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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=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
#include "PostMessageEvent.h"
#include "MessageEvent.h"
#include "mozilla/dom/BrowsingContext.h"
#include "mozilla/dom/BrowsingContextGroup.h"
#include "mozilla/dom/DocGroup.h"
#include "mozilla/dom/DocumentInlines.h"
#include "mozilla/dom/MessageEventBinding.h"
#include "mozilla/dom/MessagePort.h"
#include "mozilla/dom/RootedDictionary.h"
#include "mozilla/BasePrincipal.h"
#include "mozilla/EventDispatcher.h"
#include "mozilla/StaticPrefs_dom.h"
#include "nsDocShell.h"
#include "nsGlobalWindowInner.h"
#include "nsGlobalWindowOuter.h"
#include "nsIConsoleService.h"
#include "nsIPrincipal.h"
#include "nsIScriptError.h"
#include "nsPresContext.h"
#include "nsQueryObject.h"
#include "nsServiceManagerUtils.h"
namespace mozilla::dom {
PostMessageEvent::PostMessageEvent(BrowsingContext* aSource,
const nsAString& aCallerOrigin,
nsGlobalWindowOuter* aTargetWindow,
nsIPrincipal* aProvidedPrincipal,
uint64_t aCallerWindowID, nsIURI* aCallerURI,
const nsCString& aScriptLocation,
bool aIsFromPrivateWindow,
const Maybe<nsID>& aCallerAgentClusterId)
: Runnable("dom::PostMessageEvent"),
mSource(aSource),
mCallerOrigin(aCallerOrigin),
mTargetWindow(aTargetWindow),
mProvidedPrincipal(aProvidedPrincipal),
mCallerWindowID(aCallerWindowID),
mCallerAgentClusterId(aCallerAgentClusterId),
mCallerURI(aCallerURI),
mScriptLocation(Some(aScriptLocation)),
mIsFromPrivateWindow(aIsFromPrivateWindow) {}
PostMessageEvent::~PostMessageEvent() = default;
MOZ_CAN_RUN_SCRIPT_BOUNDARY NS_IMETHODIMP PostMessageEvent::Run() {
// Note: We don't init this AutoJSAPI with targetWindow, because we do not
// want exceptions during message deserialization to trigger error events on
// targetWindow.
AutoJSAPI jsapi;
jsapi.Init();
JSContext* cx = jsapi.cx();
// The document URI is just used for the principal mismatch error message
// below. Use a stack variable so mCallerURI is not held onto after
// this method finishes, regardless of the method outcome.
nsCOMPtr<nsIURI> callerURI = std::move(mCallerURI);
// If we bailed before this point we're going to leak mMessage, but
// that's probably better than crashing.
RefPtr<nsGlobalWindowInner> targetWindow;
if (mTargetWindow->IsClosedOrClosing() ||
!(targetWindow = nsGlobalWindowInner::Cast(
mTargetWindow->GetCurrentInnerWindow())) ||
targetWindow->IsDying())
return NS_OK;
// If the window's document has suppressed event handling, hand off this event
// for running later. We check the top window's document so that when multiple
// same-origin windows exist in the same top window, postMessage events will
// be delivered in the same order they were posted, regardless of which window
// they were posted to.
if (nsCOMPtr<nsPIDOMWindowOuter> topWindow =
targetWindow->GetOuterWindow()->GetInProcessTop()) {
if (nsCOMPtr<nsPIDOMWindowInner> topInner =
topWindow->GetCurrentInnerWindow()) {
if (topInner->GetExtantDoc() &&
topInner->GetExtantDoc()->SuspendPostMessageEvent(this)) {
return NS_OK;
}
}
}
JSAutoRealm ar(cx, targetWindow->GetWrapper());
// Ensure that any origin which might have been provided is the origin of this
// window's document. Note that we do this *now* instead of when postMessage
// is called because the target window might have been navigated to a
// different location between then and now. If this check happened when
// postMessage was called, it would be fairly easy for a malicious webpage to
// intercept messages intended for another site by carefully timing navigation
// of the target window so it changed location after postMessage but before
// now.
