gecko-dev/dom/xbl/nsXBLDocumentInfo.cpp

/* -*- 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 "mozilla/DebugOnly.h"

#include "nsXBLDocumentInfo.h"
#include "mozilla/dom/Document.h"
#include "nsXBLPrototypeBinding.h"
#include "nsIScriptObjectPrincipal.h"
#include "nsIScriptContext.h"
#include "jsapi.h"
#include "jsfriendapi.h"
#include "nsIURI.h"
#include "nsIConsoleService.h"
#include "nsIScriptError.h"
#include "nsIChromeRegistry.h"
#include "nsIPrincipal.h"
#include "nsJSPrincipals.h"
#include "nsIScriptSecurityManager.h"
#include "nsContentUtils.h"
#include "nsDOMJSUtils.h"
#include "nsWindowSizes.h"
#include "mozilla/Services.h"
#include "xpcpublic.h"
#include "mozilla/scache/StartupCache.h"
#include "mozilla/scache/StartupCacheUtils.h"
#include "nsCCUncollectableMarker.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/URL.h"

using namespace mozilla;
using namespace mozilla::scache;
using namespace mozilla::dom;

static const char kXBLCachePrefix[] = "xblcache";

/* Implementation file */
NS_IMPL_CYCLE_COLLECTION_CLASS(nsXBLDocumentInfo)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsXBLDocumentInfo)
  if (tmp->mBindingTable) {
    for (auto iter = tmp->mBindingTable->ConstIter(); !iter.Done();
         iter.Next()) {
      iter.UserData()->Unlink();
    }
  }
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDocument)
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsXBLDocumentInfo)
  if (tmp->mDocument && nsCCUncollectableMarker::InGeneration(
                            cb, tmp->mDocument->GetMarkedCCGeneration())) {
    return NS_SUCCESS_INTERRUPTED_TRAVERSE;
  }
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDocument)
  if (tmp->mBindingTable) {
    for (auto iter = tmp->mBindingTable->ConstIter(); !iter.Done();
         iter.Next()) {
      iter.UserData()->Traverse(cb);
    }
  }
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(nsXBLDocumentInfo)
  if (tmp->mBindingTable) {
    for (auto iter = tmp->mBindingTable->ConstIter(); !iter.Done();
         iter.Next()) {
      iter.UserData()->Trace(aCallbacks, aClosure);
    }
  }
NS_IMPL_CYCLE_COLLECTION_TRACE_END

static void UnmarkXBLJSObject(JS::GCCellPtr aPtr, const char* aName,
                              void* aClosure) {
  JS::ExposeObjectToActiveJS(&aPtr.as<JSObject>());
}

void nsXBLDocumentInfo::MarkInCCGeneration(uint32_t aGeneration) {
  if (mDocument) {
    mDocument->MarkUncollectableForCCGeneration(aGeneration);
  }
  // Unmark any JS we hold
  if (mBindingTable) {
    for (auto iter = mBindingTable->Iter(); !iter.Done(); iter.Next()) {
      iter.UserData()->Trace(TraceCallbackFunc(UnmarkXBLJSObject), nullptr);
    }
  }
}

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsXBLDocumentInfo)
  NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

NS_IMPL_CYCLE_COLLECTING_ADDREF(nsXBLDocumentInfo)
NS_IMPL_CYCLE_COLLECTING_RELEASE(nsXBLDocumentInfo)

