/* -*- 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

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "PostMessageEvent.h"

#include "MessageEvent.h"

#include "mozilla/dom/BlobBinding.h"

#include "mozilla/dom/File.h"

#include "mozilla/dom/FileList.h"

#include "mozilla/dom/FileListBinding.h"

#include "mozilla/dom/MessageEventBinding.h"

#include "mozilla/dom/MessagePort.h"

#include "mozilla/dom/MessagePortBinding.h"

#include "mozilla/dom/PMessagePort.h"

#include "mozilla/dom/StructuredCloneTags.h"

#include "mozilla/dom/UnionConversions.h"

#include "mozilla/EventDispatcher.h"

#include "nsContentUtils.h"

#include "nsGlobalWindow.h"

#include "nsIPresShell.h"

#include "nsIPrincipal.h"

#include "nsIScriptError.h"

#include "nsPresContext.h"

#include "nsQueryObject.h"

namespace mozilla {

namespace dom {

PostMessageEvent::PostMessageEvent(nsGlobalWindowOuter* aSource,

                                   const nsAString& aCallerOrigin,

                                   nsGlobalWindowOuter* aTargetWindow,

                                   nsIPrincipal* aProvidedPrincipal,

                                   nsIDocument* aSourceDocument,

                                   bool aTrustedCaller)

  : Runnable("dom::PostMessageEvent")

  , StructuredCloneHolder(CloningSupported,

                          TransferringSupported,

                          StructuredCloneScope::SameProcessSameThread)

  , mSource(aSource)

  , mCallerOrigin(aCallerOrigin)

  , mTargetWindow(aTargetWindow)

  , mProvidedPrincipal(aProvidedPrincipal)

  , mSourceDocument(aSourceDocument)

  , mTrustedCaller(aTrustedCaller)

{

}

PostMessageEvent::~PostMessageEvent()

{

}

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 is just used for the principal mismatch error message below.

  // Use a stack variable so mSourceDocument is not held onto after this method

  // finishes, regardless of the method outcome.

  nsCOMPtr<nsIDocument> sourceDocument;

  sourceDocument.swap(mSourceDocument);

  // 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 = mTargetWindow->GetCurrentInnerWindowInternal()) ||

      targetWindow->IsDying())

    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.mAppId == targetAttrs.mAppId,

        "Target and source should have the same mAppId attribute.");

      MOZ_DIAGNOSTIC_ASSERT(sourceAttrs.mUserContextId == targetAttrs.mUserContextId,

        "Target and source should have the same userContextId attribute.");

      MOZ_DIAGNOSTIC_ASSERT(sourceAttrs.mInIsolatedMozBrowser == targetAttrs.mInIsolatedMozBrowser,

        "Target and source should have the same inIsolatedMozBrowser attribute.");

      if (!nsContentUtils::IsSystemOrExpandedPrincipal(targetPrin) &&

          !nsContentUtils::IsSystemOrExpandedPrincipal(mProvidedPrincipal) &&

          !mTrustedCaller) {

        MOZ_DIAGNOSTIC_ASSERT(sourceAttrs.mPrivateBrowsingId == targetAttrs.mPrivateBrowsingId,

          "Target and source should have the same mPrivateBrowsingId attribute.");

      }

      nsAutoString providedOrigin, targetOrigin;

      nsresult rv = nsContentUtils::GetUTFOrigin(targetPrin, targetOrigin);

      NS_ENSURE_SUCCESS(rv, rv);

      rv = nsContentUtils::GetUTFOrigin(mProvidedPrincipal, providedOrigin);

      NS_ENSURE_SUCCESS(rv, rv);

      const char16_t* params[] = { providedOrigin.get(), targetOrigin.get() };

      nsContentUtils::ReportToConsole(nsIScriptError::errorFlag,

        NS_LITERAL_CSTRING("DOM Window"), sourceDocument,

        nsContentUtils::eDOM_PROPERTIES,

        "TargetPrincipalDoesNotMatch",

        params, ArrayLength(params));

      return NS_OK;

    }

  }

  IgnoredErrorResult rv;

  JS::Rooted<JS::Value> messageData(cx);

  nsCOMPtr<mozilla::dom::EventTarget> eventTarget = do_QueryObject(targetWindow);

  Read(targetWindow->AsInner(), cx, &messageData, rv);

  if (NS_WARN_IF(rv.Failed())) {

    DispatchError(cx, targetWindow, eventTarget);

    return NS_OK;

  }

  // Create the event

  RefPtr<MessageEvent> event = new MessageEvent(eventTarget, nullptr, nullptr);

  Nullable<WindowProxyOrMessagePortOrServiceWorker> source;

  source.SetValue().SetAsWindowProxy() = mSource ? mSource->AsOuter() : nullptr;

  Sequence<OwningNonNull<MessagePort>> ports;

  if (!TakeTransferredPortsAsSequence(ports)) {

    DispatchError(cx, targetWindow, eventTarget);

    return NS_OK;

  }

  event->InitMessageEvent(nullptr, NS_LITERAL_STRING("message"),

                          CanBubble::eNo, Cancelable::eNo,

                          messageData, mCallerOrigin,

                          EmptyString(), 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->AsOuter();

  }

  RefPtr<Event> event =

    MessageEvent::Constructor(aEventTarget, NS_LITERAL_STRING("messageerror"),

                              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(mTrustedCaller);

  WidgetEvent* internalEvent = aEvent->WidgetEventPtr();

  nsEventStatus status = nsEventStatus_eIgnore;

  EventDispatcher::Dispatch(aTargetWindow->AsInner(),

                            presContext,

                            internalEvent,

                            aEvent,

                            &status);

}

} // namespace dom

} // namespace mozilla