if (mProvidedPrincipal) {
// Get the target's origin either from its principal or, in the case the
// principal doesn't carry a URI (e.g. the system principal), the target's
// document.
nsIPrincipal* targetPrin = targetWindow->GetPrincipal();
if (NS_WARN_IF(!targetPrin)) return NS_OK;
// Note: This is contrary to the spec with respect to file: URLs, which
// the spec groups into a single origin, but given we intentionally
// don't do that in other places it seems better to hold the line for
// now. Long-term, we want HTML5 to address this so that we can
// be compliant while being safer.
if (!targetPrin->Equals(mProvidedPrincipal)) {
OriginAttributes sourceAttrs = mProvidedPrincipal->OriginAttributesRef();
OriginAttributes targetAttrs = targetPrin->OriginAttributesRef();
MOZ_DIAGNOSTIC_ASSERT(
sourceAttrs.mUserContextId == targetAttrs.mUserContextId,
"Target and source should have the same userContextId attribute.");
nsAutoString providedOrigin, targetOrigin;
nsresult rv = nsContentUtils::GetWebExposedOriginSerialization(
targetPrin, targetOrigin);
NS_ENSURE_SUCCESS(rv, rv);
rv = nsContentUtils::GetWebExposedOriginSerialization(mProvidedPrincipal,
providedOrigin);
NS_ENSURE_SUCCESS(rv, rv);
nsAutoString errorText;
nsContentUtils::FormatLocalizedString(
errorText, nsContentUtils::eDOM_PROPERTIES,
"TargetPrincipalDoesNotMatch", providedOrigin, targetOrigin);
nsCOMPtr<nsIScriptError> errorObject =
do_CreateInstance(NS_SCRIPTERROR_CONTRACTID, &rv);
NS_ENSURE_SUCCESS(rv, rv);
if (mCallerWindowID == 0) {
rv = errorObject->Init(
errorText, NS_ConvertUTF8toUTF16(mScriptLocation.value()), u""_ns,
0, 0, nsIScriptError::errorFlag, "DOM Window"_ns,
mIsFromPrivateWindow, mProvidedPrincipal->IsSystemPrincipal());
} else if (callerURI) {
rv = errorObject->InitWithSourceURI(errorText, callerURI, u""_ns, 0, 0,
nsIScriptError::errorFlag,
"DOM Window"_ns, mCallerWindowID);
} else {
rv = errorObject->InitWithWindowID(
errorText, NS_ConvertUTF8toUTF16(mScriptLocation.value()), u""_ns,
0, 0, nsIScriptError::errorFlag, "DOM Window"_ns, mCallerWindowID);
}
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIConsoleService> consoleService =
do_GetService(NS_CONSOLESERVICE_CONTRACTID, &rv);
NS_ENSURE_SUCCESS(rv, rv);
return consoleService->LogMessage(errorObject);
}
}
IgnoredErrorResult rv;
JS::Rooted<JS::Value> messageData(cx);
nsCOMPtr<mozilla::dom::EventTarget> eventTarget =
do_QueryObject(targetWindow);
JS::CloneDataPolicy cloneDataPolicy;
MOZ_DIAGNOSTIC_ASSERT(targetWindow);
if (mCallerAgentClusterId.isSome() && targetWindow->GetDocGroup() &&
targetWindow->GetDocGroup()->AgentClusterId().Equals(
mCallerAgentClusterId.ref())) {
cloneDataPolicy.allowIntraClusterClonableSharedObjects();
}
if (targetWindow->IsSharedMemoryAllowed()) {
cloneDataPolicy.allowSharedMemoryObjects();
}
if (mHolder.empty()) {
DispatchError(cx, targetWindow, eventTarget);
return NS_OK;
}
StructuredCloneHolder* holder;
if (mHolder.constructed<StructuredCloneHolder>()) {