nsXBLDocumentInfo::nsXBLDocumentInfo(Document* aDocument)
    : mDocument(aDocument),
      mScriptAccess(true),
      mIsChrome(false),
      mFirstBinding(nullptr) {
  nsIURI* uri = aDocument->GetDocumentURI();
  if (IsChromeURI(uri)) {
    // Cache whether or not this chrome XBL can execute scripts.
    nsCOMPtr<nsIXULChromeRegistry> reg =
        mozilla::services::GetXULChromeRegistryService();
    if (reg) {
      bool allow = true;
      reg->AllowScriptsForPackage(uri, &allow);
      mScriptAccess = allow;
    }
    mIsChrome = true;
  } else {
    // If this binding isn't running with system principal, then it's running
    // from a remote-XUL whitelisted domain. This is already a not-really-
    // supported configuration (among other things, we don't use XBL scopes in
    // that configuration for compatibility reasons). But we should still at
    // least make an effort to prevent binding code from running if content
    // script is disabled or if the source domain is blacklisted (since the
    // source domain for remote XBL must always be the same as the source domain
    // of the bound content).
    //
    // If we just ask the binding document if script is enabled, it will
    // discover that it has no inner window, and return false. So instead, we
    // short-circuit the normal compartment-managed script-disabling machinery,
    // and query the policy for the URI directly.
    bool allow;
    nsIScriptSecurityManager* ssm = nsContentUtils::GetSecurityManager();
    nsresult rv = ssm->PolicyAllowsScript(uri, &allow);
    mScriptAccess = NS_SUCCEEDED(rv) && allow;
  }
}

nsXBLDocumentInfo::~nsXBLDocumentInfo() { mozilla::DropJSObjects(this); }

nsXBLPrototypeBinding* nsXBLDocumentInfo::GetPrototypeBinding(
    const nsACString& aRef) {
  if (!mBindingTable) return nullptr;

  if (aRef.IsEmpty()) {
    // Return our first binding
    return mFirstBinding;
  }

  return mBindingTable->Get(aRef);
}

nsresult nsXBLDocumentInfo::SetPrototypeBinding(
    const nsACString& aRef, nsXBLPrototypeBinding* aBinding) {
  if (!mBindingTable) {
    mBindingTable =
        new nsClassHashtable<nsCStringHashKey, nsXBLPrototypeBinding>();
    mozilla::HoldJSObjects(this);
  }

  NS_ENSURE_STATE(!mBindingTable->Get(aRef));
  mBindingTable->Put(aRef, aBinding);

  return NS_OK;
}

void nsXBLDocumentInfo::RemovePrototypeBinding(const nsACString& aRef) {
  if (mBindingTable) {
    nsAutoPtr<nsXBLPrototypeBinding> bindingToRemove;
    mBindingTable->Remove(aRef, &bindingToRemove);

    // We do not want to destroy the binding, so just forget it.
    bindingToRemove.forget();
  }
}

// static
nsresult nsXBLDocumentInfo::ReadPrototypeBindings(nsIURI* aURI,
                                                  nsXBLDocumentInfo** aDocInfo,
                                                  Document* aBoundDocument) {
  *aDocInfo = nullptr;

  nsAutoCString spec(kXBLCachePrefix);
  nsresult rv = PathifyURI(aURI, spec);
  NS_ENSURE_SUCCESS(rv, rv);

  StartupCache* startupCache = StartupCache::GetSingleton();
  if (!startupCache) {
    return NS_ERROR_FAILURE;
  }

  UniquePtr<char[]> buf;
  uint32_t len;
  rv = startupCache->GetBuffer(spec.get(), &buf, &len);
  // GetBuffer will fail if the binding is not in the cache.
  if (NS_FAILED(rv)) return rv;

  nsCOMPtr<nsIObjectInputStream> stream;
  rv = NewObjectInputStreamFromBuffer(std::move(buf), len,
                                      getter_AddRefs(stream));
  NS_ENSURE_SUCCESS(rv, rv);

