext,
+                                 proxy: HandleObject,
+                                 receiver: HandleValue,
+                                 id: HandleId,
+                                 vp: MutableHandleValue)
+                                 -> bool
+{
+    let mut found = false;
+    has_xorigin(cx, proxy, id, &mut found);
+    found && get(cx, proxy, receiver, id, vp)
+}
+
+#[allow(unsafe_code)]
+unsafe extern "C" fn set_xorigin(cx: *mut JSContext,
+                                 _: HandleObject,
+                                 _: HandleId,
+                                 _: HandleValue,
+                                 _: HandleValue,
+                                 _: *mut ObjectOpResult)
+                                 -> bool
+{
+    throw_security_error(cx)
+}
+
+#[allow(unsafe_code)]
+unsafe extern "C" fn delete_xorigin(cx: *mut JSContext,
+                                    _: HandleObject,
+                                    _: HandleId,
+                                    _: *mut ObjectOpResult)
+                                    -> bool
+{
+    throw_security_error(cx)
+}
+
+#[allow(unsafe_code)]
+unsafe extern "C" fn getOwnPropertyDescriptor_xorigin(cx: *mut JSContext,
+                                                      proxy: HandleObject,
+                                                      id: HandleId,
+                                                      desc: MutableHandle<PropertyDescriptor>)
+                                                      -> bool
+{
+    let mut found = false;
+    has_xorigin(cx, proxy, id, &mut found);
+    found && getOwnPropertyDescriptor(cx, proxy, id, desc)
+}
+
+#[allow(unsafe_code)]
+unsafe extern "C" fn defineProperty_xorigin(cx: *mut JSContext,
+                                            _: HandleObject,
+                                            _: HandleId,
+                                            _: Handle<PropertyDescriptor>,
+                                            _: *mut ObjectOpResult)
+                                            -> bool
+{
+    throw_security_error(cx)
+}
+
+#[allow(unsafe_code)]
+unsafe extern "C" fn preventExtensions_xorigin(cx: *mut JSContext,
+                                               _: HandleObject,
+                                               _: *mut ObjectOpResult)
+                                               -> bool
+{
+    throw_security_error(cx)
+}
+
+static XORIGIN_PROXY_HANDLER: ProxyTraps = ProxyTraps {
+    enter: None,
+    getOwnPropertyDescriptor: Some(getOwnPropertyDescriptor_xorigin),
+    defineProperty: Some(defineProperty_xorigin),
+    ownPropertyKeys: None,
+    delete_: Some(delete_xorigin),
+    enumerate: None,
+    getPrototypeIfOrdinary: None,
+    preventExtensions: Some(preventExtensions_xorigin),
+    isExtensible: None,
+    has: Some(has_xorigin),
+    get: Some(get_xorigin),
+    set: Some(set_xorigin),
+    call: None,
+    construct: None,
+    getPropertyDescriptor: Some(getOwnPropertyDescriptor_xorigin),
+    hasOwn: Some(has_xorigin),
+    getOwnEnumerablePropertyKeys: None,
+    nativeCall: None,
+    hasInstance: None,
+    objectClassIs: None,
+    className: None,
+    fun_toString: None,
+    boxedValue_unbox: None,
+    defaultValue: None,
+    trace: Some(trace),
+    finalize: Some(finalize),
+    objectMoved: None,
+    isCallable: None,
+    isConstructor: None,
+};
+
+// How WindowProxy objects are garbage collected.
+
 #[allow(unsafe_code)]
 unsafe extern fn finalize(_fop: *mut JSFreeOp, obj: *mut JSObject) {
     let this = GetProxyExtra(obj, 0).to_private() as *mut BrowsingContext;
@@ -354,9 +523,3 @@ unsafe extern fn trace(trc: *mut JSTracer, obj: *mut JSObject) {
     (*this).trace(trc);
 }
 
-#[allow(unsafe_code)]
-pub fn new_window_proxy_handler() -> WindowProxyHandler {
-    unsafe {
-        WindowProxyHandler(CreateWrapperProxyHandler(&PROXY_HANDLER))
-    }
-}

components/script/dom/dissimilaroriginlocation.rs

@@ -0,0 +1,80 @@
+/* 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 http://mozilla.org/MPL/2.0/. */
+
+use dom::bindings::codegen::Bindings::DissimilarOriginLocationBinding;
+use dom::bindings::codegen::Bindings::DissimilarOriginLocationBinding::DissimilarOriginLocationMethods;
+use dom::bindings::error::{Error, ErrorResult, Fallible};
+use dom::bindings::js::{JS, Root};
+use dom::bindings::reflector::Reflector;
+use dom::bindings::reflector::reflect_dom_object;
+use dom::bindings::str::DOMString;
+use dom::bindings::str::USVString;
+use dom::dissimilaroriginwindow::DissimilarOriginWindow;
+
+/// Represents a dissimilar-origin `Location` that exists in another script thread.
+///
+/// Since the `Location` is in a different script thread, we cannot access it
+/// directly, but some of its accessors (for example setting `location.href`)
+/// still need to function.
+
+#[dom_struct]
+pub struct DissimilarOriginLocation {
+    /// The reflector. Once we have XOWs, this will have a cross-origin
+    /// wrapper placed around it.
+    reflector: Reflector,
+
+    /// The window associated with this location.
+    window: JS<DissimilarOriginWindow>,
+}
+
+impl DissimilarOriginLocation {
+    #[allow(unrooted_must_root)]
+    fn new_inherited(window: &DissimilarOriginWindow) -> DissimilarOriginLocation {
+        DissimilarOriginLocation {
+            reflector: Reflector::new(),
+            window: JS::from_ref(window),
+        }
+    }
+
+    pub fn new(window: &DissimilarOriginWindow) -> Root<DissimilarOriginLocation> {
+        reflect_dom_object(box DissimilarOriginLocation::new_inherited(window),
+                           window,
+                           DissimilarOriginLocationBinding::Wrap)
+    }
+}
+
+impl DissimilarOriginLocationMethods for DissimilarOriginLocation {
+    // https://html.spec.whatwg.org/multipage/#dom-location-href
+    fn GetHref(&self) -> Fallible<USVString> {
+        Err(Error::Security)
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-location-href
+    fn SetHref(&self, _: USVString) -> ErrorResult {
+        // TODO: setting href on a cross-origin window should succeed?
+        Err(Error::Security)
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-location-assign
+    fn Assign(&self, _: USVString) -> Fallible<()> {
+        // TODO: setting href on a cross-origin window should succeed?
+        Err(Error::Security)
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-location-replace
+    fn Replace(&self, _: USVString) -> Fallible<()> {
+        // TODO: replacing href on a cross-origin window should succeed?
+        Err(Error::Security)
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-location-reload
+    fn Reload(&self) -> Fallible<()> {
+        Err(Error::Security)
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-location-href
+    fn Stringifier(&self) -> Fallible<DOMString> {
+        Err(Error::Security)
+    }
+}