mHolder.ref<StructuredCloneHolder>().Read(
targetWindow->AsGlobal(), cx, &messageData, cloneDataPolicy, rv);
holder = &mHolder.ref<StructuredCloneHolder>();
} else {
MOZ_ASSERT(mHolder.constructed<ipc::StructuredCloneData>());
mHolder.ref<ipc::StructuredCloneData>().Read(cx, &messageData, rv);
holder = &mHolder.ref<ipc::StructuredCloneData>();
}
if (NS_WARN_IF(rv.Failed())) {
JS_ClearPendingException(cx);
DispatchError(cx, targetWindow, eventTarget);
return NS_OK;
}
// Create the event
RefPtr<MessageEvent> event = new MessageEvent(eventTarget, nullptr, nullptr);
Nullable<WindowProxyOrMessagePortOrServiceWorker> source;
if (mSource) {
source.SetValue().SetAsWindowProxy() = mSource;
}
Sequence<OwningNonNull<MessagePort>> ports;
if (!holder->TakeTransferredPortsAsSequence(ports)) {
DispatchError(cx, targetWindow, eventTarget);
return NS_OK;
}
event->InitMessageEvent(nullptr, u"message"_ns, CanBubble::eNo,
Cancelable::eNo, messageData, mCallerOrigin, u""_ns,
source, ports);
Dispatch(targetWindow, event);
return NS_OK;
}
void PostMessageEvent::DispatchError(JSContext* aCx,
nsGlobalWindowInner* aTargetWindow,
mozilla::dom::EventTarget* aEventTarget) {
RootedDictionary<MessageEventInit> init(aCx);
init.mBubbles = false;
init.mCancelable = false;
init.mOrigin = mCallerOrigin;
if (mSource) {
init.mSource.SetValue().SetAsWindowProxy() = mSource;
}
RefPtr<Event> event =
MessageEvent::Constructor(aEventTarget, u"messageerror"_ns, init);
Dispatch(aTargetWindow, event);
}
void PostMessageEvent::Dispatch(nsGlobalWindowInner* aTargetWindow,
Event* aEvent) {
// We can't simply call dispatchEvent on the window because doing so ends
// up flipping the trusted bit on the event, and we don't want that to
// happen because then untrusted content can call postMessage on a chrome
// window if it can get a reference to it.
RefPtr<nsPresContext> presContext =
aTargetWindow->GetExtantDoc()->GetPresContext();
aEvent->SetTrusted(true);
WidgetEvent* internalEvent = aEvent->WidgetEventPtr();
nsEventStatus status = nsEventStatus_eIgnore;
EventDispatcher::Dispatch(aTargetWindow, presContext, internalEvent, aEvent,
&status);
}
static nsresult MaybeThrottle(nsGlobalWindowOuter* aTargetWindow,
PostMessageEvent* aEvent) {
BrowsingContext* bc = aTargetWindow->GetBrowsingContext();
if (!bc) {
return NS_ERROR_FAILURE;
}
bc = bc->Top();
if (!bc->IsLoading()) {
return NS_ERROR_FAILURE;
}
if (nsContentUtils::IsPDFJS(aTargetWindow->GetPrincipal())) {
// pdf.js is known to block the load event on a worker's postMessage event.
// Avoid throttling postMessage for pdf.js to avoid pathological wait times,
return NS_ERROR_FAILURE;
}
if (!StaticPrefs::dom_separate_event_queue_for_post_message_enabled()) {
return NS_ERROR_FAILURE;
}
return bc->Group()->QueuePostMessageEvent(aEvent);
}
void PostMessageEvent::DispatchToTargetThread(ErrorResult& aError) {
if (NS_SUCCEEDED(MaybeThrottle(mTargetWindow, this))) {
return;
}
aError = mTargetWindow->Dispatch(do_AddRef(this));
}
} // namespace mozilla::dom