  // The file compatibility.ini stores the build id. This is checked in
  // nsAppRunner.cpp and will delete the cache if a different build is
  // present. However, we check that the version matches here to be safe.
  uint32_t version;
  rv = stream->Read32(&version);
  NS_ENSURE_SUCCESS(rv, rv);
  if (version != XBLBinding_Serialize_Version) {
    // The version that exists is different than expected, likely created with a
    // different build, so invalidate the cache.
    startupCache->InvalidateCache();
    return NS_ERROR_NOT_AVAILABLE;
  }

  nsCOMPtr<nsIPrincipal> principal;
  nsContentUtils::GetSecurityManager()->GetSystemPrincipal(
      getter_AddRefs(principal));

  nsCOMPtr<Document> doc;
  rv = NS_NewXBLDocument(getter_AddRefs(doc), aURI, nullptr, principal);
  NS_ENSURE_SUCCESS(rv, rv);

  RefPtr<nsXBLDocumentInfo> docInfo = new nsXBLDocumentInfo(doc);

  while (1) {
    uint8_t flags;
    nsresult rv = stream->Read8(&flags);
    NS_ENSURE_SUCCESS(rv, rv);
    if (flags == XBLBinding_Serialize_NoMoreBindings) break;

    rv = nsXBLPrototypeBinding::ReadNewBinding(stream, docInfo, doc, flags);
    if (NS_FAILED(rv)) {
      return rv;
    }
  }

  docInfo.forget(aDocInfo);
  return NS_OK;
}

nsresult nsXBLDocumentInfo::WritePrototypeBindings() {
  // Only write out bindings with the system principal
  if (!nsContentUtils::IsSystemPrincipal(mDocument->NodePrincipal()))
    return NS_OK;

  nsAutoCString spec(kXBLCachePrefix);
  nsresult rv = PathifyURI(DocumentURI(), spec);
  NS_ENSURE_SUCCESS(rv, rv);

  StartupCache* startupCache = StartupCache::GetSingleton();
  if (!startupCache) {
    return rv;
  }

  nsCOMPtr<nsIObjectOutputStream> stream;
  nsCOMPtr<nsIStorageStream> storageStream;
  rv = NewObjectOutputWrappedStorageStream(getter_AddRefs(stream),
                                           getter_AddRefs(storageStream), true);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = stream->Write32(XBLBinding_Serialize_Version);
  NS_ENSURE_SUCCESS(rv, rv);

  if (mBindingTable) {
    for (auto iter = mBindingTable->Iter(); !iter.Done(); iter.Next()) {
      iter.UserData()->Write(stream);
    }
  }

  // write a end marker at the end
  rv = stream->Write8(XBLBinding_Serialize_NoMoreBindings);
  NS_ENSURE_SUCCESS(rv, rv);

  stream->Close();
  NS_ENSURE_SUCCESS(rv, rv);

  uint32_t len;
  UniquePtr<char[]> buf;
  rv = NewBufferFromStorageStream(storageStream, &buf, &len);
  NS_ENSURE_SUCCESS(rv, rv);

  return startupCache->PutBuffer(spec.get(), std::move(buf), len);
}

void nsXBLDocumentInfo::SetFirstPrototypeBinding(
    nsXBLPrototypeBinding* aBinding) {
  mFirstBinding = aBinding;
}

#ifdef DEBUG
void AssertInCompilationScope() {
  AutoJSContext cx;
  MOZ_ASSERT(xpc::CompilationScope() == JS::CurrentGlobalOrNull(cx));
}
#endif

size_t nsXBLDocumentInfo::SizeOfIncludingThis(
    MallocSizeOf aMallocSizeOf) const {
  size_t n = aMallocSizeOf(this);
  if (mDocument) {
    SizeOfState state(aMallocSizeOf);
    nsWindowSizes windowSizes(state);
    mDocument->DocAddSizeOfIncludingThis(windowSizes);
    n += windowSizes.getTotalSize();
  }
  if (mBindingTable) {
    n += mBindingTable->ShallowSizeOfIncludingThis(aMallocSizeOf);
    for (auto iter = mBindingTable->Iter(); !iter.Done(); iter.Next()) {
      nsXBLPrototypeBinding* binding = iter.UserData();
      n += binding->SizeOfIncludingThis(aMallocSizeOf);
    }
  }
  return n;
}